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Home My WebLink About2019-09-17 Stormwater Management Plan LDP 7/2019 Date:July 2019 Project: Grogan's Field—Stoi-inwater Nlattagemettt Plait Grogan 's Field Town of North Andover STORM 'WATER MANAGEMENT PLAN July 2019 bA"4a4 OF►f ti CIVI cn No,38 I87Sv /ONALN Prepared by: 'VW Waterfield Design Group 50 Cross Street I Winchester,Massachusetts 1018901 t 781.756.0001 f 781.756.0007 WDG Project No.: 1573 Date:July 2019 Project: Grogan's Field—Stormwater ianagement Plan Introduction This Stormwater Management Plan has been prepared in conformance with the requirements of the 2008 Massachusetts Department of Environmental Protection(MADEP)Stormwater Handbook,the 2008 amendments to 310 CMR 10.00 et. seq. (Massachusetts Wetlands Act Regulations(MAWPA Regs.)),the Town of North Andover Stormwater Management and Erosion Control Regulations Land Disturbance Permit Adopted February 15,2011,and the Town of North Andover Stornnwatel• Management and Erosion Control Bylaw. This Plan is prepared to meet the requirements of MADEP Stormwater Checklist and is submitted as part of a Site Plan Review and Notice of Intent submittal to the Conservation Commission. Contact Information Name: Jinn Stanford Project Manager Director, Division of Public Works Address: Town Hall 120 Man Street North Andover, MA 01845 Telephone: 978-685-0950 Parcel Numbers: Map 13 Lots 33 Narrative Site Description The proposed redevelopment project site is located at Grogan's Field at 67 Baldwin Street off of Baldwin and Gilbert Streets. The site is at the intersection of Baldwin and Gilbert Streets. The proposed project is located on land which is presently a disturbed athletic field with a full size baseball field. Grogan's Field is owned by the Town of North Andover and is shown on the Town of North Andover's Assessor's Map 13 Lot 33. Description of Proposed Project The applicant is proposing to redevelop the site by constructing one(1)full size baseball and associated paved walkways and paths. The field will be natural turf with a dirt infield. Existing Conditions The project site consists of existing full size baseball field,which has been disturbed by gravel path that have been placed on the field as roads to temporary trailers,which have been removed. The site is primarily lawn with the exception of the skinned infields and the paved parking area. The overall site gradient slopes from southeastern corner of the fields to the north. A portion of the site drains to catch basin located in the northern section of the site,which connects to the Town drainage system. The rest of the site sheet flows onto abutter's property or to the Town street. For the purposes of this report the gravel that was spread across the field for emergency access to trailers will not be treated as existing conditions. Instead this area will be treated as existing lawn similar to the surrounding areas. Proposed Conditions The applicant is proposing redevelop the site by constructing one(1)full size baseball field,32 vehicle parking space area,and associated paved walkways. Tine field will be natural turf. Tine proposed site will predominately follow the slope of the existing site and drain from the south to the north. The new paved portion of the site and some of the field will drain to an area drain located in the eastern part of the site between two oak trees. Tine area drain will outlet to an infiltration chamber system with an overflow to the existing Town drainage system in Baldwin Street. Page I of 11 Date:July 2019 Project: Grogan's Field—Storpowater Management Plan Regulatory Areas: The existing Zoning District is Residential 4 District. The surrounding districts are Residential 4 Districts with the exception of tlhe northwest corner which is Industrial 3 District. See Existing Conditions Plan for survey information,existing topography, outline of vegetation and significant trees. The site drains to a catch basin in the northern end of the property,which connects to the Town drainage system. The Town stornnvater system outlets to the Merrimack River. No portion of the site is within the 100' feet of the 100-year flood boundary based on the most recent Flood Insurance Rate Maps(FIRM)25009CO209F,dated July 3,2012. No portion of the proposed disturbance is within 500' of habitat of the Massachusetts Natural Heritage& Endangered Species or Estimated Habitats of Rare Wildlife,or Certified Vernal Pools, Potential Vernal Pools, and Priority Habitat of Rare Species. There are no existing or proposed septic systems or wells within 100 feet of the site. Watershed Plans See attached plans W-I and W-2 for existing and proposed stormwater watersheds. Soils According to the NRCS Custom Soil Resource Repoli,the soils on site are listed as 651 ---Udorthents,smoothed. The soils surrounding the site are listed as—255B—Windsor loamy sand and 420B—Canton fine sandy loans. Urdorthents, labeled 651 on the map, includes the entire site. These are filled lands. The report classifies these areas as Hydrologic Soil Group A. Paxton loamy sand, labeled on the map as 255E is located to the northwest of the site. Windsor is a well drain soil with a low groundwater table. Tile report classifies these areas as Hydrologic Soil Group A. Canton fine sandy loam, labeled 420B on the map, is located east of the site. The soil is moderately well drained with a lohv groundwater table. The report classifies these areas as Hydrologic Soil Group B. Test pits conducted at tine site found compacted sandy loam glacial till throughout the site. The high groundwater elevation at most of the site was observed to be 7.8'—8.8' from grade. One test pit near the existing home plate had a perched water table 2.7' from grade. These test pit logs are included in this report. Based on the NRCS soil classifications,the evaluated test pit classifications of the soils, and Ile groundwater evaluation,the soils are classified as sandy loam Hydrologic Soil Group B as classified by the Rawl's Rate table in the DEP handbook. Proposed Drainage Improvements See drawings for proposed improvements and all components of the proposed storlthwater management system. Hydrologic and Hydraulic Deign Calculations See MA DEP Standard 2 for Hydrologic and Hydraulic Design Calculations. Page 2 of I I Date:Jade 2019 Project: Crogan's Field—Stormwater Management Plan Low Impact Development(LID)Practices The DEP Stormwater Standards require LID measures be considered. The DEP Stormwater checklist requires that the proponent document which environmentally sensitive and LID Techniques were considered during the planning and design of the projects. Below are a list of environmentally sensitive and LID Techniques and how they were or were not able to be implemented into the project: No disturbance to any [Vedand Resource Areas The proposed project is the redevelopment of existing fields. The project does not disturb any resource areas. Site Design Practices The site is designed to incorporate the minimum amount of facilities necessary in order for the project to be financially viable. Wherever practical the design was limited to decrease disturbance. Minimize Disturbance to Existing Trees arid Shrubs The applicant has sought to minimize the disturbance of existing trees and shrubs wherever possible. No trees are being removed from the project. Two(2)trees are being added. Use of "country drainage"versrts curb and gutter conveyance and piPelvegetated filter strit's Country drainage swales are used to direct runoff to the area drain. Bioretention Area Give the distance between the new impervious areas and the best location for infiltration the use of bioretention areas was not "practical. Constructed lVellands The site is designed to be recreational fields to be used by children and adults alike. Constructed wetlands could breed mosquitos and unnecessarily bring these disease carrying insects into contact with the field's users. Treebox Filter Given the budget and location of new impervious area tree box filters were not practical for the proposed site. fl'ater Quality Swales& Grass Channels Give the use of the site as a level field grass swales could cause tripping hazards and are not practical for tite site. Green Rogr The maintenance and additional structural construction necessary to install and maintain a green roof oil the proposed concessions stand is not economically feasible for the Town. Permeable Pavements Give the perched water table in the area of the new pavement the use of permeable pavers was not possible at the site. Cisterns Page 3 of 11 Date:Jule 2019 Project: Grogan's Field—Stormwater Management Plan Cistern and water reuse are not financially viable systems to incorporate into the site design for the Town of North Andover constructing and operating the site. Total Site Area Total Site Area to be Developed=4.33 acres Existing Impervious Area=0.27 acres Proposed Impervious Area=0.50 acres Design Point Discharge Areas The site discharges to six design points,which are listed below with their eventual outflow: Design Point 1: Abutting Properties—Final Outfall Town Drainage System and Shawsheen River Design Point 2: Town Drainage System—Final Outfall Town Drainage System and Shawsheen River All of these Design Points currently outfall to the existing Town regulated collection and outfall points. Therefore the site redevelopment will not cause erosion in wetlands or waters of the Commonwealth. Standard 1: No New Untreated Discharges The redevelopment site will sheet flow and shallow concentrate flow over vegetated areas,paved parking areas,and other paved areas will flow to catch basins and then infiltration chambers. The redeveloped site will then outlet to an existing drain manhole 0 to Baldwin Street and to the Town Drainage system. The new paved area will not be treated with any salt or sanding as they are for non-winter pedestrian uses. Since the runoff from the redeveloped will be treated in excess of the treatment provided by the existing conditions and will flow to the drainage system,which currently accepts site runoff,no new stormwater conveyance(outfalls)will discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. Design Poh2t Discharge Areas The site discharges to two design points,which are listed below with their eventual outflow: Design Point 1: Abutting Properties Final Outfall Town Drainage System and Shawsheen River Design Point 2: Town Baldwin Street Drainage System—Final Outfall Town Drainage System and Shawsheen River I� All of these Design Points currently outfall to the existing Town regulated collection and outfall points. Therefore,the redevelopment of the site will not cause erosion in wetlands or waters of the Commonwealth. Therefore,Standard I has been met by the proposed project. Standard 2: Peak Rate&Volume Attenuation The proposed project involves the redevelopment of the previously developed site. Attached to this report are the existing and proposed(site developed)runoff and volume calculations for the project for the 2 year, 10 year,25 year,and 100 year storms. All calculations were prepared using SCS Methods consistent with the requirements of the Wetland Protection Regulations and the 2008 MADEP Storrrnvater Handbook. The calculations were prepared using HydroCAD version 10.00 by Applied Page 4of11 Date:July 2019 Project; Crogau's Field—Siornnwater Management Plan Microcomputers Systems. Soils data for the modeling was obtained from the National Resource Conservation Service Soil Map (Online)for the Town of North Andover(see attached Existing Conditions Plan)and field test pits(see attached Test Pit Soil Logs). Ground cover data is based on existing and proposed site conditions, and times of concentration are based oft the tributary watershed characteristics. Hydrologic soil group data was obtained from the SCS National Engineering Handbook NEH#4- Hydrology. Times of concentration for the study were computed using SCS Methodology. Rainfall data for the study is based on the NRCC publication RR93-5(The Cornell Study)for the North Shore as required by the Town of North Andover. The total flows and volumes are based on a Type III SCS synthetic rainfall distribution. The runoff from the redevelopment project uses underground infiltration chambers to retain the stormwater on site so that there is no net increase in the peak rate of runoff or volume. Underdrain Field 11odeling Assumptions The underdrai tied fields and associated crushed stone storage areas were modelled as detention ponds. Infiltration rates were for sandy loam soil with an infiltration rate of 1.02 inAr(see attached drawdown calculations). Since both the existing and proposed runoff out flow into the same systems(Baldwin Street and Abutting Properties)columon design points were utilized. A comparison of existing and proposed flows and stormwater volume from the site are shown in the table below: Discharge Point#1 Discharge Point#1 Storm Existing Peak Proposed Storm Existing Proposed Return Inflow Rate (Site Return Volume of (Site Period (c.f.s.) Developed) Period Runoff(af) Developed) (years) Peak Inflow (years) Volume of Rate c.f.s. Runoff a 2 0.68 0.68 400 2 0.085 0.085 -0.000 10 2.18 2.18 -0.00 10 0.220 0.220 -0.000 25 3.54 3.54 400 25 0.342 0.342 -0.000 100 6.87 6.86 401 100 0.643 0.642 4001 Discharge Point#2 Discharge Point#2 Storm Existing Peak Proposed Storm Existing Proposed Return Inflow Rate (Site Return Volume of (Site Period (c.f.s.) Developed) Period Runoff(al) Developed) (years) Peak Inflow (years) Volume of Rate c.f.s. Runoff a 2 1.18 1.07 -0.11 2 0.150 0.137 -0.023 10 3.33 2.71 462 10 0.354 0.300 4054 25 5.24 4.16 -1.08 25 0.535 0.462 4073 100 9.80 9.65 415 100 0.973 0.903 4070 Based on the results of the calculations as demonstrated above,the requirements of Standard 2 have been met and the redevelopment of the site will not result in any net increase in the peak rate of runoff or the runoff volume from the site. Standard 3: Recharge Page 5 of 11 Bate: July 2019 Project:Grogan's Field—Stormwater Management Plan The proposed project involves the redevelopment of a previously developed site. The proposed project will provide infiltration from the impervious areas via prefabricated infiltration/storage chambers. First flush of stormwater runoff is directed to an isolator row to pretreat the runoff and remove solids. Calculations detailing the infiltration/recharge are attached to this report under the section infiltration Drawdown Calculations. The drawdown is also summarized below: - Underground Storage Chambers -Time to Empty—38.7 hours See the infiltration calculations attached to the end of the report for the stormwater infiltration calculations. Documentation slroi>>irrg that the irlftltrrrtiar BMPs do not rr ect near6v m,etland resource areas See Standards 1,2,3,4,8&9. The infiltration BMPs will be underground and will recharge and clean the stormwater as required in Standards 3&4 of the Stormwater Handbook therefore, the documentation of these and other Standards shows that the infiltration BMPs will not affect the nearby wetland resource areas. Therefore, Standard 3 has been met by the proposed project. Standard 4: Water Quality The proposed project involves the redevelopment of a previously developed site. The Long Term Operations and Maintenance Plan details how Best Management Practices(BMPs)will be employed to minimize stormwater pollution. Adequate access is provided to all water quality BMPs for inspection and maintenance. Total Suspended Solids Narrative(TSS) The new pavement for the proposed project will not be treated. Therefore no new areas need to be treated to removed Total Suspended Solids(TSS). The existing paved areas will continue to flow to the existing Town drainage system and given the size and scope of the site it is not practical to treat these existing paved areas for TSS. Therefore, Standard 4 has been met by the proposed redevelopment project to the maximum extent practical. Standard 5. Land Uses With Higher Potential Pollutant Loads(LUHPPLs) No portion of the proposed project constitute a Land Use with Higher Potential Pollutant Loads as defined by the 2008 MADEP Stormwater Handbook and the 2008 amendments to 310 CMR 10.00 et. seq. (MAWPA Regs). Therefore, Standard 5 has been met by the proposed redevelopment project to the maximum extent practical. Standard 6: Critical Areas No portion of the site is in a critical area(including Zones A and B of Lake Cochichewick). Therefore, Standard 6 has been met by the proposed redevelopment project. Standard 7: Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable A portion of proposed project is a redevelopment project as defined by the 2008 MADEP Stormwater Handbook and the 2008 amendments to 310 CMR 10.00 et.seq. (MAWPA Regs.). Below is a surnmary of how the different Standards are met for the redevelopment portions of the site. ',tandard 1 (must be met to the maximum extent practical): Page 6 of I I Date:July 2019 Project: Grogan's Field--Stornmater Management Plan Since the runoff from the redeveloped will flow to the drainage system which currently accepts site runoff,no new stormwater conveyance(outfalls)will discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. Therefore,Standard I has been met by the redevelopment portion of the project. Standard 2(Must be met to the maximum extent practical) Based on the results of the calculations as demonstrated in the report,the requirements of Standard 2 have been met and the redevelopment of the site as proposed will not result in any net increase in the peak rate of runoff and volume from the site(See HydroCAD calculations). Therefore, Standard 2 is met for the redevelopment portion of the project. Standard 3 (must be met to the maximum extent practical) Based on the results of the calculations as demonstrated in the report,the requirements of Standard 3 have been met and the redevelopment of the site as proposed will meet the recharge requirement for the site. Therefore, Standard 3 is met for the redevelopment portion of the project. Standard 4 (must be met to the maximum extent practical) Since no new treated paved surfaces are proposed the requirements of Standard 4 have been met by the redevelopment site to the maximum extent practical. Standard 5(must be met to the maximum extent practical) Since the proposed project use does not constitute a Land Use with Higher Potential Pollutant Loads as defined by file 2008 MADEP Stormwater Handbook and the 2008 amendments to 310 CMR 10.00 et. seq.(MAWPA Regs),the redevelopment area meets Standard 5 as described above. Therefore, Standard 5 is met for the redevelopment portion of the project. Standard 6(must be met to the maximum extent practical) No portion of the site is in a critical area. Therefore, Standard 6 has been met by the redevelopment portion of the project. Standard 8(must be met) Standard 8 is met for the redevelopment portion as described in the attached Erosion and Sediment Control Plan. Standard 9(must be met) Standard 9 is met for the redevelopment portion as described in the attached Operation and Maintenance Plan. Standard 10(must be met) Standard 10 is met for the redevelopment portion as described below. I Page 7 of 11 N j Date:July 2019 Project: Grogan's Field—Storinwater Managenient Plat) Standard 8: Construction Period Pollution Prevention Plan/Erosion and Sedimentation Control Plan See attached Stormwater Pollution Prevention Plait(SWPPP). Standard 9: Long Term Operation and Maintenance Plan POST CONSTRUCTION PERIOD LONG-TERM POLLUTION PREVENTION PLAN Post-Construction BMP's for Water Quality and to Prevent Illicit Discharges Good housekeeping practices for long-term pollution prevention are a detailed below. All material and waste products used for maintaining the site shall be stored inside,outside under cover,or placed in the dunpster if it is being disposed of. No post-construction vehicle washing shall occur on site. - Requirements for routine inspections and maintenance of stormwater BMPs are detailed below. Spill prevention and response plans are detailed below. - Provisions for maintenance of lawns,gardens,and other landscaped areas are detailed below. Storage of all fertilizers,herbicides,and pesticides shall follow the material storage requirements listed above. Use of all fertilizers,herbicides,and pesticides is detailed below. All pet waste shall be disposed of in the dumpster facilities. No septic system is on site. Solid waste management shall be relegated to the disposal facilities placed oil site. Snow disposal and plow pions are detailed below. Winter salt and sand use are detailed below. Street sweeping schedules are detailed below. Provisions for prevention of illicit discharges to the stornnvater management system are detailed below. - Training of staff involved with implementing the Long-Term Pollution Prevention Plan is detailed below. - List of Emergency contacts responsible for implementing the Long-Term Pollution Prevention Plan are listed above in the Basic Information section. Several types of structural and non-structural water quality controls in various combinations are proposed to treat storrnwater generated on the site.These measures include deep sump catch basins with hoods and stormwater treatment runts. These Water quality treatment measures will result in the removal of total suspended solids(TSS) load in runoff prior to discharge fi•om the site,consistent with DEP's TSS removal standard. The following best management practices are specified in the proposed development program to mitigate the increase ill stormwater runoff from the site. BMPs Used ➢ Nyloplast Area Drains ➢ Underground Stormwater Storage Chambers Page 8 of I I Date:July 2019 Project: Grogan's Field—Stormwater Management Plan Post-Development Aeti,ities I. The underground flood storage chambers and the inlet/outlet pipes shall be inspected a minimum of twice/year for signs of accumulated water or debris. Implement appropriate corrective action if any issues are discovered durijig the inspection. Cleaning shall be in strict conformance with the manufacturer's recommendations,which are attached to and made part of this Long Term Operation and Maintenance Plan. 2. All sediments removed from the site drainage facilities shall be disposed of properly and in accordance with all applicable local and state regulations. 3. All vegetated slope areas on the site shall be stabilized following completion of construction and maintained to control erosion. Any disturbed areas shall be re-seeded and stabilized by the application of jute mesh if the slope exceeds 3 feet horizontal to 1 foot vertical. 4. Snow storage at the site will be managed to prevent blockage of the area drain and other elements of the storm drainage system. 5. Snow shall not be dumped into any waterbody,pond,wetland resource area,wet basin or detention basin. 6. Sand and debris deposited on vegetated and paved areas at the site shall be cleared from the site and disposed of at the end of the snow season,no later than May 15. 7. Snow should be trucked off-site to an approved disposal area operated in accordance with MADEP Snow Management Standards when there is insufficient space for snow storage at the site. All structural BMP's and maintenance responsibi lities as identified on the site plans and within this document will be owned and maintained by the owner of the property and shall run witli the title of the property. Annual Reporting Form The Owner shall keep complete records of all BMP maintenance activities using the following form. Page 9 of I t ba o h � O N OPERATION AND MAINTENANCE PLAN Project:67 Baldwin Street Date:July 201.9 Location: North Andover MA 1 0 Structure or Task Inspection Inspection Performed Method Notes/Remarks S Schedule y Date By: f9 7 March ma Area Drain June Clam shell or vacuum sumps Clean when sediment is 12"deep September December Underground Storage Aril 1 May Inspect maintenance ports Remove accumulated debris and silt ti Chambers A Sept.I Oct. a 0 Party responsible for O& M Plan: Name Town of North Andover Address 384 Osgood Street,North Andover, MA 01 W Contact Jim Stanford Phone (978)685-0950 Date:July 2019 Project:Grogan's Field—Stormwater Management Plan Annual Operating Budget The estimated annual operating budget for maintaining sormwater system in the O&M Plan is$1,000f. Plan of BMP's Reference is made to the Proposed Utility Plan for the location of all BMP's. Training Training sessions must be provided by the Owner for property managers and operations personnel. The training will review specific procedures to be put in place that may be needed by operations personnel to implement the Operations and Maintenance plan. The Training Log shall be kept up to date by the Owner. Standard 10: Probibition of Illicit Discharges As provided for in the 2008 MADEP Stormwater Handbook and the 2008 amendments to 310 CMR 10.00 et. sect. (MAWPA Regs.)the following will serve as the Illicit Discharge Compliance Statement for the project. The existing developed site has no existing illicit discharges from the site. The new site is being designed such that there will not be any illicit discharges fronn the site. Conclusion As demonstrated in this report,the construction of the proposed development will meet the requirements of the 2008 MADEP Stornnvater Handbook and the 2008 amendments to 310 CMR 10.00 et. seq. (MAWPA Regs.)MADEP Stornnvater Guidelines and the North Andover Stormwater Management and Erosion Control Regulations except where as noted above. i i i u 9 Y i j i l I Page I I of 11 1 Date:July 2019 Project: Grogan's Field—Storrnwater Management Plan LOCUS MAP & N RCS SOIL MAP TEST PIT/SOILS DATA u u u u 3 i Reg; nal Locus 67 Baldwin Street, forth Andover, MA �\ \ 51 �� 11 t K Fg \1v~ }� ¢ors USSR ti•� i J LQwrence Municipal, Ems, i r 1s\.. - Rk Aso sm, IL z _1 VVG / -F ,r,tpNsTc, ENCM-i= `O Reilly7- age J� Suctons`Miils `A � y \ Casey =Duck$rdgaEr,FIN ,ea Ole IACK sT: a�� T�t r t�yes Rridgee. L5 tl 7 P S � P. s� SITE ANDO- R �`At l Sounow th Lawrence?o ,t \\ _ 1<41 �- lint' f t�h N r-- KEh SO �a -`� t i Park r 3 S¢pu,ch7 Cem AM\3tv a �VMS VA USDA United States A product of the National Custom Soil Resource Department of Cooperative Soil Survey, Agriculture a joint effort of the United Report for States Department of 1� N RCS Agriculture and other Essex County, Federal agencies, State Natural agencies including the Massachusetts, Resources Agricultural Experiment Conservation Stations, and local Service participants Northern or°tharn Part i I I w. 5 «4 1 b N 16 i 0 MMOMMOMMON 1,000 ft July 10, 2019 � / ) Preface Soil surveys contain information that affects land use planning in Survey areas. They highlight soil limitations that affect various land uses and provide information � about the properties ofthe soils in the survey areas. Soil surveys are designed for � many different users, including farmers, nannh8na, fureob*rs, aQronornia\s, urban p|annera. community officials, engineers, deve|opera, bui|dera, and home buyers. Also, oonaervati0niatu, heachers, atudentn, and specialists in rennaaUon, waste disposal, and pollution control can use the surveys to help them understand, protect, Vr enhance the eOV|r0nnnenL Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Gni| surveys identify soil properties that are used in making various land use or land treatment decisions. The information ie intended k) help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some ' cases. Examples include soil quality assessments(littp://www,rircs.usda.gov/wps/ portaVnroo/nnoin/ooi/a/hea|thi0mndood@inuonsewationendengine8hng applications. For more detailed information, contact your|Dom| USDA Gewin8 Center /bt|pe://off(ces,sc,egow.Wmde,gov/|ocator/app?agency=nros\Vr your NRCS State Soil Scientist(httpi/kmww,nrcm.usda gov/vmpo/pmrta|/nn2S/detai|/so{|m/cgntaCtus/? oid=nrCe142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject tuflooding. Some are too unstable tobe used esm foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements nr underground installations. The National Cooperative Soil Survey |na joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information |aavailable through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department ofAgriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where epp|ioab|e, enx. marital status, familial atutua, parental ntatUa, rm|ig|nn, sexual orientation, genetic |nf0rmction, political beliefs, rapheo|, or because all Dra , part of an individual's income is derived from any public assistance program. (Not / � all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at(202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, Q.C. 20250-9410 or call (800) 795-3272 (voice)or(202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. i I i 0 u 3 3j I 33 6 A 'I 3 - -\ . � Contents �� N� ��N� �� Preface.............-- ...... ...... -- ..........— ........ ..................................................2 How Soil Surveys Are Made... --------------------------O SoilMap.................................................. .......... ........ ...... ................................. 8 8ui| Map................................................................................................................9 Legend..................................................................... .......................................... O Map Unit Legend.. ------------------------------- 11 yNuA Unit Descriptions..........................................................-------..........11 Essex County, Massachusetts, Northern Part................................................ 13 255B--VVnduur loamy sand, 3ho8 percent slopes..................... ...........— 13 42O8--Conton fine sandy loam, 3bu8 percent slopes............................... 14 651--Udorthent . onloodhgd-----------------------.. 16 References.........— .................. .......... .............. ............ ......... ........................18 | / / 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas(MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes(units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 B 6 tl Custom Soil Resource Report scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and 6 0 Custom Soil Resource Report identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. 7 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. I I 8 j ♦. 11 �• 11 IN f r 11 � '11 r' S r � 4 � e 1< /i r P✓n„° ate, ..nartlk �Sa"' � ��' ^ r 40 ro f 9q 00 Iota 'rb dl��` m ri i�' ' i fir ro �� a✓ N, w4 S PM r=b(p' Yam� ` �'` � 4f sp• p}L 1 � r � � � ,��:'ate a rk ✓�/ . ,,�f J°r ��, �{'�, �S Q.Z • � ''"� ' '�a � aim w d ��a °� �, �� r sus Xm�,O f 1 f kr Po a " D � �f„ a J/ �✓ �� uwYeAlral��/ M� I �` r ,,l� V�_ f0! .UnionSt a +u l Un�on� ,p�'�, ^mow r �'.•.mmu a '� ya♦all"» ' Y^ a a �tl m 4mw I M �p ry Rraa N r ff /M If 1 � 11 1 1 -r• " rr • Custom Sail t .ource Report MAP LEGEND MAP INFORMATION i Area of Interest(AOI) c Spoil Area The soil surveys that comprise your AQl were mapped at Area of Interest(AOI) 1:15,800. Stony Spot Soils Soil Map Unit Polygons Very Stony Spot Warning:Soil Map may not be valid at this scale. � Wet Spot Soil Map Unit Lines Enlargement of maps beyond the scale of mapping can cause ® Soil Map Unit Points Other misunderstanding of the detail of mapping and accuracy of soil Special tine Features 1 line placement.The maps do not show the small areas of Special Point Features ! contrasting soils that could have been shown at a more detailed U Blowout Water Features scale. Streams and Canals Borrow Pit Transportation Please rely on the bar scale on each map sheet for map Clay Spot Rails measurements. r,,\ Closed Depression Interstate Highways Gravel Pit Source of Map: Natural Resources Conservation Service US Routes Web Soil Survey URL: �a Gravelly Spot Major Roads Coordinate System: Web Mercator(EPSG:3857) Landfill Local Roads Maps from the Web Soil Surrey are based on the Web Mercator Lava Flow Background projection,which preserves direction and shape but distorts distance and area.A projection that preserves area,such as the Marsh or swamp IM Aerial Photography Albers equal-area conic projection,should be used if more Mine or Quarry accurate calculations of distance or area are required. Miscellaneous Water This product is generated from the USDA-MRCS certified data as Perennial Water of the version dates)listed below. Rock Outcrop Soil Survey Area: Essex County,Massachusetts,Northern Part + Saline Spot Survey Area Data: Version 14,Sep 7,2018 $ Sandy Spot Soil map units are labeled(as space allows)for map scales Severely Eroded Spot 1:50,000 or larger. Al Sinkhole Date(s)aerial images were photographed: Aug 29,2014—Sep Slide or Slip 19,2014 Sadie Spot 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. 10 Custom Soil Resource Report Map Unit Legend Map Unit Symbol Map Unit Name Acres. n AOI Percent of AOI 255B Windsor loamy sand,3 to 8 21.0 37.2% percent slopes ..._................ - - _................�.......... ....----- - -- percent 4208 Canton finea sandy 55.5% loam,3 to 8 I 31.3 - --..._............._.._.___..__., opes 651 Udorthents,smoothed @ 4.1 7.4/o Totals for Area of Interest 3 _66.4 100.0%J Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The 11 Custom Soil Resource Report delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 12 Custom Soil Resource Report Essex County, Massachusetts, Northern Part 25513—Windsor loamy sand, 3 to 8 percent slopes Map Unit Setting National map unit symbol: 2svkf Elevation: 0 to 1,210 feet Mean annual precipitation: 36 to 71 inches Mean annual air temperature: 39 to 55 degrees F Frost-free period. 140 to 240 days Farmland classification: Farmland of statewide importance Map Unit Composition Windsor, loamy sand, and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Windsor, loamy Sand Setting Landform: Deltas, outwash plains, dunes, outwash terraces Landform position (three-dimensional): Riser, tread Down-slope shape: Linear, convex Across-slope shape: Linear, convex Parent material: Loose sandy glaciofluvial deposits derived from granite and/or loose sandy glaciofluvial deposits derived from schist and/or loose sandy glaciofluvial deposits derived from gneiss Typical profile O-0 to 1 inches: moderately decomposed plant material A - 1 to 3 inches: loamy sand Bw-3 to 25 inches: loamy sand 9 C- 25 to 65 inches: sand q I Properties and qualities Slope: 3 to 8 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Excessively drained r Runoff class: Low Capacity of the most limiting layer to transmit water(Ksat): Moderately high to very high (1.42 to 99.90 inlhr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Salinity, maximum in profile: Nonsaline (0.0 to 1.9 mmhos/cm) Available water storage in profile: Low(about 4.5 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2s Hydrologic Soil Group: A Hydric soil rating: No i 13 Custom Soil Resource Report Minor Components Hinckley, loamy sand Percent of map unit: 10 percent Landform: Karnes, deltas, outwash plains, eskers Landform position (two-dimensional): Summit, shoulder, backslope Landform position (three-dimensional): Nose slope, side slope, crest, head slope, rise Down-slope shape: Convex Across-slope shape: Convex, linear Hydric soil rating: No Deerfield, loamy sand Percent of map unit: 5 percent Landform: Outwash plains, terraces, deltas Landform position (two-dimensional): Footslope Landform position (three-dimensional): Tread, talf Down-slope shape: Linear Across-slope shape: Linear Hydric soil rating: No 42013----Canton fine sandy loam, 3 to 8 percent slopes Map Unit Setting National map unit symbol: 2w81 b Elevation: 0 to 1,180 feet Mean annual precipitation: 36 to 71 inches Mean annual air temperature: 39 to 55 degrees F Frost-free period. 140 to 240 days Farmland classification: All areas are prime farmland Map Unit Composition Canton and similar soils: 80 percent Minor components: 20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Canton Setting Landform: Ridges, moraines, hills Landform position (two-dimensional): Backslope, summit, shoulder Landform position (three-dimensional): Side slope, crest, nose slope Down-slope shape: Convex, linear Across-slope shape: Convex Parent material: Coarse-loamy over sandy melt-out till derived from gneiss, granite, and/or schist Typical profile Ap- 0 to 7 inches: fine sandy loam Bw1 - 7 to 15 inches: fine sandy loam 3 3 ' 14 1 3 Custom Soil Resource Report Bw2- 15 to 26 inches., gravelly fine sandy loam 2C- 26 to 65 inches: gravelly loamy sand Properties and qualities Slope: 3 to 8 percent Depth to restrictive feature: 19 to 39 inches to strongly contrasting textural stratification Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water(Ksat): Moderately low to high (0.14 to 14.17 inlhr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available waterstorage in profile: Very low(about 2.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2s Hydrologic Soil Group: B Hydric soil rating: No Minor Components Scituate Percent of map unit: 10 percent Landform: Ground moraines, drumlins, hills Landform position (two-dimensional): Backslope, footslope, summit Landform position (three-dimensional): Side slope, crest Down-slope shape: Linear, convex Across-slope shape: Convex Hydric soil rating: No Montauk Percent of map unit: 5 percent Landform: Drumlins, hills, ground moraines, moraines Landform position (two-dimensional): Backslope, shoulder, summit Landform position (three-dimensional): Side slope, crest Down-slope shape: Linear, convex Across-slope shape: Convex Hydric soil rating: No Charlton Percent of map unit: 4 percent Landform: Ridges, hills, ground moraines Landform position (two-dimensional): Backslope, shoulder, summit Landform position (three-dimensional): Side slope, crest Down-slope shape: Linear, convex Across-slope shape: Convex Hydric soil rating: No Swansea Percent of map unit: 1 percent Landform: Bogs, depressions, marshes, kettles, swamps Down-slope shape: Concave Across-slope shape: Concave Hydric soil rating: Yes 15 Custom Soil Resource Report 651---Udorthents, smoothed Map Unit Setting National map unit symbol. vjwk Elevation: 0 to 3,000 feet Mean annual precipitation: 45 to 54 inches Mean annual air temperature: 43 to 54 degrees F Frost-free period. 145 to 240 days Farmland classification: Not prime farmland 0 Map Unit Composition Udorthents and similar soils: 80 percent Minor components: 20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Udorthents Setting Parent material. Excavated and filled land loamy and/or excavated and filled land r sandy and gravelly 'i Typical profile H1 -0 to 6 inches: variable H2- 6 to 60 inches: variable Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Capacity of the most limiting layer to transmit water(Ksat): Moderately low to very high (0.06 to 20.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6s Hydrologic Soil Group: A Hydric soil rating: Unranked Minor Components Urban land Percent of map unit. 10 percent Hydric soil rating: Unranked Beaches Percent of map unit: 8 percent Hydric soil rating: Unranked 16 Custom Soil Resource Report Dumps Percent of map unit: 2 percent Hydric soil rating: Unranked 17 P References American Association of State Highway and Transportation Officials(AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials(ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. [Ittp://www.nres.usda.gov/wps/pol'tal/ nres/detail/national/soilsl?c'id=nresl42p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http.// www,i�res.usda.gov/wps/portal/rires/detailfnationa&/soils/?cid=nresl42p2_0 3577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nres.usda,gov/wps/portal/nres/detail/national/soils/?cad=nresl42p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical j Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http l/ w,nres.Lisda,gov/wps/pouIal/arcs/detail/soils/ home/?cid=nres 142 p2_053374 j United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nres.usda,govlwps/portal/arcs/ cietail/national/landrase/rangepastun°e/?cid=stelprdb1043�084 f r i 18 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. littp://www,nrcs,Lisda.gov/wps/portal/ ni°cs/detall/soills/scientists/?cid=nrcs,142p2-054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.Lisda.gov/wps/portal/nrcs/detaiV/iiational/soils/? 6d=nrcsI42p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S, Department of Agriculture Handbook 210. http:// www,nrcs,usda.gov/lnternet/FSE—DOCUMENTS/iircsl42p2_052290.pdf 19 Commonwealth of Massachusetts City/Town of Winchester - Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal •vy C. On-Site Review (continued) Deep Observation Hole Number: TP-1 Redoximorphic Features Coarse Fragments Soil Horizon!Soil Matrix:Color- (mottles) Soil Texture %by Volume Soil Soil Depth(in.) Layer Moist Munsell (USDA) Structure Consistence Other y ( } Depth Color Percent } Gravel Cobbles& (Moist) Stones 0-6" A 10YR3/2 Fine Sandy Loam 6-20" B 10YR5/6 Sandy Loam 20-39" C1 2.5Y6/3 co Sandy Loam Gravellye1�y S 5% 5% andy 39-130" C2 2.5Y713 CompactedGravelly 5% 5% SanddyyLoam Additional Notes: Weeping at 111„ Not standing water observed. C1 &C2 have high sand content. Forms stable cast. No ribboning. Estimate groundwater level 102" 130"depth not to refusal,but limits of backhoe. Tested By:Jacob Murray TP-1 &2.doc•rev. 1110 Form 11 —Soil Suitability Assessment for On-Site Sewage Disposal -Page 3 of 9 ......... ........ ......... Commonwealth of Massachusetts City/Town of Winchester Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number: TP-2 Redoximorphic Features Coarse Fragments Soil Horizon]Soil Matrix:Color- (mottles) Soil Texture %by Volume Soil Soil Depth(in.) Layer Moist Munsell (USDA) Structure Consistence Other y ( ) Depth Color Percent ) Gravel Cobbles (Moist) &Stones 0-18" A 10YR312 Fine Sandy Loam 18-30" B 1OYR516 Sandy Loam Compacted 30-125" C 2.5Y7/3 Gravelly Sandy 5% 5% Loam Additional Notes: Weeping at 108" Not standing water observed. C has high sand content. Estimate groundwater level 94" 125"depth not to refusal,but limits of backhoe. Tested By:Jacob Murray TP-1 &2.doc-rev. 1110 Form 11 —Soil Suitability Assessment for On-Site Sewage Disposal •Page 5 of 9 Commonwealth of Massachusetts = '' City/Town of Winchester Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal ,a C. On-Site Review (continued) Deep Observation Hole Number: TP-3 Redoximorphic Features Coarse Fragments Soil Horizont Soil Matrix: Color- (mottles) Soil Texture %by Volume Soil Soil Depth(in.) Layer Moist Munsell (USDA) Structure Consistence Other y ( Depth Color Percent Gravel Cobbles& (Moist) Stones 0-6" Fill 2.5Y5/3 Sandy Loam 6-12" Fill 10YR3/3 Sandy Loam 12-16" Ab 2.5Y3/2 Fine Sandy Loam 16-25" B 10YR5/6 Sandy Loam 25-127" C 2Y7/3 Compacted Gravelly 5% 5% Sandy Loam Additional Notes: Weeping at 112" Not standing water observed. Chas pockets of sand. Estimate groundwater level 106". 127"depth not to refusal,but limits of backhoe. Tested By:Jacob Murray 0-T Fill TP-3&4.doc•rev, 1/10 Form 11 —Soil Suitability Assessment for On-Site Sewage Disposal •Page 3 of 9 Commonwealth of Massachusetts City/Town of Winchester Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number: TP4 Redoximorphic Features Coarse Fragments Soil Horizon!Soil Matrix:Color- (mottles) Soil Texture %by Volume Soil Soil Depth(in.) Layer Moist Munsell USDA Structure Consistence Other y ( ) Depth Color Percent ( ) Gravel Cobbles (Moist) &Stones 0-20" Fill 2.5Y513 Additional Notes: '/"Copper and plastic water line with wire exposed 20"deep. Test pit abandoned. Tested By:Jacob Murray TP-3 8 4.doc•rev. 1110 Form 11—Soil Suitability Assessment for On-Site Sewage Disposal •Page 5 of 9 .............................. ................................... ....................... ....................... . Commonwealth of Massachusetts City/Town of Winchester Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number: TP-5 Redoximorphic Features Coarse Fragments Soil Horizon/Soil Matrix: Color- (mottles) Soil Texture %by Volume Soil Soil Depth(in.) Layer Moist(Mansell) (USDA) Cobbles& Structure Consistence Other Depth Color Percent Gravel Stones (Moist) 0-14" Fill Irregular Fine Sandy Loam 14-24" ARI 1 OYR3/2 Fine Sandy Loam 24-30" BFill 1 OYR5/6 Sandy Loam 30-42" cl 2.5Y7/3 32"perched Compacted Gravetly 5% 5% Sandy Loam 42-70" C2 2.5Y7/4 Compacted Gravelly 5% 5% Sandy Loam 70-125" C3 2.5Y7/3 Compandy Lcted oam Gravelly 5% 5% Sa Additional Notes: Weeping water at 108". No standing water observed. Natural groundwater level estimated at 100". 125"depth not to refusal, but limits of backhoe. Tested By:Jacob Murray TP-5&6.doc-rev. 1110 Form 11 —Soil Suitability Assessment for On-Site Sewage Disposal •Page 3 of 9 Commonwealth of Massachusetts City/Town of Winchester Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number: TP-6 Redoximorphic Features Coarse Fragments Soil Horizon/Soil Matrix:Color- (mottles) Soil Texture % by Volume Soil Soil Depth(in.) Consistence Other Layer Moist(Munsell) (USDA) Cobbles Structure Depth Color Percent Gravel (Moist) &Stones 0-6" Fill Reclaimed Asphalt 6-191, Fill Sandy Loam wlsome gravel 19-25" Ab 10YR3/2 Fine Sandy Loam Additional Notes: Test pit done to determine subgrade under existing gravel area not to determine groundwater or existing natural soil conditions. Test pit abandoned at 25". Tested By:Jacob Murray TP-5&6.doc-rev. 1/10 Form 11 —Soil Suitability Assessment for On-Site Sewage Disposal •Page 5 of 9 Date:July 2019 Project: Grogan's Field—Stormwater Nlanagement Plan I CHECKLIST FOR STORMWATER REPORT pu V 9 u u u u V ij j if Massachusetts Department of Environmental Protection Bureau oJ Resource Protection - Wetlands Program ��0= 0�N° � �= �� Report ��0N�� NN�� N ��U� ��U�� U� �� ~ A. Introduction | When ASbormwahyrReport must be submitted with the Notice of Intent permit application to document filling out forms compliance with the Stormwater Management Standards. The following checklist is NOT a substitute for on the computer, the �to/mvvober Report(which should provide nnnna substantive and detailed information) but is offered uaoon/ym�mn ` ' key m move your here as a tool to help the applicant organize their Stormwater Management documentation for their n«mor-d»not Report and for the reviewer to assess this information in a consistent format. As noted in the CherNiat, use the return the 5horn)webar Report must contain the engineering computations and supporting information set forth in key. Volume 3 of the Massachusetts Stormwater Handbook, The 8hurmmxater Report mumt be prepared and certified by m Registered Professional Engineer(RPE) licensed in the Commonwealth. � The Gh»rnlmmter Report must include: w The StV/novveter Checklist completed and stamped by a Registered Professional Engineer(see x�—�--� page 2) that certifies that the Storn�wxaharRepod contains aU required submittals.' This Checklist � ish) be used es the cover for the completed StormwusberReport. � • Applicant/Project Name � • Project Address * Name of Firm and Registered Professional Engineer that prepared the Report w 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 Gtnrmvvater Report must include a brief narrative � describing stormwater management practices, including environmentally sensitive site design and LID | y techniques, along with a diagram depicting runoff through the proposed BMP treatment train. Plans are required to show existing and proposed oonditions, identify all wetland resource oreaa. NRCS soil typgm, critical erege. Land Uses with Higher Potential Pollutant Loads (LUHPPL), and any areas on the site where infiltration rate io 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 StorrnvvaharK4anagemeni Report shall document compliance with each of the Gtormm/ohar Management Standards as provided in the Massachusetts SturmvvabyrHandbooh. The soils evaluation and calculations shall be done using the methodologies set forth in Volume 3 of the Massachusetts StVrmmwmtar Handbook. To ensure that the S\ormvvmtarRoport is complete, applicants are required to fill in the Gtormovvotar Report Checklist by checking the box to indicate that the specified information has been included in the Stormvvmtnr Report. If any of the information specified in the checklist has not been oubmittod, the applicant must provide an explanation. The completed Btormnwoter Report Checklist and Certification must be submitted with the Sk>rnlwabsrRapurL 'The Sxo/mwaterReport may also include the Illicit Discharge Compliance Statement required by Standard 10. If not included in the 8(onnweher Report,the|||iod Discharge Compliance Statement moo\be submitted prior to the Uiauba/gc ofm\nrm*mter runoff to the post-construction best management practices. 2 For some complex projoum,it may not be possible to ipdodo the CunekunUnn Period Erosion and Sedimentation Control Plan in the 8tormwmherReport. 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 un the site. Massachusetts Department of Environmental Protection Bureau OfResource Protection - Wetlands Program Checklist � �= �� Report ��N��0� 0N�� N �0U� ��U��i�� U� �� °r------~ � B. Stormwater Checklist and Certification The following ohmok|ind is intended to nenx* as a guide for applicants as to the ek3monhe 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 nf the components necessary for a comprehensive Stormwater Report that addresses the ten Stormwater Standards. KkoA*: Because otornovveha,requirements vary from project to project, it is possible that o complete Stormwater Report may not include information on some of the subjects specified in the Checklist. |[itin determined that a specific item does not apply to the project underreview` p{ugnannte that the item isnot applicable (N.A.) and provide the reasons for that determination. Aoomp|eba checklist must include the Certification set forth below signed by the Registered Professional Engineer who prepared the ShnrmnwabarReport. Registered Professional Engineer's Certification | have reviewed the Sb)rmwabarReport. 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 StormwoterHanUbook. | have also determined that the information presented in the Stormwater Checklist is accurate and that the information presented in the Shorrnwehar Report accurately reflects conditions at the site as of the date of this permit application. ) / Registered Professional Engineer Block and Signature CIVI ISTS ONAL Signa ate Checklist Project Type: |s the application for new development, redevelopment, ora mix of new and redevelopment? [] New development D� Redevelopment [� Mix nf New Development and Redevelopment / ) swcheck CM stamp and signature 7-23-19.doo-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 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 I ❑ Credit 2 ❑ Credit 3 ❑ Use of"country drainage" versus curb and gutter conveyance and pipe ❑ Bioretention Cells (includes Rain Gardens) ❑ Constructed Stormwater Wetlands (includes Gravel Wetlands designs) ❑ Treebox Filter ❑ Water Quality Swale ❑ Grass Channel ❑ Green Roof ❑ Other(describe): Standard 1: No New Untreated Discharges ® No new untreated discharges ® Outlets have been designed so there is no erosion or scour to wetlands and waters of the Commonwealth ® Supporting calculations specified in Volume 3 of the Massachusetts Stormwater Handbook included. swcheck CM stamp and signature 7-23-19.doc•04/01/08 Stormwater Report Checklist•Page 3 of 6 LlMassachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program ly� 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 Field' ❑ 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 %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. 21 E site or a solid waste landfill and a mounding analysis is included. 80%TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used. swcheck CM stamp and signature 7-23.19.doc•MOV08 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 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. ❑ Caiculations documenting that the treatment train meets the 80%TSS removal requirement and, if applicable, the 44%TSS removal pretreatment requirement, are provided. swcheck CM stamp and signature 7-23.19.doc•04/01/08 Stormwater Report Checklist•Page 5 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 4: Water Quality (continued) ® The BMP is sized (and calculations provided) based on: ® The %"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. swcheck CM stamp and signature 7-23-19.doe•04/01/08 Stormwater Report Checklist•Page 6 of 8 Massachusetts Department of Environmental Protection r Bureau of Resource Protection - Wetlands Program 1 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. swcheck CM stamp and signature 7-23-19.doc•04/01/08 Stormwater Report Checklist•Page 7 of 8 Massachusetts Department of Environmental Protection f 1 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. swcheck CM stamp and signature 7-23-19.doc•04/01/08 Stormwater Report Checklist•Page 8 of 8 Date:July 2019 Project:Grogan's Field—Stormwater Management Plan WATER QUALITY CALCULATION INFILTRATION DRAWDOWN CALCULATION Project Name: Grogan's Field Restoration Sheet No.: 1 Done by: 1RM Date: 7/26/2019 Ir` `<3tion Calculations Proposed Paved Impervious Area Design Point 1= 0 SF 1. All impervious areas as defined Design Point 2= 9947 SF by North Andover Stormwater Management Regulations. 2. Does not include existing impervious Infiltration Volume Water duality volume equals 0.5 inch of runoff times the total impervious area of the post-developlement project site. Water Quality Volume (WQV) = 0.5"/12 0,0416667 ft. WQV Desgin Point#1= .04167 ft. * 0 SF 0 cu. ft. Volume Provided (See HydroCAD calculations) = 0 cu.ft. \A " ' Design Point#2 = .0, 1 ft. * 9,947 SF 414 cu. ft. Volume Provided (See HydroCAD calculations) = 3,675 cu. ft. Therefore the infiltration volume is in excess of Water Quality 0.5" of Runoff Standard. Infiltration Drawdown Calculations for Grogan's Field Underground Storage Chambers Peak Elevation of Water in Chamber from HydroCAD for 100 Year Storm. Bottom of stones from Drainge drawings. Time to empty based on Rawls Rate for Class B Soils: u 96.79-93.50= 3.29'= 39.5" 3 Rate from Table for B soils (Sandy Loam) = 1.02 in./hr. Time to empty= 39.5"/1.02 in./hr.= 38.7 hrs. 38.7 hrs. <72 hrs. GN" _:ESHGWT=89.2 TP-2 (See Soil Test Pits) Bottom of Underground Storage-93.50-89.2=4.3' 2 foot seperation is provided. Rate:July 2019 Project: Grogan's Field—Storinwater Management Plan EXISTING CONDITIONS RUNOFFAND VOLUME CALCULATIONS (2, 10, 25, & 100 YEAR STORMS) 4S SUB 4 is DP-1 SUB 1 Desgn Point #1 - Abutting Properties (2"S SUB 2 3S DP-2 SUB 3 esign Point #2 - Town Drainage System 5S SUB 5 CSucat Reach on Link Routing Diagram for Existing Conditions Prepared by Waterfield Design Group, Printed 7/24/2019 HydroCADp 10.00-22 sln 02870 02018 HydroCAD Software Solutions LLC Existing Conditions Type /// 24-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 Fi droCAD® 10.00-22 sin 02870 0 2018 ♦-I droCAD Software Solutions LLC Page 2 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: SUB 1 Runoff Area=74,808 sf 3.64% Impervious Runoff Depth=0.56" Flow Length=415' Slope=0.0200 '1' Tc=14.3 min CN=64 Runoff=0.64 cfs 0.080 of Subcatchment2S: SUB 2 Runoff Area=97,897 sf 2.70% Impervious Runoff Depth=0.60" Flow Length=463' Slope=0.0200 7' Tc=15.2 min CN=65 Runoff=0.92 cfs 0.112 of Subcatchment3S: SUB 3 Runoff Area=6,784 sf 82.71% Impervious Runoff Depth=2.35" Tc=6.0 min CN=92 Runoff=0.42 cfs 0.031 of Subcatchment4S: SUB 4 Runoff Area=3,398 sf 25.37% Impervious Runoff Depth=0.83" Tc=6.0 min CN=70 Runoff=0.07 cfs 0.005 of Subcatchment5S: SUB 5 Runoff Area=6,132 sf 0.00% Impervious Runoff Depth=0.64" Tc=6.0 min CN=66 Runoff=0.09 cfs 0.008 of Link DP-1: Desgn Point#1 -Abutting Properties Inflow=0,68 cfs 0.085 of Primary=0.68 cfs 0.085 of Link DP-2: Design Point#2 -Town Drainage System Inflow=1.18 cfs 0.150 of Primary=1.18 cfs 0.150 of Total Runoff Area = 4.339 ac Runoff Volume = 0.236 of Average Runoff Depth = 0.65" 93.74% Pervious = 4.067 ac 6.26% Impervious = 0.272 ac Existing Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 sln 02870 ©2018 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 1S: SUB 1 Runoff - 0.64 cfs @ 12.25 hrs, Volume= 0.080 af, Depth= 0.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Area (so CN Description 66,855 61 >75% Grass cover, Good, HSG B 2,722 98 Paved Basketball Court 5,231 82 Mulch 74,808 64 Weighted Average 72,086 96.36% Pervious Area 2,722 3.64% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 8.2 50 0.0200 0.10 Sheet Plow, Lawn Grass: Dense n= 0.240 P2= 3.20" 6.1 365 0.0200 0.99 Shallow Concentrated Plow, Lawn Short Grass Pasture Kv= 7.0 fps 14.3 415 Total Subcatchment 1S: SUB 1 Hydrograph . . . .. . ... .. ......... . ............. 0.7- ❑Runoff 0.64 cfs 0.65- Type 11111124-hr 0.6 2-yr 24 hr Storm.Rainfall=3.20" 0.55 Runoff Area=74,808 sf °5 Runoff Volume=0.080 of 0.45 Runoff Depth=0.56" 0.4= Flow Length=415' ... 0 0.35- Slope=fl,0200.'f' 0.3= Tc=14.3 min 0.25- CN=64 0.2- 0.1s= 0.1 0.05= 0:,,,,,,,,,,,,,,,,,,,,, ....... ............, .....,. ..,.,,.,,,.,,., 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) I i I Existing Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 M drOCAD® 10.00-22 sln 02870 ©2018 M droCAD Software Solutions LLC Page 4 Summary for Subcatchment 2S: SUB 2 Runoff - 0.92 cfs @ 12.25 hrs, Volume= 0.112 af, Depth= 0.60" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Area (sf) CN Description 83,094 61 >75% Grass cover, Good, HSG B 1,489 98 Paved parking, HSG B 1,157 98 Building 10,827 82 Dirt Infield 1,330 85 Gravel Parking, HSG B 97,897 65 Average Weighted .,_ 9 ge ,_., ..... 95,251 97.30% Pervious Area 2,646 2.70% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 8.2 50 0.0200 0.10 Sheet Flow, Field Grass: Dense n= 0.240 P2= 3.20" 7.0 413 0.0200 0.99 Shallow Concentrated Flow, Field Short Grass Pasture I<v= 7.,0, fps 15.2 463 Total Subcatchment 2S: SUB 2 Hydrograph 1 ❑riunoif 0.92 cfs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Runoff Area=97,897 sf Runoff Volume=0.112 of Runoff Depth=0.60" Flow Length=463' Slope=0.0200 Tc=15.2 min CN=65 0- ......... ... .............. .. ... ............ .. ..1....,.... 0 2 4 6 8 10 12 14 16 18 20 22 24 26 2$30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD010,00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 3S: SUB 3 Runoff = 0.42 cfs @ 12.09 hrs, Volume= 0.031 af, Depth= 2.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Areas CN Description 1,173 61 >75% Grass cover, Good, HSG B 5,611 98 Paved parking, HSG B 6,784 92 Weighted Average 1,173 17.29% Pervious Area 5,611 82.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Pavement Subcatchment 3S: SUB 3 Hydrograph D.4S _ L7 Runoff 0.44 0.42 cfs 0.42 Type III 24=hr 0.4 0.38 2-yr 24-hr Storm Rainfall=3.20" 0.36= Runoff Area=6,784 sf 0.34 0,32- Runoff Volume=0.031 of 0.3 Runoff De th=2.35" o.2s p - _ Tc-6.0 min u '.. D.24. _0 D.22= CN=92 LL D.1$ o.16 0.14= 0.12- D.1 .. ... ..... 0.08 0.06 0.04 0.02 0= ,,,,,,,,,,,,,,..........,,,,,,,,, ,,,,,,,,, ,,,, ,,, , , ,, ,,,,,,, ,,, , ,,,,,,,,;,,,,,,,,,, ,, ,,,,,,,,, ,,,,,,,, ,,,;,,,,,,,,,, ,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,, 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Tune (hours) Existing Conditions Type Ill 24-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 H droCADO 10.00-22 s/n 02870 ©2018 H droCAD Software Solutions LLC Page 6 Summary for Subcatchment 4S: SUB 4 Runoff = 0.07 cfs @ 12.10 hrs, Volume= 0.005 af, Depth= 0,83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Area (sf) CN Description 2,536 61 >75% Grass cover, Good, HSG B 862 98 Paved parkinq, HSG B 3,398 70 Weighted Average 2,536 74.63% Pervious Area 862 25.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec)__ (cfs) 6.0 Direct Entry, Subcatchment 4S: SUB 4 Hydrograph 0.075- 0.07' 0.07 Cfs _ _ . . . . ❑Runoti 0.065= Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" 0.06 0.055 Runoff Area=3,398 sf D.os -RunoffVolume=0.005 of . 0.045 Runoff Depth=0.83" w m Tc=6.0 min 0.04= o 0.035.LL CN=70 0.D3 0.025 0.02- 0.015- 0.01= 0.005- 0 ,.... .,,,,,,,,,,,,,, . .....................,....... ..........,,,.., ............... ... ...... .,,,,,,, 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 sln 02870 ©2018 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 5S: SUB 5 Runoff - 0.09 cfs @ 12.11 hrs, Volume= 0.008 af, Depth= 0.64" Runoff by SCS TR-20 method, UH-SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Area (sf CN Description 4,607 61 >75% Grass cover, Good, HSG B 1,525 82 Dirt path, HSG B 6,132 66 Weighted Average 6,132 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 6.0 Direct Entry, Lawn Subcatchment 5S: SUB 5 Hydrograph 0.095- ❑Runaff 0.09 0.09 cfs 0.085: Type III 24 -hr 0.08; 2-yr 24 hr Storm Rainfall=3.20" 0.075 Runoff Area=6,132 sf 0.07= o.065 Runoff Volume..=.0.008.of.. 0.06= Runoff Depth=0.64' o.oss Tc=6.0 min 0.05. Q04s CN=66 oLL 0.04 0.035= 0,03= 0.025 0.02 ... ........ 0.015•- 0.01 0.005 i0 ........... ....... .. . ....:.........---.. . -, ..., . ,.., ....,.. ,.,,, .,. ........................ ,. ......... ....... .,.,.. ......, ., ....,... .....,,.,, 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 sh 02870 0 2018 HydroCAD Software Solutions LLC „ Page 8 Summary for Link DP-1: Desgn Point #1 - Abutting Properties Inflow Area = 1.795 ac, 4.58% Impervious, Inflow Depth = 0.57" for 2-yr 24 hr Storm event Inflow - 0.68 cfs @ 12.25 hrs, Volume= 0.085 of Primary - 0.68 cfs @ 12.25 hrs, Volume= 0.085 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-1: Desgn Point #1 - Abutting Properties Hydrocgraph o inflow 0.75- 0.68 cfs Q Primary 0.7: Inflow Area=1 .795 ac 0.6= 0.5= 0.45: 0.4= a 0.35' LL 0.3 0.25: / 0.2= 0.15- / 0.1 f ._.,... 0.05= 0 2 4 8 8 10 12 14 tfi 18 20 22 24 26 28 30 32 34 36 36 40 42 44 46 48 50 52 54 56 58 60 62 64 66 66 70 72 Time (hours) Existing Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 H droCADO 10.00-22 s/n 02870 OO 2018 H droCAD Software Solutions LLC Page 9 Summary for Link DP-2: Design Point #2 - Town Drainage System Inflow Area = 2.544 ac, 7.45% Impervious, Inflow Depth = 0.71" for 2-yr 24 hr Storm event Inflow — 1.18 cfs @ 12.23 hrs, Volume= 0.150 of Primary = 1.18 efs @ 12.23 hrs, Volume= 0.150 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-2: Design Point #2 - Town Drainage System Hydrograph ❑Inflow 1.18 CfS ❑Primary Inflow Area=2.544 ac 1- ZE W � O LL D ..,, ,., ,....,... ............. ...................................., 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 3D 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) i 'i i Existing Conditions Type 11l 24-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAM 10.00-22 s/n 02870 02018 HydroCAD Software Solutions LLC Page 10 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment'IS: SUB 1 Runoff Area=74,808 sf 3.64% Impervious Runoff Depth=1.45" Flow Length=415' Slope=0.0200 '1' Tc=14.3 min CN=64 Runoff=2.08 cfs 0.208 of Subcatchment2S: SUB 2 Runoff Area=97,897 sf 2.70% Impervious Runoff Depth=1.52" Flow Length=463' Slope=0.0200 '1' Tc=15.2 min CN=65 Runoff=2.82 cfs 0.285 of Subcatchment3S: SUB 3 Runoff Area=6,784 sf 82,71% Impervious Runoff Depth=3.89" Tc=6.0 min CN=92 Runoff=0.68 cfs 0.051 of Subcatchment4S: SUB 4 Runoff Area=3,398 sf 25.37% Impervious Runoff Depth=1.89" Tc=6.0 min CN=70 Runoff=0.17 cfs 0.012 of Subcatchment5S: SUB 5 Runoff Area=6,132 sf 0.00% Impervious Runoff Depth=1.59" Tc=6.0 min CN=66 Runoff=0.25 cfs 0.019 of Link DP-1: Desgn Point#1 -Abutting Properties Inflow=2.18 cfs 0.220 of Primary=2.18 cfs 0.220 of Link DP-2: Design Point#2 -Town Drainage System lnflow=3.33 cfs 0.354 of Primary=3.33 cfs 0.354 of Total Runoff Area =4.339 ac Runoff Volume = 0.574 of Average Runoff Depth = 1.59" 93.74% Pervious = 4.067 ac 6.26% Impervious = 0.272 ac Existing Conditions Type U124-hr I0-yr24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 sin 02870 CO 2018 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment 1S: SUB 1 Runoff - 2.08 cfs @ 12.22 hrs, Volume= 0.208 af, Depth= 1.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Area (sf) CN Description 66,855 61 >75% Grass cover, Good, HSG B 2,722 98 Paved Basketball Court 5,231 82 Mulch 74,808 64 Weighted Average 72,086 96.36% Pervious Area 2,722 3,64% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft) (ft/sec) (cfs 8.2 50 0.0200 0.10 Sheet Flow, Lawn Grass: Dense n= 0.240 P2= 3.20" 6.1 365 0.0200 0.99 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0 fps _ 14.3 415 Total Subcatchment 1S: SUB 1 Hydrograph ❑RunaH 2.08 cfs z- Type III 24-hr 10»yr 24 hr Storm Rainfall=4.80" Runoff Area=74,808 sf Runoff Volume=0.208 of Runoff Depth=1.45" w Flow Length=415' U Slope=0.0200 '1' Tc=14.3 min CN=64 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) I i I Existing Conditions Type 11124-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 H droCADO 10.00-22 sln 02870 0 2018 H droCAD Software Solutions LLC Page 12 Summary for Subcatchment 2S: SUB 2 Runoff = 2.82 cfs @ 12.22 hrs, Volume= 0.285 af, Depth= 1.52" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Area (sf) CN Description 83,094 61 >75% Grass cover, Good ,H . SG B 1,489 98 Paved parking, HSG B 1,157 98 Building 10,827 82 Dirt Infield 1,330 85 Gravel Parking, HSG B 97,897 65 Weighted Average 95,251 97.30% Pervious Area 2,646 2.70% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 8.2 50 0.0200 0.10 Sheet Flow, Field Grass: Dense n= 0.240 P2= 3.20" 7.0 413 0.0200 0.99 Shallow Concentrated Flow, Field Pasture Kv= 7.0 fps ShortGrass a,5,t . _.....,... 15.2 463 Total Subcatchment 2S: SUB 2 Hydrograph 3- 2.82 cfs ❑1zu�afl Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Runoff Area=97,897 sf Runoff Volume=0.285 of 2- Runoff Depth=1.52" w Flow Length=463' Slope=0.0200 '/' tL Tc=15.2 min CN=65 1- 0 „ ......... ............ ............. . ........................................................ ........ .............................................................. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 10-yr 24 hr Storm Rainfall=4.60" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 sln 02870 ©2018 H droCAD Software Solutions LLC Page 13 Summary for Subcatchment 3S: SUB 3 Runoff - 0.68 cfs @ 12.08 hrs, Volume= 0.051 af, Depth= 3.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Area (sf CN Description 1,173 61 >75% Grass cover, Good, HSG B 5,611 98 Paved parking, HSG B 6,784 92 Weighted Average 1,173 17.29% Pervious Area 5,611 82.71% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 6.0 Direct Entry, Pavement Subcatchment 3S: SUB 3 Hydrograph 0.75- ❑Runoff 07 0.68 cfs Type III 24-hr 0,65 10-yr 24 hr Storm_Rainfall=4.80" Runoff Area=6,784 sf 0.55- Runoff Volume=0.051 of 0.5 Runoff Depth=3.89" 0.45 Tc=6.0 min W 0.4- CN=92 0 0.35: U. 0.3= 0.25- 0.2 0.15 0.1- 0,05- 0 ........................: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) i Existing Conditions Type Ill 24-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 sln 02870 0 2018 H droCAD Software Solutions LLC Page 14 Summary for Subcatchment 4S: SUB 4 Runoff - 0.17 cfs @ 12.09 hrs, Volume= 0.012 af, Depth= 1.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0,00-72.00 hrs, dt= 0.01 hrs Type Ill 24-hr 10-yr 24 hr Storm Rainfall=4.80" Areas CN Description 2,536 61 >75% Grass cover, Good, HSG B 862. 98 Paved parking, HSG B 3,398 70 Weighted Average 2,536 74.63% Pervious Area 862 25.37% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 6.0 Direct Entry, Subcatchment 4S: SUB 4 Hydrograph C7 Runoff 0.18 0,17 cfs 0.17= Type III 24-hr . ... ... .._ .. ... ... . .. 10-yr 24 hr Storm Rainfall=4.80" 0.15 0.14 Runoff Area=3,398 sf 0.13- Runoff Volume=0.012 of 0.12 Runoff Depth=1.89". . w 0.11= Tc=6.0 min 0.1: 0 0.09 CN=70 V 0.08 ... ... ... 0.07 0.06 0.05-: 0.04 0.03- 0.02 0.01. O-m ..... .............„..... ,��.� .... ...,......�......._..�.,��„��,.i............., .. ,..,��....,�. �,,, ��,��.�, .�.,.. ,....,.... 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 66 70 72 Time (hours) Existing Conditions Type Ill 24-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD010.00-22 s/n 028 70 00 20 1 8 HydroCAD Software Solutions LLC Page 15 Summary for Subcatchment 5S: SUB 5 Runoff = 0.25 cfs @ 12.10 hrs, Volume= 0.019 af, Depth= 1.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Area (sf) CN Description 4,607 61 >75% Grass cover, Good, HSG B 1,525 82 Dirt path, HSG B 6,132 66 Weighted Average 6,132 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Lawn Subcatchment 5S: SUB 5 Hydrograph 0.28- ❑Runoff 0.26- 0.25 cfs Type III 24-hr 0.24 - - 10-yr 24 hr Storm Rainfall=4.80" 0.22 Runoff Area=6,132 sf 0.2 Runoff Volume=0.019 of _Runoff Depth=1.59" 6.16- Tc=6.0 min U 3 0.14: CN=66 o ; CC u- 0.08" 0.06- 0.04. 0.02- 0- ..............................:.......... ,.,,... ,.:.,..,.,....,..,.,,,. 0 2 4 6 8 10 12 94 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 iS 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 Y 18 HydroCAD Software Solutions LLC Page 16 Summary for Link DP-1; Desgn Point #1 - Abutting Properties Inflow Area = 1.795 ac, 4.58% Impervious, Inflow Depth = 1.47" for 10-yr 24 hr Storm event Inflow = 2.18 cfs @ 12.21 hrs, Volume= 0.220 of Primary - 2.18 cfs @ 12.21 hrs, Volume= 0.220 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-1: Desgn Point #1 - Abutting Properties Wydrograph n Inflow ❑Primary 2.18 cfs Inflow Area=1 .795 ac 2- LL 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 4D 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC Paste 17 Summary for Link DP-2: Design Point #2 - Town Drainage System Inflow Area = 2.544 ac, 7.45% Impervious, Inflow Depth = 1.67" for 10-yr 24 hr Storm event Inflow = 3.33 cfs @ 12.21 hrs, Volume= 0.354 of Primary - 3.33 cfs @ 12.21 hrs, Volume= 0.354 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-2: Design Point #2 - Town Drainage System Hydrograph ©tri—fI ❑Primary 3.33 cfs Inflow Area=2.544 ac 3- u 2- LL 0 1 0 .., .........::.. ..:.:: .::. : ..: .:.:..:.:.::...:::..:. .:.... .... . ... 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 66 70 72 Time (hours) Existing Conditions Type 11l 24-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 y..__ D Software Solutions LLC P . ro 0A0-22 _s/n 02870 OO 2018 HydroCA ape 18_ , ,_ „...� Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchmentl S: SUB 1 Runoff Area=74,808 sf 3.64% Impervious Runoff Depth=226" Flow Length=415' Slope=0.0200'/' Tc=14.3 min CN=64 Runoff=3.39 cfs 0.324 of Subcatchment2S: SUB 2 Runoff Area=97,897 sf 2.70% Impervious Runoff Depth=2.35" Flow Length=463' Slope=0.0200'1' Tc=15.2 min CN=65 Runoff=4.54 cfs 0.440 of Subcatchment3S: SUB 3 Runoff Area=6,784 sf 82.71% Impervious Runoff Depth=5.07" Tc=6.0 min CN=92 Runoff=0.87 cfs 0.066 of Subcatchment4S: SUB 4 Runoff Area=3,398 sf 25.37% Impervious Runoff Depth=2.81" Tc=6.0 min CN=70 Runoff=0.26 cfs 0.018 of Subcatchment5S: SUB 5 Runoff Area=6,132 sf 0.00% Impervious Runoff Depth=2.44" Tc=6.0 min CN=66 Runoff=0.40 cfs 0.029 of Link DP-1: Desgn Point#1 -Abutting Properties Inflow=3.54 cfs 0,342 of Primary=3.54 cfs 0.342 of Link DP-2. Design Point#2 -Town Drainage System Inflow=5.24 cfs 0.535 of Primary=5.24 cfs 0.535 of Total Runoff Area = 4.339 ac Runoff Volume = 0.877 of Average Runoff Depth = 2.43" 93.74% Pervious = 4.067 ac 6.26% Impervious = 0.272 ac Existing Conditions Type 1Il 24-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 0 2018 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 1S: SUB 1 Runoff = 3.39 cfs @ 12.21 hrs, Volume= 0.324 af, Depths 2.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Area (sf) CN Description 66,855 61 >75% Grass cover, Good, HSG B 2,722 98 Paved Basketball Court 5,231 82 Mulch 74,808 64 Weighted Average 72,086 96.36% Pervious Area 2,722 3.64% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 8.2 50 0.0200 0.10 Sheet Flow, Lawn Grass: Dense n= 0.240 P2= 3.20" 6A 365 0.0200 0.99 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0 fps 14.3 415 Total Subcatchment 1 S: SUB 1 Hydrograph 3.39 cfs Runoff Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" s Runoff Area=74,808 sf Runoff Volume=0.324 of Runoff Depth=2.26" Flow Length=415' 3 2 Slope=0.0200 '1' Tc=14.3 min CN=64 1- 0- 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 25-yr 24 hr Storm Rainfall=6,00" Prepared by Waterfield Design Group Printed 7/24/2019 H droCADO 10.00-22 sln 02870 0 2018 H droCAD Software Solutions LLC Page 20 Summary for Subcatchment 2S: SUB 2 Runoff = 4.54 cfs @ 12.21 hrs, Volume= 0.440 af, Depth= 2.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Areas CN Description 83,094 61 >75% Grass cover, Good, HSG B 1,489 98 Paved parking, HSG B 1,157 98 Building 10,827 82 Dirt Infield 1,330 85 Gravel Parking, HSG B 97,897 65 Weighted Average 95,251 97.30% Pervious Area 2,646 2.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 8.2 50 0,0200 0.10 Sheet Flow, Field Grass: Dense n= 0.240 P2= 3.20" 7.0 413 0.0200 0.99 Shallow Concentrated Flow, Field Short Grass Pasture Kv= 7.0 fps _ 15.2 463 Total Subcatchment 2S: SUB 2 Hydrograph 5- ❑Runoff 4.54 cfs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Runoff Area=97,897 sf Runoff Volume=0.440 of Runoff Depth=2.35" Flow Length=463' 3 Slope=0.0200 '/' n Tc=15.2 min 2. CN=65 1 0 2 4 6 8 10 12 14 16 18 20 22 24 2& 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type /// 24-hr 25-yr 24 hr Storm Rainfall=6.00° Prepared by Waterfield Design Group Printed 7/24/2019 H droCADO 10.00-22 sln 02870 ©2018 H droCAD Software Solutions LLC Page 21 Summary for Subcatchment 3S: SUB 3 Runoff 0.87 cfs @ 12.08 hrs, Volume= 0.066 af, Depth= 5.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type Ili 24-hr 25-yr 24 hr Storm Rainfall=6.00° Area (sD CN Description 1,173 61 >75% Grass cover, Good, HSG B 5,611 98 Pavedparking, HSG B 6,784 92 Weighted Average 1,173 17.29% Pervious Area 5,611 82.71% Impervious Area Te Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) _ 6.0 Direct Entry, Pavement Subcatchment 3S: SUB 3 Hydrograph 0.95 - ❑Runoff o.s 0.87 cfs Q.sS Type III 24-hr 0.8 _ 25-yr 24 hr Storm Rainfall=6.00" 0.7 0 Runoff Area=6,784 sf 0.7= Runoff Volume=0.066 of Q.65 0.6 Runoff Depth=5.07" 0.55 Tc=6.0 min 0.5 CN=92 .. .. .. . ... ... .. . ... ... .. . 0 0.45- LL 0.4-: 0.35.,; fl,25= 0.15.i _ 0.1 0.Q5 0 0 2 14„16 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 j Time (hours) I i 9 I i Existing Conditions Type 11124-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 sln 02870 ©2018 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment 4S: SUB 4 Runoff = 0.26 cfs @ 12.09 hrs, Volume= 0.018 af, Depth= 2.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Area (sf) CN Description 2,536 61 >75% Grass cover, Good, HSG B 862 98 Paved parking, HSG B 3,398 70 Weighted Average 2,536 74.63% Pervious Area 862 25.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftlsec) (cfs) 6.0 Direct Entry, Subcatchment 4S: SUB 4 Hydrograph 0.28 0.26 cfs [7 Runoff 0.26- Type III 24-hr . 0.24 25-yr 24 hr Storm Rainfall=6.00" 0.22: Runoff Area=3,398 sf °2- Runoff Volume=0.018 of 0.167. Runoff Depth=2.81" F 0,16: Tc=6.0 min 3 0.14; C N=70 _o LL 0.12- 0.1- 0.08- 0.06- 0.04- 0.02- o .......................... ............. ............................., .................,,,,,....... 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type !ll 24-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 sln 02870 ©2018 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment 5S: SUB 5 Runoff - 0.40 cfs @ 12.09 hrs, Volume= 0.029 af, Depth= 2.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Areas CN Description 4,607 61 >75% Grass cover, Good, HSG B 1,525 82 Dirt path, HSG B 6,132 66 Weighted Average 6,132 100.00% Pervious Area Te Length Slope Velocity Capacity Description min feet ftlft) (ft/sec) (cfs 6.0 Direct Entry, Lawn Subcatchment 5S: SUB 5 Hydrograph 0.44, 0.42 0.40 cfS C1 Runoff 0.4- Type 111 24-hr 0.38_ 0.36 25-yr.24 hr Storm.Rainfall=6.00" 0.3a Runoff Area=6,132 sf 0.32-0.3-: Runoff Volume=0.029 of a.2s- Runoff Depth=2.44" 0.26 Tc=6.0 min 0.24' � 0.z2_ - CN=66 ti 0.2 0.16 0.14- 0.12 0.1 0.08- " 0.06= 0.04 0.02= 0- .r.,..r. ....�i.ir�...i�r...�.�:.�....�.:i.E...E....�...��..i.E....�..i �..r.,i.ii�...r�.i.r�.ii.�.irr�i .�ii..,r...�i.rr�r...�.r..�i...�..i.�....��.�.j....�....�....�..i.,..� �.... 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) I i Existing Conditions Type il124-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 s/n 02870 02018 H droCAD Software Solutions LLC Page 24 Summary for Link DP-1: Desgn Point #1 - Abutting Properties Inflow Area = 1.795 ac, 4.58% Impervious, Inflow Depth = 2.29" for 25-yr 24 hr Storm event Inflow = 3.54 cfs @ 12.20 hrs, Volume= 0.342 of Primary = 3.54 cfs @ 12.20 hrs, Volume= 0.342 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-1: Desgn Point #1 - Abutting Properties Hydrograph ❑Inflow 3.54 cfs ❑Primary _ Inflow Area=1 .795 ac 3- 2- 0- .... . ..... ....................... „ „ s .,. .,.,.,..,.,..,.,... ,...,....,...,........,,.., ..,.... D 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 4D 42 44 46 46 50 52 54 56 58 60 62 64 66 68 70 72 Time {hours} Existing Conditions Type 111 24-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC _ _ Page 25 Summary for Link DP-2: Design Point #2 - Town Drainage System Inflow Area = 2.544 ac, 7.45% Impervious, Inflow Depth = 2.52" for 25-yr 24 hr Storm event Inflow - 5.24 cfs @ 12.21 hrs, Volume= 0.535 of Primary = 5.24 cfs @ 12.21 hrs, Volume= 0.535 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-2: Design Point #2 - Town Drainage System Hydrograph U Inflow Cl Primary 5.24 cfs Inflow Area=2.544 ac 5- 4- 3- LL 0 2-- 0- ..... ....... ... .....i ...,....,..,.,,................,,..., 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 900-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 H Software Solutions LLC y ro 10.00-22 sin 0287q ©2018 HydroCAD Page 26,..., . Time span=0,00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment IS: SUB 1 Runoff Area=74,808 sf 3.64% Impervious Runoff Depth=4.27" Flow Length=415' Slope=0.0200 T Tc=14.3 min CN=64 Runoff=6.59 cfs 0.610 of Subcatchment2S: SUB 2 Runoff Area=97,897 sf 2.70% Impervious Runoff Depth=4.38" Flow Length=463' Slope=0.0200 '1' Tc=15.2 min CN=65 Runoff=8.69 cfs 0.821 of Subcatchment3S: SUB 3 Runoff Area=6,784 sf 82.71% Impervious Runoff Depth=7.64" Tc=6.0 min CN=92 Runoff=1.28 cfs 0.099 of Subcatchment4S: SUB 4 Runoff Area=3,398 sf 25.37% Impervious Runoff Depth=4.98" Tc=6.0 rein CN=70 Runoff=0.46 cfs 0.032 of Subcatehment5S: SUB 5 RunoffArea=6,132 sf 0.00% Impervious Runoff Depth=4.50" Tc=6.0 min CN=66 Runoff=0.74 cfs 0.053 of Link DPA: Desgn Point#1 -Abutting Properties Inflow=6.87 cfs 0.643 of Primary=6.87 cfs 0.643 of Link DP-2: Design Point#2 -Town Drainage System Inflow=9.80 cfs 0.973 of Primary=9.80 cfs 0.973 of Total Runoff Area = 4.339 ac Runoff Volume = 1.616 of Average Runoff Depth = 4.47" 93.74% Pervious = 4.067 ac 6.26% Impervious = 0.272 ac Existing Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 sln 02870 ©2018 H droCAD Software Solutions LLC Pacie 27 Summary for Subcatchment 1S: SUB 1 Runoff - 6.59 cfs @ 12.20 hrs, Volume= 0.61Oaf, Depth= 4.27" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Area (sf) CN Description 66,855 61 >75% Grass cover, Good, HSG B 2,722 98 Paved Basketball Court " 5,231 82 Mulch 74,808 64 Weighted Average 72,086 96.36% Pervious Area 2,722 3.64% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 8.2 50 0.0200 0.10 Sheet Flow, Lawn Grass: Dense n= 0.240 P2= 3.20" 6.1 365 0.0200 0.99 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0 fps 14.3 415 Total Subcatchment IS: SUB 1 Hydrograph Q Runoff 7- 6.59 cfs Type III 24-hr 6- 100-yr 24 hr Storm Rainfall=8.60" Runoff Area=74,808 sf 5- Runoff Volume=0.610 of Runoff Depth=4.27" w 4- Flow Length-415' Slope=0.0200 '1' U. Tc=14.3 min 3- CN=64 2- 1-- 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type H/ 24-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC Page 28 Summary for Subcatchment 2S: SUB 2 Runoff = 8.69 cfs @ 12.21 hrs, Volume= 0.821 af, Depth= 4,38" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Area (sf) CN Description 83,094 61 75/o Grass cover, Good,, ',HSG B 1,489 98 Paved parking, HSG B 1,157 98 Building 10,827 82 Dirt Infield 1,330 85 Gravel Parking, HSG B 97,897 65 Weighted Average 95,251 97.30% Pervious Area 2,646 2.70% Impervious Area Tc Length Slope Velocity Capacity Description (rein) (feet) (ft/ft) (ft/sec} (cfs) _ 8.2 50 0.0200 0.10 Sheet Flow, Field Grass: Dense n= 0.240 P2= 3.20" 7.0 413 0.0200 0.99 Shallow Concentrated Flow, Field Short Grass Pasture Kv= 7.0 fps 15.2 463 Total Subcatchment 2S: SUB 2 Hydrogranh p Runoff 9_ 8.69 cfs Type 111 24-hr 6 100-yr 24 hr Storm Rainfall=8.60" Runoff Area=97,897 sf 7 Runoff Volume=0.821 of 6- Runoff Depth=4.38" Flow Length=463' 3 5 Slope=0.0200 '/' a- Tc=15.2 min C N=65 3- 2- 1- 0 .. . ..... .. ........ ............ „„ ., 0 2 4 6 8 10 12 14 16 . 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 H droCADO 10.00-22 sln 02870 O 2018 H droCAD Software Solutions LLC Page 29 Summary for Subcatchment 3S: SUB 3 Runoff = 1.28 cfs @ 12.08 hrs, Volume= 0.099 af, Depth= 7.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Areas CN Description 1,173 61 >75% Grass cover, Good, HSG B 5,611 98 Paved parking, HSG B 6,784 92 Weighted Average 1,173 17.29% Pervious Area 5,611 82.71% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 6.0 Direct Entry, Pavement Subcatchment 3S: SUB 3 Hydrograph €1 Runoff 1.28 cfs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Runoff Area=6,784 sf 1 Runoff Volume=0.099 of Runoff Depth=7.64" Tc=6.0 min 3 CN=92 0 u- .... .. ........... 3 ................,�r�ij��.��..�..��....�....�..i.E....� ... .... 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 sln 0_2870 ©2018 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment 4S. SUB 4 Runoff = 0.46 cfs @ 12.09 hrs, Volume= 0.032 af, Depth= 4.98" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Area (sfl CN Description 2,536 61 75/o Grass cove r,er Good HSG B 862 98 Paved parking, HSG B 3,398 70 Weighted Average 2,536 74.63% Pervious Area 862 25.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: SUB 4 Hydrograph 0.5 ❑Runoff 0.48 0.46 cfs . . . 0.4 0.444 Type III 24-hr = 0.42 100-yr 24 hr Storm Rainfall=8.60" 0.4. 0.38 Runoff Area=3,398 sf 0.36=0.34= Runoff Volume=0.032 of 0.32 Runoff Depth=4.98" .... 0.28 Tc=6.0 min 0.2s CN-70 0 0.24 0.2 0.18 . ... .. . .. ... .. 0.16' 0.14- 0.12 0.1. 0.08 0.06 0.04.:' 0.02= 0' .. ............ .. ... .... . .. .......... 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type /// 24-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 sln 02870 0 2018 H droCAD Software Solutions LLC Page 31 Summary for Subcatchment 5S: SUB 5 Runoff = 0.74 cfs @ 12.09 hrs, Volume= 0.053 af, Depth= 4.50" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60° Areas CN Descri tion 4,607 61 >75% Grass cover, Good, HSG B 1,525 82 Dirt path, HSG B 6,132 66 Weighted Average 6,132 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ftj (ft/sec) (cfs) T 6.0 Direct Entry, Lawn Subcatchment 5S: SUB 5 Hydrograph 0.8Z0.74 cfs €�Runoff 0.75 Type III 24-hr D' 100-yr 24 hr Storm Rainfall=8.60" 0.65: Runoff Area=6,132 sf 0'6 Runoff Volume=0.053 of o.5s Runoff Depth=4.50" .. Tc=6.0 min N u 0.45- CN=66 0,4 0.35 � D.3 0.25-i 0.2- 0.15 0 0.05= 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) 3 3 i 3 i r i R Existing Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 s/n 02870 Q 2018„HydroCAD Software Solutions LLC Page 32 Summary for Link DP-1: Desgn Point #1 - Abutting Properties Inflow Area = 1.795 ac, 4,58% Impervious, Inflow Depth = 4.30" for 100-yr 24 hr Storm event Inflow = 6.87 cfs @ 12,19 hrs, Volume= 0.643 of Primary - 6.87 cfs @ 12.19 hrs, Volume= 0.643 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-1: Desgn Point #1 - Abutting Properties Hydrograph r-Inflow €7 Primary 7- 6.87 cfs Inflow Area=1 .795 ac f 4.,. 3 0 a 3- 2- 1- 0 ,, ,, ,,, ,,,,,, ..... ....,.. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Existing Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutons_LLC Page 33 Summary for Link DP-2: Design Point #2 - Town Drainage System Inflow Area = 2.544 ac, 7.45% Impervious, Inflow Depth = 4.59" for 100-yr 24 hr Storm event Inflow - 9.80 cfs @ 12.20 hrs, Volume= 0.973 of Primary = 9.80 cfs @ 12.20 hrs, Volume= 0.973 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-2: Design Point #2 - Town Drainage System Hydrograph ❑Inflow D Primary 10 9.$0 cfs Inflow Area=2.544 ac 8 - LL 0 5 q; %.. . ... . .. ... 2 WO 1- 0 ......................s..,.�.. ............................................. .....„............,�..�.,..�.�..., 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) i Date:July 2019 Project: Grogao's Field—Stormwater Management Plan PROPOSED (SITE DEVELOPED) CONDITIONS RUNOFF AND VOLUME CALCULATIONS (2, 10, 25, & 100 YEAR STORMS) 4S SUB 4 1S DP-1 SUB 1 Desgn Point #1 - Abutting Properties 2S DP-2 SUB 2 esign oin #2 - Town Dr inage System C6S) - � 7P SUB 6 SC-740 SS 5S SUB 3 SUB 5 OSubcat Reaeh pn �Linki Routing Diagram for Proposed Conditions Prepared by Waterfield Design Croup, Printed 7/24/2019 j EHydroCAEO 10.00-22 sln 02870 Q 2018 HydroCAD Software Solutions LLC Proposed Conditions Prepared by Waterfield Design Group Printed 7/24/2019 HydroC__AD010.00-22 s/n 02870 02018 HydroCAD Software Solutions LLC Pace 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 3.514 61 >75% Grass cover, Good, HSG B (1S, 2S, 3S, 4S, 5S, 6S) 0.027 98 Building (2S) 0.160 98 Concrete and Asphalt Pavement, HSG B (6S) 0.209 82 Dirt Infield (2S) 0.120 82 Mulch (1S) 0.060 98 Paved Basketball Court (1S) 0.219 98 Paved parking, HSG B (3S) 0.012 98 Paved, HSG B (2S) 0.018 98 Pavement (4S) 4.339 67 TOTAL AREA Proposed Conditions Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 sln 02870 ©2018 H droCAD Software Solutions LLC Page 3 Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 1906 HSG B 1S, 2S, 3S, 4S, 5S, 6S 0.000 HSG C 0.000 HSG D 0.433 Other 1 S, 2S, 4S 4,339 TOTAL AREA Proposed Conditions Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 sln 02870 0 2018 H droCAD Software Solutions LLC Page 4 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchmeni (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 3.514 0.000 0.000 0.000 3.514 >75%Grass cover, Good is, 2S, 3S, 4S, 5S, 6S 0.000 0.000 0.000 0.000 0.027 0.027 Building 2S 0.000 0.160 0,000 0.000 0.000 0.160 Concrete and Asphalt Pavement 6S 0.000 0.000 0,000 0.000 0.209 0.209 Dirt Infield 2S 0.000 0.000 0.000 0.000 0.120 0.120 Mulch 1S 0.000 0.012 0.000 0.000 0.000 0.012 Paved 2S 0.000 0.000 0.000 0.000 0.060 0.060 Paved Basketball Court is 0.000 0.219 0.000 0.000 0.000 0.219 Paved parking 3S 0.000 0.000 0.000 0.000 0.018 0.018 Pavement 4S 0.000 3.906 0.000 0.000 0.433 4.339 TOTAL AREA i Proposed Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 , HydroCAD®„10.00-22 sln_0287fl ©2018 HydroCAD Software Solutions LLC, . Page 5 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: SUB 1 Runoff Area=74,808 sf 3.48% Impervious Runoff Depth=0.56" Flow Length=415' Slope=0.0200 `I' Tc=14.3 min CN=64 Runoff=0.64 cfs 0.080 of Subcatchment2S: SUB 2 Runoff Area=68,832 sf 2.45% Impervious Runoff Depth=0.60" Flow Length=463' Slope=0.0200 T Tc=15.2 min CN=65 Runoff=0,65 cfs 0.079 of Subcatchment3S: SUB 3 Runoff Area=10,482 sf 91.06% Impervious Runoff Depth=2.64" Tc=6.0 min CN=95 Runoff=0.71 cfs 0.053 of Subcatchment4S: SUB 4 Runoff Area=3,335 sf 23.33% Impervious Runoff Depth=0.83" Tc=6.0 min CN=70 Runoff=0.07 cfs 0.005 of Subcatchment5S: SUB 5 Runoff Area=6,132 sf 0.00% Impervious Runoff Depth=0.44" Tc=6.0 min CN=61 Runoff=0.05 cfs 0.005 of Subcatchment6S: SUB 6 Runoff Area=25,403 sf 27.44% Impervious Runoff Depth=0.88" Flow Length=260' Slope=0.0100'1' Tc=8.9 min CN=71 Runoff=0.49 cfs 0.043 of Pond 7P: SC-740 Peak Elev=94.32' Storage=792 cf Inflow=0.49 cfs 0.043 of Discarded=0.04 cfs 0.043 of Primary=0.00 cfs. 0.000 of Outflow=0.04 cfs 0.043 of Link DP-1: Desgn Point#1 -Abutting Properties Inflow=0.68 cfs 0.085 of Primary=0.68 cfs 0.085 of Link DP-2: Design Point#f2 -Town Drainage System Inflow=1.07 cfs 0.137 of Primary=1.07 cfs 0.137 of Total Runoff Area = 4.339 ac Runoff Volume = 0.265 of Average Runoff Depth = 0.73" 88.58% Pervious = 3.843 ac 11.42% Impervious = 0.495 ac Proposed Conditions Type 1/1 24-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 H droCADV 10.00-22 sln 02870 ©2018 H droCAD Software Solutions LLC Pa e 6 Summary for Subcatchment 1S: SUB 1 Runoff = 0.64 cfs @ 12.25 hrs, Volume= 0.080 af, Depth= 0.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Area (so CN Description 66,975 61 >75% Grass cover, Good, HSG B * 2,602 98 Paved Basketball Court * 5,231 82 Mulch 74,808 64 Weighted Average 72,206 96.52% Pervious Area 2,602 3.48% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft) (ft/sec) (cfs 8.2 50 0.0200 0.10 Sheet Flow, Lawn Grass: Dense n= 0.240 P2= 3.20" 6.1 365 0.0200 0.99 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0_fps___ _ 14.3 415 Total Subcatchment 1S: SUB 1 Hydrograph 0.7-: ❑Runoff 0.64 cfs 0.65 Type III 24-hr 0.6 2-yr 24 hr Storm.Rainfall=3.20" 0.55- Runoff Area=74,808 sf 0.5 Runoff Volume=0.080 of a.as- Runoff Depth=0,56" 0,47 Flow Length=415' 0 0.35 Slope=0.0200 T 0.3- Tc=14.3 min 0.25 CN=64 0.2_ . .. . . ... ... . 0.15- 0.1- 0.05- 0 ....... ........ ... ...... .. . . . . ........ ...... ........ . . .....,.,...., .. ,.,.i ,.,,,„t, , ,, .,.,, .,.............,.. , 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 111 24-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 s/n 02870 O 2018 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 2S: SUB 2 Runoff = 0.65 cfs @ 12.25 hrs, Volume= 0.079 af, Depth= 0.60" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Areas CN Descri tion 58,052 61 >75% Grass cover, Good, HSG B 527 98 Paved, HSG B 1,157 98 Building 9,096 82 Dirt Infield 68,832 65 Weighted Average 67,148 97.55% Pervious Area 1,684 2.45% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ftlsec) (cfs 8.2 50 0.0200 0.10 Sheet Flow, Field Grass: Dense n= 0.240 P2= 3.20" 7.0 413 0.0200 0.99 Shallow Concentrated Flow, Field Short Grass Pasture Kv= 7.0 fps 15.2 463 Total Subcatchment 2S: SUB 2 Hydrograph 0.7- 0.6rJ Cf5 Cl Runoff 0.65- Type 111.24. .. 0.6- 2-yr 24 hr Storm Rainfall=3.20" 0.55 Runoff Area=68,832 sf Runoff Volume=0.079 of 0.45 Runoff Depth=0.60" 0.4 Flow Length=463' 0 0.35 _ Slope=0.0200_'1' a.3= Tc=15.2 m i n 0.25 CN=65 0.2- 0.15- O.i. 0.05- a ............. ....... r,... ,....,. ..,.... 0 2 4 6 8 10 12 14 16 i8 20 22 24 26 28 30 32 34 36 3$ 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type Ill 24-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 0 2018 HydroCAD_Software Solutions LLC Page g Summary for Subcatchment 3S: SUB 3 Runoff = 0.71 cfs @ 12.08 hrs, Volume= 0.053 af, Depth= 2.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Area (sf) CN Description 937 61 >75% Grass cover,Good, HSG B 9,545 98 Paved parking, HSG B 10,482 95 Weighted Average 937 8.94% Pervious Area 9,545 91.06% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Pavement ement Subcatchment 3S: SUB 3 Hydrograph . ... .. .... ... ❑Runafi 0.75. 0.71 cfs 0.7- Type III 24-hr 0.65: 2-yr 24 hr Storm Rainfall=3.20." 0.6 Runoff Area=10,482 sf 0.55 Runoff Volume=0.053 of o.s- Runoff Depth=2.64" 0.45- Tc=6.0 min U 0.4: CN=95 LL 0.35' 0.3= 0.25, 0.2-i 0.15 0.1= 0.05 o ...... .................................................... ...... 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 s/n 02870 0 2018 H droCAD Software Solutions LLC Page 9 Summary for Subcatchment 4S: SUB 4 Runoff - 0.07 cfs @ 12.10 hrs, Volume= 0.005 af, Depth= 0,83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Areas CN Description 2,557 61 >75% Grass cover, Good, HSG B 778 98 Pavement 3,335 70 Weighted Average 2,557 76.67% Pervious Area 778 23.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: SUB 4 Hydrograph _ ... . . .. ... .. . .. _ ... .. . ... q Runoff 0.07' " 0.07 cfs 0.065 Type III 24-hr 0.06 2-yr 24 hr Storm Rainfall=3.20" 0.055= Runoff Area=3,335 sf 0,05. Runoff Volume=0.005 of 0.045 Runoff Depth=0.83" 0.04-` Tc=6.0 min o 0,035 CN=70 0.03- 0.025 0.02- 0.015 0.01- .. . ... ..... .. . ... . ... ... 0.005- 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 1II 24-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 s/n 02870 cO 2018 Hydr_aCAD Software Solutions LLC Page 10 Summary for Subcatchment 5S: SUB 5 Runoff - 0.05 cfs @ 12.12 hrs, Volume= 0.005 af, Depth= 0.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Area (sf) CN Description 6,132 61 >75% Grass cover, Good, HSG 13 6,132 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftlsec) (cfs) 6.0 Direct Entry, Lawn Subcatchment 5S: SUB 5 Hydrograph _ 0.05 ❑Runoff 0.048: 0.05 cfs 0.046- 05, Type III 24-hr 0.04 4-= 0.042 2-yr 24 hr Storm Rainfall=3.20" 0.04 0.036; Runoff Area=6,132 sf 0.036 0.034; Runoff Volume=0.005 of 0.032- Runoff Depth=0.44" 0.03 0.028 Tc=6.0 min 0.026: ... ... ... . 0 0.024-- CN=61 . 7- 0.022- 0.02 0.018 0.016 0.014- .. ... . .. .. ... ... ... ... ... . . 0.012 0.01 0.008 . . . . . . . . . 0.006 0.004 0.002 0.e ....... .............. ...........r,.-«-„wr 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 3D 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 7Q 72 Time (hours) Proposed Conditions Type 11124-hr 2-yr 24 hr Storm Rainfal1=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 sln 02870 ©2018 H droCAD Software Solutions LLC Page 11 Summary for Subcatchment 6S: SUB 6 Runoff — 0.49 cfs @ 12.14 hrs, Volume= 0.043 af, Depth= 0.88" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr 24 hr Storm Rainfall=3.20" Area (sf) CN Description 18,433 61 >75% Grass cover, Good, HSG B 6,970 98 Concrete and As halt Pavement HSG B 25,403 71 Weighted Average 18,433 72.56% Pervious Area 6,970 27.44% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 0.6 30 0.0100 0.82 Sheet Flow, Pavement Smooth surfaces n= 0.011 P2= 3.20" 3.6 20 0.0100 0.09 Sheet Flow, Lawn Grass: Short n= 0.150 P2= 3.20" 0.2 20 0.0100 2.03 Shallow Concentrated Flow, Pavement Paved Kv= 20.3 fps 4.5 190 0.0100 0.70 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0 fps 8.9 260 Total Subcatchment 6S: SUB 6 Hydrograph a.ss- 0.49 cfs C1 Runoff 0.5 Type III 24-hr 0.45 2-yr 24.hr Storm Rainfall=3.20" 0.4 Runoff Area=25,403 sf Runoff Volume=0.043 of 0.35 Runoff Depth=0.88" Flow Length=260' Slope=0.0100 'I' 0 0.25- " Tc=8.9 min 0.2 CN=71 0.15- 0.1- 0.05- -L.. ..ii�..�ii...�i...4......... ..,......-........,ii�....�i..��..ii�..i.�. ....E........r ....jii.. ii.. ...iy.... ..ii E.... ii.. ....3.. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 y_._ H droCADO 10.00-22 s/n 02870 OO 2018 HydroCAD Software Solutions LLC Page 12 Summary for Pond 7P: SC-740 Inflow Area = 0.583 ac, 27.44% Impervious, Inflow Depth = 0.88" for 2-yr 24 hr Storm event Inflow = 0.49 cfs @ 12.14 hrs, Volume= 0.043 of Outflow = 0.04 cfs @ 11.87 hrs, Volume= 0.043 af, Atten= 92%, Lag= 0.0 min Discarded = 0.04 cfs @ 11.87 hrs, Volume= 0.043 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 94.32' @ 14.82 hrs Surf.Area= 1,739 sf Storage= 792 cf Plug-Flow detention time= 205.5 min calculated for 0.043 of(100% of inflow) Center-of-Mass det. time= 205.5 min ( 1,080.3 - 874.9 ) Volume Invert Avail.Storage Storage Description f#1A 93.50' 1,608 of 15.75'W x 110.421 x 3.50'H Field A 6,087 cf Overall - 2,067 cf Embedded = 4,019 cf x 40.0% Voids ##2A 94.00' 2,067 cf ADS_StormTech SC-740 +Cap x 45 Inside#1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.561 with 0.44' Overlap 3 Rows of 15 Chambers 3,675 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 93.50' 1.020 inlhr.E, xfiltltration over Surface area #2 Primary 96.50' 5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 scarded OutFlow Max=0.04 cfs @ 11.87 hrs HW=93.54' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=93.50' (Free Discharge) t--2=Broad-Crested Rectangular Weir( Controls 0.00 cfs) Proposed Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAM 10.00-22 s/n 02870 02018 H droCAD Software Solutions LLC Page 13 Pond 7P: SC-740 - Chamber Wizard Field A ChamberModel =ADS_StormTechSC-740+Cap(ADS StormTech®SC-740with cap length) Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 =45.9 cf Overall Size= 51.0"W x 30.0"H x 7.561 with 0.44' Overlap 51.0" Wide + 6.0" Spacing = 57.0" C-C Row Spacing 15 Chambers/Row x 7.12' Long +0.81' Cap Length x 2 = 108.42' Row Length +12.0" End Stone x 2 = 110.42' Base Length 3 Rows x 51.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 15.75' Base Width 6.0" Base + 30.0" Chamber Height + 6.0" Cover = 3.50' Field Height 45 Chambers x 45.9 cf= 2,067.3 cf Chamber Storage 6,086.7 cf Field - 2,067.3 cf Chambers = 4,019.4 cf Stone x 40.0% Voids = 1,607.8 cf Stone Storage Chamber Storage + Stone Storage = 3,675.1 cf= 0.084 of Overall Storage Efficiency = 60.4% Overall System Size = 110.42' x 15.75' x 3.50' 45 Chambers 225.4 cy Field 148.9 cy Stone 000 Proposed Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 sin 02870 ©2018 HydroCAD Software Solutions LLC Page 14 Pond 7P: SC-740 Hydrograph 0.49 Cfs U inflow n Outflow 0.55- - Inflow Area=0.583 aC U Discarded ©Primary Peak Elev=94.32' 0.45= Storage=792 cf 0.4 0.35- / u 0.3 0 0.25- k / 0.2- 0.15- 0.1= 0 04 cfs F. 0 2 4 & 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 4648 50 52 54 5658 60 62 64 6668 70 72 Time (hours) Proposed Conditions Type Ill 24-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 02018 HydroCAD Software Solutions LLC Page 15 Summary for Link DP-1: Desgn Point #1 - Abutting Properties Inflow Area = 1.794 ac, 4.33% Impervious, Inflow Depth = 0.57" for 2-yr 24 hr Storm event Inflow - 0.68 cfs @ 12.25 hrs, Volume= 0.085 of Primary = 0.68 cfs @ 12.25 hrs, Volume= 0.085 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DPA: Desgn Point #1 - Abutting Properties Hydrocgraph n inflow 0.75. ©Primary 0.7 0.68 cfs Inflow Area=1 .794 ac . ... . ... . 0.65 0.55 0.45= N 0 0.35: LL D.3 0.25 0.2 0.15= D.1 O.D5- 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 6668 7072 Time (hours) Proposed Conditions Type 11124-hr 2-yr 24 hr Storm Rainfall=3.20" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC Page 16 Summary for Link DP-2: Design Point #2 - Town Drainage System Inflow Area = 2.545 ac, 16.42% Impervious, Inflow Depth = 0.65" for 2-yr 24 hr Storm event Inflow = 1.07 cfs @ 12.13 hrs, Volume= 0.137 of Primary = 1.07 cfs @ 12.13 hrs, Volume= 0.137 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-2: Design Point #2 - Town Drainage System Hydrograph ❑Inflow p Primary 1.0' cfs Inflow Area=2.545 ac LL 0 ,...,.. ........... ... ......................... ............................ 0 2 4 6 8 1012 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 90-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC Page 17 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: SUB 1 Runoff Area=74,808 sf 3.48% Impervious Runoff Depth=1.45" Flow Length=415' Slope=0.0200 '1' Tc=14.3 min CN=64 Runoff=2.08 cfs 0.208 of Subcatchment2S: SUB 2 Runoff Area=68,832 sf 2,45% Impervious Runoff Depth=1.52" Flow Length=463' Slope=0.0200 '1' Tc=15.2 min CN=65 Runoff=1.98 cfs 0.200 of Subcatchment3S; SUB 3 Runoff Area=10,482 sf 91.06% Impervious Runoff Depth=4.22" Tc=6.0 min CN=95 Runoff=1.10 cfs 0.085 of Subcatchment4S: SUB 4 Runoff Area=3,335 sf 23.33% Impervious Runoff Depth=1.89" Tc=6.0 min CN=70 Runoff=0.17 cfs 0.012 of Subcatchment6S: SUB 5 Runoff Area=6,132 sf 0.00% Impervious Runoff Depth=1.25" Tc=6.0 min CN=61 Runoff=0.19 cfs 0.015 of Subcatchment6S: SUB 6 Runoff Area=25,403 sf 27.44% Impervious Runoff Depth=1.97" Flow Length=260' Slope=0.0100'1' Tc=8.9 min CN=71 Runoff=1.19 cfs 0.096 of Pond 7P: SC-740 Peak Elev=95.68' Storage=2,559 cf Inflow=1.19 cfs 0.096 of Discarded=0.04 cfs 0.096 of Primary=0.00 cfs 0.000 of Outflow=0.04 cfs 0.096 of Link DP-1: Desgn Point#1 -Abutting Properties Inflow=2.18 cfs 0.220 of Primary=2.18 cfs 0.220 of Link DP-2: Design Point#2 -Town Drainage System Inflow=2.71 cfs 0.300 of Primary=2.71 cfs 0.300 of Total Runoff Area =4.339 ac Runoff Volume = 0.615 of Average Runoff Depth = 1.70" 88.58% Pervious = 3.843 ac 11.42% Impervious = 0.495 ac Proposed Conditions Type 11124-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 sln 02870 0 2018H-ydroCAD Software Solutions LLC Page 18 Summary for Subcatchment 1S: SUB 1 Runoff = 2.08 cfs @ 12.22 hrs, Volume= 0.208 af, Depth= 1.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Area (sf) CN Description 66,975 61 >75% Grass cover, Good, HSG B 2,602 98 Paved Basketball Court 5,231 82 Mulch 74,808 64 Weighted Average 72,206 96.52% Pervious Area 2,602 3.48% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 8.2 50 0.0200 0.10 Sheet Flow, Lawn Grass: Dense n= 0.240 P2= 3.20" 6.1 365 0.0200 0.99 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0 fps 143 415 Total Subcatchment 1S: SUB 1 Hydrograph ❑Runoff 2.0$ cfs 2- Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Runoff Area=74,808 sf Runoff Volume=0.208 of Runoff Depth=1.45" Flow Length=415' 3 Slope=0.0200 '1' U- 1- Tc=14.3 min CN=64 oF,,,,,.,,,,, ..... ..................... .„ ,,,,.,..... .. ,..,.,.,..,....,.,..,,.,.,,,. ,,,,,,.,,.,.,..,,.,.,,.., ...,....,....,....,..,,,,.,,,., ,,,.,,,,,,., 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type U124-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 sln 02870 ©2018 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 2S: SUB 2 Runoff - 1.98 cfs @ 12.22 hrs, Volume= 0.200 af, Depth= 1.52" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs. Type Ill 24-hr 10-yr 24 hr Storm Rainfall=4.80" Area (sf CN Description 58,052 61 >75% Grass cover, Good, HSG B 527 98 Paved, HSG B 1,157 98 Building 9,096 82 Dirt Infield 68,832 65 Weighted Average 67,148 97.55% Pervious Area 1,684 2.45% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 8.2 50 0.0200 0.10 Sheet Flow, Field Grass: Dense n= 0.240 P2= 3.20" 7.0 413 0.0200 0.99 Shallow Concentrated Flow, Field Short Grass Pasture Kv= 7.0 fps 15.2 463 Total Subcatchment 2S: SUB 2 Hydrograph Cl Runof€ 1.98 cfs 2- Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Runoff Area=68,832 sf Runoff Volume=0.200 of Runoff Depth=1.52" w Flow Length=463' u Slope=0.0200 `I' 1 Tc=15.2 min C N=65 o „..... O... .. .................... .......... ...,,...,.,.,,. ,....,. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (flours) Proposed Conditions Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 Y y Solutions LLC Page 20 _ ro - 2 s n 02870 ©2D18 H droCAD Software 501 , Summary for Subcatchment 3S: SUB 3 Runoff - 1.10 cfs @ 12.08 hrs, Volume= 0.085 af, Depth= 4.22" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Area (sf) CN Description 937 61 >75% Grass cover, Good, HSG B 9,545 98 Paved parking, HSG B 10,482 95 Weighted Average 937 8.94% Pervious Area 9,545 91.06% Impervious Area Tc Length Slope Velocity Capacity Description (rain) (feet) _ (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Pavement Subcatchment 3S: SUB 3 Hydrograph 1.10 cfs I�Ruoff Type III 24-hr 1-1 10-yr 24 hr Storm Rainfall=4.80" Runoff Area=10,482 sf Runoff Volume=0.085 of Runoff Depth=4.22" w Tc=6.0 m i n 0 CN=95 LL O ..... : ............... ............ E.... ., ........ 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 AO 42 44 46 48 50 52 54 56 S8 SO 62 64 66 68 70 72 Time (hours) Proposed Conditions Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 H droCADO 10.00-22 sln 02870 ©2018 H droCAD Software Solutions LLC Page 21 Summary for Subcatchment 4S: SUB 4 Runoff - 0.17 cfs @ 12.09 hrs, Volume= 0.012 af, Depth= 1.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Area (sfl CN Description 2,557 61 >75% Grass cover, Good, HSG B 778 98 Pavement 3,335 70 Weighted Average 2,557 76,67% Pervious Area 778 23.33% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 6.0 Direct Entry, Subcatchment 4S: SUB 4 Hydrograph 0.18 0.17 cfs ❑Runofl 0.17: 0.1 s Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" .. .. 0.14: Runoff Area=3,335 sf 0.13-7 Runoff Volume=0.012 of 0.12= Runoff Depth=1.89" w Tc=6.0 min u 0.1- 3 0.09 C N=70 O iL 0.aa 0.07 o.os� 0.05= . .. .. ... _ ... ... _.. ... ........ 0.04- 0.03- 0.02 0 .........,,,,,,k,,,,,,,,,,,,, , 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type Ill 24-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 H „Solutions LLC Page 22 y ro 1fl.fl0-22 sln 02870 ©2018 HydroCAD Software I, Summary for Subcatchment 58: SUB 5 Runoff = 0.19 cfs @ 12.10 hrs, Volume= 0.015 af, Depth= 1.25" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Area (sf) CN Description 6,132 61 >75/o Grass cover, Good, HSG B 6,132 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Direct ... 6.0 Entry, Lawn Subcatchment 5S: SUB 5 Hydrograph o.z 0.19 cfs _ ❑Runoff 0.19- _ o.1a Type III 24-hr 0.17 10-yr 24 hr Storm Rainfall=4.80" 0.15 0.15= Runoff Area=6,132 sf a.14 Runoff Volume=0.015 of 0.13- Runoff Depth=1.25".. 0i2 Tc=6.0 min V 0.11 0.1- CN=61. LL 0.09 0.08: 0.06= 0.05 0.04; 0, r 0.02 0.01 0 2 q 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD010.00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment 6S: SUB 6 Runoff - 1.19 cfs @ 12.13 hrs, Volume= 0.096 af, Depth= 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" Area (sf) CN Description 18,433 61 >75% Grass cover, Good, HSG B 6,970 98 Concrete and Asphalt Pavement, HSG B 25,403 71 Weighted Average 18,433 72.56% Pervious Area 6,970 27.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.6 30 0.0100 0.82 Sheet Flow, Pavement Smooth surfaces n= 0.011 P2= 3.20" 3.6 20 0.0100 0.09 Sheet Flow, Lawn Grass: Short n= 0.150 P2= 3.20" 0.2 20 0.0100 2.03 Shallow Concentrated Flow, Pavement Paved Kv= 20.3 fps 4.5 190 0.0100 0.70 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0 fps 8.9 260 Total Subcatchment 6S: SUB 6 Hydrograph 1.19 ef5 ❑Runoff Type III 24-hr 10-yr 24 hr Storm Rainfall=4.80" 1_ Runoff Area=25,403 sf rx Runoff Volume=0.096 of Runoff Depth=1.97" N Flow Length=260' u 3 Slope=0.0100 '/' Tc=8.9 min C N=71 o :..,— �,...,... 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 3$40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.0.0-22 sin 02870 ©2018 HydroCAD Software Solutions LLC Page 24 Summary for Pond 7P: SC-740 Inflow Area = 0.583 ac, 27.44% Impervious, Inflow Depth = 1.97" for 10-yr 24 hr Storm event Inflow = 1.19 cfs @ 12.13 hrs, Volume= 0.096 of Outflow - 0.04 cfs @ 11.37 hrs, Volume= 0.096 af, Atten= 97%, Lag= 0.0 min Discarded = 0.04 cfs @ 11.37 hrs, Volume= 0.096 of Primary - 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 95.68' @ 17.27 hrs Surf.Area= 1,739 sf Storage= 2,559 cf Plug-Flow detention time= 643.8 min calculated for 0.096 of(100% of inflow) Center-of-Mass det. time= 643.8 min ( 1,493.8 - 850.0 ) Volume Invert Avail.Storage Storage Description #1 A 93.50' 1,608 cf 15.75 W x' 110.421 x 3.50'H Field A 6,087 cf Overall - 2,067 cf Embedded = 4,019 cf x 40.0%Voids #2A 94.00' 2,067 cf ADS_StormTech SC-740 +Cap x 45 Inside#1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.561 with 0.44' Overlap 3 Rows of 15 Chambers 3,675 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 93.50' 1.020 inlhr Exfiltration over Surface area #2 Primary 96.50' 6.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Discarded OutFlow Max=0.04 cfs @ 11.37 hrs HW=93.54' (Free Discharge) T 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=93.50' (Free Discharge) L2=Broad-Crested Rectangular Weir( Controls 0.00 cfs) Proposed Conditions Type 111 24-hr 90-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD010.00-22 s/n 02870 02018 HydroCAD Software Solutions LLC Page 25 Pond 7P: SC-740 - Chamber Wizard Field A Chamber Model=ADS StormTech SC-740+Cap(ADS StormTech®SC-740 with cap length) Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.561 with 0.44' Overlap 51.0" Wide + 6.0" Spacing = 57.0" C-C Row Spacing 15 Chambers/Row x 7.12' Long +0.81' Cap Length x 2 = 108.42' Row Length +12.0" End Stone x 2 110.42' Base Length 3 Rows x 51.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 15.75' Base Width 6.0" Base + 30.0" Chamber Height + 6.0" Cover= 3.50' Field Height 45 Chambers x 45.9 cf= 2,067.3 cf Chamber Storage 6,086.7 cf Field - 2,067.3 cf Chambers = 4,019.4 cf Stone x 40.0% Voids = 1,607.8 cf Stone Storage Chamber Storage + Stone Storage = 3,675.1 cf= 0.084 of Overall Storage Efficiency = 60.4% Overall System Size - 110.42' x 15.75' x 3.50' 45 Chambers 225.4 cy Field 148.9 cy Stone I Proposed Conditions Type 11124-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 Hy droCAD® 10.00-22 sln 02870 0 2018 H droCAD Software Solutions LLC Page 26 Pond 7P: SC-740 Hydrograph 0 Inflow 1.19 Cfs I Outflow Inflow Area=4.583 ac 0�pssoarded Primary Peak Elev=95.68' Storage=2,559 cf 1- nd o f.� 0 04 cfs 0.00 cfs o ........................ 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 3638 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) I Proposed Conditions Type 11124-hr 10-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 sln 02870 ©2018 H droCAD Software Solutions LLC Page 27 Summary for Link DP-1: Desgn Point #1 - Abutting Properties Inflow Area = 1.794 ac, 4.33% Impervious, Inflow Depth = 1.47" for 10-yr 24 hr Storm event Inflow = 2.18 cfs @ 1221 hrs, Volume= 0.220 of Primary - 2.18 cfs @ 12.21 hrs, Volume= 0.220 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-1: Desgn Point #1 - Abutting Properties Hydrograph Q fnilow p Primary 2.18 cfs Inflow Area=1 .794 ac: 2- N u 3 0 a 1 f 0 ., ..,,,, .,, .-.,, ...........„,,,.,j„.,, „., ,,,;...................... .....3 ...,... ,.,.,..,,..,.,.. ,,.,,.,.... ... ..,,,..,., 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 36 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 90-yr 24 hr Storm Rainfall=4.80" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD®10.00-22 s/n 02870 ©2018 H droCAD Software Solutions LLC Page 28 Summary for Link DP-2: Design Point #2 - Town Drainage System Inflow Area = 2.545 ac, 16.42% Impervious, inflow Depth = 1.41" for 10-yr 24 hr Storm event Inflow = 2.71 cfs @ 12.18 hrs, Volume= 0.300 of Primary - 2.71 cfs @ 12.18 hrs, Volume= 0.300 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-2: Design Point #2 - Town Drainage System Hydrocgraph 3 ❑Inflow ❑Primary z.71 cfs Inflow Area=2.545 ac z- U O W 3- �... .. _ 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 fib 68 70 72 Time (hours) Proposed Conditions Type Ill 24-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 H droCADO 10.00-22 sln 02870 0 2018 H droCAD Software Solutions LLC Pacie 29 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment' S: SUB 1 Runoff Area=74,808 sf 3.48% Impervious Runoff Depth=2.26" Flow Length=415' Slope=0.0200 T Tc=14.3 min CN=64 Runoff=3.39 cfs 0.324 of Subcatchment2S: SUB 2 Runoff Area=68,832 sf 2.45% Impervious Runoff Depth=2.35" Flow Length=463' Slope=0.0200 '1' Tc=15.2 min CN=65 Runoff=3.19 cfs 0.310 of Subcatchment3S: SUB 3 Runoff Area=10,482 sf 91.06% Impervious Runoff Depth=5.41" Tc=6.0 min CN=95 Runoff=1.39 cfs 0.109 of Subcatchment4S: SUB 4 Runoff Area=3,335 sf 23.33% Impervious Runoff Depth=2.81" Tc=6.0 min CN=70 Runoff=0.25 cfs 0.018 of Subcatchment5S: SUB 5 Runoff Area=6,132 sf 0.00% Impervious Runoff Depth=2.01" Tc=6.0 min CN=61 Runoff=0.32 cfs 0.024 of Subcatchment6S: SUB 6 Runoff Area=25,403 sf 27.44% Impervious Runoff Depth=2.90" Flow Length=260' Slope=0.01 00T Tc=8.9 min CN=71 Runoff=1.79 cfs 0.141 of Pond 7P: SC-740 Peak Elev=96.54' Storage=3,357 cf Inflow=1.79 cfs 0.141 of Discarded=0.04 cfs 0.120 of Primary=0.12 cfs 0.020 of Outflow=0.16 cfs 0.141 of Link DP-1: Desgn Point#1 -Abutting Properties Inflow=3.54 cfs 0.342 of Primary=3.54 cfs 0.342 of Link DP-2: Design Point#2 -Town Drainage System Inflow=4.16 cfs 0.462 of Primary=4.16 cfs 0.462 of Total Runoff Area = 4.339 ac Runoff Volume = 0.924 of Average Runoff Depth = 2.56" 88.58% Pervious = 3.843 ac 11.42% Impervious = 0.495 ac Proposed Conditions Type 11124-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 sln 02870 ©2018 H droCAD Software Solutions LLC Page 30 Summary for Subcatchment 1S: SUB 1 Runoff 3.39 cfs @ 12.21 hrs, Volume= 0.324 af, Depth= 2.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Area-(sf) CN Description 66,975 61 >75% Grass cover, Good, HSG B 2,602 98 Paved Basketball Court 5,231 82 Mulch 74,808 64 Weighted Average 72,206 96.52% Pervious Area 2,602 3.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ft/sec) (cfs) 8.2 50 0.0200 0.10 Sheet Flow, o Lawn Grass: Dense n= 0.240 P2= 3.20" 6.1 365 0.0200 0.99 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0 fps 14.3 415 Total Subcatchment 1S: SUB 1 Hydrograph 3.39 cfs ❑RunoH Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" 3- Runoff Area=74,808 sf Runoff Volume=0.324 of Runoff Depth=2.26" ZF u 2_ Flow Length=415' 3 Slope=0.0200 '1' E° Tc=14.3 min C N=64 . .. .. ... ... .. .. .. .. 1- 0 2 4 6 8 10 12 14 16 i$20 22 24 2$ 28 30 32 34 36 3$40 42 44 46 48 50 52 54 56 58 60 62 64 66 6B 70 72 Time (hours) Proposed Conditions Type 11124-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 s/n 02870 ©2018 H droCAD Software Solutions LLC Page 31 Summary for Subcatchment 2S: SUB 2 Runoff - 3.19 cfs @ 12.21 hrs, Volume= 0.310 af, Depth= 2.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Area (sf) CN Description 58,052 61 >75% Grass cover, Good, HSG B 527 98 Paved, HSG B 1,157 98 Building 9,096 82 Dirt Infield 68,832 65 Weighted Average 67,148 97.55% Pervious Area 1,684 2.45% Impervious Area Tc Length Slope Velocity Capacity Description (rain) (feet) (ft/ft) (ft/sec) (cfs) 8.2 50 0.0200 0.10 Sheet Flow, Field Grass: Dense n= 0.240 P2= 3.20" 7.0 413 0.0200 0.99 Shallow Concentrated Flow, Field Short Grass Pasture Kv= 7.0 fps 15.2 463 Total Subcatchment 2S: SUB 2 Hydrogranh 3.19 cfs Q Runoff Type III 24-hr s 25-yr 24 hr Storm Rainfall=6.00" Runoff Area=68,832 sf Runoff Volume=0.310 of Runoff Depth=2.35" 2- Flow Length=463' 3 Slope=0.0200 '/' LL Tc=15.2 min CN=65 i 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 HHdroCAD® 10.00-22 s/n 02870 0 2018 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment 3S: SUB 3 Runoff = 1.39 cfs @ 12.08 hrs, Volume= 0.109 af, Depth= 5.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Area (sf) CN Description 937 61 >75% Grass cover, Good, HSG B 9,545 98 Paved parking, HSG B 10,482 95 Weighted Average 937 8.94% Pervious Area 9,545 91.06% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft� _(ft/sec) (cfs) 6.0 Direct Entry, Pavement Subcatchment 3S: SUB 3 Hydrograph 1.39 cfs ❑Runoff Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Runoff Area=10,482 sf Runoff Volume=0.109 of 1 Runoff Depth=5.41" u Tc=6.0 min 0 C N=95 L 0 2 4 6 $ 10 12 14 L- 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type I1124-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment 4S: SUB 4 Runoff = 0.25 cfs @ 12.09 hrs, Volume= 0.018 af, Depth= 2.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Areas CN Description 2,557 61 >75% Grass cover, Good, HSG B 778 98 Pavement 3,335 70 Weighted Average 2,557 76.67% Pervious Area 778 23.33% Impervious Area Tc Length Slope Velocity Capacity Description (ruin) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: SUB 4 Hydrograph 0.28- 0.26' 0.25 cfs _ _ ❑Runoff 0.24.: Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" ° 2 0.2: Runoff Area=3,335 sf 0 Runoff Volume=0.018 of 0.1s Runoff Depth=2.8'i. F 0,16=- Tc=6.0 min 3 0.14= CN=70 0 L- 0.12- 0.1- 0.08- 0.06- 0.04- 0.02= 0''' .i.r ... ...i .i.. .... .ii. ii.. .... ii..{i........ .... .. ..,. iiE... ..i.E,... .. ..r. .i.. ... .. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type li! 24-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO-10.00-22 s/n 02870 Q 2018 HydroCAD Software Solutions„LLC Page 34 Summary for Subcatchment 5S: SUB 5 Runoff - 0.32 cfs @ 12.10 hrs, Volume= 0.024 af, Depth= 2.01" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Area (so CN Description 6,132 61 >75% Grass cover, Good, HSG: ,.,,..._ B 6,132 100.00% Pervious Area Tc Length Slope Velocity Capacity Description ___(min) (feet) (ft/ft) (ftlsec) (cfs) 6•0 Direct,,.,.,.,_.. Entry, Lawn Subcatchment 5S: SUB 5 Hydrograph ❑rtunoff 0.34= 0.32 cfs 0.32- Type III 24-hr 0.3 0.28= _ 25-yr 24 hr Storm Rainfall=6.00" Runoff Area=6,132 sf 0.26 0.24 Runoff Volume=0.024 of O12 Runoff Depth=2.01" y 0.2 Tc=6.0 m i n u 3 0.1a: CN=61 0.14= 0.12= 0.1.: 0.06-' 0.04 0.02 0-.... ... ....................-,--,,,,,-,.:,.,.:..,,----,.:..,....,...,.,,.,,:.,,,,.., ,..,,...,... ,...,....,.. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 36 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 s/n 02870 02018 HydroCAD Software Solutions LLC Page 35 Summary for Subcatchment 6S: SUB 6 Runoff = 1.79 cfs @ 12.13 hrs, Volume= 0.141 af, Depth= 2.90" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Areas CN Descri tion 18,433 61 >75% Grass cover, Good, HSG B 6,970 98 Concrete and Asphalt Pavement HSG B 25,403 71 Weighted Average 18,433 72.56% Pervious Area 6,970 27.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftlsec) (cfs) _ 0.6 30 0.0100 0.82 Sheet Flow, Pavement ^ Smooth surfaces n= 0.011 P2= 3.20" 3.6 20 0.0100 0.09 Sheet Flow, Lawn Grass: Short n= 0.150 P2= 3.20" 0.2 20 0.0100 2.03 Shallow Concentrated Flow, Pavement Paved Kv= 20.3 fps 4.5 190 0.0100 0.70 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0 fps 8.9 260 Total Subcatchment 6S: SUB 6 Hydrograph 2- 1.79 cfs ❑Runoff Type III 24-hr 25-yr 24 hr Storm Rainfall=6.00" Runoff Area=25,403 sf Runoff Volume=0.141 of Runoff Depth=2.90" Flow Length=260' 3 1.. Slope=0.0100 '1' LL Tc=8.9 min C N=71 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC Page 36 Summary for Pond 7P: SC-740 Inflow Area = 0.583 ac, 27.44% Impervious, Inflow Depth = 2.90" for 25-yr 24 hr Storm event Inflow = 1.79 cfs @ 12.13 hrs, Volume= 0.141 of Outflow = 0.16 cfs @ 13.53 hrs, Volume= 0.141 af, Atten= 91%, Lag= 84.1 min Discarded = 0.04 cfs @ 10.75 hrs, Volume= 0.120 of Primary - 0.12 cfs @ 13.53 hrs, Volume= 0.020 of Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 96.54' @ 13.53 hrs Surf.Area= 1,739 sf Storage= 3,357 cf Plug-Flow detention time= 716.2 min calculated for 0.141 of(100% of inflow) Center-of-Mass det. time= 716.3 min ( 1,554.8 - 838.6 ) Volume Invert Avail.Storage Storage Description #1A 93.50' 1,608 cf 15.75'W x 110.42'L.x 3.50'H Field A.,,.. 6,087 cf Overall - 2,067 cf Embedded = 4,019 of x 40.0%Voids #2A 94.00' 2,067 cf ADS StormTech SC-740 *Cap x 45 Inside #1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.561 with 0.44' Overlap 3 Rows of 15 Chambers 3,675 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 93.50' 1.020 in/hr Exfiltration over Su rface area #2 Primary 96.50' 5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2,80 2.92 3.08 3.30 3.32 Qiscarded OutFlow Max=0.04 cfs @ 10.75 hrs HW=93.54' (Free Discharge) �-1-Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.12 cfs @ 13.53 hrs HW=96.54' (Free Discharge) L2=Broad-Crested Rectangular Weir(Weir Controls 0.12 cfs @ 0.57 fps) Proposed Conditions Type 111 24-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfieid Design Group Printed 7/24/2019 H droCAD® 10.00-22 s/n 02870 ©2018 H droCAD Software Solutions LLC Pa e 37 Pond 7P: SC-740 - Chamber Wizard Field A Chamber Model=ADS_StormTechSC-740+Cap(ADS StormTech®SC-740 with cap length) Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap 51.0" Wide + 6.0" Spacing = 57.0" C-C Row Spacing 15 Chambers/Row x 7.12' Long +0.81' Cap Length x 2 = 108.42' Row Length +12.0" End Stone x 2 110.42' Base Length 3 Rows x 51.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 15.75' Base Width 6.0" Base + 30.0" Chamber Height + 6.0" Cover = 3.50' Field Height 45 Chambers x 45.9 cf= 2,067.3 cf Chamber Storage 6,086.7 cf Field - 2,067.3 cf Chambers = 4,019.4 cf Stone x 40.0% Voids - 1,607.8 of Stone Storage Chamber Storage + Stone Storage = 3,675.1 cf= 0.084 of Overall Storage Efficiency = 60.4% Overall System Size = 110.42' x 15.75' x 3.50' 45 Chambers 225.4 cy Field 148.9 cy Stone oo� Proposed Conditions Type 11l 24-hr 25-yr 24 hr Storm Rainfall=6.00° Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 ©2018_H_ydroCAD Software Solutions LLC _ Page 38 Pond 7P: SC-740 Hydroyraph 1.79 cfs 0 Inflow H Outflow 2- Inflow Area=0.583 ac 0Prmarryed Peak Elev=96.54' Storage=3,357 cf Iso 0.16 cfs 0.12 cfs ,, o ,,, ,, , ,,,,,,,, , ....,..........,.,,..,,,..,,,,,,,,., 0 2 4 6 8 1012141618202224262830323436384042444648505254565860626466687072 Time (hours) Proposed Conditions Type 1/1 24-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 H dmCADO 10.00-22 s/n 02870 ©2018 H droCAD Software Solutions LLC Page 39 Summary for Link DP-1; Desgn Point #1 - Abutting Properties Inflow Area = 1.794 ac, 4.33% Impervious, Inflow Depth = 2.29" for 25-yr 24 hr Storm event Inflow = 3.54 cfs @ 12.20 hrs, Volume= 0.342 of Primary — 3.54 cfs @ 12.20 hrs, Volume= 0.342 af, Men= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-1: Desgn Point #1 - Abutting Properties Hydrograph ©InRow ©Primary 3.54 cfs Inflow Area=1 .794 ac 3- u 2... O lL / a ..,.,.,,.,, ,,,,,,,,,,,,,,,,,,,, ,, , 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type It/ 24-hr 25-yr 24 hr Storm Rainfall=6.00" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 sln 02870 ©2018 H droCAD Software Solutions LLC Page 40 Summary for Link DP-2: Design Point #2 - Town Drainage System Inflow Area = 2.545 ac, 16.42% Impervious, Inflow Depth = 2.18" for 25-yr 24 hr Storm event Inflow = 4.16 cfs @ 12.18 hrs, Volume= 0.462 of Primary = 4.16 cfs @ 12.18 hrs, Volume= 0.462 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-2: Design Point #2 - Town Drainage System Hydrocgraph 0 lnfiow Ej Primary 4.16 cfs Inflow Area=2.545 ac 4- 3- 2- 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 900-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutions„LLC__,. Page 41 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: SUB 1 Runoff Area=74,808 sf 3.48% Impervious Runoff Depth=4.27" Flow Length=415' Slope=0.0200? Tc=14.3 min CN=64 Runoff=6.59 cfs 0.610 of Subcatchment2S: SUB 2 Runoff Area=68,832 sf 2.45% Impervious Runoff Depth=4.38" Flow Length=463' Slope=0.0200 '1' Tc=15.2 min CN=65 Runoff=6.11 cfs 0.577 of Subcatchment3S: SUB 3 Runoff Area=10,482 sf 91.06% Impervious Runoff Depth=8.00" Tc=6.0 min CN=95 Runoff=2.01 cfs 0.160 of Subcatchment4S: SUB 4 Runoff Area=3,335 sf 23.33% Impervious Runoff Depth=4.98" Tc=6.0 min CN=70 Runoff=0.45 cfs 0.032 of Subcatchment5S: SUB 5 Runoff Area=6,132 sf 0.00% Impervious Runoff Depth=3.91" Tc=6.0 min CN=61 Runoff=0.64 cfs 0.046 of Subcatchment6S: SUB 6 Runoff Area=25,403 sf 27.44% Impervious Runoff Depth=5.10" Flow Length=260' Slope=0.0100 '1' Tc=8.9 min CN=71 Runoff=3.16 cfs 0.248 of Pond 7P: SC-740 Peak Elev=96.79' Storage=3,527 cf Inflow=3.16 cfs 0,248 of Discarded=0.04 cfs 0.129 of Primary=2.20 cfs 0.119 of Outflow=2.24 cfs 0.248 of Link DP-1: Desgn Point#1 -Abutting Properties Inflow=6.86 cfs 0.642 of Primary=6.86 cfs 0.642 of Link DP-2: Design Point#2 -Town Drainage System Inflow=9.65 cfs 0.903 of Primary=9.65 cfs 0.903 of Total Runoff Area =4.339 ac Runoff Volume = 1.674 of Average Runoff Depth =4.63" 88.58% Pervious = 3.843 ac 11.42% Impervious = 0.495 ac Proposed Conditions Type Nl 24-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD010.00-22 s/n 02870 02018 H droCAD Software Solutions LLC Page 42 Summary for Subcatchment 1S: SUB 1 Runoff = 6.59 cfs @ 12.20 hrs, Volume= 0.610 af, Depth= 4.27" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Area (sD CN Description 66,975 61 >75% Grass cover, Good, HSG B 2,602 98 Paved Basketball Court 5,231 82 Mulch 74,808 64 Weighted Average 72,206 96.52% Pervious Area 2,602 3.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.2 50 0.0200 0.10 Sheet Flow, Lawn Grass: Dense n= 0.240 P2= 3.20" 6.1 365 0.0200 0.99 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0 fps 14.3 415 Total Subcatchment 1S: SUB 1 Hydrograph 7- 6.59 cfs` ❑izunorr 11 Type III 24-hr 6- 100-yr 24 hr Storm Rainfall=8.60" Runoff Area=74,808 sf 5..: Runoff Volume=0.610 of Runoff Depth=4.27" 4 Flow Length=415' 0 Slope=0.0200 T Tc=14.3 min 3- CN=64 2- 1. 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 36 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 sln 02870 ©2018 HydroCAD Software Solutions LLC Page 43 Summary for Subcatchment 2S: SUB 2 Runoff = 6.11 cfs @ 12.21 hrs, Volume= 0.577 af, Depth= 4.38" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Areas CN Descri tion 58,052 61 >75% Grass cover, Good, HSG B 527 98 Paved, HSG B ' 1,157 98 Building 9,096 82 Dirt Infield 68,832 65 Weighted Average 67,148 97.55% Pervious Area 1,684 2.45% Impervious Area Tc Length Slope Velocity Capacity Description (min) feet �f#Ift� (ftlsec) _ (cfs) 8.2 50 0.0200 0.10 Sheet Flow, Field Grass: Dense n= 0.240 P2= 3.20" 7.0 413 0,0200 0.99 Shallow Concentrated Flow, Field Short Grass Pasture Kv= 7.0 fps 15.2 463 Total Subcatchment 2S: SUB 2 Hydrograph 6.11 cfs n rcuoff 6- Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Runoff Area=68,832 sf 5.. Runoff Volume=0.577 of - _ Runoff Depth=4.38 Flow Length=463' u Slope=0.0200 M 3- Tc=15.2 min CN=65 2- 1- o ....,.. --............................ ............ ,.,,,, ...,....,,..,,..,,,. .,,,..,...,....,....,.. ., 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870_©2018 HydroCAD Software Solutions LLC Page 44 Summary for Subcatchment 3S: SUB 3 Runoff = 2.01 cfs @ 12.08 hrs, Volume= 0.160 af, Depth= 8.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Areas CN Description 937 61 >75% Grass cover, Good, HSG B 9,545 98 Paved parking, HSG B 10,482 95 Weighted Average 937 8.94% Pervious Area 9,545 91.06% Impervious Area Tc Length Slope Velocity Capacity Description min)_ --(feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, ry, Pavement Subcatchment 3S: SUB 3 Hydrograph 2.01 cfs ❑Runoti 2 Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Runoff Area=10,482 sf Runoff Volume=0.160 of Runoff Depth=8.00" Tc=6.0 m i n 3 C N=93 0 1- Q- ....i��. ,..��i...��.... .,��,��.��,..��..........�.��. .�.��.��;�.��. .... .. ......................�.......�..� ..,. .... ... .... ....4....... ... i... ....i... ...,i 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 fib 70 72 Time (hours) Proposed Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 H droCAD® 10.00-22 s/n 02870 ©2018 H droCAD Software Solutions LLC Page 45 Summary for Subcatchment 4S: SUB 4 Runoff - 0.45 cfs @ 12.09 hrs, Volume= 0.032 af, Depth= 4.98" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Area (so CN Description 2,557 61 >75% Grass cover, Good, HSG B 778 98 Pavement 3,335 70 Weighted Average 2,557 76.67% Pervious Area 778 23.33% Impervious Area Tc Length Slope Velocity Capacity Description min (feet) (ft/ft) (ft/sec) (cfs) _ 6.0 Direct Entry, Subcatchment 4S: SUB 4 Hydrograph 0.48- 0,45 cfs 17 Runoff 0.46.; 0.44- _ ... ....... .. Type 111 24-hr 0.42 0.4-: 104-yr 24 hr.Stor.m.Rainfall=8.60" 0.3s Runoff Area=3,335 sf 0.3s 0.34 Runoff Volume=0.032 of 0.32 Runoff Depth=4.98" 0.3 .. . .. . .... .. ..... . . . a 0.28- Tc=6.0 min 0.26 0 0.241 C+N=70 u 0.22- 0.2 0.18 0.16- 0.14 0.12 OA8' 0.06_ .. . ... ... . 0.04 0.02 0`,,,,,,,,.i... ... .....................................................i . ................... ......,,,..,3, ,,,. .,..,..,.,.,..,,. .,,,.., 0 2 4 6 8 10 1214 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 fib 70 72 Time (hours) Proposed Conditions Type 111 24-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 0 2018 HydroCAD Software Solutions LLC Page 46 Summary for Subcatchment 5S: SUB 5 Runoff = 0.64 cfs @ 12.09 hrs, Volume= 0.046 af, Depth= 3.91" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Area (sf) CN Description 6,132 61 >75% Grass cover, Good HSG B 6,132 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Lawn Subcatchment 5S: SUB 5 Hydrograpll 0,7: C7 Runoff 0.64 cfs a.ss Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" 0.55 Runoff Area-6,132 sf 0.5= Runoff Volume=0.046 of 0.45- Runoff Depth=3.91" 0.4 Tc=6.0 m i n 0.3s C N=61 o - LL 0.3- 0.25- 0.2- 0.15- 0.1- 0.05- 0- „ . -- .,.,,,. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Sfl 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type /// 24-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC Page 47 Summary for Subcatchment 6S: SUB 6 Runoff- 3.16 cfs @ 12.13 hrs, Volume= 0.248 af, Depth= 5.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs. Type III 24-hr 100-yr 24 hr Storm Rainfall=8.60" Area (sf) CN Description 18,433 61 >75% Grass cover, Good, HSG B 6,970 98 Concrete and Asphalt Pavement, HSG B 25,403 71 Weighted Average 18,433 72.56% Pervious Area 6,970 27.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.6 30 0.0100 0.82 Sheet Flow, Pavement Smooth surfaces n= 0.011 P2= 3.20" 3.6 20 0.0100 0.09 Sheet Flow, Lawn Grass: Short n= 0.150 P2= 3.20" 0.2 20 0.0100 2.03 Shallow Concentrated Flow, Pavement Paved Kv= 20.3 fps 4.5 190 0.0100 0.70 Shallow Concentrated Flow, Lawn Short Grass Pasture Kv= 7.0 fps 8.9 260 Total Subcatchment 6S: SUB 6 Hydrograph 3.16 cfs ❑Ru,off Type Ill 24-hr 3- 1 00-yr 24 hr Storm Rainfall=8.60" Runoff Area=25,403 sf Runoff Volume=0.248 of Runoff Depth=5.10" w 2- Flow Length=260' Slope=0.0100 '1' LL Tc=8.9 m i n CN=71 1- oL - ......,�...,...�,..,.,., �� .............. ,....,...,.... 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 H droCADO 10.00-22 sln 02870 0 2018 H droCAD Software Solutions LLC Page 48 Summary for Pond 7P; SC-740 Inflow Area = 0.583 ac, 27.44% Impervious, Inflow Depth = 5.10" for 100-yr 24 hr Storm event Inflow = 3.16 cfs @ 12.13 hrs, Volume= 0.248 of Outflow - 2.24 cfs @ 12.23 hrs, Volume= 0.248 af, Atten= 29%, Lag= 6.2 min Discarded = 0.04 cfs @ 9.48 hrs, Volume= 0.129 of Primary = 2.20 cfs @ 12.23 hrs, Volume= 0.119 of Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 96.79' @ 12.23 hrs Surf.Area= 1,739 sf Storage= 3,527 cf Plug-Flow detention time= 436.9 min calculated for 0.248 of(100% of inflow) Center-of-Mass det. time= 437.1 min ( 1,259.4 - 822.3 ) Volume Invert Avail.Storage Storage Description_ #1A 93.50' 1,608 cf 15.75'W x 110.421 x 3.50'H Field A 6,087 cf Overall - 2,067 cf Embedded = 4,019 cf x 40.0% Voids #2A 94.00' 2,067 cf ADS_StormTech SC-740 +Cap x 45 Inside #1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.561 with 0.44' Overlap 3 Rows of 15 Chambers 3,675 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 93.50' 1.020 in/hr Exfiltration over Surface area #2 Primary 96.50' 5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Iscarded OutFlow Max=0.04 cfs @ 9.48 hrs HW=93.54' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=2.20 cfs @ 12.23 hrs HW=96.79' (Free Discharge) t2=Broad-Crested Rectangular Weir(Weir Controls 2.20 cfs @ 1.53 fps) Proposed Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 sln 02870 0 2018 HydroCAD Software Solutions LLC Page 49 Pond 7P: SC-740 - Chamber Wizard Field A Chamber Model =ADS_StormTech SC-740+Cap(ADS StormTech®SC-740 with cap length) Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.561 with 0.44' Overlap 51.0" Wide + 6.0" Spacing = 57.0" C-C Row Spacing 15 Chambers/Row x 7.12' Long +0.81' Cap Length x 2 = 108.42' Row Length +12.0" End Stone x 2 = 110.42' Base Length 3 Rows x 51.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 15.75' Base Width 6.0" Base + 30.0" Chamber Height + 6.0" Cover = 3.50' Field Height 45 Chambers x 45.9 cf= 2,067.3 of Chamber Storage 6,086.7 cf Field - 2,067.3 cf Chambers = 4,019.4 cf Stone x 40.0% Voids = 1,607.8 cf Stone Storage Chamber Storage + Stone Storage = 3,675.1 cf= 0.084 of Overall Storage Efficiency = 60.4% Overall System Size = 110.42' x 15.75' x 3.50' 45 Chambers 225.4 cy Field 148.9 cy Stone I � Proposed Conditions Type III 24-hr I00-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 Hydro 0.00-22 sln 02870 02018 HydroCAD Software,Solutions LLC Page 50•,.__. Pond 7P: SC-740 Hydrograph 3.1 CfS now i Outflow Inflow Area=4.583 ac Discarded ©Primary Peak Elev=96.79' 3 fs Stora a=3 527 cf z.z4 cfs g 2.20 cfs 2 0.04 r� 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Proposed Conditions Type 11124-hr 100-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCADO 10.00-22 sln 02870__0.2018_HydroCAD Software Solutions L.LC Page 51 Summary for Link DP-1: Desgn Point #1 - Abutting Properties Inflow Area - 1.794 ac, 4.33% Impervious, Inflow Depth = 4.30" for 100-yr 24 hr Storm event Inflow = 6.86 cfs @ 12.19 hrs, Volume= 0.642 of Primary = 6.86 cfs @ 12.19 hrs, Volume= 0.642 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-1: Desgn Point#1 - Abutting Properties Hydrograph 0 Inflow 7- 0 Primary 6.86 cfs Inflow Alrea=1 .794 ac 6- ......... 5- N w 4- 3- 2- 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 64 62 64 66 66 70 72 Time (hours) Proposed Conditions Type 11124-hr 900-yr 24 hr Storm Rainfall=8.60" Prepared by Waterfield Design Group Printed 7/24/2019 HydroCAD® 10.00-22 s/n 02870 ©2018 HydroCAD Software Solutions LLC Page 52 Summary for Link DP-2: Design Point #2 - Town Drainage System Inflow Area = 2.545 ac, 16.42% Impervious, Inflow Depth = 4.26" for 100-yr 24 hr Storm event Inflow - 9.65 cfs @ 12.22 hrs, Volume= 0.903 of Primary = 9.65 cfs @ 12.22 hrs, Volume= 0.903 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Link DP-2: Design Point #2 - Town Drainage System Hydrograph 0 Inflow C[Primary 10- 9.65 cfs Inflow Area=2;545 ac 8- 7- w 6 u 0 5- / 4W . ... ... . ... ... 3- ... .. ... . 2-- 0- 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)