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20230524 12 Ballston Chipotle Site Plan Narrative 2023 10 18
PROJECT NARRATIVE & STORMWATER REPORT For the Proposed: CHIPOTLE Located At: 12 Ballston Avenue Saratoga Springs, New York 12866 Prepared On: June 9, 2023 Revised On: October 16, 2023 Prepared By: 11 Vanderbilt Avenue, Suite 240 Norwood, Massachusetts 02062 T: (781) 352-8491 Prepared For: CollabDev 2 LLC 529 Main Street Boston, Massachusetts 02129 T: (781) 690-0275 Kevin Solli, P.E. NY 092156 Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 1 TABLE OF CONTENTS INTRODUCTION ........................................................................................................................................ 4 EXISTING CONDITIONS ........................................................................................................................... 4 PROJECT SITE ........................................................................................................................................ 4 SITE LOCATION ................................................................................................................................. 4 SITE CHARACTERISTICS ................................................................................................................. 4 REGULATED AREAS ............................................................................................................................ 4 FEMA FLOODPLAIN ......................................................................................................................... 4 ZONING ASSESSMENT ......................................................................................................................... 5 NC NEIGHBORHOOD CENTER (T-5) ZONING DISTRICT ........................................................... 5 PARKING REGULATIONS ................................................................................................................ 5 PROPOSED CONDITIONS ......................................................................................................................... 5 PROJECT DESCRIPTION ....................................................................................................................... 5 SITE ACCESS / EGRESS .................................................................................................................... 6 PARKING, LOADING & OPERATIONS ........................................................................................... 6 TRAFFIC IMPACT STATEMENT ......................................................................................................... 7 SITE UTILITIES ...................................................................................................................................... 7 WATER ................................................................................................................................................ 7 SANITARY .......................................................................................................................................... 7 ELECTRIC / CABLE / TELECOMMUNICATIONS ......................................................................... 8 GAS ...................................................................................................................................................... 8 SITE LANDSCAPING & LIGHTING ..................................................................................................... 8 STORMWATER MANAGEMENT & SOIL EROSION CONTROL ......................................................... 9 METHODOLOGY ................................................................................................................................... 9 HYDROLOGY ....................................................................................................................................... 10 EXISTING CONDITIONS ................................................................................................................. 10 PROPOSED CONDITIONS ............................................................................................................... 11 HYDROLOGIC CONCLUSIONS ..................................................................................................... 12 HYDRAULICS ....................................................................................................................................... 12 EXISTING CONDITIONS ................................................................................................................. 12 PROPOSED CONDITIONS ............................................................................................................... 12 HYDRAULIC CONCLUSIONS ........................................................................................................ 12 WATER QUALITY ................................................................................................................................ 13 Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 2 SOIL EROSION & SEDIMENT CONTROL ........................................................................................ 13 LIST OF TABLES & CALCULATIONS Table 1: Neighborhood Center (T-5) Zoning District Dimensional Requirements ....................................................... 5 Table 2: Sewer Design Flow .......................................................................................................................................... 7 Table 3: Rainfall Data .................................................................................................................................................... 9 Table 4: IDF Table ........................................................................................................................................................ 9 Table 5: Existing Drainage Areas ................................................................................................................................ 10 Table 6: Proposed Drainage Areas .............................................................................................................................. 11 Table 7: Peak Flow Comparison Table ........................................................................................................................ 12 Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 3 APPENDICES APPENDIX A: FIGURES Site Location Map (Figure 1) FEMA Flood Map (Figure 2) Soil Survey Map (Figure 3) Truck Turning Figure (Figure 4) APPENDIX B: SUPPORTING DOCUMENTS Property Card APPENDIX C: STORMWATER CALCULATIONS Hydrology Calculations (2-, 5-, 10-, 25-, 50-, 100-year storm events) NOAA Atlas Precipitation Data Watershed Model Schematic HydroCAD Reporting – Existing & Proposed Conditions Storm Sewer Calculations (10-year storm event) Proposed Storm Sewer System – Schematic, DOT Reporting, Profiles Best Management Practices WQS TSS Removal Calculations Water Quality Flow Calculations Hydrodynamic Separator Details APPENDIX D: DETAILED DESIGN PLANS Property Survey of 12 Ballston Avenue, Saratoga Springs, New York Prepared by Van Dusen & Steves Land Surveyors Existing Drainage Area Map (DA-1) Proposed Drainage Area Map (DA-2) Subcatchment Drainage Area Map (DA-3) For more information regarding the Design Plans, refer to the Permitting Plan Set, prepared by Solli Engineering, submitted in conjunction with this Report. APPENDIX E: LONG-TERM OPERATION & MAINTENANCE Long-Term Operation & Maintenance Manual Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 4 INTRODUCTION Solli Engineering (Solli) has prepared this Project Narrative & Stormwater Report (Report) to provide an analysis of the zoning regulations, the project’s stormwater management, utility design and coordination, soil erosion and sediment control measures, and subsurface conditions for the proposed Commercial Redevelopment located at 12 Ballston Avenue (Route 50) in the City of Saratoga Springs, New York (Site). The proposed redevelopment has been designed in compliance with the City of Saratoga Springs Zoning Ordinances, the City’s Stormwater Management Program Plan, dated August 2016, the 2015 New York State Stormwater Design Manual, the 2016 New York State Standards and Specifications for Erosion and Sediment Control, as well as all other applicable state and federal requirements and regulations. EXISTING CONDITIONS PROJECT SITE SITE LOCATION The Site consists of a 0.32-acre parcel situated at the corner of Ballston Avenue (Route 50) and Hamilton Street. The Site is located within the NC Neighborhood Center District (T-5) Zoning District of the City of Saratoga Springs. The Site is bound by Ballston Avenue (Route 50) to the north and west, Hamilton Street to the east, and a commercially developed property occupied by Saratoga Strike Zone Bowling Alley to the south. For more information regarding the Site location, refer to Appendix A, Figure 1 - Site Location Map. SITE CHARACTERISTICS The Site is currently improved with a vacant 2,703± square-foot building formerly occupied by Paddy Duggan’s Irish Pub. The Site is almost entirely developed and is improved with a building, areas of pavement, utilities, and areas of landscaping. Based on record mapping, the Site appears to have natural gas, water, and sewer services. The Site is accessed from a 31-foot curb cut off Ballston Avenue (Route 50). Currently, the Site is improved with approximately 13,447± square feet of impervious surfaces. The site currently drains to three discharge points; southwest to the Ballston Avenue drainage system, north to the Ballston Avenue drainage system, and southeast across Hamilton Street. Slopes on site range from approximately 1 percent to 33 percent, with a high elevation of approximately 320 feet near the western edge of the building and a low elevation of approximately 317 feet on the southwestern property edge. According to the United States Department of Agriculture Natural Resources Conservation Service, the entirety of the site in which the development is proposed is comprised of Windsor loamy sand, characterized as a hydrologic soil group rating of A. A breakdown of all the soils, located within the property limits, as well as the NRCS Soil Survey Map for the site, can be found in Appendix A, Figure 3. For more information regarding the existing conditions of the Site, refer to the Property Survey in Appendix D of this Report. REGULATED AREAS FEMA FLOODPLAIN According to FEMA Flood Insurance Rate Map, Map Number 36091C0433E, effective date August 16, 1995, the Site is within an area of minimal flood hazard, also known as Zone X, which indicates areas outside of the 0.2% annual chance floodplain: also known as the 500-year floodplain. The site is not within Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 5 a 100-year floodplain. For more information regarding the FEMA Floodplain Boundaries refer to Appendix A, Figure 2 – FEMA Flood Map. ZONING ASSESSMENT As shown on the City of Saratoga Springs Unified Development Ordinance Zoning Map (2023), the Site is located entirely within the NC Neighborhood Center District (T-5) Zoning District. The Site is bordered on the north, east, and south by properties zoned NC Neighborhood Center District (T-5) and to the west by a property zoned Urban Residential 4 (UR-4). NC NEIGHBORHOOD CENTER (T-5) ZONING DISTRICT The general purpose of the NC Neighborhood Center (T-5) Zoning District, in accordance with the City of Saratoga Springs Zoning Ordinances, is to accommodate a wide variety of residential and non-residential uses, building and frontage types and to provide quality streetscape amenities and civic spaces to enhance pedestrian activity. All developments within the T-5 Zoning District are required to comply with the dimensional standards set forth in Article 4.4 of the Saratoga Springs Zoning Ordinances; the T-5 dimensional standards are provided below: Table 1: NC Neighborhood Center (T-5) Zoning District Dimensional Standards Zoning District Min. Setback from Lot Line Abutting Public ROW Min. Build- Out Percentage Abutting any Public ROW Min. Side Setback Min. Rear Setback Min. Building Height Max. Building Height Max. Area of New & Existing Structures on One Lot T-5 0 ft to 12 ft build-to- zone 70% 0 ft 0 ft 24 ft 1.1 x Width of ROW or 50 ft, whichever is less 3,000 sf PARKING REGULATIONS According to Article 10.5, Required Off-Street Vehicles and Bicycle Parking Spaces, of the City of Saratoga Springs Unified Development Ordinance, eating & drinking establishments are required to provide one (1) parking space per 100 square feet of gross floor area (GFA). Perpendicular parking spaces shall be 9’ wide and 18’ long in accordance with Article 10.3. No loading spaces are required for commercial uses under 10,000 square feet according to Article 10.8. PROPOSED CONDITIONS PROJECT DESCRIPTION The Applicant, CollabDev 2 LLC, is proposing to demolish the existing 2,703± square foot building and construct a 2,344± square foot quick-service restaurant with twenty-three (23) parking spaces, located at 12 Ballston Avenue (Route 50) in Saratoga Springs, New York. The proposed project includes various site improvements, including associated parking, drives, drainage, utilities, landscaping, and lighting features to support the proposed use. As part of this project, a perpetual easement (totaling 3,134 SF) will be established on the property of 32 Ballston Avenue (M-B-L: 165.83-1-42 / Owner: Saratoga 16 LLC) and benefiting 12 Ballston Avenue. The purpose of this perpetual easement is to provide the necessary area to establish the parking spaces for the proposed Chipotle restaurant. The area currently located within the easement is comprised of a landscaped buffer between the properties as well as a portion of paved area used for an existing parking lot drive aisle at 32 Ballston Avenue. Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 6 ZONING COMPLIANCE The purposed redevelopment accommodates the City of Saratoga Springs Zoning Ordinances for the NC Neighborhood Center (T-5) Zoning District standards as listed in Table 1. The compliances to these standards are provided below: Table 2: NC Neighborhood Center (T-5) Zoning District Compliance Zoning District Min. Setback from Lot Line Abutting Public ROW Min. Build- Out Percentage Abutting any Public ROW Min. Side Setback Min. Rear Setback Min. Building Height Max. Building Height Max. Area of New & Existing Structures on One Lot T-5 0 ft to 12 ft build-to- zone 70% 0 ft 0 ft 24 ft 1.1 x Width of ROW or 50 ft, whichever is less 3,000 sf Proposed 12 ft build- to-zone on both ROW 34.7% (Ballston) (23.0% (Hamilton) 0 ft 50 ft 24 ft < 50 ft 2,344 sf SITE ACCESS / EGRESS The redevelopment proposes to modify the access and egress for the Site and improve the Site with a full- movement, 24-foot-wide driveway off Hamilton Street and maintain the full-movement 31-foot-wide driveway off Ballston Avenue (Route 50). The driveway off Hamilton Street is proposed to be located 170± feet to the south of the Ballston Avenue (Route 50) & Hamilton Street intersection. Traffic signage and painted markings are proposed throughout the site to improve traffic flow and vehicular safety. For more information pertaining to the Site’s access and egress, refer to the Site Layout Plan (Sheet 2.11) within the Permitting Plan Set, submitted in conjunction with this Report. PARKING, LOADING & OPERATIONS The project proposes to demolish the existing 2,703± square-foot building for a new 2,344± square foot quick-service restaurant. The proposed redevelopment will provide a total of twenty-three (23) passenger parking spaces, including one (1) ADA accessible parking space. The parking spaces have been designed in accordance with Chapter 6.2.6, Off-Street Parking Schedule, of the Saratoga Springs Zoning Ordinances and have been located to provide efficient and adequate access to the building’s entrances. The ADA accessible parking space has been designed in accordance with the US Access Board Accessibility Standards, and the space is proposed to be a width of 8-feet with an 8-foot-wide loading aisle. The project proposes a concrete dumpster pad and cedar enclosure (gray stain) to store the quick-service restaurant’s dumpster. The dumpster enclosure is proposed to be located mostly within the property expansion along the southern property line and a stainless steel wire trellis will be added to the outside face of dumpster enclosure to support flowering trumpet vine (campsis radicans) or similar alternate to grow up the sides of the enclosure and provide natural screening. For more information pertaining to the proposed parking and operations refer to the Site Layout Plan (Sheet 2.11) within the Permitting Plan Set, submitted in conjunction with this Report. Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 7 TRAFFIC IMPACT STATEMENT To evaluate the potential traffic impact of the proposed redevelopment, the potential trips to be generated by the proposed quick-service restaurant were estimated using data from the Institute of Transportation Engineers (ITE) Trip Generation, 11th Edition. The trip generation was calculated for the PM and Saturday peak hours. Based on the proposed use, it is anticipated that the proposed quick-service restaurant will generate 29 new roadway network trips (16 entering, 13 exiting) during the PM peak hour and 77 trips (42 entering, 35 exiting) during the Saturday midday peak hour. A detailed breakdown of the proposed trip generation is included in Appendix F of this Report. Based on existing traffic volume data along Ballston Avenue (Route 50) from TMC Traffic Data, there is a weekday PM peak hour volume of approximately 382 vehicles eastbound and 437 vehicles westbound and a Saturday midday peak hour volume of 442 vehicles eastbound and 350 vehicles westbound. The proposed development is expected to result in less than a 9% increase to traffic volumes along Ballston Avenue (Route 50) during the peak hours. Based on the number of trips estimated to be generated by the proposed development, it is anticipated that the new trips can be accommodated by the adjacent roadway network. SITE UTILITIES WATER The City of Saratoga Springs Utilities Group is the utility provider for water service in the City of Saratoga Springs. The proposed restaurant requires a 2-inch domestic water service per prototypical requirements. The Site has an existing domestic water service that is proposed to be abandoned in place. The restaurant’s water service is proposed off the existing lateral water main within Hamilton Street. Prior to construction the Site general contractor will coordinate with the utility provider to receive approval and confirmation of location, size, and adequate capacity of the proposed service. For more information pertaining to the proposed utility layout refer to the Utility Plan (Sheet 2.51) within the Permitting Plan Set, submitted in conjunction with this Report. SANITARY The City of Saratoga Springs Utilities Group is the utility provider for sanitary sewer service in the City of Saratoga Springs. The redevelopment proposes to tie into the municipal sewer system via a single discharge into the existing sewer manhole located to the southeast of the property within Hamilton Street. Based upon perspective tenant prototypical requirements, a 2,000-gallon grease interceptor has been proposed downstream of the kitchens sanitary discharge. The proposed redevelopment is expected to generate approximately 1,350 gallons of effluent per day based upon the rates provided in the New York State Design Standards for Intermediate Sized Wastewater Treatment Systems (March 5, 2014). Table 3: Sewer Flow Design Type of Establishment Total Seat Count Unit Gallons Per Day Per Unit* Total Gallons Per Day Fast-Casual Restaurant 54 Seats Per Seat 25 GPD 1,350 GPD Total 1,350 GPD Rates were taken from the Typical Per-Unit Hydraulic Loading Rates provided in the New York State Design Standards for Intermediate Sized Wastewater Treatment Systems (March 5, 2014). The proposed sanitary system will utilize gravity lines from the building’s Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 8 inverts to the proposed discharge point. The proposed sanitary system design will be submitted to the City of Saratoga Springs Engineering Department and Department of Public Work’s for review and approval prior to construction. For more information pertaining to the proposed utility layout refer to the Utility Plan (Sheet 2.51) within the Permitting Plan Set, submitted in conjunction with this Report. ELECTRIC / CABLE / TELECOMMUNICATIONS The Project proposes secondary electrical conduit to be fed underground from a proposed utility pole along the frontage of Hamilton Street assuming the utility provider will utilize an existing pole mounted transformer or install a new one for the redevelopment. The secondary electrical conduit will tie into the building in the prototypical locations for the perspective tenant. Prior to construction, detailed conduit plans will be designed in accordance with utility providers standards and requirements following approvals from the City of Saratoga Springs. The Project proposes cable and telecommunications to be fed underground from the proposed utility pole along Hamilton Street. The cable and telecommunications conduit will tie into the building in the prototypical locations for the perspective tenant. Prior to construction, detailed conduit plans will be designed in accordance with utility providers standards and requirements following approvals from the City of Saratoga Springs. For more information pertaining to the proposed utility layout refer to the Utility Plan (Sheet 2.51) within the Permitting Plan Set, submitted in conjunction with this Report. GAS The project proposes to utilize natural gas as a source of energy for the building. The project proposed gas service off an existing gas main that is located in Hamilton Street. An existing gas service is located on the property that enters the existing building along its eastern side. The project proposes to relocate the existing service. Prior to construction, detailed plans will be designed in accordance with utility providers standards and requirements as well as design recommendations regarding the existing service relocation following approvals from the City of Saratoga Springs. For more information pertaining to the proposed utility layout refer to the Utility Plan (Sheet 2.51) within the Permitting Plan Set, submitted in conjunction with this Report. SITE LANDSCAPING & LIGHTING A comprehensive landscape plan has been provided. The proposed landscaping improvements include a variety of native species containing trees, shrubs, ground cover, and seed mixes. The landscaping plan has been designed to provide vegetative screening surrounding the dumpster enclosures and provides as much shade within the proposed parking areas as possible. The landscape plan has been designed in compliance with the landscape regulations within the City of Saratoga Springs Unified Development Ordinance. The proposed Site Lighting Plan is comprised of pole mounted light fixtures and wall mounted building lights. The proposed wall mounted building lights and canopy lights are consistent with prototypical light fixtures for the restaurant. All fixtures area proposed to be LED and meet “dark sky” principles. The lighting plan has been designed to ensure the Site has adequate light levels within parking areas, sidewalks, pedestrian area, while also minimizing light spillage across the property lines. For more information pertaining to the landscape and lighting for the Site refer to the Planting Plan (Sheet 2.61), Planting Details (Sheet 2.62), and Lighting Plan (Sheet 2.71) within the Permitting Plan Set, submitted in conjunction with this Report. Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 9 STORMWATER MANAGEMENT & SOIL EROSION CONTROL The Stormwater Management & Soil Erosion Control section of this Report has been designed for the proposed commercial redevelopment at 12 Ballston Avenue (Route 50) in Saratoga Springs, New York. The proposed stormwater management has been designed to be in compliance with the City’s Stormwater Management Program Plan, dated August 2016, Article 17 – Stormwater Management of the City of Saratoga Springs Unified Development Ordinance, the New York State Stormwater Management Design Manual (January 2015) and the New York State Standards and Specifications for Erosion and Sediment Control Manual (November 2016). The commercial redevelopment is considered a “Redevelopment Activity” in accordance with Chapter 9 of The New York State Stormwater Design Manual and has been evaluated as such. The redevelopment of the Site will provide approximately 13,378± square feet of impervious area, a decrease in overall impervious surfaces compared to existing conditions. The proposed hydraulics have been designed to accommodate the 10-year storm event without surcharging the structure’s rim/grate. The proposed stormwater conveyance system has been designed with a catch basin with hooded outlet, a water quality unit, and an underground stormwater detention system. For more information regarding the stormwater management improvements refer to the Stormwater Management & Soil Erosion Control section of this Report. METHODOLOGY Stormwater runoff analysis, for both existing and proposed conditions, was performed using the software package HydroCAD. This software uses a computer implementation of the SCS / NRCS – TR-55 methodology to compute volumes and rates of runoff. The watershed area, rainfall depths and intensity, curve number, and time of concentration are factors that influence the computed results. Rainfall depths for the site were used for calculating the volumes and rates of runoff for this project. The depths were taken from the NOAA Atlas documents (Latitude: 43.0747º, Longitude: -73.7887º, approximate elevation of 318.29 ft) and the rainfall values are listed in Table 4 below. Table 4: Rainfall Data Return Period (Storm Event) 24-hr Rainfall Depth (inches) 2-year 2.66 5-year 3.28 10-year 3.79 25-year 4.49 50-year 5.02 100-year 5.57 HydroCAD automatically computes the rainfall intensity from its own IDF curves when the rainfall intensity data is provided. This information was taken from the NOAA Atlas documents (Latitude: 43.0747º, Longitude: -73.7887º, approximate elevation of 318.29 ft) and the rainfall values are listed in Table 5 below. Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 10 Table 5: IDF Table Intermediate Intensity Values (in/hr) Return Period (Storm Event) 5-Minute 15-Minute 30-Minute 60-Minute 2-year 4.18 2.32 1.60 1.02 5-year 5.36 2.98 2.04 1.30 10-year 6.34 3.52 2.42 1.54 25-year 7.68 4.27 2.93 1.86 50-year 8.70 4.83 3.32 2.11 100-year 9.77 5.43 3.72 2.36 SCS / NRCS uses the runoff curve number (CN) method to estimate runoff from storm rainfall. The major factors that determine CN are the watershed’s soil and cover conditions, cover type, treatment, and hydrologic condition. The higher percentage of impervious cover within a watershed will result in a higher curve number. A composite curve number was calculated for each analyzed watershed. Refer to Appendix C for the calculations used in determining the existing and proposed curve numbers for the individual drainage areas. The time of concentration is the time it takes for runoff to travel from the hydraulically most distant point of the watershed to a point of interest within the watershed. The time of concentration is calculated by adding the travel times of sheet flow, shallow concentrated flow, and open channel flow, or some combination of these depending on the watershed and its features. Refer to Appendix C for the calculations used in determining the existing and proposed time of concentrations for the individual drainage areas. HYDROLOGY EXISTING CONDITIONS A total of 0.39-acres were analyzed for stormwater management purposes. Based on existing drainage patterns, the 0.39-acre area was divided into three (3) contributing drainage areas, labeled Existing Drainage Area 1 (EDA-1), Existing Drainage Area 2 (EDA-2) and Existing Drainage Area 3 (EDA-3). EDA-1 has a contributing drainage area of approximately 0.20 acres. The area of EDA-1 includes the southwestern portion of the existing parking area for the existing building and landscaped area south of the parking area. The majority of the runoff from EDA-1 flows to the southwest off-site and is captured by an existing catch basin located approximately 250 feet from the southwest property corner in Ballston Avenue. EDA-2 has a contributing drainage area of approximately 0.11 acres. The area of EDA-2 includes the north and northwestern portion of the existing parking area for the existing building The majority of the runoff from EDA-2 flows to the northeast off-site and is captured by an existing drainage structure located at the corner of Ballston Avenue and Hamilton Street. EDA-3 has a contributing drainage area of approximately 0.08 acres. The area of EDA-3 includes the existing building and a portion of the area to the south and east of the building. The majority of the runoff from EDA-3 flows to the southeast and sheet flows off the property into Hamilton Street. Characteristics of these drainage areas are summarized in Table 6: Table 6: Existing Drainage Areas Drainage Area Label Drainage Area Curve Number Time of Concentration Existing Drainage Area 1 (EDA-1) 0.20 AC 83 6.00 Min. Existing Drainage Area 2 (EDA-2) 0.11 AC 98 6.00 Min. Existing Drainage Area 3 (EDA-3) 0.08 AC 91 6.00 Min. Total 0.39 AC - - Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 11 For more information regarding the existing drainage conditions of the Site refer to the Existing Drainage Area Map (DA-1) within Appendix D of this Report. PROPOSED CONDITIONS The redevelopment of the Site proposes a new drainage structure within a low spot of the proposed quick- service restaurant as well as a water quality unit and an underground detention system located on the northern portion of the Site. This drainage structures will discharge runoff into the three (3) open-bottom, concrete chambers before entering the existing drainage system that is located within Ballston Avenue (Route 50). Prior to discharging into the existing catch basin within Ballston Avenue (Route 50), the stormwater runoff will be conveyed through a proposed water quality unit that will provide treatment to the runoff. Similar to existing conditions, a total of 0.39 acres were analyzed for proposed conditions. Based on the proposed drainage patterns, the 0.39-acre area was divided into four (4) contributing drainage areas, labeled Proposed Drainage Area 1 (PDA-1), Proposed Drainage Area 2A (PDA-2A), Proposed Drainage Area 2B (PDA-2B), and Proposed Drainage Area 3 (PDA-3). PDA-1 has a contributing area of approximately 0.12 acres. This area encompasses the western portion of the proposed parking area. The majority of runoff from PDA-1 travels southwest off-site into an existing catch basin located within Ballston Avenue (Route 50), approximately 250 feet from the southwest property corner. PDA-2A has a contributing area of approximately 0.15 acres. This area encompasses the central portion of the parking area as well as the pervious/impervious area to the west of the proposed restaurant, and the restaurant roof area. Runoff from PDA-2A travels into the proposed drainage structures located in the parking area. From this point, the runoff passes through a water quality unit and the underground detention system before it eventually discharges to the existing catch basin located within Ballston Avenue (Route 50). PDA-2B has a contributing area of approximately 0.04 acres. This area encompasses the pervious/impervious area to the north and east of the proposed restaurant. Runoff from PDA-2B travels north overland and into the existing catch basin located within Ballston Avenue (Route 50). PDA-3 has a contributing area of approximately 0.08 acres, which includes the eastern portion of the parking area and the site driveway along Hamilton Street. The majority of the runoff from EDA-3 flows to the southeast and sheet flows off the property into Hamilton Street. Characteristics of these drainage areas are summarized in Table 7: Table 7: Proposed Drainage Areas Drainage Area Label Drainage Area Curve Number Time of Concentration Proposed Drainage Area 1 (PDA-1) 0.12 AC 78 6.00 Min. Proposed Drainage Area 2A (PDA-2A) 0.15 AC 94 6.00 Min. Proposed Drainage Area 2B (PDA-2B) 0.04 AC 54 6.00 Min. Proposed Drainage Area 3 (PDA-3) 0.08 AC 91 6.00 Min. Total 0.39 AC - - For more information regarding the existing drainage conditions of the Site refer to the Proposed Drainage Area Map (DA-2) within Appendix D of this Report. Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 12 HYDROLOGIC CONCLUSIONS In existing conditions, the Site has no stormwater drainage structures, water quality, or attenuation measures in place. The redevelopment proposes a decrease in impervious area compared to existing conditions, and the proposed stormwater management system includes the installation of one catch basin, water quality unit, and an underground detention system. The redevelopment results in decreased peak flows, in all storm events, compared to existing conditions. Refer to Table 8A, 8B, and 8C for more information. Table 8A: Peak Flow Comparison Table (DA-1) Peak Flow (cfs) Storm Event Total Drainage Areas Percent Reduction in Peak Flow EDA-1 PDA-1 2-Year 0.27 0.12 55.6% 5-Year 0.38 0.18 52.6% 10-Year 0.48 0.24 50.0% 25-Year 0.62 0.31 50.0% 50-Year 0.73 0.38 47.9% 100-Year 0.84 0.44 47.6% Table 8B: Peak Flow Comparison Table (DA-2) Peak Flow (cfs) Storm Event Total Drainage Areas Percent Reduction in Peak Flow EDA-2 PDA-2 2-Year 0.28 0.27 3.6% 5-Year 0.34 0.33 2.9% 10-Year 0.40 0.38 5.0% 25-Year 0.47 0.44 6.4% 50-Year 0.53 0.49 7.5% 100-Year 0.59 0.54 8.5% Table 8C: Peak Flow Comparison Table (DA-3) Peak Flow (cfs) Storm Event Total Drainage Areas Percent Reduction in Peak Flow EDA-3 PDA-3 2-Year 0.16 0.16 N/A 5-Year 0.21 0.21 N/A 10-Year 0.25 0.25 N/A 25-Year 0.31 0.31 N/A 50-Year 0.35 0.35 N/A 100-Year 0.40 0.40 N/A For more information regarding the hydrological analysis, refer to Appendix C. HYDRAULICS PROPOSED CONDITIONS The redevelopment of the Site proposes a new drainage structure within a low spot of the proposed quick- service restaurant. The catch basin will capture runoff from its respective drainage area and convey runoff into an existing catch basin that is located off-site within Ballston Avenue (Route 50). Prior to discharging into the existing catch basin within Ballston Avenue (Route 50), the stormwater runoff will be conveyed through a water quality unit that will provide treatment to the runoff and an underground detention system Proposed Redevelopment 12 Ballston Avenue (Route 50) Saratoga Springs, New York 12866 13 to attenuate peak flows from the Site. Improvements to the off-site drainage network are not proposed as part of this project. The stormwater management system proposes the installation of a subsurface system incorporating 3.0’ Retain-it chambers (Or approved equal). The chambers have a total height of 3.0’, with an additional 6” of stone bedding provided below the bottom of the chambers. The system has a total storage capacity of 568 cf. The system has been designed with an outlet riser that controls the rate of runoff. The outlet riser contains a 4” low-flow orifice at the bottom of stone elevation (312.30’) and 12” riser at an elevation of 313.85’. More information regarding the system can be found in the Permitting Plan Set (Sheet 2.21 & 3.03). The proposed hydraulics were sized and analyzed based upon the 10-year storm event in accordance with Chapter 4: Unified Stormwater Sizing Criteria within The New York State Stormwater Design Manual. The hydraulic analysis provided assumed “crown” flow conditions of the discharge pipe, located down gradient of the proposed water quality unit. This conservative approach was utilized due to the lack of information regarding the off-site stormwater management system. In conclusion, the proposed hydraulics satisfies the sizing criteria outlined in The New York State Stormwater Design Manual and the system does not surcharge any of the proposed structures rim or grate in the 10-year storm event. For more information refer to the Storm Sewer analysis provided in Appendix C. WATER QUALITY In existing conditions, the Site’s stormwater runoff discharges into the Ballston Avenue (Route 50) drainage network with no water quality structures or devices. In an effort to improve the quality of stormwater discharge associated with the proposed parking area, the Project has been designed with catch basins with 1-foot-deep sumps and hooded outlets and a water quality unit. The water quality treatment objective has been achieved using Option IV, Chapter 9 from the NYS Stormwater Management Design Manual: The plan proposes a combination of impervious cover (IC) reduction and standard or alternative SMPs that provide a weighted average of at least two of the above methods. The redevelopment currently reduces the existing impervious cover of the project area by approximately 9.1%. In addition, the proposed hydrodynamic separator will treat the water quality volume (WQV) associated with the first inch of rainfall for PDA-2A. The unit is sized to treat the water quality flow (WQF) which is the peak flow rate associated with the water quality volume of PDA-2A. Refer to Appendix C for more information related to Water Quality Volume and Water Quality Flow. SOIL EROSION & SEDIMENT CONTROL The proposed plans for soil erosion and sediment control prepared for this project have been developed in accordance with the City’s Stormwater Management Program Plan, dated August 2016, Article 17 – Stormwater Management of the City of Saratoga Springs Unified Development Ordinance, the 2015 New York State Stormwater Management Design Manual, and the New York State Standards and Specifications for Erosion and Sediment Control, prepared by the New York State Department of Environmental Conservation, dated July 2016. The soil erosion and sediment control measures that will be proposed as part of this project include geotextile silt fences, composite filter socks, construction entrance, concrete truck washout, dust control measures, and inlet protection for existing and proposed drainage features. The soil erosion and sediment control measures on site will be implemented in two (2) phases. Phase I measures are associated with the clearing, grubbing and demolition of the existing Site features. Phase II measures are associated with fine grading and installation of the building, hardscape and utilities on-site. For more information pertaining to the soil erosion and sediment control plans for the Site refer to Sheets 2.31 and 2.41 within the Permitting Plan Set, submitted in conjunction with this Report. APPENDICES Appendix A – Figures Appendix B – Supporting Documents Appendix C – Stormwater Calculations Appendix D – Detailed Design Plans Appendix E – Long-Term Operation & Maintenance Appendix A – Figures Figure 1 – Site Location Map Figure 2 – FEMA Flood Map Figure 3 – Soil Survey Map Figure 4 – Truck Turning Figure ENGINEERING 21206201Project #: Plan Date: Scale:12 BALLSTON AVENUE SARATOGA SPRINGS, NEW YORK Figure: 11 Vanderbilt Ave, Norwood, MA 02062 T: (781) 352-8491 F: (203) 880-9695 1,000 0 1,000 06/09/23 1" = 1,000' 500 SITE LOCATION MAP 1 PROJECT SITE NOTE: BASE MAP INFORMATION TAKEN FROM USGS SARATOGA SPRINGS, NEW YORK QUADRANGLE 7.5-MINUTE SERIES. NGA REF. NO. USGSX24K39968 ENGINEERING 21206201Project #: Plan Date: Scale:12 BALLSTON AVENUE SARATOGA SPRINGS, NEW YORK Figure: 11 Vanderbilt Ave, Norwood, MA 02062 T: (781) 352-8491 F: (203) 880-9695 1,000 0 1,000 06/09/23 1" = 1,000' 500 FEMA FLOOD MAP 2 PROJECT SITE NOTE: BASE MAP INFORMATION TAKEN FROM FEMA FLOOD INSURANCE RATE MAP, MAP NUMBER 36091C0433E, EFFECTIVE 08/16/1995. ENGINEERING 21206201Project #: Plan Date: Scale:12 BALLSTON AVENUE SARATOGA SPRINGS, NEW YORK Figure: 11 Vanderbilt Ave, Norwood, MA 02062 T: (781) 352-8491 F: (203) 880-9695 300 0 300 06/09/23 1" = 300' 150 SOIL SURVEY MAP 3 PROJECT SITE NOTE: BASE MAP RESOURCES TAKEN FROM THE NATURAL RESOURCES CONSERVATION SERVICE, URL: https://websoilsurvey.sc.egov.usda.gov. 2" Crabapple 2" Crabapp le 2" CrabapplePROPOSED2,344± SF31'32'74'BALLSTON AVENUE HA M I L T O N S T R E E T 2" Crabapple 2" Crabapple 2" CrabapplePROPOSED2,344± SF31'32'74'BALLSTON AVENUE HA M I L T O N S T R E E TENGINEERINGDrawn By:21206201Project #:Plan Date:Scale:SHEET #:Sheet Title:Rev. #:DateDescriptionProject:PROPOSED CHIPOTLE12 BALLSTON AVENUE (M-B-L: 165.83-1-3)SARATOGA SPRINGS, NEW YORKOWNER: SARATOGA PRIME PROPERTIES LLC / 215 BALLARD ROAD, WILTON NY 12831APPLICANT: COLLABDEV 2 LLC / 529 MAIN STREET,BOSTON, MA 02129Checked By:KMS501 Main Street, Monroe, CT 06468T: (203) 880-5455 F: (203) 880-969510/16/231" = 30'AWCFIG. 4TRUCK TURNINGFIGURE3003015TRASH TRUCK (DUMPSTER #1)TRASH TRUCK (DUMPSTER #2) Appendix B – Supporting Documents Property Record Card 6/27/23, 12:22 PM Printer Friendly Report - Image Mate Online https://saratoga.sdgnys.com/report.aspx?file=4115/vollocal\T000005/411501165083000100300000000001.JPG&swiscode=411501&printkey=1650830…1/2 LLC Saratoga Prime Properties 215 Ballard Rd Gansevoort NY 12831 Property Description Report For: 12 Ballston Ave, Municipality of City of Saratoga Springs, Inside Status:Active Roll Section:Taxable Swis:411501 Tax Map ID #:165.83-1-3 Property Class:485 - >1use sm bld Site:COM 1 In Ag. District:No Site Property Class:485 - >1use sm bld Zoning Code:C3 Neighborhood Code:15194 Total Acreage/Size:0.32 School District:Saratoga Springs Land Assessment:2023 - Tentative $306,000 2022 - $306,000 Total Assessment:2023 - Tentative $484,800 2022 - $484,800 Full Market Value:2023 - Tentative $932,308 2022 - $881,455 Equalization Rate: ----Property Desc:S-14 B-K L-1Pta Inside Deed Book:2015 Deed Page:7841 Grid East:682101 Grid North:1545968 Owners Sales No Sales Information Available Utilities Sewer Type:Comm/public Water Supply:Comm/public Utilities:Gas & elec Inventory Overall Eff Year Built:2000 Overall Condition:Normal Overall Grade:Average Overall Desirability:3 Buildings AC%Sprinkler%Alarm%Elevators Basement Type Year Built Eff Year Built Condition Quality Gross Floor Area (sqft)Stories 100 0 0 0 Unfinished 1962 2000 Normal Average 2538 1 6/27/23, 12:22 PM Printer Friendly Report - Image Mate Online https://saratoga.sdgnys.com/report.aspx?file=4115/vollocal\T000005/411501165083000100300000000001.JPG&swiscode=411501&printkey=1650830…2/2 Improvements Structure Size Grade Condition Year Pavng-asphlt 15000 × 4 Average Normal 1975 Porch-enclsd 36.00 sq ft Average Normal 1940 Special Districts for 2023 (Tentative) Description Units Percent Type Value SE010-County sewer dist #1 0 0%0 Special Districts for 2022 Description Units Percent Type Value SE010-County sewer dist #1 0 0%0 Exemptions Year Description Amount Exempt %Start Yr End Yr V Flag H Code Own % Taxes Year Description Amount 2023 County $5,151.91 2022 County $5,030.00 * Taxes reflect exemptions, but may not include recent changes in assessment. Appendix C – Stormwater Calculations Hydrology Calculations (2-, 10-, 25-, 50-, 100-year storm events) NOAA Atlas Precipitation Data Watershed Model Schematic HydroCAD Reporting – Existing & Proposed Conditions Hydraulic Calculations (10-year storm event) Storm Sewer Model Schematic & Reporting Hydraulic Profiles Best Management Practices TSS Removal Worksheets Water Quality Unit TSS Removal, Sizing & Details 11/17/22, 5:00 PM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=43.0747&lon=-73.7887&data=depth&units=english&series=pds 1/4 NOAA Atlas 14, Volume 10, Version 3 Location name: Saratoga Springs, New York, USA* Latitude: 43.0747°, Longitude: -73.7887° Elevation: 318.29 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Sandra Pavlovic, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Orlan Wilhite NOAA, National Weather Service, Silver Spring, Maryland PF_tabular | PF_graphical | Maps_&_aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 5-min 0.287 (0.222‑0.372) 0.348 (0.268‑0.451) 0.447 (0.343‑0.581) 0.528 (0.403‑0.690) 0.640 (0.475‑0.869) 0.725 (0.527‑1.00) 0.814 (0.576‑1.16) 0.915 (0.614‑1.33) 1.06 (0.685‑1.58) 1.18 (0.745‑1.79) 10-min 0.407 (0.314‑0.528) 0.493 (0.379‑0.639) 0.633 (0.485‑0.823) 0.748 (0.571‑0.977) 0.907 (0.672‑1.23) 1.03 (0.747‑1.42) 1.15 (0.816‑1.65) 1.30 (0.869‑1.88) 1.50 (0.971‑2.24) 1.67 (1.06‑2.54) 15-min 0.479 (0.369‑0.621) 0.580 (0.446‑0.752) 0.744 (0.571‑0.967) 0.880 (0.672‑1.15) 1.07 (0.791‑1.45) 1.21 (0.878‑1.67) 1.36 (0.960‑1.94) 1.52 (1.02‑2.21) 1.77 (1.14‑2.64) 1.96 (1.24‑2.98) 30-min 0.661 (0.509‑0.856) 0.798 (0.614‑1.03) 1.02 (0.785‑1.33) 1.21 (0.923‑1.58) 1.47 (1.09‑1.99) 1.66 (1.20‑2.29) 1.86 (1.32‑2.65) 2.09 (1.40‑3.03) 2.42 (1.56‑3.61) 2.69 (1.70‑4.08) 60-min 0.842 (0.649‑1.09) 1.02 (0.782‑1.32) 1.30 (0.999‑1.69) 1.54 (1.17‑2.01) 1.86 (1.38‑2.53) 2.11 (1.53‑2.91) 2.36 (1.67‑3.37) 2.65 (1.78‑3.85) 3.07 (1.99‑4.59) 3.41 (2.16‑5.18) 2-hr 1.07 (0.836‑1.38) 1.28 (0.998‑1.65) 1.62 (1.26‑2.09) 1.91 (1.47‑2.46) 2.30 (1.72‑3.08) 2.59 (1.90‑3.54) 2.90 (2.07‑4.09) 3.25 (2.20‑4.65) 3.76 (2.45‑5.55) 4.18 (2.67‑6.28) 3-hr 1.23 (0.965‑1.57) 1.46 (1.14‑1.86) 1.84 (1.43‑2.35) 2.15 (1.67‑2.76) 2.58 (1.94‑3.44) 2.90 (2.14‑3.94) 3.24 (2.33‑4.55) 3.63 (2.47‑5.17) 4.20 (2.75‑6.16) 4.68 (2.99‑6.97) 6-hr 1.54 (1.22‑1.94) 1.82 (1.44‑2.29) 2.26 (1.78‑2.85) 2.63 (2.06‑3.33) 3.13 (2.38‑4.13) 3.51 (2.62‑4.71) 3.91 (2.84‑5.43) 4.38 (3.00‑6.15) 5.06 (3.34‑7.32) 5.63 (3.63‑8.29) 12-hr 1.91 (1.53‑2.38) 2.23 (1.78‑2.78) 2.76 (2.19‑3.44) 3.19 (2.52‑4.00) 3.79 (2.91‑4.93) 4.24 (3.19‑5.62) 4.71 (3.44‑6.45) 5.26 (3.63‑7.30) 6.06 (4.02‑8.65) 6.72 (4.36‑9.77) 24-hr 2.29 (1.85‑2.81) 2.66 (2.15‑3.28) 3.28 (2.64‑4.05) 3.79 (3.03‑4.70) 4.49 (3.48‑5.77) 5.02 (3.80‑6.56) 5.57 (4.10‑7.52) 6.20 (4.32‑8.50) 7.11 (4.76‑10.0) 7.85 (5.13‑11.3) 2-day 2.65 (2.16‑3.22) 3.08 (2.51‑3.75) 3.79 (3.08‑4.62) 4.37 (3.53‑5.36) 5.18 (4.04‑6.57) 5.79 (4.42‑7.46) 6.42 (4.75‑8.53) 7.12 (5.00‑9.64) 8.12 (5.48‑11.3) 8.93 (5.88‑12.7) 3-day 2.90 (2.38‑3.50) 3.36 (2.75‑4.05) 4.11 (3.36‑4.97) 4.73 (3.84‑5.76) 5.59 (4.39‑7.03) 6.23 (4.79‑7.98) 6.91 (5.14‑9.11) 7.65 (5.40‑10.3) 8.70 (5.90‑12.0) 9.55 (6.31‑13.4) 4-day 3.11 (2.56‑3.73) 3.58 (2.95‑4.31) 4.37 (3.58‑5.26) 5.01 (4.09‑6.07) 5.90 (4.66‑7.39) 6.58 (5.07‑8.38) 7.28 (5.43‑9.54) 8.05 (5.70‑10.8) 9.14 (6.22‑12.6) 10.0 (6.64‑14.0) 7-day 3.68 (3.07‑4.38) 4.20 (3.49‑5.00) 5.04 (4.17‑6.02) 5.74 (4.72‑6.88) 6.70 (5.33‑8.30) 7.43 (5.77‑9.36) 8.18 (6.15‑10.6) 9.01 (6.42‑11.9) 10.2 (6.96‑13.8) 11.1 (7.41‑15.4) 10-day 4.27 (3.57‑5.05) 4.81 (4.02‑5.70) 5.70 (4.75‑6.76) 6.43 (5.32‑7.67) 7.44 (5.95‑9.16) 8.21 (6.41‑10.3) 9.00 (6.79‑11.6) 9.86 (7.07‑13.0) 11.1 (7.60‑14.9) 12.0 (8.03‑16.5) 20-day 6.14 (5.19‑7.17) 6.75 (5.70‑7.89) 7.74 (6.52‑9.08) 8.57 (7.17‑10.1) 9.71 (7.83‑11.7) 10.6 (8.32‑13.0) 11.5 (8.68‑14.4) 12.3 (8.93‑16.0) 13.5 (9.36‑18.0) 14.4 (9.69‑19.5) 30-day 7.72 (6.58‑8.96) 8.38 (7.13‑9.73) 9.46 (8.02‑11.0) 10.4 (8.72‑12.1) 11.6 (9.40‑13.9) 12.6 (9.92‑15.3) 13.5 (10.2‑16.8) 14.4 (10.5‑18.5) 15.5 (10.8‑20.5) 16.3 (11.0‑21.9) 45-day 9.70 (8.31‑11.2) 10.4 (8.92‑12.0) 11.6 (9.89‑13.4) 12.6 (10.7‑14.6) 13.9 (11.3‑16.5) 15.0 (11.9‑18.0) 16.0 (12.2‑19.7) 16.9 (12.4‑21.5) 18.0 (12.6‑23.5) 18.7 (12.7‑24.9) 60-day 11.3 (9.77‑13.0) 12.1 (10.4‑13.9) 13.4 (11.5‑15.4) 14.4 (12.3‑16.6) 15.9 (13.0‑18.7) 17.0 (13.6‑20.4) 18.1 (13.8‑22.1) 19.0 (14.0‑24.0) 20.1 (14.1‑26.1) 20.7 (14.2‑27.5) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical 11/17/22, 5:00 PM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=43.0747&lon=-73.7887&data=depth&units=english&series=pds 2/4 Back to Top Maps & aerials Small scale terrain 11/17/22, 5:00 PM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=43.0747&lon=-73.7887&data=depth&units=english&series=pds 3/4 Large scale terrain Large scale map Large scale aerial + – 3km 2mi + – 100km 60mi + – 100km 60mi 11/17/22, 5:00 PM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=43.0747&lon=-73.7887&data=depth&units=english&series=pds 4/4 Back to Top US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring, MD 20910 Questions?: HDSC.Questions@noaa.gov Disclaimer + – 100km 60mi 1S EDA-1 2S EDA-2 3S EDA-3 4S PDA-1 5S PDA-2A 6S PDA-3 8S PDA-2B 7P UGS 9L PDA-2 TOTAL Routing Diagram for 12 Ballston Avenue Hydrology Prepared by Solli Engineering, Printed 10/11/2023 HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Subcat Reach Pond Link Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 2HydroCAD® 10.20-3f s/n 13171 © 2023 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=0.200 ac 75.00% Impervious Runoff Depth>1.18"Subcatchment 1S: EDA-1 Tc=6.0 min CN=83 Runoff=0.27 cfs 0.020 af Runoff Area=0.110 ac 100.00% Impervious Runoff Depth>2.43"Subcatchment 2S: EDA-2 Tc=6.0 min CN=98 Runoff=0.28 cfs 0.022 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>1.76"Subcatchment 3S: EDA-3 Tc=6.0 min CN=91 Runoff=0.16 cfs 0.012 af Runoff Area=0.120 ac 66.67% Impervious Runoff Depth>0.89"Subcatchment 4S: PDA-1 Tc=6.0 min CN=78 Runoff=0.12 cfs 0.009 af Runoff Area=0.150 ac 93.33% Impervious Runoff Depth>2.02"Subcatchment 5S: PDA-2A Tc=6.0 min CN=94 Runoff=0.34 cfs 0.025 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>1.76"Subcatchment 6S: PDA-3 Tc=6.0 min CN=91 Runoff=0.16 cfs 0.012 af Runoff Area=0.040 ac 25.00% Impervious Runoff Depth>0.10"Subcatchment 8S: PDA-2B Tc=6.0 min CN=54 Runoff=0.00 cfs 0.000 af Peak Elev=312.89' Storage=0.001 af Inflow=0.34 cfs 0.025 afPond 7P: UGS Outflow=0.27 cfs 0.025 af Inflow=0.27 cfs 0.026 afLink 9L: PDA-2 TOTAL Primary=0.27 cfs 0.026 af Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 3HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: EDA-1 Runoff = 0.27 cfs @ 12.10 hrs, Volume= 0.020 af, Depth> 1.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=2.66" Area (ac) CN Description 0.150 98 Paved parking, HSG A 0.050 39 >75% Grass cover, Good, HSG A 0.200 83 Weighted Average 0.050 25.00% Pervious Area 0.150 75.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 1S: EDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 2-yr Rainfall=2.66" Runoff Area=0.200 ac Runoff Volume=0.020 af Runoff Depth>1.18" Tc=6.0 min CN=83 0.27 cfs Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 4HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: EDA-2 Runoff = 0.28 cfs @ 12.09 hrs, Volume= 0.022 af, Depth> 2.43" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=2.66" Area (ac) CN Description 0.110 98 Paved parking, HSG A 0.110 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 2S: EDA-2 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 2-yr Rainfall=2.66" Runoff Area=0.110 ac Runoff Volume=0.022 af Runoff Depth>2.43" Tc=6.0 min CN=98 0.28 cfs Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 5HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: EDA-3 Runoff = 0.16 cfs @ 12.09 hrs, Volume= 0.012 af, Depth> 1.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=2.66" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 3S: EDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 2-yr Rainfall=2.66" Runoff Area=0.080 ac Runoff Volume=0.012 af Runoff Depth>1.76" Tc=6.0 min CN=91 0.16 cfs Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 6HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: PDA-1 Runoff = 0.12 cfs @ 12.10 hrs, Volume= 0.009 af, Depth> 0.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=2.66" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.040 39 >75% Grass cover, Good, HSG A 0.120 78 Weighted Average 0.040 33.33% Pervious Area 0.080 66.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 4S: PDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.13 0.125 0.12 0.115 0.11 0.105 0.1 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 III 24-hr 2-yr Rainfall=2.66" Runoff Area=0.120 ac Runoff Volume=0.009 af Runoff Depth>0.89" Tc=6.0 min CN=78 0.12 cfs Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 7HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PDA-2A Runoff = 0.34 cfs @ 12.09 hrs, Volume= 0.025 af, Depth> 2.02" Routed to Pond 7P : UGS Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=2.66" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.150 94 Weighted Average 0.010 6.67% Pervious Area 0.140 93.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, ab Subcatchment 5S: PDA-2A Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 2-yr Rainfall=2.66" Runoff Area=0.150 ac Runoff Volume=0.025 af Runoff Depth>2.02" Tc=6.0 min CN=94 0.34 cfs Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 8HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: PDA-3 Runoff = 0.16 cfs @ 12.09 hrs, Volume= 0.012 af, Depth> 1.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=2.66" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 6S: PDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 2-yr Rainfall=2.66" Runoff Area=0.080 ac Runoff Volume=0.012 af Runoff Depth>1.76" Tc=6.0 min CN=91 0.16 cfs Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 9HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: PDA-2B Runoff = 0.00 cfs @ 12.50 hrs, Volume= 0.000 af, Depth> 0.10" Routed to Link 9L : PDA-2 TOTAL Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=2.66" Area (ac) CN Description 0.010 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.040 54 Weighted Average 0.030 75.00% Pervious Area 0.010 25.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 8S: PDA-2B Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0 0 0 Type III 24-hr 2-yr Rainfall=2.66" Runoff Area=0.040 ac Runoff Volume=0.000 af Runoff Depth>0.10" Tc=6.0 min CN=54 0.00 cfs Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 10HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Pond 7P: UGS Inflow Area = 0.150 ac, 93.33% Impervious, Inflow Depth > 2.02" for 2-yr event Inflow = 0.34 cfs @ 12.09 hrs, Volume= 0.025 af Outflow = 0.27 cfs @ 12.15 hrs, Volume= 0.025 af, Atten= 19%, Lag= 3.6 min Primary = 0.27 cfs @ 12.15 hrs, Volume= 0.025 af Routed to Link 9L : PDA-2 TOTAL Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 312.89' @ 12.15 hrs Surf.Area= 0.005 ac Storage= 0.001 af Plug-Flow detention time= 6.2 min calculated for 0.025 af (100% of inflow) Center-of-Mass det. time= 4.5 min ( 797.4 - 792.9 ) Volume Invert Avail.Storage Storage Description #1A 312.30' 0.002 af 9.00'W x 25.00'L x 4.17'H Field A 0.022 af Overall - 0.016 af Embedded = 0.005 af x 40.0% Voids #2A 312.80' 0.011 af retain_it retain_it 3.0' x 3 Inside #1 Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 0.013 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 311.30'12.0" Round Culvert L= 18.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 311.30' / 310.94' S= 0.0200 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 312.30'4.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 313.85'12.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.27 cfs @ 12.15 hrs HW=312.89' (Free Discharge) 1=Culvert (Passes 0.27 cfs of 3.12 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.27 cfs @ 3.14 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 11HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS - Chamber Wizard Field A Chamber Model = retain_it retain_it 3.0' (retain-it®) Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 3 Chambers/Row x 8.00' Long = 24.00' Row Length +6.0" End Stone x 2 = 25.00' Base Length 1 Rows x 96.0" Wide + 6.0" Side Stone x 2 = 9.00' Base Width 6.0" Stone Base + 44.0" Chamber Height = 4.17' Field Height 4.7 cf Sidewall x 3 x 2 + 4.7 cf Endwall x 1 x 2 = 37.8 cf Perimeter Wall 3 Chambers x 170.6 cf - 37.8 cf Perimeter wall = 474.1 cf Chamber Storage 3 Chambers x 234.7 cf = 704.0 cf Displacement 937.5 cf Field - 704.0 cf Chambers = 233.5 cf Stone x 40.0% Voids = 93.4 cf Stone Storage Chamber Storage + Stone Storage = 567.5 cf = 0.013 af Overall Storage Efficiency = 60.5% Overall System Size = 25.00' x 9.00' x 4.17' 3 Chambers 34.7 cy Field 8.6 cy Stone Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 12HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.150 ac Peak Elev=312.89' Storage=0.001 af 0.34 cfs 0.27 cfs Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 13HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Discharge for Pond 7P: UGS Elevation (feet) Primary (cfs) 312.30 0.00 312.32 0.00 312.34 0.00 312.36 0.01 312.38 0.02 312.40 0.02 312.42 0.03 312.44 0.04 312.46 0.06 312.48 0.07 312.50 0.08 312.52 0.10 312.54 0.11 312.56 0.13 312.58 0.14 312.60 0.15 312.62 0.17 312.64 0.17 312.66 0.18 312.68 0.19 312.70 0.20 312.72 0.21 312.74 0.22 312.76 0.23 312.78 0.24 312.80 0.24 312.82 0.25 312.84 0.26 312.86 0.26 312.88 0.27 312.90 0.28 312.92 0.28 312.94 0.29 312.96 0.30 312.98 0.30 313.00 0.31 313.02 0.31 313.04 0.32 313.06 0.32 313.08 0.33 313.10 0.33 313.12 0.34 313.14 0.34 313.16 0.35 313.18 0.35 313.20 0.36 313.22 0.36 313.24 0.37 313.26 0.37 313.28 0.38 313.30 0.38 313.32 0.39 313.34 0.39 Elevation (feet) Primary (cfs) 313.36 0.40 313.38 0.40 313.40 0.41 313.42 0.41 313.44 0.41 313.46 0.42 313.48 0.42 313.50 0.43 313.52 0.43 313.54 0.44 313.56 0.44 313.58 0.44 313.60 0.45 313.62 0.45 313.64 0.46 313.66 0.46 313.68 0.46 313.70 0.47 313.72 0.47 313.74 0.47 313.76 0.48 313.78 0.48 313.80 0.49 313.82 0.49 313.84 0.49 313.86 0.50 313.88 0.50 313.90 0.51 313.92 0.53 313.94 0.55 313.96 0.57 313.98 0.59 314.00 0.62 314.02 0.65 314.04 0.68 314.06 0.72 314.08 0.76 314.10 0.80 314.12 0.84 314.14 0.89 314.16 0.94 314.18 0.99 314.20 1.05 314.22 1.10 314.24 1.16 314.26 1.22 314.28 1.29 314.30 1.35 314.32 1.42 314.34 1.49 314.36 1.56 314.38 1.63 314.40 1.70 Elevation (feet) Primary (cfs) 314.42 1.78 314.44 1.85 314.46 1.93 314.48 2.00 314.50 2.08 314.52 2.16 314.54 2.24 314.56 2.32 314.58 2.40 314.60 2.48 314.62 2.56 314.64 2.63 314.66 2.71 314.68 2.79 314.70 2.86 314.72 2.93 314.74 3.01 314.76 3.07 314.78 3.14 314.80 3.20 314.82 3.26 314.84 3.30 314.86 3.35 314.88 3.41 314.90 3.46 314.92 3.51 314.94 3.57 314.96 3.62 314.98 3.67 315.00 3.72 315.02 3.77 315.04 3.82 315.06 3.86 315.08 3.91 315.10 3.96 315.12 4.00 315.14 4.05 315.16 4.09 315.18 4.14 315.20 4.18 315.22 4.22 315.24 4.27 315.26 4.31 315.28 4.35 315.30 4.39 315.32 4.43 315.34 4.47 315.36 4.52 315.38 4.56 315.40 4.59 315.42 4.63 315.44 4.67 315.46 4.71 Elevation (feet) Primary (cfs) 315.48 4.75 315.50 4.79 315.52 4.82 315.54 4.86 315.56 4.90 315.58 4.94 315.60 4.97 315.62 5.01 315.64 5.04 315.66 5.08 315.68 5.11 315.70 5.15 315.72 5.18 315.74 5.22 315.76 5.25 315.78 5.29 315.80 5.32 315.82 5.35 315.84 5.39 315.86 5.42 315.88 5.45 315.90 5.49 315.92 5.52 315.94 5.55 315.96 5.58 315.98 5.62 316.00 5.65 316.02 5.68 316.04 5.71 316.06 5.74 316.08 5.77 316.10 5.80 316.12 5.83 316.14 5.86 316.16 5.90 316.18 5.93 316.20 5.96 316.22 5.99 316.24 6.02 316.26 6.04 316.28 6.07 316.30 6.10 316.32 6.13 316.34 6.16 316.36 6.19 316.38 6.22 316.40 6.25 316.42 6.28 316.44 6.30 316.46 6.33 Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 14HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 7P: UGS Elevation (feet) Storage (acre-feet) 312.30 0.000 312.35 0.000 312.40 0.000 312.45 0.000 312.50 0.000 312.55 0.001 312.60 0.001 312.65 0.001 312.70 0.001 312.75 0.001 312.80 0.001 312.85 0.001 312.90 0.001 312.95 0.002 313.00 0.002 313.05 0.002 313.10 0.002 313.15 0.002 313.20 0.003 313.25 0.003 313.30 0.003 313.35 0.003 313.40 0.003 313.45 0.004 313.50 0.004 313.55 0.004 313.60 0.004 313.65 0.004 313.70 0.005 313.75 0.005 313.80 0.005 313.85 0.005 313.90 0.005 313.95 0.006 314.00 0.006 314.05 0.006 314.10 0.006 314.15 0.006 314.20 0.007 314.25 0.007 314.30 0.007 314.35 0.007 314.40 0.007 314.45 0.008 314.50 0.008 314.55 0.008 314.60 0.008 314.65 0.008 314.70 0.009 314.75 0.009 314.80 0.009 314.85 0.009 314.90 0.009 Elevation (feet) Storage (acre-feet) 314.95 0.009 315.00 0.010 315.05 0.010 315.10 0.010 315.15 0.010 315.20 0.010 315.25 0.011 315.30 0.011 315.35 0.011 315.40 0.011 315.45 0.011 315.50 0.012 315.55 0.012 315.60 0.012 315.65 0.012 315.70 0.012 315.75 0.013 315.80 0.013 315.85 0.013 315.90 0.013 315.95 0.013 316.00 0.013 316.05 0.013 316.10 0.013 316.15 0.013 316.20 0.013 316.25 0.013 316.30 0.013 316.35 0.013 316.40 0.013 316.45 0.013 Type III 24-hr 2-yr Rainfall=2.66"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 15HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Link 9L: PDA-2 TOTAL Inflow Area = 0.190 ac, 78.95% Impervious, Inflow Depth > 1.61" for 2-yr event Inflow = 0.27 cfs @ 12.15 hrs, Volume= 0.026 af Primary = 0.27 cfs @ 12.15 hrs, Volume= 0.026 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 9L: PDA-2 TOTAL Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.190 ac 0.27 cfs0.27 cfs Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 16HydroCAD® 10.20-3f s/n 13171 © 2023 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=0.200 ac 75.00% Impervious Runoff Depth>1.67"Subcatchment 1S: EDA-1 Tc=6.0 min CN=83 Runoff=0.38 cfs 0.028 af Runoff Area=0.110 ac 100.00% Impervious Runoff Depth>3.05"Subcatchment 2S: EDA-2 Tc=6.0 min CN=98 Runoff=0.34 cfs 0.028 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>2.33"Subcatchment 3S: EDA-3 Tc=6.0 min CN=91 Runoff=0.21 cfs 0.016 af Runoff Area=0.120 ac 66.67% Impervious Runoff Depth>1.33"Subcatchment 4S: PDA-1 Tc=6.0 min CN=78 Runoff=0.18 cfs 0.013 af Runoff Area=0.150 ac 93.33% Impervious Runoff Depth>2.62"Subcatchment 5S: PDA-2A Tc=6.0 min CN=94 Runoff=0.43 cfs 0.033 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>2.33"Subcatchment 6S: PDA-3 Tc=6.0 min CN=91 Runoff=0.21 cfs 0.016 af Runoff Area=0.040 ac 25.00% Impervious Runoff Depth>0.25"Subcatchment 8S: PDA-2B Tc=6.0 min CN=54 Runoff=0.00 cfs 0.001 af Peak Elev=313.07' Storage=0.002 af Inflow=0.43 cfs 0.033 afPond 7P: UGS Outflow=0.33 cfs 0.033 af Inflow=0.33 cfs 0.033 afLink 9L: PDA-2 TOTAL Primary=0.33 cfs 0.033 af Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 17HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: EDA-1 Runoff = 0.38 cfs @ 12.09 hrs, Volume= 0.028 af, Depth> 1.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 5-yr Rainfall=3.28" Area (ac) CN Description 0.150 98 Paved parking, HSG A 0.050 39 >75% Grass cover, Good, HSG A 0.200 83 Weighted Average 0.050 25.00% Pervious Area 0.150 75.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 1S: EDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 5-yr Rainfall=3.28" Runoff Area=0.200 ac Runoff Volume=0.028 af Runoff Depth>1.67" Tc=6.0 min CN=83 0.38 cfs Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 18HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: EDA-2 Runoff = 0.34 cfs @ 12.09 hrs, Volume= 0.028 af, Depth> 3.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 5-yr Rainfall=3.28" Area (ac) CN Description 0.110 98 Paved parking, HSG A 0.110 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 2S: EDA-2 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 5-yr Rainfall=3.28" Runoff Area=0.110 ac Runoff Volume=0.028 af Runoff Depth>3.05" Tc=6.0 min CN=98 0.34 cfs Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 19HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: EDA-3 Runoff = 0.21 cfs @ 12.09 hrs, Volume= 0.016 af, Depth> 2.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 5-yr Rainfall=3.28" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 3S: EDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 5-yr Rainfall=3.28" Runoff Area=0.080 ac Runoff Volume=0.016 af Runoff Depth>2.33" Tc=6.0 min CN=91 0.21 cfs Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 20HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: PDA-1 Runoff = 0.18 cfs @ 12.10 hrs, Volume= 0.013 af, Depth> 1.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 5-yr Rainfall=3.28" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.040 39 >75% Grass cover, Good, HSG A 0.120 78 Weighted Average 0.040 33.33% Pervious Area 0.080 66.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 4S: PDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 5-yr Rainfall=3.28" Runoff Area=0.120 ac Runoff Volume=0.013 af Runoff Depth>1.33" Tc=6.0 min CN=78 0.18 cfs Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 21HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PDA-2A Runoff = 0.43 cfs @ 12.09 hrs, Volume= 0.033 af, Depth> 2.62" Routed to Pond 7P : UGS Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 5-yr Rainfall=3.28" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.150 94 Weighted Average 0.010 6.67% Pervious Area 0.140 93.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, ab Subcatchment 5S: PDA-2A Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.48 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 III 24-hr 5-yr Rainfall=3.28" Runoff Area=0.150 ac Runoff Volume=0.033 af Runoff Depth>2.62" Tc=6.0 min CN=94 0.43 cfs Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 22HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: PDA-3 Runoff = 0.21 cfs @ 12.09 hrs, Volume= 0.016 af, Depth> 2.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 5-yr Rainfall=3.28" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 6S: PDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 5-yr Rainfall=3.28" Runoff Area=0.080 ac Runoff Volume=0.016 af Runoff Depth>2.33" Tc=6.0 min CN=91 0.21 cfs Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 23HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: PDA-2B Runoff = 0.00 cfs @ 12.34 hrs, Volume= 0.001 af, Depth> 0.25" Routed to Link 9L : PDA-2 TOTAL Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 5-yr Rainfall=3.28" Area (ac) CN Description 0.010 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.040 54 Weighted Average 0.030 75.00% Pervious Area 0.010 25.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 8S: PDA-2B Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.004 0.004 0.004 0.004 0.004 0.003 0.003 0.003 0.003 0.003 0.002 0.002 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0 Type III 24-hr 5-yr Rainfall=3.28" Runoff Area=0.040 ac Runoff Volume=0.001 af Runoff Depth>0.25" Tc=6.0 min CN=54 0.00 cfs Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 24HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Pond 7P: UGS Inflow Area = 0.150 ac, 93.33% Impervious, Inflow Depth > 2.62" for 5-yr event Inflow = 0.43 cfs @ 12.09 hrs, Volume= 0.033 af Outflow = 0.33 cfs @ 12.16 hrs, Volume= 0.033 af, Atten= 24%, Lag= 4.4 min Primary = 0.33 cfs @ 12.16 hrs, Volume= 0.033 af Routed to Link 9L : PDA-2 TOTAL Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 313.07' @ 12.16 hrs Surf.Area= 0.005 ac Storage= 0.002 af Plug-Flow detention time= 5.9 min calculated for 0.033 af (100% of inflow) Center-of-Mass det. time= 4.2 min ( 790.1 - 785.8 ) Volume Invert Avail.Storage Storage Description #1A 312.30' 0.002 af 9.00'W x 25.00'L x 4.17'H Field A 0.022 af Overall - 0.016 af Embedded = 0.005 af x 40.0% Voids #2A 312.80' 0.011 af retain_it retain_it 3.0' x 3 Inside #1 Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 0.013 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 311.30'12.0" Round Culvert L= 18.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 311.30' / 310.94' S= 0.0200 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 312.30'4.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 313.85'12.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.32 cfs @ 12.16 hrs HW=313.06' (Free Discharge) 1=Culvert (Passes 0.32 cfs of 3.35 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.32 cfs @ 3.71 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 25HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS - Chamber Wizard Field A Chamber Model = retain_it retain_it 3.0' (retain-it®) Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 3 Chambers/Row x 8.00' Long = 24.00' Row Length +6.0" End Stone x 2 = 25.00' Base Length 1 Rows x 96.0" Wide + 6.0" Side Stone x 2 = 9.00' Base Width 6.0" Stone Base + 44.0" Chamber Height = 4.17' Field Height 4.7 cf Sidewall x 3 x 2 + 4.7 cf Endwall x 1 x 2 = 37.8 cf Perimeter Wall 3 Chambers x 170.6 cf - 37.8 cf Perimeter wall = 474.1 cf Chamber Storage 3 Chambers x 234.7 cf = 704.0 cf Displacement 937.5 cf Field - 704.0 cf Chambers = 233.5 cf Stone x 40.0% Voids = 93.4 cf Stone Storage Chamber Storage + Stone Storage = 567.5 cf = 0.013 af Overall Storage Efficiency = 60.5% Overall System Size = 25.00' x 9.00' x 4.17' 3 Chambers 34.7 cy Field 8.6 cy Stone Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 26HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.48 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=0.150 ac Peak Elev=313.07' Storage=0.002 af 0.43 cfs 0.33 cfs Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 27HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Discharge for Pond 7P: UGS Elevation (feet) Primary (cfs) 312.30 0.00 312.32 0.00 312.34 0.00 312.36 0.01 312.38 0.02 312.40 0.02 312.42 0.03 312.44 0.04 312.46 0.06 312.48 0.07 312.50 0.08 312.52 0.10 312.54 0.11 312.56 0.13 312.58 0.14 312.60 0.15 312.62 0.17 312.64 0.17 312.66 0.18 312.68 0.19 312.70 0.20 312.72 0.21 312.74 0.22 312.76 0.23 312.78 0.24 312.80 0.24 312.82 0.25 312.84 0.26 312.86 0.26 312.88 0.27 312.90 0.28 312.92 0.28 312.94 0.29 312.96 0.30 312.98 0.30 313.00 0.31 313.02 0.31 313.04 0.32 313.06 0.32 313.08 0.33 313.10 0.33 313.12 0.34 313.14 0.34 313.16 0.35 313.18 0.35 313.20 0.36 313.22 0.36 313.24 0.37 313.26 0.37 313.28 0.38 313.30 0.38 313.32 0.39 313.34 0.39 Elevation (feet) Primary (cfs) 313.36 0.40 313.38 0.40 313.40 0.41 313.42 0.41 313.44 0.41 313.46 0.42 313.48 0.42 313.50 0.43 313.52 0.43 313.54 0.44 313.56 0.44 313.58 0.44 313.60 0.45 313.62 0.45 313.64 0.46 313.66 0.46 313.68 0.46 313.70 0.47 313.72 0.47 313.74 0.47 313.76 0.48 313.78 0.48 313.80 0.49 313.82 0.49 313.84 0.49 313.86 0.50 313.88 0.50 313.90 0.51 313.92 0.53 313.94 0.55 313.96 0.57 313.98 0.59 314.00 0.62 314.02 0.65 314.04 0.68 314.06 0.72 314.08 0.76 314.10 0.80 314.12 0.84 314.14 0.89 314.16 0.94 314.18 0.99 314.20 1.05 314.22 1.10 314.24 1.16 314.26 1.22 314.28 1.29 314.30 1.35 314.32 1.42 314.34 1.49 314.36 1.56 314.38 1.63 314.40 1.70 Elevation (feet) Primary (cfs) 314.42 1.78 314.44 1.85 314.46 1.93 314.48 2.00 314.50 2.08 314.52 2.16 314.54 2.24 314.56 2.32 314.58 2.40 314.60 2.48 314.62 2.56 314.64 2.63 314.66 2.71 314.68 2.79 314.70 2.86 314.72 2.93 314.74 3.01 314.76 3.07 314.78 3.14 314.80 3.20 314.82 3.26 314.84 3.30 314.86 3.35 314.88 3.41 314.90 3.46 314.92 3.51 314.94 3.57 314.96 3.62 314.98 3.67 315.00 3.72 315.02 3.77 315.04 3.82 315.06 3.86 315.08 3.91 315.10 3.96 315.12 4.00 315.14 4.05 315.16 4.09 315.18 4.14 315.20 4.18 315.22 4.22 315.24 4.27 315.26 4.31 315.28 4.35 315.30 4.39 315.32 4.43 315.34 4.47 315.36 4.52 315.38 4.56 315.40 4.59 315.42 4.63 315.44 4.67 315.46 4.71 Elevation (feet) Primary (cfs) 315.48 4.75 315.50 4.79 315.52 4.82 315.54 4.86 315.56 4.90 315.58 4.94 315.60 4.97 315.62 5.01 315.64 5.04 315.66 5.08 315.68 5.11 315.70 5.15 315.72 5.18 315.74 5.22 315.76 5.25 315.78 5.29 315.80 5.32 315.82 5.35 315.84 5.39 315.86 5.42 315.88 5.45 315.90 5.49 315.92 5.52 315.94 5.55 315.96 5.58 315.98 5.62 316.00 5.65 316.02 5.68 316.04 5.71 316.06 5.74 316.08 5.77 316.10 5.80 316.12 5.83 316.14 5.86 316.16 5.90 316.18 5.93 316.20 5.96 316.22 5.99 316.24 6.02 316.26 6.04 316.28 6.07 316.30 6.10 316.32 6.13 316.34 6.16 316.36 6.19 316.38 6.22 316.40 6.25 316.42 6.28 316.44 6.30 316.46 6.33 Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 28HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 7P: UGS Elevation (feet) Storage (acre-feet) 312.30 0.000 312.35 0.000 312.40 0.000 312.45 0.000 312.50 0.000 312.55 0.001 312.60 0.001 312.65 0.001 312.70 0.001 312.75 0.001 312.80 0.001 312.85 0.001 312.90 0.001 312.95 0.002 313.00 0.002 313.05 0.002 313.10 0.002 313.15 0.002 313.20 0.003 313.25 0.003 313.30 0.003 313.35 0.003 313.40 0.003 313.45 0.004 313.50 0.004 313.55 0.004 313.60 0.004 313.65 0.004 313.70 0.005 313.75 0.005 313.80 0.005 313.85 0.005 313.90 0.005 313.95 0.006 314.00 0.006 314.05 0.006 314.10 0.006 314.15 0.006 314.20 0.007 314.25 0.007 314.30 0.007 314.35 0.007 314.40 0.007 314.45 0.008 314.50 0.008 314.55 0.008 314.60 0.008 314.65 0.008 314.70 0.009 314.75 0.009 314.80 0.009 314.85 0.009 314.90 0.009 Elevation (feet) Storage (acre-feet) 314.95 0.009 315.00 0.010 315.05 0.010 315.10 0.010 315.15 0.010 315.20 0.010 315.25 0.011 315.30 0.011 315.35 0.011 315.40 0.011 315.45 0.011 315.50 0.012 315.55 0.012 315.60 0.012 315.65 0.012 315.70 0.012 315.75 0.013 315.80 0.013 315.85 0.013 315.90 0.013 315.95 0.013 316.00 0.013 316.05 0.013 316.10 0.013 316.15 0.013 316.20 0.013 316.25 0.013 316.30 0.013 316.35 0.013 316.40 0.013 316.45 0.013 Type III 24-hr 5-yr Rainfall=3.28"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 29HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Link 9L: PDA-2 TOTAL Inflow Area = 0.190 ac, 78.95% Impervious, Inflow Depth > 2.11" for 5-yr event Inflow = 0.33 cfs @ 12.16 hrs, Volume= 0.033 af Primary = 0.33 cfs @ 12.16 hrs, Volume= 0.033 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 9L: PDA-2 TOTAL Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.190 ac 0.33 cfs0.33 cfs Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 30HydroCAD® 10.20-3f s/n 13171 © 2023 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=0.200 ac 75.00% Impervious Runoff Depth>2.10"Subcatchment 1S: EDA-1 Tc=6.0 min CN=83 Runoff=0.48 cfs 0.035 af Runoff Area=0.110 ac 100.00% Impervious Runoff Depth>3.55"Subcatchment 2S: EDA-2 Tc=6.0 min CN=98 Runoff=0.40 cfs 0.033 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>2.81"Subcatchment 3S: EDA-3 Tc=6.0 min CN=91 Runoff=0.25 cfs 0.019 af Runoff Area=0.120 ac 66.67% Impervious Runoff Depth>1.72"Subcatchment 4S: PDA-1 Tc=6.0 min CN=78 Runoff=0.24 cfs 0.017 af Runoff Area=0.150 ac 93.33% Impervious Runoff Depth>3.12"Subcatchment 5S: PDA-2A Tc=6.0 min CN=94 Runoff=0.51 cfs 0.039 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>2.81"Subcatchment 6S: PDA-3 Tc=6.0 min CN=91 Runoff=0.25 cfs 0.019 af Runoff Area=0.040 ac 25.00% Impervious Runoff Depth>0.41"Subcatchment 8S: PDA-2B Tc=6.0 min CN=54 Runoff=0.01 cfs 0.001 af Peak Elev=313.23' Storage=0.003 af Inflow=0.51 cfs 0.039 afPond 7P: UGS Outflow=0.37 cfs 0.039 af Inflow=0.38 cfs 0.040 afLink 9L: PDA-2 TOTAL Primary=0.38 cfs 0.040 af Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 31HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: EDA-1 Runoff = 0.48 cfs @ 12.09 hrs, Volume= 0.035 af, Depth> 2.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=3.79" Area (ac) CN Description 0.150 98 Paved parking, HSG A 0.050 39 >75% Grass cover, Good, HSG A 0.200 83 Weighted Average 0.050 25.00% Pervious Area 0.150 75.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 1S: EDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 10-yr Rainfall=3.79" Runoff Area=0.200 ac Runoff Volume=0.035 af Runoff Depth>2.10" Tc=6.0 min CN=83 0.48 cfs Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 32HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: EDA-2 Runoff = 0.40 cfs @ 12.09 hrs, Volume= 0.033 af, Depth> 3.55" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=3.79" Area (ac) CN Description 0.110 98 Paved parking, HSG A 0.110 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 2S: EDA-2 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 10-yr Rainfall=3.79" Runoff Area=0.110 ac Runoff Volume=0.033 af Runoff Depth>3.55" Tc=6.0 min CN=98 0.40 cfs Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 33HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: EDA-3 Runoff = 0.25 cfs @ 12.09 hrs, Volume= 0.019 af, Depth> 2.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=3.79" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 3S: EDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 10-yr Rainfall=3.79" Runoff Area=0.080 ac Runoff Volume=0.019 af Runoff Depth>2.81" Tc=6.0 min CN=91 0.25 cfs Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 34HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: PDA-1 Runoff = 0.24 cfs @ 12.10 hrs, Volume= 0.017 af, Depth> 1.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=3.79" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.040 39 >75% Grass cover, Good, HSG A 0.120 78 Weighted Average 0.040 33.33% Pervious Area 0.080 66.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 4S: PDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.26 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 III 24-hr 10-yr Rainfall=3.79" Runoff Area=0.120 ac Runoff Volume=0.017 af Runoff Depth>1.72" Tc=6.0 min CN=78 0.24 cfs Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 35HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PDA-2A Runoff = 0.51 cfs @ 12.09 hrs, Volume= 0.039 af, Depth> 3.12" Routed to Pond 7P : UGS Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=3.79" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.150 94 Weighted Average 0.010 6.67% Pervious Area 0.140 93.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, ab Subcatchment 5S: PDA-2A Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 10-yr Rainfall=3.79" Runoff Area=0.150 ac Runoff Volume=0.039 af Runoff Depth>3.12" Tc=6.0 min CN=94 0.51 cfs Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 36HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: PDA-3 Runoff = 0.25 cfs @ 12.09 hrs, Volume= 0.019 af, Depth> 2.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=3.79" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 6S: PDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 10-yr Rainfall=3.79" Runoff Area=0.080 ac Runoff Volume=0.019 af Runoff Depth>2.81" Tc=6.0 min CN=91 0.25 cfs Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 37HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: PDA-2B Runoff = 0.01 cfs @ 12.16 hrs, Volume= 0.001 af, Depth> 0.41" Routed to Link 9L : PDA-2 TOTAL Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=3.79" Area (ac) CN Description 0.010 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.040 54 Weighted Average 0.030 75.00% Pervious Area 0.010 25.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 8S: PDA-2B Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.01 0.009 0.009 0.008 0.008 0.007 0.007 0.006 0.006 0.005 0.005 0.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0.000 0 Type III 24-hr 10-yr Rainfall=3.79" Runoff Area=0.040 ac Runoff Volume=0.001 af Runoff Depth>0.41" Tc=6.0 min CN=54 0.01 cfs Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 38HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Pond 7P: UGS Inflow Area = 0.150 ac, 93.33% Impervious, Inflow Depth > 3.12" for 10-yr event Inflow = 0.51 cfs @ 12.09 hrs, Volume= 0.039 af Outflow = 0.37 cfs @ 12.17 hrs, Volume= 0.039 af, Atten= 28%, Lag= 4.8 min Primary = 0.37 cfs @ 12.17 hrs, Volume= 0.039 af Routed to Link 9L : PDA-2 TOTAL Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 313.23' @ 12.17 hrs Surf.Area= 0.005 ac Storage= 0.003 af Plug-Flow detention time= 5.8 min calculated for 0.039 af (100% of inflow) Center-of-Mass det. time= 4.3 min ( 785.5 - 781.3 ) Volume Invert Avail.Storage Storage Description #1A 312.30' 0.002 af 9.00'W x 25.00'L x 4.17'H Field A 0.022 af Overall - 0.016 af Embedded = 0.005 af x 40.0% Voids #2A 312.80' 0.011 af retain_it retain_it 3.0' x 3 Inside #1 Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 0.013 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 311.30'12.0" Round Culvert L= 18.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 311.30' / 310.94' S= 0.0200 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 312.30'4.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 313.85'12.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.36 cfs @ 12.17 hrs HW=313.22' (Free Discharge) 1=Culvert (Passes 0.36 cfs of 3.55 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.36 cfs @ 4.17 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 39HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS - Chamber Wizard Field A Chamber Model = retain_it retain_it 3.0' (retain-it®) Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 3 Chambers/Row x 8.00' Long = 24.00' Row Length +6.0" End Stone x 2 = 25.00' Base Length 1 Rows x 96.0" Wide + 6.0" Side Stone x 2 = 9.00' Base Width 6.0" Stone Base + 44.0" Chamber Height = 4.17' Field Height 4.7 cf Sidewall x 3 x 2 + 4.7 cf Endwall x 1 x 2 = 37.8 cf Perimeter Wall 3 Chambers x 170.6 cf - 37.8 cf Perimeter wall = 474.1 cf Chamber Storage 3 Chambers x 234.7 cf = 704.0 cf Displacement 937.5 cf Field - 704.0 cf Chambers = 233.5 cf Stone x 40.0% Voids = 93.4 cf Stone Storage Chamber Storage + Stone Storage = 567.5 cf = 0.013 af Overall Storage Efficiency = 60.5% Overall System Size = 25.00' x 9.00' x 4.17' 3 Chambers 34.7 cy Field 8.6 cy Stone Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 40HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.150 ac Peak Elev=313.23' Storage=0.003 af 0.51 cfs 0.37 cfs Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 41HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Discharge for Pond 7P: UGS Elevation (feet) Primary (cfs) 312.30 0.00 312.32 0.00 312.34 0.00 312.36 0.01 312.38 0.02 312.40 0.02 312.42 0.03 312.44 0.04 312.46 0.06 312.48 0.07 312.50 0.08 312.52 0.10 312.54 0.11 312.56 0.13 312.58 0.14 312.60 0.15 312.62 0.17 312.64 0.17 312.66 0.18 312.68 0.19 312.70 0.20 312.72 0.21 312.74 0.22 312.76 0.23 312.78 0.24 312.80 0.24 312.82 0.25 312.84 0.26 312.86 0.26 312.88 0.27 312.90 0.28 312.92 0.28 312.94 0.29 312.96 0.30 312.98 0.30 313.00 0.31 313.02 0.31 313.04 0.32 313.06 0.32 313.08 0.33 313.10 0.33 313.12 0.34 313.14 0.34 313.16 0.35 313.18 0.35 313.20 0.36 313.22 0.36 313.24 0.37 313.26 0.37 313.28 0.38 313.30 0.38 313.32 0.39 313.34 0.39 Elevation (feet) Primary (cfs) 313.36 0.40 313.38 0.40 313.40 0.41 313.42 0.41 313.44 0.41 313.46 0.42 313.48 0.42 313.50 0.43 313.52 0.43 313.54 0.44 313.56 0.44 313.58 0.44 313.60 0.45 313.62 0.45 313.64 0.46 313.66 0.46 313.68 0.46 313.70 0.47 313.72 0.47 313.74 0.47 313.76 0.48 313.78 0.48 313.80 0.49 313.82 0.49 313.84 0.49 313.86 0.50 313.88 0.50 313.90 0.51 313.92 0.53 313.94 0.55 313.96 0.57 313.98 0.59 314.00 0.62 314.02 0.65 314.04 0.68 314.06 0.72 314.08 0.76 314.10 0.80 314.12 0.84 314.14 0.89 314.16 0.94 314.18 0.99 314.20 1.05 314.22 1.10 314.24 1.16 314.26 1.22 314.28 1.29 314.30 1.35 314.32 1.42 314.34 1.49 314.36 1.56 314.38 1.63 314.40 1.70 Elevation (feet) Primary (cfs) 314.42 1.78 314.44 1.85 314.46 1.93 314.48 2.00 314.50 2.08 314.52 2.16 314.54 2.24 314.56 2.32 314.58 2.40 314.60 2.48 314.62 2.56 314.64 2.63 314.66 2.71 314.68 2.79 314.70 2.86 314.72 2.93 314.74 3.01 314.76 3.07 314.78 3.14 314.80 3.20 314.82 3.26 314.84 3.30 314.86 3.35 314.88 3.41 314.90 3.46 314.92 3.51 314.94 3.57 314.96 3.62 314.98 3.67 315.00 3.72 315.02 3.77 315.04 3.82 315.06 3.86 315.08 3.91 315.10 3.96 315.12 4.00 315.14 4.05 315.16 4.09 315.18 4.14 315.20 4.18 315.22 4.22 315.24 4.27 315.26 4.31 315.28 4.35 315.30 4.39 315.32 4.43 315.34 4.47 315.36 4.52 315.38 4.56 315.40 4.59 315.42 4.63 315.44 4.67 315.46 4.71 Elevation (feet) Primary (cfs) 315.48 4.75 315.50 4.79 315.52 4.82 315.54 4.86 315.56 4.90 315.58 4.94 315.60 4.97 315.62 5.01 315.64 5.04 315.66 5.08 315.68 5.11 315.70 5.15 315.72 5.18 315.74 5.22 315.76 5.25 315.78 5.29 315.80 5.32 315.82 5.35 315.84 5.39 315.86 5.42 315.88 5.45 315.90 5.49 315.92 5.52 315.94 5.55 315.96 5.58 315.98 5.62 316.00 5.65 316.02 5.68 316.04 5.71 316.06 5.74 316.08 5.77 316.10 5.80 316.12 5.83 316.14 5.86 316.16 5.90 316.18 5.93 316.20 5.96 316.22 5.99 316.24 6.02 316.26 6.04 316.28 6.07 316.30 6.10 316.32 6.13 316.34 6.16 316.36 6.19 316.38 6.22 316.40 6.25 316.42 6.28 316.44 6.30 316.46 6.33 Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 42HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 7P: UGS Elevation (feet) Storage (acre-feet) 312.30 0.000 312.35 0.000 312.40 0.000 312.45 0.000 312.50 0.000 312.55 0.001 312.60 0.001 312.65 0.001 312.70 0.001 312.75 0.001 312.80 0.001 312.85 0.001 312.90 0.001 312.95 0.002 313.00 0.002 313.05 0.002 313.10 0.002 313.15 0.002 313.20 0.003 313.25 0.003 313.30 0.003 313.35 0.003 313.40 0.003 313.45 0.004 313.50 0.004 313.55 0.004 313.60 0.004 313.65 0.004 313.70 0.005 313.75 0.005 313.80 0.005 313.85 0.005 313.90 0.005 313.95 0.006 314.00 0.006 314.05 0.006 314.10 0.006 314.15 0.006 314.20 0.007 314.25 0.007 314.30 0.007 314.35 0.007 314.40 0.007 314.45 0.008 314.50 0.008 314.55 0.008 314.60 0.008 314.65 0.008 314.70 0.009 314.75 0.009 314.80 0.009 314.85 0.009 314.90 0.009 Elevation (feet) Storage (acre-feet) 314.95 0.009 315.00 0.010 315.05 0.010 315.10 0.010 315.15 0.010 315.20 0.010 315.25 0.011 315.30 0.011 315.35 0.011 315.40 0.011 315.45 0.011 315.50 0.012 315.55 0.012 315.60 0.012 315.65 0.012 315.70 0.012 315.75 0.013 315.80 0.013 315.85 0.013 315.90 0.013 315.95 0.013 316.00 0.013 316.05 0.013 316.10 0.013 316.15 0.013 316.20 0.013 316.25 0.013 316.30 0.013 316.35 0.013 316.40 0.013 316.45 0.013 Type III 24-hr 10-yr Rainfall=3.79"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 43HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Link 9L: PDA-2 TOTAL Inflow Area = 0.190 ac, 78.95% Impervious, Inflow Depth > 2.54" for 10-yr event Inflow = 0.38 cfs @ 12.17 hrs, Volume= 0.040 af Primary = 0.38 cfs @ 12.17 hrs, Volume= 0.040 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 9L: PDA-2 TOTAL Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.190 ac 0.38 cfs0.38 cfs Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 44HydroCAD® 10.20-3f s/n 13171 © 2023 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=0.200 ac 75.00% Impervious Runoff Depth>2.71"Subcatchment 1S: EDA-1 Tc=6.0 min CN=83 Runoff=0.62 cfs 0.045 af Runoff Area=0.110 ac 100.00% Impervious Runoff Depth>4.25"Subcatchment 2S: EDA-2 Tc=6.0 min CN=98 Runoff=0.47 cfs 0.039 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>3.49"Subcatchment 3S: EDA-3 Tc=6.0 min CN=91 Runoff=0.31 cfs 0.023 af Runoff Area=0.120 ac 66.67% Impervious Runoff Depth>2.28"Subcatchment 4S: PDA-1 Tc=6.0 min CN=78 Runoff=0.31 cfs 0.023 af Runoff Area=0.150 ac 93.33% Impervious Runoff Depth>3.80"Subcatchment 5S: PDA-2A Tc=6.0 min CN=94 Runoff=0.61 cfs 0.048 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>3.49"Subcatchment 6S: PDA-3 Tc=6.0 min CN=91 Runoff=0.31 cfs 0.023 af Runoff Area=0.040 ac 25.00% Impervious Runoff Depth>0.69"Subcatchment 8S: PDA-2B Tc=6.0 min CN=54 Runoff=0.02 cfs 0.002 af Peak Elev=313.48' Storage=0.004 af Inflow=0.61 cfs 0.048 afPond 7P: UGS Outflow=0.42 cfs 0.047 af Inflow=0.44 cfs 0.050 afLink 9L: PDA-2 TOTAL Primary=0.44 cfs 0.050 af Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 45HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: EDA-1 Runoff = 0.62 cfs @ 12.09 hrs, Volume= 0.045 af, Depth> 2.71" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=4.49" Area (ac) CN Description 0.150 98 Paved parking, HSG A 0.050 39 >75% Grass cover, Good, HSG A 0.200 83 Weighted Average 0.050 25.00% Pervious Area 0.150 75.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 1S: EDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 25-yr Rainfall=4.49" Runoff Area=0.200 ac Runoff Volume=0.045 af Runoff Depth>2.71" Tc=6.0 min CN=83 0.62 cfs Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 46HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: EDA-2 Runoff = 0.47 cfs @ 12.09 hrs, Volume= 0.039 af, Depth> 4.25" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=4.49" Area (ac) CN Description 0.110 98 Paved parking, HSG A 0.110 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 2S: EDA-2 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.52 0.5 0.48 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 III 24-hr 25-yr Rainfall=4.49" Runoff Area=0.110 ac Runoff Volume=0.039 af Runoff Depth>4.25" Tc=6.0 min CN=98 0.47 cfs Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 47HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: EDA-3 Runoff = 0.31 cfs @ 12.09 hrs, Volume= 0.023 af, Depth> 3.49" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=4.49" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 3S: EDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 25-yr Rainfall=4.49" Runoff Area=0.080 ac Runoff Volume=0.023 af Runoff Depth>3.49" Tc=6.0 min CN=91 0.31 cfs Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 48HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: PDA-1 Runoff = 0.31 cfs @ 12.09 hrs, Volume= 0.023 af, Depth> 2.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=4.49" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.040 39 >75% Grass cover, Good, HSG A 0.120 78 Weighted Average 0.040 33.33% Pervious Area 0.080 66.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 4S: PDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 25-yr Rainfall=4.49" Runoff Area=0.120 ac Runoff Volume=0.023 af Runoff Depth>2.28" Tc=6.0 min CN=78 0.31 cfs Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 49HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PDA-2A Runoff = 0.61 cfs @ 12.09 hrs, Volume= 0.048 af, Depth> 3.80" Routed to Pond 7P : UGS Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=4.49" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.150 94 Weighted Average 0.010 6.67% Pervious Area 0.140 93.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, ab Subcatchment 5S: PDA-2A Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 25-yr Rainfall=4.49" Runoff Area=0.150 ac Runoff Volume=0.048 af Runoff Depth>3.80" Tc=6.0 min CN=94 0.61 cfs Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 50HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: PDA-3 Runoff = 0.31 cfs @ 12.09 hrs, Volume= 0.023 af, Depth> 3.49" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=4.49" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 6S: PDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 25-yr Rainfall=4.49" Runoff Area=0.080 ac Runoff Volume=0.023 af Runoff Depth>3.49" Tc=6.0 min CN=91 0.31 cfs Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 51HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: PDA-2B Runoff = 0.02 cfs @ 12.12 hrs, Volume= 0.002 af, Depth> 0.69" Routed to Link 9L : PDA-2 TOTAL Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=4.49" Area (ac) CN Description 0.010 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.040 54 Weighted Average 0.030 75.00% Pervious Area 0.010 25.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 8S: PDA-2B Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.024 0.023 0.022 0.021 0.02 0.019 0.018 0.017 0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Type III 24-hr 25-yr Rainfall=4.49" Runoff Area=0.040 ac Runoff Volume=0.002 af Runoff Depth>0.69" Tc=6.0 min CN=54 0.02 cfs Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 52HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Pond 7P: UGS Inflow Area = 0.150 ac, 93.33% Impervious, Inflow Depth > 3.80" for 25-yr event Inflow = 0.61 cfs @ 12.09 hrs, Volume= 0.048 af Outflow = 0.42 cfs @ 12.17 hrs, Volume= 0.047 af, Atten= 31%, Lag= 5.2 min Primary = 0.42 cfs @ 12.17 hrs, Volume= 0.047 af Routed to Link 9L : PDA-2 TOTAL Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 313.48' @ 12.17 hrs Surf.Area= 0.005 ac Storage= 0.004 af Plug-Flow detention time= 5.7 min calculated for 0.047 af (100% of inflow) Center-of-Mass det. time= 4.4 min ( 780.5 - 776.1 ) Volume Invert Avail.Storage Storage Description #1A 312.30' 0.002 af 9.00'W x 25.00'L x 4.17'H Field A 0.022 af Overall - 0.016 af Embedded = 0.005 af x 40.0% Voids #2A 312.80' 0.011 af retain_it retain_it 3.0' x 3 Inside #1 Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 0.013 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 311.30'12.0" Round Culvert L= 18.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 311.30' / 310.94' S= 0.0200 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 312.30'4.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 313.85'12.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.42 cfs @ 12.17 hrs HW=313.46' (Free Discharge) 1=Culvert (Passes 0.42 cfs of 3.85 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.42 cfs @ 4.80 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 53HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS - Chamber Wizard Field A Chamber Model = retain_it retain_it 3.0' (retain-it®) Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 3 Chambers/Row x 8.00' Long = 24.00' Row Length +6.0" End Stone x 2 = 25.00' Base Length 1 Rows x 96.0" Wide + 6.0" Side Stone x 2 = 9.00' Base Width 6.0" Stone Base + 44.0" Chamber Height = 4.17' Field Height 4.7 cf Sidewall x 3 x 2 + 4.7 cf Endwall x 1 x 2 = 37.8 cf Perimeter Wall 3 Chambers x 170.6 cf - 37.8 cf Perimeter wall = 474.1 cf Chamber Storage 3 Chambers x 234.7 cf = 704.0 cf Displacement 937.5 cf Field - 704.0 cf Chambers = 233.5 cf Stone x 40.0% Voids = 93.4 cf Stone Storage Chamber Storage + Stone Storage = 567.5 cf = 0.013 af Overall Storage Efficiency = 60.5% Overall System Size = 25.00' x 9.00' x 4.17' 3 Chambers 34.7 cy Field 8.6 cy Stone Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 54HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.150 ac Peak Elev=313.48' Storage=0.004 af 0.61 cfs 0.42 cfs Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 55HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Discharge for Pond 7P: UGS Elevation (feet) Primary (cfs) 312.30 0.00 312.32 0.00 312.34 0.00 312.36 0.01 312.38 0.02 312.40 0.02 312.42 0.03 312.44 0.04 312.46 0.06 312.48 0.07 312.50 0.08 312.52 0.10 312.54 0.11 312.56 0.13 312.58 0.14 312.60 0.15 312.62 0.17 312.64 0.17 312.66 0.18 312.68 0.19 312.70 0.20 312.72 0.21 312.74 0.22 312.76 0.23 312.78 0.24 312.80 0.24 312.82 0.25 312.84 0.26 312.86 0.26 312.88 0.27 312.90 0.28 312.92 0.28 312.94 0.29 312.96 0.30 312.98 0.30 313.00 0.31 313.02 0.31 313.04 0.32 313.06 0.32 313.08 0.33 313.10 0.33 313.12 0.34 313.14 0.34 313.16 0.35 313.18 0.35 313.20 0.36 313.22 0.36 313.24 0.37 313.26 0.37 313.28 0.38 313.30 0.38 313.32 0.39 313.34 0.39 Elevation (feet) Primary (cfs) 313.36 0.40 313.38 0.40 313.40 0.41 313.42 0.41 313.44 0.41 313.46 0.42 313.48 0.42 313.50 0.43 313.52 0.43 313.54 0.44 313.56 0.44 313.58 0.44 313.60 0.45 313.62 0.45 313.64 0.46 313.66 0.46 313.68 0.46 313.70 0.47 313.72 0.47 313.74 0.47 313.76 0.48 313.78 0.48 313.80 0.49 313.82 0.49 313.84 0.49 313.86 0.50 313.88 0.50 313.90 0.51 313.92 0.53 313.94 0.55 313.96 0.57 313.98 0.59 314.00 0.62 314.02 0.65 314.04 0.68 314.06 0.72 314.08 0.76 314.10 0.80 314.12 0.84 314.14 0.89 314.16 0.94 314.18 0.99 314.20 1.05 314.22 1.10 314.24 1.16 314.26 1.22 314.28 1.29 314.30 1.35 314.32 1.42 314.34 1.49 314.36 1.56 314.38 1.63 314.40 1.70 Elevation (feet) Primary (cfs) 314.42 1.78 314.44 1.85 314.46 1.93 314.48 2.00 314.50 2.08 314.52 2.16 314.54 2.24 314.56 2.32 314.58 2.40 314.60 2.48 314.62 2.56 314.64 2.63 314.66 2.71 314.68 2.79 314.70 2.86 314.72 2.93 314.74 3.01 314.76 3.07 314.78 3.14 314.80 3.20 314.82 3.26 314.84 3.30 314.86 3.35 314.88 3.41 314.90 3.46 314.92 3.51 314.94 3.57 314.96 3.62 314.98 3.67 315.00 3.72 315.02 3.77 315.04 3.82 315.06 3.86 315.08 3.91 315.10 3.96 315.12 4.00 315.14 4.05 315.16 4.09 315.18 4.14 315.20 4.18 315.22 4.22 315.24 4.27 315.26 4.31 315.28 4.35 315.30 4.39 315.32 4.43 315.34 4.47 315.36 4.52 315.38 4.56 315.40 4.59 315.42 4.63 315.44 4.67 315.46 4.71 Elevation (feet) Primary (cfs) 315.48 4.75 315.50 4.79 315.52 4.82 315.54 4.86 315.56 4.90 315.58 4.94 315.60 4.97 315.62 5.01 315.64 5.04 315.66 5.08 315.68 5.11 315.70 5.15 315.72 5.18 315.74 5.22 315.76 5.25 315.78 5.29 315.80 5.32 315.82 5.35 315.84 5.39 315.86 5.42 315.88 5.45 315.90 5.49 315.92 5.52 315.94 5.55 315.96 5.58 315.98 5.62 316.00 5.65 316.02 5.68 316.04 5.71 316.06 5.74 316.08 5.77 316.10 5.80 316.12 5.83 316.14 5.86 316.16 5.90 316.18 5.93 316.20 5.96 316.22 5.99 316.24 6.02 316.26 6.04 316.28 6.07 316.30 6.10 316.32 6.13 316.34 6.16 316.36 6.19 316.38 6.22 316.40 6.25 316.42 6.28 316.44 6.30 316.46 6.33 Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 56HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 7P: UGS Elevation (feet) Storage (acre-feet) 312.30 0.000 312.35 0.000 312.40 0.000 312.45 0.000 312.50 0.000 312.55 0.001 312.60 0.001 312.65 0.001 312.70 0.001 312.75 0.001 312.80 0.001 312.85 0.001 312.90 0.001 312.95 0.002 313.00 0.002 313.05 0.002 313.10 0.002 313.15 0.002 313.20 0.003 313.25 0.003 313.30 0.003 313.35 0.003 313.40 0.003 313.45 0.004 313.50 0.004 313.55 0.004 313.60 0.004 313.65 0.004 313.70 0.005 313.75 0.005 313.80 0.005 313.85 0.005 313.90 0.005 313.95 0.006 314.00 0.006 314.05 0.006 314.10 0.006 314.15 0.006 314.20 0.007 314.25 0.007 314.30 0.007 314.35 0.007 314.40 0.007 314.45 0.008 314.50 0.008 314.55 0.008 314.60 0.008 314.65 0.008 314.70 0.009 314.75 0.009 314.80 0.009 314.85 0.009 314.90 0.009 Elevation (feet) Storage (acre-feet) 314.95 0.009 315.00 0.010 315.05 0.010 315.10 0.010 315.15 0.010 315.20 0.010 315.25 0.011 315.30 0.011 315.35 0.011 315.40 0.011 315.45 0.011 315.50 0.012 315.55 0.012 315.60 0.012 315.65 0.012 315.70 0.012 315.75 0.013 315.80 0.013 315.85 0.013 315.90 0.013 315.95 0.013 316.00 0.013 316.05 0.013 316.10 0.013 316.15 0.013 316.20 0.013 316.25 0.013 316.30 0.013 316.35 0.013 316.40 0.013 316.45 0.013 Type III 24-hr 25-yr Rainfall=4.49"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 57HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Link 9L: PDA-2 TOTAL Inflow Area = 0.190 ac, 78.95% Impervious, Inflow Depth > 3.14" for 25-yr event Inflow = 0.44 cfs @ 12.17 hrs, Volume= 0.050 af Primary = 0.44 cfs @ 12.17 hrs, Volume= 0.050 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 9L: PDA-2 TOTAL Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.48 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=0.190 ac 0.44 cfs0.44 cfs Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 58HydroCAD® 10.20-3f s/n 13171 © 2023 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=0.200 ac 75.00% Impervious Runoff Depth>3.19"Subcatchment 1S: EDA-1 Tc=6.0 min CN=83 Runoff=0.73 cfs 0.053 af Runoff Area=0.110 ac 100.00% Impervious Runoff Depth>4.78"Subcatchment 2S: EDA-2 Tc=6.0 min CN=98 Runoff=0.53 cfs 0.044 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>4.00"Subcatchment 3S: EDA-3 Tc=6.0 min CN=91 Runoff=0.35 cfs 0.027 af Runoff Area=0.120 ac 66.67% Impervious Runoff Depth>2.73"Subcatchment 4S: PDA-1 Tc=6.0 min CN=78 Runoff=0.38 cfs 0.027 af Runoff Area=0.150 ac 93.33% Impervious Runoff Depth>4.32"Subcatchment 5S: PDA-2A Tc=6.0 min CN=94 Runoff=0.69 cfs 0.054 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>4.00"Subcatchment 6S: PDA-3 Tc=6.0 min CN=91 Runoff=0.35 cfs 0.027 af Runoff Area=0.040 ac 25.00% Impervious Runoff Depth>0.93"Subcatchment 8S: PDA-2B Tc=6.0 min CN=54 Runoff=0.03 cfs 0.003 af Peak Elev=313.67' Storage=0.004 af Inflow=0.69 cfs 0.054 afPond 7P: UGS Outflow=0.46 cfs 0.054 af Inflow=0.49 cfs 0.057 afLink 9L: PDA-2 TOTAL Primary=0.49 cfs 0.057 af Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 59HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: EDA-1 Runoff = 0.73 cfs @ 12.09 hrs, Volume= 0.053 af, Depth> 3.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=5.02" Area (ac) CN Description 0.150 98 Paved parking, HSG A 0.050 39 >75% Grass cover, Good, HSG A 0.200 83 Weighted Average 0.050 25.00% Pervious Area 0.150 75.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 1S: EDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 50-yr Rainfall=5.02" Runoff Area=0.200 ac Runoff Volume=0.053 af Runoff Depth>3.19" Tc=6.0 min CN=83 0.73 cfs Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 60HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: EDA-2 Runoff = 0.53 cfs @ 12.09 hrs, Volume= 0.044 af, Depth> 4.78" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=5.02" Area (ac) CN Description 0.110 98 Paved parking, HSG A 0.110 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 2S: EDA-2 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 50-yr Rainfall=5.02" Runoff Area=0.110 ac Runoff Volume=0.044 af Runoff Depth>4.78" Tc=6.0 min CN=98 0.53 cfs Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 61HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: EDA-3 Runoff = 0.35 cfs @ 12.09 hrs, Volume= 0.027 af, Depth> 4.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=5.02" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 3S: EDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 50-yr Rainfall=5.02" Runoff Area=0.080 ac Runoff Volume=0.027 af Runoff Depth>4.00" Tc=6.0 min CN=91 0.35 cfs Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 62HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: PDA-1 Runoff = 0.38 cfs @ 12.09 hrs, Volume= 0.027 af, Depth> 2.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=5.02" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.040 39 >75% Grass cover, Good, HSG A 0.120 78 Weighted Average 0.040 33.33% Pervious Area 0.080 66.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 4S: PDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 50-yr Rainfall=5.02" Runoff Area=0.120 ac Runoff Volume=0.027 af Runoff Depth>2.73" Tc=6.0 min CN=78 0.38 cfs Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 63HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PDA-2A Runoff = 0.69 cfs @ 12.09 hrs, Volume= 0.054 af, Depth> 4.32" Routed to Pond 7P : UGS Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=5.02" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.150 94 Weighted Average 0.010 6.67% Pervious Area 0.140 93.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, ab Subcatchment 5S: PDA-2A Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 50-yr Rainfall=5.02" Runoff Area=0.150 ac Runoff Volume=0.054 af Runoff Depth>4.32" Tc=6.0 min CN=94 0.69 cfs Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 64HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: PDA-3 Runoff = 0.35 cfs @ 12.09 hrs, Volume= 0.027 af, Depth> 4.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=5.02" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 6S: PDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 50-yr Rainfall=5.02" Runoff Area=0.080 ac Runoff Volume=0.027 af Runoff Depth>4.00" Tc=6.0 min CN=91 0.35 cfs Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 65HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: PDA-2B Runoff = 0.03 cfs @ 12.11 hrs, Volume= 0.003 af, Depth> 0.93" Routed to Link 9L : PDA-2 TOTAL Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=5.02" Area (ac) CN Description 0.010 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.040 54 Weighted Average 0.030 75.00% Pervious Area 0.010 25.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 8S: PDA-2B Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 50-yr Rainfall=5.02" Runoff Area=0.040 ac Runoff Volume=0.003 af Runoff Depth>0.93" Tc=6.0 min CN=54 0.03 cfs Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 66HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Pond 7P: UGS Inflow Area = 0.150 ac, 93.33% Impervious, Inflow Depth > 4.32" for 50-yr event Inflow = 0.69 cfs @ 12.09 hrs, Volume= 0.054 af Outflow = 0.46 cfs @ 12.18 hrs, Volume= 0.054 af, Atten= 33%, Lag= 5.6 min Primary = 0.46 cfs @ 12.18 hrs, Volume= 0.054 af Routed to Link 9L : PDA-2 TOTAL Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 313.67' @ 12.18 hrs Surf.Area= 0.005 ac Storage= 0.004 af Plug-Flow detention time= 5.7 min calculated for 0.054 af (100% of inflow) Center-of-Mass det. time= 4.5 min ( 777.4 - 772.9 ) Volume Invert Avail.Storage Storage Description #1A 312.30' 0.002 af 9.00'W x 25.00'L x 4.17'H Field A 0.022 af Overall - 0.016 af Embedded = 0.005 af x 40.0% Voids #2A 312.80' 0.011 af retain_it retain_it 3.0' x 3 Inside #1 Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 0.013 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 311.30'12.0" Round Culvert L= 18.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 311.30' / 310.94' S= 0.0200 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 312.30'4.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 313.85'12.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.46 cfs @ 12.18 hrs HW=313.66' (Free Discharge) 1=Culvert (Passes 0.46 cfs of 4.07 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.46 cfs @ 5.26 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 67HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS - Chamber Wizard Field A Chamber Model = retain_it retain_it 3.0' (retain-it®) Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 3 Chambers/Row x 8.00' Long = 24.00' Row Length +6.0" End Stone x 2 = 25.00' Base Length 1 Rows x 96.0" Wide + 6.0" Side Stone x 2 = 9.00' Base Width 6.0" Stone Base + 44.0" Chamber Height = 4.17' Field Height 4.7 cf Sidewall x 3 x 2 + 4.7 cf Endwall x 1 x 2 = 37.8 cf Perimeter Wall 3 Chambers x 170.6 cf - 37.8 cf Perimeter wall = 474.1 cf Chamber Storage 3 Chambers x 234.7 cf = 704.0 cf Displacement 937.5 cf Field - 704.0 cf Chambers = 233.5 cf Stone x 40.0% Voids = 93.4 cf Stone Storage Chamber Storage + Stone Storage = 567.5 cf = 0.013 af Overall Storage Efficiency = 60.5% Overall System Size = 25.00' x 9.00' x 4.17' 3 Chambers 34.7 cy Field 8.6 cy Stone Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 68HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.150 ac Peak Elev=313.67' Storage=0.004 af 0.69 cfs 0.46 cfs Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 69HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Discharge for Pond 7P: UGS Elevation (feet) Primary (cfs) 312.30 0.00 312.32 0.00 312.34 0.00 312.36 0.01 312.38 0.02 312.40 0.02 312.42 0.03 312.44 0.04 312.46 0.06 312.48 0.07 312.50 0.08 312.52 0.10 312.54 0.11 312.56 0.13 312.58 0.14 312.60 0.15 312.62 0.17 312.64 0.17 312.66 0.18 312.68 0.19 312.70 0.20 312.72 0.21 312.74 0.22 312.76 0.23 312.78 0.24 312.80 0.24 312.82 0.25 312.84 0.26 312.86 0.26 312.88 0.27 312.90 0.28 312.92 0.28 312.94 0.29 312.96 0.30 312.98 0.30 313.00 0.31 313.02 0.31 313.04 0.32 313.06 0.32 313.08 0.33 313.10 0.33 313.12 0.34 313.14 0.34 313.16 0.35 313.18 0.35 313.20 0.36 313.22 0.36 313.24 0.37 313.26 0.37 313.28 0.38 313.30 0.38 313.32 0.39 313.34 0.39 Elevation (feet) Primary (cfs) 313.36 0.40 313.38 0.40 313.40 0.41 313.42 0.41 313.44 0.41 313.46 0.42 313.48 0.42 313.50 0.43 313.52 0.43 313.54 0.44 313.56 0.44 313.58 0.44 313.60 0.45 313.62 0.45 313.64 0.46 313.66 0.46 313.68 0.46 313.70 0.47 313.72 0.47 313.74 0.47 313.76 0.48 313.78 0.48 313.80 0.49 313.82 0.49 313.84 0.49 313.86 0.50 313.88 0.50 313.90 0.51 313.92 0.53 313.94 0.55 313.96 0.57 313.98 0.59 314.00 0.62 314.02 0.65 314.04 0.68 314.06 0.72 314.08 0.76 314.10 0.80 314.12 0.84 314.14 0.89 314.16 0.94 314.18 0.99 314.20 1.05 314.22 1.10 314.24 1.16 314.26 1.22 314.28 1.29 314.30 1.35 314.32 1.42 314.34 1.49 314.36 1.56 314.38 1.63 314.40 1.70 Elevation (feet) Primary (cfs) 314.42 1.78 314.44 1.85 314.46 1.93 314.48 2.00 314.50 2.08 314.52 2.16 314.54 2.24 314.56 2.32 314.58 2.40 314.60 2.48 314.62 2.56 314.64 2.63 314.66 2.71 314.68 2.79 314.70 2.86 314.72 2.93 314.74 3.01 314.76 3.07 314.78 3.14 314.80 3.20 314.82 3.26 314.84 3.30 314.86 3.35 314.88 3.41 314.90 3.46 314.92 3.51 314.94 3.57 314.96 3.62 314.98 3.67 315.00 3.72 315.02 3.77 315.04 3.82 315.06 3.86 315.08 3.91 315.10 3.96 315.12 4.00 315.14 4.05 315.16 4.09 315.18 4.14 315.20 4.18 315.22 4.22 315.24 4.27 315.26 4.31 315.28 4.35 315.30 4.39 315.32 4.43 315.34 4.47 315.36 4.52 315.38 4.56 315.40 4.59 315.42 4.63 315.44 4.67 315.46 4.71 Elevation (feet) Primary (cfs) 315.48 4.75 315.50 4.79 315.52 4.82 315.54 4.86 315.56 4.90 315.58 4.94 315.60 4.97 315.62 5.01 315.64 5.04 315.66 5.08 315.68 5.11 315.70 5.15 315.72 5.18 315.74 5.22 315.76 5.25 315.78 5.29 315.80 5.32 315.82 5.35 315.84 5.39 315.86 5.42 315.88 5.45 315.90 5.49 315.92 5.52 315.94 5.55 315.96 5.58 315.98 5.62 316.00 5.65 316.02 5.68 316.04 5.71 316.06 5.74 316.08 5.77 316.10 5.80 316.12 5.83 316.14 5.86 316.16 5.90 316.18 5.93 316.20 5.96 316.22 5.99 316.24 6.02 316.26 6.04 316.28 6.07 316.30 6.10 316.32 6.13 316.34 6.16 316.36 6.19 316.38 6.22 316.40 6.25 316.42 6.28 316.44 6.30 316.46 6.33 Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 70HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 7P: UGS Elevation (feet) Storage (acre-feet) 312.30 0.000 312.35 0.000 312.40 0.000 312.45 0.000 312.50 0.000 312.55 0.001 312.60 0.001 312.65 0.001 312.70 0.001 312.75 0.001 312.80 0.001 312.85 0.001 312.90 0.001 312.95 0.002 313.00 0.002 313.05 0.002 313.10 0.002 313.15 0.002 313.20 0.003 313.25 0.003 313.30 0.003 313.35 0.003 313.40 0.003 313.45 0.004 313.50 0.004 313.55 0.004 313.60 0.004 313.65 0.004 313.70 0.005 313.75 0.005 313.80 0.005 313.85 0.005 313.90 0.005 313.95 0.006 314.00 0.006 314.05 0.006 314.10 0.006 314.15 0.006 314.20 0.007 314.25 0.007 314.30 0.007 314.35 0.007 314.40 0.007 314.45 0.008 314.50 0.008 314.55 0.008 314.60 0.008 314.65 0.008 314.70 0.009 314.75 0.009 314.80 0.009 314.85 0.009 314.90 0.009 Elevation (feet) Storage (acre-feet) 314.95 0.009 315.00 0.010 315.05 0.010 315.10 0.010 315.15 0.010 315.20 0.010 315.25 0.011 315.30 0.011 315.35 0.011 315.40 0.011 315.45 0.011 315.50 0.012 315.55 0.012 315.60 0.012 315.65 0.012 315.70 0.012 315.75 0.013 315.80 0.013 315.85 0.013 315.90 0.013 315.95 0.013 316.00 0.013 316.05 0.013 316.10 0.013 316.15 0.013 316.20 0.013 316.25 0.013 316.30 0.013 316.35 0.013 316.40 0.013 316.45 0.013 Type III 24-hr 50-yr Rainfall=5.02"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 71HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Link 9L: PDA-2 TOTAL Inflow Area = 0.190 ac, 78.95% Impervious, Inflow Depth > 3.60" for 50-yr event Inflow = 0.49 cfs @ 12.17 hrs, Volume= 0.057 af Primary = 0.49 cfs @ 12.17 hrs, Volume= 0.057 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 9L: PDA-2 TOTAL Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.190 ac 0.49 cfs0.49 cfs Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 72HydroCAD® 10.20-3f s/n 13171 © 2023 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=0.200 ac 75.00% Impervious Runoff Depth>3.69"Subcatchment 1S: EDA-1 Tc=6.0 min CN=83 Runoff=0.84 cfs 0.062 af Runoff Area=0.110 ac 100.00% Impervious Runoff Depth>5.33"Subcatchment 2S: EDA-2 Tc=6.0 min CN=98 Runoff=0.59 cfs 0.049 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>4.53"Subcatchment 3S: EDA-3 Tc=6.0 min CN=91 Runoff=0.40 cfs 0.030 af Runoff Area=0.120 ac 66.67% Impervious Runoff Depth>3.20"Subcatchment 4S: PDA-1 Tc=6.0 min CN=78 Runoff=0.44 cfs 0.032 af Runoff Area=0.150 ac 93.33% Impervious Runoff Depth>4.87"Subcatchment 5S: PDA-2A Tc=6.0 min CN=94 Runoff=0.77 cfs 0.061 af Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>4.53"Subcatchment 6S: PDA-3 Tc=6.0 min CN=91 Runoff=0.40 cfs 0.030 af Runoff Area=0.040 ac 25.00% Impervious Runoff Depth>1.21"Subcatchment 8S: PDA-2B Tc=6.0 min CN=54 Runoff=0.05 cfs 0.004 af Peak Elev=313.89' Storage=0.005 af Inflow=0.77 cfs 0.061 afPond 7P: UGS Outflow=0.51 cfs 0.061 af Inflow=0.54 cfs 0.065 afLink 9L: PDA-2 TOTAL Primary=0.54 cfs 0.065 af Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 73HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: EDA-1 Runoff = 0.84 cfs @ 12.09 hrs, Volume= 0.062 af, Depth> 3.69" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=5.57" Area (ac) CN Description 0.150 98 Paved parking, HSG A 0.050 39 >75% Grass cover, Good, HSG A 0.200 83 Weighted Average 0.050 25.00% Pervious Area 0.150 75.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 1S: EDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 100-yr Rainfall=5.57" Runoff Area=0.200 ac Runoff Volume=0.062 af Runoff Depth>3.69" Tc=6.0 min CN=83 0.84 cfs Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 74HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: EDA-2 Runoff = 0.59 cfs @ 12.09 hrs, Volume= 0.049 af, Depth> 5.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=5.57" Area (ac) CN Description 0.110 98 Paved parking, HSG A 0.110 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 2S: EDA-2 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 100-yr Rainfall=5.57" Runoff Area=0.110 ac Runoff Volume=0.049 af Runoff Depth>5.33" Tc=6.0 min CN=98 0.59 cfs Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 75HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: EDA-3 Runoff = 0.40 cfs @ 12.09 hrs, Volume= 0.030 af, Depth> 4.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=5.57" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 3S: EDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 100-yr Rainfall=5.57" Runoff Area=0.080 ac Runoff Volume=0.030 af Runoff Depth>4.53" Tc=6.0 min CN=91 0.40 cfs Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 76HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: PDA-1 Runoff = 0.44 cfs @ 12.09 hrs, Volume= 0.032 af, Depth> 3.20" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=5.57" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.040 39 >75% Grass cover, Good, HSG A 0.120 78 Weighted Average 0.040 33.33% Pervious Area 0.080 66.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 4S: PDA-1 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.48 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 III 24-hr 100-yr Rainfall=5.57" Runoff Area=0.120 ac Runoff Volume=0.032 af Runoff Depth>3.20" Tc=6.0 min CN=78 0.44 cfs Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 77HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PDA-2A Runoff = 0.77 cfs @ 12.09 hrs, Volume= 0.061 af, Depth> 4.87" Routed to Pond 7P : UGS Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=5.57" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.150 94 Weighted Average 0.010 6.67% Pervious Area 0.140 93.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, ab Subcatchment 5S: PDA-2A Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 100-yr Rainfall=5.57" Runoff Area=0.150 ac Runoff Volume=0.061 af Runoff Depth>4.87" Tc=6.0 min CN=94 0.77 cfs Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 78HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: PDA-3 Runoff = 0.40 cfs @ 12.09 hrs, Volume= 0.030 af, Depth> 4.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=5.57" Area (ac) CN Description 0.070 98 Paved parking, HSG A 0.010 39 >75% Grass cover, Good, HSG A 0.080 91 Weighted Average 0.010 12.50% Pervious Area 0.070 87.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 6S: PDA-3 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 III 24-hr 100-yr Rainfall=5.57" Runoff Area=0.080 ac Runoff Volume=0.030 af Runoff Depth>4.53" Tc=6.0 min CN=91 0.40 cfs Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 79HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: PDA-2B Runoff = 0.05 cfs @ 12.11 hrs, Volume= 0.004 af, Depth> 1.21" Routed to Link 9L : PDA-2 TOTAL Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=5.57" Area (ac) CN Description 0.010 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.040 54 Weighted Average 0.030 75.00% Pervious Area 0.010 25.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, AB Subcatchment 8S: PDA-2B Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.052 0.05 0.048 0.046 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 III 24-hr 100-yr Rainfall=5.57" Runoff Area=0.040 ac Runoff Volume=0.004 af Runoff Depth>1.21" Tc=6.0 min CN=54 0.05 cfs Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 80HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Pond 7P: UGS Inflow Area = 0.150 ac, 93.33% Impervious, Inflow Depth > 4.87" for 100-yr event Inflow = 0.77 cfs @ 12.09 hrs, Volume= 0.061 af Outflow = 0.51 cfs @ 12.19 hrs, Volume= 0.061 af, Atten= 34%, Lag= 6.1 min Primary = 0.51 cfs @ 12.19 hrs, Volume= 0.061 af Routed to Link 9L : PDA-2 TOTAL Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 313.89' @ 12.18 hrs Surf.Area= 0.005 ac Storage= 0.005 af Plug-Flow detention time= 5.8 min calculated for 0.061 af (100% of inflow) Center-of-Mass det. time= 4.6 min ( 774.7 - 770.1 ) Volume Invert Avail.Storage Storage Description #1A 312.30' 0.002 af 9.00'W x 25.00'L x 4.17'H Field A 0.022 af Overall - 0.016 af Embedded = 0.005 af x 40.0% Voids #2A 312.80' 0.011 af retain_it retain_it 3.0' x 3 Inside #1 Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 0.013 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 311.30'12.0" Round Culvert L= 18.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 311.30' / 310.94' S= 0.0200 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 312.30'4.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 313.85'12.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.50 cfs @ 12.19 hrs HW=313.88' (Free Discharge) 1=Culvert (Passes 0.50 cfs of 4.31 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.50 cfs @ 5.73 fps) 3=Orifice/Grate (Orifice Controls 0.00 cfs @ 0.59 fps) Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 81HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS - Chamber Wizard Field A Chamber Model = retain_it retain_it 3.0' (retain-it®) Inside= 84.0"W x 36.0"H => 21.33 sf x 8.00'L = 170.6 cf Outside= 96.0"W x 44.0"H => 29.33 sf x 8.00'L = 234.7 cf 1 Rows adjusted for 37.8 cf perimeter wall 3 Chambers/Row x 8.00' Long = 24.00' Row Length +6.0" End Stone x 2 = 25.00' Base Length 1 Rows x 96.0" Wide + 6.0" Side Stone x 2 = 9.00' Base Width 6.0" Stone Base + 44.0" Chamber Height = 4.17' Field Height 4.7 cf Sidewall x 3 x 2 + 4.7 cf Endwall x 1 x 2 = 37.8 cf Perimeter Wall 3 Chambers x 170.6 cf - 37.8 cf Perimeter wall = 474.1 cf Chamber Storage 3 Chambers x 234.7 cf = 704.0 cf Displacement 937.5 cf Field - 704.0 cf Chambers = 233.5 cf Stone x 40.0% Voids = 93.4 cf Stone Storage Chamber Storage + Stone Storage = 567.5 cf = 0.013 af Overall Storage Efficiency = 60.5% Overall System Size = 25.00' x 9.00' x 4.17' 3 Chambers 34.7 cy Field 8.6 cy Stone Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 82HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Pond 7P: UGS Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.150 ac Peak Elev=313.89' Storage=0.005 af 0.77 cfs 0.51 cfs Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 83HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Discharge for Pond 7P: UGS Elevation (feet) Primary (cfs) 312.30 0.00 312.32 0.00 312.34 0.00 312.36 0.01 312.38 0.02 312.40 0.02 312.42 0.03 312.44 0.04 312.46 0.06 312.48 0.07 312.50 0.08 312.52 0.10 312.54 0.11 312.56 0.13 312.58 0.14 312.60 0.15 312.62 0.17 312.64 0.17 312.66 0.18 312.68 0.19 312.70 0.20 312.72 0.21 312.74 0.22 312.76 0.23 312.78 0.24 312.80 0.24 312.82 0.25 312.84 0.26 312.86 0.26 312.88 0.27 312.90 0.28 312.92 0.28 312.94 0.29 312.96 0.30 312.98 0.30 313.00 0.31 313.02 0.31 313.04 0.32 313.06 0.32 313.08 0.33 313.10 0.33 313.12 0.34 313.14 0.34 313.16 0.35 313.18 0.35 313.20 0.36 313.22 0.36 313.24 0.37 313.26 0.37 313.28 0.38 313.30 0.38 313.32 0.39 313.34 0.39 Elevation (feet) Primary (cfs) 313.36 0.40 313.38 0.40 313.40 0.41 313.42 0.41 313.44 0.41 313.46 0.42 313.48 0.42 313.50 0.43 313.52 0.43 313.54 0.44 313.56 0.44 313.58 0.44 313.60 0.45 313.62 0.45 313.64 0.46 313.66 0.46 313.68 0.46 313.70 0.47 313.72 0.47 313.74 0.47 313.76 0.48 313.78 0.48 313.80 0.49 313.82 0.49 313.84 0.49 313.86 0.50 313.88 0.50 313.90 0.51 313.92 0.53 313.94 0.55 313.96 0.57 313.98 0.59 314.00 0.62 314.02 0.65 314.04 0.68 314.06 0.72 314.08 0.76 314.10 0.80 314.12 0.84 314.14 0.89 314.16 0.94 314.18 0.99 314.20 1.05 314.22 1.10 314.24 1.16 314.26 1.22 314.28 1.29 314.30 1.35 314.32 1.42 314.34 1.49 314.36 1.56 314.38 1.63 314.40 1.70 Elevation (feet) Primary (cfs) 314.42 1.78 314.44 1.85 314.46 1.93 314.48 2.00 314.50 2.08 314.52 2.16 314.54 2.24 314.56 2.32 314.58 2.40 314.60 2.48 314.62 2.56 314.64 2.63 314.66 2.71 314.68 2.79 314.70 2.86 314.72 2.93 314.74 3.01 314.76 3.07 314.78 3.14 314.80 3.20 314.82 3.26 314.84 3.30 314.86 3.35 314.88 3.41 314.90 3.46 314.92 3.51 314.94 3.57 314.96 3.62 314.98 3.67 315.00 3.72 315.02 3.77 315.04 3.82 315.06 3.86 315.08 3.91 315.10 3.96 315.12 4.00 315.14 4.05 315.16 4.09 315.18 4.14 315.20 4.18 315.22 4.22 315.24 4.27 315.26 4.31 315.28 4.35 315.30 4.39 315.32 4.43 315.34 4.47 315.36 4.52 315.38 4.56 315.40 4.59 315.42 4.63 315.44 4.67 315.46 4.71 Elevation (feet) Primary (cfs) 315.48 4.75 315.50 4.79 315.52 4.82 315.54 4.86 315.56 4.90 315.58 4.94 315.60 4.97 315.62 5.01 315.64 5.04 315.66 5.08 315.68 5.11 315.70 5.15 315.72 5.18 315.74 5.22 315.76 5.25 315.78 5.29 315.80 5.32 315.82 5.35 315.84 5.39 315.86 5.42 315.88 5.45 315.90 5.49 315.92 5.52 315.94 5.55 315.96 5.58 315.98 5.62 316.00 5.65 316.02 5.68 316.04 5.71 316.06 5.74 316.08 5.77 316.10 5.80 316.12 5.83 316.14 5.86 316.16 5.90 316.18 5.93 316.20 5.96 316.22 5.99 316.24 6.02 316.26 6.04 316.28 6.07 316.30 6.10 316.32 6.13 316.34 6.16 316.36 6.19 316.38 6.22 316.40 6.25 316.42 6.28 316.44 6.30 316.46 6.33 Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 84HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 7P: UGS Elevation (feet) Storage (acre-feet) 312.30 0.000 312.35 0.000 312.40 0.000 312.45 0.000 312.50 0.000 312.55 0.001 312.60 0.001 312.65 0.001 312.70 0.001 312.75 0.001 312.80 0.001 312.85 0.001 312.90 0.001 312.95 0.002 313.00 0.002 313.05 0.002 313.10 0.002 313.15 0.002 313.20 0.003 313.25 0.003 313.30 0.003 313.35 0.003 313.40 0.003 313.45 0.004 313.50 0.004 313.55 0.004 313.60 0.004 313.65 0.004 313.70 0.005 313.75 0.005 313.80 0.005 313.85 0.005 313.90 0.005 313.95 0.006 314.00 0.006 314.05 0.006 314.10 0.006 314.15 0.006 314.20 0.007 314.25 0.007 314.30 0.007 314.35 0.007 314.40 0.007 314.45 0.008 314.50 0.008 314.55 0.008 314.60 0.008 314.65 0.008 314.70 0.009 314.75 0.009 314.80 0.009 314.85 0.009 314.90 0.009 Elevation (feet) Storage (acre-feet) 314.95 0.009 315.00 0.010 315.05 0.010 315.10 0.010 315.15 0.010 315.20 0.010 315.25 0.011 315.30 0.011 315.35 0.011 315.40 0.011 315.45 0.011 315.50 0.012 315.55 0.012 315.60 0.012 315.65 0.012 315.70 0.012 315.75 0.013 315.80 0.013 315.85 0.013 315.90 0.013 315.95 0.013 316.00 0.013 316.05 0.013 316.10 0.013 316.15 0.013 316.20 0.013 316.25 0.013 316.30 0.013 316.35 0.013 316.40 0.013 316.45 0.013 Type III 24-hr 100-yr Rainfall=5.57"12 Ballston Avenue Hydrology Printed 10/11/2023Prepared by Solli Engineering Page 85HydroCAD® 10.20-3f s/n 13171 © 2023 HydroCAD Software Solutions LLC Summary for Link 9L: PDA-2 TOTAL Inflow Area = 0.190 ac, 78.95% Impervious, Inflow Depth > 4.09" for 100-yr event Inflow = 0.54 cfs @ 12.18 hrs, Volume= 0.065 af Primary = 0.54 cfs @ 12.18 hrs, Volume= 0.065 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 9L: PDA-2 TOTAL Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.190 ac 0.54 cfs0.54 cfs Project By AWC 06/09/23 Location CJB 06/09/23 Bold one: Present Developed 1. Runoff Coefficient © Product of C x area x acres mi2 % 0.95 0.08 0.35 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1 Use only one C source per line 0.08 0.08 0.09 0.88total area Totals =0.09 C (weighted) =total product = = 0.88 Use C = Impervious Area 0.08 Pervious Area 0.01 hydrologic hydrologic condition; group percent impervious; (Appendix A) unconnected/connected impervious area ratio) Soil Name Cover description C 1 Area and (cover type, treatment, and Proposed Redevelopment Date 12 Ballston Avenue, Saratoga Springs, NY Checked Date CB-1 Runoff Coefficient - Saratoga.xls Project By AWC 06/09/23 Location CJB 06/09/23 Bold one: Present Developed 1. Runoff Coefficient © Product of C x area x acres mi2 % 0.95 0.05 0.35 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1 Use only one C source per line 0.05 0.05 0.05 0.95total area Totals =0.05 C (weighted) =total product = = 0.95 Use C = Impervious Area 0.05 Pervious Area 0.00 hydrologic hydrologic condition; group percent impervious; (Appendix A) unconnected/connected impervious area ratio) Soil Name Cover description C 1 Area and (cover type, treatment, and Proposed Redevelopment Date 12 Ballston Avenue, Saratoga Springs, NY Checked Date RF-1 Runoff Coefficient - Saratoga.xls AREA 0.08 acres CS-3 WEIGHTED C 0.88 110 microns TC 6.00 minutes RAINFALL STATION 119 Rainfall Intensity1 (in/hr) Hydraulic Loading Rate (gpm/ft2) Removal Efficiency (%) Incremental Removal (%) 0.08 0.36 100.0 44.6 0.16 0.72 100.0 22.0 0.24 1.07 100.0 10.9 0.32 1.43 100.0 4.1 0.40 1.79 100.0 3.2 0.48 2.15 100.0 2.4 0.56 2.50 100.0 2.2 0.64 2.86 100.0 1.1 0.72 3.22 100.0 1.4 0.80 3.58 100.0 0.7 1.00 4.47 100.0 1.9 1.20 5.36 100.0 1.4 1.60 7.15 100.0 1.2 2.00 8.94 100.0 1.6 98.5 0.0% 98.5% 98.5% 1 - Based on 10 years of 15-minute precipitation data from NCDC station 7514 in Schenectady County, NY 2 - Reduction due to use of 60-minute data for a site that has a time of concentration less than 30-minutes. WQU Estimated Net Annual Solids Load Reduction Based on the Rational Rainfall Method PROPOSED CHIPOTLE SARATOGA SPRINGS, NY 2.4% CASCADE MODEL PARTICLE SIZE Percent Rainfall Volume1 44.6% 22.0% 10.9% 4.1% 3.2% 2.2% 1.1% 1.4% 0.7% 1.9% 1.4% 1.2% 1.6% Removal Efficiency Adjustment2 = Predicted % Annual Rainfall Treated = Predicted Net Annual Load Removal Efficiency = (3'-0" [914])SOLIDS STORAGE SUMP INLET PIPE (MULTIPLE INLET PIPES MAY BE ACCOMMODATED) OUTLET PIPE VARIESBB 1'-814" [514]PLAN VIEW B-B NOT TO SCALE ELEVATION A-A NOT TO SCALE FIBERGLASS OR ALUMINUM INTERNAL COMPONENTS FLOW CONTRACTOR TO GROUT TO FINISHED GRADE GRADE RINGS/RISERS A A 36" [914] I.D. MANHOLE STRUCTURE TOP SLAB ACCESS (SEE FRAME AND COVER DETAIL) FLOW TOP OF CENTER CHAMBER (EXTENSIONS AVAILABLE AS REQUIRED) INLET PIPE(S) LOCATION MAY VARY WITHIN 256° PERMANENT POOL ELEVATION FRAME AND COVER (DIAMETER VARIES) NOT TO SCALE www.ContechES.com ® 800-338-1122 513-645-7000 513-645-7993 FAX 9100 Centre Pointe Dr., Suite 400, West Chester, OH 45069 CS-3 CASCADE SEPARATOR STANDARD DETAIL I:\COMMON\CAD\TREATMENT\21 CASCADE\40 STANDARD DRAWINGS\DWG\IN PROCESS\CS-3-DTL.DWG 6/26/2023 2:40 PMwww.contechES.com CASCADE SEPARATOR DESIGN NOTES THE STANDARD CS-3 CONFIGURATION IS SHOWN. ALTERNATE CONFIGURATIONS ARE AVAILABLE AND ARE LISTED BELOW. SOME CONFIGURATIONS MAY BE COMBINED TO SUIT SITE REQUIREMENTS. CONFIGURATION DESCRIPTION CURB INLET ONLY (NO INLET PIPE) CURB INLET WITH INLET PIPE OR PIPES GENERAL NOTES 1.CONTECH TO PROVIDE ALL MATERIALS UNLESS NOTED OTHERWISE. 2.FOR SITE SPECIFIC DRAWINGS WITH DETAILED STRUCTURE DIMENSIONS AND WEIGHT, PLEASE CONTACT YOUR CONTECH ENGINEERED SOLUTIONS LLC REPRESENTATIVE. www.ContechES.com 3.CASCADE SEPARATOR WATER QUALITY STRUCTURE SHALL BE IN ACCORDANCE WITH ALL DESIGN DATA AND INFORMATION CONTAINED IN THIS DRAWING. CONTRACTOR TO CONFIRM STRUCTURE MEETS REQUIREMENTS OF PROJECT. 4.CASCADE SEPARATOR STRUCTURE SHALL MEET AASHTO HS20 LOAD RATING, ASSUMING EARTH COVER OF 0' - 2' [610], AND GROUNDWATER ELEVATION AT, OR BELOW, THE OUTLET PIPE INVERT ELEVATION. ENGINEER OF RECORD TO CONFIRM ACTUAL GROUNDWATER ELEVATION. CASTINGS SHALL MEET AASHTO M306 AND BE CAST WITH THE CONTECH LOGO. 5.CASCADE SEPARATOR STRUCTURE SHALL BE PRECAST CONCRETE CONFORMING TO ASTM C478 AND AASHTO LOAD FACTOR DESIGN METHOD. 6.ALTERNATE UNITS ARE SHOWN IN MILLIMETERS [mm ]. INSTALLATION NOTES A.ANY SUB-BASE, BACKFILL DEPTH, AND/OR ANTI-FLOTATION PROVISIONS ARE SITE-SPECIFIC DESIGN CONSIDERATIONS AND SHALL BE SPECIFIED BY ENGINEER OF RECORD. B.CONTRACTOR TO PROVIDE EQUIPMENT WITH SUFFICIENT LIFTING AND REACH CAPACITY TO LIFT AND SET THE CASCADE SEPARATOR MANHOLE STRUCTURE. C.CONTRACTOR TO INSTALL JOINT SEALANT BETWEEN ALL STRUCTURE SECTIONS AND ASSEMBLE STRUCTURE. D.CONTRACTOR TO PROVIDE, INSTALL, AND GROUT INLET AND OUTLET PIPE(S). MATCH PIPE INVERTS WITH ELEVATIONS SHOWN. ALL PIPE CENTERLINES TO MATCH PIPE OPENING CENTERLINES. E.CONTRACTOR TO TAKE APPROPRIATE MEASURES TO ASSURE UNIT IS WATER TIGHT, HOLDING WATER TO FLOWLINE INVERT MINIMUM. IT IS SUGGESTED THAT ALL JOINTS BELOW PIPE INVERTS ARE GROUTED. SITE SPECIFIC DATA REQUIREMENTS STRUCTURE ID WATER QUALITY FLOW RATE (cfs [L/s]) PEAK FLOW RATE (cfs [L/s]) RETURN PERIOD OF PEAK FLOW (yrs) RIM ELEVATION PIPE DATA:INVERT MATERIAL DIAMETER INLET PIPE 1 INLET PIPE 2 OUTLET PIPE NOTES / SPECIAL REQUIREMENTS: Appendix D – Detailed Design Plans Property Survey Prepared by Van Dusen & Steves Land Surveyors Existing Drainage Area Map (DA-1) Proposed Drainage Area Map (DA-2) Subcatchment Drainage Area Map (DA-3) For more information regarding the Design Plans refer to the Permitting Plan Set, prepared by Solli Engineering, submitted in conjunction with this Report. CIRF CIRF WV WV WV WV WV G G FF=32 1 . 2 2 ' FF=32 0 . 7 2 'One Story Wood Frame BuildingGas Met e r Electric M e t e r EnclosureA/C G Traffic Si g n al B o x Traffic Si g n al B o x 2" Cra b a p pl e 2" Cra b a p pl e 2" Crabapple Sign-T r u c k s No Rig h t T u r n LP CB CB CB Orange Paint Lines (Faded)Traffic Signal BoxYellow P a i n t L i n e Orange Paint LinesLP LP LP Concrete Si de walk Sign-Traffic Lights AheadBrick Planter Brick PlanterBrick PlanterBrick Planter Concrete SidewalkAsphaltOrange P ai n t Li n e s Util Access Cover Rim=316.58'Util Access Cover Rim=316.71' Access Cover Rim=316.40' Catch Basin Rim=315.75'Crosswalk Signal Pole Crosswalk Signal Pole Crosswalk Signal Pole Crosswalk Signal Pole Traffic Signal Pole U.P. NM7 U.P. NM8 U.P. NM6SSAC Blue Paint L i n e 2" Cedar (4 Tr e e s ) 4" Elm Clump 4" Elm Clump Crosswalk Signal Pole D W S Bollards Concrete SidewalkConcrete Wheel Stop (Typ.) Orang e P ai n t Li n e Util Access CoverRim=316.97'Hydrant BM Bolt @ Arrow=318.45' Tr a f f i c L i g h t s 320320320320 315 3 1 5 31 6 317 318 318 317 316 319 318316 317 318 319 3183173173 1 8 Asphalt Parking U.P. NM5 Area 13959.8 Sq. Feet 0.32 Acres Deed References Karl Wolf and Wolf Hi-Roc Lanes, Inc. To Saratoga 16, LLC Dated: June 05, 2006 Recorded on: June 08, 2006 B:1759 P:260 12 Ballston Avenue, LLC To The City of Saratoga Springs Dated: September 18, 2014 Recorded on: October 07, 2014 Instrument No. 2014029210 12 Ballston Avenue, LLC To Saratoga Prime Properties, LLC Dated: March 20, 2015 Recorded on: March 20, 2015 Instrument No. 2015007841 Map Reference Map of a survey of lands of Carmen & Josephine Palma Dated: March 13, 1969 By: John B. Van Dusen Legend CIRF = Capped Iron Rod Found U.P. = Utility Pole = Overhead Utility Wire = Water Valve = Gas Valve CB = Catch Basin SSAC = Sanitary Sewer Access Cover = Traffic Control Box LP = Light Pole G WV1 (103.93'1 ( 64.60 ' 1 ( 76.4 1 '40.95'6 :78.90'6 :174.73' 6 : LP StepPorch Wood Fen c e LP Roof O v e r h a n g Roof O v e r h a n g Porch Rim=316.77' 8" PVC IN Inv.=312.38' 6" PVC IN Inv.=311.79' 8" PVC OUT Inv.=311.41'MARKED WITH AN ORIGINAL OF THE LAND SURVEYORS"ONLY COPIES FROM THE ORIGINAL OF THIS SURVEYAGENCY AND LENDING INSTITUTION LISTED HEREON, ANDON HIS BEHALF TO THE TITLE COMPANY, GOVERNMENTALTO THE PERSON FOR WHOM THE SURVEY IS PREPARED, ANDLAND SURVEYORS. SAID CERTIFICATIONS SHALL RUN ONLYBY THE NEW YORK STATE ASSOCIATION OF PROFESSIONALEXISTING CODE OF PRACTICE FOR LAND SURVEYORS ADOPTEDTHIS SURVEY WAS PREPARED IN ACCORDANCE WITH THE "CERTIFICATIONS INDICATED HEREON SIGNIFY THATSEAL SHALL BE CONSIDERED TO BE VALID TRUE COPIES."VIOLATION OF SECTION 7209, SUB-DIVISION 2, OF THEMAP BEARING A LICENSED LAND SURVEYORS SEAL IS A "UNAUTHORIZED ALTERATION OR ADDITION TO A SURVEYNEW YORK STATE EDUCATION LAW."TO THE ASSIGNEES OF THE LENDING INSTITUTION."Scale 1"=20' Date: XXX SHEET 1 OF 1 DWG. NO. 22-239MagneticSOLLI ENGINEERING 165.83-1-3 165.83-1-3D3062 6.) 3.) 4.) PARCEL IS SUBJECT TO ANY EASEMENTS OF RECORD.2.) NOTES: 1.) 7.) 5.) THIS MAP WAS PREPARED WITHOUT THE BENEFIT OF AN ABSTRACT OF TITLE OR AN UP TO DATE TITLE REPORT AND IS THEREFORE SUBJECT TO ANY STATEMENT OF FACTS SHOWN THEREON. THIS MAP WAS PREPARED FROM AN ACTUAL FIELD SURVEY MADE IN ACCORDANCE WITH THE EXISTING CODE OF PRACTICE ADOPTED BY THE NEW YORK STATE ASSOCIATION OF PROFESSIONAL LAND SURVEYORS. 7+,60$3,6&23<5,*+79$1'86(1 67(9(6/$1' SURVEYORS. UNAUTHORIZED ALTERATION OR ADDITION TO THIS DOCUMENT IS VIOLATION OF SECTION 7209, SUBDIVISION 2, OF NEW YORK STATE EDUCATION LAW. DIMENSIONS BETWEEN PROPERTY LINES AND STRUCTURES ARE TO THE NEAREST HALF FOOT AND ARE FOR THE SOLE PURPOSE OF INTERPRETING THEIR CONFORMANCE WITH ZONING AND NOT INTENDED TO AID IN THE ESTABLISHMENT OR RETRACEMENT OF PROPERTY LINES. CONTOURS SHOWN HEREON ARE REFERENCED TO THE NORTH AMERICAN VERTICAL DATUM OF 1988 (NAVD88). THE SURVEYED PARCEL IS SUBJECT TO WHATEVER RIGHTS, TITLE OR INTEREST THE CITY OF SARATOGA SPRINGS, THE COUNTY OF SARATOGA, AND THE PEOPLE OF THE STATE OF NEW YORK MAY HAVE TO MAINTAIN THE ROADS, AND TO WHATEVER RIGHTS, TITLE OR INTEREST THE TRAVELING PUBLIC MAY HAVE TO THE BED OF THE ROADS. 8.)OFFSETS BETWEEN PROPERTY LINES AND STRUCTURES SHOWN HEREON ARE TO ROOF OVERHANGS UNLESS OTHERWISE NOTED. One Story Wood Frame BuildingGas M e t e r Elect r i c M e t e r EnclosureA/C 2" Craba p pl e 2" Craba p pl e 2" Crabapple Brick Planter Brick PlanterBrick PlanterBrick Planter 2" Ced a r ( 4 T r e e s ) 4" Elm Clump 4" Elm Clump 320320320320 3153 1 6 317 318 318 317 319 318316 317 318 319 318317317318Porc h StepsStepsRoof O v e r h a n g Roof O v e r h a n g Step s PorchBALLST O N A V E N U E HAMILTON STREETEXISTING DRAINAGE AREA 1 (EDA-1) TOTAL DRAINAGE AREA = 0.20 AC OPEN SPACE (GOOD, A) = 0.05 AC IMPERVIOUS AREA = 0.15 AC CURVE NUMBER = 83 TIME OF CONCENTRATION = 6.0 MIN. EXISTING DRAINAGE AREA 2 (EDA-2) TOTAL DRAINAGE AREA = 0.11 AC IMPERVIOUS AREA = 0.11 AC CURVE NUMBER = 98 TIME OF CONCENTRATION = 6.0 MIN. EXISTING DRAINAGE AREA 3 (EDA-3) TOTAL DRAINAGE AREA = 0.08 AC OPEN SPACE (GOOD, A) = 0.01 AC IMPERVIOUS AREA = 0.07 AC CURVE NUMBER = 91 TIME OF CONCENTRATION = 6.0 MIN. PERVIOUS AREA (NO PLOT) LEGEND LIMIT OF DRAINAGE AREA FLOW PATH PROPERTY LINE RIGHT-OF-WAY LINE ADJOINING LOT LINE 501 Main Street, Monroe, CT 06468 11 Vanderbilt Ave, Norwood, MA 02062 Sheet Title:Sheet #: Project: Drawn By: Checked By: Approved By: Project #: Plan Date: Scale: PROPOSED CHIPOTLE 12 BALLSTON AVENUE (M-B-L: 165.83-1-3) SARATOGA SPRINGS, NEW YORK OWNER: SARATOGA PRIME PROPERTIES LLC / 215 BALLARD ROAD, WILTON NY 12831 APPLICANT: COLLABDEV 2 LLC / 529 MAIN STREET, BOSTON, MA 02129 Graphic Scale: Rev. #:Date Description KMS 21206201 ENGINEERING Kevin Solli, P.E. NY 092156 T: (203) 880-5455 F: (203) 880-9695 T: (781) 352-8491 F: (203) 880-9695 EXISTING DRAINAGE AREA MAP DA-1 10 0 10 20 06/09/23 1" = 10' CJB AWC GENERAL NOTESGENERAL NOTES 1.THE STORMWATER MANAGEMENT PLAN AND DESIGN IS INTENDED TO BE IN COMPLIANCE WITH THE 2015 NEW YORK STATE STORMWATER DESIGN MANUAL. 2.STORMWATER RUNOFF ANALYSIS WAS CALCULATED USING THE SCS TR-55 METHODOLOGY. 1 10/16/23 Revised Per Engineering Comments One Story Wood Frame BuildingGas M e t e r Elect r i c M e t e r EnclosureA/C 2" Craba p pl e 2" Craba p pl e 2" Crabapple Brick Planter Brick PlanterBrick PlanterBrick Planter 2" Ced a r ( 4 T r e e s ) 4" Elm Clump 4" Elm Clump 320320320320 31 53153 1 6 317 318 318 317 319 318316 317 318 319 318317317318Porc h StepsStepsRoof O v e r h a n g Roof O v e r h a n g Step s PorchBALLST O N A V E N U E HAMILTON STREET316 3 1 8 317317317 318317318 31831 7 317 317 318318318 319 319 PROPOSED DRAINAGE AREA 1 (PDA-1) TOTAL DRAINAGE AREA = 0.12 AC OPEN SPACE (GOOD, A) = 0.04 AC IMPERVIOUS AREA = 0.08 AC CURVE NUMBER = 78 TIME OF CONCENTRATION = 6.0 MIN. PROPOSED DRAINAGE AREA 2A (PDA-2A) TOTAL DRAINAGE AREA = 0.15 AC OPEN SPACE (GOOD, A) = 0.01 AC IMPERVIOUS AREA = 0.14 AC CURVE NUMBER = 94 TIME OF CONCENTRATION = 6.0 MIN. PROPOSED DRAINAGE AREA 3 (PDA-3) TOTAL DRAINAGE AREA = 0.08 AC OPEN SPACE (GOOD, A) = 0.01 AC IMPERVIOUS AREA = 0.07 AC CURVE NUMBER = 91 TIME OF CONCENTRATION = 6.0 MIN. PROPOSED DRAINAGE AREA 2B (PDA-2B) TOTAL DRAINAGE AREA = 0.04 AC OPEN SPACE (GOOD, A) = 0.03 AC IMPERVIOUS AREA = 0.01 AC CURVE NUMBER = 54 TIME OF CONCENTRATION = 6.0 MIN. PERVIOUS AREA (NO PLOT) LEGEND LIMIT OF DRAINAGE AREA FLOW PATH PROPERTY LINE RIGHT-OF-WAY LINE ADJOINING LOT LINE 501 Main Street, Monroe, CT 06468 11 Vanderbilt Ave, Norwood, MA 02062 Sheet Title:Sheet #: Project: Drawn By: Checked By: Approved By: Project #: Plan Date: Scale: PROPOSED CHIPOTLE 12 BALLSTON AVENUE (M-B-L: 165.83-1-3) SARATOGA SPRINGS, NEW YORK OWNER: SARATOGA PRIME PROPERTIES LLC / 215 BALLARD ROAD, WILTON NY 12831 APPLICANT: COLLABDEV 2 LLC / 529 MAIN STREET, BOSTON, MA 02129 Graphic Scale: Rev. #:Date Description KMS 21206201 ENGINEERING Kevin Solli, P.E. NY 092156 T: (203) 880-5455 F: (203) 880-9695 T: (781) 352-8491 F: (203) 880-9695 PROPOSED DRAINAGE AREA MAP DA-2 10 0 10 20 06/09/23 1" = 10' CJB AWC GENERAL NOTESGENERAL NOTES 1.THE STORMWATER MANAGEMENT PLAN AND DESIGN IS INTENDED TO BE IN COMPLIANCE WITH THE 2015 NEW YORK STATE STORMWATER DESIGN MANUAL. 2.STORMWATER RUNOFF ANALYSIS WAS CALCULATED USING THE SCS TR-55 METHODOLOGY. 1 10/16/23 Revised Per Engineering Comments 2" Craba p pl e 2" Craba p pl e 2" Crabapple 2" Ced a r ( 4 T r e e s ) 4" Elm Clump 4" Elm Clump 320320320320 31 53153 1 6 317 318 318 317 319 318316 317 318 319 318317317318BALLST O N A V E N U E HAMILTON STREET316 3 1 8 317317317 318317318 319 319 318318 31 7 317 317 318318SUBCATCHMENT AREA 1 (CB-1) TOTAL DRAINAGE AREA = 0.09 AC PERVIOUS AREA = 0.01 AC IMPERVIOUS AREA = 0.08 AC RUNOFF COEFFICIENT = 0.88 TIME OF CONCENTRATION = 6.0 MIN. SUBCATCHMENT AREA 2 (RF-1) TOTAL DRAINAGE AREA = 0.05 AC PERVIOUS AREA = 0.00 AC IMPERVIOUS AREA = 0.05 AC RUNOFF COEFFICIENT = 0.95 TIME OF CONCENTRATION = 6.0 MIN. PERVIOUS AREA (NO PLOT) LEGEND LIMIT OF DRAINAGE AREA FLOW PATH PROPERTY LINE RIGHT-OF-WAY LINE ADJOINING LOT LINE 501 Main Street, Monroe, CT 06468 11 Vanderbilt Ave, Norwood, MA 02062 Sheet Title:Sheet #: Project: Drawn By: Checked By: Approved By: Project #: Plan Date: Scale: PROPOSED CHIPOTLE 12 BALLSTON AVENUE (M-B-L: 165.83-1-3) SARATOGA SPRINGS, NEW YORK OWNER: SARATOGA PRIME PROPERTIES LLC / 215 BALLARD ROAD, WILTON NY 12831 APPLICANT: COLLABDEV 2 LLC / 529 MAIN STREET, BOSTON, MA 02129 Graphic Scale: Rev. #:Date Description KMS 21206201 ENGINEERING Kevin Solli, P.E. NY 092156 T: (203) 880-5455 F: (203) 880-9695 T: (781) 352-8491 F: (203) 880-9695 SUBCATCHMENT DRAINAGE AREA MAP DA-3 10 0 10 20 06/09/23 1" = 10' CJB AWC GENERAL NOTESGENERAL NOTES 1.THE STORMWATER MANAGEMENT PLAN AND DESIGN IS INTENDED TO BE IN COMPLIANCE WITH THE 2015 NEW YORK STATE STORMWATER DESIGN MANUAL. 2.STORMWATER RUNOFF ANALYSIS WAS CALCULATED USING THE SCS TR-55 METHODOLOGY. Appendix E – Long-Term Operation & Maintenance Operation & Maintenance Manual LONG-TERM OPERATION & MAINTENANCE MANUAL For the Proposed: CHIPOTLE Located At: 12 Ballston Avenue Saratoga Springs, New York Prepared On: June 9, 2023 Prepared For: City of Saratoga Springs Site Plan Review Prepared By: 11 Vanderbilt Avenue, Suite 240 Norwood, Massachusetts 02062 T: (781) 352-8491 Prepared For: CollabDev 2 LLC 529 Main Street Boston, Massachusetts 02129 T: (781) 690-0275 Proposed Commercial Redevelopment 12 Ballston Avenue Saratoga Springs, NY 12866 1 TABLE OF CONTENTS INTRODUCTION ........................................................................................................................................ 2 RESPONSIBILITY ................................................................................................................................... 2 DOCUMENTATION ............................................................................................................................... 2 MAINTENANCE PROGRAM .................................................................................................................... 3 SUBSURFACE STORMWATER SYSTEM ........................................................................................... 3 HYDRODYNAMIC SEPARATOR UNIT .............................................................................................. 3 CATCH BASIN ........................................................................................................................................ 4 STREET MAINTENANCE ...................................................................................................................... 5 PESTICIDES, HERBICIDES AND FERTILIZERS ................................................................................ 5 EMEREGENCY SPILL CONTAINMENT ................................................................................................. 5 Proposed Commercial Redevelopment 12 Ballston Avenue Saratoga Springs, NY 12866 2 INTRODUCTION Solli Engineering (Solli) has prepared this Long-Term Operations and Maintenance (O&M), to be filed with the City of Saratoga Springs, New York for the proposed quick-service restaurant at 12 Ballston Avenue in Saratoga Springs, NY. The O&M Manual has been prepared to ensure that the stormwater management functions as designed. The owner possesses the primary responsibility for overseeing and implementing the O&M plan and assigning a Property Manager who will be responsible for the proper operation and maintenance of the stormwater structures. In case of transfer of property ownership, future property owners shall be notified of the presence of the stormwater management system and the requirements for proper implementation of the O&M plan. Included in the O&M plan identifying key components of the stormwater system as well as a log for tracking inspections and maintenance. The stormwater management system protects and enhances the stormwater runoff water quality through the removal of sediment and pollutants, and source control significantly reduces the number of pollutants entering the system. Preventive maintenance of the system will include a comprehensive source reduction program of regular vacuuming and litter removal, prohibitions on the use of pesticides, and maintenance of designated waste and recycling. RESPONSIBILITY The purpose of the Long-Term Operation and Maintenance (O&M) Manual is to ensure inspection of the system, removal of accumulated sediments, oils, and debris and implementation of corrective action and record keeping activities. The below O&M activities associated with the site will be performed by a Contract Operator for the scope of maintenance. The Contract Operator will be a professional engineer or other technical professional with expertise and experience with stormwater management facilities operation and maintenance. The ongoing responsibility is the Owner, its successors, and assigns. Adequate maintenance is defined in this document as good working condition. Responsibility for O&M (to be transferred upon sale of property / development): Contact: John Roche / CollabDev2 LLC Number: (781) 690-0275 Address: 529 Main Street City, State: Boston, MA 02129 DOCUMENTATION An inspection and maintenance record log and schedule will be kept by the Owner or Property Manager summarizing inspections, maintenance, repairs and any corrective actions taken. The log will include the date on which each inspection or maintenance task was performed, a description of the inspection findings or maintenance completed, and the name of the inspector or maintenance personnel performing the task. If a maintenance task requires the clean-out of any sediments or debris, the location where the sediment and debris was disposed after removal will be indicated. Inspection & Maintenance Logs will be kept on file at the on-site Property Management office. Proposed Commercial Redevelopment 12 Ballston Avenue Saratoga Springs, NY 12866 3 MAINTENANCE PROGRAM The Owner, Property Manager and maintenance staff will conduct the Operation and Maintenance program set forth in this document. The Owner or Property Manager will ensure that inspections and record keeping are timely and accurate, and that cleaning and maintenance are performed in accordance with the recommended frequency for each stormwater component. Inspection & Maintenance Log Forms shall include the date and the amount of the last significant storm event in excess of 1-inch of rain in a 24- hour period, physical conditions of the structures, depth of sediment in structures, evidence of overtopping or debris blockage and maintenance required of each structure. The following areas, facilities, and measures will be inspected by the Owner or Property Manager and maintained as specified below. Identified deficiencies will be corrected. Accumulated sediments and debris will be properly handled and disposed of off-site, in accordance with local, state, and federal guidelines and regulations. SUBSURFACE STORMWATER SYSTEM Subsurface infiltration / detention systems are used widely for controlling the quantity of stormwater runoff as well as the quality where space is limited. Subsurface systems’ performance varies by manufacturer and system design. The stormwater management system proposes the installation of a subsurface system incorporating 3.0’ Retain-it chambers (Or approved equal). According to the Owners Maintenance Manual provided by Retain-It, the infiltration / detention chambers are “self-sufficient and operate without requiring any outside assistance, except for periodic inspection to verify optimal performance and maintenance for removal of collected pollutants.” The chambers should be inspected periodically with a greater number of inspections to take place during the system start up (just after installation). To successfully maintain the design parameters the following will be required for upkeep: Periodically: Inspector shall visually inspect the system to help identify issues of concern. The inspector should look for signs of slow flows, backed up water, visible oil, trash, and debris or an excessive amount of sediment in the storage area. During periodic inspections the inspector should visibly inspect the outlet control structure for issues of concern. If sediment is observed to be causing issues of concern, a vacuum truck should be used to suck the accumulated sediments, oils, greases, trash, and debris from the system. Sediments, trash, and debris shall be removed and disposed of in an approved manner. Any indications of hazardous material, determined by visual inspection, testing, smell or abnormality, should be reported and handled per appropriate regulations. For more information regarding the Retain-It Owners Maintenance Guide visit: http://retain-it.com/library/retain-it-sms-owners-maintenance-guide.pdf HYDRODYNAMIC SEPARATOR UNIT Hydrodynamic separators protect the environment by removing a wide range of pollutants from stormwater runoff. Periodic removal of these captures pollutants is essential to the continuous, long-term functioning of the separator. The unit 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 structure will no longer be able to store removed sediment and oil. Proposed Commercial Redevelopment 12 Ballston Avenue Saratoga Springs, NY 12866 4 The stormwater management system proposes to incorporate a Contech water quality unit. According to the Contech Guide Operation, Design, Performance and Maintenance, inspections shall take place at regular intervals to ensure optimum performance. At a minimum, inspections shall be performed twice a year (Ex.: spring & fall) however more frequent inspections may be required depending on several things one being severity of winter (excessive sanding/salting). The frequency of cleanout is determined in the field after installation. During the first year of operation, the units should be inspected regularly and then after, every six months (twice a year) to determine the rate of sediment and floatables accumulation. A simple probe can be used to determine the level of accumulated solids stored in the sump. This information should be recorded in the inspection logs. On the log it is important to note the date, location of structure (or identification), estimated volume of floatables, and depth of sediment. Securely replace the top of the structure and take down any safety equipment. Then notify the engineer of record for any irregularities in the structure’s performance if any. The system should be cleaned when the level of sediment has reached 75% of capacity in the isolated sump or when an appreciable level of hydrocarbons and trash has accumulated. Sediment and debris removal can be done manually or with approved sumpvac (or equal). For more information regarding the CDS Guide Operation, Design, Performance and Maintenance visit: https://www.conteches.com/Portals/0/Documents/Design%20Guides/CDSDesign%20Guide.pdf?ver=201 8-05-16-083621-907 CATCH BASIN Catch basins are underground concrete structures which are designed to retain removed trash, debris, and coarse sediment from stormwater runoff and serve as temporary spill containment devices for floatables such as oil and greases prior to discharge into a storm sewer pipe. The functions of a catch basin include: A grate and/or vertical notch found in the curbing that allow stormwater to enter the structure while filtering out larger objects such as trash and leaves. A two-foot (minimum) sump below the invert of the storm sewer pipe provides an area for detention time which allows sands and other sediments to settle out of the runoff prior discharge. An attached hooded outlet, that prevents floatables and sediment from entering the storm sewer pipes. At a minimum, catch basins and drain manholes shall be inspected quarterly (four times per year). Ideally, inspections should be conducted in the fall, at the end of the leaf-drop, in the spring following snowmelt and following heavy rain falls, defined as a storm event exceeding 1-inch of rain fall within a twenty- four-hour period to verify that inlet openings are not clogged by debris. Each structure should be cleaned whenever the depth of sediment deposits is greater than or equal to one half the depth of the sump from the bottom of the structure to the bottom of the lowest pipe invert. Structures shall be inspected for a buildup of sediments, oils, debris, cracks, breaks, or deformations. Any function of the catch basin and drain manhole that is not in working order will be replaced with similar materials, as per detail, to prevent the storm sewer system from failing. If floating hydrocarbons are observed during an inspection, the material should be removed immediately by skimming, absorbent materials, or other method and disposed in conformance with applicable state and federal regulations. The catch basins shall be cleaned by means of handheld shovels, scallop shovel and/or vacuum truck. Vacuum truck may be required instead of shovels to avoid damage to structure. The grate opening shall be clear of any foreign or lodged object. If floating hydrocarbons are Proposed Commercial Redevelopment 12 Ballston Avenue Saratoga Springs, NY 12866 5 observed during an inspection, the material should be removed immediately by skimming, absorbent materials or other methods and salts used in the winter will be removed from the catch basin sumps in the early spring. Leaves, pine needles and branches brought down by autumn winds, rain, and cold weather will be removed from the catch basin sumps in the late fall. Collected sediment, debris and hydrocarbons will be properly disposed of per local, state and federal requirements. Damaged Hoods should be replaced when noted by inspection. STREET MAINTENANCE Street maintenance is a non-structural source control performed by mechanical means to limit sediment and particulates from impervious surfaces as an effort to control or limit the sediment migration to other stormwater BMP’s during storm events. There are three typical types of sweeping methods, including mechanical, regenerative air and vacuum filter. Mechanical sweepers are the most common and use brooms or brushes to scour the pavement. Regenerative air sweepers blow air onto the impervious surface causing sediment and other fine particles to be blown from the surface so they can be vacuumed. Vacuum filter sweepers are available in wet and dry types. Dry types use brooms to agitate the sediment prior to vacuuming. Wet types work in a similar fashion but use water to suppress dust during the collection activity. Because of street maintenance, sediment and other fine particulates are limited on the impervious surfaces and be further controlled from entering other BMP’s. They also allow for the removal and prevention of accumulation of sediment along parking or road edges. This should be done periodically during dry weather to remove excess sediments to reduce the amount of sediments that the drainage system shall have to remove from runoff. Sweeping should mostly be conducted between the months of March and November, with special attention to sweeping during the wetter (earlier) months. Salt used for de-icing should be limited as much as possible as this will reduce the need for the removal and treatment. However, sand containing the minimum amount of calcium chloride (or approved equal) needed for handling may be applied as part of the routine winter maintenance activities. PESTICIDES, HERBICIDES AND FERTILIZERS Pesticides and herbicides shall be used sparingly. Fertilizers should be restricted to the use of organic fertilizers only. Exterior storage of fertilizers, herbicides, pesticides or other toxic or hazardous materials should be prohibited. EMEREGENCY SPILL CONTAINMENT The Owner, along with the on-site Property Manager is responsible for educating staff and informing tenants on the environmental benefits associated with the use of pavement at the site. Staff must be trained, and tenants informed via the community website as to the proper spill prevention control and response procedures should a spill occur on the pavement surface. Proper spill control products, such as a granular dry absorbent, must be kept on-site at the property management office in a clean, dry chemical and corrosion resistant container. A spill of greater than 10 gallons of oil or a spill of any quantity that has reached a surface water, into a sewer, storm drain, ditch, or culvert leading to a surface water, is immediately reported to one or more municipal, state, or federal authority. In the event of a hazardous waste spill on-site, the following protocol should be followed. Proposed Commercial Redevelopment 12 Ballston Avenue Saratoga Springs, NY 12866 6 If it is safe to do so, maintenance staff or tenants detecting an oil spill should immediately stop the release and use available materials to prevent the spread of oil. If there is a potentially flammable, toxic, or explosive condition, evacuate the vicinity of the spill. If it’s believed that a reportable or dangerous condition exists, immediately call your local Fire Department to notify them of the release. If it is believed that a reportable condition exists, immediately call the New York Department of Environmental Conservation (DEC) to notify them of the release. Call the NYS DEC Spill Hotline toll free statewide number, 1-800-457-7362. Be prepared to provide the following information to the DEC and the Fire Department: o Identity of the caller o Contact phone number Location of the spill o Type of product spilled o Approximate quantity or product spilled Extent of actual and/or potential water pollution o Date and time of spill o Cause of spill o Contact a Licensed Site Professional (LSP) to assist in further handling of the material(s) and DEC.