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Home My WebLink About20260062 33 Marion Ave Site Plan SWPPPPage | 1 Stormwater Pollution Prevention Plan (SWPPP) for STEWART’S SHOPS 33 Marion Avenue City of Saratoga Springs Saratoga County, New York December 29, 2025 Prepared by: Scott E. Kitchner, PE Stewart’s Shops PO Box 435 Saratoga Springs, NY 12866 Phone: (518) 581-1201 Ext. 4249 Fax: (518) 581-1209 skitchner@stewartsshops.com Page | 2 TABLE OF CONTENTS 1.0 Executive Summary 4 1.1 Design Methodology 5 2.0 Site Conditions 6 2.1 Topography 6 2.2 Soil Data 6 2.3 Surface and Groundwater 6 2.4 Flood Plains 7 2.5 Wetlands 7 2.6 Historic and Cultural Resources 7 2.7 Endangered Species 7 3.0 Stormwater Erosion and Sediment Controls 8 3.1 Construction Phasing 8 3.2 Construction Erosion and Sediment Controls 9 3.3 Erosion and Sediment Control Practices 9 3.4 Winter Operations 10 3.5 Materials and Substance Management 10 3.6 Best Management Practices 11 3.7 Spill Prevention Practices 11 4.0 Pre and Post Development Graphical Peak 13 4.1 Pre Development Area Descriptions and Discharge Points 13 4.2 Post Development Area Descriptions and Discharge Points 14 4.3 Soil Restoration 15 4.4 Weighted Curve Number (CN) 16 4.5 Peak Discharges for Pre and Post Development Areas 16 4.6 Pre Development versus Post Development Peak Discharges 17 4.7 Graphical Peak Discharge Usage 17 5.0 Uniform Sizing Criteria 18 5.1 Water Quality Volume (WQv) 18 5.2 Runoff Reduction Volume 19 5.3 Channel Protection Volume 21 5.4 Overbank Flood Protection Volume 21 5.5 Extreme Flood Protection Volume 21 5.6 Safe Passage of the 100-Year Design Storm 21 6.0 Proposed Water Quality and Quantity Controls 22 6.1 Proposed Stormwater Management Strategy 22 6.2 Water Quality and Pretreatment for Post Development Areas 22 6.3 Water Quantity Control for Post Development Areas 23 Page | 3 7.0 Proposed Conveyance System 26 8.0 Maintenance Requirements for Permanent Practices 26 8.1 Storm Tech® Subsurface Stormwater Detention System 26 8.2 Subsurface Infiltration Array (I-4) 26 8.3 Closed Drainage System 27 8.4 First Defense FD-4HC Hydrodynamic Separator 27 8.5 Special Considerations 28 9.0 Conclusion 29 10.0 Exhibits 30 Exhibit A: Graphical Peak Discharge Calculations A.1 Cornell Extreme Precipitation Estimates A.2 Pre Development CN A.3 Post Development CN A.4 NRCS Soil Information A.5 Flood Mapping Information Exhibit B: Water Quality Volume and Channel Protection Volume B.1 Water Quality Volume (WQv) and Minimum Runoff Reduction Volume (RRv) Calculations B.2 WQv Peak Flow Calculations B.3 Channel Protection Volume (CPv) Exhibit C: Hydrologic Model Simulations Using HydroCAD C.1 Pre Development C.2 Post Development Exhibit D: Drainage Calculations D.1 Closed Drainage System Expected Flow Calculations Exhibit E: Maps E.1 Pre Development Subcatchments E.2 Post Development Subcatchments E.3 Catch Basin Subcatchments Exhibit F: Certifications F.1 Owner/Contractor Certifications Exhibit G: NOI/NOT G.1 Notice of Intent G.2 Notice of Termination G.3 MS4 Acceptance Form G.4 SPDES General Permit GP-0-25-001 G.5 SWPPP Inspection Reports Exhibit H: Maintenance Checklist Page | 4 1.0 EXECUTIVE SUMMARY Stewart’s Shops is proposing to construct a 4,500 sf convenient store, 3,000 sf rental structure, a parking lot and covered gas pumps on an approximately 2.01 acre parcel located at 33 Marion Avenue in the City of Saratoga Springs, Saratoga County. Currently occupying the site is the Marion Avenue Gas Station, a car wash, existing gasoline canopy and associated parking areas. Stewart’s Shops is the current owner and under the proposed Plan, Stewart’s will redevelop the existing parcel and replace the existing structures and associated parking lots. This action will result in approximately 1.91 acres of soil disturbances. The development of the project will be subject to the NYSDEC SPDES General Permit No. GP-0-25-001 for water quality and quantity as it will disturb greater than 1 acre for this project. Per Chapter 9 of the NYSDEC Stormwater Design Manual (SWDM), the project site can be considered a redevelopment project. As such, in order to establish the stormwater treatment requirements, the NYSDEC SWDM was consulted. The NYSDEC requires the water quality and quantity controls for all developments, and as of calendar year 2010, requires the use of “green” infrastructure practices to encourage groundwater recharge. The subject property is currently in use as a convenient store with gasoline sales. As such, a significant portion of the property has already undergone disturbances and development. According to the NYSDEC SWDM Chapter 9, the redevelopment requirements are to be used when the following criteria is applicable: Per section 9.2.1.B.II Water Quality Treatment Objectives for Redevelopment Projects states: “The Plan proposes that a minimum of 25% of the water quality volume (WQv) from disturbed, impervious area is captured and treated by the implementation of standard SMP or reduced by application of green infrastructure techniques (see Chapter 5 of this Manual). For all sites that utilize structural SMPs, these practices should be targeted to treat areas with the greatest pollutant generation potential (e.g. parking areas, service stations, etc.). If the construction project includes both new development and redevelopment activities, treatment would be required for 25% of the existing impervious area plus 100% of the additional impervious area. As with design of any practice, sizing of structures should be based on all areas contributing to the SMP. Construction projects that involve redevelopment of a portion of the site, may choose diversion or flow splitters to be able to size the control structures for the reconstructed area only. For all sites that utilize green infrastructure techniques (see Table 3.2), a proposed plan is effective when runoff is controlled near the source and managed by infiltration, reuse, and evapotranspiration. The objective of controlling water quantity is to ensure that the peak rate of runoff leaving the site does not increase as the result of development. The proposed management strategy consists of the use of an on-site infiltration basin to collect stormwater runoff generated from portions of the site, as well as, any additional tributary areas and safely exfiltrate it into the existing on-site soils. The proposed system will not receive any “hot spot” runoff from the portions of the site that contain the re-fueling pumps, as those areas have been segregated by the proposed Grading Plan. The “hot spot” areas will be also be collected in a segregated closed drainage system and routed to a subsurface detention system for water quality treatment and attenuation prior to discharge from the project site. Routine maintenance is a key component in the successful operation of each stormwater management practice. Provisions ensuring the upkeep are necessary and are submitted in the Page | 5 accompanying maintenance plan. The Stormwater Pollution Prevention Plan (SWPPP), MS4 Acceptance Form and Notice-of-Intent (NOI) Application have been completed for this project site. The MS4 Acceptance Form and NOI are required to be submitted to the NYSDEC in order to obtain a SPDES permit to construct the site. Application to the NYSDEC for permit coverage occurs prior to construction activities and after municipal site plan approvals have been obtained. The following SWPPP quantitatively assesses the pre-development and post-development runoff conditions of the project site. The report documents that the proposed improvements will meet the water quality parameters as set forth in the NYSDEC guidelines. 1.1 DESIGN METHODOLOGY 1. Determine contributory watershed area(s) and subsequent sub-watersheds for the project according to site conditions. 2. Evaluate pre and post development stormwater runoff conditions for various storm intensities, durations and frequencies of occurrences using USDA Technical Release 55 (TR-55) methodology. 3. Evaluate and obtain the RRv. 4. Evaluate peak runoff and storage requirements for the 1, 10, and 100-year storm frequencies. Page | 6 2.0 SITE CONDITIONS 2.1 Topography The project area is urban in nature and consists primarily of a mix of commercial and residential properties. The proposed site is currently home to the existing Marion Avenue Mobile Station, car wash, gasoline canopy and parking areas. The existing topography is generally split down the east/west axis of the project site and slopes to the north and south. Existing stormwater runoff is discharged to both the closed drainage system located along Marion Avenue and the adjacent lands located to the south of the project site, belonging to the City of Saratoga Springs. 2.2 Soil Data The United States Department of Agriculture (USDA) classifies soils into four hydrologic soil groups (A, B, C and D). Soil group A consists of soils that have a higher potential for increased rates of infiltration of surface runoff, while soils in group D have much slower rates of runoff infiltration. Using the USDA’s National Resources Conservation (NRCS) Soil Survey Data, the soil maps of the existing watershed area reveals the entire site is situated over very well draining soils. The project soils consist entirely of Windsor loamy sand, 3 to 8 percent slopes. This soil type falls into Soil Group A. The existing drainage area was determined to have a composite curve number (CN) of 86. See Exhibit A.4 for the NRCS Soil Survey Mapping information. 2.3 Surface and Groundwater 1) Surface Waters The nearest receiving body of water is the Loughberry Lake. The lake is located approximately 400 feet to the east of the project site. 2) Groundwater The project will not affect any wells within the project area. This project will be designed to ensure that here is no adverse effect on any active sources of water or to the quality of the groundwater. A test pit dug on-site did not reveal the presence of groundwater. The test pit was dug to a depth of approximately 297.20 feet. The NYSDEC SWDM requires that the bottom of any proposed infiltration facility be vertically separated from groundwater by a minimum of 2 feet. As groundwater was not encountered, the depth to groundwater will be assumed to be 297.20 and the required vertical separation will be provided from this depth. Utilizing the assumed groundwater elevation of 297.20 feet, the proposed bottom of any infiltration facility shall be a minimum of two (2) feet higher vertically, or a minimum depth of 299.20 Page | 7 feet. The proposed subsurface infiltration arrays have been designed to meet this requirement. The bottom elevation of the proposed void stone surrounding subsurface array #1 and #2 are 299.85 feet and 300.07 feet, respectively. This provides a minimum of 2.67 of vertical separation to the assumed groundwater elevation from the deepest of the arrays. The project is not located within a Federal Sole Source Aquifer or any State Primary Aquifers. 2.4 Flood Plains The Flood Hazard Boundary Maps for the project areas (36091C0434E) dated August 16, 1995, were reviewed (See Exhibit A.5). The Federal Emergency Management Agency (FEMA) mapping indicates that the proposed project is not located in a 100-year flood zone. 2.5 Wetlands The project area was reviewed utilizing the online Environmental Resources Mapper provided by the NYSDEC. Based on the information provided by the NYSDEC Mapper, there are no state or federally regulated wetlands located within the project site. 2.6 Historic and Cultural Resources Information obtained from the New York State Office of Parks, Recreation and Historic Places (OHRHP) website, revealed that this project site is not located in an archeologically sensitive area. A “No Impact” letter, dated May 6, 2021, was received from OHRHP stating that the proposed project will have no effect on archaeological or historic resources within the project area. 2.7 Endangered Species The NYSDEC Environmental Resource Online Mapper was reviewed, and it was determined that no threatened or endangered plant or animal species will be impacted by the proposed project. Page | 8 3.0 STORMWATER EROSION AND SEDIMENT CONTROLS 3.1 Construction Phasing All erosion and sediment controls measures will be required to be in place prior to any soil disturbances. The following is a summary of the suggested sequence and estimated duration of construction operations. The final placement and extent of proposed erosion and sediment controls are shown on the Construction Drawings. Construction Activities Duration 1. Obtain all necessary permits. 2 weeks 2. Install perimeter sediment controls in accordance with NYS DEC Guidelines for Erosion and Sediment Control (silt fence (SF), inlet protection (IP) as needed and Stabilized Construction Entrance (SCE) for construction of road and infrastructure). 7 days 3. Remove existing building and utilities 2 weeks 4. Establish Staging and storage areas on site for parking area and infrastructure construction and protect from erosion and soil migration. 2 days 5. Clear site of existing trees to limit of disturbance and grub stumps (if necessary). Remove stumps from site and dispose of in a legal manner off-site. Mulch all areas which will not be disturbed within 14 days. 1 week 6. Strip topsoil from proposed areas, and stockpile. Protect stockpile area from migration with silt fence and temp seeding. Mulch all areas which will not be disturbed within 14 days. 1 week 7. Rough grade proposed parking areas and building site area. Imported and exported material to be delivered to site through SCE. Contractor to keep all debris off public roadways. Sweep roadways as necessary during construction. 1 week 8. Construct proposed building, gas canopy and install proposed building utilities. 4 weeks 9. Install drainage culverts & SWM system and stabilize disturbed areas immediately upon completion of grading operation. 2 weeks 10. Install temporary catch basin inlet protection. 2 days 11. Import base material for parking areas and grade to elevations shown on plans. 1 week 12. Install pavement to lines and grades shown on plans. 2 days 13. Fine grade areas outside of paving. Topsoil and permanently seed all disturbed areas. 1 week 14. Stabilize all other disturbed areas. Upon stabilization, remove sediment controls and stabilize any disturbance caused by the removal of controls. 2 weeks Page | 9 3.2 Construction Erosion and Sediment Controls A site specific Sediment and Erosion Control Plan has been developed for the project to contain and control the migration of water and wind dispersed soil and dust particles. The complete Sediment and Erosion Control Plan is included with the Construction Drawings. All disturbed areas will be maintained in accordance with the SPDES General Permit GP-0-20-001 and the soil erosion and sediment control plan. The NYSDEC’s “New York Standards and Specifications for Erosion and Sediment Control”, latest edition addresses protecting all water resources within the project limits and measures to maintain the water quality of receiving bodies. The Contractor shall be held responsible for this issue, to review the Erosion and Sediment Control Plans included in the Contract Documents and, if necessary, modify the Plan for compatibility with the Contractor’s intended sequence of construction operations. Any changes to the Erosion and Sediment Control Plans included in the Contract Documents made by the Contractor to facilitate his/her sequence of construction shall be in accordance with the requirements in the “New York Standards and Specifications for Erosion and Sediment Control”, latest edition. Additionally, the Contractor shall ensure a minimum of one (1) “Trained Contractor” is present on-site at anytime soil disturbance activities are being performed. The “Trained Contractor” shall have received a minimum of four (4) hours of NYSDEC endorsed training in the principles of proper erosion and sediment control and shall be able to produce evidence of said training upon request. 3.3 Erosion and Sediment Control Practices Erosion and sediment control measures will be inspected in accordance with the SPDES General Permit GP-0-25-001 and installed in accordance with “New York Standards and Specifications for Erosion and Sediment Control”, latest edition. The Contractor shall inspect all erosion and sediment controls identified in this SWPPP and ensure that they are being maintained in effective operating conditions at all times. A Qualified Inspector shall conduct a site inspection at least once every seven (7) calendar days while construction activities are ongoing. Measures identified as deficient, shall be cleaned and/or repaired as necessary. The following measures have been identified for use on the project: Temporary Surface Stabilization: Areas within the project limits that may be disturbed more than once during the construction activities will be stabilized using temporary seed and mulch or as directed. Disturbed areas, including stockpiles, remaining exposed for more than fourteen (14) days during construction operations shall be stabilized temporarily. Inlet Protection: Inlets to drainage structures shall be protected in order to prevent sediments from entering the proposed closed drainage system and migrating off site. The location and type of inlet protection to be provided is shown on the Construction Drawings. Silt Fence: A silt fence will be constructed along the areas of earthwork. The locations are shown on the Construction Drawings. Additional silt fence may be needed as site conditions warrant. The Contractor and Qualified Inspector are encouraged to identify addition placement opportunities in Page | 10 order to maintain the highest water quality standards possible. The provision of silt fence will prevent/reduce sediment from migrating off the construction site and entering the drainage system. Surface Stabilization: Stabilizing of graded areas will be accomplished by applying topsoil to newly graded areas and using various seed mixes for the establishment of vegetation. Refer to the Construction Drawings for notes and details pertaining to surface stabilization. Dust Control: Water shall be applied at a rate to minimize airborne particles from leaving the construction site as directed by the Qualified Inspector. Final Inspection: Prior to the project being finally accepted, it shall be inspected for any evidence of erosion or slope failure. If any such condition becomes apparent upon final inspection, temporary soil erosion and sediment controls shall be installed immediately as directed by the Qualified Inspector. The situation shall be corrected according to a schedule agreed to by the Qualified Inspector and the Contractor. 3.4 Winter Operations It is not anticipated that soil disturbing operations will extend beyond the initial construction season. If the project enters a state of temporary wintertime shutdown, the owner/operator has the option to modify the SWPPP inspection schedule. Prior to modifying the inspection schedule, all disturbed areas must first have temporary stabilization measures in place in accordance with the Erosion and Sediment Control Plan and to the satisfaction of the Qualified Inspector. During periods of winter shutdown, SWPPP inspections shall occur a minimum of once every thirty (30) calendar days. Once soil disturbing activities have resumed, the inspection schedule shall return to once every seven (7) calendar days. 3.5 Materials and Substance Management The materials and substances listed below are expected to be on site during construction. 1. If construction vehicles are to be re-fueled on site, petroleum products will be stored in above ground storage tanks. The tanks will either be steel with an enclosure capable of holding 110% of the storage tank volume or Convault-type, concrete encased type with integral secondary storage. Hydraulic oil and other oils will be stored in their original containers. Concrete and asphalt will be stored in the original delivery trucks. 2. 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. 3. Paints or other similar materials will be stored in their original containers and all empty z containers will be disposed of in accordance with label directions. Page | 11 4. Portable sanitary facilities, which contain chemical disinfectants (deodorants), will be located on site, with the disinfectants held in the tank of the toilet. All waste materials generated during construction will be disposed of in a suitable landfill, transfer station or Construction & Demolition landfill. Any hazardous waste generated during demolition or construction operations will be disposed of by a licensed hazardous waste carrier at a suitable disposal facility. If unexpected hazardous waste is discovered during construction, the related work in that area will cease until the issue is resolved. Portable temporary sanitary facilities will be serviced regularly. 3.6 Best Management Practices During construction, the following procedures and practices will be followed on site to reduce the risk of spill or other accidental exposure of materials and substances to stormwater runoff: 1. Equipment cleaning, maintenance and repair will be conducted in designated areas protected by berms. 2. Sediment and erosion controls will be inspected weekly for sediment build-up and failure. The controls will be cleaned at the discretion of the Qualified Inspector. 3. Cleared brush, debris and soils will be stockpiled up slope from and protected by erosion and sediment controls. 4. Materials brought on site shall be in the minimum quantities required. 5. 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. 6. Products will be kept in original containers with the original manufacturer’s labels and safety data sheets will be retained. 7. Substances will not be mixed with one another unless recommended by the manufacturer. 8. Whenever possible, the entire product will be used up before container disposal. Recycle empty containers as applicable. 9. Manufacturer recommendations for proper use and disposal will be followed. 10. All above grade storage tanks are to be protected from vehicle damage by temporary barriers. 3.7 Spill Prevention Practices The following practices will be followed for spill prevention and cleanup. The site contractor responsible for the day-to-day site operations will be the spill prevention and cleanup coordinator. He/she will designate at least one 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 on-site construction office or trailer. 1. Manufacturer’s 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 Page | 12 cleanup supplies. Any spill in excess or suspected to be in excess of two (2) gallons will be reported to the NYSDEC Regional Response Unit. Notification to the NYSDEC (1-800-457- 7362) must be completed within two hours of the discovery of the spill. This is a legal requirement that must be complied with. 2. Materials and equipment necessary for spill cleanup will be kept in the material storage area on site. Equipment and materials will include, by 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. 3. All spills will be cleaned up immediately after discovery. 4. The spill area will be kept well-ventilated and personnel will wear appropriate protective clothing to prevent injury from contact with spilled substances. 5. Spills of toxic or hazardous materials will be reported to the appropriate State of local government agency, regardless of size. 6. Concrete trucks will not be allowed to wash out or discharge surplus concrete or drum water on site, except in areas specified. 7. Asphalt trucks shall not discharge surplus asphalt on site, except in areas specified. Page | 13 4.0 PRE AND POST DEVELOPMENT GRAPHICAL PEAK DISCHARGE This section describes the stormwater analysis internal to the site, including the runoff generated. Analysis of the greater upstream/downstream watershed to the receiving waters for this project site is not included in the computations for this report. The non-delineated Pre and Post Development upstream/downstream watersheds are considered base flow and the proposed site improvements will not have an effect on the greater stormwater runoff. Therefore, the Pre and Post Development upstream/downstream watershed will have the exact same stormwater runoff characteristics. 4.1 Pre-Development Area Descriptions and Discharge Points The pre development stormwater systems were analyzed to estimate runoff generated from the site. To adequately analyze and compare the post development conditions against the pre development conditions, the watershed was analyzed as eight (8) subcatchment areas. (See Pre Development Subcatchments in Exhibit E.1) Pre-Development Subcatchment Area #1 (E1) discharges stormwater runoff to the existing municipally owned catch basin located at the intersection of Marion Avenue and NYS Route 50, Discharge Point #1 (DP1). This subcatchment area totals approximately 0.21 acres and is comprised areas of impervious cover to include portions of the existing parking lot and existing lawn areas adjacent to Marion Avenue. This subcatchment has a pre development CN of 69. Pre-Development Subcatchment Area #2 (E2A) discharges stormwater runoff to an existing on-site drywall and exfiltrated into the existing on-site soils. Runoff from E2A is not discharged from the project site. This subcatchment area totals approximately 0.04 acres and is comprised of a small portion of the impervious parking lot and green space along the southern property line. This subcatchment has a pre development CN of 81. Pre-Development Subcatchment Area #3 (E2B), similar to E2A, discharges stormwater runoff to the same existing on-site drywell as E2A. Runoff from E2B is also not discharged from the project site. This subcatchment area totals approximately 0.02 acres and is comprised entirely of impervious cover associated with the existing parking lot. This subcatchment has a pre development CN of 98. Pre-Development Subcatchment Area #4 (E3) collects stormwater runoff from the existing parking lot in the area of the subsurface fuel storage tanks. Runoff from this subcatchment is collected in an existing drywell and exfiltrated into the existing on-site soils. Runoff from E3 is not discharged from the project site. This subcatchment area totals approximately 0.07 acres and is comprised entirely of impervious cover associated with the existing parking lot. This subcatchment has a pre development CN of 98. Pre-Development Subcatchment Area #5 (E4) collects stormwater runoff from the existing parking lot, the rooftop of the existing gasoline canopy and half the rooftop of the existing Marion Avenue Mobile Station. Runoff from this subcatchment is collected in an existing drywell and exfiltrated into the existing on-site soils. Runoff from E4 is not discharged from the project site. This subcatchment area totals approximately 0.17 acres and has a pre development CN of 98. Page | 14 Pre-Development Subcatchment Area #6 (E5) collects stormwater runoff from the existing parking lot, a portion of the rooftop of the existing Marion Avenue Mobile Station, the rooftop of the existing car wash and some small lawn areas adjacent to Marion Avenue. Runoff from this subcatchment is collected in an existing drywell and exfiltrated into the existing on-site soils. Runoff from E5 is not discharged from the project site. This subcatchment area totals approximately 0.17 acres and has a pre development CN of 91. Pre-Development Subcatchment Area #7 (E6) constitutes a significant portion of the existing project site and consists of 87% asphalt, gravel, and rooftop impervious cover. Stormwater runoff from large areas of the existing parking lots, a portion of the rooftop of the existing Marion Avenue Mobile Station and some existing areas of green space are discharged from the project site at Discharge Point #2 (DP2), the lands of the City of Saratoga Springs. This subcatchment area totals approximately 0.97 acres and has a pre development CN of 89. Pre-Development Subcatchment Area #8 (E7) collects stormwater runoff from the existing parking lot in the area of the existing car wash, a portion of the rooftop of the existing car wash and existing areas of green space adjacent to the parking lot. Runoff from this subcatchment is collected in an existing on-site low point and exfiltrated into the existing on-site soils. Runoff from E7 is not discharged from the project site. This subcatchment area totals approximately 0.25 acres and has a pre development CN of 69. 4.2 Post-Development Area Descriptions and Discharge Points The following section describes the post development stormwater management system. The post development watershed has been analyzed and subdivided in order to estimate runoff from the watershed and the effect of the proposed development. To adequately analyze and compare the post development conditions with the pre development conditions, the watershed was divided into six (6) subcatchment areas. (See Post Development Subcatchments in Exhibit E.2) Post-Development Subcatchment Area #1 (P1) discharges stormwater runoff to the existing municipally owned catch basin located at the intersection of Marion Avenue and NYS Route 50, DP1. This subcatchment area totals approximately 0.40 acres and is comprised of the eastern portions of the proposed parking lot (surrounding the proposed gasoline canopy and subsurface fuel storage tanks) and some densely vegetated (sodded) lawn areas adjacent to the eastern property line. This area of the site includes all the “hot spot” areas associated with the refueling activities that will occur on-site. Runoff from this subcatchment is collected in the proposed on-site closed drainage system and routed through a proposed hydrodynamic separator for water quality treatment and to a proposed subsurface detention array for attenuation prior to discharge from the project site. This subcatchment has a post development CN of 92. Post-Development Subcatchment Area #2 (P2A) consists primarily of impervious cover associated with the proposed parking lot located to the rear of the proposed Shop and a small, landscaped island adjacent to the proposed parking stalls. This subcatchment totals approximately 0.24 acres and stormwater runoff is collected in a proposed on-site closed drainage system and routed to a proposed subsurface infiltration array, where it combines with runoff from P2B for exfiltration into the existing on-site soils. The subcatchment has a post development CN of 97. Page | 15 Post-Development Subcatchment Area #3 (P2B) consists entirely of the rooftop of the proposed gasoline canopy. This subcatchment totals approximately 0.07 acres and roof runoff is routed via downspouts to a proposed subsurface infiltration array, where it combines with runoff from P2A, for exfiltration into the existing on-site soils. The subcatchment has a post development CN of 98. Post-Development Subcatchment Area #4 (P3) consists of the remainder of the developed site. This subcatchment area totals approximately 0.70 acres and is comprised primarily of impervious cover associated with the proposed project. These areas included the rooftop of the proposed Shop, the rooftop of the proposed rental structure, the proposed parking lot located to the North and East of the rental structure and some densely vegetated (sodded) lawn areas adjacent to the edges of the proposed parking lot. Runoff from this subcatchment is collected in the proposed on-site closed drainage system and routed to a second proposed subsurface infiltration array for exfiltration into the existing on-site soils. This subcatchment has a post development CN of 86. Post-Development Subcatchment Area #5 (P4) consists of the areas of the project site immediately adjacent to Marion Avenue. This subcatchment area totals approximately 0.14 acres and is comprised primarily of impervious cover associated with the proposed driveway entrances and street sidewalks. There are also some small areas of densely vegetated (sodded) lawn adjacent to Marion Avenue. Runoff from this subcatchment is discharged to the existing municipally owned catch basin located at the intersection of Marion Avenue and NYS Route 50, DP1 where it combines with attenuated discharges from P1. This subcatchment has a post development CN of 70. Post-Development Subcatchment Area #6 (P5) consists of the remaining areas of the project site located along the eastern property line. This area contains a large area where existing gravel parking will be converted into green space. This subcatchment area totals approximately 0.36 acres and is comprised of 99% green space. Runoff from this subcatchment is discharged from the project site at DP2, lands belonging to the City of Saratoga Springs. This subcatchment has a post development CN of 40. 4.3 Soil Restoration Per Section 5.1.6 of the NYSDEC SEDM, soil restoration techniques shall be applied to this project. The specifications listed in this section, particularly in areas of cuts/fills and existing impervious areas that will be converted to pervious areas, shall be performed across the project site. As the project is considered a Redevelopment Activity, Soil Restoration is required in areas where existing impervious areas will be converted to pervious surfaces. The following techniques shall be applied: • Following removal of the impervious cover, three (3) inches of compost shall be applied over the subsoil surface. Compost shall be aged, from plant derived materials, free of viable weed seeds, have no visible free water or dust produced when handling, pass through a ½” screen and have a suitable pH for plant growth. • Compost shall be tilled into the subsoil to a depth of at least twelve (12) inches using a cat- mounted ripper, tractor-mounted disk or tiller. • Any uplifted stone/rock material of four (4) inches or larger in size shall be removed. Page | 16 • Six (6) inches of topsoil shall be applied and the areas shall be vegetated in accordance with the approved Plan. 4.4 Weighted Curve Number (CN) Within each subcatchment, cover type, hydrologic conditions and the hydrologic soil group are analyzed to determine a runoff curve number for sub-areas of each subcatchment. A weighted runoff curve number (CN), or composite, is then determined for each subcatchment. Calculations supporting the pre-development and post-development scenarios are presented in Exhibit A.2 and A.3. 4.5 Peak Discharges for Pre and Post Development Areas Using the TR-55 graphical method and HydroCAD design software, the peak discharges for both the pre and post development subcatchments were determined. The results generated by the software for each subcatchment are shown in the following tables. Table 1 Pre-Development Peak Discharge Rates Subcatchment Discharge Point 1-Yr Peak Flow (cfs) 10-Yr Peak Flow (cfs) 100-Yr Peak Flow (cfs) CN Area (acres) Tc (min)* E1 DP1 0.09 0.39 1.05 69 0.21 7.3 E2A NA 0.05 0.13 0.28 81 0.04 6.0 E2B NA 0.07 0.12 0.21 98 0.02 6.0 E3 NA 0.21 0.35 0.59 98 0.07 6.0 E4 NA 0.52 0.88 1.49 98 0.17 6.0 E5 NA 0.21 0.42 0.77 91 0.17 28.3 E6 DP2 0.62 1.28 2.44 89 0.97 63.2 E7 NA 0.03 0.15 0.42 69 0.25 53.2 * A minimum Tc of 6.0 minutes shall be used for all stormwater modeling. Page | 17 Table 2 Post-Development Peak Discharge Rates Subcatchment Discharge Point 1-Yr Peak Flow (cfs) 10-Yr Peak Flow (cfs) 100-Yr Peak Flow (cfs) CN Area (acres) Tc (min)* P1 DP1 1.03 1.95 3.47 92 0.04 4.9 P2A NA 0.71 1.22 2.06 97 0.001 6.0 P2B NA 0.23 0.38 0.64 98 0.03 6.0 P3 NA 0.89 1.97 3.88 86 0.97 16.7 P4 DP1 0.04 0.18 0.50 70 0.97 16.7 P5 DP2 0.00 0.00 0.07 39 0.97 27.1 Total Unattenuated Discharge at DP1 (cfs): 1.07 2.13 3.97 Total Unattenuated Discharge at DP2 (cfs): 0.00 0.00 0.07 * A minimum Tc of 6.0 minutes shall be used for all stormwater modeling. 4.6 Pre-Development versus Post Development Peak Discharges at Discharge Points As shown in Table 2, post development areas P2A, P2B and P3 do not discharge stormwater runoff from the project site. The post development discharge rate at DP2, as demonstrated in Tables 1 and 2, without attenuation, is less than or equal to the pre development discharge rate. Therefore, stormwater management facilities to attenuate discharge rates are not required for post development area P2A, P2B, P3 of P5. Post development area P1 would combine to discharge runoff with P4 from the project site at DP1. Without attenuation, the combined post development discharges would have a peak discharge rate greater than the pre development rate at DP1. Therefore, proposed stormwater management facilities for P1 shall be required to control the peak flows so the resultant peak discharge rate at DP1 is attenuated to the pre development rate up to and including the 100-year storm event. 4.7 Graphical Peak Discharge Usage The graphical peak discharge method was used to determine the following: 1) Preliminary sizing of both the proposed Subsurface Infiltration Array (I-4); 2) Preliminary calculations of WQv and RRv values; 3) Sizing of the proposed closed drainage system; Page | 18 5.0 UNIFORM SIZING CRITERIA The United States Environmental Protection Agency (USEPA) and the NYSDEC have placed greater emphasis on ensuring that water quality standards are maintained both onsite as well as downstream of development. Maintaining water quality involves the removal or reduction of pollutants including suspended solids, phosphates, nitrates and other chemicals generated by development. The new water quality standards expand upon the peak flow attenuation concept to include parameters designed to protect downstream channels from stream bank erosion and flooding. The NYSDEC assumes that, by default, the proposed stormwater management practices meet water quality objectives if the proposed practices are designed in accordance with the List of Acceptable Stormwater Management Practices set forth in the NYSDEC SWDM. Additionally, updates to the NYSDEC SWDM have mandated additional treatment practices in the form of “green” infrastructure used to further reduce the volume of runoff produced. 5.1 Water Quality Volume (WQv) The water quality volume is designed to improve the water quality of the discharged stormwater runoff to capture and treat 90% of the average annual stormwater runoff volume. The WQv is defined as: WQv = [(P)(Rv)(A)]/12 Where: WQv = Water Quality Volume (acre-feet) P = 90% Rainfall Event Number (inches) Rv = 0.05+0.009(I); Minimum Rv = 0.20 I = Impervious Cover (percent) A = Site Area (acres) The WQv for post development project site was determined to be 0.041 acre-feet (1,774 ft3). The WQv was determined based upon 25% of any existing impervious areas and 100% of the newly proposed impervious area. See Exhibit B.1. Water quality treatment for the project will be achieved within the proposed subsurface infiltration arrays, sized in accordance with the NYSDEC SWDM. See Exhibit B.2. Page | 19 5.2 Runoff Reduction Volume (RRv) Implementation of “green” infrastructure practices aid in the reduction of runoff by proactively reducing runoff volume, peak flow and flow duration. It also promotes infiltration and evapotranspiration to improve groundwater recharge and relieve pollutants for the “end of pipe” stormwater treatment practice. The “green” infrastructure techniques listed below are pre- approved methods that the NYSDEC has deemed acceptable to be used towards planning of development projects and runoff reduction. Some standard SMPs may also be used instead of the options below. Table 3 Runoff Reduction Techniques Group Practice Project Implementation/Justification Preservation of Natural Resources Preservation of Undisturbed Areas To the extent practical, undisturbed areas have been preserved by adhering to the minimum site development requirements of the Stewart’s Shops Corporation. Preservation of Buffers The NYSDEC 100 foot buffer zone will not be impacted. Reduction of Clearing and Grading To the extent practical, clearing and grading has been minimized to meet the minimum site development requirements of the Stewart’s Shops Corporation. Locating Development in Less Sensitive Areas None presently exist on the site. Open Space Design This project is not conducive to open space design due to the proximity to the NYSDEC wetland buffer. Soil Restoration Soil restoration measures shall be provided for this project. (See Construction Drawings) Reduction of Impervious Cover Roadway Reduction None presently exist on the site. Sidewalk Reduction On-site sidewalk width was limited to the minimum practical width. Driveway Reduction None presently exist on the site. Cul-de-sac Reduction None presently exist on the site. Building Footprint Reduction Per the sizing requirements of the Stewart’s Shops Corporation, a second story for a convenient store is not practical for this location. Parking Reduction Parking area and drive aisles are designed to Town standards. Runoff Reduction Techniques Conservation of Natural Areas None presently exist on the site. Sheetflow to Riparian buffers or filter strips None presently exist on the site. Vegetated Open Swale The use of vegetated open swales is not practical with the proposed site design. Tree Planting/Tree Box Landscaped areas are proposed along the western property line and adjacent to both Glen Street and Sherman Avenue. Trees are proposed in both the Glen Street and Sherman Avenue landscaping beds. Disconnection of Rooftop Runoff Disconnection of rooftop runoff is not practical with the proposed site design. Page | 20 Runoff Reduction Techniques (cont.) Stream Daylighting for Redevelopment Projects None presently exist on site. Rain Garden Not allowed on “Hot Spot” sites. Green Roof The use of a green roof at this location would not be practical with the proposed building design. Stormwater Planter Practice is not being proposed as it would make access areas to the building non ADA compliant. Rain Tank/Cistern Proposed landscaped areas will not require the volume of water needed to be stored in cisterns. Porous Pavement Not allowed on “Hot Spot” sites. The RRv is the minimum volume of runoff that is to be removed from the runoff volume that is sent to the “end of pipe” treatment practice by utilizing infiltration, evaporation, recycling, recharging, etc. The intent of implementing the “green” infrastructure techniques is to redistribute the WQv prior to runoff being collected by the proposed stormwater drainage system. As it is often difficult to remove the whole WQv, the minimum volume required is set as the RRv. The remaining volume that is not treated (WQv – RRv) will then be treated at the “end of pipe” treatment system. The minimum RRv is defined as: RRv(min) = [(P)(Rv*)(Ai)]/12 Where: RRv(min) = Minimum runoff reduction volume (acre-feet) Rv* = 0.05+0.009(I); where I is 100% impervious cover Ai = (S)(Aic) Aic = Total area of new impervious cover S = Hydrologic soil group reduction factor HSG A; S = 0.55 HSG B; S = 0.40 HSG C; S = 0.30 HSG D; S = 0.20 Because impervious cover is being reduced in all the post development areas on-site (with the exception of P3), the Aic value in the above equation equals zero (0). This causes the entire equation to have a value of zero (0) and the minimum RRv for the project to also be zero (0). As mentioned above, there is an increase in impervious cover in post development area P3. As such, RRv shall be required for P3. Based upon the calculations found in Exhibits B.1, the following was determined: Minimum RRv for Post Development Area P3 = 215 ft3 Runoff generated within post development area P3 will be directed into a proposed Subsurface Infiltration Array (I-4). As can be seen from the post development stormwater model, 100% of the WQv and by extension, the minimum RRv for P3 is reduced on-site Page | 21 within the proposed infiltration facility. This, combined with impervious cover reductions in the remaining catchment areas, meets the minimum RRv requirements for the project. 5.3 Channel Protection Volume (CPv) Channel Protection (CPv) is not required for the redevelopment activity portion of the project as there are no changes to hydrology that increase the discharge rate from the project site. The new development portion of the site is tributary to the proposed Subsurface Infiltration Array systems which have no off-site discharges for all subject storm events, thus satisfying the CPv requirements for the project. 5.4 Overbank Flood Protection Volume (Qp) The overbank flood protection volume requirements are incorporated to prevent an increase in the frequency of flooding and magnitude of out-of-bank flooding downstream of the stormwater management practice. Overbank control requires storage to attenuate the post development 10- year, 24-hour peak discharge rate to the pre development rates. 5.5 Extreme Flood Protection Volume (Qf) The intent of the extreme flood protection volume is utilized to prevent the increased risk of flood damage from large storm events, maintain the boundaries of the pre development 100-year flood plain and protect the physical integrity of the stormwater management practices. Extreme flood protection control requires storage to attenuate the 100-year, 24-hour peak discharge rate to the pre development rates. 5.6 Safe Passage of the 100-Year Design Storm The physical integrity of the stormwater management practice must be maintained. The outlet structure(s) must be designed to accommodate the 100-year design storm. Used in conjunction with the stage-storage relationship, the safe passage of the 100-year design storm reveals the maximum water surface elevation anticipated for the proposed stormwater management facilities. Page | 22 6.0 PROPOSED WATER QUALITY AND QUANTITY CONTROLS 6.1 Proposed Stormwater Management Strategy Stormwater is to be collected in catch basins and routed via a proposed closed drainage system to a proposed stormwater management facilities. The “hot spot” areas of the project site are to be routed to a Subsurface Detention Array for attenuation of stormwater rates prior to discharge at DP1. The non “hot spot” areas of the project site are to be routed to one (1) of two (2) Subsurface Infiltration Arrays (I-4). The proposed infiltration arrays have been designed to safely store and exfiltrate runoff from all anticipated on-site storm events, up to and including the 100-year storm event. The stormwater analysis was performed using HydroCAD. HydroCAD is a computer aided design program, developed by HydroCAD Software Solutions, used for the analysis of hydrologic and hydraulic properties of a watershed. The software uses the NRCS hydrologic methods to compute the 24-hour precipitation event. The runoff curve numbers were computed using TR-55 tabular methodology based on site conditions. The 24-hour extreme rainfall amounts for project area are documented in Exhibit A.1. The hydrograph model is set to simulate pre development areas versus post development areas. Exhibit C.2 shows a schematic of the model elements. It is the goal of the hydraulic model to demonstrate the water surface elevation within the proposed infiltration basin and the net changes in peak discharge rates that occur between the pre development and post development conditions for the 1, 10, and 100-year storm events. 6.2 Water Quality and Pretreatment for Post Development Areas Post-Development Area P1 has been designed in accordance with the NYSDEC water quality requirements. Per Table 4.3 of the NYSDEC SWDM, the proposed site is classified as a “Hot Spot” due to the re-fueling activities that will occur on the site. As such, constraints are placed on stormwater management facilities with regard to infiltration and recharge of stormwater on the site. Stormwater runoff generated will contain runoff from the area of the refueling pumps and therefore is prohibited from being infiltrated on-site. In order to accomplish this and still allow non “hot spot” areas of the site to infiltrate stormwater runoff, the proposed on-site grading has segregated the “hot spot” areas and will route collected runoff to a proposed Subsurface Detention Array. Runoff will first be routed through a hydrodynamic separator for water quality treatment. As Area P1 is considered a redevelopment area, NYSDEC considers hydrodynamic separators acceptable treatment practices for stormwater runoff. The proposed hydrodynamic separator is a First Defense Model FD-3HC manufactured by Hydro International. As a hydrodynamic separator is a flow through device, the WQv peak flow rate must be determined. The WQv peak flow rate has been determined to be 0.17 cubic feet per second (cfs). This calculation can be found in Exhibit B.2. The FD-3HC is capable of providing treatment of flow rates up to 0.84 cfs and bypassing flow rates up to 15 cfs. The maximum flow rate that will be routed through the proposed device, the 100-year storm event, is 3.47 cfs. A copy of the manufacturer’s data supporting these flow rates in provided in Exhibit B.3. Page | 23 Post-Development Areas P2A and P2B has been designed in accordance with the NYSDEC water quality requirements. Stormwater runoff generated will be routed to a Subsurface Infiltration Array (I-4) for water quality treatment and exfiltration into the existing on-site soils. Using the SWDM, the WQv was determined to be 0.008 ac-ft (340 cf). This calculation can be found in Exhibit B.1. Pretreatment of stormwater runoff generated will be provided via a proposed oil/water separator. The oil/water separator is capable of filtering out any grit and/or debris from the stormwater stream prior to it entering the infiltration facility. It is also capable of trapping and petroleum products within it for removal and proper disposal. Details of the proposed pretreatment device can be found in the Construction Drawings. Infiltration testing in accordance with Appendix D of the SWDM was conducted on-site. The observed average on-site exfiltration rate was determined to be 72.0 inches/hour. As designed, the proposed Subsurface Infiltration Array that will accept stormwater runoff from Areas P2A and P2B is capable of reducing the entire WQv generated within those areas of the project site. Post-Development Areas P3 has been designed in accordance with the NYSDEC water quality requirements. Stormwater runoff generated will be routed to a Subsurface Infiltration Array (I-4) for water quality treatment and exfiltration into the existing on-site soils. Using the SWDM, the WQv was determined to be 0.018 ac-ft (789 cf). This calculation can be found in Exhibit B.1. Pretreatment of stormwater runoff generated will be provided via a proposed oil/water separator. The oil/water separator is capable of filtering out any grit and/or debris from the stormwater stream prior to it entering the infiltration facility. It is also capable of trapping and petroleum products within it for removal and proper disposal. Details of the proposed pretreatment device can be found in the Construction Drawings. Infiltration testing in accordance with Appendix D of the SWDM was conducted on-site. The observed average on-site exfiltration rate was determined to be 72.0 inches/hour. As designed, the proposed Subsurface Infiltration Array that will accept stormwater runoff from Area P3 is capable of reducing the entire WQv generated within that area of the project site. 6.3 Water Quantity Control for Post Development Areas As previously stated, unattenuated discharges from Post-Development Areas P1 and P4 would combine and exceed the pre development peak discharge rate at DP1. As such, a stormwater management facility is required in order to attenuate the post development discharge rate at DP3. To manage the increase in stormwater runoff associated with the site improvements in the post developed conditions, an ADS Storm Tech® MC-3500 Subsurface Stormwater Detention System will be utilized. The Storm Tech® System designed for area P1 is comprised of 20 individual MC-3500 HDPE arches. Each arch is 7.50’ (L) x 6.25’ (W) x 3.75’ (H). The arch chambers are aligned in rows with a 12” HDPE manifold connecting the rows. Each row receives an end cap on each end of the row. The arches are placed on a 9” stone foundation layer and void stone is placed in between the rows and along the perimeter of the system. A 12” layer of void stone is then placed above the arches. A void ratio of 40% was used in modeling the stone. A 30 MIL thick pond liner will be installed encapsulating the void stone to prevent infiltration of stormwater runoff due to P1 receiving “hotspot” runoff Page | 24 from the area of the refueling pumps. All seams and penetrations in the liner will be field welded in order to make the system water tight. Details pertaining to the design and installation of the proposed StormTech® MC-3500 detention system can be found in the Construction Drawings. ADS Storm Tech® MC-3500 Subsurface Stormwater Systems will also be utilized to control generated stormwater runoff within Post-Development Areas P2A and P2B. A separate MC-3500 will also be utilized to manage runoff within Post-Development Area P3 as well. As previously stated, stormwater runoff routed to these systems will be allowed to exfiltrate into the existing on- site soils. Both systems have been designed to safely store and exfiltrate generated runoff up to and including the 100-year design storm. Runoff generated within these catchment areas do not contribute to the post-development off-site stormwater discharges. The Storm Tech® System designed for area P2A and P2B is comprised of 15 individual MC-3500 HDPE arches. Each arch is 7.50’ (L) x 6.25’ (W) x 3.75’ (H). The arch chambers are aligned in rows with a 12” HDPE manifold connecting the rows. Each row receives an end cap on each end of the row. The arches are placed on a 9” stone foundation layer and void stone is placed in between the rows and along the perimeter of the system. A 12” layer of void stone is then placed above the arches. A void ratio of 40% was used in modeling the stone. In place of a pond liner, the void stone is wrapped with a geotextile membrane to allow for the exfiltration of stored stormwater. The Storm Tech® System designed for area P3 is comprised of 9 individual MC-3500 HDPE arches. Each arch is 7.50’ (L) x 6.25’ (W) x 3.75’ (H). The arch chambers are aligned in rows with a 12” HDPE manifold connecting the rows. Each row receives an end cap on each end of the row. The arches are placed on a 9” stone foundation layer and void stone is placed in between the rows and along the perimeter of the system. A 12” layer of void stone is then placed above the arches. A void ratio of 40% was used in modeling the stone. In place of a pond liner, the void stone is wrapped with a geotextile membrane to allow for the exfiltration of stored stormwater. Details pertaining to the design and installation of the proposed StormTech® MC-3500 infiltration systems can be found in the Construction Drawings. HydroCAD software was used to develop a hydraulic model of the proposed infiltration basin. The model demonstrates that the proposed Subsurface Infiltration Array (I-4) will store and safely pass up to the 100-year storm event. The hydraulic modeling was simulated for the 1, 10 and 100-year storm events. See Exhibit C.1 and C.2 for model information and design. Table 4 Pre versus Post Discharge Rates (Attenuated) Discharge Point (DP) 1-Year Flow (cfs) 10-Year Flow (cfs) 100-Year Flow (cfs) Pre Post Pre Post Pre Post DP1 0.09 0.07 0.39 0.31 1.05 1.01 Page | 25 To obtain the peak outflow from the proposed subsurface infiltration array for P1 labeled “Detention” in the software model, the arch and void stone configurations were entered into the software and multiple orifices were set to safely discharge storm events to DP1 (See Construction Drawings). In order to obtain the results in Table 4, inflow versus outflow hydrographs and routing tables were calculated for the proposed system and the results are as follows: Table 5 Storm Tech® MC-3500 Detention System Summary 1-Year (cfs) 10-Year (cfs) 100-Year (cfs) Peak Inflow 0.99 1.86 3.32 Peak Outflow from System 0.03 0.13 0.51 Max. Water Surface Elevation (WSEL) 298.90 299.77 301.47 The 100-year WSEL for area P1 has been determined to be 301.47. The top elevation of the void stone surrounding the system is 302.97. This allows for approximately an additional 1.50 feet of additional storage within the proposed subsurface infiltration system. The lowest top of frame within the proposed closed drainage system in P1 is elevation 302.89 (CB#2). This allows for approximately 1.42 feet of additional storage within proposed system before stormwater would surcharge out the frame of the CB#2. Page | 26 7.0 PROPOSED CONVEYANCE SYSTEM The proposed closed drainage system was designed and checked to pass the 10-year storm event. Calculations for anticipated flow through each pipe run can be found in Exhibit D.1. The anticipated flows through each were based on the percentage of each area of the project site flowing to each proposed catch basin. The delineated surface water runoff area to each proposed catch basin can be found in Exhibit E.3. 8.0 MAINTENANCE REQUIREMENTS FOR PERMANENT PRACTICES Stewart’s Shops, as the owner and operator of the proposed convenient store location, will be responsible for the long term maintenance and operation of each permanent practice in place. Inspection of the proposed practices shall be conducted by a professional engineer. Additionally, the municipality has the authority to enter the site and perform their own inspections. The municipal inspection schedule shall be determined at a later date. Example inspection checklists can be found in Exhibit H.1. 8.1 Storm Tech® Subsurface Stormwater Detention System At a minimum, Storm Tech recommends annual inspections. Initially, the system should be inspected every six (6) months for the first year of operation. For subsequent years, the inspection should be adjusted based upon the previous observation of sediment deposition. The inspection ports allow for easy access to the system from the surface, eliminating the need to perform a confined space entry for inspection purposes. If upon visual inspection it is found that sediment has accumulated, a stadia rod should be inserted to determine the depth of sediment. When the average depth of sediment exceeds three (3) inches throughout the length of a row, clean-out should be performed. Maintenance is accomplished with the JetVac process. The JetVac process utilizes a high-pressure water nozzle to propel itself down the row while scouring and suspending sediments. As the nozzle is retrieved, the captured pollutants are flushed back into the manhole for vacuuming. It is imperative that accumulated sediment within the system be tested per NYSDEC requirements to determine levels of toxicity prior to removal and disposal. 8.2 Storm Tech® Subsurface Infiltration Array (I-4) At a minimum, the system should receive annual inspections. Initially, the system should be inspected every six (6) months for the first year of operation. For subsequent years, the inspection should be adjusted based upon the previous observation of sediment deposition. The system incorporates a combination of standard manholes and inspection ports. The inspection ports allow for easy access to the system from the surface, eliminating the need to perform a confined space entry for inspection purposes. If upon visual inspection it is found that sediment has accumulated, a stadia rod should be inserted to determine the depth of sediment. When the Page | 27 average depth of sediment exceeds three (3) inches throughout the length of a row, clean-out should be performed. Maintenance is accomplished with the JetVac process. The JetVac process utilizes a high-pressure water nozzle to propel itself down the row while scouring and suspending sediments. As the nozzle is retrieved, the captured pollutants are flushed back into the manhole for vacuuming. It is imperative that accumulated sediment within the system be tested per NYSDEC requirements to determine levels of toxicity prior to removal and disposal. 8.3 Closed Drainage System At a minimum, the private closed drainage system located on site shall be inspected annually. During the inspection, the depth of sediment and condition of the pipe and drainage structures should be recorded and maintained on file. Sediment shall be removed when six (6) inches of sediment has accumulated within the system. It is anticipated that this will occur approximately every ten (10) years. Removal of sediment will require the use of high pressure water to clean the system. Water and accumulated sediment can be removed from the system using a Vacuum Truck at the next downstream drainage structure. If it is noted that any drainage pipes or catch basins are in need of repair or replacement, repairs will be scheduled at that time. 8.4 First Defense Model FD-3HC Hydrodynamic Separator The First Defense® protects the environment by removing a wide range of pollutants from stormwater runoff. Periodic removal of these captured pollutants is essential to the continuous, long-term functioning of the First Defense®. The First Defense® will capture and retain sediment and oil until the sediment and oil storage volumes are full to capacity. When sediment and oil storage capacities are reached, the First Defense® will no longer be able to store removed sediment and oil. Maximum pollutant storage capacities are provided in Table 1. The First Defense® allows for easy and safe inspection, monitoring and clean-out procedures. A commercially or municipally owned sump-vac is used to remove captured sediment and floatables. Access ports are located in the top of the manhole. Maintenance events may include Inspection, Oil & Floatables Removal, and Sediment Removal. Maintenance events do not require entry into the First Defense®, nor do they require the internal components of the First Defense® to be removed. In the case of inspection and floatables removal, a vactor truck is not required. However, a vactor truck is required if the maintenance event is to include oil removal and/or sediment removal. The frequency of clean out is determined in the field after installation. During the first year of operation, the unit should be inspected every six months to determine the rate of sediment and floatables accumulation. A simple probe such as a Sludge-Judge® can be used to determine the level of accumulated solids stored in the sump. This information can be recorded in the maintenance log to establish a routine maintenance schedule. Sediment removal shall occur when the sediment storage volume in the table below has been reached. Based upon the internal Page | 28 dimensions of the FD-5HC manhole, an accumulated sediment volume of 0.7 cy will be reached when sediment depths approach 1.5 feet. Should an oil or fuel spill occur, it should be immediately cleaned out. Motor oil and other hydrocarbons that occur on a more routine basis should be removed when an appreciable layer has been captured. The preferred method of removing these pollutants is the use of absorbent pads, which solidify the oil. These are usually easier to remove from the unit and less expensive to dispose of than the oil/water emulsion created by vacuuming the oily layer. Floating trash can be netted out to separate it from other pollutants. Disposal of all materials from the unit should be done so at an appropriate disposal facility. 8.5 Special Considerations When inspecting the stormwater facilities, it may be necessary for inspectors to enter the manholes. It may be necessary for inspectors to be certified in confined space entry. Page | 29 9.0 CONCLUSION The design intent of providing the required pretreatment/treatment of the WQv is achieved by the use of the proposed hydrodynamic separator, oil/water separators and on-site subsurface infiltration proposed for this project. Through these mitigative measures, stormwater quality impacts from the proposed finished project will be minimized. Based on hydrological modeling of the stormwater management system and professional analysis of site conditions, the proposed site improvements will function to provide stormwater management for the proposed project as required by applicable state and local regulations. This system will not adversely affect adjacent or downstream structures, groundwater or properties beyond what is already experienced at this location. Page | 30 10.0 EXHIBITS Exhibit A – Project Site Information A.1 24-hour Extreme Rainfall Intensities A.2 Pre Development CN A.3 Post Development CN A.4 NRCS Soil Information A.5 FEMA Floodplain Mapping A.6 OPRHP No Impact Letter Extreme Precipitation Tables Northeast Regional Climate Center Data represents point estimates calculated from partial duration series. All precipitation amounts are displayed in inches. Metadata for Point Smoothing Yes State Location Latitude 43.093 degrees North Longitude 73.771 degrees West Elevation 90 feet Date/Time Mon Dec 29 2025 08:37:07 GMT-0500 (Eastern Standard Time) Extreme Precipitation Estimates 5min 10min 15min 30min 60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 1day 2day 4day 7day 10day 1yr 0.27 0.42 0.52 0.68 0.84 1.05 1yr 0.73 0.97 1.21 1.49 1.83 2.25 2.54 1yr 1.99 2.44 2.81 3.45 3.95 1yr 2yr 0.33 0.51 0.63 0.83 1.04 1.30 2yr 0.90 1.15 1.48 1.80 2.18 2.61 2.94 2yr 2.31 2.82 3.29 3.93 4.45 2yr 5yr 0.39 0.61 0.76 1.02 1.30 1.63 5yr 1.12 1.43 1.86 2.25 2.70 3.20 3.61 5yr 2.83 3.47 3.99 4.65 5.28 5yr 10yr 0.44 0.69 0.87 1.18 1.54 1.93 10yr 1.33 1.69 2.21 2.67 3.18 3.74 4.22 10yr 3.31 4.06 4.63 5.29 6.01 10yr 25yr 0.52 0.83 1.05 1.45 1.92 2.42 25yr 1.66 2.09 2.77 3.34 3.94 4.58 5.19 25yr 4.06 4.99 5.64 6.28 7.14 25yr 50yr 0.58 0.94 1.20 1.68 2.28 2.89 50yr 1.97 2.47 3.31 3.97 4.65 5.36 6.07 50yr 4.74 5.84 6.54 7.15 8.14 50yr 100yr 0.67 1.08 1.40 1.98 2.70 3.43 100yr 2.33 2.91 3.93 4.69 5.46 6.26 7.11 100yr 5.54 6.83 7.60 8.14 9.28 100yr 200yr 0.76 1.24 1.61 2.31 3.20 4.08 200yr 2.76 3.43 4.67 5.55 6.43 7.32 8.32 200yr 6.48 8.00 8.84 9.28 10.58 200yr 500yr 0.91 1.50 1.96 2.86 4.01 5.13 500yr 3.46 4.27 5.87 6.94 7.99 9.00 10.27 500yr 7.97 9.87 10.79 11.04 12.59 500yr Lower Confidence Limits 5min 10min 15min 30min 60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 1day 2day 4day 7day 10day 1yr 0.23 0.35 0.43 0.57 0.70 0.82 1yr 0.61 0.80 0.94 1.22 1.60 1.99 2.28 1yr 1.76 2.19 2.39 3.13 3.58 1yr 2yr 0.31 0.48 0.59 0.80 0.98 1.15 2yr 0.85 1.12 1.29 1.65 2.07 2.53 2.83 2yr 2.24 2.72 3.17 3.81 4.33 2yr 5yr 0.36 0.56 0.69 0.95 1.21 1.35 5yr 1.04 1.32 1.51 1.93 2.45 2.95 3.32 5yr 2.61 3.20 3.70 4.32 4.90 5yr 10yr 0.40 0.61 0.76 1.06 1.38 1.53 10yr 1.19 1.50 1.71 2.16 2.73 3.30 3.73 10yr 2.92 3.58 4.12 4.74 5.38 10yr 25yr 0.46 0.71 0.88 1.25 1.65 1.80 25yr 1.42 1.76 2.02 2.50 3.19 3.85 4.34 25yr 3.41 4.17 4.75 5.35 6.06 25yr 50yr 0.52 0.78 0.98 1.41 1.89 2.03 50yr 1.63 1.99 2.26 2.79 3.57 4.31 4.86 50yr 3.82 4.67 5.30 5.87 6.63 50yr 100yr 0.58 0.87 1.10 1.58 2.17 2.30 100yr 1.87 2.25 2.56 3.11 4.00 4.83 5.43 100yr 4.27 5.22 5.92 6.44 7.25 100yr 200yr 0.65 0.98 1.24 1.79 2.50 2.60 200yr 2.15 2.54 2.89 3.48 4.48 5.40 6.05 200yr 4.78 5.82 6.60 7.05 7.92 200yr 500yr 0.76 1.13 1.46 2.12 3.01 3.08 500yr 2.60 3.01 3.40 4.02 5.21 6.27 6.98 500yr 5.55 6.71 7.66 7.93 8.88 500yr Upper Confidence Limits 5min 10min 15min 30min 60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 1day 2day 4day 7day 10day 1yr 0.30 0.46 0.57 0.76 0.93 1.08 1yr 0.81 1.05 1.22 1.56 1.98 2.42 2.76 1yr 2.14 2.65 3.03 3.70 4.22 1yr 2yr 0.35 0.53 0.66 0.89 1.10 1.23 2yr 0.95 1.20 1.38 1.77 2.25 2.72 3.06 2yr 2.41 2.94 3.41 4.06 4.62 2yr 5yr 0.42 0.65 0.80 1.10 1.40 1.59 5yr 1.21 1.56 1.77 2.24 2.77 3.48 3.93 5yr 3.08 3.78 4.32 5.01 5.70 5yr 10yr 0.50 0.77 0.95 1.33 1.72 1.94 10yr 1.48 1.90 2.16 2.69 3.27 4.20 4.76 10yr 3.72 4.58 5.20 5.88 6.72 10yr 25yr 0.63 0.97 1.20 1.72 2.26 2.53 25yr 1.95 2.47 2.91 3.46 4.12 5.42 6.17 25yr 4.79 5.93 6.64 7.30 8.34 25yr 50yr 0.75 1.15 1.43 2.05 2.77 3.09 50yr 2.39 3.02 3.42 4.19 4.90 6.55 7.50 50yr 5.80 7.21 7.99 8.61 9.85 50yr 100yr 0.90 1.36 1.71 2.47 3.38 3.77 100yr 2.92 3.69 4.17 5.06 5.83 7.93 9.13 100yr 7.02 8.78 9.64 10.16 11.64 100yr 200yr 1.08 1.63 2.06 2.98 4.16 4.62 200yr 3.59 4.51 5.09 6.14 6.95 9.64 11.14 200yr 8.53 10.71 11.62 11.98 13.75 200yr 500yr 1.38 2.05 2.64 3.83 5.45 6.03 500yr 4.70 5.90 6.63 7.91 8.80 12.47 14.53 500yr 11.04 13.97 14.85 14.95 17.18 500yr 29/12/2025, 08:37 Extreme Precipitation https://precip.eas.cornell.edu/#/product/xprecip_results 1/1 Project # Sheet # 1 of 1 Page # 1 of 3 Created By: Date: Checked By: Date: Project: Revised By: Date: Subject: Checked By: Date: %CN 4,557 Lawn Area, Good 49% 19.0 4,780 Impervious (Pvmt, Bldg, etc) 51% 50.2 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 9,337 100% %CN 511 Lawn Area, Good 29% 11.3 1,255 Impervious (Pvmt, Bldg, etc) 71% 69.6 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 1,766 100% %CN 1,052 Impervious (Pvmt, Bldg, etc) 100% 98.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 1,052 100% = 0.024 acres sq. miles 0.000 Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN #E2B A981,052 98 sq. feet = sq. miles = 0.041 0.000 Area (feet2) Factored CN Weighted CN #E2A A391,766 81 A98sq. feet = Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN acres 12/29/2025 PRE-DEVELOPMENTApplicable Standards: Urban Hydrology for Small Watersheds, Techincal Release 55. USDA, June 1986 Marion Avenue Pre Development Weighted CN S. Kitchner Area (feet2) #E1 9,337 sq. feet = 0.214 acres = Drainage Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Weighted CN A A 0.000 sq. miles Factored CN 69 39 98 Project # Sheet # 1 of 1 Page # 2 of 3 Created By: Date: Checked By: Date: Project: Revised By: Date: Subject: Checked By: Date: %CN 2,940 Impervious (Pvmt, Bldg, etc) 100% 98.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 2,940 100% %CN 7,451 Impervious (Pvmt, Bldg, etc) 100% 98.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 7,451 100% %CN 838 Lawn Area, Good 11% 4.4 6,620 Impervious (Pvmt, Bldg, etc) 89% 87.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 7,458 100% 0.171 0.000 sq. miles #E5 A397,458 91 A98sq. feet acres = = Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN #E4 A987,451 0.000 sq. miles acres = 98 sq. feet Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN = 0.171 A982,940 0.000 sq. miles acres = 98 sq. feet Drainage Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN = 0.067#E3 Pre Development Weighted CN Applicable Standards:PRE-DEVELOPMENTUrban Hydrology for Small Watersheds, Techincal Release 55. USDA, June 1986 S. Kitchner 12/29/2025 Marion Avenue Project # Sheet # 1 of 1 Page # 3 of 3 Created By: Date: Checked By: Date: Project: Revised By: Date: Subject: Checked By: Date: %CN 5,619 Lawn Area, Good 13% 5.2 36,629 Impervious (Pvmt, Bldg, etc) 87% 85.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 42,248 100% %CN 5,200 Lawn Area, Good 47% 18.3 5,857 Impervious (Pvmt, Bldg, etc) 53% 51.9 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 11,057 100% %CN 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0 0% 0.000 sq. miles acres = = 0.000 0 0 sq. feet Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN 0.000 sq. miles acres = = 0.254#E7 A3911,057 70 A98sq. feet Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN 0.002 sq. miles acres = = 0.970#E6 A3942,248 90 A98sq. feet Drainage Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN Pre Development Weighted CN Applicable Standards:PRE-DEVELOPMENTUrban Hydrology for Small Watersheds, Techincal Release 55. USDA, June 1986 S. Kitchner 12/29/2025 Marion Avenue Project # Sheet # 1 of 1 Page # 1 of 2 Created By: Date: Checked By: Date: Project: Revised By: Date: Subject: Checked By: Date: %CN 1,739 Lawn Area, Good 10% 3.9 15,726 Impervious (Pvmt, Bldg, etc) 90% 88.2 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 17,465 100% %CN 216 Impervious (Pvmt, Bldg, etc) 2% 2.0 10,184 Lawn Area, Good 98% 38.2 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 10,400 100% %CN 3,212 Impervious (Pvmt, Bldg, etc) 100% 98.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 3,212 100% 92 39 98 Area (feet2) #1 17,465 sq. feet = 0.401 acres = Drainage Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Weighted CN A A 0.001 sq. miles Factored CN 12/29/2025 POST-DEVELOPMENTApplicable Standards: Urban Hydrology for Small Watersheds, Techincal Release 55. USDA, June 1986 Marion Avenue Post Development Weighted CN S. Kitchner Area (feet2) Factored CN Weighted CN #2A A9810,400 40 A39sq. feet = Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN acres 0.239 0.000 sq. miles = Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN #2B A983,212 98 sq. feet = sq. miles 0.000 = 0.074 acres Project # Sheet # 1 of 1 Page # 2 of 2 Created By: Date: Checked By: Date: Project: Revised By: Date: Subject: Checked By: Date: %CN 6,477 Lawn Area, Good 21% 8.3 24,102 Impervious (Pvmt, Bldg, etc) 79% 77.2 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 30,579 100% %CN 2,796 Lawn Area, Good 47% 18.4 3,126 Impervious (Pvmt, Bldg, etc) 53% 51.7 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 5,922 100% %CN 15,554 Lawn Area, Good 99% 38.6 177 Impervious (Pvmt, Bldg, etc) 1% 1.1 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 0% 0.0 15,731 100% Post Development Weighted CN Applicable Standards:POST-DEVELOPMENTUrban Hydrology for Small Watersheds, Techincal Release 55. USDA, June 1986 S. Kitchner 12/29/2025 Marion Avenue 86 A98sq. feet Drainage Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN = 0.702#3 A3930,579 0.001 sq. miles acres = Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN = 70 A98sq. feet = 0.136 Area Land Use Area (feet2) Land Use / Cover Description Hydrologic Soil Group Actual CN Area (feet2) Factored CN Weighted CN #4 A395,922 0.000 sq. miles acres #5 A3915,731 40 A98sq. feet acres = = 0.361 0.001 sq. miles Hydrologic Soil Group—Saratoga County, New York (Stewart's Shops - Marion Avenue - Saratoga Springs,NY) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/29/2025 Page 1 of 4 47 7 1 7 8 0 47 7 1 8 2 0 47 7 1 8 6 0 47 7 1 9 0 0 47 7 1 9 4 0 47 7 1 9 8 0 47 7 2 0 2 0 47 7 2 0 6 0 47 7 2 1 0 0 47 7 1 7 8 0 47 7 1 8 2 0 47 7 1 8 6 0 47 7 1 9 0 0 47 7 1 9 4 0 47 7 1 9 8 0 47 7 2 0 2 0 47 7 2 0 6 0 47 7 2 1 0 0 599910 599950 599990 600030 600070 600110 600150 599910 599950 599990 600030 600070 600110 600150 43° 5' 42'' N 73 ° 4 6 ' 2 0 ' ' W 43° 5' 42'' N 73 ° 4 6 ' 9 ' ' W 43° 5' 31'' N 73 ° 4 6 ' 2 0 ' ' W 43° 5' 31'' N 73 ° 4 6 ' 9 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 50 100 200 300 Feet 0 25 50 100 150 Meters Map Scale: 1:1,690 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MA P L E G E N D MA P I N F O R M A T I O N Ar e a o f I n t e r e s t ( A O I ) Ar e a o f I n t e r e s t ( A O I ) So i l s So i l R a t i n g P o l y g o n s A A/ D B B/ D C C/ D D No t r a t e d o r n o t a v a i l a b l e So i l R a t i n g L i n e s A A/ D B B/ D C C/ D D No t r a t e d o r n o t a v a i l a b l e So i l R a t i n g P o i n t s A A/ D B B/ D C C/ D D No t r a t e d o r n o t a v a i l a b l e Wa t e r F e a t u r e s St r e a m s a n d C a n a l s Tr a n s p o r t a t i o n Ra i l s In t e r s t a t e H i g h w a y s US R o u t e s Ma j o r R o a d s Lo c a l R o a d s Ba c k g r o u n d Ae r i a l P h o t o g r a p h y Th e s o i l s u r v e y s t h a t c o m p r i s e y o u r A O I w e r e m a p p e d a t 1: 2 4 , 0 0 0 . Wa r n i n g : S o i l M a p m a y n o t b e v a l i d a t t h i s s c a l e . En l a r g e m e n t o f m a p s b e y o n d t h e s c a l e o f m a p p i n g c a n c a u s e mi s u n d e r s t a n d i n g o f t h e d e t a i l o f m a p p i n g a n d a c c u r a c y o f s o i l li n e p l a c e m e n t . T h e m a p s d o n o t s h o w t h e s m a l l a r e a s o f co n t r a s t i n g s o i l s t h a t c o u l d h a v e b e e n s h o w n a t a m o r e d e t a i l e d sc a l e . Pl e a s e r e l y o n t h e b a r s c a l e o n e a c h m a p s h e e t f o r m a p me a s u r e m e n t s . So u r c e o f M a p : Na t u r a l R e s o u r c e s C o n s e r v a t i o n S e r v i c e We b S o i l S u r v e y U R L : Co o r d i n a t e S y s t e m : We b M e r c a t o r ( E P S G : 3 8 5 7 ) Ma p s f r o m t h e W e b S o i l S u r v e y a r e b a s e d o n t h e W e b M e r c a t o r pr o j e c t i o n , w h i c h p r e s e r v e s d i r e c t i o n a n d s h a p e b u t d i s t o r t s di s t a n c e a n d a r e a . A p r o j e c t i o n t h a t p r e s e r v e s a r e a , s u c h a s t h e Al b e r s e q u a l - a r e a c o n i c p r o j e c t i o n , s h o u l d b e u s e d i f m o r e ac c u r a t e c a l c u l a t i o n s o f d i s t a n c e o r a r e a a r e r e q u i r e d . Th i s p r o d u c t i s g e n e r a t e d f r o m t h e U S D A - N R C S c e r t i f i e d d a t a a s of t h e v e r s i o n d a t e ( s ) l i s t e d b e l o w . So i l S u r v e y A r e a : Sa r a t o g a C o u n t y , N e w Y o r k Su r v e y A r e a D a t a : Ve r s i o n 2 5 , S e p 2 , 2 0 2 5 So i l m a p u n i t s a r e l a b e l e d ( a s s p a c e a l l o w s ) f o r m a p s c a l e s 1: 5 0 , 0 0 0 o r l a r g e r . Da t e ( s ) a e r i a l i m a g e s w e r e p h o t o g r a p h e d : Se p 9 , 2 0 2 2 — O c t 2 2 , 20 2 2 Th e o r t h o p h o t o o r o t h e r b a s e m a p o n w h i c h t h e s o i l l i n e s w e r e co m p i l e d a n d d i g i t i z e d p r o b a b l y d i f f e r s f r o m t h e b a c k g r o u n d im a g e r y d i s p l a y e d o n t h e s e m a p s . A s a r e s u l t , s o m e m i n o r sh i f t i n g o f m a p u n i t b o u n d a r i e s m a y b e e v i d e n t . Hy d r o l o g i c S o i l G r o u p — S a r a t o g a C o u n t y , N e w Y o r k (S t e w a r t ' s S h o p s - M a r i o n A v e n u e - S a r a t o g a S p r i n g s , N Y ) Na t u r a l R e s o u r c e s Co n s e r v a t i o n S e r v i c e We b S o i l S u r v e y Na t i o n a l C o o p e r a t i v e S o i l S u r v e y 12 / 2 9 / 2 0 2 5 Pa g e 2 o f 4 Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI WnB Windsor loamy sand, 3 to 8 percent slopes A 9.0 100.0% Totals for Area of Interest 9.0 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Hydrologic Soil Group—Saratoga County, New York Stewart's Shops - Marion Avenue - Saratoga Springs,NY Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/29/2025 Page 3 of 4 Sincerely, R. Daniel Mackay Deputy Commissioner for Historic Preservation Division for Historic Preservation Based upon this review, it is the opinion of OPRHP that no properties, including archaeological and/or historic resources, listed in or eligible for the New York State and National Registers of Historic Places will be impacted by this project. If further correspondence is required regarding this project, please be sure to refer to the OPRHP Project Review (PR) number noted above. Re: Thank you for requesting the comments of the Office of Parks, Recreation and Historic Preservation (OPRHP). We have reviewed the project 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). May 06, 2021 Charles Marshall Stewart's Shops Corp. PO Box 435 Saratoga Springs, NY 12866 SEQRA Stewart's PUD Marion Ave and Maple Dell 33 Marion Ave, Saratoga Springs, NY 12866 21PR02830 Dear Charles Marshall: Division for Historic Preservation P.O. Box 189, Waterford, New York 12188-0189 parks.ny.gov ANDREW M. CUOMO Governor ERIK KULLESEID Commissioner Exhibit B – WQv and CPv B.1 Post Development Water Quality Volume (WQv) and Minimum Runoff Reduction Volume (RRv) B.2 WQv Peak Flow Calculations B.3 Channel Protection Volume (CPv) Project # Sheet # 1 of 1 Page # 1 of 4 Created By: Date: Checked By: Date: Project: Revised By: Date: Subject:WATER QUALITY VOLUME - Total Project Area Checked By: Date: Rainfall Distribution Type: 2 (1, 1A, 2 or 3) 90% Storm Event (P): 1.1 inches Weighted Hydrologic Soil Group (HSG): A (A, B, C or D) Redevelopment Project: 1 (Yes = 1, No = 2) New Impervious Cover Within Watershed Area: 0.000 Existing Impervious Cover Within Watershed Area: 1.55 Total Impervious Cover: 1.550 Impervious Area for WQv Calculation (New Const): NA Impervious Area for WQv Calculation (Redevelopment): 0.388 1.910 acres I = Impervious Area / Total Watershed Area: 0.203 I = 20.3 % Compute Runoff Coefficient, Rv Rv = 0.05 + 0.009 (I) Rv = 0.23 (Min Rv = 0.20, use 0.23 ) Compute WQv, (Includes both on-site and off-site drainage) (Use the 90% capture rule, Figure 4.1 NYS-SWDM) WQv = WQv =ac-ft = ft 3 WQv = 1774 HSG A = 0.55 S = 0.55 HSG B = 0.40 RRv(MIN) =(P)(0.95)(S)(Aic) HSG C = 0.30 12 HSG D = 0.20 RRv(MIN) =0.000 ac-ft = 0 ft3 R. Rubado 10/3/2025 S. Kitchner 1/9/2026 Marion Ave (P)(Rv)(A) Computation of Preliminary Stormwater Storage Volumes and Peak Discharges (Designed for compliance with New York State Stormwater Management Design Manual) Hydrologic Input Parameters and Site Hydrology Water Quality Volume, WQv Compute Impervious Cover Total Watershed Area: Cell requires a direct entry 12 0.041 1774 Runoff Reduction Volume, RRv Specific Reduction Factors (S) for HSGs Project # Sheet # 1 of 1 Page # 2 of 4 Created By: Date: Checked By: Date: Project: Revised By: Date: Subject:WATER QUALITY VOLUME - P1 Checked By: Date: Rainfall Distribution Type: 2 (1, 1A, 2 or 3) 90% Storm Event (P): 1.1 inches Weighted Hydrologic Soil Group (HSG): A (A, B, C or D) Redevelopment Project: 1 (Yes = 1, No = 2) New Impervious Cover Within Watershed Area: 0.000 Existing Impervious Cover Within Watershed Area: 0.37 Total Impervious Cover: 0.370 Impervious Area for WQv Calculation (New Const): NA Impervious Area for WQv Calculation (Redevelopment): 0.093 0.400 acres I = Impervious Area / Total Watershed Area: 0.231 I = 23.1 % Compute Runoff Coefficient, Rv Rv = 0.05 + 0.009 (I) Rv = 0.26 (Min Rv = 0.20, use 0.26 ) Compute WQv, (Includes both on-site and off-site drainage) (Use the 90% capture rule, Figure 4.1 NYS-SWDM) WQv = WQv =ac-ft = ft 3 WQv = 412 HSG A = 0.55 S = 0.55 HSG B = 0.40 RRv(MIN) =(P)(0.95)(S)(Aic) HSG C = 0.30 12 HSG D = 0.20 RRv(MIN) =0.000 ac-ft = 0 ft3 Cell requires a direct entry Hydrologic Input Parameters and Site Hydrology Water Quality Volume, WQv Compute Impervious Cover Total Watershed Area: (P)(Rv)(A) 12 0.009 412 Runoff Reduction Volume, RRv Specific Reduction Factors (S) for HSGs R. Rubado 1/9/2026 S. Kitchner 1/9/2026 Marion Ave Computation of Preliminary Stormwater Storage Volumes and Peak Discharges (Designed for compliance with New York State Stormwater Management Design Manual) Project # Sheet # 1 of 1 Page # 3 of 4 Created By: Date: Checked By: Date: Project: Revised By: Date: Subject:WATER QUALITY VOLUME - P2 Checked By: Date: Rainfall Distribution Type: 2 (1, 1A, 2 or 3) 90% Storm Event (P): 1.1 inches Weighted Hydrologic Soil Group (HSG): A (A, B, C or D) Redevelopment Project: 1 (Yes = 1, No = 2) New Impervious Cover Within Watershed Area: 0.000 Existing Impervious Cover Within Watershed Area: 0.31 Total Impervious Cover: 0.310 Impervious Area for WQv Calculation (New Const): NA Impervious Area for WQv Calculation (Redevelopment): 0.078 0.310 acres I = Impervious Area / Total Watershed Area: 0.250 I = 25.0 % Compute Runoff Coefficient, Rv Rv = 0.05 + 0.009 (I) Rv = 0.28 (Min Rv = 0.20, use 0.28 ) Compute WQv, (Includes both on-site and off-site drainage) (Use the 90% capture rule, Figure 4.1 NYS-SWDM) WQv = WQv =ac-ft = ft 3 WQv = 340 HSG A = 0.55 S = 0.55 HSG B = 0.40 RRv(MIN) =(P)(0.95)(S)(Aic) HSG C = 0.30 12 HSG D = 0.20 RRv(MIN) =0.000 ac-ft = 0 ft3 R. Rubado 1/9/2026 S. Kitchner 1/9/2026 Marion Ave Computation of Preliminary Stormwater Storage Volumes and Peak Discharges (Designed for compliance with New York State Stormwater Management Design Manual) Cell requires a direct entry Hydrologic Input Parameters and Site Hydrology Water Quality Volume, WQv Compute Impervious Cover Total Watershed Area: (P)(Rv)(A) 12 0.008 340 Runoff Reduction Volume, RRv Specific Reduction Factors (S) for HSGs Project # Sheet # 1 of 1 Page # 4 of 4 Created By: Date: Checked By: Date: Project: Revised By: Date: Subject:WATER QUALITY VOLUME - P3 Checked By: Date: Rainfall Distribution Type: 2 (1, 1A, 2 or 3) 90% Storm Event (P): 1.1 inches Weighted Hydrologic Soil Group (HSG): A (A, B, C or D) Redevelopment Project: 1 (Yes = 1, No = 2) New Impervious Cover Within Watershed Area: 0.103 Existing Impervious Cover Within Watershed Area: 0.31 Total Impervious Cover: 0.413 Impervious Area for WQv Calculation (New Const): NA Impervious Area for WQv Calculation (Redevelopment): 0.181 0.702 acres I = Impervious Area / Total Watershed Area: 0.257 I = 25.7 % Compute Runoff Coefficient, Rv Rv = 0.05 + 0.009 (I) Rv = 0.28 (Min Rv = 0.20, use 0.28 ) Compute WQv, (Includes both on-site and off-site drainage) (Use the 90% capture rule, Figure 4.1 NYS-SWDM) WQv = WQv =ac-ft = ft 3 WQv = 789 HSG A = 0.55 S = 0.55 HSG B = 0.40 RRv(MIN) =(P)(0.95)(S)(Aic) HSG C = 0.30 12 HSG D = 0.20 RRv(MIN) =0.005 ac-ft = 215 ft3 R. Rubado 1/9/2026 S. Kitchner 1/9/2026 Marion Ave Computation of Preliminary Stormwater Storage Volumes and Peak Discharges (Designed for compliance with New York State Stormwater Management Design Manual) Cell requires a direct entry Hydrologic Input Parameters and Site Hydrology Water Quality Volume, WQv Compute Impervious Cover Total Watershed Area: (P)(Rv)(A) 12 0.018 789 Runoff Reduction Volume, RRv Specific Reduction Factors (S) for HSGs Project # Sheet # 1 of 1 Page # 1 of 1 Created By: Date: Checked By: Date: Project: Revised By: Date: Subject: Checked By: Date: One-year Storm Event (P) =2.25 acres = sq. miles Weighted CN for this post-development drainage area: 92 = Calculated time of concentration, Tc = 0.10 ac-ft Calculate the initial abstraction, Ia = (200 / CN) -2 = cubic in. Ia = 0.17 in. Calculate Ia/P = 0.08 qu = 1,000 csm/in (where csm = cubic feet per second per square mile per year) Qp = qu x A x WQv Where: Qp = (1000 csm/in) (0.0014 sq. mi.) (0.297 in.) Qp = peak discharge (cfs) Qp =0.17 cfs qu =unit peak discharge (cfs/mi2/inch) A = drainage area (square miles) WQv = water quality volume (watershed inches) (Designed for compliance with New York State Stormwater Management Design Manual) R. Rubado 12/29/2025 S. Kitchner Marion Avenue WQv Peak Flow - P1 Computation of Preliminary Stormwater Storage Volumes and Peak Discharges Cell requires a direct entry Determination of qu Total Drainage Area = 0.401 Determine qu based on Tc and Ia/P 2,515,473 square in. Calculated WQv = (See Exhibit B.1) From Appendix B.2 of the NYSDEC SWDM: 0.009 677,430 WQv (in inches) = 0.0006 0.269 Exhibit C – Hydrologic Model Simulations Using HydroCAD C.1 Pre Development C.2 Post Development E1 E1 E2A E2A E2B E2B E3 E3 E4 E4 E5 E5 E6 E6 E7 E7 DP1 Marion Ave DP2 City property 7P Low spot DWE2 Drywell E2 DWE3 Drywell E3 DWE4 Drywell E4 DWE5 Drywell E5 Routing Diagram for Marion Ave-Pre Prepared by Stewart's Shops Corp, Printed 1/5/2026 HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcat Reach Pond Link Stewart's Shops - Marion Ave - Pre Development Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 2HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.384 39 >75% Grass cover, Good, HSG A (E1, E2A, E5, E6, E7) 0.502 96 Gravel surface, HSG A (E6, E7) 0.842 98 Unconnected pavement, HSG A (E1, E2A, E2B, E3, E4, E5, E6) 0.184 98 Unconnected roofs, HSG A (E4, E5, E6) 1.913 86 TOTAL AREA Stewart's Shops - Marion Ave - Pre Development Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 3HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 1.913 HSG A E1, E2A, E2B, E3, E4, E5, E6, E7 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.000 Other 1.913 TOTAL AREA Stewart's Shops - Marion Ave - Pre Development Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 4HydroCAD® 10.20-6a s/n 08847 © 2024 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 0.384 0.000 0.000 0.000 0.000 0.384 >75% Grass cover, Good E1, E2A, E5, E6, E7 0.502 0.000 0.000 0.000 0.000 0.502 Gravel surface E6, E7 0.842 0.000 0.000 0.000 0.000 0.842 Unconnected pavement E1, E2A, E2B, E3, E4, E5, E6 0.184 0.000 0.000 0.000 0.000 0.184 Unconnected roofs E4, E5, E6 1.913 0.000 0.000 0.000 0.000 1.913 TOTAL AREA Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 5HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,337 sf 51.19% Impervious Runoff Depth>0.31"Subcatchment E1: E1 Flow Length=409' Tc=7.3 min CN=69 Runoff=0.09 cfs 0.006 af Runoff Area=1,766 sf 71.06% Impervious Runoff Depth>0.77"Subcatchment E2A: E2A Tc=6.0 min CN=81 Runoff=0.05 cfs 0.003 af Runoff Area=1,052 sf 100.00% Impervious Runoff Depth>2.02"Subcatchment E2B: E2B Tc=6.0 min CN=98 Runoff=0.07 cfs 0.004 af Runoff Area=2,940 sf 100.00% Impervious Runoff Depth>2.02"Subcatchment E3: E3 Tc=6.0 min CN=98 Runoff=0.21 cfs 0.011 af Runoff Area=7,452 sf 100.00% Impervious Runoff Depth>2.02"Subcatchment E4: E4 Tc=6.0 min CN=98 Runoff=0.52 cfs 0.029 af Runoff Area=7,458 sf 88.76% Impervious Runoff Depth>1.38"Subcatchment E5: E5 Flow Length=110' Tc=28.3 min CN=91 Runoff=0.21 cfs 0.020 af Runoff Area=42,248 sf 48.77% Impervious Runoff Depth>1.22"Subcatchment E6: E6 Flow Length=427' Tc=63.2 min CN=89 Runoff=0.62 cfs 0.098 af Runoff Area=11,057 sf 0.00% Impervious Runoff Depth>0.30"Subcatchment E7: E7 Flow Length=126' Tc=53.2 min CN=69 Runoff=0.03 cfs 0.006 af Inflow=0.09 cfs 0.006 afReach DP1: Marion Ave Outflow=0.09 cfs 0.006 af Inflow=0.62 cfs 0.098 afReach DP2: City property Outflow=0.62 cfs 0.098 af Peak Elev=307.00' Storage=0 cf Inflow=0.03 cfs 0.006 afPond 7P: Low spot Discarded=0.03 cfs 0.006 af Primary=0.00 cfs 0.000 af Outflow=0.03 cfs 0.006 af Peak Elev=299.08' Storage=14 cf Inflow=0.13 cfs 0.007 afPond DWE2: Drywell E2 Discarded=0.12 cfs 0.007 af Primary=0.00 cfs 0.000 af Outflow=0.12 cfs 0.007 af Peak Elev=298.73' Storage=21 cf Inflow=0.21 cfs 0.011 afPond DWE3: Drywell E3 Discarded=0.20 cfs 0.011 af Primary=0.00 cfs 0.000 af Outflow=0.20 cfs 0.011 af Peak Elev=300.72' Storage=118 cf Inflow=0.52 cfs 0.029 afPond DWE4: Drywell E4 Discarded=0.35 cfs 0.029 af Primary=0.00 cfs 0.000 af Outflow=0.35 cfs 0.029 af Peak Elev=299.40' Storage=22 cf Inflow=0.21 cfs 0.020 afPond DWE5: Drywell E5 Discarded=0.21 cfs 0.020 af Primary=0.00 cfs 0.000 af Outflow=0.21 cfs 0.020 af Total Runoff Area = 1.913 ac Runoff Volume = 0.177 af Average Runoff Depth = 1.11" 46.34% Pervious = 0.886 ac 53.66% Impervious = 1.026 ac Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 6HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E1: E1 Runoff = 0.09 cfs @ 12.01 hrs, Volume= 0.006 af, Depth> 0.31" Routed to Reach DP1 : Marion Ave Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 4,557 39 >75% Grass cover, Good, HSG A 4,780 98 Unconnected pavement, HSG A 9,337 69 Weighted Average 4,557 48.81% Pervious Area 4,780 51.19% Impervious Area 4,780 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.7 24 0.0420 0.11 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.4 21 0.0160 0.83 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 3.2 364 0.0090 1.93 Shallow Concentrated Flow, Paved Kv= 20.3 fps 7.3 409 Total Subcatchment E1: E1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=9,337 sf Runoff Volume=0.006 af Runoff Depth>0.31" Flow Length=409' Tc=7.3 min CN=69 0.09 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 7HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E2A: E2A Runoff = 0.05 cfs @ 11.98 hrs, Volume= 0.003 af, Depth> 0.77" Routed to Pond DWE2 : Drywell E2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 511 39 >75% Grass cover, Good, HSG A 1,255 98 Unconnected pavement, HSG A 1,766 81 Weighted Average 511 28.94% Pervious Area 1,255 71.06% Impervious Area 1,255 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E2A: E2A Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=1,766 sf Runoff Volume=0.003 af Runoff Depth>0.77" Tc=6.0 min CN=81 0.05 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 8HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E2B: E2B Runoff = 0.07 cfs @ 11.96 hrs, Volume= 0.004 af, Depth> 2.02" Routed to Pond DWE2 : Drywell E2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 1,052 98 Unconnected pavement, HSG A 1,052 100.00% Impervious Area 1,052 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E2B: E2B Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=1,052 sf Runoff Volume=0.004 af Runoff Depth>2.02" Tc=6.0 min CN=98 0.07 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 9HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E3: E3 Runoff = 0.21 cfs @ 11.96 hrs, Volume= 0.011 af, Depth> 2.02" Routed to Pond DWE3 : Drywell E3 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 2,940 98 Unconnected pavement, HSG A 2,940 100.00% Impervious Area 2,940 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E3: E3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=2,940 sf Runoff Volume=0.011 af Runoff Depth>2.02" Tc=6.0 min CN=98 0.21 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 10HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E4: E4 Runoff = 0.52 cfs @ 11.96 hrs, Volume= 0.029 af, Depth> 2.02" Routed to Pond DWE4 : Drywell E4 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 3,413 98 Unconnected roofs, HSG A 4,039 98 Unconnected pavement, HSG A 7,452 98 Weighted Average 7,452 100.00% Impervious Area 7,452 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E4: E4 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=7,452 sf Runoff Volume=0.029 af Runoff Depth>2.02" Tc=6.0 min CN=98 0.52 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 11HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E5: E5 Runoff = 0.21 cfs @ 12.22 hrs, Volume= 0.020 af, Depth> 1.38" Routed to Pond DWE5 : Drywell E5 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 2,894 98 Unconnected roofs, HSG A 3,726 98 Unconnected pavement, HSG A 838 39 >75% Grass cover, Good, HSG A 7,458 91 Weighted Average 838 11.24% Pervious Area 6,620 88.76% Impervious Area 6,620 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.1 11 0.0660 1.29 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 0.8 20 0.0030 0.42 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 3.1 15 0.0260 0.08 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 24.2 38 0.0010 0.03 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.1 26 0.0310 3.57 Shallow Concentrated Flow, Paved Kv= 20.3 fps 28.3 110 Total Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 12HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment E5: E5 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=7,458 sf Runoff Volume=0.020 af Runoff Depth>1.38" Flow Length=110' Tc=28.3 min CN=91 0.21 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 13HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E6: E6 Runoff = 0.62 cfs @ 12.68 hrs, Volume= 0.098 af, Depth> 1.22" Routed to Reach DP2 : City property Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 1,706 98 Unconnected roofs, HSG A 18,899 98 Unconnected pavement, HSG A 16,024 96 Gravel surface, HSG A 5,619 39 >75% Grass cover, Good, HSG A 42,248 89 Weighted Average 21,643 51.23% Pervious Area 20,605 48.77% Impervious Area 20,605 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.7 28 0.0200 0.08 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 17.1 35 0.0020 0.03 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 34.1 37 0.0004 0.02 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.4 8 0.0004 0.30 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 3.8 46 0.0001 0.20 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.2 36 0.0150 2.49 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 67 0.0070 1.35 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.1 170 0.0148 2.47 Shallow Concentrated Flow, Paved Kv= 20.3 fps 63.2 427 Total Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 14HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment E6: E6 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=42,248 sf Runoff Volume=0.098 af Runoff Depth>1.22" Flow Length=427' Tc=63.2 min CN=89 0.62 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 15HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E7: E7 Runoff = 0.03 cfs @ 12.69 hrs, Volume= 0.006 af, Depth> 0.30" Routed to Pond 7P : Low spot Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 5,200 39 >75% Grass cover, Good, HSG A 5,857 96 Gravel surface, HSG A 11,057 69 Weighted Average 11,057 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 34 0.0060 0.62 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 49.8 66 0.0055 0.02 Sheet Flow, Woods: Dense underbrush n= 0.800 P2= 2.61" 2.5 26 0.0050 0.18 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 53.2 126 Total Subcatchment E7: E7 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=11,057 sf Runoff Volume=0.006 af Runoff Depth>0.30" Flow Length=126' Tc=53.2 min CN=69 0.03 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 16HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP1: Marion Ave Inflow Area = 0.639 ac, 40.93% Impervious, Inflow Depth > 0.10" for 1 yr event Inflow = 0.09 cfs @ 12.01 hrs, Volume= 0.006 af Outflow = 0.09 cfs @ 12.01 hrs, Volume= 0.006 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach DP1: Marion Ave Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.639 ac 0.09 cfs0.09 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 17HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP2: City property Inflow Area = 1.273 ac, 60.05% Impervious, Inflow Depth > 0.93" for 1 yr event Inflow = 0.62 cfs @ 12.68 hrs, Volume= 0.098 af Outflow = 0.62 cfs @ 12.68 hrs, Volume= 0.098 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach DP2: City property Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=1.273 ac 0.62 cfs0.62 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 18HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 7P: Low spot Inflow Area = 0.254 ac, 0.00% Impervious, Inflow Depth > 0.30" for 1 yr event Inflow = 0.03 cfs @ 12.69 hrs, Volume= 0.006 af Outflow = 0.03 cfs @ 12.69 hrs, Volume= 0.006 af, Atten= 0%, Lag= 0.0 min Discarded = 0.03 cfs @ 12.69 hrs, Volume= 0.006 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 307.00' @ 12.69 hrs Surf.Area= 67 sf Storage= 0 cf Plug-Flow detention time= 0.0 min calculated for 0.006 af (100% of inflow) Center-of-Mass det. time= 0.0 min ( 943.2 - 943.2 ) Volume Invert Avail.Storage Storage Description #1 307.00' 235 cf Watershed low point (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 307.00 66 39.0 0 0 66 307.26 2,263 238.2 235 235 4,460 Device Routing Invert Outlet Devices #1 Discarded 307.00'72.000 in/hr Exfiltration over Wetted area #2 Primary 307.25'5.0' long x 1.0' 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 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 Discarded OutFlow Max=0.11 cfs @ 12.69 hrs HW=307.00' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=307.00' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 19HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 7P: Low spot Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Inflow Area=0.254 ac Peak Elev=307.00' Storage=0 cf 0.03 cfs0.03 cfs0.03 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 20HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE2: Drywell E2 Inflow Area = 0.065 ac, 81.87% Impervious, Inflow Depth > 1.24" for 1 yr event Inflow = 0.13 cfs @ 11.97 hrs, Volume= 0.007 af Outflow = 0.12 cfs @ 12.00 hrs, Volume= 0.007 af, Atten= 5%, Lag= 1.7 min Discarded = 0.12 cfs @ 12.00 hrs, Volume= 0.007 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP2 : City property Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 299.08' @ 12.00 hrs Surf.Area= 129 sf Storage= 14 cf Plug-Flow detention time= 2.0 min calculated for 0.007 af (100% of inflow) Center-of-Mass det. time= 1.7 min ( 798.6 - 796.9 ) Volume Invert Avail.Storage Storage Description #1 298.80' 274 cf Drywell stone surround (Conic) Listed below (Recalc) 826 cf Overall - 140 cf Embedded = 686 cf x 40.0% Voids #2 300.03' 140 cf Drywell Interior (Conic) Listed below (Recalc) Inside #1 #3 302.68' 19 cf 12.0" Round Pipe Storage -Impervious L= 24.0' S= 0.0100 '/' #4 302.63' 33 cf 12.0" Round Pipe Storage -Impervious L= 42.0' S= 0.0100 '/' #5 300.92' 24 cf Entrance CB (Prismatic) Listed below (Recalc) -Impervious #6 304.92' 1 cf Entrance CB rim (Irregular) Listed below (Recalc) -Impervious #7 300.78' 24 cf Bank entrance CB (Irregular) Listed below (Recalc) -Impervious #8 304.78' 1 cf Bank entrance cb rim (Irregular) Listed below (Recalc) -Impervious 517 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.80 129 0 0 129 305.20 129 826 826 387 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 300.03 28 0 0 28 305.03 28 140 140 122 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 300.92 6 0 0 304.92 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.92 4 8.0 0 0 4 305.25 4 8.0 1 1 7 Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 21HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 300.78 6 10.0 0 0 6 304.78 6 10.0 24 24 46 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.78 4 8.0 0 0 4 305.11 4 8.0 1 1 7 Device Routing Invert Outlet Devices #1 Discarded 298.80'72.000 in/hr Exfiltration over Surface area Phase-In= 0.50' #2 Primary 305.11'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.12 cfs @ 12.00 hrs HW=299.08' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.12 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.80' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond DWE2: Drywell E2 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.065 ac Peak Elev=299.08' Storage=14 cf 0.13 cfs 0.12 cfs0.12 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 22HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE3: Drywell E3 Inflow Area = 0.067 ac,100.00% Impervious, Inflow Depth > 2.02" for 1 yr event Inflow = 0.21 cfs @ 11.96 hrs, Volume= 0.011 af Outflow = 0.20 cfs @ 11.99 hrs, Volume= 0.011 af, Atten= 4%, Lag= 1.6 min Discarded = 0.20 cfs @ 11.99 hrs, Volume= 0.011 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP2 : City property Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 298.73' @ 11.99 hrs Surf.Area= 129 sf Storage= 21 cf Plug-Flow detention time= 1.9 min calculated for 0.011 af (100% of inflow) Center-of-Mass det. time= 1.6 min ( 761.8 - 760.2 ) Volume Invert Avail.Storage Storage Description #1 298.32' 282 cf Drywell stone surround (Conic) Listed below (Recalc) 818 cf Overall - 112 cf Embedded = 706 cf x 40.0% Voids #2 299.49' 112 cf Drywell Interior (Conic) Listed below (Recalc) Inside #1 #3 302.14' 22 cf 12.0" Round Pipe Storage -Impervious L= 28.0' S= 0.0100 '/' #4 300.84' 24 cf CB (Prismatic) Listed below (Recalc) -Impervious #5 304.84' 1 cf CB rim (Irregular) Listed below (Recalc) -Impervious #6 305.17' 0 cf Surge head (Prismatic) Listed below (Recalc) -Impervious 442 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.32 129 0 0 129 304.66 129 818 818 384 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 299.49 28 0 0 28 303.49 28 112 112 103 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 300.84 6 0 0 304.84 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.84 4 8.0 0 0 4 305.17 4 8.0 1 1 7 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 305.17 4 0 0 305.21 4 0 0 Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 23HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Discarded 298.32'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.50' #2 Primary 305.17'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.19 cfs @ 11.99 hrs HW=298.72' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.19 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.32' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond DWE3: Drywell E3 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.067 ac Peak Elev=298.73' Storage=21 cf 0.21 cfs 0.20 cfs0.20 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 24HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE4: Drywell E4 Inflow Area = 0.171 ac,100.00% Impervious, Inflow Depth > 2.02" for 1 yr event Inflow = 0.52 cfs @ 11.96 hrs, Volume= 0.029 af Outflow = 0.35 cfs @ 12.04 hrs, Volume= 0.029 af, Atten= 33%, Lag= 4.6 min Discarded = 0.35 cfs @ 12.04 hrs, Volume= 0.029 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP2 : City property Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 300.72' @ 12.04 hrs Surf.Area= 129 sf Storage= 118 cf Plug-Flow detention time= 2.6 min calculated for 0.029 af (100% of inflow) Center-of-Mass det. time= 2.4 min ( 762.5 - 760.2 ) Volume Invert Avail.Storage Storage Description #1 298.70' 282 cf Drywell stone surround (Conic) Listed below (Recalc) 818 cf Overall - 112 cf Embedded = 706 cf x 40.0% Voids #2 299.87' 112 cf Drywell Interior (Conic) Listed below (Recalc) Inside #1 #3 302.52' 8 cf 12.0" Round Pipe Storage-DW to CB -Impervious L= 10.0' S= 0.0170 '/' #4 301.19' 24 cf CB-Closest to DW (Prismatic) Listed below (Recalc) -Impervious #5 305.19' 1 cf CB rim-Closest to DW (Irregular) Listed below (Recalc) -Impervious #6 302.79' 36 cf 12.0" Round Pipe Storage-CB to CB -Impervious L= 46.0' S= 0.0170 '/' #7 301.16' 24 cf CB-Closest to street (Prismatic) Listed below (Recalc) -Impervious #8 305.16' 1 cf CB rim-Closest to street (Irregular) Listed below (Recalc) -Impervious #9 305.49' 280 cf Surface Storage (Irregular) Listed below (Recalc) -Impervious 769 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.70 129 0 0 129 305.04 129 818 818 384 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 299.87 28 0 0 28 303.87 28 112 112 103 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 301.19 6 0 0 305.19 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.19 4 8.0 0 0 4 305.52 4 8.0 1 1 7 Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 25HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 301.16 6 0 0 305.16 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.16 4 8.0 0 0 4 305.49 4 8.0 1 1 7 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.49 4 8.0 0 0 4 306.00 1,566 198.5 280 280 3,135 Device Routing Invert Outlet Devices #1 Discarded 298.70'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.50' #2 Primary 305.85'1.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.35 cfs @ 12.04 hrs HW=300.68' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.35 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.70' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond DWE4: Drywell E4 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.171 ac Peak Elev=300.72' Storage=118 cf 0.52 cfs 0.35 cfs0.35 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 26HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE5: Drywell E5 Inflow Area = 0.171 ac, 88.76% Impervious, Inflow Depth > 1.38" for 1 yr event Inflow = 0.21 cfs @ 12.22 hrs, Volume= 0.020 af Outflow = 0.21 cfs @ 12.25 hrs, Volume= 0.020 af, Atten= 1%, Lag= 1.7 min Discarded = 0.21 cfs @ 12.25 hrs, Volume= 0.020 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 299.40' @ 12.25 hrs Surf.Area= 129 sf Storage= 22 cf Plug-Flow detention time= 1.9 min calculated for 0.020 af (100% of inflow) Center-of-Mass det. time= 1.6 min ( 831.3 - 829.8 ) Volume Invert Avail.Storage Storage Description #1 298.97' 282 cf Drywell Stone surround (Conic) Listed below (Recalc) 818 cf Overall - 112 cf Embedded = 706 cf x 40.0% Voids #2 300.14' 112 cf Drywell interior (Conic) Listed below (Recalc) Inside #1 #3 304.14' 5 cf Riser (Irregular) Listed below (Recalc) -Impervious #4 305.81' 0 cf Surge (Irregular) Listed below (Recalc) -Impervious 399 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.97 129 0 0 129 305.31 129 818 818 384 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 300.14 28 0 0 28 304.14 28 112 112 103 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.14 3 7.0 0 0 3 305.81 3 7.0 5 5 15 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.81 3 7.0 0 0 3 305.85 3 7.0 0 0 3 Device Routing Invert Outlet Devices #1 Discarded 298.97'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.50' #2 Primary 305.81'18.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 27HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.21 cfs @ 12.25 hrs HW=299.40' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.21 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.97' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond DWE5: Drywell E5 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.171 ac Peak Elev=299.40' Storage=22 cf 0.21 cfs 0.21 cfs0.21 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 28HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,337 sf 51.19% Impervious Runoff Depth>1.10"Subcatchment E1: E1 Flow Length=409' Tc=7.3 min CN=69 Runoff=0.39 cfs 0.020 af Runoff Area=1,766 sf 71.06% Impervious Runoff Depth>1.90"Subcatchment E2A: E2A Tc=6.0 min CN=81 Runoff=0.13 cfs 0.006 af Runoff Area=1,052 sf 100.00% Impervious Runoff Depth>3.50"Subcatchment E2B: E2B Tc=6.0 min CN=98 Runoff=0.12 cfs 0.007 af Runoff Area=2,940 sf 100.00% Impervious Runoff Depth>3.50"Subcatchment E3: E3 Tc=6.0 min CN=98 Runoff=0.35 cfs 0.020 af Runoff Area=7,452 sf 100.00% Impervious Runoff Depth>3.50"Subcatchment E4: E4 Tc=6.0 min CN=98 Runoff=0.88 cfs 0.050 af Runoff Area=7,458 sf 88.76% Impervious Runoff Depth>2.75"Subcatchment E5: E5 Flow Length=110' Tc=28.3 min CN=91 Runoff=0.42 cfs 0.039 af Runoff Area=42,248 sf 48.77% Impervious Runoff Depth>2.54"Subcatchment E6: E6 Flow Length=427' Tc=63.2 min CN=89 Runoff=1.28 cfs 0.205 af Runoff Area=11,057 sf 0.00% Impervious Runoff Depth>1.08"Subcatchment E7: E7 Flow Length=126' Tc=53.2 min CN=69 Runoff=0.15 cfs 0.023 af Inflow=0.39 cfs 0.020 afReach DP1: Marion Ave Outflow=0.39 cfs 0.020 af Inflow=1.28 cfs 0.205 afReach DP2: City property Outflow=1.28 cfs 0.205 af Peak Elev=307.00' Storage=0 cf Inflow=0.15 cfs 0.023 afPond 7P: Low spot Discarded=0.15 cfs 0.023 af Primary=0.00 cfs 0.000 af Outflow=0.15 cfs 0.023 af Peak Elev=299.43' Storage=32 cf Inflow=0.26 cfs 0.013 afPond DWE2: Drywell E2 Discarded=0.22 cfs 0.013 af Primary=0.00 cfs 0.000 af Outflow=0.22 cfs 0.013 af Peak Elev=299.26' Storage=48 cf Inflow=0.35 cfs 0.020 afPond DWE3: Drywell E3 Discarded=0.28 cfs 0.020 af Primary=0.00 cfs 0.000 af Outflow=0.28 cfs 0.020 af Peak Elev=303.00' Storage=300 cf Inflow=0.88 cfs 0.050 afPond DWE4: Drywell E4 Discarded=0.50 cfs 0.050 af Primary=0.00 cfs 0.000 af Outflow=0.50 cfs 0.050 af Peak Elev=300.86' Storage=110 cf Inflow=0.42 cfs 0.039 afPond DWE5: Drywell E5 Discarded=0.34 cfs 0.039 af Primary=0.00 cfs 0.000 af Outflow=0.34 cfs 0.039 af Total Runoff Area = 1.913 ac Runoff Volume = 0.370 af Average Runoff Depth = 2.32" 46.34% Pervious = 0.886 ac 53.66% Impervious = 1.026 ac Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 29HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E1: E1 Runoff = 0.39 cfs @ 12.00 hrs, Volume= 0.020 af, Depth> 1.10" Routed to Reach DP1 : Marion Ave Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 4,557 39 >75% Grass cover, Good, HSG A 4,780 98 Unconnected pavement, HSG A 9,337 69 Weighted Average 4,557 48.81% Pervious Area 4,780 51.19% Impervious Area 4,780 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.7 24 0.0420 0.11 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.4 21 0.0160 0.83 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 3.2 364 0.0090 1.93 Shallow Concentrated Flow, Paved Kv= 20.3 fps 7.3 409 Total Subcatchment E1: E1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=9,337 sf Runoff Volume=0.020 af Runoff Depth>1.10" Flow Length=409' Tc=7.3 min CN=69 0.39 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 30HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E2A: E2A Runoff = 0.13 cfs @ 11.97 hrs, Volume= 0.006 af, Depth> 1.90" Routed to Pond DWE2 : Drywell E2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 511 39 >75% Grass cover, Good, HSG A 1,255 98 Unconnected pavement, HSG A 1,766 81 Weighted Average 511 28.94% Pervious Area 1,255 71.06% Impervious Area 1,255 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E2A: E2A Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=1,766 sf Runoff Volume=0.006 af Runoff Depth>1.90" Tc=6.0 min CN=81 0.13 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 31HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E2B: E2B Runoff = 0.12 cfs @ 11.96 hrs, Volume= 0.007 af, Depth> 3.50" Routed to Pond DWE2 : Drywell E2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 1,052 98 Unconnected pavement, HSG A 1,052 100.00% Impervious Area 1,052 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E2B: E2B Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=1,052 sf Runoff Volume=0.007 af Runoff Depth>3.50" Tc=6.0 min CN=98 0.12 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 32HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E3: E3 Runoff = 0.35 cfs @ 11.96 hrs, Volume= 0.020 af, Depth> 3.50" Routed to Pond DWE3 : Drywell E3 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 2,940 98 Unconnected pavement, HSG A 2,940 100.00% Impervious Area 2,940 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E3: E3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=2,940 sf Runoff Volume=0.020 af Runoff Depth>3.50" Tc=6.0 min CN=98 0.35 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 33HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E4: E4 Runoff = 0.88 cfs @ 11.96 hrs, Volume= 0.050 af, Depth> 3.50" Routed to Pond DWE4 : Drywell E4 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 3,413 98 Unconnected roofs, HSG A 4,039 98 Unconnected pavement, HSG A 7,452 98 Weighted Average 7,452 100.00% Impervious Area 7,452 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E4: E4 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=7,452 sf Runoff Volume=0.050 af Runoff Depth>3.50" Tc=6.0 min CN=98 0.88 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 34HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E5: E5 Runoff = 0.42 cfs @ 12.22 hrs, Volume= 0.039 af, Depth> 2.75" Routed to Pond DWE5 : Drywell E5 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 2,894 98 Unconnected roofs, HSG A 3,726 98 Unconnected pavement, HSG A 838 39 >75% Grass cover, Good, HSG A 7,458 91 Weighted Average 838 11.24% Pervious Area 6,620 88.76% Impervious Area 6,620 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.1 11 0.0660 1.29 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 0.8 20 0.0030 0.42 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 3.1 15 0.0260 0.08 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 24.2 38 0.0010 0.03 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.1 26 0.0310 3.57 Shallow Concentrated Flow, Paved Kv= 20.3 fps 28.3 110 Total Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 35HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment E5: E5 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=7,458 sf Runoff Volume=0.039 af Runoff Depth>2.75" Flow Length=110' Tc=28.3 min CN=91 0.42 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 36HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E6: E6 Runoff = 1.28 cfs @ 12.66 hrs, Volume= 0.205 af, Depth> 2.54" Routed to Reach DP2 : City property Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 1,706 98 Unconnected roofs, HSG A 18,899 98 Unconnected pavement, HSG A 16,024 96 Gravel surface, HSG A 5,619 39 >75% Grass cover, Good, HSG A 42,248 89 Weighted Average 21,643 51.23% Pervious Area 20,605 48.77% Impervious Area 20,605 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.7 28 0.0200 0.08 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 17.1 35 0.0020 0.03 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 34.1 37 0.0004 0.02 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.4 8 0.0004 0.30 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 3.8 46 0.0001 0.20 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.2 36 0.0150 2.49 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 67 0.0070 1.35 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.1 170 0.0148 2.47 Shallow Concentrated Flow, Paved Kv= 20.3 fps 63.2 427 Total Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 37HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment E6: E6 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=42,248 sf Runoff Volume=0.205 af Runoff Depth>2.54" Flow Length=427' Tc=63.2 min CN=89 1.28 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 38HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E7: E7 Runoff = 0.15 cfs @ 12.59 hrs, Volume= 0.023 af, Depth> 1.08" Routed to Pond 7P : Low spot Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 5,200 39 >75% Grass cover, Good, HSG A 5,857 96 Gravel surface, HSG A 11,057 69 Weighted Average 11,057 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 34 0.0060 0.62 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 49.8 66 0.0055 0.02 Sheet Flow, Woods: Dense underbrush n= 0.800 P2= 2.61" 2.5 26 0.0050 0.18 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 53.2 126 Total Subcatchment E7: E7 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=11,057 sf Runoff Volume=0.023 af Runoff Depth>1.08" Flow Length=126' Tc=53.2 min CN=69 0.15 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 39HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP1: Marion Ave Inflow Area = 0.639 ac, 40.93% Impervious, Inflow Depth > 0.37" for 10 yr event Inflow = 0.39 cfs @ 12.00 hrs, Volume= 0.020 af Outflow = 0.39 cfs @ 12.00 hrs, Volume= 0.020 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach DP1: Marion Ave Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.639 ac 0.39 cfs0.39 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 40HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP2: City property Inflow Area = 1.273 ac, 60.05% Impervious, Inflow Depth > 1.94" for 10 yr event Inflow = 1.28 cfs @ 12.66 hrs, Volume= 0.205 af Outflow = 1.28 cfs @ 12.66 hrs, Volume= 0.205 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach DP2: City property Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Inflow Area=1.273 ac 1.28 cfs1.28 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 41HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 7P: Low spot Inflow Area = 0.254 ac, 0.00% Impervious, Inflow Depth > 1.08" for 10 yr event Inflow = 0.15 cfs @ 12.59 hrs, Volume= 0.023 af Outflow = 0.15 cfs @ 12.59 hrs, Volume= 0.023 af, Atten= 0%, Lag= 0.1 min Discarded = 0.15 cfs @ 12.59 hrs, Volume= 0.023 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 307.00' @ 12.59 hrs Surf.Area= 77 sf Storage= 0 cf Plug-Flow detention time= 0.0 min calculated for 0.023 af (100% of inflow) Center-of-Mass det. time= 0.0 min ( 897.6 - 897.6 ) Volume Invert Avail.Storage Storage Description #1 307.00' 235 cf Watershed low point (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 307.00 66 39.0 0 0 66 307.26 2,263 238.2 235 235 4,460 Device Routing Invert Outlet Devices #1 Discarded 307.00'72.000 in/hr Exfiltration over Wetted area #2 Primary 307.25'5.0' long x 1.0' 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 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 Discarded OutFlow Max=0.15 cfs @ 12.59 hrs HW=307.00' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=307.00' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 42HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 7P: Low spot Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.254 ac Peak Elev=307.00' Storage=0 cf 0.15 cfs0.15 cfs0.15 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 43HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE2: Drywell E2 Inflow Area = 0.065 ac, 81.87% Impervious, Inflow Depth > 2.50" for 10 yr event Inflow = 0.26 cfs @ 11.97 hrs, Volume= 0.013 af Outflow = 0.22 cfs @ 12.03 hrs, Volume= 0.013 af, Atten= 16%, Lag= 3.5 min Discarded = 0.22 cfs @ 12.03 hrs, Volume= 0.013 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP2 : City property Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 299.43' @ 12.01 hrs Surf.Area= 129 sf Storage= 32 cf Plug-Flow detention time= 2.1 min calculated for 0.013 af (100% of inflow) Center-of-Mass det. time= 1.7 min ( 788.3 - 786.6 ) Volume Invert Avail.Storage Storage Description #1 298.80' 274 cf Drywell stone surround (Conic) Listed below (Recalc) 826 cf Overall - 140 cf Embedded = 686 cf x 40.0% Voids #2 300.03' 140 cf Drywell Interior (Conic) Listed below (Recalc) Inside #1 #3 302.68' 19 cf 12.0" Round Pipe Storage -Impervious L= 24.0' S= 0.0100 '/' #4 302.63' 33 cf 12.0" Round Pipe Storage -Impervious L= 42.0' S= 0.0100 '/' #5 300.92' 24 cf Entrance CB (Prismatic) Listed below (Recalc) -Impervious #6 304.92' 1 cf Entrance CB rim (Irregular) Listed below (Recalc) -Impervious #7 300.78' 24 cf Bank entrance CB (Irregular) Listed below (Recalc) -Impervious #8 304.78' 1 cf Bank entrance cb rim (Irregular) Listed below (Recalc) -Impervious 517 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.80 129 0 0 129 305.20 129 826 826 387 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 300.03 28 0 0 28 305.03 28 140 140 122 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 300.92 6 0 0 304.92 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.92 4 8.0 0 0 4 305.25 4 8.0 1 1 7 Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 44HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 300.78 6 10.0 0 0 6 304.78 6 10.0 24 24 46 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.78 4 8.0 0 0 4 305.11 4 8.0 1 1 7 Device Routing Invert Outlet Devices #1 Discarded 298.80'72.000 in/hr Exfiltration over Surface area Phase-In= 0.50' #2 Primary 305.11'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.22 cfs @ 12.03 hrs HW=299.40' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.22 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.80' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond DWE2: Drywell E2 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.065 ac Peak Elev=299.43' Storage=32 cf 0.26 cfs 0.22 cfs0.22 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 45HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE3: Drywell E3 Inflow Area = 0.067 ac,100.00% Impervious, Inflow Depth > 3.50" for 10 yr event Inflow = 0.35 cfs @ 11.96 hrs, Volume= 0.020 af Outflow = 0.28 cfs @ 12.02 hrs, Volume= 0.020 af, Atten= 20%, Lag= 3.2 min Discarded = 0.28 cfs @ 12.02 hrs, Volume= 0.020 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP2 : City property Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 299.26' @ 12.02 hrs Surf.Area= 129 sf Storage= 48 cf Plug-Flow detention time= 2.0 min calculated for 0.020 af (100% of inflow) Center-of-Mass det. time= 1.8 min ( 750.5 - 748.7 ) Volume Invert Avail.Storage Storage Description #1 298.32' 282 cf Drywell stone surround (Conic) Listed below (Recalc) 818 cf Overall - 112 cf Embedded = 706 cf x 40.0% Voids #2 299.49' 112 cf Drywell Interior (Conic) Listed below (Recalc) Inside #1 #3 302.14' 22 cf 12.0" Round Pipe Storage -Impervious L= 28.0' S= 0.0100 '/' #4 300.84' 24 cf CB (Prismatic) Listed below (Recalc) -Impervious #5 304.84' 1 cf CB rim (Irregular) Listed below (Recalc) -Impervious #6 305.17' 0 cf Surge head (Prismatic) Listed below (Recalc) -Impervious 442 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.32 129 0 0 129 304.66 129 818 818 384 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 299.49 28 0 0 28 303.49 28 112 112 103 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 300.84 6 0 0 304.84 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.84 4 8.0 0 0 4 305.17 4 8.0 1 1 7 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 305.17 4 0 0 305.21 4 0 0 Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 46HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Discarded 298.32'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.50' #2 Primary 305.17'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.28 cfs @ 12.02 hrs HW=299.23' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.28 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.32' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond DWE3: Drywell E3 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.067 ac Peak Elev=299.26' Storage=48 cf 0.35 cfs 0.28 cfs0.28 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 47HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE4: Drywell E4 Inflow Area = 0.171 ac,100.00% Impervious, Inflow Depth > 3.50" for 10 yr event Inflow = 0.88 cfs @ 11.96 hrs, Volume= 0.050 af Outflow = 0.50 cfs @ 12.05 hrs, Volume= 0.050 af, Atten= 43%, Lag= 5.6 min Discarded = 0.50 cfs @ 12.05 hrs, Volume= 0.050 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP2 : City property Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 303.00' @ 12.05 hrs Surf.Area= 129 sf Storage= 300 cf Plug-Flow detention time= 3.9 min calculated for 0.050 af (100% of inflow) Center-of-Mass det. time= 3.6 min ( 752.4 - 748.7 ) Volume Invert Avail.Storage Storage Description #1 298.70' 282 cf Drywell stone surround (Conic) Listed below (Recalc) 818 cf Overall - 112 cf Embedded = 706 cf x 40.0% Voids #2 299.87' 112 cf Drywell Interior (Conic) Listed below (Recalc) Inside #1 #3 302.52' 8 cf 12.0" Round Pipe Storage-DW to CB -Impervious L= 10.0' S= 0.0170 '/' #4 301.19' 24 cf CB-Closest to DW (Prismatic) Listed below (Recalc) -Impervious #5 305.19' 1 cf CB rim-Closest to DW (Irregular) Listed below (Recalc) -Impervious #6 302.79' 36 cf 12.0" Round Pipe Storage-CB to CB -Impervious L= 46.0' S= 0.0170 '/' #7 301.16' 24 cf CB-Closest to street (Prismatic) Listed below (Recalc) -Impervious #8 305.16' 1 cf CB rim-Closest to street (Irregular) Listed below (Recalc) -Impervious #9 305.49' 280 cf Surface Storage (Irregular) Listed below (Recalc) -Impervious 769 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.70 129 0 0 129 305.04 129 818 818 384 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 299.87 28 0 0 28 303.87 28 112 112 103 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 301.19 6 0 0 305.19 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.19 4 8.0 0 0 4 305.52 4 8.0 1 1 7 Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 48HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 301.16 6 0 0 305.16 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.16 4 8.0 0 0 4 305.49 4 8.0 1 1 7 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.49 4 8.0 0 0 4 306.00 1,566 198.5 280 280 3,135 Device Routing Invert Outlet Devices #1 Discarded 298.70'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.50' #2 Primary 305.85'1.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.50 cfs @ 12.05 hrs HW=302.97' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.50 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.70' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond DWE4: Drywell E4 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.171 ac Peak Elev=303.00' Storage=300 cf 0.88 cfs 0.50 cfs0.50 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 49HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE5: Drywell E5 Inflow Area = 0.171 ac, 88.76% Impervious, Inflow Depth > 2.75" for 10 yr event Inflow = 0.42 cfs @ 12.22 hrs, Volume= 0.039 af Outflow = 0.34 cfs @ 12.35 hrs, Volume= 0.039 af, Atten= 18%, Lag= 8.3 min Discarded = 0.34 cfs @ 12.35 hrs, Volume= 0.039 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 300.86' @ 12.35 hrs Surf.Area= 129 sf Storage= 110 cf Plug-Flow detention time= 2.7 min calculated for 0.039 af (100% of inflow) Center-of-Mass det. time= 2.4 min ( 812.9 - 810.5 ) Volume Invert Avail.Storage Storage Description #1 298.97' 282 cf Drywell Stone surround (Conic) Listed below (Recalc) 818 cf Overall - 112 cf Embedded = 706 cf x 40.0% Voids #2 300.14' 112 cf Drywell interior (Conic) Listed below (Recalc) Inside #1 #3 304.14' 5 cf Riser (Irregular) Listed below (Recalc) -Impervious #4 305.81' 0 cf Surge (Irregular) Listed below (Recalc) -Impervious 399 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.97 129 0 0 129 305.31 129 818 818 384 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 300.14 28 0 0 28 304.14 28 112 112 103 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.14 3 7.0 0 0 3 305.81 3 7.0 5 5 15 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.81 3 7.0 0 0 3 305.85 3 7.0 0 0 3 Device Routing Invert Outlet Devices #1 Discarded 298.97'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.50' #2 Primary 305.81'18.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 50HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.34 cfs @ 12.35 hrs HW=300.86' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.34 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.97' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond DWE5: Drywell E5 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.171 ac Peak Elev=300.86' Storage=110 cf 0.42 cfs 0.34 cfs0.34 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 51HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,337 sf 51.19% Impervious Runoff Depth>2.91"Subcatchment E1: E1 Flow Length=409' Tc=7.3 min CN=69 Runoff=1.05 cfs 0.052 af Runoff Area=1,766 sf 71.06% Impervious Runoff Depth>4.12"Subcatchment E2A: E2A Tc=6.0 min CN=81 Runoff=0.28 cfs 0.014 af Runoff Area=1,052 sf 100.00% Impervious Runoff Depth>6.02"Subcatchment E2B: E2B Tc=6.0 min CN=98 Runoff=0.21 cfs 0.012 af Runoff Area=2,940 sf 100.00% Impervious Runoff Depth>6.02"Subcatchment E3: E3 Tc=6.0 min CN=98 Runoff=0.59 cfs 0.034 af Runoff Area=7,452 sf 100.00% Impervious Runoff Depth>6.02"Subcatchment E4: E4 Tc=6.0 min CN=98 Runoff=1.49 cfs 0.086 af Runoff Area=7,458 sf 88.76% Impervious Runoff Depth>5.18"Subcatchment E5: E5 Flow Length=110' Tc=28.3 min CN=91 Runoff=0.77 cfs 0.074 af Runoff Area=42,248 sf 48.77% Impervious Runoff Depth>4.92"Subcatchment E6: E6 Flow Length=427' Tc=63.2 min CN=89 Runoff=2.44 cfs 0.398 af Runoff Area=11,057 sf 0.00% Impervious Runoff Depth>2.87"Subcatchment E7: E7 Flow Length=126' Tc=53.2 min CN=69 Runoff=0.42 cfs 0.061 af Inflow=1.05 cfs 0.052 afReach DP1: Marion Ave Outflow=1.05 cfs 0.052 af Inflow=2.44 cfs 0.398 afReach DP2: City property Outflow=2.44 cfs 0.398 af Peak Elev=307.03' Storage=3 cf Inflow=0.42 cfs 0.061 afPond 7P: Low spot Discarded=0.42 cfs 0.061 af Primary=0.00 cfs 0.000 af Outflow=0.42 cfs 0.061 af Peak Elev=301.41' Storage=165 cf Inflow=0.49 cfs 0.026 afPond DWE2: Drywell E2 Discarded=0.22 cfs 0.026 af Primary=0.00 cfs 0.000 af Outflow=0.22 cfs 0.026 af Peak Elev=300.77' Storage=148 cf Inflow=0.59 cfs 0.034 afPond DWE3: Drywell E3 Discarded=0.38 cfs 0.034 af Primary=0.00 cfs 0.000 af Outflow=0.38 cfs 0.034 af Peak Elev=305.92' Storage=660 cf Inflow=1.49 cfs 0.086 afPond DWE4: Drywell E4 Discarded=0.64 cfs 0.085 af Primary=0.06 cfs 0.000 af Outflow=0.70 cfs 0.086 af Peak Elev=304.30' Storage=343 cf Inflow=0.77 cfs 0.074 afPond DWE5: Drywell E5 Discarded=0.57 cfs 0.074 af Primary=0.00 cfs 0.000 af Outflow=0.57 cfs 0.074 af Total Runoff Area = 1.913 ac Runoff Volume = 0.730 af Average Runoff Depth = 4.58" 46.34% Pervious = 0.886 ac 53.66% Impervious = 1.026 ac Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 52HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E1: E1 Runoff = 1.05 cfs @ 11.99 hrs, Volume= 0.052 af, Depth> 2.91" Routed to Reach DP1 : Marion Ave Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 4,557 39 >75% Grass cover, Good, HSG A 4,780 98 Unconnected pavement, HSG A 9,337 69 Weighted Average 4,557 48.81% Pervious Area 4,780 51.19% Impervious Area 4,780 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.7 24 0.0420 0.11 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.4 21 0.0160 0.83 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 3.2 364 0.0090 1.93 Shallow Concentrated Flow, Paved Kv= 20.3 fps 7.3 409 Total Subcatchment E1: E1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=9,337 sf Runoff Volume=0.052 af Runoff Depth>2.91" Flow Length=409' Tc=7.3 min CN=69 1.05 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 53HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E2A: E2A Runoff = 0.28 cfs @ 11.97 hrs, Volume= 0.014 af, Depth> 4.12" Routed to Pond DWE2 : Drywell E2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 511 39 >75% Grass cover, Good, HSG A 1,255 98 Unconnected pavement, HSG A 1,766 81 Weighted Average 511 28.94% Pervious Area 1,255 71.06% Impervious Area 1,255 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E2A: E2A Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=1,766 sf Runoff Volume=0.014 af Runoff Depth>4.12" Tc=6.0 min CN=81 0.28 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 54HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E2B: E2B Runoff = 0.21 cfs @ 11.96 hrs, Volume= 0.012 af, Depth> 6.02" Routed to Pond DWE2 : Drywell E2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 1,052 98 Unconnected pavement, HSG A 1,052 100.00% Impervious Area 1,052 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E2B: E2B Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=1,052 sf Runoff Volume=0.012 af Runoff Depth>6.02" Tc=6.0 min CN=98 0.21 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 55HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E3: E3 Runoff = 0.59 cfs @ 11.96 hrs, Volume= 0.034 af, Depth> 6.02" Routed to Pond DWE3 : Drywell E3 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 2,940 98 Unconnected pavement, HSG A 2,940 100.00% Impervious Area 2,940 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E3: E3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=2,940 sf Runoff Volume=0.034 af Runoff Depth>6.02" Tc=6.0 min CN=98 0.59 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 56HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E4: E4 Runoff = 1.49 cfs @ 11.96 hrs, Volume= 0.086 af, Depth> 6.02" Routed to Pond DWE4 : Drywell E4 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 3,413 98 Unconnected roofs, HSG A 4,039 98 Unconnected pavement, HSG A 7,452 98 Weighted Average 7,452 100.00% Impervious Area 7,452 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment E4: E4 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=7,452 sf Runoff Volume=0.086 af Runoff Depth>6.02" Tc=6.0 min CN=98 1.49 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 57HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E5: E5 Runoff = 0.77 cfs @ 12.21 hrs, Volume= 0.074 af, Depth> 5.18" Routed to Pond DWE5 : Drywell E5 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 2,894 98 Unconnected roofs, HSG A 3,726 98 Unconnected pavement, HSG A 838 39 >75% Grass cover, Good, HSG A 7,458 91 Weighted Average 838 11.24% Pervious Area 6,620 88.76% Impervious Area 6,620 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.1 11 0.0660 1.29 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 0.8 20 0.0030 0.42 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 3.1 15 0.0260 0.08 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 24.2 38 0.0010 0.03 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.1 26 0.0310 3.57 Shallow Concentrated Flow, Paved Kv= 20.3 fps 28.3 110 Total Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 58HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment E5: E5 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=7,458 sf Runoff Volume=0.074 af Runoff Depth>5.18" Flow Length=110' Tc=28.3 min CN=91 0.77 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 59HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E6: E6 Runoff = 2.44 cfs @ 12.64 hrs, Volume= 0.398 af, Depth> 4.92" Routed to Reach DP2 : City property Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 1,706 98 Unconnected roofs, HSG A 18,899 98 Unconnected pavement, HSG A 16,024 96 Gravel surface, HSG A 5,619 39 >75% Grass cover, Good, HSG A 42,248 89 Weighted Average 21,643 51.23% Pervious Area 20,605 48.77% Impervious Area 20,605 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.7 28 0.0200 0.08 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 17.1 35 0.0020 0.03 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 34.1 37 0.0004 0.02 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.4 8 0.0004 0.30 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 3.8 46 0.0001 0.20 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.2 36 0.0150 2.49 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 67 0.0070 1.35 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.1 170 0.0148 2.47 Shallow Concentrated Flow, Paved Kv= 20.3 fps 63.2 427 Total Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 60HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment E6: E6 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 2 1 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=42,248 sf Runoff Volume=0.398 af Runoff Depth>4.92" Flow Length=427' Tc=63.2 min CN=89 2.44 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 61HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment E7: E7 Runoff = 0.42 cfs @ 12.55 hrs, Volume= 0.061 af, Depth> 2.87" Routed to Pond 7P : Low spot Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 5,200 39 >75% Grass cover, Good, HSG A 5,857 96 Gravel surface, HSG A 11,057 69 Weighted Average 11,057 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 34 0.0060 0.62 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 49.8 66 0.0055 0.02 Sheet Flow, Woods: Dense underbrush n= 0.800 P2= 2.61" 2.5 26 0.0050 0.18 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 53.2 126 Total Subcatchment E7: E7 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=11,057 sf Runoff Volume=0.061 af Runoff Depth>2.87" Flow Length=126' Tc=53.2 min CN=69 0.42 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 62HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP1: Marion Ave Inflow Area = 0.639 ac, 40.93% Impervious, Inflow Depth > 0.98" for 100 yr event Inflow = 1.05 cfs @ 11.99 hrs, Volume= 0.052 af Outflow = 1.05 cfs @ 11.99 hrs, Volume= 0.052 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach DP1: Marion Ave Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Inflow Area=0.639 ac 1.05 cfs1.05 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 63HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP2: City property Inflow Area = 1.273 ac, 60.05% Impervious, Inflow Depth > 3.75" for 100 yr event Inflow = 2.44 cfs @ 12.64 hrs, Volume= 0.398 af Outflow = 2.44 cfs @ 12.64 hrs, Volume= 0.398 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach DP2: City property Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 2 1 0 Inflow Area=1.273 ac 2.44 cfs2.44 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 64HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 7P: Low spot Inflow Area = 0.254 ac, 0.00% Impervious, Inflow Depth > 2.87" for 100 yr event Inflow = 0.42 cfs @ 12.55 hrs, Volume= 0.061 af Outflow = 0.42 cfs @ 12.56 hrs, Volume= 0.061 af, Atten= 0%, Lag= 0.2 min Discarded = 0.42 cfs @ 12.56 hrs, Volume= 0.061 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 307.03' @ 12.56 hrs Surf.Area= 162 sf Storage= 3 cf Plug-Flow detention time= 0.1 min calculated for 0.061 af (100% of inflow) Center-of-Mass det. time= 0.1 min ( 869.9 - 869.8 ) Volume Invert Avail.Storage Storage Description #1 307.00' 235 cf Watershed low point (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 307.00 66 39.0 0 0 66 307.26 2,263 238.2 235 235 4,460 Device Routing Invert Outlet Devices #1 Discarded 307.00'72.000 in/hr Exfiltration over Wetted area #2 Primary 307.25'5.0' long x 1.0' 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 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 Discarded OutFlow Max=0.42 cfs @ 12.56 hrs HW=307.03' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.42 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=307.00' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 65HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 7P: Low spot Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.254 ac Peak Elev=307.03' Storage=3 cf 0.42 cfs0.42 cfs0.42 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 66HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE2: Drywell E2 Inflow Area = 0.065 ac, 81.87% Impervious, Inflow Depth > 4.83" for 100 yr event Inflow = 0.49 cfs @ 11.96 hrs, Volume= 0.026 af Outflow = 0.22 cfs @ 11.85 hrs, Volume= 0.026 af, Atten= 56%, Lag= 0.0 min Discarded = 0.22 cfs @ 11.85 hrs, Volume= 0.026 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP2 : City property Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 301.41' @ 12.08 hrs Surf.Area= 129 sf Storage= 165 cf Plug-Flow detention time= 4.1 min calculated for 0.026 af (100% of inflow) Center-of-Mass det. time= 3.8 min ( 779.1 - 775.3 ) Volume Invert Avail.Storage Storage Description #1 298.80' 274 cf Drywell stone surround (Conic) Listed below (Recalc) 826 cf Overall - 140 cf Embedded = 686 cf x 40.0% Voids #2 300.03' 140 cf Drywell Interior (Conic) Listed below (Recalc) Inside #1 #3 302.68' 19 cf 12.0" Round Pipe Storage -Impervious L= 24.0' S= 0.0100 '/' #4 302.63' 33 cf 12.0" Round Pipe Storage -Impervious L= 42.0' S= 0.0100 '/' #5 300.92' 24 cf Entrance CB (Prismatic) Listed below (Recalc) -Impervious #6 304.92' 1 cf Entrance CB rim (Irregular) Listed below (Recalc) -Impervious #7 300.78' 24 cf Bank entrance CB (Irregular) Listed below (Recalc) -Impervious #8 304.78' 1 cf Bank entrance cb rim (Irregular) Listed below (Recalc) -Impervious 517 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.80 129 0 0 129 305.20 129 826 826 387 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 300.03 28 0 0 28 305.03 28 140 140 122 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 300.92 6 0 0 304.92 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.92 4 8.0 0 0 4 305.25 4 8.0 1 1 7 Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 67HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 300.78 6 10.0 0 0 6 304.78 6 10.0 24 24 46 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.78 4 8.0 0 0 4 305.11 4 8.0 1 1 7 Device Routing Invert Outlet Devices #1 Discarded 298.80'72.000 in/hr Exfiltration over Surface area Phase-In= 0.50' #2 Primary 305.11'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.22 cfs @ 11.85 hrs HW=299.36' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.22 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.80' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond DWE2: Drywell E2 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.065 ac Peak Elev=301.41' Storage=165 cf 0.49 cfs 0.22 cfs0.22 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 68HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE3: Drywell E3 Inflow Area = 0.067 ac,100.00% Impervious, Inflow Depth > 6.02" for 100 yr event Inflow = 0.59 cfs @ 11.96 hrs, Volume= 0.034 af Outflow = 0.38 cfs @ 12.04 hrs, Volume= 0.034 af, Atten= 35%, Lag= 4.9 min Discarded = 0.38 cfs @ 12.04 hrs, Volume= 0.034 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP2 : City property Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 300.77' @ 12.04 hrs Surf.Area= 129 sf Storage= 148 cf Plug-Flow detention time= 2.8 min calculated for 0.034 af (100% of inflow) Center-of-Mass det. time= 2.6 min ( 742.4 - 739.8 ) Volume Invert Avail.Storage Storage Description #1 298.32' 282 cf Drywell stone surround (Conic) Listed below (Recalc) 818 cf Overall - 112 cf Embedded = 706 cf x 40.0% Voids #2 299.49' 112 cf Drywell Interior (Conic) Listed below (Recalc) Inside #1 #3 302.14' 22 cf 12.0" Round Pipe Storage -Impervious L= 28.0' S= 0.0100 '/' #4 300.84' 24 cf CB (Prismatic) Listed below (Recalc) -Impervious #5 304.84' 1 cf CB rim (Irregular) Listed below (Recalc) -Impervious #6 305.17' 0 cf Surge head (Prismatic) Listed below (Recalc) -Impervious 442 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.32 129 0 0 129 304.66 129 818 818 384 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 299.49 28 0 0 28 303.49 28 112 112 103 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 300.84 6 0 0 304.84 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.84 4 8.0 0 0 4 305.17 4 8.0 1 1 7 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 305.17 4 0 0 305.21 4 0 0 Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 69HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Discarded 298.32'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.50' #2 Primary 305.17'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.38 cfs @ 12.04 hrs HW=300.74' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.38 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.32' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond DWE3: Drywell E3 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.067 ac Peak Elev=300.77' Storage=148 cf 0.59 cfs 0.38 cfs0.38 cfs 0.00 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 70HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE4: Drywell E4 Inflow Area = 0.171 ac,100.00% Impervious, Inflow Depth > 6.02" for 100 yr event Inflow = 1.49 cfs @ 11.96 hrs, Volume= 0.086 af Outflow = 0.70 cfs @ 12.07 hrs, Volume= 0.086 af, Atten= 53%, Lag= 6.4 min Discarded = 0.64 cfs @ 12.00 hrs, Volume= 0.085 af Primary = 0.06 cfs @ 12.07 hrs, Volume= 0.000 af Routed to Reach DP2 : City property Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 305.92' @ 12.05 hrs Surf.Area= 129 sf Storage= 660 cf Plug-Flow detention time= 5.9 min calculated for 0.086 af (100% of inflow) Center-of-Mass det. time= 5.7 min ( 745.5 - 739.8 ) Volume Invert Avail.Storage Storage Description #1 298.70' 282 cf Drywell stone surround (Conic) Listed below (Recalc) 818 cf Overall - 112 cf Embedded = 706 cf x 40.0% Voids #2 299.87' 112 cf Drywell Interior (Conic) Listed below (Recalc) Inside #1 #3 302.52' 8 cf 12.0" Round Pipe Storage-DW to CB -Impervious L= 10.0' S= 0.0170 '/' #4 301.19' 24 cf CB-Closest to DW (Prismatic) Listed below (Recalc) -Impervious #5 305.19' 1 cf CB rim-Closest to DW (Irregular) Listed below (Recalc) -Impervious #6 302.79' 36 cf 12.0" Round Pipe Storage-CB to CB -Impervious L= 46.0' S= 0.0170 '/' #7 301.16' 24 cf CB-Closest to street (Prismatic) Listed below (Recalc) -Impervious #8 305.16' 1 cf CB rim-Closest to street (Irregular) Listed below (Recalc) -Impervious #9 305.49' 280 cf Surface Storage (Irregular) Listed below (Recalc) -Impervious 769 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.70 129 0 0 129 305.04 129 818 818 384 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 299.87 28 0 0 28 303.87 28 112 112 103 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 301.19 6 0 0 305.19 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.19 4 8.0 0 0 4 305.52 4 8.0 1 1 7 Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 71HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 301.16 6 0 0 305.16 6 24 24 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.16 4 8.0 0 0 4 305.49 4 8.0 1 1 7 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.49 4 8.0 0 0 4 306.00 1,566 198.5 280 280 3,135 Device Routing Invert Outlet Devices #1 Discarded 298.70'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.50' #2 Primary 305.85'1.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.64 cfs @ 12.00 hrs HW=305.83' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.64 cfs) Primary OutFlow Max=0.05 cfs @ 12.07 hrs HW=305.92' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 0.05 cfs @ 0.72 fps) Pond DWE4: Drywell E4 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Inflow Area=0.171 ac Peak Elev=305.92' Storage=660 cf 1.49 cfs 0.70 cfs 0.64 cfs 0.06 cfs Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 72HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond DWE5: Drywell E5 Inflow Area = 0.171 ac, 88.76% Impervious, Inflow Depth > 5.18" for 100 yr event Inflow = 0.77 cfs @ 12.21 hrs, Volume= 0.074 af Outflow = 0.57 cfs @ 12.38 hrs, Volume= 0.074 af, Atten= 25%, Lag= 10.3 min Discarded = 0.57 cfs @ 12.38 hrs, Volume= 0.074 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 304.30' @ 12.38 hrs Surf.Area= 129 sf Storage= 343 cf Plug-Flow detention time= 4.7 min calculated for 0.074 af (100% of inflow) Center-of-Mass det. time= 4.4 min ( 797.8 - 793.4 ) Volume Invert Avail.Storage Storage Description #1 298.97' 282 cf Drywell Stone surround (Conic) Listed below (Recalc) 818 cf Overall - 112 cf Embedded = 706 cf x 40.0% Voids #2 300.14' 112 cf Drywell interior (Conic) Listed below (Recalc) Inside #1 #3 304.14' 5 cf Riser (Irregular) Listed below (Recalc) -Impervious #4 305.81' 0 cf Surge (Irregular) Listed below (Recalc) -Impervious 399 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 298.97 129 0 0 129 305.31 129 818 818 384 Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 300.14 28 0 0 28 304.14 28 112 112 103 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 304.14 3 7.0 0 0 3 305.81 3 7.0 5 5 15 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 305.81 3 7.0 0 0 3 305.85 3 7.0 0 0 3 Device Routing Invert Outlet Devices #1 Discarded 298.97'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.50' #2 Primary 305.81'18.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Stewart's Shops - Marion Ave - Pre Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Pre Printed 1/5/2026Prepared by Stewart's Shops Corp Page 73HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.57 cfs @ 12.38 hrs HW=304.27' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.57 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=298.97' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond DWE5: Drywell E5 Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210 Fl o w ( c f s ) 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.171 ac Peak Elev=304.30' Storage=343 cf 0.77 cfs 0.57 cfs0.57 cfs 0.00 cfs P1 WS P2A WS P2B WS P3 WS P4 WS P5 WS DP1 Marion Ave DP2 City property 1P Detention 2P Infiltration 3P Infiltration Routing Diagram for Marion Ave-Post Prepared by Stewart's Shops Corp, Printed 1/5/2026 HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcat Reach Pond Link Stewart's Shops - Marion Ave - Post Development Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 2HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.615 39 >75% Grass cover, Good, HSG A (P1, P2A, P3, P4, P5) 1.017 98 Unconnected pavement, HSG A (P1, P2A, P3, P4, P5) 0.281 98 Unconnected roofs, HSG A (P2B, P3) 1.913 79 TOTAL AREA Stewart's Shops - Marion Ave - Post Development Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 3HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 1.913 HSG A P1, P2A, P2B, P3, P4, P5 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.000 Other 1.913 TOTAL AREA Stewart's Shops - Marion Ave - Post Development Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 4HydroCAD® 10.20-6a s/n 08847 © 2024 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 0.615 0.000 0.000 0.000 0.000 0.615 >75% Grass cover, Good P1, P2A, P3, P4, P5 1.017 0.000 0.000 0.000 0.000 1.017 Unconnected pavement P1, P2A, P3, P4, P5 0.281 0.000 0.000 0.000 0.000 0.281 Unconnected roofs P2B, P3 1.913 0.000 0.000 0.000 0.000 1.913 TOTAL AREA Stewart's Shops - Marion Ave - Post Development Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 5HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Width (inches) Diam/Height (inches) Inside-Fill (inches) Node Name 1 1P 297.47 297.44 6.0 0.0050 0.013 0.0 12.0 0.0 Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 6HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Time span=0.00-28.00 hrs, dt=0.05 hrs, 561 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=17,465 sf 90.04% Impervious Runoff Depth=1.46"Subcatchment P1: WS Tc=6.0 min CN=92 Runoff=0.99 cfs 0.049 af Runoff Area=10,400 sf 97.92% Impervious Runoff Depth=1.92"Subcatchment P2A: WS Tc=6.0 min CN=97 Runoff=0.71 cfs 0.038 af Runoff Area=3,212 sf 100.00% Impervious Runoff Depth=2.02"Subcatchment P2B: WS Tc=6.0 min CN=98 Runoff=0.23 cfs 0.012 af Runoff Area=30,579 sf 78.82% Impervious Runoff Depth=1.04"Subcatchment P3: WS Flow Length=96' Slope=0.0160 '/' Tc=16.7 min CN=86 Runoff=0.89 cfs 0.061 af Runoff Area=5,922 sf 52.79% Impervious Runoff Depth=0.34"Subcatchment P4: WS Flow Length=242' Tc=16.7 min CN=70 Runoff=0.04 cfs 0.004 af Runoff Area=15,731 sf 1.13% Impervious Runoff Depth=0.00"Subcatchment P5: WS Flow Length=258' Tc=27.1 min UI Adjusted CN=39 Runoff=0.00 cfs 0.000 af Inflow=0.07 cfs 0.043 afReach DP1: Marion Ave Outflow=0.07 cfs 0.043 af Inflow=0.00 cfs 0.000 afReach DP2: City property Outflow=0.00 cfs 0.000 af Peak Elev=298.90' Storage=0.029 af Inflow=0.99 cfs 0.049 afPond 1P: Detention Outflow=0.03 cfs 0.039 af Peak Elev=300.62' Storage=210 cf Inflow=0.94 cfs 0.051 afPond 2P: Infiltration Discarded=0.75 cfs 0.051 af Primary=0.00 cfs 0.000 af Outflow=0.75 cfs 0.051 af Peak Elev=300.24' Storage=0.001 af Inflow=0.89 cfs 0.061 afPond 3P: Infiltration Discarded=0.88 cfs 0.061 af Primary=0.00 cfs 0.000 af Outflow=0.88 cfs 0.061 af Total Runoff Area = 1.913 ac Runoff Volume = 0.164 af Average Runoff Depth = 1.03" 32.15% Pervious = 0.615 ac 67.85% Impervious = 1.298 ac Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 7HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P1: WS Runoff = 0.99 cfs @ 11.97 hrs, Volume= 0.049 af, Depth= 1.46" Routed to Pond 1P : Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 1,739 39 >75% Grass cover, Good, HSG A 15,726 98 Unconnected pavement, HSG A 17,465 92 Weighted Average 1,739 9.96% Pervious Area 15,726 90.04% Impervious Area 15,726 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P1: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=17,465 sf Runoff Volume=0.049 af Runoff Depth=1.46" Tc=6.0 min CN=92 0.99 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 8HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P2A: WS Runoff = 0.71 cfs @ 11.96 hrs, Volume= 0.038 af, Depth= 1.92" Routed to Pond 2P : Infiltration Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 216 39 >75% Grass cover, Good, HSG A 10,184 98 Unconnected pavement, HSG A 10,400 97 Weighted Average 216 2.08% Pervious Area 10,184 97.92% Impervious Area 10,184 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P2A: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=10,400 sf Runoff Volume=0.038 af Runoff Depth=1.92" Tc=6.0 min CN=97 0.71 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 9HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P2B: WS Runoff = 0.23 cfs @ 11.96 hrs, Volume= 0.012 af, Depth= 2.02" Routed to Pond 2P : Infiltration Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 3,212 98 Unconnected roofs, HSG A 3,212 100.00% Impervious Area 3,212 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P2B: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.25 0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=3,212 sf Runoff Volume=0.012 af Runoff Depth=2.02" Tc=6.0 min CN=98 0.23 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 10HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P3: WS Runoff = 0.89 cfs @ 12.09 hrs, Volume= 0.061 af, Depth= 1.04" Routed to Pond 3P : Infiltration Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 6,477 39 >75% Grass cover, Good, HSG A 15,078 98 Unconnected pavement, HSG A 9,024 98 Unconnected roofs, HSG A 30,579 86 Weighted Average 6,477 21.18% Pervious Area 24,102 78.82% Impervious Area 24,102 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 16.7 96 0.0160 0.10 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" Subcatchment P3: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=30,579 sf Runoff Volume=0.061 af Runoff Depth=1.04" Flow Length=96' Slope=0.0160 '/' Tc=16.7 min CN=86 0.89 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 11HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P4: WS Runoff = 0.04 cfs @ 12.13 hrs, Volume= 0.004 af, Depth= 0.34" Routed to Reach DP1 : Marion Ave Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Description 2,796 39 >75% Grass cover, Good, HSG A 3,126 98 Unconnected pavement, HSG A 5,922 70 Weighted Average 2,796 47.21% Pervious Area 3,126 52.79% Impervious Area 3,126 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.3 10 0.0970 0.13 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.2 7 0.0220 0.76 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 14.1 75 0.0150 0.09 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 1.1 150 0.0120 2.22 Shallow Concentrated Flow, Paved Kv= 20.3 fps 16.7 242 Total Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 12HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment P4: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.044 0.042 0.04 0.038 0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=5,922 sf Runoff Volume=0.004 af Runoff Depth=0.34" Flow Length=242' Tc=16.7 min CN=70 0.04 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 13HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P5: WS Runoff = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Depth= 0.00" Routed to Reach DP2 : City property Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr Rainfall=2.25" Area (sf) CN Adj Description 15,554 39 >75% Grass cover, Good, HSG A 177 98 Unconnected pavement, HSG A 15,731 40 39 Weighted Average, UI Adjusted 15,554 98.87% Pervious Area 177 1.13% Impervious Area 177 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 25.6 100 0.0060 0.07 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.5 39 0.0080 1.34 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.1 21 0.0140 2.40 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 87 0.0150 1.84 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.1 11 0.0320 2.88 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 27.1 258 Total Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 14HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment P5: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Type II 24-hr 1 yr Rainfall=2.25" Runoff Area=15,731 sf Runoff Volume=0.000 af Runoff Depth=0.00" Flow Length=258' Tc=27.1 min UI Adjusted CN=39 0.00 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 15HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP1: Marion Ave Inflow Area = 1.551 ac, 83.39% Impervious, Inflow Depth > 0.33" for 1 yr event Inflow = 0.07 cfs @ 12.13 hrs, Volume= 0.043 af Outflow = 0.07 cfs @ 12.13 hrs, Volume= 0.043 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Reach DP1: Marion Ave Inflow Outflow Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=1.551 ac 0.07 cfs0.07 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 16HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP2: City property Inflow Area = 0.361 ac, 1.13% Impervious, Inflow Depth = 0.00" for 1 yr event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Reach DP2: City property Inflow Outflow Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Inflow Area=0.361 ac 0.00 cfs0.00 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 17HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1P: Detention Inflow Area = 0.713 ac, 93.71% Impervious, Inflow Depth = 0.82" for 1 yr event Inflow = 0.99 cfs @ 11.97 hrs, Volume= 0.049 af Outflow = 0.03 cfs @ 14.01 hrs, Volume= 0.039 af, Atten= 97%, Lag= 122.7 min Primary = 0.03 cfs @ 14.01 hrs, Volume= 0.039 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Peak Elev= 298.90' @ 14.01 hrs Surf.Area= 0.034 ac Storage= 0.029 af Plug-Flow detention time= 419.4 min calculated for 0.039 af (80% of inflow) Center-of-Mass det. time= 337.8 min ( 1,145.8 - 808.0 ) Volume Invert Avail.Storage Storage Description #1A 297.47' 0.048 af 29.92'W x 48.72'L x 5.50'H Detention Field 0.184 af Overall - 0.063 af Embedded = 0.121 af x 40.0% Voids #2A 298.22' 0.063 af ADS_StormTech MC-3500 d +Cap x 24 Inside #1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap 24 Chambers in 4 Rows Cap Storage= 14.9 cf x 2 x 4 rows = 119.2 cf #3 298.33' 0.001 af 12.0" Round Pipe Storage L= 44.0' 0.112 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Device 5 297.47'1.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Device 5 298.90'2.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 5 299.77'3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Device 5 301.48'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Primary 297.47'12.0" Round Culvert L= 6.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 297.47' / 297.44' S= 0.0050 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.03 cfs @ 14.01 hrs HW=298.90' (Free Discharge) 5=Culvert (Passes 0.03 cfs of 2.88 cfs potential flow) 1=Orifice/Grate (Orifice Controls 0.03 cfs @ 5.67 fps) 2=Orifice/Grate (Orifice Controls 0.00 cfs @ 0.08 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 18HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 1P: Detention - Chamber Wizard Detention Field Chamber Model = ADS_StormTech MC-3500 d +Cap (ADS StormTech® MC-3500 d rev 03/14 with Cap volume) Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= 14.9 cf x 2 x 4 rows = 119.2 cf 77.0" Wide + 9.0" Spacing = 86.0" C-C Row Spacing 6 Chambers/Row x 7.17' Long +1.85' Cap Length x 2 = 46.72' Row Length +12.0" End Stone x 2 = 48.72' Base Length 4 Rows x 77.0" Wide + 9.0" Spacing x 3 + 12.0" Side Stone x 2 = 29.92' Base Width 9.0" Stone Base + 45.0" Chamber Height + 12.0" Stone Cover = 5.50' Field Height 24 Chambers x 110.0 cf + 14.9 cf Cap Volume x 2 x 4 Rows = 2,758.0 cf Chamber Storage 8,016.5 cf Field - 2,758.0 cf Chambers = 5,258.4 cf Stone x 40.0% Voids = 2,103.4 cf Stone Storage Chamber Storage + Stone Storage = 4,861.4 cf = 0.112 af Overall Storage Efficiency = 60.6% Overall System Size = 48.72' x 29.92' x 5.50' 24 Chambers 296.9 cy Field 194.8 cy Stone Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 19HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 1P: Detention Inflow Primary Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Inflow Area=0.713 ac Peak Elev=298.90' Storage=0.029 af 0.99 cfs 0.03 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 20HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 2P: Infiltration Inflow Area = 0.312 ac, 98.41% Impervious, Inflow Depth = 1.94" for 1 yr event Inflow = 0.94 cfs @ 11.96 hrs, Volume= 0.051 af Outflow = 0.75 cfs @ 12.02 hrs, Volume= 0.051 af, Atten= 20%, Lag= 3.4 min Discarded = 0.75 cfs @ 12.02 hrs, Volume= 0.051 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 1P : Detention Routing by Stor-Ind method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Peak Elev= 300.62' @ 12.02 hrs Surf.Area= 508 sf Storage= 210 cf Plug-Flow detention time= 4.0 min calculated for 0.050 af (100% of inflow) Center-of-Mass det. time= 4.0 min ( 773.4 - 769.3 ) Volume Invert Avail.Storage Storage Description #1A 299.85' 612 cf 15.75'W x 32.23'L x 4.25'H Infiltration field P2 2,158 cf Overall - 628 cf Embedded = 1,530 cf x 40.0% Voids #2A 300.35' 628 cf ADS_StormTech SC-800 +Cap x 12 Inside #1 Effective Size= 45.0"W x 33.0"H => 7.11 sf x 7.12'L = 50.6 cf Overall Size= 51.0"W x 33.0"H x 7.55'L with 0.43' Overlap 12 Chambers in 3 Rows Cap Storage= 3.4 cf x 2 x 3 rows = 20.5 cf #3 301.55' 14 cf 12.0" Round Pipe Storage -Impervious L= 18.0' #4 301.55' 71 cf 12.0" Round Pipe Storage -Impervious L= 90.0' S= 0.0100 '/' #5 304.10' 0 cf Surge (Prismatic) Listed below (Recalc) -Impervious 1,325 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 304.10 6 0 0 304.14 6 0 0 Device Routing Invert Outlet Devices #1 Discarded 299.85'72.000 in/hr Exfiltration over Wetted area Phase-In= 1.00' #2 Primary 304.10'30.0" x 30.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.74 cfs @ 12.02 hrs HW=300.61' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.74 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=299.85' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 21HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 2P: Infiltration - Chamber Wizard Infiltration field P2 Chamber Model = ADS_StormTech SC-800 +Cap (ADS StormTech® SC-800 with cap volume) Effective Size= 45.0"W x 33.0"H => 7.11 sf x 7.12'L = 50.6 cf Overall Size= 51.0"W x 33.0"H x 7.55'L with 0.43' Overlap Cap Storage= 3.4 cf x 2 x 3 rows = 20.5 cf 51.0" Wide + 6.0" Spacing = 57.0" C-C Row Spacing 4 Chambers/Row x 7.12' Long +0.88' Cap Length x 2 = 30.23' Row Length +12.0" End Stone x 2 = 32.23' Base Length 3 Rows x 51.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 15.75' Base Width 6.0" Stone Base + 33.0" Chamber Height + 12.0" Stone Cover = 4.25' Field Height 12 Chambers x 50.6 cf + 3.4 cf Cap Volume x 2 x 3 Rows = 627.6 cf Chamber Storage 2,157.6 cf Field - 627.6 cf Chambers = 1,530.0 cf Stone x 40.0% Voids = 612.0 cf Stone Storage Chamber Storage + Stone Storage = 1,239.6 cf = 0.028 af Overall Storage Efficiency = 57.5% Overall System Size = 32.23' x 15.75' x 4.25' 12 Chambers 79.9 cy Field 56.7 cy Stone Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 22HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 2P: Infiltration Inflow Outflow Discarded Primary Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Inflow Area=0.312 ac Peak Elev=300.62' Storage=210 cf 0.94 cfs 0.75 cfs0.75 cfs 0.00 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 23HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 3P: Infiltration Inflow Area = 0.702 ac, 78.82% Impervious, Inflow Depth = 1.04" for 1 yr event Inflow = 0.89 cfs @ 12.09 hrs, Volume= 0.061 af Outflow = 0.88 cfs @ 12.11 hrs, Volume= 0.061 af, Atten= 1%, Lag= 0.8 min Discarded = 0.88 cfs @ 12.11 hrs, Volume= 0.061 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Peak Elev= 300.24' @ 12.11 hrs Surf.Area= 0.014 ac Storage= 0.001 af Plug-Flow detention time= 0.8 min calculated for 0.061 af (100% of inflow) Center-of-Mass det. time= 0.8 min ( 846.3 - 845.6 ) Volume Invert Avail.Storage Storage Description #1A 300.07' 0.021 af 22.75'W x 27.21'L x 5.50'H Infiltration Field 0.078 af Overall - 0.025 af Embedded = 0.053 af x 40.0% Voids #2A 300.82' 0.025 af ADS_StormTech MC-3500 d +Cap x 9 Inside #1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap 9 Chambers in 3 Rows Cap Storage= 14.9 cf x 2 x 3 rows = 89.4 cf #3 303.02' 0.001 af 12.0" Round Pipe Storage L= 68.0' S= 0.0050 '/' 0.047 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 300.07'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.20' #2 Primary 305.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.88 cfs @ 12.11 hrs HW=300.24' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.88 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=300.07' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 24HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 3P: Infiltration - Chamber Wizard Infiltration Field Chamber Model = ADS_StormTech MC-3500 d +Cap (ADS StormTech® MC-3500 d rev 03/14 with Cap volume) Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= 14.9 cf x 2 x 3 rows = 89.4 cf 77.0" Wide + 9.0" Spacing = 86.0" C-C Row Spacing 3 Chambers/Row x 7.17' Long +1.85' Cap Length x 2 = 25.21' Row Length +12.0" End Stone x 2 = 27.21' Base Length 3 Rows x 77.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 22.75' Base Width 9.0" Stone Base + 45.0" Chamber Height + 12.0" Stone Cover = 5.50' Field Height 9 Chambers x 110.0 cf + 14.9 cf Cap Volume x 2 x 3 Rows = 1,079.0 cf Chamber Storage 3,404.7 cf Field - 1,079.0 cf Chambers = 2,325.7 cf Stone x 40.0% Voids = 930.3 cf Stone Storage Chamber Storage + Stone Storage = 2,009.2 cf = 0.046 af Overall Storage Efficiency = 59.0% Overall System Size = 27.21' x 22.75' x 5.50' 9 Chambers 126.1 cy Field 86.1 cy Stone Stewart's Shops - Marion Ave - Post Development Type II 24-hr 1 yr Rainfall=2.25"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 25HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 3P: Infiltration Inflow Outflow Discarded Primary Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.702 ac Peak Elev=300.24' Storage=0.001 af 0.89 cfs0.88 cfs0.88 cfs 0.00 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 26HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Time span=0.00-28.00 hrs, dt=0.05 hrs, 561 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=17,465 sf 90.04% Impervious Runoff Depth=2.87"Subcatchment P1: WS Tc=6.0 min CN=92 Runoff=1.86 cfs 0.096 af Runoff Area=10,400 sf 97.92% Impervious Runoff Depth=3.39"Subcatchment P2A: WS Tc=6.0 min CN=97 Runoff=1.22 cfs 0.068 af Runoff Area=3,212 sf 100.00% Impervious Runoff Depth=3.51"Subcatchment P2B: WS Tc=6.0 min CN=98 Runoff=0.38 cfs 0.022 af Runoff Area=30,579 sf 78.82% Impervious Runoff Depth=2.31"Subcatchment P3: WS Flow Length=96' Slope=0.0160 '/' Tc=16.7 min CN=86 Runoff=1.97 cfs 0.135 af Runoff Area=5,922 sf 52.79% Impervious Runoff Depth=1.16"Subcatchment P4: WS Flow Length=242' Tc=16.7 min CN=70 Runoff=0.18 cfs 0.013 af Runoff Area=15,731 sf 1.13% Impervious Runoff Depth=0.02"Subcatchment P5: WS Flow Length=258' Tc=27.1 min UI Adjusted CN=39 Runoff=0.00 cfs 0.001 af Inflow=0.30 cfs 0.093 afReach DP1: Marion Ave Outflow=0.30 cfs 0.093 af Inflow=0.00 cfs 0.001 afReach DP2: City property Outflow=0.00 cfs 0.001 af Peak Elev=299.77' Storage=0.053 af Inflow=1.86 cfs 0.096 afPond 1P: Detention Outflow=0.13 cfs 0.079 af Peak Elev=301.22' Storage=444 cf Inflow=1.60 cfs 0.089 afPond 2P: Infiltration Discarded=1.07 cfs 0.089 af Primary=0.00 cfs 0.000 af Outflow=1.07 cfs 0.089 af Peak Elev=301.51' Storage=0.012 af Inflow=1.97 cfs 0.135 afPond 3P: Infiltration Discarded=1.27 cfs 0.135 af Primary=0.00 cfs 0.000 af Outflow=1.27 cfs 0.135 af Total Runoff Area = 1.913 ac Runoff Volume = 0.334 af Average Runoff Depth = 2.10" 32.15% Pervious = 0.615 ac 67.85% Impervious = 1.298 ac Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 27HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P1: WS Runoff = 1.86 cfs @ 11.96 hrs, Volume= 0.096 af, Depth= 2.87" Routed to Pond 1P : Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 1,739 39 >75% Grass cover, Good, HSG A 15,726 98 Unconnected pavement, HSG A 17,465 92 Weighted Average 1,739 9.96% Pervious Area 15,726 90.04% Impervious Area 15,726 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P1: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 2 1 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=17,465 sf Runoff Volume=0.096 af Runoff Depth=2.87" Tc=6.0 min CN=92 1.86 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 28HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P2A: WS Runoff = 1.22 cfs @ 11.96 hrs, Volume= 0.068 af, Depth= 3.39" Routed to Pond 2P : Infiltration Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 216 39 >75% Grass cover, Good, HSG A 10,184 98 Unconnected pavement, HSG A 10,400 97 Weighted Average 216 2.08% Pervious Area 10,184 97.92% Impervious Area 10,184 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P2A: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=10,400 sf Runoff Volume=0.068 af Runoff Depth=3.39" Tc=6.0 min CN=97 1.22 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 29HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P2B: WS Runoff = 0.38 cfs @ 11.96 hrs, Volume= 0.022 af, Depth= 3.51" Routed to Pond 2P : Infiltration Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 3,212 98 Unconnected roofs, HSG A 3,212 100.00% Impervious Area 3,212 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P2B: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=3,212 sf Runoff Volume=0.022 af Runoff Depth=3.51" Tc=6.0 min CN=98 0.38 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 30HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P3: WS Runoff = 1.97 cfs @ 12.09 hrs, Volume= 0.135 af, Depth= 2.31" Routed to Pond 3P : Infiltration Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 6,477 39 >75% Grass cover, Good, HSG A 15,078 98 Unconnected pavement, HSG A 9,024 98 Unconnected roofs, HSG A 30,579 86 Weighted Average 6,477 21.18% Pervious Area 24,102 78.82% Impervious Area 24,102 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 16.7 96 0.0160 0.10 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" Subcatchment P3: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 2 1 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=30,579 sf Runoff Volume=0.135 af Runoff Depth=2.31" Flow Length=96' Slope=0.0160 '/' Tc=16.7 min CN=86 1.97 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 31HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P4: WS Runoff = 0.18 cfs @ 12.10 hrs, Volume= 0.013 af, Depth= 1.16" Routed to Reach DP1 : Marion Ave Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Description 2,796 39 >75% Grass cover, Good, HSG A 3,126 98 Unconnected pavement, HSG A 5,922 70 Weighted Average 2,796 47.21% Pervious Area 3,126 52.79% Impervious Area 3,126 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.3 10 0.0970 0.13 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.2 7 0.0220 0.76 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 14.1 75 0.0150 0.09 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 1.1 150 0.0120 2.22 Shallow Concentrated Flow, Paved Kv= 20.3 fps 16.7 242 Total Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 32HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment P4: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=5,922 sf Runoff Volume=0.013 af Runoff Depth=1.16" Flow Length=242' Tc=16.7 min CN=70 0.18 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 33HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P5: WS Runoff = 0.00 cfs @ 24.01 hrs, Volume= 0.001 af, Depth= 0.02" Routed to Reach DP2 : City property Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=3.74" Area (sf) CN Adj Description 15,554 39 >75% Grass cover, Good, HSG A 177 98 Unconnected pavement, HSG A 15,731 40 39 Weighted Average, UI Adjusted 15,554 98.87% Pervious Area 177 1.13% Impervious Area 177 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 25.6 100 0.0060 0.07 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.5 39 0.0080 1.34 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.1 21 0.0140 2.40 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 87 0.0150 1.84 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.1 11 0.0320 2.88 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 27.1 258 Total Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 34HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment P5: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0 0 Type II 24-hr 10 yr Rainfall=3.74" Runoff Area=15,731 sf Runoff Volume=0.001 af Runoff Depth=0.02" Flow Length=258' Tc=27.1 min UI Adjusted CN=39 0.00 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 35HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP1: Marion Ave Inflow Area = 1.551 ac, 83.39% Impervious, Inflow Depth > 0.72" for 10 yr event Inflow = 0.30 cfs @ 12.11 hrs, Volume= 0.093 af Outflow = 0.30 cfs @ 12.11 hrs, Volume= 0.093 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Reach DP1: Marion Ave Inflow Outflow Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=1.551 ac 0.30 cfs0.30 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 36HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP2: City property Inflow Area = 0.361 ac, 1.13% Impervious, Inflow Depth = 0.02" for 10 yr event Inflow = 0.00 cfs @ 24.01 hrs, Volume= 0.001 af Outflow = 0.00 cfs @ 24.01 hrs, Volume= 0.001 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Reach DP2: City property Inflow Outflow Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0 0 Inflow Area=0.361 ac 0.00 cfs0.00 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 37HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1P: Detention Inflow Area = 0.713 ac, 93.71% Impervious, Inflow Depth = 1.61" for 10 yr event Inflow = 1.86 cfs @ 11.96 hrs, Volume= 0.096 af Outflow = 0.13 cfs @ 12.57 hrs, Volume= 0.079 af, Atten= 93%, Lag= 36.5 min Primary = 0.13 cfs @ 12.57 hrs, Volume= 0.079 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Peak Elev= 299.77' @ 12.57 hrs Surf.Area= 0.033 ac Storage= 0.053 af Plug-Flow detention time= 292.8 min calculated for 0.079 af (83% of inflow) Center-of-Mass det. time= 220.1 min ( 1,009.1 - 789.1 ) Volume Invert Avail.Storage Storage Description #1A 297.47' 0.048 af 29.92'W x 48.72'L x 5.50'H Detention Field 0.184 af Overall - 0.063 af Embedded = 0.121 af x 40.0% Voids #2A 298.22' 0.063 af ADS_StormTech MC-3500 d +Cap x 24 Inside #1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap 24 Chambers in 4 Rows Cap Storage= 14.9 cf x 2 x 4 rows = 119.2 cf #3 298.33' 0.001 af 12.0" Round Pipe Storage L= 44.0' 0.112 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Device 5 297.47'1.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Device 5 298.90'2.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 5 299.77'3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Device 5 301.48'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Primary 297.47'12.0" Round Culvert L= 6.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 297.47' / 297.44' S= 0.0050 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.13 cfs @ 12.57 hrs HW=299.77' (Free Discharge) 5=Culvert (Passes 0.13 cfs of 4.00 cfs potential flow) 1=Orifice/Grate (Orifice Controls 0.04 cfs @ 7.23 fps) 2=Orifice/Grate (Orifice Controls 0.09 cfs @ 4.26 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 38HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 1P: Detention - Chamber Wizard Detention Field Chamber Model = ADS_StormTech MC-3500 d +Cap (ADS StormTech® MC-3500 d rev 03/14 with Cap volume) Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= 14.9 cf x 2 x 4 rows = 119.2 cf 77.0" Wide + 9.0" Spacing = 86.0" C-C Row Spacing 6 Chambers/Row x 7.17' Long +1.85' Cap Length x 2 = 46.72' Row Length +12.0" End Stone x 2 = 48.72' Base Length 4 Rows x 77.0" Wide + 9.0" Spacing x 3 + 12.0" Side Stone x 2 = 29.92' Base Width 9.0" Stone Base + 45.0" Chamber Height + 12.0" Stone Cover = 5.50' Field Height 24 Chambers x 110.0 cf + 14.9 cf Cap Volume x 2 x 4 Rows = 2,758.0 cf Chamber Storage 8,016.5 cf Field - 2,758.0 cf Chambers = 5,258.4 cf Stone x 40.0% Voids = 2,103.4 cf Stone Storage Chamber Storage + Stone Storage = 4,861.4 cf = 0.112 af Overall Storage Efficiency = 60.6% Overall System Size = 48.72' x 29.92' x 5.50' 24 Chambers 296.9 cy Field 194.8 cy Stone Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 39HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 1P: Detention Inflow Primary Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 2 1 0 Inflow Area=0.713 ac Peak Elev=299.77' Storage=0.053 af 1.86 cfs 0.13 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 40HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 2P: Infiltration Inflow Area = 0.312 ac, 98.41% Impervious, Inflow Depth = 3.42" for 10 yr event Inflow = 1.60 cfs @ 11.96 hrs, Volume= 0.089 af Outflow = 1.07 cfs @ 12.04 hrs, Volume= 0.089 af, Atten= 33%, Lag= 4.6 min Discarded = 1.07 cfs @ 12.04 hrs, Volume= 0.089 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 1P : Detention Routing by Stor-Ind method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Peak Elev= 301.22' @ 12.04 hrs Surf.Area= 508 sf Storage= 444 cf Plug-Flow detention time= 4.5 min calculated for 0.089 af (100% of inflow) Center-of-Mass det. time= 4.5 min ( 760.7 - 756.2 ) Volume Invert Avail.Storage Storage Description #1A 299.85' 612 cf 15.75'W x 32.23'L x 4.25'H Infiltration field P2 2,158 cf Overall - 628 cf Embedded = 1,530 cf x 40.0% Voids #2A 300.35' 628 cf ADS_StormTech SC-800 +Cap x 12 Inside #1 Effective Size= 45.0"W x 33.0"H => 7.11 sf x 7.12'L = 50.6 cf Overall Size= 51.0"W x 33.0"H x 7.55'L with 0.43' Overlap 12 Chambers in 3 Rows Cap Storage= 3.4 cf x 2 x 3 rows = 20.5 cf #3 301.55' 14 cf 12.0" Round Pipe Storage -Impervious L= 18.0' #4 301.55' 71 cf 12.0" Round Pipe Storage -Impervious L= 90.0' S= 0.0100 '/' #5 304.10' 0 cf Surge (Prismatic) Listed below (Recalc) -Impervious 1,325 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 304.10 6 0 0 304.14 6 0 0 Device Routing Invert Outlet Devices #1 Discarded 299.85'72.000 in/hr Exfiltration over Wetted area Phase-In= 1.00' #2 Primary 304.10'30.0" x 30.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.06 cfs @ 12.04 hrs HW=301.20' (Free Discharge) 1=Exfiltration (Exfiltration Controls 1.06 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=299.85' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 41HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 2P: Infiltration - Chamber Wizard Infiltration field P2 Chamber Model = ADS_StormTech SC-800 +Cap (ADS StormTech® SC-800 with cap volume) Effective Size= 45.0"W x 33.0"H => 7.11 sf x 7.12'L = 50.6 cf Overall Size= 51.0"W x 33.0"H x 7.55'L with 0.43' Overlap Cap Storage= 3.4 cf x 2 x 3 rows = 20.5 cf 51.0" Wide + 6.0" Spacing = 57.0" C-C Row Spacing 4 Chambers/Row x 7.12' Long +0.88' Cap Length x 2 = 30.23' Row Length +12.0" End Stone x 2 = 32.23' Base Length 3 Rows x 51.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 15.75' Base Width 6.0" Stone Base + 33.0" Chamber Height + 12.0" Stone Cover = 4.25' Field Height 12 Chambers x 50.6 cf + 3.4 cf Cap Volume x 2 x 3 Rows = 627.6 cf Chamber Storage 2,157.6 cf Field - 627.6 cf Chambers = 1,530.0 cf Stone x 40.0% Voids = 612.0 cf Stone Storage Chamber Storage + Stone Storage = 1,239.6 cf = 0.028 af Overall Storage Efficiency = 57.5% Overall System Size = 32.23' x 15.75' x 4.25' 12 Chambers 79.9 cy Field 56.7 cy Stone Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 42HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 2P: Infiltration Inflow Outflow Discarded Primary Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Inflow Area=0.312 ac Peak Elev=301.22' Storage=444 cf 1.60 cfs 1.07 cfs1.07 cfs 0.00 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 43HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 3P: Infiltration Inflow Area = 0.702 ac, 78.82% Impervious, Inflow Depth = 2.31" for 10 yr event Inflow = 1.97 cfs @ 12.09 hrs, Volume= 0.135 af Outflow = 1.27 cfs @ 12.22 hrs, Volume= 0.135 af, Atten= 35%, Lag= 8.0 min Discarded = 1.27 cfs @ 12.22 hrs, Volume= 0.135 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Peak Elev= 301.51' @ 12.22 hrs Surf.Area= 0.014 ac Storage= 0.012 af Plug-Flow detention time= 2.2 min calculated for 0.135 af (100% of inflow) Center-of-Mass det. time= 2.2 min ( 825.0 - 822.8 ) Volume Invert Avail.Storage Storage Description #1A 300.07' 0.021 af 22.75'W x 27.21'L x 5.50'H Infiltration Field 0.078 af Overall - 0.025 af Embedded = 0.053 af x 40.0% Voids #2A 300.82' 0.025 af ADS_StormTech MC-3500 d +Cap x 9 Inside #1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap 9 Chambers in 3 Rows Cap Storage= 14.9 cf x 2 x 3 rows = 89.4 cf #3 303.02' 0.001 af 12.0" Round Pipe Storage L= 68.0' S= 0.0050 '/' 0.047 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 300.07'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.20' #2 Primary 305.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.27 cfs @ 12.22 hrs HW=301.50' (Free Discharge) 1=Exfiltration (Exfiltration Controls 1.27 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=300.07' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 44HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 3P: Infiltration - Chamber Wizard Infiltration Field Chamber Model = ADS_StormTech MC-3500 d +Cap (ADS StormTech® MC-3500 d rev 03/14 with Cap volume) Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= 14.9 cf x 2 x 3 rows = 89.4 cf 77.0" Wide + 9.0" Spacing = 86.0" C-C Row Spacing 3 Chambers/Row x 7.17' Long +1.85' Cap Length x 2 = 25.21' Row Length +12.0" End Stone x 2 = 27.21' Base Length 3 Rows x 77.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 22.75' Base Width 9.0" Stone Base + 45.0" Chamber Height + 12.0" Stone Cover = 5.50' Field Height 9 Chambers x 110.0 cf + 14.9 cf Cap Volume x 2 x 3 Rows = 1,079.0 cf Chamber Storage 3,404.7 cf Field - 1,079.0 cf Chambers = 2,325.7 cf Stone x 40.0% Voids = 930.3 cf Stone Storage Chamber Storage + Stone Storage = 2,009.2 cf = 0.046 af Overall Storage Efficiency = 59.0% Overall System Size = 27.21' x 22.75' x 5.50' 9 Chambers 126.1 cy Field 86.1 cy Stone Stewart's Shops - Marion Ave - Post Development Type II 24-hr 10 yr Rainfall=3.74"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 45HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 3P: Infiltration Inflow Outflow Discarded Primary Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 2 1 0 Inflow Area=0.702 ac Peak Elev=301.51' Storage=0.012 af 1.97 cfs 1.27 cfs1.27 cfs 0.00 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 46HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Time span=0.00-28.00 hrs, dt=0.05 hrs, 561 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=17,465 sf 90.04% Impervious Runoff Depth=5.33"Subcatchment P1: WS Tc=6.0 min CN=92 Runoff=3.32 cfs 0.178 af Runoff Area=10,400 sf 97.92% Impervious Runoff Depth=5.90"Subcatchment P2A: WS Tc=6.0 min CN=97 Runoff=2.06 cfs 0.117 af Runoff Area=3,212 sf 100.00% Impervious Runoff Depth=6.02"Subcatchment P2B: WS Tc=6.0 min CN=98 Runoff=0.64 cfs 0.037 af Runoff Area=30,579 sf 78.82% Impervious Runoff Depth=4.66"Subcatchment P3: WS Flow Length=96' Slope=0.0160 '/' Tc=16.7 min CN=86 Runoff=3.88 cfs 0.272 af Runoff Area=5,922 sf 52.79% Impervious Runoff Depth=3.01"Subcatchment P4: WS Flow Length=242' Tc=16.7 min CN=70 Runoff=0.50 cfs 0.034 af Runoff Area=15,731 sf 1.13% Impervious Runoff Depth=0.52"Subcatchment P5: WS Flow Length=258' Tc=27.1 min UI Adjusted CN=39 Runoff=0.07 cfs 0.016 af Inflow=1.00 cfs 0.192 afReach DP1: Marion Ave Outflow=1.00 cfs 0.192 af Inflow=0.07 cfs 0.016 afReach DP2: City property Outflow=0.07 cfs 0.016 af Peak Elev=301.47' Storage=0.091 af Inflow=3.32 cfs 0.178 afPond 1P: Detention Outflow=0.51 cfs 0.158 af Peak Elev=302.96' Storage=1,083 cf Inflow=2.70 cfs 0.154 afPond 2P: Infiltration Discarded=1.34 cfs 0.154 af Primary=0.00 cfs 0.000 af Outflow=1.34 cfs 0.154 af Peak Elev=304.98' Storage=0.044 af Inflow=3.88 cfs 0.272 afPond 3P: Infiltration Discarded=2.21 cfs 0.272 af Primary=0.00 cfs 0.000 af Outflow=2.21 cfs 0.272 af Total Runoff Area = 1.913 ac Runoff Volume = 0.655 af Average Runoff Depth = 4.11" 32.15% Pervious = 0.615 ac 67.85% Impervious = 1.298 ac Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 47HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P1: WS Runoff = 3.32 cfs @ 11.96 hrs, Volume= 0.178 af, Depth= 5.33" Routed to Pond 1P : Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 1,739 39 >75% Grass cover, Good, HSG A 15,726 98 Unconnected pavement, HSG A 17,465 92 Weighted Average 1,739 9.96% Pervious Area 15,726 90.04% Impervious Area 15,726 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P1: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 3 2 1 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=17,465 sf Runoff Volume=0.178 af Runoff Depth=5.33" Tc=6.0 min CN=92 3.32 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 48HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P2A: WS Runoff = 2.06 cfs @ 11.96 hrs, Volume= 0.117 af, Depth= 5.90" Routed to Pond 2P : Infiltration Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 216 39 >75% Grass cover, Good, HSG A 10,184 98 Unconnected pavement, HSG A 10,400 97 Weighted Average 216 2.08% Pervious Area 10,184 97.92% Impervious Area 10,184 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P2A: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 2 1 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=10,400 sf Runoff Volume=0.117 af Runoff Depth=5.90" Tc=6.0 min CN=97 2.06 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 49HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P2B: WS Runoff = 0.64 cfs @ 11.96 hrs, Volume= 0.037 af, Depth= 6.02" Routed to Pond 2P : Infiltration Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 3,212 98 Unconnected roofs, HSG A 3,212 100.00% Impervious Area 3,212 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P2B: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=3,212 sf Runoff Volume=0.037 af Runoff Depth=6.02" Tc=6.0 min CN=98 0.64 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 50HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P3: WS Runoff = 3.88 cfs @ 12.08 hrs, Volume= 0.272 af, Depth= 4.66" Routed to Pond 3P : Infiltration Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 6,477 39 >75% Grass cover, Good, HSG A 15,078 98 Unconnected pavement, HSG A 9,024 98 Unconnected roofs, HSG A 30,579 86 Weighted Average 6,477 21.18% Pervious Area 24,102 78.82% Impervious Area 24,102 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 16.7 96 0.0160 0.10 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" Subcatchment P3: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 4 3 2 1 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=30,579 sf Runoff Volume=0.272 af Runoff Depth=4.66" Flow Length=96' Slope=0.0160 '/' Tc=16.7 min CN=86 3.88 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 51HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P4: WS Runoff = 0.50 cfs @ 12.09 hrs, Volume= 0.034 af, Depth= 3.01" Routed to Reach DP1 : Marion Ave Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Description 2,796 39 >75% Grass cover, Good, HSG A 3,126 98 Unconnected pavement, HSG A 5,922 70 Weighted Average 2,796 47.21% Pervious Area 3,126 52.79% Impervious Area 3,126 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.3 10 0.0970 0.13 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.2 7 0.0220 0.76 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.61" 14.1 75 0.0150 0.09 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 1.1 150 0.0120 2.22 Shallow Concentrated Flow, Paved Kv= 20.3 fps 16.7 242 Total Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 52HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment P4: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=5,922 sf Runoff Volume=0.034 af Runoff Depth=3.01" Flow Length=242' Tc=16.7 min CN=70 0.50 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 53HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment P5: WS Runoff = 0.07 cfs @ 12.34 hrs, Volume= 0.016 af, Depth= 0.52" Routed to Reach DP2 : City property Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.26" Area (sf) CN Adj Description 15,554 39 >75% Grass cover, Good, HSG A 177 98 Unconnected pavement, HSG A 15,731 40 39 Weighted Average, UI Adjusted 15,554 98.87% Pervious Area 177 1.13% Impervious Area 177 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 25.6 100 0.0060 0.07 Sheet Flow, Grass: Dense n= 0.240 P2= 2.61" 0.5 39 0.0080 1.34 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.1 21 0.0140 2.40 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 87 0.0150 1.84 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.1 11 0.0320 2.88 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 27.1 258 Total Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 54HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Subcatchment P5: WS Runoff Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 100 yr Rainfall=6.26" Runoff Area=15,731 sf Runoff Volume=0.016 af Runoff Depth=0.52" Flow Length=258' Tc=27.1 min UI Adjusted CN=39 0.07 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 55HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP1: Marion Ave Inflow Area = 1.551 ac, 83.39% Impervious, Inflow Depth > 1.48" for 100 yr event Inflow = 1.00 cfs @ 12.11 hrs, Volume= 0.192 af Outflow = 1.00 cfs @ 12.11 hrs, Volume= 0.192 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Reach DP1: Marion Ave Inflow Outflow Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 1 0 Inflow Area=1.551 ac 1.00 cfs1.00 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 56HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Reach DP2: City property Inflow Area = 0.361 ac, 1.13% Impervious, Inflow Depth = 0.52" for 100 yr event Inflow = 0.07 cfs @ 12.34 hrs, Volume= 0.016 af Outflow = 0.07 cfs @ 12.34 hrs, Volume= 0.016 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Reach DP2: City property Inflow Outflow Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.361 ac 0.07 cfs0.07 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 57HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1P: Detention Inflow Area = 0.713 ac, 93.71% Impervious, Inflow Depth = 2.99" for 100 yr event Inflow = 3.32 cfs @ 11.96 hrs, Volume= 0.178 af Outflow = 0.51 cfs @ 12.19 hrs, Volume= 0.158 af, Atten= 85%, Lag= 13.4 min Primary = 0.51 cfs @ 12.19 hrs, Volume= 0.158 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Peak Elev= 301.47' @ 12.19 hrs Surf.Area= 0.033 ac Storage= 0.091 af Plug-Flow detention time= 209.9 min calculated for 0.158 af (89% of inflow) Center-of-Mass det. time= 153.2 min ( 925.7 - 772.4 ) Volume Invert Avail.Storage Storage Description #1A 297.47' 0.048 af 29.92'W x 48.72'L x 5.50'H Detention Field 0.184 af Overall - 0.063 af Embedded = 0.121 af x 40.0% Voids #2A 298.22' 0.063 af ADS_StormTech MC-3500 d +Cap x 24 Inside #1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap 24 Chambers in 4 Rows Cap Storage= 14.9 cf x 2 x 4 rows = 119.2 cf #3 298.33' 0.001 af 12.0" Round Pipe Storage L= 44.0' 0.112 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Device 5 297.47'1.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Device 5 298.90'2.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 5 299.77'3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Device 5 301.48'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Primary 297.47'12.0" Round Culvert L= 6.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 297.47' / 297.44' S= 0.0050 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.51 cfs @ 12.19 hrs HW=301.47' (Free Discharge) 5=Culvert (Passes 0.51 cfs of 5.59 cfs potential flow) 1=Orifice/Grate (Orifice Controls 0.05 cfs @ 9.58 fps) 2=Orifice/Grate (Orifice Controls 0.17 cfs @ 7.59 fps) 3=Orifice/Grate (Orifice Controls 0.30 cfs @ 6.05 fps) 4=Orifice/Grate ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 58HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 1P: Detention - Chamber Wizard Detention Field Chamber Model = ADS_StormTech MC-3500 d +Cap (ADS StormTech® MC-3500 d rev 03/14 with Cap volume) Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= 14.9 cf x 2 x 4 rows = 119.2 cf 77.0" Wide + 9.0" Spacing = 86.0" C-C Row Spacing 6 Chambers/Row x 7.17' Long +1.85' Cap Length x 2 = 46.72' Row Length +12.0" End Stone x 2 = 48.72' Base Length 4 Rows x 77.0" Wide + 9.0" Spacing x 3 + 12.0" Side Stone x 2 = 29.92' Base Width 9.0" Stone Base + 45.0" Chamber Height + 12.0" Stone Cover = 5.50' Field Height 24 Chambers x 110.0 cf + 14.9 cf Cap Volume x 2 x 4 Rows = 2,758.0 cf Chamber Storage 8,016.5 cf Field - 2,758.0 cf Chambers = 5,258.4 cf Stone x 40.0% Voids = 2,103.4 cf Stone Storage Chamber Storage + Stone Storage = 4,861.4 cf = 0.112 af Overall Storage Efficiency = 60.6% Overall System Size = 48.72' x 29.92' x 5.50' 24 Chambers 296.9 cy Field 194.8 cy Stone Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 59HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 1P: Detention Inflow Primary Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 3 2 1 0 Inflow Area=0.713 ac Peak Elev=301.47' Storage=0.091 af 3.32 cfs 0.51 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 60HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 2P: Infiltration Inflow Area = 0.312 ac, 98.41% Impervious, Inflow Depth = 5.93" for 100 yr event Inflow = 2.70 cfs @ 11.96 hrs, Volume= 0.154 af Outflow = 1.34 cfs @ 12.06 hrs, Volume= 0.154 af, Atten= 50%, Lag= 6.2 min Discarded = 1.34 cfs @ 12.06 hrs, Volume= 0.154 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 1P : Detention Routing by Stor-Ind method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Peak Elev= 302.96' @ 12.06 hrs Surf.Area= 508 sf Storage= 1,083 cf Plug-Flow detention time= 6.1 min calculated for 0.154 af (100% of inflow) Center-of-Mass det. time= 6.1 min ( 751.7 - 745.7 ) Volume Invert Avail.Storage Storage Description #1A 299.85' 612 cf 15.75'W x 32.23'L x 4.25'H Infiltration field P2 2,158 cf Overall - 628 cf Embedded = 1,530 cf x 40.0% Voids #2A 300.35' 628 cf ADS_StormTech SC-800 +Cap x 12 Inside #1 Effective Size= 45.0"W x 33.0"H => 7.11 sf x 7.12'L = 50.6 cf Overall Size= 51.0"W x 33.0"H x 7.55'L with 0.43' Overlap 12 Chambers in 3 Rows Cap Storage= 3.4 cf x 2 x 3 rows = 20.5 cf #3 301.55' 14 cf 12.0" Round Pipe Storage -Impervious L= 18.0' #4 301.55' 71 cf 12.0" Round Pipe Storage -Impervious L= 90.0' S= 0.0100 '/' #5 304.10' 0 cf Surge (Prismatic) Listed below (Recalc) -Impervious 1,325 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 304.10 6 0 0 304.14 6 0 0 Device Routing Invert Outlet Devices #1 Discarded 299.85'72.000 in/hr Exfiltration over Wetted area Phase-In= 1.00' #2 Primary 304.10'30.0" x 30.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.34 cfs @ 12.06 hrs HW=302.91' (Free Discharge) 1=Exfiltration (Exfiltration Controls 1.34 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=299.85' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 61HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 2P: Infiltration - Chamber Wizard Infiltration field P2 Chamber Model = ADS_StormTech SC-800 +Cap (ADS StormTech® SC-800 with cap volume) Effective Size= 45.0"W x 33.0"H => 7.11 sf x 7.12'L = 50.6 cf Overall Size= 51.0"W x 33.0"H x 7.55'L with 0.43' Overlap Cap Storage= 3.4 cf x 2 x 3 rows = 20.5 cf 51.0" Wide + 6.0" Spacing = 57.0" C-C Row Spacing 4 Chambers/Row x 7.12' Long +0.88' Cap Length x 2 = 30.23' Row Length +12.0" End Stone x 2 = 32.23' Base Length 3 Rows x 51.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 15.75' Base Width 6.0" Stone Base + 33.0" Chamber Height + 12.0" Stone Cover = 4.25' Field Height 12 Chambers x 50.6 cf + 3.4 cf Cap Volume x 2 x 3 Rows = 627.6 cf Chamber Storage 2,157.6 cf Field - 627.6 cf Chambers = 1,530.0 cf Stone x 40.0% Voids = 612.0 cf Stone Storage Chamber Storage + Stone Storage = 1,239.6 cf = 0.028 af Overall Storage Efficiency = 57.5% Overall System Size = 32.23' x 15.75' x 4.25' 12 Chambers 79.9 cy Field 56.7 cy Stone Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 62HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 2P: Infiltration Inflow Outflow Discarded Primary Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 3 2 1 0 Inflow Area=0.312 ac Peak Elev=302.96' Storage=1,083 cf 2.70 cfs 1.34 cfs1.34 cfs 0.00 cfs Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 63HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Summary for Pond 3P: Infiltration Inflow Area = 0.702 ac, 78.82% Impervious, Inflow Depth = 4.66" for 100 yr event Inflow = 3.88 cfs @ 12.08 hrs, Volume= 0.272 af Outflow = 2.21 cfs @ 12.24 hrs, Volume= 0.272 af, Atten= 43%, Lag= 9.5 min Discarded = 2.21 cfs @ 12.24 hrs, Volume= 0.272 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach DP1 : Marion Ave Routing by Stor-Ind method, Time Span= 0.00-28.00 hrs, dt= 0.05 hrs Peak Elev= 304.98' @ 12.24 hrs Surf.Area= 0.014 ac Storage= 0.044 af Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 5.8 min ( 808.8 - 802.9 ) Volume Invert Avail.Storage Storage Description #1A 300.07' 0.021 af 22.75'W x 27.21'L x 5.50'H Infiltration Field 0.078 af Overall - 0.025 af Embedded = 0.053 af x 40.0% Voids #2A 300.82' 0.025 af ADS_StormTech MC-3500 d +Cap x 9 Inside #1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap 9 Chambers in 3 Rows Cap Storage= 14.9 cf x 2 x 3 rows = 89.4 cf #3 303.02' 0.001 af 12.0" Round Pipe Storage L= 68.0' S= 0.0050 '/' 0.047 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 300.07'72.000 in/hr Exfiltration over Wetted area Phase-In= 0.20' #2 Primary 305.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=2.20 cfs @ 12.24 hrs HW=304.96' (Free Discharge) 1=Exfiltration (Exfiltration Controls 2.20 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=300.07' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 64HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 3P: Infiltration - Chamber Wizard Infiltration Field Chamber Model = ADS_StormTech MC-3500 d +Cap (ADS StormTech® MC-3500 d rev 03/14 with Cap volume) Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= 14.9 cf x 2 x 3 rows = 89.4 cf 77.0" Wide + 9.0" Spacing = 86.0" C-C Row Spacing 3 Chambers/Row x 7.17' Long +1.85' Cap Length x 2 = 25.21' Row Length +12.0" End Stone x 2 = 27.21' Base Length 3 Rows x 77.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 22.75' Base Width 9.0" Stone Base + 45.0" Chamber Height + 12.0" Stone Cover = 5.50' Field Height 9 Chambers x 110.0 cf + 14.9 cf Cap Volume x 2 x 3 Rows = 1,079.0 cf Chamber Storage 3,404.7 cf Field - 1,079.0 cf Chambers = 2,325.7 cf Stone x 40.0% Voids = 930.3 cf Stone Storage Chamber Storage + Stone Storage = 2,009.2 cf = 0.046 af Overall Storage Efficiency = 59.0% Overall System Size = 27.21' x 22.75' x 5.50' 9 Chambers 126.1 cy Field 86.1 cy Stone Stewart's Shops - Marion Ave - Post Development Type II 24-hr 100 yr Rainfall=6.26"Marion Ave-Post Printed 1/5/2026Prepared by Stewart's Shops Corp Page 65HydroCAD® 10.20-6a s/n 08847 © 2024 HydroCAD Software Solutions LLC Pond 3P: Infiltration Inflow Outflow Discarded Primary Hydrograph Time (hours) 282726252423222120191817161514131211109876543210 Fl o w ( c f s ) 4 3 2 1 0 Inflow Area=0.702 ac Peak Elev=304.98' Storage=0.044 af 3.88 cfs 2.21 cfs2.21 cfs 0.00 cfs Exhibit D – Drainage Calculations D.1 Closed Drainage System Expected Flow Calculations ST O R M D R A I N A G E B y : Da t e : 1 / 6 / 2 0 2 6 Ma r i o n A v e Re v i s e d : PI P E L I N E D E S I G N E D F O R : 10 - Y E A R D R A I N A G E D E S I G N CA T C H M E N T A R E A S 1 - 5 == = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = == = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = F O R F O R F O R F O R F O R F O R F O R F O R F O R F O R F O R F O R F O R C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E EN T E R C A T C H B A S I N L I N E # ' s H E R E : CB # 1 - M H # 2 C B # 2 - M H # 2 M H # 2 - H D U H D U - S M P C B # 3 - M H # 6 C B # 4 - M H # 6 M H # 6 - O W S # 1 O W S # 1 - S M P == = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = == = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = AR E A LE N G T H ( f t . ) 75 5 0 4 4 4 8 2 2 4 3 4 Qa , R U N O F F ( c f s . ) 0. 3 9 1 . 4 8 1 . 8 6 1 . 8 6 0 . 5 5 0 . 6 7 1 . 2 1 1 . 5 9 D, P I P E D I A M E T E R ( i n . ) 12 1 2 1 2 1 2 1 2 1 2 1 2 1 2 A, P I P E A R E A ( s f . ) 0 . 7 8 5 0 . 7 8 5 0 . 7 8 5 0 . 7 8 5 0 . 7 8 5 0 . 7 8 5 0 . 7 8 5 0 . 7 8 5 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 n, F R I C T I O N A L P I P E V A L U E 0 . 0 1 2 0 . 0 1 2 0 . 0 1 2 0 . 0 1 2 0 . 0 1 2 0 . 0 1 2 0 . 0 1 2 0 . 0 1 0 0 . 0 1 2 0 . 0 1 2 0 . 0 1 0 0 . 0 1 2 0 . 0 1 2 s, P I P E S L O P E 0. 0 2 0 0 . 0 2 0 0 . 0 1 0 0 . 0 1 0 0 . 0 0 5 0 . 0 6 4 0 . 0 1 0 0 . 0 1 0 s^ 1 / 2 = 0 . 1 4 1 4 0 . 1 4 1 4 0 . 1 0 0 0 0 . 1 0 0 0 0 . 0 7 0 7 0 . 2 5 3 0 0 . 1 0 0 0 0 . 1 0 0 0 0 . 0 0 0 0 0 . 0 0 0 0 0 . 0 0 0 0 0 . 0 0 0 0 0 . 0 0 0 0 r, W E T T E D P E R I M E T E R ( f t . ) 0 . 2 5 0 . 2 5 0 . 2 5 0 . 2 5 0 . 2 5 0 . 2 5 0 . 2 5 0 . 2 5 0 0 0 0 0 r^ 2 / 3 = 0 . 3 9 7 0 . 3 9 7 0 . 3 9 7 0 . 3 9 7 0 . 3 9 7 0 . 3 9 7 0 . 3 9 7 0 . 3 9 7 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 Qc , P I P E C A P A C I T Y ( c f s . ) ( A ) ( 1 . 4 8 6 / n ) ( r ^ 2 / 3 ) ( s ^ 1 / 2 ) = 5 . 4 5 6 5 . 4 5 6 3 . 8 5 8 3 . 8 5 8 2 . 7 2 8 9 . 7 5 9 3 . 8 5 8 4 . 6 2 9 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 .. . . T H I S S I Z E P I P E I S A C C E P T A B L E 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 0 0 0 0 0 .. . . T H I S S I Z E P I P E H A S F A I L E D 0 0 0 0 0 0 0 0 0 0 0 0 0 PI P E V E L O C I T Y ( 1 . 4 8 6 / n ) ( r ^ 2 / 3 ) ( s ^ 1 / 2 ) = 6 . 9 5 0 6 . 9 5 0 4 . 9 1 4 4 . 9 1 4 3 . 4 7 5 1 2 . 4 3 2 4 . 9 1 4 5 . 8 9 7 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 S. K i t c h n e r ST O R M D R A I N A G E B y : Da t e : 1 / 6 / 2 0 2 6 Ma r i o n A v e Re v i s e d : PI P E L I N E D E S I G N E D F O R : 10 - Y E A R D R A I N A G E D E S I G N CA T C H M E N T A R E A S 6 - 9 == = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = == = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = F O R F O R F O R F O R F O R F O R F O R F O R F O R F O R F O R F O R F O R C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . C . B . L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E L I N E EN T E R C A T C H B A S I N L I N E # ' s H E R E : CB # 5 - M H # 8 M H # 8 - C B # 6 C B # 6 - M H # 9 M H # 9 - C B # 7 C B # 7 - O W S # 2 O W S # 2 - S M P C - D R A I N - M H # 1 2 M H # 1 2 - M H # 1 1 M H # 1 1 - S M P == = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = == = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = AR E A ( a c . ) 0. 2 1 9 0 . 2 1 9 0 . 3 4 4 0 . 3 4 4 0 . 6 4 0 0 . 6 4 0 0 . 0 6 2 0 . 0 6 2 0 . 0 6 LE N G T H ( f t . ) 74 4 0 7 5 5 4 5 4 1 0 5 2 3 0 Qa , R U N O F F ( c f s . ) 1. 1 3 1 . 1 3 1 . 7 8 1 . 7 8 2 . 1 6 2 . 1 6 0 . 0 4 0 . 0 4 0 . 0 4 D, P I P E D I A M E T E R ( i n . ) 12 1 2 1 2 1 2 1 2 1 2 8 1 2 1 2 A, P I P E A R E A ( s f . ) 0 . 7 8 5 0 . 7 8 5 0 . 7 8 5 0 . 7 8 5 0 . 7 8 5 0 . 7 8 5 0 . 3 4 9 0 . 7 8 5 0 . 7 8 5 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 n, F R I C T I O N A L P I P E V A L U E 0 . 0 1 2 0 . 0 1 2 0 . 0 1 2 0 . 0 1 2 0 . 0 1 2 0 . 0 1 2 0 . 0 1 2 0 . 0 1 0 0 . 0 1 2 0 . 0 1 2 0 . 0 1 0 0 . 0 1 2 0 . 0 1 2 s, P I P E S L O P E 0. 0 0 5 0 . 0 0 5 0 . 0 0 5 0 . 0 0 5 0 . 0 0 5 0 . 0 0 5 0 . 0 1 0 0 . 0 0 5 0 . 0 0 5 s^ 1 / 2 = 0 . 0 7 0 7 0 . 0 7 0 7 0 . 0 7 0 7 0 . 0 7 0 7 0 . 0 7 0 7 0 . 0 7 0 7 0 . 1 0 0 0 0 . 0 7 0 7 0 . 0 7 0 7 0 . 0 0 0 0 0 . 0 0 0 0 0 . 0 0 0 0 0 . 0 0 0 0 r, W E T T E D P E R I M E T E R ( f t . ) 0 . 2 5 0 . 2 5 0 . 2 5 0 . 2 5 0 . 2 5 0 . 2 5 0 . 1 6 6 6 6 6 6 6 7 0 . 2 5 0 . 2 5 0 0 0 0 r^ 2 / 3 = 0 . 3 9 7 0 . 3 9 7 0 . 3 9 7 0 . 3 9 7 0 . 3 9 7 0 . 3 9 7 0 . 3 0 3 0 . 3 9 7 0 . 3 9 7 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 Qc , P I P E C A P A C I T Y ( c f s . ) ( A ) ( 1 . 4 8 6 / n ) ( r ^ 2 / 3 ) ( s ^ 1 / 2 ) = 2 . 7 2 8 2 . 7 2 8 2 . 7 2 8 2 . 7 2 8 2 . 7 2 8 2 . 7 2 8 1 . 3 0 8 3 . 2 7 3 2 . 7 2 8 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 .. . . T H I S S I Z E P I P E I S A C C E P T A B L E 1 2 1 2 1 2 1 2 1 2 1 2 8 1 2 1 2 0 0 0 0 .. . . T H I S S I Z E P I P E H A S F A I L E D 0 0 0 0 0 0 0 0 0 0 0 0 0 PI P E V E L O C I T Y ( 1 . 4 8 6 / n ) ( r ^ 2 / 3 ) ( s ^ 1 / 2 ) = 3 . 4 7 5 3 . 4 7 5 3 . 4 7 5 3 . 4 7 5 3 . 4 7 5 3 . 4 7 5 3 . 7 5 0 4 . 1 7 0 3 . 4 7 5 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 S. K i t c h n e r Exhibit E – Maps E.1 Pre Development Subcatchments E.2 Post Development Subcatchments E.3 Catch Basin Subcatchments Exhibit F – Certifications F.1 Owner/Contractor Certifications OWNER AND CONTRACTOR’S/SUBCONTRACTOR’S CERTIFICATION Notice of Intent (NOI) Permitee and General Contractor and Subcontractors shall thoroughly read the Stormwater Pollution Prevention Plan (SWPPP). Each representative of his or her company shall fully understand, based upon their scope of work, that Erosion and Pollution Controls are required for this project and when their individual responsibilities are. The NOI Permitee, General Contractor and all Subcontractors shall sign the “logbook” listed below. If a Subcontractor wishes to NOT sign the logbook, the General Contractor is to obtain the name, company and phone number of this Subcontractor and list the information in the logbook. 1.1 NOI Permittee’s 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 (GP-0-20-001) for Stormwater Discharges from Construction Activity 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 referenced permit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceedings.” Print Name: Company Name: Signature: Company Address: Phone #: 1.2 General Site Contractor’s Contractor and Subcontractor’s 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 (GP-0-20-001) for Stormwater Discharges from Construction Activity 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 referenced permit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceedings.” General Site Contractor Print Name: Company Name: Signature: Company Address: Phone #: Each Subcontractor to the General Contractor (GC) or contractor responsible for site construction aspects shall list their company responsibility (e.g. Landscaper, Underground Utilities (water or sewer) Installer, Electric Service Installer, Gas Service Installer, Asphalt Pavement Installer, etc.) Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: For each Subcontractor listed, the affidavit statement in Section 1.2 of this document shall apply. Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: Subcontractor to the Site GC (list responsibility) Print Name: Company Name: Signature: Phone #: For each Subcontractor listed, the affidavit statement in Section 1.2 of this document shall apply. Exhibit G – NOI/NOT G.1 Notice of Intent G.2 Notice of Termination G.3 MS4 Acceptance Form G.4 SPDES General Permit GP-0-20-001 G.5 SWPPP Inspection Reports Construction General Permit (CGP) Electronic Notice of Intent (eNOI) GP-0-25-001 version 1.14 (Submission #: HQJ-J2JM-8PDH9, version 1) Details Originally Started By Ryan Rubado Alternate Identifier Stewart's Shops-Marion Ave-Shop #208—Region 5 Submission ID HQJ-J2JM-8PDH9 Status Draft Form Input Eligibility Disturbance Threshold Yes No No No 1. Will the construction activity involve soil disturbances listed in Part I.A.1 of GP-0- 25-001? 1.a. Will any runoff from the site enter a sewer system classified as a combined sewer? 1.b. Is this a remediation project being done under a Department approved work plan (i.e. CERCLA, RCRA, Voluntary Cleanup Agreement, etc.) with a SWPPP which meets the substantive requirements of GP-0-25-001? 1.c. Is the construction activity related to a stormwater discharge that does not require a permit as described in 40 CFR 122.3(e), e.g. non-point source agriculture or silviculture activities? Other SPDES Permits Yes Threatened and Endangered Species No State Historic Preservation Act (SHPA) Yes State Environmental Quality Review (SEQR) Yes Yes Uniform Procedures Act (UPA) Permits Yes Steep Slope 2. Will the discharge from the construction activity meet all conditions listed in Part I.A.2 of GP-0-25-001? 3. Will the construction activity potentially adversely affect a species that is endangered or threatened per Part I.A.3.? 4. Is the construction activity designated by the Commissioner of the Office of Parks, Recreation and Historic Preservation (OPRHP), pursuant to 9 NYCRR §§428.12 or 428.13 as exempt from the SHPA review (see Attachment 2 of the Letter of Resolution between NYSDEC and OPRHP, dated January 9, 2015)? 5. Is the construction activity subject to SEQR (Part I.A.5.), or the equivalent environmental review from another NYS or federal agency (Part I.A.6.)? 5.a. Has the owner/operator obtained documentation that the project review pursuant to SEQR, or the equivalent, has been satisfied per Part I.A.5. or I.A.6. of GP-0-25-001? 6. Has the owner/operator obtained all necessary UPA permits from NYSDEC, or the equivalent from another NYS or federal agency per Part I.A.7.a. of GP-0-25-001? Select "Yes" if no UPA permits, or the equivalent, are required for this construction activity. No Owner/Operator Information 8. Owner/Operator Name Stewart's Shops Corp. 9. Owner/Operator Contact Person Information First and Last Name Phone E-mail Ryan Rubado 518-581-1201 rrubado@stewartsshops.com 10. Owner/Operator Mailing Address PO Box 435 Saratoga Springs, NY 12866 USA No Corporation Yes 12.b.i. Department of State ID # 64420 The Department of State ID can be found using the following link: Department of State | Division of Corporations Site Information 13. Project/Site Name Stewart's Shops-Marion Ave-Shop #208 14. Site Address 33 Marion Ave Saratoga Springs, NY 12866 Saratoga 7. Is the construction activity within the watershed of surface waters of the State classified as AA or AA-S identified utilizing the Stormwater Interactive Map on NYSDEC’s website? 11. Is the billing contact different from the Owner/Operator Contact? 12. What type of organization is the owner/operator? 12.b. Is the owner/operator registered with the Department of State to do business in New York State? DEC Region 5 15. Site Latitude & Longitude 43.09334558180237,-73.77109645281503 Project Details A construction activity not part of a common plan of development or sale in accordance with Part I.D.1.a. Table 2 18. Consistent with Part III.B.1.c.i. of GP-0-25-001, provide a concise overview of the project. Describe existing and proposed conditions, and include any other relevant information. The project consists of razing the existing auto service station, fuel pumps & canopy, and car wash for redevelopment. The planned redivelopment consists of a new 4,500 sf convienence store with new fuel canopy and a 3,000 sf retail rental space. Enter the total project site acreage, the acreage to be disturbed, and the future impervious area (acreage) within the disturbed area, rounded to the nearest tenth of an acre. 19. Total Site Area (acres) 1.9 20. Total Area to be Disturbed (acres) 1.9 21. Existing Impervious Area to be Disturbed (acres) 1.6 22. Future Impervious Area Within Disturbed Area (acres) 1.3 Nature of the project: Redevelopment with no increase in impervious area No 16. This eNOI submission is for: 17. Does the project type fall under Table 1 or Table 2 of Appendix B of GP-0-25-001? If any portion of the construction activity falls under Table 2, regardless of the size of the disturbance, select "Table 2". 23. Do you plan to disturb more than 5 acres of soil at any one time? 24. Indicate the percentage (%) of each Hydrologic Soil Group(HSG) at the site. A (%) 100 B (%) 0 C (%) 0 D (%) 0 25. Enter the planned start and end dates of the disturbance activities. Start Date 08/31/2026 End Date 08/31/2027 26. Identify the nearest surface waterbody(ies) to which construction site runoff will discharge. Loughberry Lake - 1101-0068 Lake Off Site No No No Yes 31.a. What is the name of the municipality/entity that owns the separate storm sewer system? If the separate sewer system is owned by an MS4 Operator, enter the MS4 Operator name. NYSDOT 27. Type of waterbody identified in question 26? 28. Has the surface waterbody in question 26 been identified as a 303(d) segment in Appendix D of GP-0-25-001? 29. Is this project located in one of the Watersheds identified in Appendix C of GP-0- 25-001? 30. Will the project disturb soils within a State regulated wetland or the protected 100 foot adjacent area? 31. Does the site runoff enter a separate storm sewer system (including roadside drains, swales, ditches, culverts, etc)? No No Required SWPPP Components General SWPPP Requirements Yes Yes Yes Yes 2024 Yes SWPPP Preparer Professional Engineer (P.E.) 40. Name of the person who prepared the SWPPP Scott Kitchner 32. Will future use of this site be an agricultural property as defined by the NYS Agriculture and Markets Law? 33. Is this property owned by a state authority, state agency, federal government or local government? 34. Has a SWPPP been developed in conformance with the requirements in Part III. of GP-0-25-001? 35. Does the SWPPP demonstrate consideration of the future physical risks due to climate change pursuant to the CRRA, 6 NYCRR Part 490, and associated guidance per Part III.A.2. of GP-0-25-001? 36. 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)? 37. Has the post-construction stormwater management practice component of the SWPPP been developed in conformance with the NYS Stormwater Management Design Manual? 37.a. Which version of the NYS Stormwater Management Design Manual was used to develop the SWPPP? 38. Has the post-construction stormwater management practice component of the SWPPP been developed by a qualified professional per Part III.A.4.? 39. The Stormwater Pollution Prevention Plan (SWPPP) was prepared by: 41. SWPPP Preparer Organization Name Stewart's Shops Corp. 42. SWPPP Preparer Contact Information First and Last Name Phone E-mail Scott Kitchner 5185811201 skitchner@stewartsshops.com 43. SWPPP Preparer Address PO Box 435 Saratoga Springs, NY 12866 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) Upload the completed form Download SWPPP Preparer Certification Form 44. Please upload the SWPPP Preparer Certification 208-appf_swppcertform.pdf - 01/14/2026 02:45 PM Comment Yes Erosion & Sediment Control Criteria Yes Post-Construction Criteria Site Planning and Soil Restoration NONE PROVIDED 44.a. Has the SWPPP Preparer Certification Form been signed by the SWPPP preparer in accordance with Part VII.J of GP-0-25-001? 45. Has a construction sequence schedule for the planned management practices been prepared? Parking Reduction Preservation of Undisturbed Area Preservation of Buffers Reduction of Clearing and Grading Locating Development in Less Sensitive Areas 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). Water Quality Criteria No 49. Water Quality Sizing Criteria Total WQv required (acre-feet) Total RRv provided (acre-feet) Minimum RRv (acre- feet) Total WQv provided (acre-feet) Sum of RRv and WQv provided 0.041 .09 NaN Water Quantity Criteria Yes Operation and Maintenance Yes 53.a. Identify the entity responsible for the long-term Operation and Maintenance. Stewart's Shops Corp. Post-Construction SMP Identification 54. Post-Construction RR Techniques and Standard SMPs 46. Identify all site planning practices that were used to prepare the final site plan/layout for the project. 47. 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. 48. Is the reduction in impervious area greater than 25%? 50. Per Section 9.2.1.C.VI and VII of the 2024 Design Manual, is there 0% change to hydrology that increases the discharge rate and volume from the project site? 53. Has a long-term Operation and Maintenance Plan for the post-construction stormwater management practice(s) been developed? RR Techniques and SMPs Contributing Impervious Area (acres) Total Contributing Area (acres) Underground Infiltration System (I-4)1.010 55. Alternative SMPs Type of Alternative SMP Manufacturer of the Alternative SMP Name of the Alternative SMP Contributing Impervious Area (acres) Hydrodynamic Hyrdo International First Defense High Capacity 3HC .36 Other Permits None No MS4 SWPPP Acceptance Yes MS4 SWPPP Acceptance Form MS4 SWPPP Acceptance Form Download Download the MS4 SWPPP Acceptance Form from the link below. MS4 SWPPP Acceptance Form 60. MS4 Acceptance or No Jurisdiction Form Upload Comment Owner/Operator Certification 56. Identify other permits, existing and new, that are required for this project/facility. 57. Is this NOI for a change in owner/operator per Part I.G.? 59. Will the construction activities be within the municipal boundary(ies) of Traditional Land Use Control MS4 Operator(s) and discharge to the MS4(s)? 59.a. Which form is required per Part I.D.2.b.ii.? NONE PROVIDED NONE PROVIDED 60.a. Has the form been signed by the principal executive officer or ranking elected official—or duly authorized representative of that person—in accordance with Part VII.J. and submitted along with this NOI? NONE PROVIDED Owner/Operator Certification Form Download Download the Owner/Operator Certification Form by clicking the link below. Owner/Operator Certification Form 61. Upload Owner/Operator Certification Form 208-appj_operatorcertform.pdf - 01/15/2026 11:46 AM Comment Yes Additional Project Information 62. Enter any additional pertinent project information in the text box below. Attachments Date Attachment Name Context User 1/15/2026 11:46 AM 208-appj_operatorcertform.pdf Attachment Ryan Rubado 1/14/2026 2:45 PM 208-appf_swppcertform.pdf Attachment Ryan Rubado NONE PROVIDED 61.a. Has the Owner/Operator Certification Form from Appendix J been signed by the owner/operator, or a representative of the owner/operator in accordance with Part VII.J of GP-0-25-001 and uploaded to the eNOI? NONE PROVIDED New York State Department of Environmental Conservation Division of Water 625 Broadway, 4th Floor Albany, New York 12233-3505 *(NOTE: Submit completed form to address above)* NOTICE OF TERMINATION for Storm Water Discharges Authorized under the SPDES General Permit for Construction Activity Please indicate your permit identification number: NYR ___ ___ ___ ___ ___ ___ I. Owner or Operator Information 1. Owner/Operator Name: 2. Street Address: 3. City/State/Zip: 4. Contact Person: 4a.Telephone: 4b. Contact Person E-Mail: II. Project Site Information 5. Project/Site Name: 6. Street Address: 7. City/Zip: 8. County: III. Reason for Termination 9a. □ All disturbed areas have achieved final stabilization in accordance with the general permit and SWPPP. *Date final stabilization completed (month/year): 9b. □ Permit coverage has been transferred to new owner/operator. Indicate new owner/operator’s permit identification number: NYR ___ ___ ___ ___ ___ ___ (Note: Permit coverage can not be terminated by owner identified in I.1. above until new owner/operator obtains coverage under the general permit) 9c. □ Other (Explain on Page 2) IV. Final Site Information: 10a. Did this construction activity require the development of a SWPPP that includes post-construction stormwater management practices? □ yes □ no ( If no, go to question 10f.) 10b. Have all post-construction stormwater management practices included in the final SWPPP been constructed? □ yes □ no (If no, explain on Page 2) 10c. Identify the entity responsible for long-term operation and maintenance of practice(s)? Page 1 of 3 Saratoga Springs, NY 12866 Ryan Rubado 518-581-1201 x4260 Saratoga Springs, 12866 33 Marion Ave. rrubado@stewartsshops.com Stewart's Shops Corp. Saratoga Stewart's Shops-Marion Ave-Shop #208 PO Box 435 Stewart's Shops Corp. NOTICE OF TERMINATION for Storm Water Discharges Authorized under the SPDES General Permit for Construction Activity - continued 10d. Has the entity responsible for long-term operation and maintenance been given a copy of the operation and maintenance plan required by the general permit? □ yes □ no 10e. Indicate the method used to ensure long-term operation and maintenance of the post-construction stormwater management practice(s): □ Post-construction stormwater management practice(s) and any right-of-way(s) needed to maintain practice(s) have been deeded to the municipality. □ Executed maintenance agreement is in place with the municipality that will maintain the post-construction stormwater management practice(s). □ For post-construction stormwater management practices that are privately owned, a mechanism is 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. □ For post-construction stormwater management practices that are owned by a public or private institution (e.g. school, university or hospital), government agency or authority, or public utility; policy and procedures are in place that ensures operation and maintenance of the practice(s) in accordance with the operation and maintenance plan. 10f. Provide the total area of impervious surface (i.e. roof, pavement, concrete, gravel, etc.) constructed within the disturbance area? (acres) 11. Is this project subject to the requirements of a regulated, traditional land use control MS4? □ yes □ no (If Yes, complete section VI - “MS4 Acceptance” statement V. Additional Information/Explanation: (Use this section to answer questions 9c. and 10b., if applicable) VI. MS4 Acceptance - MS4 Official (principal executive officer or ranking elected official) or Duly Authorized Representative (Note: Not required when 9b. is checked -transfer of coverage) I have determined that it is acceptable for the owner or operator of the construction project identified in question 5 to submit the Notice of Termination at this time. Printed Name: Title/Position: Signature: Date: Page 2 of 3 1.3 NOTICE OF TERMINATION for Storm Water Discharges Authorized under the SPDES General Permit for Construction Activity - continued VII. Qualified Inspector Certification - Final Stabilization: I hereby certify that all disturbed areas have achieved final stabilization as defined in the current version of the general permit, and that all temporary, structural erosion and sediment control measures have been removed. 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 proceedings. Printed Name: Title/Position: Signature: Date: VIII. Qualified Inspector Certification - Post-construction Stormwater Management Practice(s): I hereby certify that all post-construction stormwater management practices have been constructed in conformance with the SWPPP. 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 proceedings. Printed Name: Title/Position: Signature: Date: IX. Owner or Operator Certification I hereby certify that this document was prepared by me or under my direction or supervision. My determination, based upon my inquiry of the person(s) who managed the construction activity, or those persons directly responsible for gathering the information, is that the information provided in this document is true, accurate and complete. 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 proceedings. Printed Name: Title/Position: Signature: Date: (NYS DEC Notice of Termination - January 2015) Page 3 of 3 Ryan Rubado Project Manager/Designer Ryan Rubado Project Manager/Designer Ryan Rubado Project Manager/Designer Stewart’s Shops, Corp. Routine Weekly Inspection Stormwater Pollution Prevention Plan Construction Inspection Form Page 1 of 3 Site Assessment / Inspection Report SWPPP Construction Activities Stewart’s Shops Corp. 33 Marion Ave. City of Saratoga Springs, Saratoga County, New York General Permit: GP-0-25-001 Permit ID: TBD Weather: Temperature: Date: Time: a.m. p.m. Soil Condition: Contractor: Observation Instructions: On a site map, indicate the extent of all disturbed areas and drainage pathways. Indicate site areas are expected to undergo initial disturbance or significant site work within the next 14-day period. Indicate on a site map all areas of the site that have undergone temporary or permanent stabilization. Indicate on a site map all areas that have not undergone active work during the previous 14-day period. Inspect all sediment control practices and record the approximate degree of sediment accumulation as a percentage of the sediment storage volume. Note if a substantial increase in turbidity in downstream water courses/bodies exist. Inspect all erosion and sediment control practices and record all maintenance requirements such as verifying the integrity of sediment control barriers or diversion systems (i.e. silt fence, diversion swales, earthen berms, etc.) and containment systems (i.e. sediment basins and sediment traps, etc.). Inspect all equipment, material handling or storage areas for evidence of apparent spills, leaks or deleterious materials. Stewart’s Shops, Corp. Routine Weekly Inspection Stormwater Pollution Prevention Plan Construction Inspection Form Page 2 of 3 Practice Condition Comments Stabilized Construction Entrance Good / Fair / Poor / N/A Temporary Parking Good / Fair / Poor / N/A Silt Fence Good / Fair / Poor / N/A Temporary Swales & Berms Good / Fair / Poor / N/A Check Dams (Stone) Good / Fair / Poor / N/A Slope Protection Good / Fair / Poor / N/A Dewatering Operations Good / Fair / Poor / N/A Sediment Traps Good / Fair / Poor / N/A Inlet Protection Good / Fair / Poor / N/A Mulching I Seeding Good / Fair / Poor / N/A Temporary Stockpiles Good / Fair / Poor / N/A Dust Control Good / Fair / Poor / N/A Sedimentation on Public Streets Good / Fair / Poor / N/A Less Than 5 Acres of Disturbance Good / Fair / Poor / N/A Other: Good / Fair / Poor / N/A Other: Good / Fair / Poor / N/A Non-conforming work item still outstanding (list item number): Inspection Notes: Inspectors Signature: Date: Inspectors Printed Name: SI T E M A P Exhibit H – Maintenance Checklist H.1 Maintenance Checklist Stormwater Practice Maintenance and Management Inspection Checklist Project: Location: Site Status: Date/Time: Inspector: Maintenance Item Satisfactory / Unsatisfactory Comments 1. Closed Drainage System (Annual) Condition of piping Excessive sediment accumulation Condition of drainage structures a. Cracks or displacement b. Minor spalling (<1”) c. Major spalling (rebar exposed) d. Joint failures e. Water tightness 2. Debris Cleanout (Monthly) Contributing areas clean of debris 3. Subsurface Stormwater Infiltration System (Annual or after 3” rainfall event within 24-hour period Initial Year/Semi-Annual (min.) Follow On Years) Excessive sediment accumulation a. Depth of sediment Condition of inlet/array pipes Evidence of clogging Accumulation of debris Condition of inspection ports 4. Hydrodynamic Separator (Tri-Annual Initial Year/Bi-Annual Follow On Years) Condition of concrete a. Cracks or displacement b. Minor spalling (<1”) c. Major spalling (rebar exposed) d. Joint failures e. Water tightness Excessive sediment accumulation Depth of floatables Hydrocarbons requiring removal Stewart's Shop-Marion Ave-Shop #208 33 Marion Ave, Saratoga Springs, NY 12866 Comments: ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ Actions to be Taken: ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________