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Stormwater Management Report 10-31-19Stormwater Management Report Hawley Street Condominiums 10 Hawley St., Northampton, MA PREPARED FOR O’Connell Development Group 800 Kelly Way Holyoke, MA 01040 413.534.0243 PREPARED BY 1 Federal Street Building 103-3N Springfield, MA 01105 413.747.7113 August 29, 2019 Revised: October 31, 2019 i Table of Contents Table of Contents Table of Contents ..................................................................................................................................... i Project Summary ..................................................................................................................................... 1 Existing Conditions ................................................................................................................................. 4 Hydrologic Information ............................................................................................................... 5 Proposed Conditions .............................................................................................................................. 8 Water Quantity and Quality Control ........................................................................................... 8 Hydrologic Information ............................................................................................................. 10 Hydrologic/Hydraulic Analysis ............................................................................................................. 14 Hydrologic Analysis ................................................................................................................. 14 Hydraulic Analysis ................................................................................................................... 15 Stormwater Management Regulations ................................................................................................ 16 Stormwater Regulations and Permitting .................................................................................. 16 Stormwater Management Standards and Guidelines ...................................... 17 Federal NPDES Construction-Related General Stormwater Permits .................. 20 List of Figures Figure 1: Site Location Map Figure 2: Existing Drainage Areas Figure 3: Proposed Drainage Areas List of Tables Table 1: Existing Conditions Hydrologic Data Table 2: Proposed Conditions Hydrologic Data Table 3: Peak Discharge Rates Appendices Appendix A: DEP Stormwater Checklist Appendix B: NRCS Soil Survey Information, On-Site Subsurface Investigation Appendix C: FEMA Map Appendix D: Long Term Stormwater Operation and Maintenance Measures Appendix E: Hydraulic Analysis StormCAD Analysis Recharge Calculations Water Quality Volume Calculations ii Table of Contents Appendix F: Erosion and Sedimentation Control Measures Appendix G: Spill Prevention & Response Appendix H: Illicit Discharge Compliance Statement Appendix I: Infiltration System Registration Appendix J: Hydrologic Analysis HydroCAD Analysis: Existing Conditions HydroCAD Analysis: Proposed Conditions 1 Project Summary Project Summary The 1.83 – acre Site is located at 10 Hawley Street in Northampton, MA (see Figure 1). The Site is bounded by the post office property and residential properties to the north, Hawley Street, Phillips Place and residential properties to the south, residential properties to the east, and Hawley Street and business properties to the west. The Site is currently zoned Central Business (CB) with some of the surrounding properties zoned as Urban Residential C (URC). The Site is located within the surface watershed of the Connecticut River. There are no wetland resources on the Site. The Phase 2 portion of the project which is not part of this analysis is located across the street at the southeast corner of the intersection at Hawley Street and Phillips Place. The Site is presently occupied by St. John Cantius church, a rectory building, a garage and a recreation building. Under existing conditions, stormwater runoff from the rear of the site is collected in a few catch basins before it is conveyed to the municipal system in Phillips Place. The entire front portion of the site and the easement drive out to Phillips Place allows stormwater to sheet flow directly off site without and collection or treatment. The proposed redevelopment of the site includes the demolition of the rectory, the garage and the recreation building. The church will remain on site. There will be 6 new buildings constructed with 23 townhouse units. Under proposed conditions, stormwater runoff from the road will be collected in Stormceptor water quality units and conveyed to an underground storage or infiltration systems. Roof stormwater will be collected in gutters and conveyed to either the underground storage systems or the underground infiltration systems. Some grass areas will be collected in area drains. Wherever possible existing drainage and grading patterns were maintained in the proposed design. Additionally, water quality and quantity control measures such as street sweeping and underground storage have been designed to protect the surrounding natural resources from potential stormwater runoff impacts. Low impact development stormwater management techniques have been incorporated into the site and are described herein. A HydroCAD model, using TR-20 methodology, was developed to evaluate the existing and proposed drainage conditions on the Site. The results of the analyses indicate that there is no increase in peak discharge rates between the pre- and post- 1 2 Project Summary development conditions for the 2, 10, 25 and 100-year storm events. The pre- and post-development peak discharge values are presented in Table 3 at the end of this report. The Stormwater Management Plan (the Plan), including Best Management Practices (BMPs) for maintaining stormwater runoff quality both during and after construction, was prepared in accordance with the applicable local, state, and federal regulations. Details of the Plan are provided herein. Vanasse Hangen Brustlin, Inc. \\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\Figure 1 - Site Location Map.dwg Hawley Street Residential Development 10 Hawley Street Northampton, MA Figure 1 - Site Location Map August 2019 N.T.S. 4 Existing Conditions Existing Conditions Summary The approximately 1.83 – acre Site consists of St. John Cantius church, a rectory building, a garage and a recreation building. Some large trees at the front of the Site will need to be removed for the construction of the residential development. A good portion of the Site is allowed to just sheet flow off Site into the road without any treatment. See Figure 2. The project is not located within the 100-year flood plain as shown on the FEMA Flood Insurance Rate Map, City of Northampton, Massachusetts, Hampshire County, Community Panel Number 250167 002 A, Page 2 of 2, Effective Date April 3, 1978, included in Appendix C. The site has ranging elevation changes with an elevation change of approximately 16 feet from the rear of the site to Hawley Street. There are existing retaining walls and steep slopes on the north and south sides of the site making the site higher than its surrounding properties. The good portion of the site is impervious with paved areas and buildings. Grass is located at the perimeter with a larger area located in front of the church along Hawley Street. Half of the site stormwater is allowed to sheet flow off site without any treatment. No on-site subsurface investigations were conducted for this project; however, based on previous submittals for this site the soils are poor, and groundwater is high. Based on the NRCS Web Soil Survey the site is within the Amostown-Windsor silty substratum-Urban land complex which carry a Hydrologic Soil Group of A and B. NRCS soils map are included in Appendix B. 2 5 Existing Conditions Hydrologic Information For the existing conditions hydrologic analysis, the site was divided into 10 drainage areas that contribute to 4 design points, where peak discharge rates were evaluated (see Figure 2). Drainage Area 10 - This 5,403 sf area consists of a grass and trees along Hawley Street. Stormwater sheet flows towards Hawley Street. This drainage system contributes to Design Point x1000. Drainage Area 15 - This 11,518 sf area consists of a grass and sidewalks around the perimeter of the church. Stormwater sheet flows towards Hawley Street. This drainage system contributes to Design Point x2000. Drainage Area 20 - This 6,628 sf area consists of the church roof. Stormwater is collected in roof drains and is assumed to be connected to either the Hawley Street or Phillips Place drainage system. This drainage system contributes to Design Point x2000. Drainage Area 25 - This 2,008 sf area consists of the rectory roof. Stormwater is collected in roof drains and is assumed to be connected to the Hawley Street drainage system. This drainage system contributes to Design Point x1000. Drainage Area 30 - This 6,849 sf area consists of grass and sidewalks at the rear of the church. Stormwater is collected in yard drains and is assumed to be connected to either the Hawley Street or Phillips Place drainage system. This drainage system contributes to Design Point x2000. Drainage Area 35 - This 8,584 sf area consists of mostly paved areas with a garage and some grass at the perimeter. Stormwater is allowed to sheet flow down the entrance drive and into Hawley Street. This drainage system contributes to Design Point x1000. Drainage Area 40 - This 9,231 sf area consists of the recreation building roof. Stormwater is collected in roof drains and is assumed to be connected to the Phillips Place drainage system. This drainage system contributes to Design Point x4000. Drainage Area 45 - This 1,723 sf area consists of a small strip of grass between the recreation building and the rear of the residential properties along Phillips Place. Stormwater sheet flows off site to the south. This drainage system contributes to Design Point x3000. 6 Existing Conditions Drainage Area 50 - This 27,647 sf area consists of mostly paved areas with some grass areas surrounding the recreation building. Stormwater is collected in catch basins and is conveyed to the Phillips Place drainage system. This drainage system contributes to Design Point x4000. Drainage Area 55 - This 2,884 sf area consists of the paved entrance drive easement to the site off of Phillips Place. Stormwater is allowed to sheet flow into Phillips Place. This drainage system contributes to Design Point x4000. Table 1 summarizes the key hydrologic parameters for each drainage area used in the existing conditions analysis. Table 1 Existing Conditions Hydrologic Data Description (Drainage Area #) Discharge Location Design Point Area (sf) Curve Number Time of Concentratio n (min) 10 Hawley St Top x1000 5,403 63 6 15 Hawley St Bottom x2000 11,518 67 15.5 20 Hawley St Bottom x2000 6,628 98 6 25 Hawley St Top x1000 2,008 98 6 30 35 40 45 50 55 Hawley St Bottom Hawley St Top Phillips Place Off-Site South Phillips Place Phillips Place x2000 x1000 x4000 x3000 x4000 x4000 6,849 8,584 9,231 1,723 27,647 2,884 66 90 98 61 88 90 15.2 6 6 6 6 6 Existing Drainage Areas (SF) Area 10 =5,403 Pervious =5,044 Impervious =359 Area 15 =11,518 Pervious =9,674 Impervious =1,844 Area 20 =6,628 Impervious =6,628 Area 25 =2,008 Impervious =2,008 Area 30 =6,849 Pervious =5,866 Impervious =983 Area 35 =8,584 Pervious =1,886 Impervious =6,698 Area 40 =9,231 Impervious =9,231 Area 45 =1,723 Pervious =1,723 Area 50 =27,647 Pervious =7,667 Impervious =19,980 Area 55 =2,884 Pervious =637 Impervious =2,247 TOTAL = 82,475 x100010253530201540505545x2000x3000x4000HAWLEY STREETPHILLIPS PLACE02550Feet\\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\Figure 2 - Existing Conditions.dwgAugust 2019Figure 2Existing Condtions Drainage AreasHawley Street Residential Development10 Hawley StreetNorthampton, MALegendx100010 8 Proposed Conditions Proposed Conditions Summary The project will include the construction of 6 new buildings containing 23 townhouse units. A paved driveway will be constructed thru the site from Hawley Street out to Phillips Place. Landscape areas including grass, trees and ground plantings will be included throughout the site. Low impact development stormwater management techniques have been incorporated into the design. These practices are focused at decentralizing stormwater management at the site and incorporating many smaller stormwater management techniques into the design that will reduce peak runoff rates, maximizing groundwater recharge and treating for water quality. Water quality and quantity attenuation measures, such as Stormceptor water quality units, street sweeping, subsurface storage systems and subsurface infiltration systems have been included in the design of the site. The front portion of the site stormwater will eventually outlet to Hawley Street while the rear of the site will outlet to Phillips Place. Stormwater from the roofs will be conveyed to the underground storage pipes or the underground infiltration pipes. Stormwater from the roadway will be collected in water quality units and then conveyed to the underground storage pipes or the underground infiltration pipes. The infiltration pipes will be 24” diameter surrounded by stone and filter fabric. The underground systems will have an outlet control structure either with a weir at the top or with an orifice and a weir to release water at a controlled rate. There are a couple grassed low point areas on site where water will be collected with area drains and the conveyed to the drainage system on site. Water Quantity and Quality Control Source Control A comprehensive source control program will be implemented at the site, which includes regular pavement sweeping, catch basin cleaning, and enclosure and 3 9 Proposed Conditions maintenance of all dumpsters. Further discussion of the site maintenance is included in the Stormwater Management Regulations Section 5. Details of the ongoing Stormwater Management Practices for the developed site are included in the Stormwater Management System Long Term Operation and Maintenance Plan to be prepared under separate cover. Snow Management There are a couple areas around the site where snow can be placed outside of the fire truck concrete areas. Should areas on site be exceeded then snow will be removed from the site within 24 hours of the snow event. Spill Prevention Spill prevention is achieved with the proper storage and handling of hazardous materials. During construction, this is addressed in the Stormwater Pollution Prevention Plan (SWPPP) for Construction Activities to be prepared and implemented by the Site Contractor. The general response procedures for spills at any time are outlined in Appendix G or are included in the O&M Plan. Subsurface Infiltration System The system will consist of 24” diameter perforated HDPE pipes surrounded by stone and filter fabric. The corners of the system will either have a manhole or an inspection port. Should the system exceed its capacity, stormwater will be allowed to enter an overflow invert into a 12” diameter HDPE pipe which conveys the stormwater to the municipal system. Water Quality Units The Stormceptor® Water Quality units proposed, efficiently remove total suspended solids (TSS) and free oil from the stormwater run-off. The units prevent the resuspension of settled material, and allow for safe and easy removal of collected material. The water quality units will be inspected two times per year and cleaned a minimum of once per year, or when the sediment reaches a depth recommended by the manufacturer. 10 Proposed Conditions Hydrologic Information For the proposed conditions hydrologic analysis, the site was divided into 6 drainage areas (see Figure 3). These areas discharge to the 4 design points where peak discharge rates were evaluated for both existing and proposed conditions. Drainage Area 100 – This 19,086 sf area consists of the roofs at the front of the buildings, paved driveway and some small grass areas. Stormwater from the roofs will be collected and conveyed to the underground storage system and eventually to the drainage system in Hawley Street. Stormwater from the driveway will be collected in a water quality unit and conveyed to the underground storage system and eventually to the drainage system in Hawley Street. This drainage system contributes to Design Point x1000. Drainage Area 150 – This 3,227 sf area consists of a small stretch og grass along the north side of the site. This drainage system contributes to Design Point x1000. Drainage Area 200 – This 6,628 sf area consists of the church roof. Stormwater is collected in roof drains and is assumed to be connected to either the Hawley Street or Phillips Place drainage system. This drainage system contributes to Design Point x2000. Drainage Area 300 – This 18,250 sf area consists of grass and sidewalks around the perimeter of the church, concrete patios at the rear of the units, grass and sidewalk areas along Hawley Street. Stormwater sheet flows towards Hawley Street. Small portions of this area are collected in yard drains and conveyed to the Hawley Street system. This drainage system contributes to Design Point x2000. Drainage Area 400 – This 3,345 sf area consists of the roofs at the rear of the buildings. Stormwater from the roofs will be collected and conveyed to the underground storage system and eventually to the drainage system in Hawley Street. This drainage system contributes to Design Point x1000. Drainage Area 450 – This 4,888 sf area consists of some roof areas. Stormwater from the roofs will be collected and conveyed to the underground infiltration system and eventually to the drainage system in Hawley Street. This drainage system contributes to Design Point x1000. Drainage Area 500 – This 588 sf area consists of a small strip of grass between the recreation building and the rear of the residential properties along Phillips Place. Stormwater sheet flows off site to the south just as it does under existing conditions. This drainage system contributes to Design Point x3000. 11 Proposed Conditions Drainage Area 600 – This 8,414 sf area consists a portion of the road, driveways to garages and grass. Stormwater sheet flows to a Stormceptor water quality unit then to the underground infiltration system and then eventually to the drainage system in Hawley Street. This drainage system contributes to Design Point x1000. Drainage Area 700 – This 7,449 sf area consists the roofs, a portion of the paved driveway, concrete patios and grass. Stormwater sheet flows to a Stormceptor water quality unit and then eventually to the drainage system in Phillips Place. This drainage system contributes to Design Point x4000. Drainage Area 750 – This 7,879 sf area consists the roofs, concrete patios and grass. Stormwater is collected and conveyed to a subsurface recharge trench along the rear of the site and then eventually to the drainage system in Phillips Place. This drainage system contributes to Design Point x4000. Drainage Area 800 – This 2,720 sf area consists of the paved entrance drive easement to the site off of Phillips Place. Stormwater from the roof will be collected and conveyed to the drainage system in Phillips Place. Stormwater from the paved driveway sheet flows to a Stormceptor water quality unit and then eventually to the drainage system in Phillips Place. This drainage system contributes to Design Point x4000. 12 Proposed Conditions Table 2 summarizes the key hydrologic parameters for each drainage area used in the proposed conditions analyses. Table 2 Proposed Conditions Hydrologic Data Description (Drainage Area #) Discharge Location Design Point Area (sf) Curve Number Time of Concentration (min) 100 150 Hawley St Top Hawley St Top x1000 x1000 19,086 3,227 95 61 6 6 200 Hawley St Bottom x2000 6,628 98 6 300 Hawley St Bottom x2000 18,250 70 15.6 400 450 Hawley St Top Phillips Place x1000 x4000 3,345 4,888 98 98 6 6 500 600 700 750 800 Off-Site South Phillips Place Phillips Place Phillips Place Phillips Place x3000 x4000 x4000 x4000 x4000 588 8,414 7,449 7,879 2,720 61 85 90 82 90 6 6 6 6 6 Proposed Drainage Areas (SF) Area 100 =19,086 Pervious =1,584 Impervious =17,502 Area 150 =3,227 Pervious =3,227 Area 200 =6,628 Impervious =6,628 Area 300 =18,250 Pervious =13,714 Impervious =4,536 Area 400 =3,345 Impervious =3,345 Area 450 =4,888 Impervious =4,888 Area 500 =588 Pervious =588 Area 600 =8,414 Pervious =2,917 Impervious =5,497 Area 700 =7,449 Pervious =1,561 Impervious =5,888 Area 750 =7,879 Pervious =3,364 Impervious =4,515 Area 800 =2,720 Pervious =561 Impervious =2,159 TOTAL = 82,474 PHILLIPS PLACE x1000 200 x2000 x4000 100 300 700 500 800 x3000 400 600 S1 S2 450 150 750 S3 0 25 50 Feet \\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\Figure 3 - Proposed Conditions.dwg October 2019Figure 3 Proposed Condtions Drainage Areas Hawley Street Residential Development 10 Hawley Street Northampton, MA Legend x1000 100 S1 14 Hydrologic/Hydraulic Analysis Hydrologic/Hydraulic Analysis Hydrologic Analysis The rainfall-runoff response of the Site under existing and proposed conditions was evaluated for storm events with recurrence intervals of 2, 10, 25 and 100-years. Rainfall volumes used for this analysis were based on NOAA Atlas 14, Volume 10, Version 2 Northeastern States maps, Type III, 24-hour storm event; they were 3.15, 4.9, 6.1 and 7.9 inches, respectively. Runoff coefficients for the pre- and post- development conditions, as previously shown in Tables 1 and 2 respectively, were determined using NRCS Technical Release 55 (TR-55) methodology as provided in HydroCAD. Drainage areas used in the analyses were described in previous sections and shown on Figures 2 and 3. The HydroCAD model is based on the NRCS Technical Release 20 (TR-20) Model for Project Formulation Hydrology. Detailed printouts of the HydroCAD analyses are included in Appendix J. Table 3 presents a summary of the existing and proposed conditions peak discharge rates. Table 3 Peak Discharge Rates (cfs*) 2-year 10-year 25-year 100-year Existing 3.4 6.2 8.2 11.2 Proposed 2.4 3.9 5.0 7.5 * Expressed in cubic feet per second The results of the analysis indicate that there is no increase in peak discharge rates between the pre- and post-development conditions for the 2, 10, 25 and 100-year storm events. 4 15 Hydrologic/Hydraulic Analysis Hydraulic Analysis The closed drainage system was designed for the 10-year storm event. Drainage pipes were sized using Manning’s Equation for full-flow capacity and the Rational Method. Additionally, the performance of the system was analyzed using StormCAD, a HEC-22 based program. Pipe sizing calculations are included in Appendix E of this report. 16 Stormwater Management Regulations Stormwater Management Regulations The purpose of the Stormwater Management Plan (the Plan) is to provide long-term protection of natural resources in and around the Site. This is achieved by implementing water quality and quantity control measures designed to decrease the amount of pollutants discharged from the Site, increase the quality of stormwater recharged on the Site, and control discharge rates. The following sections describe the regulations pertinent to stormwater management and the specific components of the Plan to be implemented. Stormwater Regulations and Permitting The following stormwater related regulations and guidelines apply to the proposed site development: Massachusetts State Stormwater Management Regulations and Performance Standards included in the Stormwater Handbook, (Department of Environmental Protection February 2008). Environmental Protection Agency (EPA) National Pollutant Discharge Elimination System (NPDES) Stormwater Permit for Construction Activities disturbing greater than one acre (EPA, Federal Register, December 8, 1999 and amendments) Compliance with these regulations is described in the following sections. 5 17 Stormwater Management Regulations Stormwater Management Standards and Guidelines The methods for compliance with the ten stormwater performance standards developed by the MA DEP are summarized below. 1. No new stormwater conveyances may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. Response: There are no wetland areas located on the Site. 2. Stormwater management systems shall be designed so that post- development peak discharge rates do not exceed pre-development peak discharge rates. This Standard may be waived for discharges to land subject to coastal storm flowage as defined in 310 CMR 10.04. Response: The results of the analysis indicate that there is no increase in peak discharge rates between the pre- and post-development conditions for the 2, 10, 25 and 100-year storm events. 3. Loss of annual recharge to ground water shall be eliminated or minimized through the use of infiltration measures including environmentally sensitive site design, low impact development techniques, stormwater best management practices, and good operation and maintenance. At a minimum, the annual recharge from the post-development site shall approximate the annual recharge from pre-development conditions based on soil type. This Standard is met when the stormwater management system is designed to infiltrate the required recharge volume as determined in accordance with the Massachusetts Stormwater Handbook. Response: Based on an on-site soils analysis some portions of the site will allow infiltration while some other areas will not due to the seasonal high groundwater elevation. Underground infiltration pipes will be proposed at the rear of the site while the front of the site will have solid underground pipes for storage with an outlet control structure for a controlled release. See recharge calculations in Appendix E for the areas of the site that will be infiltrated. 4. Stormwater management systems shall be designed to remove 80% of the average annual post-construction load of Total Suspended Solids (TSS). This Standard is met when: Suitable practices for source control and pollution prevention are identified in a long- term pollution prevention plan, and thereafter are implemented and maintained; 18 Stormwater Management Regulations Structural stormwater best management practices are sized to capture the required water quality volume determined in accordance with the Massachusetts Stormwater Handbook; and Pretreatment is provided in accordance with the Massachusetts Stormwater Handbook. Response: All stormwater collection structures on Site are Stormceptor water quality units which will provide TSS removal where there was no TSS removal under existing conditions. See attached the Stormceptor Sizing Sheet and Water Quality Flow Rate chart which provides 80% TSS removal. The maintenance of these mechanisms is detailed in the Long Term Stormwater Operation and Maintenance Measures in Appendix D of this report. 5. For land uses with higher potential pollutant loads, source control and pollution prevention shall be implemented in accordance with the Massachusetts Stormwater Handbook to eliminate or reduce the discharge of stormwater runoff from such land uses to the maximum extent practicable. If through source control and/or pollution prevention all land uses with higher potential pollutant loads cannot be completely protected from exposure to rain, snow, snow melt, and stormwater runoff, the proponent shall use the specific structural stormwater BMPs determined by the Department to be suitable for such uses as provided in the Massachusetts Stormwater Handbook. Stormwater discharges from land uses with higher potential pollutant loads shall also comply with the requirements of the Massachusetts Clean Waters Act, M.G.L. c. 21, §§ 26-53 and the regulations promulgated thereunder at 314 CMR 3.00, 314 CMR 4.00 and 314 CMR 5.00. Response: This site is not considered a LUHPPL. 6. Stormwater discharges within the Zone II or Interim Wellhead Protection Area of a public water supply and stormwater discharges near or to any other critical area require the use of the specific source control and pollution prevention measures and the specific structural stormwater best management practices determined by the Department to be suitable for managing discharges to such areas as provided in the Massachusetts Stormwater Handbook. A discharge is near a critical area, if there is a strong likelihood of a significant impact occurring to said area, taking into account site-specific factors. Stormwater discharges to Outstanding Resource Waters and Special Resource Waters shall be removed and set back from the receiving water or wetland and receive the highest and best practical method of treatment. A “storm water discharge” as defined in 314 CMR 3.04(2)(a)1 or (b) to an Outstanding Resource Water or Special Resource Water shall comply with 314 CMR 3.00 and 314 CMR 4.00. Stormwater discharges to a Zone I or Zone A are prohibited unless essential to the operation of a public 19 Stormwater Management Regulations water supply Response: This site is not located within any Critical Areas; however, MassDEP approved BMP’s have been used to treat the storm water before it outlets to the infiltration system. 7. A redevelopment project is required to meet the following Stormwater Management Standards only to the maximum extent practicable: Standard 2, Standard 3, and the pretreatment and structural best management practice requirements of Standards 4, 5, and 6. Existing stormwater discharges shall comply with Standard 1 only to the maximum extent practicable. A redevelopment project shall also comply with all other requirements of the Stormwater Management Standards and improve existing conditions. Response: Although the project area previously included pavement areas and was previously developed, there is an increase in impervious areas from existing to proposed conditions of approximately 5,000 sf and therefore, is not considered a redevelopment. The site has been designed to improve Water Quality from the existing pavement areas and full comply with the standards. 8. A plan to control construction related impacts including erosion, sedimentation and other pollutant sources during construction and land disturbance activities (construction period erosion, sedimentation, and pollution prevention plan) shall be developed and implemented. Response – Recommended erosion and sedimentation control practices are included in Appendix F. A maintenance checklist recommended for evaluating erosion control BMPs is also included. 9. A long-term operation and maintenance plan shall be developed and implemented to ensure that stormwater management systems function as designed Response – Recommended practices for operating and maintaining long term stormwater BMPs is included in Appendix D. A recommended checklist for maintenance inspections and follow up is also included. 10. All illicit discharges to the stormwater management system are prohibited. Response: Sanitary sewer and storm drainage structures remaining from previous development which are part of the redevelopment area will be removed or will be incorporated into updated sanitary sewer and separate stormwater sewer systems. The design plans submitted with this report have been designed so that the components included therein are in full 20 Stormwater Management Regulations compliance with current standards. No statement is made with regard to the drainage system in portions of the site not included in the redevelopment project area. The Long-Term Pollution Prevention Plan includes measures to prevent illicit discharges.  Federal NPDES Construction-Related General Stormwater Permits The proposed project will result in the disturbance of more than one acre of land and thus requires the preparation and implementation of a Stormwater Pollution Prevention Plan (SWPPP) by the site contractor and owner in accordance with the Environmental Protection Agency’s (EPA’s) National Pollutant Discharge Elimination System (NPDES) General Permit Program for Stormwater Discharges from Construction Sites. The SWPPP is not included in this report. However, standard recommended components of the Stormwater Pollution Prevention Plan for construction phases of the development to be prepared and implemented by the site contractor are described in Appendix F. Appendix A: DEP Stormwater Checklist Appendix A: DEP Stormwater Checklist DEP Stormwater Checklist.doc • 04/01/08 Stormwater Report Checklist • Page 1 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report A. Introduction Important: When filling out forms on the computer, use only the tab key to move your cursor - do not use the return key. A Stormwater Report must be submitted with the Notice of Intent permit application to document compliance with the Stormwater Management Standards. The following checklist is NOT a substitute for the Stormwater Report (which should provide more substantive and detailed information) but is offered here as a tool to help the applicant organize their Stormwater Management documentation for their Report and for the reviewer to assess this information in a consistent format. As noted in the Checklist, the Stormwater Report must contain the engineering computations and supporting information set forth in Volume 3 of the Massachusetts Stormwater Handbook. The Stormwater Report must be prepared and certified by a Registered Professional Engineer (RPE) licensed in the Commonwealth. The Stormwater Report must include: · The Stormwater Checklist completed and stamped by a Registered Professional Engineer (see page 2) that certifies that the Stormwater Report contains all required submittals.1 This Checklist is to be used as the cover for the completed Stormwater Report. · Applicant/Project Name · Project Address · Name of Firm and Registered Professional Engineer that prepared the Report · Long-Term Pollution Prevention Plan required by Standards 4-6 · Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan required by Standard 82 · Operation and Maintenance Plan required by Standard 9 In addition to all plans and supporting information, the Stormwater Report must include a brief narrative describing stormwater management practices, including environmentally sensitive site design and LID techniques, along with a diagram depicting runoff through the proposed BMP treatment train. Plans are required to show existing and proposed conditions, identify all wetland resource areas, NRCS soil types, critical areas, Land Uses with Higher Potential Pollutant Loads (LUHPPL), and any areas on the site where infiltration rate is greater than 2.4 inches per hour. The Plans shall identify the drainage areas for both existing and proposed conditions at a scale that enables verification of supporting calculations. As noted in the Checklist, the Stormwater Management Report shall document compliance with each of the Stormwater Management Standards as provided in the Massachusetts Stormwater Handbook. The soils evaluation and calculations shall be done using the methodologies set forth in Volume 3 of the Massachusetts Stormwater Handbook. To ensure that the Stormwater Report is complete, applicants are required to fill in the Stormwater Report Checklist by checking the box to indicate that the specified information has been included in the Stormwater Report. If any of the information specified in the checklist has not been submitted, the applicant must provide an explanation. The completed Stormwater Report Checklist and Certification must be submitted with the Stormwater Report. 1 The Stormwater Report may also include the Illicit Discharge Compliance Statement required by Standard 10. If not included in the Stormwater Report, the Illicit Discharge Compliance Statement must be submitted prior to the discharge of stormwater runoff to the post-construction best management practices. 2 For some complex projects, it may not be possible to include the Construction Period Erosion and Sedimentation Control Plan in the Stormwater Report. In that event, the issuing authority has the discretion to issue an Order of Conditions that approves the project and includes a condition requiring the proponent to submit the Construction Period Erosion and Sedimentation Control Plan before commencing any land disturbance activity on the site. DEP Stormwater Checklist.doc • 04/01/08 Stormwater Report Checklist • Page 2 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report B. Stormwater Checklist and Certification The following checklist is intended to serve as a guide for applicants as to the elements that ordinarily need to be addressed in a complete Stormwater Report. The checklist is also intended to provide conservation commissions and other reviewing authorities with a summary of the components necessary for a comprehensive Stormwater Report that addresses the ten Stormwater Standards. Note: Because stormwater requirements vary from project to project, it is possible that a complete Stormwater Report may not include information on some of the subjects specified in the Checklist. If it is determined that a specific item does not apply to the project under review, please note that the item is not applicable (N.A.) and provide the reasons for that determination. A complete checklist must include the Certification set forth below signed by the Registered Professional Engineer who prepared the Stormwater Report. Registered Professional Engineer’s Certification I have reviewed the Stormwater Report, including the soil evaluation, computations, Long-term Pollution Prevention Plan, the Construction Period Erosion and Sedimentation Control Plan (if included), the Long- term Post-Construction Operation and Maintenance Plan, the Illicit Discharge Compliance Statement (if included) and the plans showing the stormwater management system, and have determined that they have been prepared in accordance with the requirements of the Stormwater Management Standards as further elaborated by the Massachusetts Stormwater Handbook. I have also determined that the information presented in the Stormwater Checklist is accurate and that the information presented in the Stormwater Report accurately reflects conditions at the site as of the date of this permit application. Registered Professional Engineer Block and Signature Signature and Date Checklist Project Type: Is the application for new development, redevelopment, or a mix of new and redevelopment? New development Redevelopment Mix of New Development and Redevelopment DEP Stormwater Checklist.doc • 04/01/08 Stormwater Report Checklist • Page 3 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) LID Measures: Stormwater Standards require LID measures to be considered. Document what environmentally sensitive design and LID Techniques were considered during the planning and design of the project: No disturbance to any Wetland Resource Areas Site Design Practices (e.g. clustered development, reduced frontage setbacks) Reduced Impervious Area (Redevelopment Only) Minimizing disturbance to existing trees and shrubs LID Site Design Credit Requested: Credit 1 Credit 2 Credit 3 Use of “country drainage” versus curb and gutter conveyance and pipe Bioretention Cells (includes Rain Gardens) Constructed Stormwater Wetlands (includes Gravel Wetlands designs) Treebox Filter Water Quality Swale Grass Channel Green Roof Other (describe): Subsurface Infiltration System Standard 1: No New Untreated Discharges No new untreated discharges Outlets have been designed so there is no erosion or scour to wetlands and waters of the Commonwealth Supporting calculations specified in Volume 3 of the Massachusetts Stormwater Handbook included. DEP Stormwater Checklist.doc • 04/01/08 Stormwater Report Checklist • Page 4 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 2: Peak Rate Attenuation Standard 2 waiver requested because the project is located in land subject to coastal storm flowage and stormwater discharge is to a wetland subject to coastal flooding. Evaluation provided to determine whether off-site flooding increases during the 100-year 24-hour storm. Calculations provided to show that post-development peak discharge rates do not exceed pre- development rates for the 2-year and 10-year 24-hour storms. If evaluation shows that off-site flooding increases during the 100-year 24-hour storm, calculations are also provided to show that post-development peak discharge rates do not exceed pre-development rates for the 100-year 24- hour storm. Standard 3: Recharge Soil Analysis provided. Required Recharge Volume calculation provided. Required Recharge volume reduced through use of the LID site Design Credits. Sizing the infiltration, BMPs is based on the following method: Check the method used. Static Simple Dynamic Dynamic Field1 Runoff from all impervious areas at the site discharging to the infiltration BMP. Runoff from all impervious areas at the site is not discharging to the infiltration BMP and calculations are provided showing that the drainage area contributing runoff to the infiltration BMPs is sufficient to generate the required recharge volume. Recharge BMPs have been sized to infiltrate the Required Recharge Volume. Recharge BMPs have been sized to infiltrate the Required Recharge Volume only to the maximum extent practicable for the following reason: Site is comprised solely of C and D soils and/or bedrock at the land surface M.G.L. c. 21E sites pursuant to 310 CMR 40.0000 Solid Waste Landfill pursuant to 310 CMR 19.000 Project is otherwise subject to Stormwater Management Standards only to the maximum extent practicable. Calculations showing that the infiltration BMPs will drain in 72 hours are provided. Property includes a M.G.L. c. 21E site or a solid waste landfill and a mounding analysis is included. 1 80% TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used. DEP Stormwater Checklist.doc • 04/01/08 Stormwater Report Checklist • Page 5 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 3: Recharge (continued) The infiltration BMP is used to attenuate peak flows during storms greater than or equal to the 10- year 24-hour storm and separation to seasonal high groundwater is less than 4 feet and a mounding analysis is provided. Documentation is provided showing that infiltration BMPs do not adversely impact nearby wetland resource areas. Standard 4: Water Quality The Long-Term Pollution Prevention Plan typically includes the following: · Good housekeeping practices; · Provisions for storing materials and waste products inside or under cover; · Vehicle washing controls; · Requirements for routine inspections and maintenance of stormwater BMPs; · Spill prevention and response plans; · Provisions for maintenance of lawns, gardens, and other landscaped areas; · Requirements for storage and use of fertilizers, herbicides, and pesticides; · Pet waste management provisions; · Provisions for operation and management of septic systems; · Provisions for solid waste management; · Snow disposal and plowing plans relative to Wetland Resource Areas; · Winter Road Salt and/or Sand Use and Storage restrictions; · Street sweeping schedules; · Provisions for prevention of illicit discharges to the stormwater management system; · Documentation that Stormwater BMPs are designed to provide for shutdown and containment in the event of a spill or discharges to or near critical areas or from LUHPPL; · Training for staff or personnel involved with implementing Long-Term Pollution Prevention Plan; · List of Emergency contacts for implementing Long-Term Pollution Prevention Plan. A Long-Term Pollution Prevention Plan is attached to Stormwater Report and is included as an attachment to the Wetlands Notice of Intent. Treatment BMPs subject to the 44% TSS removal pretreatment requirement and the one inch rule for calculating the water quality volume are included, and discharge: is within the Zone II or Interim Wellhead Protection Area is near or to other critical areas is within soils with a rapid infiltration rate (greater than 2.4 inches per hour) involves runoff from land uses with higher potential pollutant loads. The Required Water Quality Volume is reduced through use of the LID site Design Credits. Calculations documenting that the treatment train meets the 80% TSS removal requirement and, if applicable, the 44% TSS removal pretreatment requirement, are provided. DEP Stormwater Checklist.doc • 04/01/08 Stormwater Report Checklist • Page 6 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 4: Water Quality (continued) The BMP is sized (and calculations provided) based on: The ½” or 1” Water Quality Volume or The equivalent flow rate associated with the Water Quality Volume and documentation is provided showing that the BMP treats the required water quality volume. The applicant proposes to use proprietary BMPs, and documentation supporting use of proprietary BMP and proposed TSS removal rate is provided. This documentation may be in the form of the propriety BMP checklist found in Volume 2, Chapter 4 of the Massachusetts Stormwater Handbook and submitting copies of the TARP Report, STEP Report, and/or other third party studies verifying performance of the proprietary BMPs. A TMDL exists that indicates a need to reduce pollutants other than TSS and documentation showing that the BMPs selected are consistent with the TMDL is provided. Standard 5: Land Uses With Higher Potential Pollutant Loads (LUHPPLs) The NPDES Multi-Sector General Permit covers the land use and the Stormwater Pollution Prevention Plan (SWPPP) has been included with the Stormwater Report. The NPDES Multi-Sector General Permit covers the land use and the SWPPP will be submitted prior to the discharge of stormwater to the post-construction stormwater BMPs. The NPDES Multi-Sector General Permit does not cover the land use. LUHPPLs are located at the site and industry specific source control and pollution prevention measures have been proposed to reduce or eliminate the exposure of LUHPPLs to rain, snow, snow melt and runoff, and been included in the long term Pollution Prevention Plan. All exposure has been eliminated. All exposure has not been eliminated and all BMPs selected are on MassDEP LUHPPL list. The LUHPPL has the potential to generate runoff with moderate to higher concentrations of oil and grease (e.g. all parking lots with >1000 vehicle trips per day) and the treatment train includes an oil grit separator, a filtering bioretention area, a sand filter or equivalent. Standard 6: Critical Areas The discharge is near or to a critical area and the treatment train includes only BMPs that MassDEP has approved for stormwater discharges to or near that particular class of critical area. Critical areas and BMPs are identified in the Stormwater Report. DEP Stormwater Checklist.doc • 04/01/08 Stormwater Report Checklist • Page 7 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 7: Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable The project is subject to the Stormwater Management Standards only to the maximum Extent Practicable as a: Limited Project Small Residential Projects: 5-9 single family houses or 5-9 units in a multi-family development provided there is no discharge that may potentially affect a critical area. Small Residential Projects: 2-4 single family houses or 2-4 units in a multi-family development with a discharge to a critical area Marina and/or boatyard provided the hull painting, service and maintenance areas are protected from exposure to rain, snow, snow melt and runoff Bike Path and/or Foot Path Redevelopment Project Redevelopment portion of mix of new and redevelopment. Certain standards are not fully met (Standard No. 1, 8, 9, and 10 must always be fully met) and an explanation of why these standards are not met is contained in the Stormwater Report. The project involves redevelopment and a description of all measures that have been taken to improve existing conditions is provided in the Stormwater Report. The redevelopment checklist found in Volume 2 Chapter 3 of the Massachusetts Stormwater Handbook may be used to document that the proposed stormwater management system (a) complies with Standards 2, 3 and the pretreatment and structural BMP requirements of Standards 4-6 to the maximum extent practicable and (b) improves existing conditions. Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan must include the following information: · Narrative; · Construction Period Operation and Maintenance Plan; · Names of Persons or Entity Responsible for Plan Compliance; · Construction Period Pollution Prevention Measures; · Erosion and Sedimentation Control Plan Drawings; · Detail drawings and specifications for erosion control BMPs, including sizing calculations; · Vegetation Planning; · Site Development Plan; · Construction Sequencing Plan; · Sequencing of Erosion and Sedimentation Controls; · Operation and Maintenance of Erosion and Sedimentation Controls; · Inspection Schedule; · Maintenance Schedule; · Inspection and Maintenance Log Form. A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan containing the information set forth above has been included in the Stormwater Report. DEP Stormwater Checklist.doc • 04/01/08 Stormwater Report Checklist • Page 8 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control (continued) The project is highly complex and information is included in the Stormwater Report that explains why it is not possible to submit the Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan with the application. A Construction Period Pollution Prevention and Erosion and Sedimentation Control has not been included in the Stormwater Report but will be submitted before land disturbance begins. The project is not covered by a NPDES Construction General Permit. The project is covered by a NPDES Construction General Permit and a copy of the SWPPP is in the Stormwater Report. The project is covered by a NPDES Construction General Permit but no SWPPP been submitted. The SWPPP will be submitted BEFORE land disturbance begins. Standard 9: Operation and Maintenance Plan The Post Construction Operation and Maintenance Plan is included in the Stormwater Report and includes the following information: Name of the stormwater management system owners; Party responsible for operation and maintenance; Schedule for implementation of routine and non-routine maintenance tasks; Plan showing the location of all stormwater BMPs maintenance access areas; Description and delineation of public safety features; Estimated operation and maintenance budget; and Operation and Maintenance Log Form. The responsible party is not the owner of the parcel where the BMP is located and the Stormwater Report includes the following submissions: A copy of the legal instrument (deed, homeowner’s association, utility trust or other legal entity) that establishes the terms of and legal responsibility for the operation and maintenance of the project site stormwater BMPs; A plan and easement deed that allows site access for the legal entity to operate and maintain BMP functions. Standard 10: Prohibition of Illicit Discharges The Long-Term Pollution Prevention Plan includes measures to prevent illicit discharges; An Illicit Discharge Compliance Statement is attached; NO Illicit Discharge Compliance Statement is attached but will be submitted prior to the discharge of any stormwater to post-construction BMPs. Appendix B: Soils Information Appendix B: NRCS Soil Survey Information On-Site Subsurface Investigation Soil Map—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 8/22/2019 Page 1 of 346880704688090468811046881304688150468817046881904688210468807046880904688110468813046881504688170468819046882104688230695460695480695500695520695540695560695580695600695620695640695660695680695700 695460 695480 695500 695520 695540 695560 695580 695600 695620 695640 695660 695680 695700 695720 42° 19' 18'' N 72° 37' 40'' W42° 19' 18'' N72° 37' 29'' W42° 19' 12'' N 72° 37' 40'' W42° 19' 12'' N 72° 37' 29'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 50 100 200 300 Feet 0 15 30 60 90 Meters Map Scale: 1:1,210 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Hampshire County, Massachusetts, Central Part Survey Area Data: Version 13, Sep 10, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Sep 29, 2013—Oct 16, 2016 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Soil Map—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 8/22/2019 Page 2 of 3 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 741A Amostown-Windsor silty substratum-Urban land complex, 0 to 3 percent slopes 2.6 100.0% Totals for Area of Interest 2.6 100.0% Soil Map—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 8/22/2019 Page 3 of 3 Hampshire County, Massachusetts, Central Part 741A—Amostown-Windsor silty substratum-Urban land complex, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 99z2 Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 120 to 240 days Farmland classification: Not prime farmland Map Unit Composition Amostown and similar soils: 35 percent Windsor, silty substratum, and similar soils: 25 percent Urban land: 25 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Amostown Setting Landform: Terraces, outwash plains, deltas Landform position (two-dimensional): Summit, footslope Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Friable sandy glaciofluvial deposits over silty glaciolacustrine deposits Typical profile H1 - 0 to 7 inches: fine sandy loam H2 - 7 to 32 inches: fine sandy loam H3 - 32 to 60 inches: stratified very fine sand to silt loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.60 in/hr) Depth to water table: About 18 to 36 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: High (about 9.3 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: B Map Unit Description: Amostown-Windsor silty substratum-Urban land complex, 0 to 3 percent slopes---Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 8/22/2019 Page 1 of 2 Hydric soil rating: No Description of Windsor, Silty Substratum Setting Landform: Outwash plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Loose sandy glaciofluvial deposits over silty glaciolacustrine deposits Typical profile H1 - 0 to 8 inches: loamy sand H2 - 8 to 21 inches: loamy sand H3 - 21 to 45 inches: sand H4 - 45 to 60 inches: silt loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat excessively drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 5.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3s Hydrologic Soil Group: A Hydric soil rating: No Minor Components Enosburg Percent of map unit: 10 percent Landform: Terraces Hydric soil rating: Yes Maybid Percent of map unit: 5 percent Landform: Depressions Hydric soil rating: Yes Data Source Information Soil Survey Area: Hampshire County, Massachusetts, Central Part Survey Area Data: Version 13, Sep 10, 2018 Map Unit Description: Amostown-Windsor silty substratum-Urban land complex, 0 to 3 percent slopes---Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 8/22/2019 Page 2 of 2 J1305-55-01 October 21, 2019 Mr. John Furman Vanasse Hangen Brustlin, Inc. One Federal Street, Building 103-3 N Springfield, Massachusetts 01105 Re: Stormwater Design Recommendations 10 Hawley Street Northampton, Massachusetts Dear Mr. Furman: O’Reilly Talbot & Okun Associates, Inc. (OTO) is pleased to provide this letter report summarizing our investigations for the design of underground stormwater infiltration systems, to be located at 10 Hawley Street in Northampton, Massachusetts. This report is subject to the attached limitations. SUBSURFACE EXPLORATIONS Subsurface explorations consisted of five test pits (TP-1 through TP-5), which were performed on October 18, 2019. The test pits were performed by Charlie Arment Trucking using a John Deere 120 excavator, equipped with a cubic yard bucket. The test pits extended to a depth of between 10 to 12.75 feet (approximate) below ground surface. Infiltration (hydraulic conductivity) tests were performed within each of the test pits (tests designated IF-1 through IF-5, respectively). These test were performed at a depth of between 4.8 to 5.25 feet below ground surface. An OTO geotechnical engineer and Massachusetts licensed soil evaluator logged the test pits, and performed the hydraulic conductivity tests. The test pit logs are attached. The test pit locations are shown on the attached Site Sketch (Figure 1). SUBSURFACE CONDITIONS Test pits TP-4 and TP-5 were performed in paved areas. The pavement consisted of between two to three inches of asphalt underlain by 10 to 12 inches of sand and gravel. Test pits TP-1 through TP-3 were performed in grass covered areas. Between 9 and 16 inches of topsoil was present at the ground surface. The topsoil generally consisted of fine sand with some to little silt, and little organics (roots, branches). In test pits TP-3 and TP-5, the surficial layer was underlain by fill, consisting of dark brown or gray, fine sand, with little to trace silt, trace organics (roots), and trace amounts of debris (coal, brick, ash). The fill extended to a depth of between two to three feet below ground surface. Natural granular soils were encountered beneath the fill layer or surficial layer in each of the test pits. The granular soils consisted of fine sand, with little to trace amounts of silt, Stormwater Design Recommendations 10 Hawley Street Northampton, Massachusetts October 21, 2019 2 and trace organics (roots) between a depth of 4 to 10 fee in test pits TP-1 through TP-3. Trace amounts of gravel were observed within this layer at test pit TP-1. Test pits TP-3 through TP-5 terminated within this layer at a depth of between 10 to 12 feet, below ground surface. In test pits TP-1 and TP-2 the native granular soils contained increased amounts of silt starting at a depth of 10 and 9 feet, respectively. This layer consisted of fine sand with some silt. Trace organics (roots) were observed within this layer at test pit TP-1. In test pit TP-2, little to some gravel with occasional boulders was encountered along the eastern portion of the test pit, at a depth of 8 feet. Test pits TP-1 and TP-2 terminated within the silty sand layer at a depth of 12.75 and 12.5 feet, respectively. Groundwater No groundwater was observed in the test pits. However, moist soils were observed at a depth of 10 and 9 feet in test pits TP-1 and TP-2, respectively. The Estimated Seasonal High Groundwater Table (ESHGWT) was observed in test pits TP-1 and TP-2 at a depth of 11 and 10 feet, respectively. No other indications of an ESHGWT was observed in the remainder of the test pits. HYDRAULIC CONDUCTIVITY TESTING RESULTS In-Situ hydraulic conductivity (or permeability) tests were performed in each of the test pits to aid in the design of the stormwater disposal system. The tests and results are described below. The constant head tests were performed using a Guelph permeameter. The Guelph permeameter allows the rate of water recharge into an unsaturated soil to be measured while a constant water head is maintained. The permeability test was performed by augering a shallow hole into the soil at the base of an adjacent test pit (performed at each test pit location). The Guelph apparatus was then inserted, water was added to the apparatus, and the change in the rate of water flow from a reservoir over time was recorded. This data was then used to estimate the coefficient of permeability or hydraulic conductivity. The tests were performed at a depth of between 4.8 to 5.25 feet below ground surface, within what appears to be a granular layer observed throughout the Site. The soils encountered at the test interval consisted of fine sand with little to trace amounts of silt. The hydraulic conductivity (K) values determined by these tests are also presented in Table 1. Stormwater Design Recommendations 10 Hawley Street Northampton, Massachusetts October 21, 2019 3 O:\J1300\1305 Vanasse Hangen Brustlin Inc\55-01 10 Hawley Street\Hydraulic Report.docx Table 1 Hydraulic Conductivity Test Results Infiltration Test/Test Pit Test Depth (feet) Soil Conditions K Value (feet/day) IF-1/TP-1 4.9 Light brown, fine SAND, little to trace silt 38 IF-2/TP-2 4.8 Light brown, fine SAND, trace silt 30 IF-3/TP-3 5.25 Light gray, fine SAND, trace silt 25 IF-4/TP-4 5 Light brown, fine SAND, trace silt 29 IF-5/TP-5 5 Light brown, fine SAND, little silt 15 We recommend that OTO visit the Site during the excavation and installation of the stormwater structures to document that actual conditions are similar to those observed during these investigations, and assumed for design. We appreciated the opportunity to be of service on this project. If you have any questions, please contact the undersigned. Sincerely yours O'Reilly, Talbot & Okun Associates, Inc. Stephen McLaughlin Michael J. Talbot, P.E. Project Manager Principal Attachments: Limitations, Site Locus, Site Sketch, Test Pit Logs, Photographs LIMITATIONS 1. The observations presented in this report were made under the conditions described herein. The conclusions presented in this report were based solely upon the services described in the report and not on scientific tasks or procedures beyond the scope of the project or the time and budgetary constraints imposed by the client. The work described in this report was carried out in accordance with the Statement of Terms and Conditions attached to our proposal. 2. The analysis and recommendations submitted in this report are based in part upon the data obtained from widely spaced subsurface explorations. The nature and extent of variations between these explorations may not become evident until construction. If variations then appear evident, it may be necessary to reevaluate the recommendations of this report. 3. The generalized soil profile described in the text is intended to convey trends in subsurface conditions. The boundaries between strata are approximate and idealized and have been developed by interpretations of widely spaced explorations and samples; actual soil transitions are probably more erratic. For specific information, refer to the boring logs. 4. In the event that any changes in the nature, design or location of the proposed structures are planned, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and conclusions of this report modified or verified in writing by O'Reilly, Talbot & Okun Associates Inc. It is recommended that we be retained to provide a general review of final plans and specifications. 5. Our report was prepared for the exclusive benefit of our client. Reliance upon the report and its conclusions is not made to third parties or future property owners. PROJECT No. FIGURE No. 293 Bridge Street, Suite 500 Springfield, MA 01103 413.788.6222 www.OTO-ENV.com 10 HAWLEY STREET NORTHAMPTON, MASSACHUSETTS SITE LOCUSO:\J1300\1305 Vanasse Hangen Brustlin Inc\55-01 10 Hawley Street\Figure 1 - Site Locus.pdfJ1305-55-01 1 Map Version: 1964 Current As Of: 1979 Date: OCTOBER 2019 Topographic Map Quadrant: EASTHAMPTON/ MT HOLYOKE, MA SITE 1:25,000 SCALE NATIONAL GEODETIC VERTICAL DATUM 1929 10 FOOT CONTOUR INTERVAL 0 1000 FEET 0 0.5 1.0 MILES 0 0.5 1 KILOMETERS PROJECT NO. FIGURE NO.293 Bridge Street, Suite 500 Springfield, MA 01103 413.788.6222www.OTO-ENV.comPHILLIPS PLACE HAWLE PHILLIPS PL A C E Designed By: JE Drawn By: JE Checked By: Date: 10/21/2019 Revised Date: J1305-55-01 210 HAWLEY STREETSITE SKETCHNORTHAMPTON, MASSACHUSETTSO:\J1300\1305 Vanasse Hangen Brustlin Inc\55-01 10 Hawley Street\Figure 2 - Site Sketch.pdfNOT TO SCALE NOTES: 1. PLAN PROVIDED TO OTO IN ELECTRONIC FORMAT 2. SAMPLE LOCATIONS ARE APPROXIMATE AND ARE SHOWN ACCORDING TOEXISTING SITE FEATURES 3. ALL DATA IS TO BE CONSIDERED ACCURATE ONLY TO THE DEGREE IMPLIED BY THE METHOD(S) USED IN THE DEVELOPMENT OF THIS PLAN. LEGEND: APPROXIMATE LOCATION OF TEST PITS PERFORMED BY CHARLIE ARMENT TRUCKING ON 10/18/2019, OBSERVED BY OTO TP-4/IF-4 TP-3/IF-3TP-2/IF-2 TP-1/IF-1 TP-5/IF-5 COUNT CLASS E---- -- -- 5'E---- -- -- 2. 10'1. E---- -- -- 15' 20' Easy …..E Size Abbr.Term Moderate …..M 3" - 6" C and Difficult …..D 6" - 18" S some Very Difficult …..V 18" - 36" M little 36" and Larger L trace 1. Estimated Seasonal High Groundwater at 10'. 2. Infiltration test performed adjacent to test pit at 4.9' below grade 10/18/2019 TP-1 10 Hawley Street 1305-55-01 Southwestern Portion of Site FINAL DEPTH (ft) FIELD TEST DATA EXCAV. EFFORT BOULDERS/ COBBLES 50ºs, Overcast LOG OF TEST PIT START TIME REMARKS TEST PIT LOCATION CAPACITY (cy) 1305-55-01 DEPTH (ft) SAMPLE NO. Remarks:PROJECT NO. LOCATION SOIL DESCRIPTION PROJECT JOB NO. Northampton, MA LOG OF TEST PIT TP-1 BACKHOE 12.75 Cameron John Deere 120 1/2 yd3 OPERATOR OTO STAFF WEATHER DATE 8:00 AM JE & SMM FINISH TIME 10% or less Type Cobble End of exploration at 12.75' (Max reach of machine) GW Elevation (ft): 20% - 35% 10% - 20% Elapsed Time (min): Light brown, fine SAND, little to trace silt, trace organics (roots), trace gravel, dry (LOAMY SAND) Large Relative Quantity EXCAVATION EFFORT BOULDER/COBBLE CLASS 35% - 50% CONTRACTOR GROUNDWATER CONDITIONSPROPORTIONS USED 7:45 AM Arment GS ELEV. (ft) GW Encountered?: GW Depth (ft): moist (SANDY LOAM), ~10% Redox features at 10' Dark brown, fine SAND, some silt, trace organics (roots) Small Medium Top 16": Dark brown, fine SAND, some silt, little organics (roots, branches), damp NE TEST PIT PLAN 3' 8' COUNT CLASS E-------- 2. E-------- 5'3. E~83-6"-- -- 10' 1. 15' 20' Easy …..E Size Abbr.Term Moderate …..M 3" - 6" C and Difficult …..D 6" - 18" S some Very Difficult …..V 18" - 36" M little 36" and Larger L trace 1. Estimated Seasonal High Groundwater at 11'. 2. Infiltration test performed adjacent to test pit at 4.8' below grade 3. 4" Clay pipe encountered and broke at 3' below grade JOB NO. 1305-55-01 DATE 10/18/2019 OPERATOR Cameron LOG OF TEST PIT TP-2 PROJECT 10 Hawley Street CONTRACTOR Arment 1/2 yd3 FINISH TIME 9:00 AM GS ELEV. (ft) LOCATION Northampton, MA WEATHER 50ºs, Overcast BACKHOE John Deere 120 DEPTH (ft) EXCAV. EFFORT BOULDERS/ COBBLES SAMPLE NO. TEST PIT LOCATION Southwestern Portion of Site START TIME 8:40 AM CAPACITY (cy) FIELD TEST DATA REMARKSSOIL DESCRIPTION Top 9": Dark brown, fine SAND, some silt, little organics (roots), dry OTO STAFF JE & SMM FINAL DEPTH (ft) 12.5 Light brown, fine SAND, trace to little silt, trace organics (roots in upper 4'), dry (LOAMY SAND) (SANDY LOAM), ~10% REDOX FEATURES AT 11' End of exploration at 12.5' TEST PIT PLAN EXCAVATION EFFORT BOULDER/COBBLE CLASS PROPORTIONS USED GROUNDWATER CONDITIONS 10% - 20% GW Elevation (ft): Type Relative Quantity GW Encountered?: NE Cobble 35% - 50% Brown, fine SAND, some silt, moist 1305-55-01 LOG OF TEST PIT TP-2 Brown, fine to medium SAND, little to some gravel, trace silt, dry (SAND) Occasional cobbles Large 10% or less Elapsed Time (min): Remarks:PROJECT NO. Small 20% - 35% GW Depth (ft): Medium 3' 8' COUNT CLASS E---- -- -- E---- -- -- E---- -- -- 5' 2. E---- -- -- 10' 15' 20' Easy …..E Size Abbr.Term Moderate …..M 3" - 6" C and Difficult …..D 6" - 18" S some Very Difficult …..V 18" - 36" M little 36" and Larger L trace 1. No indications of Estimated Seasonal High Groundwater observed 2. Infiltration test performed adjacent to test pit at 5.25' below grade LOG OF TEST PIT TP-3 PROJECT 10 Hawley Street CONTRACTOR Arment LOCATION Northampton, MA WEATHER 50ºs, Overcast BACKHOE John Deere 120 JOB NO. 1305-55-01 DATE 10/18/2019 OPERATOR Cameron OTO STAFF JE & SMM FINAL DEPTH (ft) 12.0 DEPTH (ft) EXCAV. EFFORT BOULDERS/ COBBLES SAMPLE NO. TEST PIT LOCATION Center Portion of Site START TIME 10:10 AM CAPACITY (cy)1/2 yd3 FINISH TIME 10:30 AM GS ELEV. (ft) Brown-gray, fine SAND, trace to little silt, trace organics (roots), trace debris (brick, ash), dry (FILL/REWORKED SOILS) Brown, fine SAND, little silt, trace organics (roots), dry (LOAMY SAND) FIELD TEST DATA REMARKSSOIL DESCRIPTION Top 9": Dark brown, fine SAND, little silt, little organics (roots), dry (TOPSOIL) Gray, fine SAND, trace silt, dry (SAND) End of exploration at 12' Type Relative Quantity GW Encountered?: NE Cobble 35% - 50% TEST PIT PLAN EXCAVATION EFFORT BOULDER/COBBLE CLASS PROPORTIONS USED GROUNDWATER CONDITIONS Small 20% - 35% GW Depth (ft): Medium 10% - 20% GW Elevation (ft): 1305-55-01 LOG OF TEST PIT TP-3 Large 10% or less Elapsed Time (min): Remarks:PROJECT NO. 3' 12' COUNT CLASS E---- -- -- E---- -- -- 5'2. E---- -- -- 10' 15' 20' Easy …..E Size Abbr.Term Moderate …..M 3" - 6" C and Difficult …..D 6" - 18" S some Very Difficult …..V 18" - 36" M little 36" and Larger L trace 1. No indications of Estimated Seasonal High Groundwater observed 2. Infiltration test performed adjacent to test pit at 5' below grade LOG OF TEST PIT TP-4 PROJECT 10 Hawley Street CONTRACTOR Arment LOCATION Northampton, MA WEATHER 50ºs, Overcast BACKHOE John Deere 120 JOB NO. 1305-55-01 DATE 10/18/2019 OPERATOR Cameron OTO STAFF JE & SMM FINAL DEPTH (ft) 10.0 DEPTH (ft) EXCAV. EFFORT BOULDERS/ COBBLES SAMPLE NO. TEST PIT LOCATION Northeastern Portion of Site START TIME 10:40 AM CAPACITY (cy)1/2 yd3 FINISH TIME 11:15 AM GS ELEV. (ft) Light brown, fine SAND, trace to little silt, dry (LOAMY SAND) FIELD TEST DATA REMARKSSOIL DESCRIPTION Top 3" ASPHALT, 12" SAND and GRAVEL Base Light gray, fine SAND, little silt, dry (LOAMY SAND) End of exploration at 10' Type Relative Quantity GW Encountered?: NE Cobble 35% - 50% TEST PIT PLAN EXCAVATION EFFORT BOULDER/COBBLE CLASS PROPORTIONS USED GROUNDWATER CONDITIONS Small 20% - 35% GW Depth (ft): Medium 10% - 20% GW Elevation (ft): 1305-55-01 LOG OF TEST PIT TP-4 Large 10% or less Elapsed Time (min): Remarks:PROJECT NO. 3' 7' COUNT CLASS E---- -- -- E---- -- -- 5'2. E---- -- -- 10' 15' 20' Easy …..E Size Abbr.Term Moderate …..M 3" - 6" C and Difficult …..D 6" - 18" S some Very Difficult …..V 18" - 36" M little 36" and Larger L trace 1. No indications of Estimated Seasonal High Groundwater observed 2. Infiltration test performed adjacent to test pit at 5' below grade LOG OF TEST PIT TP-5 PROJECT 10 Hawley Street CONTRACTOR Arment LOCATION Northampton, MA WEATHER 50ºs, Overcast BACKHOE John Deere 120 JOB NO. 1305-55-01 DATE 10/18/2019 OPERATOR Cameron OTO STAFF JE & SMM FINAL DEPTH (ft) 10.0 DEPTH (ft) EXCAV. EFFORT BOULDERS/ COBBLES SAMPLE NO. TEST PIT LOCATION Northeastern Portion of Site START TIME 11:20 AM CAPACITY (cy)1/2 yd3 FINISH TIME 11:40 AM GS ELEV. (ft) trace organics (roots), dry (FILL) FIELD TEST DATA REMARKSSOIL DESCRIPTION Top 2" ASPHALT, 10" SAND and GRAVEL Base Dark brown, fine SAND, little silt, trace debris (brick, coal), End of exploration at 10' Light brown, fine SAND, trace to little silt, dry (LOAMY SAND) Type Relative Quantity GW Encountered?: NE Cobble 35% - 50% TEST PIT PLAN EXCAVATION EFFORT BOULDER/COBBLE CLASS PROPORTIONS USED GROUNDWATER CONDITIONS Small 20% - 35% GW Depth (ft): Medium 10% - 20% GW Elevation (ft): 1305-55-01 LOG OF TEST PIT TP-5 Large 10% or less Elapsed Time (min): Remarks:PROJECT NO. 7' 12' 10 Hawley Street Northampton, Massachusetts J1305-55-01 October 21, 2019 TP-1 TP-1 10 Hawley Street Northampton, Massachusetts J1305-55-01 October 21, 2019 TP-2 TP-2 10 Hawley Street Northampton, Massachusetts J1305-55-01 October 21, 2019 TP-3 TP-3 10 Hawley Street Northampton, Massachusetts J1305-55-01 October 21, 2019 TP-4 TP-4 10 Hawley Street Northampton, Massachusetts J1305-55-01 October 21, 2019 TP-5 TP-5 Appendix C: FEMA Map Appendix C: FEMA Map Appendix D: Long Term Operation and Maintenance Measures Appendix D: Long Term Stormwater Operation and Maintenance Measures Appendix D: Long Term Operation and Maintenance Measures Project Information Site Project Name: Address or Locus: City, State & Zip: Developer Client Name: Client Address: Client City, State & Zip: Client Telephone No.: Client Cell Phone: Client E-Mail: Site Supervisor Site Manager Name: Site Manager Address: Site Manager City, State & Zip: Site Manager Telephone No.: Site Manager Cell Phone: Site Manager E-Mail: Appendix D: Long Term Operation and Maintenance Measures Long Term Stormwater Maintenance Measures – The following maintenance program is proposed to ensure the continued effectiveness of the structural water quality controls previously described. Clean all catch basins twice annually to remove accumulated sand, sediment, and floatable products or as needed based on use. Paved areas will be swept, at a minimum, 4 times per year. Routinely pick up and remove litter from the parking areas, islands and perimeter landscape areas in addition to regular pavement sweeping. Routinely inspect all dumpster and compactor locations for spills. Remove all trash litter from the enclosure and dispose of properly. Pavement Systems Standard Asphalt Pavement Sweep or vacuum standard asphalt pavement areas at least four times per year with a commercial cleaning unit and properly dispose of removed material. Recommended sweeping schedule:  Oct/Nov  Feb/Mar  Apr/May  Aug/Sep  More frequent sweeping of paved surfaces will result in less accumulation in catch basins, less cleaning of subsurface structures, and less disposal costs. Check loading docks and dumpster areas frequently for spillage and/or pavement staining and clean as necessary. Structural Stormwater Management Devices Catch Basins / Area Drains All catch basins shall be inspected and cleaned a minimum of at least once per year. Sediment (if more than six inches deep) and/or floatable pollutants shall be pumped from the basin and disposed of at an approved offsite facility in accordance with all applicable regulations. Any structural damage or other indication of malfunction will be reported to the site manager and repaired as necessary During colder periods, the catch basin grates must be kept free of snow and ice. Appendix D: Long Term Operation and Maintenance Measures During warmer periods, the catch basin grates must be kept free of leaves, litter, sand, and debris. Structural Water Quality Devices CHECK SPECIFIC MANUFACTURER’S INSTRUCTIONS ON O&M REQUIREMENTS AND METHODOLOGY Inspect devices monthly for the first three months after construction. After initial three month period, all water quality units are to be inspected at least four times per year and cleaned a minimum of at least once per year or when sediment reaches 8” in depth. Follow manufacturer instructions for inspection and cleaning and contact manufacturer if system is malfunctioning. Subsurface Infiltration System The subsurface infiltration systems will be inspected at least once each year by removing the manhole/access port covers and determining the thickness of sediment that has accumulated in the sediment removal row. If sediment is more than six inches deep, it must be suspended via flushing with clean water and removed using a vactor truck. Manufacturer’s specifications and instructions for cleaning the sediment removal row is provided as an attachment to this section. Emergency overflow pipes will be examined at least once each year and verified that no blockage has occurred. System will be observed after rainfalls to see if it is properly draining Roof Drain Leaders Perform routine roof inspections quarterly. Keep roofs clean and free of debris. Keep roof drainage systems clear. Keep roof access limited to authorized personnel. Clean inlets draining to the subsurface bed twice per year as necessary. Vegetated Stormwater Management Devices Vegetated Areas Maintenance Although not a structural component of the drainage system, the maintenance of vegetated areas may affect the functioning of stormwater management practices. This includes the health/density of vegetative cover and activities such as the Appendix D: Long Term Operation and Maintenance Measures application and disposal of lawn and garden care products, disposal of leaves and yard trimmings. Inspect planted areas on a semi-annual basis and remove any litter. Maintain planted areas adjacent to pavement to prevent soil washout. Immediately clean any soil deposited on pavement. Re-seed bare areas; install appropriate erosion control measures when native soil is exposed or erosion channels are forming. Plant alternative mixture of grass species in the event of unsuccessful establishment. The grass vegetation should be cut to a height between three and four inches. Pesticide/Herbicide Usage – No pesticides are to be used unless a single spot treatment is required for a specific control application. Fertilizer usage should be avoided. If deemed necessary, slow release fertilizer should be used. Fertilizer may be used to begin the establishment of vegetation in bare or damaged areas, but should not be applied on a regular basis unless necessary. Long Term Best Management Practices Checklist The Long-Term BMP Maintenance/Evaluation Checklist is attached. Appendix D: Long Term Stormwater Operation and Maintenance Hawley Street Residential Development, Northampton, MA Long Term Best Management Practices – Maintenance/ Evaluation Checklist Best Management Practice Inspection Frequency Date Inspected Inspector Minimum Maintenance and Key Items to Check Cleaning/Repair Needed yes no (List Items) Date of Cleaning/Repair Performed by Subsurface Infiltration System Bi-annually yes no Subsurface Recharge Trench Bi-annually yes no Water Quality Inlet Bi-annually yes no Street Sweeping Bi-annually yes no yes no yes no yes no yes no yes no yes no yes no yes no yes no Stormwater Control Manager Appendix E: Hydrologic Analysis Appendix E: Hydraulic Analysis StormCAD Analysis Recharge Calculations Water Quality Volume Calculations Appendix E: Hydrologic Analysis StormCAD Analysis Scenario: BaseCurrent Time Step: 0.000 hFlexTable: Network Elements Table\\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\StormCAD\42540-PR.stswLabelStation (Calculated) (ft)InletInlet LocationInlet CInlet Drainage Area (ft²)Total Inlet Intensity (in/h)Flow (Total In)Flow (Captured) (cfs)Flow (Total Bypassed) (cfs)Bypass TargetSpread / Top Width (ft)System CA (ft²)System Flow Time (min)System Rational Flow (cfs)Flow (cfs)Start NodeStop NodeNumber of BarrelsRise (Unified) (ft)Span (ft)Length (Unified) (ft)Slope (Calculated) (ft/ft)Friction Slope (ft/ft)Headloss (ft)Velocity (ft/s)Depth (Normal) (ft)Invert (Start) (ft)Hydraulic Grade Line (In) (ft)Elevation Ground (Start) (ft)Invert (Stop) (ft)Hydraulic Grade Line (Out) (ft)Elevation Ground (Stop) 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Sag0.8501,855.0006.3000.2298666983842850.230.00-0.01,576.7505.0000.23-<None><None>------0.00---128.74--128.74-Roof Area 62+56<None>In Sag0.8501,500.0006.3000.1858760267496110.190.00-0.01,275.0005.0000.19-<None><None>------0.00---131.72--131.72-CB-181+36<None>In Sag0.8501,600.0006.3000.198267772793770.200.00-0.01,360.0005.0000.20-<None><None>------0.00---134.12--134.12-WQU-50+25<None>In Sag0.8505,250.0006.3000.6505661010742190.650.00-0.04,462.5005.0000.65-<None><None>------0.00---133.64--133.64-CB-200+33<None>In Sag0.850700.0006.3000.08674214780330660.090.00-0.0595.0005.0000.09-<None><None>------0.00---134.56--134.56-CB-212+73<None>In 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Area 5False129.90DMH-4False129.60True20.037.80.015Circle4.00.0100.133.340.230.3042.945.8-82CO-25Roof Area 6False128.50DMH-3False128.30True18.035.20.011Circle6.00.0100.233.420.190.7729.937.5-97CO-27DMH-2False119.20O-2False119.00True5.022.70.040Circle24.00.0102.058.770.3558.823.512.8-99CO-28Roof Area 6False131.50DMH-4False129.50True86.054.10.023Circle6.00.0100.194.210.331.1116.727.6-103CO-29CB-18False133.90DMH-5False133.20True129.062.60.005Circle6.00.0100.202.530.210.5436.942.0-106CO-30WQU-5False133.30DMH-5False133.20True18.039.90.006Circle12.00.0100.653.370.303.4518.829.4-108CO-31DMH-5False132.10OCS-2False132.00True7.025.00.014Circle12.00.0100.905.180.315.5416.227.2-110CO-32CB-20False134.40DMH-5False134.20True26.036.80.008Circle4.00.0100.092.350.150.2240.043.9-115CO-33DMH-7False132.20DMH-8False131.60True108.073.80.006Circle12.00.0100.252.540.233.457.118.1-117CO-34CB-21False134.40DMH-7False134.20True27.030.60.007Circle6.00.0100.253.010.220.6339.543.6-Page 1 of 110/31/2019file:///C:/Users/jgalarneau/AppData/Local/Temp/Bentley/StormCAD/pvdqvq2z.xml Scenario: BaseCurrent Time Step: 0.000 hConduit FlexTable: Combined Pipe/Node Report\\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\StormCAD\42540-PR.stswLabelStart NodeStop NodeBranch IDBranch Element IDLength (Unified) (ft)Upstream Inlet CSystem Intensity (in/h)Upstream Inlet Area (ft²)Upstream Structure Flow (Total Surface) (cfs)System CA (ft²)System Intensity (in/h)System Rational Flow (cfs)Flow (cfs)Rise (Unified) (ft)Capacity (Full Flow) (cfs)Velocity (ft/s)Invert (Start) (ft)Invert (Stop) (ft)Slope (Calculated) (ft/ft)NotesCO-4WQU-6DMH-8914.00.8506.3003,172.0000.392,696.2006.3000.390.391.007.324.96133.80133.700.025-CO-5DMH-8DMH-9834.0(N/A)6.043(N/A)0.004,396.2006.0430.610.611.007.325.66131.50131.400.025-CO-8DMH-9DMH-108499.0(N/A)6.039(N/A)0.004,396.2006.0390.610.611.003.293.21131.30130.800.005-CO-11DMH-10O-18535.0(N/A)5.885(N/A)0.006,081.7505.8850.830.831.003.503.65130.70130.500.006-CO-12WQU-7DMH-1010110.00.8506.3001,983.0000.251,685.5506.3000.250.251.006.553.99132.80132.600.020-CO-14WQU-1DMH-16115.00.8506.3003,000.0000.372,550.0006.3000.370.371.003.783.06121.60121.500.007-CO-15WQU-2DMH-1717.00.8506.3003,600.0000.453,060.0006.3000.450.451.009.596.23122.00121.700.043-CO-16DMH-1DMH-26235.0(N/A)6.276(N/A)0.005,610.0006.2760.810.811.003.503.63121.40121.200.006-CO-19DMH-4DMH-31266.0(N/A)6.198(N/A)0.007,352.5006.1981.051.051.006.986.41129.40127.900.023-CO-20DMH-3DMH-21399.0(N/A)6.146(N/A)0.008,929.2506.1461.271.271.0011.029.35126.80121.200.057-CO-21WQU-3DMH-4119.00.8506.3002,700.0000.332,295.0006.3000.330.331.004.883.56130.00129.900.011-CO-22WQU-4DMH-4417.00.8506.3003,400.0000.422,890.0006.3000.420.421.005.544.16130.00129.900.014-CO-24Roof Area 5DMH-43120.00.8506.3001,050.0000.13892.5006.3000.130.130.330.303.34129.90129.600.015-CO-25Roof Area 6DMH-35118.00.8506.3001,855.0000.231,576.7506.3000.230.230.500.773.42128.50128.300.011-CO-27DMH-2O-2145.0(N/A)6.093(N/A)0.0014,539.2506.0932.052.052.0058.828.77119.20119.000.040-CO-28Roof Area 6DMH-42186.00.8506.3001,500.0000.191,275.0006.3000.190.190.501.114.21131.50129.500.023-CO-29CB-18DMH-5131129.00.8506.3001,600.0000.201,360.0006.3000.200.200.500.542.53133.90133.200.005-CO-30WQU-5DMH-512118.00.8506.3005,250.0000.654,462.5006.3000.650.651.003.453.37133.30133.200.006-CO-31DMH-5OCS-21127.0(N/A)6.045(N/A)0.006,417.5006.0450.900.901.005.545.18132.10132.000.014-CO-32CB-20DMH-511126.00.8506.300700.0000.09595.0006.3000.090.090.330.222.35134.40134.200.008-CO-33DMH-7DMH-882108.0(N/A)6.255(N/A)0.001,700.0006.2550.250.251.003.452.54132.20131.600.006-CO-34CB-21DMH-78127.00.8506.3002,000.0000.251,700.0006.3000.250.250.500.633.01134.40134.200.007-Page 1 of 110/31/2019file:///C:/Users/jgalarneau/AppData/Local/Temp/Bentley/StormCAD/dk4qlq0h.xml Scenario: BaseCurrent Time Step: 0.000 hFlexTable: Catch Basin Table\\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\StormCAD\42540-PR.stswIDLabelElevation (Ground) (ft)Set Rim to Ground Elevation?Elevation (Rim) (ft)Elevation (Invert) (ft)Length (ft)Width (ft)Inlet TypeFlow (Maximum in) (cfs)Inflow-Capture CurveCapture Efficiency (Calculated) (%)Flow (Captured) (cfs)Hydraulic Grade Line (In) (ft)Spread / Top Width (ft)Notes35WQU-6137.80True137.80133.80--Full Capture-<Collection: 0 items>100.00.39134.060.0-43WQU-7136.80True136.80132.80--Full Capture-<Collection: 0 items>100.00.25133.000.0-61WQU-3133.50True133.50130.00--Full Capture-<Collection: 0 items>100.00.33130.240.0-62WQU-4133.50True133.50130.00--Full Capture-<Collection: 0 items>100.00.42130.270.0-66WQU-1125.00True125.00121.60--Full Capture-<Collection: 0 items>100.00.37121.850.0-67WQU-2125.00True125.00122.00--Full Capture-<Collection: 0 items>100.00.45122.280.0-79Roof Area 5133.80True133.80129.90--Full Capture-<Collection: 0 items>100.00.13130.100.0-81Roof Area 6131.80True131.80128.50--Full Capture-<Collection: 0 items>100.00.23128.740.0-98Roof Area 6135.50True135.50131.50--Full Capture-<Collection: 0 items>100.00.19131.720.0-101CB-18135.50True135.50133.90--Full Capture-<Collection: 0 items>100.00.20134.120.0-104WQU-5137.00True137.00133.30--Full Capture-<Collection: 0 items>100.00.65133.640.0-109CB-20137.80True137.80134.40--Full Capture-<Collection: 0 items>100.00.09134.560.0-116CB-21137.80True137.80134.40--Full Capture-<Collection: 0 items>100.00.25134.650.0-Page 1 of 110/31/2019file:///C:/Users/jgalarneau/AppData/Local/Temp/Bentley/StormCAD/t0gongcc.xml Scenario: BaseCurrent Time Step: 0.000 hFlexTable: Manhole Table\\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\StormCAD\42540-PR.stswIDLabelElevation (Ground) (ft)Set Rim to Ground Elevation?Elevation (Rim) (ft)Bolted Cover?Elevation (Invert in 1) (ft)Flow (Total In)Flow (Total Out) (cfs)Depth (Out) (ft)Hydraulic Grade Line (Out) (ft)Headloss MethodHydraulic Grade Line (In) (ft)Notes33DMH-9137.90True137.90False131.400.6147519946098330.610.33131.63Absolute131.63-36DMH-8137.90True137.90False133.700.6391367316246030.610.33131.83Absolute131.83-44DMH-10137.00True137.00False130.800.8601208925247190.830.38131.08Absolute131.08-60DMH-4133.40True133.40False129.901.071885108947751.050.43129.83Absolute129.83-63DMH-3131.80True131.80False127.901.284373283386231.270.48127.28Absolute127.28-64DMH-2128.90True128.90False121.202.084680795669562.050.50119.70Absolute119.70-65DMH-1125.70True125.70False121.500.8178545236587520.810.38121.78Absolute121.78-102DMH-5137.60True137.60False133.200.9355760216712950.900.40132.50Absolute132.50-114DMH-7137.30True137.30False134.200.2478347122669220.250.20132.40Absolute132.40-Page 1 of 110/31/2019file:///C:/Users/jgalarneau/AppData/Local/Temp/Bentley/StormCAD/2uak4o4x.xml Scenario: BaseCurrent Time Step: 0.000 hFlexTable: Outfall Table\\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\StormCAD\42540-PR.stswIDLabelElevation (Ground) (ft)Set Rim to Ground Elevation?Elevation (Invert) (ft)Boundary Condition TypeBoundary ElementElevation (User Defined Tailwater) (ft)Hydraulic Grade (ft)Flow (Total Out) (cfs)Notes47O-1136.20True128.40Free Outfall<None>-130.830.82-96O-2128.50True119.00Free Outfall<None>-119.352.05-107OCS-2137.70True132.00Free Outfall<None>-132.310.90-Page 1 of 110/31/2019file:///C:/Users/jgalarneau/AppData/Local/Temp/Bentley/StormCAD/znmamlq2.xml Scenario: BaseCurrent Time Step: 0.000 hFlexTable: Catchment Table\\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\StormCAD\42540-PR.stswIDLabelOutflow ElementArea (User Defined) (ft²)Runoff Coefficient (Rational)Time of Concentration (min)Flow (Total Out) (cfs)Notes52CM-1WQU-71,983.0000.8505.0000.25-53CM-2WQU-63,172.0000.8505.0000.39-85CM-5WQU-13,000.0000.8505.0000.37-86CM-6WQU-23,600.0000.8505.0000.45-87CM-7WQU-32,700.0000.8505.0000.33-88CM-8WQU-43,400.0000.8505.0000.42-94CM-11Roof Area 51,050.0000.8505.0000.13-95CM-12Roof Area 61,855.0000.8505.0000.23-100CM-13Roof Area 61,500.0000.8505.0000.19-111ROOF AREA 7CB-181,600.0000.8505.0000.20-112CM-15CB-20700.0000.8505.0000.09-113CM-16WQU-55,250.0000.8505.0000.65-118ROOF AREA 8CB-212,000.0000.8505.0000.25-Page 1 of 110/31/2019file:///C:/Users/jgalarneau/AppData/Local/Temp/Bentley/StormCAD/ozsbt3nk.xml Appendix E: Hydrologic Analysis Recharge Calculations Recharge Calculations Project Name:Resid. Dev.Proj. No.:`42540 Project Location:N.Hamp.Date: 10/23/2019 Calculated by: JAG Checked by: Net Proposed Impervious Areas by Hydrologic Soil Group (HSG) in acres Subcatchment HSG A HSG B HSG C HSG D Total Area All 0.3 0.3 2 0.0 3 0.0 4 0.0 5 0.0 TOTAL 0.0 0.3 0.0 0.0 0.3 HSG Area Recharge Depth * Volume (acres) (in.) (c.f.) A 0.0 0.60 0 B 0.3 0.35 432 C 0.0 0.25 0 D 0.0 0.10 0 TOTAL 432 * Per 2008 Massachusetts DEP Recharge Requirement Infiltration Volumes Provided in Infiltration Basins (below lowest overflow outlet - see attached sheets) Infiltration System 2669.0 Total 2,669 c.f. Required Recharge Volume (Cubic Feet) Proposed Impervious Surface Summary Provided Recharge Volume (Cubic Feet) \\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\Recharge Requirement.xls Appendix E: Hydrologic Analysis Water Quality Volume Calculations VHB Water Quality Volume Calculations Project Name:Resid. Dev.Proj. No.:42540.0 Project Location:N. Hamp., MA Date: 10/23/2019 Calculated by: JAG Runoff from impervious areas Total Impervious Area =1.10 Acres Required: Required Volume (c.f.) Water Quality Volume 1,997 Water Quality Provided 4,152 cf Runoff Depth to 0.5 be Treated (in.) Sheet1\\vhb\gbl\proj\Springfield\42540.00\Reports\Drainage\Water Quality Volume Analysis.xls Project:TSS For Stormceptor Location:Springfield, MA Prepared For:VHB Springfield / Jeff Galarneau, PE Purpose: Reference: Procedure: where: A = impervious surface drainage area (in square miles) WQV = water quality volume in watershed inches (1" in this case) Structure Name Impv. (acres) A (miles2) tc (min) tc (hr) WQV (in)qu (csm/in.)Q (cfs) WQU - 1 0.05 0.0000781 5.0 0.083 1.00 795.00 0.06 WQU - 2 0.08 0.0001250 5.0 0.083 1.00 795.00 0.10 WQU - 3 0.04 0.0000625 5.0 0.083 1.00 795.00 0.05 WQU - 4 0.08 0.0001250 5.0 0.083 1.00 795.00 0.10 WQU - 5 0.10 0.0001563 5.0 0.083 1.00 795.00 0.12 WQU - 6 0.07 0.0001094 5.0 0.083 1.00 795.00 0.09 WQU - 7 0.06 0.0000938 5.0 0.083 1.00 795.00 0.07 qu = the unit peak discharge, in csm/in. To calculate the water quality flow rate (WQF) over a given site area. In this situation the WQF is derived from the first 1" of runoff from the contributing impervious surface. Massachusetts Dept. of Environmental Protection Wetlands Program / United States Department of Agriculture Natural Resources Conservation Service TR-55 Manual Determine unit peak discharge using Figure 1 or 2. Figure 2 is in tabular form so is preferred. Using the tc, read the unit peak discharge (qu) from Figure 1 or Table in Figure 2. qu is expressed in the following units: cfs/mi2/watershed inches (csm/in). Compute Q Rate using the following equation: Q = (qu) (A) (WQV) Q = flow rate associated with first 1" of runoff www.rinkerstormceptor.com Phone: (413) 562-3647 Environmentally Engineered Stormwater Solutions... that exceed your client’s needs! Stormwater Treatment Made Simple! Dirty water enters the unit Inlet Vortex draws pollutants into the lower chamber Optimized for hydraulic efficiency, pollutant capture and retention Large pollutant storage volume reduces maintenance frequency Design Flexibility Easy to inspect and maintain Clean water enters the environment Spill protection limits liability Proven Performance TSS & Oil Removal n Scour Prevention n Small Footprint Stormceptor® is an underground stormwater quality treatment device that is unparalleled in its effectiveness for pollutant capture and retention. With thousands of systems operating worldwide, Stormceptor delivers protection every day in every storm. With patented technology, optimal treatment occurs by allowing free oil to rise and sediment to settle. The Stormceptor design prohibits scour and release of previously captured pollutants, ensuring superior treatment and protection during even the most extreme storm events. Stormceptor is very easy to design and provides flexibility under varying site constraints such as tight right-of-ways, zero lot lines and retrofit projects. Design flexibility allows for a cost-effective approach to stormwater treatment. Stormceptor has proven performance backed by the longest record of lab and field verification in the industry. Tested Performance n Fine particle capture n Prevents scour or release n 95%+ Oil removal 1 Depth Below Pipe Inlet Invert to the Bottom of Base Slab, and Maximum Sediment Capacity can vary to accommodate specific site designs and pollutant loads. Depths can vary to accommodate special designs or site conditions. Contact your local representative for assistance. 2 Water Quality Flow Rate (Q) is based on 80% annual average TSS removal of the OK110 particle size distribution. 3 Peak Conveyance Flow Rate is based upon ideal velocity of 3 feet per second and outlet pipe diameters of 18-inch, 36-inch, and 54-inch diameters. 4 Hydrocarbon & Sediment capacities can be modified to accommodate specific site design requirements, contact your local representative for assistance. Massachusetts – Water Quality (Q) Flow Rate www.rinkerstormceptor.com Manufacturing Plant: Westfield, MA Phone: (413) 562-3647 11-22-13-R13-802 MDEPwww.stormceptor.com Stormceptor STC Model Inside Diameter Typical Depth Below Inlet Pipe Invert 1 Water Quality Flow Rate Q 2 Peak Conveyance Flow Rate 3 Hydrocarbon Capacity 4 Maximum Sediment Capacity 4 (ft)(in)(cfs)(cfs)(Gallons)(ft3) STC 450i 4 68 0.40 5.5 86 46 STC 900 6 63 0.89 22 251 89 STC 2400 8 104 1.58 22 840 205 STC 4800 10 140 2.47 22 909 543 STC 7200 12 148 3.56 22 1,059 839 STC 11000 2 x 10 142 4.94 48 2,792 1,086 STC 16000 2 x 12 148 7.12 48 3,055 1,677 Appendix F: Erosion and Sedimentation Control Measures Appendix F: Erosion and Sedimentation Control Measures An erosion and sedimentation control plan will be developed, and will include measures such as those described below. Appendix F: Erosion and Sedimentation Control Measures Erosion and Sedimentation Control Measures The following erosion and sedimentation controls are for use during the earthwork and construction phases of the project. The following controls are provided as recommendations for the site contractor and do not constitute or replace the final Stormwater Pollution Prevention Plan that must be fully implemented by the Contractor and owner in Compliance with EPA NPDES regulations. Silt Fencing In areas where high runoff velocities or high sediment loads are expected, Straw wattles will be backed up with silt fencing. This semi-permeable barrier made of a synthetic porous fabric will provide additional protection. The silt fences and Straw wattles will be replaced as determined by periodic field inspections. Catch Basin / Water Quality Unit Protection Newly constructed and existing catch basins / water quality units will be protected with Straw bale barriers (where appropriate) or silt sacks throughout construction. Gravel and Construction Entrance/Exit A temporary crushed-stone construction entrance/exit will be constructed. A cross slope will be placed in the entrance to direct runoff to a protected catch basin inlet or settling area. If deemed necessary after construction begins, a wash pad may be included to wash off vehicle wheels before leaving the project site. Vegetative Slope Stabilization Stabilization of open soil surfaces will be implemented within 14 days after grading or construction activities have temporarily or permanently ceased, unless there is sufficient snow cover to prohibit implementation. Vegetative slope stabilization will be used to minimize erosion on slopes of 3:1 or flatter. Annual grasses, such as annual rye, will be used to ensure rapid germination and production of root mass. Permanent stabilization will be completed with the planting of perennial grasses or legumes. Establishment of temporary and permanent vegetative cover may be established by hydro-seeding or sodding. A suitable topsoil, good seedbed preparation, and adequate lime, fertilizer and water will be provided for effective establishment of these vegetative stabilization methods. Mulch will also be used after Appendix F: Erosion and Sedimentation Control Measures permanent seeding to protect soil from the impact of falling rain and to increase the capacity of the soil to absorb water. Maintenance The contractor or subcontractor will be responsible for implementing each control shown on the Sedimentation and Erosion Control Plan. In accordance with EPA regulations, the contractor must sign a copy of a certification to verify that a plan has been prepared and that permit regulations are understood. The on-site contractor will inspect all sediment and erosion control structures periodically and after each rainfall event. Records of the inspections will be prepared and maintained on-site by the contractor. Silt shall be removed from behind barriers if greater than 6-inches deep or as needed. Damaged or deteriorated items will be repaired immediately after identification. The underside of Straw bales should be kept in close contact with the earth and reset as necessary. Sediment that is collected in structures shall be disposed of properly and covered if stored on-site. Erosion control structures shall remain in place until all disturbed earth has been securely stabilized. After removal of structures, disturbed areas shall be regraded and stabilized as necessary. The sedimentation and erosion control plan is included in project plan set; a reduced version and Erosion Control Maintenance checklist is included here for quick reference. Appendix F: Erosion and Sedimentation Control Measures Construction Best Management Practices - Maintenance/Evaluation Checklist Appendix F: Erosion and Sedimentation Control Measures Hawley Street Residential Development, Northampton, MA Construction Best Management Practices – Maintenance/ Evaluation Checklist Best Management Practice Inspection Frequency Date Inspected Inspector Minimum Maintenance and Key Items to Check Cleaning/Repair Needed yes no (List Items) Date of Cleaning/Repair Performed by: Straw Wattles/Silt Fencing Weekly and after storm events yes no Gravel Construction Entrance Weekly and after storm events yes no Water Quality Inlet Protection Weekly and after storm events yes no Vegetated Slope Stabilization Weekly and after storm events yes no yes no yes no yes no Stormwater Control Manager Appendix G: Spill Prevention & Response Appendix G: Spill Prevention & Response Appendix G: Spill Prevention & Response Spill Response Procedure Initial Notification In the event of a spill the facility and/or construction manager or supervisor will be notified immediately. Facility Manager Name: Facility Manager Phone No.: Construction Manager Name: Construction Manager Phone No.: Assessment - Initial Containment The supervisor or manager will assess the incident and initiate containment control measures with the appropriate spill containment equipment included in the spill kit kept on-site. The supervisor will first contact the Fire Department and then notify the Police Department, Board of Health and Conservation Commission. The fire department is ultimately responsible for matters of public health and safety and should be notified immediately. Fire Department Telephone No.: 911 Police Department Telephone No.: 911 Board of Health Telephone No.: 413-587-4900 Conservation Commission Telephone: 413-587-1263 Further Notification Based on the assessment from the Fire Chief, additional notification to a cleanup contractor may be made. The Massachusetts Department of Environmental Protection (DEP) and the EPA may be notified depending upon the nature and severity of the spill. The Fire Chief will be responsible for determining the level of cleanup and notification required. The attached list of emergency phone numbers shall be posted in the main construction/facility office and readily accessible to all employees. Appendix G: Spill Prevention & Response HAZARDOUS WASTE / OIL SPILL REPORT Date Time AM / PM Exact location (Transformer #) Type of equipment Make Size S / N Weather Conditions On or near Water ☐ Yes If Yes, name of body of Water ☐ No Type of chemical/oil spilled Amount of chemical/oil spilled Cause of Spill Measures taken to contain or clean up spill Amount of chemical/oil recovered Method Material collected as a result of cleanup: Drums containing Drums containing Drums containing Location and method of debris disposal Name and address of any person, firm, or corporation suffering damages: Procedures, method, and precautions instituted to prevent a similar occurrence from recurring: Spill reported to General Office by Time AM / PM Spill reported to DEP / National Response Center by DEP Date Time AM / PM Inspector NRC Date Time AM / PM Inspector Additional comments: Appendix G: Spill Prevention & Response EMERGENCY RESPONSE EQUIPMENT INVENTORY The following equipment and materials shall be maintained at all times and stored in a secure area for long-term emergency response need. -- SORBENT PADS 2 BALES -- SORBENT BOOM 100 FEET -- SAND BAGS (empty) 50 -- SEWER PIPE PLUGS -- 12 INCH DIAM. 1 -- SPEEDI-DRI ABSORBENT 5 40# BAGS -- SQUARE END SHOVELS 1 -- PICK 1 -- PRY BAR 1 -- DRAIN COVERS 2 Appendix G: Spill Prevention & Response EMERGENCY NOTIFICATION PHONE NUMBERS 1. SUPERVISOR/MANAGER Name: Beeper: Phone: Home Phone: ALTERENATE Name: Beeper: Phone: Home Phone: 2. FIRE DEPARTMENT Emergency: 911 Business: (413) 587-1109 POLICE DEPARTMENT Emergency: 911 Business: (413) 587-1100 3. CLEANUP CONTRACTOR: Address: Phone: 4. MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION Emergency: Western Region – Springfield Office: 413-784-1100 5. NATIONAL RESPONSE CENTER Phone: (800) 424-8802 ALTERNATE: U.S. ENVIRONMENTAL PROTECTION AGENCY Emergency: (617) 223-7265 Business: (617) 860-4300 6. CONSERVATION COMMISSION Contact: Sarah LaValley 413-587-1263 BOARD OF HEALTH Contact: Joanne Levin 413-587-4900 7. FACILITY MANAGER Name: Phone: Appendix H: Illicit Discharge Compliance Statement Appendix H: Illicit Discharge Compliance Statement Sanitary sewer and storm drainage structures remaining from previous development which are part of the redevelopment area will be removed or will be incorporated into updated sanitary sewer and separate stormwater sewer systems. The design plans submitted with this report have been designed so that the components included therein are in full compliance with current standards. No statement is made with regard to the drainage system in portions of the site not included in the redevelopment project area. The Long-Term Pollution Prevention Plan includes measures to prevent illicit discharges. Appendix I: Infiltration System Registration Appendix I: Infiltration System Registration (1) UIC Injection - Transmittal.doc • rev. 1/07 Page 1 of 1 Enter your transmittal number Transmittal Number Your unique Transmittal Number can be accessed online: http://mass.gov/dep/service/online/trasmfrm.shtml Massachusetts Department of Environmental Protection Transmittal Form for Permit Application and Payment 1. Please type or print. A separate Transmittal Form must be completed for each permit application. 2. Make your check payable to the Commonwealth of Massachusetts and mail it with a copy of this form to: DEP, P.O. Box 4062, Boston, MA 02211. 3. Three copies of this form will be needed. Copy 1 - the original must accompany your permit application. Copy 2 must accompany your fee payment. Copy 3 should be retained for your records 4. Both fee-paying and exempt applicants must mail a copy of this transmittal form to: MassDEP P.O. Box 4062 Boston, MA 02211 * Note: For BWSC Permits, enter the LSP. A. Permit Information 1. Permit Code: 7 or 8 character code from permit instructions 2. Name of Permit Category 3. Type of Project or Activity B. Applicant Information – Firm or Individual 1. Name of Firm - Or, if party needing this approval is an individual enter name below: 2. Last Name of Individual 3. First Name of Individual 4. MI 5. Street Address 6. City/Town 7. State 8. Zip Code 9. Telephone # 10. Ext. # 11. Contact Person 12. e-mail address (optional) C. Facility, Site or Individual Requiring Approval 1. Name of Facility, Site Or Individual 2. Street Address 3. City/Town 4. State 5. Zip Code 6. Telephone # 7. Ext. # 8. DEP Facility Number (if Known) 9. Federal I.D. Number (if Known) 10. BWSC Tracking # (if Known) D. Application Prepared by (if different from Section B)* 1. Name of Firm Or Individual 2. Address 3. City/Town 4. State 5. Zip Code 6. Telephone # 7. Ext. # 8. Contact Person 9. LSP Number (BWSC Permits only) E. Permit - Project Coordination 1. Is this project subject to MEPA review? yes no If yes, enter the project’s EOEA file number - assigned when an Environmental Notification Form is submitted to the MEPA unit: EOEA File Number F. Amount Due DEP Use Only Special Provisions: 1. Fee Exempt (city, town or municipal housing authority)(state agency if fee is $100 or less). There are no fee exemptions for BWSC permits, regardless of applicant status. 2. Hardship Request - payment extensions according to 310 CMR 4.04(3)(c). 3. Alternative Schedule Project (according to 310 CMR 4.05 and 4.10). 4. Homeowner (according to 310 CMR 4.02). Permit No: Rec’d Date: Reviewer: Check Number Dollar Amount Date (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 1 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well Note: this application form only applies to Stormwater Discharge Wells. Refer to the Instructions and Supporting Materials document that corresponds to this UIC Registration form for detailed instructions regarding the completion of this form and the required attachments. Transmittal # (not required for 1- to 4-unit residential applications) A. Registration Category and Fee Registration Category Important: When filling out forms on the computer, use only the tab key to move your cursor - do not use the return key. 1. Identify the type of registration activity you are conducting (check one): a. Registration of a Proposed or Existing Unregistered UIC Well(s) b. Pre-Closure of an Unregistered or Registered UIC Well(s) c. Pre-Closure of an Unregistered or Registered UIC Well(s)and Conversion to New Well Type* * Note: Conversion also requires submittal of a separate registration application for the new well type. d. Modification of a UIC Registration Application that is Still Under Review at MassDEP e. Modification of an Existing UIC Registration that Does Not Include Increasing the Number of Registered Wells f. Modification of an Existing UIC Registration that Includes Increasing the Number of Registered Wells Note: For the above Pre-Closure categories (items b and c), if you are submitting for a UIC well(s) that has received a MassDEP issued UIC registration number complete Sections A, B, L, and M of this application and for all other Sections only complete the data/information fields where you are entering new or revised information. For any of the above Modification categories (items d, e, and f) complete Sections A, B, and M of this application and for all other Sections only complete the data/information fields where you are entering new or revised information. For Modifications, Pre-Closures, or Pre-Closures and Conversions of a UIC Registered Well: Enter UIC Registration Number (required): UIC Registration Number issued by MassDEP Basic Well Information 2. Well Category, Well Type and registration fee Well Category: Stormwater Well Type (select one): No Land Uses with Higher Potential Pollutant Loads per MassDEP Stormwater Handbook One or more Land Uses with Higher Potential Pollutant Loads per MassDEP Stormwater Handbook Agricultural Karst (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 2 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well A. Registration Category and Fee (cont.) 3. Is the facility serviced by the well(s) both: a. For four (4) residential units or fewer; and, b. Only used for residential purposes? Yes No 4. Are any of the wells included in this registration application also being used for another type of UIC Class V discharge? Yes No 5. If you answered “yes” to the above question 4, enter the well category and well type for the other type of discharge (refer to the Class V Injection Well Category, Well Type, and Fee Table (see instructions document for web link)): Well Category Well Type UIC Registration Fee Notes: For Registration of More than One Type of Discharge – This form may only be used to apply for UIC registration of discharge from one type of stormwater discharge well(s). A separate BRP WS06 registration application, payment transmittal form, and applicable fee shall be submitted for each additional type of discharge even if one discharge well is used for more than one well category and well type combination. For Conversion of Unregistered Wells - If your application is for the conversion of a well(s) that was not previously registered, you shall submit one application form, payment transmittal form, and applicable fee for the registration and closure or partial closure of each of the unregistered well uses. You shall also submit a separate registration application form, payment transmittal form, and applicable fee for each type of new UIC Class V discharge well. For Conversion of Registered Wells - If your application is for the conversion of a Registered UIC well(s), you shall submit a separate registration application form, payment transmittal form, and applicable fee for each type of new UIC Class V discharge. In addition one BRP WS06d Pre-Closure application must be submitted for the closure of the previous well use. Fee Table Instructions: Determine which fee applies to your well using the following fee table in conjunction with the answers you provided for questions 1 (registration category), 2 (well type), and 3 (residential status). Step 1: Find the Registration Category in the first row (this will limit the number of columns you have to choose from to either 1 or 2). Step 2: In the second row find the one column that matches your response to Question 3. Step 3: Follow this column downward to the row that matches your well category (selected in Question 2). (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 3 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well A. Registration Category and Fee (cont.) Your Registration Category Selection (from question 1 above) 1.a. or 1.f. 1.b. or 1.c. 1.d. or 1.e. Your Answer to Question 3 Yes No Yes No Yes or No No land uses with higher potential pollutant loads per MassDEP Stormwater Handbook $0 $110 $0 $220 $0 One or more land uses with higher potential pollutant loads per MassDEP Stormwater Handbook $585 $585 $695 $695 Agricultural $290 $290 $400 $400 Karst $0 $0 $0 $110 Exceptions: If the well(s) is owned by a local or regional government the fee is $0. If the well(s) is owned by the Commonwealth of Massachusetts, the standard fees indicated above apply. If the fee would have exceeded $100 then the entire fee indicated above applies. Enter fee here: $ Annual Compliance Fee: There is no annual compliance fee associated with this Registration. B. Residential/Facility Information Facility/Residential Property Name Facility/Residential Street Address City/Town State Zip Code Additional information (for facilities only): Company Name (MassDEP use only) Facility # Facility Public Water Supplier (PWS) ID# (if applicable) NAICS or SIC Code # (if applicable) Facility Telephone # Facility Mailing Address (if different from street address) City/Town State Zip Code EPA Hazardous Waste Generator ID # (if applicable) EPA Hazardous Waste Generator ID # (if applicable) Tenant Name (if applicable) Tenant’s EPA Haz. Waste Generator ID # (if applicable) (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 4 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well C. Current Status of Activity(ies) Being Registered (check one) Designed, but not yet constructed/modified/closed/converted Proposed activity partially completed or completed but not active Discharge discontinued but closure activities not completed Proposed activity completed and active or closure completed Date placed in service (or date closure completed) Is the applicant requesting a waiver of the 30-day waiting period for closure applications? Yes No If you answered “yes” to this question, indicate your reasons for requesting the waiver in a cover letter attached to this application. D. Owner/Operator Information Name of Owner Address of Owner (enter “same” if same as facility) City/Town State Zip Code Owner Email Address Owner’s Legal Contact Legal Contact Phone # Legal Contact Fax # Legal Contact Email Address Name of Operator (if different from owner) Address of Operator (enter “same” if same as facility) City/Town State Zip Code Operator’s Legal Contact Legal Contact Phone # Legal Contact Fax # Legal Contact Email Address Ownership Type (choose one): Private: Industrial Commercial Non-profit Residential Public: Local Regional State Federal E. Designer Name of Designer Name of Company Massachusetts Engineer License # (if applicable) Designer Phone # Email LSP # (if applicable) National 3rd party or manufacturer approval & ID # (if applicable) (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 5 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well F. Installer Name of Installer Name of Company National 3rd party or manufacturer approval & ID # (if applicable) Installer Phone # Email G. Preparer Name of Preparer Preparer Address City/Town State Zip Code Preparer Phone # Email address Massachusetts Engineer License # (if applicable) LSP # (if applicable) H. Registered Well Driller (if applicable) MassDEP Well Driller Registration # Name of Well Driller Phone # Name of Company Email address I. Site Information Water Supply: Public Private Sewer: Public Private Other Discharges: Are there other current or proposed discharges on site? Yes No If yes, are they permitted with MassDEP? Yes No If yes, permit #: Permit # If no, are they registered with MassDEP as UIC Class V wells? Yes No If yes, registration #: Registration # Please list the type or types of other discharges: Check any of the following that apply to this site: a. Bureau of Waste Site Cleanup Priority Site If yes, file number b. Bureau of Waste Site Cleanup Waiver Site If yes, file number c. Superfund site If yes, Federal ID # (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 6 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well I. Site Information (cont.) If the site is currently being regulated by the Bureau of Waste Site Cleanup, check any of the following that apply: Incident Response Short Term Measure Activity and Use Limitations: Confirm that the applicant has checked that the site does not have any activity restrictions with respect to limiting discharges on the site. No restrictions Restrictions (please explain; attach additional sheets if necessary): Location of Wells: Only enter the location of wells for the one well type you are including in this registration. Note: Latitude & Longitude are required data. Well ID# is assigned by you and each well should have a unique ID#. Please check the closure box for any well(s) being completely closed to the well category and well type associated with this registration application. If you need additional well locations, please provide all information on a separate sheet. If you do not have access to a GPS unit, see instructions to this form for Internet tools that may be used to select well locations. Well ID (name and/or number) Latitude in Decimal Degrees (e.g., 42.355767) Longitude in Decimal Degrees (e.g., -71.060996) Check here if well is either being physically closed or if all entry points (discharges) associated with this well category and well type will be discontinued. (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 7 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well I. Site Information (cont.) Identify the method used for locating the latitude/longitude coordinates for the UIC Class V well(s) (check one): Location Type: Approximate location of well Approximate center of area where discharge is located (i.e. center of drainfield or trench) Accuracy – Estimated horizontal accuracy is less than (check one): +/-100 feet +/- 500 feet +/- 1000 feet Provide a narrative description of the site and the feature to be permitted. As an example: “The site is on the west side of Main Street, the third building north of High Street. The disposal field lies 100 feet off the southwest corner of the building.” Attachments: All of the following shall be attached to this application (unless submitted with a previous application and the information contained in the original submittal has not changed): UIC Class V Stormwater Non Exposure Form and Certification Statement (required for all registrations unless filing for Pre-Closure of all stormwater wells associated with this UIC registration application or you answered “yes” to Question #3 in Section A). Topographic or Orthophoto Map Design Sheets MSDS Sheets (if applicable) Site Plan (include bar scale, stormwater collection system, and delineation of drainage area contributing to the stormwater wells). Equipment Specification Sheets (if applicable) Narrative Statement Cross Sectional Diagram Depicting All Underground Components of the UIC System Analytical Testing Data Other information J. Injection Well Information Number of proposed new wells Maximum well depth Number of existing wells Month/year of UIC wells construction (for existing wells) (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 8 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well J. Injection Well Information (cont.) Total Number of Existing Plus Proposed Wells (do not include wells that are in a different UIC well category and well type (those must be registered under a separate UIC registration number)): Well Construction (check all that apply): Drywell Drilled Well Manufactured System Dug Well Improved Sinkhole Drainfield/Leachfield Trench Drain Other (describe): Well Additives: Are any well additives being used or proposed for use? Yes No If you answered yes, attach a completed Proposal for Chemical Use (additive) in a UIC Class V Well supplemental form. Please note that chemical additives are not typically allowed for UIC registered stormwater wells. Source of Injection Fluid and Potential Contaminants Source of injection fluid #1 Potential contaminants for Source #1 Source of injection fluid #2 Potential contaminants for Source #2 Source of injection fluid #3 Potential contaminants for Source #3 Source of injection fluid #4 Potential contaminants for Source #4 Treatment Devices If applicable, list any treatment devices prior to the injection point that will serve to remove contaminants from the water that is discharged into the stormwater well(s) (attach specification sheets & include on site plan and cross section): Rate of Injection Maximum total rate of injection (of all wells combined): Gallons per minute and Gallons per day Month/Year ceased using well(s) for previous use(s) (only applies to wells being closed or converted if applicable): (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 9 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well J. Injection Well Information (cont.) Number of Entry Points Note: The number of entry points equals the number of collection points to the stormwater system that are or will be discharging to the stormwater well(s). This includes catch basins (including leaching catch basins which are considered both an entry point and a Class V UIC well), surface drainage structures (trench, grate, channel & certain Low Impact Development (LID) Best Management Proctices (BMPs)) and roof drain downspouts. # of entry points to existing system Total # of entry points for proposed system (existing plus proposed) Well setback distances and depths (all distances shall be provided in feet): Distance to nearest wetland or water body (enter “NA” if distance is greater than 200 feet) Distance to nearest septic system (enter “NA” if distance is greater than 200 feet) Distance to nearest building foundation (existing or proposed) (enter “NA” if distance is greater than 25 feet) Distance to nearest property line (enter “NA” if distance is greater than 25 feet) Depth to water table (feet) (indicate “unknown” if unknown) Depth to bedrock (feet) (indicate “unknown” if unknown) Soil type(s) at site - e.g., fill, sandy till, gravel, sand Distance to nearest private drinking water well (existing or proposed) (enter “NA” if distance is greater than 1,250 feet) Distance to nearest Public Water Supply source (e.g., well or reservoir) (enter “NA” if distance is greater than 2,500 feet) K. Additional Well-Type-Specific Information In addition to completing the questions in this section, all registration applications for a new stormwater well(s) and for an existing stormwater well(s) that was not previously registered with the MassDEP UIC program must attach a completed UIC Stormwater Non Exposure Form (unless you answered “yes” to Question #3 in Section A). The non-exposure form is required for a Pre-Closure of unregistered wells unless all of the wells being registered with this application are also being closed. The non-exposure form is also required if filing a Modification of an existing UIC registration for the purpose of adding an additional stormwater well(s) or for all other modifications where any of the information previously submitted on the non exposure form has changed or needs to be corrected. Does overflow from the UIC well(s) discharge to groundwater or surface water on a different property or to a stormwater system that is owned/operated by another entity? Yes No If yes, the applicant must attach a copy of the approval letter/permit/Order of Conditions from the entity owning the property that is receiving the overflow water or from the entity that controls the municipal stormwater system or from the local conservation commission. (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 10 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well K. Additional Well-Type-Specific Information (cont.) Does the overflow from the UIC well(s) discharge to surface water or within a wetland or surface water buffer on-site? Yes No If yes, the applicant must attach a copy of the Order of Conditions from the local conservation commission allowing the discharge. L. Injection Well(s) or Activity(ies) Being Closed Note: Section L should only be filled in if you are closing a well(s). Is the closure being required by a federal, state, or local entity? Yes No If yes, which regulatory entity? Name Contact name for regulatory entity Contact Phone # Number of Wells Being Closed with this Application Will this proposed closure activity result in the complete closure of all wells associated with this registration application or with the existing UIC registration number? Yes No If you answered “no” to the above question, how many wells of this well category and well type will remain after the proposed closure activities have been completed? The following three (3) data entry fields are only associated with the well type being registered with this application. Do not include the numbers of entry points associated with any converted new well type (if applicable). Number of entry points to system before closure Number of entry points proposed for closure Number of entry points to system after closure Proposed or previously completed well closure activities (check all that apply): Clean out well(s) Sample fluids/sediments in the bottom of the injection well(s) Remove well(s) and any contaminated soil Appropriate disposal of remaining fluids /sediments Conversion to other Well Category/Type / Well Category/Well Type Note: a separate UIC registration application (BRP WS06) must be submitted for any conversion to a new well type. Well(s) and all entry points physically decommissioned Partial Closure (some but not all entry points eliminated or well(s) still in use for other types of discharge) (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 11 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well L. Injection Well(s) or Activity(ies) Being Closed (cont.) Sample fluids/sediments from the area surrounding the injection well(s) (as applicable) Other (specify): Proposed Laboratory Analytical Parameters for Soil Sampling Activities: Soil Sampling Parameter #1 Soil Sampling Parameter #2 Proposed Laboratory Analytical Parameters for Groundwater Sampling Activities: Groundwater Sampling Parameter #1 Groundwater Sampling Parameter #2 (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 12 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well M. Certifications for UIC Well(s) that is/are Being Registered for Continued Use or Proposed Future Use for the Stormwater Well Type Activity Selected for this Application Operator: The injection well(s) described above is used for placement or injection of fluids into the ground. I understand that this well(s) is subject to inventory requirements and compliance with the regulations under the Underground Injection Control Program established pursuant to the Safe Drinking Water Act, P.L. 93-523 and amendments, and UIC guidelines, and I hereby serve notice that the well(s) is proposed or in service. I agree: 1. That the well(s) described herein will not be used for discharges other than those described above (unless I have applied for and received the required Massachusetts and local government approvals); 2. That I will notify the MassDEP Drinking Water Program/UIC Program (on forms provided by the UIC program) if any of the information (including ownership, location or type of discharge, and installation of additional wells,) for the above well(s) changes, but before the change occurs (30- day minimum notice on ownership/operator and 60-day notice on all other changes) (ownership changes not required after a UIC registration number has been completely closed (i.e. all wells associated with the approved registration application have been closed and closure has been approved by MassDEP)); 3. That I will notify the MassDEP Drinking Water Program/UIC Program (on forms provided by the UIC program) if the well(s) becomes inactive; 4. That I will notify the MassDEP Drinking Water Program/UIC Program (on forms provided by the UIC program) when the above well(s) is no longer in use, but before physically decommissioning the well(s) and that I will file a Post-Closure Notification Form within seven days of completing the closure with the UIC program; 5. That I will maintain financial responsibility for the well(s) described above; and 6. That I will provide a sampling tap (approved by MassDEP) and allow sampling at the point of injection (not required for a closed well). I certify under pains and penalties of law that I have personally examined and am familiar with the information submitted in this document and all attachments and based on my personal knowledge or inquiry of those agents immediately responsible for obtaining the information on my behalf, I believe the information is true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including possible fines and imprisonment. Signature of Operator Date Name of Operator Position/Title (2) UIC Injection - Registration.doc • 08/2013 UIC Registration – Stormwater Discharge Well • Page 13 of 13 Massachusetts Department of Environmental Protection Bureau of Resource Protection – drinking water program BRP WS 06 UIC Registration Stormwater Discharge Well M. Certifications for UIC Well(s) that is/are Being Registered for Continued Use or Proposed Future Use for the Stormwater Well Type Activity Selected for this Application (cont.) Owner (must be completed if owner has not signed above as operator) I certify that I have personally examined and am familiar with the information submitted in this document and agree to the installation, conversion, or closure of the discharge well(s) described in this application. I also agree that I will assume the responsibilities of the operator in the event that the operator leaves the property and a replacement operator has not been established and reported to MassDEP (on forms provided by the UIC program). Signature of Owner Date Printed Name Position/Title N. Certifications for UIC Well(s) that is/are Being Registered for Complete Closure of all Future Stormwater Activities Associated with the Well Type Selected for this Application: Operator I certify under pains and penalties of law that I have personally examined and am familiar with the information submitted in this document and all attachments and based on my personal knowledge or inquiry of those agents immediately responsible for obtaining the information on my behalf, I believe the information is true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including possible fines and imprisonment. Signature of Operator Date Name of Operator Position/Title Owner (must be completed if owner has not signed above as operator) I certify that I have personally examined and am familiar with the information submitted in this document and agree to the conversion or closure of the discharge well(s) described in this application. Signature of Owner Date Printed Name Position/Title Submit a signed and complete application package to: MassDEP Bureau of Resource Protection UIC Program One Winter Street, 5th Floor Boston, MA 02108 Send duplicate copies of this form to: Local Board of Health stormexp.doc • 04/2012 UIC Class V Well Stormwater Non-Exposure Form & Certification Statement • Page 1 of 5 Massachusetts Department of Environmental Protection Bureau of Resource Protection – Drinking Water Program UIC Class V Well Stormwater Non-Exposure Form and Certification Statement (attach to your BRP WS-06 Registration – Stormwater Discharge Well application form) Enter UIC Registration Number (if applicable): UIC Registration Number The UIC Stormwater Non-Exposure Form must be submitted with all Underground Injection Control (UIC) registration applications for UIC Class V stormwater wells unless the land is only used for one to four residential units. The Stormwater Non-Exposure Form is used by the applicant and Massachusetts Department of Environmental Protection (MassDEP) to determine whether a UIC Registration for stormwater discharge may be approved and whether best management practices BMP must be in place in order to protect public sources of drinking water and critical areas (critical areas as defined by MassDEP’s Massachusetts Stormwater Handbook). A. Residential/Facility Information Important: When filling out forms on the computer, use only the tab key to move your cursor - do not use the return key. Facility/Residential Property Name Facility/Residential Property Street Address City/Town State Zip Code B. Preparer Information Preparer Name Preparer Address (if different from facility) City/Town State Zip Code Zip Telephone Number Preparer’s Email Preparer’s Phone # C. Stormwater Non-Exposure Questions 1. Is the existing or proposed stormwater well(s) located within a Zone I or Zone A of a public water supply (PWS) source? Yes No If No, skip to Question #3 2. Is the stormwater discharge well(s) approved by MassDEP Drinking Water Program and/or essential to the operation of the public water supply (PWS)? Yes No 3. Is the existing or proposed stormwater well(s) in a Zone II or Interim Wellhead Protection Area (IWPA) of a public water supply (PWS)? Yes No If No, skip to Question #5. 4. Is there infiltration of runoff from a metal roof? Yes No If Yes, does the discharge receive pretreatment by means of a Best Management Practice (BMP) capable of removing metals, such as a sand filter, organic filter, filtering bioretention area or equivalent or, if proposed, will it receive such pretreatment prior to being placed into service? (Metal roofs are galvanized steel or copper.) Yes No stormexp.doc • 04/2012 UIC Class V Well Stormwater Non-Exposure Form & Certification Statement • Page 2 of 5 Massachusetts Department of Environmental Protection Bureau of Resource Protection – Drinking Water Program UIC Class V Well Stormwater Non-Exposure Form and Certification Statement (attach to your BRP WS-06 Registration – Stormwater Discharge Well application form) C. Non-Exposure Checklist (cont.) 5. Does the drainage area serving the existing or proposed stormwater well(s) contain any of the activities listed in Standard 5 of the Massachusetts Stormwater Handbook as “Land Uses With Higher Potential Pollutant Loads” (LUHPPL)? Yes No If No, skip to Question #11. If Yes, identify each of the LUHPPL activities that occur within the drainage area(s) for the existing and/or proposed stormwater discharge wells that are included in this UIC registration application by checking each applicable box below. Activity landfills and open dumps landfills receiving only wastewater residuals and/or septage automobile graveyards and junkyards the storage of snow or ice that has been removed from highways and roads outside of Zone II and that contains sodium chloride, chemically treated abrasives or other chemicals used for snow and ice removal petroleum, fuel oil and heating oil bulk stations and terminals treatment or disposal works subject to 314 CMR 5.00 for wastewater other than sanitary sewage facilities that generate, treat, store or dispose of hazardous waste that are subject to M.G.L. c. 21C and 310 CMR 30.000 storage of sludge and/or septage storage of sodium chloride, chemically treated abrasives or other chemicals used for the removal of ice and snow on roads storage of commercial fertilizers storage of animal manures storage of liquid hazardous materials, as defined in M.G.L. c. 21E, and/or liquid petroleum products the removal of soil, loam, sand, gravel or any other mineral substances within four feet of the historical high groundwater table elevation motor vehicle fueling facility industrial facilities that would be subject to EPA NPDES Multi-Sector General Permit (MSGP) if discharging to surface water exterior fleet storage area(s) exterior vehicle service and/or equipment cleaning area(s) stormexp.doc • 04/2012 UIC Class V Well Stormwater Non-Exposure Form & Certification Statement • Page 3 of 5 Massachusetts Department of Environmental Protection Bureau of Resource Protection – Drinking Water Program UIC Class V Well Stormwater Non-Exposure Form and Certification Statement (attach to your BRP WS-06 Registration – Stormwater Discharge Well application form) C. Non-Exposure Checklist (cont.) marinas and/or boatyards parking lots with high-intensity use (1000 vehicle trips per day or more) confined disposal facilities and disposal sites outdoor washing of commercial or industrial vehicles and/or commercial car wash disposal sites as defined in M.G.L. c. 21E and 310 CMR 40.000 particulate manner or visible deposits of residue from roof stacks and/ or vents 6. Is the existing or proposed stormwater well(s) located within a Zone II of a public water supply well or within a locally adopted Aquifer Protection Overlay District (or its equivalence by a different name)? Yes No If no, skip to Question #8. 7. Does the site include any of the following activities (check all that apply)? Yes No Activity landfills and open dumps landfills receiving only wastewater residuals and/or septage automobile graveyards and junkyards the storage of snow or ice that has been removed from highways and roads outside of Zone II and that contains sodium chloride, chemically treated abrasives or other chemicals used for snow and ice removal petroleum, fuel oil and heating oil bulk stations and terminals treatment or disposal works subject to 314 CMR 5.00 for wastewater other than sanitary sewage facilities that generate, treat, store or dispose of hazardous waste that are subject to M.G.L. c. 21C and 310 CMR 30.000 Were any of the above activities started after the municipality adopted its wellhead protection controls prohibiting this activity in the Zone II and/or in the locally adopted Aquifer Protection Overlay District (or its equivalence) in which the discharge well(s) is located or were any of the above activities expanded or are they proposed to be expanded after the municipality adopted these controls? Yes No If Yes, the discharge is not allowed as it applies to activity(ies) either started or expanded or proposed to be expanded after the municipality adopted its wellhead protection controls (see instructions for exceptions). stormexp.doc • 04/2012 UIC Class V Well Stormwater Non-Exposure Form & Certification Statement • Page 4 of 5 Massachusetts Department of Environmental Protection Bureau of Resource Protection – Drinking Water Program UIC Class V Well Stormwater Non-Exposure Form and Certification Statement (attach to your BRP WS-06 Registration – Stormwater Discharge Well application form) C. Non-Exposure Checklist (cont.) 8. Is the existing or proposed stormwater well(s) located within a Zone A, Zone II or IWPA of a public water supply or discharging into or near any other “critical area” (as defined in Standard 6 of the Stormwater Handbook)? Yes No 9. Does or, if proposed, will the site have source controls (including both non- structural and structural Best Management Practices) and a detailed pollution prevention plan as required in the Massachusetts Stormwater Handbook for the specific LUHPPL that pertain to your existing or proposed stormwater discharge (including designs that allow for shut down & containment (if applicable) in response to spill emergencies); and, if you answered “yes” to the above Question #8, have the applicable Best Management Practices requirements been met? Yes No 10. Is the land use one that has the potential to generate higher potential pollutant loads of oil and grease? Yes No If Yes, does the existing or proposed discharge include the following pretreatment prior to discharge to the UIC well: an oil grit separator, a sand filter, organic filter, filtering bioretention area, or equivalent? Yes No 11. Is there infiltration of runoff from a metal roof and is the site an industrial site? Yes No If Yes does or, if proposed, will the discharge receive pretreatment by means of a Best Management Practice capable of removing metals, such as a sand filter, organic filter, filtering bioretention area or equivalent? (Metal roofs are galvanized steel or copper.) Yes No 12. Does the drainage area serving the existing or proposed stormwater well(s) contain any of the activities listed in Standard 5 of the Massachusetts Stormwater Handbook as Land Uses With Higher Potential Pollutant Loads (LUHPPL), or is the discharge into or near any other “critical area” (as defined in Standard 6 of the Stormwater Handbook), or is the applicant proposing an infiltration structure within an area with a rapid infiltration rate (greater than 2.4 inches per hour)? Yes No If Yes has the proponent installed or, if proposed, will the proponent install structural stormwater Best Management Practices (BMP) determined by the Department to be suitable to remove at least 44% of the Total Suspended Solids (TSS) prior to discharge to the infiltration structure? Yes No 13. Was the infiltration structure designed based upon data obtained from the Dynamic Field Method? Yes No If Yes, is the system designed to remove at least 80% of the Total Suspended Solids (TSS) prior to discharge to the infiltration structure? Yes No 14. Have the requirements described in Standard 4 of the Massachusetts Stormwater Handbook been met or, if proposed, will these requirements be met prior to placing the well(s) in service? Yes No 15. Does the site have a site specific long term pollution prevention plan and a long-term operation and maintenance (O&M) plan to ensure that stormwater management systems function as designed or, if proposed, will these requirements be met prior to placing the well(s) in service? Yes No stormexp.doc • 04/2012 UIC Class V Well Stormwater Non-Exposure Form & Certification Statement • Page 5 of 5 Massachusetts Department of Environmental Protection Bureau of Resource Protection – Drinking Water Program UIC Class V Well Stormwater Non-Exposure Form and Certification Statement (attach to your BRP WS-06 Registration – Stormwater Discharge Well application form) C. Non-Exposure Checklist (cont.) 16. Has the infiltration structure been designed with at least a two-foot separation between the bottom of the infiltration structure and the seasonal high groundwater table? Yes No 17. Does the existing or proposed stormwater discharge well location meet the applicable setback distances as required by the Massachusetts Stormwater Handbook? Yes No D. Certification Statement I certify under penalty of law the following: This document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is to the best of my knowledge and belief true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment. I also understand that I am obligated to submit an updated UIC Class V Well Stormwater Non- Exposure Form and Certification Statement when the activities change in the UIC Class V well drainage area which may cause ineligibility for the well’s “non-exposure” status. I understand that I must allow MassDEP staff on-site to perform inspections to confirm the condition of non-exposure and to make such inspection reports publicly available upon request. Signature Date Print Name Position/Title Appendix J: Hydrologic Analysis Appendix J: Hydrologic Analysis Appendix J: Hydrologic Analysis HydroCAD Analysis: Existing Conditions Appendix J: Hydrologic Analysis 2-Year Storm Event – Existing 10 Drainage Area 10 15 Drainage Area 15 20 Drainage Area 20 25 Drainage Area 25 30 Drainage Area 30 35 Drainage Area 35 40 Drainage Area 40 45 Drainage Area 45 50 Drainage Area 50 55 Drainage Area 55 x1000 Hawley Street Top x2000 Hawley Street Bottom x3000 Off-Site South x4000 Phillips Place Routing Diagram for 42540-EX Prepared by VHB, Printed 10/31/2019 HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link 42540-EX Printed 10/31/2019Prepared by VHB Page 2HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Project Notes Rainfall events imported from "Northampton MA.hcp" 42540-EX Printed 10/31/2019Prepared by VHB Page 3HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.746 61 >75% Grass cover, Good, HSG B (10, 15, 30, 35, 45, 50, 55) 0.152 98 Church Roof, HSG B (20) 0.737 98 Impervious, HSG B (10, 15, 30, 35, 50, 55) 0.212 98 Rear Building Roof, HSG B (40) 0.046 98 Roofs, HSG B (25) 1.893 83 TOTAL AREA 42540-EX Printed 10/31/2019Prepared by VHB Page 4HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 1.893 HSG B 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 0.000 HSG C 0.000 HSG D 0.000 Other 1.893 TOTAL AREA 42540-EX Printed 10/31/2019Prepared by VHB Page 5HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.746 0.000 0.000 0.000 0.746 >75% Grass cover, Good 10, 15, 30, 35, 45, 50, 55 0.000 0.152 0.000 0.000 0.000 0.152 Church Roof 20 0.000 0.737 0.000 0.000 0.000 0.737 Impervious 10, 15, 30, 35, 50, 55 0.000 0.212 0.000 0.000 0.000 0.212 Rear Building Roof 40 0.000 0.046 0.000 0.000 0.000 0.046 Roofs 25 0.000 1.893 0.000 0.000 0.000 1.893 TOTAL AREA Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 6HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=5,403 sf 6.64% Impervious Runoff Depth>0.44"Subcatchment 10: Drainage Area 10 Tc=6.0 min CN=63 Runoff=0.05 cfs 0.005 af Runoff Area=11,518 sf 16.01% Impervious Runoff Depth>0.59"Subcatchment 15: Drainage Area 15 Flow Length=127' Tc=15.5 min CN=67 Runoff=0.12 cfs 0.013 af Runoff Area=6,628 sf 100.00% Impervious Runoff Depth>2.73"Subcatchment 20: Drainage Area 20 Tc=6.0 min CN=98 Runoff=0.45 cfs 0.035 af Runoff Area=2,008 sf 100.00% Impervious Runoff Depth>2.73"Subcatchment 25: Drainage Area 25 Tc=6.0 min CN=98 Runoff=0.14 cfs 0.010 af Runoff Area=6,849 sf 14.35% Impervious Runoff Depth>0.55"Subcatchment 30: Drainage Area 30 Flow Length=107' Tc=15.2 min CN=66 Runoff=0.07 cfs 0.007 af Runoff Area=8,584 sf 78.03% Impervious Runoff Depth>1.99"Subcatchment 35: Drainage Area 35 Tc=6.0 min CN=90 Runoff=0.47 cfs 0.033 af Runoff Area=9,231 sf 100.00% Impervious Runoff Depth>2.73"Subcatchment 40: Drainage Area 40 Tc=6.0 min CN=98 Runoff=0.63 cfs 0.048 af Runoff Area=1,723 sf 0.00% Impervious Runoff Depth>0.37"Subcatchment 45: Drainage Area 45 Tc=6.0 min CN=61 Runoff=0.01 cfs 0.001 af Runoff Area=27,647 sf 72.27% Impervious Runoff Depth>1.83"Subcatchment 50: Drainage Area 50 Tc=6.0 min CN=88 Runoff=1.42 cfs 0.097 af Runoff Area=2,884 sf 77.91% Impervious Runoff Depth>1.99"Subcatchment 55: Drainage Area 55 Tc=6.0 min CN=90 Runoff=0.16 cfs 0.011 af Inflow=0.66 cfs 0.048 afLink x1000: Hawley Street Top Primary=0.66 cfs 0.048 af Inflow=0.55 cfs 0.055 afLink x2000: Hawley Street Bottom Primary=0.55 cfs 0.055 af Inflow=0.01 cfs 0.001 afLink x3000: Off-Site South Primary=0.01 cfs 0.001 af Inflow=2.21 cfs 0.156 afLink x4000: Phillips Place Primary=2.21 cfs 0.156 af Total Runoff Area = 1.893 ac Runoff Volume = 0.260 af Average Runoff Depth = 1.65" 39.40% Pervious = 0.746 ac 60.60% Impervious = 1.147 ac Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 7HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 10: Drainage Area 10 Runoff = 0.05 cfs @ 12.12 hrs, Volume= 0.005 af, Depth> 0.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 5,044 61 >75% Grass cover, Good, HSG B * 359 98 Impervious, HSG B 5,403 63 Weighted Average 5,044 93.36% Pervious Area 359 6.64% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 10: Drainage Area 10 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=5,403 sf Runoff Volume=0.005 af Runoff Depth>0.44" Tc=6.0 min CN=63 0.05 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 8HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 15: Drainage Area 15 Runoff = 0.12 cfs @ 12.26 hrs, Volume= 0.013 af, Depth> 0.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 9,674 61 >75% Grass cover, Good, HSG B * 1,844 98 Impervious, HSG B 11,518 67 Weighted Average 9,674 83.99% Pervious Area 1,844 16.01% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.8 20 0.4000 0.41 Sheet Flow, First 20 feet Grass: Short n= 0.150 P2= 3.15" 14.4 80 0.0050 0.09 Sheet Flow, Next 80 feet Grass: Short n= 0.150 P2= 3.15" 0.3 27 0.0625 1.75 Shallow Concentrated Flow, Last 27 feet Short Grass Pasture Kv= 7.0 fps 15.5 127 Total Subcatchment 15: Drainage Area 15 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=11,518 sf Runoff Volume=0.013 af Runoff Depth>0.59" Flow Length=127' Tc=15.5 min CN=67 0.12 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 9HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 20: Drainage Area 20 Runoff = 0.45 cfs @ 12.09 hrs, Volume= 0.035 af, Depth> 2.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description * 6,628 98 Church Roof, HSG B 6,628 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 20: Drainage Area 20 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=6,628 sf Runoff Volume=0.035 af Runoff Depth>2.73" Tc=6.0 min CN=98 0.45 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 10HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 25: Drainage Area 25 Runoff = 0.14 cfs @ 12.09 hrs, Volume= 0.010 af, Depth> 2.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 2,008 98 Roofs, HSG B 2,008 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 25: Drainage Area 25 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=2,008 sf Runoff Volume=0.010 af Runoff Depth>2.73" Tc=6.0 min CN=98 0.14 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 11HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 30: Drainage Area 30 Runoff = 0.07 cfs @ 12.26 hrs, Volume= 0.007 af, Depth> 0.55" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 5,866 61 >75% Grass cover, Good, HSG B * 983 98 Impervious, HSG B 6,849 66 Weighted Average 5,866 85.65% Pervious Area 983 14.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 22 0.3700 0.40 Sheet Flow, First 22 feet Grass: Short n= 0.150 P2= 3.15" 14.1 78 0.0050 0.09 Sheet Flow, Next 78 feet of grass Grass: Short n= 0.150 P2= 3.15" 0.2 7 0.0050 0.49 Shallow Concentrated Flow, Last 7 feet of grass Short Grass Pasture Kv= 7.0 fps 15.2 107 Total Subcatchment 30: Drainage Area 30 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=6,849 sf Runoff Volume=0.007 af Runoff Depth>0.55" Flow Length=107' Tc=15.2 min CN=66 0.07 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 12HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 35: Drainage Area 35 Runoff = 0.47 cfs @ 12.09 hrs, Volume= 0.033 af, Depth> 1.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 1,886 61 >75% Grass cover, Good, HSG B * 6,698 98 Impervious, HSG B 8,584 90 Weighted Average 1,886 21.97% Pervious Area 6,698 78.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 35: Drainage Area 35 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-02 Rainfall=3.15" Runoff Area=8,584 sf Runoff Volume=0.033 af Runoff Depth>1.99" Tc=6.0 min CN=90 0.47 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 13HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 40: Drainage Area 40 Runoff = 0.63 cfs @ 12.09 hrs, Volume= 0.048 af, Depth> 2.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description * 9,231 98 Rear Building Roof, HSG B 9,231 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 40: Drainage Area 40 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=9,231 sf Runoff Volume=0.048 af Runoff Depth>2.73" Tc=6.0 min CN=98 0.63 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 14HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 45: Drainage Area 45 Runoff = 0.01 cfs @ 12.13 hrs, Volume= 0.001 af, Depth> 0.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 1,723 61 >75% Grass cover, Good, HSG B 1,723 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 45: Drainage Area 45 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.013 0.012 0.011 0.011 0.01 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 NoHo-02 Rainfall=3.15" Runoff Area=1,723 sf Runoff Volume=0.001 af Runoff Depth>0.37" Tc=6.0 min CN=61 0.01 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 15HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 50: Drainage Area 50 Runoff = 1.42 cfs @ 12.09 hrs, Volume= 0.097 af, Depth> 1.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 7,667 61 >75% Grass cover, Good, HSG B * 19,980 98 Impervious, HSG B 27,647 88 Weighted Average 7,667 27.73% Pervious Area 19,980 72.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 50: Drainage Area 50 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-02 Rainfall=3.15" Runoff Area=27,647 sf Runoff Volume=0.097 af Runoff Depth>1.83" Tc=6.0 min CN=88 1.42 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 16HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 55: Drainage Area 55 Runoff = 0.16 cfs @ 12.09 hrs, Volume= 0.011 af, Depth> 1.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 637 61 >75% Grass cover, Good, HSG B * 2,247 98 Impervious, HSG B 2,884 90 Weighted Average 637 22.09% Pervious Area 2,247 77.91% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 55: Drainage Area 55 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-02 Rainfall=3.15" Runoff Area=2,884 sf Runoff Volume=0.011 af Runoff Depth>1.99" Tc=6.0 min CN=90 0.16 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 17HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x1000: Hawley Street Top Inflow Area = 0.367 ac, 56.67% Impervious, Inflow Depth > 1.56" for NoHo-02 event Inflow = 0.66 cfs @ 12.09 hrs, Volume= 0.048 af Primary = 0.66 cfs @ 12.09 hrs, Volume= 0.048 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x1000: Hawley Street Top Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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=0.367 ac 0.66 cfs 0.66 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 18HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x2000: Hawley Street Bottom Inflow Area = 0.574 ac, 37.83% Impervious, Inflow Depth > 1.14" for NoHo-02 event Inflow = 0.55 cfs @ 12.10 hrs, Volume= 0.055 af Primary = 0.55 cfs @ 12.10 hrs, Volume= 0.055 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x2000: Hawley Street Bottom Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (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=0.574 ac 0.55 cfs 0.55 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 19HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x3000: Off-Site South Inflow Area = 0.040 ac, 0.00% Impervious, Inflow Depth > 0.37" for NoHo-02 event Inflow = 0.01 cfs @ 12.13 hrs, Volume= 0.001 af Primary = 0.01 cfs @ 12.13 hrs, Volume= 0.001 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x3000: Off-Site South Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 Inflow Area=0.040 ac 0.01 cfs 0.01 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-EX Printed 10/31/2019Prepared by VHB Page 20HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x4000: Phillips Place Inflow Area = 0.913 ac, 79.12% Impervious, Inflow Depth > 2.05" for NoHo-02 event Inflow = 2.21 cfs @ 12.09 hrs, Volume= 0.156 af Primary = 2.21 cfs @ 12.09 hrs, Volume= 0.156 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x4000: Phillips Place Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.913 ac 2.21 cfs 2.21 cfs Appendix J: Hydrologic Analysis 10-Year Storm Event – Existing 10 Drainage Area 10 15 Drainage Area 15 20 Drainage Area 20 25 Drainage Area 25 30 Drainage Area 30 35 Drainage Area 35 40 Drainage Area 40 45 Drainage Area 45 50 Drainage Area 50 55 Drainage Area 55 x1000 Hawley Street Top x2000 Hawley Street Bottom x3000 Off-Site South x4000 Phillips Place Routing Diagram for 42540-EX Prepared by VHB, Printed 10/31/2019 HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link 42540-EX Printed 10/31/2019Prepared by VHB Page 2HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Project Notes Rainfall events imported from "Northampton MA.hcp" 42540-EX Printed 10/31/2019Prepared by VHB Page 3HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.746 61 >75% Grass cover, Good, HSG B (10, 15, 30, 35, 45, 50, 55) 0.152 98 Church Roof, HSG B (20) 0.737 98 Impervious, HSG B (10, 15, 30, 35, 50, 55) 0.212 98 Rear Building Roof, HSG B (40) 0.046 98 Roofs, HSG B (25) 1.893 83 TOTAL AREA 42540-EX Printed 10/31/2019Prepared by VHB Page 4HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 1.893 HSG B 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 0.000 HSG C 0.000 HSG D 0.000 Other 1.893 TOTAL AREA 42540-EX Printed 10/31/2019Prepared by VHB Page 5HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.746 0.000 0.000 0.000 0.746 >75% Grass cover, Good 10, 15, 30, 35, 45, 50, 55 0.000 0.152 0.000 0.000 0.000 0.152 Church Roof 20 0.000 0.737 0.000 0.000 0.000 0.737 Impervious 10, 15, 30, 35, 50, 55 0.000 0.212 0.000 0.000 0.000 0.212 Rear Building Roof 40 0.000 0.046 0.000 0.000 0.000 0.046 Roofs 25 0.000 1.893 0.000 0.000 0.000 1.893 TOTAL AREA Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 6HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=5,403 sf 6.64% Impervious Runoff Depth>1.31"Subcatchment 10: Drainage Area 10 Tc=6.0 min CN=63 Runoff=0.19 cfs 0.014 af Runoff Area=11,518 sf 16.01% Impervious Runoff Depth>1.58"Subcatchment 15: Drainage Area 15 Flow Length=127' Tc=15.5 min CN=67 Runoff=0.38 cfs 0.035 af Runoff Area=6,628 sf 100.00% Impervious Runoff Depth>4.33"Subcatchment 20: Drainage Area 20 Tc=6.0 min CN=98 Runoff=0.71 cfs 0.055 af Runoff Area=2,008 sf 100.00% Impervious Runoff Depth>4.33"Subcatchment 25: Drainage Area 25 Tc=6.0 min CN=98 Runoff=0.22 cfs 0.017 af Runoff Area=6,849 sf 14.35% Impervious Runoff Depth>1.51"Subcatchment 30: Drainage Area 30 Flow Length=107' Tc=15.2 min CN=66 Runoff=0.22 cfs 0.020 af Runoff Area=8,584 sf 78.03% Impervious Runoff Depth>3.57"Subcatchment 35: Drainage Area 35 Tc=6.0 min CN=90 Runoff=0.82 cfs 0.059 af Runoff Area=9,231 sf 100.00% Impervious Runoff Depth>4.33"Subcatchment 40: Drainage Area 40 Tc=6.0 min CN=98 Runoff=0.99 cfs 0.076 af Runoff Area=1,723 sf 0.00% Impervious Runoff Depth>1.18"Subcatchment 45: Drainage Area 45 Tc=6.0 min CN=61 Runoff=0.05 cfs 0.004 af Runoff Area=27,647 sf 72.27% Impervious Runoff Depth>3.37"Subcatchment 50: Drainage Area 50 Tc=6.0 min CN=88 Runoff=2.54 cfs 0.178 af Runoff Area=2,884 sf 77.91% Impervious Runoff Depth>3.57"Subcatchment 55: Drainage Area 55 Tc=6.0 min CN=90 Runoff=0.28 cfs 0.020 af Inflow=1.23 cfs 0.089 afLink x1000: Hawley Street Top Primary=1.23 cfs 0.089 af Inflow=1.11 cfs 0.109 afLink x2000: Hawley Street Bottom Primary=1.11 cfs 0.109 af Inflow=0.05 cfs 0.004 afLink x3000: Off-Site South Primary=0.05 cfs 0.004 af Inflow=3.81 cfs 0.274 afLink x4000: Phillips Place Primary=3.81 cfs 0.274 af Total Runoff Area = 1.893 ac Runoff Volume = 0.477 af Average Runoff Depth = 3.02" 39.40% Pervious = 0.746 ac 60.60% Impervious = 1.147 ac Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 7HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 10: Drainage Area 10 Runoff = 0.19 cfs @ 12.10 hrs, Volume= 0.014 af, Depth> 1.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 5,044 61 >75% Grass cover, Good, HSG B * 359 98 Impervious, HSG B 5,403 63 Weighted Average 5,044 93.36% Pervious Area 359 6.64% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 10: Drainage Area 10 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-10 Rainfall=4.90" Runoff Area=5,403 sf Runoff Volume=0.014 af Runoff Depth>1.31" Tc=6.0 min CN=63 0.19 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 8HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 15: Drainage Area 15 Runoff = 0.38 cfs @ 12.23 hrs, Volume= 0.035 af, Depth> 1.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 9,674 61 >75% Grass cover, Good, HSG B * 1,844 98 Impervious, HSG B 11,518 67 Weighted Average 9,674 83.99% Pervious Area 1,844 16.01% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.8 20 0.4000 0.41 Sheet Flow, First 20 feet Grass: Short n= 0.150 P2= 3.15" 14.4 80 0.0050 0.09 Sheet Flow, Next 80 feet Grass: Short n= 0.150 P2= 3.15" 0.3 27 0.0625 1.75 Shallow Concentrated Flow, Last 27 feet Short Grass Pasture Kv= 7.0 fps 15.5 127 Total Subcatchment 15: Drainage Area 15 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=11,518 sf Runoff Volume=0.035 af Runoff Depth>1.58" Flow Length=127' Tc=15.5 min CN=67 0.38 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 9HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 20: Drainage Area 20 Runoff = 0.71 cfs @ 12.09 hrs, Volume= 0.055 af, Depth> 4.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description * 6,628 98 Church Roof, HSG B 6,628 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 20: Drainage Area 20 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=6,628 sf Runoff Volume=0.055 af Runoff Depth>4.33" Tc=6.0 min CN=98 0.71 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 10HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 25: Drainage Area 25 Runoff = 0.22 cfs @ 12.09 hrs, Volume= 0.017 af, Depth> 4.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 2,008 98 Roofs, HSG B 2,008 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 25: Drainage Area 25 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-10 Rainfall=4.90" Runoff Area=2,008 sf Runoff Volume=0.017 af Runoff Depth>4.33" Tc=6.0 min CN=98 0.22 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 11HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 30: Drainage Area 30 Runoff = 0.22 cfs @ 12.22 hrs, Volume= 0.020 af, Depth> 1.51" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 5,866 61 >75% Grass cover, Good, HSG B * 983 98 Impervious, HSG B 6,849 66 Weighted Average 5,866 85.65% Pervious Area 983 14.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 22 0.3700 0.40 Sheet Flow, First 22 feet Grass: Short n= 0.150 P2= 3.15" 14.1 78 0.0050 0.09 Sheet Flow, Next 78 feet of grass Grass: Short n= 0.150 P2= 3.15" 0.2 7 0.0050 0.49 Shallow Concentrated Flow, Last 7 feet of grass Short Grass Pasture Kv= 7.0 fps 15.2 107 Total Subcatchment 30: Drainage Area 30 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-10 Rainfall=4.90" Runoff Area=6,849 sf Runoff Volume=0.020 af Runoff Depth>1.51" Flow Length=107' Tc=15.2 min CN=66 0.22 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 12HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 35: Drainage Area 35 Runoff = 0.82 cfs @ 12.09 hrs, Volume= 0.059 af, Depth> 3.57" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 1,886 61 >75% Grass cover, Good, HSG B * 6,698 98 Impervious, HSG B 8,584 90 Weighted Average 1,886 21.97% Pervious Area 6,698 78.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 35: Drainage Area 35 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=8,584 sf Runoff Volume=0.059 af Runoff Depth>3.57" Tc=6.0 min CN=90 0.82 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 13HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 40: Drainage Area 40 Runoff = 0.99 cfs @ 12.09 hrs, Volume= 0.076 af, Depth> 4.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description * 9,231 98 Rear Building Roof, HSG B 9,231 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 40: Drainage Area 40 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-10 Rainfall=4.90" Runoff Area=9,231 sf Runoff Volume=0.076 af Runoff Depth>4.33" Tc=6.0 min CN=98 0.99 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 14HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 45: Drainage Area 45 Runoff = 0.05 cfs @ 12.10 hrs, Volume= 0.004 af, Depth> 1.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 1,723 61 >75% Grass cover, Good, HSG B 1,723 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 45: Drainage Area 45 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-10 Rainfall=4.90" Runoff Area=1,723 sf Runoff Volume=0.004 af Runoff Depth>1.18" Tc=6.0 min CN=61 0.05 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 15HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 50: Drainage Area 50 Runoff = 2.54 cfs @ 12.09 hrs, Volume= 0.178 af, Depth> 3.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 7,667 61 >75% Grass cover, Good, HSG B * 19,980 98 Impervious, HSG B 27,647 88 Weighted Average 7,667 27.73% Pervious Area 19,980 72.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 50: Drainage Area 50 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Type III 24-hr NoHo-10 Rainfall=4.90" Runoff Area=27,647 sf Runoff Volume=0.178 af Runoff Depth>3.37" Tc=6.0 min CN=88 2.54 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 16HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 55: Drainage Area 55 Runoff = 0.28 cfs @ 12.09 hrs, Volume= 0.020 af, Depth> 3.57" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 637 61 >75% Grass cover, Good, HSG B * 2,247 98 Impervious, HSG B 2,884 90 Weighted Average 637 22.09% Pervious Area 2,247 77.91% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 55: Drainage Area 55 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=2,884 sf Runoff Volume=0.020 af Runoff Depth>3.57" Tc=6.0 min CN=90 0.28 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 17HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x1000: Hawley Street Top Inflow Area = 0.367 ac, 56.67% Impervious, Inflow Depth > 2.90" for NoHo-10 event Inflow = 1.23 cfs @ 12.09 hrs, Volume= 0.089 af Primary = 1.23 cfs @ 12.09 hrs, Volume= 0.089 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x1000: Hawley Street Top Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.367 ac 1.23 cfs 1.23 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 18HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x2000: Hawley Street Bottom Inflow Area = 0.574 ac, 37.83% Impervious, Inflow Depth > 2.29" for NoHo-10 event Inflow = 1.11 cfs @ 12.12 hrs, Volume= 0.109 af Primary = 1.11 cfs @ 12.12 hrs, Volume= 0.109 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x2000: Hawley Street Bottom Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.574 ac 1.11 cfs 1.11 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 19HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x3000: Off-Site South Inflow Area = 0.040 ac, 0.00% Impervious, Inflow Depth > 1.18" for NoHo-10 event Inflow = 0.05 cfs @ 12.10 hrs, Volume= 0.004 af Primary = 0.05 cfs @ 12.10 hrs, Volume= 0.004 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x3000: Off-Site South Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.040 ac 0.05 cfs 0.05 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-EX Printed 10/31/2019Prepared by VHB Page 20HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x4000: Phillips Place Inflow Area = 0.913 ac, 79.12% Impervious, Inflow Depth > 3.61" for NoHo-10 event Inflow = 3.81 cfs @ 12.09 hrs, Volume= 0.274 af Primary = 3.81 cfs @ 12.09 hrs, Volume= 0.274 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x4000: Phillips Place Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)4 3 2 1 0 Inflow Area=0.913 ac 3.81 cfs 3.81 cfs Appendix J: Hydrologic Analysis 25-Year Storm Event- Existing 10 Drainage Area 10 15 Drainage Area 15 20 Drainage Area 20 25 Drainage Area 25 30 Drainage Area 30 35 Drainage Area 35 40 Drainage Area 40 45 Drainage Area 45 50 Drainage Area 50 55 Drainage Area 55 x1000 Hawley Street Top x2000 Hawley Street Bottom x3000 Off-Site South x4000 Phillips Place Routing Diagram for 42540-EX Prepared by VHB, Printed 10/31/2019 HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link 42540-EX Printed 10/31/2019Prepared by VHB Page 2HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Project Notes Rainfall events imported from "Northampton MA.hcp" 42540-EX Printed 10/31/2019Prepared by VHB Page 3HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.746 61 >75% Grass cover, Good, HSG B (10, 15, 30, 35, 45, 50, 55) 0.152 98 Church Roof, HSG B (20) 0.737 98 Impervious, HSG B (10, 15, 30, 35, 50, 55) 0.212 98 Rear Building Roof, HSG B (40) 0.046 98 Roofs, HSG B (25) 1.893 83 TOTAL AREA 42540-EX Printed 10/31/2019Prepared by VHB Page 4HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 1.893 HSG B 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 0.000 HSG C 0.000 HSG D 0.000 Other 1.893 TOTAL AREA 42540-EX Printed 10/31/2019Prepared by VHB Page 5HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.746 0.000 0.000 0.000 0.746 >75% Grass cover, Good 10, 15, 30, 35, 45, 50, 55 0.000 0.152 0.000 0.000 0.000 0.152 Church Roof 20 0.000 0.737 0.000 0.000 0.000 0.737 Impervious 10, 15, 30, 35, 50, 55 0.000 0.212 0.000 0.000 0.000 0.212 Rear Building Roof 40 0.000 0.046 0.000 0.000 0.000 0.046 Roofs 25 0.000 1.893 0.000 0.000 0.000 1.893 TOTAL AREA Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 6HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=5,403 sf 6.64% Impervious Runoff Depth>2.06"Subcatchment 10: Drainage Area 10 Tc=6.0 min CN=63 Runoff=0.31 cfs 0.021 af Runoff Area=11,518 sf 16.01% Impervious Runoff Depth>2.40"Subcatchment 15: Drainage Area 15 Flow Length=127' Tc=15.5 min CN=67 Runoff=0.59 cfs 0.053 af Runoff Area=6,628 sf 100.00% Impervious Runoff Depth>5.42"Subcatchment 20: Drainage Area 20 Tc=6.0 min CN=98 Runoff=0.89 cfs 0.069 af Runoff Area=2,008 sf 100.00% Impervious Runoff Depth>5.42"Subcatchment 25: Drainage Area 25 Tc=6.0 min CN=98 Runoff=0.27 cfs 0.021 af Runoff Area=6,849 sf 14.35% Impervious Runoff Depth>2.31"Subcatchment 30: Drainage Area 30 Flow Length=107' Tc=15.2 min CN=66 Runoff=0.34 cfs 0.030 af Runoff Area=8,584 sf 78.03% Impervious Runoff Depth>4.67"Subcatchment 35: Drainage Area 35 Tc=6.0 min CN=90 Runoff=1.06 cfs 0.077 af Runoff Area=9,231 sf 100.00% Impervious Runoff Depth>5.42"Subcatchment 40: Drainage Area 40 Tc=6.0 min CN=98 Runoff=1.24 cfs 0.096 af Runoff Area=1,723 sf 0.00% Impervious Runoff Depth>1.89"Subcatchment 45: Drainage Area 45 Tc=6.0 min CN=61 Runoff=0.09 cfs 0.006 af Runoff Area=27,647 sf 72.27% Impervious Runoff Depth>4.46"Subcatchment 50: Drainage Area 50 Tc=6.0 min CN=88 Runoff=3.31 cfs 0.236 af Runoff Area=2,884 sf 77.91% Impervious Runoff Depth>4.67"Subcatchment 55: Drainage Area 55 Tc=6.0 min CN=90 Runoff=0.36 cfs 0.026 af Inflow=1.64 cfs 0.119 afLink x1000: Hawley Street Top Primary=1.64 cfs 0.119 af Inflow=1.54 cfs 0.152 afLink x2000: Hawley Street Bottom Primary=1.54 cfs 0.152 af Inflow=0.09 cfs 0.006 afLink x3000: Off-Site South Primary=0.09 cfs 0.006 af Inflow=4.91 cfs 0.357 afLink x4000: Phillips Place Primary=4.91 cfs 0.357 af Total Runoff Area = 1.893 ac Runoff Volume = 0.634 af Average Runoff Depth = 4.02" 39.40% Pervious = 0.746 ac 60.60% Impervious = 1.147 ac Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 7HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 10: Drainage Area 10 Runoff = 0.31 cfs @ 12.10 hrs, Volume= 0.021 af, Depth> 2.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 5,044 61 >75% Grass cover, Good, HSG B * 359 98 Impervious, HSG B 5,403 63 Weighted Average 5,044 93.36% Pervious Area 359 6.64% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 10: Drainage Area 10 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-25 Rainfall=6.10" Runoff Area=5,403 sf Runoff Volume=0.021 af Runoff Depth>2.06" Tc=6.0 min CN=63 0.31 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 8HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 15: Drainage Area 15 Runoff = 0.59 cfs @ 12.22 hrs, Volume= 0.053 af, Depth> 2.40" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 9,674 61 >75% Grass cover, Good, HSG B * 1,844 98 Impervious, HSG B 11,518 67 Weighted Average 9,674 83.99% Pervious Area 1,844 16.01% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.8 20 0.4000 0.41 Sheet Flow, First 20 feet Grass: Short n= 0.150 P2= 3.15" 14.4 80 0.0050 0.09 Sheet Flow, Next 80 feet Grass: Short n= 0.150 P2= 3.15" 0.3 27 0.0625 1.75 Shallow Concentrated Flow, Last 27 feet Short Grass Pasture Kv= 7.0 fps 15.5 127 Total Subcatchment 15: Drainage Area 15 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-25 Rainfall=6.10" Runoff Area=11,518 sf Runoff Volume=0.053 af Runoff Depth>2.40" Flow Length=127' Tc=15.5 min CN=67 0.59 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 9HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 20: Drainage Area 20 Runoff = 0.89 cfs @ 12.09 hrs, Volume= 0.069 af, Depth> 5.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description * 6,628 98 Church Roof, HSG B 6,628 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 20: Drainage Area 20 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr NoHo-25 Rainfall=6.10" Runoff Area=6,628 sf Runoff Volume=0.069 af Runoff Depth>5.42" Tc=6.0 min CN=98 0.89 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 10HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 25: Drainage Area 25 Runoff = 0.27 cfs @ 12.09 hrs, Volume= 0.021 af, Depth> 5.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 2,008 98 Roofs, HSG B 2,008 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 25: Drainage Area 25 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-25 Rainfall=6.10" Runoff Area=2,008 sf Runoff Volume=0.021 af Runoff Depth>5.42" Tc=6.0 min CN=98 0.27 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 11HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 30: Drainage Area 30 Runoff = 0.34 cfs @ 12.22 hrs, Volume= 0.030 af, Depth> 2.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 5,866 61 >75% Grass cover, Good, HSG B * 983 98 Impervious, HSG B 6,849 66 Weighted Average 5,866 85.65% Pervious Area 983 14.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 22 0.3700 0.40 Sheet Flow, First 22 feet Grass: Short n= 0.150 P2= 3.15" 14.1 78 0.0050 0.09 Sheet Flow, Next 78 feet of grass Grass: Short n= 0.150 P2= 3.15" 0.2 7 0.0050 0.49 Shallow Concentrated Flow, Last 7 feet of grass Short Grass Pasture Kv= 7.0 fps 15.2 107 Total Subcatchment 30: Drainage Area 30 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-25 Rainfall=6.10" Runoff Area=6,849 sf Runoff Volume=0.030 af Runoff Depth>2.31" Flow Length=107' Tc=15.2 min CN=66 0.34 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 12HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 35: Drainage Area 35 Runoff = 1.06 cfs @ 12.09 hrs, Volume= 0.077 af, Depth> 4.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 1,886 61 >75% Grass cover, Good, HSG B * 6,698 98 Impervious, HSG B 8,584 90 Weighted Average 1,886 21.97% Pervious Area 6,698 78.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 35: Drainage Area 35 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-25 Rainfall=6.10" Runoff Area=8,584 sf Runoff Volume=0.077 af Runoff Depth>4.67" Tc=6.0 min CN=90 1.06 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 13HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 40: Drainage Area 40 Runoff = 1.24 cfs @ 12.09 hrs, Volume= 0.096 af, Depth> 5.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description * 9,231 98 Rear Building Roof, HSG B 9,231 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 40: Drainage Area 40 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-25 Rainfall=6.10" Runoff Area=9,231 sf Runoff Volume=0.096 af Runoff Depth>5.42" Tc=6.0 min CN=98 1.24 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 14HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 45: Drainage Area 45 Runoff = 0.09 cfs @ 12.10 hrs, Volume= 0.006 af, Depth> 1.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 1,723 61 >75% Grass cover, Good, HSG B 1,723 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 45: Drainage Area 45 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-25 Rainfall=6.10" Runoff Area=1,723 sf Runoff Volume=0.006 af Runoff Depth>1.89" Tc=6.0 min CN=61 0.09 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 15HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 50: Drainage Area 50 Runoff = 3.31 cfs @ 12.09 hrs, Volume= 0.236 af, Depth> 4.46" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 7,667 61 >75% Grass cover, Good, HSG B * 19,980 98 Impervious, HSG B 27,647 88 Weighted Average 7,667 27.73% Pervious Area 19,980 72.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 50: Drainage Area 50 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)3 2 1 0 Type III 24-hr NoHo-25 Rainfall=6.10" Runoff Area=27,647 sf Runoff Volume=0.236 af Runoff Depth>4.46" Tc=6.0 min CN=88 3.31 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 16HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 55: Drainage Area 55 Runoff = 0.36 cfs @ 12.09 hrs, Volume= 0.026 af, Depth> 4.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 637 61 >75% Grass cover, Good, HSG B * 2,247 98 Impervious, HSG B 2,884 90 Weighted Average 637 22.09% Pervious Area 2,247 77.91% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 55: Drainage Area 55 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-25 Rainfall=6.10" Runoff Area=2,884 sf Runoff Volume=0.026 af Runoff Depth>4.67" Tc=6.0 min CN=90 0.36 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 17HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x1000: Hawley Street Top Inflow Area = 0.367 ac, 56.67% Impervious, Inflow Depth > 3.88" for NoHo-25 event Inflow = 1.64 cfs @ 12.09 hrs, Volume= 0.119 af Primary = 1.64 cfs @ 12.09 hrs, Volume= 0.119 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x1000: Hawley Street Top Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.367 ac 1.64 cfs 1.64 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 18HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x2000: Hawley Street Bottom Inflow Area = 0.574 ac, 37.83% Impervious, Inflow Depth > 3.17" for NoHo-25 event Inflow = 1.54 cfs @ 12.12 hrs, Volume= 0.152 af Primary = 1.54 cfs @ 12.12 hrs, Volume= 0.152 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x2000: Hawley Street Bottom Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.574 ac 1.54 cfs 1.54 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 19HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x3000: Off-Site South Inflow Area = 0.040 ac, 0.00% Impervious, Inflow Depth > 1.89" for NoHo-25 event Inflow = 0.09 cfs @ 12.10 hrs, Volume= 0.006 af Primary = 0.09 cfs @ 12.10 hrs, Volume= 0.006 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x3000: Off-Site South Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 Inflow Area=0.040 ac 0.09 cfs 0.09 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-EX Printed 10/31/2019Prepared by VHB Page 20HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x4000: Phillips Place Inflow Area = 0.913 ac, 79.12% Impervious, Inflow Depth > 4.70" for NoHo-25 event Inflow = 4.91 cfs @ 12.09 hrs, Volume= 0.357 af Primary = 4.91 cfs @ 12.09 hrs, Volume= 0.357 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x4000: Phillips Place Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)5 4 3 2 1 0 Inflow Area=0.913 ac 4.91 cfs 4.91 cfs Appendix J: Hydrologic Analysis 100-Year Storm Event – Existing 10 Drainage Area 10 15 Drainage Area 15 20 Drainage Area 20 25 Drainage Area 25 30 Drainage Area 30 35 Drainage Area 35 40 Drainage Area 40 45 Drainage Area 45 50 Drainage Area 50 55 Drainage Area 55 x1000 Hawley Street Top x2000 Hawley Street Bottom x3000 Off-Site South x4000 Phillips Place Routing Diagram for 42540-EX Prepared by VHB, Printed 10/31/2019 HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link 42540-EX Printed 10/31/2019Prepared by VHB Page 2HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Project Notes Rainfall events imported from "Northampton MA.hcp" 42540-EX Printed 10/31/2019Prepared by VHB Page 3HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.746 61 >75% Grass cover, Good, HSG B (10, 15, 30, 35, 45, 50, 55) 0.152 98 Church Roof, HSG B (20) 0.737 98 Impervious, HSG B (10, 15, 30, 35, 50, 55) 0.212 98 Rear Building Roof, HSG B (40) 0.046 98 Roofs, HSG B (25) 1.893 83 TOTAL AREA 42540-EX Printed 10/31/2019Prepared by VHB Page 4HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 1.893 HSG B 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 0.000 HSG C 0.000 HSG D 0.000 Other 1.893 TOTAL AREA 42540-EX Printed 10/31/2019Prepared by VHB Page 5HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.746 0.000 0.000 0.000 0.746 >75% Grass cover, Good 10, 15, 30, 35, 45, 50, 55 0.000 0.152 0.000 0.000 0.000 0.152 Church Roof 20 0.000 0.737 0.000 0.000 0.000 0.737 Impervious 10, 15, 30, 35, 50, 55 0.000 0.212 0.000 0.000 0.000 0.212 Rear Building Roof 40 0.000 0.046 0.000 0.000 0.000 0.046 Roofs 25 0.000 1.893 0.000 0.000 0.000 1.893 TOTAL AREA Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 6HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=5,403 sf 6.64% Impervious Runoff Depth>3.32"Subcatchment 10: Drainage Area 10 Tc=6.0 min CN=63 Runoff=0.51 cfs 0.034 af Runoff Area=11,518 sf 16.01% Impervious Runoff Depth>3.74"Subcatchment 15: Drainage Area 15 Flow Length=127' Tc=15.5 min CN=67 Runoff=0.93 cfs 0.082 af Runoff Area=6,628 sf 100.00% Impervious Runoff Depth>7.05"Subcatchment 20: Drainage Area 20 Tc=6.0 min CN=98 Runoff=1.15 cfs 0.089 af Runoff Area=2,008 sf 100.00% Impervious Runoff Depth>7.05"Subcatchment 25: Drainage Area 25 Tc=6.0 min CN=98 Runoff=0.35 cfs 0.027 af Runoff Area=6,849 sf 14.35% Impervious Runoff Depth>3.63"Subcatchment 30: Drainage Area 30 Flow Length=107' Tc=15.2 min CN=66 Runoff=0.54 cfs 0.048 af Runoff Area=8,584 sf 78.03% Impervious Runoff Depth>6.33"Subcatchment 35: Drainage Area 35 Tc=6.0 min CN=90 Runoff=1.42 cfs 0.104 af Runoff Area=9,231 sf 100.00% Impervious Runoff Depth>7.05"Subcatchment 40: Drainage Area 40 Tc=6.0 min CN=98 Runoff=1.60 cfs 0.125 af Runoff Area=1,723 sf 0.00% Impervious Runoff Depth>3.11"Subcatchment 45: Drainage Area 45 Tc=6.0 min CN=61 Runoff=0.15 cfs 0.010 af Runoff Area=27,647 sf 72.27% Impervious Runoff Depth>6.11"Subcatchment 50: Drainage Area 50 Tc=6.0 min CN=88 Runoff=4.46 cfs 0.323 af Runoff Area=2,884 sf 77.91% Impervious Runoff Depth>6.33"Subcatchment 55: Drainage Area 55 Tc=6.0 min CN=90 Runoff=0.48 cfs 0.035 af Inflow=2.27 cfs 0.165 afLink x1000: Hawley Street Top Primary=2.27 cfs 0.165 af Inflow=2.22 cfs 0.219 afLink x2000: Hawley Street Bottom Primary=2.22 cfs 0.219 af Inflow=0.15 cfs 0.010 afLink x3000: Off-Site South Primary=0.15 cfs 0.010 af Inflow=6.54 cfs 0.483 afLink x4000: Phillips Place Primary=6.54 cfs 0.483 af Total Runoff Area = 1.893 ac Runoff Volume = 0.878 af Average Runoff Depth = 5.57" 39.40% Pervious = 0.746 ac 60.60% Impervious = 1.147 ac Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 7HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 10: Drainage Area 10 Runoff = 0.51 cfs @ 12.10 hrs, Volume= 0.034 af, Depth> 3.32" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 5,044 61 >75% Grass cover, Good, HSG B * 359 98 Impervious, HSG B 5,403 63 Weighted Average 5,044 93.36% Pervious Area 359 6.64% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 10: Drainage Area 10 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-100 Rainfall=7.90" Runoff Area=5,403 sf Runoff Volume=0.034 af Runoff Depth>3.32" Tc=6.0 min CN=63 0.51 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 8HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 15: Drainage Area 15 Runoff = 0.93 cfs @ 12.22 hrs, Volume= 0.082 af, Depth> 3.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 9,674 61 >75% Grass cover, Good, HSG B * 1,844 98 Impervious, HSG B 11,518 67 Weighted Average 9,674 83.99% Pervious Area 1,844 16.01% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.8 20 0.4000 0.41 Sheet Flow, First 20 feet Grass: Short n= 0.150 P2= 3.15" 14.4 80 0.0050 0.09 Sheet Flow, Next 80 feet Grass: Short n= 0.150 P2= 3.15" 0.3 27 0.0625 1.75 Shallow Concentrated Flow, Last 27 feet Short Grass Pasture Kv= 7.0 fps 15.5 127 Total Subcatchment 15: Drainage Area 15 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=11,518 sf Runoff Volume=0.082 af Runoff Depth>3.74" Flow Length=127' Tc=15.5 min CN=67 0.93 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 9HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 20: Drainage Area 20 Runoff = 1.15 cfs @ 12.09 hrs, Volume= 0.089 af, Depth> 7.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description * 6,628 98 Church Roof, HSG B 6,628 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 20: Drainage Area 20 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=6,628 sf Runoff Volume=0.089 af Runoff Depth>7.05" Tc=6.0 min CN=98 1.15 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 10HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 25: Drainage Area 25 Runoff = 0.35 cfs @ 12.09 hrs, Volume= 0.027 af, Depth> 7.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 2,008 98 Roofs, HSG B 2,008 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 25: Drainage Area 25 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-100 Rainfall=7.90" Runoff Area=2,008 sf Runoff Volume=0.027 af Runoff Depth>7.05" Tc=6.0 min CN=98 0.35 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 11HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 30: Drainage Area 30 Runoff = 0.54 cfs @ 12.21 hrs, Volume= 0.048 af, Depth> 3.63" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 5,866 61 >75% Grass cover, Good, HSG B * 983 98 Impervious, HSG B 6,849 66 Weighted Average 5,866 85.65% Pervious Area 983 14.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 22 0.3700 0.40 Sheet Flow, First 22 feet Grass: Short n= 0.150 P2= 3.15" 14.1 78 0.0050 0.09 Sheet Flow, Next 78 feet of grass Grass: Short n= 0.150 P2= 3.15" 0.2 7 0.0050 0.49 Shallow Concentrated Flow, Last 7 feet of grass Short Grass Pasture Kv= 7.0 fps 15.2 107 Total Subcatchment 30: Drainage Area 30 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=6,849 sf Runoff Volume=0.048 af Runoff Depth>3.63" Flow Length=107' Tc=15.2 min CN=66 0.54 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 12HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 35: Drainage Area 35 Runoff = 1.42 cfs @ 12.09 hrs, Volume= 0.104 af, Depth> 6.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 1,886 61 >75% Grass cover, Good, HSG B * 6,698 98 Impervious, HSG B 8,584 90 Weighted Average 1,886 21.97% Pervious Area 6,698 78.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 35: Drainage Area 35 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=8,584 sf Runoff Volume=0.104 af Runoff Depth>6.33" Tc=6.0 min CN=90 1.42 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 13HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 40: Drainage Area 40 Runoff = 1.60 cfs @ 12.09 hrs, Volume= 0.125 af, Depth> 7.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description * 9,231 98 Rear Building Roof, HSG B 9,231 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 40: Drainage Area 40 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=9,231 sf Runoff Volume=0.125 af Runoff Depth>7.05" Tc=6.0 min CN=98 1.60 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 14HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 45: Drainage Area 45 Runoff = 0.15 cfs @ 12.10 hrs, Volume= 0.010 af, Depth> 3.11" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 1,723 61 >75% Grass cover, Good, HSG B 1,723 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 45: Drainage Area 45 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-100 Rainfall=7.90" Runoff Area=1,723 sf Runoff Volume=0.010 af Runoff Depth>3.11" Tc=6.0 min CN=61 0.15 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 15HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 50: Drainage Area 50 Runoff = 4.46 cfs @ 12.09 hrs, Volume= 0.323 af, Depth> 6.11" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 7,667 61 >75% Grass cover, Good, HSG B * 19,980 98 Impervious, HSG B 27,647 88 Weighted Average 7,667 27.73% Pervious Area 19,980 72.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 50: Drainage Area 50 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)4 3 2 1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=27,647 sf Runoff Volume=0.323 af Runoff Depth>6.11" Tc=6.0 min CN=88 4.46 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 16HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 55: Drainage Area 55 Runoff = 0.48 cfs @ 12.09 hrs, Volume= 0.035 af, Depth> 6.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 637 61 >75% Grass cover, Good, HSG B * 2,247 98 Impervious, HSG B 2,884 90 Weighted Average 637 22.09% Pervious Area 2,247 77.91% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 55: Drainage Area 55 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-100 Rainfall=7.90" Runoff Area=2,884 sf Runoff Volume=0.035 af Runoff Depth>6.33" Tc=6.0 min CN=90 0.48 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 17HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x1000: Hawley Street Top Inflow Area = 0.367 ac, 56.67% Impervious, Inflow Depth > 5.41" for NoHo-100 event Inflow = 2.27 cfs @ 12.09 hrs, Volume= 0.165 af Primary = 2.27 cfs @ 12.09 hrs, Volume= 0.165 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x1000: Hawley Street Top Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.367 ac 2.27 cfs 2.27 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 18HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x2000: Hawley Street Bottom Inflow Area = 0.574 ac, 37.83% Impervious, Inflow Depth > 4.59" for NoHo-100 event Inflow = 2.22 cfs @ 12.14 hrs, Volume= 0.219 af Primary = 2.22 cfs @ 12.14 hrs, Volume= 0.219 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x2000: Hawley Street Bottom Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.574 ac 2.22 cfs 2.22 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 19HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x3000: Off-Site South Inflow Area = 0.040 ac, 0.00% Impervious, Inflow Depth > 3.11" for NoHo-100 event Inflow = 0.15 cfs @ 12.10 hrs, Volume= 0.010 af Primary = 0.15 cfs @ 12.10 hrs, Volume= 0.010 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x3000: Off-Site South Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.040 ac 0.15 cfs 0.15 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-EX Printed 10/31/2019Prepared by VHB Page 20HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x4000: Phillips Place Inflow Area = 0.913 ac, 79.12% Impervious, Inflow Depth > 6.35" for NoHo-100 event Inflow = 6.54 cfs @ 12.09 hrs, Volume= 0.483 af Primary = 6.54 cfs @ 12.09 hrs, Volume= 0.483 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x4000: Phillips Place Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=0.913 ac 6.54 cfs 6.54 cfs Appendix J: Hydrologic Analysis HydroCAD Analysis: Proposed Conditions Appendix J: Hydrologic Analysis 2-Year Storm Event – Proposed 100 Drainage Area 100 150 Drainage Area 150 200 Drainage Area 200 300 Drainage Area 300 400 Drainage Area 400 450 Drainage Area 450 500 Drainage Area 500 600 Drainage Area 600 700 Drainage Area 700 750 Drainage Area 750 800 Drainage Area 800 12"(1) 12" Overflow Pipe 12"(2) 12" Overflow Pipe15" 15" Overflow Pipe S1 Subsurface Storage System #1 S2 Subsurface Recharge Trench System #1 S3 Subsurface Recharge Trench System #2 x1000 Hawley Street Top x2000 Hawley Street Bottom x3000 Off-Site South x4000 Phillips Place Routing Diagram for 42540-PR Prepared by VHB, Printed 10/31/2019 HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link 42540-PR Printed 10/31/2019Prepared by VHB Page 2HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Project Notes Rainfall events imported from "Northampton MA.hcp" 42540-PR Printed 10/31/2019Prepared by VHB Page 3HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.632 61 >75% Grass cover, Good, HSG B (100, 150, 300, 500, 600, 700, 750, 800) 0.050 98 Paved parking, HSG B (800) 0.956 98 Paving and Roofs, HSG B (100, 400, 450, 600, 700, 750) 0.152 98 Roofs, HSG B (200) 0.104 98 Walks, HSG B (300) 1.893 86 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 4HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 1.893 HSG B 100, 150, 200, 300, 400, 450, 500, 600, 700, 750, 800 0.000 HSG C 0.000 HSG D 0.000 Other 1.893 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 5HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.632 0.000 0.000 0.000 0.632 >75% Grass cover, Good 100, 150, 300, 500, 600, 700, 750, 800 0.000 0.050 0.000 0.000 0.000 0.050 Paved parking 800 0.000 0.956 0.000 0.000 0.000 0.956 Paving and Roofs 100, 400, 450, 600, 700, 750 0.000 0.152 0.000 0.000 0.000 0.152 Roofs 200 0.000 0.104 0.000 0.000 0.000 0.104 Walks 300 0.000 1.893 0.000 0.000 0.000 1.893 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 6HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Diam/Width (inches) Height (inches) Inside-Fill (inches) 1 12"(1) 130.50 130.30 34.0 0.0059 0.013 12.0 0.0 0.0 2 12"(2) 133.50 133.20 45.0 0.0067 0.013 12.0 0.0 0.0 3 15" 118.90 118.80 19.0 0.0053 0.020 15.0 0.0 0.0 Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 7HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=19,086 sf 91.70% Impervious Runoff Depth>2.45"Subcatchment 100: Drainage Area 100 Tc=6.0 min CN=95 Runoff=1.23 cfs 0.090 af Runoff Area=3,227 sf 0.00% Impervious Runoff Depth>0.37"Subcatchment 150: Drainage Area 150 Tc=6.0 min CN=61 Runoff=0.02 cfs 0.002 af Runoff Area=6,628 sf 100.00% Impervious Runoff Depth>2.73"Subcatchment 200: Drainage Area 200 Tc=6.0 min CN=98 Runoff=0.45 cfs 0.035 af Runoff Area=18,250 sf 24.85% Impervious Runoff Depth>0.72"Subcatchment 300: Drainage Area 300 Flow Length=336' Tc=15.6 min CN=70 Runoff=0.26 cfs 0.025 af Runoff Area=3,345 sf 100.00% Impervious Runoff Depth>2.73"Subcatchment 400: Drainage Area 400 Tc=6.0 min CN=98 Runoff=0.23 cfs 0.017 af Runoff Area=4,888 sf 100.00% Impervious Runoff Depth>2.73"Subcatchment 450: Drainage Area 450 Tc=6.0 min CN=98 Runoff=0.33 cfs 0.026 af Runoff Area=588 sf 0.00% Impervious Runoff Depth>0.37"Subcatchment 500: Drainage Area 500 Tc=6.0 min CN=61 Runoff=0.00 cfs 0.000 af Runoff Area=8,414 sf 65.33% Impervious Runoff Depth>1.60"Subcatchment 600: Drainage Area 600 Tc=6.0 min CN=85 Runoff=0.38 cfs 0.026 af Runoff Area=7,449 sf 79.04% Impervious Runoff Depth>1.99"Subcatchment 700: Drainage Area 700 Tc=6.0 min CN=90 Runoff=0.41 cfs 0.028 af Runoff Area=7,879 sf 57.30% Impervious Runoff Depth>1.39"Subcatchment 750: Drainage Area 750 Tc=6.0 min CN=82 Runoff=0.31 cfs 0.021 af Runoff Area=2,720 sf 79.37% Impervious Runoff Depth>1.99"Subcatchment 800: Drainage Area 800 Tc=6.0 min CN=90 Runoff=0.15 cfs 0.010 af Avg. Flow Depth=0.00' Max Vel=0.00 fps Inflow=0.00 cfs 0.000 afReach 12"(1): 12" Overflow Pipe 12.0" Round Pipe n=0.013 L=34.0' S=0.0059 '/' Capacity=2.73 cfs Outflow=0.00 cfs 0.000 af Avg. Flow Depth=0.00' Max Vel=0.00 fps Inflow=0.00 cfs 0.000 afReach 12"(2): 12" Overflow Pipe 12.0" Round Pipe n=0.013 L=45.0' S=0.0067 '/' Capacity=2.91 cfs Outflow=0.00 cfs 0.000 af Avg. Flow Depth=0.54' Max Vel=2.33 fps Inflow=1.18 cfs 0.107 afReach 15": 15" Overflow Pipe 15.0" Round Pipe n=0.020 L=19.0' S=0.0053 '/' Capacity=3.05 cfs Outflow=1.18 cfs 0.107 af Peak Elev=119.83' Storage=214 cf Inflow=1.46 cfs 0.107 afPond S1: Subsurface Storage System #1 Primary=1.18 cfs 0.107 af Secondary=0.00 cfs 0.000 af Outflow=1.18 cfs 0.107 af Peak Elev=131.08' Storage=571 cf Inflow=0.72 cfs 0.051 afPond S2: Subsurface Recharge Trench Discarded=0.15 cfs 0.051 af Primary=0.00 cfs 0.000 af Outflow=0.15 cfs 0.051 af Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 8HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Peak Elev=134.00' Storage=255 cf Inflow=0.31 cfs 0.021 afPond S3: Subsurface Recharge Trench Discarded=0.06 cfs 0.021 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.021 af Inflow=1.20 cfs 0.109 afLink x1000: Hawley Street Top Primary=1.20 cfs 0.109 af Inflow=0.60 cfs 0.060 afLink x2000: Hawley Street Bottom Primary=0.60 cfs 0.060 af Inflow=0.00 cfs 0.000 afLink x3000: Off-Site South Primary=0.00 cfs 0.000 af Inflow=0.56 cfs 0.039 afLink x4000: Phillips Place Primary=0.56 cfs 0.039 af Total Runoff Area = 1.893 ac Runoff Volume = 0.280 af Average Runoff Depth = 1.78" 33.36% Pervious = 0.632 ac 66.64% Impervious = 1.262 ac Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 9HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 100: Drainage Area 100 Runoff = 1.23 cfs @ 12.09 hrs, Volume= 0.090 af, Depth> 2.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 1,584 61 >75% Grass cover, Good, HSG B * 17,502 98 Paving and Roofs, HSG B 19,086 95 Weighted Average 1,584 8.30% Pervious Area 17,502 91.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 100: Drainage Area 100 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-02 Rainfall=3.15" Runoff Area=19,086 sf Runoff Volume=0.090 af Runoff Depth>2.45" Tc=6.0 min CN=95 1.23 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 10HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 150: Drainage Area 150 Runoff = 0.02 cfs @ 12.13 hrs, Volume= 0.002 af, Depth> 0.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 3,227 61 >75% Grass cover, Good, HSG B 3,227 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 150: Drainage Area 150 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-02 Rainfall=3.15" Runoff Area=3,227 sf Runoff Volume=0.002 af Runoff Depth>0.37" Tc=6.0 min CN=61 0.02 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 11HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 200: Drainage Area 200 Runoff = 0.45 cfs @ 12.09 hrs, Volume= 0.035 af, Depth> 2.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 6,628 98 Roofs, HSG B 6,628 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 200: Drainage Area 200 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=6,628 sf Runoff Volume=0.035 af Runoff Depth>2.73" Tc=6.0 min CN=98 0.45 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 12HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 300: Drainage Area 300 Runoff = 0.26 cfs @ 12.25 hrs, Volume= 0.025 af, Depth> 0.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 13,714 61 >75% Grass cover, Good, HSG B * 4,536 98 Walks, HSG B 18,250 70 Weighted Average 13,714 75.15% Pervious Area 4,536 24.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.8 100 0.0270 0.19 Sheet Flow, First 100 feet of grass Grass: Short n= 0.150 P2= 3.15" 0.7 50 0.0270 1.15 Shallow Concentrated Flow, Next 50 feet of grass Short Grass Pasture Kv= 7.0 fps 5.4 160 0.0050 0.49 Shallow Concentrated Flow, Next 160 feet of grass Short Grass Pasture Kv= 7.0 fps 0.7 20 0.0050 0.49 Shallow Concentrated Flow, Next 20 feet of grass Short Grass Pasture Kv= 7.0 fps 0.0 6 0.5000 4.95 Shallow Concentrated Flow, Last 6 feet of grass Short Grass Pasture Kv= 7.0 fps 15.6 336 Total Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 13HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcatchment 300: Drainage Area 300 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-02 Rainfall=3.15" Runoff Area=18,250 sf Runoff Volume=0.025 af Runoff Depth>0.72" Flow Length=336' Tc=15.6 min CN=70 0.26 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 14HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 400: Drainage Area 400 Runoff = 0.23 cfs @ 12.09 hrs, Volume= 0.017 af, Depth> 2.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description * 3,345 98 Paving and Roofs, HSG B 3,345 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 400: Drainage Area 400 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=3,345 sf Runoff Volume=0.017 af Runoff Depth>2.73" Tc=6.0 min CN=98 0.23 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 15HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 450: Drainage Area 450 Runoff = 0.33 cfs @ 12.09 hrs, Volume= 0.026 af, Depth> 2.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description * 4,888 98 Paving and Roofs, HSG B 4,888 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 450: Drainage Area 450 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-02 Rainfall=3.15" Runoff Area=4,888 sf Runoff Volume=0.026 af Runoff Depth>2.73" Tc=6.0 min CN=98 0.33 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 16HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 500: Drainage Area 500 Runoff = 0.00 cfs @ 12.13 hrs, Volume= 0.000 af, Depth> 0.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 588 61 >75% Grass cover, Good, HSG B 588 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 500: Drainage Area 500 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=588 sf Runoff Volume=0.000 af Runoff Depth>0.37" Tc=6.0 min CN=61 0.00 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 17HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 600: Drainage Area 600 Runoff = 0.38 cfs @ 12.09 hrs, Volume= 0.026 af, Depth> 1.60" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 2,917 61 >75% Grass cover, Good, HSG B * 5,497 98 Paving and Roofs, HSG B 8,414 85 Weighted Average 2,917 34.67% Pervious Area 5,497 65.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 600: Drainage Area 600 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-02 Rainfall=3.15" Runoff Area=8,414 sf Runoff Volume=0.026 af Runoff Depth>1.60" Tc=6.0 min CN=85 0.38 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 18HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 700: Drainage Area 700 Runoff = 0.41 cfs @ 12.09 hrs, Volume= 0.028 af, Depth> 1.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 1,561 61 >75% Grass cover, Good, HSG B * 5,888 98 Paving and Roofs, HSG B 7,449 90 Weighted Average 1,561 20.96% Pervious Area 5,888 79.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 700: Drainage Area 700 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=7,449 sf Runoff Volume=0.028 af Runoff Depth>1.99" Tc=6.0 min CN=90 0.41 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 19HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 750: Drainage Area 750 Runoff = 0.31 cfs @ 12.09 hrs, Volume= 0.021 af, Depth> 1.39" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 3,364 61 >75% Grass cover, Good, HSG B * 4,515 98 Paving and Roofs, HSG B 7,879 82 Weighted Average 3,364 42.70% Pervious Area 4,515 57.30% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 750: Drainage Area 750 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-02 Rainfall=3.15" Runoff Area=7,879 sf Runoff Volume=0.021 af Runoff Depth>1.39" Tc=6.0 min CN=82 0.31 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 20HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 800: Drainage Area 800 Runoff = 0.15 cfs @ 12.09 hrs, Volume= 0.010 af, Depth> 1.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-02 Rainfall=3.15" Area (sf) CN Description 561 61 >75% Grass cover, Good, HSG B 2,159 98 Paved parking, HSG B 2,720 90 Weighted Average 561 20.62% Pervious Area 2,159 79.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 800: Drainage Area 800 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-02 Rainfall=3.15" Runoff Area=2,720 sf Runoff Volume=0.010 af Runoff Depth>1.99" Tc=6.0 min CN=90 0.15 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 21HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 12"(1): 12" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 0.305 ac, 78.07% Impervious, Inflow Depth = 0.00" for NoHo-02 event Inflow = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Outflow = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.00 fps, Min. Travel Time= 0.0 min Avg. Velocity = 0.00 fps, Avg. Travel Time= 0.0 min Peak Storage= 0 cf @ 5.00 hrs Average Depth at Peak Storage= 0.00' Bank-Full Depth= 1.00' Flow Area= 0.8 sf, Capacity= 2.73 cfs 12.0" Round Pipe n= 0.013 Corrugated PE, smooth interior Length= 34.0' Slope= 0.0059 '/' Inlet Invert= 130.50', Outlet Invert= 130.30' Reach 12"(1): 12" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.305 ac Avg. Flow Depth=0.00' Max Vel=0.00 fps 12.0" Round Pipe n=0.013 L=34.0' S=0.0059 '/' Capacity=2.73 cfs 0.00 cfs 0.00 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 22HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 12"(1): 12" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 130.50 0.0 0 130.51 0.0 0 130.52 0.0 0 130.53 0.0 0 130.54 0.0 0 130.55 0.0 0 130.56 0.0 1 130.57 0.0 1 130.58 0.0 1 130.59 0.0 1 130.60 0.0 1 130.61 0.0 2 130.62 0.1 2 130.63 0.1 2 130.64 0.1 2 130.65 0.1 3 130.66 0.1 3 130.67 0.1 3 130.68 0.1 3 130.69 0.1 4 130.70 0.1 4 130.71 0.1 4 130.72 0.1 4 130.73 0.1 5 130.74 0.1 5 130.75 0.2 5 130.76 0.2 6 130.77 0.2 6 130.78 0.2 6 130.79 0.2 6 130.80 0.2 7 130.81 0.2 7 130.82 0.2 7 130.83 0.2 8 130.84 0.2 8 130.85 0.2 8 130.86 0.3 9 130.87 0.3 9 130.88 0.3 9 130.89 0.3 10 130.90 0.3 10 130.91 0.3 10 130.92 0.3 11 130.93 0.3 11 130.94 0.3 11 130.95 0.3 12 130.96 0.4 12 130.97 0.4 12 130.98 0.4 13 130.99 0.4 13 131.00 0.4 13 131.01 0.4 14 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 131.02 0.4 14 131.03 0.4 14 131.04 0.4 15 131.05 0.4 15 131.06 0.5 15 131.07 0.5 16 131.08 0.5 16 131.09 0.5 16 131.10 0.5 17 131.11 0.5 17 131.12 0.5 17 131.13 0.5 18 131.14 0.5 18 131.15 0.5 18 131.16 0.5 19 131.17 0.6 19 131.18 0.6 19 131.19 0.6 20 131.20 0.6 20 131.21 0.6 20 131.22 0.6 21 131.23 0.6 21 131.24 0.6 21 131.25 0.6 21 131.26 0.6 22 131.27 0.6 22 131.28 0.7 22 131.29 0.7 23 131.30 0.7 23 131.31 0.7 23 131.32 0.7 23 131.33 0.7 24 131.34 0.7 24 131.35 0.7 24 131.36 0.7 24 131.37 0.7 25 131.38 0.7 25 131.39 0.7 25 131.40 0.7 25 131.41 0.8 26 131.42 0.8 26 131.43 0.8 26 131.44 0.8 26 131.45 0.8 26 131.46 0.8 26 131.47 0.8 26 131.48 0.8 27 131.49 0.8 27 131.50 0.8 27 Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 23HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 12"(2): 12" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 0.181 ac, 57.30% Impervious, Inflow Depth = 0.00" for NoHo-02 event Inflow = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Outflow = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.00 fps, Min. Travel Time= 0.0 min Avg. Velocity = 0.00 fps, Avg. Travel Time= 0.0 min Peak Storage= 0 cf @ 5.00 hrs Average Depth at Peak Storage= 0.00' Bank-Full Depth= 1.00' Flow Area= 0.8 sf, Capacity= 2.91 cfs 12.0" Round Pipe n= 0.013 Corrugated PE, smooth interior Length= 45.0' Slope= 0.0067 '/' Inlet Invert= 133.50', Outlet Invert= 133.20' Reach 12"(2): 12" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.181 ac Avg. Flow Depth=0.00' Max Vel=0.00 fps 12.0" Round Pipe n=0.013 L=45.0' S=0.0067 '/' Capacity=2.91 cfs 0.00 cfs 0.00 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 24HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 12"(2): 12" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 133.50 0.0 0 133.51 0.0 0 133.52 0.0 0 133.53 0.0 0 133.54 0.0 0 133.55 0.0 1 133.56 0.0 1 133.57 0.0 1 133.58 0.0 1 133.59 0.0 2 133.60 0.0 2 133.61 0.0 2 133.62 0.1 2 133.63 0.1 3 133.64 0.1 3 133.65 0.1 3 133.66 0.1 4 133.67 0.1 4 133.68 0.1 4 133.69 0.1 5 133.70 0.1 5 133.71 0.1 5 133.72 0.1 6 133.73 0.1 6 133.74 0.1 7 133.75 0.2 7 133.76 0.2 7 133.77 0.2 8 133.78 0.2 8 133.79 0.2 9 133.80 0.2 9 133.81 0.2 9 133.82 0.2 10 133.83 0.2 10 133.84 0.2 11 133.85 0.2 11 133.86 0.3 11 133.87 0.3 12 133.88 0.3 12 133.89 0.3 13 133.90 0.3 13 133.91 0.3 14 133.92 0.3 14 133.93 0.3 15 133.94 0.3 15 133.95 0.3 15 133.96 0.4 16 133.97 0.4 16 133.98 0.4 17 133.99 0.4 17 134.00 0.4 18 134.01 0.4 18 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 134.02 0.4 19 134.03 0.4 19 134.04 0.4 19 134.05 0.4 20 134.06 0.5 20 134.07 0.5 21 134.08 0.5 21 134.09 0.5 22 134.10 0.5 22 134.11 0.5 23 134.12 0.5 23 134.13 0.5 23 134.14 0.5 24 134.15 0.5 24 134.16 0.5 25 134.17 0.6 25 134.18 0.6 26 134.19 0.6 26 134.20 0.6 26 134.21 0.6 27 134.22 0.6 27 134.23 0.6 28 134.24 0.6 28 134.25 0.6 28 134.26 0.6 29 134.27 0.6 29 134.28 0.7 30 134.29 0.7 30 134.30 0.7 30 134.31 0.7 31 134.32 0.7 31 134.33 0.7 31 134.34 0.7 32 134.35 0.7 32 134.36 0.7 32 134.37 0.7 33 134.38 0.7 33 134.39 0.7 33 134.40 0.7 34 134.41 0.8 34 134.42 0.8 34 134.43 0.8 34 134.44 0.8 34 134.45 0.8 35 134.46 0.8 35 134.47 0.8 35 134.48 0.8 35 134.49 0.8 35 134.50 0.8 35 Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 25HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 15": 15" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated [82] Warning: Early inflow requires earlier time span [79] Warning: Submerged Pond S1 Primary device # 1 by 0.44' Inflow Area = 0.515 ac, 92.94% Impervious, Inflow Depth > 2.49" for NoHo-02 event Inflow = 1.18 cfs @ 12.15 hrs, Volume= 0.107 af Outflow = 1.18 cfs @ 12.15 hrs, Volume= 0.107 af, Atten= 0%, Lag= 0.2 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.33 fps, Min. Travel Time= 0.1 min Avg. Velocity = 0.93 fps, Avg. Travel Time= 0.3 min Peak Storage= 10 cf @ 12.15 hrs Average Depth at Peak Storage= 0.54' Bank-Full Depth= 1.25' Flow Area= 1.2 sf, Capacity= 3.05 cfs 15.0" Round Pipe n= 0.020 Corrugated PE, corrugated interior Length= 19.0' Slope= 0.0053 '/' Inlet Invert= 118.90', Outlet Invert= 118.80' Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 26HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Reach 15": 15" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.515 ac Avg. Flow Depth=0.54' Max Vel=2.33 fps 15.0" Round Pipe n=0.020 L=19.0' S=0.0053 '/' Capacity=3.05 cfs 1.18 cfs 1.18 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 27HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 15": 15" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 118.90 0.0 0 118.92 0.0 0 118.94 0.0 0 118.96 0.0 0 118.98 0.0 1 119.00 0.0 1 119.02 0.1 1 119.04 0.1 1 119.06 0.1 2 119.08 0.1 2 119.10 0.1 2 119.12 0.1 3 119.14 0.2 3 119.16 0.2 4 119.18 0.2 4 119.20 0.2 4 119.22 0.2 5 119.24 0.3 5 119.26 0.3 6 119.28 0.3 6 119.30 0.3 6 119.32 0.4 7 119.34 0.4 7 119.36 0.4 8 119.38 0.4 8 119.40 0.5 9 119.42 0.5 9 119.44 0.5 10 119.46 0.5 10 119.48 0.6 11 119.50 0.6 11 119.52 0.6 12 119.54 0.6 12 119.56 0.7 12 119.58 0.7 13 119.60 0.7 13 119.62 0.7 14 119.64 0.8 14 119.66 0.8 15 119.68 0.8 15 119.70 0.8 16 119.72 0.9 16 119.74 0.9 17 119.76 0.9 17 119.78 0.9 18 119.80 0.9 18 119.82 1.0 18 119.84 1.0 19 119.86 1.0 19 119.88 1.0 20 119.90 1.1 20 119.92 1.1 20 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 119.94 1.1 21 119.96 1.1 21 119.98 1.1 21 120.00 1.1 22 120.02 1.2 22 120.04 1.2 22 120.06 1.2 23 120.08 1.2 23 120.10 1.2 23 120.12 1.2 23 120.14 1.2 23 Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 28HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S1: Subsurface Storage System #1 [82] Warning: Early inflow requires earlier time span Inflow Area = 0.515 ac, 92.94% Impervious, Inflow Depth > 2.49" for NoHo-02 event Inflow = 1.46 cfs @ 12.09 hrs, Volume= 0.107 af Outflow = 1.18 cfs @ 12.15 hrs, Volume= 0.107 af, Atten= 19%, Lag= 3.7 min Primary = 1.18 cfs @ 12.15 hrs, Volume= 0.107 af Secondary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 119.83' @ 12.15 hrs Surf.Area= 616 sf Storage= 214 cf Plug-Flow detention time= 1.3 min calculated for 0.107 af (100% of inflow) Center-of-Mass det. time= 1.2 min ( 752.5 - 751.3 ) Volume Invert Avail.Storage Storage Description #1 119.00' 1,483 cf 24.0" Round Pipe Storage L= 472.0' S= 0.0020 '/' Device Routing Invert Outlet Devices #1 Primary 119.00'8.0" Vert. Orifice/Grate C= 0.600 #2 Secondary 121.20'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Primary OutFlow Max=1.18 cfs @ 12.15 hrs HW=119.83' (Free Discharge) 1=Orifice/Grate (Orifice Controls 1.18 cfs @ 3.39 fps) Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=119.04' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 29HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S1: Subsurface Storage System #1 Inflow Outflow Primary Secondary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.515 ac Peak Elev=119.83' Storage=214 cf 1.46 cfs 1.18 cfs 1.18 cfs 0.00 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 30HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S1: Subsurface Storage System #1 Elevation (feet) Storage (cubic-feet) 119.00 0 119.02 0 119.04 0 119.06 0 119.08 1 119.10 1 119.12 2 119.14 3 119.16 4 119.18 5 119.20 7 119.22 8 119.24 10 119.26 13 119.28 15 119.30 18 119.32 21 119.34 24 119.36 28 119.38 32 119.40 36 119.42 41 119.44 46 119.46 51 119.48 57 119.50 63 119.52 69 119.54 76 119.56 83 119.58 90 119.60 98 119.62 106 119.64 115 119.66 124 119.68 133 119.70 142 119.72 152 119.74 163 119.76 173 119.78 185 119.80 196 119.82 208 119.84 220 119.86 233 119.88 246 119.90 260 119.92 274 119.94 288 119.96 303 119.98 318 120.00 333 120.02 349 Elevation (feet) Storage (cubic-feet) 120.04 364 120.06 381 120.08 397 120.10 413 120.12 430 120.14 447 120.16 464 120.18 481 120.20 498 120.22 516 120.24 533 120.26 551 120.28 568 120.30 586 120.32 604 120.34 622 120.36 640 120.38 658 120.40 676 120.42 694 120.44 712 120.46 731 120.48 749 120.50 767 120.52 785 120.54 803 120.56 821 120.58 839 120.60 857 120.62 875 120.64 893 120.66 911 120.68 929 120.70 946 120.72 964 120.74 981 120.76 998 120.78 1,016 120.80 1,033 120.82 1,050 120.84 1,066 120.86 1,083 120.88 1,099 120.90 1,115 120.92 1,131 120.94 1,147 120.96 1,162 120.98 1,177 121.00 1,192 121.02 1,206 121.04 1,220 121.06 1,234 Elevation (feet) Storage (cubic-feet) 121.08 1,247 121.10 1,260 121.12 1,272 121.14 1,284 121.16 1,296 121.18 1,307 121.20 1,318 121.22 1,328 121.24 1,338 121.26 1,348 121.28 1,357 121.30 1,366 121.32 1,375 121.34 1,383 121.36 1,391 121.38 1,398 121.40 1,406 121.42 1,412 121.44 1,419 121.46 1,425 121.48 1,430 121.50 1,436 121.52 1,441 121.54 1,445 121.56 1,450 121.58 1,454 121.60 1,458 121.62 1,461 121.64 1,464 121.66 1,467 121.68 1,470 121.70 1,472 121.72 1,474 121.74 1,476 121.76 1,477 121.78 1,479 121.80 1,480 121.82 1,481 121.84 1,482 121.86 1,482 121.88 1,482 121.90 1,483 121.92 1,483 121.94 1,483 Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 31HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S2: Subsurface Recharge Trench System #1 [82] Warning: Early inflow requires earlier time span Inflow Area = 0.305 ac, 78.07% Impervious, Inflow Depth > 2.01" for NoHo-02 event Inflow = 0.72 cfs @ 12.09 hrs, Volume= 0.051 af Outflow = 0.15 cfs @ 11.80 hrs, Volume= 0.051 af, Atten= 79%, Lag= 0.0 min Discarded = 0.15 cfs @ 11.80 hrs, Volume= 0.051 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 131.08' @ 12.52 hrs Surf.Area= 1,033 sf Storage= 571 cf Plug-Flow detention time= 22.6 min calculated for 0.051 af (100% of inflow) Center-of-Mass det. time= 22.3 min ( 787.3 - 765.0 ) Volume Invert Avail.Storage Storage Description #1A 129.70' 976 cf 16.67'W x 62.00'L x 3.50'H Field A 3,617 cf Overall - 1,176 cf Embedded = 2,440 cf x 40.0% Voids #2A 130.70' 930 cf ADS N-12 24" x 15 Inside #1 Inside= 23.8"W x 23.8"H => 3.10 sf x 20.00'L = 62.0 cf Outside= 28.0"W x 28.0"H => 3.92 sf x 20.00'L = 78.4 cf 15 Chambers in 5 Rows 1,906 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 129.70'6.250 in/hr Exfiltration over Surface area #2 Primary 133.00'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.15 cfs @ 11.80 hrs HW=129.75' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=129.70' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 32HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S2: Subsurface Recharge Trench System #1 - Chamber Wizard Field A Chamber Model = ADS N-12 24" (ADS N-12® Pipe) Inside= 23.8"W x 23.8"H => 3.10 sf x 20.00'L = 62.0 cf Outside= 28.0"W x 28.0"H => 3.92 sf x 20.00'L = 78.4 cf 28.0" Wide + 12.0" Spacing = 40.0" C-C Row Spacing 3 Chambers/Row x 20.00' Long = 60.00' Row Length +12.0" End Stone x 2 = 62.00' Base Length 5 Rows x 28.0" Wide + 12.0" Spacing x 4 + 6.0" Side Stone x 2 = 16.67' Base Width 12.0" Base + 28.0" Chamber Height + 2.0" Cover = 3.50' Field Height 15 Chambers x 62.0 cf = 930.0 cf Chamber Storage 15 Chambers x 78.4 cf = 1,175.9 cf Displacement 3,616.8 cf Field - 1,175.9 cf Chambers = 2,440.9 cf Stone x 40.0% Voids = 976.4 cf Stone Storage Chamber Storage + Stone Storage = 1,906.4 cf = 0.044 af Overall Storage Efficiency = 52.7% Overall System Size = 62.00' x 16.67' x 3.50' 15 Chambers 134.0 cy Field 90.4 cy Stone Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 33HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S2: Subsurface Recharge Trench System #1 Inflow Outflow Discarded Primary Hydrograph Time (hours) 201918171615141312111098765Flow (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 Inflow Area=0.305 ac Peak Elev=131.08' Storage=571 cf 0.72 cfs 0.15 cfs 0.15 cfs 0.00 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 34HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S2: Subsurface Recharge Trench System #1 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 129.70 1,033 0 129.75 1,033 21 129.80 1,033 41 129.85 1,033 62 129.90 1,033 83 129.95 1,033 103 130.00 1,033 124 130.05 1,033 145 130.10 1,033 165 130.15 1,033 186 130.20 1,033 207 130.25 1,033 227 130.30 1,033 248 130.35 1,033 269 130.40 1,033 289 130.45 1,033 310 130.50 1,033 331 130.55 1,033 351 130.60 1,033 372 130.65 1,033 393 130.70 1,033 413 130.75 1,033 432 130.80 1,033 448 130.85 1,033 463 130.90 1,033 479 130.95 1,033 501 131.00 1,033 527 131.05 1,033 554 131.10 1,033 584 131.15 1,033 614 131.20 1,033 646 131.25 1,033 679 131.30 1,033 712 131.35 1,033 746 131.40 1,033 781 131.45 1,033 817 131.50 1,033 853 131.55 1,033 889 131.60 1,033 926 131.65 1,033 963 131.70 1,033 1,000 131.75 1,033 1,038 131.80 1,033 1,075 131.85 1,033 1,113 131.90 1,033 1,150 131.95 1,033 1,188 132.00 1,033 1,225 132.05 1,033 1,263 132.10 1,033 1,300 132.15 1,033 1,337 132.20 1,033 1,374 132.25 1,033 1,410 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 132.30 1,033 1,446 132.35 1,033 1,481 132.40 1,033 1,516 132.45 1,033 1,550 132.50 1,033 1,583 132.55 1,033 1,615 132.60 1,033 1,647 132.65 1,033 1,677 132.70 1,033 1,705 132.75 1,033 1,732 132.80 1,033 1,757 132.85 1,033 1,778 132.90 1,033 1,793 132.95 1,033 1,808 133.00 1,033 1,825 133.05 1,033 1,844 133.10 1,033 1,865 133.15 1,033 1,885 133.20 1,033 1,906 Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 35HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S3: Subsurface Recharge Trench System #2 [92] Warning: Device #2 is above defined storage Inflow Area = 0.181 ac, 57.30% Impervious, Inflow Depth > 1.39" for NoHo-02 event Inflow = 0.31 cfs @ 12.09 hrs, Volume= 0.021 af Outflow = 0.06 cfs @ 11.85 hrs, Volume= 0.021 af, Atten= 80%, Lag= 0.0 min Discarded = 0.06 cfs @ 11.85 hrs, Volume= 0.021 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 134.00' @ 12.56 hrs Surf.Area= 712 sf Storage= 255 cf Plug-Flow detention time= 27.7 min calculated for 0.021 af (100% of inflow) Center-of-Mass det. time= 27.3 min ( 826.6 - 799.2 ) Volume Invert Avail.Storage Storage Description #1A 133.10' 585 cf 3.21'W x 222.00'L x 2.38'H Field A 1,692 cf Overall - 230 cf Embedded = 1,462 cf x 40.0% Voids #2A 134.10' 178 cf ADS N-12 12" x 11 Inside #1 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 763 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 133.10'3.750 in/hr Exfiltration over Surface area #2 Primary 135.70'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.06 cfs @ 11.85 hrs HW=133.14' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=133.10' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 36HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S3: Subsurface Recharge Trench System #2 - Chamber Wizard Field A Chamber Model = ADS N-12 12" (ADS N-12® Pipe) Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 11 Chambers/Row x 20.00' Long = 220.00' Row Length +12.0" End Stone x 2 = 222.00' Base Length 1 Rows x 14.5" Wide + 12.0" Side Stone x 2 = 3.21' Base Width 12.0" Base + 14.5" Chamber Height + 2.0" Cover = 2.38' Field Height 11 Chambers x 16.2 cf = 178.2 cf Chamber Storage 11 Chambers x 20.9 cf = 230.3 cf Displacement 1,692.3 cf Field - 230.3 cf Chambers = 1,462.0 cf Stone x 40.0% Voids = 584.8 cf Stone Storage Chamber Storage + Stone Storage = 763.0 cf = 0.018 af Overall Storage Efficiency = 45.1% Overall System Size = 222.00' x 3.21' x 2.38' 11 Chambers 62.7 cy Field 54.1 cy Stone Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 37HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S3: Subsurface Recharge Trench System #2 Inflow Outflow Discarded Primary Hydrograph Time (hours) 201918171615141312111098765Flow (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 Inflow Area=0.181 ac Peak Elev=134.00' Storage=255 cf 0.31 cfs 0.06 cfs 0.06 cfs 0.00 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 38HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S3: Subsurface Recharge Trench System #2 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 133.10 712 0 133.15 712 14 133.20 712 28 133.25 712 43 133.30 712 57 133.35 712 71 133.40 712 85 133.45 712 100 133.50 712 114 133.55 712 128 133.60 712 142 133.65 712 157 133.70 712 171 133.75 712 185 133.80 712 199 133.85 712 214 133.90 712 228 133.95 712 242 134.00 712 256 134.05 712 271 134.10 712 285 134.15 712 298 134.20 712 310 134.25 712 325 134.30 712 341 134.35 712 359 134.40 712 378 134.45 712 397 134.50 712 417 134.55 712 437 134.60 712 457 134.65 712 478 134.70 712 498 134.75 712 519 134.80 712 539 134.85 712 560 134.90 712 580 134.95 712 600 135.00 712 619 135.05 712 638 135.10 712 656 135.15 712 673 135.20 712 688 135.25 712 700 135.30 712 713 135.35 712 727 135.40 712 741 135.45 712 756 135.50 712 763 135.55 712 763 135.60 712 763 135.65 712 763 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 135.70 712 763 Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 39HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x1000: Hawley Street Top Inflow Area = 0.589 ac, 81.25% Impervious, Inflow Depth > 2.23" for NoHo-02 event Inflow = 1.20 cfs @ 12.15 hrs, Volume= 0.109 af Primary = 1.20 cfs @ 12.15 hrs, Volume= 0.109 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x1000: Hawley Street Top Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.589 ac 1.20 cfs 1.20 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 40HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x2000: Hawley Street Bottom Inflow Area = 0.571 ac, 44.87% Impervious, Inflow Depth > 1.25" for NoHo-02 event Inflow = 0.60 cfs @ 12.11 hrs, Volume= 0.060 af Primary = 0.60 cfs @ 12.11 hrs, Volume= 0.060 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x2000: Hawley Street Bottom Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (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=0.571 ac 0.60 cfs 0.60 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 41HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x3000: Off-Site South Inflow Area = 0.013 ac, 0.00% Impervious, Inflow Depth > 0.37" for NoHo-02 event Inflow = 0.00 cfs @ 12.13 hrs, Volume= 0.000 af Primary = 0.00 cfs @ 12.13 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x3000: Off-Site South Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 Inflow Area=0.013 ac 0.00 cfs 0.00 cfs Type III 24-hr NoHo-02 Rainfall=3.15"42540-PR Printed 10/31/2019Prepared by VHB Page 42HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x4000: Phillips Place Inflow Area = 0.720 ac, 73.20% Impervious, Inflow Depth > 0.65" for NoHo-02 event Inflow = 0.56 cfs @ 12.09 hrs, Volume= 0.039 af Primary = 0.56 cfs @ 12.09 hrs, Volume= 0.039 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x4000: Phillips Place Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (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=0.720 ac 0.56 cfs 0.56 cfs Appendix J: Hydrologic Analysis 10-Year Storm Event- Proposed 100 Drainage Area 100 150 Drainage Area 150 200 Drainage Area 200 300 Drainage Area 300 400 Drainage Area 400 450 Drainage Area 450 500 Drainage Area 500 600 Drainage Area 600 700 Drainage Area 700 750 Drainage Area 750 800 Drainage Area 800 12"(1) 12" Overflow Pipe 12"(2) 12" Overflow Pipe15" 15" Overflow Pipe S1 Subsurface Storage System #1 S2 Subsurface Recharge Trench System #1 S3 Subsurface Recharge Trench System #2 x1000 Hawley Street Top x2000 Hawley Street Bottom x3000 Off-Site South x4000 Phillips Place Routing Diagram for 42540-PR Prepared by VHB, Printed 10/31/2019 HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link 42540-PR Printed 10/31/2019Prepared by VHB Page 2HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Project Notes Rainfall events imported from "Northampton MA.hcp" 42540-PR Printed 10/31/2019Prepared by VHB Page 3HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.632 61 >75% Grass cover, Good, HSG B (100, 150, 300, 500, 600, 700, 750, 800) 0.050 98 Paved parking, HSG B (800) 0.956 98 Paving and Roofs, HSG B (100, 400, 450, 600, 700, 750) 0.152 98 Roofs, HSG B (200) 0.104 98 Walks, HSG B (300) 1.893 86 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 4HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 1.893 HSG B 100, 150, 200, 300, 400, 450, 500, 600, 700, 750, 800 0.000 HSG C 0.000 HSG D 0.000 Other 1.893 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 5HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.632 0.000 0.000 0.000 0.632 >75% Grass cover, Good 100, 150, 300, 500, 600, 700, 750, 800 0.000 0.050 0.000 0.000 0.000 0.050 Paved parking 800 0.000 0.956 0.000 0.000 0.000 0.956 Paving and Roofs 100, 400, 450, 600, 700, 750 0.000 0.152 0.000 0.000 0.000 0.152 Roofs 200 0.000 0.104 0.000 0.000 0.000 0.104 Walks 300 0.000 1.893 0.000 0.000 0.000 1.893 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 6HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Diam/Width (inches) Height (inches) Inside-Fill (inches) 1 12"(1) 130.50 130.30 34.0 0.0059 0.013 12.0 0.0 0.0 2 12"(2) 133.50 133.20 45.0 0.0067 0.013 12.0 0.0 0.0 3 15" 118.90 118.80 19.0 0.0053 0.020 15.0 0.0 0.0 Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 7HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=19,086 sf 91.70% Impervious Runoff Depth>4.07"Subcatchment 100: Drainage Area 100 Tc=6.0 min CN=95 Runoff=1.99 cfs 0.149 af Runoff Area=3,227 sf 0.00% Impervious Runoff Depth>1.18"Subcatchment 150: Drainage Area 150 Tc=6.0 min CN=61 Runoff=0.10 cfs 0.007 af Runoff Area=6,628 sf 100.00% Impervious Runoff Depth>4.33"Subcatchment 200: Drainage Area 200 Tc=6.0 min CN=98 Runoff=0.71 cfs 0.055 af Runoff Area=18,250 sf 24.85% Impervious Runoff Depth>1.80"Subcatchment 300: Drainage Area 300 Flow Length=336' Tc=15.6 min CN=70 Runoff=0.70 cfs 0.063 af Runoff Area=3,345 sf 100.00% Impervious Runoff Depth>4.33"Subcatchment 400: Drainage Area 400 Tc=6.0 min CN=98 Runoff=0.36 cfs 0.028 af Runoff Area=4,888 sf 100.00% Impervious Runoff Depth>4.33"Subcatchment 450: Drainage Area 450 Tc=6.0 min CN=98 Runoff=0.53 cfs 0.040 af Runoff Area=588 sf 0.00% Impervious Runoff Depth>1.18"Subcatchment 500: Drainage Area 500 Tc=6.0 min CN=61 Runoff=0.02 cfs 0.001 af Runoff Area=8,414 sf 65.33% Impervious Runoff Depth>3.08"Subcatchment 600: Drainage Area 600 Tc=6.0 min CN=85 Runoff=0.72 cfs 0.050 af Runoff Area=7,449 sf 79.04% Impervious Runoff Depth>3.57"Subcatchment 700: Drainage Area 700 Tc=6.0 min CN=90 Runoff=0.72 cfs 0.051 af Runoff Area=7,879 sf 57.30% Impervious Runoff Depth>2.80"Subcatchment 750: Drainage Area 750 Tc=6.0 min CN=82 Runoff=0.62 cfs 0.042 af Runoff Area=2,720 sf 79.37% Impervious Runoff Depth>3.57"Subcatchment 800: Drainage Area 800 Tc=6.0 min CN=90 Runoff=0.26 cfs 0.019 af Avg. Flow Depth=0.00' Max Vel=0.00 fps Inflow=0.00 cfs 0.000 afReach 12"(1): 12" Overflow Pipe 12.0" Round Pipe n=0.013 L=34.0' S=0.0059 '/' Capacity=2.73 cfs Outflow=0.00 cfs 0.000 af Avg. Flow Depth=0.00' Max Vel=0.00 fps Inflow=0.00 cfs 0.000 afReach 12"(2): 12" Overflow Pipe 12.0" Round Pipe n=0.013 L=45.0' S=0.0067 '/' Capacity=2.91 cfs Outflow=0.00 cfs 0.000 af Avg. Flow Depth=0.65' Max Vel=2.51 fps Inflow=1.61 cfs 0.176 afReach 15": 15" Overflow Pipe 15.0" Round Pipe n=0.020 L=19.0' S=0.0053 '/' Capacity=3.05 cfs Outflow=1.61 cfs 0.176 af Peak Elev=120.26' Storage=547 cf Inflow=2.35 cfs 0.176 afPond S1: Subsurface Storage System #1 Primary=1.61 cfs 0.176 af Secondary=0.00 cfs 0.000 af Outflow=1.61 cfs 0.176 af Peak Elev=132.17' Storage=1,355 cf Inflow=1.24 cfs 0.090 afPond S2: Subsurface Recharge Trench Discarded=0.15 cfs 0.090 af Primary=0.00 cfs 0.000 af Outflow=0.15 cfs 0.090 af Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 8HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Peak Elev=135.35' Storage=726 cf Inflow=0.62 cfs 0.042 afPond S3: Subsurface Recharge Trench Discarded=0.06 cfs 0.042 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.042 af Inflow=1.69 cfs 0.183 afLink x1000: Hawley Street Top Primary=1.69 cfs 0.183 af Inflow=1.19 cfs 0.118 afLink x2000: Hawley Street Bottom Primary=1.19 cfs 0.118 af Inflow=0.02 cfs 0.001 afLink x3000: Off-Site South Primary=0.02 cfs 0.001 af Inflow=0.98 cfs 0.069 afLink x4000: Phillips Place Primary=0.98 cfs 0.069 af Total Runoff Area = 1.893 ac Runoff Volume = 0.504 af Average Runoff Depth = 3.20" 33.36% Pervious = 0.632 ac 66.64% Impervious = 1.262 ac Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 9HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 100: Drainage Area 100 Runoff = 1.99 cfs @ 12.09 hrs, Volume= 0.149 af, Depth> 4.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 1,584 61 >75% Grass cover, Good, HSG B * 17,502 98 Paving and Roofs, HSG B 19,086 95 Weighted Average 1,584 8.30% Pervious Area 17,502 91.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 100: Drainage Area 100 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Type III 24-hr NoHo-10 Rainfall=4.90" Runoff Area=19,086 sf Runoff Volume=0.149 af Runoff Depth>4.07" Tc=6.0 min CN=95 1.99 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 10HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 150: Drainage Area 150 Runoff = 0.10 cfs @ 12.10 hrs, Volume= 0.007 af, Depth> 1.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 3,227 61 >75% Grass cover, Good, HSG B 3,227 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 150: Drainage Area 150 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-10 Rainfall=4.90" Runoff Area=3,227 sf Runoff Volume=0.007 af Runoff Depth>1.18" Tc=6.0 min CN=61 0.10 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 11HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 200: Drainage Area 200 Runoff = 0.71 cfs @ 12.09 hrs, Volume= 0.055 af, Depth> 4.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 6,628 98 Roofs, HSG B 6,628 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 200: Drainage Area 200 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=6,628 sf Runoff Volume=0.055 af Runoff Depth>4.33" Tc=6.0 min CN=98 0.71 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 12HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 300: Drainage Area 300 Runoff = 0.70 cfs @ 12.22 hrs, Volume= 0.063 af, Depth> 1.80" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 13,714 61 >75% Grass cover, Good, HSG B * 4,536 98 Walks, HSG B 18,250 70 Weighted Average 13,714 75.15% Pervious Area 4,536 24.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.8 100 0.0270 0.19 Sheet Flow, First 100 feet of grass Grass: Short n= 0.150 P2= 3.15" 0.7 50 0.0270 1.15 Shallow Concentrated Flow, Next 50 feet of grass Short Grass Pasture Kv= 7.0 fps 5.4 160 0.0050 0.49 Shallow Concentrated Flow, Next 160 feet of grass Short Grass Pasture Kv= 7.0 fps 0.7 20 0.0050 0.49 Shallow Concentrated Flow, Next 20 feet of grass Short Grass Pasture Kv= 7.0 fps 0.0 6 0.5000 4.95 Shallow Concentrated Flow, Last 6 feet of grass Short Grass Pasture Kv= 7.0 fps 15.6 336 Total Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 13HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcatchment 300: Drainage Area 300 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=18,250 sf Runoff Volume=0.063 af Runoff Depth>1.80" Flow Length=336' Tc=15.6 min CN=70 0.70 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 14HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 400: Drainage Area 400 Runoff = 0.36 cfs @ 12.09 hrs, Volume= 0.028 af, Depth> 4.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description * 3,345 98 Paving and Roofs, HSG B 3,345 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 400: Drainage Area 400 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-10 Rainfall=4.90" Runoff Area=3,345 sf Runoff Volume=0.028 af Runoff Depth>4.33" Tc=6.0 min CN=98 0.36 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 15HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 450: Drainage Area 450 Runoff = 0.53 cfs @ 12.09 hrs, Volume= 0.040 af, Depth> 4.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description * 4,888 98 Paving and Roofs, HSG B 4,888 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 450: Drainage Area 450 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=4,888 sf Runoff Volume=0.040 af Runoff Depth>4.33" Tc=6.0 min CN=98 0.53 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 16HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 500: Drainage Area 500 Runoff = 0.02 cfs @ 12.10 hrs, Volume= 0.001 af, Depth> 1.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 588 61 >75% Grass cover, Good, HSG B 588 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 500: Drainage Area 500 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-10 Rainfall=4.90" Runoff Area=588 sf Runoff Volume=0.001 af Runoff Depth>1.18" Tc=6.0 min CN=61 0.02 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 17HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 600: Drainage Area 600 Runoff = 0.72 cfs @ 12.09 hrs, Volume= 0.050 af, Depth> 3.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 2,917 61 >75% Grass cover, Good, HSG B * 5,497 98 Paving and Roofs, HSG B 8,414 85 Weighted Average 2,917 34.67% Pervious Area 5,497 65.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 600: Drainage Area 600 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=8,414 sf Runoff Volume=0.050 af Runoff Depth>3.08" Tc=6.0 min CN=85 0.72 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 18HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 700: Drainage Area 700 Runoff = 0.72 cfs @ 12.09 hrs, Volume= 0.051 af, Depth> 3.57" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 1,561 61 >75% Grass cover, Good, HSG B * 5,888 98 Paving and Roofs, HSG B 7,449 90 Weighted Average 1,561 20.96% Pervious Area 5,888 79.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 700: Drainage Area 700 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=7,449 sf Runoff Volume=0.051 af Runoff Depth>3.57" Tc=6.0 min CN=90 0.72 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 19HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 750: Drainage Area 750 Runoff = 0.62 cfs @ 12.09 hrs, Volume= 0.042 af, Depth> 2.80" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 3,364 61 >75% Grass cover, Good, HSG B * 4,515 98 Paving and Roofs, HSG B 7,879 82 Weighted Average 3,364 42.70% Pervious Area 4,515 57.30% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 750: Drainage Area 750 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=7,879 sf Runoff Volume=0.042 af Runoff Depth>2.80" Tc=6.0 min CN=82 0.62 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 20HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 800: Drainage Area 800 Runoff = 0.26 cfs @ 12.09 hrs, Volume= 0.019 af, Depth> 3.57" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-10 Rainfall=4.90" Area (sf) CN Description 561 61 >75% Grass cover, Good, HSG B 2,159 98 Paved parking, HSG B 2,720 90 Weighted Average 561 20.62% Pervious Area 2,159 79.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 800: Drainage Area 800 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-10 Rainfall=4.90" Runoff Area=2,720 sf Runoff Volume=0.019 af Runoff Depth>3.57" Tc=6.0 min CN=90 0.26 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 21HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 12"(1): 12" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 0.305 ac, 78.07% Impervious, Inflow Depth = 0.00" for NoHo-10 event Inflow = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Outflow = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.00 fps, Min. Travel Time= 0.0 min Avg. Velocity = 0.00 fps, Avg. Travel Time= 0.0 min Peak Storage= 0 cf @ 5.00 hrs Average Depth at Peak Storage= 0.00' Bank-Full Depth= 1.00' Flow Area= 0.8 sf, Capacity= 2.73 cfs 12.0" Round Pipe n= 0.013 Corrugated PE, smooth interior Length= 34.0' Slope= 0.0059 '/' Inlet Invert= 130.50', Outlet Invert= 130.30' Reach 12"(1): 12" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.305 ac Avg. Flow Depth=0.00' Max Vel=0.00 fps 12.0" Round Pipe n=0.013 L=34.0' S=0.0059 '/' Capacity=2.73 cfs 0.00 cfs 0.00 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 22HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 12"(1): 12" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 130.50 0.0 0 130.51 0.0 0 130.52 0.0 0 130.53 0.0 0 130.54 0.0 0 130.55 0.0 0 130.56 0.0 1 130.57 0.0 1 130.58 0.0 1 130.59 0.0 1 130.60 0.0 1 130.61 0.0 2 130.62 0.1 2 130.63 0.1 2 130.64 0.1 2 130.65 0.1 3 130.66 0.1 3 130.67 0.1 3 130.68 0.1 3 130.69 0.1 4 130.70 0.1 4 130.71 0.1 4 130.72 0.1 4 130.73 0.1 5 130.74 0.1 5 130.75 0.2 5 130.76 0.2 6 130.77 0.2 6 130.78 0.2 6 130.79 0.2 6 130.80 0.2 7 130.81 0.2 7 130.82 0.2 7 130.83 0.2 8 130.84 0.2 8 130.85 0.2 8 130.86 0.3 9 130.87 0.3 9 130.88 0.3 9 130.89 0.3 10 130.90 0.3 10 130.91 0.3 10 130.92 0.3 11 130.93 0.3 11 130.94 0.3 11 130.95 0.3 12 130.96 0.4 12 130.97 0.4 12 130.98 0.4 13 130.99 0.4 13 131.00 0.4 13 131.01 0.4 14 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 131.02 0.4 14 131.03 0.4 14 131.04 0.4 15 131.05 0.4 15 131.06 0.5 15 131.07 0.5 16 131.08 0.5 16 131.09 0.5 16 131.10 0.5 17 131.11 0.5 17 131.12 0.5 17 131.13 0.5 18 131.14 0.5 18 131.15 0.5 18 131.16 0.5 19 131.17 0.6 19 131.18 0.6 19 131.19 0.6 20 131.20 0.6 20 131.21 0.6 20 131.22 0.6 21 131.23 0.6 21 131.24 0.6 21 131.25 0.6 21 131.26 0.6 22 131.27 0.6 22 131.28 0.7 22 131.29 0.7 23 131.30 0.7 23 131.31 0.7 23 131.32 0.7 23 131.33 0.7 24 131.34 0.7 24 131.35 0.7 24 131.36 0.7 24 131.37 0.7 25 131.38 0.7 25 131.39 0.7 25 131.40 0.7 25 131.41 0.8 26 131.42 0.8 26 131.43 0.8 26 131.44 0.8 26 131.45 0.8 26 131.46 0.8 26 131.47 0.8 26 131.48 0.8 27 131.49 0.8 27 131.50 0.8 27 Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 23HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 12"(2): 12" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 0.181 ac, 57.30% Impervious, Inflow Depth = 0.00" for NoHo-10 event Inflow = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Outflow = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.00 fps, Min. Travel Time= 0.0 min Avg. Velocity = 0.00 fps, Avg. Travel Time= 0.0 min Peak Storage= 0 cf @ 5.00 hrs Average Depth at Peak Storage= 0.00' Bank-Full Depth= 1.00' Flow Area= 0.8 sf, Capacity= 2.91 cfs 12.0" Round Pipe n= 0.013 Corrugated PE, smooth interior Length= 45.0' Slope= 0.0067 '/' Inlet Invert= 133.50', Outlet Invert= 133.20' Reach 12"(2): 12" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.181 ac Avg. Flow Depth=0.00' Max Vel=0.00 fps 12.0" Round Pipe n=0.013 L=45.0' S=0.0067 '/' Capacity=2.91 cfs 0.00 cfs 0.00 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 24HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 12"(2): 12" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 133.50 0.0 0 133.51 0.0 0 133.52 0.0 0 133.53 0.0 0 133.54 0.0 0 133.55 0.0 1 133.56 0.0 1 133.57 0.0 1 133.58 0.0 1 133.59 0.0 2 133.60 0.0 2 133.61 0.0 2 133.62 0.1 2 133.63 0.1 3 133.64 0.1 3 133.65 0.1 3 133.66 0.1 4 133.67 0.1 4 133.68 0.1 4 133.69 0.1 5 133.70 0.1 5 133.71 0.1 5 133.72 0.1 6 133.73 0.1 6 133.74 0.1 7 133.75 0.2 7 133.76 0.2 7 133.77 0.2 8 133.78 0.2 8 133.79 0.2 9 133.80 0.2 9 133.81 0.2 9 133.82 0.2 10 133.83 0.2 10 133.84 0.2 11 133.85 0.2 11 133.86 0.3 11 133.87 0.3 12 133.88 0.3 12 133.89 0.3 13 133.90 0.3 13 133.91 0.3 14 133.92 0.3 14 133.93 0.3 15 133.94 0.3 15 133.95 0.3 15 133.96 0.4 16 133.97 0.4 16 133.98 0.4 17 133.99 0.4 17 134.00 0.4 18 134.01 0.4 18 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 134.02 0.4 19 134.03 0.4 19 134.04 0.4 19 134.05 0.4 20 134.06 0.5 20 134.07 0.5 21 134.08 0.5 21 134.09 0.5 22 134.10 0.5 22 134.11 0.5 23 134.12 0.5 23 134.13 0.5 23 134.14 0.5 24 134.15 0.5 24 134.16 0.5 25 134.17 0.6 25 134.18 0.6 26 134.19 0.6 26 134.20 0.6 26 134.21 0.6 27 134.22 0.6 27 134.23 0.6 28 134.24 0.6 28 134.25 0.6 28 134.26 0.6 29 134.27 0.6 29 134.28 0.7 30 134.29 0.7 30 134.30 0.7 30 134.31 0.7 31 134.32 0.7 31 134.33 0.7 31 134.34 0.7 32 134.35 0.7 32 134.36 0.7 32 134.37 0.7 33 134.38 0.7 33 134.39 0.7 33 134.40 0.7 34 134.41 0.8 34 134.42 0.8 34 134.43 0.8 34 134.44 0.8 34 134.45 0.8 35 134.46 0.8 35 134.47 0.8 35 134.48 0.8 35 134.49 0.8 35 134.50 0.8 35 Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 25HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 15": 15" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated [82] Warning: Early inflow requires earlier time span [79] Warning: Submerged Pond S1 Primary device # 1 by 0.54' Inflow Area = 0.515 ac, 92.94% Impervious, Inflow Depth > 4.11" for NoHo-10 event Inflow = 1.61 cfs @ 12.17 hrs, Volume= 0.176 af Outflow = 1.61 cfs @ 12.18 hrs, Volume= 0.176 af, Atten= 0%, Lag= 0.3 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.51 fps, Min. Travel Time= 0.1 min Avg. Velocity = 1.10 fps, Avg. Travel Time= 0.3 min Peak Storage= 12 cf @ 12.18 hrs Average Depth at Peak Storage= 0.65' Bank-Full Depth= 1.25' Flow Area= 1.2 sf, Capacity= 3.05 cfs 15.0" Round Pipe n= 0.020 Corrugated PE, corrugated interior Length= 19.0' Slope= 0.0053 '/' Inlet Invert= 118.90', Outlet Invert= 118.80' Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 26HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Reach 15": 15" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.515 ac Avg. Flow Depth=0.65' Max Vel=2.51 fps 15.0" Round Pipe n=0.020 L=19.0' S=0.0053 '/' Capacity=3.05 cfs 1.61 cfs 1.61 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 27HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 15": 15" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 118.90 0.0 0 118.92 0.0 0 118.94 0.0 0 118.96 0.0 0 118.98 0.0 1 119.00 0.0 1 119.02 0.1 1 119.04 0.1 1 119.06 0.1 2 119.08 0.1 2 119.10 0.1 2 119.12 0.1 3 119.14 0.2 3 119.16 0.2 4 119.18 0.2 4 119.20 0.2 4 119.22 0.2 5 119.24 0.3 5 119.26 0.3 6 119.28 0.3 6 119.30 0.3 6 119.32 0.4 7 119.34 0.4 7 119.36 0.4 8 119.38 0.4 8 119.40 0.5 9 119.42 0.5 9 119.44 0.5 10 119.46 0.5 10 119.48 0.6 11 119.50 0.6 11 119.52 0.6 12 119.54 0.6 12 119.56 0.7 12 119.58 0.7 13 119.60 0.7 13 119.62 0.7 14 119.64 0.8 14 119.66 0.8 15 119.68 0.8 15 119.70 0.8 16 119.72 0.9 16 119.74 0.9 17 119.76 0.9 17 119.78 0.9 18 119.80 0.9 18 119.82 1.0 18 119.84 1.0 19 119.86 1.0 19 119.88 1.0 20 119.90 1.1 20 119.92 1.1 20 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 119.94 1.1 21 119.96 1.1 21 119.98 1.1 21 120.00 1.1 22 120.02 1.2 22 120.04 1.2 22 120.06 1.2 23 120.08 1.2 23 120.10 1.2 23 120.12 1.2 23 120.14 1.2 23 Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 28HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S1: Subsurface Storage System #1 [82] Warning: Early inflow requires earlier time span Inflow Area = 0.515 ac, 92.94% Impervious, Inflow Depth > 4.11" for NoHo-10 event Inflow = 2.35 cfs @ 12.09 hrs, Volume= 0.176 af Outflow = 1.61 cfs @ 12.17 hrs, Volume= 0.176 af, Atten= 31%, Lag= 5.3 min Primary = 1.61 cfs @ 12.17 hrs, Volume= 0.176 af Secondary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 120.26' @ 12.17 hrs Surf.Area= 882 sf Storage= 547 cf Plug-Flow detention time= 2.1 min calculated for 0.176 af (100% of inflow) Center-of-Mass det. time= 1.9 min ( 745.6 - 743.7 ) Volume Invert Avail.Storage Storage Description #1 119.00' 1,483 cf 24.0" Round Pipe Storage L= 472.0' S= 0.0020 '/' Device Routing Invert Outlet Devices #1 Primary 119.00'8.0" Vert. Orifice/Grate C= 0.600 #2 Secondary 121.20'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Primary OutFlow Max=1.60 cfs @ 12.17 hrs HW=120.24' (Free Discharge) 1=Orifice/Grate (Orifice Controls 1.60 cfs @ 4.59 fps) Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=119.06' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 29HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S1: Subsurface Storage System #1 Inflow Outflow Primary Secondary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.515 ac Peak Elev=120.26' Storage=547 cf 2.35 cfs 1.61 cfs 1.61 cfs 0.00 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 30HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S1: Subsurface Storage System #1 Elevation (feet) Storage (cubic-feet) 119.00 0 119.02 0 119.04 0 119.06 0 119.08 1 119.10 1 119.12 2 119.14 3 119.16 4 119.18 5 119.20 7 119.22 8 119.24 10 119.26 13 119.28 15 119.30 18 119.32 21 119.34 24 119.36 28 119.38 32 119.40 36 119.42 41 119.44 46 119.46 51 119.48 57 119.50 63 119.52 69 119.54 76 119.56 83 119.58 90 119.60 98 119.62 106 119.64 115 119.66 124 119.68 133 119.70 142 119.72 152 119.74 163 119.76 173 119.78 185 119.80 196 119.82 208 119.84 220 119.86 233 119.88 246 119.90 260 119.92 274 119.94 288 119.96 303 119.98 318 120.00 333 120.02 349 Elevation (feet) Storage (cubic-feet) 120.04 364 120.06 381 120.08 397 120.10 413 120.12 430 120.14 447 120.16 464 120.18 481 120.20 498 120.22 516 120.24 533 120.26 551 120.28 568 120.30 586 120.32 604 120.34 622 120.36 640 120.38 658 120.40 676 120.42 694 120.44 712 120.46 731 120.48 749 120.50 767 120.52 785 120.54 803 120.56 821 120.58 839 120.60 857 120.62 875 120.64 893 120.66 911 120.68 929 120.70 946 120.72 964 120.74 981 120.76 998 120.78 1,016 120.80 1,033 120.82 1,050 120.84 1,066 120.86 1,083 120.88 1,099 120.90 1,115 120.92 1,131 120.94 1,147 120.96 1,162 120.98 1,177 121.00 1,192 121.02 1,206 121.04 1,220 121.06 1,234 Elevation (feet) Storage (cubic-feet) 121.08 1,247 121.10 1,260 121.12 1,272 121.14 1,284 121.16 1,296 121.18 1,307 121.20 1,318 121.22 1,328 121.24 1,338 121.26 1,348 121.28 1,357 121.30 1,366 121.32 1,375 121.34 1,383 121.36 1,391 121.38 1,398 121.40 1,406 121.42 1,412 121.44 1,419 121.46 1,425 121.48 1,430 121.50 1,436 121.52 1,441 121.54 1,445 121.56 1,450 121.58 1,454 121.60 1,458 121.62 1,461 121.64 1,464 121.66 1,467 121.68 1,470 121.70 1,472 121.72 1,474 121.74 1,476 121.76 1,477 121.78 1,479 121.80 1,480 121.82 1,481 121.84 1,482 121.86 1,482 121.88 1,482 121.90 1,483 121.92 1,483 121.94 1,483 Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 31HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S2: Subsurface Recharge Trench System #1 [82] Warning: Early inflow requires earlier time span Inflow Area = 0.305 ac, 78.07% Impervious, Inflow Depth > 3.54" for NoHo-10 event Inflow = 1.24 cfs @ 12.09 hrs, Volume= 0.090 af Outflow = 0.15 cfs @ 11.65 hrs, Volume= 0.090 af, Atten= 88%, Lag= 0.0 min Discarded = 0.15 cfs @ 11.65 hrs, Volume= 0.090 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 132.17' @ 12.72 hrs Surf.Area= 1,033 sf Storage= 1,355 cf Plug-Flow detention time= 65.8 min calculated for 0.090 af (100% of inflow) Center-of-Mass det. time= 65.5 min ( 823.1 - 757.6 ) Volume Invert Avail.Storage Storage Description #1A 129.70' 976 cf 16.67'W x 62.00'L x 3.50'H Field A 3,617 cf Overall - 1,176 cf Embedded = 2,440 cf x 40.0% Voids #2A 130.70' 930 cf ADS N-12 24" x 15 Inside #1 Inside= 23.8"W x 23.8"H => 3.10 sf x 20.00'L = 62.0 cf Outside= 28.0"W x 28.0"H => 3.92 sf x 20.00'L = 78.4 cf 15 Chambers in 5 Rows 1,906 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 129.70'6.250 in/hr Exfiltration over Surface area #2 Primary 133.00'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.15 cfs @ 11.65 hrs HW=129.75' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=129.70' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 32HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S2: Subsurface Recharge Trench System #1 - Chamber Wizard Field A Chamber Model = ADS N-12 24" (ADS N-12® Pipe) Inside= 23.8"W x 23.8"H => 3.10 sf x 20.00'L = 62.0 cf Outside= 28.0"W x 28.0"H => 3.92 sf x 20.00'L = 78.4 cf 28.0" Wide + 12.0" Spacing = 40.0" C-C Row Spacing 3 Chambers/Row x 20.00' Long = 60.00' Row Length +12.0" End Stone x 2 = 62.00' Base Length 5 Rows x 28.0" Wide + 12.0" Spacing x 4 + 6.0" Side Stone x 2 = 16.67' Base Width 12.0" Base + 28.0" Chamber Height + 2.0" Cover = 3.50' Field Height 15 Chambers x 62.0 cf = 930.0 cf Chamber Storage 15 Chambers x 78.4 cf = 1,175.9 cf Displacement 3,616.8 cf Field - 1,175.9 cf Chambers = 2,440.9 cf Stone x 40.0% Voids = 976.4 cf Stone Storage Chamber Storage + Stone Storage = 1,906.4 cf = 0.044 af Overall Storage Efficiency = 52.7% Overall System Size = 62.00' x 16.67' x 3.50' 15 Chambers 134.0 cy Field 90.4 cy Stone Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 33HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S2: Subsurface Recharge Trench System #1 Inflow Outflow Discarded Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.305 ac Peak Elev=132.17' Storage=1,355 cf 1.24 cfs 0.15 cfs 0.15 cfs 0.00 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 34HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S2: Subsurface Recharge Trench System #1 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 129.70 1,033 0 129.75 1,033 21 129.80 1,033 41 129.85 1,033 62 129.90 1,033 83 129.95 1,033 103 130.00 1,033 124 130.05 1,033 145 130.10 1,033 165 130.15 1,033 186 130.20 1,033 207 130.25 1,033 227 130.30 1,033 248 130.35 1,033 269 130.40 1,033 289 130.45 1,033 310 130.50 1,033 331 130.55 1,033 351 130.60 1,033 372 130.65 1,033 393 130.70 1,033 413 130.75 1,033 432 130.80 1,033 448 130.85 1,033 463 130.90 1,033 479 130.95 1,033 501 131.00 1,033 527 131.05 1,033 554 131.10 1,033 584 131.15 1,033 614 131.20 1,033 646 131.25 1,033 679 131.30 1,033 712 131.35 1,033 746 131.40 1,033 781 131.45 1,033 817 131.50 1,033 853 131.55 1,033 889 131.60 1,033 926 131.65 1,033 963 131.70 1,033 1,000 131.75 1,033 1,038 131.80 1,033 1,075 131.85 1,033 1,113 131.90 1,033 1,150 131.95 1,033 1,188 132.00 1,033 1,225 132.05 1,033 1,263 132.10 1,033 1,300 132.15 1,033 1,337 132.20 1,033 1,374 132.25 1,033 1,410 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 132.30 1,033 1,446 132.35 1,033 1,481 132.40 1,033 1,516 132.45 1,033 1,550 132.50 1,033 1,583 132.55 1,033 1,615 132.60 1,033 1,647 132.65 1,033 1,677 132.70 1,033 1,705 132.75 1,033 1,732 132.80 1,033 1,757 132.85 1,033 1,778 132.90 1,033 1,793 132.95 1,033 1,808 133.00 1,033 1,825 133.05 1,033 1,844 133.10 1,033 1,865 133.15 1,033 1,885 133.20 1,033 1,906 Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 35HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S3: Subsurface Recharge Trench System #2 [92] Warning: Device #2 is above defined storage Inflow Area = 0.181 ac, 57.30% Impervious, Inflow Depth > 2.80" for NoHo-10 event Inflow = 0.62 cfs @ 12.09 hrs, Volume= 0.042 af Outflow = 0.06 cfs @ 11.65 hrs, Volume= 0.042 af, Atten= 90%, Lag= 0.0 min Discarded = 0.06 cfs @ 11.65 hrs, Volume= 0.042 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 135.35' @ 12.98 hrs Surf.Area= 712 sf Storage= 726 cf Plug-Flow detention time= 101.4 min calculated for 0.042 af (100% of inflow) Center-of-Mass det. time= 101.1 min ( 884.3 - 783.2 ) Volume Invert Avail.Storage Storage Description #1A 133.10' 585 cf 3.21'W x 222.00'L x 2.38'H Field A 1,692 cf Overall - 230 cf Embedded = 1,462 cf x 40.0% Voids #2A 134.10' 178 cf ADS N-12 12" x 11 Inside #1 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 763 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 133.10'3.750 in/hr Exfiltration over Surface area #2 Primary 135.70'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.06 cfs @ 11.65 hrs HW=133.13' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=133.10' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 36HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S3: Subsurface Recharge Trench System #2 - Chamber Wizard Field A Chamber Model = ADS N-12 12" (ADS N-12® Pipe) Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 11 Chambers/Row x 20.00' Long = 220.00' Row Length +12.0" End Stone x 2 = 222.00' Base Length 1 Rows x 14.5" Wide + 12.0" Side Stone x 2 = 3.21' Base Width 12.0" Base + 14.5" Chamber Height + 2.0" Cover = 2.38' Field Height 11 Chambers x 16.2 cf = 178.2 cf Chamber Storage 11 Chambers x 20.9 cf = 230.3 cf Displacement 1,692.3 cf Field - 230.3 cf Chambers = 1,462.0 cf Stone x 40.0% Voids = 584.8 cf Stone Storage Chamber Storage + Stone Storage = 763.0 cf = 0.018 af Overall Storage Efficiency = 45.1% Overall System Size = 222.00' x 3.21' x 2.38' 11 Chambers 62.7 cy Field 54.1 cy Stone Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 37HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S3: Subsurface Recharge Trench System #2 Inflow Outflow Discarded Primary Hydrograph Time (hours) 201918171615141312111098765Flow (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=0.181 ac Peak Elev=135.35' Storage=726 cf 0.62 cfs 0.06 cfs 0.06 cfs 0.00 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 38HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S3: Subsurface Recharge Trench System #2 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 133.10 712 0 133.15 712 14 133.20 712 28 133.25 712 43 133.30 712 57 133.35 712 71 133.40 712 85 133.45 712 100 133.50 712 114 133.55 712 128 133.60 712 142 133.65 712 157 133.70 712 171 133.75 712 185 133.80 712 199 133.85 712 214 133.90 712 228 133.95 712 242 134.00 712 256 134.05 712 271 134.10 712 285 134.15 712 298 134.20 712 310 134.25 712 325 134.30 712 341 134.35 712 359 134.40 712 378 134.45 712 397 134.50 712 417 134.55 712 437 134.60 712 457 134.65 712 478 134.70 712 498 134.75 712 519 134.80 712 539 134.85 712 560 134.90 712 580 134.95 712 600 135.00 712 619 135.05 712 638 135.10 712 656 135.15 712 673 135.20 712 688 135.25 712 700 135.30 712 713 135.35 712 727 135.40 712 741 135.45 712 756 135.50 712 763 135.55 712 763 135.60 712 763 135.65 712 763 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 135.70 712 763 Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 39HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x1000: Hawley Street Top Inflow Area = 0.589 ac, 81.25% Impervious, Inflow Depth > 3.74" for NoHo-10 event Inflow = 1.69 cfs @ 12.17 hrs, Volume= 0.183 af Primary = 1.69 cfs @ 12.17 hrs, Volume= 0.183 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x1000: Hawley Street Top Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.589 ac 1.69 cfs 1.69 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 40HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x2000: Hawley Street Bottom Inflow Area = 0.571 ac, 44.87% Impervious, Inflow Depth > 2.47" for NoHo-10 event Inflow = 1.19 cfs @ 12.12 hrs, Volume= 0.118 af Primary = 1.19 cfs @ 12.12 hrs, Volume= 0.118 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x2000: Hawley Street Bottom Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.571 ac 1.19 cfs 1.19 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 41HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x3000: Off-Site South Inflow Area = 0.013 ac, 0.00% Impervious, Inflow Depth > 1.18" for NoHo-10 event Inflow = 0.02 cfs @ 12.10 hrs, Volume= 0.001 af Primary = 0.02 cfs @ 12.10 hrs, Volume= 0.001 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x3000: Off-Site South Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 Inflow Area=0.013 ac 0.02 cfs 0.02 cfs Type III 24-hr NoHo-10 Rainfall=4.90"42540-PR Printed 10/31/2019Prepared by VHB Page 42HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x4000: Phillips Place Inflow Area = 0.720 ac, 73.20% Impervious, Inflow Depth > 1.16" for NoHo-10 event Inflow = 0.98 cfs @ 12.09 hrs, Volume= 0.069 af Primary = 0.98 cfs @ 12.09 hrs, Volume= 0.069 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x4000: Phillips Place Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.720 ac 0.98 cfs 0.98 cfs Appendix J: Hydrologic Analysis 25-Year Storm Event- Proposed 100 Drainage Area 100 150 Drainage Area 150 200 Drainage Area 200 300 Drainage Area 300 400 Drainage Area 400 450 Drainage Area 450 500 Drainage Area 500 600 Drainage Area 600 700 Drainage Area 700 750 Drainage Area 750 800 Drainage Area 800 12"(1) 12" Overflow Pipe 12"(2) 12" Overflow Pipe15" 15" Overflow Pipe S1 Subsurface Storage System #1 S2 Subsurface Recharge Trench System #1 S3 Subsurface Recharge Trench System #2 x1000 Hawley Street Top x2000 Hawley Street Bottom x3000 Off-Site South x4000 Phillips Place Routing Diagram for 42540-PR Prepared by VHB, Printed 10/31/2019 HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link 42540-PR Printed 10/31/2019Prepared by VHB Page 2HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Project Notes Rainfall events imported from "Northampton MA.hcp" 42540-PR Printed 10/31/2019Prepared by VHB Page 3HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.632 61 >75% Grass cover, Good, HSG B (100, 150, 300, 500, 600, 700, 750, 800) 0.050 98 Paved parking, HSG B (800) 0.956 98 Paving and Roofs, HSG B (100, 400, 450, 600, 700, 750) 0.152 98 Roofs, HSG B (200) 0.104 98 Walks, HSG B (300) 1.893 86 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 4HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 1.893 HSG B 100, 150, 200, 300, 400, 450, 500, 600, 700, 750, 800 0.000 HSG C 0.000 HSG D 0.000 Other 1.893 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 5HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.632 0.000 0.000 0.000 0.632 >75% Grass cover, Good 100, 150, 300, 500, 600, 700, 750, 800 0.000 0.050 0.000 0.000 0.000 0.050 Paved parking 800 0.000 0.956 0.000 0.000 0.000 0.956 Paving and Roofs 100, 400, 450, 600, 700, 750 0.000 0.152 0.000 0.000 0.000 0.152 Roofs 200 0.000 0.104 0.000 0.000 0.000 0.104 Walks 300 0.000 1.893 0.000 0.000 0.000 1.893 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 6HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Diam/Width (inches) Height (inches) Inside-Fill (inches) 1 12"(1) 130.50 130.30 34.0 0.0059 0.013 12.0 0.0 0.0 2 12"(2) 133.50 133.20 45.0 0.0067 0.013 12.0 0.0 0.0 3 15" 118.90 118.80 19.0 0.0053 0.020 15.0 0.0 0.0 Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 7HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=19,086 sf 91.70% Impervious Runoff Depth>5.17"Subcatchment 100: Drainage Area 100 Tc=6.0 min CN=95 Runoff=2.51 cfs 0.189 af Runoff Area=3,227 sf 0.00% Impervious Runoff Depth>1.89"Subcatchment 150: Drainage Area 150 Tc=6.0 min CN=61 Runoff=0.17 cfs 0.012 af Runoff Area=6,628 sf 100.00% Impervious Runoff Depth>5.42"Subcatchment 200: Drainage Area 200 Tc=6.0 min CN=98 Runoff=0.89 cfs 0.069 af Runoff Area=18,250 sf 24.85% Impervious Runoff Depth>2.66"Subcatchment 300: Drainage Area 300 Flow Length=336' Tc=15.6 min CN=70 Runoff=1.05 cfs 0.093 af Runoff Area=3,345 sf 100.00% Impervious Runoff Depth>5.42"Subcatchment 400: Drainage Area 400 Tc=6.0 min CN=98 Runoff=0.45 cfs 0.035 af Runoff Area=4,888 sf 100.00% Impervious Runoff Depth>5.42"Subcatchment 450: Drainage Area 450 Tc=6.0 min CN=98 Runoff=0.66 cfs 0.051 af Runoff Area=588 sf 0.00% Impervious Runoff Depth>1.89"Subcatchment 500: Drainage Area 500 Tc=6.0 min CN=61 Runoff=0.03 cfs 0.002 af Runoff Area=8,414 sf 65.33% Impervious Runoff Depth>4.14"Subcatchment 600: Drainage Area 600 Tc=6.0 min CN=85 Runoff=0.95 cfs 0.067 af Runoff Area=7,449 sf 79.04% Impervious Runoff Depth>4.67"Subcatchment 700: Drainage Area 700 Tc=6.0 min CN=90 Runoff=0.92 cfs 0.067 af Runoff Area=7,879 sf 57.30% Impervious Runoff Depth>3.83"Subcatchment 750: Drainage Area 750 Tc=6.0 min CN=82 Runoff=0.84 cfs 0.058 af Runoff Area=2,720 sf 79.37% Impervious Runoff Depth>4.67"Subcatchment 800: Drainage Area 800 Tc=6.0 min CN=90 Runoff=0.34 cfs 0.024 af Avg. Flow Depth=0.19' Max Vel=2.02 fps Inflow=0.23 cfs 0.003 afReach 12"(1): 12" Overflow Pipe 12.0" Round Pipe n=0.013 L=34.0' S=0.0059 '/' Capacity=2.73 cfs Outflow=0.20 cfs 0.003 af Avg. Flow Depth=0.26' Max Vel=2.56 fps Inflow=0.46 cfs 0.008 afReach 12"(2): 12" Overflow Pipe 12.0" Round Pipe n=0.013 L=45.0' S=0.0067 '/' Capacity=2.91 cfs Outflow=0.37 cfs 0.008 af Avg. Flow Depth=0.71' Max Vel=2.61 fps Inflow=1.87 cfs 0.224 afReach 15": 15" Overflow Pipe 15.0" Round Pipe n=0.020 L=19.0' S=0.0053 '/' Capacity=3.05 cfs Outflow=1.87 cfs 0.224 af Peak Elev=120.57' Storage=831 cf Inflow=2.96 cfs 0.224 afPond S1: Subsurface Storage System #1 Primary=1.87 cfs 0.224 af Secondary=0.00 cfs 0.000 af Outflow=1.87 cfs 0.224 af Peak Elev=133.07' Storage=1,851 cf Inflow=1.61 cfs 0.117 afPond S2: Subsurface Recharge Trench Discarded=0.15 cfs 0.114 af Primary=0.23 cfs 0.003 af Outflow=0.38 cfs 0.117 af Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 8HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Peak Elev=135.82' Storage=763 cf Inflow=0.84 cfs 0.058 afPond S3: Subsurface Recharge Trench Discarded=0.06 cfs 0.050 af Primary=0.46 cfs 0.008 af Outflow=0.52 cfs 0.058 af Inflow=2.00 cfs 0.235 afLink x1000: Hawley Street Top Primary=2.00 cfs 0.235 af Inflow=1.62 cfs 0.162 afLink x2000: Hawley Street Bottom Primary=1.62 cfs 0.162 af Inflow=0.03 cfs 0.002 afLink x3000: Off-Site South Primary=0.03 cfs 0.002 af Inflow=1.26 cfs 0.102 afLink x4000: Phillips Place Primary=1.26 cfs 0.102 af Total Runoff Area = 1.893 ac Runoff Volume = 0.665 af Average Runoff Depth = 4.22" 33.36% Pervious = 0.632 ac 66.64% Impervious = 1.262 ac Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 9HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 100: Drainage Area 100 Runoff = 2.51 cfs @ 12.09 hrs, Volume= 0.189 af, Depth> 5.17" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 1,584 61 >75% Grass cover, Good, HSG B * 17,502 98 Paving and Roofs, HSG B 19,086 95 Weighted Average 1,584 8.30% Pervious Area 17,502 91.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 100: Drainage Area 100 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Type III 24-hr NoHo-25 Rainfall=6.10" Runoff Area=19,086 sf Runoff Volume=0.189 af Runoff Depth>5.17" Tc=6.0 min CN=95 2.51 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 10HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 150: Drainage Area 150 Runoff = 0.17 cfs @ 12.10 hrs, Volume= 0.012 af, Depth> 1.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 3,227 61 >75% Grass cover, Good, HSG B 3,227 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 150: Drainage Area 150 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-25 Rainfall=6.10" Runoff Area=3,227 sf Runoff Volume=0.012 af Runoff Depth>1.89" Tc=6.0 min CN=61 0.17 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 11HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 200: Drainage Area 200 Runoff = 0.89 cfs @ 12.09 hrs, Volume= 0.069 af, Depth> 5.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 6,628 98 Roofs, HSG B 6,628 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 200: Drainage Area 200 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr NoHo-25 Rainfall=6.10" Runoff Area=6,628 sf Runoff Volume=0.069 af Runoff Depth>5.42" Tc=6.0 min CN=98 0.89 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 12HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 300: Drainage Area 300 Runoff = 1.05 cfs @ 12.22 hrs, Volume= 0.093 af, Depth> 2.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 13,714 61 >75% Grass cover, Good, HSG B * 4,536 98 Walks, HSG B 18,250 70 Weighted Average 13,714 75.15% Pervious Area 4,536 24.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.8 100 0.0270 0.19 Sheet Flow, First 100 feet of grass Grass: Short n= 0.150 P2= 3.15" 0.7 50 0.0270 1.15 Shallow Concentrated Flow, Next 50 feet of grass Short Grass Pasture Kv= 7.0 fps 5.4 160 0.0050 0.49 Shallow Concentrated Flow, Next 160 feet of grass Short Grass Pasture Kv= 7.0 fps 0.7 20 0.0050 0.49 Shallow Concentrated Flow, Next 20 feet of grass Short Grass Pasture Kv= 7.0 fps 0.0 6 0.5000 4.95 Shallow Concentrated Flow, Last 6 feet of grass Short Grass Pasture Kv= 7.0 fps 15.6 336 Total Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 13HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcatchment 300: Drainage Area 300 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-25 Rainfall=6.10" Runoff Area=18,250 sf Runoff Volume=0.093 af Runoff Depth>2.66" Flow Length=336' Tc=15.6 min CN=70 1.05 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 14HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 400: Drainage Area 400 Runoff = 0.45 cfs @ 12.09 hrs, Volume= 0.035 af, Depth> 5.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description * 3,345 98 Paving and Roofs, HSG B 3,345 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 400: Drainage Area 400 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-25 Rainfall=6.10" Runoff Area=3,345 sf Runoff Volume=0.035 af Runoff Depth>5.42" Tc=6.0 min CN=98 0.45 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 15HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 450: Drainage Area 450 Runoff = 0.66 cfs @ 12.09 hrs, Volume= 0.051 af, Depth> 5.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description * 4,888 98 Paving and Roofs, HSG B 4,888 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 450: Drainage Area 450 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-25 Rainfall=6.10" Runoff Area=4,888 sf Runoff Volume=0.051 af Runoff Depth>5.42" Tc=6.0 min CN=98 0.66 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 16HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 500: Drainage Area 500 Runoff = 0.03 cfs @ 12.10 hrs, Volume= 0.002 af, Depth> 1.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 588 61 >75% Grass cover, Good, HSG B 588 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 500: Drainage Area 500 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-25 Rainfall=6.10" Runoff Area=588 sf Runoff Volume=0.002 af Runoff Depth>1.89" Tc=6.0 min CN=61 0.03 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 17HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 600: Drainage Area 600 Runoff = 0.95 cfs @ 12.09 hrs, Volume= 0.067 af, Depth> 4.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 2,917 61 >75% Grass cover, Good, HSG B * 5,497 98 Paving and Roofs, HSG B 8,414 85 Weighted Average 2,917 34.67% Pervious Area 5,497 65.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 600: Drainage Area 600 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-25 Rainfall=6.10" Runoff Area=8,414 sf Runoff Volume=0.067 af Runoff Depth>4.14" Tc=6.0 min CN=85 0.95 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 18HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 700: Drainage Area 700 Runoff = 0.92 cfs @ 12.09 hrs, Volume= 0.067 af, Depth> 4.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 1,561 61 >75% Grass cover, Good, HSG B * 5,888 98 Paving and Roofs, HSG B 7,449 90 Weighted Average 1,561 20.96% Pervious Area 5,888 79.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 700: Drainage Area 700 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-25 Rainfall=6.10" Runoff Area=7,449 sf Runoff Volume=0.067 af Runoff Depth>4.67" Tc=6.0 min CN=90 0.92 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 19HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 750: Drainage Area 750 Runoff = 0.84 cfs @ 12.09 hrs, Volume= 0.058 af, Depth> 3.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 3,364 61 >75% Grass cover, Good, HSG B * 4,515 98 Paving and Roofs, HSG B 7,879 82 Weighted Average 3,364 42.70% Pervious Area 4,515 57.30% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 750: Drainage Area 750 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-25 Rainfall=6.10" Runoff Area=7,879 sf Runoff Volume=0.058 af Runoff Depth>3.83" Tc=6.0 min CN=82 0.84 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 20HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 800: Drainage Area 800 Runoff = 0.34 cfs @ 12.09 hrs, Volume= 0.024 af, Depth> 4.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-25 Rainfall=6.10" Area (sf) CN Description 561 61 >75% Grass cover, Good, HSG B 2,159 98 Paved parking, HSG B 2,720 90 Weighted Average 561 20.62% Pervious Area 2,159 79.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 800: Drainage Area 800 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-25 Rainfall=6.10" Runoff Area=2,720 sf Runoff Volume=0.024 af Runoff Depth>4.67" Tc=6.0 min CN=90 0.34 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 21HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 12"(1): 12" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 0.305 ac, 78.07% Impervious, Inflow Depth = 0.12" for NoHo-25 event Inflow = 0.23 cfs @ 12.51 hrs, Volume= 0.003 af Outflow = 0.20 cfs @ 12.54 hrs, Volume= 0.003 af, Atten= 13%, Lag= 1.2 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.02 fps, Min. Travel Time= 0.3 min Avg. Velocity = 1.20 fps, Avg. Travel Time= 0.5 min Peak Storage= 3 cf @ 12.53 hrs Average Depth at Peak Storage= 0.19' Bank-Full Depth= 1.00' Flow Area= 0.8 sf, Capacity= 2.73 cfs 12.0" Round Pipe n= 0.013 Corrugated PE, smooth interior Length= 34.0' Slope= 0.0059 '/' Inlet Invert= 130.50', Outlet Invert= 130.30' Reach 12"(1): 12" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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=0.305 ac Avg. Flow Depth=0.19' Max Vel=2.02 fps 12.0" Round Pipe n=0.013 L=34.0' S=0.0059 '/' Capacity=2.73 cfs 0.23 cfs 0.20 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 22HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 12"(1): 12" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 130.50 0.0 0 130.51 0.0 0 130.52 0.0 0 130.53 0.0 0 130.54 0.0 0 130.55 0.0 0 130.56 0.0 1 130.57 0.0 1 130.58 0.0 1 130.59 0.0 1 130.60 0.0 1 130.61 0.0 2 130.62 0.1 2 130.63 0.1 2 130.64 0.1 2 130.65 0.1 3 130.66 0.1 3 130.67 0.1 3 130.68 0.1 3 130.69 0.1 4 130.70 0.1 4 130.71 0.1 4 130.72 0.1 4 130.73 0.1 5 130.74 0.1 5 130.75 0.2 5 130.76 0.2 6 130.77 0.2 6 130.78 0.2 6 130.79 0.2 6 130.80 0.2 7 130.81 0.2 7 130.82 0.2 7 130.83 0.2 8 130.84 0.2 8 130.85 0.2 8 130.86 0.3 9 130.87 0.3 9 130.88 0.3 9 130.89 0.3 10 130.90 0.3 10 130.91 0.3 10 130.92 0.3 11 130.93 0.3 11 130.94 0.3 11 130.95 0.3 12 130.96 0.4 12 130.97 0.4 12 130.98 0.4 13 130.99 0.4 13 131.00 0.4 13 131.01 0.4 14 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 131.02 0.4 14 131.03 0.4 14 131.04 0.4 15 131.05 0.4 15 131.06 0.5 15 131.07 0.5 16 131.08 0.5 16 131.09 0.5 16 131.10 0.5 17 131.11 0.5 17 131.12 0.5 17 131.13 0.5 18 131.14 0.5 18 131.15 0.5 18 131.16 0.5 19 131.17 0.6 19 131.18 0.6 19 131.19 0.6 20 131.20 0.6 20 131.21 0.6 20 131.22 0.6 21 131.23 0.6 21 131.24 0.6 21 131.25 0.6 21 131.26 0.6 22 131.27 0.6 22 131.28 0.7 22 131.29 0.7 23 131.30 0.7 23 131.31 0.7 23 131.32 0.7 23 131.33 0.7 24 131.34 0.7 24 131.35 0.7 24 131.36 0.7 24 131.37 0.7 25 131.38 0.7 25 131.39 0.7 25 131.40 0.7 25 131.41 0.8 26 131.42 0.8 26 131.43 0.8 26 131.44 0.8 26 131.45 0.8 26 131.46 0.8 26 131.47 0.8 26 131.48 0.8 27 131.49 0.8 27 131.50 0.8 27 Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 23HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 12"(2): 12" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 0.181 ac, 57.30% Impervious, Inflow Depth = 0.54" for NoHo-25 event Inflow = 0.46 cfs @ 12.26 hrs, Volume= 0.008 af Outflow = 0.37 cfs @ 12.27 hrs, Volume= 0.008 af, Atten= 20%, Lag= 0.7 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.56 fps, Min. Travel Time= 0.3 min Avg. Velocity = 1.27 fps, Avg. Travel Time= 0.6 min Peak Storage= 7 cf @ 12.27 hrs Average Depth at Peak Storage= 0.26' Bank-Full Depth= 1.00' Flow Area= 0.8 sf, Capacity= 2.91 cfs 12.0" Round Pipe n= 0.013 Corrugated PE, smooth interior Length= 45.0' Slope= 0.0067 '/' Inlet Invert= 133.50', Outlet Invert= 133.20' Reach 12"(2): 12" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.181 ac Avg. Flow Depth=0.26' Max Vel=2.56 fps 12.0" Round Pipe n=0.013 L=45.0' S=0.0067 '/' Capacity=2.91 cfs 0.46 cfs 0.37 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 24HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 12"(2): 12" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 133.50 0.0 0 133.51 0.0 0 133.52 0.0 0 133.53 0.0 0 133.54 0.0 0 133.55 0.0 1 133.56 0.0 1 133.57 0.0 1 133.58 0.0 1 133.59 0.0 2 133.60 0.0 2 133.61 0.0 2 133.62 0.1 2 133.63 0.1 3 133.64 0.1 3 133.65 0.1 3 133.66 0.1 4 133.67 0.1 4 133.68 0.1 4 133.69 0.1 5 133.70 0.1 5 133.71 0.1 5 133.72 0.1 6 133.73 0.1 6 133.74 0.1 7 133.75 0.2 7 133.76 0.2 7 133.77 0.2 8 133.78 0.2 8 133.79 0.2 9 133.80 0.2 9 133.81 0.2 9 133.82 0.2 10 133.83 0.2 10 133.84 0.2 11 133.85 0.2 11 133.86 0.3 11 133.87 0.3 12 133.88 0.3 12 133.89 0.3 13 133.90 0.3 13 133.91 0.3 14 133.92 0.3 14 133.93 0.3 15 133.94 0.3 15 133.95 0.3 15 133.96 0.4 16 133.97 0.4 16 133.98 0.4 17 133.99 0.4 17 134.00 0.4 18 134.01 0.4 18 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 134.02 0.4 19 134.03 0.4 19 134.04 0.4 19 134.05 0.4 20 134.06 0.5 20 134.07 0.5 21 134.08 0.5 21 134.09 0.5 22 134.10 0.5 22 134.11 0.5 23 134.12 0.5 23 134.13 0.5 23 134.14 0.5 24 134.15 0.5 24 134.16 0.5 25 134.17 0.6 25 134.18 0.6 26 134.19 0.6 26 134.20 0.6 26 134.21 0.6 27 134.22 0.6 27 134.23 0.6 28 134.24 0.6 28 134.25 0.6 28 134.26 0.6 29 134.27 0.6 29 134.28 0.7 30 134.29 0.7 30 134.30 0.7 30 134.31 0.7 31 134.32 0.7 31 134.33 0.7 31 134.34 0.7 32 134.35 0.7 32 134.36 0.7 32 134.37 0.7 33 134.38 0.7 33 134.39 0.7 33 134.40 0.7 34 134.41 0.8 34 134.42 0.8 34 134.43 0.8 34 134.44 0.8 34 134.45 0.8 35 134.46 0.8 35 134.47 0.8 35 134.48 0.8 35 134.49 0.8 35 134.50 0.8 35 Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 25HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 15": 15" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated [82] Warning: Early inflow requires earlier time span [79] Warning: Submerged Pond S1 Primary device # 1 by 0.61' Inflow Area = 0.515 ac, 92.94% Impervious, Inflow Depth > 5.21" for NoHo-25 event Inflow = 1.87 cfs @ 12.19 hrs, Volume= 0.224 af Outflow = 1.87 cfs @ 12.20 hrs, Volume= 0.224 af, Atten= 0%, Lag= 0.3 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.61 fps, Min. Travel Time= 0.1 min Avg. Velocity = 1.18 fps, Avg. Travel Time= 0.3 min Peak Storage= 14 cf @ 12.19 hrs Average Depth at Peak Storage= 0.71' Bank-Full Depth= 1.25' Flow Area= 1.2 sf, Capacity= 3.05 cfs 15.0" Round Pipe n= 0.020 Corrugated PE, corrugated interior Length= 19.0' Slope= 0.0053 '/' Inlet Invert= 118.90', Outlet Invert= 118.80' Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 26HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Reach 15": 15" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.515 ac Avg. Flow Depth=0.71' Max Vel=2.61 fps 15.0" Round Pipe n=0.020 L=19.0' S=0.0053 '/' Capacity=3.05 cfs 1.87 cfs 1.87 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 27HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 15": 15" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 118.90 0.0 0 118.92 0.0 0 118.94 0.0 0 118.96 0.0 0 118.98 0.0 1 119.00 0.0 1 119.02 0.1 1 119.04 0.1 1 119.06 0.1 2 119.08 0.1 2 119.10 0.1 2 119.12 0.1 3 119.14 0.2 3 119.16 0.2 4 119.18 0.2 4 119.20 0.2 4 119.22 0.2 5 119.24 0.3 5 119.26 0.3 6 119.28 0.3 6 119.30 0.3 6 119.32 0.4 7 119.34 0.4 7 119.36 0.4 8 119.38 0.4 8 119.40 0.5 9 119.42 0.5 9 119.44 0.5 10 119.46 0.5 10 119.48 0.6 11 119.50 0.6 11 119.52 0.6 12 119.54 0.6 12 119.56 0.7 12 119.58 0.7 13 119.60 0.7 13 119.62 0.7 14 119.64 0.8 14 119.66 0.8 15 119.68 0.8 15 119.70 0.8 16 119.72 0.9 16 119.74 0.9 17 119.76 0.9 17 119.78 0.9 18 119.80 0.9 18 119.82 1.0 18 119.84 1.0 19 119.86 1.0 19 119.88 1.0 20 119.90 1.1 20 119.92 1.1 20 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 119.94 1.1 21 119.96 1.1 21 119.98 1.1 21 120.00 1.1 22 120.02 1.2 22 120.04 1.2 22 120.06 1.2 23 120.08 1.2 23 120.10 1.2 23 120.12 1.2 23 120.14 1.2 23 Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 28HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S1: Subsurface Storage System #1 [82] Warning: Early inflow requires earlier time span Inflow Area = 0.515 ac, 92.94% Impervious, Inflow Depth > 5.21" for NoHo-25 event Inflow = 2.96 cfs @ 12.09 hrs, Volume= 0.224 af Outflow = 1.87 cfs @ 12.19 hrs, Volume= 0.224 af, Atten= 37%, Lag= 6.3 min Primary = 1.87 cfs @ 12.19 hrs, Volume= 0.224 af Secondary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 120.57' @ 12.19 hrs Surf.Area= 902 sf Storage= 831 cf Plug-Flow detention time= 2.7 min calculated for 0.223 af (100% of inflow) Center-of-Mass det. time= 2.5 min ( 743.3 - 740.8 ) Volume Invert Avail.Storage Storage Description #1 119.00' 1,483 cf 24.0" Round Pipe Storage L= 472.0' S= 0.0020 '/' Device Routing Invert Outlet Devices #1 Primary 119.00'8.0" Vert. Orifice/Grate C= 0.600 #2 Secondary 121.20'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Primary OutFlow Max=1.87 cfs @ 12.19 hrs HW=120.56' (Free Discharge) 1=Orifice/Grate (Orifice Controls 1.87 cfs @ 5.34 fps) Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=119.07' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 29HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S1: Subsurface Storage System #1 Inflow Outflow Primary Secondary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)3 2 1 0 Inflow Area=0.515 ac Peak Elev=120.57' Storage=831 cf 2.96 cfs 1.87 cfs 1.87 cfs 0.00 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 30HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S1: Subsurface Storage System #1 Elevation (feet) Storage (cubic-feet) 119.00 0 119.02 0 119.04 0 119.06 0 119.08 1 119.10 1 119.12 2 119.14 3 119.16 4 119.18 5 119.20 7 119.22 8 119.24 10 119.26 13 119.28 15 119.30 18 119.32 21 119.34 24 119.36 28 119.38 32 119.40 36 119.42 41 119.44 46 119.46 51 119.48 57 119.50 63 119.52 69 119.54 76 119.56 83 119.58 90 119.60 98 119.62 106 119.64 115 119.66 124 119.68 133 119.70 142 119.72 152 119.74 163 119.76 173 119.78 185 119.80 196 119.82 208 119.84 220 119.86 233 119.88 246 119.90 260 119.92 274 119.94 288 119.96 303 119.98 318 120.00 333 120.02 349 Elevation (feet) Storage (cubic-feet) 120.04 364 120.06 381 120.08 397 120.10 413 120.12 430 120.14 447 120.16 464 120.18 481 120.20 498 120.22 516 120.24 533 120.26 551 120.28 568 120.30 586 120.32 604 120.34 622 120.36 640 120.38 658 120.40 676 120.42 694 120.44 712 120.46 731 120.48 749 120.50 767 120.52 785 120.54 803 120.56 821 120.58 839 120.60 857 120.62 875 120.64 893 120.66 911 120.68 929 120.70 946 120.72 964 120.74 981 120.76 998 120.78 1,016 120.80 1,033 120.82 1,050 120.84 1,066 120.86 1,083 120.88 1,099 120.90 1,115 120.92 1,131 120.94 1,147 120.96 1,162 120.98 1,177 121.00 1,192 121.02 1,206 121.04 1,220 121.06 1,234 Elevation (feet) Storage (cubic-feet) 121.08 1,247 121.10 1,260 121.12 1,272 121.14 1,284 121.16 1,296 121.18 1,307 121.20 1,318 121.22 1,328 121.24 1,338 121.26 1,348 121.28 1,357 121.30 1,366 121.32 1,375 121.34 1,383 121.36 1,391 121.38 1,398 121.40 1,406 121.42 1,412 121.44 1,419 121.46 1,425 121.48 1,430 121.50 1,436 121.52 1,441 121.54 1,445 121.56 1,450 121.58 1,454 121.60 1,458 121.62 1,461 121.64 1,464 121.66 1,467 121.68 1,470 121.70 1,472 121.72 1,474 121.74 1,476 121.76 1,477 121.78 1,479 121.80 1,480 121.82 1,481 121.84 1,482 121.86 1,482 121.88 1,482 121.90 1,483 121.92 1,483 121.94 1,483 Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 31HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S2: Subsurface Recharge Trench System #1 [82] Warning: Early inflow requires earlier time span Inflow Area = 0.305 ac, 78.07% Impervious, Inflow Depth > 4.61" for NoHo-25 event Inflow = 1.61 cfs @ 12.09 hrs, Volume= 0.117 af Outflow = 0.38 cfs @ 12.51 hrs, Volume= 0.117 af, Atten= 76%, Lag= 25.6 min Discarded = 0.15 cfs @ 11.45 hrs, Volume= 0.114 af Primary = 0.23 cfs @ 12.51 hrs, Volume= 0.003 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 133.07' @ 12.52 hrs Surf.Area= 1,033 sf Storage= 1,851 cf Plug-Flow detention time= 93.5 min calculated for 0.117 af (100% of inflow) Center-of-Mass det. time= 92.9 min ( 846.6 - 753.7 ) Volume Invert Avail.Storage Storage Description #1A 129.70' 976 cf 16.67'W x 62.00'L x 3.50'H Field A 3,617 cf Overall - 1,176 cf Embedded = 2,440 cf x 40.0% Voids #2A 130.70' 930 cf ADS N-12 24" x 15 Inside #1 Inside= 23.8"W x 23.8"H => 3.10 sf x 20.00'L = 62.0 cf Outside= 28.0"W x 28.0"H => 3.92 sf x 20.00'L = 78.4 cf 15 Chambers in 5 Rows 1,906 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 129.70'6.250 in/hr Exfiltration over Surface area #2 Primary 133.00'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.15 cfs @ 11.45 hrs HW=129.74' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) Primary OutFlow Max=0.20 cfs @ 12.51 hrs HW=133.06' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 0.20 cfs @ 0.68 fps) Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 32HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S2: Subsurface Recharge Trench System #1 - Chamber Wizard Field A Chamber Model = ADS N-12 24" (ADS N-12® Pipe) Inside= 23.8"W x 23.8"H => 3.10 sf x 20.00'L = 62.0 cf Outside= 28.0"W x 28.0"H => 3.92 sf x 20.00'L = 78.4 cf 28.0" Wide + 12.0" Spacing = 40.0" C-C Row Spacing 3 Chambers/Row x 20.00' Long = 60.00' Row Length +12.0" End Stone x 2 = 62.00' Base Length 5 Rows x 28.0" Wide + 12.0" Spacing x 4 + 6.0" Side Stone x 2 = 16.67' Base Width 12.0" Base + 28.0" Chamber Height + 2.0" Cover = 3.50' Field Height 15 Chambers x 62.0 cf = 930.0 cf Chamber Storage 15 Chambers x 78.4 cf = 1,175.9 cf Displacement 3,616.8 cf Field - 1,175.9 cf Chambers = 2,440.9 cf Stone x 40.0% Voids = 976.4 cf Stone Storage Chamber Storage + Stone Storage = 1,906.4 cf = 0.044 af Overall Storage Efficiency = 52.7% Overall System Size = 62.00' x 16.67' x 3.50' 15 Chambers 134.0 cy Field 90.4 cy Stone Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 33HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S2: Subsurface Recharge Trench System #1 Inflow Outflow Discarded Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.305 ac Peak Elev=133.07' Storage=1,851 cf 1.61 cfs 0.38 cfs 0.15 cfs0.23 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 34HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S2: Subsurface Recharge Trench System #1 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 129.70 1,033 0 129.75 1,033 21 129.80 1,033 41 129.85 1,033 62 129.90 1,033 83 129.95 1,033 103 130.00 1,033 124 130.05 1,033 145 130.10 1,033 165 130.15 1,033 186 130.20 1,033 207 130.25 1,033 227 130.30 1,033 248 130.35 1,033 269 130.40 1,033 289 130.45 1,033 310 130.50 1,033 331 130.55 1,033 351 130.60 1,033 372 130.65 1,033 393 130.70 1,033 413 130.75 1,033 432 130.80 1,033 448 130.85 1,033 463 130.90 1,033 479 130.95 1,033 501 131.00 1,033 527 131.05 1,033 554 131.10 1,033 584 131.15 1,033 614 131.20 1,033 646 131.25 1,033 679 131.30 1,033 712 131.35 1,033 746 131.40 1,033 781 131.45 1,033 817 131.50 1,033 853 131.55 1,033 889 131.60 1,033 926 131.65 1,033 963 131.70 1,033 1,000 131.75 1,033 1,038 131.80 1,033 1,075 131.85 1,033 1,113 131.90 1,033 1,150 131.95 1,033 1,188 132.00 1,033 1,225 132.05 1,033 1,263 132.10 1,033 1,300 132.15 1,033 1,337 132.20 1,033 1,374 132.25 1,033 1,410 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 132.30 1,033 1,446 132.35 1,033 1,481 132.40 1,033 1,516 132.45 1,033 1,550 132.50 1,033 1,583 132.55 1,033 1,615 132.60 1,033 1,647 132.65 1,033 1,677 132.70 1,033 1,705 132.75 1,033 1,732 132.80 1,033 1,757 132.85 1,033 1,778 132.90 1,033 1,793 132.95 1,033 1,808 133.00 1,033 1,825 133.05 1,033 1,844 133.10 1,033 1,865 133.15 1,033 1,885 133.20 1,033 1,906 Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 35HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S3: Subsurface Recharge Trench System #2 [92] Warning: Device #2 is above defined storage [93] Warning: Storage range exceeded by 0.34' [85] Warning: Oscillations may require smaller dt or Finer Routing (severity=9) Inflow Area = 0.181 ac, 57.30% Impervious, Inflow Depth > 3.83" for NoHo-25 event Inflow = 0.84 cfs @ 12.09 hrs, Volume= 0.058 af Outflow = 0.52 cfs @ 12.26 hrs, Volume= 0.058 af, Atten= 38%, Lag= 10.0 min Discarded = 0.06 cfs @ 11.40 hrs, Volume= 0.050 af Primary = 0.46 cfs @ 12.26 hrs, Volume= 0.008 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 135.82' @ 12.25 hrs Surf.Area= 712 sf Storage= 763 cf Plug-Flow detention time= 97.1 min calculated for 0.058 af (100% of inflow) Center-of-Mass det. time= 96.5 min ( 872.2 - 775.8 ) Volume Invert Avail.Storage Storage Description #1A 133.10' 585 cf 3.21'W x 222.00'L x 2.38'H Field A 1,692 cf Overall - 230 cf Embedded = 1,462 cf x 40.0% Voids #2A 134.10' 178 cf ADS N-12 12" x 11 Inside #1 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 763 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 133.10'3.750 in/hr Exfiltration over Surface area #2 Primary 135.70'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.06 cfs @ 11.40 hrs HW=133.13' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.41 cfs @ 12.26 hrs HW=135.81' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 0.41 cfs @ 0.93 fps) Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 36HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S3: Subsurface Recharge Trench System #2 - Chamber Wizard Field A Chamber Model = ADS N-12 12" (ADS N-12® Pipe) Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 11 Chambers/Row x 20.00' Long = 220.00' Row Length +12.0" End Stone x 2 = 222.00' Base Length 1 Rows x 14.5" Wide + 12.0" Side Stone x 2 = 3.21' Base Width 12.0" Base + 14.5" Chamber Height + 2.0" Cover = 2.38' Field Height 11 Chambers x 16.2 cf = 178.2 cf Chamber Storage 11 Chambers x 20.9 cf = 230.3 cf Displacement 1,692.3 cf Field - 230.3 cf Chambers = 1,462.0 cf Stone x 40.0% Voids = 584.8 cf Stone Storage Chamber Storage + Stone Storage = 763.0 cf = 0.018 af Overall Storage Efficiency = 45.1% Overall System Size = 222.00' x 3.21' x 2.38' 11 Chambers 62.7 cy Field 54.1 cy Stone Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 37HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S3: Subsurface Recharge Trench System #2 Inflow Outflow Discarded Primary Hydrograph Time (hours) 201918171615141312111098765Flow (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 Inflow Area=0.181 ac Peak Elev=135.82' Storage=763 cf 0.84 cfs 0.52 cfs 0.06 cfs 0.46 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 38HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S3: Subsurface Recharge Trench System #2 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 133.10 712 0 133.15 712 14 133.20 712 28 133.25 712 43 133.30 712 57 133.35 712 71 133.40 712 85 133.45 712 100 133.50 712 114 133.55 712 128 133.60 712 142 133.65 712 157 133.70 712 171 133.75 712 185 133.80 712 199 133.85 712 214 133.90 712 228 133.95 712 242 134.00 712 256 134.05 712 271 134.10 712 285 134.15 712 298 134.20 712 310 134.25 712 325 134.30 712 341 134.35 712 359 134.40 712 378 134.45 712 397 134.50 712 417 134.55 712 437 134.60 712 457 134.65 712 478 134.70 712 498 134.75 712 519 134.80 712 539 134.85 712 560 134.90 712 580 134.95 712 600 135.00 712 619 135.05 712 638 135.10 712 656 135.15 712 673 135.20 712 688 135.25 712 700 135.30 712 713 135.35 712 727 135.40 712 741 135.45 712 756 135.50 712 763 135.55 712 763 135.60 712 763 135.65 712 763 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 135.70 712 763 135.75 712 763 135.80 712 763 Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 39HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x1000: Hawley Street Top Inflow Area = 0.589 ac, 81.25% Impervious, Inflow Depth > 4.79" for NoHo-25 event Inflow = 2.00 cfs @ 12.17 hrs, Volume= 0.235 af Primary = 2.00 cfs @ 12.17 hrs, Volume= 0.235 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x1000: Hawley Street Top Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.589 ac 2.00 cfs 2.00 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 40HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x2000: Hawley Street Bottom Inflow Area = 0.571 ac, 44.87% Impervious, Inflow Depth > 3.40" for NoHo-25 event Inflow = 1.62 cfs @ 12.13 hrs, Volume= 0.162 af Primary = 1.62 cfs @ 12.13 hrs, Volume= 0.162 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x2000: Hawley Street Bottom Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.571 ac 1.62 cfs 1.62 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 41HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x3000: Off-Site South Inflow Area = 0.013 ac, 0.00% Impervious, Inflow Depth > 1.89" for NoHo-25 event Inflow = 0.03 cfs @ 12.10 hrs, Volume= 0.002 af Primary = 0.03 cfs @ 12.10 hrs, Volume= 0.002 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x3000: Off-Site South Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 Inflow Area=0.013 ac 0.03 cfs 0.03 cfs Type III 24-hr NoHo-25 Rainfall=6.10"42540-PR Printed 10/31/2019Prepared by VHB Page 42HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x4000: Phillips Place Inflow Area = 0.720 ac, 73.20% Impervious, Inflow Depth > 1.70" for NoHo-25 event Inflow = 1.26 cfs @ 12.09 hrs, Volume= 0.102 af Primary = 1.26 cfs @ 12.09 hrs, Volume= 0.102 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x4000: Phillips Place Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.720 ac 1.26 cfs 1.26 cfs Appendix J: Hydrologic Analysis 100-Year Storm Event – Proposed 100 Drainage Area 100 150 Drainage Area 150 200 Drainage Area 200 300 Drainage Area 300 400 Drainage Area 400 450 Drainage Area 450 500 Drainage Area 500 600 Drainage Area 600 700 Drainage Area 700 750 Drainage Area 750 800 Drainage Area 800 12"(1) 12" Overflow Pipe 12"(2) 12" Overflow Pipe15" 15" Overflow Pipe S1 Subsurface Storage System #1 S2 Subsurface Recharge Trench System #1 S3 Subsurface Recharge Trench System #2 x1000 Hawley Street Top x2000 Hawley Street Bottom x3000 Off-Site South x4000 Phillips Place Routing Diagram for 42540-PR Prepared by VHB, Printed 10/31/2019 HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link 42540-PR Printed 10/31/2019Prepared by VHB Page 2HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Project Notes Rainfall events imported from "Northampton MA.hcp" 42540-PR Printed 10/31/2019Prepared by VHB Page 3HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.632 61 >75% Grass cover, Good, HSG B (100, 150, 300, 500, 600, 700, 750, 800) 0.050 98 Paved parking, HSG B (800) 0.956 98 Paving and Roofs, HSG B (100, 400, 450, 600, 700, 750) 0.152 98 Roofs, HSG B (200) 0.104 98 Walks, HSG B (300) 1.893 86 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 4HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 1.893 HSG B 100, 150, 200, 300, 400, 450, 500, 600, 700, 750, 800 0.000 HSG C 0.000 HSG D 0.000 Other 1.893 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 5HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.632 0.000 0.000 0.000 0.632 >75% Grass cover, Good 100, 150, 300, 500, 600, 700, 750, 800 0.000 0.050 0.000 0.000 0.000 0.050 Paved parking 800 0.000 0.956 0.000 0.000 0.000 0.956 Paving and Roofs 100, 400, 450, 600, 700, 750 0.000 0.152 0.000 0.000 0.000 0.152 Roofs 200 0.000 0.104 0.000 0.000 0.000 0.104 Walks 300 0.000 1.893 0.000 0.000 0.000 1.893 TOTAL AREA 42540-PR Printed 10/31/2019Prepared by VHB Page 6HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Diam/Width (inches) Height (inches) Inside-Fill (inches) 1 12"(1) 130.50 130.30 34.0 0.0059 0.013 12.0 0.0 0.0 2 12"(2) 133.50 133.20 45.0 0.0067 0.013 12.0 0.0 0.0 3 15" 118.90 118.80 19.0 0.0053 0.020 15.0 0.0 0.0 Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 7HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=19,086 sf 91.70% Impervious Runoff Depth>6.83"Subcatchment 100: Drainage Area 100 Tc=6.0 min CN=95 Runoff=3.28 cfs 0.249 af Runoff Area=3,227 sf 0.00% Impervious Runoff Depth>3.11"Subcatchment 150: Drainage Area 150 Tc=6.0 min CN=61 Runoff=0.28 cfs 0.019 af Runoff Area=6,628 sf 100.00% Impervious Runoff Depth>7.05"Subcatchment 200: Drainage Area 200 Tc=6.0 min CN=98 Runoff=1.15 cfs 0.089 af Runoff Area=18,250 sf 24.85% Impervious Runoff Depth>4.07"Subcatchment 300: Drainage Area 300 Flow Length=336' Tc=15.6 min CN=70 Runoff=1.60 cfs 0.142 af Runoff Area=3,345 sf 100.00% Impervious Runoff Depth>7.05"Subcatchment 400: Drainage Area 400 Tc=6.0 min CN=98 Runoff=0.58 cfs 0.045 af Runoff Area=4,888 sf 100.00% Impervious Runoff Depth>7.05"Subcatchment 450: Drainage Area 450 Tc=6.0 min CN=98 Runoff=0.85 cfs 0.066 af Runoff Area=588 sf 0.00% Impervious Runoff Depth>3.11"Subcatchment 500: Drainage Area 500 Tc=6.0 min CN=61 Runoff=0.05 cfs 0.003 af Runoff Area=8,414 sf 65.33% Impervious Runoff Depth>5.78"Subcatchment 600: Drainage Area 600 Tc=6.0 min CN=85 Runoff=1.31 cfs 0.093 af Runoff Area=7,449 sf 79.04% Impervious Runoff Depth>6.33"Subcatchment 700: Drainage Area 700 Tc=6.0 min CN=90 Runoff=1.23 cfs 0.090 af Runoff Area=7,879 sf 57.30% Impervious Runoff Depth>5.44"Subcatchment 750: Drainage Area 750 Tc=6.0 min CN=82 Runoff=1.17 cfs 0.082 af Runoff Area=2,720 sf 79.37% Impervious Runoff Depth>6.33"Subcatchment 800: Drainage Area 800 Tc=6.0 min CN=90 Runoff=0.45 cfs 0.033 af Avg. Flow Depth=0.54' Max Vel=3.50 fps Inflow=1.58 cfs 0.026 afReach 12"(1): 12" Overflow Pipe 12.0" Round Pipe n=0.013 L=34.0' S=0.0059 '/' Capacity=2.73 cfs Outflow=1.39 cfs 0.026 af Avg. Flow Depth=0.47' Max Vel=3.58 fps Inflow=1.26 cfs 0.024 afReach 12"(2): 12" Overflow Pipe 12.0" Round Pipe n=0.013 L=45.0' S=0.0067 '/' Capacity=2.91 cfs Outflow=1.23 cfs 0.024 af Avg. Flow Depth=0.81' Max Vel=2.73 fps Inflow=2.29 cfs 0.294 afReach 15": 15" Overflow Pipe 15.0" Round Pipe n=0.020 L=19.0' S=0.0053 '/' Capacity=3.05 cfs Outflow=2.29 cfs 0.294 af Peak Elev=121.20' Storage=1,316 cf Inflow=3.86 cfs 0.295 afPond S1: Subsurface Storage System #1 Primary=2.29 cfs 0.294 af Secondary=0.00 cfs 0.000 af Outflow=2.29 cfs 0.294 af Peak Elev=133.24' Storage=1,906 cf Inflow=2.16 cfs 0.159 afPond S2: Subsurface Recharge Trench Discarded=0.15 cfs 0.132 af Primary=1.58 cfs 0.026 af Outflow=1.73 cfs 0.159 af Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 8HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Peak Elev=135.93' Storage=763 cf Inflow=1.17 cfs 0.082 afPond S3: Subsurface Recharge Trench Discarded=0.06 cfs 0.055 af Primary=1.26 cfs 0.024 af Outflow=1.32 cfs 0.079 af Inflow=2.47 cfs 0.314 afLink x1000: Hawley Street Top Primary=2.47 cfs 0.314 af Inflow=2.33 cfs 0.232 afLink x2000: Hawley Street Bottom Primary=2.33 cfs 0.232 af Inflow=0.05 cfs 0.003 afLink x3000: Off-Site South Primary=0.05 cfs 0.003 af Inflow=2.69 cfs 0.173 afLink x4000: Phillips Place Primary=2.69 cfs 0.173 af Total Runoff Area = 1.893 ac Runoff Volume = 0.913 af Average Runoff Depth = 5.79" 33.36% Pervious = 0.632 ac 66.64% Impervious = 1.262 ac Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 9HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 100: Drainage Area 100 Runoff = 3.28 cfs @ 12.09 hrs, Volume= 0.249 af, Depth> 6.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 1,584 61 >75% Grass cover, Good, HSG B * 17,502 98 Paving and Roofs, HSG B 19,086 95 Weighted Average 1,584 8.30% Pervious Area 17,502 91.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 100: Drainage Area 100 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)3 2 1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=19,086 sf Runoff Volume=0.249 af Runoff Depth>6.83" Tc=6.0 min CN=95 3.28 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 10HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 150: Drainage Area 150 Runoff = 0.28 cfs @ 12.10 hrs, Volume= 0.019 af, Depth> 3.11" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 3,227 61 >75% Grass cover, Good, HSG B 3,227 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 150: Drainage Area 150 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-100 Rainfall=7.90" Runoff Area=3,227 sf Runoff Volume=0.019 af Runoff Depth>3.11" Tc=6.0 min CN=61 0.28 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 11HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 200: Drainage Area 200 Runoff = 1.15 cfs @ 12.09 hrs, Volume= 0.089 af, Depth> 7.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 6,628 98 Roofs, HSG B 6,628 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 200: Drainage Area 200 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=6,628 sf Runoff Volume=0.089 af Runoff Depth>7.05" Tc=6.0 min CN=98 1.15 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 12HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 300: Drainage Area 300 Runoff = 1.60 cfs @ 12.22 hrs, Volume= 0.142 af, Depth> 4.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 13,714 61 >75% Grass cover, Good, HSG B * 4,536 98 Walks, HSG B 18,250 70 Weighted Average 13,714 75.15% Pervious Area 4,536 24.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.8 100 0.0270 0.19 Sheet Flow, First 100 feet of grass Grass: Short n= 0.150 P2= 3.15" 0.7 50 0.0270 1.15 Shallow Concentrated Flow, Next 50 feet of grass Short Grass Pasture Kv= 7.0 fps 5.4 160 0.0050 0.49 Shallow Concentrated Flow, Next 160 feet of grass Short Grass Pasture Kv= 7.0 fps 0.7 20 0.0050 0.49 Shallow Concentrated Flow, Next 20 feet of grass Short Grass Pasture Kv= 7.0 fps 0.0 6 0.5000 4.95 Shallow Concentrated Flow, Last 6 feet of grass Short Grass Pasture Kv= 7.0 fps 15.6 336 Total Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 13HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Subcatchment 300: Drainage Area 300 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=18,250 sf Runoff Volume=0.142 af Runoff Depth>4.07" Flow Length=336' Tc=15.6 min CN=70 1.60 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 14HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 400: Drainage Area 400 Runoff = 0.58 cfs @ 12.09 hrs, Volume= 0.045 af, Depth> 7.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description * 3,345 98 Paving and Roofs, HSG B 3,345 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 400: Drainage Area 400 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (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 NoHo-100 Rainfall=7.90" Runoff Area=3,345 sf Runoff Volume=0.045 af Runoff Depth>7.05" Tc=6.0 min CN=98 0.58 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 15HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 450: Drainage Area 450 Runoff = 0.85 cfs @ 12.09 hrs, Volume= 0.066 af, Depth> 7.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description * 4,888 98 Paving and Roofs, HSG B 4,888 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 450: Drainage Area 450 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=4,888 sf Runoff Volume=0.066 af Runoff Depth>7.05" Tc=6.0 min CN=98 0.85 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 16HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 500: Drainage Area 500 Runoff = 0.05 cfs @ 12.10 hrs, Volume= 0.003 af, Depth> 3.11" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 588 61 >75% Grass cover, Good, HSG B 588 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 500: Drainage Area 500 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-100 Rainfall=7.90" Runoff Area=588 sf Runoff Volume=0.003 af Runoff Depth>3.11" Tc=6.0 min CN=61 0.05 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 17HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 600: Drainage Area 600 Runoff = 1.31 cfs @ 12.09 hrs, Volume= 0.093 af, Depth> 5.78" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 2,917 61 >75% Grass cover, Good, HSG B * 5,497 98 Paving and Roofs, HSG B 8,414 85 Weighted Average 2,917 34.67% Pervious Area 5,497 65.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 600: Drainage Area 600 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=8,414 sf Runoff Volume=0.093 af Runoff Depth>5.78" Tc=6.0 min CN=85 1.31 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 18HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 700: Drainage Area 700 Runoff = 1.23 cfs @ 12.09 hrs, Volume= 0.090 af, Depth> 6.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 1,561 61 >75% Grass cover, Good, HSG B * 5,888 98 Paving and Roofs, HSG B 7,449 90 Weighted Average 1,561 20.96% Pervious Area 5,888 79.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 700: Drainage Area 700 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=7,449 sf Runoff Volume=0.090 af Runoff Depth>6.33" Tc=6.0 min CN=90 1.23 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 19HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 750: Drainage Area 750 Runoff = 1.17 cfs @ 12.09 hrs, Volume= 0.082 af, Depth> 5.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 3,364 61 >75% Grass cover, Good, HSG B * 4,515 98 Paving and Roofs, HSG B 7,879 82 Weighted Average 3,364 42.70% Pervious Area 4,515 57.30% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 750: Drainage Area 750 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Type III 24-hr NoHo-100 Rainfall=7.90" Runoff Area=7,879 sf Runoff Volume=0.082 af Runoff Depth>5.44" Tc=6.0 min CN=82 1.17 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 20HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 800: Drainage Area 800 Runoff = 0.45 cfs @ 12.09 hrs, Volume= 0.033 af, Depth> 6.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr NoHo-100 Rainfall=7.90" Area (sf) CN Description 561 61 >75% Grass cover, Good, HSG B 2,159 98 Paved parking, HSG B 2,720 90 Weighted Average 561 20.62% Pervious Area 2,159 79.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum Subcatchment 800: Drainage Area 800 Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)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 NoHo-100 Rainfall=7.90" Runoff Area=2,720 sf Runoff Volume=0.033 af Runoff Depth>6.33" Tc=6.0 min CN=90 0.45 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 21HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 12"(1): 12" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated [85] Warning: Oscillations may require smaller dt or Finer Routing (severity=3) Inflow Area = 0.305 ac, 78.07% Impervious, Inflow Depth = 1.04" for NoHo-100 event Inflow = 1.58 cfs @ 12.21 hrs, Volume= 0.026 af Outflow = 1.39 cfs @ 12.21 hrs, Volume= 0.026 af, Atten= 12%, Lag= 0.4 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 3.50 fps, Min. Travel Time= 0.2 min Avg. Velocity = 1.66 fps, Avg. Travel Time= 0.3 min Peak Storage= 14 cf @ 12.21 hrs Average Depth at Peak Storage= 0.54' Bank-Full Depth= 1.00' Flow Area= 0.8 sf, Capacity= 2.73 cfs 12.0" Round Pipe n= 0.013 Corrugated PE, smooth interior Length= 34.0' Slope= 0.0059 '/' Inlet Invert= 130.50', Outlet Invert= 130.30' Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 22HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Reach 12"(1): 12" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.305 ac Avg. Flow Depth=0.54' Max Vel=3.50 fps 12.0" Round Pipe n=0.013 L=34.0' S=0.0059 '/' Capacity=2.73 cfs 1.58 cfs 1.39 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 23HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 12"(1): 12" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 130.50 0.0 0 130.51 0.0 0 130.52 0.0 0 130.53 0.0 0 130.54 0.0 0 130.55 0.0 0 130.56 0.0 1 130.57 0.0 1 130.58 0.0 1 130.59 0.0 1 130.60 0.0 1 130.61 0.0 2 130.62 0.1 2 130.63 0.1 2 130.64 0.1 2 130.65 0.1 3 130.66 0.1 3 130.67 0.1 3 130.68 0.1 3 130.69 0.1 4 130.70 0.1 4 130.71 0.1 4 130.72 0.1 4 130.73 0.1 5 130.74 0.1 5 130.75 0.2 5 130.76 0.2 6 130.77 0.2 6 130.78 0.2 6 130.79 0.2 6 130.80 0.2 7 130.81 0.2 7 130.82 0.2 7 130.83 0.2 8 130.84 0.2 8 130.85 0.2 8 130.86 0.3 9 130.87 0.3 9 130.88 0.3 9 130.89 0.3 10 130.90 0.3 10 130.91 0.3 10 130.92 0.3 11 130.93 0.3 11 130.94 0.3 11 130.95 0.3 12 130.96 0.4 12 130.97 0.4 12 130.98 0.4 13 130.99 0.4 13 131.00 0.4 13 131.01 0.4 14 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 131.02 0.4 14 131.03 0.4 14 131.04 0.4 15 131.05 0.4 15 131.06 0.5 15 131.07 0.5 16 131.08 0.5 16 131.09 0.5 16 131.10 0.5 17 131.11 0.5 17 131.12 0.5 17 131.13 0.5 18 131.14 0.5 18 131.15 0.5 18 131.16 0.5 19 131.17 0.6 19 131.18 0.6 19 131.19 0.6 20 131.20 0.6 20 131.21 0.6 20 131.22 0.6 21 131.23 0.6 21 131.24 0.6 21 131.25 0.6 21 131.26 0.6 22 131.27 0.6 22 131.28 0.7 22 131.29 0.7 23 131.30 0.7 23 131.31 0.7 23 131.32 0.7 23 131.33 0.7 24 131.34 0.7 24 131.35 0.7 24 131.36 0.7 24 131.37 0.7 25 131.38 0.7 25 131.39 0.7 25 131.40 0.7 25 131.41 0.8 26 131.42 0.8 26 131.43 0.8 26 131.44 0.8 26 131.45 0.8 26 131.46 0.8 26 131.47 0.8 26 131.48 0.8 27 131.49 0.8 27 131.50 0.8 27 Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 24HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 12"(2): 12" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 0.181 ac, 57.30% Impervious, Inflow Depth = 1.57" for NoHo-100 event Inflow = 1.26 cfs @ 12.14 hrs, Volume= 0.024 af Outflow = 1.23 cfs @ 12.15 hrs, Volume= 0.024 af, Atten= 2%, Lag= 0.3 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 3.58 fps, Min. Travel Time= 0.2 min Avg. Velocity = 1.41 fps, Avg. Travel Time= 0.5 min Peak Storage= 16 cf @ 12.14 hrs Average Depth at Peak Storage= 0.47' Bank-Full Depth= 1.00' Flow Area= 0.8 sf, Capacity= 2.91 cfs 12.0" Round Pipe n= 0.013 Corrugated PE, smooth interior Length= 45.0' Slope= 0.0067 '/' Inlet Invert= 133.50', Outlet Invert= 133.20' Reach 12"(2): 12" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.181 ac Avg. Flow Depth=0.47' Max Vel=3.58 fps 12.0" Round Pipe n=0.013 L=45.0' S=0.0067 '/' Capacity=2.91 cfs 1.26 cfs 1.23 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 25HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 12"(2): 12" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 133.50 0.0 0 133.51 0.0 0 133.52 0.0 0 133.53 0.0 0 133.54 0.0 0 133.55 0.0 1 133.56 0.0 1 133.57 0.0 1 133.58 0.0 1 133.59 0.0 2 133.60 0.0 2 133.61 0.0 2 133.62 0.1 2 133.63 0.1 3 133.64 0.1 3 133.65 0.1 3 133.66 0.1 4 133.67 0.1 4 133.68 0.1 4 133.69 0.1 5 133.70 0.1 5 133.71 0.1 5 133.72 0.1 6 133.73 0.1 6 133.74 0.1 7 133.75 0.2 7 133.76 0.2 7 133.77 0.2 8 133.78 0.2 8 133.79 0.2 9 133.80 0.2 9 133.81 0.2 9 133.82 0.2 10 133.83 0.2 10 133.84 0.2 11 133.85 0.2 11 133.86 0.3 11 133.87 0.3 12 133.88 0.3 12 133.89 0.3 13 133.90 0.3 13 133.91 0.3 14 133.92 0.3 14 133.93 0.3 15 133.94 0.3 15 133.95 0.3 15 133.96 0.4 16 133.97 0.4 16 133.98 0.4 17 133.99 0.4 17 134.00 0.4 18 134.01 0.4 18 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 134.02 0.4 19 134.03 0.4 19 134.04 0.4 19 134.05 0.4 20 134.06 0.5 20 134.07 0.5 21 134.08 0.5 21 134.09 0.5 22 134.10 0.5 22 134.11 0.5 23 134.12 0.5 23 134.13 0.5 23 134.14 0.5 24 134.15 0.5 24 134.16 0.5 25 134.17 0.6 25 134.18 0.6 26 134.19 0.6 26 134.20 0.6 26 134.21 0.6 27 134.22 0.6 27 134.23 0.6 28 134.24 0.6 28 134.25 0.6 28 134.26 0.6 29 134.27 0.6 29 134.28 0.7 30 134.29 0.7 30 134.30 0.7 30 134.31 0.7 31 134.32 0.7 31 134.33 0.7 31 134.34 0.7 32 134.35 0.7 32 134.36 0.7 32 134.37 0.7 33 134.38 0.7 33 134.39 0.7 33 134.40 0.7 34 134.41 0.8 34 134.42 0.8 34 134.43 0.8 34 134.44 0.8 34 134.45 0.8 35 134.46 0.8 35 134.47 0.8 35 134.48 0.8 35 134.49 0.8 35 134.50 0.8 35 Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 26HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Reach 15": 15" Overflow Pipe [52] Hint: Inlet/Outlet conditions not evaluated [82] Warning: Early inflow requires earlier time span [79] Warning: Submerged Pond S1 Primary device # 1 by 0.71' Inflow Area = 0.515 ac, 92.94% Impervious, Inflow Depth > 6.86" for NoHo-100 event Inflow = 2.29 cfs @ 12.20 hrs, Volume= 0.294 af Outflow = 2.29 cfs @ 12.21 hrs, Volume= 0.294 af, Atten= 0%, Lag= 0.2 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.73 fps, Min. Travel Time= 0.1 min Avg. Velocity = 1.29 fps, Avg. Travel Time= 0.2 min Peak Storage= 16 cf @ 12.21 hrs Average Depth at Peak Storage= 0.81' Bank-Full Depth= 1.25' Flow Area= 1.2 sf, Capacity= 3.05 cfs 15.0" Round Pipe n= 0.020 Corrugated PE, corrugated interior Length= 19.0' Slope= 0.0053 '/' Inlet Invert= 118.90', Outlet Invert= 118.80' Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 27HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Reach 15": 15" Overflow Pipe Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.515 ac Avg. Flow Depth=0.81' Max Vel=2.73 fps 15.0" Round Pipe n=0.020 L=19.0' S=0.0053 '/' Capacity=3.05 cfs 2.29 cfs 2.29 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 28HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Reach 15": 15" Overflow Pipe Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 118.90 0.0 0 118.92 0.0 0 118.94 0.0 0 118.96 0.0 0 118.98 0.0 1 119.00 0.0 1 119.02 0.1 1 119.04 0.1 1 119.06 0.1 2 119.08 0.1 2 119.10 0.1 2 119.12 0.1 3 119.14 0.2 3 119.16 0.2 4 119.18 0.2 4 119.20 0.2 4 119.22 0.2 5 119.24 0.3 5 119.26 0.3 6 119.28 0.3 6 119.30 0.3 6 119.32 0.4 7 119.34 0.4 7 119.36 0.4 8 119.38 0.4 8 119.40 0.5 9 119.42 0.5 9 119.44 0.5 10 119.46 0.5 10 119.48 0.6 11 119.50 0.6 11 119.52 0.6 12 119.54 0.6 12 119.56 0.7 12 119.58 0.7 13 119.60 0.7 13 119.62 0.7 14 119.64 0.8 14 119.66 0.8 15 119.68 0.8 15 119.70 0.8 16 119.72 0.9 16 119.74 0.9 17 119.76 0.9 17 119.78 0.9 18 119.80 0.9 18 119.82 1.0 18 119.84 1.0 19 119.86 1.0 19 119.88 1.0 20 119.90 1.1 20 119.92 1.1 20 Elevation (feet) End-Area (sq-ft) Storage (cubic-feet) 119.94 1.1 21 119.96 1.1 21 119.98 1.1 21 120.00 1.1 22 120.02 1.2 22 120.04 1.2 22 120.06 1.2 23 120.08 1.2 23 120.10 1.2 23 120.12 1.2 23 120.14 1.2 23 Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 29HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S1: Subsurface Storage System #1 [82] Warning: Early inflow requires earlier time span Inflow Area = 0.515 ac, 92.94% Impervious, Inflow Depth > 6.86" for NoHo-100 event Inflow = 3.86 cfs @ 12.09 hrs, Volume= 0.295 af Outflow = 2.29 cfs @ 12.20 hrs, Volume= 0.294 af, Atten= 41%, Lag= 7.0 min Primary = 2.29 cfs @ 12.20 hrs, Volume= 0.294 af Secondary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 121.20' @ 12.20 hrs Surf.Area= 537 sf Storage= 1,316 cf Plug-Flow detention time= 3.5 min calculated for 0.293 af (100% of inflow) Center-of-Mass det. time= 3.4 min ( 741.5 - 738.1 ) Volume Invert Avail.Storage Storage Description #1 119.00' 1,483 cf 24.0" Round Pipe Storage L= 472.0' S= 0.0020 '/' Device Routing Invert Outlet Devices #1 Primary 119.00'8.0" Vert. Orifice/Grate C= 0.600 #2 Secondary 121.20'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Primary OutFlow Max=2.29 cfs @ 12.20 hrs HW=121.19' (Free Discharge) 1=Orifice/Grate (Orifice Controls 2.29 cfs @ 6.56 fps) Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=119.09' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 30HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S1: Subsurface Storage System #1 Inflow Outflow Primary Secondary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)4 3 2 1 0 Inflow Area=0.515 ac Peak Elev=121.20' Storage=1,316 cf 3.86 cfs 2.29 cfs 2.29 cfs 0.00 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 31HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S1: Subsurface Storage System #1 Elevation (feet) Storage (cubic-feet) 119.00 0 119.02 0 119.04 0 119.06 0 119.08 1 119.10 1 119.12 2 119.14 3 119.16 4 119.18 5 119.20 7 119.22 8 119.24 10 119.26 13 119.28 15 119.30 18 119.32 21 119.34 24 119.36 28 119.38 32 119.40 36 119.42 41 119.44 46 119.46 51 119.48 57 119.50 63 119.52 69 119.54 76 119.56 83 119.58 90 119.60 98 119.62 106 119.64 115 119.66 124 119.68 133 119.70 142 119.72 152 119.74 163 119.76 173 119.78 185 119.80 196 119.82 208 119.84 220 119.86 233 119.88 246 119.90 260 119.92 274 119.94 288 119.96 303 119.98 318 120.00 333 120.02 349 Elevation (feet) Storage (cubic-feet) 120.04 364 120.06 381 120.08 397 120.10 413 120.12 430 120.14 447 120.16 464 120.18 481 120.20 498 120.22 516 120.24 533 120.26 551 120.28 568 120.30 586 120.32 604 120.34 622 120.36 640 120.38 658 120.40 676 120.42 694 120.44 712 120.46 731 120.48 749 120.50 767 120.52 785 120.54 803 120.56 821 120.58 839 120.60 857 120.62 875 120.64 893 120.66 911 120.68 929 120.70 946 120.72 964 120.74 981 120.76 998 120.78 1,016 120.80 1,033 120.82 1,050 120.84 1,066 120.86 1,083 120.88 1,099 120.90 1,115 120.92 1,131 120.94 1,147 120.96 1,162 120.98 1,177 121.00 1,192 121.02 1,206 121.04 1,220 121.06 1,234 Elevation (feet) Storage (cubic-feet) 121.08 1,247 121.10 1,260 121.12 1,272 121.14 1,284 121.16 1,296 121.18 1,307 121.20 1,318 121.22 1,328 121.24 1,338 121.26 1,348 121.28 1,357 121.30 1,366 121.32 1,375 121.34 1,383 121.36 1,391 121.38 1,398 121.40 1,406 121.42 1,412 121.44 1,419 121.46 1,425 121.48 1,430 121.50 1,436 121.52 1,441 121.54 1,445 121.56 1,450 121.58 1,454 121.60 1,458 121.62 1,461 121.64 1,464 121.66 1,467 121.68 1,470 121.70 1,472 121.72 1,474 121.74 1,476 121.76 1,477 121.78 1,479 121.80 1,480 121.82 1,481 121.84 1,482 121.86 1,482 121.88 1,482 121.90 1,483 121.92 1,483 121.94 1,483 Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 32HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S2: Subsurface Recharge Trench System #1 [82] Warning: Early inflow requires earlier time span [93] Warning: Storage range exceeded by 0.04' Inflow Area = 0.305 ac, 78.07% Impervious, Inflow Depth > 6.25" for NoHo-100 event Inflow = 2.16 cfs @ 12.09 hrs, Volume= 0.159 af Outflow = 1.73 cfs @ 12.21 hrs, Volume= 0.159 af, Atten= 20%, Lag= 7.2 min Discarded = 0.15 cfs @ 11.15 hrs, Volume= 0.132 af Primary = 1.58 cfs @ 12.21 hrs, Volume= 0.026 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 133.24' @ 12.21 hrs Surf.Area= 1,033 sf Storage= 1,906 cf Plug-Flow detention time= 83.8 min calculated for 0.159 af (100% of inflow) Center-of-Mass det. time= 83.6 min ( 833.0 - 749.4 ) Volume Invert Avail.Storage Storage Description #1A 129.70' 976 cf 16.67'W x 62.00'L x 3.50'H Field A 3,617 cf Overall - 1,176 cf Embedded = 2,440 cf x 40.0% Voids #2A 130.70' 930 cf ADS N-12 24" x 15 Inside #1 Inside= 23.8"W x 23.8"H => 3.10 sf x 20.00'L = 62.0 cf Outside= 28.0"W x 28.0"H => 3.92 sf x 20.00'L = 78.4 cf 15 Chambers in 5 Rows 1,906 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 129.70'6.250 in/hr Exfiltration over Surface area #2 Primary 133.00'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.15 cfs @ 11.15 hrs HW=129.74' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) Primary OutFlow Max=1.41 cfs @ 12.21 hrs HW=133.22' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 1.41 cfs @ 1.30 fps) Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 33HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S2: Subsurface Recharge Trench System #1 - Chamber Wizard Field A Chamber Model = ADS N-12 24" (ADS N-12® Pipe) Inside= 23.8"W x 23.8"H => 3.10 sf x 20.00'L = 62.0 cf Outside= 28.0"W x 28.0"H => 3.92 sf x 20.00'L = 78.4 cf 28.0" Wide + 12.0" Spacing = 40.0" C-C Row Spacing 3 Chambers/Row x 20.00' Long = 60.00' Row Length +12.0" End Stone x 2 = 62.00' Base Length 5 Rows x 28.0" Wide + 12.0" Spacing x 4 + 6.0" Side Stone x 2 = 16.67' Base Width 12.0" Base + 28.0" Chamber Height + 2.0" Cover = 3.50' Field Height 15 Chambers x 62.0 cf = 930.0 cf Chamber Storage 15 Chambers x 78.4 cf = 1,175.9 cf Displacement 3,616.8 cf Field - 1,175.9 cf Chambers = 2,440.9 cf Stone x 40.0% Voids = 976.4 cf Stone Storage Chamber Storage + Stone Storage = 1,906.4 cf = 0.044 af Overall Storage Efficiency = 52.7% Overall System Size = 62.00' x 16.67' x 3.50' 15 Chambers 134.0 cy Field 90.4 cy Stone Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 34HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S2: Subsurface Recharge Trench System #1 Inflow Outflow Discarded Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.305 ac Peak Elev=133.24' Storage=1,906 cf 2.16 cfs 1.73 cfs 0.15 cfs 1.58 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 35HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S2: Subsurface Recharge Trench System #1 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 129.70 1,033 0 129.75 1,033 21 129.80 1,033 41 129.85 1,033 62 129.90 1,033 83 129.95 1,033 103 130.00 1,033 124 130.05 1,033 145 130.10 1,033 165 130.15 1,033 186 130.20 1,033 207 130.25 1,033 227 130.30 1,033 248 130.35 1,033 269 130.40 1,033 289 130.45 1,033 310 130.50 1,033 331 130.55 1,033 351 130.60 1,033 372 130.65 1,033 393 130.70 1,033 413 130.75 1,033 432 130.80 1,033 448 130.85 1,033 463 130.90 1,033 479 130.95 1,033 501 131.00 1,033 527 131.05 1,033 554 131.10 1,033 584 131.15 1,033 614 131.20 1,033 646 131.25 1,033 679 131.30 1,033 712 131.35 1,033 746 131.40 1,033 781 131.45 1,033 817 131.50 1,033 853 131.55 1,033 889 131.60 1,033 926 131.65 1,033 963 131.70 1,033 1,000 131.75 1,033 1,038 131.80 1,033 1,075 131.85 1,033 1,113 131.90 1,033 1,150 131.95 1,033 1,188 132.00 1,033 1,225 132.05 1,033 1,263 132.10 1,033 1,300 132.15 1,033 1,337 132.20 1,033 1,374 132.25 1,033 1,410 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 132.30 1,033 1,446 132.35 1,033 1,481 132.40 1,033 1,516 132.45 1,033 1,550 132.50 1,033 1,583 132.55 1,033 1,615 132.60 1,033 1,647 132.65 1,033 1,677 132.70 1,033 1,705 132.75 1,033 1,732 132.80 1,033 1,757 132.85 1,033 1,778 132.90 1,033 1,793 132.95 1,033 1,808 133.00 1,033 1,825 133.05 1,033 1,844 133.10 1,033 1,865 133.15 1,033 1,885 133.20 1,033 1,906 Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 36HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Pond S3: Subsurface Recharge Trench System #2 [92] Warning: Device #2 is above defined storage [93] Warning: Storage range exceeded by 0.46' [88] Warning: Qout>Qin may require smaller dt or Finer Routing [85] Warning: Oscillations may require smaller dt or Finer Routing (severity=17) Inflow Area = 0.181 ac, 57.30% Impervious, Inflow Depth > 5.44" for NoHo-100 event Inflow = 1.17 cfs @ 12.09 hrs, Volume= 0.082 af Outflow = 1.32 cfs @ 12.14 hrs, Volume= 0.079 af, Atten= 0%, Lag= 3.2 min Discarded = 0.06 cfs @ 10.95 hrs, Volume= 0.055 af Primary = 1.26 cfs @ 12.14 hrs, Volume= 0.024 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 135.93' @ 12.14 hrs Surf.Area= 712 sf Storage= 763 cf Plug-Flow detention time= 82.8 min calculated for 0.079 af (96% of inflow) Center-of-Mass det. time= 67.1 min ( 834.4 - 767.4 ) Volume Invert Avail.Storage Storage Description #1A 133.10' 585 cf 3.21'W x 222.00'L x 2.38'H Field A 1,692 cf Overall - 230 cf Embedded = 1,462 cf x 40.0% Voids #2A 134.10' 178 cf ADS N-12 12" x 11 Inside #1 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 763 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 133.10'3.750 in/hr Exfiltration over Surface area #2 Primary 135.70'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.06 cfs @ 10.95 hrs HW=133.13' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=1.15 cfs @ 12.14 hrs HW=135.92' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 1.15 cfs @ 1.32 fps) Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 37HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S3: Subsurface Recharge Trench System #2 - Chamber Wizard Field A Chamber Model = ADS N-12 12" (ADS N-12® Pipe) Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 11 Chambers/Row x 20.00' Long = 220.00' Row Length +12.0" End Stone x 2 = 222.00' Base Length 1 Rows x 14.5" Wide + 12.0" Side Stone x 2 = 3.21' Base Width 12.0" Base + 14.5" Chamber Height + 2.0" Cover = 2.38' Field Height 11 Chambers x 16.2 cf = 178.2 cf Chamber Storage 11 Chambers x 20.9 cf = 230.3 cf Displacement 1,692.3 cf Field - 230.3 cf Chambers = 1,462.0 cf Stone x 40.0% Voids = 584.8 cf Stone Storage Chamber Storage + Stone Storage = 763.0 cf = 0.018 af Overall Storage Efficiency = 45.1% Overall System Size = 222.00' x 3.21' x 2.38' 11 Chambers 62.7 cy Field 54.1 cy Stone Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 38HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Pond S3: Subsurface Recharge Trench System #2 Inflow Outflow Discarded Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.181 ac Peak Elev=135.93' Storage=763 cf 1.17 cfs 1.32 cfs 0.06 cfs 1.26 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 39HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond S3: Subsurface Recharge Trench System #2 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 133.10 712 0 133.15 712 14 133.20 712 28 133.25 712 43 133.30 712 57 133.35 712 71 133.40 712 85 133.45 712 100 133.50 712 114 133.55 712 128 133.60 712 142 133.65 712 157 133.70 712 171 133.75 712 185 133.80 712 199 133.85 712 214 133.90 712 228 133.95 712 242 134.00 712 256 134.05 712 271 134.10 712 285 134.15 712 298 134.20 712 310 134.25 712 325 134.30 712 341 134.35 712 359 134.40 712 378 134.45 712 397 134.50 712 417 134.55 712 437 134.60 712 457 134.65 712 478 134.70 712 498 134.75 712 519 134.80 712 539 134.85 712 560 134.90 712 580 134.95 712 600 135.00 712 619 135.05 712 638 135.10 712 656 135.15 712 673 135.20 712 688 135.25 712 700 135.30 712 713 135.35 712 727 135.40 712 741 135.45 712 756 135.50 712 763 135.55 712 763 135.60 712 763 135.65 712 763 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 135.70 712 763 135.75 712 763 135.80 712 763 135.85 712 763 135.90 712 763 Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 40HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x1000: Hawley Street Top Inflow Area = 0.589 ac, 81.25% Impervious, Inflow Depth > 6.39" for NoHo-100 event Inflow = 2.47 cfs @ 12.19 hrs, Volume= 0.314 af Primary = 2.47 cfs @ 12.19 hrs, Volume= 0.314 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x1000: Hawley Street Top Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.589 ac 2.47 cfs 2.47 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 41HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x2000: Hawley Street Bottom Inflow Area = 0.571 ac, 44.87% Impervious, Inflow Depth > 4.86" for NoHo-100 event Inflow = 2.33 cfs @ 12.14 hrs, Volume= 0.232 af Primary = 2.33 cfs @ 12.14 hrs, Volume= 0.232 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x2000: Hawley Street Bottom Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.571 ac 2.33 cfs 2.33 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 42HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x3000: Off-Site South Inflow Area = 0.013 ac, 0.00% Impervious, Inflow Depth > 3.11" for NoHo-100 event Inflow = 0.05 cfs @ 12.10 hrs, Volume= 0.003 af Primary = 0.05 cfs @ 12.10 hrs, Volume= 0.003 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x3000: Off-Site South Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.013 ac 0.05 cfs 0.05 cfs Type III 24-hr NoHo-100 Rainfall=7.90"42540-PR Printed 10/31/2019Prepared by VHB Page 43HydroCAD® 10.00-25 s/n 01038 © 2019 HydroCAD Software Solutions LLC Summary for Link x4000: Phillips Place Inflow Area = 0.720 ac, 73.20% Impervious, Inflow Depth > 2.89" for NoHo-100 event Inflow = 2.69 cfs @ 12.19 hrs, Volume= 0.173 af Primary = 2.69 cfs @ 12.19 hrs, Volume= 0.173 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link x4000: Phillips Place Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)3 2 1 0 Inflow Area=0.720 ac 2.69 cfs 2.69 cfs