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HomeMy WebLinkAbout20221027 Skidmore Construction Wellness Center SWPPP Stormwater Pollution Prevention Plan Prepared in accordance with NYS DEC General Permit GP-0-20-001 for: Skidmore College Athletic Expansion Owner/Operator(s): Skidmore College 815 N Broadway Saratoga Springs, NY 12866 SWPPP Contact(s): The LA Group, PC 40 Long Alley Saratoga Springs, NY 12866 1-518-587-8100 1-518-587-0180 SWPPP Preparation Date: November 4, 2022 Table of Contents 1.0 PERMIT OVERVIEW AND REQUIREMENTS ..................................................................... 1 1.1 PERMIT OVERVIEW ...................................................................................................................... 1 2.0 SWPPP REVIEW, UPDATE ....................................................................................................... 1 2.1 SWPPP REVIEW .......................................................................................................................... 1 2.2 SWPPP UPDATE .......................................................................................................................... 2 3.0 SITE ASSESSMENT, EVALUATION AND PLANNING ....................................................... 2 3.1 PROJECT LOCATION ..................................................................................................................... 2 3.2 PRE-DEVELOPMENT CONDITIONS ................................................................................................ 3 3.3 PROJECT TYPE ............................................................................................................................. 3 3.4 PROJECT SCOPE ............................................................................................................................ 3 3.5 HISTORIC PRESERVATION DETERMINATION/ENDANGERED SPECIES ............................................ 3 3.6 RECEIVING WATERS .................................................................................................................... 3 3.7 SOILS ........................................................................................................................................... 3 4.0 EROSION AND SEDIMENT CONTROL ................................................................................. 3 4.1 EROSION AND SEDIMENT CONTROL PRACTICES ........................................................................... 3 4.2 EROSION AND SEDIMENT CONTROL DRAWINGS ........................................................................... 4 4.3 CONSTRUCTION PHASING PLAN AND SEQUENCE OF OPERATIONS ................................................ 4 4.4 EROSION AND SEDIMENT CONTROL PRACTICE MAINTENANCE .................................................... 5 4.5 EROSION AND SEDIMENT CONTROL INSPECTION.......................................................................... 6 4.6 CONTRACTOR SEQUENCE FORM .................................................................................................. 7 5.0 POST CONSTRUCTION STORMWATER MANAGEMENT PRACTICES ...................... 7 5.1 STORMWATER MANAGEMENT CONTROLS ................................................................................... 7 5.2 GREEN INFRASTRUCTURE PRACTICES/RUNOFF REDUCTION TECHNIQUES ................................... 7 5.3 POST CONSTRUCTION STORMWATER MANAGEMENT DRAWINGS ................................................ 8 5.4 HYDRAULIC AND HYDROLOGIC ANALYSIS .................................................................................. 8 5.5 COMPARISON OF PRE AND POST CONSTRUCTION STORMWATER RUNOFF .................................... 9 6.0 POST CONSTRUCTION STORMWATER MAINTENANCE .............................................. 9 6.1 MAINTENANCE TO BE PERFORMED .............................................................................................. 9 7.0 CONSTRUCTION WASTE ...................................................................................................... 10 8.0 OFFSITE VEHICLE TRACKING ........................................................................................... 11 9.0 TEMPORARY STABILIZATION FOR FROZEN CONDITIONS ..................................... 11 10.0 SPILL PREVENTION PRACTICES ....................................................................................... 12 11.0 CERTIFICATIONS .................................................................................................................... 16 12.0 DEFINITIONS ............................................................................................................................ 21 Appendices A Notice of Intent (NOI) and MS4 Acceptance Form B Stormwater Management Report and Hydro CAD C Map Set – Location Map and Construction Drawing D SWPPP Inspection Forms –SWPPP Inspection Report E Other SWPPP Forms – Construction Sequence, SWPPP Plan Changes, Spill Response Form, Stormwater Management Practice Maintenance Log F SPDES General Permit GP-0-20-001 G Historic Preservation/Endangered Species Documentation H Deep Ripping and De-compaction (DEC, 2008) I Stormwater Maintenance Agreement Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 1 1.0 PERMIT OVERVIEW AND REQUIREMENTS 1.1 Permit Overview This Stormwater Pollution Prevention Plan (SWPPP) is prepared to inform the landowner and construction personnel of the measures to be implemented for controlling runoff and pollutants from the site during and after construction activities. The objective of this plan is to comply with the New York Department of Environmental Conservation (NYSDEC) State Pollutant Discharge Elimination System (SPDES) General Permit for Stormwater Discharges from Construction Activities, Permit No. GP- 0-20-001 requirements. Any material conflicts between this plan and the site plans, specification or instructions, must be brought to the attention of the design professional. The project may have other permits and it is the responsibility of the owner and contractor to know and understand all permits. The operator will be issued a bill from New York State for a one hundred and ten dollar ($110.00) annual fee for the open GP-0-20-001 permit. The operator will also be billed by New York State for a one time one hundred and ten dollar ($110.00) per acre fee for the proposed disturbed soil area listed in the NOI, and finally a one time six hundred and seventy five ($675.00) per acre fee for the proposed increased impervious area listed in the NOI. The operator is responsible to maintain onsite in a secure location that is accessible during normal working hours to an individual performing a compliance inspection, the following information: ✓ the Notice of Intent (NOI), ✓ the NYS Department of Environmental Conservation NOI Acknowledgement Letter, ✓ the SWPPP, ✓ a copy of the General Permit (included in the SWPPP), ✓ MS4 SWPPP Acceptance Form (where applicable), and ✓ All inspection reports. Technical standards are detailed in the “New York State Standards and Specifications for Sediment and Erosion and Sediment Control (November 2016)”, as well as illustrated on the Construction Drawings included in Appendix C. The design of post- construction stormwater control practices follow the guidance provided by “New York State Stormwater Management Design Manual.” 2.0 SWPPP REVIEW, UPDATE 2.1 SWPPP Review Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 2 Applicable Federal, State, and local regulatory agencies that have jurisdiction may elect to review this SWPPP and notify the permittee in writing that the SWPPP does not meet the requirements of their regulations. If the SWPPP needs to be revised, the permittee and the site contractor will make the required modifications within seven days of such notification and submit written certification to the notifying agency that the changes have been implemented. A copy of the SWPPP will be kept available on site for review by regulatory agencies, engineers, and subcontractors. This Project is located in the City of Saratoga Springs which is a regulated MS4 community; so, a copy of this SWPPP was sent to the city for review. A copy of the signed MS4 Acceptance form is provided in Appendix A of this SWPPP. 2.2 SWPPP Update The permittee identified in this SWPPP shall amend the SWPPP under the following conditions: ✓ Whenever the current provisions prove to be ineffective in minimizing pollutants in stormwater discharge from the site ✓ Whenever there is a change in design, construction or operation that could have an effect on the discharge of pollutants ✓ To address issues or deficiencies identified during an inspection by the qualified inspector, the Department or other regulatory authority ✓ To identify a new subcontractor that will implement any part of the SWPPP. If modifications are required to the post-stormwater management practices and the Project is within a regulated, traditional land use control MS4, the owner or operator of the Project must notify the MS4 in writing of any planned amendments or modifications to the post-construction stormwater management practice component of the SWPPP. Unless otherwise notified by the MS4, the owner or operator shall have the SWPPP amendments or modifications reviewed and accepted by the MS4 prior to commencing construction of the post-construction stormwater management practice. The SWPPP PLAN CHANGES, AUTHORIZATION, AND CHANGE CERTIFICATION form (Appendix E) must be filled out and a copy retained onsite during construction. If modifications are required to the post-stormwater management practices and the Project is not within a Regulated, Traditional Land Use Control MS4, the changes shall be documented in the SWPPP kept onsite. 3.0 SITE ASSESSMENT, EVALUATION AND PLANNING 3.1 Project Location Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 3 The Project is located at Skidmore College 815 North Broadway Saratoga Springs, Saratoga County, NY 12866. Access to the site is off Perimeter Road. See Appendix C for a general site location map. 3.2 Pre-Development Conditions The project area is located in the southern portion of the Skidmore College campus. The project area is comprised of paved tennis courts, sidewalks, road, lawn, forested area, and existing stormwater features. 3.3 Project Type The project is a mixture of redevelopment and new development. Any increases in impervious area at the sites have been designed in accordance with Chapter 4 of the NYSDEC Stormwater Management Design Manual and NYSDEC’s General Permit (GP-0-20-001) for construction activities. All existing impervious area to be disturbed have been designed in accordance with Chapter 9 of the NYSDEC Stormwater Management Manual. 3.4 Project Scope The project includes the construction of a Health, Wellness, Fitness and Tennis facility, outdoor tennis courts and sidewalks. The remainder of the proposed site improvements includes landscaping and stormwater controls. The Project Site represents the area that will be disturbed as a result of the Project. 3.5 Historic Preservation Determination/Endangered Species The project is not anticipated to disturb any historical or cultural resources nor will it impact any significant natural communities. Maps of the location and nearby historical and natural resources are included in Appendix E. 3.6 Receiving Waters The site drains to existing detention ponds on the south east corner of the lot which discharge to the city of Saratoga Springs closed drainage system. 3.7 Soils According to the Natural Resources Conservation Service (NRCS) Web Soil Survey, the area including and surrounding the Project Site is comprised of Galway Loam. Galway Loam is classified as ‘C’. Therefore, the site has been analyzed using ‘C’ soils. Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 4 4.0 EROSION AND SEDIMENT CONTROL 4.1 Erosion and Sediment Control Practices Temporary Structural Practices ✓ Silt Fence ✓ Stabilized Construction Entrance ✓ Storm Drain Inlet Protection ✓ Rock Outlet Protection Permanent Structural Controls ✓ Grading Temporary Stabilization Practices (including vegetative practices) ✓ Seed and mulch bare soil areas within 14 days of disturbance unless construction will resume in that area within 21 days. Permanent Stabilization Practices (including vegetative practices) ✓ Seed and mulch all disturbed areas. Slopes that are 3:1 or steeper should receive a Rolled Erosion Control Product (RECP), sodding, and or hydro- seeding a homogenous mixture of wood fiber mulch with tackifying agent. Refer to Construction Drawings attached in Appendix C for detailed information on each practice. 4.2 Erosion and Sediment Control Drawings Erosion and Sediment Control practices are shown on Construction Drawings included in Appendix C. 4.3 Construction Phasing Plan and Sequence of Operations The project will be phased to disturb less than five acres at a single time. ✓ Temporary structural erosion controls will be installed prior to earthwork as per the attached plans. ✓ Areas to be undisturbed for more than 14 days will be temporarily stabilized by seeding. ✓ Disturbed areas will be reseeded and mulched immediately after final contours are re-established and no more than 14 days after the completion of construction at that site. Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 5 ✓ Temporary erosion control devices will not be removed until the area served is stabilized by the growth of vegetation and the area is certified as being stabilized by the Erosion Control Superintendent. Construction Activities Reference Sheet Number Start → Stop Sequence must include major items such as, but not limited to, clearing and grubbing, excavation and grading, utility and infrastructure installation and any other activity resulting in soil disturbance. Include installation of erosion and sediment control practices and timing of installation. Install erosion and sediment controls Week 1 Rough grade site Weeks 2-3 Begin utility installation Weeks 3-6 Begin site construction Weeks 4- completion Monitor/maintain erosion and sediment control measures Ongoing Remove erosion and sediment control measures upon stabilization of contributing areas Ongoing 4.4 Erosion and Sediment Control Practice Maintenance ✓ Silt fence – maintenance shall be performed as needed and material removed when “bulges” develop in the silt fence. ✓ Stabilized construction entrance – entrance shall be maintained in a condition which shall prevent tracking. This may require periodic top dressing with additional aggregate. All sediment tracked onto or spilled on public rights of way shall be removed immediately. When necessary, wheels must be cleaned to remove sediment prior to entrance on public rights of way. When washing is required, it shall be done in an area Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 6 stabilized with aggregate and wash water shall be directed away from streams or wetlands preferably to a broad grassed area or a stormwater pond. ✓ Rock outlet protection – once a riprap outlet has been installed, the maintenance needs are very low. It should be inspected after high flows for evidence of scour beneath the riprap. Repair should be immediate. ✓ Replace top-soil, mulch and seed where seeding has been disturbed. 4.5 Erosion and Sediment Control Inspection ▪ It is recommended that a rain gage be installed at the site. ▪ A qualified inspector shall conduct an assessment of the site prior to the commencement of construction and certify in an inspection report that the appropriate erosion and sediment controls described in the SWPPP and required by GP-0-20-001 have been adequately installed to ensure overall preparedness of the site for commencement of construction. ▪ This qualified inspector must be a Licensed Professional Engineer, Certified Professional in Erosion and Sediment Control (CPESC), Registered Landscape Architect, or someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided they have received 4 hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity. After receiving the initial training, the qualified inspector shall receive 4 hours of training every 3 years. ▪ The day-to-day erosion control activities on the site will be monitored by the construction manager. The qualified inspector (as defined by the NYS DEC SPDES regulations) and his crews will make at least one inspection every seven (7) days of erosion control devices, and non-stabilized areas during construction. A maintenance inspection report will be completed by the qualified inspector after each inspection. The report form to be completed by the inspector is attached in Appendix D. Reports should be compiled and maintained on-site in the SWPPP 3-ring binder. ▪ All measures will be maintained in good working order; if repair is necessary, it will be initiated within 24 hours of report. The qualified inspector shall take photographs of any needed repairs and also photograph when the repairs are completed. These photographs will be time and date stamped and attached to the weekly inspection report. ▪ Seeded and planted areas will be inspected for bare spots, washouts, and healthy growth. If necessary, spot reseeding or sodding will be implemented. Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 7 ▪ A trained contractor will be an employee from the contracting company responsible for the implementation of the SWPPP. This person will be onsite when any soil disturbing activities are being conducted. The trained contractor must have received 4 hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity. After receiving the initial training, the qualified inspector shall receive 4 hours of training every 3 years. This trained contractor cannot conduct the regular SWPPP compliance inspections unless they meet the qualified inspector qualifications. 4.6 Contractor Sequence Form The operator shall prepare a summary of construction status using the Construction Sequence Form (included in Appendix E) once every month. Significant deviations to the sequence and reasons for those deviations (i.e. weather, subcontractor availability, etc.), shall be noted by the contractor. The schedule shall be used to record the dates for initiation of construction, implementation of erosion control measures, stabilization, etc. A copy of this table will be maintained at the construction site and updated. 5.0 POST CONSTRUCTION STORMWATER MANAGEMENT PRACTICES 5.1 Stormwater Management Controls The proposed Post Construction Stormwater Management controls on this project are listed below: ✓ Bioretention Basins ✓ Hydrodynamic Separator 5.2 Green Infrastructure Practices/Runoff Reduction Techniques The proposed Green Infrastructure practices or Standard Management practices with Runoff Reduction capabilities on this project are listed below: ✓ Bioretention Basins The provided runoff reduction volume is 0.064 ac-ft, which is less than the required water quality volume, 0.251 ac-ft. The minimum runoff reduction volume is 0.046 ac-ft, which is less than the provided runoff reduction volume. Soil Restoration Excessively compacted areas and areas of cut and fill on the Project Site will have soil restoration applied as needed and as specified in the table below. Attached in Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 8 Appendix H is “Deep Ripping and De-compaction, (DEC 2008).” This methodology should be followed for soil restoration as specified in the table below: • If compost amendment is required, 2 to 4 inches of screened compost will be incorporated into the soil. • Prior to application of the deep-ripping and de-compaction, the depth to bedrock or naturally occurring hardpan should be known so that the depth of tillage be adjusted according to those restrictive depths. • Soils with a slope that exceeds 10% will not have full soil restoration with deep-ripping and de-compaction due to potential for erosion from tilled soil. • Any soil tillage (deep or shallow) will not be done on soils that are excessively wet, as this will damage the soil. • Any tillage will not be done within approximately 10’ of the drip-line of any existing established trees. • Any large stones that are unearthed during tillage should be removed from the surface prior to final surface preparation and vegetation establishment. 5.3 Post Construction Stormwater Management Drawings Post construction stormwater management controls are shown on Construction Drawings included in Appendix C. Type of Soil Disturbance Comments/Examples Minimal Soil Disturbance Preservation of Natural Features Areas where topsoil is stripped only-no change in grade Clearing and Grubbing HSG A& B HSG C & D apply 6 inches of topsoil Aerate* and apply 6 inches of topsoil HSG A& B HSG C & D Aerate and apply 6 inches of topsoil Apply full Soil Restoration** Areas where Runoff Reduction and/or infiltration practices are applied Keep construction equipment from crossing these areas. To protect newly installed practice from any ongoing construction activities construct a single phase operation fence area. **Per "Deep Ripping and Decopmpaction, DEC 2008" *Aeration includes the use of machines such as tractor-drawn implements with coulters making a narrow slit in the soil, a roller with many spikes making indentations in the soil, or prongs which function like a mini-subsoiler Restoration not permitted Restoration not required Soil Restoration Requirement Restoration not required, but may be applied to enhance the reduction specified for appropriate practices Areas of cut and fill Heavy traffic areas onsite (especially in a zone 5-25 feet around buildings, but not within a 5 foot perimeter around foundation walls) Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 9 5.4 Hydraulic and Hydrologic Analysis The program utilized for quantifying stormwater runoff rates and volumes was HydroCAD software, produced by Applied Microcomputer Systems of Chocorua, NH. The SCS 24-hour Type II design storms for 1, 10, and 100-year frequency rainfall were analyzed. ✓ Hydrologic/hydraulic analysis for all structural components of the stormwater control system for the applicable design storms (see Appendix B). ✓ Comparison of post-development stormwater runoff conditions with pre- development conditions (see Appendix B). ✓ Dimensions, material specifications and installation details for each post- construction stormwater control practice (see Appendix B and C). 5.5 Comparison of Pre and Post Construction Stormwater Runoff Stormwater Quantity. These calculations are based on the HydroCAD analysis. Pre Development Post Development 10 year, 24 hour storm (Qp) 63.64 CFS 60.23 CFS 100 year, 24 hour storm (Qf) 133.98 CFS 123.05 CFS Water Quality Volume Calculations The following was utilized to determine water quality volume: WQV= (P) (RV)(A) 12 Where: WQV= Water Quality Volume (acre/feet) P = 90% Rainfall Event RV = 0.05 + 0.009(I) where I is impervious cover in percent A = Subcatchment area in acres Required Provided Water Quality Volume (WQv) 0.251 AC FT 0.501 AC FT 6.0 POST CONSTRUCTION STORMWATER MAINTENANCE 6.1 Maintenance to be Performed Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 10 Skidmore College will be responsible for the continuous upkeep and maintenance of all post construction stormwater management facilities. Post-construction maintenance for this project will consist of regular inspections of permanent stormwater management facilities. These maintenance procedures are essential to assure continual performance of the stormwater management practices on your site. During the inspection and any maintenance activity to the stormwater management practices, the responsible party should fill out an inspection and maintenance log (Appendix E) to record that it was done. Catch Basins (All) ▪ Sediment removal with a vacuum truck should be done at least once a year, preferably after spring runoff and then in early fall, or when they are at 50% capacity, whichever comes first. ▪ Any mechanical valves should be operated for inspection every two months. Bioretention ▪ Clean sediment out of pretreatment portion of the system when it accumulates to a depth of three inches or more ▪ Clean trash and debris out of system as necessary ▪ Dead or diseased vegetation should be replaced ▪ When the filtering capacity of the filter diminishes substantially (when water ponds for more than 48 hours), the top few inches of discolored material shall be removed and be replaced with fresh material. The removed sediments shall be disposed of in an acceptable manner (i.e. landfill). ▪ Silt and sediment should be removed from the filter bed when the accumulation exceeds one inch. ▪ Areas devoid of mulch shall be re-mulched on an annual basis Hydrodynamic Separator ▪ Inspections of the separator must be completed at a minimum of twice a year (Site specific maintenance frequency should be established during the first two or three years or operation) ▪ Maintenance shall be performed if any internal components are broken or missing, inlet or outlet is obstructed or if the accumulation of trash, debris and/or oil in the baffled chambers around the vortex is significant. All maintenance shall be completed during dry weather when no flow is entering the system. ▪ Maintenance shall be performed in accordance with the manufacturer’s specifications provided in Appendix E. 7.0 CONSTRUCTION WASTE Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 11 Waste Materials: All waste materials generated during construction will be disposed at a suitable landfill, or transfer station. Hazardous Waste: The project will not be a generator of hazardous waste and it is not anticipated that any hazardous waste will be generated during construction. If there are any materials generated, a licensed hazardous waste carrier will be contracted to dispose the hazardous material at a suitable disposal site. If hazardous materials are discovered during construction, the work will be stopped until the issue is resolved. Waste: Portable sanitary facilities will be made available to construction personnel and will be serviced regularly. 8.0 OFFSITE VEHICLE TRACKING Excavation equipment involved with the construction will remain on the project site and will not regularly egress or ingress the site. Any trucks used to bring in materials or remove materials via municipal paved roads will do so over a stabilized construction entrance. If any off-site vehicle tracking occurs, the contractor will be directed to initiate, street sweeping program in the immediate vicinity of the site. 9.0 TEMPORARY STABILIZATION FOR FROZEN CONDITIONS The following temporary stabilization measures MUST be performed when construction is occurring during winter/frozen ground conditions. The following requirements do not supersede any other requirements of this SWPPP as they apply to non-frozen ground conditions. ▪ Perimeter erosion control MUST still be installed prior to earthwork disturbance as per this SWPPP. ▪ Any areas that cannot be seeded to turf by October 1 or earlier will receive a temporary seeding. The temporary seeding will consist of winter rye seeded at the rate of 120 pounds per acre (2.5 pounds per 1,000 square feet) or stabilized as per the temporary stabilization for winter construction/frozen conditions. ▪ Any area of disturbance that will remain inactive for a period of 14 consecutive days MUST be mulched. This includes any previously disturbed areas that are covered with snow. ▪ Mulch MUST consist of loose straw applied at the rate of 2 to 3 bales (90 to 100 pounds) per thousand square feet. ▪ Mulch MUST be applied uniformly over the area of bare soil or bare soil that is covered with snow. For the latter condition, mulch MUST be applied on top of snow. ▪ Using a tracked vehicle, mulch MUST be crimped into the bare soil/snow. The tracked vehicle MUST be driven across the mulched Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 12 areas in at least two directions to maximize crimping of mulch into the soil/snow. ▪ If mulch gets blown off an area to a significant degree, the site inspector WILL require that an area be re-mulched in accordance with Items 2 through 5 above, and this area WILL be included on the inspection checklist for the next inspection. ▪ If a particular area repeatedly experiences loss of mulch due to wind, then the inspector WILL require that an alternative method be used to secure the mulch in place. Such alternatives may include the use of netting, tackifier or other methods deemed appropriate by the inspector. ▪ During periods when snow is melting and/or surface soils are thawing during daytime hours, mulched areas MUST be re-tracked (crimped) as per Item 5 above at least once every seven days, more frequently if directed by the inspector. Additional mulch may be required to obtain complete coverage of an area. Biodegradable erosion control matting may be required on steeper slopes. ▪ Additional stabilization measures for non-frozen ground conditions described in this SWPPP WILL be implemented at the time deemed appropriate by the inspector. During the winter season, if a site has been stabilized and soil disturbing activities have been suspended for the winter, weekly inspections can be suspended. However, monthly inspections must still be conducted. All normal weekly inspections must resume when soil disturbing activities resume. 10.0 SPILL PREVENTION PRACTICES Good Housekeeping and Material Management Practices The following good housekeeping and material management practices will be followed on site during the construction project to reduce the risk of spills or other accidental exposure of materials and substances to stormwater runoff. ▪ Materials will be brought on site in the minimum quantities required. ▪ All materials stored on site will be stored in a neat, orderly manner in their appropriate containers, and if possible, under a roof or other enclosure. ▪ Products will be kept in their original containers with the original manufacturer’s label. ▪ Substances will not be mixed with one another unless recommended by the manufacturer. ▪ Whenever possible, all of a product will be used up before disposal. ▪ Manufacturer’s recommendations for proper use and disposal will be followed. Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 13 ▪ The construction manager or his designee will inspect regularly to ensure proper use and disposal of materials on site. ▪ The contractor shall prohibit washing of tools, equipment, and machinery in or within 100 feet of any watercourse or wetland. ▪ All above grade storage tanks are to be protected from vehicle damage by temporary barriers. Inventory for Pollution Prevention Plan The materials and substances listed below are expected to be on-site during construction. ▪ Petroleum for fueling vehicles will be stored in above ground storage tanks. Tanks will either be steel with an enclosure capable of holding 110% of the storage tank volume or of a Con-Store, concrete encased type typically employed by NYSDOT. Hydraulic oil and other oils will be stored in their original containers. Concrete and asphalt will be stored in the original delivery trucks. ▪ Fertilizer may be stored on site in its original container for a short period of time prior to seeding. Original containers will be safely piled on pallets or similar devices to protect from moisture. ▪ Paints and other similar materials will be stored in their original containers and all empty containers will be disposed of in accordance with label directions. ▪ Portable sanitary facilities, which contain chemical disinfectants (deodorants) will be located on-site, with the disinfectants held in the tank of the toilet. Hazardous Products These practices are used to reduce the risks associated with hazardous materials. ▪ Products will be kept in original containers unless they are not re- sealable. ▪ Original labels and material safety data sheets will be retained; they contain important product information. ▪ If surplus product must be disposed of, manufacturers’ or local and State recommended methods for proper disposal will be followed. Spill Prevention The following product specific practices will be followed on site. Petroleum Products: Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 14 ▪ Construction personnel should be made aware that emergency telephone numbers are located in this SWPPP. ▪ The contractor shall immediately contact NYSDEC in the event of a spill, and shall take all appropriate steps to contain the spill, including construction of a dike around the spill and placing absorbent material over this spill. ▪ The contractor shall instruct personnel that spillage of fuels, oils, and similar chemicals must be avoided and will have arranged with a qualified spill remediation company to serve the site. ▪ Fuels, oils, and chemicals will be stored in appropriate and tightly capped containers. Containers shall not be disposed of on the project site. ▪ Fuels, oils, chemicals, material, equipment, and sanitary facilities will be stored/located away from trees and at least 100 feet from streams, wells, wet areas, and other environmentally sensitive sites. ▪ Dispose of chemical containers and surplus chemicals off the project site in accordance with label directions. ▪ Use tight connections and hoses with appropriate nozzles in all operations involving fuels, lubricating materials or chemicals. ▪ Use funnels when pouring fuels, lubricating materials or chemicals. ▪ Refueling and cleaning of construction equipment will take place in parking areas to provide rapid response to emergency situations. ▪ All on-site vehicles will be monitored for leaks and receive regular preventative maintenance to reduce the chance of leakage. Any vehicle leaking fuel or hydraulic fuel will be immediately scheduled for repairs and use will be discontinued until repairs are made. Fertilizers: ▪ Fertilizer will be stored in its original containers on pallets with water resistant coverings. ▪ Proper delivery scheduling will minimize storage time. ▪ Any damaged containers will be repaired immediately upon discovery and any released fertilizer recovered to the fullest extent practicable. Paints: ▪ All containers will be tightly sealed and stored when not required for use. ▪ Excess paint will not be discharged to the storm water system or wastewater system, but will be properly disposed of according to manufacturers’ instructions or State and local regulations. Concrete Trucks: Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 15 ▪ Concrete trucks will be allowed to wash out or discharge surplus concrete or drum wash water only at designated locations on site. Asphalt Trucks: ▪ Asphalt trucks shall not discharge surplus asphalt on the site. Spill Control Practices In addition to the good housekeeping and material management practices discussed in the previous sections of this plan, the following practices will be followed for spill prevention and cleanup. The construction manager or site superintendent responsible for the day-to-day site operations will be the spill prevention and cleanup coordinator. He will designate at least three other site personnel who will receive spill prevention and cleanup training. These individuals will each become responsible for a particular phase of prevention and cleanup. The names of responsible spill personnel will be posted in the material storage area and in the onsite construction office or trailer. ▪ Manufacturers’ recommended methods for spill cleanup will be clearly posted and site personnel will be made aware of the procedures and the location of the information and cleanup supplies. Any spill in excess or suspected to be in excess of two gallons will be reported to the NYSDEC Regional Spill Response Unit. Notification to the NYSDEC (1-800-457-7362) must be completed within two hours of the discovery of the spill. ▪ Materials and equipment necessary for spill cleanup will be kept in the material storage area onsite. Equipment and materials will include but not be limited to absorbent pads, brooms, dust pans, mops, rags, gloves, goggles, activated clay, sand, sawdust, and plastic and metal trash containers specifically for this purpose. ▪ All spills will be cleaned up immediately after discovery. ▪ The spill area will be kept well ventilated and personnel will wear appropriate protective clothing to prevent injury from contact with spilled substance. ▪ Spills of toxic or hazardous material will be reported to the appropriate State or local government agency, regardless of the size Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 16 11 .0 CERTIFICATIONS Preparer Certification of Compliance with Federal, State, and Local Regulations This Stormwater Pollution Prevention Plan was prepared in accordance with the New York State Department of Environmental Conservation SPDES General Permit for Stormwater Discharges from Construction Activities (Permit No. GP-0-20-001), pursuant to Article 17, Titles 7, 8 and Article 70 of the Environmental Conservation Law. This SPDES General Permit implements the Federal Clean Water Act pertaining to stormwater discharges. Name: Brett Strom Title: Civil Engineer Signature: Date: Company Name: The LA Group, PC Owner Pollution Prevention Plan Certification I certify under penalty of law that this document and all attachments were prepared under my direction or supervision to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who are directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that false statements made herein are punishable as a Class A misdemeanor pursuant to Section 210.45 of the Penal Law. I understand that GP-0-20-001 requires site inspections be conducted by a qualified professional once every seven (7) days and when approved in writing by the NYSDEC, disturbances of greater than five (5) acres at one time require site inspections two (2) times every seven (7) days. These inspections shall be performed by a qualified professional as defined by the General Permit. The Owner/Operator will be held financially responsible for any and all fines related to work tasks that are not specified by the Contractor(s)/Subcontractor(s) below. Name: Title: Signature: Date: Company Name: Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 17 Contractor and Subcontractor Certification I hereby certify that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with the terms and conditions of the New York State Pollutant Discharge Elimination System (“SPDES”) general permit for stormwater discharges from construction activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of the referenced permit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceeding. Name Title Signature Date Company Name Address City, State, Zip Phone Number SWPPP Components You Are Responsible For 1. 2. 3. 4. 5. 6. Name of Trained Individual Responsible for SWPPP Implementation Title Signature of Trained Individual Responsible for SWPPP Implementation Date Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 18 Contractor and Subcontractor Certification I hereby certify that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with the terms and conditions of the New York State Pollutant Discharge Elimination System (“SPDES”) general permit for stormwater discharges from construction activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of the referenced permit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceeding. Name Title Signature Date Company Name Address City, State, Zip Phone Number SWPPP Components You Are Responsible For 1. 2. 3. 4. 5. 6. Name of Trained Individual Responsible for SWPPP Implementation Title Signature of Trained Individual Responsible for SWPPP Implementation Date Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 19 Contractor and Subcontractor Certification I hereby certify that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with the terms and conditions of the New York State Pollutant Discharge Elimination System (“SPDES”) general permit for stormwater discharges from construction activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of the referenced permit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceeding. Name Title Signature Date Company Name Address City, State, Zip Phone Number SWPPP Components You Are Responsible For 1. 2. 3. 4. 5. 6. Name of Trained Individual Responsible for SWPPP Implementation Title Signature of Trained Individual Responsible for SWPPP Implementation Date Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 20 Contractor and Subcontractor Certification I hereby certify that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with the terms and conditions of the New York State Pollutant Discharge Elimination System (“SPDES”) general permit for stormwater discharges from construction activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of the referenced permit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceeding. Name Title Signature Date Company Name Address City, State, Zip Phone Number SWPPP Components You Are Responsible For 1. 2. 3. 4. 5. 6. Name of Trained Individual Responsible for SWPPP Implementation Title Signature of Trained Individual Responsible for SWPPP Implementation Date Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 21 12.0 DEFINITIONS Construction Activity(ies) - means any clearing, grading, excavation, filling, demolition, or stockpiling activities that result in soil disturbance. Clearing activities can include, but are not limited to, logging equipment operation, the cutting and skidding of trees, tree removal, stump removal and/or brush removal. Construction activity does not include routine maintenance that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of a facility. Construction Phasing Plan - a plan designed to construct particular portions of an individual project at different times. Phasing is often used when a project is very large to limit the disturbance at a single time to 5 acres per phase. Erosion and Sediment Control Practices – temporary measures installed prior to construction and maintained during construction to temporarily treat any stormwater runoff. Once construction is completed and post-construction stormwater management practices are installed and the site is stabilized, the erosion and sediment control practices are removed from the site. Final Stabilization - means that all soil disturbance activities have ceased and a uniform, perennial vegetative cover with a density of eighty (80) percent over the entire pervious surface has been established; or other equivalent stabilization measures, such as permanent landscape mulches, rock rip-rap or washed/crushed stone have been applied on all disturbed areas that are not covered by permanent structures, concrete pavement. Green Infrastructure – in the context of stormwater management, the term green infrastructure includes a wide array of practices at multiple scales to manage and treat stormwater, maintain and restore natural hydrology and ecological function by infiltration, evapotranspiration, capture and reuse of stormwater, and establishment of natural vegetative features. On a regional scale, green infrastructure is the preservation and restoration of natural landscape features, such as forests, floodplains and wetlands, coupled with policies such as infill and redevelopment that reduce overall imperviousness in a watershed or ecoregion. On the local scale green infrastructure consist of site and neighborhood specific practices and runoff reduction techniques. Such practices essentially result in runoff reduction and or establishment of habitat areas with significant utilization of soils, vegetation, and engineered media rather than traditional hardscape collection, conveyance and storage structures. Some examples include green roofs, trees and tree boxes, pervious pavement, rain gardens, vegetated swales, planters, reforestation and protection and enhancement of riparian buffers and floodplains. Impervious Area (Cover) - means all impermeable surfaces that cannot effectively infiltrate rainfall. This includes paved, concrete and gravel surfaces (i.e. parking lots, driveways, roads, runways, and sidewalks); building rooftops, and miscellaneous impermeable structures such as patios, pools, and sheds. Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 22 Municipal Separate Storm Sewer (MS4) – a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains): i. Owned or operated by a state, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to State law) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the CWA that discharges to surface waters of the State. ii. Designed or used for collecting or conveying stormwater iii. Which is not a combined sewer iv. Which is not part of a Publicly Owned Treatment Works (POTW) as defined at 40 CFR 122.2. Notice of Intent – a standardized format notification sent to the NYSDEC to inform them of the proposed activity to be sent after the SWPPP has been completed. Owner or Operator – means the person, persons or legal entity which owns or leases the property on which the construction activity is occurring; and/or an entity that has operational control over the construction plans and specifications, including the ability to make modifications to the plans and specifications. Post-Construction Stormwater Management Practices – permanent devices constructed or installed onsite to treat stormwater from a site when construction is completed. Qualified Inspector – means a person that is knowledgeable in the principles and practices of erosion and sediment control, such as a licensed Professional Engineer, Certified Professional in Erosion and Sediment Control (CPESC), Registered Landscape Architect, or other Department endorsed individual(s). It can also mean someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided that person has training in the principles and practices of erosion and sediment control. Training in the principles and practices of erosion and sediment control means that the individual working under the direct supervision of the licensed Professional Engineer or Registered Landscape Architect has received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity. After receiving the initial training, the individual working under the direct supervision of the licensed Professional Engineer or Registered Landscape Architect shall receive four (4) hours of training every three (3) years. It can also mean a person that meets the Qualified Professional qualifications in addition to the Qualified Inspector qualifications. Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 23 Qualified Professional – means a person that is knowledgeable in the principles and practices of stormwater management and treatment, such as a licensed Professional Engineer, Registered Landscape Architect or other Department endorsed individual(s). Individuals preparing SWPPPs that require the post-construction stormwater management practice component must have an understanding of the principles of hydrology, water quality management practice design, water quantity control design, and, in many cases, the principles of hydraulics. All components of the SWPPP that involve the practice of engineering, as defined by the NYS Education Law (see Article 145) , shall be prepared by, or under the direct supervision of, a professional engineer licensed ot practice in the State of New York. Regulated, Traditional Land Use Control MS4 - means a city, town, or village with land use control authority that is required to gain coverage under New York State DEC’s SPDES General Permit for Stormwater Discharges from Municipal Separate Stormwater Sewer Systems (MS4s). Sequence of Operations – the individual steps and their specific order which are undertaken in order to construct a project or a given phase of a project from beginning to end. (i.e. clearing, grading, foundation work, landscaping, etc.) State Pollutant Discharge Elimination System (SPDES) – means the system established pursuant to Article 17 of the Environmental Conservation Law (ECL) and 6 NYCRR Part 750 for issuance of permits authorizing discharges to the waters of the state. Stormwater Pollution Prevention Plan (SWPPP) - a report that is compiled providing detailed information about the proposed activity and the specifics to how the stormwater will be managed during construction and after construction is completed. Surface Waters of the State - shall be construed to include lakes, bays, sounds, ponds, impounding reservoirs, springs, rivers, streams, creeks, estuaries, marshes, inlets, canals, the Atlantic Ocean, within the territorial seas of the state of New York and all other bodies of surface water, natural or artificial, inland or coastal, fresh or salt, public or private (except those private waters that do not combine or effect a junction with natural surface or underground waters), which are wholly or partially within or bordering the state or within its jurisdiction. Waters of the state are further defined in 6 NYCRR Parts 800-941. Temporary Stabilization – means that exposed soil has been covered with material(s) as set forth in the technical standard, New York Standards and Specifications for Erosion and Sediment Control, to prevent the exposed soil from eroding. The materials can include, but are not limited to, mulch, seed and mulch, and erosion control mats (e.g. jute twisted yarn, excelsior wood fiber mats). Trained Contractor – means an employee from a contracting (construction) company responsible for the day to day implementation of the SWPPP. The trained contractor Stormwater Pollution Prevention Plan Skidmore College Health, Wellness, Fitness and Tennis Facility The LA Group Project # 2016098 Page 24 must have received 4 hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity. After receiving the initial training, the qualified inspector shall receive 4 hours of training every 3 years. It can also mean an employee from the contracting (construction) company that meets the qualified inspector qualifications (e.g. licensed Professional Engineer, Certified Professional in Erosion and Sediment Control (CPESC), Registered Landscape Architect, or someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided they have received 4 hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity. G:\Proj-2016\2016098_Skidmore_College_Athletic_Expansion\2016098_Enviro\02SWPPP\2016098_SWPPP.docx Appendix A Notice of Intent (NOI) and MS4 Acceptance Form 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 1/12 NOI for coverage under Stormwater General Permit for Construction Activity version 1.35 (Submission #: HPN-XH9W-DANYT, version 1) Details Originally Started By Brett Strom Alternate Identifier Skidmore College Athletic Expansion Submission ID HPN-XH9W-DANYT Submission Reason New Status Draft Form Input Owner/Operator Information Owner/Operator Name (Company/Private Owner/Municipality/Agency/Institution, etc.) Skidmore College Owner/Operator Contact Person Last Name (NOT CONSULTANT) Rodecker Owner/Operator Contact Person First Name Dan Owner/Operator Mailing Address 815 North Broadway City Saratoga Springs State NY Zip 12866 Phone 5185805860 Email drodecke@skidmore.edu 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 2/12 Federal Tax ID NONE PROVIDED Project Location Project/Site Name Skidmore College Athletic Expansion Street Address (Not P.O. Box) 815 North Broadway West City/Town/Village (THAT ISSUES BUILDING PERMIT) Saratoga Springs NY Zip 12866 5 SARATOGA Name of Nearest Cross Street 4th Street Distance to Nearest Cross Street (Feet) 530 North Tax Map Numbers Section-Block-Parcel 152-1-3 Tax Map Numbers NONE PROVIDED 1. Coordinates Provide the Geographic Coordinates for the project site. The two methods are: - Navigate to the project location on the map (below) and click to place a marker and obtain the XY coordinates. - The "Find Me" button will provide the lat/long for the person filling out this form. Then pan the map to the correct location and click the map to place a marker and obtain the XY coordinates. Navigate to your location and click on the map to get the X,Y coordinates 43.09354999581493,-73.78557523827584 Project Details Side of Street State DEC Region County Project In Relation to Cross Street 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 3/12 Redevelopment with increase in impervious area 3. Select the predominant land use for both pre and post development conditions. Institutional/School Institutional/School 3a. If Single Family Subdivision was selected in question 3, enter the number of subdivision lots. NONE PROVIDED 4. In accordance with the larger common plan of development or sale, enter the total project site acreage, the acreage to be disturbed and the future impervious area (acreage)within the disturbed area. *** ROUND TO THE NEAREST TENTH OF AN ACRE. *** Total Site Area (acres) 9.8 Total Area to be Disturbed (acres) 7.2 Existing Impervious Area to be Disturbed (acres) 1.4 Future Impervious Area Within Disturbed Area (acres) 3.1 No 6. Indicate the percentage (%) of each Hydrologic Soil Group(HSG) at the site. A (%) 0 B (%) 0 C (%) 100 D (%) 0 No 8. Enter the planned start and end dates of the disturbance activities. Start Date 03/01/2023 End Date 03/01/2024 2. What is the nature of this project? Pre-Development Existing Landuse Post-Development Future Land Use 5. Do you plan to disturb more than 5 acres of soil at any one time? 7. Is this a phased project? 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 4/12 9. Identify the nearest surface waterbody(ies) to which construction site runoff will discharge. Unnamed stream Stream/Creek Off Site Other Waterbody Type Off Site Description NONE PROVIDED NONE PROVIDED No No No If No, skip question 13. NONE PROVIDED If Yes, what is the acreage to be disturbed? NONE PROVIDED No Yes 16. What is the name of the municipality/entity that owns the separate storm sewer system? City of Saratoga Springs No No No No 9a. Type of waterbody identified in question 9? 9b. If "wetland" was selected in 9A, how was the wetland identified? 10. Has the surface waterbody(ies in question 9 been identified as a 303(d) segment in Appendix E of GP-0-20-001? 11. Is this project located in one of the Watersheds identified in Appendix C of GP-0-20-001? 12. Is the project located in one of the watershed areas associated with AA and AA-S classified waters? 13. Does this construction activity disturb land with no existing impervious cover and where the Soil Slope Phase is identified as D (provided the map unit name is inclusive of slopes greater than 25%), E or F on the USDA Soil Survey? 14. Will the project disturb soils within a State regulated wetland or the protected 100 foot adjacent area? 15. Does the site runoff enter a separate storm sewer system (including roadside drains, swales, ditches, culverts, etc)? 17. Does any runoff from the site enter a sewer classified as a Combined Sewer? 18. Will future use of this site be an agricultural property as defined by the NYS Agriculture and Markets Law? 19. Is this property owned by a state authority, state agency, federal government or local government? 20. Is this a remediation project being done under a Department approved work plan? (i.e. CERCLA, RCRA, Voluntary Cleanup Agreement, etc.) 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 5/12 Required SWPPP Components Yes Yes If you answered No in question 22, skip question 23 and the Post-construction Criteria and Post- construction SMP Identification sections. Yes Professional Engineer (P.E.) SWPPP Preparer The LA Group Contact Name (Last, Space, First) Strom, Brett Mailing Address 40 Long Alley City Saratoga Springs State NY Zip 12866 Phone 5185878100 Email bstrom@thelagroup.com Download SWPPP Preparer Certification Form Please take the following steps to prepare and upload your preparer certification form: 1) Click on the link below to download a blank certification form 2) The certified SWPPP preparer should sign this form 3) Scan the signed form 4) Upload the scanned document Download SWPPP Preparer Certification Form Please upload the SWPPP Preparer Certification NONE PROVIDED Comment NONE PROVIDED 21. Has the required Erosion and Sediment Control component of the SWPPP been developed in conformance with the current NYS Standards and Specifications for Erosion and Sediment Control (aka Blue Book)? 22. Does this construction activity require the development of a SWPPP that includes the post- construction stormwater management practice component (i.e. Runoff Reduction, Water Quality and Quantity Control practices/techniques)? 23. Has the post-construction stormwater management practice component of the SWPPP been developed in conformance with the current NYS Stormwater Management Design Manual? 24. The Stormwater Pollution Prevention Plan (SWPPP) was prepared by: 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 6/12 Erosion & Sediment Control Criteria Yes 26. Select all of the erosion and sediment control practices that will be employed on the project site: Construction Road Stabilization Silt Fence Storm Drain Inlet Protection None Seeding Mulching Rock Outlet Protection Land Grading Other NONE PROVIDED Post-Construction Criteria * IMPORTANT: Completion of Questions 27-39 is not required if response to Question 22 is No. Preservation of Undisturbed Area All disturbed areas will be restored in accordance with the Soil Restoration requirements in Table 5.3 of the Design Manual (see page 5-22). 28. Provide the total Water Quality Volume (WQv) required for this project (based on final site plan/layout). (Acre-feet) 0.251 29. Post-construction SMP Identification Use the Post-construction SMP Identification section to identify the RR techniques (Area Reduction), RR techniques(Volume Reduction) and Standard SMPs with RRv Capacity that were used to reduce the Total WQv Required (#28). Identify the SMPs to be used by providing the total impervious area that contributes runoff to each technique/practice selected. For the Area Reduction Techniques, provide the total contributing area (includes pervious area) and, if applicable, the total impervious area that contributes runoff to the technique/practice. Note: Redevelopment projects shall use the Post-Construction SMP Identification section to identify the SMPs used to treat and/or reduce the WQv required. If runoff reduction techniques will not be used to reduce the required WQv, skip to question 33a after identifying the SMPs. 25. Has a construction sequence schedule for the planned management practices been prepared? Temporary Structural Biotechnical Vegetative Measures Permanent Structural 27. Identify all site planning practices that were used to prepare the final site plan/layout for the project. 27a. Indicate which of the following soil restoration criteria was used to address the requirements in Section 5.1.6("Soil Restoration") of the Design Manual (2010 version). 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 7/12 30. Indicate the Total RRv provided by the RR techniques (Area/Volume Reduction) and Standard SMPs with RRv capacity identified in question 29. (acre-feet) 0.064 No If Yes, go to question 36. If No, go to question 32. 32. Provide the Minimum RRv required based on HSG. [Minimum RRv Required = (P) (0.95) (Ai) / 12, Ai=(s) (Aic)] (acre-feet) 0.046 Yes If Yes, go to question 33. Note: Use the space provided in question #39 to summarize the specific site limitations and justification for not reducing 100% of WQv required (#28). A detailed evaluation of the specific site limitations and justification for not reducing 100% of the WQv required (#28) must also be included in the SWPPP. If No, sizing criteria has not been met; therefore, NOI can not be processed. SWPPP preparer must modify design to meet sizing criteria. 33. SMPs Use the Post-construction SMP Identification section to identify the Standard SMPs and, if applicable, the Alternative SMPs to be used to treat the remaining total WQv (=Total WQv Required in #28 - Total RRv Provided in #30). Also, provide the total impervious area that contributes runoff to each practice selected. NOTE: Use the Post-construction SMP Identification section to identify the SMPs used on Redevelopment projects. 33a. Indicate the Total WQv provided (i.e. WQv treated) by the SMPs identified in question #33 and Standard SMPs with RRv Capacity identified in question #29. (acre-feet) 0.437 Note: For the standard SMPs with RRv capacity, the WQv provided by each practice = the WQv calculated using the contributing drainage area to the practice - provided by the practice. (See Table 3.5 in Design Manual) 34. Provide the sum of the Total RRv provided (#30) and the WQv provided (#33a). 0.501 Yes If Yes, go to question 36. If No, sizing criteria has not been met; therefore, NOI can not be processed. SWPPP preparer must modify design to meet sizing criteria. 36. Provide the total Channel Protection Storage Volume (CPv required and provided or select waiver (#36a), if applicable. CPv Required (acre-feet) 0.08 31. Is the Total RRv provided (#30) greater than or equal to the total WQv required (#28)? 32a. Is the Total RRv provided (#30) greater than or equal to the Minimum RRv Required (#32)? 35. Is the sum of the RRv provided (#30) and the WQv provided (#33a) greater than or equal to the total WQv required (#28)? 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 8/12 CPv Provided (acre-feet) 0.28 Reduction of the total CPv is achieved on site through runoff reduction techniques or infiltration systems. 37. Provide the Overbank Flood (Qp) and Extreme Flood (Qf) control criteria or select waiver (#37a), if applicable. Overbank Flood Control Criteria (Qp) Pre-Development (CFS) 63.64 Post-Development (CFS) 60.23 Total Extreme Flood Control Criteria (Qf) Pre-Development (CFS) 133.98 Post-Development (CFS) 123.05 NONE PROVIDED Yes If Yes, Identify the entity responsible for the long term Operation and Maintenance Skidmore College 39. Use this space to summarize the specific site limitations and justification for not reducing 100% of WQv required (#28). (See question #32a) This space can also be used for other pertinent project information. The full WQv is not reduced due to shallow depth to seasonal high groundwater. Post-Construction SMP Identification Runoff Reduction (RR) Techniques, Standard Stormwater Management Practices (SMPs) and Alternative SMPs Identify the Post-construction SMPs to be used by providing the total impervious area that contributes runoff to each technique/practice selected. For the Area Reduction Techniques, provide the total contributing area (includes pervious area) and, if applicable, the total impervious area that contributes runoff to the technique/practice. RR Techniques (Area Reduction) Round to the nearest tenth Total Contributing Acres for Conservation of Natural Area (RR-1) NONE PROVIDED Total Contributing Impervious Acres for Conservation of Natural Area (RR-1) NONE PROVIDED 36a. The need to provide channel protection has been waived because: 37a. The need to meet the Qp and Qf criteria has been waived because: 38. Has a long term Operation and Maintenance Plan for the post-construction stormwater management practice(s) been developed? 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 9/12 Total Contributing Acres for Sheetflow to Riparian Buffers/Filter Strips (RR-2) NONE PROVIDED Total Contributing Impervious Acres for Sheetflow to Riparian Buffers/Filter Strips (RR-2) NONE PROVIDED Total Contributing Acres for Tree Planting/Tree Pit (RR-3) NONE PROVIDED Total Contributing Impervious Acres for Tree Planting/Tree Pit (RR-3) NONE PROVIDED Total Contributing Acres for Disconnection of Rooftop Runoff (RR-4) NONE PROVIDED RR Techniques (Volume Reduction) Total Contributing Impervious Acres for Disconnection of Rooftop Runoff (RR-4) NONE PROVIDED Total Contributing Impervious Acres for Vegetated Swale (RR-5) NONE PROVIDED Total Contributing Impervious Acres for Rain Garden (RR-6) NONE PROVIDED Total Contributing Impervious Acres for Stormwater Planter (RR-7) NONE PROVIDED Total Contributing Impervious Acres for Rain Barrel/Cistern (RR-8) NONE PROVIDED Total Contributing Impervious Acres for Porous Pavement (RR-9) NONE PROVIDED Total Contributing Impervious Acres for Green Roof (RR-10) NONE PROVIDED Standard SMPs with RRv Capacity Total Contributing Impervious Acres for Infiltration Trench (I-1) NONE PROVIDED Total Contributing Impervious Acres for Infiltration Basin (I-2) NONE PROVIDED Total Contributing Impervious Acres for Dry Well (I-3) NONE PROVIDED Total Contributing Impervious Acres for Underground Infiltration System (I-4) NONE PROVIDED Total Contributing Impervious Acres for Bioretention (F-5) 1.7 Total Contributing Impervious Acres for Dry Swale (O-1) NONE PROVIDED 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 10/12 Standard SMPs Total Contributing Impervious Acres for Micropool Extended Detention (P-1) NONE PROVIDED Total Contributing Impervious Acres for Wet Pond (P-2) NONE PROVIDED Total Contributing Impervious Acres for Wet Extended Detention (P-3) NONE PROVIDED Total Contributing Impervious Acres for Multiple Pond System (P-4) NONE PROVIDED Total Contributing Impervious Acres for Pocket Pond (P-5) NONE PROVIDED Total Contributing Impervious Acres for Surface Sand Filter (F-1) NONE PROVIDED Total Contributing Impervious Acres for Underground Sand Filter (F-2) NONE PROVIDED Total Contributing Impervious Acres for Perimeter Sand Filter (F-3) NONE PROVIDED Total Contributing Impervious Acres for Organic Filter (F-4) NONE PROVIDED Total Contributing Impervious Acres for Shallow Wetland (W-1) NONE PROVIDED Total Contributing Impervious Acres for Extended Detention Wetland (W-2) NONE PROVIDED Total Contributing Impervious Acres for Pond/Wetland System (W-3) NONE PROVIDED Total Contributing Impervious Acres for Pocket Wetland (W-4) NONE PROVIDED Total Contributing Impervious Acres for Wet Swale (O-2) NONE PROVIDED Alternative SMPs (DO NOT INCLUDE PRACTICES BEING USED FOR PRETREATMENT ONLY) Total Contributing Impervious Area for Hydrodynamic 3.7 Total Contributing Impervious Area for Wet Vault NONE PROVIDED Total Contributing Impervious Area for Media Filter NONE PROVIDED "Other" Alternative SMP? NONE PROVIDED 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 11/12 Total Contributing Impervious Area for "Other" NONE PROVIDED Provide the name and manufaturer of the alternative SMPs (i.e. proprietary practice(s)) being used for WQv treatment. Note: Redevelopment projects which do not use RR techniques, shall use questions 28, 29, 33 and 33a to provide SMPs used, total WQv required and total WQv provided for the project. Manufacturer of Alternative SMP Contech Engineered Solution LLC Name of Alternative SMP CS-5 Other Permits None If SPDES Multi-Sector GP, then give permit ID NONE PROVIDED If Other, then identify NONE PROVIDED No If "Yes," then indicate Size of Impact, in acres, to the nearest tenth NONE PROVIDED 42. If this NOI is being submitted for the purpose of continuing or transferring coverage under a general permit for stormwater runoff from construction activities, please indicate the former SPDES number assigned. NONE PROVIDED MS4 SWPPP Acceptance Yes - Please attach the MS4 Acceptance form below If No, skip question 44 Yes MS4 SWPPP Acceptance Form Download Download form from the link below. Complete, sign, and upload. MS4 SWPPP Acceptance Form MS4 Acceptance Form Upload NONE PROVIDED Comment NONE PROVIDED 40. Identify other DEC permits, existing and new, that are required for this project/facility. 41. Does this project require a US Army Corps of Engineers Wetland Permit? 43. Is this project subject to the requirements of a regulated, traditional land use control MS4? 44. Has the "MS4 SWPPP Acceptance" form been signed by the principal executive officer or ranking elected official and submitted along with this NOI? 11/4/22, 8:48 AM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/5819cffe-7910-454f-863d-d5a03320df2e/11 12/12 Owner/Operator Certification Owner/Operator Certification Form Download Download the certification form by clicking the link below. Complete, sign, scan, and upload the form. Owner/Operator Certification Form (PDF, 45KB) Upload Owner/Operator Certification Form NONE PROVIDED Comment NONE PROVIDED Appendix B Stormwater Management Report Hydro CAD Stormwater Management Report for: Skidmore College Athletic Expansion at Skidmore College, 815 N Broadway, Saratoga Springs, NY 12866 Saratoga County Owner/Operator(s): Skidmore College 815 N Broadway Saratoga Springs, NY 12866 SWM Report Contact(s): The LA Group, PC 40 Long Alley Saratoga Springs, NY 12866 1-518-587-8100 Project No. 2016098 Preparation Date: November 4, 2022 Stormwater Management Report Skidmore College Athletic Expansion 2016098 Table of Contents 1.0 INTRODUCTION.................................................................................................................4 2.0 PROJECT DESCRIPTION .................................................................................................4 2.1 SITE LOCATION ....................................................................................................................4 2.2 PROJECT DESCRIPTION .........................................................................................................4 2.3 SOIL CONDITIONS/SOIL TESTING .........................................................................................4 2.4 CURVE NUMBERS AND RAINFALL DATA ..............................................................................4 3.0 EXISTING CONDITIONS ..................................................................................................5 4.0 PROPOSED CONDITIONS ................................................................................................5 5.0 NYSDEC DESIGN CRITERIA ...........................................................................................6 5.1 SITE PLANNING TO PRESERVE NATURAL FEATURES ............................................................7 5.2 WATER QUALITY VOLUME (WQV) ......................................................................................8 5.3 RUNOFF REDUCTION VOLUME (RRV) ..................................................................................9 5.4 OVERBANK FLOOD (QP) AND EXTREME FLOOD (QF) ATTENUATION .................................10 6.0 PROPOSED STORMWATER FACILITIES ..................................................................11 6.1 PRETREATMENT .................................................................................................................11 6.2 TREATMENT .......................................................................................................................11 7.0 POST-CONSTRUCTION MAINTENANCE REQUIREMENTS.................................11 7.0 REFERENCES ....................................................................................................................11 Stormwater Management Report Skidmore College Athletic Expansion 2016098 Attachment A Soil Investigations Soil Survey Natural Resource Map B Existing Conditions Watershed Map and HydroCAD Calculations C Proposed Conditions Watershed Map, HydroCAD Calculations D Storm Data Stormwater Management Report Skidmore College Health, Wellness, Fitness & Tennis Facility 2016098 4 1.0 INTRODUCTION The following is a Stormwater Management Report (SWM Report) developed for the Operator, Skidmore College, for the Skidmore College Health, Wellness, Fitness & Tennis Facility, herein referred to as the “Project.” It is prepared in accordance with the New York State Department of Environmental Conservation (NYSDEC) Stormwater Management Design Manual, dated January, 2015. The project is a mixture of redevelopment and new development. Any increases in impervious area at the sites have been designed in accordance with Chapter 4 of the NYSDEC Stormwater Management Design Manual and NYSDEC’s General Permit (GP-0-20-001) for construction activities. All existing impervious area to be disturbed have been designed in accordance with Chapter 9 of the NYSDEC Stormwater Management Manual. Stormwater calculations were performed utilizing widely accepted engineering methodologies, including TR-55, and the stormwater modeling computer program HydroCAD (version 10.00) produced by HydroCAD Software Solutions, LLC. 2.0 PROJECT DESCRIPTION 2.1 Site Location The Project is located at Skidmore College in Saratoga Springs, Saratoga County, NY 12866. Access to the site is off Perimeter Road. 2.2 Project Description The proposed project includes the construction of a new Health, Wellness, Fitness & Tennis Facility, tennis courts, and sidewalks. The property is currently comprised of grass and two tennis courts to the east of the Williamson Sports Center. The remainder of the proposed site improvements includes landscaping and stormwater controls. The project is considered a new redevelopment project per Chapters 9 of the SWMDM. The Project Site represents the area that will be disturbed as a result of the Project. 2.3 Soil Conditions/Soil Testing According to the Natural Resources Conservation Service (NRCS) Web Soil Survey, the area including and surrounding the Project Site is comprised of Galway Loam. Galway Loam is classified as ‘C’. Therefore, the site has been analyzed using ‘C’ soils. Stormwater Management Report Skidmore College Health, Wellness, Fitness & Tennis Facility 2016098 5 2.4 Curve Numbers and Rainfall Data The surface cover for the project area is grass and an impervious driveway. The curve numbers utilized in the modeling were assigned based on cover type and HSG soil classification. The design storms used for the pre-development versus post-development comparison were the 1, 10, and 100-year, 24-hour duration, SCS Type II events. The rainfall amounts for these storms are 2.15, 3.75, and 6.20 inches, respectively. 3.0 EXISTING CONDITIONS The Project area existing condition, for which this stormwater management plan is based, consists of grass, woods, and impervious cover. Under the watershed’s existing condition, runoff from the site flows offsite to the south (Analysis Point 1 & 2). Analysis Points 1-2 were utilized in comparing all pre- versus post-runoff conditions. Refer to drawing “W-1 Existing Conditions Watershed Map,” located in Attachment B for more information. Table 3-1 below provides a summary of the existing conditions peak discharge rates for the Project’s watershed. Table 3-1 Existing Conditions Peak Discharge Rates Analysis Point AP-1 AP-2 Design Storm (cfs) (cfs) 10-Year 1.57 62.07 100-Year 3.60 130.38 Refer to Attachment B for more information on the existing conditions watershed modeling. 4.0 PROPOSED CONDITIONS Under the watershed’s Proposed Condition, stormwater from the Project will continue to discharge to the same points as in the Existing Condition (Analysis Points 1 & 2). AP-1 represents runoff flowing into the city property to the south. AP-2 represents flow discharging to the existing detention basins to the south of the project area. The total watershed is shown on the drawing “W-2 Proposed Conditions Watershed Map” contained in Attachment C. To meet NYSDEC requirements (see Section 5.0 NYSDEC Design Criteria of this report) bioretention basins, a hydrodynamic separator and an expansion to the existing detention pond have been incorporated into the stormwater management design to mitigate the quality and quantity of stormwater runoff discharged from the Project Site. Stormwater Management Report Skidmore College Health, Wellness, Fitness & Tennis Facility 2016098 6 Table 4-1 below provides a summary of the existing conditions versus proposed conditions peak discharge rates for the Project’s watershed. Table 4-1 Existing Conditions Versus Proposed Conditions Peak Discharge Rates Analysis Point AP-1 AP-2 Existing Proposed Existing Proposed Design Storm (cfs) (cfs) (cfs) (cfs) 10-Year 1.57 1.00 62.07 59.23 100-Year 3.60 2.08 130.38 120.97 Refer to Attachment C for more information on the proposed conditions watershed modeling. 5.0 NYSDEC DESIGN CRITERIA The New York State Stormwater Management Design Manual, dated January 2015 (The Manual) has been utilized to develop the stormwater management plan. The Manual includes a five-step process that involves site planning and stormwater management practice selection. The five steps include; • Site planning to preserve natural features and reduce impervious cover, • Calculation of the Water Quality Volume (WQv) for the Site, • Incorporation of green infrastructure techniques and standard SMPs with Runoff Reduction Volume (RRv) capacity, • Use of standard SMPs where applicable, to treat the portion of WQv not addressed by green infrastructure techniques and standard SMPs with RRv capacity, and • Design of volume and peak rate control (where required) The approach of the stormwater management plan was to address the stormwater requirements separately. The five steps were reduced to Site Planning to Preserve Natural Features, Water Quality Volume, Runoff Reduction Volume, Channel Protection Volume, and Overbank Flood and Extreme Storm Attenuation, as discussed in the following sections. Attachment D of this report contains detailed calculations for determining and summarizing the required and provided volumes for Water Quality and Runoff Reduction. In general, the Stormwater Management Report Skidmore College Health, Wellness, Fitness & Tennis Facility 2016098 7 required design criteria (WQv and RRv) were calculated for all areas where site disturbance or green infrastructure techniques are proposed. 5.1 Site Planning to Preserve Natural Features Within Chapter 3 of The Manual, Table 3.1 Green Infrastructure Planning General Categories and Specific Practices includes a list of planning practices utilized in the planning and design of a project. There are two categories, Preservation of Natural Resources and Reduction of Imperious Cover. Preservation of Natural Resources includes: • Preservation of Undisturbed Areas • Preservation of Buffers • Reduction of Clearing and Grading • Locating Development in Less Sensitive Areas • Open Space Design • Soil Restoration Reduction of Impervious Cover includes: • Roadway Reduction • Sidewalk Reduction • Driveway Reduction • Cul-de-sac Reduction • Building Footprint Reduction • Parking Reduction A Natural Resource Map for Green Infrastructure Planning has been developed which indicates natural resource areas and critical environmental areas to be protected (where feasible). As required in Section 3.6 of The Manual, the map includes (where applicable): • Jurisdictional Wetlands o There are no wetlands located near the project site. • Waterways o No waterways are impacted by the Project. • Wetland Adjacent Area o There are no wetlands located near the project site. • Floodplains o The project is not within the flood plain. • Forest, vegetative cover o Impact to forested area is limited where feasible. • Topography/Steep slopes Stormwater Management Report Skidmore College Health, Wellness, Fitness & Tennis Facility 2016098 8 o There are no steep slopes located throughout the project. • Existing soils, including hydrologic soil groups and soil erodibility o See Section 2.3 of this Report. • Drainage Patterns o See Section 3.0 of this Report. • Bedrock/Significant geological features o See Section 2.3 of this Report. 5.2 Water Quality Volume (WQv) The Water Quality Volume (WQv) requirement is designed to improve water quality sizing to capture and treat 90% of the average annual stormwater runoff volumes. The WQv is directly related to the amount of impervious cover created at a site. The following equation is used to determine the water quality storage volume. WQv = (P)(Rv)(A) 12 Where: WQv = Water quality volume (acre/feet) P = 90% Rainfall Event (1.15” Saratoga Springs) Rv = 0.05 + 0.009(I) where I is percent impervious cover A = Site area in acres The required WQv will be provided by three bioretention basins and a hydrodynamic separator designed in accordance with the SWMDM. The total required WQv for the project is 0.251 ac-ft. Refer to Table 5-1 for a summary of the provided water quality volumes for the Project. Table 5-1 Water Quality Volume (WQv) Summary SMP Type Provided (ac-ft) SMP-1 Bioretention Basin 0.128 SMP-2 Bioretention Basin 0.020 SMP-3 Bioretention Basin 0.011 SMP-4 Hydrodynamic Separator 0.342 TOTAL 0.501 Refer to Attachment D for detailed WQv calculations. Stormwater Management Report Skidmore College Health, Wellness, Fitness & Tennis Facility 2016098 9 5.3 Runoff Reduction Volume (RRv) Section 4.3 of the Manual states, “Runoff reduction shall be achieved by infiltration, groundwater recharge, reuse, recycle, evaporation/evapotranspiration of 100 percent of the post- development water quality volumes to replicate pre-development hydrology by maintaining pre- construction infiltration, peak runoff flow, discharge volume, as well as minimizing concentrated flow by using runoff control techniques to provide treatment in a distributed manner before runoff reaches the collection system.” The stormwater management plan must demonstrate that all green infrastructure planning and design options were evaluated to meet the runoff reduction requirement. The following is a list of green infrastructure practices that were evaluated during design and specific limitations of the site: • 5.3.1 Conservation of Natural Areas o No conservation areas are proposed as part of this project due to lack of sufficient area on-site. • 5.3.2 Sheetflow to Riparian Buffers/Filter Strips o No filter strips are proposed as part of this project due to lack of sufficient area on-site. • 5.3.3 Vegetated Open Swales o Vegetated open swales were not proposed as a part of this project due to lack of sufficient area on-site. • 5.3.4 Tree Planting/Tree Box o Tree plantings have been proposed throughout the site but credit is not taken due to the low RRv credit (<0.001 ac-ft) provided. • 5.3.5 Disconnection of Rooftop Runoff o Rooftop disconnection was not utilized as there is not sufficient receiving area. • 5.3.6 Stream Daylighting o All subsurface storm sewer piping will be daylighted as soon as possible. • 5.3.7 Rain Garden o Rain gardens are typically applied for residential applications. The contributing drainage areas of project components exceed the maximum contributing area of 1,000 sf (for a rain garden), specified in the SWMDM. • 5.3.8 Green Roof o A green roof is not financially feasible. • 5.3.9 Stormwater Planters o Stormwater planters are not proposed as roof area is greater than 15,000 square feet of contributing area. • 5.3.10 Rain Tanks/Cisterns Stormwater Management Report Skidmore College Health, Wellness, Fitness & Tennis Facility 2016098 10 o Rain tanks/cisterns do not have any tangible functionality on this site as there is little potential for reuse. • 5.3.11 Porous Pavement o Porous pavement is not used as a part of the Project due to shallow depth to groundwater. Table 5-2 Runoff Reduction Volume (RRv) Summary SMP Provided (ac-ft) 5.3.1 Conservation of Natural Areas - 5.3.2 Sheetflow to Riparian Buffers/Filter Strips - 5.3.3 Vegetated Open Swales - 5.3.4 Tree Planting/Tree Box - 5.3.5 Disconnection of Rooftop Runoff - 5.3.6 Stream Daylighting - 5.3.7 Rain Garden - 5.3.8 Green Roof - 5.3.9 Stormwater Planters - 5.3.10 Rain Tanks/Cisterns - 5.3.11 Porous Pavement - Bioretention Basin (SMP-1) 0.033 Bioretention Basin (SMP-2) 0.020 Bioretention Basin (SMP-3) 0.011 TOTAL 0.064 (ac-ft) Refer to Attachment D for detailed RRv calculations. 5.4 Overbank Flood (Qp) and Extreme Flood (Qf) Attenuation The primary purpose of the Overbank Flood (Qp) control sizing criterion is to prevent an increase in the frequency and magnitude of out-of-bank flooding generated by urban development. It requires storage and attenuation of the 10-year, 24-hour storm to ensure post- development peak discharge rates do not exceed the pre-development condition. The intent of the Extreme Flood (Qf) criteria is to (a) prevent the increased risk of flood damage from large storm events, (b) maintain the boundaries of the pre-development 100-year floodplain, and (c) protect the physical integrity of stormwater management practices. It requires Stormwater Management Report Skidmore College Health, Wellness, Fitness & Tennis Facility 2016098 11 storage and attenuation of the 100-year, 24-hour storm to ensure post-development peak discharge rates do not exceed the pre-development condition. During the 10-year and 100-year 24-hour storm the post-development peak discharge rates do not exceed the pre-development rates. See Table 4-1 of this Report for detailed comparison of pre- and post-development peak rates. 6.0 PROPOSED STORMWATER FACILITIES The Project is proposing the installation of three bioretention basins and the use of one Contech CS-5 hydrodynamic separator to address stormwater requirements for the project. The stormwater facilities have been indicated on the plans and HydroCAD reports as SMP-1, SMP-2, SMP-3 and SMP-4. 6.1 Pretreatment Pretreatment of runoff to SMP-1 is provided by a forebay. Pretreatment for SMP-2 and SMP-3 is provided by vegetated filter strips. All pretreatment practices are designed in accordance to the SWMDM. 6.2 Treatment Treatment for runoff is provided by capturing and treating the entire WQv though infiltration through planting soils in the bioretention basins and treating WQv through the swirl chamber of the hydrodynamic separator. 7.0 POST-CONSTRUCTION MAINTENANCE REQUIREMENTS Skidmore College will be responsible for the continuous upkeep and maintenance of all stormwater management facilities. Maintenance includes, but is not limited to, cleaning of sediment from drainage inlet sumps, removal of sediment from SMPs, cleaning conveyance piping and channels of obstructions, inspection and repair as required of any outlet control mechanisms, and repairing any other detriments in the design that is resulting in the facilities to not function as intended in the design. 7.0 REFERENCES 1. Urban Hydrology for Small Watersheds. Published by the U.S. Soil Conservation Service, Washington, D.C., June 1986. 2. HydroCAD 10.00 Computer Program, by HydroCAD Software Solutions, LLC. Stormwater Management Report Skidmore College Health, Wellness, Fitness & Tennis Facility 2016098 12 3. NYSDEC Stormwater Management Design Manual. Published by the New York State Department of Environmental Conservation, Updated January 2015. Attachment A Soil Investigations Soil Survey Natural Resource Map United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Saratoga County, New York Natural Resources Conservation Service October 9, 2019 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................11 Map Unit Descriptions.........................................................................................11 Saratoga County, New York............................................................................13 GaB—Galway loam, 3 to 8 percent slopes.................................................13 References............................................................................................................15 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 9 Custom Soil Resource Report Soil Map 477180047719004772000477210047722004772300477240047725004772600477180047719004772000477210047722004772300477240047725004772600598500 598600 598700 598800 598900 599000 599100 598600 598700 598800 598900 599000 599100 43° 5' 59'' N 73° 47' 22'' W43° 5' 59'' N73° 46' 53'' W43° 5' 31'' N 73° 47' 22'' W43° 5' 31'' N 73° 46' 53'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 200 400 800 1200 Feet 0 50 100 200 300 Meters Map Scale: 1:4,230 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Saratoga County, New York Survey Area Data: Version 19, Sep 16, 2019 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 10, 2015—Mar 29, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 10 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI GaB Galway loam, 3 to 8 percent slopes 62.8 100.0% Totals for Area of Interest 62.8 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. Custom Soil Resource Report 11 An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 12 Saratoga County, New York GaB—Galway loam, 3 to 8 percent slopes Map Unit Setting National map unit symbol: 9wb1 Elevation: 150 to 1,000 feet Mean annual precipitation: 36 to 48 inches Mean annual air temperature: 45 to 48 degrees F Frost-free period: 125 to 160 days Farmland classification: All areas are prime farmland Map Unit Composition Galway and similar soils: 65 percent Minor components: 35 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Galway Setting Landform: Benches, ridges, till plains Landform position (two-dimensional): Summit Landform position (three-dimensional): Crest Down-slope shape: Concave Across-slope shape: Convex Parent material: Calcareous loamy till Typical profile H1 - 0 to 6 inches: loam H2 - 6 to 28 inches: loam BC - 28 to 30 inches: fine sandy loam 2R - 30 to 40 inches: unweathered bedrock Properties and qualities Slope: 3 to 8 percent Depth to restrictive feature: 20 to 40 inches to lithic bedrock Natural drainage class: Moderately well drained Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00 to 1.98 in/hr) Depth to water table: About 18 to 36 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 5 percent Available water storage in profile: Low (about 4.4 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: C Hydric soil rating: No Minor Components Charlton Percent of map unit: 15 percent Hydric soil rating: No Custom Soil Resource Report 13 Newstead Percent of map unit: 10 percent Hydric soil rating: No Farmington Percent of map unit: 10 percent Hydric soil rating: No Custom Soil Resource Report 14 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 15 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 16 Attachment B Existing Conditions Watershed Map and HydroCAD Calculations AP-2AP-113251.14Skidmore College Athletic Expansion815 North Broadway, Saratoga Springs, NY 12866Pre-DevelopmentDate: 11/4/2022Save Date: 9/22/2022 3:09 PMFile Name: G:\Proj-2016\2016098_Skidmore_ College_ Athletic _Expansion\2016098_HydroCad\PRE-DEV.dwgPlotted By:BRETT STROM SCALE: 1"=100'02550100200 1 Subcat 1 1.1 Subcat 1.1 2 Subcat 2 3 Subcat 3 4 Subcat 4 5 Subcat 5 S1 N Pond to Outlet S2 Outlet to Inlet from Pond S3 Inlet from Pond to AP-2 CB-1 CB 18" Pipe CB-2 CB 24" Pipe CB-3 CB 24" Pipe DMH CB Storm MH OUTLET CB Outlet Stream/Pond P1 Existing North Pond P2 Existing Retention Pond AP-1 AP-1 AP-2 AP-2 Routing Diagram for PRE-DEV Prepared by The LA Group, Printed 11/1/2022 HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 2HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 18.547 74 >75% Grass cover, Good, HSG C (1, 1.1, 2, 3, 4, 5) 10.936 98 Paved parking, HSG C (1, 1.1, 2, 3, 5) 1.492 70 Woods, Good, HSG C (3, 5) 30.974 82 TOTAL AREA PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 3HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.000 HSG B 30.974 HSG C 1, 1.1, 2, 3, 4, 5 0.000 HSG D 0.000 Other 30.974 TOTAL AREA PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 4HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 18.547 0.000 0.000 18.547 >75% Grass cover, Good 1, 1.1, 2, 3, 4, 5 0.000 0.000 10.936 0.000 0.000 10.936 Paved parking 1, 1.1, 2, 3, 5 0.000 0.000 1.492 0.000 0.000 1.492 Woods, Good 3, 5 0.000 0.000 30.974 0.000 0.000 30.974 TOTAL AREA Type II 24-hr 1YR Rainfall=2.15"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 5HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=10.347 ac 22.57% Impervious Runoff Depth>0.55"Subcatchment 1: Subcat 1 Flow Length=820' Slope=0.0600 '/' Tc=11.4 min CN=79 Runoff=8.74 cfs 0.472 af Runoff Area=7.700 ac 29.99% Impervious Runoff Depth>0.63"Subcatchment 1.1: Subcat 1.1 Tc=6.0 min CN=81 Runoff=9.32 cfs 0.406 af Runoff Area=6.831 ac 64.52% Impervious Runoff Depth>1.07"Subcatchment 2: Subcat 2 Tc=6.0 min CN=89 Runoff=13.52 cfs 0.606 af Runoff Area=5.132 ac 35.32% Impervious Runoff Depth>0.63"Subcatchment 3: Subcat 3 Flow Length=430' Tc=14.5 min CN=81 Runoff=4.51 cfs 0.270 af Runoff Area=0.256 ac 0.00% Impervious Runoff Depth>0.37"Subcatchment 4: Subcat 4 Tc=6.0 min CN=74 Runoff=0.17 cfs 0.008 af Runoff Area=0.708 ac 10.04% Impervious Runoff Depth>0.44"Subcatchment 5: Subcat 5 Flow Length=156' Tc=11.6 min CN=76 Runoff=0.45 cfs 0.026 af Avg. Flow Depth=0.49' Max Vel=3.05 fps Inflow=9.79 cfs 0.842 afReach S1: N Pond to Outlet n=0.030 L=724.0' S=0.0124 '/' Capacity=419.15 cfs Outflow=8.66 cfs 0.836 af Avg. Flow Depth=0.71' Max Vel=2.96 fps Inflow=12.78 cfs 1.105 afReach S2: Outlet to Inlet from Pond n=0.030 L=262.0' S=0.0076 '/' Capacity=526.29 cfs Outflow=12.67 cfs 1.102 af Avg. Flow Depth=0.63' Max Vel=3.33 fps Inflow=12.80 cfs 1.110 afReach S3: Inlet from Pond to AP-2 n=0.030 L=272.0' S=0.0110 '/' Capacity=632.61 cfs Outflow=12.66 cfs 1.108 af Peak Elev=387.67' Inflow=13.52 cfs 0.606 afPond CB-1: 18" Pipe 18.0" Round Culvert n=0.012 L=147.0' S=0.0123 '/' Outflow=13.52 cfs 0.606 af Peak Elev=384.56' Inflow=13.52 cfs 0.606 afPond CB-2: 24" Pipe 24.0" Round Culvert n=0.012 L=72.0' S=0.0060 '/' Outflow=13.52 cfs 0.606 af Peak Elev=383.97' Inflow=13.52 cfs 0.606 afPond CB-3: 24" Pipe 24.0" Round Culvert n=0.012 L=234.0' S=0.0041 '/' Outflow=13.52 cfs 0.606 af Peak Elev=382.74' Inflow=13.52 cfs 0.606 afPond DMH: Storm MH 24.0" Round Culvert n=0.012 L=95.0' S=0.0058 '/' Outflow=13.52 cfs 0.606 af Peak Elev=389.75' Inflow=8.66 cfs 0.836 afPond OUTLET: Outlet Stream/Pond Primary=8.64 cfs 0.836 af Secondary=0.03 cfs 0.000 af Outflow=8.66 cfs 0.836 af Peak Elev=401.32' Storage=46,747 cf Inflow=8.74 cfs 0.472 afPond P1: Existing North Pond Outflow=2.18 cfs 0.436 af Peak Elev=387.00' Storage=0 cf Inflow=0.20 cfs 0.008 afPond P2: Existing Retention Pond 12.0" Round Culvert n=0.012 L=61.0' S=0.0156 '/' Outflow=0.20 cfs 0.008 af Type II 24-hr 1YR Rainfall=2.15"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 6HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Inflow=0.45 cfs 0.026 afLink AP-1: AP-1 Primary=0.45 cfs 0.026 af Inflow=22.71 cfs 1.714 afLink AP-2: AP-2 Primary=22.71 cfs 1.714 af Total Runoff Area = 30.974 ac Runoff Volume = 1.788 af Average Runoff Depth = 0.69" 64.69% Pervious = 20.039 ac 35.31% Impervious = 10.936 ac Type II 24-hr 1YR Rainfall=2.15"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 7HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Subcat 1 Runoff = 8.74 cfs @ 12.04 hrs, Volume= 0.472 af, Depth> 0.55" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 8.011 74 >75% Grass cover, Good, HSG C 2.335 98 Paved parking, HSG C 10.347 79 Weighted Average 8.011 77.43% Pervious Area 2.335 22.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.4 820 0.0600 1.20 Lag/CN Method, Summary for Subcatchment 1.1: Subcat 1.1 Runoff = 9.32 cfs @ 11.98 hrs, Volume= 0.406 af, Depth> 0.63" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 5.391 74 >75% Grass cover, Good, HSG C 2.310 98 Paved parking, HSG C 7.700 81 Weighted Average 5.391 70.01% Pervious Area 2.310 29.99% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2: Subcat 2 Runoff = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af, Depth> 1.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 2.424 74 >75% Grass cover, Good, HSG C 4.407 98 Paved parking, HSG C 6.831 89 Weighted Average 2.424 35.48% Pervious Area 4.407 64.52% Impervious Area Type II 24-hr 1YR Rainfall=2.15"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 8HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 3: Subcat 3 Runoff = 4.51 cfs @ 12.08 hrs, Volume= 0.270 af, Depth> 0.63" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 1.873 74 >75% Grass cover, Good, HSG C 1.813 98 Paved parking, HSG C 1.446 70 Woods, Good, HSG C 5.132 81 Weighted Average 3.319 64.68% Pervious Area 1.813 35.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.2 100 0.0150 0.14 Sheet Flow, Grass: Short n= 0.150 P2= 2.60" 2.3 330 0.0250 2.37 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 14.5 430 Total Summary for Subcatchment 4: Subcat 4 Runoff = 0.17 cfs @ 11.99 hrs, Volume= 0.008 af, Depth> 0.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.256 74 >75% Grass cover, Good, HSG C 0.256 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5: Subcat 5 Runoff = 0.45 cfs @ 12.05 hrs, Volume= 0.026 af, Depth> 0.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Type II 24-hr 1YR Rainfall=2.15"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 9HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area (ac) CN Description 0.591 74 >75% Grass cover, Good, HSG C 0.071 98 Paved parking, HSG C 0.046 70 Woods, Good, HSG C 0.708 76 Weighted Average 0.637 89.96% Pervious Area 0.071 10.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.0 80 0.0125 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 2.60" 0.6 76 0.1050 2.27 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 11.6 156 Total Summary for Reach S1: N Pond to Outlet Inflow Area = 18.047 ac, 25.74% Impervious, Inflow Depth > 0.56" for 1YR event Inflow = 9.79 cfs @ 11.98 hrs, Volume= 0.842 af Outflow = 8.66 cfs @ 12.02 hrs, Volume= 0.836 af, Atten= 11%, Lag= 2.3 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 3.05 fps, Min. Travel Time= 4.0 min Avg. Velocity = 1.33 fps, Avg. Travel Time= 9.1 min Peak Storage= 2,040 cf @ 12.02 hrs Average Depth at Peak Storage= 0.49' Bank-Full Depth= 4.00' Flow Area= 44.0 sf, Capacity= 419.15 cfs 5.00' x 4.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 17.00' Length= 724.0' Slope= 0.0124 '/' Inlet Invert= 399.00', Outlet Invert= 390.00' Summary for Reach S2: Outlet to Inlet from Pond Inflow Area = 23.179 ac, 27.86% Impervious, Inflow Depth > 0.57" for 1YR event Inflow = 12.78 cfs @ 12.04 hrs, Volume= 1.105 af Outflow = 12.67 cfs @ 12.06 hrs, Volume= 1.102 af, Atten= 1%, Lag= 1.1 min Type II 24-hr 1YR Rainfall=2.15"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 10HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.96 fps, Min. Travel Time= 1.5 min Avg. Velocity = 1.24 fps, Avg. Travel Time= 3.5 min Peak Storage= 1,120 cf @ 12.06 hrs Average Depth at Peak Storage= 0.71' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 526.29 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 262.0' Slope= 0.0076 '/' Inlet Invert= 388.00', Outlet Invert= 386.00' Summary for Reach S3: Inlet from Pond to AP-2 Inflow Area = 23.435 ac, 27.55% Impervious, Inflow Depth > 0.57" for 1YR event Inflow = 12.80 cfs @ 12.06 hrs, Volume= 1.110 af Outflow = 12.66 cfs @ 12.07 hrs, Volume= 1.108 af, Atten= 1%, Lag= 0.9 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 3.33 fps, Min. Travel Time= 1.4 min Avg. Velocity = 1.41 fps, Avg. Travel Time= 3.2 min Peak Storage= 1,026 cf @ 12.07 hrs Average Depth at Peak Storage= 0.63' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 632.61 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 272.0' Slope= 0.0110 '/' Inlet Invert= 385.00', Outlet Invert= 382.00' Type II 24-hr 1YR Rainfall=2.15"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 11HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond CB-1: 18" Pipe Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 1.07" for 1YR event Inflow = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af Outflow = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af, Atten= 0%, Lag= 0.0 min Primary = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 387.67' @ 11.98 hrs Device Routing Invert Outlet Devices #1 Primary 384.27'18.0" Round Culvert L= 147.0' Ke= 0.500 Inlet / Outlet Invert= 384.27' / 382.46' S= 0.0123 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.77 sf Primary OutFlow Max=12.65 cfs @ 11.97 hrs HW=387.46' TW=384.44' (Dynamic Tailwater) 1=Culvert (Outlet Controls 12.65 cfs @ 7.16 fps) Summary for Pond CB-2: 24" Pipe Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 1.07" for 1YR event Inflow = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af Outflow = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af, Atten= 0%, Lag= 0.0 min Primary = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 384.56' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 382.36'24.0" Round Culvert L= 72.0' Ke= 0.500 Inlet / Outlet Invert= 382.36' / 381.93' S= 0.0060 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=10.92 cfs @ 11.97 hrs HW=384.44' TW=383.88' (Dynamic Tailwater) 1=Culvert (Outlet Controls 10.92 cfs @ 4.16 fps) Summary for Pond CB-3: 24" Pipe Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 1.07" for 1YR event Inflow = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af Outflow = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af, Atten= 0%, Lag= 0.0 min Primary = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 383.97' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 381.83'24.0" Round Culvert L= 234.0' Ke= 0.500 Inlet / Outlet Invert= 381.83' / 380.87' S= 0.0041 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Type II 24-hr 1YR Rainfall=2.15"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 12HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=12.20 cfs @ 11.97 hrs HW=383.88' TW=382.70' (Dynamic Tailwater) 1=Culvert (Outlet Controls 12.20 cfs @ 4.71 fps) Summary for Pond DMH: Storm MH Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 1.07" for 1YR event Inflow = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af Outflow = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af, Atten= 0%, Lag= 0.0 min Primary = 13.52 cfs @ 11.97 hrs, Volume= 0.606 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 382.74' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 380.77'24.0" Round Culvert L= 95.0' Ke= 0.500 Inlet / Outlet Invert= 380.77' / 380.22' S= 0.0058 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=13.08 cfs @ 11.97 hrs HW=382.70' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 13.08 cfs @ 5.38 fps) Summary for Pond OUTLET: Outlet Stream/Pond Inflow Area = 18.047 ac, 25.74% Impervious, Inflow Depth > 0.56" for 1YR event Inflow = 8.66 cfs @ 12.02 hrs, Volume= 0.836 af Outflow = 8.66 cfs @ 12.02 hrs, Volume= 0.836 af, Atten= 0%, Lag= 0.0 min Primary = 8.64 cfs @ 12.02 hrs, Volume= 0.836 af Secondary = 0.03 cfs @ 12.02 hrs, Volume= 0.000 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 389.75' @ 12.02 hrs Device Routing Invert Outlet Devices #1 Primary 389.00'5.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 #2 Secondary 389.65'15.0" Round Culvert L= 50.0' Ke= 0.500 Inlet / Outlet Invert= 389.65' / 389.31' S= 0.0068 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=8.36 cfs @ 12.02 hrs HW=389.73' TW=388.67' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 8.36 cfs @ 2.29 fps) Secondary OutFlow Max=0.02 cfs @ 12.02 hrs HW=389.73' TW=387.00' (Dynamic Tailwater) 2=Culvert (Barrel Controls 0.02 cfs @ 1.15 fps) Type II 24-hr 1YR Rainfall=2.15"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 13HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond P1: Existing North Pond Inflow Area = 10.347 ac, 22.57% Impervious, Inflow Depth > 0.55" for 1YR event Inflow = 8.74 cfs @ 12.04 hrs, Volume= 0.472 af Outflow = 2.18 cfs @ 12.31 hrs, Volume= 0.436 af, Atten= 75%, Lag= 16.2 min Primary = 2.18 cfs @ 12.31 hrs, Volume= 0.436 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Starting Elev= 401.00' Surf.Area= 22,263 sf Storage= 39,555 cf Peak Elev= 401.32' @ 12.31 hrs Surf.Area= 23,057 sf Storage= 46,747 cf (7,192 cf above start) Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= 47.1 min ( 865.3 - 818.2 ) Volume Invert Avail.Storage Storage Description #1 399.00' 117,925 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 399.00 17,348 799.0 0 0 17,348 400.00 19,775 819.0 18,548 18,548 20,047 401.00 22,263 839.0 21,007 39,555 22,813 402.00 24,812 859.0 23,526 63,081 25,646 403.00 27,418 878.0 26,104 89,185 28,412 404.00 30,082 897.0 28,740 117,925 31,239 Device Routing Invert Outlet Devices #1 Primary 401.00'5.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Primary OutFlow Max=2.17 cfs @ 12.31 hrs HW=401.32' TW=399.29' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 2.17 cfs @ 1.37 fps) Summary for Pond P2: Existing Retention Pond Inflow Area = 0.256 ac, 0.00% Impervious, Inflow Depth > 0.38" for 1YR event Inflow = 0.20 cfs @ 12.00 hrs, Volume= 0.008 af Outflow = 0.20 cfs @ 12.00 hrs, Volume= 0.008 af, Atten= 0%, Lag= 0.0 min Primary = 0.20 cfs @ 12.00 hrs, Volume= 0.008 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 387.00' @ 5.00 hrs Surf.Area= 2,922 sf Storage= 0 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.0 min ( 827.8 - 827.8 ) Type II 24-hr 1YR Rainfall=2.15"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 14HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 387.00' 19,774 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 387.00 2,922 268.0 0 0 2,922 388.00 4,041 334.0 3,466 3,466 6,098 389.00 4,964 365.0 4,495 7,961 7,857 390.00 5,904 388.0 5,427 13,388 9,286 391.00 6,879 406.0 6,385 19,774 10,491 Device Routing Invert Outlet Devices #1 Primary 386.44'12.0" Round Culvert L= 61.0' Ke= 0.500 Inlet / Outlet Invert= 386.44' / 385.49' S= 0.0156 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.00 cfs @ 12.00 hrs HW=387.00' TW=385.54' (Dynamic Tailwater) 1=Culvert (Passes 0.00 cfs of 1.15 cfs potential flow) Summary for Link AP-1: AP-1 Inflow Area = 0.708 ac, 10.04% Impervious, Inflow Depth > 0.44" for 1YR event Inflow = 0.45 cfs @ 12.05 hrs, Volume= 0.026 af Primary = 0.45 cfs @ 12.05 hrs, Volume= 0.026 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link AP-2: AP-2 Inflow Area = 30.266 ac, 35.90% Impervious, Inflow Depth > 0.68" for 1YR event Inflow = 22.71 cfs @ 12.01 hrs, Volume= 1.714 af Primary = 22.71 cfs @ 12.01 hrs, Volume= 1.714 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 15HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=10.347 ac 22.57% Impervious Runoff Depth>1.61"Subcatchment 1: Subcat 1 Flow Length=820' Slope=0.0600 '/' Tc=11.4 min CN=79 Runoff=26.39 cfs 1.392 af Runoff Area=7.700 ac 29.99% Impervious Runoff Depth>1.76"Subcatchment 1.1: Subcat 1.1 Tc=6.0 min CN=81 Runoff=25.34 cfs 1.131 af Runoff Area=6.831 ac 64.52% Impervious Runoff Depth>2.42"Subcatchment 2: Subcat 2 Tc=6.0 min CN=89 Runoff=29.42 cfs 1.377 af Runoff Area=5.132 ac 35.32% Impervious Runoff Depth>1.76"Subcatchment 3: Subcat 3 Flow Length=430' Tc=14.5 min CN=81 Runoff=12.82 cfs 0.751 af Runoff Area=0.256 ac 0.00% Impervious Runoff Depth>1.29"Subcatchment 4: Subcat 4 Tc=6.0 min CN=74 Runoff=0.63 cfs 0.027 af Runoff Area=0.708 ac 10.04% Impervious Runoff Depth>1.41"Subcatchment 5: Subcat 5 Flow Length=156' Tc=11.6 min CN=76 Runoff=1.57 cfs 0.083 af Avg. Flow Depth=0.98' Max Vel=4.51 fps Inflow=30.11 cfs 2.462 afReach S1: N Pond to Outlet n=0.030 L=724.0' S=0.0124 '/' Capacity=419.15 cfs Outflow=28.48 cfs 2.452 af Avg. Flow Depth=1.30' Max Vel=4.13 fps Inflow=37.40 cfs 3.146 afReach S2: Outlet to Inlet from Pond n=0.030 L=262.0' S=0.0076 '/' Capacity=526.29 cfs Outflow=37.36 cfs 3.141 af Avg. Flow Depth=1.21' Max Vel=4.77 fps Inflow=39.23 cfs 3.226 afReach S3: Inlet from Pond to AP-2 n=0.030 L=272.0' S=0.0110 '/' Capacity=632.61 cfs Outflow=39.13 cfs 3.221 af Peak Elev=404.54' Inflow=29.42 cfs 1.377 afPond CB-1: 18" Pipe 18.0" Round Culvert n=0.012 L=147.0' S=0.0123 '/' Outflow=29.42 cfs 1.377 af Peak Elev=392.93' Inflow=29.42 cfs 1.377 afPond CB-2: 24" Pipe 24.0" Round Culvert n=0.012 L=72.0' S=0.0060 '/' Outflow=29.42 cfs 1.377 af Peak Elev=390.51' Inflow=29.42 cfs 1.377 afPond CB-3: 24" Pipe 24.0" Round Culvert n=0.012 L=234.0' S=0.0041 '/' Outflow=29.42 cfs 1.377 af Peak Elev=385.62' Inflow=29.42 cfs 1.377 afPond DMH: Storm MH 24.0" Round Culvert n=0.012 L=95.0' S=0.0058 '/' Outflow=29.42 cfs 1.377 af Peak Elev=390.57' Inflow=28.48 cfs 2.452 afPond OUTLET: Outlet Stream/Pond Primary=25.79 cfs 2.394 af Secondary=2.70 cfs 0.057 af Outflow=28.48 cfs 2.452 af Peak Elev=401.88' Storage=60,087 cf Inflow=26.39 cfs 1.392 afPond P1: Existing North Pond Outflow=11.03 cfs 1.331 af Peak Elev=387.22' Storage=674 cf Inflow=3.27 cfs 0.085 afPond P2: Existing Retention Pond 12.0" Round Culvert n=0.012 L=61.0' S=0.0156 '/' Outflow=1.98 cfs 0.085 af Type II 24-hr 10YR Rainfall=3.75"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 16HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Inflow=1.57 cfs 0.083 afLink AP-1: AP-1 Primary=1.57 cfs 0.083 af Inflow=62.07 cfs 4.598 afLink AP-2: AP-2 Primary=62.07 cfs 4.598 af Total Runoff Area = 30.974 ac Runoff Volume = 4.763 af Average Runoff Depth = 1.85" 64.69% Pervious = 20.039 ac 35.31% Impervious = 10.936 ac Type II 24-hr 10YR Rainfall=3.75"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 17HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Subcat 1 Runoff = 26.39 cfs @ 12.04 hrs, Volume= 1.392 af, Depth> 1.61" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 8.011 74 >75% Grass cover, Good, HSG C 2.335 98 Paved parking, HSG C 10.347 79 Weighted Average 8.011 77.43% Pervious Area 2.335 22.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.4 820 0.0600 1.20 Lag/CN Method, Summary for Subcatchment 1.1: Subcat 1.1 Runoff = 25.34 cfs @ 11.97 hrs, Volume= 1.131 af, Depth> 1.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 5.391 74 >75% Grass cover, Good, HSG C 2.310 98 Paved parking, HSG C 7.700 81 Weighted Average 5.391 70.01% Pervious Area 2.310 29.99% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2: Subcat 2 Runoff = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af, Depth> 2.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 2.424 74 >75% Grass cover, Good, HSG C 4.407 98 Paved parking, HSG C 6.831 89 Weighted Average 2.424 35.48% Pervious Area 4.407 64.52% Impervious Area Type II 24-hr 10YR Rainfall=3.75"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 18HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 3: Subcat 3 Runoff = 12.82 cfs @ 12.07 hrs, Volume= 0.751 af, Depth> 1.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 1.873 74 >75% Grass cover, Good, HSG C 1.813 98 Paved parking, HSG C 1.446 70 Woods, Good, HSG C 5.132 81 Weighted Average 3.319 64.68% Pervious Area 1.813 35.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.2 100 0.0150 0.14 Sheet Flow, Grass: Short n= 0.150 P2= 2.60" 2.3 330 0.0250 2.37 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 14.5 430 Total Summary for Subcatchment 4: Subcat 4 Runoff = 0.63 cfs @ 11.98 hrs, Volume= 0.027 af, Depth> 1.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.256 74 >75% Grass cover, Good, HSG C 0.256 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5: Subcat 5 Runoff = 1.57 cfs @ 12.04 hrs, Volume= 0.083 af, Depth> 1.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Type II 24-hr 10YR Rainfall=3.75"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 19HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area (ac) CN Description 0.591 74 >75% Grass cover, Good, HSG C 0.071 98 Paved parking, HSG C 0.046 70 Woods, Good, HSG C 0.708 76 Weighted Average 0.637 89.96% Pervious Area 0.071 10.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.0 80 0.0125 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 2.60" 0.6 76 0.1050 2.27 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 11.6 156 Total Summary for Reach S1: N Pond to Outlet Inflow Area = 18.047 ac, 25.74% Impervious, Inflow Depth > 1.64" for 10YR event Inflow = 30.11 cfs @ 11.99 hrs, Volume= 2.462 af Outflow = 28.48 cfs @ 12.01 hrs, Volume= 2.452 af, Atten= 5%, Lag= 1.7 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 4.51 fps, Min. Travel Time= 2.7 min Avg. Velocity = 1.64 fps, Avg. Travel Time= 7.4 min Peak Storage= 4,564 cf @ 12.01 hrs Average Depth at Peak Storage= 0.98' Bank-Full Depth= 4.00' Flow Area= 44.0 sf, Capacity= 419.15 cfs 5.00' x 4.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 17.00' Length= 724.0' Slope= 0.0124 '/' Inlet Invert= 399.00', Outlet Invert= 390.00' Summary for Reach S2: Outlet to Inlet from Pond Inflow Area = 23.179 ac, 27.86% Impervious, Inflow Depth > 1.63" for 10YR event Inflow = 37.40 cfs @ 12.03 hrs, Volume= 3.146 af Outflow = 37.36 cfs @ 12.05 hrs, Volume= 3.141 af, Atten= 0%, Lag= 0.9 min Type II 24-hr 10YR Rainfall=3.75"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 20HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 4.13 fps, Min. Travel Time= 1.1 min Avg. Velocity = 1.53 fps, Avg. Travel Time= 2.9 min Peak Storage= 2,369 cf @ 12.05 hrs Average Depth at Peak Storage= 1.30' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 526.29 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 262.0' Slope= 0.0076 '/' Inlet Invert= 388.00', Outlet Invert= 386.00' Summary for Reach S3: Inlet from Pond to AP-2 Inflow Area = 23.435 ac, 27.55% Impervious, Inflow Depth > 1.65" for 10YR event Inflow = 39.23 cfs @ 12.05 hrs, Volume= 3.226 af Outflow = 39.13 cfs @ 12.06 hrs, Volume= 3.221 af, Atten= 0%, Lag= 0.7 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 4.77 fps, Min. Travel Time= 1.0 min Avg. Velocity = 1.74 fps, Avg. Travel Time= 2.6 min Peak Storage= 2,232 cf @ 12.06 hrs Average Depth at Peak Storage= 1.21' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 632.61 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 272.0' Slope= 0.0110 '/' Inlet Invert= 385.00', Outlet Invert= 382.00' Type II 24-hr 10YR Rainfall=3.75"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 21HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond CB-1: 18" Pipe Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 2.42" for 10YR event Inflow = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af Outflow = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af, Atten= 0%, Lag= 0.0 min Primary = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 404.54' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 384.27'18.0" Round Culvert L= 147.0' Ke= 0.500 Inlet / Outlet Invert= 384.27' / 382.46' S= 0.0123 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.77 sf Primary OutFlow Max=25.33 cfs @ 11.97 hrs HW=402.96' TW=390.86' (Dynamic Tailwater) 1=Culvert (Outlet Controls 25.33 cfs @ 14.34 fps) Summary for Pond CB-2: 24" Pipe Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 2.42" for 10YR event Inflow = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af Outflow = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af, Atten= 0%, Lag= 0.0 min Primary = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 392.93' @ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 382.36'24.0" Round Culvert L= 72.0' Ke= 0.500 Inlet / Outlet Invert= 382.36' / 381.93' S= 0.0060 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=15.83 cfs @ 11.97 hrs HW=390.86' TW=389.77' (Dynamic Tailwater) 1=Culvert (Inlet Controls 15.83 cfs @ 5.04 fps) Summary for Pond CB-3: 24" Pipe Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 2.42" for 10YR event Inflow = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af Outflow = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af, Atten= 0%, Lag= 0.0 min Primary = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 390.51' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 381.83'24.0" Round Culvert L= 234.0' Ke= 0.500 Inlet / Outlet Invert= 381.83' / 380.87' S= 0.0041 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Type II 24-hr 10YR Rainfall=3.75"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 22HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=26.28 cfs @ 11.97 hrs HW=389.77' TW=385.44' (Dynamic Tailwater) 1=Culvert (Outlet Controls 26.28 cfs @ 8.36 fps) Summary for Pond DMH: Storm MH Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 2.42" for 10YR event Inflow = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af Outflow = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af, Atten= 0%, Lag= 0.0 min Primary = 29.42 cfs @ 11.97 hrs, Volume= 1.377 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 385.62' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 380.77'24.0" Round Culvert L= 95.0' Ke= 0.500 Inlet / Outlet Invert= 380.77' / 380.22' S= 0.0058 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=28.56 cfs @ 11.97 hrs HW=385.44' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 28.56 cfs @ 9.09 fps) Summary for Pond OUTLET: Outlet Stream/Pond Inflow Area = 18.047 ac, 25.74% Impervious, Inflow Depth > 1.63" for 10YR event Inflow = 28.48 cfs @ 12.01 hrs, Volume= 2.452 af Outflow = 28.48 cfs @ 12.01 hrs, Volume= 2.452 af, Atten= 0%, Lag= 0.0 min Primary = 25.79 cfs @ 12.01 hrs, Volume= 2.394 af Secondary = 2.70 cfs @ 12.02 hrs, Volume= 0.057 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 390.57' @ 12.02 hrs Device Routing Invert Outlet Devices #1 Primary 389.00'5.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 #2 Secondary 389.65'15.0" Round Culvert L= 50.0' Ke= 0.500 Inlet / Outlet Invert= 389.65' / 389.31' S= 0.0068 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=24.77 cfs @ 12.01 hrs HW=390.55' TW=389.26' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 24.77 cfs @ 3.20 fps) Secondary OutFlow Max=2.59 cfs @ 12.02 hrs HW=390.54' TW=387.15' (Dynamic Tailwater) 2=Culvert (Barrel Controls 2.59 cfs @ 3.86 fps) Type II 24-hr 10YR Rainfall=3.75"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 23HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond P1: Existing North Pond Inflow Area = 10.347 ac, 22.57% Impervious, Inflow Depth > 1.61" for 10YR event Inflow = 26.39 cfs @ 12.04 hrs, Volume= 1.392 af Outflow = 11.03 cfs @ 12.20 hrs, Volume= 1.331 af, Atten= 58%, Lag= 9.7 min Primary = 11.03 cfs @ 12.20 hrs, Volume= 1.331 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Starting Elev= 401.00' Surf.Area= 22,263 sf Storage= 39,555 cf Peak Elev= 401.88' @ 12.20 hrs Surf.Area= 24,495 sf Storage= 60,087 cf (20,532 cf above start) Plug-Flow detention time= 278.2 min calculated for 0.423 af (30% of inflow) Center-of-Mass det. time= 33.5 min ( 828.9 - 795.4 ) Volume Invert Avail.Storage Storage Description #1 399.00' 117,925 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 399.00 17,348 799.0 0 0 17,348 400.00 19,775 819.0 18,548 18,548 20,047 401.00 22,263 839.0 21,007 39,555 22,813 402.00 24,812 859.0 23,526 63,081 25,646 403.00 27,418 878.0 26,104 89,185 28,412 404.00 30,082 897.0 28,740 117,925 31,239 Device Routing Invert Outlet Devices #1 Primary 401.00'5.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Primary OutFlow Max=11.02 cfs @ 12.20 hrs HW=401.88' TW=399.70' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 11.02 cfs @ 2.51 fps) Summary for Pond P2: Existing Retention Pond Inflow Area = 0.256 ac, 0.00% Impervious, Inflow Depth > 3.97" for 10YR event Inflow = 3.27 cfs @ 12.01 hrs, Volume= 0.085 af Outflow = 1.98 cfs @ 12.10 hrs, Volume= 0.085 af, Atten= 39%, Lag= 5.5 min Primary = 1.98 cfs @ 12.10 hrs, Volume= 0.085 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 387.22' @ 12.10 hrs Surf.Area= 3,155 sf Storage= 674 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 2.7 min ( 753.2 - 750.5 ) Type II 24-hr 10YR Rainfall=3.75"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 24HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 387.00' 19,774 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 387.00 2,922 268.0 0 0 2,922 388.00 4,041 334.0 3,466 3,466 6,098 389.00 4,964 365.0 4,495 7,961 7,857 390.00 5,904 388.0 5,427 13,388 9,286 391.00 6,879 406.0 6,385 19,774 10,491 Device Routing Invert Outlet Devices #1 Primary 386.44'12.0" Round Culvert L= 61.0' Ke= 0.500 Inlet / Outlet Invert= 386.44' / 385.49' S= 0.0156 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.98 cfs @ 12.10 hrs HW=387.22' TW=386.16' (Dynamic Tailwater) 1=Culvert (Inlet Controls 1.98 cfs @ 3.01 fps) Summary for Link AP-1: AP-1 Inflow Area = 0.708 ac, 10.04% Impervious, Inflow Depth > 1.41" for 10YR event Inflow = 1.57 cfs @ 12.04 hrs, Volume= 0.083 af Primary = 1.57 cfs @ 12.04 hrs, Volume= 0.083 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link AP-2: AP-2 Inflow Area = 30.266 ac, 35.90% Impervious, Inflow Depth > 1.82" for 10YR event Inflow = 62.07 cfs @ 12.00 hrs, Volume= 4.598 af Primary = 62.07 cfs @ 12.00 hrs, Volume= 4.598 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 1HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=10.347 ac 22.57% Impervious Runoff Depth>3.58"Subcatchment 1: Subcat 1 Flow Length=820' Slope=0.0600 '/' Tc=11.4 min CN=79 Runoff=57.15 cfs 3.088 af Runoff Area=7.700 ac 29.99% Impervious Runoff Depth>3.79"Subcatchment 1.1: Subcat 1.1 Tc=6.0 min CN=81 Runoff=52.57 cfs 2.432 af Runoff Area=6.831 ac 64.52% Impervious Runoff Depth>4.62"Subcatchment 2: Subcat 2 Tc=6.0 min CN=89 Runoff=53.91 cfs 2.632 af Runoff Area=5.132 ac 35.32% Impervious Runoff Depth>3.78"Subcatchment 3: Subcat 3 Flow Length=430' Tc=14.5 min CN=81 Runoff=26.96 cfs 1.616 af Runoff Area=0.256 ac 0.00% Impervious Runoff Depth>3.10"Subcatchment 4: Subcat 4 Tc=6.0 min CN=74 Runoff=1.47 cfs 0.066 af Runoff Area=0.708 ac 10.04% Impervious Runoff Depth>3.29"Subcatchment 5: Subcat 5 Flow Length=156' Tc=11.6 min CN=76 Runoff=3.60 cfs 0.194 af Avg. Flow Depth=1.55' Max Vel=5.78 fps Inflow=67.79 cfs 5.428 afReach S1: N Pond to Outlet n=0.030 L=724.0' S=0.0124 '/' Capacity=419.15 cfs Outflow=65.71 cfs 5.413 af Avg. Flow Depth=2.00' Max Vel=5.17 fps Inflow=83.43 cfs 6.743 afReach S2: Outlet to Inlet from Pond n=0.030 L=262.0' S=0.0076 '/' Capacity=526.29 cfs Outflow=82.79 cfs 6.735 af Avg. Flow Depth=1.86' Max Vel=5.99 fps Inflow=86.44 cfs 7.089 afReach S3: Inlet from Pond to AP-2 n=0.030 L=272.0' S=0.0110 '/' Capacity=632.61 cfs Outflow=86.50 cfs 7.082 af Peak Elev=458.12' Inflow=53.91 cfs 2.632 afPond CB-1: 18" Pipe 18.0" Round Culvert n=0.012 L=147.0' S=0.0123 '/' Outflow=53.91 cfs 2.632 af Peak Elev=418.64' Inflow=53.91 cfs 2.632 afPond CB-2: 24" Pipe 24.0" Round Culvert n=0.012 L=72.0' S=0.0060 '/' Outflow=53.91 cfs 2.632 af Peak Elev=410.67' Inflow=53.91 cfs 2.632 afPond CB-3: 24" Pipe 24.0" Round Culvert n=0.012 L=234.0' S=0.0041 '/' Outflow=53.91 cfs 2.632 af Peak Elev=394.42' Inflow=53.91 cfs 2.632 afPond DMH: Storm MH 24.0" Round Culvert n=0.012 L=95.0' S=0.0058 '/' Outflow=53.91 cfs 2.632 af Peak Elev=391.80' Inflow=65.71 cfs 5.413 afPond OUTLET: Outlet Stream/Pond Primary=58.76 cfs 5.126 af Secondary=6.96 cfs 0.286 af Outflow=65.71 cfs 5.413 af Peak Elev=402.69' Storage=80,915 cf Inflow=57.15 cfs 3.088 afPond P1: Existing North Pond Outflow=29.21 cfs 2.996 af Peak Elev=388.19' Storage=4,235 cf Inflow=8.32 cfs 0.353 afPond P2: Existing Retention Pond 12.0" Round Culvert n=0.012 L=61.0' S=0.0156 '/' Outflow=4.22 cfs 0.353 af Type II 24-hr 100YR Rainfall=6.20"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 2HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Inflow=3.60 cfs 0.194 afLink AP-1: AP-1 Primary=3.60 cfs 0.194 af Inflow=130.38 cfs 9.713 afLink AP-2: AP-2 Primary=130.38 cfs 9.713 af Total Runoff Area = 30.974 ac Runoff Volume = 10.028 af Average Runoff Depth = 3.89" 64.69% Pervious = 20.039 ac 35.31% Impervious = 10.936 ac Type II 24-hr 100YR Rainfall=6.20"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 3HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Subcat 1 Runoff = 57.15 cfs @ 12.03 hrs, Volume= 3.088 af, Depth> 3.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 8.011 74 >75% Grass cover, Good, HSG C 2.335 98 Paved parking, HSG C 10.347 79 Weighted Average 8.011 77.43% Pervious Area 2.335 22.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.4 820 0.0600 1.20 Lag/CN Method, Summary for Subcatchment 1.1: Subcat 1.1 Runoff = 52.57 cfs @ 11.97 hrs, Volume= 2.432 af, Depth> 3.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 5.391 74 >75% Grass cover, Good, HSG C 2.310 98 Paved parking, HSG C 7.700 81 Weighted Average 5.391 70.01% Pervious Area 2.310 29.99% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2: Subcat 2 Runoff = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af, Depth> 4.62" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 2.424 74 >75% Grass cover, Good, HSG C 4.407 98 Paved parking, HSG C 6.831 89 Weighted Average 2.424 35.48% Pervious Area 4.407 64.52% Impervious Area Type II 24-hr 100YR Rainfall=6.20"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 4HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 3: Subcat 3 Runoff = 26.96 cfs @ 12.06 hrs, Volume= 1.616 af, Depth> 3.78" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 1.873 74 >75% Grass cover, Good, HSG C 1.813 98 Paved parking, HSG C 1.446 70 Woods, Good, HSG C 5.132 81 Weighted Average 3.319 64.68% Pervious Area 1.813 35.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.2 100 0.0150 0.14 Sheet Flow, Grass: Short n= 0.150 P2= 2.60" 2.3 330 0.0250 2.37 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 14.5 430 Total Summary for Subcatchment 4: Subcat 4 Runoff = 1.47 cfs @ 11.97 hrs, Volume= 0.066 af, Depth> 3.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.256 74 >75% Grass cover, Good, HSG C 0.256 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5: Subcat 5 Runoff = 3.60 cfs @ 12.03 hrs, Volume= 0.194 af, Depth> 3.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Type II 24-hr 100YR Rainfall=6.20"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 5HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area (ac) CN Description 0.591 74 >75% Grass cover, Good, HSG C 0.071 98 Paved parking, HSG C 0.046 70 Woods, Good, HSG C 0.708 76 Weighted Average 0.637 89.96% Pervious Area 0.071 10.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.0 80 0.0125 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 2.60" 0.6 76 0.1050 2.27 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 11.6 156 Total Summary for Reach S1: N Pond to Outlet Inflow Area = 18.047 ac, 25.74% Impervious, Inflow Depth > 3.61" for 100YR event Inflow = 67.79 cfs @ 11.98 hrs, Volume= 5.428 af Outflow = 65.71 cfs @ 12.01 hrs, Volume= 5.413 af, Atten= 3%, Lag= 1.4 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 5.78 fps, Min. Travel Time= 2.1 min Avg. Velocity = 1.93 fps, Avg. Travel Time= 6.3 min Peak Storage= 8,222 cf @ 12.01 hrs Average Depth at Peak Storage= 1.55' Bank-Full Depth= 4.00' Flow Area= 44.0 sf, Capacity= 419.15 cfs 5.00' x 4.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 17.00' Length= 724.0' Slope= 0.0124 '/' Inlet Invert= 399.00', Outlet Invert= 390.00' Summary for Reach S2: Outlet to Inlet from Pond Inflow Area = 23.179 ac, 27.86% Impervious, Inflow Depth > 3.49" for 100YR event Inflow = 83.43 cfs @ 12.02 hrs, Volume= 6.743 af Outflow = 82.79 cfs @ 12.03 hrs, Volume= 6.735 af, Atten= 1%, Lag= 0.8 min Type II 24-hr 100YR Rainfall=6.20"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 6HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 5.17 fps, Min. Travel Time= 0.8 min Avg. Velocity = 1.80 fps, Avg. Travel Time= 2.4 min Peak Storage= 4,188 cf @ 12.03 hrs Average Depth at Peak Storage= 2.00' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 526.29 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 262.0' Slope= 0.0076 '/' Inlet Invert= 388.00', Outlet Invert= 386.00' Summary for Reach S3: Inlet from Pond to AP-2 Inflow Area = 23.435 ac, 27.55% Impervious, Inflow Depth > 3.63" for 100YR event Inflow = 86.44 cfs @ 12.04 hrs, Volume= 7.089 af Outflow = 86.50 cfs @ 12.05 hrs, Volume= 7.082 af, Atten= 0%, Lag= 0.6 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 5.99 fps, Min. Travel Time= 0.8 min Avg. Velocity = 2.05 fps, Avg. Travel Time= 2.2 min Peak Storage= 3,928 cf @ 12.05 hrs Average Depth at Peak Storage= 1.86' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 632.61 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 272.0' Slope= 0.0110 '/' Inlet Invert= 385.00', Outlet Invert= 382.00' Type II 24-hr 100YR Rainfall=6.20"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 7HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond CB-1: 18" Pipe Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 4.62" for 100YR event Inflow = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af Outflow = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af, Atten= 0%, Lag= 0.0 min Primary = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 458.12' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 384.27'18.0" Round Culvert L= 147.0' Ke= 0.500 Inlet / Outlet Invert= 384.27' / 382.46' S= 0.0123 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.77 sf Primary OutFlow Max=46.69 cfs @ 11.96 hrs HW=453.13' TW=412.03' (Dynamic Tailwater) 1=Culvert (Outlet Controls 46.69 cfs @ 26.42 fps) Summary for Pond CB-2: 24" Pipe Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 4.62" for 100YR event Inflow = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af Outflow = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af, Atten= 0%, Lag= 0.0 min Primary = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 418.64' @ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 382.36'24.0" Round Culvert L= 72.0' Ke= 0.500 Inlet / Outlet Invert= 382.36' / 381.93' S= 0.0060 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=29.87 cfs @ 11.96 hrs HW=412.03' TW=408.13' (Dynamic Tailwater) 1=Culvert (Inlet Controls 29.87 cfs @ 9.51 fps) Summary for Pond CB-3: 24" Pipe Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 4.62" for 100YR event Inflow = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af Outflow = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af, Atten= 0%, Lag= 0.0 min Primary = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 410.67' @ 11.98 hrs Device Routing Invert Outlet Devices #1 Primary 381.83'24.0" Round Culvert L= 234.0' Ke= 0.500 Inlet / Outlet Invert= 381.83' / 380.87' S= 0.0041 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Type II 24-hr 100YR Rainfall=6.20"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 8HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=47.80 cfs @ 11.96 hrs HW=408.13' TW=393.81' (Dynamic Tailwater) 1=Culvert (Outlet Controls 47.80 cfs @ 15.21 fps) Summary for Pond DMH: Storm MH Inflow Area = 6.831 ac, 64.52% Impervious, Inflow Depth > 4.62" for 100YR event Inflow = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af Outflow = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af, Atten= 0%, Lag= 0.0 min Primary = 53.91 cfs @ 11.96 hrs, Volume= 2.632 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 394.42' @ 11.96 hrs Device Routing Invert Outlet Devices #1 Primary 380.77'24.0" Round Culvert L= 95.0' Ke= 0.500 Inlet / Outlet Invert= 380.77' / 380.22' S= 0.0058 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=52.49 cfs @ 11.96 hrs HW=393.81' TW=0.00' (Dynamic Tailwater) 1=Culvert (Inlet Controls 52.49 cfs @ 16.71 fps) Summary for Pond OUTLET: Outlet Stream/Pond Inflow Area = 18.047 ac, 25.74% Impervious, Inflow Depth > 3.60" for 100YR event Inflow = 65.71 cfs @ 12.01 hrs, Volume= 5.413 af Outflow = 65.71 cfs @ 12.01 hrs, Volume= 5.413 af, Atten= 0%, Lag= 0.0 min Primary = 58.76 cfs @ 12.01 hrs, Volume= 5.126 af Secondary = 6.96 cfs @ 12.02 hrs, Volume= 0.286 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 391.80' @ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 389.00'5.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 #2 Secondary 389.65'15.0" Round Culvert L= 50.0' Ke= 0.500 Inlet / Outlet Invert= 389.65' / 389.31' S= 0.0068 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=56.33 cfs @ 12.01 hrs HW=391.77' TW=389.96' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 56.33 cfs @ 4.06 fps) Secondary OutFlow Max=6.83 cfs @ 12.02 hrs HW=391.76' TW=387.78' (Dynamic Tailwater) 2=Culvert (Barrel Controls 6.83 cfs @ 5.57 fps) Type II 24-hr 100YR Rainfall=6.20"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 9HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond P1: Existing North Pond Inflow Area = 10.347 ac, 22.57% Impervious, Inflow Depth > 3.58" for 100YR event Inflow = 57.15 cfs @ 12.03 hrs, Volume= 3.088 af Outflow = 29.21 cfs @ 12.16 hrs, Volume= 2.996 af, Atten= 49%, Lag= 8.1 min Primary = 29.21 cfs @ 12.16 hrs, Volume= 2.996 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Starting Elev= 401.00' Surf.Area= 22,263 sf Storage= 39,555 cf Peak Elev= 402.69' @ 12.16 hrs Surf.Area= 26,606 sf Storage= 80,915 cf (41,360 cf above start) Plug-Flow detention time= 137.9 min calculated for 2.088 af (68% of inflow) Center-of-Mass det. time= 27.8 min ( 805.9 - 778.1 ) Volume Invert Avail.Storage Storage Description #1 399.00' 117,925 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 399.00 17,348 799.0 0 0 17,348 400.00 19,775 819.0 18,548 18,548 20,047 401.00 22,263 839.0 21,007 39,555 22,813 402.00 24,812 859.0 23,526 63,081 25,646 403.00 27,418 878.0 26,104 89,185 28,412 404.00 30,082 897.0 28,740 117,925 31,239 Device Routing Invert Outlet Devices #1 Primary 401.00'5.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Primary OutFlow Max=28.98 cfs @ 12.16 hrs HW=402.68' TW=400.19' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 28.98 cfs @ 3.44 fps) Summary for Pond P2: Existing Retention Pond Inflow Area = 0.256 ac, 0.00% Impervious, Inflow Depth > 16.51" for 100YR event Inflow = 8.32 cfs @ 12.00 hrs, Volume= 0.353 af Outflow = 4.22 cfs @ 12.25 hrs, Volume= 0.353 af, Atten= 49%, Lag= 15.1 min Primary = 4.22 cfs @ 12.25 hrs, Volume= 0.353 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 388.19' @ 12.25 hrs Surf.Area= 4,206 sf Storage= 4,235 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 11.3 min ( 752.0 - 740.7 ) Type II 24-hr 100YR Rainfall=6.20"PRE-DEV Printed 11/1/2022Prepared by The LA Group Page 10HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 387.00' 19,774 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 387.00 2,922 268.0 0 0 2,922 388.00 4,041 334.0 3,466 3,466 6,098 389.00 4,964 365.0 4,495 7,961 7,857 390.00 5,904 388.0 5,427 13,388 9,286 391.00 6,879 406.0 6,385 19,774 10,491 Device Routing Invert Outlet Devices #1 Primary 386.44'12.0" Round Culvert L= 61.0' Ke= 0.500 Inlet / Outlet Invert= 386.44' / 385.49' S= 0.0156 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=4.22 cfs @ 12.25 hrs HW=388.19' TW=386.36' (Dynamic Tailwater) 1=Culvert (Inlet Controls 4.22 cfs @ 5.37 fps) Summary for Link AP-1: AP-1 Inflow Area = 0.708 ac, 10.04% Impervious, Inflow Depth > 3.29" for 100YR event Inflow = 3.60 cfs @ 12.03 hrs, Volume= 0.194 af Primary = 3.60 cfs @ 12.03 hrs, Volume= 0.194 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link AP-2: AP-2 Inflow Area = 30.266 ac, 35.90% Impervious, Inflow Depth > 3.85" for 100YR event Inflow = 130.38 cfs @ 12.00 hrs, Volume= 9.713 af Primary = 130.38 cfs @ 12.00 hrs, Volume= 9.713 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Attachment C Proposed Conditions Watershed Map, HydroCAD Calculations STATE STREET STATE STREET CLINTON STREET 12' S IDE SETBACK12' SIDE SETBACK30' FRONT SETBACK 30' FRONT SETBACK 30' FRONT SETBACK 12' SI D E S E T B A C K 12' SIDE SETBACKPERIMETER ROADWILL IAMSON SPORTS CENTERDANCECENTERPROPERTY L INE PROP E R T Y LI N E PROPERTY LINE PROPERTY LINE COLLEGEHOUSE395 39 5 390390395385390 386387388 388 38939039139239 3 396 397 398399 394 393 392 393 394 400 402 386 387 388 389 390 391 392 389 395 400 FFE:403 .3BFE:389 .3390395395390400404395 400 400 402 401 389 AP-2AP-112355.15.2671.17.18942aSMP-1SMP-2SMP-3SMP-42b2c5.3Skidmore College Athletic Expansion815 N Broadway, Saratoga Springs, NY 12866Post DevelopmentDate: 11/4/2022Save Date: 11/2/2022 4:52 PMFile Name: G:\Proj-2016\2016098_Skidmore_ College_ Athletic _Expansion\2016098_HydroCad\POST-DEV.dwgPlotted By:BRETT STROM SCALE: 1"=100'02550100200 1 Subcat 1 1.1 Subcat 1.1 2 Subcat 2 2a Subcat 2a 2b Subcat 2b 2c Subcat 2c 3 Subcat 3 4 Subcat 4 5 Subcat 5 5.1 Subcat 5.1 5.2 Subcat 5.2 5.3 Subcat 5.3 6 Subcat 6 7 Subcat 7 7.1 Subcat 7.1 8 Subcat 8 9 Subcat 9 S-1 N Pond to Outlet S-2 Outlet to Inlet from SMP-1 S-3 Inlet from SMP-1 to Inlet from Pond S-4 Inlet from Pond to AP-2 3PCB YD-2/Trench Drains CB-2 CB 24" CB-4CB 24" CB-5CB 18" CB-6 CB 15" CB-7 CB 12" CB-8 CB 12" DMH-1 CB 24" DMH-2 CB 24" DMH-3 CB 30" DMH-5 CB 15" DMH-6 CB 15" DMH-7 CB 12" FB-1 FB-1 OUTLET CB Outlet Stream/Pond P-1 Existing North Pond P-2 Enlarged Pond with OCS SMP-1 Bioretention Basin SMP-2 Bioretention Basin SMP-3 Bioretention Basin SMP-4 CB CS-5 YD-3 CB 12" AP-1 AP-1 AP-2 AP-2 Routing Diagram for POST-DEV Prepared by The LA Group, Printed 11/4/2022 HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link POST-DEV Printed 11/4/2022Prepared by The LA Group Page 2HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 17.594 74 >75% Grass cover, Good, HSG C (1, 1.1, 2, 2a, 2b, 2c, 3, 4, 5, 5.1, 5.2, 6, 7, 7.1, 8, 9) 12.678 98 Paved parking, HSG C (1, 1.1, 2, 2a, 2b, 2c, 3, 4, 5, 5.1, 5.2, 5.3, 6, 7, 8, 9) 0.711 70 Woods, Good, HSG C (7, 7.1, 9) 30.983 84 TOTAL AREA POST-DEV Printed 11/4/2022Prepared by The LA Group Page 3HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.000 HSG B 30.983 HSG C 1, 1.1, 2, 2a, 2b, 2c, 3, 4, 5, 5.1, 5.2, 5.3, 6, 7, 7.1, 8, 9 0.000 HSG D 0.000 Other 30.983 TOTAL AREA POST-DEV Printed 11/4/2022Prepared by The LA Group Page 4HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 17.594 0.000 0.000 17.594 >75% Grass cover, Good 1, 1.1, 2, 2a, 2b, 2c, 3, 4, 5, 5.1, 5.2, 6, 7, 7.1, 8, 9 0.000 0.000 12.678 0.000 0.000 12.678 Paved parking 1, 1.1, 2, 2a, 2b, 2c, 3, 4, 5, 5.1, 5.2, 5.3, 6, 7, 8, 9 0.000 0.000 0.711 0.000 0.000 0.711 Woods, Good 7, 7.1, 9 0.000 0.000 30.983 0.000 0.000 30.983 TOTAL AREA Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 5HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=10.347 ac 22.57% Impervious Runoff Depth>0.55"Subcatchment 1: Subcat 1 Flow Length=820' Slope=0.0600 '/' Tc=11.4 min CN=79 Runoff=8.74 cfs 0.472 af Runoff Area=7.700 ac 29.99% Impervious Runoff Depth>0.63"Subcatchment 1.1: Subcat 1.1 Tc=6.0 min CN=81 Runoff=9.32 cfs 0.406 af Runoff Area=3.811 ac 82.05% Impervious Runoff Depth>1.44"Subcatchment 2: Subcat 2 Tc=6.0 min CN=94 Runoff=9.67 cfs 0.457 af Runoff Area=0.291 ac 39.17% Impervious Runoff Depth>0.73"Subcatchment 2a: Subcat 2a Tc=6.0 min CN=83 Runoff=0.40 cfs 0.018 af Runoff Area=0.452 ac 33.85% Impervious Runoff Depth>0.68"Subcatchment 2b: Subcat 2b Tc=6.0 min CN=82 Runoff=0.59 cfs 0.026 af Runoff Area=1.795 ac 59.87% Impervious Runoff Depth>1.00"Subcatchment 2c: Subcat 2c Tc=6.0 min CN=88 Runoff=3.36 cfs 0.150 af Runoff Area=1.660 ac 83.71% Impervious Runoff Depth>1.44"Subcatchment 3: Subcat 3 Tc=6.0 min CN=94 Runoff=4.21 cfs 0.199 af Runoff Area=0.617 ac 61.67% Impervious Runoff Depth>1.07"Subcatchment 4: Subcat 4 Tc=6.0 min CN=89 Runoff=1.22 cfs 0.055 af Runoff Area=0.157 ac 100.00% Impervious Runoff Depth>1.79"Subcatchment 5: Subcat 5 Tc=6.0 min CN=98 Runoff=0.46 cfs 0.023 af Runoff Area=0.519 ac 99.70% Impervious Runoff Depth>1.79"Subcatchment 5.1: Subcat 5.1 Tc=6.0 min CN=98 Runoff=1.51 cfs 0.077 af Runoff Area=0.442 ac 98.87% Impervious Runoff Depth>1.79"Subcatchment 5.2: Subcat 5.2 Tc=6.0 min CN=98 Runoff=1.29 cfs 0.066 af Runoff Area=0.183 ac 100.00% Impervious Runoff Depth>1.79"Subcatchment 5.3: Subcat 5.3 Tc=6.0 min CN=98 Runoff=0.53 cfs 0.027 af Runoff Area=0.376 ac 27.01% Impervious Runoff Depth>0.59"Subcatchment 6: Subcat 6 Tc=6.0 min CN=80 Runoff=0.42 cfs 0.019 af Runoff Area=1.091 ac 9.37% Impervious Runoff Depth>0.37"Subcatchment 7: Subcat 7 Tc=6.0 min CN=74 Runoff=0.73 cfs 0.034 af Runoff Area=0.666 ac 0.00% Impervious Runoff Depth>0.34"Subcatchment 7.1: Subcat 7.1 Tc=6.0 min CN=73 Runoff=0.40 cfs 0.019 af Runoff Area=0.572 ac 35.03% Impervious Runoff Depth>0.68"Subcatchment 8: Subcat 8 Tc=6.0 min CN=82 Runoff=0.74 cfs 0.032 af Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 6HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Runoff Area=0.304 ac 31.94% Impervious Runoff Depth>0.63"Subcatchment 9: Subcat 9 Tc=6.0 min CN=81 Runoff=0.37 cfs 0.016 af Avg. Flow Depth=0.43' Max Vel=3.94 fps Inflow=9.79 cfs 0.842 afReach S-1: N Pond to Outlet n=0.030 L=380.0' S=0.0237 '/' Capacity=578.56 cfs Outflow=9.55 cfs 0.839 af Avg. Flow Depth=0.41' Max Vel=2.61 fps Inflow=6.09 cfs 0.481 afReach S-2: Outlet to Inlet from SMP-1 n=0.030 L=92.0' S=0.0109 '/' Capacity=628.01 cfs Outflow=6.05 cfs 0.480 af Avg. Flow Depth=0.53' Max Vel=2.63 fps Inflow=8.47 cfs 0.598 afReach S-3: Inlet from SMP-1 to Inlet n=0.030 L=244.0' S=0.0082 '/' Capacity=545.36 cfs Outflow=8.14 cfs 0.596 af Avg. Flow Depth=0.51' Max Vel=2.71 fps Inflow=8.35 cfs 0.859 afReach S-4: Inlet from Pond to AP-2 n=0.030 L=215.0' S=0.0093 '/' Capacity=580.98 cfs Outflow=8.04 cfs 0.856 af Peak Elev=387.58' Inflow=0.59 cfs 0.026 afPond 3P: YD-2/Trench Drains 12.0" Round Culvert n=0.012 L=101.0' S=0.0079 '/' Outflow=0.59 cfs 0.026 af Peak Elev=384.96' Inflow=10.13 cfs 0.480 afPond CB-2: 24" 24.0" Round Culvert n=0.012 L=171.0' S=0.0056 '/' Outflow=10.13 cfs 0.480 af Peak Elev=384.05' Inflow=11.41 cfs 0.546 afPond CB-4: 24" 24.0" Round Culvert n=0.012 L=81.0' S=0.0058 '/' Outflow=11.41 cfs 0.546 af Peak Elev=383.01' Inflow=6.37 cfs 0.298 afPond CB-5: 18" 18.0" Round Culvert n=0.012 L=97.0' S=0.0077 '/' Outflow=6.37 cfs 0.298 af Peak Elev=384.30' Inflow=4.87 cfs 0.220 afPond CB-6: 15" 15.0" Round Culvert n=0.012 L=127.0' S=0.0100 '/' Outflow=4.87 cfs 0.220 af Peak Elev=398.16' Inflow=3.36 cfs 0.150 afPond CB-7: 12" 12.0" Round Culvert n=0.012 L=49.0' S=0.0100 '/' Outflow=3.36 cfs 0.150 af Peak Elev=398.86' Inflow=3.36 cfs 0.150 afPond CB-8: 12" 12.0" Round Culvert n=0.012 L=90.0' S=0.0100 '/' Outflow=3.36 cfs 0.150 af Peak Elev=382.09' Inflow=9.85 cfs 0.347 afPond DMH-1: 24" 30.0" Round Culvert n=0.012 L=80.0' S=0.0050 '/' Outflow=9.85 cfs 0.347 af Peak Elev=382.34' Inflow=11.41 cfs 0.546 afPond DMH-2: 24" Primary=8.28 cfs 0.497 af Secondary=3.46 cfs 0.049 af Outflow=11.41 cfs 0.546 af Peak Elev=383.35' Inflow=11.41 cfs 0.546 afPond DMH-3: 30" 30.0" Round Culvert n=0.012 L=240.0' S=0.0043 '/' Outflow=11.41 cfs 0.546 af Peak Elev=385.69' Inflow=4.87 cfs 0.220 afPond DMH-5: 15" 15.0" Round Culvert n=0.012 L=91.0' S=0.0080 '/' Outflow=4.87 cfs 0.220 af Peak Elev=387.40' Inflow=4.87 cfs 0.220 afPond DMH-6: 15" 15.0" Round Culvert n=0.012 L=201.0' S=0.0080 '/' Outflow=4.87 cfs 0.220 af Peak Elev=397.47' Inflow=3.76 cfs 0.167 afPond DMH-7: 12" 12.0" Round Culvert n=0.012 L=78.0' S=0.0100 '/' Outflow=3.76 cfs 0.167 af Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 7HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Peak Elev=394.21' Storage=2,004 cf Inflow=4.21 cfs 0.199 afPond FB-1: FB-1 Outflow=4.20 cfs 0.160 af Peak Elev=389.49' Inflow=10.72 cfs 0.894 afPond OUTLET: Outlet Stream/Pond Primary=5.36 cfs 0.447 af Secondary=5.36 cfs 0.447 af Outflow=10.72 cfs 0.894 af Peak Elev=401.32' Storage=46,747 cf Inflow=8.74 cfs 0.472 afPond P-1: Existing North Pond Outflow=2.18 cfs 0.436 af Peak Elev=387.50' Storage=10,469 cf Inflow=5.76 cfs 0.466 afPond P-2: Enlarged Pond with OCS Outflow=0.56 cfs 0.263 af Peak Elev=394.21' Storage=2,322 cf Inflow=4.20 cfs 0.160 afPond SMP-1: Bioretention Basin Outflow=3.13 cfs 0.117 af Peak Elev=387.01' Storage=1,407 cf Inflow=0.74 cfs 0.032 afPond SMP-2: Bioretention Basin Outflow=0.00 cfs 0.000 af Peak Elev=386.93' Storage=805 cf Inflow=0.42 cfs 0.019 afPond SMP-3: Bioretention Basin Outflow=0.00 cfs 0.000 af Peak Elev=382.05' Inflow=8.28 cfs 0.497 afPond SMP-4: CS-5 24.0" Round Culvert n=0.012 L=70.0' S=0.0047 '/' Outflow=8.28 cfs 0.497 af Peak Elev=397.53' Inflow=0.40 cfs 0.018 afPond YD-3: 12" 12.0" Round Culvert n=0.012 L=67.0' S=0.0100 '/' Outflow=0.40 cfs 0.018 af Inflow=0.37 cfs 0.016 afLink AP-1: AP-1 Primary=0.37 cfs 0.016 af Inflow=22.63 cfs 1.700 afLink AP-2: AP-2 Primary=22.63 cfs 1.700 af Total Runoff Area = 30.983 ac Runoff Volume = 2.095 af Average Runoff Depth = 0.81" 59.08% Pervious = 18.305 ac 40.92% Impervious = 12.678 ac Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 8HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Subcat 1 Runoff = 8.74 cfs @ 12.04 hrs, Volume= 0.472 af, Depth> 0.55" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 8.011 74 >75% Grass cover, Good, HSG C 2.335 98 Paved parking, HSG C 10.347 79 Weighted Average 8.011 77.43% Pervious Area 2.335 22.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.4 820 0.0600 1.20 Lag/CN Method, Summary for Subcatchment 1.1: Subcat 1.1 Runoff = 9.32 cfs @ 11.98 hrs, Volume= 0.406 af, Depth> 0.63" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 5.391 74 >75% Grass cover, Good, HSG C 2.309 98 Paved parking, HSG C 7.700 81 Weighted Average 5.391 70.01% Pervious Area 2.309 29.99% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2: Subcat 2 Runoff = 9.67 cfs @ 11.97 hrs, Volume= 0.457 af, Depth> 1.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.684 74 >75% Grass cover, Good, HSG C 3.127 98 Paved parking, HSG C 3.811 94 Weighted Average 0.684 17.95% Pervious Area 3.127 82.05% Impervious Area Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 9HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2a: Subcat 2a Runoff = 0.40 cfs @ 11.98 hrs, Volume= 0.018 af, Depth> 0.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.177 74 >75% Grass cover, Good, HSG C 0.114 98 Paved parking, HSG C 0.291 83 Weighted Average 0.177 60.83% Pervious Area 0.114 39.17% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2b: Subcat 2b Runoff = 0.59 cfs @ 11.98 hrs, Volume= 0.026 af, Depth> 0.68" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.299 74 >75% Grass cover, Good, HSG C 0.153 98 Paved parking, HSG C 0.452 82 Weighted Average 0.299 66.15% Pervious Area 0.153 33.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2c: Subcat 2c Runoff = 3.36 cfs @ 11.97 hrs, Volume= 0.150 af, Depth> 1.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 10HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area (ac) CN Description 0.721 74 >75% Grass cover, Good, HSG C 1.075 98 Paved parking, HSG C 1.795 88 Weighted Average 0.721 40.13% Pervious Area 1.075 59.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 3: Subcat 3 Runoff = 4.21 cfs @ 11.97 hrs, Volume= 0.199 af, Depth> 1.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.270 74 >75% Grass cover, Good, HSG C 1.390 98 Paved parking, HSG C 1.660 94 Weighted Average 0.270 16.29% Pervious Area 1.390 83.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 4: Subcat 4 Runoff = 1.22 cfs @ 11.97 hrs, Volume= 0.055 af, Depth> 1.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.236 74 >75% Grass cover, Good, HSG C 0.380 98 Paved parking, HSG C 0.617 89 Weighted Average 0.236 38.33% Pervious Area 0.380 61.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 11HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 5: Subcat 5 Runoff = 0.46 cfs @ 11.96 hrs, Volume= 0.023 af, Depth> 1.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.000 74 >75% Grass cover, Good, HSG C 0.157 98 Paved parking, HSG C 0.157 98 Weighted Average 0.000 0.00% Pervious Area 0.157 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5.1: Subcat 5.1 Runoff = 1.51 cfs @ 11.96 hrs, Volume= 0.077 af, Depth> 1.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.002 74 >75% Grass cover, Good, HSG C 0.518 98 Paved parking, HSG C 0.519 98 Weighted Average 0.002 0.30% Pervious Area 0.518 99.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5.2: Subcat 5.2 Runoff = 1.29 cfs @ 11.96 hrs, Volume= 0.066 af, Depth> 1.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.005 74 >75% Grass cover, Good, HSG C 0.437 98 Paved parking, HSG C 0.442 98 Weighted Average 0.005 1.13% Pervious Area 0.437 98.87% Impervious Area Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 12HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5.3: Subcat 5.3 Runoff = 0.53 cfs @ 11.96 hrs, Volume= 0.027 af, Depth> 1.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.183 98 Paved parking, HSG C 0.183 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 6: Subcat 6 Runoff = 0.42 cfs @ 11.98 hrs, Volume= 0.019 af, Depth> 0.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.275 74 >75% Grass cover, Good, HSG C 0.102 98 Paved parking, HSG C 0.376 80 Weighted Average 0.275 72.99% Pervious Area 0.102 27.01% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 7: Subcat 7 Runoff = 0.73 cfs @ 11.99 hrs, Volume= 0.034 af, Depth> 0.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 13HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area (ac) CN Description 0.424 74 >75% Grass cover, Good, HSG C 0.102 98 Paved parking, HSG C 0.565 70 Woods, Good, HSG C 1.091 74 Weighted Average 0.989 90.63% Pervious Area 0.102 9.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 7.1: Subcat 7.1 Runoff = 0.40 cfs @ 11.99 hrs, Volume= 0.019 af, Depth> 0.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.545 74 >75% Grass cover, Good, HSG C 0.121 70 Woods, Good, HSG C 0.666 73 Weighted Average 0.666 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 8: Subcat 8 Runoff = 0.74 cfs @ 11.98 hrs, Volume= 0.032 af, Depth> 0.68" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.372 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking, HSG C 0.572 82 Weighted Average 0.372 64.97% Pervious Area 0.200 35.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 14HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 9: Subcat 9 Runoff = 0.37 cfs @ 11.98 hrs, Volume= 0.016 af, Depth> 0.63" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15" Area (ac) CN Description 0.182 74 >75% Grass cover, Good, HSG C 0.097 98 Paved parking, HSG C 0.025 70 Woods, Good, HSG C 0.304 81 Weighted Average 0.207 68.06% Pervious Area 0.097 31.94% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Reach S-1: N Pond to Outlet Inflow Area = 18.047 ac, 25.74% Impervious, Inflow Depth > 0.56" for 1YR event Inflow = 9.79 cfs @ 11.98 hrs, Volume= 0.842 af Outflow = 9.55 cfs @ 12.00 hrs, Volume= 0.839 af, Atten= 2%, Lag= 1.0 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 3.94 fps, Min. Travel Time= 1.6 min Avg. Velocity = 1.64 fps, Avg. Travel Time= 3.9 min Peak Storage= 922 cf @ 12.00 hrs Average Depth at Peak Storage= 0.43' Bank-Full Depth= 4.00' Flow Area= 44.0 sf, Capacity= 578.56 cfs 5.00' x 4.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 17.00' Length= 380.0' Slope= 0.0237 '/' Inlet Invert= 399.00', Outlet Invert= 390.00' Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 15HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Reach S-2: Outlet to Inlet from SMP-1 Inflow Area = 19.755 ac, 25.95% Impervious, Inflow Depth > 0.29" for 1YR event Inflow = 6.09 cfs @ 12.00 hrs, Volume= 0.481 af Outflow = 6.05 cfs @ 12.00 hrs, Volume= 0.480 af, Atten= 0%, Lag= 0.4 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.61 fps, Min. Travel Time= 0.6 min Avg. Velocity = 0.97 fps, Avg. Travel Time= 1.6 min Peak Storage= 214 cf @ 12.00 hrs Average Depth at Peak Storage= 0.41' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 628.01 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 92.0' Slope= 0.0109 '/' Inlet Invert= 388.00', Outlet Invert= 387.00' Summary for Reach S-3: Inlet from SMP-1 to Inlet from Pond Inflow Area = 21.415 ac, 30.43% Impervious, Inflow Depth > 0.33" for 1YR event Inflow = 8.47 cfs @ 12.04 hrs, Volume= 0.598 af Outflow = 8.14 cfs @ 12.05 hrs, Volume= 0.596 af, Atten= 4%, Lag= 0.9 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.63 fps, Min. Travel Time= 1.5 min Avg. Velocity = 0.93 fps, Avg. Travel Time= 4.4 min Peak Storage= 757 cf @ 12.05 hrs Average Depth at Peak Storage= 0.53' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 545.36 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 244.0' Slope= 0.0082 '/' Inlet Invert= 386.50', Outlet Invert= 384.50' Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 16HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Reach S-4: Inlet from Pond to AP-2 Inflow Area = 22.081 ac, 29.51% Impervious, Inflow Depth > 0.47" for 1YR event Inflow = 8.35 cfs @ 12.05 hrs, Volume= 0.859 af Outflow = 8.04 cfs @ 12.07 hrs, Volume= 0.856 af, Atten= 4%, Lag= 0.9 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.71 fps, Min. Travel Time= 1.3 min Avg. Velocity = 1.13 fps, Avg. Travel Time= 3.2 min Peak Storage= 635 cf @ 12.07 hrs Average Depth at Peak Storage= 0.51' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 580.98 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 215.0' Slope= 0.0093 '/' Inlet Invert= 384.00', Outlet Invert= 382.00' Summary for Pond 3P: YD-2/Trench Drains Inflow Area = 0.452 ac, 33.85% Impervious, Inflow Depth > 0.68" for 1YR event Inflow = 0.59 cfs @ 11.98 hrs, Volume= 0.026 af Outflow = 0.59 cfs @ 11.98 hrs, Volume= 0.026 af, Atten= 0%, Lag= 0.0 min Primary = 0.59 cfs @ 11.98 hrs, Volume= 0.026 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 387.58' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 387.00'12.0" Round Culvert L= 101.0' Ke= 0.500 Inlet / Outlet Invert= 387.00' / 386.20' S= 0.0079 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.46 cfs @ 11.98 hrs HW=387.54' TW=387.36' (Dynamic Tailwater) 1=Culvert (Outlet Controls 0.46 cfs @ 1.55 fps) Summary for Pond CB-2: 24" Inflow Area = 3.967 ac, 82.76% Impervious, Inflow Depth > 1.45" for 1YR event Inflow = 10.13 cfs @ 11.97 hrs, Volume= 0.480 af Outflow = 10.13 cfs @ 11.97 hrs, Volume= 0.480 af, Atten= 0%, Lag= 0.0 min Primary = 10.13 cfs @ 11.97 hrs, Volume= 0.480 af Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 17HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 384.96' @ 11.98 hrs Device Routing Invert Outlet Devices #1 Primary 383.26'24.0" Round Culvert L= 171.0' Ke= 0.500 Inlet / Outlet Invert= 383.26' / 382.30' S= 0.0056 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=8.90 cfs @ 11.97 hrs HW=384.90' TW=383.99' (Dynamic Tailwater) 1=Culvert (Outlet Controls 8.90 cfs @ 4.39 fps) Summary for Pond CB-4: 24" Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 1.49" for 1YR event Inflow = 11.41 cfs @ 11.97 hrs, Volume= 0.546 af Outflow = 11.41 cfs @ 11.97 hrs, Volume= 0.546 af, Atten= 0%, Lag= 0.0 min Primary = 11.41 cfs @ 11.97 hrs, Volume= 0.546 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 384.05' @ 11.98 hrs Device Routing Invert Outlet Devices #1 Primary 382.20'24.0" Round Culvert L= 81.0' Ke= 0.500 Inlet / Outlet Invert= 382.20' / 381.73' S= 0.0058 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=9.98 cfs @ 11.97 hrs HW=383.99' TW=383.31' (Dynamic Tailwater) 1=Culvert (Outlet Controls 9.98 cfs @ 4.46 fps) Summary for Pond CB-5: 18" Inflow Area = 4.189 ac, 55.97% Impervious, Inflow Depth > 0.85" for 1YR event Inflow = 6.37 cfs @ 11.97 hrs, Volume= 0.298 af Outflow = 6.37 cfs @ 11.97 hrs, Volume= 0.298 af, Atten= 0%, Lag= 0.0 min Primary = 6.37 cfs @ 11.97 hrs, Volume= 0.298 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 383.01' @ 11.98 hrs Device Routing Invert Outlet Devices #1 Primary 381.63'18.0" Round Culvert L= 97.0' Ke= 0.500 Inlet / Outlet Invert= 381.63' / 380.88' S= 0.0077 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.77 sf Primary OutFlow Max=5.86 cfs @ 11.97 hrs HW=382.97' TW=382.04' (Dynamic Tailwater) 1=Culvert (Outlet Controls 5.86 cfs @ 4.67 fps) Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 18HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond CB-6: 15" Inflow Area = 2.722 ac, 56.03% Impervious, Inflow Depth > 0.97" for 1YR event Inflow = 4.87 cfs @ 11.97 hrs, Volume= 0.220 af Outflow = 4.87 cfs @ 11.97 hrs, Volume= 0.220 af, Atten= 0%, Lag= 0.0 min Primary = 4.87 cfs @ 11.97 hrs, Volume= 0.220 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 384.30' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 383.00'15.0" Round Culvert L= 127.0' Ke= 0.500 Inlet / Outlet Invert= 383.00' / 381.73' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=4.71 cfs @ 11.97 hrs HW=384.26' TW=382.97' (Dynamic Tailwater) 1=Culvert (Inlet Controls 4.71 cfs @ 3.84 fps) Summary for Pond CB-7: 12" Inflow Area = 1.795 ac, 59.87% Impervious, Inflow Depth > 1.00" for 1YR event Inflow = 3.36 cfs @ 11.97 hrs, Volume= 0.150 af Outflow = 3.36 cfs @ 11.97 hrs, Volume= 0.150 af, Atten= 0%, Lag= 0.0 min Primary = 3.36 cfs @ 11.97 hrs, Volume= 0.150 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 398.16' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 396.58'12.0" Round Culvert L= 49.0' Ke= 0.500 Inlet / Outlet Invert= 396.58' / 396.09' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=2.82 cfs @ 11.97 hrs HW=397.98' TW=397.41' (Dynamic Tailwater) 1=Culvert (Outlet Controls 2.82 cfs @ 3.59 fps) Summary for Pond CB-8: 12" Inflow Area = 1.795 ac, 59.87% Impervious, Inflow Depth > 1.00" for 1YR event Inflow = 3.36 cfs @ 11.97 hrs, Volume= 0.150 af Outflow = 3.36 cfs @ 11.97 hrs, Volume= 0.150 af, Atten= 0%, Lag= 0.0 min Primary = 3.36 cfs @ 11.97 hrs, Volume= 0.150 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 398.86' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 397.58'12.0" Round Culvert L= 90.0' Ke= 0.500 Inlet / Outlet Invert= 397.58' / 396.68' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 19HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=3.02 cfs @ 11.97 hrs HW=398.82' TW=397.98' (Dynamic Tailwater) 1=Culvert (Outlet Controls 3.02 cfs @ 3.97 fps) Summary for Pond DMH-1: 24" Inflow Area = 4.189 ac, 55.97% Impervious, Inflow Depth > 0.99" for 1YR event Inflow = 9.85 cfs @ 11.98 hrs, Volume= 0.347 af Outflow = 9.85 cfs @ 11.98 hrs, Volume= 0.347 af, Atten= 0%, Lag= 0.0 min Primary = 9.85 cfs @ 11.98 hrs, Volume= 0.347 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 382.09' @ 11.98 hrs Device Routing Invert Outlet Devices #1 Primary 380.62'30.0" Round Culvert L= 80.0' Ke= 0.500 Inlet / Outlet Invert= 380.62' / 380.22' S= 0.0050 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 4.91 sf Primary OutFlow Max=9.32 cfs @ 11.98 hrs HW=382.04' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 9.32 cfs @ 4.67 fps) Summary for Pond DMH-2: 24" Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 1.49" for 1YR event Inflow = 11.41 cfs @ 11.97 hrs, Volume= 0.546 af Outflow = 11.41 cfs @ 11.97 hrs, Volume= 0.546 af, Atten= 0%, Lag= 0.0 min Primary = 8.28 cfs @ 11.95 hrs, Volume= 0.497 af Secondary = 3.46 cfs @ 11.98 hrs, Volume= 0.049 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 382.34' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 380.60'24.0" Round Culvert L= 10.0' Ke= 0.500 Inlet / Outlet Invert= 380.60' / 380.55' S= 0.0050 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf #2 Secondary 381.39'24.0" Round Culvert L= 10.0' Ke= 0.500 Inlet / Outlet Invert= 381.39' / 381.34' S= 0.0050 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=6.69 cfs @ 11.95 hrs HW=382.29' TW=382.04' (Dynamic Tailwater) 1=Culvert (Outlet Controls 6.69 cfs @ 3.19 fps) Secondary OutFlow Max=3.15 cfs @ 11.98 hrs HW=382.31' TW=382.04' (Dynamic Tailwater) 2=Culvert (Outlet Controls 3.15 cfs @ 3.26 fps) Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 20HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond DMH-3: 30" Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 1.49" for 1YR event Inflow = 11.41 cfs @ 11.97 hrs, Volume= 0.546 af Outflow = 11.41 cfs @ 11.97 hrs, Volume= 0.546 af, Atten= 0%, Lag= 0.0 min Primary = 11.41 cfs @ 11.97 hrs, Volume= 0.546 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 383.35' @ 11.98 hrs Device Routing Invert Outlet Devices #1 Primary 381.68'30.0" Round Culvert L= 240.0' Ke= 0.500 Inlet / Outlet Invert= 381.68' / 380.65' S= 0.0043 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 4.91 sf Primary OutFlow Max=10.34 cfs @ 11.97 hrs HW=383.31' TW=382.30' (Dynamic Tailwater) 1=Culvert (Outlet Controls 10.34 cfs @ 4.35 fps) Summary for Pond DMH-5: 15" Inflow Area = 2.722 ac, 56.03% Impervious, Inflow Depth > 0.97" for 1YR event Inflow = 4.87 cfs @ 11.97 hrs, Volume= 0.220 af Outflow = 4.87 cfs @ 11.97 hrs, Volume= 0.220 af, Atten= 0%, Lag= 0.0 min Primary = 4.87 cfs @ 11.97 hrs, Volume= 0.220 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 385.69' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 384.40'15.0" Round Culvert L= 91.0' Ke= 0.500 Inlet / Outlet Invert= 384.40' / 383.67' S= 0.0080 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=4.71 cfs @ 11.97 hrs HW=385.66' TW=384.26' (Dynamic Tailwater) 1=Culvert (Inlet Controls 4.71 cfs @ 3.84 fps) Summary for Pond DMH-6: 15" Inflow Area = 2.722 ac, 56.03% Impervious, Inflow Depth > 0.97" for 1YR event Inflow = 4.87 cfs @ 11.97 hrs, Volume= 0.220 af Outflow = 4.87 cfs @ 11.97 hrs, Volume= 0.220 af, Atten= 0%, Lag= 0.0 min Primary = 4.87 cfs @ 11.97 hrs, Volume= 0.220 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 387.40' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 386.10'15.0" Round Culvert L= 201.0' Ke= 0.500 Inlet / Outlet Invert= 386.10' / 384.50' S= 0.0080 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 21HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=4.71 cfs @ 11.97 hrs HW=387.36' TW=385.66' (Dynamic Tailwater) 1=Culvert (Inlet Controls 4.71 cfs @ 3.84 fps) Summary for Pond DMH-7: 12" Inflow Area = 2.086 ac, 56.99% Impervious, Inflow Depth > 0.96" for 1YR event Inflow = 3.76 cfs @ 11.97 hrs, Volume= 0.167 af Outflow = 3.76 cfs @ 11.97 hrs, Volume= 0.167 af, Atten= 0%, Lag= 0.0 min Primary = 3.76 cfs @ 11.97 hrs, Volume= 0.167 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 397.47' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 395.99'12.0" Round Culvert L= 78.0' Ke= 0.500 Inlet / Outlet Invert= 395.99' / 395.21' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=3.63 cfs @ 11.97 hrs HW=397.41' TW=387.36' (Dynamic Tailwater) 1=Culvert (Inlet Controls 3.63 cfs @ 4.63 fps) Summary for Pond FB-1: FB-1 Inflow Area = 1.660 ac, 83.71% Impervious, Inflow Depth > 1.44" for 1YR event Inflow = 4.21 cfs @ 11.97 hrs, Volume= 0.199 af Outflow = 4.20 cfs @ 11.98 hrs, Volume= 0.160 af, Atten= 0%, Lag= 1.0 min Primary = 4.20 cfs @ 11.98 hrs, Volume= 0.160 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 394.21' @ 12.10 hrs Surf.Area= 1,755 sf Storage= 2,004 cf Plug-Flow detention time= 86.4 min calculated for 0.160 af (80% of inflow) Center-of-Mass det. time= 33.5 min ( 795.5 - 762.0 ) Volume Invert Avail.Storage Storage Description #1 392.00' 3,728 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 392.00 225 100.0 0 0 225 393.00 820 165.0 492 492 1,602 394.00 1,550 195.0 1,166 1,657 2,480 395.00 2,640 250.0 2,071 3,728 4,441 Device Routing Invert Outlet Devices #1 Primary 394.00'18.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 22HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=3.92 cfs @ 11.98 hrs HW=394.20' TW=394.03' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 3.92 cfs @ 1.09 fps) Summary for Pond OUTLET: Outlet Stream/Pond Inflow Area = 18.664 ac, 26.92% Impervious, Inflow Depth > 0.57" for 1YR event Inflow = 10.72 cfs @ 12.00 hrs, Volume= 0.894 af Outflow = 10.72 cfs @ 12.00 hrs, Volume= 0.894 af, Atten= 0%, Lag= 0.0 min Primary = 5.36 cfs @ 12.00 hrs, Volume= 0.447 af Secondary = 5.36 cfs @ 12.00 hrs, Volume= 0.447 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 389.49' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 389.00'6.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Secondary 389.00'6.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=5.34 cfs @ 12.00 hrs HW=389.49' TW=388.41' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 5.34 cfs @ 1.83 fps) Secondary OutFlow Max=5.34 cfs @ 12.00 hrs HW=389.49' TW=386.46' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir (Weir Controls 5.34 cfs @ 1.83 fps) Summary for Pond P-1: Existing North Pond Inflow Area = 10.347 ac, 22.57% Impervious, Inflow Depth > 0.55" for 1YR event Inflow = 8.74 cfs @ 12.04 hrs, Volume= 0.472 af Outflow = 2.18 cfs @ 12.31 hrs, Volume= 0.436 af, Atten= 75%, Lag= 16.2 min Primary = 2.18 cfs @ 12.31 hrs, Volume= 0.436 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Starting Elev= 401.00' Surf.Area= 22,263 sf Storage= 39,555 cf Peak Elev= 401.32' @ 12.31 hrs Surf.Area= 23,057 sf Storage= 46,747 cf (7,192 cf above start) Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= 47.1 min ( 865.3 - 818.2 ) Volume Invert Avail.Storage Storage Description #1 399.00' 117,925 cf Custom Stage Data (Irregular) Listed below (Recalc) Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 23HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 399.00 17,348 799.0 0 0 17,348 400.00 19,775 819.0 18,548 18,548 20,047 401.00 22,263 839.0 21,007 39,555 22,813 402.00 24,812 859.0 23,526 63,081 25,646 403.00 27,418 878.0 26,104 89,185 28,412 404.00 30,082 897.0 28,740 117,925 31,239 Device Routing Invert Outlet Devices #1 Primary 401.00'5.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Primary OutFlow Max=2.17 cfs @ 12.31 hrs HW=401.32' TW=399.24' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 2.17 cfs @ 1.37 fps) Summary for Pond P-2: Enlarged Pond with OCS Inflow Area = 0.666 ac, 0.00% Impervious, Inflow Depth > 8.39" for 1YR event Inflow = 5.76 cfs @ 12.00 hrs, Volume= 0.466 af Outflow = 0.56 cfs @ 14.38 hrs, Volume= 0.263 af, Atten= 90%, Lag= 143.0 min Primary = 0.56 cfs @ 14.38 hrs, Volume= 0.263 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 387.50' @ 14.38 hrs Surf.Area= 8,143 sf Storage= 10,469 cf Plug-Flow detention time= 210.9 min calculated for 0.263 af (56% of inflow) Center-of-Mass det. time= 116.4 min ( 952.7 - 836.3 ) Volume Invert Avail.Storage Storage Description #1 386.00' 48,113 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 386.00 5,878 348.0 0 0 5,878 387.00 7,311 402.0 6,581 6,581 9,123 387.40 7,985 441.0 3,058 9,640 11,744 388.00 8,931 483.0 5,072 14,712 14,845 389.00 10,379 517.0 9,646 24,358 17,596 390.00 11,869 542.0 11,116 35,473 19,769 391.00 13,427 562.0 12,640 48,113 21,611 Device Routing Invert Outlet Devices #1 Primary 386.00'24.0" Round Culvert L= 60.0' Ke= 0.500 Inlet / Outlet Invert= 386.00' / 385.50' S= 0.0083 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf #2 Device 1 386.00'3.0" W x 3.0" H Vert. Orifice/Grate C= 0.600 #3 Device 1 387.40'24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 389.00'24.0" Horiz. Orifice/Grate C= 0.600 Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 24HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Limited to weir flow at low heads Primary OutFlow Max=0.56 cfs @ 14.38 hrs HW=387.50' TW=384.17' (Dynamic Tailwater) 1=Culvert (Passes 0.56 cfs of 9.50 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.35 cfs @ 5.65 fps) 3=Orifice/Grate (Orifice Controls 0.21 cfs @ 1.03 fps) 4=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond SMP-1: Bioretention Basin Inflow Area = 1.660 ac, 83.71% Impervious, Inflow Depth > 1.16" for 1YR event Inflow = 4.20 cfs @ 11.98 hrs, Volume= 0.160 af Outflow = 3.13 cfs @ 12.05 hrs, Volume= 0.117 af, Atten= 25%, Lag= 4.3 min Primary = 3.13 cfs @ 12.05 hrs, Volume= 0.117 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 394.21' @ 12.05 hrs Surf.Area= 2,358 sf Storage= 2,322 cf Plug-Flow detention time= 97.1 min calculated for 0.117 af (73% of inflow) Center-of-Mass det. time= 33.0 min ( 828.5 - 795.5 ) Volume Invert Avail.Storage Storage Description #1 393.00' 4,422 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 393.00 1,500 155.0 0 0 1,500 394.00 2,210 185.0 1,844 1,844 2,329 394.50 2,570 196.0 1,194 3,037 2,676 395.00 2,975 205.0 1,385 4,422 2,980 Device Routing Invert Outlet Devices #1 Device 2 394.00'30.0" x 30.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 389.73'12.0" Round Culvert L= 69.0' Ke= 0.500 Inlet / Outlet Invert= 389.73' / 389.04' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=3.04 cfs @ 12.05 hrs HW=394.21' TW=387.03' (Dynamic Tailwater) 2=Culvert (Passes 3.04 cfs of 7.03 cfs potential flow) 1=Orifice/Grate (Weir Controls 3.04 cfs @ 1.48 fps) Summary for Pond SMP-2: Bioretention Basin Inflow Area = 0.572 ac, 35.03% Impervious, Inflow Depth > 0.68" for 1YR event Inflow = 0.74 cfs @ 11.98 hrs, Volume= 0.032 af Outflow = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 25HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Peak Elev= 387.01' @ 20.00 hrs Surf.Area= 1,787 sf Storage= 1,407 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 386.00' 3,576 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 386.00 1,025 175.0 0 0 1,025 387.00 1,776 200.0 1,383 1,383 1,794 387.50 2,190 213.0 990 2,373 2,234 388.00 2,628 225.0 1,203 3,576 2,666 Device Routing Invert Outlet Devices #1 Device 2 387.50'15.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 381.63'18.0" Round Culvert L= 97.0' Ke= 0.500 Inlet / Outlet Invert= 381.63' / 380.88' S= 0.0077 '/' Cc= 0.900 n= 0.012, Flow Area= 1.77 sf Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=386.00' TW=381.68' (Dynamic Tailwater) 2=Culvert (Passes 0.00 cfs of 15.55 cfs potential flow) 1=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond SMP-3: Bioretention Basin Inflow Area = 0.376 ac, 27.01% Impervious, Inflow Depth > 0.59" for 1YR event Inflow = 0.42 cfs @ 11.98 hrs, Volume= 0.019 af Outflow = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 386.93' @ 20.00 hrs Surf.Area= 1,117 sf Storage= 805 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 386.00' 2,509 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 386.00 643 117.0 0 0 643 387.00 1,160 142.0 889 889 1,174 387.50 1,457 154.0 653 1,542 1,466 388.00 2,455 213.0 967 2,509 3,192 Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 26HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Device 2 387.50'15.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 383.00'15.0" Round Culvert L= 127.0' Ke= 0.500 Inlet / Outlet Invert= 383.00' / 381.73' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=386.00' TW=381.68' (Dynamic Tailwater) 2=Culvert (Passes 0.00 cfs of 8.53 cfs potential flow) 1=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond SMP-4: CS-5 Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 1.35" for 1YR event Inflow = 8.28 cfs @ 11.95 hrs, Volume= 0.497 af Outflow = 8.28 cfs @ 11.95 hrs, Volume= 0.497 af, Atten= 0%, Lag= 0.0 min Primary = 8.28 cfs @ 11.95 hrs, Volume= 0.497 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 382.05' @ 11.95 hrs Device Routing Invert Outlet Devices #1 Primary 380.55'24.0" Round Culvert L= 70.0' Ke= 0.500 Inlet / Outlet Invert= 380.55' / 380.22' S= 0.0047 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=8.18 cfs @ 11.95 hrs HW=382.04' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 8.18 cfs @ 4.55 fps) Summary for Pond YD-3: 12" Inflow Area = 0.291 ac, 39.17% Impervious, Inflow Depth > 0.73" for 1YR event Inflow = 0.40 cfs @ 11.98 hrs, Volume= 0.018 af Outflow = 0.40 cfs @ 11.98 hrs, Volume= 0.018 af, Atten= 0%, Lag= 0.0 min Primary = 0.40 cfs @ 11.98 hrs, Volume= 0.018 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 397.53' @ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 396.98'12.0" Round Culvert L= 67.0' Ke= 0.500 Inlet / Outlet Invert= 396.98' / 396.31' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.17 cfs @ 11.98 hrs HW=397.44' TW=397.41' (Dynamic Tailwater) 1=Culvert (Outlet Controls 0.17 cfs @ 0.71 fps) Type II 24-hr 1YR Rainfall=2.15"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 27HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Link AP-1: AP-1 Inflow Area = 0.304 ac, 31.94% Impervious, Inflow Depth > 0.63" for 1YR event Inflow = 0.37 cfs @ 11.98 hrs, Volume= 0.016 af Primary = 0.37 cfs @ 11.98 hrs, Volume= 0.016 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link AP-2: AP-2 Inflow Area = 30.679 ac, 41.01% Impervious, Inflow Depth > 0.66" for 1YR event Inflow = 22.63 cfs @ 11.99 hrs, Volume= 1.700 af Primary = 22.63 cfs @ 11.99 hrs, Volume= 1.700 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 28HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=10.347 ac 22.57% Impervious Runoff Depth>1.61"Subcatchment 1: Subcat 1 Flow Length=820' Slope=0.0600 '/' Tc=11.4 min CN=79 Runoff=26.39 cfs 1.392 af Runoff Area=7.700 ac 29.99% Impervious Runoff Depth>1.76"Subcatchment 1.1: Subcat 1.1 Tc=6.0 min CN=81 Runoff=25.34 cfs 1.131 af Runoff Area=3.811 ac 82.05% Impervious Runoff Depth>2.89"Subcatchment 2: Subcat 2 Tc=6.0 min CN=94 Runoff=18.56 cfs 0.917 af Runoff Area=0.291 ac 39.17% Impervious Runoff Depth>1.91"Subcatchment 2a: Subcat 2a Tc=6.0 min CN=83 Runoff=1.03 cfs 0.046 af Runoff Area=0.452 ac 33.85% Impervious Runoff Depth>1.84"Subcatchment 2b: Subcat 2b Tc=6.0 min CN=82 Runoff=1.55 cfs 0.069 af Runoff Area=1.795 ac 59.87% Impervious Runoff Depth>2.33"Subcatchment 2c: Subcat 2c Tc=6.0 min CN=88 Runoff=7.51 cfs 0.349 af Runoff Area=1.660 ac 83.71% Impervious Runoff Depth>2.89"Subcatchment 3: Subcat 3 Tc=6.0 min CN=94 Runoff=8.09 cfs 0.399 af Runoff Area=0.617 ac 61.67% Impervious Runoff Depth>2.42"Subcatchment 4: Subcat 4 Tc=6.0 min CN=89 Runoff=2.66 cfs 0.124 af Runoff Area=0.157 ac 100.00% Impervious Runoff Depth>3.24"Subcatchment 5: Subcat 5 Tc=6.0 min CN=98 Runoff=0.81 cfs 0.042 af Runoff Area=0.519 ac 99.70% Impervious Runoff Depth>3.24"Subcatchment 5.1: Subcat 5.1 Tc=6.0 min CN=98 Runoff=2.68 cfs 0.140 af Runoff Area=0.442 ac 98.87% Impervious Runoff Depth>3.24"Subcatchment 5.2: Subcat 5.2 Tc=6.0 min CN=98 Runoff=2.28 cfs 0.119 af Runoff Area=0.183 ac 100.00% Impervious Runoff Depth>3.24"Subcatchment 5.3: Subcat 5.3 Tc=6.0 min CN=98 Runoff=0.95 cfs 0.049 af Runoff Area=0.376 ac 27.01% Impervious Runoff Depth>1.69"Subcatchment 6: Subcat 6 Tc=6.0 min CN=80 Runoff=1.19 cfs 0.053 af Runoff Area=1.091 ac 9.37% Impervious Runoff Depth>1.29"Subcatchment 7: Subcat 7 Tc=6.0 min CN=74 Runoff=2.69 cfs 0.117 af Runoff Area=0.666 ac 0.00% Impervious Runoff Depth>1.22"Subcatchment 7.1: Subcat 7.1 Tc=6.0 min CN=73 Runoff=1.56 cfs 0.068 af Runoff Area=0.572 ac 35.03% Impervious Runoff Depth>1.84"Subcatchment 8: Subcat 8 Tc=6.0 min CN=82 Runoff=1.95 cfs 0.088 af Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 29HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Runoff Area=0.304 ac 31.94% Impervious Runoff Depth>1.76"Subcatchment 9: Subcat 9 Tc=6.0 min CN=81 Runoff=1.00 cfs 0.045 af Avg. Flow Depth=0.83' Max Vel=5.73 fps Inflow=30.10 cfs 2.462 afReach S-1: N Pond to Outlet n=0.030 L=380.0' S=0.0237 '/' Capacity=578.56 cfs Outflow=29.86 cfs 2.457 af Avg. Flow Depth=0.80' Max Vel=3.79 fps Inflow=18.83 cfs 1.408 afReach S-2: Outlet to Inlet from SMP-1 n=0.030 L=92.0' S=0.0109 '/' Capacity=628.01 cfs Outflow=18.80 cfs 1.407 af Avg. Flow Depth=1.03' Max Vel=3.78 fps Inflow=25.98 cfs 1.724 afReach S-3: Inlet from SMP-1 to Inlet n=0.030 L=244.0' S=0.0082 '/' Capacity=545.36 cfs Outflow=25.64 cfs 1.721 af Avg. Flow Depth=1.03' Max Vel=4.03 fps Inflow=27.46 cfs 2.844 afReach S-4: Inlet from Pond to AP-2 n=0.030 L=215.0' S=0.0093 '/' Capacity=580.98 cfs Outflow=27.36 cfs 2.840 af Peak Elev=396.33' Inflow=1.55 cfs 0.069 afPond 3P: YD-2/Trench Drains 12.0" Round Culvert n=0.012 L=101.0' S=0.0079 '/' Outflow=1.55 cfs 0.069 af Peak Elev=387.44' Inflow=19.37 cfs 0.959 afPond CB-2: 24" 24.0" Round Culvert n=0.012 L=171.0' S=0.0056 '/' Outflow=19.37 cfs 0.959 af Peak Elev=385.97' Inflow=21.65 cfs 1.078 afPond CB-4: 24" 24.0" Round Culvert n=0.012 L=81.0' S=0.0058 '/' Outflow=21.65 cfs 1.078 af Peak Elev=385.72' Inflow=13.71 cfs 0.703 afPond CB-5: 18" 18.0" Round Culvert n=0.012 L=97.0' S=0.0077 '/' Outflow=13.71 cfs 0.703 af Peak Elev=389.94' Inflow=11.03 cfs 0.514 afPond CB-6: 15" 15.0" Round Culvert n=0.012 L=127.0' S=0.0100 '/' Outflow=11.03 cfs 0.514 af Peak Elev=406.13' Inflow=7.51 cfs 0.349 afPond CB-7: 12" 12.0" Round Culvert n=0.012 L=49.0' S=0.0100 '/' Outflow=7.51 cfs 0.349 af Peak Elev=408.96' Inflow=7.51 cfs 0.349 afPond CB-8: 12" 12.0" Round Culvert n=0.012 L=90.0' S=0.0100 '/' Outflow=7.51 cfs 0.349 af Peak Elev=383.10' Inflow=22.51 cfs 0.848 afPond DMH-1: 24" 30.0" Round Culvert n=0.012 L=80.0' S=0.0050 '/' Outflow=22.51 cfs 0.848 af Peak Elev=383.30' Inflow=21.65 cfs 1.078 afPond DMH-2: 24" Primary=13.61 cfs 0.934 af Secondary=8.86 cfs 0.145 af Outflow=21.65 cfs 1.078 af Peak Elev=384.24' Inflow=21.65 cfs 1.078 afPond DMH-3: 30" 30.0" Round Culvert n=0.012 L=240.0' S=0.0043 '/' Outflow=21.65 cfs 1.078 af Peak Elev=392.66' Inflow=11.03 cfs 0.514 afPond DMH-5: 15" 15.0" Round Culvert n=0.012 L=91.0' S=0.0080 '/' Outflow=11.03 cfs 0.514 af Peak Elev=396.25' Inflow=11.03 cfs 0.514 afPond DMH-6: 15" 15.0" Round Culvert n=0.012 L=201.0' S=0.0080 '/' Outflow=11.03 cfs 0.514 af Peak Elev=402.76' Inflow=8.54 cfs 0.395 afPond DMH-7: 12" 12.0" Round Culvert n=0.012 L=78.0' S=0.0100 '/' Outflow=8.54 cfs 0.395 af Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 30HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Peak Elev=394.42' Storage=2,393 cf Inflow=8.09 cfs 0.399 afPond FB-1: FB-1 Outflow=7.68 cfs 0.361 af Peak Elev=390.00' Inflow=32.39 cfs 2.582 afPond OUTLET: Outlet Stream/Pond Primary=16.19 cfs 1.291 af Secondary=16.19 cfs 1.291 af Outflow=32.39 cfs 2.582 af Peak Elev=401.88' Storage=60,087 cf Inflow=26.39 cfs 1.392 afPond P-1: Existing North Pond Outflow=11.03 cfs 1.331 af Peak Elev=388.57' Storage=20,011 cf Inflow=17.73 cfs 1.359 afPond P-2: Enlarged Pond with OCS Outflow=5.07 cfs 1.123 af Peak Elev=394.38' Storage=2,731 cf Inflow=7.68 cfs 0.361 afPond SMP-1: Bioretention Basin Outflow=7.18 cfs 0.317 af Peak Elev=387.54' Storage=2,472 cf Inflow=1.95 cfs 0.088 afPond SMP-2: Bioretention Basin Outflow=0.12 cfs 0.032 af Peak Elev=387.53' Storage=1,582 cf Inflow=1.19 cfs 0.053 afPond SMP-3: Bioretention Basin Outflow=0.06 cfs 0.017 af Peak Elev=382.64' Inflow=13.61 cfs 0.934 afPond SMP-4: CS-5 24.0" Round Culvert n=0.012 L=70.0' S=0.0047 '/' Outflow=13.61 cfs 0.934 af Peak Elev=402.83' Inflow=1.03 cfs 0.046 afPond YD-3: 12" 12.0" Round Culvert n=0.012 L=67.0' S=0.0100 '/' Outflow=1.03 cfs 0.046 af Inflow=1.00 cfs 0.045 afLink AP-1: AP-1 Primary=1.00 cfs 0.045 af Inflow=59.23 cfs 4.622 afLink AP-2: AP-2 Primary=59.23 cfs 4.622 af Total Runoff Area = 30.983 ac Runoff Volume = 5.149 af Average Runoff Depth = 1.99" 59.08% Pervious = 18.305 ac 40.92% Impervious = 12.678 ac Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 31HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Subcat 1 Runoff = 26.39 cfs @ 12.04 hrs, Volume= 1.392 af, Depth> 1.61" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 8.011 74 >75% Grass cover, Good, HSG C 2.335 98 Paved parking, HSG C 10.347 79 Weighted Average 8.011 77.43% Pervious Area 2.335 22.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.4 820 0.0600 1.20 Lag/CN Method, Summary for Subcatchment 1.1: Subcat 1.1 Runoff = 25.34 cfs @ 11.97 hrs, Volume= 1.131 af, Depth> 1.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 5.391 74 >75% Grass cover, Good, HSG C 2.309 98 Paved parking, HSG C 7.700 81 Weighted Average 5.391 70.01% Pervious Area 2.309 29.99% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2: Subcat 2 Runoff = 18.56 cfs @ 11.96 hrs, Volume= 0.917 af, Depth> 2.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.684 74 >75% Grass cover, Good, HSG C 3.127 98 Paved parking, HSG C 3.811 94 Weighted Average 0.684 17.95% Pervious Area 3.127 82.05% Impervious Area Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 32HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2a: Subcat 2a Runoff = 1.03 cfs @ 11.97 hrs, Volume= 0.046 af, Depth> 1.91" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.177 74 >75% Grass cover, Good, HSG C 0.114 98 Paved parking, HSG C 0.291 83 Weighted Average 0.177 60.83% Pervious Area 0.114 39.17% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2b: Subcat 2b Runoff = 1.55 cfs @ 11.97 hrs, Volume= 0.069 af, Depth> 1.84" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.299 74 >75% Grass cover, Good, HSG C 0.153 98 Paved parking, HSG C 0.452 82 Weighted Average 0.299 66.15% Pervious Area 0.153 33.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2c: Subcat 2c Runoff = 7.51 cfs @ 11.97 hrs, Volume= 0.349 af, Depth> 2.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 33HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area (ac) CN Description 0.721 74 >75% Grass cover, Good, HSG C 1.075 98 Paved parking, HSG C 1.795 88 Weighted Average 0.721 40.13% Pervious Area 1.075 59.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 3: Subcat 3 Runoff = 8.09 cfs @ 11.96 hrs, Volume= 0.399 af, Depth> 2.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.270 74 >75% Grass cover, Good, HSG C 1.390 98 Paved parking, HSG C 1.660 94 Weighted Average 0.270 16.29% Pervious Area 1.390 83.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 4: Subcat 4 Runoff = 2.66 cfs @ 11.97 hrs, Volume= 0.124 af, Depth> 2.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.236 74 >75% Grass cover, Good, HSG C 0.380 98 Paved parking, HSG C 0.617 89 Weighted Average 0.236 38.33% Pervious Area 0.380 61.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 34HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 5: Subcat 5 Runoff = 0.81 cfs @ 11.96 hrs, Volume= 0.042 af, Depth> 3.24" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.000 74 >75% Grass cover, Good, HSG C 0.157 98 Paved parking, HSG C 0.157 98 Weighted Average 0.000 0.00% Pervious Area 0.157 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5.1: Subcat 5.1 Runoff = 2.68 cfs @ 11.96 hrs, Volume= 0.140 af, Depth> 3.24" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.002 74 >75% Grass cover, Good, HSG C 0.518 98 Paved parking, HSG C 0.519 98 Weighted Average 0.002 0.30% Pervious Area 0.518 99.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5.2: Subcat 5.2 Runoff = 2.28 cfs @ 11.96 hrs, Volume= 0.119 af, Depth> 3.24" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.005 74 >75% Grass cover, Good, HSG C 0.437 98 Paved parking, HSG C 0.442 98 Weighted Average 0.005 1.13% Pervious Area 0.437 98.87% Impervious Area Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 35HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5.3: Subcat 5.3 Runoff = 0.95 cfs @ 11.96 hrs, Volume= 0.049 af, Depth> 3.24" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.183 98 Paved parking, HSG C 0.183 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 6: Subcat 6 Runoff = 1.19 cfs @ 11.97 hrs, Volume= 0.053 af, Depth> 1.69" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.275 74 >75% Grass cover, Good, HSG C 0.102 98 Paved parking, HSG C 0.376 80 Weighted Average 0.275 72.99% Pervious Area 0.102 27.01% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 7: Subcat 7 Runoff = 2.69 cfs @ 11.98 hrs, Volume= 0.117 af, Depth> 1.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 36HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area (ac) CN Description 0.424 74 >75% Grass cover, Good, HSG C 0.102 98 Paved parking, HSG C 0.565 70 Woods, Good, HSG C 1.091 74 Weighted Average 0.989 90.63% Pervious Area 0.102 9.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 7.1: Subcat 7.1 Runoff = 1.56 cfs @ 11.98 hrs, Volume= 0.068 af, Depth> 1.22" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.545 74 >75% Grass cover, Good, HSG C 0.121 70 Woods, Good, HSG C 0.666 73 Weighted Average 0.666 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 8: Subcat 8 Runoff = 1.95 cfs @ 11.97 hrs, Volume= 0.088 af, Depth> 1.84" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.372 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking, HSG C 0.572 82 Weighted Average 0.372 64.97% Pervious Area 0.200 35.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 37HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 9: Subcat 9 Runoff = 1.00 cfs @ 11.97 hrs, Volume= 0.045 af, Depth> 1.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75" Area (ac) CN Description 0.182 74 >75% Grass cover, Good, HSG C 0.097 98 Paved parking, HSG C 0.025 70 Woods, Good, HSG C 0.304 81 Weighted Average 0.207 68.06% Pervious Area 0.097 31.94% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Reach S-1: N Pond to Outlet Inflow Area = 18.047 ac, 25.74% Impervious, Inflow Depth > 1.64" for 10YR event Inflow = 30.10 cfs @ 11.99 hrs, Volume= 2.462 af Outflow = 29.86 cfs @ 12.00 hrs, Volume= 2.457 af, Atten= 1%, Lag= 0.8 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 5.73 fps, Min. Travel Time= 1.1 min Avg. Velocity = 2.03 fps, Avg. Travel Time= 3.1 min Peak Storage= 1,981 cf @ 12.00 hrs Average Depth at Peak Storage= 0.83' Bank-Full Depth= 4.00' Flow Area= 44.0 sf, Capacity= 578.56 cfs 5.00' x 4.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 17.00' Length= 380.0' Slope= 0.0237 '/' Inlet Invert= 399.00', Outlet Invert= 390.00' Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 38HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Reach S-2: Outlet to Inlet from SMP-1 Inflow Area = 19.755 ac, 25.95% Impervious, Inflow Depth > 0.86" for 10YR event Inflow = 18.83 cfs @ 11.99 hrs, Volume= 1.408 af Outflow = 18.80 cfs @ 12.00 hrs, Volume= 1.407 af, Atten= 0%, Lag= 0.3 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 3.79 fps, Min. Travel Time= 0.4 min Avg. Velocity = 1.19 fps, Avg. Travel Time= 1.3 min Peak Storage= 456 cf @ 12.00 hrs Average Depth at Peak Storage= 0.80' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 628.01 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 92.0' Slope= 0.0109 '/' Inlet Invert= 388.00', Outlet Invert= 387.00' Summary for Reach S-3: Inlet from SMP-1 to Inlet from Pond Inflow Area = 21.415 ac, 30.43% Impervious, Inflow Depth > 0.97" for 10YR event Inflow = 25.98 cfs @ 12.00 hrs, Volume= 1.724 af Outflow = 25.64 cfs @ 12.01 hrs, Volume= 1.721 af, Atten= 1%, Lag= 0.8 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 3.78 fps, Min. Travel Time= 1.1 min Avg. Velocity = 1.13 fps, Avg. Travel Time= 3.6 min Peak Storage= 1,652 cf @ 12.01 hrs Average Depth at Peak Storage= 1.03' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 545.36 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 244.0' Slope= 0.0082 '/' Inlet Invert= 386.50', Outlet Invert= 384.50' Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 39HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Reach S-4: Inlet from Pond to AP-2 Inflow Area = 22.081 ac, 29.51% Impervious, Inflow Depth > 1.55" for 10YR event Inflow = 27.46 cfs @ 12.02 hrs, Volume= 2.844 af Outflow = 27.36 cfs @ 12.04 hrs, Volume= 2.840 af, Atten= 0%, Lag= 0.8 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 4.03 fps, Min. Travel Time= 0.9 min Avg. Velocity = 1.41 fps, Avg. Travel Time= 2.5 min Peak Storage= 1,458 cf @ 12.04 hrs Average Depth at Peak Storage= 1.03' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 580.98 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 215.0' Slope= 0.0093 '/' Inlet Invert= 384.00', Outlet Invert= 382.00' Summary for Pond 3P: YD-2/Trench Drains Inflow Area = 0.452 ac, 33.85% Impervious, Inflow Depth > 1.84" for 10YR event Inflow = 1.55 cfs @ 11.97 hrs, Volume= 0.069 af Outflow = 1.55 cfs @ 11.97 hrs, Volume= 0.069 af, Atten= 0%, Lag= 0.0 min Primary = 1.55 cfs @ 11.97 hrs, Volume= 0.069 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 396.33' @ 12.06 hrs Device Routing Invert Outlet Devices #1 Primary 387.00'12.0" Round Culvert L= 101.0' Ke= 0.500 Inlet / Outlet Invert= 387.00' / 386.20' S= 0.0079 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.00 cfs @ 11.97 hrs HW=391.92' TW=394.92' (Dynamic Tailwater) 1=Culvert ( Controls 0.00 cfs) Summary for Pond CB-2: 24" Inflow Area = 3.967 ac, 82.76% Impervious, Inflow Depth > 2.90" for 10YR event Inflow = 19.37 cfs @ 11.96 hrs, Volume= 0.959 af Outflow = 19.37 cfs @ 11.96 hrs, Volume= 0.959 af, Atten= 0%, Lag= 0.0 min Primary = 19.37 cfs @ 11.96 hrs, Volume= 0.959 af Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 40HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 387.44' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 383.26'24.0" Round Culvert L= 171.0' Ke= 0.500 Inlet / Outlet Invert= 383.26' / 382.30' S= 0.0056 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=14.04 cfs @ 11.96 hrs HW=386.82' TW=385.79' (Dynamic Tailwater) 1=Culvert (Outlet Controls 14.04 cfs @ 4.47 fps) Summary for Pond CB-4: 24" Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 2.93" for 10YR event Inflow = 21.65 cfs @ 11.96 hrs, Volume= 1.078 af Outflow = 21.65 cfs @ 11.96 hrs, Volume= 1.078 af, Atten= 0%, Lag= 0.0 min Primary = 21.65 cfs @ 11.96 hrs, Volume= 1.078 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 385.97' @ 11.98 hrs Device Routing Invert Outlet Devices #1 Primary 382.20'24.0" Round Culvert L= 81.0' Ke= 0.500 Inlet / Outlet Invert= 382.20' / 381.73' S= 0.0058 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=19.36 cfs @ 11.96 hrs HW=385.79' TW=384.15' (Dynamic Tailwater) 1=Culvert (Inlet Controls 19.36 cfs @ 6.16 fps) Summary for Pond CB-5: 18" Inflow Area = 4.189 ac, 55.97% Impervious, Inflow Depth > 2.02" for 10YR event Inflow = 13.71 cfs @ 11.97 hrs, Volume= 0.703 af Outflow = 13.71 cfs @ 11.97 hrs, Volume= 0.703 af, Atten= 0%, Lag= 0.0 min Primary = 13.71 cfs @ 11.97 hrs, Volume= 0.703 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 385.72' @ 11.98 hrs Device Routing Invert Outlet Devices #1 Primary 381.63'18.0" Round Culvert L= 97.0' Ke= 0.500 Inlet / Outlet Invert= 381.63' / 380.88' S= 0.0077 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.77 sf Primary OutFlow Max=12.68 cfs @ 11.97 hrs HW=385.43' TW=383.02' (Dynamic Tailwater) 1=Culvert (Outlet Controls 12.68 cfs @ 7.18 fps) Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 41HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond CB-6: 15" Inflow Area = 2.722 ac, 56.03% Impervious, Inflow Depth > 2.26" for 10YR event Inflow = 11.03 cfs @ 11.97 hrs, Volume= 0.514 af Outflow = 11.03 cfs @ 11.97 hrs, Volume= 0.514 af, Atten= 0%, Lag= 0.0 min Primary = 11.03 cfs @ 11.97 hrs, Volume= 0.514 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 389.94' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 383.00'15.0" Round Culvert L= 127.0' Ke= 0.500 Inlet / Outlet Invert= 383.00' / 381.73' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=9.58 cfs @ 11.97 hrs HW=389.24' TW=385.43' (Dynamic Tailwater) 1=Culvert (Outlet Controls 9.58 cfs @ 7.81 fps) Summary for Pond CB-7: 12" Inflow Area = 1.795 ac, 59.87% Impervious, Inflow Depth > 2.33" for 10YR event Inflow = 7.51 cfs @ 11.97 hrs, Volume= 0.349 af Outflow = 7.51 cfs @ 11.97 hrs, Volume= 0.349 af, Atten= 0%, Lag= 0.0 min Primary = 7.51 cfs @ 11.97 hrs, Volume= 0.349 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 406.13' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 396.58'12.0" Round Culvert L= 49.0' Ke= 0.500 Inlet / Outlet Invert= 396.58' / 396.09' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=5.61 cfs @ 11.97 hrs HW=404.63' TW=402.41' (Dynamic Tailwater) 1=Culvert (Outlet Controls 5.61 cfs @ 7.14 fps) Summary for Pond CB-8: 12" Inflow Area = 1.795 ac, 59.87% Impervious, Inflow Depth > 2.33" for 10YR event Inflow = 7.51 cfs @ 11.97 hrs, Volume= 0.349 af Outflow = 7.51 cfs @ 11.97 hrs, Volume= 0.349 af, Atten= 0%, Lag= 0.0 min Primary = 7.51 cfs @ 11.97 hrs, Volume= 0.349 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 408.96' @ 12.02 hrs Device Routing Invert Outlet Devices #1 Primary 397.58'12.0" Round Culvert L= 90.0' Ke= 0.500 Inlet / Outlet Invert= 397.58' / 396.68' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 42HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=4.70 cfs @ 11.97 hrs HW=406.81' TW=404.63' (Dynamic Tailwater) 1=Culvert (Outlet Controls 4.70 cfs @ 5.99 fps) Summary for Pond DMH-1: 24" Inflow Area = 4.189 ac, 55.97% Impervious, Inflow Depth > 2.43" for 10YR event Inflow = 22.51 cfs @ 11.96 hrs, Volume= 0.848 af Outflow = 22.51 cfs @ 11.96 hrs, Volume= 0.848 af, Atten= 0%, Lag= 0.0 min Primary = 22.51 cfs @ 11.96 hrs, Volume= 0.848 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 383.10' @ 11.96 hrs Device Routing Invert Outlet Devices #1 Primary 380.62'30.0" Round Culvert L= 80.0' Ke= 0.500 Inlet / Outlet Invert= 380.62' / 380.22' S= 0.0050 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 4.91 sf Primary OutFlow Max=21.84 cfs @ 11.96 hrs HW=383.05' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 21.84 cfs @ 5.70 fps) Summary for Pond DMH-2: 24" Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 2.93" for 10YR event Inflow = 21.65 cfs @ 11.96 hrs, Volume= 1.078 af Outflow = 21.65 cfs @ 11.96 hrs, Volume= 1.078 af, Atten= 0%, Lag= 0.0 min Primary = 13.61 cfs @ 11.98 hrs, Volume= 0.934 af Secondary = 8.86 cfs @ 11.95 hrs, Volume= 0.145 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 383.30' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 380.60'24.0" Round Culvert L= 10.0' Ke= 0.500 Inlet / Outlet Invert= 380.60' / 380.55' S= 0.0050 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf #2 Secondary 381.39'24.0" Round Culvert L= 10.0' Ke= 0.500 Inlet / Outlet Invert= 381.39' / 381.34' S= 0.0050 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=12.08 cfs @ 11.98 hrs HW=383.21' TW=382.58' (Dynamic Tailwater) 1=Culvert (Inlet Controls 12.08 cfs @ 3.85 fps) Secondary OutFlow Max=1.88 cfs @ 11.95 hrs HW=383.09' TW=383.07' (Dynamic Tailwater) 2=Culvert (Outlet Controls 1.88 cfs @ 0.89 fps) Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 43HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond DMH-3: 30" Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 2.93" for 10YR event Inflow = 21.65 cfs @ 11.96 hrs, Volume= 1.078 af Outflow = 21.65 cfs @ 11.96 hrs, Volume= 1.078 af, Atten= 0%, Lag= 0.0 min Primary = 21.65 cfs @ 11.96 hrs, Volume= 1.078 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 384.24' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 381.68'30.0" Round Culvert L= 240.0' Ke= 0.500 Inlet / Outlet Invert= 381.68' / 380.65' S= 0.0043 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 4.91 sf Primary OutFlow Max=18.30 cfs @ 11.96 hrs HW=384.15' TW=383.13' (Dynamic Tailwater) 1=Culvert (Outlet Controls 18.30 cfs @ 4.70 fps) Summary for Pond DMH-5: 15" Inflow Area = 2.722 ac, 56.03% Impervious, Inflow Depth > 2.26" for 10YR event Inflow = 11.03 cfs @ 11.97 hrs, Volume= 0.514 af Outflow = 11.03 cfs @ 11.97 hrs, Volume= 0.514 af, Atten= 0%, Lag= 0.0 min Primary = 11.03 cfs @ 11.97 hrs, Volume= 0.514 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 392.66' @ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 384.40'15.0" Round Culvert L= 91.0' Ke= 0.500 Inlet / Outlet Invert= 384.40' / 383.67' S= 0.0080 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=7.09 cfs @ 11.97 hrs HW=390.96' TW=389.24' (Dynamic Tailwater) 1=Culvert (Outlet Controls 7.09 cfs @ 5.78 fps) Summary for Pond DMH-6: 15" Inflow Area = 2.722 ac, 56.03% Impervious, Inflow Depth > 2.26" for 10YR event Inflow = 11.03 cfs @ 11.97 hrs, Volume= 0.514 af Outflow = 11.03 cfs @ 11.97 hrs, Volume= 0.514 af, Atten= 0%, Lag= 0.0 min Primary = 11.03 cfs @ 11.97 hrs, Volume= 0.514 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 396.25' @ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 386.10'15.0" Round Culvert L= 201.0' Ke= 0.500 Inlet / Outlet Invert= 386.10' / 384.50' S= 0.0080 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 44HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=8.18 cfs @ 11.97 hrs HW=394.76' TW=390.96' (Dynamic Tailwater) 1=Culvert (Outlet Controls 8.18 cfs @ 6.67 fps) Summary for Pond DMH-7: 12" Inflow Area = 2.086 ac, 56.99% Impervious, Inflow Depth > 2.27" for 10YR event Inflow = 8.54 cfs @ 11.97 hrs, Volume= 0.395 af Outflow = 8.54 cfs @ 11.97 hrs, Volume= 0.395 af, Atten= 0%, Lag= 0.0 min Primary = 8.54 cfs @ 11.97 hrs, Volume= 0.395 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 402.76' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 395.99'12.0" Round Culvert L= 78.0' Ke= 0.500 Inlet / Outlet Invert= 395.99' / 395.21' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=8.28 cfs @ 11.97 hrs HW=402.40' TW=394.75' (Dynamic Tailwater) 1=Culvert (Barrel Controls 8.28 cfs @ 10.55 fps) Summary for Pond FB-1: FB-1 Inflow Area = 1.660 ac, 83.71% Impervious, Inflow Depth > 2.89" for 10YR event Inflow = 8.09 cfs @ 11.96 hrs, Volume= 0.399 af Outflow = 7.68 cfs @ 11.98 hrs, Volume= 0.361 af, Atten= 5%, Lag= 0.8 min Primary = 7.68 cfs @ 11.98 hrs, Volume= 0.361 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 394.42' @ 12.01 hrs Surf.Area= 1,971 sf Storage= 2,393 cf Plug-Flow detention time= 60.8 min calculated for 0.359 af (90% of inflow) Center-of-Mass det. time= 27.2 min ( 774.8 - 747.6 ) Volume Invert Avail.Storage Storage Description #1 392.00' 3,728 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 392.00 225 100.0 0 0 225 393.00 820 165.0 492 492 1,602 394.00 1,550 195.0 1,166 1,657 2,480 395.00 2,640 250.0 2,071 3,728 4,441 Device Routing Invert Outlet Devices #1 Primary 394.00'18.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 45HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=5.47 cfs @ 11.98 hrs HW=394.40' TW=394.36' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 5.47 cfs @ 0.76 fps) Summary for Pond OUTLET: Outlet Stream/Pond Inflow Area = 18.664 ac, 26.92% Impervious, Inflow Depth > 1.66" for 10YR event Inflow = 32.39 cfs @ 12.00 hrs, Volume= 2.582 af Outflow = 32.39 cfs @ 12.00 hrs, Volume= 2.582 af, Atten= 0%, Lag= 0.0 min Primary = 16.19 cfs @ 12.00 hrs, Volume= 1.291 af Secondary = 16.19 cfs @ 12.00 hrs, Volume= 1.291 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 390.00' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 389.00'6.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Secondary 389.00'6.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=16.01 cfs @ 12.00 hrs HW=390.00' TW=388.79' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 16.01 cfs @ 2.68 fps) Secondary OutFlow Max=16.01 cfs @ 12.00 hrs HW=390.00' TW=387.65' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir (Weir Controls 16.01 cfs @ 2.68 fps) Summary for Pond P-1: Existing North Pond Inflow Area = 10.347 ac, 22.57% Impervious, Inflow Depth > 1.61" for 10YR event Inflow = 26.39 cfs @ 12.04 hrs, Volume= 1.392 af Outflow = 11.03 cfs @ 12.20 hrs, Volume= 1.331 af, Atten= 58%, Lag= 9.7 min Primary = 11.03 cfs @ 12.20 hrs, Volume= 1.331 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Starting Elev= 401.00' Surf.Area= 22,263 sf Storage= 39,555 cf Peak Elev= 401.88' @ 12.20 hrs Surf.Area= 24,495 sf Storage= 60,087 cf (20,532 cf above start) Plug-Flow detention time= 277.5 min calculated for 0.421 af (30% of inflow) Center-of-Mass det. time= 33.5 min ( 828.9 - 795.4 ) Volume Invert Avail.Storage Storage Description #1 399.00' 117,925 cf Custom Stage Data (Irregular) Listed below (Recalc) Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 46HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 399.00 17,348 799.0 0 0 17,348 400.00 19,775 819.0 18,548 18,548 20,047 401.00 22,263 839.0 21,007 39,555 22,813 402.00 24,812 859.0 23,526 63,081 25,646 403.00 27,418 878.0 26,104 89,185 28,412 404.00 30,082 897.0 28,740 117,925 31,239 Device Routing Invert Outlet Devices #1 Primary 401.00'5.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Primary OutFlow Max=11.02 cfs @ 12.20 hrs HW=401.88' TW=399.57' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 11.02 cfs @ 2.51 fps) Summary for Pond P-2: Enlarged Pond with OCS Inflow Area = 0.666 ac, 0.00% Impervious, Inflow Depth > 24.47" for 10YR event Inflow = 17.73 cfs @ 11.99 hrs, Volume= 1.359 af Outflow = 5.07 cfs @ 12.56 hrs, Volume= 1.123 af, Atten= 71%, Lag= 33.8 min Primary = 5.07 cfs @ 12.56 hrs, Volume= 1.123 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 388.57' @ 12.56 hrs Surf.Area= 9,740 sf Storage= 20,011 cf Plug-Flow detention time= 95.3 min calculated for 1.119 af (82% of inflow) Center-of-Mass det. time= 45.7 min ( 854.3 - 808.5 ) Volume Invert Avail.Storage Storage Description #1 386.00' 48,113 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 386.00 5,878 348.0 0 0 5,878 387.00 7,311 402.0 6,581 6,581 9,123 387.40 7,985 441.0 3,058 9,640 11,744 388.00 8,931 483.0 5,072 14,712 14,845 389.00 10,379 517.0 9,646 24,358 17,596 390.00 11,869 542.0 11,116 35,473 19,769 391.00 13,427 562.0 12,640 48,113 21,611 Device Routing Invert Outlet Devices #1 Primary 386.00'24.0" Round Culvert L= 60.0' Ke= 0.500 Inlet / Outlet Invert= 386.00' / 385.50' S= 0.0083 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf #2 Device 1 386.00'3.0" W x 3.0" H Vert. Orifice/Grate C= 0.600 #3 Device 1 387.40'24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 389.00'24.0" Horiz. Orifice/Grate C= 0.600 Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 47HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Limited to weir flow at low heads Primary OutFlow Max=5.07 cfs @ 12.56 hrs HW=388.57' TW=384.62' (Dynamic Tailwater) 1=Culvert (Passes 5.07 cfs of 18.62 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.47 cfs @ 7.52 fps) 3=Orifice/Grate (Orifice Controls 4.60 cfs @ 4.60 fps) 4=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond SMP-1: Bioretention Basin Inflow Area = 1.660 ac, 83.71% Impervious, Inflow Depth > 2.61" for 10YR event Inflow = 7.68 cfs @ 11.98 hrs, Volume= 0.361 af Outflow = 7.18 cfs @ 12.00 hrs, Volume= 0.317 af, Atten= 7%, Lag= 1.3 min Primary = 7.18 cfs @ 12.00 hrs, Volume= 0.317 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 394.38' @ 12.00 hrs Surf.Area= 2,480 sf Storage= 2,731 cf Plug-Flow detention time= 54.0 min calculated for 0.317 af (88% of inflow) Center-of-Mass det. time= 16.2 min ( 791.0 - 774.8 ) Volume Invert Avail.Storage Storage Description #1 393.00' 4,422 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 393.00 1,500 155.0 0 0 1,500 394.00 2,210 185.0 1,844 1,844 2,329 394.50 2,570 196.0 1,194 3,037 2,676 395.00 2,975 205.0 1,385 4,422 2,980 Device Routing Invert Outlet Devices #1 Device 2 394.00'30.0" x 30.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 389.73'12.0" Round Culvert L= 69.0' Ke= 0.500 Inlet / Outlet Invert= 389.73' / 389.04' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=7.18 cfs @ 12.00 hrs HW=394.38' TW=387.53' (Dynamic Tailwater) 2=Culvert (Barrel Controls 7.18 cfs @ 9.14 fps) 1=Orifice/Grate (Passes 7.18 cfs of 7.57 cfs potential flow) Summary for Pond SMP-2: Bioretention Basin Inflow Area = 0.572 ac, 35.03% Impervious, Inflow Depth > 1.84" for 10YR event Inflow = 1.95 cfs @ 11.97 hrs, Volume= 0.088 af Outflow = 0.12 cfs @ 12.87 hrs, Volume= 0.032 af, Atten= 94%, Lag= 54.2 min Primary = 0.12 cfs @ 12.87 hrs, Volume= 0.032 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 48HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Peak Elev= 387.54' @ 12.87 hrs Surf.Area= 2,227 sf Storage= 2,472 cf Plug-Flow detention time= 218.7 min calculated for 0.032 af (37% of inflow) Center-of-Mass det. time= 133.2 min ( 917.6 - 784.4 ) Volume Invert Avail.Storage Storage Description #1 386.00' 3,576 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 386.00 1,025 175.0 0 0 1,025 387.00 1,776 200.0 1,383 1,383 1,794 387.50 2,190 213.0 990 2,373 2,234 388.00 2,628 225.0 1,203 3,576 2,666 Device Routing Invert Outlet Devices #1 Device 2 387.50'15.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 381.63'18.0" Round Culvert L= 97.0' Ke= 0.500 Inlet / Outlet Invert= 381.63' / 380.88' S= 0.0077 '/' Cc= 0.900 n= 0.012, Flow Area= 1.77 sf Primary OutFlow Max=0.12 cfs @ 12.87 hrs HW=387.54' TW=382.06' (Dynamic Tailwater) 2=Culvert (Passes 0.12 cfs of 18.57 cfs potential flow) 1=Orifice/Grate (Weir Controls 0.12 cfs @ 0.69 fps) Summary for Pond SMP-3: Bioretention Basin Inflow Area = 0.376 ac, 27.01% Impervious, Inflow Depth > 1.69" for 10YR event Inflow = 1.19 cfs @ 11.97 hrs, Volume= 0.053 af Outflow = 0.06 cfs @ 13.31 hrs, Volume= 0.017 af, Atten= 95%, Lag= 80.1 min Primary = 0.06 cfs @ 13.31 hrs, Volume= 0.017 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 387.53' @ 13.31 hrs Surf.Area= 1,505 sf Storage= 1,582 cf Plug-Flow detention time= 241.9 min calculated for 0.017 af (32% of inflow) Center-of-Mass det. time= 154.5 min ( 943.5 - 789.0 ) Volume Invert Avail.Storage Storage Description #1 386.00' 2,509 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 386.00 643 117.0 0 0 643 387.00 1,160 142.0 889 889 1,174 387.50 1,457 154.0 653 1,542 1,466 388.00 2,455 213.0 967 2,509 3,192 Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 49HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Device 2 387.50'15.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 383.00'15.0" Round Culvert L= 127.0' Ke= 0.500 Inlet / Outlet Invert= 383.00' / 381.73' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=0.06 cfs @ 13.31 hrs HW=387.53' TW=382.02' (Dynamic Tailwater) 2=Culvert (Passes 0.06 cfs of 10.47 cfs potential flow) 1=Orifice/Grate (Weir Controls 0.06 cfs @ 0.54 fps) Summary for Pond SMP-4: CS-5 Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 2.54" for 10YR event Inflow = 13.61 cfs @ 11.98 hrs, Volume= 0.934 af Outflow = 13.61 cfs @ 11.98 hrs, Volume= 0.934 af, Atten= 0%, Lag= 0.0 min Primary = 13.61 cfs @ 11.98 hrs, Volume= 0.934 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 382.64' @ 11.98 hrs Device Routing Invert Outlet Devices #1 Primary 380.55'24.0" Round Culvert L= 70.0' Ke= 0.500 Inlet / Outlet Invert= 380.55' / 380.22' S= 0.0047 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=13.04 cfs @ 11.98 hrs HW=382.58' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 13.04 cfs @ 5.09 fps) Summary for Pond YD-3: 12" Inflow Area = 0.291 ac, 39.17% Impervious, Inflow Depth > 1.91" for 10YR event Inflow = 1.03 cfs @ 11.97 hrs, Volume= 0.046 af Outflow = 1.03 cfs @ 11.97 hrs, Volume= 0.046 af, Atten= 0%, Lag= 0.0 min Primary = 1.03 cfs @ 11.97 hrs, Volume= 0.046 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 402.83' @ 12.02 hrs Device Routing Invert Outlet Devices #1 Primary 396.98'12.0" Round Culvert L= 67.0' Ke= 0.500 Inlet / Outlet Invert= 396.98' / 396.31' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.00 cfs @ 11.97 hrs HW=401.14' TW=402.37' (Dynamic Tailwater) 1=Culvert ( Controls 0.00 cfs) Type II 24-hr 10YR Rainfall=3.75"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 50HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Link AP-1: AP-1 Inflow Area = 0.304 ac, 31.94% Impervious, Inflow Depth > 1.76" for 10YR event Inflow = 1.00 cfs @ 11.97 hrs, Volume= 0.045 af Primary = 1.00 cfs @ 11.97 hrs, Volume= 0.045 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link AP-2: AP-2 Inflow Area = 30.679 ac, 41.01% Impervious, Inflow Depth > 1.81" for 10YR event Inflow = 59.23 cfs @ 11.99 hrs, Volume= 4.622 af Primary = 59.23 cfs @ 11.99 hrs, Volume= 4.622 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 1HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=10.347 ac 22.57% Impervious Runoff Depth>3.58"Subcatchment 1: Subcat 1 Flow Length=820' Slope=0.0600 '/' Tc=11.4 min CN=79 Runoff=57.15 cfs 3.088 af Runoff Area=7.700 ac 29.99% Impervious Runoff Depth>3.79"Subcatchment 1.1: Subcat 1.1 Tc=6.0 min CN=81 Runoff=52.57 cfs 2.432 af Runoff Area=3.811 ac 82.05% Impervious Runoff Depth>5.12"Subcatchment 2: Subcat 2 Tc=6.0 min CN=94 Runoff=31.92 cfs 1.627 af Runoff Area=0.291 ac 39.17% Impervious Runoff Depth>4.00"Subcatchment 2a: Subcat 2a Tc=6.0 min CN=83 Runoff=2.07 cfs 0.097 af Runoff Area=0.452 ac 33.85% Impervious Runoff Depth>3.89"Subcatchment 2b: Subcat 2b Tc=6.0 min CN=82 Runoff=3.15 cfs 0.147 af Runoff Area=1.795 ac 59.87% Impervious Runoff Depth>4.52"Subcatchment 2c: Subcat 2c Tc=6.0 min CN=88 Runoff=13.96 cfs 0.676 af Runoff Area=1.660 ac 83.71% Impervious Runoff Depth>5.12"Subcatchment 3: Subcat 3 Tc=6.0 min CN=94 Runoff=13.91 cfs 0.709 af Runoff Area=0.617 ac 61.67% Impervious Runoff Depth>4.62"Subcatchment 4: Subcat 4 Tc=6.0 min CN=89 Runoff=4.87 cfs 0.238 af Runoff Area=0.157 ac 100.00% Impervious Runoff Depth>5.45"Subcatchment 5: Subcat 5 Tc=6.0 min CN=98 Runoff=1.35 cfs 0.071 af Runoff Area=0.519 ac 99.70% Impervious Runoff Depth>5.45"Subcatchment 5.1: Subcat 5.1 Tc=6.0 min CN=98 Runoff=4.46 cfs 0.236 af Runoff Area=0.442 ac 98.87% Impervious Runoff Depth>5.45"Subcatchment 5.2: Subcat 5.2 Tc=6.0 min CN=98 Runoff=3.80 cfs 0.200 af Runoff Area=0.183 ac 100.00% Impervious Runoff Depth>5.45"Subcatchment 5.3: Subcat 5.3 Tc=6.0 min CN=98 Runoff=1.57 cfs 0.083 af Runoff Area=0.376 ac 27.01% Impervious Runoff Depth>3.69"Subcatchment 6: Subcat 6 Tc=6.0 min CN=80 Runoff=2.51 cfs 0.116 af Runoff Area=1.091 ac 9.37% Impervious Runoff Depth>3.10"Subcatchment 7: Subcat 7 Tc=6.0 min CN=74 Runoff=6.28 cfs 0.282 af Runoff Area=0.666 ac 0.00% Impervious Runoff Depth>3.00"Subcatchment 7.1: Subcat 7.1 Tc=6.0 min CN=73 Runoff=3.73 cfs 0.167 af Runoff Area=0.572 ac 35.03% Impervious Runoff Depth>3.89"Subcatchment 8: Subcat 8 Tc=6.0 min CN=82 Runoff=3.99 cfs 0.185 af Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 2HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Runoff Area=0.304 ac 31.94% Impervious Runoff Depth>3.79"Subcatchment 9: Subcat 9 Tc=6.0 min CN=81 Runoff=2.08 cfs 0.096 af Avg. Flow Depth=1.32' Max Vel=7.33 fps Inflow=67.79 cfs 5.428 afReach S-1: N Pond to Outlet n=0.030 L=380.0' S=0.0237 '/' Capacity=578.56 cfs Outflow=67.61 cfs 5.421 af Avg. Flow Depth=1.26' Max Vel=4.84 fps Inflow=41.99 cfs 3.218 afReach S-2: Outlet to Inlet from SMP-1 n=0.030 L=92.0' S=0.0109 '/' Capacity=628.01 cfs Outflow=42.04 cfs 3.217 af Avg. Flow Depth=1.49' Max Vel=4.59 fps Inflow=49.67 cfs 3.843 afReach S-3: Inlet from SMP-1 to Inlet n=0.030 L=244.0' S=0.0082 '/' Capacity=545.36 cfs Outflow=49.37 cfs 3.838 af Avg. Flow Depth=1.69' Max Vel=5.24 fps Inflow=66.41 cfs 6.472 afReach S-4: Inlet from Pond to AP-2 n=0.030 L=215.0' S=0.0093 '/' Capacity=580.98 cfs Outflow=66.73 cfs 6.466 af Peak Elev=432.67' Inflow=3.15 cfs 0.147 afPond 3P: YD-2/Trench Drains 12.0" Round Culvert n=0.012 L=101.0' S=0.0079 '/' Outflow=3.15 cfs 0.147 af Peak Elev=395.70' Inflow=33.27 cfs 1.698 afPond CB-2: 24" 24.0" Round Culvert n=0.012 L=171.0' S=0.0056 '/' Outflow=33.27 cfs 1.698 af Peak Elev=391.96' Inflow=37.07 cfs 1.899 afPond CB-4: 24" 24.0" Round Culvert n=0.012 L=81.0' S=0.0058 '/' Outflow=37.07 cfs 1.899 af Peak Elev=395.16' Inflow=26.33 cfs 1.448 afPond CB-5: 18" 18.0" Round Culvert n=0.012 L=97.0' S=0.0077 '/' Outflow=26.33 cfs 1.448 af Peak Elev=409.41' Inflow=20.75 cfs 1.003 afPond CB-6: 15" 15.0" Round Culvert n=0.012 L=127.0' S=0.0100 '/' Outflow=20.75 cfs 1.003 af Peak Elev=447.32' Inflow=13.96 cfs 0.676 afPond CB-7: 12" 12.0" Round Culvert n=0.012 L=49.0' S=0.0100 '/' Outflow=13.96 cfs 0.676 af Peak Elev=449.32' Inflow=13.96 cfs 0.676 afPond CB-8: 12" 12.0" Round Culvert n=0.012 L=90.0' S=0.0100 '/' Outflow=13.96 cfs 0.676 af Peak Elev=385.03' Inflow=41.09 cfs 1.755 afPond DMH-1: 24" 30.0" Round Culvert n=0.012 L=80.0' S=0.0050 '/' Outflow=41.09 cfs 1.755 af Peak Elev=385.75' Inflow=37.07 cfs 1.899 afPond DMH-2: 24" Primary=21.69 cfs 1.592 af Secondary=15.54 cfs 0.307 af Outflow=37.07 cfs 1.899 af Peak Elev=387.78' Inflow=37.07 cfs 1.899 afPond DMH-3: 30" 30.0" Round Culvert n=0.012 L=240.0' S=0.0043 '/' Outflow=37.07 cfs 1.899 af Peak Elev=419.43' Inflow=20.75 cfs 1.003 afPond DMH-5: 15" 15.0" Round Culvert n=0.012 L=91.0' S=0.0080 '/' Outflow=20.75 cfs 1.003 af Peak Elev=432.36' Inflow=20.75 cfs 1.003 afPond DMH-6: 15" 15.0" Round Culvert n=0.012 L=201.0' S=0.0080 '/' Outflow=20.75 cfs 1.003 af Peak Elev=443.63' Inflow=16.03 cfs 0.773 afPond DMH-7: 12" 12.0" Round Culvert n=0.012 L=78.0' S=0.0100 '/' Outflow=16.03 cfs 0.773 af Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 3HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Peak Elev=394.97' Storage=3,653 cf Inflow=13.91 cfs 0.709 afPond FB-1: FB-1 Outflow=12.24 cfs 0.670 af Peak Elev=390.74' Inflow=72.25 cfs 5.659 afPond OUTLET: Outlet Stream/Pond Primary=35.83 cfs 2.936 af Secondary=36.42 cfs 2.722 af Outflow=72.25 cfs 5.659 af Peak Elev=402.69' Storage=80,915 cf Inflow=57.15 cfs 3.088 afPond P-1: Existing North Pond Outflow=29.21 cfs 2.996 af Peak Elev=389.87' Storage=33,940 cf Inflow=40.09 cfs 2.889 afPond P-2: Enlarged Pond with OCS Outflow=21.86 cfs 2.633 af Peak Elev=394.97' Storage=4,326 cf Inflow=12.24 cfs 0.670 afPond SMP-1: Bioretention Basin Outflow=7.65 cfs 0.626 af Peak Elev=395.84' Storage=3,576 cf Inflow=3.99 cfs 0.185 afPond SMP-2: Bioretention Basin Outflow=3.73 cfs 0.130 af Peak Elev=395.22' Storage=2,509 cf Inflow=2.51 cfs 0.116 afPond SMP-3: Bioretention Basin Outflow=3.27 cfs 0.080 af Peak Elev=383.87' Inflow=21.69 cfs 1.592 afPond SMP-4: CS-5 24.0" Round Culvert n=0.012 L=70.0' S=0.0047 '/' Outflow=21.69 cfs 1.592 af Peak Elev=443.72' Inflow=2.07 cfs 0.097 afPond YD-3: 12" 12.0" Round Culvert n=0.012 L=67.0' S=0.0100 '/' Outflow=2.07 cfs 0.097 af Inflow=2.08 cfs 0.096 afLink AP-1: AP-1 Primary=2.08 cfs 0.096 af Inflow=120.97 cfs 9.813 afLink AP-2: AP-2 Primary=120.97 cfs 9.813 af Total Runoff Area = 30.983 ac Runoff Volume = 10.449 af Average Runoff Depth = 4.05" 59.08% Pervious = 18.305 ac 40.92% Impervious = 12.678 ac Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 4HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Subcat 1 Runoff = 57.15 cfs @ 12.03 hrs, Volume= 3.088 af, Depth> 3.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 8.011 74 >75% Grass cover, Good, HSG C 2.335 98 Paved parking, HSG C 10.347 79 Weighted Average 8.011 77.43% Pervious Area 2.335 22.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.4 820 0.0600 1.20 Lag/CN Method, Summary for Subcatchment 1.1: Subcat 1.1 Runoff = 52.57 cfs @ 11.97 hrs, Volume= 2.432 af, Depth> 3.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 5.391 74 >75% Grass cover, Good, HSG C 2.309 98 Paved parking, HSG C 7.700 81 Weighted Average 5.391 70.01% Pervious Area 2.309 29.99% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2: Subcat 2 Runoff = 31.92 cfs @ 11.96 hrs, Volume= 1.627 af, Depth> 5.12" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.684 74 >75% Grass cover, Good, HSG C 3.127 98 Paved parking, HSG C 3.811 94 Weighted Average 0.684 17.95% Pervious Area 3.127 82.05% Impervious Area Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 5HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2a: Subcat 2a Runoff = 2.07 cfs @ 11.97 hrs, Volume= 0.097 af, Depth> 4.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.177 74 >75% Grass cover, Good, HSG C 0.114 98 Paved parking, HSG C 0.291 83 Weighted Average 0.177 60.83% Pervious Area 0.114 39.17% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2b: Subcat 2b Runoff = 3.15 cfs @ 11.97 hrs, Volume= 0.147 af, Depth> 3.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.299 74 >75% Grass cover, Good, HSG C 0.153 98 Paved parking, HSG C 0.452 82 Weighted Average 0.299 66.15% Pervious Area 0.153 33.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2c: Subcat 2c Runoff = 13.96 cfs @ 11.96 hrs, Volume= 0.676 af, Depth> 4.52" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 6HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area (ac) CN Description 0.721 74 >75% Grass cover, Good, HSG C 1.075 98 Paved parking, HSG C 1.795 88 Weighted Average 0.721 40.13% Pervious Area 1.075 59.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 3: Subcat 3 Runoff = 13.91 cfs @ 11.96 hrs, Volume= 0.709 af, Depth> 5.12" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.270 74 >75% Grass cover, Good, HSG C 1.390 98 Paved parking, HSG C 1.660 94 Weighted Average 0.270 16.29% Pervious Area 1.390 83.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 4: Subcat 4 Runoff = 4.87 cfs @ 11.96 hrs, Volume= 0.238 af, Depth> 4.62" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.236 74 >75% Grass cover, Good, HSG C 0.380 98 Paved parking, HSG C 0.617 89 Weighted Average 0.236 38.33% Pervious Area 0.380 61.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 7HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 5: Subcat 5 Runoff = 1.35 cfs @ 11.96 hrs, Volume= 0.071 af, Depth> 5.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.000 74 >75% Grass cover, Good, HSG C 0.157 98 Paved parking, HSG C 0.157 98 Weighted Average 0.000 0.00% Pervious Area 0.157 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5.1: Subcat 5.1 Runoff = 4.46 cfs @ 11.96 hrs, Volume= 0.236 af, Depth> 5.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.002 74 >75% Grass cover, Good, HSG C 0.518 98 Paved parking, HSG C 0.519 98 Weighted Average 0.002 0.30% Pervious Area 0.518 99.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5.2: Subcat 5.2 Runoff = 3.80 cfs @ 11.96 hrs, Volume= 0.200 af, Depth> 5.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.005 74 >75% Grass cover, Good, HSG C 0.437 98 Paved parking, HSG C 0.442 98 Weighted Average 0.005 1.13% Pervious Area 0.437 98.87% Impervious Area Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 8HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 5.3: Subcat 5.3 Runoff = 1.57 cfs @ 11.96 hrs, Volume= 0.083 af, Depth> 5.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.183 98 Paved parking, HSG C 0.183 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 6: Subcat 6 Runoff = 2.51 cfs @ 11.97 hrs, Volume= 0.116 af, Depth> 3.69" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.275 74 >75% Grass cover, Good, HSG C 0.102 98 Paved parking, HSG C 0.376 80 Weighted Average 0.275 72.99% Pervious Area 0.102 27.01% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 7: Subcat 7 Runoff = 6.28 cfs @ 11.97 hrs, Volume= 0.282 af, Depth> 3.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 9HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Area (ac) CN Description 0.424 74 >75% Grass cover, Good, HSG C 0.102 98 Paved parking, HSG C 0.565 70 Woods, Good, HSG C 1.091 74 Weighted Average 0.989 90.63% Pervious Area 0.102 9.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 7.1: Subcat 7.1 Runoff = 3.73 cfs @ 11.97 hrs, Volume= 0.167 af, Depth> 3.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.545 74 >75% Grass cover, Good, HSG C 0.121 70 Woods, Good, HSG C 0.666 73 Weighted Average 0.666 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 8: Subcat 8 Runoff = 3.99 cfs @ 11.97 hrs, Volume= 0.185 af, Depth> 3.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.372 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking, HSG C 0.572 82 Weighted Average 0.372 64.97% Pervious Area 0.200 35.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 10HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 9: Subcat 9 Runoff = 2.08 cfs @ 11.97 hrs, Volume= 0.096 af, Depth> 3.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20" Area (ac) CN Description 0.182 74 >75% Grass cover, Good, HSG C 0.097 98 Paved parking, HSG C 0.025 70 Woods, Good, HSG C 0.304 81 Weighted Average 0.207 68.06% Pervious Area 0.097 31.94% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Reach S-1: N Pond to Outlet Inflow Area = 18.047 ac, 25.74% Impervious, Inflow Depth > 3.61" for 100YR event Inflow = 67.79 cfs @ 11.98 hrs, Volume= 5.428 af Outflow = 67.61 cfs @ 12.00 hrs, Volume= 5.421 af, Atten= 0%, Lag= 0.7 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 7.33 fps, Min. Travel Time= 0.9 min Avg. Velocity = 2.39 fps, Avg. Travel Time= 2.6 min Peak Storage= 3,502 cf @ 12.00 hrs Average Depth at Peak Storage= 1.32' Bank-Full Depth= 4.00' Flow Area= 44.0 sf, Capacity= 578.56 cfs 5.00' x 4.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 17.00' Length= 380.0' Slope= 0.0237 '/' Inlet Invert= 399.00', Outlet Invert= 390.00' Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 11HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Reach S-2: Outlet to Inlet from SMP-1 Inflow Area = 19.755 ac, 25.95% Impervious, Inflow Depth > 1.95" for 100YR event Inflow = 41.99 cfs @ 11.99 hrs, Volume= 3.218 af Outflow = 42.04 cfs @ 11.99 hrs, Volume= 3.217 af, Atten= 0%, Lag= 0.2 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 4.84 fps, Min. Travel Time= 0.3 min Avg. Velocity = 1.51 fps, Avg. Travel Time= 1.0 min Peak Storage= 798 cf @ 11.99 hrs Average Depth at Peak Storage= 1.26' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 628.01 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 92.0' Slope= 0.0109 '/' Inlet Invert= 388.00', Outlet Invert= 387.00' Summary for Reach S-3: Inlet from SMP-1 to Inlet from Pond Inflow Area = 21.415 ac, 30.43% Impervious, Inflow Depth > 2.15" for 100YR event Inflow = 49.67 cfs @ 11.99 hrs, Volume= 3.843 af Outflow = 49.37 cfs @ 12.00 hrs, Volume= 3.838 af, Atten= 1%, Lag= 0.6 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 4.59 fps, Min. Travel Time= 0.9 min Avg. Velocity = 1.44 fps, Avg. Travel Time= 2.8 min Peak Storage= 2,622 cf @ 12.00 hrs Average Depth at Peak Storage= 1.49' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 545.36 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 244.0' Slope= 0.0082 '/' Inlet Invert= 386.50', Outlet Invert= 384.50' Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 12HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Reach S-4: Inlet from Pond to AP-2 Inflow Area = 22.081 ac, 29.51% Impervious, Inflow Depth > 3.52" for 100YR event Inflow = 66.41 cfs @ 12.04 hrs, Volume= 6.472 af Outflow = 66.73 cfs @ 12.05 hrs, Volume= 6.466 af, Atten= 0%, Lag= 0.6 min Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 5.24 fps, Min. Travel Time= 0.7 min Avg. Velocity = 1.78 fps, Avg. Travel Time= 2.0 min Peak Storage= 2,739 cf @ 12.05 hrs Average Depth at Peak Storage= 1.69' Bank-Full Depth= 5.00' Flow Area= 62.5 sf, Capacity= 580.98 cfs 5.00' x 5.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 1.5 '/' Top Width= 20.00' Length= 215.0' Slope= 0.0093 '/' Inlet Invert= 384.00', Outlet Invert= 382.00' Summary for Pond 3P: YD-2/Trench Drains Inflow Area = 0.452 ac, 33.85% Impervious, Inflow Depth > 3.89" for 100YR event Inflow = 3.15 cfs @ 11.97 hrs, Volume= 0.147 af Outflow = 3.15 cfs @ 11.97 hrs, Volume= 0.147 af, Atten= 0%, Lag= 0.0 min Primary = 3.15 cfs @ 11.97 hrs, Volume= 0.147 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 432.67' @ 12.06 hrs Device Routing Invert Outlet Devices #1 Primary 387.00'12.0" Round Culvert L= 101.0' Ke= 0.500 Inlet / Outlet Invert= 387.00' / 386.20' S= 0.0079 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.00 cfs @ 11.97 hrs HW=412.39' TW=425.70' (Dynamic Tailwater) 1=Culvert ( Controls 0.00 cfs) Summary for Pond CB-2: 24" Inflow Area = 3.967 ac, 82.76% Impervious, Inflow Depth > 5.14" for 100YR event Inflow = 33.27 cfs @ 11.96 hrs, Volume= 1.698 af Outflow = 33.27 cfs @ 11.96 hrs, Volume= 1.698 af, Atten= 0%, Lag= 0.0 min Primary = 33.27 cfs @ 11.96 hrs, Volume= 1.698 af Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 13HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 395.70' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 383.26'24.0" Round Culvert L= 171.0' Ke= 0.500 Inlet / Outlet Invert= 383.26' / 382.30' S= 0.0056 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=24.30 cfs @ 11.96 hrs HW=394.13' TW=391.04' (Dynamic Tailwater) 1=Culvert (Outlet Controls 24.30 cfs @ 7.74 fps) Summary for Pond CB-4: 24" Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 5.17" for 100YR event Inflow = 37.07 cfs @ 11.96 hrs, Volume= 1.899 af Outflow = 37.07 cfs @ 11.96 hrs, Volume= 1.899 af, Atten= 0%, Lag= 0.0 min Primary = 37.07 cfs @ 11.96 hrs, Volume= 1.899 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 391.96' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 382.20'24.0" Round Culvert L= 81.0' Ke= 0.500 Inlet / Outlet Invert= 382.20' / 381.73' S= 0.0058 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=30.29 cfs @ 11.96 hrs HW=391.04' TW=387.03' (Dynamic Tailwater) 1=Culvert (Inlet Controls 30.29 cfs @ 9.64 fps) Summary for Pond CB-5: 18" Inflow Area = 4.189 ac, 55.97% Impervious, Inflow Depth > 4.15" for 100YR event Inflow = 26.33 cfs @ 11.98 hrs, Volume= 1.448 af Outflow = 26.33 cfs @ 11.98 hrs, Volume= 1.448 af, Atten= 0%, Lag= 0.0 min Primary = 26.33 cfs @ 11.98 hrs, Volume= 1.448 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 395.16' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 381.63'18.0" Round Culvert L= 97.0' Ke= 0.500 Inlet / Outlet Invert= 381.63' / 380.88' S= 0.0077 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.77 sf Primary OutFlow Max=25.29 cfs @ 11.98 hrs HW=394.45' TW=384.88' (Dynamic Tailwater) 1=Culvert (Outlet Controls 25.29 cfs @ 14.31 fps) Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 14HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond CB-6: 15" Inflow Area = 2.722 ac, 56.03% Impervious, Inflow Depth > 4.42" for 100YR event Inflow = 20.75 cfs @ 11.96 hrs, Volume= 1.003 af Outflow = 20.75 cfs @ 11.96 hrs, Volume= 1.003 af, Atten= 0%, Lag= 0.0 min Primary = 20.75 cfs @ 11.96 hrs, Volume= 1.003 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 409.41' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 383.00'15.0" Round Culvert L= 127.0' Ke= 0.500 Inlet / Outlet Invert= 383.00' / 381.73' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=17.93 cfs @ 11.96 hrs HW=407.27' TW=393.93' (Dynamic Tailwater) 1=Culvert (Outlet Controls 17.93 cfs @ 14.61 fps) Summary for Pond CB-7: 12" Inflow Area = 1.795 ac, 59.87% Impervious, Inflow Depth > 4.52" for 100YR event Inflow = 13.96 cfs @ 11.96 hrs, Volume= 0.676 af Outflow = 13.96 cfs @ 11.96 hrs, Volume= 0.676 af, Atten= 0%, Lag= 0.0 min Primary = 13.96 cfs @ 11.96 hrs, Volume= 0.676 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 447.32' @ 12.05 hrs Device Routing Invert Outlet Devices #1 Primary 396.58'12.0" Round Culvert L= 49.0' Ke= 0.500 Inlet / Outlet Invert= 396.58' / 396.09' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.00 cfs @ 11.96 hrs HW=428.54' TW=432.51' (Dynamic Tailwater) 1=Culvert ( Controls 0.00 cfs) Summary for Pond CB-8: 12" Inflow Area = 1.795 ac, 59.87% Impervious, Inflow Depth > 4.52" for 100YR event Inflow = 13.96 cfs @ 11.96 hrs, Volume= 0.676 af Outflow = 13.96 cfs @ 11.96 hrs, Volume= 0.676 af, Atten= 0%, Lag= 0.0 min Primary = 13.96 cfs @ 11.96 hrs, Volume= 0.676 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 449.32' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 397.58'12.0" Round Culvert L= 90.0' Ke= 0.500 Inlet / Outlet Invert= 397.58' / 396.68' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 15HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=7.10 cfs @ 11.96 hrs HW=433.50' TW=428.54' (Dynamic Tailwater) 1=Culvert (Outlet Controls 7.10 cfs @ 9.04 fps) Summary for Pond DMH-1: 24" Inflow Area = 4.189 ac, 55.97% Impervious, Inflow Depth > 5.03" for 100YR event Inflow = 41.09 cfs @ 11.97 hrs, Volume= 1.755 af Outflow = 41.09 cfs @ 11.97 hrs, Volume= 1.755 af, Atten= 0%, Lag= 0.0 min Primary = 41.09 cfs @ 11.97 hrs, Volume= 1.755 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 385.03' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 380.62'30.0" Round Culvert L= 80.0' Ke= 0.500 Inlet / Outlet Invert= 380.62' / 380.22' S= 0.0050 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 4.91 sf Primary OutFlow Max=40.01 cfs @ 11.97 hrs HW=384.92' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 40.01 cfs @ 8.15 fps) Summary for Pond DMH-2: 24" Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 5.17" for 100YR event Inflow = 37.07 cfs @ 11.96 hrs, Volume= 1.899 af Outflow = 37.07 cfs @ 11.96 hrs, Volume= 1.899 af, Atten= 0%, Lag= 0.0 min Primary = 21.69 cfs @ 11.97 hrs, Volume= 1.592 af Secondary = 15.54 cfs @ 11.95 hrs, Volume= 0.307 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 385.75' @ 11.99 hrs Device Routing Invert Outlet Devices #1 Primary 380.60'24.0" Round Culvert L= 10.0' Ke= 0.500 Inlet / Outlet Invert= 380.60' / 380.55' S= 0.0050 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf #2 Secondary 381.39'24.0" Round Culvert L= 10.0' Ke= 0.500 Inlet / Outlet Invert= 381.39' / 381.34' S= 0.0050 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=19.43 cfs @ 11.97 hrs HW=385.45' TW=383.80' (Dynamic Tailwater) 1=Culvert (Inlet Controls 19.43 cfs @ 6.18 fps) Secondary OutFlow Max=8.18 cfs @ 11.95 hrs HW=385.25' TW=384.96' (Dynamic Tailwater) 2=Culvert (Inlet Controls 8.18 cfs @ 2.60 fps) Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 16HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond DMH-3: 30" Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 5.17" for 100YR event Inflow = 37.07 cfs @ 11.96 hrs, Volume= 1.899 af Outflow = 37.07 cfs @ 11.96 hrs, Volume= 1.899 af, Atten= 0%, Lag= 0.0 min Primary = 37.07 cfs @ 11.96 hrs, Volume= 1.899 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 387.78' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 381.68'30.0" Round Culvert L= 240.0' Ke= 0.500 Inlet / Outlet Invert= 381.68' / 380.65' S= 0.0043 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 4.91 sf Primary OutFlow Max=27.80 cfs @ 11.96 hrs HW=387.03' TW=385.34' (Dynamic Tailwater) 1=Culvert (Outlet Controls 27.80 cfs @ 5.66 fps) Summary for Pond DMH-5: 15" Inflow Area = 2.722 ac, 56.03% Impervious, Inflow Depth > 4.42" for 100YR event Inflow = 20.75 cfs @ 11.96 hrs, Volume= 1.003 af Outflow = 20.75 cfs @ 11.96 hrs, Volume= 1.003 af, Atten= 0%, Lag= 0.0 min Primary = 20.75 cfs @ 11.96 hrs, Volume= 1.003 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 419.43' @ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 384.40'15.0" Round Culvert L= 91.0' Ke= 0.500 Inlet / Outlet Invert= 384.40' / 383.67' S= 0.0080 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=13.35 cfs @ 11.96 hrs HW=413.34' TW=407.27' (Dynamic Tailwater) 1=Culvert (Outlet Controls 13.35 cfs @ 10.88 fps) Summary for Pond DMH-6: 15" Inflow Area = 2.722 ac, 56.03% Impervious, Inflow Depth > 4.42" for 100YR event Inflow = 20.75 cfs @ 11.96 hrs, Volume= 1.003 af Outflow = 20.75 cfs @ 11.96 hrs, Volume= 1.003 af, Atten= 0%, Lag= 0.0 min Primary = 20.75 cfs @ 11.96 hrs, Volume= 1.003 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 432.36' @ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 386.10'15.0" Round Culvert L= 201.0' Ke= 0.500 Inlet / Outlet Invert= 386.10' / 384.50' S= 0.0080 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 17HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=14.52 cfs @ 11.96 hrs HW=425.28' TW=413.34' (Dynamic Tailwater) 1=Culvert (Outlet Controls 14.52 cfs @ 11.83 fps) Summary for Pond DMH-7: 12" Inflow Area = 2.086 ac, 56.99% Impervious, Inflow Depth > 4.45" for 100YR event Inflow = 16.03 cfs @ 11.96 hrs, Volume= 0.773 af Outflow = 16.03 cfs @ 11.96 hrs, Volume= 0.773 af, Atten= 0%, Lag= 0.0 min Primary = 16.03 cfs @ 11.96 hrs, Volume= 0.773 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 443.63' @ 12.02 hrs Device Routing Invert Outlet Devices #1 Primary 395.99'12.0" Round Culvert L= 78.0' Ke= 0.500 Inlet / Outlet Invert= 395.99' / 395.21' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=9.01 cfs @ 11.96 hrs HW=432.59' TW=425.26' (Dynamic Tailwater) 1=Culvert (Outlet Controls 9.01 cfs @ 11.47 fps) Summary for Pond FB-1: FB-1 Inflow Area = 1.660 ac, 83.71% Impervious, Inflow Depth > 5.12" for 100YR event Inflow = 13.91 cfs @ 11.96 hrs, Volume= 0.709 af Outflow = 12.24 cfs @ 11.95 hrs, Volume= 0.670 af, Atten= 12%, Lag= 0.0 min Primary = 12.24 cfs @ 11.95 hrs, Volume= 0.670 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 394.97' @ 12.08 hrs Surf.Area= 2,605 sf Storage= 3,653 cf Plug-Flow detention time= 42.4 min calculated for 0.667 af (94% of inflow) Center-of-Mass det. time= 20.8 min ( 759.5 - 738.7 ) Volume Invert Avail.Storage Storage Description #1 392.00' 3,728 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 392.00 225 100.0 0 0 225 393.00 820 165.0 492 492 1,602 394.00 1,550 195.0 1,166 1,657 2,480 395.00 2,640 250.0 2,071 3,728 4,441 Device Routing Invert Outlet Devices #1 Primary 394.00'18.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 18HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Primary OutFlow Max=0.00 cfs @ 11.95 hrs HW=394.57' TW=394.73' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond OUTLET: Outlet Stream/Pond Inflow Area = 18.664 ac, 26.92% Impervious, Inflow Depth > 3.64" for 100YR event Inflow = 72.25 cfs @ 11.99 hrs, Volume= 5.659 af Outflow = 72.25 cfs @ 11.99 hrs, Volume= 5.659 af, Atten= 0%, Lag= 0.0 min Primary = 35.83 cfs @ 11.99 hrs, Volume= 2.936 af Secondary = 36.42 cfs @ 11.99 hrs, Volume= 2.722 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 390.74' @ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 389.00'6.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Secondary 389.00'6.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=35.11 cfs @ 11.99 hrs HW=390.73' TW=389.25' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 35.11 cfs @ 3.39 fps) Secondary OutFlow Max=34.09 cfs @ 11.99 hrs HW=390.72' TW=389.41' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir (Weir Controls 34.09 cfs @ 3.30 fps) Summary for Pond P-1: Existing North Pond Inflow Area = 10.347 ac, 22.57% Impervious, Inflow Depth > 3.58" for 100YR event Inflow = 57.15 cfs @ 12.03 hrs, Volume= 3.088 af Outflow = 29.21 cfs @ 12.16 hrs, Volume= 2.996 af, Atten= 49%, Lag= 8.1 min Primary = 29.21 cfs @ 12.16 hrs, Volume= 2.996 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Starting Elev= 401.00' Surf.Area= 22,263 sf Storage= 39,555 cf Peak Elev= 402.69' @ 12.16 hrs Surf.Area= 26,606 sf Storage= 80,915 cf (41,360 cf above start) Plug-Flow detention time= 137.9 min calculated for 2.088 af (68% of inflow) Center-of-Mass det. time= 27.8 min ( 805.9 - 778.1 ) Volume Invert Avail.Storage Storage Description #1 399.00' 117,925 cf Custom Stage Data (Irregular) Listed below (Recalc) Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 19HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 399.00 17,348 799.0 0 0 17,348 400.00 19,775 819.0 18,548 18,548 20,047 401.00 22,263 839.0 21,007 39,555 22,813 402.00 24,812 859.0 23,526 63,081 25,646 403.00 27,418 878.0 26,104 89,185 28,412 404.00 30,082 897.0 28,740 117,925 31,239 Device Routing Invert Outlet Devices #1 Primary 401.00'5.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Primary OutFlow Max=28.98 cfs @ 12.16 hrs HW=402.68' TW=399.97' (Dynamic Tailwater) 1=Broad-Crested Rectangular Weir (Weir Controls 28.98 cfs @ 3.44 fps) Summary for Pond P-2: Enlarged Pond with OCS Inflow Area = 0.666 ac, 0.00% Impervious, Inflow Depth > 52.02" for 100YR event Inflow = 40.09 cfs @ 11.99 hrs, Volume= 2.889 af Outflow = 21.86 cfs @ 12.11 hrs, Volume= 2.633 af, Atten= 45%, Lag= 7.4 min Primary = 21.86 cfs @ 12.11 hrs, Volume= 2.633 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 389.87' @ 12.11 hrs Surf.Area= 11,669 sf Storage= 33,940 cf Plug-Flow detention time= 65.8 min calculated for 2.633 af (91% of inflow) Center-of-Mass det. time= 35.4 min ( 826.2 - 790.8 ) Volume Invert Avail.Storage Storage Description #1 386.00' 48,113 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 386.00 5,878 348.0 0 0 5,878 387.00 7,311 402.0 6,581 6,581 9,123 387.40 7,985 441.0 3,058 9,640 11,744 388.00 8,931 483.0 5,072 14,712 14,845 389.00 10,379 517.0 9,646 24,358 17,596 390.00 11,869 542.0 11,116 35,473 19,769 391.00 13,427 562.0 12,640 48,113 21,611 Device Routing Invert Outlet Devices #1 Primary 386.00'24.0" Round Culvert L= 60.0' Ke= 0.500 Inlet / Outlet Invert= 386.00' / 385.50' S= 0.0083 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf #2 Device 1 386.00'3.0" W x 3.0" H Vert. Orifice/Grate C= 0.600 #3 Device 1 387.40'24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 389.00'24.0" Horiz. Orifice/Grate C= 0.600 Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 20HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Limited to weir flow at low heads Primary OutFlow Max=21.75 cfs @ 12.11 hrs HW=389.86' TW=385.58' (Dynamic Tailwater) 1=Culvert (Passes 21.75 cfs of 25.57 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.58 cfs @ 9.30 fps) 3=Orifice/Grate (Orifice Controls 7.15 cfs @ 7.15 fps) 4=Orifice/Grate (Orifice Controls 14.01 cfs @ 4.46 fps) Summary for Pond SMP-1: Bioretention Basin Inflow Area = 1.660 ac, 83.71% Impervious, Inflow Depth > 4.84" for 100YR event Inflow = 12.24 cfs @ 11.95 hrs, Volume= 0.670 af Outflow = 7.65 cfs @ 12.03 hrs, Volume= 0.626 af, Atten= 38%, Lag= 4.6 min Primary = 7.65 cfs @ 12.03 hrs, Volume= 0.626 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 394.97' @ 12.03 hrs Surf.Area= 2,948 sf Storage= 4,326 cf Plug-Flow detention time= 39.7 min calculated for 0.626 af (93% of inflow) Center-of-Mass det. time= 15.8 min ( 775.3 - 759.5 ) Volume Invert Avail.Storage Storage Description #1 393.00' 4,422 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 393.00 1,500 155.0 0 0 1,500 394.00 2,210 185.0 1,844 1,844 2,329 394.50 2,570 196.0 1,194 3,037 2,676 395.00 2,975 205.0 1,385 4,422 2,980 Device Routing Invert Outlet Devices #1 Device 2 394.00'30.0" x 30.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 389.73'12.0" Round Culvert L= 69.0' Ke= 0.500 Inlet / Outlet Invert= 389.73' / 389.04' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=7.64 cfs @ 12.03 hrs HW=394.95' TW=387.95' (Dynamic Tailwater) 2=Culvert (Barrel Controls 7.64 cfs @ 9.73 fps) 1=Orifice/Grate (Passes 7.64 cfs of 29.40 cfs potential flow) Summary for Pond SMP-2: Bioretention Basin Inflow Area = 0.572 ac, 35.03% Impervious, Inflow Depth > 3.89" for 100YR event Inflow = 3.99 cfs @ 11.97 hrs, Volume= 0.185 af Outflow = 3.73 cfs @ 12.05 hrs, Volume= 0.130 af, Atten= 6%, Lag= 5.0 min Primary = 3.73 cfs @ 12.05 hrs, Volume= 0.130 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 21HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Peak Elev= 395.84' @ 12.03 hrs Surf.Area= 2,628 sf Storage= 3,576 cf Plug-Flow detention time= 113.3 min calculated for 0.129 af (70% of inflow) Center-of-Mass det. time= 48.7 min ( 816.3 - 767.6 ) Volume Invert Avail.Storage Storage Description #1 386.00' 3,576 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 386.00 1,025 175.0 0 0 1,025 387.00 1,776 200.0 1,383 1,383 1,794 387.50 2,190 213.0 990 2,373 2,234 388.00 2,628 225.0 1,203 3,576 2,666 Device Routing Invert Outlet Devices #1 Device 2 387.50'15.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 381.63'18.0" Round Culvert L= 97.0' Ke= 0.500 Inlet / Outlet Invert= 381.63' / 380.88' S= 0.0077 '/' Cc= 0.900 n= 0.012, Flow Area= 1.77 sf Primary OutFlow Max=12.59 cfs @ 12.05 hrs HW=395.40' TW=390.86' (Dynamic Tailwater) 2=Culvert (Passes 12.59 cfs of 17.42 cfs potential flow) 1=Orifice/Grate (Orifice Controls 12.59 cfs @ 10.26 fps) Summary for Pond SMP-3: Bioretention Basin Inflow Area = 0.376 ac, 27.01% Impervious, Inflow Depth > 3.69" for 100YR event Inflow = 2.51 cfs @ 11.97 hrs, Volume= 0.116 af Outflow = 3.27 cfs @ 12.15 hrs, Volume= 0.080 af, Atten= 0%, Lag= 11.2 min Primary = 3.27 cfs @ 12.15 hrs, Volume= 0.080 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 395.22' @ 12.06 hrs Surf.Area= 2,455 sf Storage= 2,509 cf Plug-Flow detention time= 115.9 min calculated for 0.080 af (69% of inflow) Center-of-Mass det. time= 48.8 min ( 820.6 - 771.8 ) Volume Invert Avail.Storage Storage Description #1 386.00' 2,509 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 386.00 643 117.0 0 0 643 387.00 1,160 142.0 889 889 1,174 387.50 1,457 154.0 653 1,542 1,466 388.00 2,455 213.0 967 2,509 3,192 Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 22HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Device 2 387.50'15.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 383.00'15.0" Round Culvert L= 127.0' Ke= 0.500 Inlet / Outlet Invert= 383.00' / 381.73' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=3.06 cfs @ 12.15 hrs HW=387.88' TW=384.26' (Dynamic Tailwater) 2=Culvert (Passes 3.06 cfs of 9.34 cfs potential flow) 1=Orifice/Grate (Weir Controls 3.06 cfs @ 2.03 fps) Summary for Pond SMP-4: CS-5 Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 4.33" for 100YR event Inflow = 21.69 cfs @ 11.97 hrs, Volume= 1.592 af Outflow = 21.69 cfs @ 11.97 hrs, Volume= 1.592 af, Atten= 0%, Lag= 0.0 min Primary = 21.69 cfs @ 11.97 hrs, Volume= 1.592 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 383.87' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 380.55'24.0" Round Culvert L= 70.0' Ke= 0.500 Inlet / Outlet Invert= 380.55' / 380.22' S= 0.0047 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=21.14 cfs @ 11.97 hrs HW=383.80' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 21.14 cfs @ 6.73 fps) Summary for Pond YD-3: 12" Inflow Area = 0.291 ac, 39.17% Impervious, Inflow Depth > 4.00" for 100YR event Inflow = 2.07 cfs @ 11.97 hrs, Volume= 0.097 af Outflow = 2.07 cfs @ 11.97 hrs, Volume= 0.097 af, Atten= 0%, Lag= 0.0 min Primary = 2.07 cfs @ 11.97 hrs, Volume= 0.097 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 443.72' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 396.98'12.0" Round Culvert L= 67.0' Ke= 0.500 Inlet / Outlet Invert= 396.98' / 396.31' S= 0.0100 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.00 cfs @ 11.97 hrs HW=416.58' TW=433.10' (Dynamic Tailwater) 1=Culvert ( Controls 0.00 cfs) Type II 24-hr 100YR Rainfall=6.20"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 23HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Link AP-1: AP-1 Inflow Area = 0.304 ac, 31.94% Impervious, Inflow Depth > 3.79" for 100YR event Inflow = 2.08 cfs @ 11.97 hrs, Volume= 0.096 af Primary = 2.08 cfs @ 11.97 hrs, Volume= 0.096 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link AP-2: AP-2 Inflow Area = 30.679 ac, 41.01% Impervious, Inflow Depth > 3.84" for 100YR event Inflow = 120.97 cfs @ 12.00 hrs, Volume= 9.813 af Primary = 120.97 cfs @ 12.00 hrs, Volume= 9.813 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Attachment D Storm Data Job Name and #Skidmore College Athletic Expansion Minimum Runoff Reduction Volume 11/4/2022 RRv = [(P)(Rv*)(Ai)]/12 Where: Ai = (S)(Aic) Rv = 0.05 + 0.009(I) where I is 100% impervious Ai = impervious cover targeted for runoff reduction Aic = Total area of new impervious cover P = 90% rainfall (see Figure 4.1 in NYS Stormwater Management Design Manual) S = Hydrologic Soil Group (HSG) Specific Reduction Factor (S) A=0.55, B=0.40, C=0.30, D=0.20 S (HSG C)0.30 Aic 1.68 acres Rv 0.95 90% Rainfall 1.15 Ai 0.503 RRv =0.046 acre feet =1,993 ft3 Stormwater Practice Sizing Job Name and #Skidmore College Athletic Expansion Water Quality Volume Calculation 11/4/2022 WQv = [(P)(Rv)(A)]/12 Where: Rv = 0.05 + 0.009(I) I = impervious cover in percent P = 90% rainfall (see Figure 4.1 in NYS Stormwater Management Design Manual) A = Area in acres Proposed Bioretention Basin (SMP-1) % Impervious 83.71% Rv 0.80 90% Rainfall 1.15 Area in Square Feet 72310 WQv Required =5567 ft 3 0.128 ac-ft Proposed Bioretention Basin (SMP-2) % Impervious 35.03% Rv 0.37 90% Rainfall 1.15 Area in Square Feet 24916 WQv Required =872 ft 3 0.020 ac-ft Proposed Bioretention Basin (SMP-3) % Impervious 27.01% Rv 0.29 90% Rainfall 1.15 Area in Square Feet 16379 WQv Required =460 ft 3 0.011 ac-ft Proposed Hydrodynamic Separator (SMP-4) % Impervious 84.39% Rv 0.81 90% Rainfall 1.15 Area in Square Feet 191969 WQv Required =14893 ft 3 0.342 ac-ft REQUIRED New Impervious % Impervious 100.00% Rv 0.95 90% Rainfall 1.15 Area in Square Feet 72963 WQv Required =6643 ft3 0.152 ac-ft Existing Impervious Disturbed (75% Treatment) % Impervious 100.00% Rv 0.95 90% Rainfall 1.15 Area in Square Feet 62583 WQv Calculated =5698 ft 3 0.131 ac-ft WQv Required =4273 ft3 0.098 ac-ft WQV TOTAL=10916 ft4 0.251 ac-ft Skidmore College 2016098 Bioretention Area 2 SMP-1 SMP-2 SMP-3 1.Underlying soil permeability =0.50 0.50 0.50 in/hr 2. DA (maximum 5 acres)=72,310 24,916 16,379 ft2 =84%35%27%% Rv = .05 + .009 ( I )=0.80 0.37 0.29 =1.15 1.15 1.15 in. =5,567 872 460 ft3 75% of WQv 4,175 654 345 ft3 3.Bioretention Details: Material Filter bed depth (df) (2.5 - 4.0 ft)=2.50 2.50 2.50 ft Coefficient of permeability of filter media (k)=1.00 1.00 1.00 ft/day Avg. height of water above filter media (hf) (max. 0.5 ft)=0.50 0.50 0.50 ft Design filter bed drain time (tf)=2 2 2 days 4.Calculate required bioretention surface area (Af): 2,320 363 192 ft2 5.Bioretention surface area provided =1500 1025 645 ft2 (design) 6.Water Quality Volume provided =3600 2460 1548 ft3 (design) 7.Is Bioretention Basin Lined or in HSG C/D Soils Yes Yes Yes 8.Runoff Reduction Volume provided =1440 872 460 ft3 (design) WQv = P Rv A/12 Planting Soil Mix Surface area (Af) = WQv x df k (hf + df) (tf) Required Surface Area (Af) = BIORETENTION WORKSHEET (See Section 6.4.4 of the NYSDEC Stormwater Management Design Manual 2015) (if no underdrains proposed, must infiltrate within 48 hours, HSG A and B Soils) Calculate WQv: Percent Impervious Area, I P (90% Rainfall) Job Name Skidmore College Athletic Expansion Channel Protection Volume Calculation 11/4/2022 Pre Development Step 1: Determine Qu P =2.15 in. (1-yr. storm) Area =30.974 acres CN =82 **** Ia =0.439 Ia/P =0.20 Tc =0.1 Hrs. Using Figure 4-II, TR-55 and Tc, determine Qu (csm/in) Qu =975 csm/in Step 2: Determine Qo/Qi Using Figure B-1, DEC Manual Appendix B for T = 24 hrs. and Qu, determine Qo/Qi Qo/Qi =0.02 Step 3: Determine Vs/Vr Vs/Vr = 0.682 - 1.43(Qo/Qi) + 1.64 (Qo/Qi)^2 - 0.804 (Qo/Qi)^3 Vs/Vr = 0.654 Step 4: Determine Qd Using Figure 2.1, TR-55 or SCS TR-16 and P, determine Qd (in of runoff) Qd =0.9 in Step 5: Determine Cpv Area =30.97 acres Cpv = Vs = (Vs/Vr) * Qd * A/12 Cpv = 1.519 ac-ft Cpv = 66185 ft3 Cpv Req.=66185 ft3 Job Name Skidmore College Athletic Expansion Channel Protection Volume Calculation 11/4/2022 Post Development Step 1: Determine Qu P =2.15 in. (1-yr. storm) Area =30.974 acres CN =84 Ia =0.381 Ia/P =0.18 Tc =0.1 Hrs. Using Figure 4-II, TR-55 and Tc, determine Qu (csm/in) Qu =975 csm/in Step 2: Determine Qo/Qi Using Figure B-1, DEC Manual Appendix B for T = 24 hrs. and Qu, determine Qo/Qi Qo/Qi =0.02 Step 3: Determine Vs/Vr Vs/Vr = 0.682 - 1.43(Qo/Qi) + 1.64 (Qo/Qi)^2 - 0.804 (Qo/Qi)^3 Vs/Vr = 0.654 Step 4: Determine Qd Using Figure 2.1, TR-55 or SCS TR-16 and P, determine Qd (in of runoff) Qd =0.95 in Step 5: Determine Cpv Area =30.97 acres Cpv = Vs = (Vs/Vr) * Qd * A/12 Cpv = 1.604 ac-ft Cpv = 69862 ft3 Pre Dev 66185 ft3 CPv Required=3677 ft3 Volume reduction achieved through green infrastructure SMP 1 =1440 ft3 SMP 2 =872 ft3 SMP 3 =318 ft4 P 2 =9640 ft3 Cpv Provided=12270 ft3 Type II 24-hr 90 Rainfall=0.71"POST-DEV Printed 11/4/2022Prepared by The LA Group Page 1HydroCAD® 10.00-26 s/n 00439 © 2020 HydroCAD Software Solutions LLC Summary for Pond SMP-4: CS-5 Inflow Area = 4.409 ac, 84.37% Impervious, Inflow Depth > 0.28" for 90 event Inflow = 2.32 cfs @ 11.97 hrs, Volume= 0.104 af Outflow = 2.32 cfs @ 11.97 hrs, Volume= 0.104 af, Atten= 0%, Lag= 0.0 min Primary = 2.32 cfs @ 11.97 hrs, Volume= 0.104 af Routing by Dyn-Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 381.27' @ 11.97 hrs Device Routing Invert Outlet Devices #1 Primary 380.55'24.0" Round Culvert L= 70.0' Ke= 0.500 Inlet / Outlet Invert= 380.55' / 380.22' S= 0.0047 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=2.24 cfs @ 11.97 hrs HW=381.26' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 2.24 cfs @ 3.35 fps) Appendix C Map Set Appendix D SWPPP Inspection Form Skidmore College Athletic Expansion – Skidmore College WEEKLY SWPPP INSPECTION REPORT Inspector Name: Date: Signature (required): Time: Weather: Inspection #: Soil Conditions (dry, saturated, etc): Note: Digital photos, with date stamp required for all practices requiring corrective action, before and after, to be attached to the inspection report. YES NO N/A 1. Routine Inspection. Date of last inspection: 2. Inspection following rain event. Date/time of storm ending: Rainfall amount: Recorded by: 3. Is this a final site inspection? 4. Has site undergone final stabilization? If so, have all temporary erosion and sediment controls been removed? Site Disturbance (Indicate Locations on Plan) YES NO N/A 1. Areas previously disturbed, but have not undergone active site work in the last 14 days? 2. Areas disturbed within last 14 days? 3. Areas expected to be disturbed in next 14 days? 4. Do areas of steep slopes or complex stabilization issues exist? If “YES” explain: 5. Are there currently more than 5 acres of disturbed soil at the site? If so make sure there is an approval letter from NYS DEC. Additional Comments: Inspection of Erosion and Sediment Control Devices Type of Control Device Accumulation (if any) in % Repairs/Maintenance Needed 1. 2. 3. 4. 5. 6. Stabilization/Runoff YES NO N/A 1. Are all existing disturbed areas contained by control devices? Type of devices: 2. Are there areas that require stabilization within the next 14 days? Specify Area: 3. Have stabilization measures been initiated in inactive areas? 4. Is there current snow cover or frozen ground conditions? 5. Rills or gullies? 6. Slumping/deposition? 7. Loss of vegetation? 8. Lack of germination? 9. Loss of mulching? Receiving Structures/Water Bodies (Indicate locations where runoff leaves the project site on the site plan) YES NO N/A 1. Surface water swale or natural surface waterbody? If natural waterbody: Is waterbody located onsite, or adjacent to property boundary? Description of condition: 2. Municipal or community system? Inspect locations where runoff from project site enters the receiving waters and indicate if there is evidence of: a. Rills or gullies? b. Slumping/deposition? c. Loss of vegetation? d. Undermining of structures? e. Was there a discharge into the receiving water on the day of inspection? f. Is there evidence of turbidity, sedimentation, or oil in the receiving waters? Additional Comments: Inspection of Post-Construction Stormwater Management Control Devices Type of Control Device Phase of Construction Repairs/Maintenance Needed 1. 2. 3. 4. General Site Condition YES NO N/A 1. Have action items from previous reports been addressed? 2. Does routine maintenance of protection components occur on a regular basis? 3. Does cleaning and/or sweeping affected roadways occur, at minimum, daily? 4. Is debris and litter removed on a monthly basis, or as necessary? 5. Is the site maintained in an orderly manner? Describe the condition of all natural waterbodies within or adjacent to the Project that receive runoff from the site: Contractors progress over last 7 days: Anticipated work to be begun in the next 7 days: Additional Comments: Visual Observations YES NO N/A 1. All erosion and sediment control measures have been installed/constructed? 2. All erosion and sediment control measures are being maintained properly? SUMMARY OF ACTION ITEMS TO REPAIR/REPLACE/MAINTAIN/CORRECT DEFICIENCIES Action Reported To (no signature required): Company: Appendix E Other SWPPP Forms Construction Sequence SWPPP Plan Changes Spill Response Form Stormwater Management Practice Maintenance Log The operator shall prepare a summary of construction status using the Construction Sequence Form below once every month. Significant deviations to the sequence and reasons for those deviations (i.e. weather, subcontractor availability, etc.), shall be noted by the contractor. The schedule shall be used to record the dates for initiation of construction, implementation of erosion control measures, stabilization, etc. A copy of this table will be maintained at the construction site and updated in addition to the individual Inspection Reports completed for each inspection. Construction Sequence Form Construction Activities (Identify name of planned practices) Date Complete 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. STORM WATER POLLUTION PREVENTION PLAN PLAN CHANGES, AUTHORIZATION, AND CHANGE CERTIFICATION CHANGES REQUIRED TO THE POLLUTION PREVENTION PLAN: REASONS FOR CHANGES: REQUESTED BY: _________________________ DATE: _________________________ AUTHORIZED BY: _________________________ DATE: _________________________ CERTIFICATION OF CHANGES: I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or th ose persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that false statements made herein are punishable as a Class A misdemeanor pursuant to Section 210.45 of the penal code. SIGNATURE: DATE: SPILL RESPONSE REPORT Within 1 hour of a spill discovery less than 2 gallons in volume the following must be notified: Dan Rodecker (518) 580 5860 x 5874 Within 1 hour of a spill discovery greater than 2 gallons the following must be notified: Dan Rodecker NYSDEC Spill Response Hotline 1-800-457-7362 Spill Response Contractor Material Spilled: Approximate Volume: Location: Distance to nearest down gradient drainage: Distance to nearest down gradient open water: Temporary control measures in place: Cascade Separator™ Inspection and Maintenance Guide ENGINEERED SOLUTIONS Maintenance The Cascade Separator™ system should be inspected at regular intervals and maintained when necessary to ensure optimum performance. The rate at which the system collects sediment and debris will depend upon on-site activities and site pollutant characteristics. For example, unstable soils or heavy winter sand- ing will cause the sediment storage sump to fill more quickly but regular sweeping of paved surfaces will slow accumulation. Inspection Inspection is the key to effective maintenance and is easily per- formed. Pollutant transport and deposition may vary from year to year and regular inspections will help ensure that the system is cleaned out at the appropriate time. At a minimum, inspec- tions should be performed twice per year (i.e. spring and fall). However, more frequent inspections may be necessary in climates where winter sanding operations may lead to rapid accumula- tions, or in equipment wash-down areas. Installations should also be inspected more frequently where excessive amounts of trash are expected. A visual inspection should ascertain that the system components are in working order and that there are no blockages or obstruc- tions in the inlet chamber, flumes or outlet channel. The inspec- tion should also quantify the accumulation of hydrocarbons, trash and sediment in the system. Measuring pollutant accumu- lation can be done with a calibrated dipstick, tape measure or other measuring instrument. If absorbent material is used for enhanced removal of hydrocarbons, the level of discoloration of the sorbent material should also be identified during inspection. It is useful and often required as part of an operating permit to keep a record of each inspection. A simple form for doing so is provided in this Inspection and Maintenance Guide. Access to the Cascade Separator unit is typically achieved through one manhole access cover. The opening allows for inspection and cleanout of the center chamber (cylinder) and sediment storage sump, as well as inspection of the inlet chamber and slanted skirt. For large units, multiple manhole covers allow access to the chambers and sump. The Cascade Separator system should be cleaned before the level of sediment in the sump reaches the maximum sediment depth and/or when an appreciable level of hydrocarbons and trash has accumulated. If sorbent material is used, it must be replaced when significant discoloration has occurred. Performance may be impacted when maximum sediment storage capacity is exceeded. Contech recommends maintaining the system when sediment level reaches 50% of maximum storage volume. The level of sediment is easily determined by measuring the distance from the system outlet invert (standing water level) to the top of the sedi- ment pile. To avoid underestimating the level of sediment in the chamber, the measuring device must be lowered to the top of the sediment pile carefully. Finer, silty particles at the top of the pile typically offer less resistance to the end of the rod than larger particles toward the bottom of the pile. Once this measurement is recorded, it should be compared to the chart in this document to determine if the height of the sediment pile off the bottom of the sump floor exceeds 50% of the maximum sediment storage. Cleaning Cleaning of a Cascade Separator system should be done during dry weather conditions when no flow is entering the system. The use of a vacuum truck is generally the most effective and con- venient method of removing pollutants from the system. Simply remove the manhole cover and insert the vacuum tube down through the center chamber and into the sump. The system should be completely drained down and the sump fully evacu- ated of sediment. The areas outside the center chamber and the slanted skirt should also be washed off if pollutant build-up exists in these areas. In installations where the risk of petroleum spills is small, liquid contaminants may not accumulate as quickly as sediment. How- ever, the system should be cleaned out immediately in the event of an oil or gasoline spill. Motor oil and other hydrocarbons that accumulate on a more routine basis should be removed when an appreciable layer has been captured. To remove these pollutants, it may be preferable to use absorbent pads since they are usually less expensive to dispose than the oil/water emulsion that may be created by vacuuming the oily layer. Trash and debris can be net- ted out to separate it from the other pollutants. Then the system should be power washed to ensure it is free of trash and debris. Manhole covers should be securely seated following cleaning activities to prevent leakage of runoff into the system from above and to ensure proper safety precautions. Confined space entry procedures need to be followed if physical access is required. Disposal of all material removed from the Cascade Separator system must be done in accordance with local regulations. In many locations, disposal of evacuated sediments may be handled in the same manner as disposal of sediments removed from catch basins or deep sump manholes. Check your local regulations for specific requirements on disposal. If any components are dam- aged, replacement parts can be ordered from the manufacturer. A vacuum truck excavates pollutants from the systems.A Cascade Separator unit can be easily cleaned in less than 30 minutes. Model Number Diameter Distance from Water Surface to Top of Sediment Pile Sediment Storage Capacity ft m ft m y3 m3 CS-4 4 1.2 1.5 0.5 0.7 0.5 CS-5 5 1.3 1.5 0.5 1.1 0.8 CS-6 6 1.8 1.5 0.5 1.6 1.2 CS-8 8 2.4 1.5 0.5 2.8 2.1 CS-10 10 3.0 1.5 0.5 4.4 3.3 CS-12 12 3.6 1.5 0.5 6.3 4.8 Note: The information in the chart is for standard units. Units may have been designed with non-standard sediment storage depth. Cascade Separator™ Maintenance Indicators and Sediment Storage Capacities 800.925.5240 www.ContechES.com SUPPORT • Drawings and specifications are available at www.ContechES.com. • Site-specific design support is available from our engineers. ©2019 Contech Engineered Solutions LLC, a QUIKRETE Company Contech Engineered Solutions LLC provides site solutions for the civil engineering industry. Contech’s portfolio includes bridges, drainage, sanitary sewer, stormwater, and earth stabilization products. For information, visit www.ContechES.com or call 800.338.1122 NOTHING IN THIS CATALOG SHOULD BE CONSTRUED AS A WARRANTY. APPLICATIONS SUGGESTED HEREIN ARE DESCRIBED ONLY TO HELP READERS MAKE THEIR OWN EVALUATIONS AND DECISIONS, AND ARE NEITHER GUARANTEES NOR WARRANTIES OF SUITABILITY FOR ANY APPLICATION. CONTECH MAKES NO WARRANTY WHATSOEVER, EXPRESS OR IMPLIED, RELATED TO THE APPLICATIONS, MATERIALS, COATINGS, OR PRODUCTS DISCUSSED HEREIN. ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND ALL IMPLIED WARRANTIES OF FITNESS FOR ANY PARTICULAR PURPOSE ARE DISCLAIMED BY CONTECH. SEE CONTECH’S CONDITIONS OF SALE (AVAILABLE AT WWW.CONTECHES.COM/COS) FOR MORE INFORMATION. Cascade Separator Maintenance 11/19 ENGINEERED SOLUTIONS Cascade Separator™ Inspection & Maintenance Log Cascade Model:Location: Date Depth Below Invert to Top of Sediment1 Floatable Layer Thickness2 Describe Maintenance Performed Maintenance Personnel Comments 1. The depth to sediment is determined by taking a measurement from the manhole outlet invert (standing water level) to the top of the sediment pile. Once this measurement is recorded, it should be compared to the chart in the maintenance guide to determine if the height of the sediment pile off the bottom of the sump floor exceeds 50% of the maximum sediment storage. Note: to avoid underestimating the volume of sediment in the cham- ber, the measuring device must be carefully lowered to the top of the sediment pile. 2. For optimum performance, the system should be cleaned out when the floating hydrocarbon layer accumulates to an appreciable thickness. In the event of an oil spill, the system should be cleaned immediately. Appendix F SPDES General Permit GP-0-20-001 I PREFACE Pursuant to Section 402 of the Clean Water Act (“CWA”), stormwater discharges from certain construction activities are unlawful unless they are authorized by a National Pollutant Discharge Elimination System (“NPDES”) permit or by a state permit program. New York administers the approved State Pollutant Discharge Elimination System (SPDES) program with permits issued in accordance with the New York State Environmental Conservation Law (ECL) Article 17, Titles 7, 8 and Article 70. An owner or operator of a construction activity that is eligible for coverage under this permit must obtain coverage prior to the commencement of construction activity. Activities that fit the definition of “construction activity”, as defined under 40 CFR 122.26(b)(14)(x), (15)(i), and (15)(ii), constitute construction of a point source and therefore, pursuant to ECL section 17-0505 and 17-0701, the owner or operator must have coverage under a SPDES permit prior to commencing construction activity. The owner or operator cannot wait until there is an actual discharge from the construction site to obtain permit coverage. *Note: The italicized words/phrases within this permit are defined in Appendix A. I NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION SPDES GENERAL PERMIT FOR STORMWATER DISCHARGES FROM CONSTRUCTION ACTIVITIES Table of Contents Part 1. PERMIT COVERAGE AND LIMITATIONS ............................................................. 1 A. Permit Application ................................................................................................. 1 B. Effluent Limitations Applicable to Discharges from Construction Activities ........... 1 C. Post-construction Stormwater Management Practice Requirements .................... 4 D. Maintaining Water Quality ..................................................................................... 8 E. Eligibility Under This General Permit ..................................................................... 9 F. Activities Which Are Ineligible for Coverage Under This General Permit .............. 9 Part II. PERMIT COVERAGE ........................................................................................... 12 A. How to Obtain Coverage ..................................................................................... 12 B. Notice of Intent (NOI) Submittal .......................................................................... 13 C. Permit Authorization ............................................................................................ 13 D. General Requirements For Owners or Operators With Permit Coverage ........... 15 E. Permit Coverage for Discharges Authorized Under GP-0-15-002 ....................... 17 F. Change of Owner or Operator ............................................................................. 17 Part III. STORMWATER POLLUTION PREVENTION PLAN (SWPPP) ........................... 18 A. General SWPPP Requirements .......................................................................... 18 B. Required SWPPP Contents ................................................................................ 20 C. Required SWPPP Components by Project Type ................................................. 24 Part IV. INSPECTION AND MAINTENANCE REQUIREMENTS ..................................... 24 A. General Construction Site Inspection and Maintenance Requirements .............. 24 B. Contractor Maintenance Inspection Requirements ............................................. 24 C. Qualified Inspector Inspection Requirements ...................................................... 25 Part V. TERMINATION OF PERMIT COVERAGE ........................................................... 29 A. Termination of Permit Coverage ......................................................................... 29 Part VI. REPORTING AND RETENTION RECORDS ...................................................... 31 A. Record Retention ................................................................................................ 31 B. Addresses ........................................................................................................... 31 Part VII. STANDARD PERMIT CONDITIONS .................................................................. 31 A. Duty to Comply .................................................................................................... 31 B. Continuation of the Expired General Permit ........................................................ 32 C. Enforcement ........................................................................................................ 32 D. Need to Halt or Reduce Activity Not a Defense................................................... 32 E. Duty to Mitigate ................................................................................................... 33 F. Duty to Provide Information ................................................................................. 33 G. Other Information ................................................................................................ 33 H. Signatory Requirements ...................................................................................... 33 I. Property Rights ................................................................................................... 35 J. Severability.......................................................................................................... 35 K. Requirement to Obtain Coverage Under an Alternative Permit ........................... 35 L. Proper Operation and Maintenance .................................................................... 36 M. Inspection and Entry ........................................................................................... 36 N. Permit Actions ..................................................................................................... 37 O. Definitions ........................................................................................................... 37 P. Re-Opener Clause .............................................................................................. 37 Q. Penalties for Falsification of Forms and Reports ................................................. 37 R. Other Permits ...................................................................................................... 38 APPENDIX A – Acronyms and Definitions ....................................................................... 39 Acronyms ...................................................................................................................... 39 Definitions ..................................................................................................................... 40 APPENDIX B – Required SWPPP Components by Project Type .................................... 48 Table 1.......................................................................................................................... 48 Table 2.......................................................................................................................... 50 APPENDIX C – Watersheds Requiring Enhanced Phosphorus Removal ........................ 52 APPENDIX D – Watersheds with Lower Disturbance Threshold ..................................... 58 APPENDIX E – 303(d) Segments Impaired by Construction Related Pollutant(s) ........... 59 APPENDIX F – List of NYS DEC Regional Offices .......................................................... 65 (Part I) 1 Part 1. PERMIT COVERAGE AND LIMITATIONS A. Permit Application This permit authorizes stormwater discharges to surface waters of the State from the following construction activities identified within 40 CFR Parts 122.26(b)(14)(x), 122.26(b)(15)(i) and 122.26(b)(15)(ii), provided all of the eligibility provisions of this permit are met: 1. Construction activities involving soil disturbances of one (1) or more acres; including disturbances of less than one acre that are part of a larger common plan of development or sale that will ultimately disturb one or more acres of land; excluding routine maintenance activity that is performed to maintain the original line and grade, hydraulic capacity or original purpose of a facility; 2. Construction activities involving soil disturbances of less than one (1) acre where the Department has determined that a SPDES permit is required for stormwater discharges based on the potential for contribution to a violation of a water quality standard or for significant contribution of pollutants to surface waters of the State. 3. Construction activities located in the watershed(s) identified in Appendix D that involve soil disturbances between five thousand (5,000) square feet and one (1) acre of land. B. Effluent Limitations Applicable to Discharges from Construction Activities Discharges authorized by this permit must achieve, at a minimum, the effluent limitations in Part I.B.1. (a) – (f) of this permit. These limitations represent the degree of effluent reduction attainable by the application of best practicable technology currently available. 1. Erosion and Sediment Control Requirements - The owner or operator must select, design, install, implement and maintain control measures to minimize the discharge of pollutants and prevent a violation of the water quality standards. The selection, design, installation, implementation, and maintenance of these control measures must meet the non-numeric effluent limitations in Part I.B.1.(a) – (f) of this permit and be in accordance with the New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016, using sound engineering judgment. Where control measures are not designed in conformance with the design criteria included in the technical standard, the owner or operator must include in the Stormwater Pollution Prevention Plan (“SWPPP”) the reason(s) for the (Part I.B.1) 2 deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the technical standard. a. Erosion and Sediment Controls. Design, install and maintain effective erosion and sediment controls to minimize the discharge of pollutants and prevent a violation of the water quality standards. At a minimum, such controls must be designed, installed and maintained to: (i) Minimize soil erosion through application of runoff control and soil stabilization control measure to minimize pollutant discharges; (ii) Control stormwater discharges, including both peak flowrates and total stormwater volume, to minimize channel and streambank erosion and scour in the immediate vicinity of the discharge points; (iii) Minimize the amount of soil exposed during construction activity; (iv) Minimize the disturbance of steep slopes; (v) Minimize sediment discharges from the site; (vi) Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas and maximize stormwater infiltration to reduce pollutant discharges, unless infeasible; (vii) Minimize soil compaction. Minimizing soil compaction is not required where the intended function of a specific area of the site dictates that it be compacted; (viii) Unless infeasible, preserve a sufficient amount of topsoil to complete soil restoration and establish a uniform, dense vegetative cover; and (ix) Minimize dust. On areas of exposed soil, minimize dust through the appropriate application of water or other dust suppression techniques to control the generation of pollutants that could be discharged from the site. b. Soil Stabilization. In areas where soil disturbance activity has temporarily or permanently ceased, the application of soil stabilization measures must be initiated by the end of the next business day and completed within fourteen (14) days from the date the current soil disturbance activity ceased. For construction sites that directly discharge to one of the 303(d) segments (Part I.B.1.b) 3 listed in Appendix E or is located in one of the watersheds listed in Appendix C, the application of soil stabilization measures must be initiated by the end of the next business day and completed within seven (7) days from the date the current soil disturbance activity ceased. See Appendix A for definition of Temporarily Ceased. c. Dewatering. Discharges from dewatering activities, including discharges from dewatering of trenches and excavations, must be managed by appropriate control measures. d. Pollution Prevention Measures. Design, install, implement, and maintain effective pollution prevention measures to minimize the discharge of pollutants and prevent a violation of the water quality standards. At a minimum, such measures must be designed, installed, implemented and maintained to: (i) Minimize the discharge of pollutants from equipment and vehicle washing, wheel wash water, and other wash waters. This applies to washing operations that use clean water only. Soaps, detergents and solvents cannot be used; (ii) Minimize the exposure of building materials, building products, construction wastes, trash, landscape materials, fertilizers, pesticides, herbicides, detergents, sanitary waste, hazardous and toxic waste, and other materials present on the site to precipitation and to stormwater. Minimization of exposure is not required in cases where the exposure to precipitation and to stormwater will not result in a discharge of pollutants, or where exposure of a specific material or product poses little risk of stormwater contamination (such as final products and materials intended for outdoor use) ; and (iii) Prevent the discharge of pollutants from spills and leaks and implement chemical spill and leak prevention and response procedures. e. Prohibited Discharges. The following discharges are prohibited: (i) Wastewater from washout of concrete; (ii) Wastewater from washout and cleanout of stucco, paint, form release oils, curing compounds and other construction materials; (Part I.B.1.e.iii) 4 (iii) Fuels, oils, or other pollutants used in vehicle and equipment operation and maintenance; (iv) Soaps or solvents used in vehicle and equipment washing; and (v) Toxic or hazardous substances from a spill or other release. f. Surface Outlets. When discharging from basins and impoundments, the outlets shall be designed, constructed and maintained in such a manner that sediment does not leave the basin or impoundment and that erosion at or below the outlet does not occur. C. Post-construction Stormwater Management Practice Requirements 1. The owner or operator of a construction activity that requires post-construction stormwater management practices pursuant to Part III.C. of this permit must select, design, install, and maintain the practices to meet the performance criteria in the New York State Stormwater Management Design Manual (“Design Manual”), dated January 2015, using sound engineering judgment. Where post-construction stormwater management practices (“SMPs”) are not designed in conformance with the performance criteria in the Design Manual, the owner or operator must include in the SWPPP the reason(s) for the deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the technical standard. 2. The owner or operator of a construction activity that requires post-construction stormwater management practices pursuant to Part III.C. of this permit must design the practices to meet the applicable sizing criteria in Part I.C.2.a., b., c. or d. of this permit. a. Sizing Criteria for New Development (i) Runoff Reduction Volume (“RRv”): Reduce the total Water Quality Volume (“WQv”) by application of RR techniques and standard SMPs with RRv capacity. The total WQv shall be calculated in accordance with the criteria in Section 4.2 of the Design Manual. (ii) Minimum RRv and Treatment of Remaining Total WQv: Construction activities that cannot meet the criteria in Part I.C.2.a.(i) of this permit due to site limitations shall direct runoff from all newly constructed impervious areas to a RR technique or standard SMP with RRv capacity unless infeasible. The specific site limitations that prevent the reduction of 100% of the WQv shall be documented in the SWPPP. (Part I.C.2.a.ii) 5 For each impervious area that is not directed to a RR technique or standard SMP with RRv capacity, the SWPPP must include documentation which demonstrates that all options were considered and for each option explains why it is considered infeasible. In no case shall the runoff reduction achieved from the newly constructed impervious areas be less than the Minimum RRv as calculated using the criteria in Section 4.3 of the Design Manual. The remaining portion of the total WQv that cannot be reduced shall be treated by application of standard SMPs. (iii) Channel Protection Volume (“Cpv”): Provide 24 hour extended detention of the post-developed 1-year, 24-hour storm event; remaining after runoff reduction. The Cpv requirement does not apply when: (1) Reduction of the entire Cpv is achieved by application of runoff reduction techniques or infiltration systems, or (2) The site discharges directly to tidal waters, or fifth order or larger streams. (iv) Overbank Flood Control Criteria (“Qp”): Requires storage to attenuate the post-development 10-year, 24-hour peak discharge rate (Qp) to predevelopment rates. The Qp requirement does not apply when: (1) the site discharges directly to tidal waters or fifth order or larger streams, or (2) A downstream analysis reveals that overbank control is not required. (v) Extreme Flood Control Criteria (“Qf”): Requires storage to attenuate the post-development 100-year, 24-hour peak discharge rate (Qf) to predevelopment rates. The Qf requirement does not apply when: (1) the site discharges directly to tidal waters or fifth order or larger streams, or (2) A downstream analysis reveals that overbank control is not required. b. Sizing Criteria for New Development in Enhanced Phosphorus Removal Watershed (i) Runoff Reduction Volume (RRv): Reduce the total Water Quality Volume (WQv) by application of RR techniques and standard SMPs with RRv capacity. The total WQv is the runoff volume from the 1-year, 24 hour design storm over the post-developed watershed and shall be (Part I.C.2.b.i) 6 calculated in accordance with the criteria in Section 10.3 of the Design Manual. (ii) Minimum RRv and Treatment of Remaining Total WQv: Construction activities that cannot meet the criteria in Part I.C.2.b.(i) of this permit due to site limitations shall direct runoff from all newly constructed impervious areas to a RR technique or standard SMP with RRv capacity unless infeasible. The specific site limitations that prevent the reduction of 100% of the WQv shall be documented in the SWPPP. For each impervious area that is not directed to a RR technique or standard SMP with RRv capacity, the SWPPP must include documentation which demonstrates that all options were considered and for each option explains why it is considered infeasible. In no case shall the runoff reduction achieved from the newly constructed impervious areas be less than the Minimum RRv as calculated using the criteria in Section 10.3 of the Design Manual. The remaining portion of the total WQv that cannot be reduced shall be treated by application of standard SMPs. (iii) Channel Protection Volume (Cpv): Provide 24 hour extended detention of the post-developed 1-year, 24-hour storm event; remaining after runoff reduction. The Cpv requirement does not apply when: (1) Reduction of the entire Cpv is achieved by application of runoff reduction techniques or infiltration systems, or (2) The site discharges directly to tidal waters, or fifth order or larger streams. (iv) Overbank Flood Control Criteria (Qp): Requires storage to attenuate the post-development 10-year, 24-hour peak discharge rate (Qp) to predevelopment rates. The Qp requirement does not apply when: (1) the site discharges directly to tidal waters or fifth order or larger streams, or (2) A downstream analysis reveals that overbank control is not required. (v) Extreme Flood Control Criteria (Qf): Requires storage to attenuate the post-development 100-year, 24-hour peak discharge rate (Qf) to predevelopment rates. The Qf requirement does not apply when: (1) the site discharges directly to tidal waters or fifth order or larger streams, or (2) A downstream analysis reveals that overbank control is not required. (Part I.C.2.c) 7 c. Sizing Criteria for Redevelopment Activity (i) Water Quality Volume (WQv): The WQv treatment objective for redevelopment activity shall be addressed by one of the following options. Redevelopment activities located in an Enhanced Phosphorus Removal Watershed (see Part III.B.3. and Appendix C of this permit) shall calculate the WQv in accordance with Section 10.3 of the Design Manual. All other redevelopment activities shall calculate the WQv in accordance with Section 4.2 of the Design Manual. (1) Reduce the existing impervious cover by a minimum of 25% of the total disturbed, impervious area. The Soil Restoration criteria in Section 5.1.6 of the Design Manual must be applied to all newly created pervious areas, or (2) Capture and treat a minimum of 25% of the WQv from the disturbed, impervious area by the application of standard SMPs; or reduce 25% of the WQv from the disturbed, impervious area by the application of RR techniques or standard SMPs with RRv capacity., or (3) Capture and treat a minimum of 75% of the WQv from the disturbed, impervious area as well as any additional runoff from tributary areas by application of the alternative practices discussed in Sections 9.3 and 9.4 of the Design Manual., or (4) Application of a combination of 1, 2 and 3 above that provide a weighted average of at least two of the above methods. Application of this method shall be in accordance with the criteria in Section 9.2.1(B) (IV) of the Design Manual. If there is an existing post-construction stormwater management practice located on the site that captures and treats runoff from the impervious area that is being disturbed, the WQv treatment option selected must, at a minimum, provide treatment equal to the treatment that was being provided by the existing practice(s) if that treatment is greater than the treatment required by options 1 – 4 above. (ii) Channel Protection Volume (Cpv): Not required if there are no changes to hydrology that increase the discharge rate from the project site. (iii) Overbank Flood Control Criteria (Qp): Not required if there are no changes to hydrology that increase the discharge rate from the project site. (iv) Extreme Flood Control Criteria (Qf): Not required if there are no changes to hydrology that increase the discharge rate from the project site (Part I.C.2.d) 8 d. Sizing Criteria for Combination of Redevelopment Activity and New Development Construction projects that include both New Development and Redevelopment Activity shall provide post-construction stormwater management controls that meet the sizing criteria calculated as an aggregate of the Sizing Criteria in Part I.C.2.a. or b. of this permit for the New Development portion of the project and Part I.C.2.c of this permit for Redevelopment Activity portion of the project. D. Maintaining Water Quality The Department expects that compliance with the conditions of this permit will control discharges necessary to meet applicable water quality standards. It shall be a violation of the ECL for any discharge to either cause or contribute to a violation of water quality standards as contained in Parts 700 through 705 of Title 6 of the Official Compilation of Codes, Rules and Regulations of the State of New York, such as: 1. There shall be no increase in turbidity that will cause a substantial visible contrast to natural conditions; 2. There shall be no increase in suspended, colloidal or settleable solids that will cause deposition or impair the waters for their best usages; and 3. There shall be no residue from oil and floating substances, nor visible oil film, nor globules of grease. If there is evidence indicating that the stormwater discharges authorized by this permit are causing, have the reasonable potential to cause, or are contributing to a violation of the water quality standards; the owner or operator must take appropriate corrective action in accordance with Part IV.C.5. of this general permit and document in accordance with Part IV.C.4. of this general permit. To address the water quality standard violation the owner or operator may need to provide additional information, include and implement appropriate controls in the SWPPP to correct the problem, or obtain an individual SPDES permit. If there is evidence indicating that despite compliance with the terms and conditions of this general permit it is demonstrated that the stormwater discharges authorized by this permit are causing or contributing to a violation of water quality standards, or if the Department determines that a modification of the permit is necessary to prevent a violation of water quality standards, the authorized discharges will no longer be eligible for coverage under this permit. The Department may require the owner or operator to obtain an individual SPDES permit to continue discharging. (Part I.E) 9 E. Eligibility Under This General Permit 1. This permit may authorize all discharges of stormwater from construction activity to surface waters of the State and groundwaters except for ineligible discharges identified under subparagraph F. of this Part. 2. Except for non-stormwater discharges explicitly listed in the next paragraph, this permit only authorizes stormwater discharges; including stormwater runoff, snowmelt runoff, and surface runoff and drainage, from construction activities. 3. Notwithstanding paragraphs E.1 and E.2 above, the following non-stormwater discharges are authorized by this permit: those listed in 6 NYCRR 750- 1.2(a)(29)(vi), with the following exception: “Discharges from firefighting activities are authorized only when the firefighting activities are emergencies/unplanned”; waters to which other components have not been added that are used to control dust in accordance with the SWPPP; and uncontaminated discharges from construction site de-watering operations. All non-stormwater discharges must be identified in the SWPPP. Under all circumstances, the owner or operator must still comply with water quality standards in Part I.D of this permit. 4. The owner or operator must maintain permit eligibility to discharge under this permit. Any discharges that are not compliant with the eligibility conditions of this permit are not authorized by the permit and the owner or operator must either apply for a separate permit to cover those ineligible discharges or take steps necessary to make the discharge eligible for coverage. F. Activities Which Are Ineligible for Coverage Under This General Permit All of the following are not authorized by this permit: 1. Discharges after construction activities have been completed and the site has undergone final stabilization; 2. Discharges that are mixed with sources of non-stormwater other than those expressly authorized under subsection E.3. of this Part and identified in the SWPPP required by this permit; 3. Discharges that are required to obtain an individual SPDES permit or another SPDES general permit pursuant to Part VII.K. of this permit; 4. Construction activities or discharges from construction activities that may adversely affect an endangered or threatened species unless the owner or (Part I.F.4) 10 operator has obtained a permit issued pursuant to 6 NYCRR Part 182 for the project or the Department has issued a letter of non-jurisdiction for the project. All documentation necessary to demonstrate eligibility shall be maintained on site in accordance with Part II.D.2 of this permit; 5. Discharges which either cause or contribute to a violation of water quality standards adopted pursuant to the ECL and its accompanying regulations; 6. Construction activities for residential, commercial and institutional projects: a. Where the discharges from the construction activities are tributary to waters of the state classified as AA or AA-s; and b. Which are undertaken on land with no existing impervious cover; and c. Which disturb one (1) or more acres of land designated on the current United States Department of Agriculture (“USDA”) Soil Survey as Soil Slope Phase “D”, (provided the map unit name is inclusive of slopes greater than 25%), or Soil Slope Phase “E” or “F” (regardless of the map unit name), or a combination of the three designations. 7. Construction activities for linear transportation projects and linear utility projects: a. Where the discharges from the construction activities are tributary to waters of the state classified as AA or AA-s; and b. Which are undertaken on land with no existing impervious cover; and c. Which disturb two (2) or more acres of land designated on the current USDA Soil Survey as Soil Slope Phase “D” (provided the map unit name is inclusive of slopes greater than 25%), or Soil Slope Phase “E” or “F” (regardless of the map unit name), or a combination of the three designations. (Part I.F.8) 11 8. Construction activities that have the potential to affect an historic property, unless there is documentation that such impacts have been resolved. The following documentation necessary to demonstrate eligibility with this requirement shall be maintained on site in accordance with Part II.D.2 of this permit and made available to the Department in accordance with Part VII.F of this permit: a. Documentation that the construction activity is not within an archeologically sensitive area indicated on the sensitivity map, and that the construction activity is not located on or immediately adjacent to a property listed or determined to be eligible for listing on the National or State Registers of Historic Places, and that there is no new permanent building on the construction site within the following distances from a building, structure, or object that is more than 50 years old, or if there is such a new permanent building on the construction site within those parameters that NYS Office of Parks, Recreation and Historic Preservation (OPRHP), a Historic Preservation Commission of a Certified Local Government, or a qualified preservation professional has determined that the building, structure, or object more than 50 years old is not historically/archeologically significant. ƒ 1-5 acres of disturbance - 20 feet ƒ 5-20 acres of disturbance - 50 feet ƒ 20+ acres of disturbance - 100 feet, or b. DEC consultation form sent to OPRHP, and copied to the NYS DEC Agency Historic Preservation Officer (APO), and (i) the State Environmental Quality Review (SEQR) Environmental Assessment Form (EAF) with a negative declaration or the Findings Statement, with documentation of OPRHP’s agreement with the resolution; or (ii) documentation from OPRHP that the construction activity will result in No Impact; or (iii) documentation from OPRHP providing a determination of No Adverse Impact; or (iv) a Letter of Resolution signed by the owner/operator, OPRHP and the DEC APO which allows for this construction activity to be eligible for coverage under the general permit in terms of the State Historic Preservation Act (SHPA); or c. Documentation of satisfactory compliance with Section 106 of the National Historic Preservation Act for a coterminous project area: (Part I.F.8.c) 12 (i) No Affect (ii) No Adverse Affect (iii) Executed Memorandum of Agreement, or d. Documentation that: (i) SHPA Section 14.09 has been completed by NYS DEC or another state agency. 9. Discharges from construction activities that are subject to an existing SPDES individual or general permit where a SPDES permit for construction activity has been terminated or denied; or where the owner or operator has failed to renew an expired individual permit. Part II. PERMIT COVERAGE A. How to Obtain Coverage 1. An owner or operator of a construction activity that is not subject to the requirements of a regulated, traditional land use control MS4 must first prepare a SWPPP in accordance with all applicable requirements of this permit and then submit a completed Notice of Intent (NOI) to the Department to be authorized to discharge under this permit. 2. An owner or operator of a construction activity that is subject to the requirements of a regulated, traditional land use control MS4 must first prepare a SWPPP in accordance with all applicable requirements of this permit and then have the SWPPP reviewed and accepted by the regulated, traditional land use control MS4 prior to submitting the NOI to the Department. The owner or operator shall have the “MS4 SWPPP Acceptance” form signed in accordance with Part VII.H., and then submit that form along with a completed NOI to the Department. 3. The requirement for an owner or operator to have its SWPPP reviewed and accepted by the regulated, traditional land use control MS4 prior to submitting the NOI to the Department does not apply to an owner or operator that is obtaining permit coverage in accordance with the requirements in Part II.F. (Change of Owner or Operator) or where the owner or operator of the construction activity is the regulated, traditional land use control MS4 . This exemption does not apply to construction activities subject to the New York City Administrative Code. (Part II.B) 13 B. Notice of Intent (NOI) Submittal 1. Prior to December 21, 2020, an owner or operator shall use either the electronic (eNOI) or paper version of the NOI that the Department prepared. Both versions of the NOI are located on the Department’s website (http://www.dec.ny.gov/ ). The paper version of the NOI shall be signed in accordance with Part VII.H. of this permit and submitted to the following address: NOTICE OF INTENT NYS DEC, Bureau of Water Permits 625 Broadway, 4th Floor Albany, New York 12233-3505 2. Beginning December 21, 2020 and in accordance with EPA’s 2015 NPDES Electronic Reporting Rule (40 CFR Part 127), the owner or operator must submit the NOI electronically using the Department’s online NOI. 3. The owner or operator shall have the SWPPP preparer sign the “SWPPP Preparer Certification” statement on the NOI prior to submitting the form to the Department. 4. As of the date the NOI is submitted to the Department, the owner or operator shall make the NOI and SWPPP available for review and copying in accordance with the requirements in Part VII.F. of this permit. C. Permit Authorization 1. An owner or operator shall not commence construction activity until their authorization to discharge under this permit goes into effect. 2. Authorization to discharge under this permit will be effective when the owner or operator has satisfied all of the following criteria: a. project review pursuant to the State Environmental Quality Review Act (“SEQRA”) have been satisfied, when SEQRA is applicable. See the Department’s website (http://www.dec.ny.gov/) for more information, b. where required, all necessary Department permits subject to the Uniform Procedures Act (“UPA”) (see 6 NYCRR Part 621), or the equivalent from another New York State agency, have been obtained, unless otherwise notified by the Department pursuant to 6 NYCRR 621.3(a)(4). Owners or operators of construction activities that are required to obtain UPA permits (Part II.C.2.b) 14 must submit a preliminary SWPPP to the appropriate DEC Permit Administrator at the Regional Office listed in Appendix F at the time all other necessary UPA permit applications are submitted. The preliminary SWPPP must include sufficient information to demonstrate that the construction activity qualifies for authorization under this permit, c. the final SWPPP has been prepared, and d. a complete NOI has been submitted to the Department in accordance with the requirements of this permit. 3. An owner or operator that has satisfied the requirements of Part II.C.2 above will be authorized to discharge stormwater from their construction activity in accordance with the following schedule: a. For construction activities that are not subject to the requirements of a regulated, traditional land use control MS4: (i) Five (5) business days from the date the Department receives a complete electronic version of the NOI (eNOI) for construction activities with a SWPPP that has been prepared in conformance with the design criteria in the technical standard referenced in Part III.B.1 and the performance criteria in the technical standard referenced in Parts III.B., 2 or 3, for construction activities that require post-construction stormwater management practices pursuant to Part III.C.; or (ii) Sixty (60) business days from the date the Department receives a complete NOI (electronic or paper version) for construction activities with a SWPPP that has not been prepared in conformance with the design criteria in technical standard referenced in Part III.B.1. or, for construction activities that require post-construction stormwater management practices pursuant to Part III.C., the performance criteria in the technical standard referenced in Parts III.B., 2 or 3, or; (iii) Ten (10) business days from the date the Department receives a complete paper version of the NOI for construction activities with a SWPPP that has been prepared in conformance with the design criteria in the technical standard referenced in Part III.B.1 and the performance criteria in the technical standard referenced in Parts III.B., 2 or 3, for construction activities that require post-construction stormwater management practices pursuant to Part III.C. (Part II.C.3.b) 15 b. For construction activities that are subject to the requirements of a regulated, traditional land use control MS4: (i) Five (5) business days from the date the Department receives both a complete electronic version of the NOI (eNOI) and signed “MS4 SWPPP Acceptance” form, or (ii) Ten (10) business days from the date the Department receives both a complete paper version of the NOI and signed “MS4 SWPPP Acceptance” form. 4. Coverage under this permit authorizes stormwater discharges from only those areas of disturbance that are identified in the NOI. If an owner or operator wishes to have stormwater discharges from future or additional areas of disturbance authorized, they must submit a new NOI that addresses that phase of the development, unless otherwise notified by the Department. The owner or operator shall not commence construction activity on the future or additional areas until their authorization to discharge under this permit goes into effect in accordance with Part II.C. of this permit. D. General Requirements For Owners or Operators With Permit Coverage 1. The owner or operator shall ensure that the provisions of the SWPPP are implemented from the commencement of construction activity until all areas of disturbance have achieved final stabilization and the Notice of Termination (“NOT”) has been submitted to the Department in accordance with Part V. of this permit. This includes any changes made to the SWPPP pursuant to Part III.A.4. of this permit. 2. The owner or operator shall maintain a copy of the General Permit (GP-0-20- 001), NOI, NOI Acknowledgment Letter, SWPPP, MS4 SWPPP Acceptance form, inspection reports, responsible contractor’s or subcontractor’s certification statement (see Part III.A.6.), and all documentation necessary to demonstrate eligibility with this permit at the construction site until all disturbed areas have achieved final stabilization and the NOT has been submitted to the Department. The documents must be maintained in a secure location, such as a job trailer, on-site construction office, or mailbox with lock. The secure location must be accessible during normal business hours to an individual performing a compliance inspection. 3. The owner or operator of a construction activity shall not disturb greater than five (5) acres of soil at any one time without prior written authorization from the Department or, in areas under the jurisdiction of a regulated, traditional land (Part II.D.3) 16 use control MS4, the regulated, traditional land use control MS4 (provided the regulated, traditional land use control MS4 is not the owner or operator of the construction activity). At a minimum, the owner or operator must comply with the following requirements in order to be authorized to disturb greater than five (5) acres of soil at any one time: a. The owner or operator shall have a qualified inspector conduct at least two (2) site inspections in accordance with Part IV.C. of this permit every seven (7) calendar days, for as long as greater than five (5) acres of soil remain disturbed. The two (2) inspections shall be separated by a minimum of two (2) full calendar days. b. In areas where soil disturbance activity has temporarily or permanently ceased, the application of soil stabilization measures must be initiated by the end of the next business day and completed within seven (7) days from the date the current soil disturbance activity ceased. The soil stabilization measures selected shall be in conformance with the technical standard, New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016. c. The owner or operator shall prepare a phasing plan that defines maximum disturbed area per phase and shows required cuts and fills. d. The owner or operator shall install any additional site-specific practices needed to protect water quality. e. The owner or operator shall include the requirements above in their SWPPP. 4. In accordance with statute, regulations, and the terms and conditions of this permit, the Department may suspend or revoke an owner’s or operator’s coverage under this permit at any time if the Department determines that the SWPPP does not meet the permit requirements or consistent with Part VII.K.. 5. Upon a finding of significant non-compliance with the practices described in the SWPPP or violation of this permit, the Department may order an immediate stop to all activity at the site until the non-compliance is remedied. The stop work order shall be in writing, describe the non-compliance in detail, and be sent to the owner or operator. 6. For construction activities that are subject to the requirements of a regulated, traditional land use control MS4, the owner or operator shall notify the (Part II.D.6) 17 regulated, traditional land use control MS4 in writing of any planned amendments or modifications to the post-construction stormwater management practice component of the SWPPP required by Part III.A. 4. and 5. of this permit. Unless otherwise notified by the regulated, traditional land use control MS4, the owner or operator shall have the SWPPP amendments or modifications reviewed and accepted by the regulated, traditional land use control MS4 prior to commencing construction of the post-construction stormwater management practice. E. Permit Coverage for Discharges Authorized Under GP-0-15-002 1. Upon renewal of SPDES General Permit for Stormwater Discharges from Construction Activity (Permit No. GP-0-15-002), an owner or operator of a construction activity with coverage under GP-0-15-002, as of the effective date of GP- 0-20-001, shall be authorized to discharge in accordance with GP- 0-20- 001, unless otherwise notified by the Department. An owner or operator may continue to implement the technical/design components of the post-construction stormwater management controls provided that such design was done in conformance with the technical standards in place at the time of initial project authorization. However, they must comply with the other, non-design provisions of GP-0-20-001. F. Change of Owner or Operator 1. When property ownership changes or when there is a change in operational control over the construction plans and specifications, the original owner or operator must notify the new owner or operator, in writing, of the requirement to obtain permit coverage by submitting a NOI with the Department. For construction activities subject to the requirements of a regulated, traditional land use control MS4, the original owner or operator must also notify the MS4, in writing, of the change in ownership at least 30 calendar days prior to the change in ownership. 2. Once the new owner or operator obtains permit coverage, the original owner or operator shall then submit a completed NOT with the name and permit identification number of the new owner or operator to the Department at the address in Part II.B.1. of this permit. If the original owner or operator maintains ownership of a portion of the construction activity and will disturb soil, they must maintain their coverage under the permit. 3. Permit coverage for the new owner or operator will be effective as of the date the Department receives a complete NOI, provided the original owner or (Part II.F.3) 18 operator was not subject to a sixty (60) business day authorization period that has not expired as of the date the Department receives the NOI from the new owner or operator. Part III. STORMWATER POLLUTION PREVENTION PLAN (SWPPP) A. General SWPPP Requirements 1. A SWPPP shall be prepared and implemented by the owner or operator of each construction activity covered by this permit. The SWPPP must document the selection, design, installation, implementation and maintenance of the control measures and practices that will be used to meet the effluent limitations in Part I.B. of this permit and where applicable, the post-construction stormwater management practice requirements in Part I.C. of this permit. The SWPPP shall be prepared prior to the submittal of the NOI. The NOI shall be submitted to the Department prior to the commencement of construction activity. A copy of the completed, final NOI shall be included in the SWPPP. 2. The SWPPP shall describe the erosion and sediment control practices and where required, post-construction stormwater management practices that will be used and/or constructed to reduce the pollutants in stormwater discharges and to assure compliance with the terms and conditions of this permit. In addition, the SWPPP shall identify potential sources of pollution which may reasonably be expected to affect the quality of stormwater discharges. 3. All SWPPPs that require the post-construction stormwater management practice component shall be prepared by a qualified professional that is knowledgeable in the principles and practices of stormwater management and treatment. 4. The owner or operator must keep the SWPPP current so that it at all times accurately documents the erosion and sediment controls practices that are being used or will be used during construction, and all post-construction stormwater management practices that will be constructed on the site. At a minimum, the owner or operator shall amend the SWPPP, including construction drawings: a. whenever the current provisions prove to be ineffective in minimizing pollutants in stormwater discharges from the site; (Part III.A.4.b) 19 b. whenever there is a change in design, construction, or operation at the construction site that has or could have an effect on the discharge of pollutants; c. to address issues or deficiencies identified during an inspection by the qualified inspector, the Department or other regulatory authority; and d. to document the final construction conditions. 5. The Department may notify the owner or operator at any time that the SWPPP does not meet one or more of the minimum requirements of this permit. The notification shall be in writing and identify the provisions of the SWPPP that require modification. Within fourteen (14) calendar days of such notification, or as otherwise indicated by the Department, the owner or operator shall make the required changes to the SWPPP and submit written notification to the Department that the changes have been made. If the owner or operator does not respond to the Department’s comments in the specified time frame, the Department may suspend the owner’s or operator’s coverage under this permit or require the owner or operator to obtain coverage under an individual SPDES permit in accordance with Part II.D.4. of this permit. 6. Prior to the commencement of construction activity, the owner or operator must identify the contractor(s) and subcontractor(s) that will be responsible for installing, constructing, repairing, replacing, inspecting and maintaining the erosion and sediment control practices included in the SWPPP; and the contractor(s) and subcontractor(s) that will be responsible for constructing the post-construction stormwater management practices included in the SWPPP. The owner or operator shall have each of the contractors and subcontractors identify at least one person from their company that will be responsible for implementation of the SWPPP. This person shall be known as the trained contractor. The owner or operator shall ensure that at least one trained contractor is on site on a daily basis when soil disturbance activities are being performed. The owner or operator shall have each of the contractors and subcontractors identified above sign a copy of the following certification statement below before they commence any construction activity: "I hereby certify under penalty of law that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with (Part III.A.6) 20 the terms and conditions of the most current version of the New York State Pollutant Discharge Elimination System ("SPDES") general permit for stormwater discharges from construction activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I am aware that there are significant penalties for submitting false information, that I do not believe to be true, including the possibility of fine and imprisonment for knowing violations" In addition to providing the certification statement above, the certification page must also identify the specific elements of the SWPPP that each contractor and subcontractor will be responsible for and include the name and title of the person providing the signature; the name and title of the trained contractor responsible for SWPPP implementation; the name, address and telephone number of the contracting firm; the address (or other identifying description) of the site; and the date the certification statement is signed. The owner or operator shall attach the certification statement(s) to the copy of the SWPPP that is maintained at the construction site. If new or additional contractors are hired to implement measures identified in the SWPPP after construction has commenced, they must also sign the certification statement and provide the information listed above. 7. For projects where the Department requests a copy of the SWPPP or inspection reports, the owner or operator shall submit the documents in both electronic (PDF only) and paper format within five (5) business days, unless otherwise notified by the Department. B. Required SWPPP Contents 1. Erosion and sediment control component - All SWPPPs prepared pursuant to this permit shall include erosion and sediment control practices designed in conformance with the technical standard, New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016. Where erosion and sediment control practices are not designed in conformance with the design criteria included in the technical standard, the owner or operator must demonstrate equivalence to the technical standard. At a minimum, the erosion and sediment control component of the SWPPP shall include the following: a. Background information about the scope of the project, including the location, type and size of project (Part III.B.1.b) 21 b. A site map/construction drawing(s) for the project, including a general location map. At a minimum, the site map shall show the total site area; all improvements; areas of disturbance; areas that will not be disturbed; existing vegetation; on-site and adjacent off-site surface water(s); floodplain/floodway boundaries; wetlands and drainage patterns that could be affected by the construction activity; existing and final contours ; locations of different soil types with boundaries; material, waste, borrow or equipment storage areas located on adjacent properties; and location(s) of the stormwater discharge(s); c. A description of the soil(s) present at the site, including an identification of the Hydrologic Soil Group (HSG); d. A construction phasing plan and sequence of operations describing the intended order of construction activities, including clearing and grubbing, excavation and grading, utility and infrastructure installation and any other activity at the site that results in soil disturbance; e. A description of the minimum erosion and sediment control practices to be installed or implemented for each construction activity that will result in soil disturbance. Include a schedule that identifies the timing of initial placement or implementation of each erosion and sediment control practice and the minimum time frames that each practice should remain in place or be implemented; f. A temporary and permanent soil stabilization plan that meets the requirements of this general permit and the technical standard, New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016, for each stage of the project, including initial land clearing and grubbing to project completion and achievement of final stabilization; g. A site map/construction drawing(s) showing the specific location(s), size(s), and length(s) of each erosion and sediment control practice; h. The dimensions, material specifications, installation details, and operation and maintenance requirements for all erosion and sediment control practices. Include the location and sizing of any temporary sediment basins and structural practices that will be used to divert flows from exposed soils; i. A maintenance inspection schedule for the contractor(s) identified in Part III.A.6. of this permit, to ensure continuous and effective operation of the erosion and sediment control practices. The maintenance inspection (Part III.B.1.i) 22 schedule shall be in accordance with the requirements in the technical standard, New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016; j. A description of the pollution prevention measures that will be used to control litter, construction chemicals and construction debris from becoming a pollutant source in the stormwater discharges; k. A description and location of any stormwater discharges associated with industrial activity other than construction at the site, including, but not limited to, stormwater discharges from asphalt plants and concrete plants located on the construction site; and l. Identification of any elements of the design that are not in conformance with the design criteria in the technical standard, New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016. Include the reason for the deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the technical standard. 2. Post-construction stormwater management practice component – The owner or operator of any construction project identified in Table 2 of Appendix B as needing post-construction stormwater management practices shall prepare a SWPPP that includes practices designed in conformance with the applicable sizing criteria in Part I.C.2.a., c. or d. of this permit and the performance criteria in the technical standard, New York State Stormwater Management Design Manual dated January 2015 Where post-construction stormwater management practices are not designed in conformance with the performance criteria in the technical standard, the owner or operator must include in the SWPPP the reason(s) for the deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the technical standard. The post-construction stormwater management practice component of the SWPPP shall include the following: a. Identification of all post-construction stormwater management practices to be constructed as part of the project. Include the dimensions, material specifications and installation details for each post-construction stormwater management practice; (Part III.B.2.b) 23 b. A site map/construction drawing(s) showing the specific location and size of each post-construction stormwater management practice; c. A Stormwater Modeling and Analysis Report that includes: (i) Map(s) showing pre-development conditions, including watershed/subcatchments boundaries, flow paths/routing, and design points; (ii) Map(s) showing post-development conditions, including watershed/subcatchments boundaries, flow paths/routing, design points and post-construction stormwater management practices; (iii) Results of stormwater modeling (i.e. hydrology and hydraulic analysis) for the required storm events. Include supporting calculations (model runs), methodology, and a summary table that compares pre and post- development runoff rates and volumes for the different storm events; (iv) Summary table, with supporting calculations, which demonstrates that each post-construction stormwater management practice has been designed in conformance with the sizing criteria included in the Design Manual; (v) Identification of any sizing criteria that is not required based on the requirements included in Part I.C. of this permit; and (vi) Identification of any elements of the design that are not in conformance with the performance criteria in the Design Manual. Include the reason(s) for the deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the Design Manual; d. Soil testing results and locations (test pits, borings); e. Infiltration test results, when required; and f. An operations and maintenance plan that includes inspection and maintenance schedules and actions to ensure continuous and effective operation of each post-construction stormwater management practice. The plan shall identify the entity that will be responsible for the long term operation and maintenance of each practice. (Part III.B.3) 24 3. Enhanced Phosphorus Removal Standards - All construction projects identified in Table 2 of Appendix B that are located in the watersheds identified in Appendix C shall prepare a SWPPP that includes post-construction stormwater management practices designed in conformance with the applicable sizing criteria in Part I.C.2. b., c. or d. of this permit and the performance criteria, Enhanced Phosphorus Removal Standards included in the Design Manual. At a minimum, the post-construction stormwater management practice component of the SWPPP shall include items 2.a - 2.f. above. C. Required SWPPP Components by Project Type Unless otherwise notified by the Department, owners or operators of construction activities identified in Table 1 of Appendix B are required to prepare a SWPPP that only includes erosion and sediment control practices designed in conformance with Part III.B.1 of this permit. Owners or operators of the construction activities identified in Table 2 of Appendix B shall prepare a SWPPP that also includes post-construction stormwater management practices designed in conformance with Part III.B.2 or 3 of this permit. Part IV. INSPECTION AND MAINTENANCE REQUIREMENTS A. General Construction Site Inspection and Maintenance Requirements 1. The owner or operator must ensure that all erosion and sediment control practices (including pollution prevention measures) and all post-construction stormwater management practices identified in the SWPPP are inspected and maintained in accordance with Part IV.B. and C. of this permit. 2. The terms of this permit shall not be construed to prohibit the State of New York from exercising any authority pursuant to the ECL, common law or federal law, or prohibit New York State from taking any measures, whether civil or criminal, to prevent violations of the laws of the State of New York or protect the public health and safety and/or the environment. B. Contractor Maintenance Inspection Requirements 1. The owner or operator of each construction activity identified in Tables 1 and 2 of Appendix B shall have a trained contractor inspect the erosion and sediment control practices and pollution prevention measures being implemented within the active work area daily to ensure that they are being maintained in effective operating condition at all times. If deficiencies are identified, the contractor shall (Part IV.B.1) 25 begin implementing corrective actions within one business day and shall complete the corrective actions in a reasonable time frame. 2. For construction sites where soil disturbance activities have been temporarily suspended (e.g. winter shutdown) and temporary stabilization measures have been applied to all disturbed areas, the trained contractor can stop conducting the maintenance inspections. The trained contractor shall begin conducting the maintenance inspections in accordance with Part IV.B.1. of this permit as soon as soil disturbance activities resume. 3. For construction sites where soil disturbance activities have been shut down with partial project completion, the trained contractor can stop conducting the maintenance inspections if all areas disturbed as of the project shutdown date have achieved final stabilization and all post-construction stormwater management practices required for the completed portion of the project have been constructed in conformance with the SWPPP and are operational. C. Qualified Inspector Inspection Requirements The owner or operator shall have a qualified inspector conduct site inspections in conformance with the following requirements: [Note: The trained contractor identified in Part III.A.6. and IV.B. of this permit cannot conduct the qualified inspector site inspections unless they meet the qualified inspector qualifications included in Appendix A. In order to perform these inspections, the trained contractor would have to be a: ƒ licensed Professional Engineer, ƒ Certified Professional in Erosion and Sediment Control (CPESC), ƒ New York State Erosion and Sediment Control Certificate Program holder ƒ Registered Landscape Architect, or ƒ someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided they have received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity]. 1. A qualified inspector shall conduct site inspections for all construction activities identified in Tables 1 and 2 of Appendix B, with the exception of: a. the construction of a single family residential subdivision with 25% or less impervious cover at total site build-out that involves a soil disturbance of one (1) or more acres of land but less than five (5) acres and is not located (Part IV.C.1.a) 26 in one of the watersheds listed in Appendix C and not directly discharging to one of the 303(d) segments listed in Appendix E; b. the construction of a single family home that involves a soil disturbance of one (1) or more acres of land but less than five (5) acres and is not located in one of the watersheds listed in Appendix C and not directly discharging to one of the 303(d) segments listed in Appendix E; c. construction on agricultural property that involves a soil disturbance of one (1) or more acres of land but less than five (5) acres; and d. construction activities located in the watersheds identified in Appendix D that involve soil disturbances between five thousand (5,000) square feet and one (1) acre of land. 2. Unless otherwise notified by the Department, the qualified inspector shall conduct site inspections in accordance with the following timetable: a. For construction sites where soil disturbance activities are on-going, the qualified inspector shall conduct a site inspection at least once every seven (7) calendar days. b. For construction sites where soil disturbance activities are on-going and the owner or operator has received authorization in accordance with Part II.D.3 to disturb greater than five (5) acres of soil at any one time, the qualified inspector shall conduct at least two (2) site inspections every seven (7) calendar days. The two (2) inspections shall be separated by a minimum of two (2) full calendar days. c. For construction sites where soil disturbance activities have been temporarily suspended (e.g. winter shutdown) and temporary stabilization measures have been applied to all disturbed areas, the qualified inspector shall conduct a site inspection at least once every thirty (30) calendar days. The owner or operator shall notify the DOW Water (SPDES) Program contact at the Regional Office (see contact information in Appendix F) or, in areas under the jurisdiction of a regulated, traditional land use control MS4, the regulated, traditional land use control MS4 (provided the regulated, traditional land use control MS4 is not the owner or operator of the construction activity) in writing prior to reducing the frequency of inspections. (Part IV.C.2.d) 27 d. For construction sites where soil disturbance activities have been shut down with partial project completion, the qualified inspector can stop conducting inspections if all areas disturbed as of the project shutdown date have achieved final stabilization and all post-construction stormwater management practices required for the completed portion of the project have been constructed in conformance with the SWPPP and are operational. The owner or operator shall notify the DOW Water (SPDES) Program contact at the Regional Office (see contact information in Appendix F) or, in areas under the jurisdiction of a regulated, traditional land use control MS4, the regulated, traditional land use control MS4 (provided the regulated, traditional land use control MS4 is not the owner or operator of the construction activity) in writing prior to the shutdown. If soil disturbance activities are not resumed within 2 years from the date of shutdown, the owner or operator shall have the qualified inspector perform a final inspection and certify that all disturbed areas have achieved final stabilization, and all temporary, structural erosion and sediment control measures have been removed; and that all post-construction stormwater management practices have been constructed in conformance with the SWPPP by signing the “Final Stabilization” and “Post-Construction Stormwater Management Practice” certification statements on the NOT. The owner or operator shall then submit the completed NOT form to the address in Part II.B.1 of this permit. e. For construction sites that directly discharge to one of the 303(d) segments listed in Appendix E or is located in one of the watersheds listed in Appendix C, the qualified inspector shall conduct at least two (2) site inspections every seven (7) calendar days. The two (2) inspections shall be separated by a minimum of two (2) full calendar days. 3. At a minimum, the qualified inspector shall inspect all erosion and sediment control practices and pollution prevention measures to ensure integrity and effectiveness, all post-construction stormwater management practices under construction to ensure that they are constructed in conformance with the SWPPP, all areas of disturbance that have not achieved final stabilization, all points of discharge to natural surface waterbodies located within, or immediately adjacent to, the property boundaries of the construction site, and all points of discharge from the construction site. 4. The qualified inspector shall prepare an inspection report subsequent to each and every inspection. At a minimum, the inspection report shall include and/or address the following: (Part IV.C.4.a) 28 a. Date and time of inspection; b. Name and title of person(s) performing inspection; c. A description of the weather and soil conditions (e.g. dry, wet, saturated) at the time of the inspection; d. A description of the condition of the runoff at all points of discharge from the construction site. This shall include identification of any discharges of sediment from the construction site. Include discharges from conveyance systems (i.e. pipes, culverts, ditches, etc.) and overland flow; e. A description of the condition of all natural surface waterbodies located within, or immediately adjacent to, the property boundaries of the construction site which receive runoff from disturbed areas. This shall include identification of any discharges of sediment to the surface waterbody; f. Identification of all erosion and sediment control practices and pollution prevention measures that need repair or maintenance; g. Identification of all erosion and sediment control practices and pollution prevention measures that were not installed properly or are not functioning as designed and need to be reinstalled or replaced; h. Description and sketch of areas with active soil disturbance activity, areas that have been disturbed but are inactive at the time of the inspection, and areas that have been stabilized (temporary and/or final) since the last inspection; i. Current phase of construction of all post-construction stormwater management practices and identification of all construction that is not in conformance with the SWPPP and technical standards; j. Corrective action(s) that must be taken to install, repair, replace or maintain erosion and sediment control practices and pollution prevention measures; and to correct deficiencies identified with the construction of the post- construction stormwater management practice(s); k. Identification and status of all corrective actions that were required by previous inspection; and (Part IV.C.4.l) 29 l. Digital photographs, with date stamp, that clearly show the condition of all practices that have been identified as needing corrective actions. The qualified inspector shall attach paper color copies of the digital photographs to the inspection report being maintained onsite within seven (7) calendar days of the date of the inspection. The qualified inspector shall also take digital photographs, with date stamp, that clearly show the condition of the practice(s) after the corrective action has been completed. The qualified inspector shall attach paper color copies of the digital photographs to the inspection report that documents the completion of the corrective action work within seven (7) calendar days of that inspection. 5. Within one business day of the completion of an inspection, the qualified inspector shall notify the owner or operator and appropriate contractor or subcontractor identified in Part III.A.6. of this permit of any corrective actions that need to be taken. The contractor or subcontractor shall begin implementing the corrective actions within one business day of this notification and shall complete the corrective actions in a reasonable time frame. 6. All inspection reports shall be signed by the qualified inspector. Pursuant to Part II.D.2. of this permit, the inspection reports shall be maintained on site with the SWPPP. Part V. TERMINATION OF PERMIT COVERAGE A. Termination of Permit Coverage 1. An owner or operator that is eligible to terminate coverage under this permit must submit a completed NOT form to the address in Part II.B.1 of this permit. The NOT form shall be one which is associated with this permit, signed in accordance with Part VII.H of this permit. 2. An owner or operator may terminate coverage when one or more the following conditions have been met: a. Total project completion - All construction activity identified in the SWPPP has been completed; and all areas of disturbance have achieved final stabilization; and all temporary, structural erosion and sediment control measures have been removed; and all post-construction stormwater management practices have been constructed in conformance with the SWPPP and are operational; (Part V.A.2.b) 30 b. Planned shutdown with partial project completion - All soil disturbance activities have ceased; and all areas disturbed as of the project shutdown date have achieved final stabilization; and all temporary, structural erosion and sediment control measures have been removed; and all post- construction stormwater management practices required for the completed portion of the project have been constructed in conformance with the SWPPP and are operational; c. A new owner or operator has obtained coverage under this permit in accordance with Part II.F. of this permit. d. The owner or operator obtains coverage under an alternative SPDES general permit or an individual SPDES permit. 3. For construction activities meeting subdivision 2a. or 2b. of this Part, the owner or operator shall have the qualified inspector perform a final site inspection prior to submitting the NOT. The qualified inspector shall, by signing the “Final Stabilization” and “Post-Construction Stormwater Management Practice certification statements on the NOT, certify that all the requirements in Part V.A.2.a. or b. of this permit have been achieved. 4. For construction activities that are subject to the requirements of a regulated, traditional land use control MS4 and meet subdivision 2a. or 2b. of this Part, the owner or operator shall have the regulated, traditional land use control MS4 sign the “MS4 Acceptance” statement on the NOT in accordance with the requirements in Part VII.H. of this permit. The regulated, traditional land use control MS4 official, by signing this statement, has determined that it is acceptable for the owner or operator to submit the NOT in accordance with the requirements of this Part. The regulated, traditional land use control MS4 can make this determination by performing a final site inspection themselves or by accepting the qualified inspector’s final site inspection certification(s) required in Part V.A.3. of this permit. 5. For construction activities that require post-construction stormwater management practices and meet subdivision 2a. of this Part, the owner or operator must, prior to submitting the NOT, ensure one of the following: a. the post-construction stormwater management practice(s) and any right-of- way(s) needed to maintain such practice(s) have been deeded to the municipality in which the practice(s) is located, (Part V.A.5.b) 31 b. an executed maintenance agreement is in place with the municipality that will maintain the post-construction stormwater management practice(s), c. for post-construction stormwater management practices that are privately owned, the owner or operator has a mechanism in place that requires operation and maintenance of the practice(s) in accordance with the operation and maintenance plan, such as a deed covenant in the owner or operator’s deed of record, d. for post-construction stormwater management practices that are owned by a public or private institution (e.g. school, university, hospital), government agency or authority, or public utility; the owner or operator has policy and procedures in place that ensures operation and maintenance of the practices in accordance with the operation and maintenance plan. Part VI. REPORTING AND RETENTION RECORDS A. Record Retention The owner or operator shall retain a copy of the NOI, NOI Acknowledgment Letter, SWPPP, MS4 SWPPP Acceptance form and any inspection reports that were prepared in conjunction with this permit for a period of at least five (5) years from the date that the Department receives a complete NOT submitted in accordance with Part V. of this general permit. B. Addresses With the exception of the NOI, NOT, and MS4 SWPPP Acceptance form (which must be submitted to the address referenced in Part II.B.1 of this permit), all written correspondence requested by the Department, including individual permit applications, shall be sent to the address of the appropriate DOW Water (SPDES) Program contact at the Regional Office listed in Appendix F. Part VII. STANDARD PERMIT CONDITIONS A. Duty to Comply The owner or operator must comply with all conditions of this permit. All contractors and subcontractors associated with the project must comply with the terms of the SWPPP. Any non-compliance with this permit constitutes a violation of the Clean Water (Part VII.A) 32 Act (CWA) and the ECL and is grounds for an enforcement action against the owner or operator and/or the contractor/subcontractor; permit revocation, suspension or modification; or denial of a permit renewal application. Upon a finding of significant non- compliance with this permit or the applicable SWPPP, the Department may order an immediate stop to all construction activity at the site until the non-compliance is remedied. The stop work order shall be in writing, shall describe the non-compliance in detail, and shall be sent to the owner or operator. If any human remains or archaeological remains are encountered during excavation, the owner or operator must immediately cease, or cause to cease, all construction activity in the area of the remains and notify the appropriate Regional Water Engineer (RWE). Construction activity shall not resume until written permission to do so has been received from the RWE. B. Continuation of the Expired General Permit This permit expires five (5) years from the effective date. If a new general permit is not issued prior to the expiration of this general permit, an owner or operator with coverage under this permit may continue to operate and discharge in accordance with the terms and conditions of this general permit, if it is extended pursuant to the State Administrative Procedure Act and 6 NYCRR Part 621, until a new general permit is issued. C. Enforcement Failure of the owner or operator, its contractors, subcontractors, agents and/or assigns to strictly adhere to any of the permit requirements contained herein shall constitute a violation of this permit. There are substantial criminal, civil, and administrative penalties associated with violating the provisions of this permit. Fines of up to $37,500 per day for each violation and imprisonment for up to fifteen (15) years may be assessed depending upon the nature and degree of the offense. D. Need to Halt or Reduce Activity Not a Defense It shall not be a defense for an owner or operator in an enforcement action that it would have been necessary to halt or reduce the construction activity in order to maintain compliance with the conditions of this permit. (Part VII.E) 33 E. Duty to Mitigate The owner or operator and its contractors and subcontractors shall take all reasonable steps to minimize or prevent any discharge in violation of this permit which has a reasonable likelihood of adversely affecting human health or the environment. F. Duty to Provide Information The owner or operator shall furnish to the Department, within a reasonable specified time period of a written request, all documentation necessary to demonstrate eligibility and any information to determine compliance with this permit or to determine whether cause exists for modifying or revoking this permit, or suspending or denying coverage under this permit, in accordance with the terms and conditions of this permit. The NOI, SWPPP and inspection reports required by this permit are public documents that the owner or operator must make available for review and copying by any person within five (5) business days of the owner or operator receiving a written request by any such person to review these documents. Copying of documents will be done at the requester’s expense. G. Other Information When the owner or operator becomes aware that they failed to submit any relevant facts, or submitted incorrect information in the NOI or in any of the documents required by this permit , or have made substantive revisions to the SWPPP (e.g. the scope of the project changes significantly, the type of post-construction stormwater management practice(s) changes, there is a reduction in the sizing of the post-construction stormwater management practice, or there is an increase in the disturbance area or impervious area), which were not reflected in the original NOI submitted to the Department, they shall promptly submit such facts or information to the Department using the contact information in Part II.A. of this permit. Failure of the owner or operator to correct or supplement any relevant facts within five (5) business days of becoming aware of the deficiency shall constitute a violation of this permit. H. Signatory Requirements 1. All NOIs and NOTs shall be signed as follows: a. For a corporation these forms shall be signed by a responsible corporate officer. For the purpose of this section, a responsible corporate officer means: (Part VII.H.1.a) 34 (i) a president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy or decision-making functions for the corporation; or (ii) the manager of one or more manufacturing, production or operating facilities, provided the manager is authorized to make management decisions which govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessary systems are established or actions taken to gather complete and accurate information for permit application requirements; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures; b. For a partnership or sole proprietorship these forms shall be signed by a general partner or the proprietor, respectively; or c. For a municipality, State, Federal, or other public agency these forms shall be signed by either a principal executive officer or ranking elected official. For purposes of this section, a principal executive officer of a Federal agency includes: (i) the chief executive officer of the agency, or (ii) a senior executive officer having responsibility for the overall operations of a principal geographic unit of the agency (e.g., Regional Administrators of EPA). 2. The SWPPP and other information requested by the Department shall be signed by a person described in Part VII.H.1. of this permit or by a duly authorized representative of that person. A person is a duly authorized representative only if: a. The authorization is made in writing by a person described in Part VII.H.1. of this permit; b. The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility or activity, such as the position of plant manager, operator of a well or a well field, (Part VII.H.2.b) 35 superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters for the company. (A duly authorized representative may thus be either a named individual or any individual occupying a named position) and, c. The written authorization shall include the name, title and signature of the authorized representative and be attached to the SWPPP. 3. All inspection reports shall be signed by the qualified inspector that performs the inspection. 4. The MS4 SWPPP Acceptance form shall be signed by the principal executive officer or ranking elected official from the regulated, traditional land use control MS4, or by a duly authorized representative of that person. It shall constitute a permit violation if an incorrect and/or improper signatory authorizes any required forms, SWPPP and/or inspection reports. I. Property Rights The issuance of this permit does not convey any property rights of any sort, nor any exclusive privileges, nor does it authorize any injury to private property nor any invasion of personal rights, nor any infringement of Federal, State or local laws or regulations. Owners or operators must obtain any applicable conveyances, easements, licenses and/or access to real property prior to commencing construction activity. J. Severability The provisions of this permit are severable, and if any provision of this permit, or the application of any provision of this permit to any circumstance, is held invalid, the application of such provision to other circumstances, and the remainder of this permit shall not be affected thereby. K. Requirement to Obtain Coverage Under an Alternative Permit 1. The Department may require any owner or operator authorized by this permit to apply for and/or obtain either an individual SPDES permit or another SPDES general permit. When the Department requires any discharger authorized by a general permit to apply for an individual SPDES permit, it shall notify the discharger in writing that a permit application is required. This notice shall (Part VII.K.1) 36 include a brief statement of the reasons for this decision, an application form, a statement setting a time frame for the owner or operator to file the application for an individual SPDES permit, and a deadline, not sooner than 180 days from owner or operator receipt of the notification letter, whereby the authorization to discharge under this general permit shall be terminated. Applications must be submitted to the appropriate Permit Administrator at the Regional Office. The Department may grant additional time upon demonstration, to the satisfaction of the Department, that additional time to apply for an alternative authorization is necessary or where the Department has not provided a permit determination in accordance with Part 621 of this Title. 2. When an individual SPDES permit is issued to a discharger authorized to discharge under a general SPDES permit for the same discharge(s), the general permit authorization for outfalls authorized under the individual SPDES permit is automatically terminated on the effective date of the individual permit unless termination is earlier in accordance with 6 NYCRR Part 750. L. Proper Operation and Maintenance The owner or operator shall at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) which are installed or used by the owner or operator to achieve compliance with the conditions of this permit and with the requirements of the SWPPP. M. Inspection and Entry The owner or operator shall allow an authorized representative of the Department, EPA, applicable county health department, or, in the case of a construction site which discharges through an MS4, an authorized representative of the MS4 receiving the discharge, upon the presentation of credentials and other documents as may be required by law, to: 1. Enter upon the owner’s or operator's premises where a regulated facility or activity is located or conducted or where records must be kept under the conditions of this permit; 2. Have access to and copy at reasonable times, any records that must be kept under the conditions of this permit; and (Part VII.M.3) 37 3. Inspect at reasonable times any facilities or equipment (including monitoring and control equipment), practices or operations regulated or required by this permit. 4. Sample or monitor at reasonable times, for purposes of assuring permit compliance or as otherwise authorized by the Act or ECL, any substances or parameters at any location. N. Permit Actions This permit may, at any time, be modified, suspended, revoked, or renewed by the Department in accordance with 6 NYCRR Part 621. The filing of a request by the owner or operator for a permit modification, revocation and reissuance, termination, a notification of planned changes or anticipated noncompliance does not limit, diminish and/or stay compliance with any terms of this permit. O. Definitions Definitions of key terms are included in Appendix A of this permit. P. Re-Opener Clause 1. If there is evidence indicating potential or realized impacts on water quality due to any stormwater discharge associated with construction activity covered by this permit, the owner or operator of such discharge may be required to obtain an individual permit or alternative general permit in accordance with Part VII.K. of this permit or the permit may be modified to include different limitations and/or requirements. 2. Any Department initiated permit modification, suspension or revocation will be conducted in accordance with 6 NYCRR Part 621, 6 NYCRR 750-1.18, and 6 NYCRR 750-1.20. Q. Penalties for Falsification of Forms and Reports In accordance with 6NYCRR Part 750-2.4 and 750-2.5, any person who knowingly makes any false material statement, representation, or certification in any application, record, report or other document filed or required to be maintained under this permit, including reports of compliance or noncompliance shall, upon conviction, be punished in accordance with ECL §71-1933 and or Articles 175 and 210 of the New York State Penal Law. (Part VII.R) 38 R. Other Permits Nothing in this permit relieves the owner or operator from a requirement to obtain any other permits required by law. 39 APPENDIX A – Acronyms and Definitions Acronyms APO – Agency Preservation Officer BMP – Best Management Practice CPESC – Certified Professional in Erosion and Sediment Control Cpv – Channel Protection Volume CWA – Clean Water Act (or the Federal Water Pollution Control Act, 33 U.S.C. §1251 et seq) DOW – Division of Water EAF – Environmental Assessment Form ECL - Environmental Conservation Law EPA – U. S. Environmental Protection Agency HSG – Hydrologic Soil Group MS4 – Municipal Separate Storm Sewer System NOI – Notice of Intent NOT – Notice of Termination NPDES – National Pollutant Discharge Elimination System OPRHP – Office of Parks, Recreation and Historic Places Qf – Extreme Flood Qp – Overbank Flood RRv – Runoff Reduction Volume RWE – Regional Water Engineer SEQR – State Environmental Quality Review SEQRA - State Environmental Quality Review Act SHPA – State Historic Preservation Act SPDES – State Pollutant Discharge Elimination System SWPPP – Stormwater Pollution Prevention Plan TMDL – Total Maximum Daily Load UPA – Uniform Procedures Act USDA – United States Department of Agriculture WQv – Water Quality Volume Appendix A 40 Definitions All definitions in this section are solely for the purposes of this permit. Agricultural Building – a structure designed and constructed to house farm implements, hay, grain, poultry, livestock or other horticultural products; excluding any structure designed, constructed or used, in whole or in part, for human habitation, as a place of employment where agricultural products are processed, treated or packaged, or as a place used by the public. Agricultural Property –means the land for construction of a barn, agricultural building, silo, stockyard, pen or other structural practices identified in Table II in the “Agricultural Management Practices Catalog for Nonpoint Source Pollution in New York State” prepared by the Department in cooperation with agencies of New York Nonpoint Source Coordinating Committee (dated June 2007). Alter Hydrology from Pre to Post-Development Conditions - means the post- development peak flow rate(s) has increased by more than 5% of the pre-developed condition for the design storm of interest (e.g. 10 yr and 100 yr). Combined Sewer - means a sewer that is designed to collect and convey both “sewage” and “stormwater”. Commence (Commencement of) Construction Activities - means the initial disturbance of soils associated with clearing, grading or excavation activities; or other construction related activities that disturb or expose soils such as demolition, stockpiling of fill material, and the initial installation of erosion and sediment control practices required in the SWPPP. See definition for “Construction Activity(ies)” also. Construction Activity(ies) - means any clearing, grading, excavation, filling, demolition or stockpiling activities that result in soil disturbance. Clearing activities can include, but are not limited to, logging equipment operation, the cutting and skidding of trees, stump removal and/or brush root removal. Construction activity does not include routine maintenance that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of a facility. Construction Site – means the land area where construction activity(ies) will occur. See definition for “Commence (Commencement of) Construction Activities” and “Larger Common Plan of Development or Sale” also. Dewatering – means the act of draining rainwater and/or groundwater from building foundations, vaults or excavations/trenches. Direct Discharge (to a specific surface waterbody) - means that runoff flows from a construction site by overland flow and the first point of discharge is the specific surface waterbody, or runoff flows from a construction site to a separate storm sewer system Appendix A 41 and the first point of discharge from the separate storm sewer system is the specific surface waterbody. Discharge(s) - means any addition of any pollutant to waters of the State through an outlet or point source. Embankment –means an earthen or rock slope that supports a road/highway. Endangered or Threatened Species – see 6 NYCRR Part 182 of the Department’s rules and regulations for definition of terms and requirements. Environmental Conservation Law (ECL) - means chapter 43-B of the Consolidated Laws of the State of New York, entitled the Environmental Conservation Law. Equivalent (Equivalence) – means that the practice or measure meets all the performance, longevity, maintenance, and safety objectives of the technical standard and will provide an equal or greater degree of water quality protection. Final Stabilization - means that all soil disturbance activities have ceased and a uniform, perennial vegetative cover with a density of eighty (80) percent over the entire pervious surface has been established; or other equivalent stabilization measures, such as permanent landscape mulches, rock rip-rap or washed/crushed stone have been applied on all disturbed areas that are not covered by permanent structures, concrete or pavement. General SPDES permit - means a SPDES permit issued pursuant to 6 NYCRR Part 750-1.21 and Section 70-0117 of the ECL authorizing a category of discharges. Groundwater(s) - means waters in the saturated zone. The saturated zone is a subsurface zone in which all the interstices are filled with water under pressure greater than that of the atmosphere. Although the zone may contain gas-filled interstices or interstices filled with fluids other than water, it is still considered saturated. Historic Property – means any building, structure, site, object or district that is listed on the State or National Registers of Historic Places or is determined to be eligible for listing on the State or National Registers of Historic Places. Impervious Area (Cover) - means all impermeable surfaces that cannot effectively infiltrate rainfall. This includes paved, concrete and gravel surfaces (i.e. parking lots, driveways, roads, runways and sidewalks); building rooftops and miscellaneous impermeable structures such as patios, pools, and sheds. Infeasible – means not technologically possible, or not economically practicable and achievable in light of best industry practices. Appendix A 42 Larger Common Plan of Development or Sale - means a contiguous area where multiple separate and distinct construction activities are occurring, or will occur, under one plan. The term “plan” in “larger common plan of development or sale” is broadly defined as any announcement or piece of documentation (including a sign, public notice or hearing, marketing plan, advertisement, drawing, permit application, State Environmental Quality Review Act (SEQRA) environmental assessment form or other documents, zoning request, computer design, etc.) or physical demarcation (including boundary signs, lot stakes, surveyor markings, etc.) indicating that construction activities may occur on a specific plot. For discrete construction projects that are located within a larger common plan of development or sale that are at least 1/4 mile apart, each project can be treated as a separate plan of development or sale provided any interconnecting road, pipeline or utility project that is part of the same “common plan” is not concurrently being disturbed. Minimize – means reduce and/or eliminate to the extent achievable using control measures (including best management practices) that are technologically available and economically practicable and achievable in light of best industry practices. Municipal Separate Storm Sewer (MS4) - a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains): (i) Owned or operated by a State, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to State law) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the CWA that discharges to surface waters of the State; (ii) Designed or used for collecting or conveying stormwater; (iii) Which is not a combined sewer; and (iv) Which is not part of a Publicly Owned Treatment Works (POTW) as defined at 40 CFR 122.2. National Pollutant Discharge Elimination System (NPDES) - means the national system for the issuance of wastewater and stormwater permits under the Federal Water Pollution Control Act (Clean Water Act). Natural Buffer –means an undisturbed area with natural cover running along a surface water (e.g. wetland, stream, river, lake, etc.). New Development – means any land disturbance that does not meet the definition of Redevelopment Activity included in this appendix. Appendix A 43 New York State Erosion and Sediment Control Certificate Program – a certificate program that establishes and maintains a process to identify and recognize individuals who are capable of developing, designing, inspecting and maintaining erosion and sediment control plans on projects that disturb soils in New York State. The certificate program is administered by the New York State Conservation District Employees Association. NOI Acknowledgment Letter - means the letter that the Department sends to an owner or operator to acknowledge the Department’s receipt and acceptance of a complete Notice of Intent. This letter documents the owner’s or operator’s authorization to discharge in accordance with the general permit for stormwater discharges from construction activity. Nonpoint Source - means any source of water pollution or pollutants which is not a discrete conveyance or point source permitted pursuant to Title 7 or 8 of Article 17 of the Environmental Conservation Law (see ECL Section 17-1403). Overbank –means flow events that exceed the capacity of the stream channel and spill out into the adjacent floodplain. Owner or Operator - means the person, persons or legal entity which owns or leases the property on which the construction activity is occurring; an entity that has operational control over the construction plans and specifications, including the ability to make modifications to the plans and specifications; and/or an entity that has day-to-day operational control of those activities at a project that are necessary to ensure compliance with the permit conditions. Performance Criteria – means the design criteria listed under the “Required Elements” sections in Chapters 5, 6 and 10 of the technical standard, New York State Stormwater Management Design Manual, dated January 2015. It does not include the Sizing Criteria (i.e. WQv, RRv, Cpv, Qp and Qf ) in Part I.C.2. of the permit. Point Source - means any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, vessel or other floating craft, or landfill leachate collection system from which pollutants are or may be discharged. Pollutant - means dredged spoil, filter backwash, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand and industrial, municipal, agricultural waste and ballast discharged into water; which may cause or might reasonably be expected to cause pollution of the waters of the state in contravention of the standards or guidance values adopted as provided in 6 NYCRR Parts 700 et seq . Appendix A 44 Qualified Inspector - means a person that is knowledgeable in the principles and practices of erosion and sediment control, such as a licensed Professional Engineer, Certified Professional in Erosion and Sediment Control (CPESC), Registered Landscape Architect, New York State Erosion and Sediment Control Certificate Program holder or other Department endorsed individual(s). It can also mean someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided that person has training in the principles and practices of erosion and sediment control. Training in the principles and practices of erosion and sediment control means that the individual working under the direct supervision of the licensed Professional Engineer or Registered Landscape Architect has received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity. After receiving the initial training, the individual working under the direct supervision of the licensed Professional Engineer or Registered Landscape Architect shall receive four (4) hours of training every three (3) years. It can also mean a person that meets the Qualified Professional qualifications in addition to the Qualified Inspector qualifications. Note: Inspections of any post-construction stormwater management practices that include structural components, such as a dam for an impoundment, shall be performed by a licensed Professional Engineer. Qualified Professional - means a person that is knowledgeable in the principles and practices of stormwater management and treatment, such as a licensed Professional Engineer, Registered Landscape Architect or other Department endorsed individual(s). Individuals preparing SWPPPs that require the post-construction stormwater management practice component must have an understanding of the principles of hydrology, water quality management practice design, water quantity control design, and, in many cases, the principles of hydraulics. All components of the SWPPP that involve the practice of engineering, as defined by the NYS Education Law (see Article 145), shall be prepared by, or under the direct supervision of, a professional engineer licensed to practice in the State of New York. Redevelopment Activity(ies) – means the disturbance and reconstruction of existing impervious area, including impervious areas that were removed from a project site within five (5) years of preliminary project plan submission to the local government (i.e. site plan, subdivision, etc.). Regulated, Traditional Land Use Control MS4 - means a city, town or village with land use control authority that is authorized to discharge under New York State DEC’s Appendix A 45 SPDES General Permit For Stormwater Discharges from Municipal Separate Stormwater Sewer Systems (MS4s) or the City of New York’s Individual SPDES Permit for their Municipal Separate Storm Sewer Systems (NY-0287890). Routine Maintenance Activity - means construction activity that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of a facility, including, but not limited to: ƒ Re-grading of gravel roads or parking lots, ƒ Cleaning and shaping of existing roadside ditches and culverts that maintains the approximate original line and grade, and hydraulic capacity of the ditch, ƒ Cleaning and shaping of existing roadside ditches that does not maintain the approximate original grade, hydraulic capacity and purpose of the ditch if the changes to the line and grade, hydraulic capacity or purpose of the ditch are installed to improve water quality and quantity controls (e.g. installing grass lined ditch), ƒ Placement of aggregate shoulder backing that stabilizes the transition between the road shoulder and the ditch or embankment, ƒ Full depth milling and filling of existing asphalt pavements, replacement of concrete pavement slabs, and similar work that does not expose soil or disturb the bottom six (6) inches of subbase material, ƒ Long-term use of equipment storage areas at or near highway maintenance facilities, ƒ Removal of sediment from the edge of the highway to restore a previously existing sheet-flow drainage connection from the highway surface to the highway ditch or embankment, ƒ Existing use of Canal Corp owned upland disposal sites for the canal, and ƒ Replacement of curbs, gutters, sidewalks and guide rail posts. Site limitations – means site conditions that prevent the use of an infiltration technique and or infiltration of the total WQv. Typical site limitations include: seasonal high groundwater, shallow depth to bedrock, and soils with an infiltration rate less than 0.5 inches/hour. The existence of site limitations shall be confirmed and documented using actual field testing (i.e. test pits, soil borings, and infiltration test) or using information from the most current United States Department of Agriculture (USDA) Soil Survey for the County where the project is located. Sizing Criteria – means the criteria included in Part I.C.2 of the permit that are used to size post-construction stormwater management control practices. The criteria include; Water Quality Volume (WQv), Runoff Reduction Volume (RRv), Channel Protection Volume (Cpv), Overbank Flood (Qp), and Extreme Flood (Qf). State Pollutant Discharge Elimination System (SPDES) - means the system established pursuant to Article 17 of the ECL and 6 NYCRR Part 750 for issuance of permits authorizing discharges to the waters of the state. Appendix A 46 Steep Slope – means land area designated on the current United States Department of Agriculture (“USDA”) Soil Survey as Soil Slope Phase “D”, (provided the map unit name is inclusive of slopes greater than 25%) , or Soil Slope Phase E or F, (regardless of the map unit name), or a combination of the three designations. Streambank – as used in this permit, means the terrain alongside the bed of a creek or stream. The bank consists of the sides of the channel, between which the flow is confined. Stormwater Pollution Prevention Plan (SWPPP) – means a project specific report, including construction drawings, that among other things: describes the construction activity(ies), identifies the potential sources of pollution at the construction site; describes and shows the stormwater controls that will be used to control the pollutants (i.e. erosion and sediment controls; for many projects, includes post-construction stormwater management controls); and identifies procedures the owner or operator will implement to comply with the terms and conditions of the permit. See Part III of the permit for a complete description of the information that must be included in the SWPPP. Surface Waters of the State - shall be construed to include lakes, bays, sounds, ponds, impounding reservoirs, springs, rivers, streams, creeks, estuaries, marshes, inlets, canals, the Atlantic ocean within the territorial seas of the state of New York and all other bodies of surface water, natural or artificial, inland or coastal, fresh or salt, public or private (except those private waters that do not combine or effect a junction with natural surface waters), which are wholly or partially within or bordering the state or within its jurisdiction. Waters of the state are further defined in 6 NYCRR Parts 800 to 941. Temporarily Ceased – means that an existing disturbed area will not be disturbed again within 14 calendar days of the previous soil disturbance. Temporary Stabilization - means that exposed soil has been covered with material(s) as set forth in the technical standard, New York Standards and Specifications for Erosion and Sediment Control, to prevent the exposed soil from eroding. The materials can include, but are not limited to, mulch, seed and mulch, and erosion control mats (e.g. jute twisted yarn, excelsior wood fiber mats). Total Maximum Daily Loads (TMDLs) - A TMDL is the sum of the allowable loads of a single pollutant from all contributing point and nonpoint sources. It is a calculation of the maximum amount of a pollutant that a waterbody can receive on a daily basis and still meet water quality standards, and an allocation of that amount to the pollutant's sources. A TMDL stipulates wasteload allocations (WLAs) for point source discharges, load allocations (LAs) for nonpoint sources, and a margin of safety (MOS). Trained Contractor - means an employee from the contracting (construction) company, identified in Part III.A.6., that has received four (4) hours of Department endorsed Appendix A 47 training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity. After receiving the initial training, the trained contractor shall receive four (4) hours of training every three (3) years. It can also mean an employee from the contracting (construction) company, identified in Part III.A.6., that meets the qualified inspector qualifications (e.g. licensed Professional Engineer, Certified Professional in Erosion and Sediment Control (CPESC), Registered Landscape Architect, New York State Erosion and Sediment Control Certificate Program holder, or someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided they have received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity). The trained contractor is responsible for the day to day implementation of the SWPPP. Uniform Procedures Act (UPA) Permit - means a permit required under 6 NYCRR Part 621 of the Environmental Conservation Law (ECL), Article 70. Water Quality Standard - means such measures of purity or quality for any waters in relation to their reasonable and necessary use as promulgated in 6 NYCRR Part 700 et seq. 48 APPENDIX B – Required SWPPP Components by Project Type Table 1 Construction Activities that Require the Preparation of a SWPPP That Only Includes Erosion and Sediment Controls The following construction activities that involve soil disturbances of one (1) or more acres of land, but less than five (5) acres: • Single family home not located in one of the watersheds listed in Appendix C or not directly discharging to one of the 303(d) segments listed in Appendix E • Single family residential subdivisions with 25% or less impervious cover at total site build-out and not located in one of the watersheds listed in Appendix C and not directly discharging to one of the 303(d) segments listed in Appendix E • Construction of a barn or other agricultural building, silo, stock yard or pen. The following construction activities that involve soil disturbances between five thousand (5000) square feet and one (1) acre of land: All construction activities located in the watersheds identified in Appendix D that involve soil disturbances between five thousand (5,000) square feet and one (1) acre of land. The following construction activities that involve soil disturbances of one (1) or more acres of land: • Installation of underground, linear utilities; such as gas lines, fiber-optic cable, cable TV, electric, telephone, sewer mains, and water mains • Environmental enhancement projects, such as wetland mitigation projects, stormwater retrofits and stream restoration projects • Pond construction • Linear bike paths running through areas with vegetative cover, including bike paths surfaced with an impervious cover • Cross-country ski trails and walking/hiking trails • Sidewalk, bike path or walking path projects, surfaced with an impervious cover, that are not part of residential, commercial or institutional development; • Sidewalk, bike path or walking path projects, surfaced with an impervious cover, that include incidental shoulder or curb work along an existing highway to support construction of the sidewalk, bike path or walking path. • Slope stabilization projects • Slope flattening that changes the grade of the site, but does not significantly change the runoff characteristics Appendix B 49 Table 1 (Continued) CONSTRUCTION ACTIVITIES THAT REQUIRE THE PREPARATION OF A SWPPP THAT ONLY INCLUDES EROSION AND SEDIMENT CONTROLS The following construction activities that involve soil disturbances of one (1) or more acres of land: • Spoil areas that will be covered with vegetation • Vegetated open space projects (i.e. recreational parks, lawns, meadows, fields, downhill ski trails) excluding projects that alter hydrology from pre to post development conditions, • Athletic fields (natural grass) that do not include the construction or reconstruction of impervious area and do not alter hydrology from pre to post development conditions • Demolition project where vegetation will be established, and no redevelopment is planned • Overhead electric transmission line project that does not include the construction of permanent access roads or parking areas surfaced with impervious cover • Structural practices as identified in Table II in the “Agricultural Management Practices Catalog for Nonpoint Source Pollution in New York State”, excluding projects that involve soil disturbances of greater than five acres and construction activities that include the construction or reconstruction of impervious area • Temporary access roads, median crossovers, detour roads, lanes, or other temporary impervious areas that will be restored to pre-construction conditions once the construction activity is complete Appendix B 50 Table 2 CONSTRUCTION ACTIVITIES THAT REQUIRE THE PREPARATION OF A SWPPP THAT INCLUDES POST-CONSTRUCTION STORMWATER MANAGEMENT PRACTICES The following construction activities that involve soil disturbances of one (1) or more acres of land: • Single family home located in one of the watersheds listed in Appendix C or directly discharging to one of the 303(d) segments listed in Appendix E • Single family home that disturbs five (5) or more acres of land • Single family residential subdivisions located in one of the watersheds listed in Appendix C or directly discharging to one of the 303(d) segments listed in Appendix E • Single family residential subdivisions that involve soil disturbances of between one (1) and five (5) acres of land with greater than 25% impervious cover at total site build-out • Single family residential subdivisions that involve soil disturbances of five (5) or more acres of land, and single family residential subdivisions that involve soil disturbances of less than five (5) acres that are part of a larger common plan of development or sale that will ultimately disturb five or more acres of land • Multi-family residential developments; includes duplexes, townhomes, condominiums, senior housing complexes, apartment complexes, and mobile home parks • Airports • Amusement parks • Breweries, cideries, and wineries, including establishments constructed on agricultural land • Campgrounds • Cemeteries that include the construction or reconstruction of impervious area (>5% of disturbed area) or alter the hydrology from pre to post development conditions • Commercial developments • Churches and other places of worship • Construction of a barn or other agricultural building (e.g. silo) and structural practices as identified in Table II in the “Agricultural Management Practices Catalog for Nonpoint Source Pollution in New York State” that include the construction or reconstruction of impervious area, excluding projects that involve soil disturbances of less than five acres. • Golf courses • Institutional development; includes hospitals, prisons, schools and colleges • Industrial facilities; includes industrial parks • Landfills • Municipal facilities; includes highway garages, transfer stations, office buildings, POTW’s, water treatment plants, and water storage tanks • Office complexes • Playgrounds that include the construction or reconstruction of impervious area • Sports complexes • Racetracks; includes racetracks with earthen (dirt) surface • Road construction or reconstruction, including roads constructed as part of the construction activities listed in Table 1 Appendix B 51 Table 2 (Continued) CONSTRUCTION ACTIVITIES THAT REQUIRE THE PREPARATION OF A SWPPP THAT INCLUDES POST-CONSTRUCTION STORMWATER MANAGEMENT PRACTICES The following construction activities that involve soil disturbances of one (1) or more acres of land: • Parking lot construction or reconstruction, including parking lots constructed as part of the construction activities listed in Table 1 • Athletic fields (natural grass) that include the construction or reconstruction of impervious area (>5% of disturbed area) or alter the hydrology from pre to post development conditions • Athletic fields with artificial turf • Permanent access roads, parking areas, substations, compressor stations and well drilling pads, surfaced with impervious cover, and constructed as part of an over-head electric transmission line project, wind-power project, cell tower project, oil or gas well drilling project, sewer or water main project or other linear utility project • Sidewalk, bike path or walking path projects, surfaced with an impervious cover, that are part of a residential, commercial or institutional development • Sidewalk, bike path or walking path projects, surfaced with an impervious cover, that are part of a highway construction or reconstruction project • All other construction activities that include the construction or reconstruction of impervious area or alter the hydrology from pre to post development conditions, and are not listed in Table 1 52 APPENDIX C – Watersheds Requiring Enhanced Phosphorus Removal Watersheds where owners or operators of construction activities identified in Table 2 of Appendix B must prepare a SWPPP that includes post-construction stormwater management practices designed in conformance with the Enhanced Phosphorus Removal Standards included in the technical standard, New York State Stormwater Management Design Manual (“Design Manual”). • Entire New York City Watershed located east of the Hudson River - Figure 1 • Onondaga Lake Watershed - Figure 2 • Greenwood Lake Watershed -Figure 3 • Oscawana Lake Watershed – Figure 4 • Kinderhook Lake Watershed – Figure 5 Appendix C 53 Figure 1 - New York City Watershed East of the Hudson Appendix C 54 Figure 2 - Onondaga Lake Watershed Appendix C 55 Figure 3 - Greenwood Lake Watershed Appendix C 56 Figure 4 - Oscawana Lake Watershed Appendix C 57 Figure 5 - Kinderhook Lake Watershed 58 APPENDIX D – Watersheds with Lower Disturbance Threshold Watersheds where owners or operators of construction activities that involve soil disturbances between five thousand (5000) square feet and one (1) acre of land must obtain coverage under this permit. Entire New York City Watershed that is located east of the Hudson River - See Figure 1 in Appendix C 59 APPENDIX E – 303(d) Segments Impaired by Construction Related Pollutant(s) List of 303(d) segments impaired by pollutants related to construction activity (e.g. silt, sediment or nutrients). The list was developed using ”The Final New York State 2016 Section 303(d) List of Impaired Waters Requiring a TMDL/Other Strategy” dated November 2016. Owners or operators of single family home and single family residential subdivisions with 25% or less total impervious cover at total site build-out that involve soil disturbances of one or more acres of land, but less than 5 acres, and directly discharge to one of the listed segments below shall prepare a SWPPP that includes post-construction stormwater management practices designed in conformance with the New York State Stormwater Management Design Manual (“Design Manual”), dated January 2015. COUNTY WATERBODY POLLUTANT Albany Ann Lee (Shakers) Pond, Stump Pond Nutrients Albany Basic Creek Reservoir Nutrients Allegany Amity Lake, Saunders Pond Nutrients Bronx Long Island Sound, Bronx Nutrients Bronx Van Cortlandt Lake Nutrients Broome Fly Pond, Deer Lake, Sky Lake Nutrients Broome Minor Tribs to Lower Susquehanna (north) Nutrients Broome Whitney Point Lake/Reservoir Nutrients Cattaraugus Allegheny River/Reservoir Nutrients Cattaraugus Beaver (Alma) Lake Nutrients Cattaraugus Case Lake Nutrients Cattaraugus Linlyco/Club Pond Nutrients Cayuga Duck Lake Nutrients Cayuga Little Sodus Bay Nutrients Chautauqua Bear Lake Nutrients Chautauqua Chadakoin River and tribs Nutrients Chautauqua Chautauqua Lake, North Nutrients Chautauqua Chautauqua Lake, South Nutrients Chautauqua Findley Lake Nutrients Chautauqua Hulburt/Clymer Pond Nutrients Clinton Great Chazy River, Lower, Main Stem Silt/Sediment Clinton Lake Champlain, Main Lake, Middle Nutrients Clinton Lake Champlain, Main Lake, North Nutrients Columbia Kinderhook Lake Nutrients Columbia Robinson Pond Nutrients Cortland Dean Pond Nutrients 303(d) Segments Impaired by Construction Related Pollutant(s) 60 Dutchess Fall Kill and tribs Nutrients Dutchess Hillside Lake Nutrients Dutchess Wappingers Lake Nutrients Dutchess Wappingers Lake Silt/Sediment Erie Beeman Creek and tribs Nutrients Erie Ellicott Creek, Lower, and tribs Silt/Sediment Erie Ellicott Creek, Lower, and tribs Nutrients Erie Green Lake Nutrients Erie Little Sister Creek, Lower, and tribs Nutrients Erie Murder Creek, Lower, and tribs Nutrients Erie Rush Creek and tribs Nutrients Erie Scajaquada Creek, Lower, and tribs Nutrients Erie Scajaquada Creek, Middle, and tribs Nutrients Erie Scajaquada Creek, Upper, and tribs Nutrients Erie South Branch Smoke Cr, Lower, and tribs Silt/Sediment Erie South Branch Smoke Cr, Lower, and tribs Nutrients Essex Lake Champlain, Main Lake, South Nutrients Essex Lake Champlain, South Lake Nutrients Essex Willsboro Bay Nutrients Genesee Bigelow Creek and tribs Nutrients Genesee Black Creek, Middle, and minor tribs Nutrients Genesee Black Creek, Upper, and minor tribs Nutrients Genesee Bowen Brook and tribs Nutrients Genesee LeRoy Reservoir Nutrients Genesee Oak Orchard Cr, Upper, and tribs Nutrients Genesee Tonawanda Creek, Middle, Main Stem Nutrients Greene Schoharie Reservoir Silt/Sediment Greene Sleepy Hollow Lake Silt/Sediment Herkimer Steele Creek tribs Silt/Sediment Herkimer Steele Creek tribs Nutrients Jefferson Moon Lake Nutrients Kings Hendrix Creek Nutrients Kings Prospect Park Lake Nutrients Lewis Mill Creek/South Branch, and tribs Nutrients Livingston Christie Creek and tribs Nutrients Livingston Conesus Lake Nutrients Livingston Mill Creek and minor tribs Silt/Sediment Monroe Black Creek, Lower, and minor tribs Nutrients Monroe Buck Pond Nutrients Monroe Cranberry Pond Nutrients 303(d) Segments Impaired by Construction Related Pollutant(s) 61 Monroe Lake Ontario Shoreline, Western Nutrients Monroe Long Pond Nutrients Monroe Mill Creek and tribs Nutrients Monroe Mill Creek/Blue Pond Outlet and tribs Nutrients Monroe Minor Tribs to Irondequoit Bay Nutrients Monroe Rochester Embayment - East Nutrients Monroe Rochester Embayment - West Nutrients Monroe Shipbuilders Creek and tribs Nutrients Monroe Thomas Creek/White Brook and tribs Nutrients Nassau Beaver Lake Nutrients Nassau Camaans Pond Nutrients Nassau East Meadow Brook, Upper, and tribs Silt/Sediment Nassau East Rockaway Channel Nutrients Nassau Grant Park Pond Nutrients Nassau Hempstead Bay Nutrients Nassau Hempstead Lake Nutrients Nassau Hewlett Bay Nutrients Nassau Hog Island Channel Nutrients Nassau Long Island Sound, Nassau County Waters Nutrients Nassau Massapequa Creek and tribs Nutrients Nassau Milburn/Parsonage Creeks, Upp, and tribs Nutrients Nassau Reynolds Channel, west Nutrients Nassau Tidal Tribs to Hempstead Bay Nutrients Nassau Tribs (fresh) to East Bay Nutrients Nassau Tribs (fresh) to East Bay Silt/Sediment Nassau Tribs to Smith/Halls Ponds Nutrients Nassau Woodmere Channel Nutrients New York Harlem Meer Nutrients New York The Lake in Central Park Nutrients Niagara Bergholtz Creek and tribs Nutrients Niagara Hyde Park Lake Nutrients Niagara Lake Ontario Shoreline, Western Nutrients Niagara Lake Ontario Shoreline, Western Nutrients Oneida Ballou, Nail Creeks and tribs Nutrients Onondaga Harbor Brook, Lower, and tribs Nutrients Onondaga Ley Creek and tribs Nutrients Onondaga Minor Tribs to Onondaga Lake Nutrients Onondaga Ninemile Creek, Lower, and tribs Nutrients Onondaga Onondaga Creek, Lower, and tribs Nutrients Onondaga Onondaga Creek, Middle, and tribs Nutrients 303(d) Segments Impaired by Construction Related Pollutant(s) 62 Onondaga Onondaga Lake, northern end Nutrients Onondaga Onondaga Lake, southern end Nutrients Ontario Great Brook and minor tribs Silt/Sediment Ontario Great Brook and minor tribs Nutrients Ontario Hemlock Lake Outlet and minor tribs Nutrients Ontario Honeoye Lake Nutrients Orange Greenwood Lake Nutrients Orange Monhagen Brook and tribs Nutrients Orange Orange Lake Nutrients Orleans Lake Ontario Shoreline, Western Nutrients Orleans Lake Ontario Shoreline, Western Nutrients Oswego Lake Neatahwanta Nutrients Oswego Pleasant Lake Nutrients Putnam Bog Brook Reservoir Nutrients Putnam Boyd Corners Reservoir Nutrients Putnam Croton Falls Reservoir Nutrients Putnam Diverting Reservoir Nutrients Putnam East Branch Reservoir Nutrients Putnam Lake Carmel Nutrients Putnam Middle Branch Reservoir Nutrients Putnam Oscawana Lake Nutrients Putnam Palmer Lake Nutrients Putnam West Branch Reservoir Nutrients Queens Bergen Basin Nutrients Queens Flushing Creek/Bay Nutrients Queens Jamaica Bay, Eastern, and tribs (Queens) Nutrients Queens Kissena Lake Nutrients Queens Meadow Lake Nutrients Queens Willow Lake Nutrients Rensselaer Nassau Lake Nutrients Rensselaer Snyders Lake Nutrients Richmond Grasmere Lake/Bradys Pond Nutrients Rockland Congers Lake, Swartout Lake Nutrients Rockland Rockland Lake Nutrients Saratoga Ballston Lake Nutrients Saratoga Dwaas Kill and tribs Silt/Sediment Saratoga Dwaas Kill and tribs Nutrients Saratoga Lake Lonely Nutrients Saratoga Round Lake Nutrients Saratoga Tribs to Lake Lonely Nutrients 303(d) Segments Impaired by Construction Related Pollutant(s) 63 Schenectady Collins Lake Nutrients Schenectady Duane Lake Nutrients Schenectady Mariaville Lake Nutrients Schoharie Engleville Pond Nutrients Schoharie Summit Lake Nutrients Seneca Reeder Creek and tribs Nutrients St.Lawrence Black Lake Outlet/Black Lake Nutrients St.Lawrence Fish Creek and minor tribs Nutrients Steuben Smith Pond Nutrients Suffolk Agawam Lake Nutrients Suffolk Big/Little Fresh Ponds Nutrients Suffolk Canaan Lake Silt/Sediment Suffolk Canaan Lake Nutrients Suffolk Flanders Bay, West/Lower Sawmill Creek Nutrients Suffolk Fresh Pond Nutrients Suffolk Great South Bay, East Nutrients Suffolk Great South Bay, Middle Nutrients Suffolk Great South Bay, West Nutrients Suffolk Lake Ronkonkoma Nutrients Suffolk Long Island Sound, Suffolk County, West Nutrients Suffolk Mattituck (Marratooka) Pond Nutrients Suffolk Meetinghouse/Terrys Creeks and tribs Nutrients Suffolk Mill and Seven Ponds Nutrients Suffolk Millers Pond Nutrients Suffolk Moriches Bay, East Nutrients Suffolk Moriches Bay, West Nutrients Suffolk Peconic River, Lower, and tidal tribs Nutrients Suffolk Quantuck Bay Nutrients Suffolk Shinnecock Bay and Inlet Nutrients Suffolk Tidal tribs to West Moriches Bay Nutrients Sullivan Bodine, Montgomery Lakes Nutrients Sullivan Davies Lake Nutrients Sullivan Evens Lake Nutrients Sullivan Pleasure Lake Nutrients Tompkins Cayuga Lake, Southern End Nutrients Tompkins Cayuga Lake, Southern End Silt/Sediment Tompkins Owasco Inlet, Upper, and tribs Nutrients Ulster Ashokan Reservoir Silt/Sediment Ulster Esopus Creek, Upper, and minor tribs Silt/Sediment Warren Hague Brook and tribs Silt/Sediment 303(d) Segments Impaired by Construction Related Pollutant(s) 64 Warren Huddle/Finkle Brooks and tribs Silt/Sediment Warren Indian Brook and tribs Silt/Sediment Warren Lake George Silt/Sediment Warren Tribs to L.George, Village of L George Silt/Sediment Washington Cossayuna Lake Nutrients Washington Lake Champlain, South Bay Nutrients Washington Tribs to L.George, East Shore Silt/Sediment Washington Wood Cr/Champlain Canal and minor tribs Nutrients Wayne Port Bay Nutrients Westchester Amawalk Reservoir Nutrients Westchester Blind Brook, Upper, and tribs Silt/Sediment Westchester Cross River Reservoir Nutrients Westchester Lake Katonah Nutrients Westchester Lake Lincolndale Nutrients Westchester Lake Meahagh Nutrients Westchester Lake Mohegan Nutrients Westchester Lake Shenorock Nutrients Westchester Long Island Sound, Westchester (East) Nutrients Westchester Mamaroneck River, Lower Silt/Sediment Westchester Mamaroneck River, Upper, and minor tribs Silt/Sediment Westchester Muscoot/Upper New Croton Reservoir Nutrients Westchester New Croton Reservoir Nutrients Westchester Peach Lake Nutrients Westchester Reservoir No.1 (Lake Isle) Nutrients Westchester Saw Mill River, Lower, and tribs Nutrients Westchester Saw Mill River, Middle, and tribs Nutrients Westchester Sheldrake River and tribs Silt/Sediment Westchester Sheldrake River and tribs Nutrients Westchester Silver Lake Nutrients Westchester Teatown Lake Nutrients Westchester Titicus Reservoir Nutrients Westchester Truesdale Lake Nutrients Westchester Wallace Pond Nutrients Wyoming Java Lake Nutrients Wyoming Silver Lake Nutrients 65 APPENDIX F – List of NYS DEC Regional Offices Region COVERING THE FOLLOWING COUNTIES: DIVISION OF ENVIRONMENTAL PERMITS (DEP) PERMIT ADMINISTRATORS DIVISION OF WATER (DOW) WATER (SPDES) PROGRAM 1 NASSAU AND SUFFOLK 50 CIRCLE ROAD STONY BROOK, NY 11790 TEL. (631) 444-0365 50 CIRCLE ROAD STONY BROOK, NY 11790-3409 TEL. (631) 444-0405 2 BRONX, KINGS, NEW YORK, QUEENS AND RICHMOND 1 HUNTERS POINT PLAZA, 47-40 21ST ST. LONG ISLAND CITY, NY 11101-5407 TEL. (718) 482-4997 1 HUNTERS POINT PLAZA, 47-40 21ST ST. LONG ISLAND CITY, NY 11101-5407 TEL. (718) 482-4933 3 DUTCHESS, ORANGE, PUTNAM, ROCKLAND, SULLIVAN, ULSTER AND WESTCHESTER 21 SOUTH PUTT CORNERS ROAD NEW PALTZ, NY 12561-1696 TEL. (845) 256-3059 100 HILLSIDE AVENUE, SUITE 1W WHITE PLAINS, NY 10603 TEL. (914) 428 - 2505 4 ALBANY, COLUMBIA, DELAWARE, GREENE, MONTGOMERY, OTSEGO, RENSSELAER, SCHENECTADY AND SCHOHARIE 1150 NORTH WESTCOTT ROAD SCHENECTADY, NY 12306-2014 TEL. (518) 357-2069 1130 NORTH WESTCOTT ROAD SCHENECTADY, NY 12306-2014 TEL. (518) 357-2045 5 CLINTON, ESSEX, FRANKLIN, FULTON, HAMILTON, SARATOGA, WARREN AND WASHINGTON 1115 STATE ROUTE 86, PO BOX 296 RAY BROOK, NY 12977-0296 TEL. (518) 897-1234 232 GOLF COURSE ROAD WARRENSBURG, NY 12885-1172 TEL. (518) 623-1200 6 HERKIMER, JEFFERSON, LEWIS, ONEIDA AND ST. LAWRENCE STATE OFFICE BUILDING 317 WASHINGTON STREET WATERTOWN, NY 13601-3787 TEL. (315) 785-2245 STATE OFFICE BUILDING 207 GENESEE STREET UTICA, NY 13501-2885 TEL. (315) 793-2554 7 BROOME, CAYUGA, CHENANGO, CORTLAND, MADISON, ONONDAGA, OSWEGO, TIOGA AND TOMPKINS 615 ERIE BLVD. WEST SYRACUSE, NY 13204-2400 TEL. (315) 426-7438 615 ERIE BLVD. WEST SYRACUSE, NY 13204-2400 TEL. (315) 426-7500 8 CHEMUNG, GENESEE, LIVINGSTON, MONROE, ONTARIO, ORLEANS, SCHUYLER, SENECA, STEUBEN, WAYNE AND YATES 6274 EAST AVON-LIMA ROADAVON, NY 14414-9519 TEL. (585) 226-2466 6274 EAST AVON-LIMA RD. AVON, NY 14414-9519 TEL. (585) 226-2466 9 ALLEGANY, CATTARAUGUS, CHAUTAUQUA, ERIE, NIAGARA AND WYOMING 270 MICHIGAN AVENUE BUFFALO, NY 14203-2999 TEL. (716) 851-7165 270 MICHIGAN AVENUE BUFFALO, NY 14203-2999 TEL. (716) 851-7070 Appendix G Historic Preservation/Endangered Species Documentation Division for Historic Preservation P.O. Box 189, Waterford, New York 12188-0189 • (518) 237-8643 • parks.ny.gov ANDREW M. CUOMO ERIK KULLESEID Governor Commissioner November 25, 2019 Mrs. Jennifer Geraghty Hartgen Archeological Associates 1744 Washington Avenue Ext Rensselaer, NY 12144 Re: DEC Skidmore College Fitness and Tennis Center City of Saratoga Springs, Saratoga County, NY 19PR07574 Dear Mrs. Geraghty: Thank you for requesting the comments of the Division for Historic Preservation of the Office of Parks, Recreation and Historic Preservation (OPRHP). We have reviewed the submitted project information in accordance with the New York State Historic Preservation Act of 1980 (Section 14.09 of the New York Parks, Recreation and Historic Preservation Law). These comments are those of the OPRHP and relate only to Historic/Cultural resources. They do not include potential environmental impacts to New York State Parkland that may be involved in or near your project. Such impacts must be considered as part of the environmental review of the project pursuant to the State Environmental Quality Review Act (New York Environmental Conservation Law Article 8) and its implementing regulations (6 NYCRR Part 617). We note that the project boundary partially overlaps the Broadway Historic District Expansion building district (09140.001531; 93NR00472). Based on the project details, our Technical Services Unit does not have any concerns with impacts to this National Register listed historic resource. We are in receipt of the archaeology survey report (Phase I Archeological Investigation, Skidmore College Fitness and Tennis Center, Skidmore College, 815 North Broadway, City of Saratoga Springs, Saratoga County, New York) by Hartgen Archeological Associates, Inc. and dated October 2019. The survey did not identify any archaeological sites within the project’s Area of Potential Effects (APE), and the OPRHP concurs with the recommendation that additional archaeological investigation is not warranted. Based on this review, it is the OPRHP’s opinion that this project will have No Adverse Impact on archaeological and/or historic resources listed in or eligible for the New York State and National Registers of Historic Places. If you have any questions, please do not hesitate to contact me at 518.268.2185 or andrew.farry@parks.ny.gov. Sincerely, Andrew Farry, Ph.D. Scientist/Archaeology cc: Bradley Russell, Hartgen; Donald McPherson, LA Group 10/7/2019 Cultural Resource Information System (CRIS) https://cris.parks.ny.gov 1/1 HOMEHOMEHOMEHOMEHOME SUBMITSUBMITSUBMITSUBMITSUBMIT SEARCHSEARCHSEARCHSEARCHSEARCH COMMUNICATECOMMUNICATECOMMUNICATECOMMUNICATECOMMUNICATE + − 0 150 300ft © 2019 New© 2019 New© 2019 New Appendix H Deep Ripping and De-compaction (DEC, 2008) DEPARTMENT OF ENVIRONMENTAL CONSERVATIONNew York StateDeep-Ripping andDecompactionNew York State Department of Environmental Conservation Division of WaterApril 2008Document Prepared by: John E. Lacey, Land Resource Consultant and Environmental Compliance Monitor (Formerly with the Division of Agricultural Protection and Development Services, NYS Dept. of Agriculture & Markets) 1AlternativeȱStormwaterȱManagementȱDeepȬRippingȱandȱDecompactionȱȱȱȱȱȱȱȱȱȱDescriptionThe two-phase practice of 1) “Deep Ripping;” and 2) “Decompaction” (deep subsoiling), of the soil material as a step in the cleanup and restoration/landscaping of a construction site, helps mitigate the physically induced impacts of soil compression; i.e.: soil compaction or the substantial increase in the bulk density of the soil material. Deep Ripping and Decompaction are key factors which help in restoring soil pore space and permeability for water infiltration. Conversely, the physical actions of cut-and-fill work, land grading, the ongoing movement of construction equipment and the transport of building materials throughout a site alter the architecture and structure of the soil, resulting in: the mixing of layers (horizons) of soil materials, compression of those materials and diminished soil porosity which, if left unchecked, severely impairs the soil’s water holding capacity and vertical drainage (rainfall infiltration), from the surface downward. In a humid climate region, compaction damage on a site is virtually guaranteed over the duration of a project. Soil in very moist to wet condition when compacted, will have severely reduced permeability. Figure 1 displays the early stage of the deep-ripping phase (Note that all topsoil was stripped prior to construction access, and it remains stockpiled until the next phase – decompaction – is complete). A heavy-duty tractor is pulling a three-shank ripper on the first of several series of incrementally deepening passes through the construction access corridor's densely compressed subsoil material. Figure 2 illustrates the approximate volumetric composition of a loam surface soil when conditions are good for plant growth, with adequate natural pore space for fluctuating moisture conditions. ȱFig. 1. A typical deep ripping phase of this practice, during the first in a series of progressively deeper “rips” through severely compressed subsoil. Fig. 2. About 50% of the volume of undisturbed loam surface soil is pore space, when soil is in good condition for plant growth. Brady, 2002. 2Recommended Application of PracticeTheȱobjective of Deep Ripping and Decompaction is to effectively fracture (vertically and laterallly) through the thickness of the physically compressed subsoil material (see Figure 3), restoring soil porosity and permeability and aiding infiltration to help reduce runoff. Together with topsoil stripping, the “two-phase” practice of Deep Ripping and Decompaction first became established as a “best management practice” through ongoing success on commercial farmlands affected by heavy utility construction right-of-way projects (transmission pipelines and large power lines). Soil permeability, soil drainage and cropland productivity were restored. For broader construction application, the two-phase practice of Deep Ripping and Decompaction is best adapted to areas impacted with significant soil compaction, on contiguous open portions of large construction sites and inside long, open construction corridors used as temporary access over the duration of construction. Each mitigation area should have minimal above-and-below-ground obstructions for the easy avoidance and maneuvering of a large tractor and ripping/decompacting implements. Conversely, the complete two-phase practice is not recommended in congested or obstructed areas due to the limitations on tractor and implement movement. BenefitsAggressive “deep ripping” through the compressed thickness of exposed subsoil before the replacement/respreading of the topsoil layer, followed by “decompaction,” i.e.: “sub-soiling,” through the restored topsoil layer down into the subsoil, offers the following benefits:xIncreases the project (larger size) area’s direct surface infiltration of rainfall by providing the open site’s mitigated soil condition and lowers the demand on concentrated runoff control structures xEnhances direct groundwater recharge through greater dispersion across and through a broader surface than afforded by some runoff-control structural measures xDecreases runoff volume generated and provides hydrologic source control xMay be planned for application in feasible open locations either alone or in Fig. 3. Construction site with significant compaction of the deep basal till subsoil extends 24 inches below this exposed cut-and-fill work surface. 3conjunction with plans for structural practices (e.g., subsurface drain line or infiltration basin) serving the same or contiguous areas xPromotes successful long-term revegetation by restoring soil permeability, drainage and water holding capacity for healthy (rather than restricted) root-system development of trees, shrubs and deep rooted ground cover, minimizing plant drowning during wet periods and burnout during dry periods. Feasibility/Limitations The effectiveness of Deep Ripping and Decompaction is governed mostly by site factors such as: the original (undisturbed) soil’s hydrologic characteristics; the general slope; local weather/timing (soil moisture) for implementation; the space-related freedom of equipment/implement maneuverability (noted above in Recommended Application of Practice), and by the proper selection and operation of tractor and implements (explained below in Design Guidance). The more notable site-related factors include:SoilIn the undisturbed condition, each identified soil type comprising a site is grouped into one of four categories of soil hydrology, Hydrologic Soil Group A, B, C or D, determined primarily by a range of characteristics including soil texture, drainage capability when thoroughly wet, and depth to water table. The natural rates of infiltration and transmission of soil-water through the undisturbed soil layers for Group A is “high” with a low runoff potential while soils in Group B are moderate in infiltration and the transmission of soil-water with a moderate runoff potential, depending somewhat on slope. Soils in Group C have slow rates of infiltration and transmission of soil-water and a moderately high runoff potential influenced by soil texture and slope; while soils in Group D have exceptionally slow rates of infiltration and transmission of soil-water, and high runoff potential.In Figure 4, the profile displays the undisturbed horizons of a soil in Hydrologic Soil Group C and the naturally slow rate of infiltration through the subsoil. The slow rate of infiltration begins immediately below the topsoil horizon (30 cm), due to the limited amount of macro pores, e.g.: natural subsoil fractures, worm holes and root channels. Infiltration after the construction-induced mixing and compression of such subsoil material is virtually absent; but can be restored back to this natural level with the two-phase practice of deep ripping and decompaction, followed by the permanent establishment of an appropriate, deep taproot Fig. 4. Profile (in centimeters) displaying the infiltration test result of the natural undisturbed horizons of a soil in Hydrologic Soil Group C.4lawn/ground cover to help maintain the restored subsoil structure. Infiltration after construction-induced mixing and compression of such subsoil material can be notably rehabilitated with the Deep Ripping and Decompaction practice, which prepares the site for the appropriate long-term lawn/ground cover mix including deep taproot plants such as clover, fescue or trefoil, etc. neededfor all rehabilitated soils. Generally, soils in Hydrologic Soil Groups A and B, which respectively may include deep, well-drained, sandy-gravelly materials or deep, moderately well-drained basal till materials, are among the easier ones to restore permeability and infiltration, by deep ripping and decompaction. Among the many different soils in Hydrologic Soil Group C are those unique glacial tills having a natural fragipan zone, beginning about 12 to 18 inches (30 – 45cm), below surface. Although soils in Hydrologic Soil Group C do require a somewhat more carefully applied level of the Deep Ripping and Decompaction practice, it can greatly benefit such affected areas by reducing the runoff and fostering infiltration to a level equal to that of pre-disturbance.Soils in Hydrologic Soil Group D typically have a permanent high water table close to the surface, influenced by a clay or other highly impervious layer of material. In many locations with clay subsoil material, the bulk density is so naturally high that heavy trafficking has little or no added impact on infiltration; and structural runoff control practices rather than Deep Ripping and Decompaction should be considered. The information about Hydrologic Soil Groups is merely a general guideline. Site-specific data such as limited depths of cut-and-fill grading with minimal removal or translocation of the inherent subsoil materials (as analyzed in the county soil survey) or, conversely, the excavation and translocation of deeper, unconsolidated substratum or consolidated bedrock materials (unlike the analyzed subsoil horizons’ materials referred to in the county soil survey) should always be taken into account.Sites made up with significant quantities of large rocks, or having a very shallow depth to bedrock, are not conducive to deep ripping and decompation (subsoiling); and other measures may be more practical.SlopeThe two-phase application of 1) deep ripping and 2) decompaction (deep subsoiling), is most practical on flat, gentle and moderate slopes. In some situations, such as but not limited to temporary construction access corridors, inclusion areas that are moderately steep along a project’s otherwise gentle or moderate slope may also be deep ripped and decompacted. For limited instances of moderate steepness on other projects, however, the post-construction land use and the relative alignment of the potential ripping and decompaction work in relation to the lay of the slope should be reviewed for safety and practicality. In broad construction areas predominated by moderately steep or steep slopes, the practice is generally not used. Local Weather/Timing/Soil Moisture Effective fracturing of compressed subsoil material from the exposed work surface, laterally and vertically down through the affected zone is achieved only when the soil material is moderately dry to moderately moist. Neither one of the two-phases, deep ripping nor decompaction (deep 5Fig. 5. Augered from a depth of 19 inches below the surface of the replaced topsoil, this subsoil sample was hand rolled to a 1/8-inch diameter. The test shows the soil at this site stretches out too far without crumbling; it indicates the material is in a plastic state of consistence, too wet for final decompaction(deep subsoiling) at this time.subsoiling), can be effectively conducted when the soil material (subsoil or replaced topsoil) is in either a “plastic” or “liquid” state of soil consistency. Pulling the respective implements legs through the soil when it is overly moist only results in the “slicing and smearing” of the material or added “squeezing and compression” instead of the necessary fracturing. Ample drying time is needed for a “rippable” soil condition not merely in the material close to the surface, but throughout the material located down to the bottom of the physically compressed zone of the subsoil.The “poor man’s Atterberg field test” for soil plasticity is a simple “hand-roll” method used for quick, on-site determination of whether or not the moisture level of the affected soil material is low enough for: effective deep ripping of subsoil; respreading of topsoil in a friable state; and final decompaction (deep subsoiling). Using a sample of soil material obtained from the planned bottom depth of ripping, e.g.: 20 - 24 inches below exposed subsoil surface, the sample is hand rolled between the palms down to a 1/8-inch diameter thread. (Use the same test for stored topsoil material before respreading on the site.) If the respective soil sample crumbles apart in segments no greater than 3/8 of an inch long, by the time it is rolled down to 1/8 inch diameter, it is low enough in moisture for deep ripping (or topsoil replacement), and decompaction. Conversely, as shown in Figure 5, if the rolled sample stretches out in increments greater than 3/8 of an inch long before crumbling, it is in a “plastic” state of soil consistency and is too wet for subsoil ripping (as well as topsoil replacement) and final decompaction. Design Guidance Beyond the above-noted site factors, a vital requirement for the effective Deep Ripping and Decompaction (deep subsoiling), is implementing the practice in its distinct, two-phase process: 1) Deep rip the affected thickness of exposed subsoil material (see Figure 10 and 11), aggressively fracturing it before the protected topsoil is reapplied on the site (see Figure 12); and 2) Decompact (deep subsoil), simultaneously through the restored topsoil layer and the upper half of the affected subsoil (Figure 13). The second phase, “decompaction,” mitigates the partial recompaction which occurs during the heavy process of topsoil spreading/grading. Prior to deep ripping and decompacting the site, all construction activity, including construction equipment and material storage, site cleanup and trafficking (Figure 14), should be finished; and the site closed off to further disturbance. Likewise, once the practice is underway and the area’s soil permeability and 6Fig. 6. A light duty chisel implement, not adequate for either the deep ripping or decompaction (deep subsoiling) phase. rainfall infiltration are being restored, a policy limiting all further traffic to permanent travel lanes is maintained. The other critical elements, outlined below, are: using the proper implements (deep, heavy-duty rippers and subsoilers), and ample pulling-power equipment (tractors); and conducting the practice at the appropriate speed, depth and pattern(s) of movement. Note that an appropriate plan for the separate practice of establishing a healthy perennial ground cover, with deep rooting to help maintain the restored soil structure, should be developed in advance. This may require the assistance of an agronomist or landscape horticulturist. ImplementsAvoid the use of all undersize implements. The small-to-medium, light-duty tool will, at best, only “scarify” the uppermost surface portion of the mass of compacted subsoil material. The term “chisel plow” is commonly but incorrectly applied to a broad range of implements. While a few may be adapted for the moderate subsoiling of non-impacted soils, the majority are less durable and used for only lighter land-fitting (see Figure 6). Use a “heavy duty” agricultural-grade, deep ripper (see Figures 7,9,10 and 11) for the first phase: the lateral and vertical fracturing of the mass of exposed and compressed subsoil, down and through, to the bottom of impact, prior to the replacement of the topsoil layer. (Any oversize rocks which are uplifted to the subsoil surface during the deep ripping phase are picked and removed.) Like the heavy-duty class of implement for the first phase, the decompaction (deep subsoiling) of Phase 2 is conducted with the heavy-duty version of the deep subsoiler. More preferable is the angled-leg variety of deep subsoiler (shown in Figures 8 and 13). It minimizes the inversion of the subsoil and topsoil layers while laterally and vertically fracturing the upper half of the previously ripped subsoil layer and all of the topsoil layer by delivering a momentary, wave-like “lifting and shattering” action up through the soil layers as it is pulled.Fig. 7. One of several variations of an agricultural ripper. This unit has long, rugged shanks mounted on a steel V-frame for deep, aggressive fracturing through Phase 1. 7Fig. 8. A deep, angled-leg subsoiler, ideal for Phase 2 decompaction of after the topsoil layer is graded on top of the ripped subsoil. Pulling-Power of EquipmentUse the following rule of thumb for tractor horsepower (hp) whenever deep ripping and decompacting a significantly impacted site: For both types of implement, have at least 40 hp of tractor pull available for each mounted shank/ leg. Using the examples of a 3-shank and a 5-shank implement, the respective tractors should have 120 and 200 hp available for fracturing down to the final depth of 20-to-24 inches per phase. Final depth for the deep ripping in Phase 1 is achieved incrementally by a progressive series of passes (see Depth and Patterns of Movement, below); while for Phase 2, the full operating depth of the deep subsoiler is applied from the beginning. The operating speed for pulling both types of implement should not exceed 2 to 3 mph. At this slow and managed rate of operating speed, maximum functional performance is sustained by the tractor and the implement performing the soil fracturing. Referring to Figure 8, the implement is the 6-leg version of the deep angled-leg subsoiler. Its two outside legs are “chained up” so that only four legs will be engaged (at the maximum depth), requiring no less than 160 hp, (rather than 240 hp) of pull. The 4-wheel drive, articulated-frame tractor in Figure 8 is 174 hp. It will be decompacting this unobstructed, former construction access area simultaneously through 11 inches of replaced topsoil and the upper 12 inches of the previously deep-ripped subsoil. In constricted areas of Phase 1) Deep Ripping, a medium-size tractor with adequate hp, such as the one in Figure 9 pulling a 3-shank deep ripper, may be more maneuverable. Some industrial-grade variations of ripping implements are attached to power graders and bulldozers. Although highly durable, they are generally not recommended. Typically, the shanks or “teeth” of these rippers are too short and stout; and they are mounted too far apart to achieve the well-distributed type of lateral and vertical fracturing of the soil materials necessary to restore soil permeability and infiltration. In addition, the power graders and bulldozers, as pullers, are far less maneuverable for turns and patterns than the tractor. Fig. 9. This medium tractor is pulling a 3-shank deep ripper. The severely compacted construction access corridor is narrow, and the 120 hp tractor is more maneuverable for Phase 1 deep ripping (subsoil fracturing), here. 8Depth and Patterns of MovementAs previously noted both Phase 1 Deep Ripping through significantly compressed, exposed subsoil and Phase 2 Decompaction (deep subsoiling) through the replaced topsoil and upper subsoil need to be performed at maximum capable depth of each implement. With an implement’s guide wheels attached, some have a “normal” maximum operating depth of 18 inches, while others may go deeper. In many situations, however, the tractor/implement operator must first remove the guide wheels and other non essential elements from the implement. This adapts the ripper or the deep subsoiler for skillful pulling with its frame only a few inches above surface, while the shanks or legs, fracture the soil material 20-to-24 inches deep. There may be construction sites where the depth of the exposed subsoil’s compression is moderate, e.g.: 12 inches, rather than deep. This can be verified by using a ¾ inch cone penetrometer and a shovel to test the subsoil for its level of compaction, incrementally, every three inches of increasing depth. Once the full thickness of the subsoil’s compacted zone is finally “pieced” and there is a significant drop in the psi measurements of the soil penetrometer, the depth/thickness of compaction is determined. This is repeated at several representative locations of the construction site. If the thickness of the site’s subsoil compaction is verified as, for example, ten inches, then the Phase 1 Deep Ripping can be correspondingly reduced to the implement’s minimum operable depth of 12 inches. However, the Phase 2 simultaneous Decompation (subsoiling) of an 11 inch thick layer of replaced topsoil and the upper subsoil should run at the subsoiling implements full operating depth.Typically, three separate series (patterns) are used for both the Phase 1 Deep Ripping and the Phase 2 Decompaction on significantly compacted sites. For Phase 1, each series begins with a moderate depth of rip and, by repeat-pass, continues until full depth is reached. Phase 2 applies the full depth of Decompation (subsoiling), from the beginning. Every separate series (pattern) consists of parallel, forward-and-return runs, with each progressive Fig. 11. A repeat run of the 3-shank ripper along the same patterned pass area as Fig. 9; here, incrementally reaching 18 of the needed 22 inches of subsoil fracture.Fig. 10. An early pass with a 3-shank deep ripper penetrating only 8 inches into this worksite’s severely compressed subsoil. 9pass of the implement’s legs or shanks evenly staggered between those from the previous pass. This compensates for the shank or leg-spacing on the implement, e.g., with 24-to-30 inches between each shank or leg. The staggered return pass ensures lateral and vertical fracturing actuated every 12 to 15 inches across the densely compressed soil mass. Large, Unobstructed Areas For larger easy areas, use the standard patterns of movement: Ɣ The first series (pattern) of passes is applied lengthwise, parallel with the longest spread of the site; gradually progressing across the site’s width, with each successive pass. Ɣ The second series runs obliquely, crossing the first series at an angle of about 45 degrees.Ɣ The third series runs at right angle (or 90 degrees), to the first series to complete the fracturing and shattering on severely compacted sites, and avoid leaving large unbroken blocks of compressed soil material. (In certain instances, the third series may be optional, depending on how thoroughly the first two series loosen the material and eliminate large chunks/blocks of material as verified by tests with a ¾-inch cone penetrometer.) CorridorsIn long corridors of limited width and less maneuverability than larger sites, e.g.: along compacted areas used as temporary construction access, a modified series of pattern passes are used. Ɣ First, apply the same initial lengthwise, parallel series of passes described above. Fig. 12. Moderately dry topsoil is being replaced on the affected site now that Phase 1 deep ripping of the compressed subsoil is complete. Fig. 13. The same deep, angled-leg subsoiler shown in Fig. 7 is engaged at maximum depth for Phase 2, decompaction (deep soiling), of the replaced topsoil and the upper subsoil materials.10Fig. 15. The same site as Fig. 14 after deep ripping of the exposed subsoil, topsoil replacement, decompaction through the topsoil and upper subsoil and final surface tillage and revegetation to maintain soil permeability and infiltration. Ɣ A second series of passes makes a broad “S” shaped pattern of rips, continually and gradually alternating the “S” curves between opposite edges inside the compacted corridor. Ɣ The third and final series again uses the broad, alternating S pattern, but it is “flip-flopped” to continually cross the previous S pattern along the corridor’s centerline. This final series of the S pattern curves back along the edge areas skipped by the second series.Maintenance and Cost Once the two-phase practice of Deep Ripping and Decompation is completed, two items are essential for maintaining a site’s soil porosity and permeability for infiltration. They are: planting and maintaining the appropriate ground cover with deep roots to maintain the soil structure (see Figure 15); and keeping the site free of traffic or other weight loads.Note that site-specific choice of an appropriate vegetative ground-cover seed mix, including the proper seeding ratio of one or more perennial species with a deep taproot system and the proper amount of lime and soil nutrients (fertilizer mix) adapted to the soil-needs, are basic to the final practice of landscaping, i.e: surface tillage, seeding/planting/fertilizing and culti-packing or mulching is applied. The "maintenance" of an effectively deep-ripped and decompacted area is generally limited to the successful perennial (long-term) landscape ground cover; as long as no weight-bearing force of soil compaction is applied. Fig. 14. The severely compacted soil of a temporary construction yard used daily by heavy equipment for four months; shown before deep ripping, topsoil replacement, and decompaction. 11The Deep Ripping and Decompaction practice is, by necessity, more extensive than periodic subsoiling of farmland.The cost of deep ripping and decompacting (deep subsoiling), will vary according to the depth and severity of soil-material compression and the relative amount of tractor and implement time that is required. In some instances, depending on open maneuverability, two-to-three acres of compacted project area may be deep-ripped in one day. In other situations of more severe compaction and - or less maneuverability, as little as one acre may be fully ripped in a day. Generally, if the Phase 1) Deep Ripping is fully effective, the Phase 2) Decompaction should be completed in 2/3 to 3/4 of the time required for Phase 1. Using the example of two acres of Phase 1) Deep Ripping in one day, at $1800 per day, the net cost is $900 per acre. If the Phase 2) Decompacting or deep subsoiling takes 3/4 the time as Phase 1, it costs $675 per acre for a combined total of $1575 per acre to complete the practice (these figures do not include the cost of the separate practice of topsoil stripping and replacement). Due to the many variables, it must be recognized that cost will be determined by the specific conditions or constraints of the site and the availability of proper equipment. 12ResourcesPublications:ȱȣȱAmericanȱȱSocietyȱofȱȱAgriculturalȱEngineers.ȱ1971.ȱȱCompactionȱofȱȱAgriculturalȱȱSoils.ȱȱASAE.ȱȱȣȱBrady,ȱN.C.,ȱandȱR.R.ȱWeil.ȱ2002.ȱȱTheȱȱNatureȱȱandȱȱPropertiesȱȱofȱȱSoils.ȱ13thȱed.ȱPearsonȱEducation,ȱInc.ȱȱȣȱBaver,ȱL.D.ȱ1948.ȱSoilȱPhysics.ȱJohnȱWileyȱ&ȱSons.ȱȱȣȱCarpachi,ȱN.ȱ1987ȱ(1995ȱfifthȱprinting).ȱExcavationȱandȱGradingȱHandbook,ȱRevised.ȱȱ2ndȱed.ȱCraftsmanȱBookȱCompanyȱȣȱEllis,ȱB.ȱ(Editor).ȱ1997.ȱȱSafeȱ&ȱEasyȱLawnȱCare:ȱȱTheȱCompleteȱGuideȱtoȱOrganicȱLowȱMaintenanceȱLawn.ȱȱHoughtonȱMifflin.ȱȱȣȱHarpstead,ȱM.I.,ȱT.J.ȱSauer,ȱandȱW.F.ȱBennett.ȱ2001.ȱȱSoilȱScienceȱSimplified.ȱ4thȱed.ȱIowaȱStateȱUniversityȱȱPress.ȱȱȣȱȱMagdoff,ȱF.,ȱȱandȱȱH.ȱvanȱEs.ȱȱ2000.ȱȱBuildingȱSoilsȱȱforȱȱBetterȱCrops.ȱ2ndȱed.ȱSustainableȱAgriculturalȱNetworksȱȱȣȱȱMcCarthy,ȱD.F.ȱ1993.ȱEssentialsȱofȱSoilȱMechanicsȱandȱFoundations,ȱBasicȱGeotechnicsȱ4thȱed.ȱRegents/PrenticeȱHall.ȱȱȣȱȱȱȱȱȱPlaster,ȱE.J.ȱ1992.ȱSoilȱScienceȱ&ȱManagement.ȱ3rdȱed.ȱDelmarȱPublishers.ȱȱȣȱȱȱUnionȱGasȱLimited,ȱOntario,ȱCanada.ȱ1984.ȱRehabilitationȱofȱAgriculturalȱLands,ȱDawnȬKerwoodȱȱLoopȱȱPipeline;ȱȱȱTechnicalȱȱȱReport.ȱȱȱEcologicalȱȱȱServicesȱȱforȱȱPlanning,ȱȱLtd.;ȱRobinson,ȱMerrittȱ&ȱDevries,ȱLtd.ȱandȱSmith,ȱHoffmanȱAssociates,ȱLtd.ȱȱȣȱȱȱUSȱDepartmentȱofȱAgricultureȱinȱcooperationȱwithȱCornellȱUniversityȱAgriculturalȱExperimentȱȱStation.ȱȱVariousȱyears.ȱȱSoilȱȱSurveyȱofȱȱ(variousȱnames)ȱȱCounty,ȱȱNewȱYork.ȱUSDA.ȱȱInternetȱAccess:ȱȣȱȱȱȱExamplesȱofȱimplements:ȱȱȱVȬRippers.ȱȱAccessȱbyȱȱinternetȱsearchȱofȱJohnȱDeereȱAgȱȬNewȱEquipmentȱȱȱforȱȱ915ȱȱ(largerȬframeȱmodel)ȱȱVȬRippe;ȱȱand,ȱȱȱforȱ913ȱȱ(smallerȬframeȱmodel)ȱVȬRipper.ȱȱDeep,ȱangledȬlegȱsubsoiler.ȱȱAccessȱȱbyȱȱinternetȱsearchȱȱof:ȱBighamȱȱBrothersȱShearȱBoltȱȱParatillȬSubsoiler.ȱhttp://salesmanual.deere.com/sales/salesmanual/en_NA/primary_tillage/2008/feature/rippers/915v_pattern_frame.html?sbu=ag&link=prodcat LastȱvisitedȱMarchȱ08.ȱȱȣȱSoilsȱdataȱofȱUSDAȱNaturalȱResourcesȱConservationȱService.ȱNRCSȱWebȱSoilȱSurvey.ȱȱȱȱȱȱȱȱȱȱȱȱȱȱhttp://websoilsurvey.nrcs.usda.gov/app/ȱȱȱandȱȱUSDAȬNRCSȱȱOfficialȱȱSoilȱȱSeriesȱDescriptions;ȱViewȱbyȱName.ȱhttp://ortho.ftw.nrcs.usda.gov/cgiȬbin/osd/osdname.cgiȱ.ȱLastȱvisitedȱJan.ȱ08.ȱȱȣȱȱSoilȱȱpenetrometerȱȱinformation.ȱȱAccessȱȱbyȱȱȱinternetȱȱsearchesȱȱof:ȱȱȱDiagnosingȱSoilȱCompactionȱȱȱusingȱȱaȱPenetrometerȱ(soilȱcompactionȱtester),ȱPSUȱExtension;ȱȱasȱȱwellȱȱasȱDickeyȬjohnȱSoilȱCompactionȱTester.ȱhttp://www.dickey-johnproducts.com/pdf/SoilCompactionTest.pdf and http://cropsoil.psu.edu/Extension/Facts/uc178pdfLastȱvisitedȱSept.ȱ07ȱ