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HomeMy WebLinkAbouttm_bgy Inflatable Park Stormwater Report 11.29.2021 Prepared by: 349 Main Street West Yarmouth, MA 02673 The picture can't be displayed. STORMWATER MANAGEMENT REPORT CAPE COD INFLATABLE PARK 492, 498, 512, 518, 526, & 532 ROUTE 28 WEST YARMOUTH, MA 02673 OCTOBER 2021 REVISED: NOVEMBER 2021 Owner/Applicant: SANDBAR HOLDINGS, LLC 512 Route 28 West Yarmouth, MA 02673 BSC Job Number: 4-8592.05 Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA TABLE OF CONTENTS 1.0 PROJECT INFORMATION 1.01 PROJECT DESCRIPTION 1.02 PRE-CONSTRUCTION CONDITIONS 1.03 POST-CONSTRUCTION CONDITIONS 2.0 DRAINAGE SUMMARY 2.01 STORMWATER STANDARD 1 – NEW STORMWATER CONVEYANCES 2.02 STORMWATER STANDARD 2 – STORMWATER RUNOFF RATES 2.03 STORMWATER STANDARD 3 – GROUNDWATER RECHARGE 2.04 STORMWATER STANDARD 4 – TSS REMOVAL 2.05 STORMWATER STANDARD 5 – LUHPPL 2.06 STORMWATER STANDARD 6 – CRITICAL AREAS 2.07 STORMWATER STANDARD 7 – REDEVELOPMENT PROJECTS 2.08 STORMWATER STANDARD 8 – SEDIMENTATION & EROSION CONTROL PLAN 2.09 STORMWATER STANDARD 9 – LONG TERM O&M PLAN 2.10 STORMWATER STANDARD 10 – ILLICIT DISCHARGES 2.11 CONCLUSIONS 3.0 MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION CHECKLIST FOR STORMWATER REPORT 4.0 CONSTRUCTION PERIOD POLLUTION PREVENTION AND EROSION AND SEDIMENTATION CONTROL 5.0 LONG-TERM POLLUTION PREVENTION & OPERATION AND MAINTENANCE PLAN 6.0 HYDROLOGY CALCULATIONS 6.01 PRE-CONSTRUCTION DRAINAGE AREA MAP 6.02 PRE-CONSTRUCTION HYDROLOGY CALCULATIONS (HYDROCAD™ PRINTOUTS) 6.03 POST-CONSTRUCTION DRAINAGE AREA MAP 6.04 POST-CONSTRUCTION HYDROLOGY CALCULATIONS (HYDROCAD™ PRINTOUTS) 7.0 ADDITIONAL DRAINAGE CALCULATIONS 7.01 TSS REMOVAL CALCULATIONS 7.02 GROUNDWATER RECHARGE VOLUME CALCULATIONS 7.03 WATER QUALITY VOLUME CALCULATIONS 7.04 STORMCEPTOR SIZING REPORTS 7.05 PIPE SIZING CALCULATIONS APPENDICES APPENDIX A – USGS LOCUS MAP APPENDIX B – FEMA MAP APPENDIX C – WEB SOIL SURVEY REPORT APPENDIX D – NOAA ATLAS 14, POINT PRECIPITATION FREQUENCY ESTIMATES Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA SECTION 1.0 PROJECT INFORMATION Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 1.01 PROJECT DESCRIPTION The proposed project is located at 492, 498, 512, 518, 526, & 532 Route 28 in West Yarmouth, Massachusetts. The project site is a previously developed, 13.8± acre commercial property, that is the location of the Cape Cod Inflatable Park. In addition to the Inflatable Park, the site also comprises the sites of the former Mayflower Inn and the Beachway Motel. The site is bordered by commercial properties to the east, west and south along Route 28, and residential properties to the north. A USGS locus map is provided in Appendix A. Sandbar Holdings, LLC (Applicant) is proposing to expand the existing amusement park, known as the Cape Cod Inflatable Park, on Route 28 in West Yarmouth, Massachusetts. The improvements on the eastern half of the site are associated with the expansion of the amusement park, the creation of new rides and a general reconfiguration of this section of the park. The western half of the site, which contains the existing hotel buildings and an existing clamshell surface parking lot, is the subject of this Stormwater Report. The Applicant is proposing to demolish the existing hotels and reconfigure and expand the existing parking lot to accommodate the expansion of the amusement park. This project will entail the installation of a stormwater collection and conveyance system, stormwater management systems for the treatment, attenuation and recharge of stormwater runoff, a paved apron at the entrance, and landscaping. The stormwater analysis is limited to the proposed improvements in the western half of the site. The proposed changes include the demolition of two (2) existing buildings, construction of a building for facility use, reconfiguration of the existing clamshell surface parking area, installation of stormwater management facilities and landscaping. The Project has been designed to comply fully with the Massachusetts Department of Environmental Protection’s Stormwater Management Standards and the Town of Yarmouth Stormwater Management Regulations (for redevelopment projects). 1.02 PRE-CONSTRUCTION CONDITIONS The site topography contains moderate slopes, ranging from 0 to 3% across the site. The northern half of the site drains in an easterly direction towards the existing clamshell parking area, where it is captured and managed by existing stormwater infrastructure. This area is referred to as Subcatchment 4S in the pre-development HydroCAD model. The southern half of the site drains offsite, generally in a southerly direction towards Route 28. The pre-construction HydroCAD model has been developed with three (3) distinct catchment areas (4S, 5S, & 6S). Subcatchment 4S is currently retained onsite and flows to the east towards the previously mentioned drainage basin. Subcatchment Area 5S flows to an depression at the southwestern corner of the property, where it collects and ponds until flowing offsite onto an existing catch basin on Route 28. The existing hotels and their surrounding areas are represented by Subcatchment 6S, which flows offsite in a southerly direction towards Route 28. NRCS Web Soil Survey identifies the soils underlying the site as Map Unit 252A Carver coarse sand, 0 to 3 percent slopes. Based on Web Soil Survey, these soils are excessively drained and are categorized as belonging to Hydrologic Soil Group A. 1.03 POST-CONSTRUCTION CONDITIONS The site has been designed in such a manner that the Post-Construction drainage patterns generally mirror those of the Pre-Construction condition. Site drainage will be collected and managed on site, with negligible flows offsite to the west and south, significantly reducing the offsite flow. Stormwater runoff from all proposed impervious areas will be collected, treated and recharged onsite. Runoff from site will be collected through a stormwater collection and conveyance system, consisting of catch basins, drain manholes and stormdrains, which will convey stormwater to one of three (3) subsurface infiltration systems, consisting of Stormtech MC-4500 leaching chambers. Each of the proposed systems has been designed to attenuate and recharge a 100-year storm. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Stormwater runoff throughout the site will be collected in deep sump & hooded catch basins and routed to the various BMPs via stormdrains and drain manholes. Stormwater runoff from the impervious portions of the site will be pre- treated to achieve a minimum Total Suspended Solids (TSS) removal rate of 44% (due to the presence of rapidly draining soils), prior to recharge. Pretreatment will be accomplished through the use of deep sump/hooded catch basins and StormCeptor water quality treatment units. Following pre-treatment, stormwater will be conveyed to one of the proposed subsurface infiltration systems for recharge. Overall, the proposed stormwater management systems will achieve an 82% TSS removal rate of the average annual post-construction load. Specifics of the project’s compliance with the MassDEP Stormwater Management Standards are discussed in detail in the following sections. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA SECTION 2.0 DRAINAGE SUMMARY Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 2.01 Stormwater Standard 1 – New Stormwater Conveyances Per MassDEP Stormwater Management Standard #1, no new outfalls may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. There are no known stormwater outfalls in this development and no new outfalls are proposed. 2.02 Stormwater Standard 2 – Stormwater Runoff Rates Watershed modeling was performed using HydroCAD Stormwater Modeling Software version 10.0, a computer aided design program that combines SCS runoff methodology with standard hydraulic calculations. A model of the site’s hydrology was developed for both the Pre- and Post- Construction conditions to analyze the runoff for the design storms of 2-, 10-, 25-, 50- and 100- year, 24-hour storms. The design storm elevations have been established from NOAA Atlas 14, please see Appendix D, for this table of design storms. Please reference the table below to see the peak discharge rates for comparison between the Pre- and Post-Construction conditions. Peak Flow Discharge Rates Node 4R –Flow to Existing Drainage System (Northeast) Storm Event Pre-Construction Peak Discharge Rate (cfs) Post- Construction Peak Discharge Rate (cfs) Change in Peak Discharge Rate (cfs) 2-Year 3.45 0.81 -2.64 10-Year 5.13 1.38 -3.75 25-Year 6.18 1.74 -4.44 50-Year 6.95 2.01 -4.94 100-Year 7.78 2.30 -5.48 Node 5R – Offsite Flow to Southwest Storm Event Pre- Construction Peak Discharge Rate (cfs) Post- Construction Peak Discharge Rate (cfs) Change in Peak Discharge Rate (cfs) 2-Year 2.46 0.00 -2.46 10-Year 4.08 0.00 -4.08 25-Year 5.10 0.01 -5.09 50-Year 5.85 0.03 -5.82 100-Year 6.65 0.06 -6.59 Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Node 6R – Offsite Flow to Route 28 Storm Event Pre- Construction Peak Discharge Rate (cfs) Post- Construction Peak Discharge Rate (cfs) Change in Peak Discharge Rate (cfs) 2-Year 1.42 0.02 -1.40 10-Year 2.50 0.12 -2.38 25-Year 3.19 0.21 -2.98 50-Year 3.70 0.28 -3.42 100-Year 4.25 0.36 -3.89 2.03 Stormwater Standard 3 – Groundwater Recharge The ground water recharge is estimated based on the Massachusetts Stormwater Management Standard #3, as follows: Rv = F x impervious area Rv= Required Recharge Volume, expressed in Ft3, cubic yards, or acre-feet F= Target Depth Factor associated with each Hydrologic Soil Group Impervious Area= pavement and rooftop area on site Table 1.2 Recharge Target Depth by Hydrologic Soil Group NRCS HYDROLOGIC SOIL TYPE APPROX. SOIL TEXTURE TARGET DEPTH FACTOR (F) A sand 0.60-inch B loam 0.35-inch C silty loam 0.25-inch D clay 0.10-inch The Natural Resources Conservation Service (NRCS) has classified the soils underlying the project site as being entirely 252A “Carver Coarse Sand, 0-3 percent slopes”. To determine the recharge volume provided in the recharge system, the Static Method was used as described in the DEP’s Massachusetts Stormwater Handbook, Volume 3. A drawdown calculation was performed in accordance with the DEP’s Massachusetts Stormwater Handbook, Volume 3, to verify that the proposed recharge systems would drain completely within 72-hours. This drawdown calculation along with calculations to determine the recharge required are provided in Section 7.0 of this report. 2.04 Stormwater Standard 4 – TSS Removal As a re-development, the project stormwater management system will achieve a TSS removal greater than 80%. The proposed stormwater management system has been designed to provide treatment of runoff in order to reduce suspended solids prior to discharge off-site through the implementation of the following best management practices:  Deep Sump Hooded Catch Basins (Pre-treatment)  Stormceptor STC 450i/900 Water Quality Units (or approved equal) (Pre-treatment) Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA  Underground Stormwater Infiltration Systems (Stormtech MC-4500)(80% TSS removal) The water quality volume is defined as the runoff volume requiring TSS Removal for the site and is equal to 1-inch of runoff over the total impervious area of the post-development site. The required water quality volume required for the project is calculated below based on the post-development impervious area. 𝑊𝑄𝑉 ൌ 1.0 𝑖𝑛 𝑥 1 𝑓𝑡 12 𝑖𝑛𝑥 2.38 𝑎𝑐 𝑥 43,560 𝑓𝑡ଶ ൌ 𝟖,𝟔𝟑𝟗 𝒇𝒕𝟑 The infiltration systems have been sized to treat the required water quality volume, according to the more stringent requirements, which are those of the MassDEP Stormwater Management Standards. The Town of Yarmouth Stormwater Regulations (for redevelopment projects) also require the removal of 50% of the average annual load of Total Phosphorus and 30% of the average annual load of Total Nitrogen. Compliance with these additional requirements is achieved pursuant to the requirements of §2.05(5)(b), through the site’s compliance with the requirements of §2.05(3)(b), which requires 44% TSS removal prior to discharging stormwater to an infiltration device. 2.05 Stormwater Standard 5 – Land Uses with Higher Potential Pollutant Loads The Project is not a land use with higher potential pollutant loads; therefore this Standard does not apply. 2.06 Stormwater Standard 6 – Stormwater Discharges to a Critical Area The project is not subject to Standard 6. There are no discharges to any Critical Area, as defined by the Massachusetts Stormwater Handbook. 2.07 Stormwater Standard 7 – Redevelopment Projects This project is designed to fully comply with the MassDEP Stormwater Management Standards. 2.08 Stormwater Standard 8 – Sedimentation and Erosion Control Plan Erosion and sedimentation controls are shown on the Site Preparation page of the plan set (page 3 of 8 in Stormwater Management Site Plan Set and page 3 of 7 in the Site Plan Set). Additionally, a Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan is included in Section 4.0 of this Report. 2.09 Stormwater Standard 9 – Long Term Operation and Maintenance Plan A Long-Term Operation and Maintenance Plan is included in Section 5.0 of this Report. 2.10 Stormwater Standard 10 – Illicit Discharges There are no known illicit discharges on the project site, and none are proposed. A signed, illicit discharge compliance statement will be submitted prior to the start of construction. ∴ Water Quality Volume = 8,639 cubic feet Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 2.11 Conclusion The proposed site design includes the following LID strategies: No disturbance to any wetland resource area, minimizing disturbance to existing trees and shrubs, and use of porous paving materials in lieu of pavement (the proposed parking lot will be surfaced with crushed shells). The Project has been designed to meet or exceed the requirements of the MassDEP Stormwater Management Standards, as well as those of the Town of Yarmouth Stormwater Management Regulations for a redevelopment project. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. SECTION 3.0 MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION CHECKLIST FOR STORMWATER REPORT Stormwater Checklsit.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. Stormwater Checklsit.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 Stormwater Checklsit.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): 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. Stormwater Checklsit.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. Stormwater Checklsit.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. Stormwater Checklsit.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. Stormwater Checklsit.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. Stormwater Checklsit.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. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. SECTION 4.0 CONSTRUCTION PERIOD POLLUTION PREVENTION AND EROSION AND SEDIMENTATION CONTROL PLAN Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. 4.0 CONSTRUCTION PERIOD POLLUTION PREVENTION AND EROSION AND SEDIMENTATION CONTROL PLAN This Section specifies requirements and suggestions for implementation of a Stormwater Pollution Prevention Plan (SWPPP) for the proposed project located at 492, 494, 512, 518, 526, & 532 Route 28, West Yarmouth, Massachusetts. The SWPPP shall be provided and maintained on-site by the Contractor(s) during all construction activities. The SWPPP shall be updated as required to reflect changes to construction activity. The stormwater pollution prevention measures contained in the SWPPP shall be at least the minimum required by Local Regulations. The Contractor shall provide additional measures to prevent pollution from stormwater discharges in compliance with the National Pollution Discharge Elimination System (NPDES) Phase II permit requirements and all other local, state and federal requirements. The SWPPP shall include provisions for, but not be limited to, the following: 1. Construction Trailers 2. Lay-down Areas 3. Equipment Storage Areas 4. Stockpile Areas 5. Disturbed Areas The Contractor shall NOT begin construction without submitting evidence that a NPDES Notice of Intent (NOI) governing the discharge of stormwater from the construction site for the entire construction period has been filed at least fourteen (14) days prior to construction. It is the Contractor's responsibility to complete and file the NOI, unless otherwise determined by the project team. The cost of any fines, construction delays and remedial actions resulting from the Contractor's failure to comply with all provisions of local regulations and Federal NPDES permit requirements shall be paid for by the Contractor at no additional cost to the Owner. As a requirement of the EPA’s NPDES permitting program, each Contractor and Subcontractor responsible for implementing and maintaining stormwater Best Management Practices shall execute a Contractor's Certification form. Erosion and Sedimentation Control The Contractor shall be solely responsible for erosion and sedimentation control at the site. The Contractor shall utilize a system of operations and all necessary erosion and sedimentation control measures, even if not specified herein or elsewhere, to minimize erosion damage at the site to prevent the migration of sediment into environmentally sensitive areas. Environmentally sensitive areas include all wetland resource areas within, and downstream of, the site, and those areas of the site that are not being altered. Erosion and sedimentation control shall be in accordance with this Section, the design drawings, and the following:  “National Pollutant Discharge Elimination System General Permit for Discharges from Construction Activities (EPA Construction General Permit February 16, 2017).  Massachusetts Stormwater Management Policy Handbook issued by the Massachusetts Department of Environmental Protection, January 2008.  Massachusetts Erosion and Sediment Control Guidelines for Urban and Suburban Areas, A Guide for Planners, Designers and Municipal Officials, March 1997. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. The BMP's presented herein should be used as a guide for erosion and sedimentation control and are not intended to be considered specifications for construction. The most important BMP is maintaining a rapid construction process, resulting in prompt stabilization of surfaces, thereby reducing erosion potential. Given the primacy of rapid construction, these guidelines have been designed to allow construction to progress with essentially no hindrance by the erosion control methods prescribed. These guidelines have also been designed with sufficient flexibility to allow the Contractor to modify the suggested methods as required to suit seasonal, atmospheric, and site-specific physical constraints. Another important BMP is the prevention of concentrated water flow. Sheet flow does not have the erosive potential of a concentrated rivulet. These guidelines recommend construction methods that allow localized erosion control and a system of construction, which inhibits the development of shallow concentrated flow. These BMP's shall be maintained throughout the construction process. CONTACT INFORMATION AND RESPONSIBLE PARTIES The following is a list of all project-associated parties: Owner Sandbar Holdings, LLC 512 Route 28 West Yarmouth, MA 02673 Contractor To be determined Environmental Consultant BSC Group, Inc. 349 Route 28, Unit D West Yarmouth, MA 02673 Contact: Brian G. Yergatian, P.E., LEED AP Phone: (617) 896–4590 Email: byergatian@bscgroup.com Qualified SWPPP Inspectors To Be Determined 4.1 Procedural Conditions of the Construction General Permit (CGP) The following list outlines the stormwater responsibilities for all construction operators working on the Project. The operators below agree through a cooperative agreement to abide by the following conditions throughout the duration of the construction project, effective the date of signature of the required SWPPP. These conditions apply to all operators on the project site. The project is subject to EPA’s NPDES General Permit through the CGP. The goal of this permit is to prevent the discharge of pollutants associated with construction activity from entering the existing and proposed storm drain system or surface waters. All contractors/operators involved in clearing, grading and excavation construction activities must sign the appropriate certification statement required, which will remain with the SWPPP. The owner must also sign a certification, which is to remain with the SWPPP in accordance with the signatory requirements of the SWPPP. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. Once the SWPPP is finalized, a signed copy, plus supporting documents, must be held at the project site during construction. A copy must remain available to EPA, State and Local agencies, and other interested parties during normal business hours. The following items associated with this SWPPP must be posted in a prominent place at the construction site until final stabilization has been achieved:  The completed/submitted NOI form  Location where the public can view the SWPPP during normal business hours  A copy of the signed/submitted NOI, permit number issued by the EPA and a copy of the current CGP. Project specific SWPPP documents are not submitted to the US EPA unless the agency specifically requests a copy for review. SWPPP documents requested by a permitting authority, the permitee(s) will submit it in a timely manner. EPA inspectors will be allowed free and unrestricted access to the project site and all related documentation and records kept under the conditions of the permit. The permitee is expected to keep all BMP’s and Stormwater controls operating correctly and maintained regularly. Any additions to the project which will significantly change the anticipated discharges of pollutants, must be reported to the EPA. The EPA should also be notified in advance of any anticipated events of noncompliance. The permitee must also orally inform the EPA of any discharge, which may endanger health or the environment within 24 hours, with a written report following within 5 days. In maintaining the SWPPP, all records and supporting documents will be compiled together in an orderly fashion. Inspection reports and amendments to the SWPPP must remain with the document. Federal regulations require permitee(s) to keep their Project Specific SWPPP and all reports and documents for at least three (3) years after the project is complete. 4.2 Project Description and Intended Construction Sequence The site is currently of parcels serving various commercial uses. The proposed activities will include the following major components:  Demolition of two existing buildings on site, removal of existing septic systems  Site grading, stormwater management facilities, and new utility services, construct one building  New driveway areas, parking areas, and landscaping areas The proposed site development will disturb 2.87± acres. Soil disturbing activities will include site demolition, clearing and grubbing, installing stabilized construction exits, installation of erosion and sedimentation controls, grading, stormwater management systems, utilities, building foundations, construction of site driveways and preparation for final landscaping. Please refer to Table 1 for the projects anticipated construction timetable. A description of BMP’s associated with project timetable and construction-phasing elements is provided in this Erosion and Sediment Control Plan. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. Table 1 – Anticipated Construction Timetable Construction Phasing Activity Anticipated Timetable Demolition, Grubbing and Stripping of Limits of Construction Phase To be determined Rough Site Grading and Site Utilities To be determined Utility Plan Construction To be determined Landscaping To be determined 4.3 Potential Sources of Pollution Any project site activities that have the potential to add pollutants to runoff are subject to the requirements of the SWPPP. Listed below are a description of potential sources of pollution from both sedimentation to Stormwater runoff, and pollutants from sources other than sedimentation. Table 2 – Potential Sources of Sediment to Stormwater Runoff Table 3 – Potential Pollutants and Sources, other than Sediment to Stormwater Runoff Potential Source Activities/Comments Staging Areas and Construction Vehicles Vehicle refueling, minor equipment maintenance, sanitary facilities and hazardous waste storage Materials Storage Area General building materials, solvents, adhesives, paving materials, paints, aggregates, trash, etc. Construction Activities Construction, paving, curb/gutter installation, concrete pouring/mortar/stucco 4.4 Erosion and Sedimentation Control Best Management Practices The project site is characterized by primarily pervious surface. All construction activities will implement Best Management Practices (BMP’s) in order to minimize overall site disturbance and impacts to the sites natural features. Please refer to the following sections for a detailed description of site specific BMP’s. In addition, an Erosion and Sedimentation Control Plan is provided in the Site Plans. Potential Source Activities/Comments Construction Site Entrance and Site Vehicles Vehicles leaving the site can track soils onto public roadways. Site Vehicles can readily transport exposed soils throughout the site and off-site areas. Grading Operations Exposed soils have the potential for erosion and discharge of sediment to off-site areas. Material Excavation, Relocation, and Stockpiling Stockpiling of materials during excavation and relocation of soils can contribute to erosion and sedimentation. In addition, fugitive dust from stockpiled material, vehicle transport and site grading can be deposited in wetlands and waterway. Landscaping Operations Landscaping operations specifically associated with exposed soils can contribute to erosion and sedimentation. Hydro seeding, if not properly applied, can runoff to adjacent wetlands and waterways. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. 4.5 Timetable and Construction Phasing This section provides the Owner and Contractor with a suggested order of construction that shall minimize erosion and the transport of sediments. The individual objectives of the construction techniques described herein shall be considered an integral component of the project design intent of each project phase. The construction sequence is not intended to prescribe definitive construction methods and should not be interpreted as a construction specification document. However, the Contractor shall follow the general construction phase principles provided below:  Protect and maintain existing vegetation wherever possible.  Minimize the area of disturbance.  To the extent possible, route unpolluted flows around disturbed areas.  Install mitigation devices as early as possible.  Minimize the time disturbed areas are left un-stabilized.  Maintain siltation control devices in proper condition.  The contractor should use the suggested sequence and techniques as a general guide and modify the suggested methods and procedures as required to best suit seasonal, atmospheric, and site specific physical constraints for minimizing the environmental impact of construction. Demolition, Grubbing and Stripping of Limits of Construction Phase  Install Temporary Erosion Control (TEC) devices as required to prevent sediment transport into resource areas.  Place a ring of silt socks and/or haybales around stockpiles.  Stabilize all exposed surfaces that will not be under immediate construction.  Store and/or dispose all pavement and building demolition debris as indicated in accordance with all applicable local, state, and federal regulations. Driveway Area Sub-Base Construction  Install temporary culverts and diversion ditches and additional TEC devices as required by individual construction area constraints to direct potential runoff toward detention areas designated for the current construction phase.  Compact gravel as work progresses to control erosion potential.  Apply water to control air suspension of dust.  Avoid creating an erosive condition due to over-watering.  Install piped utility systems as required as work progresses, keeping all inlets sealed until all downstream drainage system components are functional. Binder Construction  Fine grade gravel base and install processed gravel to the design grades.  Compact pavement base as work progresses.  Install pavement binder coat starting from the downhill end of the site and work toward the top. Finish Paving  Repair and stabilize damaged side slopes.  Clean inverts of drainage structures.  Install final top coat of pavement. Final Clean-up  Clean inverts of culverts and catch basins.  Remove sediment and debris from rip-rap outlet areas. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed.  Remove TEC devices only after permanent vegetation and erosion control has been fully established. 4.6 Site Stabilization Grubbing Stripping and Grading  Erosion control devices shall be in place as shown on the design plans before grading commences.  Stripping shall be done in a manner, which will not concentrate runoff. If precipitation is expected, earthen berms shall be constructed around the area being stripped, with a silt sock, silt fence or haybale dike situated in an arc at the low point of the berm.  If intense precipitation is anticipated, silt socks, haybales, dikes and /or silt fences shall be used as required to prevent erosion and sediment transport. The materials required shall be stored on site at all time.  If water is required for soil compaction, it shall be added in a uniform manner that does not allow excess water to flow off the area being compacted.  Dust shall be held at a minimum by sprinkling exposed soil with an appropriate amount of water. Maintenance of Disturbed Surfaces  Runoff shall be diverted from disturbed side slopes in both cut and fill.  Mulching may be used for temporary stabilization.  Silt sock, haybale or silt fences shall be set where required to trap products of erosion and shall be maintained on a continuing basis during the construction process. Loaming and Seeding  Loam shall not be placed unless it is to be seeded directly thereafter.  All disturbed areas shall have a minimum of 4” of loam placed before seeded and mulched.  Consideration shall be given to hydro-mulching, especially on slopes in excess of 3 to 1.  Loamed and seeded slopes shall be protected from washout by mulching or other acceptable slope protection until vegetation begins to grow. Stormwater Collection System Installation  The Stormwater drainage system shall be installed from the downstream end up and in a manner which will not allow runoff from disturbed areas to enter pipes.  Excavation for the drainage system shall not be left open when rainfall is expected overnight. If left open under other circumstances, pipe ends shall be closed by a staked board or by an equivalent method.  All catch basin openings shall be covered by a silt bag between the grate and the frame or protected from sediment by silt fence surrounding the catch basin grate. Completion of Paved Areas  During the placement of sub-base and pavement, the entrance to the Stormwater drainage systems shall be sealed when rain is expected. When these entrances are closed, consideration must be given to the direction of run-off and measures shall be undertaken to minimize erosion and to provide for the collection of sediment.  In some situations, it may be necessary to keep catch basins open.  Appropriate arrangements shall be made downstream to remove all sediment deposition. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. Stabilization of Surfaces  Stabilization of surfaces includes the placement of pavement, rip-rap, wood bark mulch and the establishment of vegetated surfaces.  Upon completion of construction, all surfaces shall be stabilized even though it is apparent that future construction efforts will cause their disturbance.  Vegetated cover shall be established during the proper growing season and shall be enhanced by soil adjustment for proper pH, nutrients and moisture content.  Surfaces that are disturbed by erosion processes or vandalism shall be stabilized as soon as possible.  Areas where construction activities have permanently or temporarily ceased shall be stabilized within 14 days from the last construction activity, except when construction activity will resume within 21 days (e.g., the total time period that construction activity is temporarily ceased is less than 21 days).  Hydro-mulching of grass surfaces is recommended, especially if seeding of the surfaces is required outside the normal growing season.  Straw mulch is an effective method of temporarily stabilizing surfaces, but only if it is properly secured by branches, weighted snow fences or weighted chicken wire. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. 4.7 Temporary Structural Erosion Control Measures Temporary erosion control measures serve to minimize construction-associated impacts to undisturbed areas. Please refer to the following sections for a description of temporary erosion control measures implemented as part of the project and this sample SWPPP. 4.7.1 Staked Straw Wattles and/or Silt Fencing The siltation barriers will demarcate the limit of work, form a work envelope and provide additional assurance that construction equipment will not enter the undisturbed portions of the site. All barriers will remain in place until disturbed areas are stabilized. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. 4.7.2 Temporary Stormwater Diversion Swale A temporary diversion swale is an effective practice for temporarily diverting stormwater flows and to reduce stormwater runoff velocities during storm events. The swale channel can be installed before infrastructure construction begins at the site, or as needed throughout the construction process. The diversion swale should be routinely compacted or seeded to minimize the amount of exposed soil. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. 4.7.3 Dewatering Basins Dewatering may be required during stormwater system, foundation construction and utility installation. Should the need for dewatering arise, groundwater will be pumped directly into a temporary settling basin, which will act as a sediment trap during construction. All temporary settling basins will be located within close proximity of daily work activities. Prior to discharge, all groundwater will be treated by means of the settling basin or acceptable substitute. Discharges from sediment basins will be free of visible floating, suspended and settleable solids that would impair the functions of a wetland or degrade the chemical composition of the wetland resource area receiving ground or surface water flows and will be to the combined system. 4.7.4 Material Stockpiling Locations Piping and trench excavate associated with the subsurface utility work will be contained with a single row of silt socks and/or haybales. 4.8 Permanent Structural Erosion Control Measures Permanent erosion control measures serve to minimize post-construction impacts to undisturbed areas. Please refer to the following sections for a description of permanent erosion control measures implemented as part of the project and this SWPPP. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. 4.9 Good Housekeeping Best Management Practices 4.9.1 Material Handling and Waste Management Solid waste generation during the construction period will be primarily construction debris. The debris will include scrap lumber (used forming and shoring pallets and other shipping containers), waste packaging materials (plastic sheeting and cardboard), scrap cable and wire, roll-off containers (or dumpsters) and will be removed by a contract hauler to a properly licensed landfill. The roll-off containers will be covered with a properly secured tarp before the hauler exits the site. In addition to construction debris, the construction work force will generate some amount of household-type wastes (food packing, soft drink containers, and other paper). Trash containers for these wastes will be located around the site and will be emptied regularly to prevent wind-blown litter. This waste will also be removed by a contract hauler. All hazardous waste material such as oil filters, petroleum products, paint and equipment maintenance fluids will be stored in structurally sound and sealed shipping containers in the hazardous-materials storage area and segregated from other non-waste materials. Secondary containment will be provided for all materials in the hazardous materials storage area and will consist of commercially available spill pallets. Additionally, all hazardous materials will be disposed of in accordance with federal, state and municipal regulations. Two temporary sanitary facilities (portable toilets) will be provided at the site in the combined staging area. The toilets will be away from a concentrated flow path and traffic flow and will have collection pans underneath as secondary treatment. All sanitary waste will be collected from an approved party at a minimum of three times per week. 4.9.2 Building Material Staging Areas Construction equipment and maintenance materials will be stored at the combined staging area and materials storage areas. Silt fence will be installed around the perimeter to designate the staging and materials storage area. A watertight shipping container will be used to store hand tools, small parts and other construction materials. Non-hazardous building materials such as packaging material (wood, plastic and glass) and construction scrap material (brick, wood, steel, metal scraps, and pine cuttings) will be stored in a separate covered storage facility adjacent to other stored materials. All hazardous-waste materials such as oil filters, petroleum products, paint and equipment maintenance fluids will be stored in structurally sound and sealed containers under cover within the hazardous materials storage area. Large items such as framing materials and stockpiled lumber will be stored in the open storage area. Such materials will be elevated on wood blocks to minimize contact with runoff. The combined storage areas are expected to remain clean, well-organized and equipped with ample cleaning supplies as appropriate for the materials being stored. Perimeter controls such as containment structures, covers and liners will be repaired or replaced as necessary to maintain proper function. 4.9.3 Designated Washout Areas Designated temporary, below-ground concrete washout areas will be constructed, as required, to minimize the pollution potential associated with concrete, paint, stucco, mixers etc. Signs will, if required, be posted marking the location of the washout area to ensure that concrete equipment operators use the proper facility. Concrete pours will not be conducted during or before an anticipated precipitation event. All excess concrete and concrete washout slurries from the concrete mixer trucks and chutes will be discharged to the washout area or hauled off-site for disposal. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed. 4.9.4 Equipment/Vehicle Maintenance and Fueling Areas Several types of vehicles and equipment will be used on-site throughout the project including graders, scrapers, excavators, loaders, paving equipment, rollers, trucks and trailers, backhoes and forklifts. All major equipment/vehicle fueling and maintenance will be performed off-site. A small, 20-gallon pickup bed fuel tank will be kept on-site in the combined staging area. When vehicle fueling must occur on-site, the fueling activity will occur in the staging area. Only minor equipment maintenance will occur on-site. All equipment fluids generated from maintenance activities will be disposed of into designated drums stored on spill pallets. Absorbent, spill-cleanup materials and spill kits will be available at the combined staging and materials storage area. Drip pans will be placed under all equipment receiving maintenance and vehicles and equipment parked overnight. 4.9.5 Equipment/Vehicle Wash down Area All equipment and vehicle washing will be performed off-site. 4.9.6 Spill Prevention Plan A spill containment kit will be kept on-site in the Contractor’s trailer and/or the designated staging area throughout the duration of construction. Should there be an accidental release of petroleum product into a resource area, the appropriate agencies will be immediately notified. 4.9.7 Inspections Maintenance of existing and proposed BMP’s to address stormwater management facilities during construction is an on-going process. The purpose of the inspections is to observe all sources of stormwater or non-stormwater discharge as identified in the SWPPP as well as the status of the receiving waters and fulfill the requirements of the Order of Conditions. The following sections describe the appropriate inspection measures to adequately implement the project’s SWPPP. A blank inspection form is provided at the end of this section. Completed inspection forms are to be maintained on site. Inspection Personnel The owner’s appointed representative will be responsible for performing regular inspections of erosion controls and ordering repairs as necessary. Inspection Frequency Inspections will be performed by qualified personnel once every 7 days and within 24-hours after a storm event of greater than one-quarter inch, in accordance with the CGP. The inspections must be documented on the inspection form provided at the end of this section, and completed forms will be provided to the on- site supervisor and maintained at the Owner’s office throughout the entire duration of construction. Inspection Reporting Each inspection report will summarize the scope of the inspection, name(s) and qualifications of personnel making the inspection, and major observations relating to the implementation of the SWPPP, including compliance and non-compliance items. Completed inspection reports will remain with the completed SWPPP on site. 4.9.8 Amendment Requirements The final SWPPP is intended to be a working document that is utilized regularly on the construction site, and provides guidance to the Contractor. It must reflect changes made to the originally proposed plan and will be updated to include project specific activities and ensure that they are in compliance with the NPDES General Permit and state and local laws and regulations. It should be amended whenever there is a change in design, construction, operation or maintenance that affects discharge of pollutants. The following items should be addressed should an amendment to the SWPPP occur: Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA The picture can't be displayed.  Dates of certain construction activities such as major grading activities, clearing and initiation of and completion of stabilization measures should be recorded.  Future amendments to the SWPPP will be recorded as required. As this SWPPP is amended, all amendments will be kept on site and made part of the SWPPP.  Upon completion of site stabilization (completed as designed and/or 70% background vegetative cover), it can be documented and marked on the plans. Inspections are no longer required at this time.  Inspections often identify areas not included in the original SWPPP, which will require the SWPPP to be amended. These updates should be made within seven days of being recognized by the inspector. 4.10 SWPPP Inspection and Maintenance Report The following form is an example to be used for SWPPP Inspection Reporting. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Stormwater Construction Site Inspection and Maintenance Report TO BE COMPLETED AT LEAST EVERY 7 DAYS AND WITHIN 24 HOURS OF A STORM EVENT OF AT LEAST 0.25 INCHES. AFTER SITE STABILIZATION, TO BE COMPLETED AT LEAST ONCE PER MONTH FOR THREE YEARS OR UNTIL A NOTICE OF TERMINATION IS FILED (IF APPLICABLE). General Information Project Name Cape Cod Inflatable Park NPDES Tracking No. (if applicable) Location 492, 494, 512, 518, 526, & 532 Route 28, West Yarmouth, MA Date of Inspection Start/End Time Inspector’s Name(s) Inspector’s Title(s) Inspector’s Contact Information Inspector’s Qualifications Describe present phase of construction Type of Inspection:  Regular  Pre-storm event  During storm event  Post-storm event Weather Information Has there been a storm event since the last inspection? Yes No If yes, provide: Storm Start Date & Time: Storm Duration (hrs): Approximate Amount of Precipitation (in): Weather at time of this inspection?  Clear Cloudy  Rain  Sleet  Fog  Snowing  High Winds  Other: Temperature: Have any discharges occurred since the last inspection? Yes No If yes, describe: Are there any discharges at the time of inspection? Yes No If yes, describe: Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Site-specific BMPs  Number the structural and non-structural BMPs identified in your SWPPP on your site map and list them below (add as many BMPs as necessary). Carry a copy of the numbered site map with you during your inspections. This list will ensure that you are inspecting all required BMPs at your site.  Describe corrective actions initiated, date completed, and note the person that completed the work in the Corrective Action Log. BMP BMP Installed? BMP Maintenance Required? Corrective Action Needed and Notes Action required by whom and when 1 Catch Basin Protection Yes No Yes No 2 Haybale & Silt Fencing Yes No Yes No 3 Straw Wattles Yes No Yes No 4 Construction Entrance Yes No Yes No 5 Sediment Basins Yes No Yes No 6 Dewatering Pit Yes No Yes No Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Overall Site Issues Below are some general site issues that should be assessed during inspections. Customize this list as needed for conditions at your site. BMP/activity Implemented? Maintenance Required? Corrective Action Needed and Notes Action required by whom and when 1 Are all slopes and disturbed areas not actively being worked properly stabilized? Yes No Yes No 2 Are natural resource areas (e.g., streams, wetlands, mature trees, etc.) protected with barriers or similar BMPs? Yes No Yes No 3 Are perimeter controls and sediment barriers adequately installed (keyed into substrate) and maintained? Yes No Yes No 4 Are discharge points and receiving waters free of any sediment deposits? Yes No Yes No 5 Are storm drain inlets properly protected? Yes No Yes No 6 Is the construction exit preventing sediment from being tracked into the street? Yes No Yes No 7 Is trash/litter from work areas collected and placed in covered dumpsters? Yes No Yes No 8 Are washout facilities (e.g., paint, stucco, concrete) available, clearly marked, and maintained? Yes No Yes No 9 Are vehicle and equipment fueling, cleaning, and maintenance areas free of spills, leaks, or any other deleterious material? Yes No Yes No Vehicle Maintenance not allowed on site 10 Are materials that are potential stormwater contaminants stored inside or under cover? Yes No Yes No Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Non-Compliance Describe any incidents of non-compliance not described above: CERTIFICATION STATEMENT “I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or 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 for knowing violations.” Print name and title: . (Qualified Person Performing the Inspection) Signature:_____________________________________________________ Date: . Print name and title: __________________________________________________________________________ (Contractor/Operator) Signature:______________________________________________________ Date: 11 Are non-stormwater discharges (e.g., wash water, dewatering) properly controlled? Yes No Yes No 12 (Other) Yes No Yes No Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA SECTION 5.0 LONG-TERM POLLUTION PREVENTION & OPERATION AND MAINTENANCE PLAN Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 5.0 LONG-TERM POLLUTION PREVENTION & OPERATION AND MAINTENANCE PLAN As required by Standard #4 of the Stormwater Management Policy, this Long-Term Pollution Prevention Plan has been developed for source control and pollution prevention at the site after construction. MAINTENANCE RESPONSIBILITY Ensuring that the provisions of the Long-Term Pollution Prevention Plan are followed will be the responsibility of The Applicant. The applicant will be responsible for all financing and executing regular maintenance and emergency repairs. The contact information for the Applicant is below: Joe Marrama Sandbar Holdings, LLC 512 Route 28, West Yarmouth, MA 02673 (508) 771 6060 Operation & Maintenance Budget BMP Quantity Action Frequency Cost / year Catch Basin 11 Clean / Remove Debris 4 times a year $12,500 Stormceptor 3 Inspect / Remove Debris 2 times a year $3,000 Infiltration Chambers 3 Inspect 2 times a year $3,000 Emergency Repair 1 In case of emergency 1 time a year $2,000 Total Yearly Budget for Operation & Maintenance: $20,500 GOOD HOUSEKEEPING PRACTICES The site to be kept clean of trash and debris at all times. Trash, junk, etc. is not to be left outside. Remove sediment, leaf litter, and other organic debris from impervious surfaces a minimum of twice a year in the spring (after snowmelt) and fall (after leaf fall). VEHICLE WASHING CONTROLS The following BMP’s, or equivalent measures, methods or practices are required if you are engaged in vehicle washing and/or steam cleaning: It is allowable to rinse down the body or a vehicle, including the bed of a truck, with just water without doing any wash water control BMP’s. If you wash (with mild detergents) on an area that infiltrates water, such as gravel, grass, or loose soil, it is acceptable to let the wash water infiltrate as long as you only wash the body of vehicles. However, if you wash on a paved area and use detergents or other cleansers, or if you wash/rinse the engine compartment or the underside of vehicles, you must take the vehicles to a commercial vehicle wash. REQUIREMENTS FOR ROUTINE INSPECTIONS AND MAINTENANCE OF STORMWATER BMPS All stormwater BMPs are to be inspected and maintain as follows: Straw Wattles, Silt Fence, and other temporary measures The temporary erosion control measures will be installed up gradient of any area where any disturbance or alteration might otherwise allow for erosion or sedimentation. They will be regularly inspected to ensure that they are functioning adequately. Additional supplies of these temporary measures will be stockpiled on site for any immediate needs or routine replacement. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Deep Sump Hooded Catch Basins Regular maintenance is essential. Catch basins remain effective at removing pollutants only if they are cleaned out frequently. Inspect or clean basins at least four times per year and at the end of the foliage and snow removal seasons. Sediments must also be removed four times per year or whenever the depth of the deposits in the catch basin sump is greater than or equal to one half the depth from the bottom of the invert to the lowest pipe in the basin. Water Quality Treatment Units The water quality treatment structures require periodic inspection and cleaning to maintain operation and function. Owners should have these units inspected on a semi-annual basis and after periods of intense precipitation. Inspections can be done by using clear Plexiglas tube (“sludge judge”) to extract a water column sample. When sediment accumulation reaches 15% of storage capacity, cleaning of the unit is required. The water quality structures must and will be checked and cleaned immediately after petroleum spills, contact appropriate regulatory agencies. Maintenance of these units should be done by a vacuum truck that will remove the water, sediment debris, floating hydrocarbons and other materials in unit. Proper cleaning and disposal of the removed materials and liquid must be followed. Subsurface Infiltration Systems Maintenance is required for the proper operation of the underground precast infiltration systems. Infiltration systems are prone to failure due to clogging if upstream water quality units are not maintained. The use of pre-treatment BMPs will minimize failure and maintenance requirements. After construction, the infiltration system should be inspected after every major storm for the first few months to ensure proper stabilization. Water levels in the access ports should be recorded over several days to check the drainage of the systems. It is recommended that a log book be maintained showing the depth of water in the systems at each observation in order to determine the rate at which the system dewaters after runoff producing storm events. Once the performance characteristics of the system have been verified, the monitoring schedule can be reduced to annual basis, unless the performance data suggests that a more frequent schedule is required. Preventative maintenance of the systems should be performed at least twice a year, and sediment should be removed from any and all pretreatment and collection structures. Sediment should be removed when deposits approach within six inches of the invert heights of connecting pipes, or in sumped inlet structures. The system is designed with access covers such that a vacuum truck tube can be used to remove sediment. PROVISIONS FOR MAINTENANCE OF LAWNS, GARDENS AND OTHER LANDSCAPE AREAS Suggested Maintenance Operations A. Trees and Shrubs Disease and Pest Management - Prevention of disease or infestation is the first step of Pest Management. A plant that is in overall good health is far less susceptible to disease. Good general landscape maintenance can reduce problems from disease. Inspections of plant materials for signs of disease or infestation are to be performed monthly by the Landscape Maintenance Contractor’s Certified Arborist. This is a critical step for early diagnosis. Trees and Shrubs that have been diagnosed to have a plant disease or an infestation of insect pests are to be treated promptly with an appropriate material by a licensed applicator. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Fertilization - Trees and shrubs live outside their natural environment and should be given proper care to maintain health and vigor. Fertilizing trees and shrubs provides the plants with nutrients needed to resist insect attack, to resist drought and to grow thicker foliage. Fertilizing of new and old trees may be done in one of three ways, in either the early spring or the late fall.  Systemic Injection of new and existing trees on trees 2 inches or greater in diameter. You must be licensed to apply this method.  Soil Injection – a liquid fertilizer with a product such as Arbor Green or Rapid Grow injected into the soil under the drip zone of a tree or shrub. Material must be used according to manufacturers’ specifications to be effective. Outside contracting is recommended.  Punch Bar Method – a dry fertilizer such as 10-10-10, may be used by punched holes in the drip zone of the tree 12-18” deep, two feet apart around the circumference, to the edge of the drip line. Three pounds of fertilizer should be used per diameter inch for trees with trunks six inches or more in diameter.  Fertilizer of shrubs – use a fertilizer such as 10-10-10, broadcast over the planting area according to the manufacturers’ rate and water in.  All fertilization must be noted on daily maintenance log.  Restrictions on the application of fertilizer include the following: o Fertilizer shall not be applied during or immediately prior to heavy rainfall, such as but not limited to thunderstorms, hurricanes, or northeastern storms, or when the soil is saturated due to intense or extended rainfall. o Fertilizer shall not be applied between November 12 and the following March 31. o Fertilizer shall not be applied, spilled or deposited on impervious surfaces or in a manner that allows it to enter into storm drains. o Fertilizer shall not be applied within 100 feet of any surface water or within the Zone I of a public drinking water well. o Fertilizer containing phosphorous shall not be applied unless a soil test taken not more than three years before the proposed fertilizer application indicates that additional phosphorus is needed for growth of that turf, or unless establishing new turf or reestablishing or repairing turf after substantial damage or land disturbance. o A single application of fertilizer that contains nitrogen shall not exceed 1.0 pound of nitrogen per 1,000 square feet, shall consist of at least 20% slow-release nitrogen (SRN) fertilizer (Note: This represents the minimum percentage use of higher SRN content is generally preferable, especially on sand root zones, during stress and pre-stress periods, and when there are fewer annual applications of nitrogen made to a lawn) and the annual rate shall not exceed 3.2 pounds of actual nitrogen per thousand square feet. Single applications shall be done at intervals of n less than four weeks until the annual maximum is reached. o Grass clippings, leaves, or any other vegetable debris shall not be deposited into or within 50 feet of waterbodies, retention and detention areas, drainage ditches or stormwater drains, or onto impervious surfaces, such as, but not limited to, roadways and sidewalks, except during scheduled clean-up programs. Watering - Trees and Shrubs will need supplemental watering to remain in vigorous health. All new plants need to be watered once a week in cool weather, twice a week during warm weather, and up to three times in a week during periods of extreme heat and drought. Trees and shrubs should be watered in such a manner as to totally saturate the soil in the root zone area. Over-watering or constant saturation of the soil must be avoided as this could lead to root rot and other disease problems. The use of a soil moisture meter can help you monitor the soil’s water intake. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Plant Replacement - Unhealthy plants that may cause widespread infestation of other nearby plants shall be immediately removed from the site. Any vegetation removed from the site must be recorded and submitted with the daily maintenance log. The area shall be treated to prevent further infestation. The plant shall then be replaced with a healthy specimen of the same species and size. This work shall have a pre-established budget allowance for the year. A spring inspection of all plant materials shall be performed to identify those plant materials that are not in vigorously healthy condition. Unhealthy plant materials shall be evaluated. If the problem is determined to be minor the plant material shall be given appropriate restorative care in accordance with this maintenance guideline until it is restored to a vigorously healthy condition. Unhealthy plant materials that do not respond to restorative care or are determined to be beyond saving shall be replaced with a healthy specimen of the same species and size. In the case of the necessity of replacing extremely large plant materials the Landscape Architect shall determine the size of the replacement plant. Pruning - Proper pruning is the selective removal of branches without changing the plant’s natural appearance, or habit of growth. All tree pruning is to be performed by a licensed Arborist. All branches that are dead, broken, scared or crossing should be removed. All cuts should be made at the collar and not cut flush with the base. Pruning on the site shall be done for the following purposes;  To maintain or reduce the size of a tree or shrub  To remove dead, diseased or damaged branches  To rejuvenate old shrubs and encourage new growth  To stimulate future flower and fruit development  To maximize the visibility of twig color  To prevent damage and reduce hazards to people and properties All shrubs are recommended to be pruned on an annual basis to prevent the shrub from becoming overgrown and eliminate the need for drastic pruning. There are several types of pruning for deciduous shrubs. Hand snips should be used to maintain a more natural look or hand shears can be used for a more formal appearance. Winter Protection - All trees and shrubs are to be watered, fertilized, and mulched before the first frost. All stakes should be checked and ties adjusted. Damaged branches should be pruned. Broadleaf and Coniferous Evergreen plant materials are to be sprayed with an anti-desiccant product to prevent winter burn. The application shall be repeated during a suitable mid-winter thaw. Shrubs located in areas likely to be piled with snow during snow removal (but not designated as Snow Storage Areas) shall be marked by six-foot high poles with bright green banner flags. Stockpiles of snow are not to be located in these areas due to potential damage to the plant materials from both the weight of the snow and the snow melting chemicals. At the fall landscape maintenance conference parameters will be discussed between the Landscape Maintenance Contractor and the snow removal contractor to assure minimal damage and loss of landscape amenities during the winter season. Seasonal Clean Up - A thorough spring cleanup is to be performed. This includes the removal and replacement of dead or unhealthy plant materials and the cleanup of plant debris and any general debris that has accumulated over the winter season. Mulch is to be lightly raked to clean debris from the surface without removing any mulch. Twigs and debris are to be removed from the planting beds throughout the growing season. Mulching - Planting beds shall be mulched with a treated shredded hardwood mulch free from dirt, debris, and insects. A sample of this mulch shall be given to the Owner for approval prior to installation. Maintain a 2-3” maximum depth and keep free of weeds either by hand weeding or by the use of a pre-emergent weed control such as Treflan or Serfian. Seasonal re-mulching shall occur as necessary in the spring and the fall to maintain this minimum depth. When new mulch is added to the planting bed it shall be spread to create a total depth of no more than three inches. Edges should be maintained in a cleanly edged fashion. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Mulch shall not be placed directly against the trunk of any tree or shrub. B. Groundcover and Perennials Disease and Pest Management – Pesticides and herbicides should be applied only as problems occur, with the proper chemical applied only by a trained professional or in the case of pesticide, a Certified Pesticide Applicator. Plants should be monitored weekly and treated accordingly. Fertilizer – The health of the plants can be maintained or improved, and their growth encouraged by an application of complete fertilizer. Apply a fertilizer such as 4-12-4 as growth becomes apparent and before mulching. Apply to all groundcover and perennial planting areas by hand and avoid letting the fertilizer come in contact with the foliage, or use a liquid fertilizer and apply by soaking the soil. Apply according to the manufacturers’ specifications. Fertilization shall stop at the end of March. Water – Groundcovers and Perennials will need supplemental watering in order to become established, healthy plants. All new plants need to be watered once a week in cool weather, twice a week during warm weather, and up to three times in a week during periods of extreme heat and drought. Until established, groundcovers and perennials should be watered in such a manner as to totally saturate the soil in the root zone area, to a depth of 6 inches. Once established, perennials shall continue to be watered as necessary to maintain them in a vigorous healthy condition. Over-watering or constant saturation of the soil must be avoided as this could lead to root rot and other disease problems. The use of a soil moisture meter can help you monitor the soil’s water intake. On-site water shall be furnished by the Owner. Hose and other watering equipment shall be furnished by the Landscape Maintenance Contractor. Replacement – Any unhealthy plant/s that may cause widespread infestation of other nearby plants shall be immediately removed from the site. Any vegetation removed from the site must be recorded and submitted with the landscape maintenance log. The area shall be treated to prevent further infestation. The plant/s shall then be replaced with healthy specimen/s of the same species and size. Old Forge shall have a pre-established budget allowance for this type of replacement, each year. Plant material that is damaged as a result of other landscape maintenance activities, such as mowing, shall be replaced with healthy specimens of the same species and size, at no additional cost to the owner. Deadheading – Perennials shall be checked on a weekly basis and dead-headed once flowers have faded or as necessary based on plant type and duration of flower. Spent flowers can be pinched off with the thumb and forefinger. Continue to remove all faded flowers until Fall. All associated debris shall be removed from site daily. Staking – Upright-growing perennials need support especially when in flower. Use of bamboo stakes, galvanized wire hoops or mesh may be necessary for their support. Supports should be put in place before they have become too difficult to handle. The supports should not be taller than the mature height of the perennial plant. Division of Perennials – Two or three-year-old perennials are easily divided in the spring if more plants are needed. To divide, cut out the entire section of plant to be divided, including roots. The larger divisions (those with three or more shoots), can be set out immediately in their permanent location, where they can be expected to bloom the same season. Smaller divisions are best planted in an out-of-the-way planting bed until the following autumn or spring, when they can be moved to their permanent location. Weeding – All planting beds should be kept weed-free. Weed either by hand or with a pre-emergent herbicide such as Treflen used according to manufacturers’ specifications. Manual weeding is to be used in combination with the use of spot applications of herbicides. Both live and dead weeds are to be pulled and removed from the site. All herbicide applications shall be documented in the Landscape Maintenance Log. The actual product label or the manufacturer’s product specification sheet for the specific product shall also be included in the Log. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Only personnel with appropriate applicator licenses shall supervise and/or perform the application of pesticide products requiring a license. Winterizing – Perennial gardens should be cleaned-up when growth ceases in the fall. Remove foliage of plants that normally die down to the ground. Divide and replant over-grown clumps. C. Lawn Areas - Turf Systems Mowing – Proper mowing is an integral part of any good turf maintenance program. Without it, the finest in fertilization, watering and other vital maintenance practices would be completely ineffective. Proper mowing will help control dicot weeds; help the turf survive during periods of extreme heat, and gain strength and vigor to resist disease and other infestations. Mowing height – The proper mowing height will vary somewhat according to the type of grass. The most common type of seed & sod lawns contains a mixture of bluegrass, fine fescue and perennial rye, which should be mowed at 2-3 inches. Mowing frequency – The basic rule of thumb for mowing frequency is to never remove more than 1/3 of the grass blade in one mowing. Example: if you want to mow your turf at 2 inches, you should cut it when it reaches 3 inches. Removing more than ½ of the grass plant at a time can put the plant into shock, thus making it more susceptible to stress disease and weed infestation. Mowing frequency will vary with the growing season and should be set by the plant height and not a set date. It will often be necessary to mow twice a week during periods of surge growth to help maintain plant health and color. Mowing should be cut back during periods of stress. Grass clippings should be removed whenever they are thick enough to layer the turf. The return of clippings to the soil actually adds nutrients and helps retain moisture. Heavily clumped grass clippings are a sign of infrequent mowing, calling for an adjustment in the mowing schedule. When mowing any area, try to alternate mowing patterns. This tends to keep grass blades more erect and assures an even cut. A dull mower will cause color loss due to tearing of the turf plant, and since mowing will ultimately determine the appearance of any turf area there is an absolute necessity for a clean sharp cut. Weed & Pest Control and Fertilizing- In order to maintain turf grass health, vigor color, and nutrients, fertilizer must be added to the soil. Recommendations for fertilization of lawn areas are as follows; fertilize at the rate of one (1) pound of nitrogen per thousand square feet, per year is optimum. Fertilizer should be a balanced slow release, sulfur coated type fertilizer. Weed Control - All turf areas will require some weed control, for both weed grasses and dicot weeds. Weeds should be treated at the appropriate time and with a material labeled for the target weed. Please refer to the fertilizer weed and pest schedule for timing. Pest Control - All turf areas will require some pest control. Pests should be treated at the appropriate time with a material labeled for the target pest. Please refer to the fertilizer, weed and pest schedule for timing. Lime - A common cause for an unhealthy lawn is acidic soil. When the PH is below the neutral range (between 6-7) vital plant nutrients become fixed in the soil and cannot be absorbed by the grass plant. Lime corrects an acid soil condition, supplies calcium for plant growth and improves air and water circulation. Limestone applied at the rate of 50 lbs. per thousand square feet will adjust the soil PH one point over a period of 6-9 months. D. Fertilizer, Weed & Pest Control Schedule – Turf Systems Spring - Fertilize one (1) pound of nitrogen per 1,000 square feet Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA (April) Pre-emergent weed grass control Broadleaf weed control Late Spring - Fertilize one (1) pound of nitrogen per 1,000 square feet (June) Pre-emergent weed grass control Broadleaf weed control Insect Control (if needed) *Summer - Fertilize one (1) pound of nitrogen per 1,000 square feet (August) Broadleaf weed control (if needed) Insect Control (if needed) Fall - Fertilize one (1) pound of nitrogen per 1,000 square feet (September) *Omit if area is not to be irrigated Lawn Maintenance Task Schedule MARCH (Weather permitting)  Clean up winter debris, sand, leaves, trash etc.  Re-edge mulch beds, maintain at 2-3” maximum.  Fertilize plants  Aerate and thatch turf (conditions permitting) APRIL  Reseed or sod all areas needing attention.  Weed control  Lime  Start mowing when grass reaches 2-1/2”, mow to 2” MAY  Mow turf to 2-2-1/2”  Weed as necessary.  Check for disease and pest problems in both turf and plants. JUNE  Mow turf to 2-1/2” – 3”  Weed  Check for disease and pest problems in both turf and plants, treat as necessary. PROVISIONS FOR SOLID WASTE MANAGEMENT (SITE TRASH) Trash will be placed in on-site dumpsters and the Owner will make provisions for its regular and timely removal. SNOW DISPOSAL AND PLOWING PLANS The purpose of the snow and snowmelt management plan is to provide guidelines regarding snow disposal site selection, site preparation and maintenance that are acceptable to the Department of Environmental Protection. For the areas that Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA require snow removal, snow storage onsite will largely be accomplished by using pervious areas along the shoulder of the roadway and development as windrowed by plows.  Avoid dumping of snow into any water body, including rivers, ponds, or wetlands. In addition to water quality impacts and flooding, snow disposed of in open water can cause navigational hazards when it freezes into ice blocks.  Avoid disposing of snow on top of storm drain catch basins or in stormwater basins. Snow combined with sand and debris may block a storm drainage system, causing localized flooding. A high volume of sand, sediment, and litter released from melting snow also may be quickly transported through the system into surface water.  In significant storm events, the melting or off-site trucking of snow may be implemented. These activities shall be conducted in accordance with all local, state and federal regulations. WINTER ROAD SALT AND/OR SAND USE AND STORAGE RESTRICTIONS The applicant will be responsible for sanding and salting the site. No storage on site. STREET SWEEPING SCHEDULES There are three types of sweepers: Mechanical, Regenerative Air, and Vacuum Filter. 1) Mechanical: Mechanical sweepers use brooms or rotary brushes to scour the pavement. 2) Regenerative Air: These sweepers blow air onto the road or parking lot surface, causing fines to rise where they are vacuumed. 3) Vacuum filter: These sweepers remove fines along roads. Two general types of vacuum filter sweepers are available - wet and dry. The dry type uses a broom in combination with the vacuum. The wet type uses water for dust suppression Regardless of the type chosen, the efficiency of street sweeping is increased when sweepers are operated in tandem. This project has not included street sweeping as part of the TSS removal calculations. However, it is recommended that street sweeping of the parking areas occur four times a year, including once after the spring snow melt. Reuse and Disposal of Street Sweepings Once removed from paved surfaces, the sweepings must be handled and disposed of properly. Mass DEP’s Bureau of Waste Prevention has issued a written policy regarding the reuse and disposal of street sweepings. These sweepings are regulated as a solid waste, and can be used in three ways:  In one of the ways already approved by Mass DEP (e.g., daily cover in a landfill, additive to compost, fill in a public way)  If approved under a Beneficial Use Determination  Disposed in a landfill TRAINING OF STAFF OR PERSONNEL INVOLVED WITH IMPLEMENTING LONG-TERM POLLUTION PREVENTION PLAN The Long-Term Pollution Prevention Plan is to be implemented by property owner of the site. Trained and, if required, licensed Professionals are to be hired by the owner as applicable to implement the Long-Term Pollution Prevention Plan. LIST OF EMERGENCY CONTACTS FOR IMPLEMENTING LONG-TERM POLLUTION PREVENTION PLAN The applicant will be required to implement the Long-Term Pollution Prevention Plan and will create and maintain a list of emergency contacts. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA POST CONSTRUCTION PHASE INSPECTION SCHEDULE AND EVALUATION CHECKLIST Inspection Date Inspector BMP Inspected Inspection Frequency Requirements Comments Recommendation Follow-up Inspection Required (yes/no) Catch Basins Four times a year Water Quality Units Four times a year Infiltration Systems Twice a year 1. Refer to the Massachusetts Stormwater Handbook Volume Two: Stormwater Technical Handbook (February 2008) for recommendations regarding frequency for inspections and maintenance of specific BMP’s 2. Inspections to be conducted by a qualified professional such as an environmental scientist or civil engineer. 3. Limited or no use of sodium chloride salts, fertilizers or pesticides recommended. 4. Other Notes: (Include deviations from Conservation Commission Approvals, Planning Board Approvals and Approved Plans) Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA SECTION 6.0 HYDROLOGY CALCULATIONS Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 6.01 PRE-CONSTRUCTION DRAINAGE AREA MAP Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 6.02 PRE-CONSTRUCTION HYDROLOGY CALCULATIONS (HYDROCAD™ PRINTOUTS) 4S Managed Flow to Northeast 5S Offsite Flow to Southwest Corner 6S Offsite to South 4R To Existing Drainage System 5R Off-site West 6R Route 28 Routing Diagram for WS-Pre Prepared by BSC Group, Printed 11/29/2021 HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 2HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=1.113 ac 0.00% Impervious Runoff Depth>2.91"Subcatchment 4S: Managed Flow to Flow Length=211' Slope=0.0200 '/' Tc=6.0 min CN=96 Runoff=3.45 cfs 0.270 af Runoff Area=1.040 ac 25.96% Impervious Runoff Depth>2.06"Subcatchment 5S: Offsite Flow to Flow Length=338' Tc=6.0 min CN=87 Runoff=2.46 cfs 0.179 af Runoff Area=0.707 ac 70.44% Impervious Runoff Depth>1.75"Subcatchment 6S: Offsite to South Flow Length=324' Tc=6.0 min CN=83 Runoff=1.42 cfs 0.103 af Inflow=3.45 cfs 0.270 afReach 4R: To Existing Drainage System Outflow=3.45 cfs 0.270 af Inflow=2.46 cfs 0.179 afReach 5R: Off-site West Outflow=2.46 cfs 0.179 af Inflow=1.42 cfs 0.103 afReach 6R: Route 28 Outflow=1.42 cfs 0.103 af Total Runoff Area = 2.860 ac Runoff Volume = 0.552 af Average Runoff Depth = 2.32" 73.15% Pervious = 2.092 ac 26.85% Impervious = 0.768 ac Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 3HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Managed Flow to Northeast Runoff = 3.45 cfs @ 12.09 hrs, Volume= 0.270 af, Depth> 2.91" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.37" Area (ac) CN Description 1.113 96 Gravel surface, HSG A 1.113 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.9 117 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 0.3 44 0.0200 2.28 Shallow Concentrated Flow, C-D Unpaved Kv= 16.1 fps 4.1 Direct Entry, 6.0 211 Total Subcatchment 4S: Managed Flow to Northeast Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Type III 24-hr 2-yr Rainfall=3.37" Runoff Area=1.113 ac Runoff Volume=0.270 af Runoff Depth>2.91" Flow Length=211' Slope=0.0200 '/' Tc=6.0 min CN=96 3.45 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 4HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Offsite Flow to Southwest Corner Runoff = 2.46 cfs @ 12.09 hrs, Volume= 0.179 af, Depth> 2.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.37" Area (ac) CN Description 0.588 96 Gravel surface, HSG A 0.212 98 Paved parking, HSG A 0.182 39 Pasture/grassland/range, Good, HSG A 0.058 98 Roofs, HSG A 1.040 87 Weighted Average 0.770 74.04% Pervious Area 0.270 25.96% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 1.1 193 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.8 95 0.0150 1.97 Shallow Concentrated Flow, C-D Unpaved Kv= 16.1 fps 3.4 Direct Entry, 6.0 338 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 5HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 5S: Offsite Flow to Southwest Corner Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Type III 24-hr 2-yr Rainfall=3.37" Runoff Area=1.040 ac Runoff Volume=0.179 af Runoff Depth>2.06" Flow Length=338' Tc=6.0 min CN=87 2.46 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 6HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Offsite to South Runoff = 1.42 cfs @ 12.09 hrs, Volume= 0.103 af, Depth> 1.75" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.37" Area (ac) CN Description 0.179 39 >75% Grass cover, Good, HSG A 0.030 96 Gravel surface, HSG A 0.347 98 Paved parking, HSG A 0.151 98 Roofs, HSG A 0.707 83 Weighted Average 0.209 29.56% Pervious Area 0.498 70.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 1.0 132 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 0.3 60 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.7 82 0.0100 2.03 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps 3.3 Direct Entry, 6.0 324 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 7HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 6S: Offsite to South Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 2-yr Rainfall=3.37" Runoff Area=0.707 ac Runoff Volume=0.103 af Runoff Depth>1.75" Flow Length=324' Tc=6.0 min CN=83 1.42 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 8HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: To Existing Drainage System [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.113 ac, 0.00% Impervious, Inflow Depth > 2.91" for 2-yr event Inflow = 3.45 cfs @ 12.09 hrs, Volume= 0.270 af Outflow = 3.45 cfs @ 12.09 hrs, Volume= 0.270 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 4R: To Existing Drainage System Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=1.113 ac 3.45 cfs3.45 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 9HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 5R: Off-site West [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.040 ac, 25.96% Impervious, Inflow Depth > 2.06" for 2-yr event Inflow = 2.46 cfs @ 12.09 hrs, Volume= 0.179 af Outflow = 2.46 cfs @ 12.09 hrs, Volume= 0.179 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 5R: Off-site West Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=1.040 ac 2.46 cfs2.46 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 10HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 6R: Route 28 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.707 ac, 70.44% Impervious, Inflow Depth > 1.75" for 2-yr event Inflow = 1.42 cfs @ 12.09 hrs, Volume= 0.103 af Outflow = 1.42 cfs @ 12.09 hrs, Volume= 0.103 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 6R: Route 28 Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.707 ac 1.42 cfs1.42 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 11HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=1.113 ac 0.00% Impervious Runoff Depth>4.44"Subcatchment 4S: Managed Flow to Flow Length=211' Slope=0.0200 '/' Tc=6.0 min CN=96 Runoff=5.13 cfs 0.412 af Runoff Area=1.040 ac 25.96% Impervious Runoff Depth>3.48"Subcatchment 5S: Offsite Flow to Flow Length=338' Tc=6.0 min CN=87 Runoff=4.08 cfs 0.302 af Runoff Area=0.707 ac 70.44% Impervious Runoff Depth>3.09"Subcatchment 6S: Offsite to South Flow Length=324' Tc=6.0 min CN=83 Runoff=2.50 cfs 0.182 af Inflow=5.13 cfs 0.412 afReach 4R: To Existing Drainage System Outflow=5.13 cfs 0.412 af Inflow=4.08 cfs 0.302 afReach 5R: Off-site West Outflow=4.08 cfs 0.302 af Inflow=2.50 cfs 0.182 afReach 6R: Route 28 Outflow=2.50 cfs 0.182 af Total Runoff Area = 2.860 ac Runoff Volume = 0.895 af Average Runoff Depth = 3.76" 73.15% Pervious = 2.092 ac 26.85% Impervious = 0.768 ac Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 12HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Managed Flow to Northeast Runoff = 5.13 cfs @ 12.09 hrs, Volume= 0.412 af, Depth> 4.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.91" Area (ac) CN Description 1.113 96 Gravel surface, HSG A 1.113 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.9 117 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 0.3 44 0.0200 2.28 Shallow Concentrated Flow, C-D Unpaved Kv= 16.1 fps 4.1 Direct Entry, 6.0 211 Total Subcatchment 4S: Managed Flow to Northeast Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Type III 24-hr 10-yr Rainfall=4.91" Runoff Area=1.113 ac Runoff Volume=0.412 af Runoff Depth>4.44" Flow Length=211' Slope=0.0200 '/' Tc=6.0 min CN=96 5.13 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 13HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Offsite Flow to Southwest Corner Runoff = 4.08 cfs @ 12.09 hrs, Volume= 0.302 af, Depth> 3.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.91" Area (ac) CN Description 0.588 96 Gravel surface, HSG A 0.212 98 Paved parking, HSG A 0.182 39 Pasture/grassland/range, Good, HSG A 0.058 98 Roofs, HSG A 1.040 87 Weighted Average 0.770 74.04% Pervious Area 0.270 25.96% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 1.1 193 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.8 95 0.0150 1.97 Shallow Concentrated Flow, C-D Unpaved Kv= 16.1 fps 3.4 Direct Entry, 6.0 338 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 14HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 5S: Offsite Flow to Southwest Corner Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Type III 24-hr 10-yr Rainfall=4.91" Runoff Area=1.040 ac Runoff Volume=0.302 af Runoff Depth>3.48" Flow Length=338' Tc=6.0 min CN=87 4.08 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 15HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Offsite to South Runoff = 2.50 cfs @ 12.09 hrs, Volume= 0.182 af, Depth> 3.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.91" Area (ac) CN Description 0.179 39 >75% Grass cover, Good, HSG A 0.030 96 Gravel surface, HSG A 0.347 98 Paved parking, HSG A 0.151 98 Roofs, HSG A 0.707 83 Weighted Average 0.209 29.56% Pervious Area 0.498 70.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 1.0 132 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 0.3 60 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.7 82 0.0100 2.03 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps 3.3 Direct Entry, 6.0 324 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 16HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 6S: Offsite to South Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Type III 24-hr 10-yr Rainfall=4.91" Runoff Area=0.707 ac Runoff Volume=0.182 af Runoff Depth>3.09" Flow Length=324' Tc=6.0 min CN=83 2.50 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 17HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: To Existing Drainage System [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.113 ac, 0.00% Impervious, Inflow Depth > 4.44" for 10-yr event Inflow = 5.13 cfs @ 12.09 hrs, Volume= 0.412 af Outflow = 5.13 cfs @ 12.09 hrs, Volume= 0.412 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 4R: To Existing Drainage System Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=1.113 ac 5.13 cfs5.13 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 18HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 5R: Off-site West [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.040 ac, 25.96% Impervious, Inflow Depth > 3.48" for 10-yr event Inflow = 4.08 cfs @ 12.09 hrs, Volume= 0.302 af Outflow = 4.08 cfs @ 12.09 hrs, Volume= 0.302 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 5R: Off-site West Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Inflow Area=1.040 ac 4.08 cfs4.08 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 19HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 6R: Route 28 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.707 ac, 70.44% Impervious, Inflow Depth > 3.09" for 10-yr event Inflow = 2.50 cfs @ 12.09 hrs, Volume= 0.182 af Outflow = 2.50 cfs @ 12.09 hrs, Volume= 0.182 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 6R: Route 28 Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.707 ac 2.50 cfs2.50 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 20HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=1.113 ac 0.00% Impervious Runoff Depth>5.39"Subcatchment 4S: Managed Flow to Flow Length=211' Slope=0.0200 '/' Tc=6.0 min CN=96 Runoff=6.18 cfs 0.500 af Runoff Area=1.040 ac 25.96% Impervious Runoff Depth>4.39"Subcatchment 5S: Offsite Flow to Flow Length=338' Tc=6.0 min CN=87 Runoff=5.10 cfs 0.380 af Runoff Area=0.707 ac 70.44% Impervious Runoff Depth>3.97"Subcatchment 6S: Offsite to South Flow Length=324' Tc=6.0 min CN=83 Runoff=3.19 cfs 0.234 af Inflow=6.18 cfs 0.500 afReach 4R: To Existing Drainage System Outflow=6.18 cfs 0.500 af Inflow=5.10 cfs 0.380 afReach 5R: Off-site West Outflow=5.10 cfs 0.380 af Inflow=3.19 cfs 0.234 afReach 6R: Route 28 Outflow=3.19 cfs 0.234 af Total Runoff Area = 2.860 ac Runoff Volume = 1.115 af Average Runoff Depth = 4.68" 73.15% Pervious = 2.092 ac 26.85% Impervious = 0.768 ac Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 21HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Managed Flow to Northeast Runoff = 6.18 cfs @ 12.09 hrs, Volume= 0.500 af, Depth> 5.39" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.87" Area (ac) CN Description 1.113 96 Gravel surface, HSG A 1.113 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.9 117 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 0.3 44 0.0200 2.28 Shallow Concentrated Flow, C-D Unpaved Kv= 16.1 fps 4.1 Direct Entry, 6.0 211 Total Subcatchment 4S: Managed Flow to Northeast Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)6 5 4 3 2 1 0 Type III 24-hr 25-yr Rainfall=5.87" Runoff Area=1.113 ac Runoff Volume=0.500 af Runoff Depth>5.39" Flow Length=211' Slope=0.0200 '/' Tc=6.0 min CN=96 6.18 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 22HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Offsite Flow to Southwest Corner Runoff = 5.10 cfs @ 12.09 hrs, Volume= 0.380 af, Depth> 4.39" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.87" Area (ac) CN Description 0.588 96 Gravel surface, HSG A 0.212 98 Paved parking, HSG A 0.182 39 Pasture/grassland/range, Good, HSG A 0.058 98 Roofs, HSG A 1.040 87 Weighted Average 0.770 74.04% Pervious Area 0.270 25.96% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 1.1 193 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.8 95 0.0150 1.97 Shallow Concentrated Flow, C-D Unpaved Kv= 16.1 fps 3.4 Direct Entry, 6.0 338 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 23HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 5S: Offsite Flow to Southwest Corner Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Type III 24-hr 25-yr Rainfall=5.87" Runoff Area=1.040 ac Runoff Volume=0.380 af Runoff Depth>4.39" Flow Length=338' Tc=6.0 min CN=87 5.10 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 24HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Offsite to South Runoff = 3.19 cfs @ 12.09 hrs, Volume= 0.234 af, Depth> 3.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.87" Area (ac) CN Description 0.179 39 >75% Grass cover, Good, HSG A 0.030 96 Gravel surface, HSG A 0.347 98 Paved parking, HSG A 0.151 98 Roofs, HSG A 0.707 83 Weighted Average 0.209 29.56% Pervious Area 0.498 70.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 1.0 132 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 0.3 60 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.7 82 0.0100 2.03 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps 3.3 Direct Entry, 6.0 324 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 25HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 6S: Offsite to South Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Type III 24-hr 25-yr Rainfall=5.87" Runoff Area=0.707 ac Runoff Volume=0.234 af Runoff Depth>3.97" Flow Length=324' Tc=6.0 min CN=83 3.19 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 26HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: To Existing Drainage System [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.113 ac, 0.00% Impervious, Inflow Depth > 5.39" for 25-yr event Inflow = 6.18 cfs @ 12.09 hrs, Volume= 0.500 af Outflow = 6.18 cfs @ 12.09 hrs, Volume= 0.500 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 4R: To Existing Drainage System Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)6 5 4 3 2 1 0 Inflow Area=1.113 ac 6.18 cfs6.18 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 27HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 5R: Off-site West [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.040 ac, 25.96% Impervious, Inflow Depth > 4.39" for 25-yr event Inflow = 5.10 cfs @ 12.09 hrs, Volume= 0.380 af Outflow = 5.10 cfs @ 12.09 hrs, Volume= 0.380 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 5R: Off-site West Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=1.040 ac 5.10 cfs5.10 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 28HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 6R: Route 28 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.707 ac, 70.44% Impervious, Inflow Depth > 3.97" for 25-yr event Inflow = 3.19 cfs @ 12.09 hrs, Volume= 0.234 af Outflow = 3.19 cfs @ 12.09 hrs, Volume= 0.234 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 6R: Route 28 Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=0.707 ac 3.19 cfs3.19 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 29HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=1.113 ac 0.00% Impervious Runoff Depth>6.11"Subcatchment 4S: Managed Flow to Flow Length=211' Slope=0.0200 '/' Tc=6.0 min CN=96 Runoff=6.95 cfs 0.567 af Runoff Area=1.040 ac 25.96% Impervious Runoff Depth>5.08"Subcatchment 5S: Offsite Flow to Flow Length=338' Tc=6.0 min CN=87 Runoff=5.85 cfs 0.440 af Runoff Area=0.707 ac 70.44% Impervious Runoff Depth>4.64"Subcatchment 6S: Offsite to South Flow Length=324' Tc=6.0 min CN=83 Runoff=3.70 cfs 0.273 af Inflow=6.95 cfs 0.567 afReach 4R: To Existing Drainage System Outflow=6.95 cfs 0.567 af Inflow=5.85 cfs 0.440 afReach 5R: Off-site West Outflow=5.85 cfs 0.440 af Inflow=3.70 cfs 0.273 afReach 6R: Route 28 Outflow=3.70 cfs 0.273 af Total Runoff Area = 2.860 ac Runoff Volume = 1.280 af Average Runoff Depth = 5.37" 73.15% Pervious = 2.092 ac 26.85% Impervious = 0.768 ac Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 30HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Managed Flow to Northeast Runoff = 6.95 cfs @ 12.09 hrs, Volume= 0.567 af, Depth> 6.11" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=6.59" Area (ac) CN Description 1.113 96 Gravel surface, HSG A 1.113 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.9 117 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 0.3 44 0.0200 2.28 Shallow Concentrated Flow, C-D Unpaved Kv= 16.1 fps 4.1 Direct Entry, 6.0 211 Total Subcatchment 4S: Managed Flow to Northeast Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Type III 24-hr 50-yr Rainfall=6.59" Runoff Area=1.113 ac Runoff Volume=0.567 af Runoff Depth>6.11" Flow Length=211' Slope=0.0200 '/' Tc=6.0 min CN=96 6.95 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 31HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Offsite Flow to Southwest Corner Runoff = 5.85 cfs @ 12.09 hrs, Volume= 0.440 af, Depth> 5.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=6.59" Area (ac) CN Description 0.588 96 Gravel surface, HSG A 0.212 98 Paved parking, HSG A 0.182 39 Pasture/grassland/range, Good, HSG A 0.058 98 Roofs, HSG A 1.040 87 Weighted Average 0.770 74.04% Pervious Area 0.270 25.96% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 1.1 193 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.8 95 0.0150 1.97 Shallow Concentrated Flow, C-D Unpaved Kv= 16.1 fps 3.4 Direct Entry, 6.0 338 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 32HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 5S: Offsite Flow to Southwest Corner Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)6 5 4 3 2 1 0 Type III 24-hr 50-yr Rainfall=6.59" Runoff Area=1.040 ac Runoff Volume=0.440 af Runoff Depth>5.08" Flow Length=338' Tc=6.0 min CN=87 5.85 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 33HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Offsite to South Runoff = 3.70 cfs @ 12.09 hrs, Volume= 0.273 af, Depth> 4.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=6.59" Area (ac) CN Description 0.179 39 >75% Grass cover, Good, HSG A 0.030 96 Gravel surface, HSG A 0.347 98 Paved parking, HSG A 0.151 98 Roofs, HSG A 0.707 83 Weighted Average 0.209 29.56% Pervious Area 0.498 70.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 1.0 132 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 0.3 60 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.7 82 0.0100 2.03 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps 3.3 Direct Entry, 6.0 324 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 34HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 6S: Offsite to South Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Type III 24-hr 50-yr Rainfall=6.59" Runoff Area=0.707 ac Runoff Volume=0.273 af Runoff Depth>4.64" Flow Length=324' Tc=6.0 min CN=83 3.70 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 35HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: To Existing Drainage System [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.113 ac, 0.00% Impervious, Inflow Depth > 6.11" for 50-yr event Inflow = 6.95 cfs @ 12.09 hrs, Volume= 0.567 af Outflow = 6.95 cfs @ 12.09 hrs, Volume= 0.567 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 4R: To Existing Drainage System Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=1.113 ac 6.95 cfs6.95 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 36HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 5R: Off-site West [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.040 ac, 25.96% Impervious, Inflow Depth > 5.08" for 50-yr event Inflow = 5.85 cfs @ 12.09 hrs, Volume= 0.440 af Outflow = 5.85 cfs @ 12.09 hrs, Volume= 0.440 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 5R: Off-site West Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)6 5 4 3 2 1 0 Inflow Area=1.040 ac 5.85 cfs5.85 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 37HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 6R: Route 28 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.707 ac, 70.44% Impervious, Inflow Depth > 4.64" for 50-yr event Inflow = 3.70 cfs @ 12.09 hrs, Volume= 0.273 af Outflow = 3.70 cfs @ 12.09 hrs, Volume= 0.273 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 6R: Route 28 Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Inflow Area=0.707 ac 3.70 cfs3.70 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 38HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=1.113 ac 0.00% Impervious Runoff Depth>6.87"Subcatchment 4S: Managed Flow to Flow Length=211' Slope=0.0200 '/' Tc=6.0 min CN=96 Runoff=7.78 cfs 0.637 af Runoff Area=1.040 ac 25.96% Impervious Runoff Depth>5.81"Subcatchment 5S: Offsite Flow to Flow Length=338' Tc=6.0 min CN=87 Runoff=6.65 cfs 0.504 af Runoff Area=0.707 ac 70.44% Impervious Runoff Depth>5.35"Subcatchment 6S: Offsite to South Flow Length=324' Tc=6.0 min CN=83 Runoff=4.25 cfs 0.315 af Inflow=7.78 cfs 0.637 afReach 4R: To Existing Drainage System Outflow=7.78 cfs 0.637 af Inflow=6.65 cfs 0.504 afReach 5R: Off-site West Outflow=6.65 cfs 0.504 af Inflow=4.25 cfs 0.315 afReach 6R: Route 28 Outflow=4.25 cfs 0.315 af Total Runoff Area = 2.860 ac Runoff Volume = 1.456 af Average Runoff Depth = 6.11" 73.15% Pervious = 2.092 ac 26.85% Impervious = 0.768 ac Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 39HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Managed Flow to Northeast Runoff = 7.78 cfs @ 12.09 hrs, Volume= 0.637 af, Depth> 6.87" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.35" Area (ac) CN Description 1.113 96 Gravel surface, HSG A 1.113 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.9 117 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 0.3 44 0.0200 2.28 Shallow Concentrated Flow, C-D Unpaved Kv= 16.1 fps 4.1 Direct Entry, 6.0 211 Total Subcatchment 4S: Managed Flow to Northeast Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 Type III 24-hr 100-yr Rainfall=7.35" Runoff Area=1.113 ac Runoff Volume=0.637 af Runoff Depth>6.87" Flow Length=211' Slope=0.0200 '/' Tc=6.0 min CN=96 7.78 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 40HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Offsite Flow to Southwest Corner Runoff = 6.65 cfs @ 12.09 hrs, Volume= 0.504 af, Depth> 5.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.35" Area (ac) CN Description 0.588 96 Gravel surface, HSG A 0.212 98 Paved parking, HSG A 0.182 39 Pasture/grassland/range, Good, HSG A 0.058 98 Roofs, HSG A 1.040 87 Weighted Average 0.770 74.04% Pervious Area 0.270 25.96% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 1.1 193 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.8 95 0.0150 1.97 Shallow Concentrated Flow, C-D Unpaved Kv= 16.1 fps 3.4 Direct Entry, 6.0 338 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 41HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 5S: Offsite Flow to Southwest Corner Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Type III 24-hr 100-yr Rainfall=7.35" Runoff Area=1.040 ac Runoff Volume=0.504 af Runoff Depth>5.81" Flow Length=338' Tc=6.0 min CN=87 6.65 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 42HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Offsite to South Runoff = 4.25 cfs @ 12.09 hrs, Volume= 0.315 af, Depth> 5.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.35" Area (ac) CN Description 0.179 39 >75% Grass cover, Good, HSG A 0.030 96 Gravel surface, HSG A 0.347 98 Paved parking, HSG A 0.151 98 Roofs, HSG A 0.707 83 Weighted Average 0.209 29.56% Pervious Area 0.498 70.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 1.0 132 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 0.3 60 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.7 82 0.0100 2.03 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps 3.3 Direct Entry, 6.0 324 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 43HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 6S: Offsite to South Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Type III 24-hr 100-yr Rainfall=7.35" Runoff Area=0.707 ac Runoff Volume=0.315 af Runoff Depth>5.35" Flow Length=324' Tc=6.0 min CN=83 4.25 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 44HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: To Existing Drainage System [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.113 ac, 0.00% Impervious, Inflow Depth > 6.87" for 100-yr event Inflow = 7.78 cfs @ 12.09 hrs, Volume= 0.637 af Outflow = 7.78 cfs @ 12.09 hrs, Volume= 0.637 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 4R: To Existing Drainage System Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=1.113 ac 7.78 cfs7.78 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 45HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 5R: Off-site West [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.040 ac, 25.96% Impervious, Inflow Depth > 5.81" for 100-yr event Inflow = 6.65 cfs @ 12.09 hrs, Volume= 0.504 af Outflow = 6.65 cfs @ 12.09 hrs, Volume= 0.504 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 5R: Off-site West Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=1.040 ac 6.65 cfs6.65 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Pre Printed 11/29/2021Prepared by BSC Group Page 46HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 6R: Route 28 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.707 ac, 70.44% Impervious, Inflow Depth > 5.35" for 100-yr event Inflow = 4.25 cfs @ 12.09 hrs, Volume= 0.315 af Outflow = 4.25 cfs @ 12.09 hrs, Volume= 0.315 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 6R: Route 28 Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Inflow Area=0.707 ac 4.25 cfs4.25 cfs Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 6.03 POST-CONSTRUCTION DRAINAGE AREA MAP Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 6.04 POST-CONSTRUCTION HYDROLOGY CALCULATIONS (HYDROCAD™ PRINTOUTS) 1S Northern Site 2S Central Site 3S Southern Site 4S Managed Flow to Northeast 5S Offsite Flow to Southwest Corner 6S Offsite to South 4R To Existing Drainage System 5R Southwest Corner of Site 6R Route 28 1P North Underground Detention System 2P Center Underground Detention System 3P South Underground Detention System Routing Diagram for WS-Post Prepared by BSC Group, Printed 11/29/2021 HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 2HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.490 ac 0.00% Impervious Runoff Depth>2.51"Subcatchment 1S: Northern Site Flow Length=213' Tc=6.0 min CN=92 Runoff=1.37 cfs 0.103 af Runoff Area=1.070 ac 0.00% Impervious Runoff Depth>2.32"Subcatchment 2S: Central Site Flow Length=339' Tc=6.0 min CN=90 Runoff=2.82 cfs 0.207 af Runoff Area=0.670 ac 7.46% Impervious Runoff Depth>2.42"Subcatchment 3S: Southern Site Flow Length=333' Tc=6.0 min CN=91 Runoff=1.82 cfs 0.135 af Runoff Area=0.370 ac 0.00% Impervious Runoff Depth>1.90"Subcatchment 4S: Managed Flow to Flow Length=96' Slope=0.0200 '/' Tc=6.0 min CN=85 Runoff=0.81 cfs 0.059 af Runoff Area=0.120 ac 0.00% Impervious Runoff Depth>0.00"Subcatchment 5S: Offsite Flow to Flow Length=9' Slope=0.0200 '/' Tc=6.0 min CN=38 Runoff=0.00 cfs 0.000 af Runoff Area=0.140 ac 0.00% Impervious Runoff Depth>0.30"Subcatchment 6S: Offsite to South Flow Length=59' Slope=0.0200 '/' Tc=6.0 min CN=55 Runoff=0.02 cfs 0.004 af Inflow=0.81 cfs 0.059 afReach 4R: To Existing Drainage System Outflow=0.81 cfs 0.059 af Inflow=0.00 cfs 0.000 afReach 5R: Southwest Corner of Site Outflow=0.00 cfs 0.000 af Inflow=0.02 cfs 0.004 afReach 6R: Route 28 Outflow=0.02 cfs 0.004 af Peak Elev=96.79' Storage=0.019 af Inflow=1.37 cfs 0.103 afPond 1P: North Underground Detention Discarded=0.58 cfs 0.102 af Primary=0.00 cfs 0.000 af Outflow=0.58 cfs 0.102 af Peak Elev=94.27' Storage=0.027 af Inflow=2.82 cfs 0.207 afPond 2P: Center Underground Detention Discarded=1.66 cfs 0.207 af Primary=0.00 cfs 0.000 af Outflow=1.66 cfs 0.207 af Peak Elev=91.07' Storage=0.027 af Inflow=1.82 cfs 0.135 afPond 3P: South Underground Detention Discarded=0.71 cfs 0.135 af Primary=0.00 cfs 0.000 af Outflow=0.71 cfs 0.135 af Total Runoff Area = 2.860 ac Runoff Volume = 0.507 af Average Runoff Depth = 2.13" 98.25% Pervious = 2.810 ac 1.75% Impervious = 0.050 ac Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 3HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Northern Site Runoff = 1.37 cfs @ 12.09 hrs, Volume= 0.103 af, Depth> 2.51" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.37" Area (ac) CN Description 0.460 96 Gravel surface, HSG A * 0.030 30 Mulch with trees, Good, HSG A 0.490 92 Weighted Average 0.490 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.1 17 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.4 76 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.2 60 0.0100 4.54 3.56 Pipe Channel, D-E 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0100 4.54 3.56 Pipe Channel, E-F 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0100 4.54 3.56 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 4.6 Direct Entry, 6.0 213 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 4HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 1S: Northern Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 2-yr Rainfall=3.37" Runoff Area=0.490 ac Runoff Volume=0.103 af Runoff Depth>2.51" Flow Length=213' Tc=6.0 min CN=92 1.37 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 5HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Central Site Runoff = 2.82 cfs @ 12.09 hrs, Volume= 0.207 af, Depth> 2.32" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.37" Area (ac) CN Description 0.980 96 Gravel surface, HSG A * 0.090 30 Mulch with trees, Good, HSG A 1.070 90 Weighted Average 1.070 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.3 45 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.4 98 0.0100 4.54 3.56 Pipe Channel, C-D 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.3 84 0.0100 4.54 3.56 Pipe Channel, D-E 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.1 51 0.0200 6.42 5.04 Pipe Channel, E-F 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0120 4.97 3.90 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 6 0.0100 4.54 3.56 Pipe Channel, G-H 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 4.2 Direct Entry, 6.0 339 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 6HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 2S: Central Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Type III 24-hr 2-yr Rainfall=3.37" Runoff Area=1.070 ac Runoff Volume=0.207 af Runoff Depth>2.32" Flow Length=339' Tc=6.0 min CN=90 2.82 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 7HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Southern Site Runoff = 1.82 cfs @ 12.09 hrs, Volume= 0.135 af, Depth> 2.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.37" Area (ac) CN Description 0.570 96 Gravel surface, HSG A * 0.050 30 Mulch with trees, Good, HSG A 0.030 98 Roofs, HSG A 0.020 98 Paved parking, HSG A 0.670 91 Weighted Average 0.620 92.54% Pervious Area 0.050 7.46% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.2 28 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.2 31 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.6 97 0.0200 2.87 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps 0.1 13 0.0200 2.87 Shallow Concentrated Flow, E-F Paved Kv= 20.3 fps 0.1 40 0.0100 4.54 3.56 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.2 68 0.0150 5.56 4.36 Pipe Channel, G-H 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 6 0.1200 15.71 12.34 Pipe Channel, H-I 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 3.9 Direct Entry, 6.0 333 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 8HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 3S: Southern Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Type III 24-hr 2-yr Rainfall=3.37" Runoff Area=0.670 ac Runoff Volume=0.135 af Runoff Depth>2.42" Flow Length=333' Tc=6.0 min CN=91 1.82 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 9HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Managed Flow to Northeast Runoff = 0.81 cfs @ 12.09 hrs, Volume= 0.059 af, Depth> 1.90" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.37" Area (ac) CN Description * 0.310 96 Gravel surface, HSG A * 0.060 30 Mulch with Trees, Good, HSG A 0.370 85 Weighted Average 0.370 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.3 46 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 5.0 Direct Entry, 6.0 96 Total Subcatchment 4S: Managed Flow to Northeast Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 2-yr Rainfall=3.37" Runoff Area=0.370 ac Runoff Volume=0.059 af Runoff Depth>1.90" Flow Length=96' Slope=0.0200 '/' Tc=6.0 min CN=85 0.81 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 10HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Offsite Flow to Southwest Corner [73] Warning: Peak may fall outside time span Runoff = 0.00 cfs @ 24.00 hrs, Volume= 0.000 af, Depth> 0.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.37" Area (ac) CN Description 0.100 39 >75% Grass cover, Good, HSG A 0.020 32 Woods/grass comb., Good, HSG A 0.120 38 Weighted Average 0.120 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.2 9 0.0200 0.87 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 5.8 Direct Entry, 6.0 9 Total Subcatchment 5S: Offsite Flow to Southwest Corner Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Type III 24-hr 2-yr Rainfall=3.37" Runoff Area=0.120 ac Runoff Volume=0.000 af Runoff Depth>0.00" Flow Length=9' Slope=0.0200 '/' Tc=6.0 min CN=38 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 11HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Offsite to South Runoff = 0.02 cfs @ 12.30 hrs, Volume= 0.004 af, Depth> 0.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.37" Area (ac) CN Description * 0.040 96 Gravel surface, HSG A 0.100 39 >75% Grass cover, Good, HSG A 0.140 55 Weighted Average 0.140 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.4 28 0.0200 1.09 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.4 22 0.0200 1.04 Sheet Flow, B-C Smooth surfaces n= 0.011 P2= 3.37" 0.1 9 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 5.1 Direct Entry, 6.0 59 Total Subcatchment 6S: Offsite to South Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 2-yr Rainfall=3.37" Runoff Area=0.140 ac Runoff Volume=0.004 af Runoff Depth>0.30" Flow Length=59' Slope=0.0200 '/' Tc=6.0 min CN=55 0.02 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 12HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: To Existing Drainage System [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.370 ac, 0.00% Impervious, Inflow Depth > 1.90" for 2-yr event Inflow = 0.81 cfs @ 12.09 hrs, Volume= 0.059 af Outflow = 0.81 cfs @ 12.09 hrs, Volume= 0.059 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 4R: To Existing Drainage System Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.370 ac 0.81 cfs0.81 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 13HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 5R: Southwest Corner of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.120 ac, 0.00% Impervious, Inflow Depth > 0.00" for 2-yr event Inflow = 0.00 cfs @ 24.00 hrs, Volume= 0.000 af Outflow = 0.00 cfs @ 24.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 5R: Southwest Corner of Site Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Inflow Area=0.120 ac 0.00 cfs0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 14HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 6R: Route 28 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.140 ac, 0.00% Impervious, Inflow Depth > 0.30" for 2-yr event Inflow = 0.02 cfs @ 12.30 hrs, Volume= 0.004 af Outflow = 0.02 cfs @ 12.30 hrs, Volume= 0.004 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 6R: Route 28 Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 Inflow Area=0.140 ac 0.02 cfs0.02 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 15HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 1P: North Underground Detention System Inflow Area = 0.490 ac, 0.00% Impervious, Inflow Depth > 2.51" for 2-yr event Inflow = 1.37 cfs @ 12.09 hrs, Volume= 0.103 af Outflow = 0.58 cfs @ 12.30 hrs, Volume= 0.102 af, Atten= 58%, Lag= 12.9 min Discarded = 0.58 cfs @ 12.30 hrs, Volume= 0.102 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 96.79' @ 12.30 hrs Surf.Area= 0.014 ac Storage= 0.019 af Plug-Flow detention time= 11.1 min calculated for 0.102 af (100% of inflow) Center-of-Mass det. time= 10.9 min ( 806.3 - 795.4 ) Volume Invert Avail.Storage Storage Description #1A 94.65' 0.025 af 19.42'W x 31.27'L x 6.75'H Field A 0.094 af Overall - 0.033 af Embedded = 0.061 af x 40.0% Voids #2A 95.40' 0.033 af ADS_StormTech MC-4500 +Cap x 12 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 2 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf 0.057 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 94.65'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 94.00' #2 Primary 101.25'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.57 cfs @ 12.30 hrs HW=96.79' (Free Discharge) 1=Exfiltration ( Controls 0.57 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=94.65' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 16HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 1P: North Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 2 Rows x 100.0" Wide + 9.0" Spacing x 1 + 12.0" Side Stone x 2 = 19.42' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 12 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 2 Rows = 1,420.7 cf Chamber Storage 4,097.9 cf Field - 1,420.7 cf Chambers = 2,677.2 cf Stone x 40.0% Voids = 1,070.9 cf Stone Storage Chamber Storage + Stone Storage = 2,491.6 cf = 0.057 af Overall Storage Efficiency = 60.8% Overall System Size = 31.27' x 19.42' x 6.75' 12 Chambers 151.8 cy Field 99.2 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 17HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 1P: North Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.490 ac Peak Elev=96.79' Storage=0.019 af 1.37 cfs 0.58 cfs0.58 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 18HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 2P: Center Underground Detention System Inflow Area = 1.070 ac, 0.00% Impervious, Inflow Depth > 2.32" for 2-yr event Inflow = 2.82 cfs @ 12.09 hrs, Volume= 0.207 af Outflow = 1.66 cfs @ 12.21 hrs, Volume= 0.207 af, Atten= 41%, Lag= 7.3 min Discarded = 1.66 cfs @ 12.21 hrs, Volume= 0.207 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 94.27' @ 12.21 hrs Surf.Area= 0.020 ac Storage= 0.027 af Plug-Flow detention time= 5.7 min calculated for 0.207 af (100% of inflow) Center-of-Mass det. time= 5.5 min ( 809.9 - 804.4 ) Volume Invert Avail.Storage Storage Description #1A 92.25' 0.036 af 28.50'W x 31.27'L x 6.75'H Field A 0.138 af Overall - 0.049 af Embedded = 0.089 af x 40.0% Voids #2A 93.00' 0.049 af ADS_StormTech MC-4500 +Cap x 18 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 3 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 0.085 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 92.25'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 92.00' #2 Primary 99.50'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.65 cfs @ 12.21 hrs HW=94.26' (Free Discharge) 1=Exfiltration ( Controls 1.65 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=92.25' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 19HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 2P: Center Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 3 Rows x 100.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 28.50' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 18 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 3 Rows = 2,131.0 cf Chamber Storage 6,014.9 cf Field - 2,131.0 cf Chambers = 3,883.9 cf Stone x 40.0% Voids = 1,553.6 cf Stone Storage Chamber Storage + Stone Storage = 3,684.6 cf = 0.085 af Overall Storage Efficiency = 61.3% Overall System Size = 31.27' x 28.50' x 6.75' 18 Chambers 222.8 cy Field 143.8 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 20HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 2P: Center Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=1.070 ac Peak Elev=94.27' Storage=0.027 af 2.82 cfs 1.66 cfs1.66 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 21HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 3P: South Underground Detention System Inflow Area = 0.670 ac, 7.46% Impervious, Inflow Depth > 2.42" for 2-yr event Inflow = 1.82 cfs @ 12.09 hrs, Volume= 0.135 af Outflow = 0.71 cfs @ 12.33 hrs, Volume= 0.135 af, Atten= 61%, Lag= 14.6 min Discarded = 0.71 cfs @ 12.33 hrs, Volume= 0.135 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 91.07' @ 12.33 hrs Surf.Area= 0.020 ac Storage= 0.027 af Plug-Flow detention time= 12.3 min calculated for 0.135 af (100% of inflow) Center-of-Mass det. time= 12.0 min ( 812.0 - 800.1 ) Volume Invert Avail.Storage Storage Description #1A 89.05' 0.036 af 28.50'W x 31.27'L x 6.75'H Field A 0.138 af Overall - 0.049 af Embedded = 0.089 af x 40.0% Voids #2A 89.80' 0.049 af ADS_StormTech MC-4500 +Cap x 18 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 3 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 0.085 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 89.05'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 88.30' #2 Primary 95.42'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.71 cfs @ 12.33 hrs HW=91.07' (Free Discharge) 1=Exfiltration ( Controls 0.71 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=89.05' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 22HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 3P: South Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 3 Rows x 100.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 28.50' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 18 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 3 Rows = 2,131.0 cf Chamber Storage 6,014.9 cf Field - 2,131.0 cf Chambers = 3,883.9 cf Stone x 40.0% Voids = 1,553.6 cf Stone Storage Chamber Storage + Stone Storage = 3,684.6 cf = 0.085 af Overall Storage Efficiency = 61.3% Overall System Size = 31.27' x 28.50' x 6.75' 18 Chambers 222.8 cy Field 143.8 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 2-yr Rainfall=3.37"WS-Post Printed 11/29/2021Prepared by BSC Group Page 23HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 3P: South Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.670 ac Peak Elev=91.07' Storage=0.027 af 1.82 cfs 0.71 cfs0.71 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 24HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.490 ac 0.00% Impervious Runoff Depth>4.00"Subcatchment 1S: Northern Site Flow Length=213' Tc=6.0 min CN=92 Runoff=2.13 cfs 0.163 af Runoff Area=1.070 ac 0.00% Impervious Runoff Depth>3.79"Subcatchment 2S: Central Site Flow Length=339' Tc=6.0 min CN=90 Runoff=4.49 cfs 0.338 af Runoff Area=0.670 ac 7.46% Impervious Runoff Depth>3.89"Subcatchment 3S: Southern Site Flow Length=333' Tc=6.0 min CN=91 Runoff=2.87 cfs 0.217 af Runoff Area=0.370 ac 0.00% Impervious Runoff Depth>3.28"Subcatchment 4S: Managed Flow to Flow Length=96' Slope=0.0200 '/' Tc=6.0 min CN=85 Runoff=1.38 cfs 0.101 af Runoff Area=0.120 ac 0.00% Impervious Runoff Depth>0.15"Subcatchment 5S: Offsite Flow to Flow Length=9' Slope=0.0200 '/' Tc=6.0 min CN=38 Runoff=0.00 cfs 0.002 af Runoff Area=0.140 ac 0.00% Impervious Runoff Depth>0.93"Subcatchment 6S: Offsite to South Flow Length=59' Slope=0.0200 '/' Tc=6.0 min CN=55 Runoff=0.12 cfs 0.011 af Inflow=1.38 cfs 0.101 afReach 4R: To Existing Drainage System Outflow=1.38 cfs 0.101 af Inflow=0.00 cfs 0.002 afReach 5R: Southwest Corner of Site Outflow=0.00 cfs 0.002 af Inflow=0.12 cfs 0.011 afReach 6R: Route 28 Outflow=0.12 cfs 0.011 af Peak Elev=98.15' Storage=0.033 af Inflow=2.13 cfs 0.163 afPond 1P: North Underground Detention Discarded=0.89 cfs 0.163 af Primary=0.00 cfs 0.000 af Outflow=0.89 cfs 0.163 af Peak Elev=95.58' Storage=0.047 af Inflow=4.49 cfs 0.338 afPond 2P: Center Underground Detention Discarded=2.65 cfs 0.338 af Primary=0.00 cfs 0.000 af Outflow=2.65 cfs 0.338 af Peak Elev=92.41' Storage=0.047 af Inflow=2.87 cfs 0.217 afPond 3P: South Underground Detention Discarded=1.09 cfs 0.217 af Primary=0.00 cfs 0.000 af Outflow=1.09 cfs 0.217 af Total Runoff Area = 2.860 ac Runoff Volume = 0.832 af Average Runoff Depth = 3.49" 98.25% Pervious = 2.810 ac 1.75% Impervious = 0.050 ac Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 25HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Northern Site Runoff = 2.13 cfs @ 12.09 hrs, Volume= 0.163 af, Depth> 4.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.91" Area (ac) CN Description 0.460 96 Gravel surface, HSG A * 0.030 30 Mulch with trees, Good, HSG A 0.490 92 Weighted Average 0.490 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.1 17 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.4 76 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.2 60 0.0100 4.54 3.56 Pipe Channel, D-E 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0100 4.54 3.56 Pipe Channel, E-F 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0100 4.54 3.56 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 4.6 Direct Entry, 6.0 213 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 26HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 1S: Northern Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Type III 24-hr 10-yr Rainfall=4.91" Runoff Area=0.490 ac Runoff Volume=0.163 af Runoff Depth>4.00" Flow Length=213' Tc=6.0 min CN=92 2.13 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 27HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Central Site Runoff = 4.49 cfs @ 12.09 hrs, Volume= 0.338 af, Depth> 3.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.91" Area (ac) CN Description 0.980 96 Gravel surface, HSG A * 0.090 30 Mulch with trees, Good, HSG A 1.070 90 Weighted Average 1.070 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.3 45 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.4 98 0.0100 4.54 3.56 Pipe Channel, C-D 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.3 84 0.0100 4.54 3.56 Pipe Channel, D-E 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.1 51 0.0200 6.42 5.04 Pipe Channel, E-F 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0120 4.97 3.90 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 6 0.0100 4.54 3.56 Pipe Channel, G-H 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 4.2 Direct Entry, 6.0 339 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 28HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 2S: Central Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Type III 24-hr 10-yr Rainfall=4.91" Runoff Area=1.070 ac Runoff Volume=0.338 af Runoff Depth>3.79" Flow Length=339' Tc=6.0 min CN=90 4.49 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 29HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Southern Site Runoff = 2.87 cfs @ 12.09 hrs, Volume= 0.217 af, Depth> 3.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.91" Area (ac) CN Description 0.570 96 Gravel surface, HSG A * 0.050 30 Mulch with trees, Good, HSG A 0.030 98 Roofs, HSG A 0.020 98 Paved parking, HSG A 0.670 91 Weighted Average 0.620 92.54% Pervious Area 0.050 7.46% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.2 28 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.2 31 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.6 97 0.0200 2.87 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps 0.1 13 0.0200 2.87 Shallow Concentrated Flow, E-F Paved Kv= 20.3 fps 0.1 40 0.0100 4.54 3.56 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.2 68 0.0150 5.56 4.36 Pipe Channel, G-H 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 6 0.1200 15.71 12.34 Pipe Channel, H-I 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 3.9 Direct Entry, 6.0 333 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 30HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 3S: Southern Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Type III 24-hr 10-yr Rainfall=4.91" Runoff Area=0.670 ac Runoff Volume=0.217 af Runoff Depth>3.89" Flow Length=333' Tc=6.0 min CN=91 2.87 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 31HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Managed Flow to Northeast Runoff = 1.38 cfs @ 12.09 hrs, Volume= 0.101 af, Depth> 3.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.91" Area (ac) CN Description * 0.310 96 Gravel surface, HSG A * 0.060 30 Mulch with Trees, Good, HSG A 0.370 85 Weighted Average 0.370 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.3 46 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 5.0 Direct Entry, 6.0 96 Total Subcatchment 4S: Managed Flow to Northeast Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 10-yr Rainfall=4.91" Runoff Area=0.370 ac Runoff Volume=0.101 af Runoff Depth>3.28" Flow Length=96' Slope=0.0200 '/' Tc=6.0 min CN=85 1.38 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 32HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Offsite Flow to Southwest Corner Runoff = 0.00 cfs @ 13.76 hrs, Volume= 0.002 af, Depth> 0.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.91" Area (ac) CN Description 0.100 39 >75% Grass cover, Good, HSG A 0.020 32 Woods/grass comb., Good, HSG A 0.120 38 Weighted Average 0.120 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.2 9 0.0200 0.87 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 5.8 Direct Entry, 6.0 9 Total Subcatchment 5S: Offsite Flow to Southwest Corner Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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 10-yr Rainfall=4.91" Runoff Area=0.120 ac Runoff Volume=0.002 af Runoff Depth>0.15" Flow Length=9' Slope=0.0200 '/' Tc=6.0 min CN=38 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 33HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Offsite to South Runoff = 0.12 cfs @ 12.11 hrs, Volume= 0.011 af, Depth> 0.93" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.91" Area (ac) CN Description * 0.040 96 Gravel surface, HSG A 0.100 39 >75% Grass cover, Good, HSG A 0.140 55 Weighted Average 0.140 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.4 28 0.0200 1.09 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.4 22 0.0200 1.04 Sheet Flow, B-C Smooth surfaces n= 0.011 P2= 3.37" 0.1 9 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 5.1 Direct Entry, 6.0 59 Total Subcatchment 6S: Offsite to South Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.13 0.125 0.12 0.115 0.11 0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type III 24-hr 10-yr Rainfall=4.91" Runoff Area=0.140 ac Runoff Volume=0.011 af Runoff Depth>0.93" Flow Length=59' Slope=0.0200 '/' Tc=6.0 min CN=55 0.12 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 34HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: To Existing Drainage System [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.370 ac, 0.00% Impervious, Inflow Depth > 3.28" for 10-yr event Inflow = 1.38 cfs @ 12.09 hrs, Volume= 0.101 af Outflow = 1.38 cfs @ 12.09 hrs, Volume= 0.101 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 4R: To Existing Drainage System Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.370 ac 1.38 cfs1.38 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 35HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 5R: Southwest Corner of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.120 ac, 0.00% Impervious, Inflow Depth > 0.15" for 10-yr event Inflow = 0.00 cfs @ 13.76 hrs, Volume= 0.002 af Outflow = 0.00 cfs @ 13.76 hrs, Volume= 0.002 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 5R: Southwest Corner of Site Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.120 ac 0.00 cfs0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 36HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 6R: Route 28 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.140 ac, 0.00% Impervious, Inflow Depth > 0.93" for 10-yr event Inflow = 0.12 cfs @ 12.11 hrs, Volume= 0.011 af Outflow = 0.12 cfs @ 12.11 hrs, Volume= 0.011 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 6R: Route 28 Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.13 0.125 0.12 0.115 0.11 0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.140 ac 0.12 cfs0.12 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 37HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 1P: North Underground Detention System Inflow Area = 0.490 ac, 0.00% Impervious, Inflow Depth > 4.00" for 10-yr event Inflow = 2.13 cfs @ 12.09 hrs, Volume= 0.163 af Outflow = 0.89 cfs @ 12.30 hrs, Volume= 0.163 af, Atten= 58%, Lag= 12.8 min Discarded = 0.89 cfs @ 12.30 hrs, Volume= 0.163 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 98.15' @ 12.30 hrs Surf.Area= 0.014 ac Storage= 0.033 af Plug-Flow detention time= 13.9 min calculated for 0.163 af (100% of inflow) Center-of-Mass det. time= 13.6 min ( 796.4 - 782.8 ) Volume Invert Avail.Storage Storage Description #1A 94.65' 0.025 af 19.42'W x 31.27'L x 6.75'H Field A 0.094 af Overall - 0.033 af Embedded = 0.061 af x 40.0% Voids #2A 95.40' 0.033 af ADS_StormTech MC-4500 +Cap x 12 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 2 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf 0.057 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 94.65'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 94.00' #2 Primary 101.25'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.89 cfs @ 12.30 hrs HW=98.15' (Free Discharge) 1=Exfiltration ( Controls 0.89 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=94.65' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 38HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 1P: North Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 2 Rows x 100.0" Wide + 9.0" Spacing x 1 + 12.0" Side Stone x 2 = 19.42' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 12 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 2 Rows = 1,420.7 cf Chamber Storage 4,097.9 cf Field - 1,420.7 cf Chambers = 2,677.2 cf Stone x 40.0% Voids = 1,070.9 cf Stone Storage Chamber Storage + Stone Storage = 2,491.6 cf = 0.057 af Overall Storage Efficiency = 60.8% Overall System Size = 31.27' x 19.42' x 6.75' 12 Chambers 151.8 cy Field 99.2 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 39HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 1P: North Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.490 ac Peak Elev=98.15' Storage=0.033 af 2.13 cfs 0.89 cfs0.89 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 40HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 2P: Center Underground Detention System Inflow Area = 1.070 ac, 0.00% Impervious, Inflow Depth > 3.79" for 10-yr event Inflow = 4.49 cfs @ 12.09 hrs, Volume= 0.338 af Outflow = 2.65 cfs @ 12.21 hrs, Volume= 0.338 af, Atten= 41%, Lag= 7.2 min Discarded = 2.65 cfs @ 12.21 hrs, Volume= 0.338 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 95.58' @ 12.21 hrs Surf.Area= 0.020 ac Storage= 0.047 af Plug-Flow detention time= 6.9 min calculated for 0.338 af (100% of inflow) Center-of-Mass det. time= 6.7 min ( 797.5 - 790.9 ) Volume Invert Avail.Storage Storage Description #1A 92.25' 0.036 af 28.50'W x 31.27'L x 6.75'H Field A 0.138 af Overall - 0.049 af Embedded = 0.089 af x 40.0% Voids #2A 93.00' 0.049 af ADS_StormTech MC-4500 +Cap x 18 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 3 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 0.085 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 92.25'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 92.00' #2 Primary 99.50'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=2.64 cfs @ 12.21 hrs HW=95.57' (Free Discharge) 1=Exfiltration ( Controls 2.64 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=92.25' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 41HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 2P: Center Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 3 Rows x 100.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 28.50' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 18 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 3 Rows = 2,131.0 cf Chamber Storage 6,014.9 cf Field - 2,131.0 cf Chambers = 3,883.9 cf Stone x 40.0% Voids = 1,553.6 cf Stone Storage Chamber Storage + Stone Storage = 3,684.6 cf = 0.085 af Overall Storage Efficiency = 61.3% Overall System Size = 31.27' x 28.50' x 6.75' 18 Chambers 222.8 cy Field 143.8 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 42HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 2P: Center Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=1.070 ac Peak Elev=95.58' Storage=0.047 af 4.49 cfs 2.65 cfs2.65 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 43HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 3P: South Underground Detention System Inflow Area = 0.670 ac, 7.46% Impervious, Inflow Depth > 3.89" for 10-yr event Inflow = 2.87 cfs @ 12.09 hrs, Volume= 0.217 af Outflow = 1.09 cfs @ 12.33 hrs, Volume= 0.217 af, Atten= 62%, Lag= 14.7 min Discarded = 1.09 cfs @ 12.33 hrs, Volume= 0.217 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 92.41' @ 12.33 hrs Surf.Area= 0.020 ac Storage= 0.047 af Plug-Flow detention time= 15.8 min calculated for 0.217 af (100% of inflow) Center-of-Mass det. time= 15.5 min ( 802.5 - 787.0 ) Volume Invert Avail.Storage Storage Description #1A 89.05' 0.036 af 28.50'W x 31.27'L x 6.75'H Field A 0.138 af Overall - 0.049 af Embedded = 0.089 af x 40.0% Voids #2A 89.80' 0.049 af ADS_StormTech MC-4500 +Cap x 18 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 3 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 0.085 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 89.05'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 88.30' #2 Primary 95.42'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.09 cfs @ 12.33 hrs HW=92.41' (Free Discharge) 1=Exfiltration ( Controls 1.09 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=89.05' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 44HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 3P: South Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 3 Rows x 100.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 28.50' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 18 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 3 Rows = 2,131.0 cf Chamber Storage 6,014.9 cf Field - 2,131.0 cf Chambers = 3,883.9 cf Stone x 40.0% Voids = 1,553.6 cf Stone Storage Chamber Storage + Stone Storage = 3,684.6 cf = 0.085 af Overall Storage Efficiency = 61.3% Overall System Size = 31.27' x 28.50' x 6.75' 18 Chambers 222.8 cy Field 143.8 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 10-yr Rainfall=4.91"WS-Post Printed 11/29/2021Prepared by BSC Group Page 45HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 3P: South Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=0.670 ac Peak Elev=92.41' Storage=0.047 af 2.87 cfs 1.09 cfs1.09 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 46HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.490 ac 0.00% Impervious Runoff Depth>4.94"Subcatchment 1S: Northern Site Flow Length=213' Tc=6.0 min CN=92 Runoff=2.60 cfs 0.202 af Runoff Area=1.070 ac 0.00% Impervious Runoff Depth>4.72"Subcatchment 2S: Central Site Flow Length=339' Tc=6.0 min CN=90 Runoff=5.52 cfs 0.421 af Runoff Area=0.670 ac 7.46% Impervious Runoff Depth>4.83"Subcatchment 3S: Southern Site Flow Length=333' Tc=6.0 min CN=91 Runoff=3.51 cfs 0.269 af Runoff Area=0.370 ac 0.00% Impervious Runoff Depth>4.18"Subcatchment 4S: Managed Flow to Flow Length=96' Slope=0.0200 '/' Tc=6.0 min CN=85 Runoff=1.74 cfs 0.129 af Runoff Area=0.120 ac 0.00% Impervious Runoff Depth>0.36"Subcatchment 5S: Offsite Flow to Flow Length=9' Slope=0.0200 '/' Tc=6.0 min CN=38 Runoff=0.01 cfs 0.004 af Runoff Area=0.140 ac 0.00% Impervious Runoff Depth>1.44"Subcatchment 6S: Offsite to South Flow Length=59' Slope=0.0200 '/' Tc=6.0 min CN=55 Runoff=0.21 cfs 0.017 af Inflow=1.74 cfs 0.129 afReach 4R: To Existing Drainage System Outflow=1.74 cfs 0.129 af Inflow=0.01 cfs 0.004 afReach 5R: Southwest Corner of Site Outflow=0.01 cfs 0.004 af Inflow=0.21 cfs 0.017 afReach 6R: Route 28 Outflow=0.21 cfs 0.017 af Peak Elev=99.06' Storage=0.042 af Inflow=2.60 cfs 0.202 afPond 1P: North Underground Detention Discarded=1.10 cfs 0.202 af Primary=0.00 cfs 0.000 af Outflow=1.10 cfs 0.202 af Peak Elev=96.45' Storage=0.059 af Inflow=5.52 cfs 0.421 afPond 2P: Center Underground Detention Discarded=3.32 cfs 0.420 af Primary=0.00 cfs 0.000 af Outflow=3.32 cfs 0.420 af Peak Elev=93.32' Storage=0.060 af Inflow=3.51 cfs 0.269 afPond 3P: South Underground Detention Discarded=1.36 cfs 0.269 af Primary=0.00 cfs 0.000 af Outflow=1.36 cfs 0.269 af Total Runoff Area = 2.860 ac Runoff Volume = 1.041 af Average Runoff Depth = 4.37" 98.25% Pervious = 2.810 ac 1.75% Impervious = 0.050 ac Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 47HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Northern Site Runoff = 2.60 cfs @ 12.09 hrs, Volume= 0.202 af, Depth> 4.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.87" Area (ac) CN Description 0.460 96 Gravel surface, HSG A * 0.030 30 Mulch with trees, Good, HSG A 0.490 92 Weighted Average 0.490 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.1 17 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.4 76 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.2 60 0.0100 4.54 3.56 Pipe Channel, D-E 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0100 4.54 3.56 Pipe Channel, E-F 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0100 4.54 3.56 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 4.6 Direct Entry, 6.0 213 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 48HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 1S: Northern Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Type III 24-hr 25-yr Rainfall=5.87" Runoff Area=0.490 ac Runoff Volume=0.202 af Runoff Depth>4.94" Flow Length=213' Tc=6.0 min CN=92 2.60 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 49HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Central Site Runoff = 5.52 cfs @ 12.09 hrs, Volume= 0.421 af, Depth> 4.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.87" Area (ac) CN Description 0.980 96 Gravel surface, HSG A * 0.090 30 Mulch with trees, Good, HSG A 1.070 90 Weighted Average 1.070 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.3 45 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.4 98 0.0100 4.54 3.56 Pipe Channel, C-D 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.3 84 0.0100 4.54 3.56 Pipe Channel, D-E 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.1 51 0.0200 6.42 5.04 Pipe Channel, E-F 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0120 4.97 3.90 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 6 0.0100 4.54 3.56 Pipe Channel, G-H 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 4.2 Direct Entry, 6.0 339 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 50HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 2S: Central Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)6 5 4 3 2 1 0 Type III 24-hr 25-yr Rainfall=5.87" Runoff Area=1.070 ac Runoff Volume=0.421 af Runoff Depth>4.72" Flow Length=339' Tc=6.0 min CN=90 5.52 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 51HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Southern Site Runoff = 3.51 cfs @ 12.09 hrs, Volume= 0.269 af, Depth> 4.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.87" Area (ac) CN Description 0.570 96 Gravel surface, HSG A * 0.050 30 Mulch with trees, Good, HSG A 0.030 98 Roofs, HSG A 0.020 98 Paved parking, HSG A 0.670 91 Weighted Average 0.620 92.54% Pervious Area 0.050 7.46% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.2 28 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.2 31 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.6 97 0.0200 2.87 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps 0.1 13 0.0200 2.87 Shallow Concentrated Flow, E-F Paved Kv= 20.3 fps 0.1 40 0.0100 4.54 3.56 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.2 68 0.0150 5.56 4.36 Pipe Channel, G-H 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 6 0.1200 15.71 12.34 Pipe Channel, H-I 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 3.9 Direct Entry, 6.0 333 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 52HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 3S: Southern Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Type III 24-hr 25-yr Rainfall=5.87" Runoff Area=0.670 ac Runoff Volume=0.269 af Runoff Depth>4.83" Flow Length=333' Tc=6.0 min CN=91 3.51 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 53HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Managed Flow to Northeast Runoff = 1.74 cfs @ 12.09 hrs, Volume= 0.129 af, Depth> 4.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.87" Area (ac) CN Description * 0.310 96 Gravel surface, HSG A * 0.060 30 Mulch with Trees, Good, HSG A 0.370 85 Weighted Average 0.370 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.3 46 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 5.0 Direct Entry, 6.0 96 Total Subcatchment 4S: Managed Flow to Northeast Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 25-yr Rainfall=5.87" Runoff Area=0.370 ac Runoff Volume=0.129 af Runoff Depth>4.18" Flow Length=96' Slope=0.0200 '/' Tc=6.0 min CN=85 1.74 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 54HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Offsite Flow to Southwest Corner Runoff = 0.01 cfs @ 12.38 hrs, Volume= 0.004 af, Depth> 0.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.87" Area (ac) CN Description 0.100 39 >75% Grass cover, Good, HSG A 0.020 32 Woods/grass comb., Good, HSG A 0.120 38 Weighted Average 0.120 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.2 9 0.0200 0.87 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 5.8 Direct Entry, 6.0 9 Total Subcatchment 5S: Offsite Flow to Southwest Corner Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Type III 24-hr 25-yr Rainfall=5.87" Runoff Area=0.120 ac Runoff Volume=0.004 af Runoff Depth>0.36" Flow Length=9' Slope=0.0200 '/' Tc=6.0 min CN=38 0.01 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 55HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Offsite to South Runoff = 0.21 cfs @ 12.11 hrs, Volume= 0.017 af, Depth> 1.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.87" Area (ac) CN Description * 0.040 96 Gravel surface, HSG A 0.100 39 >75% Grass cover, Good, HSG A 0.140 55 Weighted Average 0.140 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.4 28 0.0200 1.09 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.4 22 0.0200 1.04 Sheet Flow, B-C Smooth surfaces n= 0.011 P2= 3.37" 0.1 9 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 5.1 Direct Entry, 6.0 59 Total Subcatchment 6S: Offsite to South Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type III 24-hr 25-yr Rainfall=5.87" Runoff Area=0.140 ac Runoff Volume=0.017 af Runoff Depth>1.44" Flow Length=59' Slope=0.0200 '/' Tc=6.0 min CN=55 0.21 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 56HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: To Existing Drainage System [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.370 ac, 0.00% Impervious, Inflow Depth > 4.18" for 25-yr event Inflow = 1.74 cfs @ 12.09 hrs, Volume= 0.129 af Outflow = 1.74 cfs @ 12.09 hrs, Volume= 0.129 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 4R: To Existing Drainage System Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.370 ac 1.74 cfs1.74 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 57HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 5R: Southwest Corner of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.120 ac, 0.00% Impervious, Inflow Depth > 0.36" for 25-yr event Inflow = 0.01 cfs @ 12.38 hrs, Volume= 0.004 af Outflow = 0.01 cfs @ 12.38 hrs, Volume= 0.004 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 5R: Southwest Corner of Site Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.120 ac 0.01 cfs0.01 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 58HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 6R: Route 28 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.140 ac, 0.00% Impervious, Inflow Depth > 1.44" for 25-yr event Inflow = 0.21 cfs @ 12.11 hrs, Volume= 0.017 af Outflow = 0.21 cfs @ 12.11 hrs, Volume= 0.017 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 6R: Route 28 Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.140 ac 0.21 cfs0.21 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 59HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 1P: North Underground Detention System Inflow Area = 0.490 ac, 0.00% Impervious, Inflow Depth > 4.94" for 25-yr event Inflow = 2.60 cfs @ 12.09 hrs, Volume= 0.202 af Outflow = 1.10 cfs @ 12.29 hrs, Volume= 0.202 af, Atten= 58%, Lag= 12.3 min Discarded = 1.10 cfs @ 12.29 hrs, Volume= 0.202 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 99.06' @ 12.29 hrs Surf.Area= 0.014 ac Storage= 0.042 af Plug-Flow detention time= 15.0 min calculated for 0.201 af (100% of inflow) Center-of-Mass det. time= 14.7 min ( 792.1 - 777.4 ) Volume Invert Avail.Storage Storage Description #1A 94.65' 0.025 af 19.42'W x 31.27'L x 6.75'H Field A 0.094 af Overall - 0.033 af Embedded = 0.061 af x 40.0% Voids #2A 95.40' 0.033 af ADS_StormTech MC-4500 +Cap x 12 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 2 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf 0.057 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 94.65'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 94.00' #2 Primary 101.25'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.10 cfs @ 12.29 hrs HW=99.06' (Free Discharge) 1=Exfiltration ( Controls 1.10 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=94.65' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 60HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 1P: North Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 2 Rows x 100.0" Wide + 9.0" Spacing x 1 + 12.0" Side Stone x 2 = 19.42' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 12 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 2 Rows = 1,420.7 cf Chamber Storage 4,097.9 cf Field - 1,420.7 cf Chambers = 2,677.2 cf Stone x 40.0% Voids = 1,070.9 cf Stone Storage Chamber Storage + Stone Storage = 2,491.6 cf = 0.057 af Overall Storage Efficiency = 60.8% Overall System Size = 31.27' x 19.42' x 6.75' 12 Chambers 151.8 cy Field 99.2 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 61HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 1P: North Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.490 ac Peak Elev=99.06' Storage=0.042 af 2.60 cfs 1.10 cfs1.10 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 62HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 2P: Center Underground Detention System Inflow Area = 1.070 ac, 0.00% Impervious, Inflow Depth > 4.72" for 25-yr event Inflow = 5.52 cfs @ 12.09 hrs, Volume= 0.421 af Outflow = 3.32 cfs @ 12.20 hrs, Volume= 0.420 af, Atten= 40%, Lag= 7.0 min Discarded = 3.32 cfs @ 12.20 hrs, Volume= 0.420 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 96.45' @ 12.20 hrs Surf.Area= 0.020 ac Storage= 0.059 af Plug-Flow detention time= 7.4 min calculated for 0.419 af (100% of inflow) Center-of-Mass det. time= 7.2 min ( 792.1 - 784.9 ) Volume Invert Avail.Storage Storage Description #1A 92.25' 0.036 af 28.50'W x 31.27'L x 6.75'H Field A 0.138 af Overall - 0.049 af Embedded = 0.089 af x 40.0% Voids #2A 93.00' 0.049 af ADS_StormTech MC-4500 +Cap x 18 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 3 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 0.085 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 92.25'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 92.00' #2 Primary 99.50'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=3.31 cfs @ 12.20 hrs HW=96.44' (Free Discharge) 1=Exfiltration ( Controls 3.31 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=92.25' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 63HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 2P: Center Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 3 Rows x 100.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 28.50' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 18 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 3 Rows = 2,131.0 cf Chamber Storage 6,014.9 cf Field - 2,131.0 cf Chambers = 3,883.9 cf Stone x 40.0% Voids = 1,553.6 cf Stone Storage Chamber Storage + Stone Storage = 3,684.6 cf = 0.085 af Overall Storage Efficiency = 61.3% Overall System Size = 31.27' x 28.50' x 6.75' 18 Chambers 222.8 cy Field 143.8 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 64HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 2P: Center Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)6 5 4 3 2 1 0 Inflow Area=1.070 ac Peak Elev=96.45' Storage=0.059 af 5.52 cfs 3.32 cfs3.32 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 65HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 3P: South Underground Detention System Inflow Area = 0.670 ac, 7.46% Impervious, Inflow Depth > 4.83" for 25-yr event Inflow = 3.51 cfs @ 12.09 hrs, Volume= 0.269 af Outflow = 1.36 cfs @ 12.32 hrs, Volume= 0.269 af, Atten= 61%, Lag= 14.2 min Discarded = 1.36 cfs @ 12.32 hrs, Volume= 0.269 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 93.32' @ 12.32 hrs Surf.Area= 0.020 ac Storage= 0.060 af Plug-Flow detention time= 17.2 min calculated for 0.269 af (100% of inflow) Center-of-Mass det. time= 16.9 min ( 798.2 - 781.3 ) Volume Invert Avail.Storage Storage Description #1A 89.05' 0.036 af 28.50'W x 31.27'L x 6.75'H Field A 0.138 af Overall - 0.049 af Embedded = 0.089 af x 40.0% Voids #2A 89.80' 0.049 af ADS_StormTech MC-4500 +Cap x 18 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 3 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 0.085 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 89.05'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 88.30' #2 Primary 95.42'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.35 cfs @ 12.32 hrs HW=93.31' (Free Discharge) 1=Exfiltration ( Controls 1.35 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=89.05' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 66HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 3P: South Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 3 Rows x 100.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 28.50' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 18 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 3 Rows = 2,131.0 cf Chamber Storage 6,014.9 cf Field - 2,131.0 cf Chambers = 3,883.9 cf Stone x 40.0% Voids = 1,553.6 cf Stone Storage Chamber Storage + Stone Storage = 3,684.6 cf = 0.085 af Overall Storage Efficiency = 61.3% Overall System Size = 31.27' x 28.50' x 6.75' 18 Chambers 222.8 cy Field 143.8 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 25-yr Rainfall=5.87"WS-Post Printed 11/29/2021Prepared by BSC Group Page 67HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 3P: South Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=0.670 ac Peak Elev=93.32' Storage=0.060 af 3.51 cfs 1.36 cfs1.36 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 68HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.490 ac 0.00% Impervious Runoff Depth>5.65"Subcatchment 1S: Northern Site Flow Length=213' Tc=6.0 min CN=92 Runoff=2.95 cfs 0.231 af Runoff Area=1.070 ac 0.00% Impervious Runoff Depth>5.42"Subcatchment 2S: Central Site Flow Length=339' Tc=6.0 min CN=90 Runoff=6.29 cfs 0.483 af Runoff Area=0.670 ac 7.46% Impervious Runoff Depth>5.53"Subcatchment 3S: Southern Site Flow Length=333' Tc=6.0 min CN=91 Runoff=3.99 cfs 0.309 af Runoff Area=0.370 ac 0.00% Impervious Runoff Depth>4.86"Subcatchment 4S: Managed Flow to Flow Length=96' Slope=0.0200 '/' Tc=6.0 min CN=85 Runoff=2.01 cfs 0.150 af Runoff Area=0.120 ac 0.00% Impervious Runoff Depth>0.56"Subcatchment 5S: Offsite Flow to Flow Length=9' Slope=0.0200 '/' Tc=6.0 min CN=38 Runoff=0.03 cfs 0.006 af Runoff Area=0.140 ac 0.00% Impervious Runoff Depth>1.87"Subcatchment 6S: Offsite to South Flow Length=59' Slope=0.0200 '/' Tc=6.0 min CN=55 Runoff=0.28 cfs 0.022 af Inflow=2.01 cfs 0.150 afReach 4R: To Existing Drainage System Outflow=2.01 cfs 0.150 af Inflow=0.03 cfs 0.006 afReach 5R: Southwest Corner of Site Outflow=0.03 cfs 0.006 af Inflow=0.28 cfs 0.022 afReach 6R: Route 28 Outflow=0.28 cfs 0.022 af Peak Elev=99.82' Storage=0.048 af Inflow=2.95 cfs 0.231 afPond 1P: North Underground Detention Discarded=1.28 cfs 0.230 af Primary=0.00 cfs 0.000 af Outflow=1.28 cfs 0.230 af Peak Elev=97.15' Storage=0.068 af Inflow=6.29 cfs 0.483 afPond 2P: Center Underground Detention Discarded=3.85 cfs 0.483 af Primary=0.00 cfs 0.000 af Outflow=3.85 cfs 0.483 af Peak Elev=94.06' Storage=0.069 af Inflow=3.99 cfs 0.309 afPond 3P: South Underground Detention Discarded=1.57 cfs 0.309 af Primary=0.00 cfs 0.000 af Outflow=1.57 cfs 0.309 af Total Runoff Area = 2.860 ac Runoff Volume = 1.200 af Average Runoff Depth = 5.03" 98.25% Pervious = 2.810 ac 1.75% Impervious = 0.050 ac Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 69HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Northern Site Runoff = 2.95 cfs @ 12.09 hrs, Volume= 0.231 af, Depth> 5.65" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=6.59" Area (ac) CN Description 0.460 96 Gravel surface, HSG A * 0.030 30 Mulch with trees, Good, HSG A 0.490 92 Weighted Average 0.490 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.1 17 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.4 76 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.2 60 0.0100 4.54 3.56 Pipe Channel, D-E 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0100 4.54 3.56 Pipe Channel, E-F 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0100 4.54 3.56 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 4.6 Direct Entry, 6.0 213 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 70HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 1S: Northern Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Type III 24-hr 50-yr Rainfall=6.59" Runoff Area=0.490 ac Runoff Volume=0.231 af Runoff Depth>5.65" Flow Length=213' Tc=6.0 min CN=92 2.95 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 71HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Central Site Runoff = 6.29 cfs @ 12.09 hrs, Volume= 0.483 af, Depth> 5.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=6.59" Area (ac) CN Description 0.980 96 Gravel surface, HSG A * 0.090 30 Mulch with trees, Good, HSG A 1.070 90 Weighted Average 1.070 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.3 45 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.4 98 0.0100 4.54 3.56 Pipe Channel, C-D 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.3 84 0.0100 4.54 3.56 Pipe Channel, D-E 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.1 51 0.0200 6.42 5.04 Pipe Channel, E-F 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0120 4.97 3.90 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 6 0.0100 4.54 3.56 Pipe Channel, G-H 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 4.2 Direct Entry, 6.0 339 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 72HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 2S: Central Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Type III 24-hr 50-yr Rainfall=6.59" Runoff Area=1.070 ac Runoff Volume=0.483 af Runoff Depth>5.42" Flow Length=339' Tc=6.0 min CN=90 6.29 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 73HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Southern Site Runoff = 3.99 cfs @ 12.09 hrs, Volume= 0.309 af, Depth> 5.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=6.59" Area (ac) CN Description 0.570 96 Gravel surface, HSG A * 0.050 30 Mulch with trees, Good, HSG A 0.030 98 Roofs, HSG A 0.020 98 Paved parking, HSG A 0.670 91 Weighted Average 0.620 92.54% Pervious Area 0.050 7.46% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.2 28 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.2 31 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.6 97 0.0200 2.87 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps 0.1 13 0.0200 2.87 Shallow Concentrated Flow, E-F Paved Kv= 20.3 fps 0.1 40 0.0100 4.54 3.56 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.2 68 0.0150 5.56 4.36 Pipe Channel, G-H 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 6 0.1200 15.71 12.34 Pipe Channel, H-I 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 3.9 Direct Entry, 6.0 333 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 74HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 3S: Southern Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Type III 24-hr 50-yr Rainfall=6.59" Runoff Area=0.670 ac Runoff Volume=0.309 af Runoff Depth>5.53" Flow Length=333' Tc=6.0 min CN=91 3.99 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 75HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Managed Flow to Northeast Runoff = 2.01 cfs @ 12.09 hrs, Volume= 0.150 af, Depth> 4.86" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=6.59" Area (ac) CN Description * 0.310 96 Gravel surface, HSG A * 0.060 30 Mulch with Trees, Good, HSG A 0.370 85 Weighted Average 0.370 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.3 46 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 5.0 Direct Entry, 6.0 96 Total Subcatchment 4S: Managed Flow to Northeast Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Type III 24-hr 50-yr Rainfall=6.59" Runoff Area=0.370 ac Runoff Volume=0.150 af Runoff Depth>4.86" Flow Length=96' Slope=0.0200 '/' Tc=6.0 min CN=85 2.01 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 76HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Offsite Flow to Southwest Corner Runoff = 0.03 cfs @ 12.31 hrs, Volume= 0.006 af, Depth> 0.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=6.59" Area (ac) CN Description 0.100 39 >75% Grass cover, Good, HSG A 0.020 32 Woods/grass comb., Good, HSG A 0.120 38 Weighted Average 0.120 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.2 9 0.0200 0.87 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 5.8 Direct Entry, 6.0 9 Total Subcatchment 5S: Offsite Flow to Southwest Corner Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Type III 24-hr 50-yr Rainfall=6.59" Runoff Area=0.120 ac Runoff Volume=0.006 af Runoff Depth>0.56" Flow Length=9' Slope=0.0200 '/' Tc=6.0 min CN=38 0.03 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 77HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Offsite to South Runoff = 0.28 cfs @ 12.10 hrs, Volume= 0.022 af, Depth> 1.87" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 50-yr Rainfall=6.59" Area (ac) CN Description * 0.040 96 Gravel surface, HSG A 0.100 39 >75% Grass cover, Good, HSG A 0.140 55 Weighted Average 0.140 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.4 28 0.0200 1.09 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.4 22 0.0200 1.04 Sheet Flow, B-C Smooth surfaces n= 0.011 P2= 3.37" 0.1 9 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 5.1 Direct Entry, 6.0 59 Total Subcatchment 6S: Offsite to South Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type III 24-hr 50-yr Rainfall=6.59" Runoff Area=0.140 ac Runoff Volume=0.022 af Runoff Depth>1.87" Flow Length=59' Slope=0.0200 '/' Tc=6.0 min CN=55 0.28 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 78HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: To Existing Drainage System [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.370 ac, 0.00% Impervious, Inflow Depth > 4.86" for 50-yr event Inflow = 2.01 cfs @ 12.09 hrs, Volume= 0.150 af Outflow = 2.01 cfs @ 12.09 hrs, Volume= 0.150 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 4R: To Existing Drainage System Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.370 ac 2.01 cfs2.01 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 79HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 5R: Southwest Corner of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.120 ac, 0.00% Impervious, Inflow Depth > 0.56" for 50-yr event Inflow = 0.03 cfs @ 12.31 hrs, Volume= 0.006 af Outflow = 0.03 cfs @ 12.31 hrs, Volume= 0.006 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 5R: Southwest Corner of Site Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)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=0.120 ac 0.03 cfs0.03 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 80HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 6R: Route 28 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.140 ac, 0.00% Impervious, Inflow Depth > 1.87" for 50-yr event Inflow = 0.28 cfs @ 12.10 hrs, Volume= 0.022 af Outflow = 0.28 cfs @ 12.10 hrs, Volume= 0.022 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 6R: Route 28 Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.140 ac 0.28 cfs0.28 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 81HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 1P: North Underground Detention System Inflow Area = 0.490 ac, 0.00% Impervious, Inflow Depth > 5.65" for 50-yr event Inflow = 2.95 cfs @ 12.09 hrs, Volume= 0.231 af Outflow = 1.28 cfs @ 12.28 hrs, Volume= 0.230 af, Atten= 57%, Lag= 11.7 min Discarded = 1.28 cfs @ 12.28 hrs, Volume= 0.230 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 99.82' @ 12.28 hrs Surf.Area= 0.014 ac Storage= 0.048 af Plug-Flow detention time= 15.5 min calculated for 0.230 af (100% of inflow) Center-of-Mass det. time= 15.3 min ( 789.3 - 774.0 ) Volume Invert Avail.Storage Storage Description #1A 94.65' 0.025 af 19.42'W x 31.27'L x 6.75'H Field A 0.094 af Overall - 0.033 af Embedded = 0.061 af x 40.0% Voids #2A 95.40' 0.033 af ADS_StormTech MC-4500 +Cap x 12 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 2 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf 0.057 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 94.65'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 94.00' #2 Primary 101.25'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.28 cfs @ 12.28 hrs HW=99.81' (Free Discharge) 1=Exfiltration ( Controls 1.28 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=94.65' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 82HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 1P: North Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 2 Rows x 100.0" Wide + 9.0" Spacing x 1 + 12.0" Side Stone x 2 = 19.42' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 12 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 2 Rows = 1,420.7 cf Chamber Storage 4,097.9 cf Field - 1,420.7 cf Chambers = 2,677.2 cf Stone x 40.0% Voids = 1,070.9 cf Stone Storage Chamber Storage + Stone Storage = 2,491.6 cf = 0.057 af Overall Storage Efficiency = 60.8% Overall System Size = 31.27' x 19.42' x 6.75' 12 Chambers 151.8 cy Field 99.2 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 83HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 1P: North Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=0.490 ac Peak Elev=99.82' Storage=0.048 af 2.95 cfs 1.28 cfs1.28 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 84HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 2P: Center Underground Detention System Inflow Area = 1.070 ac, 0.00% Impervious, Inflow Depth > 5.42" for 50-yr event Inflow = 6.29 cfs @ 12.09 hrs, Volume= 0.483 af Outflow = 3.85 cfs @ 12.20 hrs, Volume= 0.483 af, Atten= 39%, Lag= 6.8 min Discarded = 3.85 cfs @ 12.20 hrs, Volume= 0.483 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 97.15' @ 12.20 hrs Surf.Area= 0.020 ac Storage= 0.068 af Plug-Flow detention time= 7.6 min calculated for 0.483 af (100% of inflow) Center-of-Mass det. time= 7.4 min ( 788.7 - 781.3 ) Volume Invert Avail.Storage Storage Description #1A 92.25' 0.036 af 28.50'W x 31.27'L x 6.75'H Field A 0.138 af Overall - 0.049 af Embedded = 0.089 af x 40.0% Voids #2A 93.00' 0.049 af ADS_StormTech MC-4500 +Cap x 18 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 3 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 0.085 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 92.25'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 92.00' #2 Primary 99.50'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=3.85 cfs @ 12.20 hrs HW=97.15' (Free Discharge) 1=Exfiltration ( Controls 3.85 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=92.25' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 85HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 2P: Center Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 3 Rows x 100.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 28.50' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 18 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 3 Rows = 2,131.0 cf Chamber Storage 6,014.9 cf Field - 2,131.0 cf Chambers = 3,883.9 cf Stone x 40.0% Voids = 1,553.6 cf Stone Storage Chamber Storage + Stone Storage = 3,684.6 cf = 0.085 af Overall Storage Efficiency = 61.3% Overall System Size = 31.27' x 28.50' x 6.75' 18 Chambers 222.8 cy Field 143.8 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 86HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 2P: Center Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=1.070 ac Peak Elev=97.15' Storage=0.068 af 6.29 cfs 3.85 cfs3.85 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 87HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 3P: South Underground Detention System Inflow Area = 0.670 ac, 7.46% Impervious, Inflow Depth > 5.53" for 50-yr event Inflow = 3.99 cfs @ 12.09 hrs, Volume= 0.309 af Outflow = 1.57 cfs @ 12.32 hrs, Volume= 0.309 af, Atten= 61%, Lag= 13.8 min Discarded = 1.57 cfs @ 12.32 hrs, Volume= 0.309 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 94.06' @ 12.32 hrs Surf.Area= 0.020 ac Storage= 0.069 af Plug-Flow detention time= 17.9 min calculated for 0.309 af (100% of inflow) Center-of-Mass det. time= 17.7 min ( 795.4 - 777.7 ) Volume Invert Avail.Storage Storage Description #1A 89.05' 0.036 af 28.50'W x 31.27'L x 6.75'H Field A 0.138 af Overall - 0.049 af Embedded = 0.089 af x 40.0% Voids #2A 89.80' 0.049 af ADS_StormTech MC-4500 +Cap x 18 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 3 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 0.085 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 89.05'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 88.30' #2 Primary 95.42'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.57 cfs @ 12.32 hrs HW=94.05' (Free Discharge) 1=Exfiltration ( Controls 1.57 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=89.05' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 88HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 3P: South Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 3 Rows x 100.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 28.50' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 18 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 3 Rows = 2,131.0 cf Chamber Storage 6,014.9 cf Field - 2,131.0 cf Chambers = 3,883.9 cf Stone x 40.0% Voids = 1,553.6 cf Stone Storage Chamber Storage + Stone Storage = 3,684.6 cf = 0.085 af Overall Storage Efficiency = 61.3% Overall System Size = 31.27' x 28.50' x 6.75' 18 Chambers 222.8 cy Field 143.8 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 50-yr Rainfall=6.59"WS-Post Printed 11/29/2021Prepared by BSC Group Page 89HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 3P: South Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Inflow Area=0.670 ac Peak Elev=94.06' Storage=0.069 af 3.99 cfs 1.57 cfs1.57 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 90HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.490 ac 0.00% Impervious Runoff Depth>6.40"Subcatchment 1S: Northern Site Flow Length=213' Tc=6.0 min CN=92 Runoff=3.32 cfs 0.261 af Runoff Area=1.070 ac 0.00% Impervious Runoff Depth>6.16"Subcatchment 2S: Central Site Flow Length=339' Tc=6.0 min CN=90 Runoff=7.11 cfs 0.549 af Runoff Area=0.670 ac 7.46% Impervious Runoff Depth>6.28"Subcatchment 3S: Southern Site Flow Length=333' Tc=6.0 min CN=91 Runoff=4.50 cfs 0.351 af Runoff Area=0.370 ac 0.00% Impervious Runoff Depth>5.58"Subcatchment 4S: Managed Flow to Flow Length=96' Slope=0.0200 '/' Tc=6.0 min CN=85 Runoff=2.30 cfs 0.172 af Runoff Area=0.120 ac 0.00% Impervious Runoff Depth>0.82"Subcatchment 5S: Offsite Flow to Flow Length=9' Slope=0.0200 '/' Tc=6.0 min CN=38 Runoff=0.06 cfs 0.008 af Runoff Area=0.140 ac 0.00% Impervious Runoff Depth>2.35"Subcatchment 6S: Offsite to South Flow Length=59' Slope=0.0200 '/' Tc=6.0 min CN=55 Runoff=0.36 cfs 0.027 af Inflow=2.30 cfs 0.172 afReach 4R: To Existing Drainage System Outflow=2.30 cfs 0.172 af Inflow=0.06 cfs 0.008 afReach 5R: Southwest Corner of Site Outflow=0.06 cfs 0.008 af Inflow=0.36 cfs 0.027 afReach 6R: Route 28 Outflow=0.36 cfs 0.027 af Peak Elev=100.82' Storage=0.054 af Inflow=3.32 cfs 0.261 afPond 1P: North Underground Detention Discarded=1.53 cfs 0.261 af Primary=0.00 cfs 0.000 af Outflow=1.53 cfs 0.261 af Peak Elev=98.01' Storage=0.077 af Inflow=7.11 cfs 0.549 afPond 2P: Center Underground Detention Discarded=4.52 cfs 0.549 af Primary=0.00 cfs 0.000 af Outflow=4.52 cfs 0.549 af Peak Elev=95.05' Storage=0.078 af Inflow=4.50 cfs 0.351 afPond 3P: South Underground Detention Discarded=1.87 cfs 0.350 af Primary=0.00 cfs 0.000 af Outflow=1.87 cfs 0.350 af Total Runoff Area = 2.860 ac Runoff Volume = 1.369 af Average Runoff Depth = 5.74" 98.25% Pervious = 2.810 ac 1.75% Impervious = 0.050 ac Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 91HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Northern Site Runoff = 3.32 cfs @ 12.09 hrs, Volume= 0.261 af, Depth> 6.40" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.35" Area (ac) CN Description 0.460 96 Gravel surface, HSG A * 0.030 30 Mulch with trees, Good, HSG A 0.490 92 Weighted Average 0.490 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.1 17 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.4 76 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.2 60 0.0100 4.54 3.56 Pipe Channel, D-E 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0100 4.54 3.56 Pipe Channel, E-F 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0100 4.54 3.56 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 4.6 Direct Entry, 6.0 213 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 92HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 1S: Northern Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Type III 24-hr 100-yr Rainfall=7.35" Runoff Area=0.490 ac Runoff Volume=0.261 af Runoff Depth>6.40" Flow Length=213' Tc=6.0 min CN=92 3.32 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 93HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Central Site Runoff = 7.11 cfs @ 12.09 hrs, Volume= 0.549 af, Depth> 6.16" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.35" Area (ac) CN Description 0.980 96 Gravel surface, HSG A * 0.090 30 Mulch with trees, Good, HSG A 1.070 90 Weighted Average 1.070 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.3 45 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.4 98 0.0100 4.54 3.56 Pipe Channel, C-D 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.3 84 0.0100 4.54 3.56 Pipe Channel, D-E 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.1 51 0.0200 6.42 5.04 Pipe Channel, E-F 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 5 0.0120 4.97 3.90 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 6 0.0100 4.54 3.56 Pipe Channel, G-H 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 4.2 Direct Entry, 6.0 339 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 94HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 2S: Central Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Type III 24-hr 100-yr Rainfall=7.35" Runoff Area=1.070 ac Runoff Volume=0.549 af Runoff Depth>6.16" Flow Length=339' Tc=6.0 min CN=90 7.11 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 95HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Southern Site Runoff = 4.50 cfs @ 12.09 hrs, Volume= 0.351 af, Depth> 6.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.35" Area (ac) CN Description 0.570 96 Gravel surface, HSG A * 0.050 30 Mulch with trees, Good, HSG A 0.030 98 Roofs, HSG A 0.020 98 Paved parking, HSG A 0.670 91 Weighted Average 0.620 92.54% Pervious Area 0.050 7.46% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.2 28 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.2 31 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 0.6 97 0.0200 2.87 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps 0.1 13 0.0200 2.87 Shallow Concentrated Flow, E-F Paved Kv= 20.3 fps 0.1 40 0.0100 4.54 3.56 Pipe Channel, F-G 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.2 68 0.0150 5.56 4.36 Pipe Channel, G-H 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 0.0 6 0.1200 15.71 12.34 Pipe Channel, H-I 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.013 Corrugated PE, smooth interior 3.9 Direct Entry, 6.0 333 Total Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 96HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Subcatchment 3S: Southern Site Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Type III 24-hr 100-yr Rainfall=7.35" Runoff Area=0.670 ac Runoff Volume=0.351 af Runoff Depth>6.28" Flow Length=333' Tc=6.0 min CN=91 4.50 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 97HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Managed Flow to Northeast Runoff = 2.30 cfs @ 12.09 hrs, Volume= 0.172 af, Depth> 5.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.35" Area (ac) CN Description * 0.310 96 Gravel surface, HSG A * 0.060 30 Mulch with Trees, Good, HSG A 0.370 85 Weighted Average 0.370 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 50 0.0200 1.23 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.3 46 0.0200 2.87 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 5.0 Direct Entry, 6.0 96 Total Subcatchment 4S: Managed Flow to Northeast Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Type III 24-hr 100-yr Rainfall=7.35" Runoff Area=0.370 ac Runoff Volume=0.172 af Runoff Depth>5.58" Flow Length=96' Slope=0.0200 '/' Tc=6.0 min CN=85 2.30 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 98HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Offsite Flow to Southwest Corner Runoff = 0.06 cfs @ 12.16 hrs, Volume= 0.008 af, Depth> 0.82" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.35" Area (ac) CN Description 0.100 39 >75% Grass cover, Good, HSG A 0.020 32 Woods/grass comb., Good, HSG A 0.120 38 Weighted Average 0.120 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.2 9 0.0200 0.87 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 5.8 Direct Entry, 6.0 9 Total Subcatchment 5S: Offsite Flow to Southwest Corner Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (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 100-yr Rainfall=7.35" Runoff Area=0.120 ac Runoff Volume=0.008 af Runoff Depth>0.82" Flow Length=9' Slope=0.0200 '/' Tc=6.0 min CN=38 0.06 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 99HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Offsite to South Runoff = 0.36 cfs @ 12.10 hrs, Volume= 0.027 af, Depth> 2.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.35" Area (ac) CN Description * 0.040 96 Gravel surface, HSG A 0.100 39 >75% Grass cover, Good, HSG A 0.140 55 Weighted Average 0.140 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.4 28 0.0200 1.09 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.37" 0.4 22 0.0200 1.04 Sheet Flow, B-C Smooth surfaces n= 0.011 P2= 3.37" 0.1 9 0.0200 2.87 Shallow Concentrated Flow, C-D Paved Kv= 20.3 fps 5.1 Direct Entry, 6.0 59 Total Subcatchment 6S: Offsite to South Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (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 100-yr Rainfall=7.35" Runoff Area=0.140 ac Runoff Volume=0.027 af Runoff Depth>2.35" Flow Length=59' Slope=0.0200 '/' Tc=6.0 min CN=55 0.36 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 100HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: To Existing Drainage System [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.370 ac, 0.00% Impervious, Inflow Depth > 5.58" for 100-yr event Inflow = 2.30 cfs @ 12.09 hrs, Volume= 0.172 af Outflow = 2.30 cfs @ 12.09 hrs, Volume= 0.172 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 4R: To Existing Drainage System Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.370 ac 2.30 cfs2.30 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 101HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 5R: Southwest Corner of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.120 ac, 0.00% Impervious, Inflow Depth > 0.82" for 100-yr event Inflow = 0.06 cfs @ 12.16 hrs, Volume= 0.008 af Outflow = 0.06 cfs @ 12.16 hrs, Volume= 0.008 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 5R: Southwest Corner of Site Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (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=0.120 ac 0.06 cfs0.06 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 102HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Reach 6R: Route 28 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.140 ac, 0.00% Impervious, Inflow Depth > 2.35" for 100-yr event Inflow = 0.36 cfs @ 12.10 hrs, Volume= 0.027 af Outflow = 0.36 cfs @ 12.10 hrs, Volume= 0.027 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach 6R: Route 28 Inflow Outflow Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (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 Inflow Area=0.140 ac 0.36 cfs0.36 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 103HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 1P: North Underground Detention System Inflow Area = 0.490 ac, 0.00% Impervious, Inflow Depth > 6.40" for 100-yr event Inflow = 3.32 cfs @ 12.09 hrs, Volume= 0.261 af Outflow = 1.53 cfs @ 12.26 hrs, Volume= 0.261 af, Atten= 54%, Lag= 10.7 min Discarded = 1.53 cfs @ 12.26 hrs, Volume= 0.261 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 100.82' @ 12.27 hrs Surf.Area= 0.014 ac Storage= 0.054 af Plug-Flow detention time= 15.9 min calculated for 0.261 af (100% of inflow) Center-of-Mass det. time= 15.7 min ( 786.6 - 770.9 ) Volume Invert Avail.Storage Storage Description #1A 94.65' 0.025 af 19.42'W x 31.27'L x 6.75'H Field A 0.094 af Overall - 0.033 af Embedded = 0.061 af x 40.0% Voids #2A 95.40' 0.033 af ADS_StormTech MC-4500 +Cap x 12 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 2 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf 0.057 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 94.65'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 94.00' #2 Primary 101.25'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.52 cfs @ 12.26 hrs HW=100.80' (Free Discharge) 1=Exfiltration ( Controls 1.52 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=94.65' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 104HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 1P: North Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 2 Rows x 100.0" Wide + 9.0" Spacing x 1 + 12.0" Side Stone x 2 = 19.42' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 12 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 2 Rows = 1,420.7 cf Chamber Storage 4,097.9 cf Field - 1,420.7 cf Chambers = 2,677.2 cf Stone x 40.0% Voids = 1,070.9 cf Stone Storage Chamber Storage + Stone Storage = 2,491.6 cf = 0.057 af Overall Storage Efficiency = 60.8% Overall System Size = 31.27' x 19.42' x 6.75' 12 Chambers 151.8 cy Field 99.2 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 105HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 1P: North Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=0.490 ac Peak Elev=100.82' Storage=0.054 af 3.32 cfs 1.53 cfs1.53 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 106HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 2P: Center Underground Detention System Inflow Area = 1.070 ac, 0.00% Impervious, Inflow Depth > 6.16" for 100-yr event Inflow = 7.11 cfs @ 12.09 hrs, Volume= 0.549 af Outflow = 4.52 cfs @ 12.19 hrs, Volume= 0.549 af, Atten= 36%, Lag= 6.3 min Discarded = 4.52 cfs @ 12.19 hrs, Volume= 0.549 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 98.01' @ 12.19 hrs Surf.Area= 0.020 ac Storage= 0.077 af Plug-Flow detention time= 7.8 min calculated for 0.549 af (100% of inflow) Center-of-Mass det. time= 7.6 min ( 785.5 - 778.0 ) Volume Invert Avail.Storage Storage Description #1A 92.25' 0.036 af 28.50'W x 31.27'L x 6.75'H Field A 0.138 af Overall - 0.049 af Embedded = 0.089 af x 40.0% Voids #2A 93.00' 0.049 af ADS_StormTech MC-4500 +Cap x 18 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 3 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 0.085 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 92.25'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 92.00' #2 Primary 99.50'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=4.50 cfs @ 12.19 hrs HW=97.98' (Free Discharge) 1=Exfiltration ( Controls 4.50 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=92.25' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 107HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 2P: Center Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 3 Rows x 100.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 28.50' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 18 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 3 Rows = 2,131.0 cf Chamber Storage 6,014.9 cf Field - 2,131.0 cf Chambers = 3,883.9 cf Stone x 40.0% Voids = 1,553.6 cf Stone Storage Chamber Storage + Stone Storage = 3,684.6 cf = 0.085 af Overall Storage Efficiency = 61.3% Overall System Size = 31.27' x 28.50' x 6.75' 18 Chambers 222.8 cy Field 143.8 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 108HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 2P: Center Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=1.070 ac Peak Elev=98.01' Storage=0.077 af 7.11 cfs 4.52 cfs4.52 cfs 0.00 cfs Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 109HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Summary for Pond 3P: South Underground Detention System Inflow Area = 0.670 ac, 7.46% Impervious, Inflow Depth > 6.28" for 100-yr event Inflow = 4.50 cfs @ 12.09 hrs, Volume= 0.351 af Outflow = 1.87 cfs @ 12.30 hrs, Volume= 0.350 af, Atten= 58%, Lag= 12.7 min Discarded = 1.87 cfs @ 12.30 hrs, Volume= 0.350 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 95.05' @ 12.30 hrs Surf.Area= 0.020 ac Storage= 0.078 af Plug-Flow detention time= 18.4 min calculated for 0.350 af (100% of inflow) Center-of-Mass det. time= 18.2 min ( 792.8 - 774.5 ) Volume Invert Avail.Storage Storage Description #1A 89.05' 0.036 af 28.50'W x 31.27'L x 6.75'H Field A 0.138 af Overall - 0.049 af Embedded = 0.089 af x 40.0% Voids #2A 89.80' 0.049 af ADS_StormTech MC-4500 +Cap x 18 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap 3 Rows of 6 Chambers Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 0.085 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 89.05'8.270 in/hr Exfiltration over Wetted area Conductivity to Groundwater Elevation = 88.30' #2 Primary 95.42'24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=1.87 cfs @ 12.30 hrs HW=95.04' (Free Discharge) 1=Exfiltration ( Controls 1.87 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=89.05' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 110HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 3P: South Underground Detention System - Chamber Wizard Field A Chamber Model = ADS_StormTech MC-4500 +Cap (ADS StormTech® MC-4500 with cap volume) Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 3 rows = 214.2 cf 100.0" Wide + 9.0" Spacing = 109.0" C-C Row Spacing 6 Chambers/Row x 4.02' Long +2.56' Cap Length x 2 = 29.27' Row Length +12.0" End Stone x 2 = 31.27' Base Length 3 Rows x 100.0" Wide + 9.0" Spacing x 2 + 12.0" Side Stone x 2 = 28.50' Base Width 9.0" Base + 60.0" Chamber Height + 12.0" Cover = 6.75' Field Height 18 Chambers x 106.5 cf + 35.7 cf Cap Volume x 2 x 3 Rows = 2,131.0 cf Chamber Storage 6,014.9 cf Field - 2,131.0 cf Chambers = 3,883.9 cf Stone x 40.0% Voids = 1,553.6 cf Stone Storage Chamber Storage + Stone Storage = 3,684.6 cf = 0.085 af Overall Storage Efficiency = 61.3% Overall System Size = 31.27' x 28.50' x 6.75' 18 Chambers 222.8 cy Field 143.8 cy Stone Cape Cod Inflatable Park, West Yarmouth, MA Type III 24-hr 100-yr Rainfall=7.35"WS-Post Printed 11/29/2021Prepared by BSC Group Page 111HydroCAD® 10.00-22 s/n 00904 © 2018 HydroCAD Software Solutions LLC Pond 3P: South Underground Detention System Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=0.670 ac Peak Elev=95.05' Storage=0.078 af 4.50 cfs 1.87 cfs1.87 cfs 0.00 cfs Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA SECTION 7.0 ADDITIONAL DRAINAGE CALCULATIONS Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 7.01 TSS REMOVAL CALCULATIONS TSS Removal Calculation Worksheet Location: 492, 498, 512, 518, 526, & 532 Route 28, West Yarmouth, MA Project: Cape Cod Inflatable Park Date: 10/20/21 Subcatchment Areas 1S, 2S, & 3S Total Impervious Area, Acres= 2.030 ABCDE BMP TSS Removal Rate Starting TSS Load* Amount Removed (BxC) Remaining Load (C-D) Deep Sump Hooded Catch Basins 0.25 1.00 0.25 0.75 Water Quality Units 0.77 0.75 0.58 0.17 Subsurface Infiltration Systems 0.80 0.17 0.14 0.03 TSS Removal = 0.97 Subcatchment Area 4S, 5S & 6S Total Impervious Area, Acres= 0.350 ABCDE BMP TSS Removal Rate Starting TSS Load* Amount Removed (BxC) Remaining Load (C-D) No Treatment 0.00 1.00 0.00 1.00 TSS Removal = 0.00 WEIGHTED AVERAGE Total Site TSS Removal Total Site TSS Removal = 0.82 *Equals remaining load from previous BMP (E) [(0.97*2.030)+(0.350*0.00)] 2.030+0.350 TSS Removal Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 7.02 GROUNDWATER RECHARGE VOLUME CALCULATIONS Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Required Recharge Volume Rv = F x Impervious Area Where: Rv = Recharge Volume F=Target Depth Factor associated with each Hydrologic Soil Group (F=0.60-inch for Soil Type A) Impervious Area = Proposed Pavement area on-site 𝑅𝑣 ൌ ൬ 0.60 𝑖𝑛 12 𝑖𝑛/𝑓𝑡൰ ሺ2.380 𝑎𝑐ሻ ൬43,560 𝑠𝑓 𝑎𝑐൰ ൌ 5,184 𝑐𝑓 Rv Total = 5,184 cf (required recharge volume) Structural Storage Provided: Subsurface Infiltration Systems = 9,104 cf cubic feet provided. Refer to the HydroCAD calculations for more information. Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Drawdown Time The following formula must be used to demonstrate that each proposed infiltration BMP will drain within 72 hours: Time drawdown = Rv (K)(Bottom Area) Rv = Storage Volume (Required Recharge Volume) K = Saturated Hydraulic Conductivity For “Static” and “Simple Dynamic” Methods, use Rawls Rate Bottom Area = Bottom Area of Recharge Structure Infiltration System #1 Time drawdown = 5,184 ft3 (8.270 in/hr)(1 ft/12 in)(607 ft2) Time drawdown = 12.39 hours Infiltration System #2 Time drawdown = 5,184 ft3 (8.270 in/hr)(1 ft/12 in)(891 ft2) Time drawdown = 8.44 hours Infiltration System #3 Time drawdown = 5,184 ft3 (8.270 in/hr)(1 ft/12 in)(891 ft2) Time drawdown = 8.44 hours Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 7.03 WATER QUALITY VOLUME CALCULATIONS Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA Water Quality Volume Calculations VWQ Required Water Quality Volume (in cubic feet) VWQ (DWQ/12 inches/foot) * (AIMP square feet) DWQ Water Quality Depth: 1.0-inch used (1-inch for rapid infiltration rates, greater than 2.4 inches per hour & 0.5-inch for other areas) AIMP Total Impervious Area (in acres) Infiltration System #1 AIMP = 0.460 ac VWQ = (1 inch/12 inches/foot) * (0.460 ac x 43,560 square feet/ac) VWQ = 1,670 cubic feet (required volume) Volume provided = 2,483 cubic feet (see HydroCAD) Infiltration System #2 AIMP = 0.980 ac VWQ = (1 inch/12 inches/foot) * (0.980 ac x 43,560 square feet/ac) VWQ = 3,557 cubic feet (required volume) Volume provided = 3,703 cubic feet (see HydroCAD) Infiltration System #3 AIMP = 0.590 ac VWQ = (1 inch/12 inches/foot) * (0.590 ac x 43,560 square feet/ac) VWQ = 2,142 cubic feet (required volume) Volume provided = 3,398 cubic feet (see HydroCAD) Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 7.04 STORMCEPTOR SIZING REPORTS Project Information & Location Project Name Cape Cod Inflatable Park Project Number 49314 City West Yarmouth State/ Province Massachusetts Country United States of America Date 11/18/2021 Designer Information EOR Information (optional) Name Todd MacDonald Name Company BSC Group Company Phone #617-896-4409 Phone # Email TMacDonald@BSCGroup.com Email Brief Stormceptor Sizing Report - #1 Site Name #1 Target TSS Removal (%)80 TSS Removal (%) Provided 83 Recommended Stormceptor Model STC 450i Stormceptor Sizing Summary Stormceptor Model % TSS Removal Provided STC 450i 83 STC 900 89 STC 1200 89 STC 1800 90 STC 2400 92 STC 3600 92 STC 4800 94 STC 6000 94 STC 7200 95 STC 11000 97 STC 13000 97 STC 16000 98 The recommended Stormceptor Model achieves the water quality objectives based on the selected inputs, historical rainfall records and selected particle size distribution. Stormwater Treatment Recommendation The recommended Stormceptor Model(s) which achieve or exceed the user defined water quality objective for each site within the project are listed in the below Sizing Summary table. Stormceptor Brief Sizing Report ±Page 1 of 2 Notes ‡Stormceptor performance estimates are based on simulations using PCSWMM for Stormceptor, which uses the EPA Rainfall and Runoff modules. ‡Design estimates listed are only representative of specific project requirements based on total suspended solids (TSS) removal defined by the selected PSD, and based on stable site conditions only, after construction is completed. ‡For submerged applications or sites specific to spill control, please contact your local Stormceptor representative for further design assistance. Drainage Area Total Area (acres)0.49 Imperviousness %93.9 Water Quality Objective TSS Removal (%)80.0 Runoff Volume Capture (%) Oil Spill Capture Volume (Gal) Peak Conveyed Flow Rate (CFS) Water Quality Flow Rate (CFS) Rainfall Station Name HYANNIS State/Province Massachusetts Station ID #3821 Years of Records 14 Latitude 41°24'0"N Longitude 70°10'47"W Up Stream Storage Storage (ac-ft)Discharge (cfs) 0.000 0.000 Particle Size Distribution (PSD) The selected PSD defines TSS removal Fine Distribution Particle Diameter (microns) Distribution % Specific Gravity 20.0 20.0 1.30 60.0 20.0 1.80 150.0 20.0 2.20 400.0 20.0 2.65 2000.0 20.0 2.65 Up Stream Flow Diversion Max. Flow to Stormceptor (cfs) Sizing Details For Stormceptor Specifications and Drawings Please Visit: https://www.conteches.com/technical-guides/search?filter=1WBC0O5EYX Stormceptor Brief Sizing Report ±Page 2 of 2 Project Information & Location Project Name Cape Cod Inflatable Park Project Number 49314 City West Yarmouth State/ Province Massachusetts Country United States of America Date 11/18/2021 Designer Information EOR Information (optional) Name Todd MacDonald Name Company BSC Group Company Phone #617-896-4409 Phone # Email TMacDonald@BSCGroup.com Email Brief Stormceptor Sizing Report - #2 Site Name #2 Target TSS Removal (%)80 TSS Removal (%) Provided 83 Recommended Stormceptor Model STC 900 Stormceptor Sizing Summary Stormceptor Model % TSS Removal Provided STC 450i 76 STC 900 83 STC 1200 84 STC 1800 84 STC 2400 87 STC 3600 88 STC 4800 90 STC 6000 90 STC 7200 92 STC 11000 94 STC 13000 94 STC 16000 95 The recommended Stormceptor Model achieves the water quality objectives based on the selected inputs, historical rainfall records and selected particle size distribution. Stormwater Treatment Recommendation The recommended Stormceptor Model(s) which achieve or exceed the user defined water quality objective for each site within the project are listed in the below Sizing Summary table. Stormceptor Brief Sizing Report ±Page 1 of 2 Notes ‡Stormceptor performance estimates are based on simulations using PCSWMM for Stormceptor, which uses the EPA Rainfall and Runoff modules. ‡Design estimates listed are only representative of specific project requirements based on total suspended solids (TSS) removal defined by the selected PSD, and based on stable site conditions only, after construction is completed. ‡For submerged applications or sites specific to spill control, please contact your local Stormceptor representative for further design assistance. Drainage Area Total Area (acres)1.07 Imperviousness %91.6 Water Quality Objective TSS Removal (%)80.0 Runoff Volume Capture (%) Oil Spill Capture Volume (Gal) Peak Conveyed Flow Rate (CFS) Water Quality Flow Rate (CFS) Rainfall Station Name HYANNIS State/Province Massachusetts Station ID #3821 Years of Records 14 Latitude 41°24'0"N Longitude 70°10'47"W Up Stream Storage Storage (ac-ft)Discharge (cfs) 0.000 0.000 Particle Size Distribution (PSD) The selected PSD defines TSS removal Fine Distribution Particle Diameter (microns) Distribution % Specific Gravity 20.0 20.0 1.30 60.0 20.0 1.80 150.0 20.0 2.20 400.0 20.0 2.65 2000.0 20.0 2.65 Up Stream Flow Diversion Max. Flow to Stormceptor (cfs) Sizing Details For Stormceptor Specifications and Drawings Please Visit: https://www.conteches.com/technical-guides/search?filter=1WBC0O5EYX Stormceptor Brief Sizing Report ±Page 2 of 2 Project Information & Location Project Name Cape Cod Inflatable Park Project Number 49314 City West Yarmouth State/ Province Massachusetts Country United States of America Date 11/18/2021 Designer Information EOR Information (optional) Name Todd MacDonald Name Company BSC Group Company Phone #617-896-4409 Phone # Email TMacDonald@BSCGroup.com Email Brief Stormceptor Sizing Report - #3 Site Name #3 Target TSS Removal (%)80 TSS Removal (%) Provided 81 Recommended Stormceptor Model STC 450i Stormceptor Sizing Summary Stormceptor Model % TSS Removal Provided STC 450i 81 STC 900 87 STC 1200 88 STC 1800 88 STC 2400 90 STC 3600 91 STC 4800 93 STC 6000 93 STC 7200 95 STC 11000 96 STC 13000 96 STC 16000 97 The recommended Stormceptor Model achieves the water quality objectives based on the selected inputs, historical rainfall records and selected particle size distribution. Stormwater Treatment Recommendation The recommended Stormceptor Model(s) which achieve or exceed the user defined water quality objective for each site within the project are listed in the below Sizing Summary table. Stormceptor Brief Sizing Report ±Page 1 of 2 Notes ‡Stormceptor performance estimates are based on simulations using PCSWMM for Stormceptor, which uses the EPA Rainfall and Runoff modules. ‡Design estimates listed are only representative of specific project requirements based on total suspended solids (TSS) removal defined by the selected PSD, and based on stable site conditions only, after construction is completed. ‡For submerged applications or sites specific to spill control, please contact your local Stormceptor representative for further design assistance. Drainage Area Total Area (acres)0.67 Imperviousness %88.0 Water Quality Objective TSS Removal (%)80.0 Runoff Volume Capture (%) Oil Spill Capture Volume (Gal) Peak Conveyed Flow Rate (CFS) Water Quality Flow Rate (CFS) Rainfall Station Name HYANNIS State/Province Massachusetts Station ID #3821 Years of Records 14 Latitude 41°24'0"N Longitude 70°10'47"W Up Stream Storage Storage (ac-ft)Discharge (cfs) 0.000 0.000 Particle Size Distribution (PSD) The selected PSD defines TSS removal Fine Distribution Particle Diameter (microns) Distribution % Specific Gravity 20.0 20.0 1.30 60.0 20.0 1.80 150.0 20.0 2.20 400.0 20.0 2.65 2000.0 20.0 2.65 Up Stream Flow Diversion Max. Flow to Stormceptor (cfs) Sizing Details For Stormceptor Specifications and Drawings Please Visit: https://www.conteches.com/technical-guides/search?filter=1WBC0O5EYX Stormceptor Brief Sizing Report ±Page 2 of 2 Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA 7.05 PIPE SIZING CALCULATIONS BSC GROUP 349 Main Street - Route 28 West Yarmouth, MA 02673 (508) 778-8919 Project: Location: 492, 498, 512, 518, 526, & 532 Route 28, West Yarmouth, MA Project Number: 4-8592.05 Date: 11/18/2021 Calculate: TRM Check: BGY CATCH BASIN #1-1 Area (SF) Area (Ac) C AxC Gravel Surface 6,909 0.159 0.96 0.15 Mulch w/ trees 300 0.007 0.30 0.00 0 0.000 0.00 0.00 TOTAL: 7,209 0.165 0.15 Area (SF) Area (Ac) C AxC Gravel Surface 7,196 0.165 0.96 0.16 Mulch w/ trees 300 0.007 0.30 0.00 0 0.000 0.00 0.00 TOTAL: 7,496 0.172 0.16 Area (SF) Area (Ac) C AxC Gravel Surface 5,982 0.137 0.96 0.13 Mulch w/ trees 710 0.016 0.30 0.00 0 0.000 0.00 0.00 TOTAL: 6,692 0.154 0.13 CATCH BASIN #2-1 Area (SF) Area (Ac) C AxC Gravel Surface 8,875 0.204 0.96 0.20 Mulch w/ trees 800 0.018 0.30 0.00 0 0.000 0.00 0.00 TOTAL: 9,675 0.222 0.20 CATCH BASIN #2-2 Area (SF) Area (Ac) C AxC Gravel Surface 6,874 0.158 0.96 0.15 Mulch w/ trees 800 0.018 0.30 0.00 0 0.000 0.00 0.00 TOTAL: 7,674 0.176 0.15 CATCH BASIN #1-2 Cape Cod Inflatable Park SUBCATCHMENT AREA BREAKDOWN CATCH BASIN #1-3 2021-11-18 PipeSizing.xlsx - Subcatchment Areas Page 1 BSC GROUP 349 Main Street - Route 28 West Yarmouth, MA 02673 (508) 778-8919 Project: Location: 492, 498, 512, 518, 526, & 532 Route 28, West Yarmouth, MA Project Number: 4-8592.05 Date: 11/18/2021 Calculate: TRM Check: BGY Cape Cod Inflatable Park SUBCATCHMENT AREA BREAKDOWN CATCH BASIN #2-3 Area (SF) Area (Ac) C AxC Gravel Surface 7,440 0.171 0.96 0.16 Mulch w/ trees 800 0.018 0.30 0.00 0 0.000 0.00 0.00 TOTAL: 8,240 0.189 0.16 CATCH BASIN #2-4 Area (SF) Area (Ac) C AxC Gravel Surface 10,638 0.244 0.96 0.23 Mulch w/ trees 800 0.018 0.30 0.00 0 0.000 0.00 0.00 TOTAL: 11,438 0.263 0.23 CATCH BASIN #2-5 Area (SF) Area (Ac) C AxC Gravel Surface 8,878 0.204 0.96 0.20 Mulch w/ trees 800 0.018 0.30 0.00 0 0.000 0.00 0.00 TOTAL: 9,678 0.222 0.20 CATCH BASIN #3-1 Area (SF) Area (Ac) C AxC Gravel Surface 5,825 0.134 0.96 0.13 Mulch w/ trees 330 0.008 0.30 0.00 Paved/ Roof 0 0.000 0.98 0.00 TOTAL: 6,155 0.141 0.13 CATCH BASIN #3-2 Area (SF) Area (Ac) C AxC Gravel Surface 7,988 0.183 0.96 0.18 Mulch w/ trees 330 0.008 0.30 0.00 Paved/ Roof 0 0.000 0.98 0.00 TOTAL: 8,318 0.191 0.18 CATCH BASIN #3-3 Area (SF) Area (Ac) C AxC Gravel Surface 11,103 0.255 0.96 0.24 Mulch w/ trees 1,500 0.034 0.30 0.01 Paved/ Roof 2,178 0.050 0.98 0.05 TOTAL: 14,781 0.339 0.30 2021-11-18 PipeSizing.xlsx - Subcatchment Areas Page 2 BSC GROUP 349 Main Street - Route 28 West Yarmouth, MA 02673 (508) 778-8919 Project:Design Parameters: Location: 492, 498, 512, 518, 526, & 532 Route 28, West Yarmouth, MA Year Storm Event: Project #:Minimum Pipe Size: Date:Pipe Material: Calculate:Mannings N Value: Check: FROM TO (From) Rim Elev. (To) Rim Elev. Slope Pipe Length (Ctr-Ctr) Actual Pipe Length (From) Cover Pipe Size (From) Invert (To) Invert (To) Cover CB 1-3 DMH 1-1 101.50 102.00 0.0101 76 72 2.00 1.00 98.50 97.77 3.23 CB 1-2 DMH 1-1 101.25 102.00 0.0099 64 60 2.00 1.00 98.25 97.65 3.35 CB 1-1 DMH 1-1 101.50 102.00 0.0102 14 10 2.00 1.00 98.50 98.40 2.60 DMH 1-1 WQU 1-1 102.00 102.15 0.0100 10 6 3.45 1.00 97.55 97.49 3.66 CB 2-1 DMH 2-1 100.45 101.90 0.0100 102 98 2.00 1.00 97.45 96.47 4.43 CB 2-2 DMH 2-1 100.60 101.90 0.0101 123 119 2.00 1.00 97.60 96.40 4.50 CB 2-3 DMH 2-1 101.25 101.90 0.0100 26 22 2.00 1.00 98.25 98.03 2.87 DMH 2-1 DMH 2-2 101.90 100.85 0.0100 88 84 4.60 1.00 96.30 95.46 4.39 CB 2-4 DMH 2-2 100.50 100.85 0.0102 29 25 2.00 1.00 97.50 97.24 2.61 DMH 2-2 DMH 2-3 100.85 100.20 0.0196 55 51 4.49 1.00 95.36 94.36 4.84 CB 2-5 DMH 2-3 99.50 100.20 0.0103 25 21 2.00 1.00 96.50 96.28 2.92 DMH 2-3 WGU 2-1 100.20 100.20 0.0124 9 5 4.69 1.25 94.26 94.20 4.75 CB 3-1 DMH 3-1 98.50 98.36 0.0104 44 40 2.00 1.00 95.50 95.08 2.28 DMH 3-1 DMH 3-2 98.36 96.94 0.0154 72 68 2.38 1.00 94.98 93.94 2.00 CB 3-2 DMH 3-2 97.50 96.94 0.0177 36 32 2.00 1.00 94.50 93.94 2.00 CB 3-3 DMH 3-2 95.42 96.94 0.0101 41 37 2.00 1.00 92.42 92.05 3.89 DMH 3-2 WQU 3-1 96.94 96.69 0.0108 10 6 3.64 1.25 92.05 91.99 3.45 Cape Cod Inflatable Park 25-Year 12" HDPE 0.013 INVERT TABLE TRM BGY 4-8592.05 11/18/2021 2021-11-18 PipeSizing.xlsx - Invert Table Page 1 BSC GROUP349 Main Street - Route 28West Yarmouth, MA 02673(508) 778-8919 Project:Design Parameters:Location: 492, 498, 512, 518, 526, & 532 Route 28, West Yarmouth, MA Year Storm Event:Project #:Date:Minimum Pipe Size:Calculate:Pipe Material:Check:Mannings N Value: 0.013Weighted Ca: 1.1FROM TOAREA (Acres) A*C A*C*CaTc (min)Tc (Pipe) T=(L/VA)/60 (min)RAINFALL INTENSITY [I] (in./hr.)DESIGN Q Actual QA = CxAxI (cfs)DESIGN V Actual VA=(VF)xVAR (f/s)LENGTH (ft)SLOPE (ft/ft)SIZE (in) NFULL V Full VF = (1.49/n) (R2/3)(S1/2)FULL Q Full QF = VFxA (cfs)CAPACITY CONCLUSIONQA/QFCB 1-3 DMH 1-1 0.154 0.132 0.15 6.0 0.3 5.8 0.84 3.71 72 0.010 12 0.013 4.55 3.57 O.K. 0.235717CB 1-2 DMH 1-1 0.172 0.159 0.17 6.0 0.2 5.8 1.85 4.55 60 0.010 12 0.013 4.52 3.54 O.K. 0.522776CB 1-1 DMH 1-1 0.165 0.152 0.17 6.0 0.0 5.8 0.97 3.85 10 0.010 12 0.013 4.57 3.58 O.K. 0.270997DMH 1-1 WQU 1-1 0.491 0.443 0.49 6.0 0.0 5.8 2.82 5.02 6 0.010 12 0.013 4.53 3.55 O.K. 0.794675CB 2-1 DMH 2-1 0.222 0.196 0.22 6.0 0.4 5.8 1.25 4.09 98 0.010 12 0.013 4.53 3.56 O.K. 0.350845CB 2-2 DMH 2-1 0.176 0.151 0.17 6.0 0.5 5.8 0.97 3.83 119 0.010 12 0.013 4.55 3.57 O.K. 0.270857CB 2-3 DMH 2-1 0.189 0.164 0.18 6.0 0.1 5.8 1.05 3.94 22 0.010 12 0.013 4.53 3.56 O.K. 0.293925DMH 2-1 DMH 2-2 0.587 0.511 0.56 6.0 0.3 5.8 3.26 5.14 84 0.010 12 0.013 4.54 3.56 O.K. 0.915117CB 2-4 DMH 2-2 0.263 0.234 0.26 6.0 0.1 5.8 1.50 4.33 25 0.010 12 0.013 4.58 3.60 O.K. 0.415705DMH 2-2 DMH 2-3 0.850 0.745 0.82 6.0 0.1 5.8 4.76 7.21 51 0.020 12 0.013 6.34 4.97 O.K. 0.956129CB 2-5 DMH 2-3 0.222 0.196 0.22 6.0 0.1 5.8 1.25 4.15 21 0.010 12 0.013 4.60 3.61 O.K. 0.345358DMH 2-3 WGU 2-1 1.072 0.941 1.04 6.0 0.0 5.8 6.00 6.55 5 0.012 15 0.013 5.87 7.20 O.K. 0.834522CB 3-1 DMH 3-1 0.141 0.131 0.14 6.0 0.2 5.8 0.83 3.71 40 0.010 12 0.013 4.62 3.63 O.K. 0.229632DMH 3-1 DMH 3-2 0.141 0.131 0.14 6.0 0.2 5.8 1.67 5.19 68 0.015 12 0.013 5.62 4.41 O.K. 0.377916CB 3-2 DMH 3-2 0.191 0.178 0.20 6.0 0.1 5.8 1.14 4.92 32 0.018 12 0.013 6.02 4.72 O.K. 0.24088CB 3-3 DMH 3-2 0.339 0.304 0.33 6.0 0.1 5.8 1.94 4.62 37 0.010 12 0.013 4.55 3.57 O.K. 0.543256DMH 3-2 WQU 3-1 0.672 0.613 0.67 6.0 0.0 5.8 3.91 5.63 6 0.011 15 0.013 5.47 6.71 O.K. 0.583267Cape Cod Inflatable ParkIDF Curve: BarnstablePIPE SIZING TABLE25-Year4-8592.05TRMBGY12"11/18/2021HDPE2021-11-18 PipeSizing.xlsx - Pipe SizingPage 1 Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA APPENDIX A USGS LOCUS MAP Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA APPENDIX B FEMA MAP National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V, A99 With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mileZone X Future Conditions 1% Annual Chance Flood HazardZone X Area with Reduced Flood Risk due to Levee. See Notes.Zone X Area with Flood Risk due to LeveeZone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood HazardZone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 10/21/2021 at 12:33 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. 1:6,000 70°14'27"W 41°39'19"N 70°13'50"W 41°38'52"N Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020 Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA APPENDIX C WEB SOIL SURVEY REPORT Soil Map—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 10/20/2021 Page 1 of 346116904611730461177046118104611850461189046119304611690461173046117704611810461185046118904611930396880396920396960397000397040397080397120397160397200397240397280 396880 396920 396960 397000 397040 397080 397120 397160 397200 397240 397280 41° 39' 9'' N 70° 14' 18'' W41° 39' 9'' N70° 14' 0'' W41° 39' 0'' N 70° 14' 18'' W41° 39' 0'' N 70° 14' 0'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 19N WGS84 0 50 100 200 300 Feet 0 25 50 100 150 Meters Map Scale: 1:1,950 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 1:25,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Barnstable County, Massachusetts Survey Area Data: Version 18, Sep 1, 2021 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 10, 2018—Nov 17, 2018 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—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 10/20/2021 Page 2 of 3 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 252A Carver coarse sand, 0 to 3 percent slopes 13.0 100.0% Totals for Area of Interest 13.0 100.0% Soil Map—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 10/20/2021 Page 3 of 3 Stormwater Management Report Cape Cod Inflatable Park West Yarmouth, MA APPENDIX D NOAA ATLAS 14, POINT PRECIPITATION FREQUENCY ESTIMATES 10/20/21, 10:31 AM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=41.6517&lon=-70.2366&data=depth&units=english&series=pds#table 1/4 NOAA Atlas 14, Volume 10, Version 3 Location name: West Yarmouth, Massachusetts, USA* Latitude: 41.6517°, Longitude: -70.2366° Elevation: 17.9 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Sandra Pavlovic, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Orlan Wilhite NOAA, National Weather Service, Silver Spring, Maryland PF_tabular | PF_graphical | Maps_&_aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 5-min 0.267 (0.216‑0.327) 0.337 (0.272‑0.414) 0.453 (0.365‑0.558) 0.549 (0.439‑0.681) 0.682 (0.525‑0.889) 0.780 (0.588‑1.04) 0.886 (0.647‑1.24) 1.01 (0.688‑1.43) 1.20 (0.783‑1.76) 1.37 (0.865‑2.04) 10-min 0.378 (0.305‑0.463) 0.478 (0.386‑0.587) 0.642 (0.516‑0.791) 0.779 (0.622‑0.965) 0.966 (0.744‑1.26) 1.11 (0.832‑1.48) 1.25 (0.916‑1.75) 1.43 (0.974‑2.03) 1.70 (1.11‑2.50) 1.94 (1.23‑2.89) 15-min 0.444 (0.359‑0.545) 0.562 (0.454‑0.690) 0.755 (0.608‑0.931) 0.915 (0.731‑1.13) 1.14 (0.875‑1.48) 1.30 (0.979‑1.74) 1.48 (1.08‑2.06) 1.69 (1.15‑2.38) 2.01 (1.30‑2.94) 2.28 (1.44‑3.40) 30-min 0.658 (0.532‑0.806) 0.828 (0.669‑1.02) 1.11 (0.891‑1.36) 1.34 (1.07‑1.66) 1.66 (1.28‑2.16) 1.89 (1.43‑2.53) 2.15 (1.57‑3.00) 2.45 (1.67‑3.47) 2.92 (1.90‑4.27) 3.31 (2.10‑4.95) 60-min 0.871 (0.705‑1.07) 1.09 (0.884‑1.34) 1.46 (1.17‑1.80) 1.76 (1.41‑2.18) 2.18 (1.68‑2.84) 2.49 (1.87‑3.32) 2.82 (2.06‑3.94) 3.22 (2.19‑4.55) 3.83 (2.49‑5.61) 4.35 (2.75‑6.50) 2-hr 1.23 (0.998‑1.49) 1.52 (1.24‑1.85) 2.00 (1.62‑2.45) 2.40 (1.93‑2.95) 2.95 (2.29‑3.81) 3.36 (2.55‑4.44) 3.80 (2.79‑5.24) 4.32 (2.96‑6.04) 5.12 (3.36‑7.40) 5.79 (3.70‑8.54) 3-hr 1.47 (1.20‑1.78) 1.80 (1.47‑2.19) 2.35 (1.91‑2.87) 2.81 (2.27‑3.44) 3.44 (2.68‑4.42) 3.91 (2.98‑5.14) 4.41 (3.26‑6.04) 5.01 (3.45‑6.94) 5.90 (3.89‑8.47) 6.66 (4.28‑9.75) 6-hr 1.92 (1.58‑2.31) 2.33 (1.91‑2.81) 2.99 (2.45‑3.62) 3.54 (2.88‑4.31) 4.30 (3.37‑5.47) 4.87 (3.73‑6.33) 5.47 (4.06‑7.38) 6.18 (4.29‑8.46) 7.21 (4.80‑10.2) 8.08 (5.24‑11.7) 12-hr 2.40 (1.99‑2.88) 2.87 (2.37‑3.44) 3.63 (2.99‑4.36) 4.26 (3.49‑5.15) 5.13 (4.05‑6.46) 5.79 (4.46‑7.43) 6.48 (4.83‑8.60) 7.25 (5.09‑9.82) 8.37 (5.62‑11.7) 9.28 (6.07‑13.2) 24-hr 2.86 (2.38‑3.40) 3.37 (2.81‑4.01) 4.21 (3.49‑5.02) 4.91 (4.04‑5.89) 5.87 (4.66‑7.30) 6.59 (5.11‑8.35) 7.35 (5.50‑9.60) 8.16 (5.78‑10.9) 9.31 (6.32‑12.8) 10.2 (6.75‑14.4) 2-day 3.26 (2.74‑3.85) 3.81 (3.19‑4.50) 4.70 (3.93‑5.57) 5.44 (4.52‑6.48) 6.46 (5.16‑7.96) 7.24 (5.65‑9.07) 8.03 (6.05‑10.4) 8.88 (6.35‑11.7) 10.0 (6.87‑13.7) 10.9 (7.29‑15.2) 3-day 3.54 (2.98‑4.16) 4.10 (3.45‑4.82) 5.00 (4.19‑5.90) 5.76 (4.79‑6.82) 6.79 (5.45‑8.31) 7.58 (5.94‑9.44) 8.38 (6.34‑10.7) 9.24 (6.64‑12.1) 10.4 (7.17‑14.1) 11.3 (7.59‑15.6) 4-day 3.78 (3.20‑4.43) 4.34 (3.66‑5.09) 5.25 (4.41‑6.18) 6.00 (5.02‑7.10) 7.04 (5.67‑8.60) 7.83 (6.16‑9.72) 8.65 (6.57‑11.0) 9.52 (6.87‑12.4) 10.7 (7.41‑14.4) 11.7 (7.85‑15.9) 7-day 4.42 (3.75‑5.15) 4.98 (4.23‑5.81) 5.91 (4.99‑6.91) 6.67 (5.61‑7.84) 7.73 (6.26‑9.35) 8.53 (6.75‑10.5) 9.35 (7.14‑11.8) 10.2 (7.43‑13.2) 11.4 (7.96‑15.2) 12.3 (8.38‑16.7) 10-day 5.02 (4.28‑5.83) 5.60 (4.77‑6.51) 6.56 (5.56‑7.64) 7.35 (6.20‑8.60) 8.44 (6.87‑10.2) 9.28 (7.37‑11.3) 10.1 (7.76‑12.7) 11.0 (8.05‑14.1) 12.2 (8.56‑16.1) 13.1 (8.96‑17.6) 20-day 6.83 (5.86‑7.88) 7.51 (6.44‑8.67) 8.63 (7.37‑9.99) 9.56 (8.12‑11.1) 10.8 (8.88‑12.9) 11.8 (9.46‑14.3) 12.8 (9.86‑15.8) 13.8 (10.2‑17.4) 15.0 (10.6‑19.5) 15.9 (10.9‑21.0) 30-day 8.39 (7.23‑9.64) 9.17 (7.89‑10.5) 10.4 (8.95‑12.0) 11.5 (9.80‑13.3) 12.9 (10.6‑15.3) 14.1 (11.3‑16.8) 15.2 (11.7‑18.5) 16.2 (12.0‑20.4) 17.4 (12.4‑22.5) 18.3 (12.7‑24.0) 45-day 10.4 (9.00‑11.9) 11.3 (9.76‑12.9) 12.7 (11.0‑14.6) 13.9 (11.9‑16.1) 15.6 (12.9‑18.3) 16.9 (13.6‑20.1) 18.2 (14.0‑21.9) 19.3 (14.4‑24.0) 20.6 (14.8‑26.3) 21.4 (14.9‑27.8) 60-day 12.1 (10.5‑13.8) 13.1 (11.4‑15.0) 14.7 (12.7‑16.8) 16.0 (13.8‑18.4) 17.9 (14.8‑20.9) 19.3 (15.6‑22.8) 20.7 (16.0‑24.8) 21.8 (16.4‑27.1) 23.2 (16.7‑29.5) 24.1 (16.9‑31.1) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical 10/20/21, 10:31 AM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=41.6517&lon=-70.2366&data=depth&units=english&series=pds#table 3/4 Large scale terrain Large scale map Large scale aerial + – 0.4km 0.2mi + – 2km 1mi + – 20km 20mi