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38A-108 CME Storm Drainage Report860.928.7848 www.cmeengineering.com 32 Crabtree Lane, PO Box 849, Woodstock CT 06281 DRAINAGE REPORT ServiceNet Olander Drive Northampton, Massachusetts Issued: January 18, 2017 Prepared for: R.P. Masiello 38 Main Street Boylston, MA 01505 SERVICENET OLANDER DRIVE NORTHAMPTON, MASSACHUSETTS TABLE OF CONTENTS A.Locus & Summary B.Massachusetts Department of Environmental Protection Checklist for Stormwater Report C.Water Quality Volume, Recharge Volume, & TSS Removal Calculations D.Existing Conditions Drainage Calculations E.Proposed Conditions Drainage Calculations F.Design Plans (Includes Construction Period Pollution Prevention and Erosion & Sedimentation Control Plan and Post Construction Operation and Maintenance Plan) G.Soils Mapping H.Hydrologic Data ServiceNet Drainage Report SECTION A Locus & Summary %/'#551%+#6'5+0% %TCDVTGG.CPG9QQFUVQEM%6 'CUV4KXGT&TKXG'CUV*CTVHQTF%6 'NO5VTGGV5QWVJDTKFIG/# ÄÄ^YYYEOGGPIKPGGTKPIEQO Drainage Report ServiceNet Northampton, Massachusetts SUMMARY ServiceNet proposes to construct a new office building on 2.2 acres located in the Planned Village District of Northampton. The proposed location is on the south side of Olander Drive approximately 300-feet east of Village Hill Road. Storm flows from the existing site flow to the south and are collected by the existing municipal drainage system in Prince Street (Route 66). Available USDA soils mapping (See Section G) indicates that soils in the proposed development area consist primarily of sandy loams with a hydrologic group of ‘B’. The proposed project will consist of a ±8,840 square foot Office Building with associated parking and access driveways. Storm flows from the parking area will be collected by a series of catch basins and discharged through a hydrodynamic separator into an underground infiltration system located to the west of the proposed building. Runoff from the building roof will be discharged directly to the infiltration system. The underground infiltration system provides the required groundwater recharge volume through infiltration, as well as providing peak flow attenuation. Soil testing performed by Beals & Thomas in December 2011 indicates that sandy soils exist in the area of the proposed infiltration system. The Berkshire Design Group utilized an infiltration rate of 5.34 inches per hour in their design of the infiltration system immediately adjacent to the proposed development based on the Beals & Thomas soil testing data. This rate is slower than the allowable Rawl’s Rate for sand, so CME utilized this value in our calculations. CME Associates, Inc. utilized a computer model, HydroCAD®, to perform drainage calculations. The model used the Soil Conservation Service TR-20 method with NOAA 24-hour rainfall data to calculate the runoff. The design point for calculating the existing and proposed peak storm flows is the Prince Street Drainage System. Calculations for the 1, 2, 10, 25, and 100-year storm events are provided. Peak storm flows for existing and proposed conditions are listed in Table No. 1. Table No. 1 Existing & Proposed Peak Storm Flows & Volumes Storm Event To Prince Street Existing Proposed 1-Year Storm 0.04 CFS 0.05 CFS 2-Year Storm 0.2 CFS 0.2 CFS 10-Year Storm 1.5 CFS 1.3 CFS 25-Year Storm 2.6 CFS 2.2 CFS 100-Year Storm 5.2 CFS 4.6 CFS Peak Flows to Prince Street will be maintained or reduced through the 100-year storm event. Table 2. STORMWATER RECHARGE VOLUME WATER QUALITY VOLUME Structure Required (Target Depth Factor = 0.35)Provided Gallery System 1,109 CF 6,401 CF @ EL. 199.80 Drainage Report ServiceNet Northampton, Massachusetts Table 3. PEAK STORMWATER ELEVATION Gallery System Peak Elevation Storage Provided 1 Year Storm 197.4 1,601 CF 2 Year Storm 197.7 2,205 CF 10 Year Storm 198.9 4,610 CF 25 Year Storm 199.8 6,401 CF 100 Year Storm 200.1 6,996 CF ServiceNet Drainage Report SECTION B Massachusetts Department of Environmental Protection Checklist for Stormwater Report ServiceNet Stormwater Checklist • 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. ServiceNet Stormwater Checklist • 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 ServiceNet Stormwater Checklist • 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): Infiltration System Standard 1: No New Untreated Discharges No new untreated discharges Outlets have been designed so there is no erosion or scour to wetlands and waters of the Commonwealth Supporting calculations specified in Volume 3 of the Massachusetts Stormwater Handbook included. ServiceNet Stormwater Checklist • 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. ServiceNet Stormwater Checklist • 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. ServiceNet Stormwater Checklist • 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. ServiceNet Stormwater Checklist • 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. ServiceNet Stormwater Checklist • 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. ServiceNet Drainage Report SECTION C Water Quality Volume, Recharge Volume, & TSS Removal Calculations Project Name: ServiceNet Project # 2016102 Date: November 30, 2016 WQV = 1" (I) / 12 Where: WQV = Water Quality Volume (ac-ft) I = Impervious Area (ac) Areas From AutoCAD SQ. FT Acres Impervious 30,215 0.694 Pervious 7,645 0.176 Total (A) 37,860 0.869 WQV REQUIRED = 0.058 ac ft 2,518 cf Ia / P = 0.034 (1" Runoff) qu = +/- 795 APP B WQF = (qu) (A) (WQV) Where: qu = unit peak discharge (cfs/sqmi/in) A = Drainage Area (sqmi) WQV = Water Quality Volume (watershed inches) WQF = 0.9 cfs Prepared By: PMP Checked By:_______ Determine Unit Peak Discharge Read Unit Peak Discharge From Figure 4 Water Quality Flow Water Quality Flow Hydrodynamic Separator 1 Water Quality Volume Following Guidelines From "Massachusetts Department of Environmental Protection Wetlands Program" MassDEP Q Rate - Sept. 10, 2013 - Page 1 Massachusetts Department of Environmental Protection Wetlands Program Standard Method to Convert Required Water Quality Volume to a Discharge Rate for Sizing Flow Based Manufactured Proprietary Stormwater Treatment Practices Effective October 15, 2013, computations following the standardized method must be submitted with a Wetlands Notice of Intent (NOI) when a proprietary manufactured stormwater treatment device sized using a flow rate is proposed in connection with work proposed in a wetland resource area or associated buffer zone. The computational method will primarily affect the sizing of the proprietary manufactured stormwater treatment separators, and not other types of stormwater treatment practices that are volume based (such as extended detention basins) or proprietary stormwater treatment filters sized using the Water Quality Volume (WQV). Stormwater Standard No. 4 requires structural stormwater management practices to be sized to capture the required WQV in accordance with the Massachusetts Stormwater Handbook (310 CMR 10.05(6)(k)(4) and 314 CMR 9.06(6)(a)(4)) . Stormwater Standard No. 4 requires that the full WQV be captured and treated to remove 80% of the Total Suspended Solid (TSS) load. Since manufactured proprietary stormwater separators are sized using discharge rates and not volume, MassDEP is requiring the standardized method described below be used to convert the required WQV to a discharge rate (Q). No other methods are allowed to convert the WQV to the Q rate. This will ensure that flow rate based manufactured proprietary stormwater treatment practices are sized consistently from manufacturer to manufacturer. This section contains the following: caveats for method use, method description, examples of how to use the method, and documentation describing how the method was derived. This method will be incorporated into the Massachusetts Stormwater Handbook. The following caveats apply to use of the method:  Device sized using the Q rate must only be used as pretreatment practice.  Device sized using this method shall be designed to be “offline”, unless approved otherwise through written reciprocity granted by MassDEP to a final certification pursuant to the Technology Acceptance Reciprocity Partnership (TARP). This means the device must be sized at a minimum to fully treat the Q rate without any overflow, by-pass, surcharge of runoff, or scouring of sediments or oils previously trapped or entrained in the device.  The computations described below must be provided in the Stormwater Report accompanying Wetlands Notice of Intent or application for 401 Water Quality Certification.  MassDEP reserves ability to revise this method in the future as may be needed to reflect documented increases to precipitation intensity (Douglas 2011), updates to design intensity storms currently being considered by the National Weather Service or Northeast Climate Center (NECC)1 to Technical Paper 40 (upon which this methodology is based), NRCS revisions to the WinTR55/TR20 methods,2 or changes to the National Pollution Discharge Elimination System (NPDES) permits issued by EPA for Massachusetts. 1 On web, see precipitation intensities at http://precip.net 2 On web, See MA-NRCS description at: http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs144p2_013763.pdf MassDEP Q Rate - Sept. 10, 2013 - Page 2 METHOD 1. Determine if the WQV is the first ½-inch or 1-inch of runoff. If WQV is the first ½ -inch, go to STEP 2. If WQV is the first 1-inch of runoff, go to STEP 7. FOR FIRST ½ INCH RUNOFF WQV 2. Use Curve Number (CN) 98 to represent the runoff potential for impervious surfaces (see Method Derivation section below for explanation regarding how CN 98 was obtained). Only use impervious surfaces for these computations. Runoff from pervious surfaces should not be included in the WQV computations for the Q rate. The WQV required by the Massachusetts Wetlands Protection (310 CMR 10.05(6)(k)(4)) and 401 Water Quality Certification (314 CMR 9.06(6)(a)(4)) regulations for Stormwater Standard No. 4 is based only on impervious surfaces. 3. Compute the time of concentration (tc) using the methods described in TR-55 1986, Chapter 3. 4. Refer to Figure 1, Ia/P Curve = 0.058 5. Determine unit peak discharge using Figure 1 or 2. Figure 2 is in tabular form so is preferred. Using the tc determined in STEP 3, read the unit peak discharge (qu) from Figure 1 or Table in Figure 2. qu is expressed in the following units: cfs/mi²/watershed inches (csm/in). 6. Compute Q rate using the following equation: Q 0.5 = (qu)(A)(WQV) Where: Q 0.5 = flow rate associated with first ½ -inch of runoff qu = the unit peak discharge, in csm/in. A = impervious surface drainage area (in square miles) WQV = water quality volume in watershed inches (½ -inch in this case) See Example 1, page 8 applying use of the method to convert first ½ -inch WQV to minimum Q 0.5 rate. MassDEP Q Rate - Sept. 10, 2013 - Page 3 Figure 1: For First ½-inch Runoff, Ia/P Curve = 0.058, Relationship Between Unit Peak Discharge and Time of Concentration for NRCS Type III Storm Distribution. MassDEP Q Rate - Sept. 10, 2013 - Page 4 Figure 2: For First ½-inch of Runoff, Table of qu values for Ia/P Curve = 0.0.058, listed by tc, for Type III Storm Distribution Tc qu Tc qu Tc qu Tc qu (Hours) (csm/in) (Hours) (csm/in) (Hours) (csm/in) (Hours) (csm/in) 0.01 821 1.8 246 5.3 116 8.8 77 0.03 821 1.9 238 5.4 115 8.9 76 0.05 813 2 230 5.5 113 9 76 0.067 794 2.1 223 5.6 112 9.1 75 0.083 773 2.2 217 5.7 110 9.2 74 0.1 752 2.3 211 5.8 109 9.3 74 0.116 733 2.4 205 5.9 107 9.4 73 0.133 713 2.5 200 6 106 9.5 72 0.15 694 2.6 194 6.1 104 9.6 72 0.167 677 2.7 190 6.2 103 9.7 71 0.183 662 2.8 185 6.3 102 9.8 70 0.2 646 2.9 181 6.4 100 9.9 70 0.217 632 3 176 6.5 99 10 69 0.233 619 3.1 173 6.6 98 0.25 606 3.2 169 6.7 97 0.3 572 3.3 165 6.8 96 0.333 552 3.4 162 6.9 94 0.35 542 3.5 158 7 93 0.4 516 3.6 155 7.1 92 0.416 508 3.7 152 7.2 91 0.5 472 3.8 149 7.3 90 0.583 443 3.9 147 7.4 89 0.6 437 4 144 7.5 88 0.667 417 4.1 141 7.6 87 0.7 408 4.2 139 7.7 86 0.8 383 4.3 136 7.8 85 0.9 361 4.4 134 7.9 84 1 342 4.5 132 8 84 1.1 325 4.6 130 8.1 83 1.2 311 4.7 128 8.2 82 1.3 297 4.8 126 8.3 81 1.4 285 4.9 124 8.4 80 1.5 274 5 122 8.5 79 1.6 264 5.1 120 8.6 79 1.7 254 5.2 118 8.7 78 MassDEP Q Rate - Sept. 10, 2013 - Page 5 FOR FIRST 1-INCH RUNOFF WQV 7. Use Curve Number (CN) 98 to represent the runoff potential for impervious surfaces (see Method Derivation section below for explanation regarding how CN 98 was obtained). Only use impervious surfaces for these computations. Runoff from pervious surfaces should not be included in the WQV computations for peak WQF. The WQV required by the Massachusetts Wetlands Protection (310 CMR 10.05(6)(k)(4)) and 401 Water Quality Certification (314 CMR 9.06(6)(a)(4)) regulations for Stormwater Standard No. 4 is based only on impervious surfaces. 8. Compute the time of concentration (tc) using the methods described in TR-55 1986, Chapter 3. 9. Refer to Ia/P Curve = 0.034 (Figure 3) 10. Determine unit peak discharge using Figure 3 or 4. Figure 4 is in tabular form so is preferred. Using the tc determined in STEP 8, read the unit peak discharge (qu) from Figure 2 or from Table in Figure 4. qu is expressed in the following units: cfs/mi²/watershed inches (csm/in). 11. Compute the water quality flow (WQF) using the following equation: Q 1 = (qu)(A)(WQV) Where: Q 1 = peak flow rate associated with first 1-inch of runoff qu = the unit peak discharge, in csm/in. A = impervious surface drainage area (in square miles) WQV = water quality volume in watershed inches (1.0-inches in this case) See Example 2, page 8 applying use of the method to convert first 1-inch WQV to minimum Q 1 rate. MassDEP Q Rate - Sept. 10, 2013 - Page 6 Figure 3: For First 1-inch Runoff, Ia/P Curve = 0.034, Relationship Between Unit Peak Discharge and Time of Concentration for NRCS Type III Storm Distribution Unit Peak Discharge, Type III Storm, Ia/P = 0.034 1 10 100 1000 0.01 0.1 1 10 Time of Concentration (Tc), hoursUnit Peak Discharge (qu), csm/inqu MassDEP Q Rate - Sept. 10, 2013 - Page 7 Figure 4: for First 1-inch Runoff, Table of qu values for Ia/P Curve = 0.034, listed by tc, for Type III Storm Distribution Tc qu Tc qu Tc qu (Hours) (csm/in) (Hours) (csm/in) (Hours) (csm/in) 0.01 835 2.7 197 7.1 95 0.03 835 2.8 192 7.2 94 0.05 831 2.9 187 7.3 93 0.067 814 3 183 7.4 92 0.083 795 3.1 179 7.5 91 0.1 774 3.2 175 7.6 90 0.116 755 3.3 171 7.7 89 0.133 736 3.4 168 7.8 88 0.15 717 3.5 164 7.9 87 0.167 700 3.6 161 8 86 0.183 685 3.7 158 8.1 85 0.2 669 3.8 155 8.2 84 0.217 654 3.9 152 8.3 84 0.233 641 4 149 8.4 83 0.25 628 4.1 146 8.5 82 0.3 593 4.2 144 8.6 81 0.333 572 4.3 141 8.7 80 0.35 563 4.4 139 8.8 79 0.4 536 4.5 137 8.9 79 0.416 528 4.6 134 9 78 0.5 491 4.7 132 9.1 77 0.583 460 4.8 130 9.2 76 0.6 454 4.9 128 9.3 76 0.667 433 5 126 9.4 75 0.7 424 5.1 124 9.5 74 0.8 398 5.2 122 9.6 74 0.9 376 5.3 120 9.7 73 1 356 5.4 119 9.8 72 1.1 339 5.5 117 9.9 72 1.2 323 5.6 115 10 71 1.3 309 5.7 114 1.4 296 5.8 112 1.5 285 5.9 111 1.6 274 6 109 1.7 264 6.1 108 1.8 255 6.2 106 1.9 247 6.3 105 2 239 6.4 104 2.1 232 6.5 102 2.2 225 6.6 101 2.3 219 6.7 100 2.4 213 6.8 99 2.5 207 6.9 98 2.6 202 7 96 MassDEP Q Rate - Sept. 10, 2013 - Page 8 Examples Example 1: 2.28-acre asphalt parking lot (impervious surface), with time of concentration equal to 0.25 hours. The proposed parking lot drains to a wetland resource area, which is not a critical area, nor is the site located “near” a critical area. A proprietary separator is proposed to pretreat runoff to be directed to an Extended Detention Basin. Because site does not drain to or located near a critical area, WQV = ½ -inch 1-acre = 0.0015625 mi2 Step 1: Use CN = 98 to represent the 2.28-acre impervious surface. Step 2: Determine tc tc = 0.25 hours (given). Step 3: Determine qu using Figure 2 With tc = 0.25 hours, qu is determined to be 606 csm/inch using Table in Figure 2. Step 4 (Final Step): Determine Q 0.5 Q 0.5 = (qu)(A)(WQV) Q 0.5 = (606 csm/in)(2.28-acre)(0.0015625 mi2/acre)( ½ -inch) Q 0.5 ≈ 1.1 CFS Example 2: One-acre site composed entirely of impervious surfaces, with time of concentration equal to 6 minutes. The proposed impervious surfaces are to be drained to a stream located in Zone II of a public drinking water supply. A proprietary separator is proposed to pretreat runoff to be directed to an Infiltration Basin. Because site drains to a critical area, WQV = 1-inch 1-acre = 0.0015625 mi2 Step 1: Use CN = 98 to represent the 1-acre impervious surface. Step 2: Determine tc MassDEP Q Rate - Sept. 10, 2013 - Page 9 tc = 6 minutes (given). Convert minutes to hours tc = (6 minutes) /(60 minutes/hr) = 0.1 hours Step 3: Determine qu using Table in Figure 4 Using the tc column, read down to find tc = 0.1 hours. Read to the right of tc = 0.1 hours to find the qu value which is 774 csm/inch. Alternatively, you may use Figure 3 (Ia/P curve = 0.034). Find tc = 0.1 hours, read up to the Ia/P curve, then follow intersecting line to the left to interpolate the qu value. You’ll note that using Figure 4 is quicker in so far as no interpolation is required. In cases where the tc is not listed in Figure 4, you may need to use Figure 3. In such instances, Figure 4 may still assist you in bracketing the qu values to interpolate. Step 4 (Final Step): Determine Q 1 Q 1 = (qu)(A)(WQV) Q 1 = (774 csm/in)(1-acre)(0.0015625 mi2/acre)(1-inch) Q 1 ≈ 1.2 CFS If the conversion factor to convert acres to square miles is not included, the result will not be correct. As different units are used in the computations, double check your units to ensure the result is correct. Method Derivation The Stormwater Advisory Committee convened to assist MassDEP with the 2008 stormwater revisions to the Wetlands and 401 Water Quality Certification regulations. The Advisory Committee tabled a method proposed at that time and asked its Proprietary BMP subcommittee to study the issue further. Subsequently, the Proprietary BMP subcommittee met from 2008 to 2011, examining multiple methods. Among the methods reviewed included the Rational Method used by New Jersey DEP, Ahlfeld et al 2004, Winkler et al 2001, Claytor and Scheuler 1996, Imbrium PCSWMM, and Bryant. The Ahlfeld and Winkler methods were funded by MassDEP through 319 funds and developed using Massachusetts precipitation data. The Claytor method is based on SCS TR-55 graphical methods. The PCSWMM method is a proprietary version of the EPA SWMM method, based on Mannings equation. The Bryant method was based on precipitation data compiled in the Ahlfeld and Winkler methods. To assist in selecting a method, Rees and Schoen 2009 conducted third party review of the different approaches. Rees and Schoen found that the various methods produced different peak rate flows. MassDEP Q Rate - Sept. 10, 2013 - Page 10 Differences were also found between peak flow rates in coastal and inland areas. With some methods, the precipitation intensity associated with the ½-inch water quality volume produced a greater flow rate than the 1-inch water quality volume. The study concluded that the Claytor and Schueler 1996 method was the most complete in attempting to transform the Water Quality Volume to a flow rate. Subsequent to the study, flow rate results from the Claytor and Schueler method were adapted for use in Massachusetts using both the first ½ - inch and 1-inch Water Quality Volumes. Flow rates were found to bypass a portion of the Water Quality Volume for the both the first ½ -inch and 1-inch of runoff depending on drainage area and treatment device size. As bypassed runoff is not treated, the Proprietary BMP Subcommittee agreed on meeting held in March 2011 that practices sized using the flow conversion method must be restricted to pretreatment only and directed to stormwater treatment practices. The Proprietary BMP Subcommittee subsequently recommended the Claytor and Schueler 1996 method be used, as adapted for use in Massachusetts, to the Stormwater Advisory Committee in May 2011. The Claytor and Schueler 1996 approach in part utilizes the U.S. Natural Resource and Conservation Service Technical Release 55 (TR-55) Graphical Peak Discharge Method (NRCS / SCS 1986), adapted for small storm hydrology (Pitt 1999). It was adapted for use in Massachusetts by determining the precipitation values that generate the first ½ -inch and 1-inch of runoff, using the NRCS / SCS 1986 equations as described below. 1. The Massachusetts Stormwater Standard No. 4 sets the required WQV equal to 0.5-inch or 1.0- inch, depending if the discharge is to or near a critical area, Land Use with Higher Potential Pollutant Load (LUHPPL), or soil with rapid infiltration rate. 2. The Claytor and Scheuler 1996 method requires a Curve Number (CN) be determined to represent the ability of a surface to effectively convey runoff. CN 98 was derived for impervious surfaces using small storm hydrology using the following equation (NRCS / SCS 1986). The precipitation depth associated with the first 1.0-inch of runoff is 1.2 watershed inches based on Figure 4 (NRCS 1986 Table 2-1) and Figure 5 (NRCS 1986 Figure 2-1). The precipitation depth associated with the first ½ - inch of runoff is 0.7 watershed inches. ½-inch WQV Derivation: Solve for Pt  CN 1000 10 5Pt 10QWQV 10(QWQV 2 1.25QWQV Pt)0.5 Where: CN = Runoff Curve Number = 98 for runoff impervious surfaces Pt = Precipitation depth QWQV = Runoff depth related to Water Quality Volume = 0.5 watershed inches This equation produces the result Pt = 0.7 inches, when CN = 98 and QWQV = 0.5 inches. MassDEP Q Rate - Sept. 10, 2013 - Page 11 1-inch WQV Derivation  CN 1000 10 5Pt 10QWQV 10(QWQV 2 1.25QWQV Pt)0.5 Where: CN = Runoff Curve Number = 98 for runoff from impervious surfaces Pt = Precipitation depth QWQV = Runoff depth related to Water Quality Volume = 1.0 watershed inches This equation produces the result Pt = 1.2 inches, when CN = 98 and QWQV = 1.0 inches 3. Potential maximum retention (S) in inches was derived using the following equation (NRCS 1986): ½-inch WQV Derivation / 1-inch WQV Derivation (result same for both): S = (1000/CN) – 10 This equation produces the result S = 0.204 when the CN = 98 4. The initial abstraction (Ia) was derived using the following equation (NRCS 1986): ½-inch WQV Derivation / 1-inch WQV Derivation (result same for both): Ia = 0.2S This equation produces the result Ia = 0.041, when S = 0.204 Also See Figure 6 (NRCS 1986, Table 4-1), where Ia = 0.041, for CN = 98 5. The Ia/P Ratio was derived using the following equation (NRCS 1986): ½-inch WQV Derivation Solve for Ia/P Ratio using the following equation (NRCS 1986): Ia/P Ratio = Ia/ Pt Where: Ia = 0.041 (for CN = 98) Pt = 0.7 watershed inches Ia/P Ratio = 0.041/ 0.7 = 0.058 MassDEP Q Rate - Sept. 10, 2013 - Page 12 1-inch WQV Derivation Ia/P Ratio = Ia/ Pt Where: Ia = 0.041 (for CN = 98) Pt = 1.2 watershed inches Ia/P Ratio = 0.041/ 1.2 = 0.034 6. For the first ½ -inch runoff, Ia/P curve for 0.058 ratio (Figure 1) and corresponding table (Figure 2) were generated using coefficients C0, C1 and C2 derived from regression of coefficients published in Appendix F in NRCS / SCS TR-55 1986. 7. For the first 1-inch runoff, Ia/P curve for 0.034 ratio (Figure 3) and corresponding table (Figure 4) were generated using coefficients C0, C1 and C2 derived from regression of coefficients published in Appendix F in NRCS / SCS TR-55 1986. MassDEP Q Rate - Sept. 10, 2013 - Page 13 Figures Used for Method Derivation Figure 5: Graph Depicting CN to Percent Impervious Relationship by Precipitation Depth (MD 2000, Figure D- 10.1). Note at 100% imperviousness, precipitation depths coincide, making corresponding Runoff CN greater than 98. MassDEP Q Rate - Sept. 10, 2013 - Page 14 Figure 6: Relationship Between Impervious Cover & Runoff Coefficient (Vermont 2002, from Schueler, 1987). Note at 100% imperviousness, Rv is between 0.9 and 1, meaning that most of the precipitation effectively becomes runoff. MassDEP Q Rate - Sept. 10, 2013 - Page 15 Figure 7: Table Depicting Relationship Between Precipitation (P) and Direct Runoff (Q) by Curve Number (NRCS 1986, Table 2-1). 1.2 inches of precipitation effectively becomes 0.99-inch of runoff. MassDEP Q Rate - Sept. 10, 2013 - Page 16 Figure 8: Graph Depicting Relationship Between Precipitation (P) and Direct Runoff (Q) by Curve Number (NRCS 1986, Figure 2-1). This indicates that for a CN 98 (representing impervious surfaces), 1.2 inches of precipitation effectively equals 1-inch of direct runoff. MassDEP Q Rate - Sept. 10, 2013 - Page 17 Figure 9: Table Listing Ia by CN (NRCS 1986, Table 4-1). This indicates Initial Abstraction (Ia) for CN 98 = 0.041 MassDEP Q Rate - Sept. 10, 2013 - Page 18 Figure 10: Graph Depicting Ia/P to Precipitation Relationship by CN (NRCS 1986, Figure 4-1). Ia/P ratio of 0.034 corresponding to 1.2 inches of precipitation added. Ia/P ratio determined for CN 98, using Ia = 0.041, P = 1.2 MassDEP Q Rate - Sept. 10, 2013 - Page 19 Figure 11: Relationship Between Time of Concentration and Unit Peak Discharge for Ia/P Ratios from 0.10 to 0.50 for NRCS Type III Storm Distribution (NRCS 1986, Exhibit 4-III). NRCS / SCS 1986 specifies Type III storm distribution (tropical influenced storms) for Massachusetts. See Figure 3 and 4 for Ia/P Ratio = 0.034 MassDEP Q Rate - Sept. 10, 2013 - Page 20 References: Ahlfeld, D.P. and Minihane, M., 2004, Storm flow from the first-flush precipitation in stormwater design, Journal of Irrigation and Drainage Engineering, 130:4, pp. 269 – 276. Bryant, G., undated, Massachusetts Rainfall Intensity Analysis, Hydroworks LLC, 9 pages Claytor, R. and T. Schueler, 1996. Design of Stormwater Filtering Systems. Center for Watershed Protection. Ellicott City, MD, Pages 2-27 to 2-29, WEB: http://www.mckenziewaterquality.org/documents/stormwater_filtration_system_design.pdf Connecticut Department of Environmental Protection, 2004, -Connecticut Stormwater Quality Manual, Appendix B, pages B-1 to B-3, WEB: http://www.ct.gov/deep/lib/deep/water_regulating_and_discharges/stormwater/manual/Apx_B_Wate r_Quality.pdf DeGaetano, A. and Zarrow, D., Extreme Precipitation in New York and New England, northeast Regional Climate Center, Cornell University, WEB: http://precip.eas.cornell.edu/docs/xprecip_techdoc.pdf Douglas, E. and Fairbank, C., 2011, Is Precipitation in Northern New England Becoming More Extreme? Statistical Analysis of Extreme Rainfall in Massachusetts, New Hampshire, and Maine and Updated Estimates of the 100-year Storm, Journal of Hydrologic Engineering, Volume 16, No. 3, pp 203 - 217 Froehlich, David C., 2009, Graphical Calculation of First Flush Flow Rates for Storm-Water Quality Control, Journal of Irrigation and Drainage Engineering, Vol. 135, No. 1 Hershfield, D. M.,1961, Rainfall frequency atlas of the United States for Durations from 30 Minutes to 24 Hours and Return Periods from 1 to 100 years. Weather Bureau Technical Paper No. 40, U.S. Weather Bureau, Washington D.C. Knox County, Stormwater Management Manual, Volume 2, Section 3.1.7.2, http://www.knoxcounty.org/stormwater/pdfs/vol2/3-1-7%20Water%20Quality%20Calculations.pdf Maryland Dept. of the Environment, 2000, Stormwater Design Manual, Appendix D.10, Method for Computing Peak Discharge for Water Quality Storm, Pages D.10.1 to D.10.4, WEB: http://mde.maryland.gov/assets/document/sedimentstormwater/Appnd_D10.pdf National Weather Service, 2013, Hydrometeorological Design Studies Center, Quarterly Progress Report, April 1, 2013 to June 30, 2013, WEB: http://www.nws.noaa.gov/oh/hdsc/current- projects/progress/201307_HDSC_PR.pdf Natural Resources Conservation Service (NRCS), 1986, Urban Hydrology for Small Watersheds, Technical Release 55 (TR-55). WEB: ftp://ftp.wcc.nrcs.usda.gov/wntsc/H&H/other/TR55documentation.pdf New Hampshire Department of Environmental Services, 2008, New Hampshire Stormwater Manual, Volume 2, Chapter 2, Pages 9 – 10, WEB: http://des.nh.gov/organization/divisions/water/stormwater/documents/wd-08-20b_ch2.pdf MassDEP Q Rate - Sept. 10, 2013 - Page 21 New Jersey Department of Environmental Protection, 2009, Protocol for Total Suspended Solids Removal Based on Field Testing Amendments to TARP Protocol, WEB: http://www.state.nj.us/dep/stormwater/pdf/field_protocol_08_05_09.pdf Pitt, R., 1999, Small Storm Hydrology and Why it is Important for the Design of Stormwater Control Practices, In: Advances in Modeling the Management of Stormwater Impacts, Volume 7. (Edited by W. James). Computational Hydraulics International, Guelph, Ontario and Lewis Publishers/CRC Press. 1999. WEB: http://rpitt.eng.ua.edu/Publications/UrbanHyandCompsoils/small%20storm%20hydrology%20Pitt%20ja mes98.pdf Rees, Paula and Schoen, Jerry, 2009, PCSWMM Evaluation, Final Technical Report, Prepared for Massachusetts Department of Environmental Protection Project 2008-08/319, University of Massachusetts at Amherst, Water Resources Research Center Rhode Island Department of Environmental Management, 2010, DRAFT Rhode Island Stormwater Design and Installation Standards Manual, Chapter 3, Section 3.3.3.2, Page 3-15, WEB: http://www.dem.ri.gov/pubs/wetmanl/stormmnl.pdf Schueler, Thomas, 1987, Controlling urban runoff: a practical manual for planning and designing urban BMPs. Appendix A. Department of Environmental Programs. Metropolitan Washington Council of Governments, Washington, DC. Vermont Agency of Natural Resources, 2002, Vermont Stormwater Management Manual, Volume I, Section 1.3.2, Pages 1-15 to 1-16, WEB: http://www.vtwaterquality.org/stormwater/docs/sw_manual- vol1.pdf Winkler, E, Ahlfeld, D., Askar, G., Minihane, M., 2001, Final Report: Development of a Rational Basis for Designing Recharging Stormwater Control Structures and Flow and Volume Design Criteria. Prepared for Massachusetts Department of Environmental Protection Project 99-06/319. University of Massachusetts at Amherst (PDF File, April, 2001) VortSentry®VortSentry® HS Hydrodynamic Separation Products Overview page 2 page 3 High performance hydrodynamic separation The Vortechs system is a high-performance hydrodynamic separator that effectively removes finer sediment, oil and grease, and floating and sinking debris. Its swirl concentrator and flow controls work together to minimize turbulence and provide stable storage of captured pollutants. The design also allows for easy inspection and unobstructed maintenance access. With comprehensive lab and field testing, the system delivers proven results and site-specific solutions. Precast models can treat peak design flows up to 25 cfs; cast-in-place models handle even greater flows. A typical system is sized to provide an 80% load reduction based on laboratory-verified removal efficiencies for varying particle size distributions such as 50-micron sediment particles. How does it work? Water enters the swirl chamber at a tangent, inducing a gentle swirling flow pattern and enhancing gravitational separation. Sinking pollutants stay in the swirl chamber while floating pollutants are stopped at the baffle wall. Typically Vortechs systems are sized such that 80% or more of runoff through the system will be controlled exclusively by the low flow control. This orifice effectively reduces inflow velocity and turbulence by inducing a slight backwater appropriate to the site. During larger storms, the water level rises above the low flow control and begins to flow through the high flow control. The layer of floating pollutants is elevated above the influent pipe, preventing re-entrainment. Swirling action increases in relation to the storm intensity, which helps prevent re-suspension. When the storm drain is flowing at peak capacity, the water surface in the system approaches the top of the high flow control. The Vortechs system will be sized large enough so that previously captured pollutants are retained in the system even during these infrequent events. As a storm subsides, treated runoff decants out of the Vortechs system at a controlled rate, restoring the water level to a dry-weather level equal to the invert of the inlet and outlet pipes. The low water level facilitates easier inspection and cleaning, and significantly reduces maintenance costs by reducing pump-out volume. Vortechs Proven performance speeds approval process Treats peak flows without bypassing Flow controls reduce inflow velocity and increase residence time Unobstructed access simplifies maintenance Shallow system profile makes installation easier and less expensive Very low headloss Flexible design fits multiple site constraints • • • • • • • Vortechs® page 2 page 3 Patented continuous deflection separation (CDS) technology Using patented continuous deflective separation technology, the CDS system screens, separates and traps sediment, debris, and oil and grease from stormwater runoff. The indirect screening capability of the system allows for 100% removal of floatables and neutrally buoyant material without blinding. Flow and screening controls physically separate captured solids, and minimize the re-suspension and release of previously trapped pollutants. Available in precast or cast-in-place. Offline units can treat flows from 30 to 8500 L/s (1 to 300 cfs). Inline units can treat up to 170 L/s (7.5 cfs), and internally bypass larger flows in excess of 1420 L/s (50 cfs). The pollutant removal capability of the CDS system has been proven in the lab and field. How does it work? Stormwater enters the CDS unit’s diversion chamber where the diversion weir guides the flow into the unit’s separation chamber and pollutants are removed. All flows up to the system’s treatment design capacity enter the separation chamber. Swirl concentration and screen deflection forces floatables and solids to the center of the separation chamber where 100% of floatables and neutrally buoyant debris larger than the screen apertures are trapped. Stormwater then moves through the separation screen, under the oil baffle and exits the system. The separation screen remains clog free due to continuous deflection. During flow events exceeding the design capacity, the diversion weir bypasses excessive flows around the separation chamber, so captured pollutants will not wash out. CDS Removes sediment, trash, and free oil and grease Patented screening technology captures and retains 100% of floatables, including neutrally buoyant and all other material larger than the screen aperture Operation independent of flow Performance verified through lab and field testing Unobstructed maintenance access Customizable/flexible design and multiple configurations available Separates and confines pollutants from outlet flow Inline, offline, grate inlet and drop inlet configurations available Multiple screen aperture sizes available • • • • • • • • • CDS® page 4 page 5 Hydrodynamic separation with internal bypass The VortSentry is a hydrodynamic separator with a small footprint that makes it an effective treatment option for projects where space is at a premium and effective removal of floating and sinking pollutants is critical. The internal bypass ensures treatment chamber velocities remain low, which improves performance and eliminates the risk of resuspension. In addition to standalone applications, the VortSentry is an ideal pretreatment device. The system is housed inside a concrete manhole structure for easy installation (often without the use of a crane) and unobstructed maintenance access. How does it work? Stormwater runoff enters the unit tangentially to promote a gentle swirling motion in the treatment chamber. As stormwater circles within the chamber, settleable solids fall into the sump and are retained. Buoyant debris and oil and grease rise to the surface and are separated from the water as it flows under the baffle wall. Treated water exits the treatment chamber through a flow control orifice located behind the baffle wall. During low-flow conditions all runoff is diverted into the treatment chamber by the flow partition. At higher flow rates, a portion of the runoff spills over the flow partition and is diverted around the treatment chamber, filling the head equalization chamber. This collapses the head differential between the treatment chamber and the outlet, resulting in a relatively constant flow rate in the treatment chamber even with a substantial increase in total flow through the system. This further reduces the potential for resuspension or washout of captured pollutants. VortSentry® VortSentry Treatment and internal bypass in one structure Compact design ideal for congested sites Unobstructed maintenance access Round, lightweight construction for easy installation • • • • page 4 page 5 VortSentry ® HS VortSentry HS Helical flow pattern enhances trapping and containment of pollutants High treatment and bypass capacities Compact footprint ideal for congested sites Lightweight design easy to install Available in both inline and grate inlet configurations Quick manufacturing turnaround time • • • • • • Engineered performance and installation simplicity The VortSentry HS system employs a helical flow pattern that enhances trapping and containment of pollutants and provides effective removal of settleable solids and floating contaminants from urban runoff. With the ability to accept a wide range of pipe sizes, the VortSentry HS can treat and convey flows from small to large sites. A unique internal bypass design means higher flows can be diverted without the use of external bypass structures. The design of the VortSentry HS minimizes adverse velocities or turbulence in the treatment chamber. This helps to prevent the washout of previously captured pollutants even during peak conditions. The VortSentry HS is also available in a grate inlet configuration, which is ideal for retrofits. How does it work? Flows from low intensity storms, which are most frequent, are directed into the treatment chamber through the primary inlet. The tangentially oriented downward pipe induces a swirling motion in the treatment chamber that increases capture and containment abilities. Moderate storm flows are directed into the treatment chamber through the secondary inlet, which allows for capture of floating trash and debris. The secondary inlet also provides for treatment of higher flows without significantly increasing the velocity or turbulence in the treatment chamber. This allows for a more quiescent separation environment. Settleable solids and floating pollutants are captured and contained in the treatment chamber. Flow exits the treatment chamber through the outlet flow control, which manages the amount of flow that is treated and helps maintain the helical flow patterns developed within the treatment chamber. Flows exceeding the system’s rated treatment flow are diverted away from the treatment chamber by the flow partition. Internal diversion of high flows eliminates the need for external bypass structures. During bypass, the head equalizing baffle applies head on the outlet flow control to limit the flow through the treatment chamber. This helps prevent re-suspension of previously captured pollutants. page 6 page 7 Available Models 1. Structure diameter represents the typical inside dimension of the concrete structure. Offline systems will require additional concrete diversion components. 2. Depth Below Pipe and Sump Capacities can vary to accommodate specific site design. 3. Water Quality Flow is based on 80% removal of a Particle Size Distribution (PSD) having a mean particle size: d50=125-µm, which is a typical PSD gradation characterizing particulate matter (TSS/SSC) in urban rainfall runoff. Water Quality Flow, Particle Size & Performance Notes: • 80% removal (Re=80%) performance forecasts of the PSD having a d50=125-µm is derived from controlled tests of a unit equipped with 2400-µm screen. Performance forecasts for specific particle size gradations or d50s=50, 75, 125, 150 & 200-µm are also available. Removal forecasts based on unit evaluations conducted in accordance with the Technology Assessment Protocol - Ecology (TAPE) protocols, Washington Department of Ecology (WASDOE). • Units can be sized to achieve specific Re performance for peak flow rates for specific Water Quality Flows, over the hydrograph of a Water Quality Storm Event or sized to meet a specific removal on an average basis using accepted probabilistic methods. When sizing based on a specific water quality flow rate, the required flow to be treated should be equal to or less than the listed water quality flow for the selected system. Contact our support staff for the most cost effective sizing for your area. Typical Internal MH Diameter or Typical Depth2 Below Water Quality Flow3 Screen Typical Equivalent ID1 Pipe Invert 125 µm Diameter/Height Sump Capacity CDS Model ft m ft m cfs L/s ft m yd3 m3 CDS2015-4 4 1.2 3.5 1.1 0.7 19.8 2.0/1.5 0.6/0.5 0.5 0.4 CDS2015 5 1.5 5.2 1.6 0.7 19.8 2.0/1.5 0.6/0.5 1.3 1.0 CDS2020 5 1.5 5.7 1.7 1.1 31.2 2.0/2.0 0.6/0.6 1.3 1.0 CDS2025 5 1.5 6.0 1.8 1.6 45.3 2.0/2.5 0.6/0.8 1.3 1.0 CDS3020 6 1.8 6.2 1.9 2.0 56.6 3.0/2.0 0.9/0.6 2.1 1.6 CDS3030 6 1.8 7.1 2.2 3.0 85.0 3.0/3.0 0.9/0.9 2.1 1.6 CDS3035 6 1.8 7.6 2.3 3.8 106.2 3.0/3.5 0.9/1.1 2.1 1.6 CDS4030 8 2.4 8.6 2.6 4.5 127.4 4.0/3.0 1.2/0.9 5.6 4.3 CDS4040 8 2.4 9.7 3.0 6.0 169.9 4.0/4.0 1.2/1.2 5.6 4.3 CDS4045 8 2.4 10.3 3.1 7.5 212.4 4.0/4.5 1.2/1.4 5.6 4.3 CDS3020-D 6 1.8 6.2 1.9 2.0 56.6 3.0/2.0 0.9/0.6 2.1 1.6 CDS3030-DV 6 1.8 6.9 2.1 3.0 85.0 3.0/3.0 0.9/0.9 2.1 1.6 CDS3030-D 6 1.8 7.1 2.2 3.0 85.0 3.0/3.0 0.9/0.9 2.1 1.6 CDS3035-D 6 1.8 8.7 2.6 3.8 106.2 3.0/3.5 0.9/1.1 2.1 1.6 CDS4030-D 7 2.1 8.6 2.6 4.5 127.4 4.0/3.0 1.2/0.9 4.3 3.3 CDS4040-D 7 2.1 9.6 2.9 6.0 169.9 4.0/4.0 1.2/1.2 4.3 3.3 CDS4045-D 7 2.1 10.1 3.1 7.5 212.4 4.0/4.5 1.2/1.4 4.3 3.3 CDS5042-DV 9.5 2.9 9.6 2.9 9.0 254.9 5.0/4.2 1.5/1.3 1.9 1.5 CDS5640-D 8 2.4 9.5 2.9 9.0 254.9 5.6/4.0 1.7/1.2 5.6 4.3 CDS5050-DV 9.5 2.9 10.3 3.1 11 311.5 5.0/5.0 1.5/1.5 1.9 1.5 CDS5653-D 8 2.4 10.9 3.3 14 396.5 5.6/5.3 1.7/1.6 5.6 4.3 CDS5668-D 8 2.4 12.4 3.8 19 538.1 5.6/6.8 1.7/2.1 5.6 4.3 CDS5678-D 8 2.4 13.4 4.1 25 708.0 5.6/7.8 1.7/2.4 5.6 4.3 CDS7070-DV 12 3.7 14 4.3 26 736.3 7.0/7.0 2.1/2.1 3.3 2.5 CDS10060-DV 17.5 5.3 12 3.7 30 849.6 10.0/6.0 3.0/1.8 5.0 or 10.2 3.8 or 7.8 CDS10080-DV 17.5 5.3 14 4.3 50 1416.0 10.0/8.0 3.0/2.4 5.0 or 10.2 3.8 or 7.8 CDS100100-DV 17.5 5.3 16 4.9 64 1812.5 10.0/10.0 3.0/3.0 5.0 or 10.2 3.8 or 7.8 CDS150134-DC 22 6.7** 22 6.7** 148 4191.4 15.0/13.4 4.6/4.1 20.4 15.6 CDS200164-DC 26 7.9** 26 7.9** 270 7646.6 20.0/16.4 6.1/5.0 20.4 15.6 CDS240160-DC 32 9.8** 25 7.6** 300 8496.2 24.0/16.0 7.3/4.9 20.4 15.6 Cast InPlace InlineOfflineOfflinePrecast****Sump Capacities and Depth Below Pipe Invert can vary due to specific site design Vortechs Swirl Chamber Internal Water Quality Flow1 Peak Sediment Model Diameter Length cfs / L/s Treatment Flow2 Storage ft m ft m 50 µm 110 µm 200 µm cfs L/s yd3 m3 1000 3 0.9 9 2.7 0.21/5.9 0.59/16.7 0.98/27.8 1.6 45.3 0.7 0.5 2000 4 1.2 10 3.0 0.36/10.2 1.0/28.3 1.7/48.1 2.8 79.3 1.2 0.9 3000 5 1.5 11 3.4 0.59/16.7 1.7/48.1 2.7/76.5 4.5 127.4 1.8 1.4 4000 6 1.8 12 3.7 0.78/22.1 2.2/62.3 3.7/104.8 6.0 169.9 2.4 1.8 5000 7 2.1 13 4.0 1.1/31.1 3.1/87.8 5.2/147.2 8.5 240.7 3.2 2.4 7000 8 2.4 14 4.3 1.4/39.6 4.1/116.1 6.7/189.7 11.0 311.5 4.0 3.1 9000 9 2.7 15 4.6 1.8/51.0 5.2/147.2 8.5/240.7 14.0 396.4 4.8 3.7 11000 10 3.0 16 4.9 2.3/65.1 6.5/184.1 10.7/303.0 17.5 495.5 5.6 4.3 16000 12 3.7 18 5.5 3.3/93.4 9.3/263.3 15.3/433.2 25.0 707.9 7.1 5.4 1. Water Quality Flow Rates are based on 80% removal for the particle size distributions (PSD) listed above with d50 = 50, 110 & 200-µm. Particle size should be chosen based on anticipated sediment load. 2. Peak Treatment Flow is maximum flow treated for each unit listed. This flow represents an infrequent storm event such as a 10 or 25 yr storm. Standard Vortechs System depth below invert is 3’ for all precast models. Cast-in-place system are available to treat higher flows. Check with your local representatives for specifications. page 6 page 7 * Denotes models may not be manufactured in your area. Check with your local representative for availability. 1. Water Quality Flow is based on 80% removal of a particle size distribution with an average particle size of 110-µm. This flow also represents the maximum flow prior to which bypass occurs. VortSentry Swirl Chamber Typical Depth Water Quality Flow1 Max. Size Sediment Model Diameter Below Invert 110 µm Inlet/Outlet Storage ft m ft m cfs L/s in mm yd3 m3 VS30* 3 0.9 5.8 1.8 0.26 7.4 12 300 0.8 0.6 VS40 4 1.2 7.0 2.1 0.58 16.4 18 460 1.4 1.1 VS50* 5 1.5 8.0 2.4 1.1 31.1 18 460 2.2 1.7 VS60 6 1.8 8.9 2.7 1.8 51.0 24 600 3.1 2.4 VS70* 7 2.1 9.7 3.0 2.7 76.5 30 750 4.3 3.3 VS80 8 2.4 10.1 3.1 3.9 110.4 36 600 5.6 4.3 VortSentry HS Swirl Chamber Typical Depth Water Quality Flow1 Max. Size Sediment Model Diameter Below Invert 240 µm Inlet/Outlet Storage ft m ft m cfs L/s in mm yd3 m3 HS36* 3 0.9 5.6 1.7 0.55 15.6 18 460 0.5 0.4 HS48 4 1.2 6.8 2.1 1.2 34.0 24 600 0.9 0.7 HS60* 5 1.5 8.0 2.4 2.2 62.3 30 760 1.5 1.1 HS72 6 1.8 9.2 2.8 3.7 104.8 36 900 2.1 1.6 HS84* 7 2.1 10.4 3.2 5.6 158.6 42 1050 2.8 2.1 HS96 8 2.4 11.5 3.5 8.1 229.4 48 1200 3.7 2.8 * Models may not be manufactured in your area. Check with your local representative for availability. 1. Water Quality Flow is based on 80% removal of a particle size distribution with an average particle size of 240-µm. This flow also represents the maximum flow prior to which bypass occurs. Notes: Systems can be sized based on a water quality flow (e.g. 1 inch storm) or on a net annual basis depending on the local regulatory requirement. When sizing based on a water quality storm, the required flow to be treated should be equal or less than the listed water quality flow for the selected system. Systems sized based on a water quality storm are generally more conservatively sized. Additional particle size distributions are available for sizing purposes upon request. Depth below invert is measured to the inside bottom of the system. This depth can be adjusted to meet specific storage or maintenance requirements. Contact our support staff for the most cost effective sizing for your area. Customer Support Installation CONTECH Stormwater Solutions’ products are some of the easiest to install in the industry. We provide comprehensive installation drawings, details and instructions, as well as full technical support on every project. Maintenance Maintenance of CONTECH Stormwater Solutions products is cost effective, straightforward and efficient. We offer a complete range of engineering planning, design and drawing, and construction services that can be tailored to your specific site needs. 800.338.1122 contech-cpi.com ©2008 CONTECH Construction Products CONTECH Construction Products Inc is your single source for hassle-free specifying and purchasing of comprehensive site solutions. CONTECH’s portfolio includes bridges, drainage, erosion control, retaining wall, sanitary sewer, soil stabilization and stormwater solutions. Nothing in this catalog should be construed as an expressed warranty or an implied warranty of merchantability or fitness for any particular purpose. See the CONTECH standard quotation or acknowledgement for applicable warranties and other terms and conditions of sale. Project Name: ServiceNet Project # 2016102 Date: November 30, 2016 Following Guidelines From "Massachusetts Stormwater Management Technical Handbook" Rv = F * Impervious Area Where: Rv = Required Recharge Volume F = Target Depth Factor Areas From AutoCAD Hydrologic Soil Group Recharge Factor Acres A 0.60 0.000 B 0.35 0.873 C 0.25 0.000 D 0.10 0.000 Rv REQUIRED = 0.025 ac ft 1,109 cf Volumes From 112 Unit 4'-0" Gallery System → 6,401 cu.ft. HydroCAD at Elev 199.80 7,421 ≥ 1,109 T = Rv / K (Btm Area) Where: T = Time (hrs) Rv = Required Recharge Volume K = Saturated Hydraulic Conductivity Table 2.3.3 K=5.34 in/hr T = 6401 / ((5.34/12) * (2902)) Per Beals & Thomas Testing T =5.0 hrs 5.0 ≤ 72 Prepared By: PMP Checked By:_______ Drawdown RECHARGE VOLUME Recharge Volume Available Storage VINSTRUCTIONS:Version 1, Automated: Mar. 4, 20081. In BMP Column, click on Blue Cell to Activate Drop Down Menu2. Select BMP from Drop Down Menu3. After BMP is selected, TSS Removal and other Columns are automatically completed.Location: B C D E FTSS Removal Starting TSS Amount RemainingBMP1Rate1Load* Removed (C*D) Load (D-E)Street Sweeping - 10% 0.101.00 0.10 0.90Deep Sump and Hooded Catch Basin 0.250.90 0.23 0.68Oil Grit Separator 0.250.68 0.17 0.51Infiltration Basin 0.800.51 0.41 0.100.000.10 0.00 0.10Total TSS Removal =90%Separate Form Needs to be Completed for Each Outlet or BMP TrainProject:ServiceNetPrepared By:PMP*Equals remaining load from previous BMP (E)Date:11/30/2016which enters the BMPTSS Removal Calculation WorksheetNorthamptonNon-automated TSS Calculation Sheetmust be used if Proprietary BMP Proposed1. From MassDEP Stormwater Handbook Vol. 1Mass. Dept. of Environmental Protection ServiceNet Drainage Report SECTION D Existing Conditions Drainage Calculations 1S Existing to Prince Street (Lot 18) 2S Existing to Lot 18 Infiltration System 3S Existing to CB (Lot 19) 4S Existing to Prince Street (Lot 19) 2P Lot 18 Infiltration System 3P CB CB 1L Discharge to Prince Street Routing Diagram for 2016102_ServiceNet Prepared by CME Associates, Inc., Printed 12/2/2016 HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcat Reach Pond Link Existing Conditions 2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 2HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (sq-ft) CN Description (subcatchment-numbers) 23,785 61 >75% Grass cover, Good, HSG B (1S, 2S, 3S) 21,150 58 Meadow, non-grazed, HSG B (4S) 24,020 98 Paved (2S, 3S, 4S) 8,240 98 Roof (2S) 64,065 55 Woods, Good, HSG B (3S, 4S) 141,260 66 TOTAL AREA Existing Conditions 2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 3HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Ground Covers (selected nodes) HSG-A (sq-ft) HSG-B (sq-ft) HSG-C (sq-ft) HSG-D (sq-ft) Other (sq-ft) Total (sq-ft) Ground Cover Subcatchment Numbers 0 23,785 0 0 0 23,785 >75% Grass cover, Good 0 21,150 0 0 0 21,150 Meadow, non-grazed 0 0 0 0 24,020 24,020 Paved 0 0 0 0 8,240 8,240 Roof 0 64,065 0 0 0 64,065 Woods, Good 0 109,000 0 0 32,260 141,260 TOTAL AREA Existing Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 4HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,990 sf 0.00% Impervious Runoff Depth=0.18"Subcatchment 1S: Existing to Prince Street Tc=5.0 min CN=61 Runoff=0.01 cfs 153 cf Runoff Area=34,740 sf 86.36% Impervious Runoff Depth=1.74"Subcatchment 2S: Existing to Lot 18 Tc=5.0 min CN=93 Runoff=2.15 cfs 5,042 cf Runoff Area=33,145 sf 1.84% Impervious Runoff Depth=0.11"Subcatchment 3S: Existing to CB (Lot 19) Flow Length=314' Tc=24.2 min CN=57 Runoff=0.01 cfs 294 cf Runoff Area=63,385 sf 2.60% Impervious Runoff Depth=0.11"Subcatchment 4S: Existing to Prince Street Flow Length=140' Tc=18.7 min CN=57 Runoff=0.02 cfs 563 cf Peak Elev=201.49' Storage=596 cf Inflow=2.15 cfs 5,042 cfPond 2P: Lot 18 Infiltration System Discarded=0.76 cfs 5,042 cf Primary=0.00 cfs 0 cf Outflow=0.76 cfs 5,042 cf Peak Elev=191.55' Inflow=0.01 cfs 294 cfPond 3P: CB 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' Outflow=0.01 cfs 294 cf Inflow=0.04 cfs 1,010 cfLink 1L: Discharge to Prince Street Primary=0.04 cfs 1,010 cf Total Runoff Area = 141,260 sf Runoff Volume = 6,053 cf Average Runoff Depth = 0.51" 77.16% Pervious = 109,000 sf 22.84% Impervious = 32,260 sf Existing Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 5HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing to Prince Street (Lot 18) Runoff = 0.01 cfs @ 12.15 hrs, Volume= 153 cf, Depth= 0.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description 9,990 61 >75% Grass cover, Good, HSG B 9,990 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: Existing to Prince Street (Lot 18) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)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 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=9,990 sf Runoff Volume=153 cf Runoff Depth=0.18" Tc=5.0 min CN=61 0.01 cfs Existing Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 6HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Existing to Lot 18 Infiltration System Runoff = 2.15 cfs @ 12.03 hrs, Volume= 5,042 cf, Depth= 1.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 8,240 98 Roof * 21,760 98 Paved 4,740 61 >75% Grass cover, Good, HSG B 34,740 93 Weighted Average 4,740 13.64% Pervious Area 30,000 86.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 2S: Existing to Lot 18 Infiltration System Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=34,740 sf Runoff Volume=5,042 cf Runoff Depth=1.74" Tc=5.0 min CN=93 2.15 cfs Existing Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 7HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Existing to CB (Lot 19) Runoff = 0.01 cfs @ 12.83 hrs, Volume= 294 cf, Depth= 0.11" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 610 98 Paved 9,055 61 >75% Grass cover, Good, HSG B 23,480 55 Woods, Good, HSG B 33,145 57 Weighted Average 32,535 98.16% Pervious Area 610 1.84% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.5 75 0.0150 0.06 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 4.0 180 0.0230 0.76 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.6 37 0.0230 1.06 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.1 22 0.1700 2.89 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 24.2 314 Total Existing Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 8HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcatchment 3S: Existing to CB (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.013 0.012 0.011 0.011 0.01 0.01 0.009 0.009 0.008 0.008 0.007 0.007 0.006 0.006 0.005 0.005 0.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0.000 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=33,145 sf Runoff Volume=294 cf Runoff Depth=0.11" Flow Length=314' Tc=24.2 min CN=57 0.01 cfs Existing Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 9HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Existing to Prince Street (Lot 19) Runoff = 0.02 cfs @ 12.70 hrs, Volume= 563 cf, Depth= 0.11" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 1,650 98 Paved 21,150 58 Meadow, non-grazed, HSG B 40,585 55 Woods, Good, HSG B 63,385 57 Weighted Average 61,735 97.40% Pervious Area 1,650 2.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 40 0.0150 0.06 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 6.2 35 0.0570 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 0.7 65 0.0900 1.50 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 18.7 140 Total Subcatchment 4S: Existing to Prince Street (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.025 0.024 0.023 0.022 0.021 0.02 0.019 0.018 0.017 0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=63,385 sf Runoff Volume=563 cf Runoff Depth=0.11" Flow Length=140' Tc=18.7 min CN=57 0.02 cfs Existing Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 10HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 2P: Lot 18 Infiltration System Inflow Area = 34,740 sf, 86.36% Impervious, Inflow Depth = 1.74" for 1-yr event Inflow = 2.15 cfs @ 12.03 hrs, Volume= 5,042 cf Outflow = 0.76 cfs @ 11.96 hrs, Volume= 5,042 cf, Atten= 64%, Lag= 0.0 min Discarded = 0.76 cfs @ 11.96 hrs, Volume= 5,042 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 201.49' @ 12.16 hrs Surf.Area= 6,187 sf Storage= 596 cf Plug-Flow detention time= 3.6 min calculated for 5,042 cf (100% of inflow) Center-of-Mass det. time= 3.6 min ( 814.0 - 810.4 ) Volume Invert Avail.Storage Storage Description #1 201.20' 3,465 cf Custom Stage Data (Prismatic) Listed below (Recalc) 12,993 cf Overall - 4,331 cf Embedded = 8,662 cf x 40.0% Voids #2 201.60' 1,692 cf 12.0" Round Pipe Storage Inside #1 L= 2,154.0' 4,331 cf Overall - 3.6" Wall Thickness = 1,692 cf 5,156 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 201.20 6,187 0 0 203.30 6,187 12,993 12,993 Device Routing Invert Outlet Devices #1 Discarded 201.20'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.00'12.0" Round Culvert L= 40.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.00' / 194.80' S= 0.0300 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 202.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.76 cfs @ 11.96 hrs HW=201.22' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=201.20' (Free Discharge) 2=Culvert (Passes 0.00 cfs of 8.20 cfs potential flow) 3=Orifice/Grate ( Controls 0.00 cfs) Existing Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 11HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 2P: Lot 18 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=34,740 sf Peak Elev=201.49' Storage=596 cf 2.15 cfs 0.76 cfs 0.76 cfs 0.00 cfs Existing Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 12HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 3P: CB Inflow Area = 67,885 sf, 45.09% Impervious, Inflow Depth = 0.05" for 1-yr event Inflow = 0.01 cfs @ 12.83 hrs, Volume= 294 cf Outflow = 0.01 cfs @ 12.83 hrs, Volume= 294 cf, Atten= 0%, Lag= 0.0 min Primary = 0.01 cfs @ 12.83 hrs, Volume= 294 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 191.55' @ 12.83 hrs Flood Elev= 194.27' Device Routing Invert Outlet Devices #1 Primary 191.50'12.0" Round Culvert L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 191.50' / 189.00' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.01 cfs @ 12.83 hrs HW=191.55' (Free Discharge) 1=Culvert (Inlet Controls 0.01 cfs @ 0.75 fps) Pond 3P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.013 0.012 0.011 0.011 0.01 0.01 0.009 0.009 0.008 0.008 0.007 0.007 0.006 0.006 0.005 0.005 0.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0.000 0 Inflow Area=67,885 sf Peak Elev=191.55' 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' 0.01 cfs 0.01 cfs Existing Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 13HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Link 1L: Discharge to Prince Street Inflow Area = 141,260 sf, 22.84% Impervious, Inflow Depth = 0.09" for 1-yr event Inflow = 0.04 cfs @ 12.73 hrs, Volume= 1,010 cf Primary = 0.04 cfs @ 12.73 hrs, Volume= 1,010 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Link 1L: Discharge to Prince Street Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.044 0.042 0.04 0.038 0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Inflow Area=141,260 sf 0.04 cfs 0.04 cfs Existing Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 14HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,990 sf 0.00% Impervious Runoff Depth=0.40"Subcatchment 1S: Existing to Prince Street Tc=5.0 min CN=61 Runoff=0.07 cfs 333 cf Runoff Area=34,740 sf 86.36% Impervious Runoff Depth=2.34"Subcatchment 2S: Existing to Lot 18 Tc=5.0 min CN=93 Runoff=2.69 cfs 6,775 cf Runoff Area=33,145 sf 1.84% Impervious Runoff Depth=0.27"Subcatchment 3S: Existing to CB (Lot 19) Flow Length=314' Tc=24.2 min CN=57 Runoff=0.06 cfs 757 cf Runoff Area=63,385 sf 2.60% Impervious Runoff Depth=0.27"Subcatchment 4S: Existing to Prince Street Flow Length=140' Tc=18.7 min CN=57 Runoff=0.11 cfs 1,447 cf Peak Elev=201.67' Storage=906 cf Inflow=2.69 cfs 6,775 cfPond 2P: Lot 18 Infiltration System Discarded=0.76 cfs 6,775 cf Primary=0.00 cfs 0 cf Outflow=0.76 cfs 6,775 cf Peak Elev=191.61' Inflow=0.06 cfs 757 cfPond 3P: CB 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' Outflow=0.06 cfs 757 cf Inflow=0.20 cfs 2,537 cfLink 1L: Discharge to Prince Street Primary=0.20 cfs 2,537 cf Total Runoff Area = 141,260 sf Runoff Volume = 9,312 cf Average Runoff Depth = 0.79" 77.16% Pervious = 109,000 sf 22.84% Impervious = 32,260 sf Existing Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 15HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing to Prince Street (Lot 18) Runoff = 0.07 cfs @ 12.05 hrs, Volume= 333 cf, Depth= 0.40" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description 9,990 61 >75% Grass cover, Good, HSG B 9,990 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: Existing to Prince Street (Lot 18) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=9,990 sf Runoff Volume=333 cf Runoff Depth=0.40" Tc=5.0 min CN=61 0.07 cfs Existing Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 16HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Existing to Lot 18 Infiltration System Runoff = 2.69 cfs @ 12.03 hrs, Volume= 6,775 cf, Depth= 2.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 8,240 98 Roof * 21,760 98 Paved 4,740 61 >75% Grass cover, Good, HSG B 34,740 93 Weighted Average 4,740 13.64% Pervious Area 30,000 86.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 2S: Existing to Lot 18 Infiltration System Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=34,740 sf Runoff Volume=6,775 cf Runoff Depth=2.34" Tc=5.0 min CN=93 2.69 cfs Existing Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 17HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Existing to CB (Lot 19) Runoff = 0.06 cfs @ 12.55 hrs, Volume= 757 cf, Depth= 0.27" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 610 98 Paved 9,055 61 >75% Grass cover, Good, HSG B 23,480 55 Woods, Good, HSG B 33,145 57 Weighted Average 32,535 98.16% Pervious Area 610 1.84% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.5 75 0.0150 0.06 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 4.0 180 0.0230 0.76 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.6 37 0.0230 1.06 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.1 22 0.1700 2.89 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 24.2 314 Total Existing Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 18HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcatchment 3S: Existing to CB (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (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 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=33,145 sf Runoff Volume=757 cf Runoff Depth=0.27" Flow Length=314' Tc=24.2 min CN=57 0.06 cfs Existing Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 19HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Existing to Prince Street (Lot 19) Runoff = 0.11 cfs @ 12.41 hrs, Volume= 1,447 cf, Depth= 0.27" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 1,650 98 Paved 21,150 58 Meadow, non-grazed, HSG B 40,585 55 Woods, Good, HSG B 63,385 57 Weighted Average 61,735 97.40% Pervious Area 1,650 2.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 40 0.0150 0.06 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 6.2 35 0.0570 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 0.7 65 0.0900 1.50 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 18.7 140 Total Subcatchment 4S: Existing to Prince Street (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)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 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=63,385 sf Runoff Volume=1,447 cf Runoff Depth=0.27" Flow Length=140' Tc=18.7 min CN=57 0.11 cfs Existing Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 20HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 2P: Lot 18 Infiltration System Inflow Area = 34,740 sf, 86.36% Impervious, Inflow Depth = 2.34" for 2-yr event Inflow = 2.69 cfs @ 12.03 hrs, Volume= 6,775 cf Outflow = 0.76 cfs @ 11.94 hrs, Volume= 6,775 cf, Atten= 72%, Lag= 0.0 min Discarded = 0.76 cfs @ 11.94 hrs, Volume= 6,775 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 201.67' @ 12.20 hrs Surf.Area= 6,187 sf Storage= 906 cf Plug-Flow detention time= 5.2 min calculated for 6,773 cf (100% of inflow) Center-of-Mass det. time= 5.2 min ( 808.1 - 802.9 ) Volume Invert Avail.Storage Storage Description #1 201.20' 3,465 cf Custom Stage Data (Prismatic) Listed below (Recalc) 12,993 cf Overall - 4,331 cf Embedded = 8,662 cf x 40.0% Voids #2 201.60' 1,692 cf 12.0" Round Pipe Storage Inside #1 L= 2,154.0' 4,331 cf Overall - 3.6" Wall Thickness = 1,692 cf 5,156 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 201.20 6,187 0 0 203.30 6,187 12,993 12,993 Device Routing Invert Outlet Devices #1 Discarded 201.20'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.00'12.0" Round Culvert L= 40.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.00' / 194.80' S= 0.0300 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 202.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.76 cfs @ 11.94 hrs HW=201.22' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=201.20' (Free Discharge) 2=Culvert (Passes 0.00 cfs of 8.20 cfs potential flow) 3=Orifice/Grate ( Controls 0.00 cfs) Existing Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 21HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 2P: Lot 18 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=34,740 sf Peak Elev=201.67' Storage=906 cf 2.69 cfs 0.76 cfs 0.76 cfs 0.00 cfs Existing Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 22HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 3P: CB Inflow Area = 67,885 sf, 45.09% Impervious, Inflow Depth = 0.13" for 2-yr event Inflow = 0.06 cfs @ 12.55 hrs, Volume= 757 cf Outflow = 0.06 cfs @ 12.55 hrs, Volume= 757 cf, Atten= 0%, Lag= 0.0 min Primary = 0.06 cfs @ 12.55 hrs, Volume= 757 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 191.61' @ 12.55 hrs Flood Elev= 194.27' Device Routing Invert Outlet Devices #1 Primary 191.50'12.0" Round Culvert L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 191.50' / 189.00' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.06 cfs @ 12.55 hrs HW=191.61' (Free Discharge) 1=Culvert (Inlet Controls 0.06 cfs @ 1.15 fps) Pond 3P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (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=67,885 sf Peak Elev=191.61' 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' 0.06 cfs 0.06 cfs Existing Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 23HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Link 1L: Discharge to Prince Street Inflow Area = 141,260 sf, 22.84% Impervious, Inflow Depth = 0.22" for 2-yr event Inflow = 0.20 cfs @ 12.45 hrs, Volume= 2,537 cf Primary = 0.20 cfs @ 12.45 hrs, Volume= 2,537 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Link 1L: Discharge to Prince Street Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=141,260 sf 0.20 cfs 0.20 cfs Existing Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 24HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,990 sf 0.00% Impervious Runoff Depth=1.34"Subcatchment 1S: Existing to Prince Street Tc=5.0 min CN=61 Runoff=0.37 cfs 1,115 cf Runoff Area=34,740 sf 86.36% Impervious Runoff Depth=4.15"Subcatchment 2S: Existing to Lot 18 Tc=5.0 min CN=93 Runoff=4.23 cfs 12,011 cf Runoff Area=33,145 sf 1.84% Impervious Runoff Depth=1.08"Subcatchment 3S: Existing to CB (Lot 19) Flow Length=314' Tc=24.2 min CN=57 Runoff=0.44 cfs 2,978 cf Runoff Area=63,385 sf 2.60% Impervious Runoff Depth=1.08"Subcatchment 4S: Existing to Prince Street Flow Length=140' Tc=18.7 min CN=57 Runoff=0.96 cfs 5,694 cf Peak Elev=202.04' Storage=2,022 cf Inflow=4.23 cfs 12,011 cfPond 2P: Lot 18 Infiltration System Discarded=0.76 cfs 12,011 cf Primary=0.00 cfs 0 cf Outflow=0.76 cfs 12,011 cf Peak Elev=191.83' Inflow=0.44 cfs 2,978 cfPond 3P: CB 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' Outflow=0.44 cfs 2,978 cf Inflow=1.48 cfs 9,787 cfLink 1L: Discharge to Prince Street Primary=1.48 cfs 9,787 cf Total Runoff Area = 141,260 sf Runoff Volume = 21,797 cf Average Runoff Depth = 1.85" 77.16% Pervious = 109,000 sf 22.84% Impervious = 32,260 sf Existing Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 25HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing to Prince Street (Lot 18) Runoff = 0.37 cfs @ 12.03 hrs, Volume= 1,115 cf, Depth= 1.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description 9,990 61 >75% Grass cover, Good, HSG B 9,990 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: Existing to Prince Street (Lot 18) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (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 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=9,990 sf Runoff Volume=1,115 cf Runoff Depth=1.34" Tc=5.0 min CN=61 0.37 cfs Existing Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 26HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Existing to Lot 18 Infiltration System Runoff = 4.23 cfs @ 12.03 hrs, Volume= 12,011 cf, Depth= 4.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 8,240 98 Roof * 21,760 98 Paved 4,740 61 >75% Grass cover, Good, HSG B 34,740 93 Weighted Average 4,740 13.64% Pervious Area 30,000 86.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 2S: Existing to Lot 18 Infiltration System Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=34,740 sf Runoff Volume=12,011 cf Runoff Depth=4.15" Tc=5.0 min CN=93 4.23 cfs Existing Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 27HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Existing to CB (Lot 19) Runoff = 0.44 cfs @ 12.32 hrs, Volume= 2,978 cf, Depth= 1.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 610 98 Paved 9,055 61 >75% Grass cover, Good, HSG B 23,480 55 Woods, Good, HSG B 33,145 57 Weighted Average 32,535 98.16% Pervious Area 610 1.84% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.5 75 0.0150 0.06 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 4.0 180 0.0230 0.76 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.6 37 0.0230 1.06 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.1 22 0.1700 2.89 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 24.2 314 Total Existing Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 28HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcatchment 3S: Existing to CB (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=33,145 sf Runoff Volume=2,978 cf Runoff Depth=1.08" Flow Length=314' Tc=24.2 min CN=57 0.44 cfs Existing Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 29HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Existing to Prince Street (Lot 19) Runoff = 0.96 cfs @ 12.24 hrs, Volume= 5,694 cf, Depth= 1.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 1,650 98 Paved 21,150 58 Meadow, non-grazed, HSG B 40,585 55 Woods, Good, HSG B 63,385 57 Weighted Average 61,735 97.40% Pervious Area 1,650 2.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 40 0.0150 0.06 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 6.2 35 0.0570 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 0.7 65 0.0900 1.50 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 18.7 140 Total Subcatchment 4S: Existing to Prince Street (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=63,385 sf Runoff Volume=5,694 cf Runoff Depth=1.08" Flow Length=140' Tc=18.7 min CN=57 0.96 cfs Existing Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 30HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 2P: Lot 18 Infiltration System Inflow Area = 34,740 sf, 86.36% Impervious, Inflow Depth = 4.15" for 10-yr event Inflow = 4.23 cfs @ 12.03 hrs, Volume= 12,011 cf Outflow = 0.76 cfs @ 11.80 hrs, Volume= 12,011 cf, Atten= 82%, Lag= 0.0 min Discarded = 0.76 cfs @ 11.80 hrs, Volume= 12,011 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 202.04' @ 12.35 hrs Surf.Area= 6,187 sf Storage= 2,022 cf Plug-Flow detention time= 11.7 min calculated for 12,007 cf (100% of inflow) Center-of-Mass det. time= 11.7 min ( 797.8 - 786.1 ) Volume Invert Avail.Storage Storage Description #1 201.20' 3,465 cf Custom Stage Data (Prismatic) Listed below (Recalc) 12,993 cf Overall - 4,331 cf Embedded = 8,662 cf x 40.0% Voids #2 201.60' 1,692 cf 12.0" Round Pipe Storage Inside #1 L= 2,154.0' 4,331 cf Overall - 3.6" Wall Thickness = 1,692 cf 5,156 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 201.20 6,187 0 0 203.30 6,187 12,993 12,993 Device Routing Invert Outlet Devices #1 Discarded 201.20'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.00'12.0" Round Culvert L= 40.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.00' / 194.80' S= 0.0300 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 202.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.76 cfs @ 11.80 hrs HW=201.22' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=201.20' (Free Discharge) 2=Culvert (Passes 0.00 cfs of 8.20 cfs potential flow) 3=Orifice/Grate ( Controls 0.00 cfs) Existing Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 31HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 2P: Lot 18 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Inflow Area=34,740 sf Peak Elev=202.04' Storage=2,022 cf 4.23 cfs 0.76 cfs 0.76 cfs 0.00 cfs Existing Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 32HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 3P: CB Inflow Area = 67,885 sf, 45.09% Impervious, Inflow Depth = 0.53" for 10-yr event Inflow = 0.44 cfs @ 12.32 hrs, Volume= 2,978 cf Outflow = 0.44 cfs @ 12.32 hrs, Volume= 2,978 cf, Atten= 0%, Lag= 0.0 min Primary = 0.44 cfs @ 12.32 hrs, Volume= 2,978 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 191.83' @ 12.32 hrs Flood Elev= 194.27' Device Routing Invert Outlet Devices #1 Primary 191.50'12.0" Round Culvert L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 191.50' / 189.00' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.44 cfs @ 12.32 hrs HW=191.83' (Free Discharge) 1=Culvert (Inlet Controls 0.44 cfs @ 1.95 fps) Pond 3P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=67,885 sf Peak Elev=191.83' 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' 0.44 cfs 0.44 cfs Existing Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 33HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Link 1L: Discharge to Prince Street Inflow Area = 141,260 sf, 22.84% Impervious, Inflow Depth = 0.83" for 10-yr event Inflow = 1.48 cfs @ 12.24 hrs, Volume= 9,787 cf Primary = 1.48 cfs @ 12.24 hrs, Volume= 9,787 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Link 1L: Discharge to Prince Street Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=141,260 sf 1.48 cfs 1.48 cfs Existing Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 34HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,990 sf 0.00% Impervious Runoff Depth=2.09"Subcatchment 1S: Existing to Prince Street Tc=5.0 min CN=61 Runoff=0.60 cfs 1,737 cf Runoff Area=34,740 sf 86.36% Impervious Runoff Depth=5.30"Subcatchment 2S: Existing to Lot 18 Tc=5.0 min CN=93 Runoff=5.22 cfs 15,347 cf Runoff Area=33,145 sf 1.84% Impervious Runoff Depth=1.75"Subcatchment 3S: Existing to CB (Lot 19) Flow Length=314' Tc=24.2 min CN=57 Runoff=0.77 cfs 4,832 cf Runoff Area=63,385 sf 2.60% Impervious Runoff Depth=1.75"Subcatchment 4S: Existing to Prince Street Flow Length=140' Tc=18.7 min CN=57 Runoff=1.69 cfs 9,240 cf Peak Elev=202.31' Storage=2,888 cf Inflow=5.22 cfs 15,347 cfPond 2P: Lot 18 Infiltration System Discarded=0.76 cfs 15,347 cf Primary=0.00 cfs 0 cf Outflow=0.76 cfs 15,347 cf Peak Elev=191.95' Inflow=0.77 cfs 4,832 cfPond 3P: CB 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' Outflow=0.77 cfs 4,832 cf Inflow=2.59 cfs 15,809 cfLink 1L: Discharge to Prince Street Primary=2.59 cfs 15,809 cf Total Runoff Area = 141,260 sf Runoff Volume = 31,155 cf Average Runoff Depth = 2.65" 77.16% Pervious = 109,000 sf 22.84% Impervious = 32,260 sf Existing Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 35HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing to Prince Street (Lot 18) Runoff = 0.60 cfs @ 12.03 hrs, Volume= 1,737 cf, Depth= 2.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description 9,990 61 >75% Grass cover, Good, HSG B 9,990 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: Existing to Prince Street (Lot 18) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=9,990 sf Runoff Volume=1,737 cf Runoff Depth=2.09" Tc=5.0 min CN=61 0.60 cfs Existing Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 36HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Existing to Lot 18 Infiltration System Runoff = 5.22 cfs @ 12.03 hrs, Volume= 15,347 cf, Depth= 5.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 8,240 98 Roof * 21,760 98 Paved 4,740 61 >75% Grass cover, Good, HSG B 34,740 93 Weighted Average 4,740 13.64% Pervious Area 30,000 86.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 2S: Existing to Lot 18 Infiltration System Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=34,740 sf Runoff Volume=15,347 cf Runoff Depth=5.30" Tc=5.0 min CN=93 5.22 cfs Existing Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 37HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Existing to CB (Lot 19) Runoff = 0.77 cfs @ 12.29 hrs, Volume= 4,832 cf, Depth= 1.75" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 610 98 Paved 9,055 61 >75% Grass cover, Good, HSG B 23,480 55 Woods, Good, HSG B 33,145 57 Weighted Average 32,535 98.16% Pervious Area 610 1.84% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.5 75 0.0150 0.06 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 4.0 180 0.0230 0.76 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.6 37 0.0230 1.06 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.1 22 0.1700 2.89 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 24.2 314 Total Existing Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 38HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcatchment 3S: Existing to CB (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=33,145 sf Runoff Volume=4,832 cf Runoff Depth=1.75" Flow Length=314' Tc=24.2 min CN=57 0.77 cfs Existing Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 39HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Existing to Prince Street (Lot 19) Runoff = 1.69 cfs @ 12.22 hrs, Volume= 9,240 cf, Depth= 1.75" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 1,650 98 Paved 21,150 58 Meadow, non-grazed, HSG B 40,585 55 Woods, Good, HSG B 63,385 57 Weighted Average 61,735 97.40% Pervious Area 1,650 2.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 40 0.0150 0.06 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 6.2 35 0.0570 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 0.7 65 0.0900 1.50 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 18.7 140 Total Subcatchment 4S: Existing to Prince Street (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=63,385 sf Runoff Volume=9,240 cf Runoff Depth=1.75" Flow Length=140' Tc=18.7 min CN=57 1.69 cfs Existing Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 40HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 2P: Lot 18 Infiltration System Inflow Area = 34,740 sf, 86.36% Impervious, Inflow Depth = 5.30" for 25-yr event Inflow = 5.22 cfs @ 12.03 hrs, Volume= 15,347 cf Outflow = 0.76 cfs @ 11.70 hrs, Volume= 15,347 cf, Atten= 85%, Lag= 0.0 min Discarded = 0.76 cfs @ 11.70 hrs, Volume= 15,347 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 202.31' @ 12.46 hrs Surf.Area= 6,187 sf Storage= 2,888 cf Plug-Flow detention time= 17.5 min calculated for 15,342 cf (100% of inflow) Center-of-Mass det. time= 17.4 min ( 796.2 - 778.8 ) Volume Invert Avail.Storage Storage Description #1 201.20' 3,465 cf Custom Stage Data (Prismatic) Listed below (Recalc) 12,993 cf Overall - 4,331 cf Embedded = 8,662 cf x 40.0% Voids #2 201.60' 1,692 cf 12.0" Round Pipe Storage Inside #1 L= 2,154.0' 4,331 cf Overall - 3.6" Wall Thickness = 1,692 cf 5,156 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 201.20 6,187 0 0 203.30 6,187 12,993 12,993 Device Routing Invert Outlet Devices #1 Discarded 201.20'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.00'12.0" Round Culvert L= 40.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.00' / 194.80' S= 0.0300 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 202.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.76 cfs @ 11.70 hrs HW=201.22' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=201.20' (Free Discharge) 2=Culvert (Passes 0.00 cfs of 8.20 cfs potential flow) 3=Orifice/Grate ( Controls 0.00 cfs) Existing Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 41HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 2P: Lot 18 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=34,740 sf Peak Elev=202.31' Storage=2,888 cf 5.22 cfs 0.76 cfs 0.76 cfs 0.00 cfs Existing Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 42HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 3P: CB Inflow Area = 67,885 sf, 45.09% Impervious, Inflow Depth = 0.85" for 25-yr event Inflow = 0.77 cfs @ 12.29 hrs, Volume= 4,832 cf Outflow = 0.77 cfs @ 12.29 hrs, Volume= 4,832 cf, Atten= 0%, Lag= 0.0 min Primary = 0.77 cfs @ 12.29 hrs, Volume= 4,832 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 191.95' @ 12.29 hrs Flood Elev= 194.27' Device Routing Invert Outlet Devices #1 Primary 191.50'12.0" Round Culvert L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 191.50' / 189.00' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.77 cfs @ 12.29 hrs HW=191.95' (Free Discharge) 1=Culvert (Inlet Controls 0.77 cfs @ 2.27 fps) Pond 3P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=67,885 sf Peak Elev=191.95' 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' 0.77 cfs 0.77 cfs Existing Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 43HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Link 1L: Discharge to Prince Street Inflow Area = 141,260 sf, 22.84% Impervious, Inflow Depth = 1.34" for 25-yr event Inflow = 2.59 cfs @ 12.24 hrs, Volume= 15,809 cf Primary = 2.59 cfs @ 12.24 hrs, Volume= 15,809 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Link 1L: Discharge to Prince Street Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=141,260 sf 2.59 cfs 2.59 cfs Existing Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 44HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,990 sf 0.00% Impervious Runoff Depth=3.38"Subcatchment 1S: Existing to Prince Street Tc=5.0 min CN=61 Runoff=0.97 cfs 2,811 cf Runoff Area=34,740 sf 86.36% Impervious Runoff Depth=7.07"Subcatchment 2S: Existing to Lot 18 Tc=5.0 min CN=93 Runoff=6.61 cfs 20,477 cf Runoff Area=33,145 sf 1.84% Impervious Runoff Depth=2.94"Subcatchment 3S: Existing to CB (Lot 19) Flow Length=314' Tc=24.2 min CN=57 Runoff=1.34 cfs 8,116 cf Runoff Area=63,385 sf 2.60% Impervious Runoff Depth=2.94"Subcatchment 4S: Existing to Prince Street Flow Length=140' Tc=18.7 min CN=57 Runoff=2.94 cfs 15,521 cf Peak Elev=202.73' Storage=3,843 cf Inflow=6.61 cfs 20,477 cfPond 2P: Lot 18 Infiltration System Discarded=0.76 cfs 19,740 cf Primary=0.72 cfs 737 cf Outflow=1.48 cfs 20,477 cf Peak Elev=192.30' Inflow=2.04 cfs 8,853 cfPond 3P: CB 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' Outflow=2.04 cfs 8,853 cf Inflow=5.17 cfs 27,184 cfLink 1L: Discharge to Prince Street Primary=5.17 cfs 27,184 cf Total Runoff Area = 141,260 sf Runoff Volume = 46,925 cf Average Runoff Depth = 3.99" 77.16% Pervious = 109,000 sf 22.84% Impervious = 32,260 sf Existing Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 45HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing to Prince Street (Lot 18) Runoff = 0.97 cfs @ 12.03 hrs, Volume= 2,811 cf, Depth= 3.38" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description 9,990 61 >75% Grass cover, Good, HSG B 9,990 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: Existing to Prince Street (Lot 18) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=9,990 sf Runoff Volume=2,811 cf Runoff Depth=3.38" Tc=5.0 min CN=61 0.97 cfs Existing Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 46HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Existing to Lot 18 Infiltration System Runoff = 6.61 cfs @ 12.03 hrs, Volume= 20,477 cf, Depth= 7.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 8,240 98 Roof * 21,760 98 Paved 4,740 61 >75% Grass cover, Good, HSG B 34,740 93 Weighted Average 4,740 13.64% Pervious Area 30,000 86.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 2S: Existing to Lot 18 Infiltration System Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=34,740 sf Runoff Volume=20,477 cf Runoff Depth=7.07" Tc=5.0 min CN=93 6.61 cfs Existing Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 47HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Existing to CB (Lot 19) Runoff = 1.34 cfs @ 12.29 hrs, Volume= 8,116 cf, Depth= 2.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 610 98 Paved 9,055 61 >75% Grass cover, Good, HSG B 23,480 55 Woods, Good, HSG B 33,145 57 Weighted Average 32,535 98.16% Pervious Area 610 1.84% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.5 75 0.0150 0.06 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 4.0 180 0.0230 0.76 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.6 37 0.0230 1.06 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.1 22 0.1700 2.89 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 24.2 314 Total Existing Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 48HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcatchment 3S: Existing to CB (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=33,145 sf Runoff Volume=8,116 cf Runoff Depth=2.94" Flow Length=314' Tc=24.2 min CN=57 1.34 cfs Existing Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 49HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Existing to Prince Street (Lot 19) Runoff = 2.94 cfs @ 12.22 hrs, Volume= 15,521 cf, Depth= 2.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 1,650 98 Paved 21,150 58 Meadow, non-grazed, HSG B 40,585 55 Woods, Good, HSG B 63,385 57 Weighted Average 61,735 97.40% Pervious Area 1,650 2.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 40 0.0150 0.06 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 6.2 35 0.0570 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 0.7 65 0.0900 1.50 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 18.7 140 Total Subcatchment 4S: Existing to Prince Street (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=63,385 sf Runoff Volume=15,521 cf Runoff Depth=2.94" Flow Length=140' Tc=18.7 min CN=57 2.94 cfs Existing Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 50HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 2P: Lot 18 Infiltration System Inflow Area = 34,740 sf, 86.36% Impervious, Inflow Depth = 7.07" for 100-yr event Inflow = 6.61 cfs @ 12.03 hrs, Volume= 20,477 cf Outflow = 1.48 cfs @ 12.26 hrs, Volume= 20,477 cf, Atten= 78%, Lag= 14.1 min Discarded = 0.76 cfs @ 11.58 hrs, Volume= 19,740 cf Primary = 0.72 cfs @ 12.26 hrs, Volume= 737 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 202.73' @ 12.26 hrs Surf.Area= 6,187 sf Storage= 3,843 cf Plug-Flow detention time= 22.4 min calculated for 20,472 cf (100% of inflow) Center-of-Mass det. time= 22.4 min ( 792.9 - 770.5 ) Volume Invert Avail.Storage Storage Description #1 201.20' 3,465 cf Custom Stage Data (Prismatic) Listed below (Recalc) 12,993 cf Overall - 4,331 cf Embedded = 8,662 cf x 40.0% Voids #2 201.60' 1,692 cf 12.0" Round Pipe Storage Inside #1 L= 2,154.0' 4,331 cf Overall - 3.6" Wall Thickness = 1,692 cf 5,156 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 201.20 6,187 0 0 203.30 6,187 12,993 12,993 Device Routing Invert Outlet Devices #1 Discarded 201.20'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.00'12.0" Round Culvert L= 40.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.00' / 194.80' S= 0.0300 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 202.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.76 cfs @ 11.58 hrs HW=201.22' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.71 cfs @ 12.26 hrs HW=202.73' (Free Discharge) 2=Culvert (Passes 0.71 cfs of 9.44 cfs potential flow) 3=Orifice/Grate (Weir Controls 0.71 cfs @ 1.34 fps) Existing Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 51HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 2P: Lot 18 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=34,740 sf Peak Elev=202.73' Storage=3,843 cf 6.61 cfs 1.48 cfs 0.76 cfs 0.72 cfs Existing Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 52HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 3P: CB Inflow Area = 67,885 sf, 45.09% Impervious, Inflow Depth = 1.56" for 100-yr event Inflow = 2.04 cfs @ 12.27 hrs, Volume= 8,853 cf Outflow = 2.04 cfs @ 12.27 hrs, Volume= 8,853 cf, Atten= 0%, Lag= 0.0 min Primary = 2.04 cfs @ 12.27 hrs, Volume= 8,853 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 192.30' @ 12.27 hrs Flood Elev= 194.27' Device Routing Invert Outlet Devices #1 Primary 191.50'12.0" Round Culvert L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 191.50' / 189.00' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=2.04 cfs @ 12.27 hrs HW=192.30' (Free Discharge) 1=Culvert (Inlet Controls 2.04 cfs @ 3.04 fps) Pond 3P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=67,885 sf Peak Elev=192.30' 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' 2.04 cfs 2.04 cfs Existing Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 12/2/2016Prepared by CME Associates, Inc. Page 53HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Link 1L: Discharge to Prince Street Inflow Area = 141,260 sf, 22.84% Impervious, Inflow Depth = 2.31" for 100-yr event Inflow = 5.17 cfs @ 12.24 hrs, Volume= 27,184 cf Primary = 5.17 cfs @ 12.24 hrs, Volume= 27,184 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Link 1L: Discharge to Prince Street Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=141,260 sf 5.17 cfs 5.17 cfs ServiceNet Drainage Report SECTION E Proposed Conditions Drainage Calculations 10S Proposed to Prince Street (Lot 18) 20S Existing to Lot 18 Infiltration System 30S Proposed to CB (Lot 19) 40S Proposed to Prince Street (Lot 19) 41S Proposed to CB 42S Proposed to CB 43S Proposed to CB 44S Proposed to CB 45S Proposed to YD 52S Roof 20P Lot 18 Infiltration System 30PCB CB 41PCB CB 42PCB CB 43PCB CB 44PCB CB 45PCB YD 46PCB DMH 47PCB DMH 48PCB DMH 49PCB Hydrodynamic Separator Unit 50P CB DMH 51P Lot 19 Infiltration System 10L Discharge to Prince Street Routing Diagram for 2016102_ServiceNet Prepared by CME Associates, Inc., Printed 1/18/2017 HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcat Reach Pond Link Proposed Conditions 2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 2HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (sq-ft) CN Description (subcatchment-numbers) 28,175 61 >75% Grass cover, Good, HSG B (10S, 20S, 30S, 41S, 42S, 43S, 44S, 45S) 33,240 58 Meadow, non-grazed, HSG B (40S) 53,225 98 Paved (20S, 40S, 41S, 42S, 43S, 44S, 45S) 17,080 98 Roof (20S, 52S) 9,540 55 Woods, Good, HSG B (40S, 41S, 45S) 141,260 78 TOTAL AREA Proposed Conditions 2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 3HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Ground Covers (selected nodes) HSG-A (sq-ft) HSG-B (sq-ft) HSG-C (sq-ft) HSG-D (sq-ft) Other (sq-ft) Total (sq-ft) Ground Cover Subcatchment Numbers 0 28,175 0 0 0 28,175 >75% Grass cover, Good 0 33,240 0 0 0 33,240 Meadow, non-grazed 0 0 0 0 53,225 53,225 Paved 0 0 0 0 17,080 17,080 Roof 0 9,540 0 0 0 9,540 Woods, Good 0 70,955 0 0 70,305 141,260 TOTAL AREA Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 4HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,990 sf 0.00% Impervious Runoff Depth=0.18"Subcatchment 10S: Proposed to Prince Tc=5.0 min CN=61 Runoff=0.01 cfs 153 cf Runoff Area=34,740 sf 86.36% Impervious Runoff Depth=1.74"Subcatchment 20S: Existing to Lot 18 Tc=5.0 min CN=93 Runoff=2.15 cfs 5,042 cf Runoff Area=8,700 sf 0.00% Impervious Runoff Depth=0.18"Subcatchment 30S: Proposed to CB (Lot 19) Flow Length=150' Tc=7.4 min CN=61 Runoff=0.01 cfs 134 cf Runoff Area=41,130 sf 3.04% Impervious Runoff Depth=0.14"Subcatchment 40S: Proposed to Prince Flow Length=85' Tc=12.4 min CN=59 Runoff=0.03 cfs 489 cf Runoff Area=14,745 sf 87.49% Impervious Runoff Depth=1.74"Subcatchment 41S: Proposed to CB Tc=5.0 min CN=93 Runoff=0.91 cfs 2,140 cf Runoff Area=2,675 sf 85.05% Impervious Runoff Depth=1.66"Subcatchment 42S: Proposed to CB Tc=5.0 min CN=92 Runoff=0.16 cfs 369 cf Runoff Area=6,225 sf 91.81% Impervious Runoff Depth=1.92"Subcatchment 43S: Proposed to CB Tc=5.0 min CN=95 Runoff=0.42 cfs 998 cf Runoff Area=10,045 sf 89.85% Impervious Runoff Depth=1.83"Subcatchment 44S: Proposed to CB Tc=5.0 min CN=94 Runoff=0.65 cfs 1,533 cf Runoff Area=4,170 sf 7.19% Impervious Runoff Depth=0.16"Subcatchment 45S: Proposed to YD Tc=5.0 min CN=60 Runoff=0.00 cfs 57 cf Runoff Area=8,840 sf 100.00% Impervious Runoff Depth=2.23"Subcatchment 52S: Roof Tc=5.0 min CN=98 Runoff=0.65 cfs 1,643 cf Peak Elev=201.49' Storage=596 cf Inflow=2.15 cfs 5,042 cfPond 20P: Lot 18 Infiltration System Discarded=0.76 cfs 5,042 cf Primary=0.00 cfs 0 cf Outflow=0.76 cfs 5,042 cf Peak Elev=191.55' Inflow=0.01 cfs 134 cfPond 30P: CB 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' Outflow=0.01 cfs 134 cf Peak Elev=199.20' Inflow=0.91 cfs 2,140 cfPond 41P: CB 12.0" Round Culvert n=0.012 L=101.0' S=0.0076 '/' Outflow=0.91 cfs 2,140 cf Peak Elev=199.39' Inflow=0.16 cfs 369 cfPond 42P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.16 cfs 369 cf Peak Elev=199.52' Inflow=0.42 cfs 998 cfPond 43P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.42 cfs 998 cf Peak Elev=199.61' Inflow=0.65 cfs 1,533 cfPond 44P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.65 cfs 1,533 cf Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 5HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Peak Elev=200.93' Inflow=0.00 cfs 57 cfPond 45P: YD 12.0" Round Culvert n=0.012 L=107.0' S=0.0250 '/' Outflow=0.00 cfs 57 cf Peak Elev=198.37' Inflow=1.07 cfs 2,509 cfPond 46P: DMH 15.0" Round Culvert n=0.012 L=53.0' S=0.0060 '/' Outflow=1.07 cfs 2,509 cf Peak Elev=198.08' Inflow=1.49 cfs 3,508 cfPond 47P: DMH 15.0" Round Culvert n=0.012 L=36.0' S=0.0061 '/' Outflow=1.49 cfs 3,508 cf Peak Elev=197.96' Inflow=2.14 cfs 5,097 cfPond 48P: DMH 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' Outflow=2.14 cfs 5,097 cf Peak Elev=197.84' Inflow=2.14 cfs 5,097 cfPond 49P: Hydrodynamic Separator Unit 15.0" Round Culvert n=0.012 L=42.0' S=0.0060 '/' Outflow=2.14 cfs 5,097 cf Peak Elev=197.54' Inflow=2.14 cfs 5,097 cfPond 50P: DMH 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' Outflow=2.14 cfs 5,097 cf Peak Elev=197.40' Storage=1,609 cf Inflow=2.78 cfs 6,741 cfPond 51P: Lot 19 Infiltration System Discarded=0.39 cfs 6,741 cf Primary=0.00 cfs 0 cf Outflow=0.39 cfs 6,741 cf Inflow=0.05 cfs 776 cfLink 10L: Discharge to Prince Street Primary=0.05 cfs 776 cf Total Runoff Area = 141,260 sf Runoff Volume = 12,560 cf Average Runoff Depth = 1.07" 50.23% Pervious = 70,955 sf 49.77% Impervious = 70,305 sf Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 6HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 10S: Proposed to Prince Street (Lot 18) Runoff = 0.01 cfs @ 12.15 hrs, Volume= 153 cf, Depth= 0.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description 9,990 61 >75% Grass cover, Good, HSG B 9,990 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 10S: Proposed to Prince Street (Lot 18) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)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 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=9,990 sf Runoff Volume=153 cf Runoff Depth=0.18" Tc=5.0 min CN=61 0.01 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 7HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 20S: Existing to Lot 18 Infiltration System Runoff = 2.15 cfs @ 12.03 hrs, Volume= 5,042 cf, Depth= 1.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 8,240 98 Roof * 21,760 98 Paved 4,740 61 >75% Grass cover, Good, HSG B 34,740 93 Weighted Average 4,740 13.64% Pervious Area 30,000 86.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 20S: Existing to Lot 18 Infiltration System Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=34,740 sf Runoff Volume=5,042 cf Runoff Depth=1.74" Tc=5.0 min CN=93 2.15 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 8HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 30S: Proposed to CB (Lot 19) Runoff = 0.01 cfs @ 12.26 hrs, Volume= 134 cf, Depth= 0.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description 8,700 61 >75% Grass cover, Good, HSG B 8,700 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.4 35 0.0350 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 3.4 40 0.0460 0.19 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 0.4 50 0.0800 1.98 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 25 0.1500 2.71 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 7.4 150 Total Subcatchment 30S: Proposed to CB (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.012 0.011 0.011 0.01 0.01 0.009 0.009 0.008 0.008 0.007 0.007 0.006 0.006 0.005 0.005 0.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0.000 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=8,700 sf Runoff Volume=134 cf Runoff Depth=0.18" Flow Length=150' Tc=7.4 min CN=61 0.01 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 9HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 40S: Proposed to Prince Street (Lot 19) Runoff = 0.03 cfs @ 12.55 hrs, Volume= 489 cf, Depth= 0.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 1,250 98 Paved 33,240 58 Meadow, non-grazed, HSG B 6,640 55 Woods, Good, HSG B 41,130 59 Weighted Average 39,880 96.96% Pervious Area 1,250 3.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.4 15 0.0150 0.05 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 4.9 30 0.0750 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 2.0 30 0.1000 0.25 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 0.1 10 0.1000 2.21 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 12.4 85 Total Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 10HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcatchment 40S: Proposed to Prince Street (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=41,130 sf Runoff Volume=489 cf Runoff Depth=0.14" Flow Length=85' Tc=12.4 min CN=59 0.03 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 11HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 41S: Proposed to CB Runoff = 0.91 cfs @ 12.03 hrs, Volume= 2,140 cf, Depth= 1.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 12,900 98 Paved 1,245 61 >75% Grass cover, Good, HSG B 600 55 Woods, Good, HSG B 14,745 93 Weighted Average 1,845 12.51% Pervious Area 12,900 87.49% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 41S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=14,745 sf Runoff Volume=2,140 cf Runoff Depth=1.74" Tc=5.0 min CN=93 0.91 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 12HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 42S: Proposed to CB Runoff = 0.16 cfs @ 12.03 hrs, Volume= 369 cf, Depth= 1.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 2,275 98 Paved 400 61 >75% Grass cover, Good, HSG B 2,675 92 Weighted Average 400 14.95% Pervious Area 2,275 85.05% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 42S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=2,675 sf Runoff Volume=369 cf Runoff Depth=1.66" Tc=5.0 min CN=92 0.16 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 13HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 43S: Proposed to CB Runoff = 0.42 cfs @ 12.03 hrs, Volume= 998 cf, Depth= 1.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 5,715 98 Paved 510 61 >75% Grass cover, Good, HSG B 6,225 95 Weighted Average 510 8.19% Pervious Area 5,715 91.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 43S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=6,225 sf Runoff Volume=998 cf Runoff Depth=1.92" Tc=5.0 min CN=95 0.42 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 14HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 44S: Proposed to CB Runoff = 0.65 cfs @ 12.03 hrs, Volume= 1,533 cf, Depth= 1.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 9,025 98 Paved 1,020 61 >75% Grass cover, Good, HSG B 10,045 94 Weighted Average 1,020 10.15% Pervious Area 9,025 89.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 44S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=10,045 sf Runoff Volume=1,533 cf Runoff Depth=1.83" Tc=5.0 min CN=94 0.65 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 15HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 45S: Proposed to YD Runoff = 0.00 cfs @ 12.34 hrs, Volume= 57 cf, Depth= 0.16" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 300 98 Paved 1,570 61 >75% Grass cover, Good, HSG B 2,300 55 Woods, Good, HSG B 4,170 60 Weighted Average 3,870 92.81% Pervious Area 300 7.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 45S: Proposed to YD Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.005 0.004 0.004 0.004 0.004 0.004 0.003 0.003 0.003 0.003 0.003 0.002 0.002 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=4,170 sf Runoff Volume=57 cf Runoff Depth=0.16" Tc=5.0 min CN=60 0.00 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 16HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 52S: Roof Runoff = 0.65 cfs @ 12.03 hrs, Volume= 1,643 cf, Depth= 2.23" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Area (sf) CN Description * 8,840 98 Roof 8,840 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 52S: Roof Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 1-yr Rainfall=2.46" Runoff Area=8,840 sf Runoff Volume=1,643 cf Runoff Depth=2.23" Tc=5.0 min CN=98 0.65 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 17HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 20P: Lot 18 Infiltration System Inflow Area = 34,740 sf, 86.36% Impervious, Inflow Depth = 1.74" for 1-yr event Inflow = 2.15 cfs @ 12.03 hrs, Volume= 5,042 cf Outflow = 0.76 cfs @ 11.96 hrs, Volume= 5,042 cf, Atten= 64%, Lag= 0.0 min Discarded = 0.76 cfs @ 11.96 hrs, Volume= 5,042 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 201.49' @ 12.16 hrs Surf.Area= 6,187 sf Storage= 596 cf Plug-Flow detention time= 3.6 min calculated for 5,042 cf (100% of inflow) Center-of-Mass det. time= 3.6 min ( 814.0 - 810.4 ) Volume Invert Avail.Storage Storage Description #1 201.20' 3,465 cf Custom Stage Data (Prismatic) Listed below (Recalc) 12,993 cf Overall - 4,331 cf Embedded = 8,662 cf x 40.0% Voids #2 201.60' 1,692 cf 12.0" Round Pipe Storage Inside #1 L= 2,154.0' 4,331 cf Overall - 3.6" Wall Thickness = 1,692 cf 5,156 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 201.20 6,187 0 0 203.30 6,187 12,993 12,993 Device Routing Invert Outlet Devices #1 Discarded 201.20'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.00'12.0" Round Culvert L= 40.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.00' / 194.80' S= 0.0300 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 202.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.76 cfs @ 11.96 hrs HW=201.22' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=201.20' (Free Discharge) 2=Culvert (Passes 0.00 cfs of 8.20 cfs potential flow) 3=Orifice/Grate ( Controls 0.00 cfs) Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 18HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 20P: Lot 18 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=34,740 sf Peak Elev=201.49' Storage=596 cf 2.15 cfs 0.76 cfs 0.76 cfs 0.00 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 19HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 30P: CB Inflow Area = 43,440 sf, 69.06% Impervious, Inflow Depth = 0.04" for 1-yr event Inflow = 0.01 cfs @ 12.26 hrs, Volume= 134 cf Outflow = 0.01 cfs @ 12.26 hrs, Volume= 134 cf, Atten= 0%, Lag= 0.0 min Primary = 0.01 cfs @ 12.26 hrs, Volume= 134 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 191.55' @ 12.26 hrs Flood Elev= 194.27' Device Routing Invert Outlet Devices #1 Primary 191.50'12.0" Round Culvert L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 191.50' / 189.00' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.01 cfs @ 12.26 hrs HW=191.55' (Free Discharge) 1=Culvert (Inlet Controls 0.01 cfs @ 0.75 fps) Pond 30P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.012 0.011 0.011 0.01 0.01 0.009 0.009 0.008 0.008 0.007 0.007 0.006 0.006 0.005 0.005 0.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0.000 0 Inflow Area=43,440 sf Peak Elev=191.55' 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' 0.01 cfs 0.01 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 20HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 41P: CB Inflow Area = 14,745 sf, 87.49% Impervious, Inflow Depth = 1.74" for 1-yr event Inflow = 0.91 cfs @ 12.03 hrs, Volume= 2,140 cf Outflow = 0.91 cfs @ 12.03 hrs, Volume= 2,140 cf, Atten= 0%, Lag= 0.0 min Primary = 0.91 cfs @ 12.03 hrs, Volume= 2,140 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.20' @ 12.03 hrs Flood Elev= 201.20' Device Routing Invert Outlet Devices #1 Primary 198.70'12.0" Round Culvert L= 101.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 198.70' / 197.93' S= 0.0076 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.91 cfs @ 12.03 hrs HW=199.20' (Free Discharge) 1=Culvert (Barrel Controls 0.91 cfs @ 3.38 fps) Pond 41P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=14,745 sf Peak Elev=199.20' 12.0" Round Culvert n=0.012 L=101.0' S=0.0076 '/' 0.91 cfs 0.91 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 21HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 42P: CB Inflow Area = 2,675 sf, 85.05% Impervious, Inflow Depth = 1.66" for 1-yr event Inflow = 0.16 cfs @ 12.03 hrs, Volume= 369 cf Outflow = 0.16 cfs @ 12.03 hrs, Volume= 369 cf, Atten= 0%, Lag= 0.0 min Primary = 0.16 cfs @ 12.03 hrs, Volume= 369 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.39' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.16 cfs @ 12.03 hrs HW=199.39' (Free Discharge) 1=Culvert (Inlet Controls 0.16 cfs @ 1.49 fps) Pond 42P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=2,675 sf Peak Elev=199.39' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.16 cfs 0.16 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 22HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 43P: CB Inflow Area = 6,225 sf, 91.81% Impervious, Inflow Depth = 1.92" for 1-yr event Inflow = 0.42 cfs @ 12.03 hrs, Volume= 998 cf Outflow = 0.42 cfs @ 12.03 hrs, Volume= 998 cf, Atten= 0%, Lag= 0.0 min Primary = 0.42 cfs @ 12.03 hrs, Volume= 998 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.52' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.42 cfs @ 12.03 hrs HW=199.52' (Free Discharge) 1=Culvert (Inlet Controls 0.42 cfs @ 1.92 fps) Pond 43P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=6,225 sf Peak Elev=199.52' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.42 cfs 0.42 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 23HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 44P: CB Inflow Area = 10,045 sf, 89.85% Impervious, Inflow Depth = 1.83" for 1-yr event Inflow = 0.65 cfs @ 12.03 hrs, Volume= 1,533 cf Outflow = 0.65 cfs @ 12.03 hrs, Volume= 1,533 cf, Atten= 0%, Lag= 0.0 min Primary = 0.65 cfs @ 12.03 hrs, Volume= 1,533 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.61' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.64 cfs @ 12.03 hrs HW=199.60' (Free Discharge) 1=Culvert (Inlet Controls 0.64 cfs @ 2.17 fps) Pond 44P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=10,045 sf Peak Elev=199.61' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.65 cfs 0.65 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 24HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 45P: YD Inflow Area = 4,170 sf, 7.19% Impervious, Inflow Depth = 0.16" for 1-yr event Inflow = 0.00 cfs @ 12.34 hrs, Volume= 57 cf Outflow = 0.00 cfs @ 12.34 hrs, Volume= 57 cf, Atten= 0%, Lag= 0.0 min Primary = 0.00 cfs @ 12.34 hrs, Volume= 57 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 200.93' @ 12.34 hrs Flood Elev= 203.40' Device Routing Invert Outlet Devices #1 Primary 200.90'12.0" Round Culvert L= 107.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 200.90' / 198.22' S= 0.0250 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.00 cfs @ 12.34 hrs HW=200.93' (Free Discharge) 1=Culvert (Inlet Controls 0.00 cfs @ 0.58 fps) Pond 45P: YD Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.005 0.004 0.004 0.004 0.004 0.004 0.003 0.003 0.003 0.003 0.003 0.002 0.002 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0 Inflow Area=4,170 sf Peak Elev=200.93' 12.0" Round Culvert n=0.012 L=107.0' S=0.0250 '/' 0.00 cfs 0.00 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 25HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 46P: DMH [79] Warning: Submerged Pond 41P Primary device # 1 OUTLET by 0.44' Inflow Area = 17,420 sf, 87.11% Impervious, Inflow Depth = 1.73" for 1-yr event Inflow = 1.07 cfs @ 12.03 hrs, Volume= 2,509 cf Outflow = 1.07 cfs @ 12.03 hrs, Volume= 2,509 cf, Atten= 0%, Lag= 0.0 min Primary = 1.07 cfs @ 12.03 hrs, Volume= 2,509 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.37' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.83'15.0" Round Culvert L= 53.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.83' / 197.51' S= 0.0060 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=1.07 cfs @ 12.03 hrs HW=198.37' (Free Discharge) 1=Culvert (Barrel Controls 1.07 cfs @ 3.08 fps) Pond 46P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=17,420 sf Peak Elev=198.37' 15.0" Round Culvert n=0.012 L=53.0' S=0.0060 '/' 1.07 cfs 1.07 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 26HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 47P: DMH [79] Warning: Submerged Pond 46P Primary device # 1 INLET by 0.25' Inflow Area = 23,645 sf, 88.35% Impervious, Inflow Depth = 1.78" for 1-yr event Inflow = 1.49 cfs @ 12.03 hrs, Volume= 3,508 cf Outflow = 1.49 cfs @ 12.03 hrs, Volume= 3,508 cf, Atten= 0%, Lag= 0.0 min Primary = 1.49 cfs @ 12.03 hrs, Volume= 3,508 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.08' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.41'15.0" Round Culvert L= 36.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.41' / 197.19' S= 0.0061 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=1.48 cfs @ 12.03 hrs HW=198.08' (Free Discharge) 1=Culvert (Barrel Controls 1.48 cfs @ 3.24 fps) Pond 47P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=23,645 sf Peak Elev=198.08' 15.0" Round Culvert n=0.012 L=36.0' S=0.0061 '/' 1.49 cfs 1.49 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 27HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 48P: DMH [79] Warning: Submerged Pond 47P Primary device # 1 INLET by 0.55' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 1.62" for 1-yr event Inflow = 2.14 cfs @ 12.03 hrs, Volume= 5,097 cf Outflow = 2.14 cfs @ 12.03 hrs, Volume= 5,097 cf, Atten= 0%, Lag= 0.0 min Primary = 2.14 cfs @ 12.03 hrs, Volume= 5,097 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 197.96' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.09'15.0" Round Culvert L= 11.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.09' / 197.02' S= 0.0064 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=2.13 cfs @ 12.03 hrs HW=197.96' (Free Discharge) 1=Culvert (Barrel Controls 2.13 cfs @ 3.29 fps) Pond 48P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=37,860 sf Peak Elev=197.96' 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' 2.14 cfs 2.14 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 28HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 49P: Hydrodynamic Separator Unit [79] Warning: Submerged Pond 48P Primary device # 1 INLET by 0.75' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 1.62" for 1-yr event Inflow = 2.14 cfs @ 12.03 hrs, Volume= 5,097 cf Outflow = 2.14 cfs @ 12.03 hrs, Volume= 5,097 cf, Atten= 0%, Lag= 0.0 min Primary = 2.14 cfs @ 12.03 hrs, Volume= 5,097 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 197.84' @ 12.03 hrs Flood Elev= 203.10' Device Routing Invert Outlet Devices #1 Primary 197.02'15.0" Round Culvert L= 42.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.02' / 196.77' S= 0.0060 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=2.13 cfs @ 12.03 hrs HW=197.84' (Free Discharge) 1=Culvert (Barrel Controls 2.13 cfs @ 3.54 fps) Pond 49P: Hydrodynamic Separator Unit Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=37,860 sf Peak Elev=197.84' 15.0" Round Culvert n=0.012 L=42.0' S=0.0060 '/' 2.14 cfs 2.14 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 29HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 50P: DMH [79] Warning: Submerged Pond 49P Primary device # 1 INLET by 0.52' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 1.62" for 1-yr event Inflow = 2.14 cfs @ 12.03 hrs, Volume= 5,097 cf Outflow = 2.14 cfs @ 12.03 hrs, Volume= 5,097 cf, Atten= 0%, Lag= 0.0 min Primary = 2.14 cfs @ 12.03 hrs, Volume= 5,097 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 197.54' @ 12.03 hrs Flood Elev= 203.70' Device Routing Invert Outlet Devices #1 Primary 196.67'15.0" Round Culvert L= 11.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.67' / 196.60' S= 0.0064 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=2.13 cfs @ 12.03 hrs HW=197.54' (Free Discharge) 1=Culvert (Barrel Controls 2.13 cfs @ 3.29 fps) Pond 50P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=37,860 sf Peak Elev=197.54' 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' 2.14 cfs 2.14 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 30HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 51P: Lot 19 Infiltration System [81] Warning: Exceeded Pond 50P by 0.49' @ 12.62 hrs Inflow Area = 46,700 sf, 83.63% Impervious, Inflow Depth = 1.73" for 1-yr event Inflow = 2.78 cfs @ 12.03 hrs, Volume= 6,741 cf Outflow = 0.39 cfs @ 11.77 hrs, Volume= 6,741 cf, Atten= 86%, Lag= 0.0 min Discarded = 0.39 cfs @ 11.77 hrs, Volume= 6,741 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 197.40' @ 12.50 hrs Surf.Area= 3,182 sf Storage= 1,609 cf Plug-Flow detention time= 23.0 min calculated for 6,741 cf (100% of inflow) Center-of-Mass det. time= 23.0 min ( 820.2 - 797.2 ) Volume Invert Avail.Storage Storage Description #1A 196.60' 2,454 cf 46.80'W x 68.00'L x 4.00'H Field A 12,730 cf Overall - 6,594 cf Embedded = 6,135 cf x 40.0% Voids #2A 196.60' 4,967 cf Galley 4x4x4 x 112 Inside #1 Inside= 42.0"W x 43.0"H => 12.67 sf x 3.50'L = 44.3 cf Outside= 52.8"W x 48.0"H => 14.72 sf x 4.00'L = 58.9 cf 7 Rows of 16 Chambers 7,421 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 196.60'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.60'12.0" Round Culvert L= 73.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.60' / 189.00' S= 0.1041 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 199.80'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.39 cfs @ 11.77 hrs HW=196.64' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.39 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=196.60' (Free Discharge) 2=Culvert ( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 31HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 51P: Lot 19 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=46,700 sf Peak Elev=197.40' Storage=1,609 cf 2.78 cfs 0.39 cfs 0.39 cfs 0.00 cfs Proposed Conditions MA_Northampton 24-hr S1 1-yr Rainfall=2.46"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 32HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Link 10L: Discharge to Prince Street Inflow Area = 141,260 sf, 49.77% Impervious, Inflow Depth = 0.07" for 1-yr event Inflow = 0.05 cfs @ 12.52 hrs, Volume= 776 cf Primary = 0.05 cfs @ 12.52 hrs, Volume= 776 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Link 10L: Discharge to Prince Street Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=141,260 sf 0.05 cfs 0.05 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 33HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,990 sf 0.00% Impervious Runoff Depth=0.40"Subcatchment 10S: Proposed to Prince Tc=5.0 min CN=61 Runoff=0.07 cfs 333 cf Runoff Area=34,740 sf 86.36% Impervious Runoff Depth=2.34"Subcatchment 20S: Existing to Lot 18 Tc=5.0 min CN=93 Runoff=2.69 cfs 6,775 cf Runoff Area=8,700 sf 0.00% Impervious Runoff Depth=0.40"Subcatchment 30S: Proposed to CB (Lot 19) Flow Length=150' Tc=7.4 min CN=61 Runoff=0.05 cfs 290 cf Runoff Area=41,130 sf 3.04% Impervious Runoff Depth=0.33"Subcatchment 40S: Proposed to Prince Flow Length=85' Tc=12.4 min CN=59 Runoff=0.13 cfs 1,145 cf Runoff Area=14,745 sf 87.49% Impervious Runoff Depth=2.34"Subcatchment 41S: Proposed to CB Tc=5.0 min CN=93 Runoff=1.14 cfs 2,876 cf Runoff Area=2,675 sf 85.05% Impervious Runoff Depth=2.25"Subcatchment 42S: Proposed to CB Tc=5.0 min CN=92 Runoff=0.20 cfs 501 cf Runoff Area=6,225 sf 91.81% Impervious Runoff Depth=2.54"Subcatchment 43S: Proposed to CB Tc=5.0 min CN=95 Runoff=0.51 cfs 1,316 cf Runoff Area=10,045 sf 89.85% Impervious Runoff Depth=2.44"Subcatchment 44S: Proposed to CB Tc=5.0 min CN=94 Runoff=0.80 cfs 2,040 cf Runoff Area=4,170 sf 7.19% Impervious Runoff Depth=0.37"Subcatchment 45S: Proposed to YD Tc=5.0 min CN=60 Runoff=0.02 cfs 127 cf Runoff Area=8,840 sf 100.00% Impervious Runoff Depth=2.86"Subcatchment 52S: Roof Tc=5.0 min CN=98 Runoff=0.77 cfs 2,105 cf Peak Elev=201.67' Storage=906 cf Inflow=2.69 cfs 6,775 cfPond 20P: Lot 18 Infiltration System Discarded=0.76 cfs 6,775 cf Primary=0.00 cfs 0 cf Outflow=0.76 cfs 6,775 cf Peak Elev=191.61' Inflow=0.05 cfs 290 cfPond 30P: CB 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' Outflow=0.05 cfs 290 cf Peak Elev=199.27' Inflow=1.14 cfs 2,876 cfPond 41P: CB 12.0" Round Culvert n=0.012 L=101.0' S=0.0076 '/' Outflow=1.14 cfs 2,876 cf Peak Elev=199.42' Inflow=0.20 cfs 501 cfPond 42P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.20 cfs 501 cf Peak Elev=199.56' Inflow=0.51 cfs 1,316 cfPond 43P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.51 cfs 1,316 cf Peak Elev=199.66' Inflow=0.80 cfs 2,040 cfPond 44P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.80 cfs 2,040 cf Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 34HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Peak Elev=200.97' Inflow=0.02 cfs 127 cfPond 45P: YD 12.0" Round Culvert n=0.012 L=107.0' S=0.0250 '/' Outflow=0.02 cfs 127 cf Peak Elev=198.45' Inflow=1.34 cfs 3,376 cfPond 46P: DMH 15.0" Round Culvert n=0.012 L=53.0' S=0.0060 '/' Outflow=1.34 cfs 3,376 cf Peak Elev=198.17' Inflow=1.85 cfs 4,693 cfPond 47P: DMH 15.0" Round Culvert n=0.012 L=36.0' S=0.0061 '/' Outflow=1.85 cfs 4,693 cf Peak Elev=198.09' Inflow=2.67 cfs 6,860 cfPond 48P: DMH 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' Outflow=2.67 cfs 6,860 cf Peak Elev=197.96' Inflow=2.67 cfs 6,860 cfPond 49P: Hydrodynamic Separator Unit 15.0" Round Culvert n=0.012 L=42.0' S=0.0060 '/' Outflow=2.67 cfs 6,860 cf Peak Elev=197.67' Inflow=2.67 cfs 6,860 cfPond 50P: DMH 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' Outflow=2.67 cfs 6,860 cf Peak Elev=197.74' Storage=2,295 cf Inflow=3.45 cfs 8,965 cfPond 51P: Lot 19 Infiltration System Discarded=0.39 cfs 8,965 cf Primary=0.00 cfs 0 cf Outflow=0.39 cfs 8,965 cf Inflow=0.21 cfs 1,768 cfLink 10L: Discharge to Prince Street Primary=0.21 cfs 1,768 cf Total Runoff Area = 141,260 sf Runoff Volume = 17,508 cf Average Runoff Depth = 1.49" 50.23% Pervious = 70,955 sf 49.77% Impervious = 70,305 sf Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 35HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 10S: Proposed to Prince Street (Lot 18) Runoff = 0.07 cfs @ 12.05 hrs, Volume= 333 cf, Depth= 0.40" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description 9,990 61 >75% Grass cover, Good, HSG B 9,990 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 10S: Proposed to Prince Street (Lot 18) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=9,990 sf Runoff Volume=333 cf Runoff Depth=0.40" Tc=5.0 min CN=61 0.07 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 36HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 20S: Existing to Lot 18 Infiltration System Runoff = 2.69 cfs @ 12.03 hrs, Volume= 6,775 cf, Depth= 2.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 8,240 98 Roof * 21,760 98 Paved 4,740 61 >75% Grass cover, Good, HSG B 34,740 93 Weighted Average 4,740 13.64% Pervious Area 30,000 86.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 20S: Existing to Lot 18 Infiltration System Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=34,740 sf Runoff Volume=6,775 cf Runoff Depth=2.34" Tc=5.0 min CN=93 2.69 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 37HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 30S: Proposed to CB (Lot 19) Runoff = 0.05 cfs @ 12.08 hrs, Volume= 290 cf, Depth= 0.40" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description 8,700 61 >75% Grass cover, Good, HSG B 8,700 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.4 35 0.0350 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 3.4 40 0.0460 0.19 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 0.4 50 0.0800 1.98 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 25 0.1500 2.71 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 7.4 150 Total Subcatchment 30S: Proposed to CB (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=8,700 sf Runoff Volume=290 cf Runoff Depth=0.40" Flow Length=150' Tc=7.4 min CN=61 0.05 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 38HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 40S: Proposed to Prince Street (Lot 19) Runoff = 0.13 cfs @ 12.21 hrs, Volume= 1,145 cf, Depth= 0.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 1,250 98 Paved 33,240 58 Meadow, non-grazed, HSG B 6,640 55 Woods, Good, HSG B 41,130 59 Weighted Average 39,880 96.96% Pervious Area 1,250 3.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.4 15 0.0150 0.05 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 4.9 30 0.0750 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 2.0 30 0.1000 0.25 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 0.1 10 0.1000 2.21 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 12.4 85 Total Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 39HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcatchment 40S: Proposed to Prince Street (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)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 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=41,130 sf Runoff Volume=1,145 cf Runoff Depth=0.33" Flow Length=85' Tc=12.4 min CN=59 0.13 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 40HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 41S: Proposed to CB Runoff = 1.14 cfs @ 12.03 hrs, Volume= 2,876 cf, Depth= 2.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 12,900 98 Paved 1,245 61 >75% Grass cover, Good, HSG B 600 55 Woods, Good, HSG B 14,745 93 Weighted Average 1,845 12.51% Pervious Area 12,900 87.49% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 41S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=14,745 sf Runoff Volume=2,876 cf Runoff Depth=2.34" Tc=5.0 min CN=93 1.14 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 41HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 42S: Proposed to CB Runoff = 0.20 cfs @ 12.03 hrs, Volume= 501 cf, Depth= 2.25" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 2,275 98 Paved 400 61 >75% Grass cover, Good, HSG B 2,675 92 Weighted Average 400 14.95% Pervious Area 2,275 85.05% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 42S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)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 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=2,675 sf Runoff Volume=501 cf Runoff Depth=2.25" Tc=5.0 min CN=92 0.20 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 42HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 43S: Proposed to CB Runoff = 0.51 cfs @ 12.03 hrs, Volume= 1,316 cf, Depth= 2.54" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 5,715 98 Paved 510 61 >75% Grass cover, Good, HSG B 6,225 95 Weighted Average 510 8.19% Pervious Area 5,715 91.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 43S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=6,225 sf Runoff Volume=1,316 cf Runoff Depth=2.54" Tc=5.0 min CN=95 0.51 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 43HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 44S: Proposed to CB Runoff = 0.80 cfs @ 12.03 hrs, Volume= 2,040 cf, Depth= 2.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 9,025 98 Paved 1,020 61 >75% Grass cover, Good, HSG B 10,045 94 Weighted Average 1,020 10.15% Pervious Area 9,025 89.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 44S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=10,045 sf Runoff Volume=2,040 cf Runoff Depth=2.44" Tc=5.0 min CN=94 0.80 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 44HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 45S: Proposed to YD Runoff = 0.02 cfs @ 12.05 hrs, Volume= 127 cf, Depth= 0.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 300 98 Paved 1,570 61 >75% Grass cover, Good, HSG B 2,300 55 Woods, Good, HSG B 4,170 60 Weighted Average 3,870 92.81% Pervious Area 300 7.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 45S: Proposed to YD Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.025 0.024 0.023 0.022 0.021 0.02 0.019 0.018 0.017 0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=4,170 sf Runoff Volume=127 cf Runoff Depth=0.37" Tc=5.0 min CN=60 0.02 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 45HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 52S: Roof Runoff = 0.77 cfs @ 12.03 hrs, Volume= 2,105 cf, Depth= 2.86" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Area (sf) CN Description * 8,840 98 Roof 8,840 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 52S: Roof Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 2-yr Rainfall=3.09" Runoff Area=8,840 sf Runoff Volume=2,105 cf Runoff Depth=2.86" Tc=5.0 min CN=98 0.77 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 46HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 20P: Lot 18 Infiltration System Inflow Area = 34,740 sf, 86.36% Impervious, Inflow Depth = 2.34" for 2-yr event Inflow = 2.69 cfs @ 12.03 hrs, Volume= 6,775 cf Outflow = 0.76 cfs @ 11.94 hrs, Volume= 6,775 cf, Atten= 72%, Lag= 0.0 min Discarded = 0.76 cfs @ 11.94 hrs, Volume= 6,775 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 201.67' @ 12.20 hrs Surf.Area= 6,187 sf Storage= 906 cf Plug-Flow detention time= 5.2 min calculated for 6,773 cf (100% of inflow) Center-of-Mass det. time= 5.2 min ( 808.1 - 802.9 ) Volume Invert Avail.Storage Storage Description #1 201.20' 3,465 cf Custom Stage Data (Prismatic) Listed below (Recalc) 12,993 cf Overall - 4,331 cf Embedded = 8,662 cf x 40.0% Voids #2 201.60' 1,692 cf 12.0" Round Pipe Storage Inside #1 L= 2,154.0' 4,331 cf Overall - 3.6" Wall Thickness = 1,692 cf 5,156 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 201.20 6,187 0 0 203.30 6,187 12,993 12,993 Device Routing Invert Outlet Devices #1 Discarded 201.20'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.00'12.0" Round Culvert L= 40.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.00' / 194.80' S= 0.0300 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 202.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.76 cfs @ 11.94 hrs HW=201.22' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=201.20' (Free Discharge) 2=Culvert (Passes 0.00 cfs of 8.20 cfs potential flow) 3=Orifice/Grate ( Controls 0.00 cfs) Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 47HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 20P: Lot 18 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=34,740 sf Peak Elev=201.67' Storage=906 cf 2.69 cfs 0.76 cfs 0.76 cfs 0.00 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 48HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 30P: CB Inflow Area = 43,440 sf, 69.06% Impervious, Inflow Depth = 0.08" for 2-yr event Inflow = 0.05 cfs @ 12.08 hrs, Volume= 290 cf Outflow = 0.05 cfs @ 12.08 hrs, Volume= 290 cf, Atten= 0%, Lag= 0.0 min Primary = 0.05 cfs @ 12.08 hrs, Volume= 290 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 191.61' @ 12.08 hrs Flood Elev= 194.27' Device Routing Invert Outlet Devices #1 Primary 191.50'12.0" Round Culvert L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 191.50' / 189.00' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.05 cfs @ 12.08 hrs HW=191.61' (Free Discharge) 1=Culvert (Inlet Controls 0.05 cfs @ 1.11 fps) Pond 30P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=43,440 sf Peak Elev=191.61' 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' 0.05 cfs 0.05 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 49HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 41P: CB Inflow Area = 14,745 sf, 87.49% Impervious, Inflow Depth = 2.34" for 2-yr event Inflow = 1.14 cfs @ 12.03 hrs, Volume= 2,876 cf Outflow = 1.14 cfs @ 12.03 hrs, Volume= 2,876 cf, Atten= 0%, Lag= 0.0 min Primary = 1.14 cfs @ 12.03 hrs, Volume= 2,876 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.27' @ 12.03 hrs Flood Elev= 201.20' Device Routing Invert Outlet Devices #1 Primary 198.70'12.0" Round Culvert L= 101.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 198.70' / 197.93' S= 0.0076 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.14 cfs @ 12.03 hrs HW=199.27' (Free Discharge) 1=Culvert (Barrel Controls 1.14 cfs @ 3.56 fps) Pond 41P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=14,745 sf Peak Elev=199.27' 12.0" Round Culvert n=0.012 L=101.0' S=0.0076 '/' 1.14 cfs 1.14 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 50HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 42P: CB Inflow Area = 2,675 sf, 85.05% Impervious, Inflow Depth = 2.25" for 2-yr event Inflow = 0.20 cfs @ 12.03 hrs, Volume= 501 cf Outflow = 0.20 cfs @ 12.03 hrs, Volume= 501 cf, Atten= 0%, Lag= 0.0 min Primary = 0.20 cfs @ 12.03 hrs, Volume= 501 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.42' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.20 cfs @ 12.03 hrs HW=199.42' (Free Discharge) 1=Culvert (Inlet Controls 0.20 cfs @ 1.59 fps) Pond 42P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)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=2,675 sf Peak Elev=199.42' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.20 cfs 0.20 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 51HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 43P: CB Inflow Area = 6,225 sf, 91.81% Impervious, Inflow Depth = 2.54" for 2-yr event Inflow = 0.51 cfs @ 12.03 hrs, Volume= 1,316 cf Outflow = 0.51 cfs @ 12.03 hrs, Volume= 1,316 cf, Atten= 0%, Lag= 0.0 min Primary = 0.51 cfs @ 12.03 hrs, Volume= 1,316 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.56' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.51 cfs @ 12.03 hrs HW=199.56' (Free Discharge) 1=Culvert (Inlet Controls 0.51 cfs @ 2.03 fps) Pond 43P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=6,225 sf Peak Elev=199.56' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.51 cfs 0.51 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 52HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 44P: CB Inflow Area = 10,045 sf, 89.85% Impervious, Inflow Depth = 2.44" for 2-yr event Inflow = 0.80 cfs @ 12.03 hrs, Volume= 2,040 cf Outflow = 0.80 cfs @ 12.03 hrs, Volume= 2,040 cf, Atten= 0%, Lag= 0.0 min Primary = 0.80 cfs @ 12.03 hrs, Volume= 2,040 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.66' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.80 cfs @ 12.03 hrs HW=199.65' (Free Discharge) 1=Culvert (Inlet Controls 0.80 cfs @ 2.30 fps) Pond 44P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=10,045 sf Peak Elev=199.66' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.80 cfs 0.80 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 53HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 45P: YD Inflow Area = 4,170 sf, 7.19% Impervious, Inflow Depth = 0.37" for 2-yr event Inflow = 0.02 cfs @ 12.05 hrs, Volume= 127 cf Outflow = 0.02 cfs @ 12.05 hrs, Volume= 127 cf, Atten= 0%, Lag= 0.0 min Primary = 0.02 cfs @ 12.05 hrs, Volume= 127 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 200.97' @ 12.05 hrs Flood Elev= 203.40' Device Routing Invert Outlet Devices #1 Primary 200.90'12.0" Round Culvert L= 107.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 200.90' / 198.22' S= 0.0250 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.02 cfs @ 12.05 hrs HW=200.97' (Free Discharge) 1=Culvert (Inlet Controls 0.02 cfs @ 0.91 fps) Pond 45P: YD Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)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=4,170 sf Peak Elev=200.97' 12.0" Round Culvert n=0.012 L=107.0' S=0.0250 '/' 0.02 cfs 0.02 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 54HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 46P: DMH [79] Warning: Submerged Pond 41P Primary device # 1 OUTLET by 0.52' Inflow Area = 17,420 sf, 87.11% Impervious, Inflow Depth = 2.33" for 2-yr event Inflow = 1.34 cfs @ 12.03 hrs, Volume= 3,376 cf Outflow = 1.34 cfs @ 12.03 hrs, Volume= 3,376 cf, Atten= 0%, Lag= 0.0 min Primary = 1.34 cfs @ 12.03 hrs, Volume= 3,376 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.45' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.83'15.0" Round Culvert L= 53.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.83' / 197.51' S= 0.0060 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=1.34 cfs @ 12.03 hrs HW=198.45' (Free Discharge) 1=Culvert (Barrel Controls 1.34 cfs @ 3.24 fps) Pond 46P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=17,420 sf Peak Elev=198.45' 15.0" Round Culvert n=0.012 L=53.0' S=0.0060 '/' 1.34 cfs 1.34 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 55HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 47P: DMH [79] Warning: Submerged Pond 46P Primary device # 1 INLET by 0.34' Inflow Area = 23,645 sf, 88.35% Impervious, Inflow Depth = 2.38" for 2-yr event Inflow = 1.85 cfs @ 12.03 hrs, Volume= 4,693 cf Outflow = 1.85 cfs @ 12.03 hrs, Volume= 4,693 cf, Atten= 0%, Lag= 0.0 min Primary = 1.85 cfs @ 12.03 hrs, Volume= 4,693 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.17' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.41'15.0" Round Culvert L= 36.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.41' / 197.19' S= 0.0061 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=1.84 cfs @ 12.03 hrs HW=198.17' (Free Discharge) 1=Culvert (Barrel Controls 1.84 cfs @ 3.40 fps) Pond 47P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=23,645 sf Peak Elev=198.17' 15.0" Round Culvert n=0.012 L=36.0' S=0.0061 '/' 1.85 cfs 1.85 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 56HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 48P: DMH [79] Warning: Submerged Pond 47P Primary device # 1 INLET by 0.68' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 2.17" for 2-yr event Inflow = 2.67 cfs @ 12.03 hrs, Volume= 6,860 cf Outflow = 2.67 cfs @ 12.03 hrs, Volume= 6,860 cf, Atten= 0%, Lag= 0.0 min Primary = 2.67 cfs @ 12.03 hrs, Volume= 6,860 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.09' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.09'15.0" Round Culvert L= 11.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.09' / 197.02' S= 0.0064 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=2.66 cfs @ 12.03 hrs HW=198.09' (Free Discharge) 1=Culvert (Barrel Controls 2.66 cfs @ 3.48 fps) Pond 48P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=37,860 sf Peak Elev=198.09' 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' 2.67 cfs 2.67 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 57HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 49P: Hydrodynamic Separator Unit [79] Warning: Submerged Pond 48P Primary device # 1 INLET by 0.87' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 2.17" for 2-yr event Inflow = 2.67 cfs @ 12.03 hrs, Volume= 6,860 cf Outflow = 2.67 cfs @ 12.03 hrs, Volume= 6,860 cf, Atten= 0%, Lag= 0.0 min Primary = 2.67 cfs @ 12.03 hrs, Volume= 6,860 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 197.96' @ 12.03 hrs Flood Elev= 203.10' Device Routing Invert Outlet Devices #1 Primary 197.02'15.0" Round Culvert L= 42.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.02' / 196.77' S= 0.0060 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=2.66 cfs @ 12.03 hrs HW=197.96' (Free Discharge) 1=Culvert (Barrel Controls 2.66 cfs @ 3.72 fps) Pond 49P: Hydrodynamic Separator Unit Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=37,860 sf Peak Elev=197.96' 15.0" Round Culvert n=0.012 L=42.0' S=0.0060 '/' 2.67 cfs 2.67 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 58HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 50P: DMH [79] Warning: Submerged Pond 49P Primary device # 1 INLET by 0.65' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 2.17" for 2-yr event Inflow = 2.67 cfs @ 12.03 hrs, Volume= 6,860 cf Outflow = 2.67 cfs @ 12.03 hrs, Volume= 6,860 cf, Atten= 0%, Lag= 0.0 min Primary = 2.67 cfs @ 12.03 hrs, Volume= 6,860 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 197.67' @ 12.03 hrs Flood Elev= 203.70' Device Routing Invert Outlet Devices #1 Primary 196.67'15.0" Round Culvert L= 11.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.67' / 196.60' S= 0.0064 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=2.66 cfs @ 12.03 hrs HW=197.67' (Free Discharge) 1=Culvert (Barrel Controls 2.66 cfs @ 3.48 fps) Pond 50P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=37,860 sf Peak Elev=197.67' 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' 2.67 cfs 2.67 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 59HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 51P: Lot 19 Infiltration System [81] Warning: Exceeded Pond 50P by 0.81' @ 12.69 hrs Inflow Area = 46,700 sf, 83.63% Impervious, Inflow Depth = 2.30" for 2-yr event Inflow = 3.45 cfs @ 12.03 hrs, Volume= 8,965 cf Outflow = 0.39 cfs @ 11.66 hrs, Volume= 8,965 cf, Atten= 89%, Lag= 0.0 min Discarded = 0.39 cfs @ 11.66 hrs, Volume= 8,965 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 197.74' @ 12.57 hrs Surf.Area= 3,182 sf Storage= 2,295 cf Plug-Flow detention time= 33.3 min calculated for 8,963 cf (100% of inflow) Center-of-Mass det. time= 33.3 min ( 824.6 - 791.4 ) Volume Invert Avail.Storage Storage Description #1A 196.60' 2,454 cf 46.80'W x 68.00'L x 4.00'H Field A 12,730 cf Overall - 6,594 cf Embedded = 6,135 cf x 40.0% Voids #2A 196.60' 4,967 cf Galley 4x4x4 x 112 Inside #1 Inside= 42.0"W x 43.0"H => 12.67 sf x 3.50'L = 44.3 cf Outside= 52.8"W x 48.0"H => 14.72 sf x 4.00'L = 58.9 cf 7 Rows of 16 Chambers 7,421 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 196.60'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.60'12.0" Round Culvert L= 73.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.60' / 189.00' S= 0.1041 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 199.80'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.39 cfs @ 11.66 hrs HW=196.64' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.39 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=196.60' (Free Discharge) 2=Culvert ( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 60HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 51P: Lot 19 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=46,700 sf Peak Elev=197.74' Storage=2,295 cf 3.45 cfs 0.39 cfs 0.39 cfs 0.00 cfs Proposed Conditions MA_Northampton 24-hr S1 2-yr Rainfall=3.09"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 61HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Link 10L: Discharge to Prince Street Inflow Area = 141,260 sf, 49.77% Impervious, Inflow Depth = 0.15" for 2-yr event Inflow = 0.21 cfs @ 12.17 hrs, Volume= 1,768 cf Primary = 0.21 cfs @ 12.17 hrs, Volume= 1,768 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Link 10L: Discharge to Prince Street Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (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=141,260 sf 0.21 cfs 0.21 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 62HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,990 sf 0.00% Impervious Runoff Depth=1.34"Subcatchment 10S: Proposed to Prince Tc=5.0 min CN=61 Runoff=0.37 cfs 1,115 cf Runoff Area=34,740 sf 86.36% Impervious Runoff Depth=4.15"Subcatchment 20S: Existing to Lot 18 Tc=5.0 min CN=93 Runoff=4.23 cfs 12,011 cf Runoff Area=8,700 sf 0.00% Impervious Runoff Depth=1.34"Subcatchment 30S: Proposed to CB (Lot 19) Flow Length=150' Tc=7.4 min CN=61 Runoff=0.28 cfs 971 cf Runoff Area=41,130 sf 3.04% Impervious Runoff Depth=1.21"Subcatchment 40S: Proposed to Prince Flow Length=85' Tc=12.4 min CN=59 Runoff=0.90 cfs 4,134 cf Runoff Area=14,745 sf 87.49% Impervious Runoff Depth=4.15"Subcatchment 41S: Proposed to CB Tc=5.0 min CN=93 Runoff=1.80 cfs 5,098 cf Runoff Area=2,675 sf 85.05% Impervious Runoff Depth=4.04"Subcatchment 42S: Proposed to CB Tc=5.0 min CN=92 Runoff=0.32 cfs 901 cf Runoff Area=6,225 sf 91.81% Impervious Runoff Depth=4.37"Subcatchment 43S: Proposed to CB Tc=5.0 min CN=95 Runoff=0.78 cfs 2,267 cf Runoff Area=10,045 sf 89.85% Impervious Runoff Depth=4.26"Subcatchment 44S: Proposed to CB Tc=5.0 min CN=94 Runoff=1.24 cfs 3,565 cf Runoff Area=4,170 sf 7.19% Impervious Runoff Depth=1.27"Subcatchment 45S: Proposed to YD Tc=5.0 min CN=60 Runoff=0.14 cfs 442 cf Runoff Area=8,840 sf 100.00% Impervious Runoff Depth=4.71"Subcatchment 52S: Roof Tc=5.0 min CN=98 Runoff=1.14 cfs 3,472 cf Peak Elev=202.04' Storage=2,022 cf Inflow=4.23 cfs 12,011 cfPond 20P: Lot 18 Infiltration System Discarded=0.76 cfs 12,011 cf Primary=0.00 cfs 0 cf Outflow=0.76 cfs 12,011 cf Peak Elev=191.76' Inflow=0.28 cfs 971 cfPond 30P: CB 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' Outflow=0.28 cfs 971 cf Peak Elev=199.45' Inflow=1.80 cfs 5,098 cfPond 41P: CB 12.0" Round Culvert n=0.012 L=101.0' S=0.0076 '/' Outflow=1.80 cfs 5,098 cf Peak Elev=199.48' Inflow=0.32 cfs 901 cfPond 42P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.32 cfs 901 cf Peak Elev=199.65' Inflow=0.78 cfs 2,267 cfPond 43P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.78 cfs 2,267 cf Peak Elev=199.78' Inflow=1.24 cfs 3,565 cfPond 44P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=1.24 cfs 3,565 cf Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 63HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Peak Elev=201.08' Inflow=0.14 cfs 442 cfPond 45P: YD 12.0" Round Culvert n=0.012 L=107.0' S=0.0250 '/' Outflow=0.14 cfs 442 cf Peak Elev=198.63' Inflow=2.12 cfs 5,999 cfPond 46P: DMH 15.0" Round Culvert n=0.012 L=53.0' S=0.0060 '/' Outflow=2.12 cfs 5,999 cf Peak Elev=198.41' Inflow=2.90 cfs 8,265 cfPond 47P: DMH 15.0" Round Culvert n=0.012 L=36.0' S=0.0061 '/' Outflow=2.90 cfs 8,265 cf Peak Elev=198.45' Inflow=4.28 cfs 12,272 cfPond 48P: DMH 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' Outflow=4.28 cfs 12,272 cf Peak Elev=198.32' Inflow=4.28 cfs 12,272 cfPond 49P: Hydrodynamic Separator Unit 15.0" Round Culvert n=0.012 L=42.0' S=0.0060 '/' Outflow=4.28 cfs 12,272 cf Peak Elev=198.03' Inflow=4.28 cfs 12,272 cfPond 50P: DMH 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' Outflow=4.28 cfs 12,272 cf Peak Elev=198.90' Storage=4,611 cf Inflow=5.42 cfs 15,744 cfPond 51P: Lot 19 Infiltration System Discarded=0.39 cfs 15,744 cf Primary=0.00 cfs 0 cf Outflow=0.39 cfs 15,744 cf Inflow=1.31 cfs 6,220 cfLink 10L: Discharge to Prince Street Primary=1.31 cfs 6,220 cf Total Runoff Area = 141,260 sf Runoff Volume = 33,975 cf Average Runoff Depth = 2.89" 50.23% Pervious = 70,955 sf 49.77% Impervious = 70,305 sf Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 64HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 10S: Proposed to Prince Street (Lot 18) Runoff = 0.37 cfs @ 12.03 hrs, Volume= 1,115 cf, Depth= 1.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description 9,990 61 >75% Grass cover, Good, HSG B 9,990 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 10S: Proposed to Prince Street (Lot 18) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (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 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=9,990 sf Runoff Volume=1,115 cf Runoff Depth=1.34" Tc=5.0 min CN=61 0.37 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 65HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 20S: Existing to Lot 18 Infiltration System Runoff = 4.23 cfs @ 12.03 hrs, Volume= 12,011 cf, Depth= 4.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 8,240 98 Roof * 21,760 98 Paved 4,740 61 >75% Grass cover, Good, HSG B 34,740 93 Weighted Average 4,740 13.64% Pervious Area 30,000 86.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 20S: Existing to Lot 18 Infiltration System Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=34,740 sf Runoff Volume=12,011 cf Runoff Depth=4.15" Tc=5.0 min CN=93 4.23 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 66HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 30S: Proposed to CB (Lot 19) Runoff = 0.28 cfs @ 12.06 hrs, Volume= 971 cf, Depth= 1.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description 8,700 61 >75% Grass cover, Good, HSG B 8,700 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.4 35 0.0350 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 3.4 40 0.0460 0.19 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 0.4 50 0.0800 1.98 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 25 0.1500 2.71 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 7.4 150 Total Subcatchment 30S: Proposed to CB (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (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 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=8,700 sf Runoff Volume=971 cf Runoff Depth=1.34" Flow Length=150' Tc=7.4 min CN=61 0.28 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 67HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 40S: Proposed to Prince Street (Lot 19) Runoff = 0.90 cfs @ 12.14 hrs, Volume= 4,134 cf, Depth= 1.21" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 1,250 98 Paved 33,240 58 Meadow, non-grazed, HSG B 6,640 55 Woods, Good, HSG B 41,130 59 Weighted Average 39,880 96.96% Pervious Area 1,250 3.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.4 15 0.0150 0.05 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 4.9 30 0.0750 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 2.0 30 0.1000 0.25 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 0.1 10 0.1000 2.21 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 12.4 85 Total Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 68HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcatchment 40S: Proposed to Prince Street (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=41,130 sf Runoff Volume=4,134 cf Runoff Depth=1.21" Flow Length=85' Tc=12.4 min CN=59 0.90 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 69HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 41S: Proposed to CB Runoff = 1.80 cfs @ 12.03 hrs, Volume= 5,098 cf, Depth= 4.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 12,900 98 Paved 1,245 61 >75% Grass cover, Good, HSG B 600 55 Woods, Good, HSG B 14,745 93 Weighted Average 1,845 12.51% Pervious Area 12,900 87.49% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 41S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=14,745 sf Runoff Volume=5,098 cf Runoff Depth=4.15" Tc=5.0 min CN=93 1.80 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 70HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 42S: Proposed to CB Runoff = 0.32 cfs @ 12.03 hrs, Volume= 901 cf, Depth= 4.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 2,275 98 Paved 400 61 >75% Grass cover, Good, HSG B 2,675 92 Weighted Average 400 14.95% Pervious Area 2,275 85.05% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 42S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=2,675 sf Runoff Volume=901 cf Runoff Depth=4.04" Tc=5.0 min CN=92 0.32 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 71HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 43S: Proposed to CB Runoff = 0.78 cfs @ 12.03 hrs, Volume= 2,267 cf, Depth= 4.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 5,715 98 Paved 510 61 >75% Grass cover, Good, HSG B 6,225 95 Weighted Average 510 8.19% Pervious Area 5,715 91.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 43S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=6,225 sf Runoff Volume=2,267 cf Runoff Depth=4.37" Tc=5.0 min CN=95 0.78 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 72HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 44S: Proposed to CB Runoff = 1.24 cfs @ 12.03 hrs, Volume= 3,565 cf, Depth= 4.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 9,025 98 Paved 1,020 61 >75% Grass cover, Good, HSG B 10,045 94 Weighted Average 1,020 10.15% Pervious Area 9,025 89.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 44S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=10,045 sf Runoff Volume=3,565 cf Runoff Depth=4.26" Tc=5.0 min CN=94 1.24 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 73HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 45S: Proposed to YD Runoff = 0.14 cfs @ 12.03 hrs, Volume= 442 cf, Depth= 1.27" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 300 98 Paved 1,570 61 >75% Grass cover, Good, HSG B 2,300 55 Woods, Good, HSG B 4,170 60 Weighted Average 3,870 92.81% Pervious Area 300 7.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 45S: Proposed to YD Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=4,170 sf Runoff Volume=442 cf Runoff Depth=1.27" Tc=5.0 min CN=60 0.14 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 74HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 52S: Roof Runoff = 1.14 cfs @ 12.03 hrs, Volume= 3,472 cf, Depth= 4.71" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Area (sf) CN Description * 8,840 98 Roof 8,840 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 52S: Roof Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 10-yr Rainfall=4.95" Runoff Area=8,840 sf Runoff Volume=3,472 cf Runoff Depth=4.71" Tc=5.0 min CN=98 1.14 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 75HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 20P: Lot 18 Infiltration System Inflow Area = 34,740 sf, 86.36% Impervious, Inflow Depth = 4.15" for 10-yr event Inflow = 4.23 cfs @ 12.03 hrs, Volume= 12,011 cf Outflow = 0.76 cfs @ 11.80 hrs, Volume= 12,011 cf, Atten= 82%, Lag= 0.0 min Discarded = 0.76 cfs @ 11.80 hrs, Volume= 12,011 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 202.04' @ 12.35 hrs Surf.Area= 6,187 sf Storage= 2,022 cf Plug-Flow detention time= 11.7 min calculated for 12,007 cf (100% of inflow) Center-of-Mass det. time= 11.7 min ( 797.8 - 786.1 ) Volume Invert Avail.Storage Storage Description #1 201.20' 3,465 cf Custom Stage Data (Prismatic) Listed below (Recalc) 12,993 cf Overall - 4,331 cf Embedded = 8,662 cf x 40.0% Voids #2 201.60' 1,692 cf 12.0" Round Pipe Storage Inside #1 L= 2,154.0' 4,331 cf Overall - 3.6" Wall Thickness = 1,692 cf 5,156 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 201.20 6,187 0 0 203.30 6,187 12,993 12,993 Device Routing Invert Outlet Devices #1 Discarded 201.20'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.00'12.0" Round Culvert L= 40.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.00' / 194.80' S= 0.0300 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 202.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.76 cfs @ 11.80 hrs HW=201.22' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=201.20' (Free Discharge) 2=Culvert (Passes 0.00 cfs of 8.20 cfs potential flow) 3=Orifice/Grate ( Controls 0.00 cfs) Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 76HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 20P: Lot 18 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Inflow Area=34,740 sf Peak Elev=202.04' Storage=2,022 cf 4.23 cfs 0.76 cfs 0.76 cfs 0.00 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 77HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 30P: CB Inflow Area = 43,440 sf, 69.06% Impervious, Inflow Depth = 0.27" for 10-yr event Inflow = 0.28 cfs @ 12.06 hrs, Volume= 971 cf Outflow = 0.28 cfs @ 12.06 hrs, Volume= 971 cf, Atten= 0%, Lag= 0.0 min Primary = 0.28 cfs @ 12.06 hrs, Volume= 971 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 191.76' @ 12.06 hrs Flood Elev= 194.27' Device Routing Invert Outlet Devices #1 Primary 191.50'12.0" Round Culvert L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 191.50' / 189.00' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.28 cfs @ 12.06 hrs HW=191.76' (Free Discharge) 1=Culvert (Inlet Controls 0.28 cfs @ 1.73 fps) Pond 30P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (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=43,440 sf Peak Elev=191.76' 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' 0.28 cfs 0.28 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 78HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 41P: CB Inflow Area = 14,745 sf, 87.49% Impervious, Inflow Depth = 4.15" for 10-yr event Inflow = 1.80 cfs @ 12.03 hrs, Volume= 5,098 cf Outflow = 1.80 cfs @ 12.03 hrs, Volume= 5,098 cf, Atten= 0%, Lag= 0.0 min Primary = 1.80 cfs @ 12.03 hrs, Volume= 5,098 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.45' @ 12.03 hrs Flood Elev= 201.20' Device Routing Invert Outlet Devices #1 Primary 198.70'12.0" Round Culvert L= 101.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 198.70' / 197.93' S= 0.0076 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.79 cfs @ 12.03 hrs HW=199.45' (Free Discharge) 1=Culvert (Barrel Controls 1.79 cfs @ 3.94 fps) Pond 41P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=14,745 sf Peak Elev=199.45' 12.0" Round Culvert n=0.012 L=101.0' S=0.0076 '/' 1.80 cfs 1.80 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 79HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 42P: CB Inflow Area = 2,675 sf, 85.05% Impervious, Inflow Depth = 4.04" for 10-yr event Inflow = 0.32 cfs @ 12.03 hrs, Volume= 901 cf Outflow = 0.32 cfs @ 12.03 hrs, Volume= 901 cf, Atten= 0%, Lag= 0.0 min Primary = 0.32 cfs @ 12.03 hrs, Volume= 901 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.48' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.32 cfs @ 12.03 hrs HW=199.48' (Free Discharge) 1=Culvert (Inlet Controls 0.32 cfs @ 1.79 fps) Pond 42P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=2,675 sf Peak Elev=199.48' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.32 cfs 0.32 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 80HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 43P: CB Inflow Area = 6,225 sf, 91.81% Impervious, Inflow Depth = 4.37" for 10-yr event Inflow = 0.78 cfs @ 12.03 hrs, Volume= 2,267 cf Outflow = 0.78 cfs @ 12.03 hrs, Volume= 2,267 cf, Atten= 0%, Lag= 0.0 min Primary = 0.78 cfs @ 12.03 hrs, Volume= 2,267 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.65' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.78 cfs @ 12.03 hrs HW=199.65' (Free Discharge) 1=Culvert (Inlet Controls 0.78 cfs @ 2.28 fps) Pond 43P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=6,225 sf Peak Elev=199.65' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.78 cfs 0.78 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 81HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 44P: CB Inflow Area = 10,045 sf, 89.85% Impervious, Inflow Depth = 4.26" for 10-yr event Inflow = 1.24 cfs @ 12.03 hrs, Volume= 3,565 cf Outflow = 1.24 cfs @ 12.03 hrs, Volume= 3,565 cf, Atten= 0%, Lag= 0.0 min Primary = 1.24 cfs @ 12.03 hrs, Volume= 3,565 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.78' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.24 cfs @ 12.03 hrs HW=199.78' (Free Discharge) 1=Culvert (Inlet Controls 1.24 cfs @ 2.60 fps) Pond 44P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=10,045 sf Peak Elev=199.78' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 1.24 cfs 1.24 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 82HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 45P: YD Inflow Area = 4,170 sf, 7.19% Impervious, Inflow Depth = 1.27" for 10-yr event Inflow = 0.14 cfs @ 12.03 hrs, Volume= 442 cf Outflow = 0.14 cfs @ 12.03 hrs, Volume= 442 cf, Atten= 0%, Lag= 0.0 min Primary = 0.14 cfs @ 12.03 hrs, Volume= 442 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 201.08' @ 12.03 hrs Flood Elev= 203.40' Device Routing Invert Outlet Devices #1 Primary 200.90'12.0" Round Culvert L= 107.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 200.90' / 198.22' S= 0.0250 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.14 cfs @ 12.03 hrs HW=201.08' (Free Discharge) 1=Culvert (Inlet Controls 0.14 cfs @ 1.45 fps) Pond 45P: YD Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=4,170 sf Peak Elev=201.08' 12.0" Round Culvert n=0.012 L=107.0' S=0.0250 '/' 0.14 cfs 0.14 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 83HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 46P: DMH [79] Warning: Submerged Pond 41P Primary device # 1 OUTLET by 0.70' Inflow Area = 17,420 sf, 87.11% Impervious, Inflow Depth = 4.13" for 10-yr event Inflow = 2.12 cfs @ 12.03 hrs, Volume= 5,999 cf Outflow = 2.12 cfs @ 12.03 hrs, Volume= 5,999 cf, Atten= 0%, Lag= 0.0 min Primary = 2.12 cfs @ 12.03 hrs, Volume= 5,999 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.63' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.83'15.0" Round Culvert L= 53.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.83' / 197.51' S= 0.0060 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=2.11 cfs @ 12.03 hrs HW=198.63' (Free Discharge) 1=Culvert (Barrel Controls 2.11 cfs @ 3.60 fps) Pond 46P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=17,420 sf Peak Elev=198.63' 15.0" Round Culvert n=0.012 L=53.0' S=0.0060 '/' 2.12 cfs 2.12 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 84HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 47P: DMH [79] Warning: Submerged Pond 46P Primary device # 1 INLET by 0.58' Inflow Area = 23,645 sf, 88.35% Impervious, Inflow Depth = 4.19" for 10-yr event Inflow = 2.90 cfs @ 12.03 hrs, Volume= 8,265 cf Outflow = 2.90 cfs @ 12.03 hrs, Volume= 8,265 cf, Atten= 0%, Lag= 0.0 min Primary = 2.90 cfs @ 12.03 hrs, Volume= 8,265 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.41' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.41'15.0" Round Culvert L= 36.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.41' / 197.19' S= 0.0061 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=2.88 cfs @ 12.03 hrs HW=198.41' (Free Discharge) 1=Culvert (Barrel Controls 2.88 cfs @ 3.77 fps) Pond 47P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=23,645 sf Peak Elev=198.41' 15.0" Round Culvert n=0.012 L=36.0' S=0.0061 '/' 2.90 cfs 2.90 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 85HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 48P: DMH [79] Warning: Submerged Pond 45P Primary device # 1 OUTLET by 0.23' [81] Warning: Exceeded Pond 47P by 0.04' @ 12.03 hrs Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 3.89" for 10-yr event Inflow = 4.28 cfs @ 12.03 hrs, Volume= 12,272 cf Outflow = 4.28 cfs @ 12.03 hrs, Volume= 12,272 cf, Atten= 0%, Lag= 0.0 min Primary = 4.28 cfs @ 12.03 hrs, Volume= 12,272 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.45' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.09'15.0" Round Culvert L= 11.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.09' / 197.02' S= 0.0064 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=4.26 cfs @ 12.03 hrs HW=198.45' (Free Discharge) 1=Culvert (Barrel Controls 4.26 cfs @ 3.98 fps) Pond 48P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Inflow Area=37,860 sf Peak Elev=198.45' 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' 4.28 cfs 4.28 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 86HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 49P: Hydrodynamic Separator Unit [79] Warning: Submerged Pond 48P Primary device # 1 INLET by 1.23' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 3.89" for 10-yr event Inflow = 4.28 cfs @ 12.03 hrs, Volume= 12,272 cf Outflow = 4.28 cfs @ 12.03 hrs, Volume= 12,272 cf, Atten= 0%, Lag= 0.0 min Primary = 4.28 cfs @ 12.03 hrs, Volume= 12,272 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.32' @ 12.03 hrs Flood Elev= 203.10' Device Routing Invert Outlet Devices #1 Primary 197.02'15.0" Round Culvert L= 42.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.02' / 196.77' S= 0.0060 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=4.26 cfs @ 12.03 hrs HW=198.32' (Free Discharge) 1=Culvert (Barrel Controls 4.26 cfs @ 4.15 fps) Pond 49P: Hydrodynamic Separator Unit Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Inflow Area=37,860 sf Peak Elev=198.32' 15.0" Round Culvert n=0.012 L=42.0' S=0.0060 '/' 4.28 cfs 4.28 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 87HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 50P: DMH [79] Warning: Submerged Pond 49P Primary device # 1 INLET by 1.01' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 3.89" for 10-yr event Inflow = 4.28 cfs @ 12.03 hrs, Volume= 12,272 cf Outflow = 4.28 cfs @ 12.03 hrs, Volume= 12,272 cf, Atten= 0%, Lag= 0.0 min Primary = 4.28 cfs @ 12.03 hrs, Volume= 12,272 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.03' @ 12.03 hrs Flood Elev= 203.70' Device Routing Invert Outlet Devices #1 Primary 196.67'15.0" Round Culvert L= 11.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.67' / 196.60' S= 0.0064 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=4.26 cfs @ 12.03 hrs HW=198.03' (Free Discharge) 1=Culvert (Barrel Controls 4.26 cfs @ 3.98 fps) Pond 50P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Inflow Area=37,860 sf Peak Elev=198.03' 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' 4.28 cfs 4.28 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 88HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 51P: Lot 19 Infiltration System [81] Warning: Exceeded Pond 50P by 1.94' @ 13.18 hrs Inflow Area = 46,700 sf, 83.63% Impervious, Inflow Depth = 4.05" for 10-yr event Inflow = 5.42 cfs @ 12.03 hrs, Volume= 15,744 cf Outflow = 0.39 cfs @ 11.36 hrs, Volume= 15,744 cf, Atten= 93%, Lag= 0.0 min Discarded = 0.39 cfs @ 11.36 hrs, Volume= 15,744 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.90' @ 12.95 hrs Surf.Area= 3,182 sf Storage= 4,611 cf Plug-Flow detention time= 76.9 min calculated for 15,740 cf (100% of inflow) Center-of-Mass det. time= 76.9 min ( 855.4 - 778.5 ) Volume Invert Avail.Storage Storage Description #1A 196.60' 2,454 cf 46.80'W x 68.00'L x 4.00'H Field A 12,730 cf Overall - 6,594 cf Embedded = 6,135 cf x 40.0% Voids #2A 196.60' 4,967 cf Galley 4x4x4 x 112 Inside #1 Inside= 42.0"W x 43.0"H => 12.67 sf x 3.50'L = 44.3 cf Outside= 52.8"W x 48.0"H => 14.72 sf x 4.00'L = 58.9 cf 7 Rows of 16 Chambers 7,421 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 196.60'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.60'12.0" Round Culvert L= 73.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.60' / 189.00' S= 0.1041 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 199.80'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.39 cfs @ 11.36 hrs HW=196.64' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.39 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=196.60' (Free Discharge) 2=Culvert ( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 89HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 51P: Lot 19 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)6 5 4 3 2 1 0 Inflow Area=46,700 sf Peak Elev=198.90' Storage=4,611 cf 5.42 cfs 0.39 cfs 0.39 cfs 0.00 cfs Proposed Conditions MA_Northampton 24-hr S1 10-yr Rainfall=4.95"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 90HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Link 10L: Discharge to Prince Street Inflow Area = 141,260 sf, 49.77% Impervious, Inflow Depth = 0.53" for 10-yr event Inflow = 1.31 cfs @ 12.11 hrs, Volume= 6,220 cf Primary = 1.31 cfs @ 12.11 hrs, Volume= 6,220 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Link 10L: Discharge to Prince Street Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=141,260 sf 1.31 cfs 1.31 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 91HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,990 sf 0.00% Impervious Runoff Depth=2.09"Subcatchment 10S: Proposed to Prince Tc=5.0 min CN=61 Runoff=0.60 cfs 1,737 cf Runoff Area=34,740 sf 86.36% Impervious Runoff Depth=5.30"Subcatchment 20S: Existing to Lot 18 Tc=5.0 min CN=93 Runoff=5.22 cfs 15,347 cf Runoff Area=8,700 sf 0.00% Impervious Runoff Depth=2.09"Subcatchment 30S: Proposed to CB (Lot 19) Flow Length=150' Tc=7.4 min CN=61 Runoff=0.45 cfs 1,513 cf Runoff Area=41,130 sf 3.04% Impervious Runoff Depth=1.92"Subcatchment 40S: Proposed to Prince Flow Length=85' Tc=12.4 min CN=59 Runoff=1.52 cfs 6,566 cf Runoff Area=14,745 sf 87.49% Impervious Runoff Depth=5.30"Subcatchment 41S: Proposed to CB Tc=5.0 min CN=93 Runoff=2.21 cfs 6,514 cf Runoff Area=2,675 sf 85.05% Impervious Runoff Depth=5.19"Subcatchment 42S: Proposed to CB Tc=5.0 min CN=92 Runoff=0.40 cfs 1,156 cf Runoff Area=6,225 sf 91.81% Impervious Runoff Depth=5.53"Subcatchment 43S: Proposed to CB Tc=5.0 min CN=95 Runoff=0.95 cfs 2,869 cf Runoff Area=10,045 sf 89.85% Impervious Runoff Depth=5.42"Subcatchment 44S: Proposed to CB Tc=5.0 min CN=94 Runoff=1.52 cfs 4,533 cf Runoff Area=4,170 sf 7.19% Impervious Runoff Depth=2.00"Subcatchment 45S: Proposed to YD Tc=5.0 min CN=60 Runoff=0.24 cfs 695 cf Runoff Area=8,840 sf 100.00% Impervious Runoff Depth=5.88"Subcatchment 52S: Roof Tc=5.0 min CN=98 Runoff=1.38 cfs 4,333 cf Peak Elev=202.31' Storage=2,888 cf Inflow=5.22 cfs 15,347 cfPond 20P: Lot 18 Infiltration System Discarded=0.76 cfs 15,347 cf Primary=0.00 cfs 0 cf Outflow=0.76 cfs 15,347 cf Peak Elev=191.83' Inflow=0.45 cfs 1,513 cfPond 30P: CB 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' Outflow=0.45 cfs 1,513 cf Peak Elev=199.56' Inflow=2.21 cfs 6,514 cfPond 41P: CB 12.0" Round Culvert n=0.012 L=101.0' S=0.0076 '/' Outflow=2.21 cfs 6,514 cf Peak Elev=199.51' Inflow=0.40 cfs 1,156 cfPond 42P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.40 cfs 1,156 cf Peak Elev=199.70' Inflow=0.95 cfs 2,869 cfPond 43P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.95 cfs 2,869 cf Peak Elev=199.86' Inflow=1.52 cfs 4,533 cfPond 44P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=1.52 cfs 4,533 cf Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 92HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Peak Elev=201.14' Inflow=0.24 cfs 695 cfPond 45P: YD 12.0" Round Culvert n=0.012 L=107.0' S=0.0250 '/' Outflow=0.24 cfs 695 cf Peak Elev=198.75' Inflow=2.61 cfs 7,670 cfPond 46P: DMH 15.0" Round Culvert n=0.012 L=53.0' S=0.0060 '/' Outflow=2.61 cfs 7,670 cf Peak Elev=198.56' Inflow=3.56 cfs 10,539 cfPond 47P: DMH 15.0" Round Culvert n=0.012 L=36.0' S=0.0061 '/' Outflow=3.56 cfs 10,539 cf Peak Elev=198.77' Inflow=5.33 cfs 15,768 cfPond 48P: DMH 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' Outflow=5.33 cfs 15,768 cf Peak Elev=198.66' Inflow=5.33 cfs 15,768 cfPond 49P: Hydrodynamic Separator Unit 15.0" Round Culvert n=0.012 L=42.0' S=0.0060 '/' Outflow=5.33 cfs 15,768 cf Peak Elev=198.35' Inflow=5.33 cfs 15,768 cfPond 50P: DMH 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' Outflow=5.33 cfs 15,768 cf Peak Elev=199.78' Storage=6,362 cf Inflow=6.71 cfs 20,100 cfPond 51P: Lot 19 Infiltration System Discarded=0.39 cfs 20,100 cf Primary=0.00 cfs 0 cf Outflow=0.39 cfs 20,100 cf Inflow=2.19 cfs 9,815 cfLink 10L: Discharge to Prince Street Primary=2.19 cfs 9,815 cf Total Runoff Area = 141,260 sf Runoff Volume = 45,262 cf Average Runoff Depth = 3.85" 50.23% Pervious = 70,955 sf 49.77% Impervious = 70,305 sf Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 93HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 10S: Proposed to Prince Street (Lot 18) Runoff = 0.60 cfs @ 12.03 hrs, Volume= 1,737 cf, Depth= 2.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description 9,990 61 >75% Grass cover, Good, HSG B 9,990 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 10S: Proposed to Prince Street (Lot 18) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=9,990 sf Runoff Volume=1,737 cf Runoff Depth=2.09" Tc=5.0 min CN=61 0.60 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 94HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 20S: Existing to Lot 18 Infiltration System Runoff = 5.22 cfs @ 12.03 hrs, Volume= 15,347 cf, Depth= 5.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 8,240 98 Roof * 21,760 98 Paved 4,740 61 >75% Grass cover, Good, HSG B 34,740 93 Weighted Average 4,740 13.64% Pervious Area 30,000 86.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 20S: Existing to Lot 18 Infiltration System Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=34,740 sf Runoff Volume=15,347 cf Runoff Depth=5.30" Tc=5.0 min CN=93 5.22 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 95HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 30S: Proposed to CB (Lot 19) Runoff = 0.45 cfs @ 12.06 hrs, Volume= 1,513 cf, Depth= 2.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description 8,700 61 >75% Grass cover, Good, HSG B 8,700 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.4 35 0.0350 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 3.4 40 0.0460 0.19 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 0.4 50 0.0800 1.98 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 25 0.1500 2.71 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 7.4 150 Total Subcatchment 30S: Proposed to CB (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.5 0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=8,700 sf Runoff Volume=1,513 cf Runoff Depth=2.09" Flow Length=150' Tc=7.4 min CN=61 0.45 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 96HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 40S: Proposed to Prince Street (Lot 19) Runoff = 1.52 cfs @ 12.13 hrs, Volume= 6,566 cf, Depth= 1.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 1,250 98 Paved 33,240 58 Meadow, non-grazed, HSG B 6,640 55 Woods, Good, HSG B 41,130 59 Weighted Average 39,880 96.96% Pervious Area 1,250 3.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.4 15 0.0150 0.05 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 4.9 30 0.0750 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 2.0 30 0.1000 0.25 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 0.1 10 0.1000 2.21 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 12.4 85 Total Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 97HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcatchment 40S: Proposed to Prince Street (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=41,130 sf Runoff Volume=6,566 cf Runoff Depth=1.92" Flow Length=85' Tc=12.4 min CN=59 1.52 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 98HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 41S: Proposed to CB Runoff = 2.21 cfs @ 12.03 hrs, Volume= 6,514 cf, Depth= 5.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 12,900 98 Paved 1,245 61 >75% Grass cover, Good, HSG B 600 55 Woods, Good, HSG B 14,745 93 Weighted Average 1,845 12.51% Pervious Area 12,900 87.49% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 41S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=14,745 sf Runoff Volume=6,514 cf Runoff Depth=5.30" Tc=5.0 min CN=93 2.21 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 99HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 42S: Proposed to CB Runoff = 0.40 cfs @ 12.03 hrs, Volume= 1,156 cf, Depth= 5.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 2,275 98 Paved 400 61 >75% Grass cover, Good, HSG B 2,675 92 Weighted Average 400 14.95% Pervious Area 2,275 85.05% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 42S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=2,675 sf Runoff Volume=1,156 cf Runoff Depth=5.19" Tc=5.0 min CN=92 0.40 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 100HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 43S: Proposed to CB Runoff = 0.95 cfs @ 12.03 hrs, Volume= 2,869 cf, Depth= 5.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 5,715 98 Paved 510 61 >75% Grass cover, Good, HSG B 6,225 95 Weighted Average 510 8.19% Pervious Area 5,715 91.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 43S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=6,225 sf Runoff Volume=2,869 cf Runoff Depth=5.53" Tc=5.0 min CN=95 0.95 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 101HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 44S: Proposed to CB Runoff = 1.52 cfs @ 12.03 hrs, Volume= 4,533 cf, Depth= 5.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 9,025 98 Paved 1,020 61 >75% Grass cover, Good, HSG B 10,045 94 Weighted Average 1,020 10.15% Pervious Area 9,025 89.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 44S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=10,045 sf Runoff Volume=4,533 cf Runoff Depth=5.42" Tc=5.0 min CN=94 1.52 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 102HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 45S: Proposed to YD Runoff = 0.24 cfs @ 12.03 hrs, Volume= 695 cf, Depth= 2.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 300 98 Paved 1,570 61 >75% Grass cover, Good, HSG B 2,300 55 Woods, Good, HSG B 4,170 60 Weighted Average 3,870 92.81% Pervious Area 300 7.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 45S: Proposed to YD Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)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 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=4,170 sf Runoff Volume=695 cf Runoff Depth=2.00" Tc=5.0 min CN=60 0.24 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 103HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 52S: Roof Runoff = 1.38 cfs @ 12.03 hrs, Volume= 4,333 cf, Depth= 5.88" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Area (sf) CN Description * 8,840 98 Roof 8,840 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 52S: Roof Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 25-yr Rainfall=6.12" Runoff Area=8,840 sf Runoff Volume=4,333 cf Runoff Depth=5.88" Tc=5.0 min CN=98 1.38 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 104HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 20P: Lot 18 Infiltration System Inflow Area = 34,740 sf, 86.36% Impervious, Inflow Depth = 5.30" for 25-yr event Inflow = 5.22 cfs @ 12.03 hrs, Volume= 15,347 cf Outflow = 0.76 cfs @ 11.70 hrs, Volume= 15,347 cf, Atten= 85%, Lag= 0.0 min Discarded = 0.76 cfs @ 11.70 hrs, Volume= 15,347 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 202.31' @ 12.46 hrs Surf.Area= 6,187 sf Storage= 2,888 cf Plug-Flow detention time= 17.5 min calculated for 15,342 cf (100% of inflow) Center-of-Mass det. time= 17.4 min ( 796.2 - 778.8 ) Volume Invert Avail.Storage Storage Description #1 201.20' 3,465 cf Custom Stage Data (Prismatic) Listed below (Recalc) 12,993 cf Overall - 4,331 cf Embedded = 8,662 cf x 40.0% Voids #2 201.60' 1,692 cf 12.0" Round Pipe Storage Inside #1 L= 2,154.0' 4,331 cf Overall - 3.6" Wall Thickness = 1,692 cf 5,156 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 201.20 6,187 0 0 203.30 6,187 12,993 12,993 Device Routing Invert Outlet Devices #1 Discarded 201.20'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.00'12.0" Round Culvert L= 40.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.00' / 194.80' S= 0.0300 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 202.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.76 cfs @ 11.70 hrs HW=201.22' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=201.20' (Free Discharge) 2=Culvert (Passes 0.00 cfs of 8.20 cfs potential flow) 3=Orifice/Grate ( Controls 0.00 cfs) Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 105HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 20P: Lot 18 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=34,740 sf Peak Elev=202.31' Storage=2,888 cf 5.22 cfs 0.76 cfs 0.76 cfs 0.00 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 106HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 30P: CB Inflow Area = 43,440 sf, 69.06% Impervious, Inflow Depth = 0.42" for 25-yr event Inflow = 0.45 cfs @ 12.06 hrs, Volume= 1,513 cf Outflow = 0.45 cfs @ 12.06 hrs, Volume= 1,513 cf, Atten= 0%, Lag= 0.0 min Primary = 0.45 cfs @ 12.06 hrs, Volume= 1,513 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 191.83' @ 12.06 hrs Flood Elev= 194.27' Device Routing Invert Outlet Devices #1 Primary 191.50'12.0" Round Culvert L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 191.50' / 189.00' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.45 cfs @ 12.06 hrs HW=191.83' (Free Discharge) 1=Culvert (Inlet Controls 0.45 cfs @ 1.97 fps) Pond 30P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.5 0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=43,440 sf Peak Elev=191.83' 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' 0.45 cfs 0.45 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 107HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 41P: CB Inflow Area = 14,745 sf, 87.49% Impervious, Inflow Depth = 5.30" for 25-yr event Inflow = 2.21 cfs @ 12.03 hrs, Volume= 6,514 cf Outflow = 2.21 cfs @ 12.03 hrs, Volume= 6,514 cf, Atten= 0%, Lag= 0.0 min Primary = 2.21 cfs @ 12.03 hrs, Volume= 6,514 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.56' @ 12.03 hrs Flood Elev= 201.20' Device Routing Invert Outlet Devices #1 Primary 198.70'12.0" Round Culvert L= 101.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 198.70' / 197.93' S= 0.0076 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=2.20 cfs @ 12.03 hrs HW=199.56' (Free Discharge) 1=Culvert (Barrel Controls 2.20 cfs @ 4.12 fps) Pond 41P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=14,745 sf Peak Elev=199.56' 12.0" Round Culvert n=0.012 L=101.0' S=0.0076 '/' 2.21 cfs 2.21 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 108HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 42P: CB Inflow Area = 2,675 sf, 85.05% Impervious, Inflow Depth = 5.19" for 25-yr event Inflow = 0.40 cfs @ 12.03 hrs, Volume= 1,156 cf Outflow = 0.40 cfs @ 12.03 hrs, Volume= 1,156 cf, Atten= 0%, Lag= 0.0 min Primary = 0.40 cfs @ 12.03 hrs, Volume= 1,156 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.51' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.39 cfs @ 12.03 hrs HW=199.51' (Free Discharge) 1=Culvert (Inlet Controls 0.39 cfs @ 1.90 fps) Pond 42P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=2,675 sf Peak Elev=199.51' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.40 cfs 0.40 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 109HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 43P: CB Inflow Area = 6,225 sf, 91.81% Impervious, Inflow Depth = 5.53" for 25-yr event Inflow = 0.95 cfs @ 12.03 hrs, Volume= 2,869 cf Outflow = 0.95 cfs @ 12.03 hrs, Volume= 2,869 cf, Atten= 0%, Lag= 0.0 min Primary = 0.95 cfs @ 12.03 hrs, Volume= 2,869 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.70' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.95 cfs @ 12.03 hrs HW=199.70' (Free Discharge) 1=Culvert (Inlet Controls 0.95 cfs @ 2.41 fps) Pond 43P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=6,225 sf Peak Elev=199.70' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.95 cfs 0.95 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 110HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 44P: CB Inflow Area = 10,045 sf, 89.85% Impervious, Inflow Depth = 5.42" for 25-yr event Inflow = 1.52 cfs @ 12.03 hrs, Volume= 4,533 cf Outflow = 1.52 cfs @ 12.03 hrs, Volume= 4,533 cf, Atten= 0%, Lag= 0.0 min Primary = 1.52 cfs @ 12.03 hrs, Volume= 4,533 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.86' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.52 cfs @ 12.03 hrs HW=199.86' (Free Discharge) 1=Culvert (Inlet Controls 1.52 cfs @ 2.76 fps) Pond 44P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=10,045 sf Peak Elev=199.86' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 1.52 cfs 1.52 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 111HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 45P: YD Inflow Area = 4,170 sf, 7.19% Impervious, Inflow Depth = 2.00" for 25-yr event Inflow = 0.24 cfs @ 12.03 hrs, Volume= 695 cf Outflow = 0.24 cfs @ 12.03 hrs, Volume= 695 cf, Atten= 0%, Lag= 0.0 min Primary = 0.24 cfs @ 12.03 hrs, Volume= 695 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 201.14' @ 12.03 hrs Flood Elev= 203.40' Device Routing Invert Outlet Devices #1 Primary 200.90'12.0" Round Culvert L= 107.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 200.90' / 198.22' S= 0.0250 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.24 cfs @ 12.03 hrs HW=201.14' (Free Discharge) 1=Culvert (Inlet Controls 0.24 cfs @ 1.66 fps) Pond 45P: YD Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)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=4,170 sf Peak Elev=201.14' 12.0" Round Culvert n=0.012 L=107.0' S=0.0250 '/' 0.24 cfs 0.24 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 112HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 46P: DMH [79] Warning: Submerged Pond 41P Primary device # 1 INLET by 0.04' Inflow Area = 17,420 sf, 87.11% Impervious, Inflow Depth = 5.28" for 25-yr event Inflow = 2.61 cfs @ 12.03 hrs, Volume= 7,670 cf Outflow = 2.61 cfs @ 12.03 hrs, Volume= 7,670 cf, Atten= 0%, Lag= 0.0 min Primary = 2.61 cfs @ 12.03 hrs, Volume= 7,670 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.75' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.83'15.0" Round Culvert L= 53.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.83' / 197.51' S= 0.0060 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=2.60 cfs @ 12.03 hrs HW=198.74' (Free Discharge) 1=Culvert (Barrel Controls 2.60 cfs @ 3.78 fps) Pond 46P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=17,420 sf Peak Elev=198.75' 15.0" Round Culvert n=0.012 L=53.0' S=0.0060 '/' 2.61 cfs 2.61 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 113HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 47P: DMH [79] Warning: Submerged Pond 46P Primary device # 1 INLET by 0.72' Inflow Area = 23,645 sf, 88.35% Impervious, Inflow Depth = 5.35" for 25-yr event Inflow = 3.56 cfs @ 12.03 hrs, Volume= 10,539 cf Outflow = 3.56 cfs @ 12.03 hrs, Volume= 10,539 cf, Atten= 0%, Lag= 0.0 min Primary = 3.56 cfs @ 12.03 hrs, Volume= 10,539 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.56' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.41'15.0" Round Culvert L= 36.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.41' / 197.19' S= 0.0061 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=3.55 cfs @ 12.03 hrs HW=198.55' (Free Discharge) 1=Culvert (Barrel Controls 3.55 cfs @ 3.96 fps) Pond 47P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=23,645 sf Peak Elev=198.56' 15.0" Round Culvert n=0.012 L=36.0' S=0.0061 '/' 3.56 cfs 3.56 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 114HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 48P: DMH [79] Warning: Submerged Pond 44P Primary device # 1 OUTLET by 0.01' [79] Warning: Submerged Pond 45P Primary device # 1 OUTLET by 0.54' [81] Warning: Exceeded Pond 47P by 0.21' @ 12.03 hrs Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 5.00" for 25-yr event Inflow = 5.33 cfs @ 12.03 hrs, Volume= 15,768 cf Outflow = 5.33 cfs @ 12.03 hrs, Volume= 15,768 cf, Atten= 0%, Lag= 0.0 min Primary = 5.33 cfs @ 12.03 hrs, Volume= 15,768 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.77' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.09'15.0" Round Culvert L= 11.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.09' / 197.02' S= 0.0064 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=5.26 cfs @ 12.03 hrs HW=198.76' (Free Discharge) 1=Culvert (Barrel Controls 5.26 cfs @ 4.28 fps) Pond 48P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=37,860 sf Peak Elev=198.77' 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' 5.33 cfs 5.33 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 115HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 49P: Hydrodynamic Separator Unit [79] Warning: Submerged Pond 48P Primary device # 1 INLET by 1.57' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 5.00" for 25-yr event Inflow = 5.33 cfs @ 12.03 hrs, Volume= 15,768 cf Outflow = 5.33 cfs @ 12.03 hrs, Volume= 15,768 cf, Atten= 0%, Lag= 0.0 min Primary = 5.33 cfs @ 12.03 hrs, Volume= 15,768 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.66' @ 12.03 hrs Flood Elev= 203.10' Device Routing Invert Outlet Devices #1 Primary 197.02'15.0" Round Culvert L= 42.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.02' / 196.77' S= 0.0060 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=5.31 cfs @ 12.03 hrs HW=198.65' (Free Discharge) 1=Culvert (Barrel Controls 5.31 cfs @ 4.35 fps) Pond 49P: Hydrodynamic Separator Unit Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=37,860 sf Peak Elev=198.66' 15.0" Round Culvert n=0.012 L=42.0' S=0.0060 '/' 5.33 cfs 5.33 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 116HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 50P: DMH [79] Warning: Submerged Pond 49P Primary device # 1 INLET by 1.32' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 5.00" for 25-yr event Inflow = 5.33 cfs @ 12.03 hrs, Volume= 15,768 cf Outflow = 5.33 cfs @ 12.03 hrs, Volume= 15,768 cf, Atten= 0%, Lag= 0.0 min Primary = 5.33 cfs @ 12.03 hrs, Volume= 15,768 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.35' @ 12.03 hrs Flood Elev= 203.70' Device Routing Invert Outlet Devices #1 Primary 196.67'15.0" Round Culvert L= 11.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.67' / 196.60' S= 0.0064 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=5.25 cfs @ 12.03 hrs HW=198.34' (Free Discharge) 1=Culvert (Barrel Controls 5.25 cfs @ 4.28 fps) Pond 50P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=37,860 sf Peak Elev=198.35' 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' 5.33 cfs 5.33 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 117HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 51P: Lot 19 Infiltration System [81] Warning: Exceeded Pond 50P by 2.82' @ 13.49 hrs Inflow Area = 46,700 sf, 83.63% Impervious, Inflow Depth = 5.16" for 25-yr event Inflow = 6.71 cfs @ 12.03 hrs, Volume= 20,100 cf Outflow = 0.39 cfs @ 11.03 hrs, Volume= 20,100 cf, Atten= 94%, Lag= 0.0 min Discarded = 0.39 cfs @ 11.03 hrs, Volume= 20,100 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.78' @ 13.32 hrs Surf.Area= 3,182 sf Storage= 6,362 cf Plug-Flow detention time= 116.1 min calculated for 20,100 cf (100% of inflow) Center-of-Mass det. time= 116.1 min ( 889.0 - 772.9 ) Volume Invert Avail.Storage Storage Description #1A 196.60' 2,454 cf 46.80'W x 68.00'L x 4.00'H Field A 12,730 cf Overall - 6,594 cf Embedded = 6,135 cf x 40.0% Voids #2A 196.60' 4,967 cf Galley 4x4x4 x 112 Inside #1 Inside= 42.0"W x 43.0"H => 12.67 sf x 3.50'L = 44.3 cf Outside= 52.8"W x 48.0"H => 14.72 sf x 4.00'L = 58.9 cf 7 Rows of 16 Chambers 7,421 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 196.60'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.60'12.0" Round Culvert L= 73.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.60' / 189.00' S= 0.1041 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 199.80'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.39 cfs @ 11.03 hrs HW=196.64' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.39 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=196.60' (Free Discharge) 2=Culvert ( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 118HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 51P: Lot 19 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=46,700 sf Peak Elev=199.78' Storage=6,362 cf 6.71 cfs 0.39 cfs 0.39 cfs 0.00 cfs Proposed Conditions MA_Northampton 24-hr S1 25-yr Rainfall=6.12"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 119HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Link 10L: Discharge to Prince Street Inflow Area = 141,260 sf, 49.77% Impervious, Inflow Depth = 0.83" for 25-yr event Inflow = 2.19 cfs @ 12.09 hrs, Volume= 9,815 cf Primary = 2.19 cfs @ 12.09 hrs, Volume= 9,815 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Link 10L: Discharge to Prince Street Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=141,260 sf 2.19 cfs 2.19 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 120HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,990 sf 0.00% Impervious Runoff Depth=3.38"Subcatchment 10S: Proposed to Prince Tc=5.0 min CN=61 Runoff=0.97 cfs 2,811 cf Runoff Area=34,740 sf 86.36% Impervious Runoff Depth=7.07"Subcatchment 20S: Existing to Lot 18 Tc=5.0 min CN=93 Runoff=6.61 cfs 20,477 cf Runoff Area=8,700 sf 0.00% Impervious Runoff Depth=3.38"Subcatchment 30S: Proposed to CB (Lot 19) Flow Length=150' Tc=7.4 min CN=61 Runoff=0.74 cfs 2,448 cf Runoff Area=41,130 sf 3.04% Impervious Runoff Depth=3.16"Subcatchment 40S: Proposed to Prince Flow Length=85' Tc=12.4 min CN=59 Runoff=2.55 cfs 10,818 cf Runoff Area=14,745 sf 87.49% Impervious Runoff Depth=7.07"Subcatchment 41S: Proposed to CB Tc=5.0 min CN=93 Runoff=2.81 cfs 8,691 cf Runoff Area=2,675 sf 85.05% Impervious Runoff Depth=6.95"Subcatchment 42S: Proposed to CB Tc=5.0 min CN=92 Runoff=0.51 cfs 1,550 cf Runoff Area=6,225 sf 91.81% Impervious Runoff Depth=7.31"Subcatchment 43S: Proposed to CB Tc=5.0 min CN=95 Runoff=1.20 cfs 3,793 cf Runoff Area=10,045 sf 89.85% Impervious Runoff Depth=7.19"Subcatchment 44S: Proposed to CB Tc=5.0 min CN=94 Runoff=1.93 cfs 6,021 cf Runoff Area=4,170 sf 7.19% Impervious Runoff Depth=3.27"Subcatchment 45S: Proposed to YD Tc=5.0 min CN=60 Runoff=0.39 cfs 1,135 cf Runoff Area=8,840 sf 100.00% Impervious Runoff Depth=7.67"Subcatchment 52S: Roof Tc=5.0 min CN=98 Runoff=1.73 cfs 5,650 cf Peak Elev=202.73' Storage=3,843 cf Inflow=6.61 cfs 20,477 cfPond 20P: Lot 18 Infiltration System Discarded=0.76 cfs 19,740 cf Primary=0.72 cfs 737 cf Outflow=1.48 cfs 20,477 cf Peak Elev=192.01' Inflow=0.98 cfs 3,185 cfPond 30P: CB 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' Outflow=0.98 cfs 3,185 cf Peak Elev=199.75' Inflow=2.81 cfs 8,691 cfPond 41P: CB 12.0" Round Culvert n=0.012 L=101.0' S=0.0076 '/' Outflow=2.81 cfs 8,691 cf Peak Elev=199.55' Inflow=0.51 cfs 1,550 cfPond 42P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=0.51 cfs 1,550 cf Peak Elev=199.77' Inflow=1.20 cfs 3,793 cfPond 43P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=1.20 cfs 3,793 cf Peak Elev=199.97' Inflow=1.93 cfs 6,021 cfPond 44P: CB 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' Outflow=1.93 cfs 6,021 cf Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 121HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Peak Elev=201.21' Inflow=0.39 cfs 1,135 cfPond 45P: YD 12.0" Round Culvert n=0.012 L=107.0' S=0.0250 '/' Outflow=0.39 cfs 1,135 cf Peak Elev=198.90' Inflow=3.31 cfs 10,242 cfPond 46P: DMH 15.0" Round Culvert n=0.012 L=53.0' S=0.0060 '/' Outflow=3.31 cfs 10,242 cf Peak Elev=198.77' Inflow=4.51 cfs 14,035 cfPond 47P: DMH 15.0" Round Culvert n=0.012 L=36.0' S=0.0061 '/' Outflow=4.51 cfs 14,035 cf Peak Elev=199.10' Inflow=6.83 cfs 21,190 cfPond 48P: DMH 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' Outflow=6.83 cfs 21,190 cf Peak Elev=199.14' Inflow=6.83 cfs 21,190 cfPond 49P: Hydrodynamic Separator Unit 15.0" Round Culvert n=0.012 L=42.0' S=0.0060 '/' Outflow=6.83 cfs 21,190 cf Peak Elev=198.68' Inflow=6.83 cfs 21,190 cfPond 50P: DMH 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' Outflow=6.83 cfs 21,190 cf Peak Elev=200.08' Storage=6,963 cf Inflow=8.56 cfs 26,841 cfPond 51P: Lot 19 Infiltration System Discarded=0.39 cfs 23,774 cf Primary=1.55 cfs 3,066 cf Outflow=1.94 cfs 26,841 cf Inflow=4.62 cfs 19,880 cfLink 10L: Discharge to Prince Street Primary=4.62 cfs 19,880 cf Total Runoff Area = 141,260 sf Runoff Volume = 63,394 cf Average Runoff Depth = 5.39" 50.23% Pervious = 70,955 sf 49.77% Impervious = 70,305 sf Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 122HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 10S: Proposed to Prince Street (Lot 18) Runoff = 0.97 cfs @ 12.03 hrs, Volume= 2,811 cf, Depth= 3.38" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description 9,990 61 >75% Grass cover, Good, HSG B 9,990 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 10S: Proposed to Prince Street (Lot 18) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=9,990 sf Runoff Volume=2,811 cf Runoff Depth=3.38" Tc=5.0 min CN=61 0.97 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 123HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 20S: Existing to Lot 18 Infiltration System Runoff = 6.61 cfs @ 12.03 hrs, Volume= 20,477 cf, Depth= 7.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 8,240 98 Roof * 21,760 98 Paved 4,740 61 >75% Grass cover, Good, HSG B 34,740 93 Weighted Average 4,740 13.64% Pervious Area 30,000 86.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 20S: Existing to Lot 18 Infiltration System Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=34,740 sf Runoff Volume=20,477 cf Runoff Depth=7.07" Tc=5.0 min CN=93 6.61 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 124HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 30S: Proposed to CB (Lot 19) Runoff = 0.74 cfs @ 12.06 hrs, Volume= 2,448 cf, Depth= 3.38" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description 8,700 61 >75% Grass cover, Good, HSG B 8,700 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.4 35 0.0350 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 3.4 40 0.0460 0.19 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 0.4 50 0.0800 1.98 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 25 0.1500 2.71 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 7.4 150 Total Subcatchment 30S: Proposed to CB (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=8,700 sf Runoff Volume=2,448 cf Runoff Depth=3.38" Flow Length=150' Tc=7.4 min CN=61 0.74 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 125HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 40S: Proposed to Prince Street (Lot 19) Runoff = 2.55 cfs @ 12.12 hrs, Volume= 10,818 cf, Depth= 3.16" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 1,250 98 Paved 33,240 58 Meadow, non-grazed, HSG B 6,640 55 Woods, Good, HSG B 41,130 59 Weighted Average 39,880 96.96% Pervious Area 1,250 3.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.4 15 0.0150 0.05 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 4.9 30 0.0750 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.09" 2.0 30 0.1000 0.25 Sheet Flow, Grass: Short n= 0.150 P2= 3.09" 0.1 10 0.1000 2.21 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 12.4 85 Total Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 126HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Subcatchment 40S: Proposed to Prince Street (Lot 19) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=41,130 sf Runoff Volume=10,818 cf Runoff Depth=3.16" Flow Length=85' Tc=12.4 min CN=59 2.55 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 127HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 41S: Proposed to CB Runoff = 2.81 cfs @ 12.03 hrs, Volume= 8,691 cf, Depth= 7.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 12,900 98 Paved 1,245 61 >75% Grass cover, Good, HSG B 600 55 Woods, Good, HSG B 14,745 93 Weighted Average 1,845 12.51% Pervious Area 12,900 87.49% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 41S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=14,745 sf Runoff Volume=8,691 cf Runoff Depth=7.07" Tc=5.0 min CN=93 2.81 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 128HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 42S: Proposed to CB Runoff = 0.51 cfs @ 12.03 hrs, Volume= 1,550 cf, Depth= 6.95" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 2,275 98 Paved 400 61 >75% Grass cover, Good, HSG B 2,675 92 Weighted Average 400 14.95% Pervious Area 2,275 85.05% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 42S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=2,675 sf Runoff Volume=1,550 cf Runoff Depth=6.95" Tc=5.0 min CN=92 0.51 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 129HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 43S: Proposed to CB Runoff = 1.20 cfs @ 12.03 hrs, Volume= 3,793 cf, Depth= 7.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 5,715 98 Paved 510 61 >75% Grass cover, Good, HSG B 6,225 95 Weighted Average 510 8.19% Pervious Area 5,715 91.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 43S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=6,225 sf Runoff Volume=3,793 cf Runoff Depth=7.31" Tc=5.0 min CN=95 1.20 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 130HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 44S: Proposed to CB Runoff = 1.93 cfs @ 12.03 hrs, Volume= 6,021 cf, Depth= 7.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 9,025 98 Paved 1,020 61 >75% Grass cover, Good, HSG B 10,045 94 Weighted Average 1,020 10.15% Pervious Area 9,025 89.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 44S: Proposed to CB Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=10,045 sf Runoff Volume=6,021 cf Runoff Depth=7.19" Tc=5.0 min CN=94 1.93 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 131HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 45S: Proposed to YD Runoff = 0.39 cfs @ 12.03 hrs, Volume= 1,135 cf, Depth= 3.27" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 300 98 Paved 1,570 61 >75% Grass cover, Good, HSG B 2,300 55 Woods, Good, HSG B 4,170 60 Weighted Average 3,870 92.81% Pervious Area 300 7.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 45S: Proposed to YD Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=4,170 sf Runoff Volume=1,135 cf Runoff Depth=3.27" Tc=5.0 min CN=60 0.39 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 132HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment 52S: Roof Runoff = 1.73 cfs @ 12.03 hrs, Volume= 5,650 cf, Depth= 7.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Area (sf) CN Description * 8,840 98 Roof 8,840 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 52S: Roof Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 MA_Northampton 24-hr S1 100-yr Rainfall=7.91" Runoff Area=8,840 sf Runoff Volume=5,650 cf Runoff Depth=7.67" Tc=5.0 min CN=98 1.73 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 133HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 20P: Lot 18 Infiltration System Inflow Area = 34,740 sf, 86.36% Impervious, Inflow Depth = 7.07" for 100-yr event Inflow = 6.61 cfs @ 12.03 hrs, Volume= 20,477 cf Outflow = 1.48 cfs @ 12.26 hrs, Volume= 20,477 cf, Atten= 78%, Lag= 14.1 min Discarded = 0.76 cfs @ 11.58 hrs, Volume= 19,740 cf Primary = 0.72 cfs @ 12.26 hrs, Volume= 737 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 202.73' @ 12.26 hrs Surf.Area= 6,187 sf Storage= 3,843 cf Plug-Flow detention time= 22.4 min calculated for 20,472 cf (100% of inflow) Center-of-Mass det. time= 22.4 min ( 792.9 - 770.5 ) Volume Invert Avail.Storage Storage Description #1 201.20' 3,465 cf Custom Stage Data (Prismatic) Listed below (Recalc) 12,993 cf Overall - 4,331 cf Embedded = 8,662 cf x 40.0% Voids #2 201.60' 1,692 cf 12.0" Round Pipe Storage Inside #1 L= 2,154.0' 4,331 cf Overall - 3.6" Wall Thickness = 1,692 cf 5,156 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 201.20 6,187 0 0 203.30 6,187 12,993 12,993 Device Routing Invert Outlet Devices #1 Discarded 201.20'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.00'12.0" Round Culvert L= 40.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.00' / 194.80' S= 0.0300 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 202.56'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.76 cfs @ 11.58 hrs HW=201.22' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.71 cfs @ 12.26 hrs HW=202.73' (Free Discharge) 2=Culvert (Passes 0.71 cfs of 9.44 cfs potential flow) 3=Orifice/Grate (Weir Controls 0.71 cfs @ 1.34 fps) Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 134HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 20P: Lot 18 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=34,740 sf Peak Elev=202.73' Storage=3,843 cf 6.61 cfs 1.48 cfs 0.76 cfs 0.72 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 135HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 30P: CB Inflow Area = 43,440 sf, 69.06% Impervious, Inflow Depth = 0.88" for 100-yr event Inflow = 0.98 cfs @ 12.25 hrs, Volume= 3,185 cf Outflow = 0.98 cfs @ 12.25 hrs, Volume= 3,185 cf, Atten= 0%, Lag= 0.0 min Primary = 0.98 cfs @ 12.25 hrs, Volume= 3,185 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 192.01' @ 12.25 hrs Flood Elev= 194.27' Device Routing Invert Outlet Devices #1 Primary 191.50'12.0" Round Culvert L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 191.50' / 189.00' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.98 cfs @ 12.25 hrs HW=192.01' (Free Discharge) 1=Culvert (Inlet Controls 0.98 cfs @ 2.43 fps) Pond 30P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=43,440 sf Peak Elev=192.01' 12.0" Round Culvert n=0.012 L=50.0' S=0.0500 '/' 0.98 cfs 0.98 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 136HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 41P: CB Inflow Area = 14,745 sf, 87.49% Impervious, Inflow Depth = 7.07" for 100-yr event Inflow = 2.81 cfs @ 12.03 hrs, Volume= 8,691 cf Outflow = 2.81 cfs @ 12.03 hrs, Volume= 8,691 cf, Atten= 0%, Lag= 0.0 min Primary = 2.81 cfs @ 12.03 hrs, Volume= 8,691 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.75' @ 12.03 hrs Flood Elev= 201.20' Device Routing Invert Outlet Devices #1 Primary 198.70'12.0" Round Culvert L= 101.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 198.70' / 197.93' S= 0.0076 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=2.80 cfs @ 12.03 hrs HW=199.75' (Free Discharge) 1=Culvert (Inlet Controls 2.80 cfs @ 3.56 fps) Pond 41P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=14,745 sf Peak Elev=199.75' 12.0" Round Culvert n=0.012 L=101.0' S=0.0076 '/' 2.81 cfs 2.81 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 137HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 42P: CB Inflow Area = 2,675 sf, 85.05% Impervious, Inflow Depth = 6.95" for 100-yr event Inflow = 0.51 cfs @ 12.03 hrs, Volume= 1,550 cf Outflow = 0.51 cfs @ 12.03 hrs, Volume= 1,550 cf, Atten= 0%, Lag= 0.0 min Primary = 0.51 cfs @ 12.03 hrs, Volume= 1,550 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.55' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.50 cfs @ 12.03 hrs HW=199.55' (Free Discharge) 1=Culvert (Inlet Controls 0.50 cfs @ 2.02 fps) Pond 42P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=2,675 sf Peak Elev=199.55' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 0.51 cfs 0.51 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 138HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 43P: CB Inflow Area = 6,225 sf, 91.81% Impervious, Inflow Depth = 7.31" for 100-yr event Inflow = 1.20 cfs @ 12.03 hrs, Volume= 3,793 cf Outflow = 1.20 cfs @ 12.03 hrs, Volume= 3,793 cf, Atten= 0%, Lag= 0.0 min Primary = 1.20 cfs @ 12.03 hrs, Volume= 3,793 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.77' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.20 cfs @ 12.03 hrs HW=199.77' (Free Discharge) 1=Culvert (Inlet Controls 1.20 cfs @ 2.58 fps) Pond 43P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=6,225 sf Peak Elev=199.77' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 1.20 cfs 1.20 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 139HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 44P: CB Inflow Area = 10,045 sf, 89.85% Impervious, Inflow Depth = 7.19" for 100-yr event Inflow = 1.93 cfs @ 12.03 hrs, Volume= 6,021 cf Outflow = 1.93 cfs @ 12.03 hrs, Volume= 6,021 cf, Atten= 0%, Lag= 0.0 min Primary = 1.93 cfs @ 12.03 hrs, Volume= 6,021 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.97' @ 12.03 hrs Flood Elev= 202.70' Device Routing Invert Outlet Devices #1 Primary 199.20'12.0" Round Culvert L= 9.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 199.20' / 198.75' S= 0.0500 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.92 cfs @ 12.03 hrs HW=199.96' (Free Discharge) 1=Culvert (Inlet Controls 1.92 cfs @ 2.98 fps) Pond 44P: CB Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=10,045 sf Peak Elev=199.97' 12.0" Round Culvert n=0.012 L=9.0' S=0.0500 '/' 1.93 cfs 1.93 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 140HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 45P: YD Inflow Area = 4,170 sf, 7.19% Impervious, Inflow Depth = 3.27" for 100-yr event Inflow = 0.39 cfs @ 12.03 hrs, Volume= 1,135 cf Outflow = 0.39 cfs @ 12.03 hrs, Volume= 1,135 cf, Atten= 0%, Lag= 0.0 min Primary = 0.39 cfs @ 12.03 hrs, Volume= 1,135 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 201.21' @ 12.03 hrs Flood Elev= 203.40' Device Routing Invert Outlet Devices #1 Primary 200.90'12.0" Round Culvert L= 107.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 200.90' / 198.22' S= 0.0250 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.39 cfs @ 12.03 hrs HW=201.21' (Free Discharge) 1=Culvert (Inlet Controls 0.39 cfs @ 1.89 fps) Pond 45P: YD Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=4,170 sf Peak Elev=201.21' 12.0" Round Culvert n=0.012 L=107.0' S=0.0250 '/' 0.39 cfs 0.39 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 141HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 46P: DMH [79] Warning: Submerged Pond 41P Primary device # 1 INLET by 0.20' [79] Warning: Submerged Pond 42P Primary device # 1 OUTLET by 0.15' Inflow Area = 17,420 sf, 87.11% Impervious, Inflow Depth = 7.06" for 100-yr event Inflow = 3.31 cfs @ 12.03 hrs, Volume= 10,242 cf Outflow = 3.31 cfs @ 12.03 hrs, Volume= 10,242 cf, Atten= 0%, Lag= 0.0 min Primary = 3.31 cfs @ 12.03 hrs, Volume= 10,242 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.90' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.83'15.0" Round Culvert L= 53.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.83' / 197.51' S= 0.0060 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=3.30 cfs @ 12.03 hrs HW=198.90' (Free Discharge) 1=Culvert (Barrel Controls 3.30 cfs @ 3.98 fps) Pond 46P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=17,420 sf Peak Elev=198.90' 15.0" Round Culvert n=0.012 L=53.0' S=0.0060 '/' 3.31 cfs 3.31 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 142HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 47P: DMH [79] Warning: Submerged Pond 43P Primary device # 1 OUTLET by 0.02' [79] Warning: Submerged Pond 46P Primary device # 1 INLET by 0.94' Inflow Area = 23,645 sf, 88.35% Impervious, Inflow Depth = 7.12" for 100-yr event Inflow = 4.51 cfs @ 12.03 hrs, Volume= 14,035 cf Outflow = 4.51 cfs @ 12.03 hrs, Volume= 14,035 cf, Atten= 0%, Lag= 0.0 min Primary = 4.51 cfs @ 12.03 hrs, Volume= 14,035 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.77' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.41'15.0" Round Culvert L= 36.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.41' / 197.19' S= 0.0061 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=4.50 cfs @ 12.03 hrs HW=198.77' (Free Discharge) 1=Culvert (Barrel Controls 4.50 cfs @ 4.19 fps) Pond 47P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=23,645 sf Peak Elev=198.77' 15.0" Round Culvert n=0.012 L=36.0' S=0.0061 '/' 4.51 cfs 4.51 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 143HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 48P: DMH [79] Warning: Submerged Pond 44P Primary device # 1 OUTLET by 0.34' [79] Warning: Submerged Pond 45P Primary device # 1 OUTLET by 0.87' [81] Warning: Exceeded Pond 47P by 0.32' @ 12.03 hrs Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 6.72" for 100-yr event Inflow = 6.83 cfs @ 12.03 hrs, Volume= 21,190 cf Outflow = 6.83 cfs @ 12.03 hrs, Volume= 21,190 cf, Atten= 0%, Lag= 0.0 min Primary = 6.83 cfs @ 12.03 hrs, Volume= 21,190 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.10' @ 12.03 hrs Flood Elev= 203.00' Device Routing Invert Outlet Devices #1 Primary 197.09'15.0" Round Culvert L= 11.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.09' / 197.02' S= 0.0064 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=6.80 cfs @ 12.03 hrs HW=199.09' (Free Discharge) 1=Culvert (Barrel Controls 6.80 cfs @ 5.54 fps) Pond 48P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=37,860 sf Peak Elev=199.10' 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' 6.83 cfs 6.83 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 144HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 49P: Hydrodynamic Separator Unit [81] Warning: Exceeded Pond 48P by 0.04' @ 12.03 hrs Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 6.72" for 100-yr event Inflow = 6.83 cfs @ 12.03 hrs, Volume= 21,190 cf Outflow = 6.83 cfs @ 12.03 hrs, Volume= 21,190 cf, Atten= 0%, Lag= 0.0 min Primary = 6.83 cfs @ 12.03 hrs, Volume= 21,190 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 199.14' @ 12.03 hrs Flood Elev= 203.10' Device Routing Invert Outlet Devices #1 Primary 197.02'15.0" Round Culvert L= 42.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 197.02' / 196.77' S= 0.0060 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=6.80 cfs @ 12.03 hrs HW=199.13' (Free Discharge) 1=Culvert (Barrel Controls 6.80 cfs @ 5.54 fps) Pond 49P: Hydrodynamic Separator Unit Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=37,860 sf Peak Elev=199.14' 15.0" Round Culvert n=0.012 L=42.0' S=0.0060 '/' 6.83 cfs 6.83 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 145HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 50P: DMH [79] Warning: Submerged Pond 49P Primary device # 1 INLET by 1.65' Inflow Area = 37,860 sf, 79.81% Impervious, Inflow Depth = 6.72" for 100-yr event Inflow = 6.83 cfs @ 12.03 hrs, Volume= 21,190 cf Outflow = 6.83 cfs @ 12.03 hrs, Volume= 21,190 cf, Atten= 0%, Lag= 0.0 min Primary = 6.83 cfs @ 12.03 hrs, Volume= 21,190 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 198.68' @ 12.03 hrs Flood Elev= 203.70' Device Routing Invert Outlet Devices #1 Primary 196.67'15.0" Round Culvert L= 11.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.67' / 196.60' S= 0.0064 '/' Cc= 0.900 n= 0.012, Flow Area= 1.23 sf Primary OutFlow Max=6.80 cfs @ 12.03 hrs HW=198.67' (Free Discharge) 1=Culvert (Barrel Controls 6.80 cfs @ 5.54 fps) Pond 50P: DMH Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=37,860 sf Peak Elev=198.68' 15.0" Round Culvert n=0.012 L=11.0' S=0.0064 '/' 6.83 cfs 6.83 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 146HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Pond 51P: Lot 19 Infiltration System [81] Warning: Exceeded Pond 50P by 2.85' @ 13.78 hrs Inflow Area = 46,700 sf, 83.63% Impervious, Inflow Depth = 6.90" for 100-yr event Inflow = 8.56 cfs @ 12.03 hrs, Volume= 26,841 cf Outflow = 1.94 cfs @ 12.26 hrs, Volume= 26,841 cf, Atten= 77%, Lag= 14.0 min Discarded = 0.39 cfs @ 10.43 hrs, Volume= 23,774 cf Primary = 1.55 cfs @ 12.26 hrs, Volume= 3,066 cf Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Peak Elev= 200.08' @ 12.26 hrs Surf.Area= 3,182 sf Storage= 6,963 cf Plug-Flow detention time= 111.8 min calculated for 26,833 cf (100% of inflow) Center-of-Mass det. time= 111.8 min ( 878.3 - 766.6 ) Volume Invert Avail.Storage Storage Description #1A 196.60' 2,454 cf 46.80'W x 68.00'L x 4.00'H Field A 12,730 cf Overall - 6,594 cf Embedded = 6,135 cf x 40.0% Voids #2A 196.60' 4,967 cf Galley 4x4x4 x 112 Inside #1 Inside= 42.0"W x 43.0"H => 12.67 sf x 3.50'L = 44.3 cf Outside= 52.8"W x 48.0"H => 14.72 sf x 4.00'L = 58.9 cf 7 Rows of 16 Chambers 7,421 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 196.60'5.340 in/hr Exfiltration over Horizontal area #2 Primary 196.60'12.0" Round Culvert L= 73.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 196.60' / 189.00' S= 0.1041 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 2 199.80'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.39 cfs @ 10.43 hrs HW=196.64' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.39 cfs) Primary OutFlow Max=1.55 cfs @ 12.26 hrs HW=200.08' (Free Discharge) 2=Culvert (Passes 1.55 cfs of 6.53 cfs potential flow) 3=Orifice/Grate (Weir Controls 1.55 cfs @ 1.74 fps) Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 147HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Pond 51P: Lot 19 Infiltration System Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)9 8 7 6 5 4 3 2 1 0 Inflow Area=46,700 sf Peak Elev=200.08' Storage=6,963 cf 8.56 cfs 1.94 cfs 0.39 cfs 1.55 cfs Proposed Conditions MA_Northampton 24-hr S1 100-yr Rainfall=7.91"2016102_ServiceNet Printed 1/18/2017Prepared by CME Associates, Inc. Page 148HydroCAD® 10.00-19 s/n 01289 © 2016 HydroCAD Software Solutions LLC Summary for Link 10L: Discharge to Prince Street Inflow Area = 141,260 sf, 49.77% Impervious, Inflow Depth = 1.69" for 100-yr event Inflow = 4.62 cfs @ 12.22 hrs, Volume= 19,880 cf Primary = 4.62 cfs @ 12.22 hrs, Volume= 19,880 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Link 10L: Discharge to Prince Street Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=141,260 sf 4.62 cfs 4.62 cfs ServiceNet Drainage Report SECTION F Design Plans (Includes Construction Period Pollution Prevention and Erosion & Sedimentation Control Plan and Post Construction Operation and Maintenance Plan) %/'#551%+#6'5+0% %TCDVTGG.CPG9QQFUVQEM%6 'CUV4KXGT&TKXG'CUV*CTVHQTF%6 'NO5VTGGV5QWVJDTKFIG/# ÄÄ^YYYEOGGPIKPGGTKPIEQO ŠŠŠŠ Š ŠŠŠŠŠŠŠŠŠŠŠŠŠŠŠŠŠ ŠŠŠ ŠŠŠŠŠŠŠŠŠŠŠŠŠŠ %/'#551%+#6'5+0%%TCDVTGG.CPG9QQFUVQEM%6'CUV4KXGT&TKXG'CUV*CTVHQTF%6'NO5VTGGV5QWVJDTKFIG/#ÄÄ^YYYEOGGPIKPGGTKPIEQO %/'#551%+#6'5+0%%TCDVTGG.CPG9QQFUVQEM%6'CUV4KXGT&TKXG'CUV*CTVHQTF%6'NO5VTGGV5QWVJDTKFIG/#ÄÄ^YYYEOGGPIKPGGTKPIEQO %/'#551%+#6'5+0%%TCDVTGG.CPG9QQFUVQEM%6'CUV4KXGT&TKXG'CUV*CTVHQTF%6'NO5VTGGV5QWVJDTKFIG/#ÄÄ^YYYEOGGPIKPGGTKPIEQO %/'#551%+#6'5+0%%TCDVTGG.CPG9QQFUVQEM%6'CUV4KXGT&TKXG'CUV*CTVHQTF%6'NO5VTGGV5QWVJDTKFIG/#ÄÄ^YYYEOGGPIKPGGTKPIEQOA %/'#551%+#6'5+0%%TCDVTGG.CPG9QQFUVQEM%6'CUV4KXGT&TKXG'CUV*CTVHQTF%6'NO5VTGGV5QWVJDTKFIG/#ÄÄ^YYYEOGGPIKPGGTKPIEQO %/'#551%+#6'5+0%%TCDVTGG.CPG9QQFUVQEM%6'CUV4KXGT&TKXG'CUV*CTVHQTF%6'NO5VTGGV5QWVJDTKFIG/#ÄÄ^YYYEOGGPIKPGGTKPIEQO %/'#551%+#6'5+0%%TCDVTGG.CPG9QQFUVQEM%6'CUV4KXGT&TKXG'CUV*CTVHQTF%6'NO5VTGGV5QWVJDTKFIG/#ÄÄ^YYYEOGGPIKPGGTKPIEQO ServiceNet Drainage Report SECTION G Soils Mapping Soil Map—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/20/2016 Page 1 of 3468695046869804687010468704046870704687100468713046871604686980468701046870404687070468710046871304687160693880693910693940693970694000694030694060694090694120694150694180694210 693910 693940 693970 694000 694030 694060 694090 694120 694150 694180 694210 42° 18' 45'' N 72° 38' 51'' W42° 18' 45'' N72° 38' 36'' W42° 18' 38'' N 72° 38' 51'' W42° 18' 38'' N 72° 38' 36'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 50 100 200 300Feet 0 20 40 80 120Meters Map Scale: 1:1,540 if printed on A landscape (11" x 8.5") sheet. Warning: Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Hampshire County, Massachusetts, Central Part Survey Area Data: Version 11, Sep 14, 2016 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 28, 2011—Apr 18, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Soil Map—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/20/2016 Page 2 of 3 Map Unit Legend Hampshire County, Massachusetts, Central Part (MA609) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 30A Raynham silt loam, 0 to 3 percent slopes 0.5 7.5% 220C Boxford silt loam, 8 to 15 percent slopes 1.2 15.8% 225A Belgrade silt loam, 0 to 3 percent slopes 2.6 35.9% 258B Amostown fine sandy loam, 3 to 8 percent slopes 3.0 40.8% Totals for Area of Interest 7.3 100.0% Soil Map—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/20/2016 Page 3 of 3 Hydrologic Soil Group—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/20/2016 Page 1 of 4468695046869804687010468704046870704687100468713046871604686980468701046870404687070468710046871304687160693880693910693940693970694000694030694060694090694120694150694180694210 693910 693940 693970 694000 694030 694060 694090 694120 694150 694180 694210 42° 18' 45'' N 72° 38' 51'' W42° 18' 45'' N72° 38' 36'' W42° 18' 38'' N 72° 38' 51'' W42° 18' 38'' N 72° 38' 36'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 50 100 200 300Feet 0 20 40 80 120Meters Map Scale: 1:1,540 if printed on A landscape (11" x 8.5") sheet. Warning: Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Hampshire County, Massachusetts, Central Part Survey Area Data: Version 11, Sep 14, 2016 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 28, 2011—Apr 18, 2011 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. Hydrologic Soil Group—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/20/2016 Page 2 of 4 Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — Hampshire County, Massachusetts, Central Part (MA609) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 30A Raynham silt loam, 0 to 3 percent slopes C/D 0.5 7.5% 220C Boxford silt loam, 8 to 15 percent slopes D 1.2 15.8% 225A Belgrade silt loam, 0 to 3 percent slopes C 2.6 35.9% 258B Amostown fine sandy loam, 3 to 8 percent slopes B 3.0 40.8% Totals for Area of Interest 7.3 100.0% Hydrologic Soil Group—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/20/2016 Page 3 of 4 Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/20/2016 Page 4 of 4 Saturated Hydraulic Conductivity (Ksat)—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/20/2016 Page 1 of 3468695046869804687010468704046870704687100468713046871604686980468701046870404687070468710046871304687160693880693910693940693970694000694030694060694090694120694150694180694210 693910 693940 693970 694000 694030 694060 694090 694120 694150 694180 694210 42° 18' 45'' N 72° 38' 51'' W42° 18' 45'' N72° 38' 36'' W42° 18' 38'' N 72° 38' 51'' W42° 18' 38'' N 72° 38' 36'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 50 100 200 300Feet 0 20 40 80 120Meters Map Scale: 1:1,540 if printed on A landscape (11" x 8.5") sheet. Warning: Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons <= 1.0899 > 1.0899 and <= 5.1500 > 5.1500 and <= 10.9372 > 10.9372 and <= 16.1320 Not rated or not available Soil Rating Lines <= 1.0899 > 1.0899 and <= 5.1500 > 5.1500 and <= 10.9372 > 10.9372 and <= 16.1320 Not rated or not available Soil Rating Points <= 1.0899 > 1.0899 and <= 5.1500 > 5.1500 and <= 10.9372 > 10.9372 and <= 16.1320 Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Hampshire County, Massachusetts, Central Part Survey Area Data: Version 11, Sep 14, 2016 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 28, 2011—Apr 18, 2011 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. Saturated Hydraulic Conductivity (Ksat)—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/20/2016 Page 2 of 3 Saturated Hydraulic Conductivity (Ksat) Saturated Hydraulic Conductivity (Ksat)— Summary by Map Unit — Hampshire County, Massachusetts, Central Part (MA609) Map unit symbol Map unit name Rating (micrometers per second) Acres in AOI Percent of AOI 30A Raynham silt loam, 0 to 3 percent slopes 5.1500 0.5 7.5% 220C Boxford silt loam, 8 to 15 percent slopes 1.0899 1.2 15.8% 225A Belgrade silt loam, 0 to 3 percent slopes 10.9372 2.6 35.9% 258B Amostown fine sandy loam, 3 to 8 percent slopes 16.1320 3.0 40.8% Totals for Area of Interest 7.3 100.0% Description Saturated hydraulic conductivity (Ksat) refers to the ease with which pores in a saturated soil transmit water. The estimates are expressed in terms of micrometers per second. They are based on soil characteristics observed in the field, particularly structure, porosity, and texture. Saturated hydraulic conductivity is considered in the design of soil drainage systems and septic tank absorption fields. For each soil layer, this attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used. The numeric Ksat values have been grouped according to standard Ksat class limits. Rating Options Units of Measure: micrometers per second Aggregation Method: Dominant Component Component Percent Cutoff: None Specified Tie-break Rule: Fastest Interpret Nulls as Zero: No Layer Options (Horizon Aggregation Method): All Layers (Weighted Average) Saturated Hydraulic Conductivity (Ksat)—Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/20/2016 Page 3 of 3 Approx. Location of Proposed Infiltration System ServiceNet Drainage Report SECTION H Hydrologic Data NOAA Atlas 14, Volume 10, Version 2 Location name: Northampton, Massachusetts, USA* Latitude: 42.3117°, Longitude: -72.6462° Elevation: 203.3 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 0.328 (0.252-0.421) 0.389 (0.299-0.501) 0.490 (0.375-0.633) 0.573 (0.436-0.745) 0.688 (0.508-0.935) 0.777 (0.562-1.08) 0.865 (0.609-1.25) 0.970 (0.651-1.44) 1.11 (0.717-1.71) 1.21 (0.768-1.91) 10-min 0.464 (0.356-0.597) 0.551 (0.423-0.709) 0.694 (0.531-0.896) 0.812 (0.618-1.06) 0.975 (0.719-1.32) 1.10 (0.796-1.53) 1.23 (0.862-1.77) 1.37 (0.922-2.04) 1.57 (1.02-2.42) 1.72 (1.09-2.70) 15-min 0.546 (0.419-0.702) 0.649 (0.498-0.835) 0.816 (0.624-1.05) 0.955 (0.727-1.24) 1.15 (0.846-1.56) 1.29 (0.937-1.80) 1.44 (1.02-2.08) 1.62 (1.09-2.40) 1.85 (1.20-2.84) 2.02 (1.28-3.18) 30-min 0.750 (0.576-0.964) 0.891 (0.684-1.15) 1.12 (0.859-1.45) 1.32 (1.00-1.71) 1.58 (1.17-2.15) 1.78 (1.29-2.48) 1.99 (1.40-2.86) 2.23 (1.49-3.30) 2.54 (1.65-3.92) 2.79 (1.76-4.38) 60-min 0.954 (0.732-1.23) 1.13 (0.870-1.46) 1.43 (1.09-1.85) 1.67 (1.27-2.18) 2.01 (1.48-2.73) 2.27 (1.64-3.15) 2.53 (1.78-3.65) 2.84 (1.90-4.21) 3.24 (2.10-4.99) 3.55 (2.25-5.58) 2-hr 1.21 (0.937-1.54) 1.44 (1.11-1.84) 1.81 (1.40-2.32) 2.12 (1.63-2.73) 2.55 (1.90-3.44) 2.87 (2.10-3.98) 3.20 (2.28-4.62) 3.63 (2.45-5.36) 4.20 (2.73-6.43) 4.63 (2.94-7.25) 3-hr 1.38 (1.08-1.75) 1.65 (1.28-2.09) 2.08 (1.61-2.66) 2.44 (1.88-3.14) 2.94 (2.20-3.97) 3.32 (2.44-4.60) 3.71 (2.66-5.36) 4.24 (2.86-6.24) 4.95 (3.22-7.56) 5.48 (3.49-8.56) 6-hr 1.71 (1.34-2.16) 2.07 (1.62-2.61) 2.66 (2.08-3.37) 3.15 (2.44-4.01) 3.82 (2.89-5.14) 4.34 (3.22-5.99) 4.85 (3.52-7.02) 5.64 (3.82-8.26) 6.68 (4.36-10.2) 7.47 (4.76-11.6) 12-hr 2.09 (1.65-2.61) 2.58 (2.04-3.23) 3.38 (2.66-4.25) 4.05 (3.17-5.11) 4.96 (3.78-6.64) 5.67 (4.24-7.80) 6.37 (4.67-9.22) 7.51 (5.11-10.9) 9.01 (5.89-13.6) 10.1 (6.49-15.7) 24-hr 2.46 (1.97-3.05) 3.09 (2.46-3.83) 4.11 (3.26-5.12) 4.95 (3.91-6.21) 6.12 (4.70-8.15) 7.02 (5.30-9.62) 7.91 (5.86-11.4) 9.42 (6.43-13.6) 11.4 (7.48-17.2) 12.9 (8.28-19.8) 2-day 2.82 (2.27-3.46) 3.55 (2.85-4.37) 4.75 (3.80-5.86) 5.74 (4.57-7.14) 7.11 (5.51-9.42) 8.16 (6.22-11.1) 9.21 (6.88-13.3) 11.0 (7.57-15.9) 13.4 (8.85-20.1) 15.3 (9.83-23.3) 3-day 3.08 (2.49-3.76) 3.87 (3.13-4.74) 5.17 (4.16-6.36) 6.25 (5.00-7.73) 7.73 (6.02-10.2) 8.88 (6.79-12.1) 10.0 (7.51-14.4) 12.0 (8.26-17.2) 14.7 (9.68-21.9) 16.7 (10.7-25.4) 4-day 3.31 (2.68-4.03) 4.15 (3.36-5.06) 5.52 (4.46-6.77) 6.66 (5.35-8.22) 8.23 (6.43-10.8) 9.44 (7.24-12.8) 10.7 (8.00-15.3) 12.8 (8.79-18.3) 15.6 (10.3-23.2) 17.7 (11.4-26.9) 7-day 3.95 (3.23-4.78) 4.88 (3.98-5.91) 6.40 (5.21-7.79) 7.66 (6.19-9.39) 9.40 (7.38-12.3) 10.7 (8.27-14.4) 12.1 (9.08-17.1) 14.3 (9.92-20.4) 17.3 (11.5-25.6) 19.6 (12.7-29.6) 10-day 4.59 (3.77-5.54) 5.57 (4.57-6.73) 7.17 (5.86-8.69) 8.50 (6.90-10.4) 10.3 (8.12-13.4) 11.7 (9.04-15.6) 13.1 (9.86-18.4) 15.4 (10.7-21.8) 18.4 (12.2-27.1) 20.6 (13.4-31.1) 20-day 6.62 (5.49-7.92) 7.66 (6.34-9.16) 9.35 (7.70-11.2) 10.7 (8.80-13.0) 12.7 (10.0-16.2) 14.2 (10.9-18.6) 15.7 (11.7-21.5) 17.7 (12.4-24.9) 20.4 (13.6-29.9) 22.4 (14.6-33.6) 30-day 8.31 (6.92-9.89) 9.38 (7.80-11.2) 11.1 (9.22-13.3) 12.6 (10.3-15.1) 14.6 (11.5-18.4) 16.1 (12.4-20.9) 17.6 (13.1-23.8) 19.5 (13.7-27.2) 21.9 (14.7-32.0) 23.8 (15.5-35.5) 45-day 10.4 (8.70-12.3) 11.5 (9.63-13.6) 13.4 (11.1-15.9) 14.9 (12.3-17.8) 17.0 (13.5-21.3) 18.6 (14.4-23.9) 20.2 (15.0-26.9) 21.9 (15.4-30.4) 24.1 (16.2-34.9) 25.7 (16.8-38.3) 60-day 12.1 (10.2-14.3) 13.3 (11.2-15.7) 15.2 (12.7-18.1) 16.8 (14.0-20.1) 19.1 (15.2-23.7) 20.8 (16.1-26.5) 22.5 (16.6-29.7) 24.0 (17.0-33.3) 26.1 (17.6-37.7) 27.6 (18.1-41.1) 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 Page 1 of 4Precipitation Frequency Data Server 11/20/2016http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=42.3117&lon=-72.6462&dat... PF graphical Back to Top Page 2 of 4Precipitation Frequency Data Server 11/20/2016http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=42.3117&lon=-72.6462&dat... Maps & aerials Small scale terrain Large scale terrain Large scale map + – 3km 2mi + – 100km 60mi + – 100km 60mi Page 3 of 4Precipitation Frequency Data Server 11/20/2016http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=42.3117&lon=-72.6462&dat... Commitment, Meaning & Excellence. In All We Do. www.cmeengineering.com ☐ Original ☐ Copy ☐ Record CME Project No. 2016102