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Co-Housing Stormwater Management ReportSunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page i Table of Contents I. Introduction .......................................................................................................................... 1 II. Existing Conditions ................................................................................................................. 4 III. Proposed Conditions .............................................................................................................. 4 IV. Calculations and Design ......................................................................................................... 6 V. MADEP Stormwater Standards Compliance ............................................................................ 8 Figures Figure 1 Location Plan Figure 2 Pre-Development Conditions (North Campus) Figure 3 Existing Conditions (North Campus) Figure 4 Existing Conditions (Co-Housing Site) Figure 5 Major Drainage Features (Existing Condition) Figure 6 Grading & Drainage Plan (Co-Housing Site) Figure 7 Pre-Development vs. Proposed Impervious Area Figure 8 Existing vs. Proposed Impervious Area Figure 9 Pre-Development Drainage Areas Figure 10 Post-Development Drainage Areas Figure 11 Post-Development Drainage Sub-Areas for Pipe Design and Water Quality Figure 12 Post-Development Drainage Sub-Area for Stormwater Treatment Chamber Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page ii Appendix Appendix A NRCS Soil Report Appendix B Subsurface Investigation Results Appendix C Stormwater Hydrology Calculations Appendix D Water Quality Calculations Appendix E Outlet Protection Riprap Design Calculations Appendix F Massachusetts Stormwater Checklist Appendix G Stormwater Management System – Operation & Maintenance Plan Appendix H Storm Drain Sizing Calculations Appendix I Impervious Area Tabulation Summary by Gale Associates, Inc. (7/20/2018) Appendix J Detention Basin #2 & #4 As-Built Survey Plan (5/11/2018) Referenced Documents Plan Set “Village Hill – Northampton, MA – Co-Housing Site Plan Amendment” Berkshire Design Group 5/1/2018 (Revised 7/23/2018) Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 1 Sunwood Builders is proposing the construction of a new multi-family residential development on a lot currently owned by the Massachusetts Economic Development and Finance Agency (Mass Development) within the Village Hill neighborhood of Northampton. The Berkshire Design Group has prepared a Stormwater Management and Erosion and Sedimentation Control Plan for the site, in compliance with the Massachusetts Stormwater Handbook and the Code of the City of Northampton. This report documents the proposed Stormwater Management Plan and that plan’s compliance with those standards. I. Introduction The proposed project is a continuation of the ongoing re-development of the former Northampton State Hospital site, a neighborhood now known as Village Hill. The site is located at the northeast corner of the Village Hill development and proposes to construct 24 residential units, consisting of 16 single family houses and 4 duplexes. The development will also include a central community building, two small accessory buildings, and two covered trash/recycling collection areas. The site will be accessed via an entry driveway off of the driveway to be constructed for the proposed Community Builders development, immediately west of the site. The development will include construction of two centralized parking lots, interior walkways, landscaping and new utility services. Site drainage will primarily be provided by a system of storm drains that tie into a trunk line that also serves the Community Builders site. The storm drains discharge to an existing detention basin immediately east of the site, and include a stormwater treatment chamber for water quality. Some impervious areas (primarily roof runoff, with some sidewalk areas) are discharged from the site via overland flow. A majority of this area drains toward the swale and detention basin to the east, with some areas discharging to the north without being intercepted by stormwater management devices. The project location is shown in Figure 1. The site is located in the “north campus” portion of Village Hill, which encompasses the land north of West Street (Route 66). The pre-development condition of the north campus, prior to demolition of the state hospital infrastructure, is shown on Figure 2. Based on pre-development maps of the State Hospital, the co-housing site was occupied primarily by grass or wooded areas and narrow roads, with one small building at the north end. The site is currently covered by wooded areas with portions of the former roadways/paths. The existing condition of the site is shown on Figure 3, which overlays the property boundaries of existing building lots over an aerial image (c. 2013) of the site. The co-housing site is bordered on the west by the proposed Community Builders project, to the north by land that will be transferred to the City for conservation, to the east by a swale and detention basin, and to the south by undeveloped land west of Olander Drive. These parcels are also shown on Figure 3. Note that the Village Hill north campus includes 3 parcels with projects that are planned but unbuilt at the time of this report. Each of these parcels is shown in Figure 3, and include (1) the Community Builders “Lot 13A” project at the north-central part of the north campus, (2) the Community Builders “Lot 20” site near the center of the campus on Village Hill Road, and (3) a parcel fronting on Ford Crossing that has been reserved by Mass Development for single-family homes. The analyses in this report are based on the condition of these lots at full buildout. The existing topography of the site is shown on Figure 4. This lot generally slopes from west to east, with a majority of runoff flowing overland toward the Mill River either directly, or via the large Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 2 detention basin to the east of the site. The major components of the existing stormwater management infrastructure are shown on Figure 5. With the exception of the Pecoy Homes development at the northwest corner, runoff is managed by three detention basins, noted in the figure as Basins #2, 3, and 4 (a previously-proposed basin, #1, was eliminated from the design during an earlier phase). Detention Basin #4 discharges to a swale, carrying water to Basin #2. Basins #2 and #3 discharge off-site. The Pecoy Homes development includes its own stormwater management infrastructure to manage runoff from that development independently from the rest of the site. The grading and drainage plan for the co-housing site is shown on Figure 6. A majority of the site is collected by the proposed storm drains, and discharged to Basin #2. A small portion of the site at the north end runs of toward the Mill River to the north. No wetlands or buffer zones are located within the proposed limit of disturbance. The Mill River, and its associated riparian zone are located north of the site, and neither is impacted by the proposed work. Figures 7 and 8 compare the new impervious area proposed at the site with the pre-development and existing conditions, respectively. Soil Data NRCS Soil Survey The NRCS Soil Survey reports that the Village Hill north campus consists of a mix of soils. The disturbed area within and adjacent to the location of the former Old Main building is disturbed urban land and fill. Subsequent soil evaluations have determined that this area is best characterized as belonging to Hydrologic Soil Group (HSG) C. The western edge of the site is made up of relatively coarse soils of HSG A. The majority of the remaining portions of the site, including the co-housing site are made up of relatively fine soils of HSG C, with a small area of medium soils belonging to HSG B. The Soil Report for the site is attached in Appendix A. The boundaries of each soil group are shown on the existing drainage area map (Figure 9). Subsurface Exploration A total of 5 test pits were conducted at the co-housing site by Cold Spring Environmental in April 2015. The soil evaluation report is attached in Appendix B.1 The test pits in the southern portion of the co-housing site (#1, #2, #3) showed fine sandy loam underlying the site with relatively shallow groundwater between 20” and 30” below grade. Test pit #13, in the northwest of the site showed silt loam with clay varves and groundwater at a depth of 26”. Test pit #14 varied from the other four, showing this area to be underlain with fine sand, and deeper groundwater at 40”. Though not noted in the soil evaluation, the location of test pit #14 is within an area previously disturbed from a former state hospital building, which may explain why the soils in this location deviate from the rest of the site. Previous Analyses The re-development of the Village Hill property has been ongoing for approximately 15 years. The 1 Note that the report includes 8 additional test pits within Community Builders “Lot 13A” development site. Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 3 earliest drainage analysis of the proposed development was conducted by Beals and Thomas, and documented in a Notice of Intent submitted in November 2003. The plan of development has been modified numerous times in the ensuing years, and the stormwater management system has been analyzed and re-analyzed several times, both by Berkshire Design and others. This report has utilized those old analyses to re-create the pre-development condition of the site, in order to determine peak runoff rates from the site prior to demolition of the state hospital infrastructure. For the previously-constructed development of Village Hill, Berkshire Design has been provided with tabulation of impervious area by Gale Associates, Inc. dated 7/20/2018. This tabulation is attached in Appendix I, and reports the total impervious areas constructed or proposed in each portion of the Village Hill development. Detention Basin Volume Discrepancy During the design process, it was discovered that the as-built volume of Basins #2 and #4 differed from the volume that was proposed in the design plans at the time of construction. An as-built survey of these basins was performed by Sherman & Frydryk, LLC, and is shown in a drawing dated 5/11/2018. This plan is attached in Appendix J. The plan set shows proposed modifications to the berm and emergency spillway of both detention basins. The stormwater model of the proposed site described in this report is based upon the survey and field measurements shown on the Sherman & Frydryk survey, as modified by the proposed work. Stormwater Model The pre-development and proposed sites have been analyzed with the HydroCAD stormwater modeling software. A full description of the results of this analysis is included later in this report. The model was built utilizing the following information: · The pre-development site was analyzed based on the inputs identified by Beals and Thomas in the original stormwater report for the site in 2003, and later used by Berkshire Design for the Phase II development in 2007. · The proposed site has been modeled by combining the best-available information on the existing condition and proposed work outside of the co-housing project site. · Impervious areas for the developed portion of the site (drainage area PDA-2C) are based on the Gale Associates tabulation attached in Appendix I. · It was observed that some of the existing development may have constructed impervious areas in addition to what was proposed in the site plan documentation (i.e. small patios, garden walkways, etc.). Due to the challenge is quantifying these small areas, the pavement and roof area reported in the Gale Associates tabulation was increased by 10% factor of safety in the HydroCAD model. · The surface area covered by detention basins is modeled as impervious area, to reflect the fact that this land will be covered in standing water during intense rainfall. · Aerial images were used to identify the approximate limits of woodland in the un- developed portions of the site. · Within the developed portions of the site, the remaining land after accounting for Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 4 impervious surfaces, is assumed to be covered in grass. · The existing detention basins have been modeled based on the inputs to previous stormwater models of the site, supplemented by as-built drawings and survey information, when available. · The HydroCAD model reflects modifications to Basins #2 and #4. These modifications are proposed to prevent the use of the existing emergency spillways, which are intended to prevent overtopping of the basing banks, and not meant to be utilized for stormwater control under any design storm. As shown in the calculations, the water level in the detention basins is estimated to remain below the spillway invert elevations during the 100-year storm. The modification is detailed in the permit plan set. II. Pre-Development Conditions The “pre-development condition” is based on the site prior to demolition of the former state hospital buildings. Drainage Areas The pre-development site was divided into drainage areas during the original drainage analysis under the master planning phase. The drainage areas (labeled EDA-1 through EDA-3) are shown on the Existing Drainage Area Plan in Figure 9. A brief description of each drainage area follows. Area EDA-1 This area includes the northwestern quadrant of the site. This area drains toward the north and west, and ultimately discharges to the Mill River to the north. Area EDA-2 This area includes the northeastern portion of the site. This area drains toward the north and east, and ultimately discharges to the Mill River to the north. Area EDA-3 This area includes the southern portion of the site, which drains toward West Street (Route 66). III. Proposed Conditions Proposed drainage areas are delineated in Figure 10. For the purposes of this report, only those drainage areas discharging toward the northeast corner of the site (toward control point “DP-2” as shown in Figure 9 and Figure 10) are considered, because the entirety of the proposed co-housing site drains toward this control point. All areas draining toward Basin #2, Basin #4 and overland toward the northeast are included. A brief summary of each drainage area follows. Drainage Areas Area PDA-2A This area includes all land at the northern and eastern edges of the site that discharge to the Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 5 northeast without first passing through Basin #2. This drainage area includes a small portion of the co-housing roof and sidewalk surface, totaling approximately 8,000 square feet. The remainder of this drainage areas consists of grass or woodlands. Area PDA-2B This area includes all of the proposed development for the Community Builders Lot 13A project, except for the southwest corner of the site, which is included in area PDA-1B above. Area PDA-2B includes a portion of the housing lot directly south of the Community Builders site, which will be developed in the future by Mass Development to include single family homes. Because the layout of the Mass Development project is unknown at this time, the area is incorporated into the stormwater model as 1/8 acre residential (townhouse) lots. This assumes that 65% of the lots will be impervious, which is consistent with the existing single family house lots at Village Hill. Runoff from this drainage area is collected by proposed storm drains, and discharges to the large detention basin at the eastern edge of the site (Basin #2) via a trunk line storm drain passing through the co-housing site. No portion of the co-housing development is within this drainage area. Area PDA-2C This area is in the central portion of the site, and has been fully-developed under previous projects, with the exception of the Community Builders “Lot 20” project, which has been permitted by the City, but is un-built. Runoff from this drainage area is discharged to a large detention basin at the eastern edge of the site (Basin #4), which then discharges to a swale that carries water to Basin #2 further north along the eastern edge of the site. Impervious area for this drainage area is based on the tabulation provided in the Gale Associates report, adjusted by a 10% factor of safety for the total area of roof and pavement, as discussed above. The footprint of Basin #4 is modeled as impervious area. The remainder of the site is modeled as grass, divided between the two soil types present within the drainage area. Area PDA-2D This area encompasses the entire co-housing development, except the small portion at the north end lying within drainage area PDA-2A. Also captured within this drainage area are two single family house lots on Olander Drive and Memorial Park. Impervious area has been calculated based on the proposed plan, as shown in Figure 10. The gravel trail running through the site is also included as impervious area. Detention Basin #2 is modeled as impervious, due to the presence of water in the basin during intense rainfall. A portion of undisturbed woodland is proposed to remain at the south end of the drainage area. The remaining area is modeled as grass. Water Quality Treatment The water quality of runoff from the co-housing project will primarily be managed by the use of a proprietary stormwater treatment chamber (Contech CDS2020-5 or equivalent), sized to remove 80% of total suspended solids. The treatment chamber will be located immediately upstream of Basin #2. The treatment chamber receives all runoff from paved areas, including the driveway and parking lots, which also pass through deep-sump hooded catch basins. Remaining impervious areas consist Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 6 of rooftops or sidewalks disconnected from pavement. The extent of the drainage sub-area is shown in Figure 12. In general, roof and sidewalk runoff is designed to sheet flow over vegetated areas. All residential units include drip strips2 to encourage infiltration of roof runoff, and to allow remaining roof runoff to run overland. Due to site grading constraints, including universal access goals requiring all units to be ADA-accessible, it is necessary for much of this water to be captured by yard drains and directed to the site storm drain system. In order to improve water quality, several yard drains have been surrounded by water quality swales, which include a porous sand layer below the loam, underlain by an underdrain consisting of perforated pipe and crushed stone. The swales will allow runoff from smaller storms to percolate through the soil to filter out suspended solids and capture nutrients in site plantings. The underdrain is necessary due to poorly-draining site soils to prevent ponding in these areas. Calculations that quantify the level of water quality treatment are included in Section IV, below. IV. Calculations and Design Water Quantity Drainage calculations were performed on Hydrocad Stormwater Modeling System version 10.0 using Soil Conservation Service (SCS) TR-20 methodology. The SCS method is based on rainfall observations, which were used to develop the Intensity-Duration-Frequency relationship, or IDF curve. The mass curve is a dimensionless distribution of rainfall over time, which indicates the fraction of the rainfall event that occurs at a given time within a 24-hour precipitation event. This synthetic distribution develops peak rates for storms of varying duration and intensities. The SCS distribution provides a cumulative rainfall at any point in time and allows volume-dependent routing runoff calculations to occur. These calculations are included in Appendix C. The watershed boundaries for calculation purposes are divided according to the proposed site grading and the natural limits of the drainage areas. The curve numbers (CNs) and times of concentration for the existing and proposed subcatchment areas are based on the soil type and the existing and proposed cover conditions at the site. Calculations were performed for the 2-, 10-, 25-, and 100-year frequency storms under existing and proposed conditions. The results of the calculations are presented in Table 1 on the following page. A control point was identified, in order to allow a pre-development/post-development comparison. Discharge Point 2 (DP-2) includes all runoff discharged to the northeast, toward the Mill River. 2 See Note 9 on Utility Plans, Sheets L.9 & L.10 Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 7 Table 1. Runoff Summary Table for Individual Control Points Condition & Point of Analysis 2-Year Storm 3.00” 10-Year Storm 4.50” 25-Year Storm 2.25” 100-Year Storm 7.00” Peak Flow Rate(cfs) Peak Flow Rate(cfs) Peak Flow Rate(cfs) Peak Flow Rate(cfs) Pre-Development to the Northeast (DP-2)* 20.50 46.04 59.97 93.89 Post-Development to the Northeast (DP-2)* 13.35 32.71 48.26 82.87 *Names in parentheses refer to HydroCad model and calculations. The model shows zero increase in stormwater runoff leaving the site for each design storm. Storm Drain Sizing Storm drain piping was sized to carry the 25-year design storm without surcharging. A summary of the design calculations is attached in Appendix H. These calculations refer to Figure 11, which shows the contributing drainage sub-area for each inlet. Appendix I also includes capacity calculations for the 100-year design storm, for use in the design of outlet armoring (see “Outlet Armoring” below. Water Quality The proposed stormwater management system is designed to remove at least 80% total suspended solids. Stormwater Treatment Chamber Runoff from all paved areas within the co-housing site (driveway and parking lots) is collected by deep-sump, hooded catch basins and discharged to the storm drain trunk line running into the site from the Community Builders “Lot 13A” site. This water is then passed through a stormwater treatment chamber (Contech CDS2020-5 or equivalent). For the stormwater treatment chamber, the TSS removal rate was estimated using Contech’s design algorithm, which is based on field testing in accordance with MassDEP standards. The entire drainage area collected by the treatment chamber is shown in Figure 12. A report estimating the average solids removal by the stormwater treatment chamber is included in Appendix D. Groundwater Recharge The co-housing site presents a number of challenges that restrict the ability of the site to rely on infiltration and groundwater recharge for stormwater management. The site is underlain by fine sandy loam soils of Hydrologic Soil Group (HSG) C, and seasonal high groundwater was estimated to be 20”-36”below grade. Certain features have been incorporated into the site plan to encourage infiltration to the extent possible. All residential units include drip strips that will allow for infiltration, and discharge runoff via overland flow over vegetated areas. The majority of sidewalks throughout the development are disconnected from paved areas, and run off via sheet flow over vegetated areas. Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 8 Outlet Armoring The proposed project includes 4 pipe outlet points. Two of these outlets are located at Detention Basin #2 (FE18 and FE31 in the plan set), including a large 24” pipe carrying runoff from both the co- housing site and the Community Builders site to the west. A third, small outlet (FE7 in the plan set) is located at the north end of the site, carrying runoff from sidewalks and part of the roof areas from three buildings. A fourth outlet (FE40) discharges to the swale that feeds into Basin #2 near the southeast corner of the co-housing site. Outlets FE7 and FE40 were provided with a splash pad of 4-6” stone protection, because the 100- year flow rates were too small (<3 cfs) to require a site-specific design. The outlets FE18 and FE31 were designed with armoring, based on the NRCS method. The NRCS design chart for each of these outlets is included in Appendix E. For outlet FE18, the 100-year flow rate is 3.1 cfs, carried by a 12” pipe. Based on the design chart, this requires a minimum apron length of 6’ with median stone size of 6”. The apron should flare from a width of 3’ at the outlet to a width of 9’ at the end of the apron. Design guidance from HEC- 11 Riprap Design Manual recommends the following stone size distribution, where d50 is the designed median stone size: Size Guidance Equivalent Size Percent Smaller 1.5(d50) – 1.7(d50) 9” – 10” 100% 1.2(d50) – 1.4(d50) 7” – 8” 85% 1.0(d50) – 1.4(d50) 6” –8” 50% 0.4(d50) – 0.6(d50) 2” – 4” 15% For outlet FE31, the 100-year flow rate is 23.2 cfs, carried by a 24” pipe. Based on the design chart, this requires a minimum apron length of 14’ with median stone size of 6”. However, the apron will be constructed as proposed in the permit documents for the Community Builders project, which assumed a larger flow rate, resulting in a larger apron and stone size. The armoring for outlet FE31 was proposed to be 22’ long with a median stone size of 10”. The proposed apron should flare from a width of 6’ at the outlet to a width of 24’ at the end of the apron. Design guidance from HEC-11 Riprap Design Manual recommends the following stone size distribution, where d50 is the designed median stone size: Size Guidance Equivalent Size Percent Smaller 1.5(d50) – 1.7(d50) 14” – 15” 100% 1.2(d50) – 1.4(d50) 11” – 13” 85% 1.0(d50) – 1.4(d50) 9” –13” 50% 0.4(d50) – 0.6(d50) 4” – 5” 15% V. MADEP Stormwater Standards Compliance The following section details how the project will meet the DEP Stormwater Management Policy’s ten stormwater management standards. A copy of the Massachusetts Stormwater Checklist is attached in Appendix F. LID Low-impact design principals were considered during the development of the stormwater management plan for this project, and have been implemented to the extent practicable. The design Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 9 of the co-housing site clusters the units, allowing the periphery of the site to remain undisturbed. Pavement area is further reduced by providing common parking with parking lots oriented toward the vehicle entrance to the site. To the extent possible, roof and sidewalk runoff have been directed to overland flow across vegetated areas prior to capture by the drainage system. Overall, the Village Hill site represents a cluster development, with relatively high density in developed areas, with large swaths of land placed into permanent conservation. No LID credits are proposed, because none of the proposed features meet the strict criteria for these credits. Standard 1 - Untreated Stormwater Discharge One new outlet that discharges water off-site is proposed. This outlet carries water from a small area of sidewalk and roof at the north end of the site. Total discharge for this outlet is estimated to be 0.41 cfs in the 100-year storm. All impervious area discharging to this outlet is directed first to vegetated areas. The outlet includes riprap protection, which has been designed to resist erosion. Two new outlets that discharge to the existing detention pond are proposed, and riprap protection has been designed to prevent erosion at this location. This protection has been designed to resist erosion, as summarized under “Outlet Armoring” in Section IV above. Standard 2 - Post-Development Peak Discharge Rates The proposed stormwater management system is designed so that post-development peak discharge rates are less than pre-development peak discharge rates leaving the site. These results are discussed in detail under “Peak Runoff Rate” in Section IV, above. Standard 3 - Recharge to Groundwater The co-housing site is underlain by poorly-draining soils and high groundwater. These factors make a significant level of infiltration virtually impossible. The site has been designed to allow roof runoff to discharge to drip strips, and for sidewalks to sheet flow directly to vegetated areas. Standard 4 – Water Quality Water quality treatment is provided primarily by a stormwater treatment chamber, the design of which is discussed under “Water Quality” in Section IV. Standard 5 - Higher Potential Pollutant Loads The proposed project is not expected to yield high potential pollutant loads. Standard 6 - Protection of Critical Areas The proposed project does not discharge water into or near any critical areas. Standard 7 - Redevelopment Projects This project is partially a redevelopment project. Standard 8 - Erosion/Sediment Control A proposed Erosion & Sediment Control Plan has been developed, and is shown in the plan set. A full Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 10 Stormwater Pollution Prevention Plan will be developed by the contractor prior to any disturbance of the site. Standard 9 - Operation/Maintenance Plan An Operation and Maintenance Plan for the proposed project is included in Appendix G. It includes general controls for construction and long term maintenance of the stormwater management system. Standard 10 – Prohibition of Illicit Discharges No Illicit Discharge Compliance Statement is included with this report. It will be the responsibility of each parcel owner to submit a statement prior to the discharge of any stormwater to post- construction BMPs. Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. FIGURES PROJECT LOCATION Drawn By: Revisions Scale: Date:Sheet Number This drawing is not intended nor shall it be used for construction purposes unless the signed professional seal of a registered landscape architect, civil engineer or land surveyor employed by The Berkshire Design Group, Inc. is affixed above. Do not scale drawing for quantity take-offs or construction. Use written dimensions only. If dimensions are incomplete, contact The Berkshire Design Group Inc. for clarification. Copyright The Berkshire Design Group, Inc. This drawing and all of its contents are the express property of The Berkshire Design Group, Inc., and shall not be copied or used in any way without the written consent of The Berkshire Design Group, Inc. c VILLAGE HILL CO-HOUSING SUNWOOD BUILDERS Landscape Architecture Civil Engineering Planning Berkshire Group Design Land Surveying FIG1 JULY 23, 2018 1"=400' CMC LOCATION PLAN 0 800400200 1200 LIMIT OF "NORTH CAMPUS" FOR PURPOSES OF STORMWATER ANALYSIS APPROXIMATELY 62 ACRES LIMIT OF PROPOSED CO-HOUSING PROJECT PRE-DEVELOPMENT EDGE OF PAVEMENT (TYP.) FORMER STATE HOSPITAL ACCESSORY BUILDING (TYP.) Drawn By: Revisions Scale: Date:Sheet Number This drawing is not intended nor shall it be used for construction purposes unless the signed professional seal of a registered landscape architect, civil engineer or land surveyor employed by The Berkshire Design Group, Inc. is affixed above. Do not scale drawing for quantity take-offs or construction. Use written dimensions only. If dimensions are incomplete, contact The Berkshire Design Group Inc. for clarification. Copyright The Berkshire Design Group, Inc. This drawing and all of its contents are the express property of The Berkshire Design Group, Inc., and shall not be copied or used in any way without the written consent of The Berkshire Design Group, Inc. c VILLAGE HILL CO-HOUSING SUNWOOD BUILDERS Landscape Architecture Civil Engineering Planning Berkshire Group Design Land Surveying FIG2 JULY 23, 2018 1"=250' CMC PRE-DEVELOPMENT CONDITIONS (NORTH CAMPUS) 0 500250125 750 NOTE THIS PLAN BASED ON THE ORIGINAL EXISTING CONDITIONS AS PRESENTED BY BEALS & THOMAS IN A DRAINAGE REPORT "PHASE I - DEFINITIVE SUBDIVISION SUBMISSION - MASTER PLAN HYDROLOGY CALCULATIONS", NOVEMBER 2003. Border i n g V e g e t a t e d W e t l a n d s 100' BufferBorder ing Vegeta ted We t lands100' Bu f fe rBord e r ing V ege t a ted We t land s A-1 A-2 HW- 1 HW-2 HW- 3 HW-4 HW- 6 HW- 7 HW- 8 HW-9 HW-11HW-12 HW-1 3 HW - 1 4 200' RiverfrontProtection AreaApproximate 100' Buffer Zone LIMIT OF "NORTH CAMPUS" FOR PURPOSES OF STORMWATER ANALYSIS APPROXIMATELY 62 ACRES PECOY HOMES DEVELOMENT (UNDER CONSTRUCTION)VILLAGE H ILL ROADOLANDER DR IVE FORD C R O S SI N G MOSER STREETMUSANTE DRIVEMOSER S T R E E T "LOT 20" LOCATION OF FUTURE COMMUNITY BUILDERS PROJECT APPROVED, UN-BUILT "LOT 13A" LOCATION OF FUTURE COMMUNITY BUILDERS PROJECT APPROVED, UN-BUILT LOCATION OF PROPOSED CO-HOUSING PROJECT LOT RETAINED BY MASS DEVELOPMENT FOR FUTURE SINGLE FAMILY HOMES WEST STREET FUTURE CITY CONSERVATION LAND Drawn By: Revisions Scale: Date:Sheet Number This drawing is not intended nor shall it be used for construction purposes unless the signed professional seal of a registered landscape architect, civil engineer or land surveyor employed by The Berkshire Design Group, Inc. is affixed above. Do not scale drawing for quantity take-offs or construction. Use written dimensions only. If dimensions are incomplete, contact The Berkshire Design Group Inc. for clarification. Copyright The Berkshire Design Group, Inc. This drawing and all of its contents are the express property of The Berkshire Design Group, Inc., and shall not be copied or used in any way without the written consent of The Berkshire Design Group, Inc. c VILLAGE HILL CO-HOUSING SUNWOOD BUILDERS Landscape Architecture Civil Engineering Planning Berkshire Group Design Land Surveying 0 500250125 750 FIG3 JULY 23, 2018 1"=250' CMC EXISTING CONDITIONS (NORTH CAMPUS) Bituminous ConcreteBituminous ConcreteGravelGravelGravelGravel GravelMeadowMeadowMeadow100' BufferBordering Vegetated WetlandsA-1HW-1HW-2HW-3200' R i v e r f r o n t Prot e c t i o n A r e a drainage channel D D D D DTree #7430"(65')Tree #76Twin 60"(65')Tree #5350"(60')N. RED OAKTree #4112"(40')Tree #4012"(45')Tree #3912"(40')Tree #3818"(45')Tree #3628"(30')Tree #3736"(60')Tree #4928"(50')Tree #48Twin 48"(75')N. RED OAKTree #4538"(65')N. SPRUCETree #4728"Tree #950"(75')Tree #354"(65')R. MAPLETree #1539"(50')G2"GGDD8" CLDI2"Tree #6950"(50')E. BEECHTree #1633"(60')N. RED OAKTree #1732"(50')Tree #950"(75')N. RED OAKTree #1539"(50')W. OAKTree #740"W. OAKTree #440"N. RED OAK232231233234236237238239239238 237 236 234233232232233234236237232231229226227228223221222224 218217219216231227226228221223222224216219217218211212213214206207208209201202203204196197198199193194192193191198199201 203 204 202203202201204207206208209228227229226222223221224216219217218214211212213226229227228224221222223216212213214211209208207206201 202 203 204 199199197198 196230225220215210205200 230230235240235235230 230225220215230225 220215210210 205205200225 220215210205200195190185180200195190200205210215220225230190201202204203200195 190 192 194 196 196 1 9 8 196 198 198 190 190 190 20 0 192 192 190200150160170180200 198 188 194 190 190 200 192 194 196 198 2 0 2FORD CROSSING "LOT 13A" LOCATION OF FUTURECOMMUNITY BUILDERS PROJECTAPPROVED, UN-BUILTLOCATION OF PROPOSEDCO-HOUSING PROJECTLOT RETAINED BY MASS DEVELOPMENTFOR FUTURE SINGLE FAMILY HOMESFUTURE CITY CONSERVATION LANDDrawn By:RevisionsScale:Date:Sheet NumberThis drawing is not intended nor shall it be used forconstruction purposes unless the signed professional seal of aregistered landscape architect, civil engineer or land surveyoremployed by The Berkshire Design Group, Inc. is affixed above.Do not scale drawing for quantity take-offs or construction. Usewritten dimensions only. If dimensions are incomplete, contactThe Berkshire Design Group Inc. for clarification.Copyright The Berkshire Design Group, Inc.This drawing and all of its contents are the express property ofThe Berkshire Design Group, Inc., and shall not be copied orused in any way without the written consent of The BerkshireDesign Group, Inc.cVILLAGE HILLCO-HOUSINGSUNWOOD BUILDERSLandscape ArchitectureCivil EngineeringPlanningBerkshireGroupDesignLand Surveying01608040240FIG4JULY 23, 20181"=80'CMCEXISTING CONDITIONS(CO-HOUSING SITE)NOTES1.EXCEPT AS STATED UNDER NOTE 2. THE TOPOGRAPHIC SURVEY DEPICTED HEREON WASOBTAINED BY PARTIAL FIELD SURVEYS CONDUCTED ON MULTIPLE DATES BETWEEN AUGUST 18,2006 AND APRIL 21, 2015 BY THE BERKSHIRE DESIGN GROUP, INC.2.TOPOGRAPHIC SURVEY OF THE EXISTING DETENTION BASINS AT THE EASTERN EDGE OF THE SITEARE BASED ON A SURVEY PREPARED BY SHERMAN & FRYDRYK, LLC AND DATED 5/11/2018. Border i n g V e g e t a t e d W e t l a n d s 100' BufferBorder ing Vegeta ted We t lands100' Bu f fe rBord e r ing V ege t a ted We t land s A-1 A-2 HW- 1 HW-2 HW- 3 HW-4 HW- 6 HW- 7 HW- 8 HW-9 HW-11HW-12 HW-1 3 HW - 1 4 200' RiverfrontProtection AreaApproximate 100' Buffer Zone VILLAGE H ILL ROADOLANDER DR IVE FORD C R O S SI N G MOSER STREETMUSANTE DRIVEMOSER S T R E E T STORMWATER INFRASTRUCTURE FOR PECOY HOMES DEVELOPMENT DETENTION BASIN #2 DETENTION BASIN #3 DETENTION BASIN #4 OUTFALL FROM DETENTION BASIN #2 SWALE CONNECTING BASIN #4 OUTLET TO BASIN #2 INLET WEST STREET Drawn By: Revisions Scale: Date:Sheet Number This drawing is not intended nor shall it be used for construction purposes unless the signed professional seal of a registered landscape architect, civil engineer or land surveyor employed by The Berkshire Design Group, Inc. is affixed above. Do not scale drawing for quantity take-offs or construction. Use written dimensions only. If dimensions are incomplete, contact The Berkshire Design Group Inc. for clarification. Copyright The Berkshire Design Group, Inc. This drawing and all of its contents are the express property of The Berkshire Design Group, Inc., and shall not be copied or used in any way without the written consent of The Berkshire Design Group, Inc. c VILLAGE HILL CO-HOUSING SUNWOOD BUILDERS Landscape Architecture Civil Engineering Planning Berkshire Group Design Land Surveying 0 500250125 750 FIG5 JULY 10, 2018 1"=250' CMC MAJOR DRAINAGE FEATURES (EXISTING CONDITION) NOTES THE ORIGINAL VILLAGE HILL MASTER PLAN DESIGN CALLED FOR DETENTION BASIN #1 TO BE LOCATED IN THE NORTHWEST CORNER OF THE SITE. THE DESIGN HAS EVOLVED TO ELIMINATE BASIN #1. 100' BufferBordering Vegetated Wet lands A-1 HW- 1 HW- 2 HW- 3 200' RiverfrontProtection AreaDDDDDG 2"GGD D 8" CLD I2" 232 231 233 2 3 4 2 3 6 2 3 7 2 3 8 2 3 9 239 238237236234 233 232 232 233 234 236 237 2 3 2 2 3 1 22 9 22622722 8 2232212222 2 4 2182172192 1 6 231 22 7 22 6 228 2 2 1 2 2 3 2 2 2 22 4 2 1 6 2 1 9 2 1 7 2 1 8 21 1 2 1 2 2 1 3 2 1 4 2 0 6 2 0 7 20 8209 2 0 1 2 0 2 2 0 3 2 0 4 196 197 198 19 9 193 194 192 193 19 1 1 9 8 1 9 9 201203204202203202 2012042072062082092282272292262222232212242162 1 9 2172182142 1 1 2 1 2 2132262292 2 7 2 2 8 2242212222232162122132142112092082072062012022032041991991971981962302252202152102052002302302 3 5 240 235 235230 23 0 2252202152302252202 1 5 210210205205200 225 2 2 0 2 1 5 21 0 2 0 5 20 0 195 190 185 180 200 195 190 20 0 2052102152202252 3 0 190 201202204203200195190192194196196198196198198190190190200192192190200150160170180200198188194190190200192194196198202+ 219.6 + 219.5 206205225200195200200200200202201203208 231231 202230231 229 231D D DD D DDD D231231229230 227 228 228228229230 230 230229 228 234236238229 229228 227 226.5 VH-1 VH-7 VH-8 VH-4 VH-3 VH-5 VH-6 14 1 3 4 5 8 6 9 11 12 2 13 229 D D D227226 227 229 230229DFORD C R O S SI N G STORM DRAIN (TYP.) REFER TO PROJECT PLANS FOR SIZES STORMWATER TREATMENT CHAMBER OUTFALL TO BASIN #2 WITH FLARED END & RIPRAP APRON D D D D D D DD D DDD DD D DD D DD DDDDD DD DDDDDDDD DDDDD D D D D D D D YARD DRAIN OUTLET CONNECTION FROM THE COMMUNITY BUILDERS PROJECT SITE MODIFY EMERGENCY SPILLWAY & RE-GRADE BERM AT DETENTION BASIN #2 SEE PLAN SET MODIFY OUTLET CONTROL STRUCTURE AT DETENTION BASIN #2 SEE PLAN SET Drawn By: Revisions Scale: Date:Sheet Number This drawing is not intended nor shall it be used for construction purposes unless the signed professional seal of a registered landscape architect, civil engineer or land surveyor employed by The Berkshire Design Group, Inc. is affixed above. Do not scale drawing for quantity take-offs or construction. Use written dimensions only. If dimensions are incomplete, contact The Berkshire Design Group Inc. for clarification. Copyright The Berkshire Design Group, Inc. This drawing and all of its contents are the express property of The Berkshire Design Group, Inc., and shall not be copied or used in any way without the written consent of The Berkshire Design Group, Inc. c VILLAGE HILL CO-HOUSING SUNWOOD BUILDERS Landscape Architecture Civil Engineering Planning Berkshire Group Design Land Surveying 0 1608040 240 FIG6 JULY 10, 2018 1"=80' CMC GRADING & DRAINAGE PLAN (CO-HOUSING SITE) 100' BufferBordering Vegetated Wet lands A-1 HW- 1 HW- 2 HW- 3 200' RiverfrontProtection AreaDDDDDG 2"GGD D 8" CLD I2" 232 231 233 2 3 4 2 3 6 2 3 7 2 3 8 2 3 9 239 238237236234 233 232 232 233 234 236 237 2 3 2 2 3 1 22 9 22622722 8 2232212222 2 4 2182172192 1 6 231 22 7 22 6 228 2 2 1 2 2 3 2 2 2 22 4 2 1 6 2 1 9 2 1 7 2 1 8 21 1 2 1 2 2 1 3 2 1 4 2 0 6 2 0 7 20 8209 2 0 1 2 0 2 2 0 3 2 0 4 196 197 198 19 9 193 194 192 193 19 1 1 9 8 1 9 9 201203204202203202 2012042072062082092282272292262222232212242162 1 9 2172182142 1 1 2 1 2 2132262292 2 7 2 2 8 2242212222232162122132142112092082072062012022032041991991971981962302252202152102052002302302 3 5 240 235 235230 23 0 2252202152302252202 1 5 210210205205200 225 2 2 0 2 1 5 21 0 2 0 5 20 0 195 190 185 180 200 195 190 20 0 2052102152202252 3 0 190 201202204203200195190192194196196198196198198190190190200192192190200150160170180200198188194190190200192194196198202+ 219.6 + 219.5 206205225200195200200200200202201203208 231231 202230231 229 231D D DD D DDD D231231229230 227 228 228228229230 230 230229 228 234236238229 229228 227 226.5 VH-1 VH-7 VH-8 VH-4 VH-3 VH-5 VH-6 14 1 3 4 5 8 6 9 11 12 2 13 229 D D D227226 227 229 230229DFORD C R O S SI N G STORM DRAIN (TYP.) REFER TO PROJECT PLANS FOR SIZES STORMWATER TREATMENT CHAMBER OUTFALL TO BASIN #2 WITH FLARED END & RIPRAP APRON D D D D D D DD D DDD DD D DD D DD DDDDD DD DDDDDDDD DDDDD D D D D D D D YARD DRAIN OUTLET CONNECTION FROM THE COMMUNITY BUILDERS PROJECT SITE MODIFY EMERGENCY SPILLWAY & RE-GRADE BERM AT DETENTION BASIN #2 SEE PLAN SET MODIFY OUTLET CONTROL STRUCTURE AT DETENTION BASIN #2 SEE PLAN SET Drawn By: Revisions Scale: Date:Sheet Number This drawing is not intended nor shall it be used for construction purposes unless the signed professional seal of a registered landscape architect, civil engineer or land surveyor employed by The Berkshire Design Group, Inc. is affixed above. Do not scale drawing for quantity take-offs or construction. Use written dimensions only. If dimensions are incomplete, contact The Berkshire Design Group Inc. for clarification. Copyright The Berkshire Design Group, Inc. This drawing and all of its contents are the express property of The Berkshire Design Group, Inc., and shall not be copied or used in any way without the written consent of The Berkshire Design Group, Inc. c VILLAGE HILL CO-HOUSING SUNWOOD BUILDERS Landscape Architecture Civil Engineering Planning Berkshire Group Design Land Surveying 0 1608040 240 FIG6 JULY 10, 2018 1"=80' CMC GRADING & DRAINAGE PLAN (CO-HOUSING SITE) E23 1 231100' BufferBordering Vegetated WetlandsA-2HW-4200' R i v e r f r o n t Prot e c t i o n A r e aFORD CROSS ING 100' BufferBordering Vegetated WetlandsA-2HW-4200' R i v e r f r o n t Prot e c t i o n A r e aFORD CROSSING Drawn By:RevisionsScale:Date:Sheet NumberThis drawing is not intended nor shall it be used forconstruction purposes unless the signed professional seal of aregistered landscape architect, civil engineer or land surveyoremployed by The Berkshire Design Group, Inc. is affixed above.Do not scale drawing for quantity take-offs or construction. Usewritten dimensions only. If dimensions are incomplete, contactThe Berkshire Design Group Inc. for clarification.Copyright The Berkshire Design Group, Inc.This drawing and all of its contents are the express property ofThe Berkshire Design Group, Inc., and shall not be copied orused in any way without the written consent of The BerkshireDesign Group, Inc.cVILLAGE HILLCO-HOUSINGSUNWOOD BUILDERSLandscape ArchitectureCivil EngineeringPlanningBerkshireGroupDesignLand Surveying020010050300FIG8JULY 23, 20181"=100'CMCEXISTINGVS.PROPOSEDIMPERVIOUS AREA(CO-HOUSING SITE)PROPOSEDEXISTINGIMPERVIOUS AREA WITHIN SITE: 16,081 SQ. FT.IMPERVIOUS AREA WITHIN SITE: 81,450 SQ. FT.(65,369 SQ. FT. INCREASE) EDA-1 PAVEMENT & ROOF 4.50 AC WOODS (HSG A) 2.70 AC GRASS (HSG A) 2.70 AC WOODS (HSG C) 1.50 AC GRASS (HSG C) 5.00 AC TOTAL IMPERVIOUS: 4.50 AC TOTAL AREA: 16.80 AC EDA-2 PAVEMENT & ROOF 3.60 AC WOODS (HSG B) 0.10 AC GRASS (HSG B) 2.80 AC WOODS (HSG C) 5.30 AC GRASS (HSG C) 10.8 AC TOTAL IMPERVIOUS: 3.60 AC TOTAL AREA: 22.60 AC EDA-3 PAVEMENT & ROOF 5.10 AC GRAVEL 0.20 AC GRASS (HSG A) 5.20 AC GRASS (HSG B) 3.80 AC GRASS (HSG C) 2.80 AC TOTAL IMPERVIOUS: 5.10 AC TOTAL AREA: 22.40 AC Drawn By: Revisions Scale: Date:Sheet Number This drawing is not intended nor shall it be used for construction purposes unless the signed professional seal of a registered landscape architect, civil engineer or land surveyor employed by The Berkshire Design Group, Inc. is affixed above. Do not scale drawing for quantity take-offs or construction. Use written dimensions only. If dimensions are incomplete, contact The Berkshire Design Group Inc. for clarification. Copyright The Berkshire Design Group, Inc. This drawing and all of its contents are the express property of The Berkshire Design Group, Inc., and shall not be copied or used in any way without the written consent of The Berkshire Design Group, Inc. c VILLAGE HILL CO-HOUSING SUNWOOD BUILDERS Landscape Architecture Civil Engineering Planning Berkshire Group Design Land Surveying FIG9 JULY 23, 2018 1"=250' CMC PRE-DEVELOPMENT DRAINAGE AREAS 0 500250125 750 NOTE THIS PLAN REPLICATES THE "PRE-DEVELOPMENT" DRAINAGE AREAS PRESENTED BY BEALS & THOMAS IN A DRAINAGE REPORT "PHASE I - DEFINITIVE SUBDIVISION SUBMISSION - MASTER PLAN HYDROLOGY CALCULATIONS", NOVEMBER 2003. Bituminous ConcreteBituminous Concrete Bituminous ConcreteGrave l GravelGravelGravel Gravel Gravel Meadow Meadow Meadow drainage channelDDDDDIN FAVOR OF HOSPITAL HILL DEVELOPMENT LLC CONSERVATION EASEMENT A 62,549 SQ.FT. OR 1.435 ACRES (SEE NOTE #9) IN FAVOR OF HOSPITAL HILL DEVELOPMENT LLC 84,663 SQ.FT. OR 1.943 ACRES DRAINAGE EASEMENT E Bike Path Ease m e n t D 6' Pedestrian Ea s e m e n t Plan Book 216, P a g e 7 1 Drainage Easement 10' Bike Path EasementPlan Book 216, Page 711 2 ' P ed e s t r i a n E a s em e n t P l a n B o o k 2 1 6 , P a g e 7 1 Drainage Easement F Plan Book 216, Page 71 Easement Area E21 Plan Book 216, Page 71Easement Area E27Sewer Easement Deed Book 9341, Page 327 Plan Book 217, Page 33 Inte r m i t t e n t S t r e a m (Fed e r a l J u r i s d i c t i o n ) X WATERELEV=136.6' (11/17/2003) Lot 13-A CenterOfRiver RiverMill Sewer Easement Deed Book 9341, Page 327 Plan Book 217, Page 33 Drainage Easemen t Ac ce s s E a s em e n t G Pl a n B o o k 2 16 , P a g e 7 1Easement Area E21-A41.0 Acres ϭϳϴϰϮϬϰ͘ϴ^Ƌ͘&ĞĞƚц Approx ima te Sho re L ine Mill R i v e r D DDD D Ford C r o s si n g Olander D r ive231231232232232231231231232233234229228216217218219221222223224226227228229231232233 2 3 4 23 6 23 7 2 3 8 23 9 239 238 237236234 233 232 232 233 234 236 237 2 3 2 23 1 229 22 6227 22 8 2232212222 2 4 2182172192 1 6 231 227 226 228 22 1 22 3 22 2224 2 1 6 21 9 21 721 8 21 1 2122132 1 4 2 0 6 2 0 7 2 0 8209 20 1 2 0 2 20 3 20 4 196 197 198 19 9 193 194 192 193 19 1 19 8 1 9 9 201203204202203202 2012042072062082092282272292262222232212242162 1 9 2172182142 1 1 2 1 2 213 2262292 2 7 2 2 8 224221222223216212213214211209208207206201202203204199199 197198196230 23 0 23022522021521020520023023023023523023 5 240 235 235 230 230 22 5 22021 5 2252202302252202 1 5 21 0210 205205200 225 22 0 2 1 5 210 2 0 5 200 195 190 185 180 175 170 165 160 155 150 145 200 195 190 20 0 205 210 2152202252 3 0 19 0 185 175 180 185 190 195 205 210 2202152102052152102 0 6 2072082092112122012022042032092082072062122112132102052001952102 0 5 215D200200200200210206200200200200200200190192194196196198196198198190190190200192192190200140150160170180204202 204202204206200198188194190190200192194196198202 TEAOVENREFRIGERATOR + 219.6+ 219.5 206205225200195200200200200202201203208 E231 231 202VH-1 VH-7 VH-2 VH-8 VH-4 VH-3 VH-5 VH-6 14 1 3 4 5 8 7 6 9 11 12 2 13 230 231 229 231231231229224230 227 228 228228229230 230 230229229 228 234236238229 229228 227 226.5 229 227 226227 229 230229D D D D DD DD DD D DDDDDD DD D D D PDA-2A PDA-2C DP-2 WATER SURFACE WOODS IMPERVIOUS 1/8 ACRE RESIDENTIAL LOTS PDA-2A PAVEMENT & ROOF* 0.326 AC WOODS (HSG C) 2.344 AC GRASS (HSG C) 3.545 AC TOTAL IMPERVIOUS:0.326 AC TOTAL AREA: 6.215 AC *INCLUDES GRAVEL WALKING TRAIL PDA-2C PAVEMENT & ROOF* 7.507 AC WATER SURFACE**0.785 AC 10% EXTRA IMPERVIOUS***0.750 AC GRASS (HSG B) 1.298 AC GRASS (HSG C) 5.705 AC TOTAL IMPERVIOUS: 9.042 AC TOTAL AREA: 16.045 AC *FROM GALE ASSOCIATES REPORT, INCLUSIVE OF PROPOSED TCB "LOT 20" PROJECT & PROPOSED HOUSES ON FORD CROSSING LOT **INCLUSIVE OF PROPOSED RAIN GARDEN AT TCB "LOT 20" PROJECT ***ADDITIONAL 10% IMPERVIOUS AREA FACTOR OF SAFETY APPLIED TO ALL PAVEMENT & ROOF; SEE DISCUSSION IN REPORT PDA-2D PAVEMENT & ROOF 1.898 AC WATER SURFACE 0.171 AC GRASS (HSG B) 1.139 AC WOODS (HSG C)0.410 AC GRASS (HSG C) 4.538 AC TOTAL IMPERVIOUS: 2.069 AC TOTAL AREA: 8.247 AC *ADDITIONAL 10% IMPERVIOUS AREA APPLIED TO ALL PAVEMENT & ROOF; SEE DISCUSSION IN REPORT HSG C PDA-2B PAVEMENT & ROOF 1.392 AC WATER SURFACE 0.068 AC GRASS (HSG B) 0.028 AC FUTURE HOUSE LOTS (HSG C) 0.436 AC GRASS (HSG C) 1.585 AC TOTAL IMPERVIOUS: 1.743 AC TOTAL AREA: 3.509 AC Drawn By: Revisions Scale: Date:Sheet Number This drawing is not intended nor shall it be used for construction purposes unless the signed professional seal of a registered landscape architect, civil engineer or land surveyor employed by The Berkshire Design Group, Inc. is affixed above. Do not scale drawing for quantity take-offs or construction. Use written dimensions only. If dimensions are incomplete, contact The Berkshire Design Group Inc. for clarification. Copyright The Berkshire Design Group, Inc. This drawing and all of its contents are the express property of The Berkshire Design Group, Inc., and shall not be copied or used in any way without the written consent of The Berkshire Design Group, Inc. c VILLAGE HILL CO-HOUSING SUNWOOD BUILDERS Landscape Architecture Civil Engineering Planning Berkshire Group Design Land Surveying FIG10 JULY 23, 2018 1"=250' CMC POST-DEVELOPMENT DRAINAGE AREAS NOTES 1.RUNOFF FROM THE ENTIRE SITE OF THE PROPOSED CO-HOUSING PROJECT IS DIRECTED TO CONTROL POINT DP-2. DRAINAGE AREAS FOR OTHER CONTROL POINTS ARE OMITTED. 2.FOR THE PURPOSE OF THE HYDROCAD MODEL, THE FUTURE HOUSE LOTS ON THE PROPERTY RESERVED BY MASS DEVELOPMENT WITHIN DRAINAGE AREA 2B ARE CONSERVATIVELY ASSUMED TO BE 1 8 ACRE (TOWNHOUSE) LOTS WITH 65% IMPERVIOUS AREA. 3.IMPERVIOUS AREAS WITHIN AREA 2C ARE BASED ON A TABULATION PUBLISHED BY GALE ASSOCIATES, DATED 1/5/2018. ALL OTHER GROUNDCOVERS ARE ESTIMATED BASED ON THE MEASUREMENTS SHOWN ON THIS PLAN. Bituminous ConcreteBituminous Concrete Bituminous ConcreteGravel GravelGravelGravel Gravel Gravel S S S S Meadow Meadow Meadowdrainage channelSpillwayD DDDD181.3'186.1'36" RCPX WATER ELEV=136.6' (11/17/2003) Lot 13-A 41.0 Acres ϭϳϴϰϮϬϰ͘ϴ^Ƌ͘&ĞĞƚц Mill R i v e r TEC TEC TEC TEC TEC TEC TEC TEC TEC TEC D TECG G G G G G G G G G G 2"S222.3 '8" PVC222.0 ' 222.0' SMH Rim: 2 3 1. 8 9' 219.7' 219.6'GWE W W W W W W W 8" PV C 8" CLDI SSWWWGGGDDD D 8" CLD I2"10" PVCSMHRim : 230 .45 '220.1 '220.1 '220.2 ' 220.3'DMHRim : 229 .94 ' 220.3' CB Rim: 2 3 0. 0 7' DMH Rim: 22 9 . 9 1' CB Rim: 2 3 0. 1 1' 221.3' 222.8'15" RCP 222.9'221.4'221.9'221.5'CB Rim: 22 9. 9 3' CB Rim: 230 . 0 2'221.9'Ford C r o s si n g Olander Dr ive231231232232232 231 231231232233234229228216217218219221222223224226227228229231232233 2 3 4 2 3 6 2 3 7 2 3 8 2 3 9 239238237236234 233 232 232 233 234 236 237 2 3 2 2 3 1 22 9 22622722 8 2232212222 2 4 2182172192 1 6 231 22 7 22 6 228 2 2 1 22 3 2 2 2 22 4 2 1 6 2 1 9 2 1 7 2 1 8 21 1 2 1 2 2 1 3 2 1 4 2 0 6 2 0 7 2 0 8209 2 0 1 2 0 2 2 0 3 2 0 4 196 197 198 19 9 193 194 192 193 19 1 1 9 8 1 9 9 201203204202203202 2012042072062082092282272292262222232212242162 1 9 2172182142 1 1 2 1 2 2132262292 2 7 2 2 8 22422122222321621221321421120920820720620120220320419919919719819623 0 2 3 0 2302252202152102052002302302302352302 3 5 240 235 235230 23 0 225 2202152252202302252202 1 5 210210205205200 225 2 2 0 2 1 5 21 0 2 0 5 20 0 195 190 185 180 175 170 165 160 155 150 145 200 195 190 20 0 2052102152202252 3 0 1 9 0 18 5 175 180 185 190 195 210 22021521020521521020120220420320920820720621221121321020520019520 5 D197.9'200200200190192194196196198196198198190190190200192192190200140150160170180202204200198188194190190200192194196198202TEAOVENREFRIGERATOR + 219.6 + 219.5 206205225200195200200200200202201203208 EEE231231 202PDA-2A BASIN #2 WATER SURFACE IMPERVIOUS 1/8 ACRE RESIDENTIAL LOTS (65% IMPERVIOUS) D D D D D D D D D D D D DDDDD D D D DDDDD DD D D DD D D D DDDDD D D D DDDDDDDDDDD D DD D DDDDDDDDDDDDDD DDDD D D D D D D D D D D D D D +A E F G H I J K L M N OP R SUB AREA A PAVEMENT & ROOF 928 SF GRASS 2,181 SF TOTAL AREA: 3,109 SF SUB AREA B PAVEMENT & ROOF 1,268 SF GRASS 10,925 SF TOTAL AREA: 12,193 SF SUB AREA C PAVEMENT & ROOF 906 SF GRASS 7,840 SF TOTAL AREA: 8,746 SF SUB AREA D PAVEMENT & ROOF 310 SF GRASS 2,470 SF TOTAL AREA: 2,780 SF SUB AREA E PAVEMENT & ROOF 1,862 SF GRASS 2,110 SF TOTAL AREA: 3,972 SF SUB AREA F PAVEMENT & ROOF 5,042 SF GRASS 11,651 SF TOTAL AREA: 16,693 SF SUB AREA G PAVEMENT & ROOF 8,065 SF GRASS 10,097 SF TOTAL AREA: 18,162 SF SUB AREA H PAVEMENT & ROOF 4,639 SF GRASS 8,422 SF TOTAL AREA: 13,061 SF SUB AREA I PAVEMENT & ROOF 1,237 SF GRASS 2,212 SF TOTAL AREA: 3,449 SF SUB AREA J PAVEMENT & ROOF 1,942 SF GRASS 3,982 SF TOTAL AREA: 5,924 SF SUB AREA K PAVEMENT & ROOF 2,188 SF GRASS 4,916 SF TOTAL AREA: 7,104 SF SUB AREA L PAVEMENT & ROOF 2,918 SF GRASS 11,578 SF TOTAL AREA: 14,496 SF SUB AREA M PAVEMENT & ROOF 723 SF GRASS 1,264 SF TOTAL AREA: 1,987 SF SUB AREA N PAVEMENT & ROOF 5,661 SF GRASS 16,440 SF TOTAL AREA: 22,101 SF SUB AREA O PAVEMENT & ROOF 7,478 SF GRASS 20,826 SF TOTAL AREA: 28,304 SF SUB AREA P PAVEMENT & ROOF 8,266 SF GRASS 13,518 SF TOTAL AREA: 21,784 SF SUB AREA R PAVEMENT & ROOF 60,658 SF WATER SURFACE 2,961 SF 1/8 ACRE RESIDENTIAL LOTS 19,000 SF GRASS 70,227 SF TOTAL AREA: 152,846 SF YD5 YD8 YD9 YD10 YD15 CB20 CB21 YD22 YD23 YD38 YD36 YD27 CB25 CB26 CB41 DMH19 DMH13 YD6 DMH24 DMH28 Q SUB AREA Q PAVEMENT & ROOF 1,027 SF TOTAL AREA: 1,027 SF Drawn By: Revisions Scale: Date:Sheet Number This drawing is not intended nor shall it be used for construction purposes unless the signed professional seal of a registered landscape architect, civil engineer or land surveyor employed by The Berkshire Design Group, Inc. is affixed above. Do not scale drawing for quantity take-offs or construction. Use written dimensions only. If dimensions are incomplete, contact The Berkshire Design Group Inc. for clarification. Copyright The Berkshire Design Group, Inc. This drawing and all of its contents are the express property of The Berkshire Design Group, Inc., and shall not be copied or used in any way without the written consent of The Berkshire Design Group, Inc. c VILLAGE HILL CO-HOUSING SUNWOOD BUILDERS Landscape Architecture Civil Engineering Planning Berkshire Group Design Land Surveying FIG11 JULY 23, 2018 1"=100' CMC POST-DEVELOPMENT DRAINAGE SUB-AREAS FOR PIPE DESIGN AND WATER QUALITY (CO-HOUSING SITE) NOTES 1.THE SUB-DRAINAGE AREAS SHOWN HERE ARE DELINEATED FOR THE PURPOSE OF DESIGNING DRAIN PIPES TO BE CONSTRUCTED WITH CO-HOUSING PROJECT. ONLY THOSE AREAS DRAINING TO PROPOSED STORM DRAIN PIPING ARE CONSIDERED. OVERALL DRAINAGE AREAS (AS SHOWN ON FIGURE 10) ARE SHOWN FOR REFERENCE. Bituminous ConcreteBituminous Concrete Bituminous ConcreteGravel GravelGravelGravel Gravel Gravel S S S S Meadow Meadow Meadowdrainage channelSpillwayD DDDD181.3'186.1'36" RCPX WATER ELEV=136.6' (11/17/2003) Lot 13-A 41.0 Acres ϭϳϴϰϮϬϰ͘ϴ^Ƌ͘&ĞĞƚц Mill R i v e r TEC TEC TEC TEC TEC TEC TEC TEC TEC TEC D TECG G G G G G G G G G G 2"S222.3 '8" PVC222.0 ' 222.0' SMH Rim: 2 3 1. 8 9' 219.7' 219.6'GWE W W W W W W W 8" PV C 8" CLDI SSWWWGGGDDD D 8" CLD I2"10" PVCSMHRim : 230 .45 '220.1 '220.1 '220.2 ' 220.3'DMHRim : 229 .94 ' 220.3' CB Rim: 2 3 0. 0 7' DMH Rim: 22 9 . 9 1' CB Rim: 2 3 0. 1 1' 221.3' 222.8'15" RCP 222.9'221.4'221.9'221.5'CB Rim: 22 9. 9 3' CB Rim: 230 . 0 2'221.9'Ford C r o s si n g Olander Dr ive231231232232232 231 231231232233234229228216217218219221222223224226227228229231232233 2 3 4 2 3 6 2 3 7 2 3 8 2 3 9 239238237236234 233 232 232 233 234 236 237 2 3 2 2 3 1 22 9 22622722 8 2232212222 2 4 2182172192 1 6 231 22 7 22 6 228 2 2 1 22 3 2 2 2 22 4 2 1 6 2 1 9 2 1 7 2 1 8 21 1 2 1 2 2 1 3 2 1 4 2 0 6 2 0 7 2 0 8209 2 0 1 2 0 2 2 0 3 2 0 4 196 197 198 19 9 193 194 192 193 19 1 1 9 8 1 9 9 201203204202203202 2012042072062082092282272292262222232212242162 1 9 2172182142 1 1 2 1 2 2132262292 2 7 2 2 8 22422122222321621221321421120920820720620120220320419919919719819623 0 2 3 0 2302252202152102052002302302302352302 3 5 240 235 235230 23 0 225 2202152252202302252202 1 5 210210205205200 225 2 2 0 2 1 5 21 0 2 0 5 20 0 195 190 185 180 175 170 165 160 155 150 145 200 195 190 20 0 2052102152202252 3 0 1 9 0 18 5 175 180 185 190 195 210 22021521020521521020120220420320920820720621221121321020520019520 5 D197.9'200200200190192194196196198196198198190190190200192192190200140150160170180202204200198188194190190200192194196198202TEAOVENREFRIGERATOR + 219.6 + 219.5 206205225200195200200200200202201203208 EEE231231 202PDA-2A WATER SURFACE IMPERVIOUS 1/8 ACRE RESIDENTIAL LOTS D D D D D D D D D D D D DDDDD D D D DDDDD DD D D DD D D D DDDDD D D D DDDDDDDDDDD D DD D DDDDDDDDDDDDDD DDDD D D D D D D D D D D D D D +CONTECH CDS STORMWATER TREATMENT CHAMBER Drawn By: Revisions Scale: Date:Sheet Number This drawing is not intended nor shall it be used for construction purposes unless the signed professional seal of a registered landscape architect, civil engineer or land surveyor employed by The Berkshire Design Group, Inc. is affixed above. Do not scale drawing for quantity take-offs or construction. Use written dimensions only. If dimensions are incomplete, contact The Berkshire Design Group Inc. for clarification. Copyright The Berkshire Design Group, Inc. This drawing and all of its contents are the express property of The Berkshire Design Group, Inc., and shall not be copied or used in any way without the written consent of The Berkshire Design Group, Inc. c VILLAGE HILL CO-HOUSING SUNWOOD BUILDERS Landscape Architecture Civil Engineering Planning Berkshire Group Design Land Surveying FIG12 JULY 23, 2018 1"=100' CMC POST-DEVELOPMENT DRAINAGE SUB-AREA FOR STORMWATER TREATMENT CHAMBER NOTES 1.THE SUB-DRAINAGE AREAS SHOWN HERE ARE DELINEATED FOR THE PURPOSE OF DESIGNING DRAIN PIPES TO BE CONSTRUCTED WITH CO-HOUSING PROJECT. ONLY THOSE AREAS DRAINING TO PROPOSED STORM DRAIN PIPING ARE CONSIDERED. OVERALL DRAINAGE AREAS (AS SHOWN ON FIGURE 10) ARE SHOWN FOR REFERENCE. Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Appendix A – NRCS Soil Report United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Hampshire County, Massachusetts, Central Part Village Hill Subdivision Natural Resources Conservation Service May 15, 2015 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 of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to 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 (http://www.nrcs.usda.gov/wps/portal/ nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (http:// offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a 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 or underground installations. The National Cooperative Soil Survey is a 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 is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a 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 2 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, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................7 Soil Map................................................................................................................8 Legend..................................................................................................................9 Map Unit Legend................................................................................................10 Map Unit Descriptions........................................................................................11 Hampshire County, Massachusetts, Central Part...........................................13 1—Water.....................................................................................................13 2A—Pootatuck fine sandy loam, 0 to 3 percent slopes...............................13 4A—Rippowam fine sandy loam, 0 to 3 percent slopes..............................14 8A—Limerick silt loam, 0 to 3 percent slopes.............................................15 30A—Raynham silt loam, 0 to 3 percent slopes.........................................16 98A—Winooski silt loam, 0 to 3 percent slopes..........................................17 220C—Boxford silt loam, 8 to 15 percent slopes........................................18 225A—Belgrade silt loam, 0 to 3 percent slopes........................................19 225B—Belgrade silt loam, 3 to 8 percent slopes........................................20 253A—Hinckley loamy sand, 0 to 3 percent slopes....................................21 253B—Hinckley loamy sand, 3 to 8 percent slopes....................................23 253C—Hinckley loamy sand, 8 to 15 percent slopes..................................24 253E—Hinckley loamy sand, 25 to 35 percent slopes................................25 254A—Merrimac fine sandy loam, 0 to 3 percent slopes............................26 258B—Amostown fine sandy loam, 3 to 8 percent slopes..........................28 260A—Sudbury fine sandy loam, 0 to 3 percent slopes.............................29 311C—Woodbridge fine sandy loam, 8 to 15 percent slopes, very stony...30 651—Udorthents, smoothed.......................................................................31 741A—Amostown-Windsor silty substratum-Urban land complex, 0 to 3 percent slopes.......................................................................................32 References............................................................................................................34 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 scientists classified and named the soils in the survey area, they compared the 5 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 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 6 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. 7 8 Custom Soil Resource Report Soil Map 4686800468690046870004687100468720046873004687400468750046876004687700468780046869004687000468710046872004687300468740046875004687600468770046878004687900693000 693100 693200 693300 693400 693500 693600 693700 693800 693900 694000 694100 694200 694300 694400 694500 694600 693000 693100 693200 693300 693400 693500 693600 693700 693800 693900 694000 694100 694200 694300 694400 694500 694600 42° 19' 9'' N 72° 39' 29'' W42° 19' 9'' N72° 38' 16'' W42° 18' 33'' N 72° 39' 29'' W42° 18' 33'' N 72° 38' 16'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 350 700 1400 2100 Feet 0 100 200 400 600 Meters Map Scale: 1:7,680 if printed on A landscape (11" x 8.5") sheet. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Hampshire County, Massachusetts, Central Part Survey Area Data: Version 9, Sep 19, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 28, 2011—Apr 18, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 9 Map Unit Legend Hampshire County, Massachusetts, Central Part (MA609) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 1 Water 11.0 4.3% 2A Pootatuck fine sandy loam, 0 to 3 percent slopes 8.0 3.1% 4A Rippowam fine sandy loam, 0 to 3 percent slopes 18.3 7.2% 8A Limerick silt loam, 0 to 3 percent slopes 3.4 1.3% 30A Raynham silt loam, 0 to 3 percent slopes 33.5 13.1% 98A Winooski silt loam, 0 to 3 percent slopes 17.0 6.7% 220C Boxford silt loam, 8 to 15 percent slopes 21.1 8.3% 225A Belgrade silt loam, 0 to 3 percent slopes 8.5 3.3% 225B Belgrade silt loam, 3 to 8 percent slopes 14.9 5.8% 253A Hinckley loamy sand, 0 to 3 percent slopes 32.6 12.8% 253B Hinckley loamy sand, 3 to 8 percent slopes 2.1 0.8% 253C Hinckley loamy sand, 8 to 15 percent slopes 4.1 1.6% 253E Hinckley loamy sand, 25 to 35 percent slopes 16.8 6.6% 254A Merrimac fine sandy loam, 0 to 3 percent slopes 6.1 2.4% 258B Amostown fine sandy loam, 3 to 8 percent slopes 4.3 1.7% 260A Sudbury fine sandy loam, 0 to 3 percent slopes 6.7 2.6% 311C Woodbridge fine sandy loam, 8 to 15 percent slopes, very stony 9.2 3.6% 651 Udorthents, smoothed 0.0 0.0% 741A Amostown-Windsor silty substratum-Urban land complex, 0 to 3 percent slopes 37.8 14.8% Totals for Area of Interest 255.3 100.0% Custom Soil Resource Report 10 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 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 Custom Soil Resource Report 11 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. Custom Soil Resource Report 12 Hampshire County, Massachusetts, Central Part 1—Water Map Unit Setting National map unit symbol: 9b24 Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 120 to 200 days Farmland classification: Not prime farmland Map Unit Composition Water: 100 percent Estimates are based on observations, descriptions, and transects of the mapunit. 2A—Pootatuck fine sandy loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 9b1f Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: All areas are prime farmland Map Unit Composition Pootatuck and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Pootatuck Setting Landform: Flood plains Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Loamy alluvium over sandy and gravelly alluvium derived from granite and gneiss Typical profile H1 - 0 to 10 inches: fine sandy loam H2 - 10 to 34 inches: fine sandy loam H3 - 34 to 60 inches: stratified sand to loamy fine sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 6.00 in/hr) Custom Soil Resource Report 13 Depth to water table: About 20 to 34 inches Frequency of flooding: Frequent Frequency of ponding: None Available water storage in profile: Moderate (about 6.5 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: B Minor Components Rippowam Percent of map unit: 15 percent Landform: Alluvial flats 4A—Rippowam fine sandy loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 9b1n Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: Not prime farmland Map Unit Composition Rippowam and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Rippowam Setting Landform: Alluvial flats Landform position (three-dimensional): Dip Down-slope shape: Linear Across-slope shape: Linear Parent material: Loamy alluvium over sandy and gravelly alluvium derived from granite and gneiss Typical profile H1 - 0 to 5 inches: fine sandy loam H2 - 5 to 24 inches: fine sandy loam H3 - 24 to 60 inches: loamy sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Very high Custom Soil Resource Report 14 Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 6.00 in/hr) Depth to water table: About 0 to 18 inches Frequency of flooding: Frequent Frequency of ponding: None Available water storage in profile: Low (about 5.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3w Hydrologic Soil Group: A/D Minor Components Pootatuck Percent of map unit: 5 percent Saco Percent of map unit: 5 percent Landform: Alluvial flats Limerick Percent of map unit: 5 percent Landform: Alluvial flats 8A—Limerick silt loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 9b0f Elevation: 50 to 500 feet Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: Not prime farmland Map Unit Composition Limerick and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Limerick Setting Landform: Alluvial flats Landform position (three-dimensional): Dip Down-slope shape: Linear Across-slope shape: Linear Parent material: Silty alluvium Typical profile H1 - 0 to 12 inches: silt loam H2 - 12 to 20 inches: very fine sandy loam Custom Soil Resource Report 15 H3 - 20 to 60 inches: silt loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Very high Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: About 0 to 18 inches Frequency of flooding: Frequent Frequency of ponding: None Available water storage in profile: Very high (about 13.4 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3w Hydrologic Soil Group: B/D Minor Components Winooski Percent of map unit: 10 percent Saco Percent of map unit: 5 percent Landform: Alluvial flats 30A—Raynham silt loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 9b1h Elevation: 50 to 500 feet Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: Not prime farmland Map Unit Composition Raynham and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Raynham Setting Landform: Depressions Landform position (three-dimensional): Dip Down-slope shape: Concave Across-slope shape: Linear Parent material: Silty glaciolacustrine deposits Custom Soil Resource Report 16 Typical profile H1 - 0 to 10 inches: silt loam H2 - 10 to 37 inches: silt loam H3 - 37 to 60 inches: stratified loamy fine sand to fine sandy loam to silt loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Very high Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table: About 0 to 31 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 5 percent Available water storage in profile: High (about 11.8 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3w Hydrologic Soil Group: C/D Minor Components Belgrade Percent of map unit: 5 percent Maybid Percent of map unit: 5 percent Landform: Depressions Scitico Percent of map unit: 5 percent Landform: Depressions 98A—Winooski silt loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 9b2p Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: All areas are prime farmland Map Unit Composition Winooski and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Custom Soil Resource Report 17 Description of Winooski Setting Landform: Flood plains Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Concave Parent material: Silty alluvium Typical profile H1 - 0 to 17 inches: silt loam H2 - 17 to 60 inches: silt loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 6.00 in/hr) Depth to water table: About 18 to 36 inches Frequency of flooding: Occasional Frequency of ponding: None Available water storage in profile: High (about 10.5 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: B Minor Components Hadley Percent of map unit: 10 percent Limerick Percent of map unit: 5 percent Landform: Alluvial flats 220C—Boxford silt loam, 8 to 15 percent slopes Map Unit Setting National map unit symbol: 99z7 Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: Farmland of statewide importance Map Unit Composition Boxford and similar soils: 85 percent Custom Soil Resource Report 18 Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Boxford Setting Landform: Terraces Landform position (two-dimensional): Summit Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Hard silty and clayey glaciolacustrine deposits derived from granite and gneiss Typical profile H1 - 0 to 8 inches: silt loam H2 - 8 to 21 inches: silt loam H3 - 21 to 37 inches: silty clay H4 - 37 to 60 inches: silty clay Properties and qualities Slope: 8 to 15 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately high (0.00 to 0.20 in/hr) Depth to water table: About 19 to 36 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: High (about 9.3 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: D Minor Components Unnamed Percent of map unit: 15 percent 225A—Belgrade silt loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 99z3 Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: All areas are prime farmland Custom Soil Resource Report 19 Map Unit Composition Belgrade and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Belgrade Setting Landform: Terraces Landform position (two-dimensional): Summit Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Coarse-silty glaciolacustrine deposits Typical profile H1 - 0 to 10 inches: silt loam H2 - 10 to 51 inches: very fine sandy loam H3 - 51 to 60 inches: loamy very fine sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately low to high (0.06 to 2.00 in/hr) Depth to water table: About 18 to 42 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: High (about 10.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: C Minor Components Raynham Percent of map unit: 15 percent Landform: Depressions 225B—Belgrade silt loam, 3 to 8 percent slopes Map Unit Setting National map unit symbol: 99z4 Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Custom Soil Resource Report 20 Farmland classification: All areas are prime farmland Map Unit Composition Belgrade and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Belgrade Setting Landform: Terraces Landform position (two-dimensional): Summit Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Coarse-silty glaciolacustrine deposits Typical profile H1 - 0 to 10 inches: silt loam H2 - 10 to 51 inches: very fine sandy loam H3 - 51 to 60 inches: loamy very fine sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately low to high (0.06 to 2.00 in/hr) Depth to water table: About 18 to 42 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: High (about 10.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: C Minor Components Raynham Percent of map unit: 15 percent Landform: Depressions 253A—Hinckley loamy sand, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 9b06 Elevation: 0 to 1,000 feet Mean annual precipitation: 40 to 50 inches Custom Soil Resource Report 21 Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: Farmland of statewide importance Map Unit Composition Hinckley and similar soils: 80 percent Minor components: 20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Hinckley Setting Landform: Outwash plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Loose sandy and gravelly glaciofluvial deposits Typical profile H1 - 0 to 8 inches: loamy sand H2 - 8 to 13 inches: loamy sand H3 - 13 to 29 inches: gravelly sand H4 - 29 to 60 inches: Error Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Excessively drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): High to very high (6.00 to 20.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 3.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3s Hydrologic Soil Group: A Minor Components Windsor Percent of map unit: 10 percent Sudbury Percent of map unit: 10 percent Custom Soil Resource Report 22 253B—Hinckley loamy sand, 3 to 8 percent slopes Map Unit Setting National map unit symbol: 9b07 Elevation: 0 to 1,000 feet Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: Farmland of statewide importance Map Unit Composition Hinckley and similar soils: 80 percent Minor components: 20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Hinckley Setting Landform: Outwash plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Loose sandy and gravelly glaciofluvial deposits Typical profile H1 - 0 to 8 inches: loamy sand H2 - 8 to 13 inches: loamy sand H3 - 13 to 29 inches: gravelly sand H4 - 29 to 60 inches: Error Properties and qualities Slope: 3 to 8 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Excessively drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): High to very high (6.00 to 20.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 3.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3s Hydrologic Soil Group: A Custom Soil Resource Report 23 Minor Components Sudbury Percent of map unit: 10 percent Windsor Percent of map unit: 10 percent 253C—Hinckley loamy sand, 8 to 15 percent slopes Map Unit Setting National map unit symbol: 9b08 Elevation: 0 to 1,000 feet Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: Not prime farmland Map Unit Composition Hinckley and similar soils: 80 percent Minor components: 20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Hinckley Setting Landform: Outwash plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Riser Down-slope shape: Convex Across-slope shape: Convex Parent material: Loose sandy and gravelly glaciofluvial deposits Typical profile H1 - 0 to 8 inches: loamy sand H2 - 8 to 13 inches: loamy sand H3 - 13 to 29 inches: gravelly sand H4 - 29 to 60 inches: Error Properties and qualities Slope: 8 to 15 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Excessively drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): High to very high (6.00 to 20.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 3.6 inches) Custom Soil Resource Report 24 Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4s Hydrologic Soil Group: A Minor Components Windsor Percent of map unit: 15 percent Sudbury Percent of map unit: 5 percent 253E—Hinckley loamy sand, 25 to 35 percent slopes Map Unit Setting National map unit symbol: 9b0b Elevation: 0 to 1,000 feet Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: Not prime farmland Map Unit Composition Hinckley and similar soils: 80 percent Minor components: 20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Hinckley Setting Landform: Outwash plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Riser Down-slope shape: Linear Across-slope shape: Convex Parent material: Loose sandy and gravelly glaciofluvial deposits Typical profile H1 - 0 to 8 inches: loamy sand H2 - 8 to 13 inches: loamy sand H3 - 13 to 29 inches: gravelly sand H4 - 29 to 60 inches: Error Properties and qualities Slope: 25 to 35 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Excessively drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): High to very high (6.00 to 20.00 in/hr) Custom Soil Resource Report 25 Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 3.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 7s Hydrologic Soil Group: A Minor Components Merrimac Percent of map unit: 10 percent Windsor Percent of map unit: 10 percent 254A—Merrimac fine sandy loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2tyqr Elevation: 0 to 1,100 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 Merrimac and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Merrimac Setting Landform: Outwash terraces, eskers, outwash plains, kames, moraines Landform position (two-dimensional): Backslope, footslope, shoulder, summit Landform position (three-dimensional): Side slope, crest, riser, tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Loamy glaciofluvial deposits derived from granite, schist, and gneiss over sandy and gravelly glaciofluvial deposits derived from granite, schist, and gneiss Typical profile Ap - 0 to 10 inches: fine sandy loam Bw1 - 10 to 22 inches: fine sandy loam Bw2 - 22 to 26 inches: stratified gravel to gravelly loamy sand 2C - 26 to 65 inches: stratified gravel to very gravelly sand Custom Soil Resource Report 26 Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat excessively drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to very high (1.42 to 99.90 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 2 percent Salinity, maximum in profile: Nonsaline (0.0 to 1.4 mmhos/cm) Sodium adsorption ratio, maximum in profile: 1.0 Available water storage in profile: Low (about 4.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2s Hydrologic Soil Group: A Minor Components Sudbury Percent of map unit: 5 percent Landform: Terraces, outwash plains, deltas Landform position (two-dimensional): Footslope Landform position (three-dimensional): Tread, dip Down-slope shape: Concave Across-slope shape: Linear Hinckley Percent of map unit: 5 percent Landform: Eskers, outwash plains, kames, deltas 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 Agawam Percent of map unit: 3 percent Landform: Outwash terraces, eskers, outwash plains, stream terraces, kames, moraines Landform position (three-dimensional): Rise Down-slope shape: Convex Across-slope shape: Convex Windsor Percent of map unit: 2 percent Landform: Outwash terraces, outwash plains, dunes, deltas Landform position (two-dimensional): Summit Landform position (three-dimensional): Tread, riser Down-slope shape: Linear, convex Across-slope shape: Linear, convex Custom Soil Resource Report 27 258B—Amostown fine sandy loam, 3 to 8 percent slopes Map Unit Setting National map unit symbol: 99z1 Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: All areas are prime farmland Map Unit Composition Amostown and similar soils: 75 percent Minor components: 25 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Amostown Setting Landform: Terraces, outwash plains, deltas Landform position (two-dimensional): Summit, footslope Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Friable sandy glaciofluvial deposits over silty glaciolacustrine deposits Typical profile H1 - 0 to 7 inches: fine sandy loam H2 - 7 to 32 inches: fine sandy loam H3 - 32 to 60 inches: stratified very fine sand to silt loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.60 in/hr) Depth to water table: About 18 to 36 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: High (about 9.3 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: B Custom Soil Resource Report 28 Minor Components Pollux Percent of map unit: 15 percent Agawam Percent of map unit: 10 percent 260A—Sudbury fine sandy loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 9b1z Elevation: 0 to 2,100 feet Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: All areas are prime farmland Map Unit Composition Sudbury and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Sudbury Setting Landform: Outwash plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Concave Parent material: Friable loamy eolian deposits over loose sandy glaciofluvial deposits Typical profile H1 - 0 to 10 inches: fine sandy loam H2 - 10 to 16 inches: fine sandy loam H3 - 16 to 28 inches: gravelly loamy sand H4 - 28 to 60 inches: stratified gravelly sand to very gravelly loamy sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): High (2.00 to 6.00 in/hr) Depth to water table: About 18 to 36 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 4.8 inches) Custom Soil Resource Report 29 Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: B Minor Components Hinckley Percent of map unit: 5 percent Walpole Percent of map unit: 5 percent Landform: Terraces Merrimac Percent of map unit: 5 percent 311C—Woodbridge fine sandy loam, 8 to 15 percent slopes, very stony Map Unit Setting National map unit symbol: 9b2x Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: Not prime farmland Map Unit Composition Woodbridge and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Woodbridge Setting Landform: Hills Landform position (two-dimensional): Backslope Landform position (three-dimensional): Side slope Down-slope shape: Linear Across-slope shape: Concave Parent material: Friable loamy eolian deposits over dense loamy lodgment till derived from granite and gneiss Typical profile H1 - 0 to 7 inches: gravelly fine sandy loam H2 - 7 to 25 inches: gravelly fine sandy loam H3 - 25 to 60 inches: gravelly fine sandy loam Properties and qualities Slope: 8 to 15 percent Percent of area covered with surface fragments: 2.0 percent Depth to restrictive feature: 18 to 35 inches to densic material Custom Soil Resource Report 30 Natural drainage class: Moderately well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately high (0.00 to 0.20 in/hr) Depth to water table: About 19 to 35 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 3.4 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 7s Hydrologic Soil Group: C Minor Components Paxton Percent of map unit: 7 percent Charlton Percent of map unit: 5 percent Ridgebury Percent of map unit: 3 percent Landform: Depressions 651—Udorthents, smoothed Map Unit Setting National map unit symbol: 9b23 Elevation: 0 to 3,000 feet Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 120 to 200 days Farmland classification: Not prime farmland Map Unit Composition Udorthents and similar soils: 100 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Udorthents Setting Down-slope shape: Convex Across-slope shape: Convex Parent material: Loamy alluvium and/or sandy glaciofluvial deposits and/or loamy glaciolacustrine deposits and/or loamy marine deposits and/or loamy basal till and/or loamy lodgment till Properties and qualities Slope: 0 to 15 percent Depth to restrictive feature: More than 80 inches Custom Soil Resource Report 31 Natural drainage class: Well drained Runoff class: Medium 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 741A—Amostown-Windsor silty substratum-Urban land complex, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 99z2 Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 120 to 240 days Farmland classification: Not prime farmland Map Unit Composition Amostown and similar soils: 35 percent Urban land: 25 percent Windsor, silty substratum, and similar soils: 25 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Amostown Setting Landform: Terraces, outwash plains, deltas Landform position (two-dimensional): Summit, footslope Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Friable sandy glaciofluvial deposits over silty glaciolacustrine deposits Typical profile H1 - 0 to 7 inches: fine sandy loam H2 - 7 to 32 inches: fine sandy loam H3 - 32 to 60 inches: stratified very fine sand to silt loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.60 in/hr) Depth to water table: About 18 to 36 inches Frequency of flooding: None Custom Soil Resource Report 32 Frequency of ponding: None Available water storage in profile: High (about 9.3 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: B Description of Windsor, Silty Substratum Setting Landform: Outwash plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Loose sandy glaciofluvial deposits over silty glaciolacustrine deposits Typical profile H1 - 0 to 8 inches: loamy sand H2 - 8 to 21 inches: loamy sand H3 - 21 to 45 inches: sand H4 - 45 to 60 inches: silt loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat excessively drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 5.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3s Hydrologic Soil Group: A Minor Components Enosburg Percent of map unit: 10 percent Landform: Terraces Maybid Percent of map unit: 5 percent Landform: Depressions Custom Soil Resource Report 33 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. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/soils/?cid=nrcs142p2_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.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http://www.nrcs.usda.gov/wps/ portal/nrcs/detail/national/soils/?cid=nrcs142p2_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 Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 34 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_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.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_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/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 35 Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Appendix B – Subsurface Investigation Results Please feel free to contact us with any questions you may have. rely, d Spring Environmental Consultants, Inc. Alan E. Weiss, M.S., R.S., LSP toik COLD SPRING ENVIRONMENTAL CONSULTANTS INC. • 21E Site Investigations • Subsurface Investigations • Pollution Remediation • LSP on Staff • Forensic Septic Investigations • Percolation Tests • Septic Designs • Regulatory Compliance • Recycling and Solid Waste • Second Opinions April 20, 2015 Mr. Jeffrey Squires The Berkshire Design Group, Inc. 4 Allen Place Northampton, MA 01060 RE: Test Pit & Soil Evaluation Results Proposed Development Village Hill, Northampton, MA CSEC Reference File #115-4538-0417 Greetings Jeff: Background: Cold Spring Environmental, Inc. was contracted to install test pits and perform soil evaluations and particle size analysis in order to evaluate drainage character of soil for the applicability of storm water drainage feasibility at the above referenced property. This task was contracted by you to supplement your work and was conducted on April 2, 2015 by the writer. Included in our job was to complete soil suitability interpretation of underlying soils at the site for drainage structures and storm water management practices. A Site Locus Map (Figure I) and Site Plan (Figure 2, From Berkshire Design Group) is included as Attachment I. The approximate test pit locations are noted on the plan from as selected by Berkshire Design Group Attached. Photos are also provided as Attachment 2. On Site Field Investigation: Test Pit locations were pre-determined by Berkshire Design Group and completed by personnel of this office on April 8, 2015 at the site based on topographic geometry of the property and planned development. thirteen (1-14, excluding #10) were installed as shown on the attached plan). It was later decided by you that the nine of the collected soil samples would be also submitted for particle size analysis at the Umass soil lab in Amherst Ma. Nearly all of the excavations had moderate or poorly permeable sandy loam substrata with perched seasonal high groundwater conditions from 24-48" below grade. Some areas also exhibited fairly disturbed and mixed fill layer of heterogeneous silty and fine sandy glacial till, fill with some crushed concrete brick constituents typical of urban fill and the historically developed and razed nature of much of the southern portion of the subject property. Due to the heterogeneity, this material also had poor drainage qualities and Estimated Seasonal High Groundwater (ESHGW), perched at 24" to 48" below grade. The test pits were excavated using a Bobcat excavator provided by BDG's contracor The soil evaluations followed procedures specified in 310 CMR 15.000for soil evaluations. Overall, native soil types concurred with USDA mapping included Amostown-Windsor Silty Substratum urban complex (Au) consisting of thick mixed deposits underlain by poorly drained soils. The Permeability of the sub soil is generally moderately slow. The Mottling and silty, clayey nature posed by the soils in these locations is the very high ESHGW from 24"-48"below existing grade, may make drainage quite challenging. 350 Old Enfield Road n Bekhertown, MA. 01007 n Phone: 413.323.5957 Fax 413.323.4916 email: aeweiss@charter.net www.coldspringenvironmental.com ATTACHMENT I Figure 1: Site Locus (USGS) Figure 2: Site Layout (labeled Test Pit Locations 1 & 2) Cold Spring Environmental Consultants, Inc. 350 Old Enfield Road Belchertown, MA. 01007 http://www.coldspringenvironmental.com Ph: 413.323.5957 Fax: 413.323.4916 email: aeweiss@charter.net FROM USGS April 2015FIGURE 1—SITE LOCUS Berkshire Design Group Northampton, MA 4GXKUKQPU.CPFUECRG#TEJKVGEVWTG%KXKN'PIKPGGTKPI2NCPPKPI$GTMUJKTG)TQWR+PE&GUKIP6JG.CPF5WTXG[KPI'ZKUVKPI%QPFKVKQPUApplicantEnergy Positive Homes, LLCc/o Transformations, Inc.323 West Main StreetǇĞƌ͕DϬϭϰϯϮOwnerHospital Hill Development, LLCc/o MA Development Finance Agency99 High StreetBoston, MA 01469&'(+0+6+8'2.#0SPECIMEN TREETYP. (SHADED)SPECIMEN TREETYP. (SHADED) ATTACHMENT II Soil Logs and Soil Textural Analysis Reports tp 1 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:1 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-7" A 10 yr 3.2 FSL friable 7-24" B 7.5 yr 5.6 24" 2.5Y 4.1 15 FSL till w/fill PLAST. Disturbed 24-40" C1 2.5 yr 4.2 " " " FS 15% sandy moist seeps 22" 40-120"C2 7.5 yr 5.3 " 7.5 yr 5.8 15% FSL 20% Massive platey ESHGW= 24" Additional Notes: tp 4 and tp 2 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:4 & 2 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-6" Af 10 YR 3.2 Fill friable fill 6-22" B 7.5 yr 5.6 24" 2.5Y 4.1 20 FSL till w/fill PLAST. Disturbed 22-118" C 2.5 yr 4.2 " " " FSL 15% massive moist seeps 22" --------- --------- ------------ --------- --------- --------- ---------- --------- --------- ----------- ---------ESHGW= 24" 0-36" Af 10 YR. 3.2 fill brick loam mix 36-118" C1 2.5 Y 4.3 30" 2.5 Y 4.1 10 FSL 10% FSL firm moist varved ESHGW= 30" Additional Notes: Soil and Plant Tissue Testing Laboratory 203 Paige Laboratory 161 Holdsworth Way University of Massachusetts Amherst, MA 01003 Phone: (413) 545-2311 e-mail: soiltest@umass.edu website: soiltest.umass.edu Prepared For: 413-323-5957 Sample Information: Sample ID:4 4' Lab Number:X150410-111 Received:4/10/2015 Reported:4/15/2015 Alan Weiss Cold Springs Environmental 350 Old Enfield Rd Belchertown, MA 01007 aweiss@coldspringenvironmental.com Order Number:12753 Particle Size Analysis - Comprehensive USDA Size Fraction Percent of Whole Sample Passing Main Fractions Size (mm)Percent 59.3Sand0.05-2.0 28.9Silt0.002-0.05 11.8Clay<0.002 Sand Fractions Size (mm)Percent 12.0Very Coarse 1.0-2.0 11.5Coarse0.5-1.0 11.4Medium0.25-0.5 14.3Fine0.10-0.25 10.1Very Fine 0.05-0.10 Silt Fractions Size (mm)Percent 10.9Coarse0.02-0.05 14.5Medium0.005-0.02 3.5Fine0.002-0.005 Size (mm)Sieve # Sample Passing Whole Sample % of 2.00 65.2#10 1.00 57.4#18 0.50 49.8#35 0.25 42.4#60 0.10 33.1#140 0.053 26.5#270 0.02 19.420 um 0.005 10.05 um 0.002 7.72 um USDA Textural Class: Gravel Content: (%) gravelly sandy loam 34.8 1 of 1 Lab Number X150410-111Sample ID: 4 4' tp 3 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:3 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-8" A 10 yr 3.2 FSL friable 8-26" B 7.5 yr 5.6 20" 2.5Y 4.1 15 FSL till w/fill PLAST. Disturbed 2.5 yr 4.2 " " " moist seeps 24" 26-126"C1 7.5 yr 5.3 " 7.5 yr 5.3 15% FSL 5% 5% Massive platey ESHGW= 20" Additional Notes: tp 5 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:5 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-30" Af 10 yr 3.4 FSL buried brick concrete Fill 4' sample 30-126" C1 7.5 yr 5.6 28" 7.5 yr 5.8 10% FSL 10 10 TILL ESHGW= 30" seeps 30" Additional Notes: tp 6 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:6 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-3" Af 10 yr 3.4 FSL buried brick concrete Fill/LOAM 4' sample 3-120" FILL 7.5 yr 5.6 34" 7.5 yr 5.8 10% FSL 10 10 MIXED W/TILL ,MASSIVE URBAN FILL ESHGW= 24" seeps 24" Additional Notes: Soil and Plant Tissue Testing Laboratory 203 Paige Laboratory 161 Holdsworth Way University of Massachusetts Amherst, MA 01003 Phone: (413) 545-2311 e-mail: soiltest@umass.edu website: soiltest.umass.edu Prepared For: 413-323-5957 Sample Information: Sample ID:6 4' Lab Number:X150410-104 Received:4/10/2015 Reported:4/15/2015 Alan Weiss Cold Springs Environmental 350 Old Enfield Rd Belchertown, MA 01007 aweiss@coldspringenvironmental.com Order Number:12753 Particle Size Analysis - Comprehensive USDA Size Fraction Percent of Whole Sample Passing Main Fractions Size (mm)Percent 59.6Sand0.05-2.0 26.1Silt0.002-0.05 14.3Clay<0.002 Sand Fractions Size (mm)Percent 7.3Very Coarse 1.0-2.0 12.3Coarse0.5-1.0 14.3Medium0.25-0.5 16.2Fine0.10-0.25 9.4Very Fine 0.05-0.10 Silt Fractions Size (mm)Percent 8.8Coarse0.02-0.05 12.4Medium0.005-0.02 4.9Fine0.002-0.005 Size (mm)Sieve # Sample Passing Whole Sample % of 2.00 79.1#10 1.00 73.3#18 0.50 63.6#35 0.25 52.2#60 0.10 39.4#140 0.053 31.9#270 0.02 25.020 um 0.005 15.25 um 0.002 11.32 um USDA Textural Class: Gravel Content: (%) sandy loam 20.9 1 of 1 Lab Number X150410-104Sample ID: 6 4' tp 7 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:7 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-8" A 10 yr 3.2 FSL friable ROOTS 8-32" B 7.5 yr 4.4 MS F sandy sample 4' 32-126" C1 2.5 yr 4.2 36" 7.5 yr 5.8 20% SL 10% 10% sandy TILL seeps 36" MASSIVE ESHGW= 36" Additional Notes: Soil and Plant Tissue Testing Laboratory 203 Paige Laboratory 161 Holdsworth Way University of Massachusetts Amherst, MA 01003 Phone: (413) 545-2311 e-mail: soiltest@umass.edu website: soiltest.umass.edu Prepared For: 413-323-5957 Sample Information: Sample ID:7 Lab Number:X150410-105 Received:4/10/2015 Reported:4/15/2015 Alan Weiss Cold Springs Environmental 350 Old Enfield Rd Belchertown, MA 01007 aweiss@coldspringenvironmental.com Order Number:12753 Particle Size Analysis - Comprehensive USDA Size Fraction Percent of Whole Sample Passing Main Fractions Size (mm)Percent 62.9Sand0.05-2.0 24.2Silt0.002-0.05 12.9Clay<0.002 Sand Fractions Size (mm)Percent 11.0Very Coarse 1.0-2.0 13.8Coarse0.5-1.0 13.7Medium0.25-0.5 15.4Fine0.10-0.25 9.1Very Fine 0.05-0.10 Silt Fractions Size (mm)Percent 8.6Coarse0.02-0.05 11.8Medium0.005-0.02 3.7Fine0.002-0.005 Size (mm)Sieve # Sample Passing Whole Sample % of 2.00 73.7#10 1.00 65.7#18 0.50 55.5#35 0.25 45.4#60 0.10 34.1#140 0.053 27.4#270 0.02 21.020 um 0.005 12.35 um 0.002 9.52 um USDA Textural Class: Gravel Content: (%) sandy loam 26.3 1 of 1 Lab Number X150410-105Sample ID: 7 tp 8 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:8 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-96" Af 10 yr 3.4 FSL buried brick concrete Fill 4' sample 96-128" C1 7.5 yr 5.6 28" 7.5 yr 5.8 10% FSL 10 10 TILL ESHGW= 28" seeps 28" Additional Notes: Soil and Plant Tissue Testing Laboratory 203 Paige Laboratory 161 Holdsworth Way University of Massachusetts Amherst, MA 01003 Phone: (413) 545-2311 e-mail: soiltest@umass.edu website: soiltest.umass.edu Prepared For: 413-323-5957 Sample Information: Sample ID:8 Lab Number:X150410-107 Received:4/10/2015 Reported:4/15/2015 Alan Weiss Cold Springs Environmental 350 Old Enfield Rd Belchertown, MA 01007 aweiss@coldspringenvironmental.com Order Number:12753 Particle Size Analysis - Comprehensive USDA Size Fraction Percent of Whole Sample Passing Main Fractions Size (mm)Percent 71.2Sand0.05-2.0 22.7Silt0.002-0.05 6.1Clay<0.002 Sand Fractions Size (mm)Percent 10.4Very Coarse 1.0-2.0 14.1Coarse0.5-1.0 15.7Medium0.25-0.5 19.3Fine0.10-0.25 11.7Very Fine 0.05-0.10 Silt Fractions Size (mm)Percent 11.8Coarse0.02-0.05 9.1Medium0.005-0.02 1.8Fine0.002-0.005 Size (mm)Sieve # Sample Passing Whole Sample % of 2.00 77.7#10 1.00 69.6#18 0.50 58.6#35 0.25 46.4#60 0.10 31.4#140 0.053 22.4#270 0.02 13.220 um 0.005 6.15 um 0.002 4.72 um USDA Textural Class: Gravel Content: (%) sandy loam 22.3 1 of 1 Lab Number X150410-107Sample ID: 8 tp 11 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:9 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-48" Af 10 yr 3.4 FSL buried brick concrete Fill 4' sample 48-128" C1 7.5 yr 5.6 48" 7.5 yr 5.8 10% FS 10 10 granular ESHGW= 48" seeps 50" Additional Notes: Soil and Plant Tissue Testing Laboratory 203 Paige Laboratory 161 Holdsworth Way University of Massachusetts Amherst, MA 01003 Phone: (413) 545-2311 e-mail: soiltest@umass.edu website: soiltest.umass.edu Prepared For: 413-323-5957 Sample Information: Sample ID:9 4' Lab Number:X150410-109 Received:4/10/2015 Reported:4/15/2015 Alan Weiss Cold Springs Environmental 350 Old Enfield Rd Belchertown, MA 01007 aweiss@coldspringenvironmental.com Order Number:12753 Particle Size Analysis - Comprehensive USDA Size Fraction Percent of Whole Sample Passing Main Fractions Size (mm)Percent 63.4Sand0.05-2.0 23.3Silt0.002-0.05 13.3Clay<0.002 Sand Fractions Size (mm)Percent 10.4Very Coarse 1.0-2.0 14.1Coarse0.5-1.0 14.8Medium0.25-0.5 15.3Fine0.10-0.25 8.8Very Fine 0.05-0.10 Silt Fractions Size (mm)Percent 8.0Coarse0.02-0.05 10.8Medium0.005-0.02 4.5Fine0.002-0.005 Size (mm)Sieve # Sample Passing Whole Sample % of 2.00 39.1#10 1.00 35.0#18 0.50 29.5#35 0.25 23.7#60 0.10 17.8#140 0.053 14.3#270 0.02 11.220 um 0.005 7.05 um 0.002 5.22 um USDA Textural Class: Gravel Content: (%) gravelly sandy loam 60.9 1 of 1 Lab Number X150410-109Sample ID: 9 4' tp 11 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:11 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-64" Af 10 yr 3.6 FSL buried brick Fill 3' sample 64-120" C1 7.5 yr 5.6 48" 7.5 yr 5.8 20% FSL 10 10 massive till loose disturbed some silt ESHGW= 48" 8' sample Additional Notes: Soil and Plant Tissue Testing Laboratory 203 Paige Laboratory 161 Holdsworth Way University of Massachusetts Amherst, MA 01003 Phone: (413) 545-2311 e-mail: soiltest@umass.edu website: soiltest.umass.edu Prepared For: 413-323-5957 Sample Information: Sample ID:11 3' Lab Number:X150410-106 Received:4/10/2015 Reported:4/15/2015 Alan Weiss Cold Springs Environmental 350 Old Enfield Rd Belchertown, MA 01007 aweiss@coldspringenvironmental.com Order Number:12753 Particle Size Analysis - Comprehensive USDA Size Fraction Percent of Whole Sample Passing Main Fractions Size (mm)Percent 74.3Sand0.05-2.0 16.3Silt0.002-0.05 9.4Clay<0.002 Sand Fractions Size (mm)Percent 13.3Very Coarse 1.0-2.0 17.6Coarse0.5-1.0 17.5Medium0.25-0.5 17.4Fine0.10-0.25 8.4Very Fine 0.05-0.10 Silt Fractions Size (mm)Percent 7.2Coarse0.02-0.05 7.2Medium0.005-0.02 1.9Fine0.002-0.005 Size (mm)Sieve # Sample Passing Whole Sample % of 2.00 69.9#10 1.00 60.6#18 0.50 48.3#35 0.25 36.1#60 0.10 23.9#140 0.053 18.0#270 0.02 12.920 um 0.005 7.95 um 0.002 6.62 um USDA Textural Class: Gravel Content: (%) coarse sandy loam 30.1 1 of 1 Lab Number X150410-106Sample ID: 11 3' Soil and Plant Tissue Testing Laboratory 203 Paige Laboratory 161 Holdsworth Way University of Massachusetts Amherst, MA 01003 Phone: (413) 545-2311 e-mail: soiltest@umass.edu website: soiltest.umass.edu Prepared For: 413-323-5957 Sample Information: Sample ID:11 8' Lab Number:X150410-108 Received:4/10/2015 Reported:4/15/2015 Alan Weiss Cold Springs Environmental 350 Old Enfield Rd Belchertown, MA 01007 aweiss@coldspringenvironmental.com Order Number:12753 Particle Size Analysis - Comprehensive USDA Size Fraction Percent of Whole Sample Passing Main Fractions Size (mm)Percent 77.4Sand0.05-2.0 14.7Silt0.002-0.05 7.8Clay<0.002 Sand Fractions Size (mm)Percent 16.5Very Coarse 1.0-2.0 18.4Coarse0.5-1.0 17.1Medium0.25-0.5 17.1Fine0.10-0.25 8.3Very Fine 0.05-0.10 Silt Fractions Size (mm)Percent 6.0Coarse0.02-0.05 7.6Medium0.005-0.02 1.2Fine0.002-0.005 Size (mm)Sieve # Sample Passing Whole Sample % of 2.00 72.3#10 1.00 60.3#18 0.50 47.0#35 0.25 34.7#60 0.10 22.3#140 0.053 16.3#270 0.02 12.020 um 0.005 6.55 um 0.002 5.62 um USDA Textural Class: Gravel Content: (%) coarse sandy loam 27.7 1 of 1 Lab Number X150410-108Sample ID: 11 8' tp 13 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:12 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-12" A 10 yr 3.3 FSL friable Roots 12-26" B 10 yr 4.6 FS F sandy 26-126" C1 10 yr 4.3 28" 7.5 yr 5.6 20% FSL 10 10 massive till some silt ESHGW= 28" Additional Notes: Soil and Plant Tissue Testing Laboratory 203 Paige Laboratory 161 Holdsworth Way University of Massachusetts Amherst, MA 01003 Phone: (413) 545-2311 e-mail: soiltest@umass.edu website: soiltest.umass.edu Prepared For: 413-323-5957 Sample Information: Sample ID:12 4' Lab Number:X150410-103 Received:4/10/2015 Reported:4/15/2015 Alan Weiss Cold Springs Environmental 350 Old Enfield Rd Belchertown, MA 01007 aweiss@coldspringenvironmental.com Order Number:12753 Particle Size Analysis - Comprehensive USDA Size Fraction Percent of Whole Sample Passing Main Fractions Size (mm)Percent 60.1Sand0.05-2.0 27.9Silt0.002-0.05 12.0Clay<0.002 Sand Fractions Size (mm)Percent 10.3Very Coarse 1.0-2.0 11.5Coarse0.5-1.0 12.3Medium0.25-0.5 15.7Fine0.10-0.25 10.4Very Fine 0.05-0.10 Silt Fractions Size (mm)Percent 10.6Coarse0.02-0.05 13.8Medium0.005-0.02 3.5Fine0.002-0.005 Size (mm)Sieve # Sample Passing Whole Sample % of 2.00 78.0#10 1.00 70.0#18 0.50 61.0#35 0.25 51.4#60 0.10 39.2#140 0.053 31.1#270 0.02 22.820 um 0.005 12.15 um 0.002 9.42 um USDA Textural Class: Gravel Content: (%) sandy loam 22.0 1 of 1 Lab Number X150410-103Sample ID: 12 4' tp 13 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:13 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-8" A 10 yr 3.2 FSL friable 8-30" B 10 yr 4.3 FS 5% granular F sandy little silt 30-126" C1 2.5 yr 4.2 26" 2.5 y 4.1 20% silt loam silty & clayey varved seeps 26" 7.5 yr 5.8 ESHGW= 26" Additional Notes: tp 14 log only t5form12 BDG soil eval form 2014.doc • rev. 3/13 Form 11 – Soil Suitability Assessment for On-Site Sewage Disposal • Page 3 of 8 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (continued) Deep Observation Hole Number:14 Depth (in.)Soil Horizon/ Layer Soil Matrix: Color- Moist (Munsell) Redoximorphic Features (mottles)Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-4" A 10 yr 3.2 FSL friable 4-22" B 10 yr 4.6 FSL F sandy little silt 22-120 C1 2.5 yr 4.2 40" 7.5 yr 5.8 20% FS 15% F sandy granular seeps 48" varved ESHGW= 40" Additional Notes: ATTACHMENT III Photographs TP-1 Village Hill Northampton, MA 04.2.2015 TP-2 Village Hill Northampton, MA 04.2.2015 TP-3 Village Hill Northampton, MA 04.2.2015 TP-4 Village Hill Northampton, MA 04.2.2015 TP-5 samples Village Hill Northampton, MA 04.2.2015 TP-6 Village Hill Northampton, MA 04.2.2015 TP-6 pic 2 Village Hill Northampton, MA 04.2.2015 TP-7 Village Hill Northampton, MA 04.2.2015 TP-8 Village Hill Northampton, MA 04.2.2015 TP-9 Village Hill Northampton, MA 04.2.2015 TP-12 Village Hill Northampton, MA 04.2.2015 11 TP-11 Village Hill Northampton, MA 04.2.2015 2 TP-14 Village Hill Northampton, MA 04.2.2015 Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Appendix C – Stormwater Hydrology Calculations EDA-2 Area in NE corner of existing site DP-2 Control point for existing runoff Routing Diagram for Village Hill - Co-Housing - Pre-Development Prepared by Microsoft, Printed 7/11/2018 HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Subcat Reach Pond Link Village Hill - Co-Housing - Pre-Development Printed 7/11/2018Prepared by Microsoft Page 2HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 2.800 61 >75% Grass cover, Good, HSG B (EDA-2) 10.800 74 >75% Grass cover, Good, HSG C (EDA-2) 3.600 98 Paved parking & roofs (EDA-2) 0.100 55 Woods, Good, HSG B (EDA-2) 5.300 70 Woods, Good, HSG C (EDA-2) Type III 24-hr 2-yr Rainfall=3.00"Village Hill - Co-Housing - Pre-Development Printed 7/11/2018Prepared by Microsoft Page 3HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=22.600 ac 15.93% Impervious Runoff Depth>0.96"Subcatchment EDA-2: Area in NE corner Flow Length=680' Tc=10.4 min CN=75 Runoff=20.50 cfs 1.805 af Inflow=20.50 cfs 1.805 afReach DP-2: Control point for existing runoff Outflow=20.50 cfs 1.805 af Type III 24-hr 2-yr Rainfall=3.00"Village Hill - Co-Housing - Pre-Development Printed 7/11/2018Prepared by Microsoft Page 4HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment EDA-2: Area in NE corner of existing site Runoff = 20.50 cfs @ 12.16 hrs, Volume= 1.805 af, Depth> 0.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.00" Area (ac) CN Description 2.800 61 >75% Grass cover, Good, HSG B 0.100 55 Woods, Good, HSG B 0.600 98 Paved parking & roofs 10.800 74 >75% Grass cover, Good, HSG C 5.300 70 Woods, Good, HSG C 3.000 98 Paved parking & roofs 22.600 75 Weighted Average 19.000 84.07% Pervious Area 3.600 15.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 50 0.0220 0.11 Sheet Flow, Flow to the east down dense grass hill Grass: Dense n= 0.240 P2= 3.20" 1.4 370 0.0780 4.50 Shallow Concentrated Flow, Flow to the east Unpaved Kv= 16.1 fps 1.1 260 0.0620 4.01 Shallow Concentrated Flow, Flow to control point Unpaved Kv= 16.1 fps 10.4 680 Total Summary for Reach DP-2: Control point for existing runoff Inflow Area = 22.600 ac, 15.93% Impervious, Inflow Depth > 0.96" for 2-yr event Inflow = 20.50 cfs @ 12.16 hrs, Volume= 1.805 af Outflow = 20.50 cfs @ 12.16 hrs, Volume= 1.805 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.50"Village Hill - Co-Housing - Pre-Development Printed 7/11/2018Prepared by Microsoft Page 5HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=22.600 ac 15.93% Impervious Runoff Depth>2.05"Subcatchment EDA-2: Area in NE corner Flow Length=680' Tc=10.4 min CN=75 Runoff=46.04 cfs 3.854 af Inflow=46.04 cfs 3.854 afReach DP-2: Control point for existing runoff Outflow=46.04 cfs 3.854 af Type III 24-hr 10-yr Rainfall=4.50"Village Hill - Co-Housing - Pre-Development Printed 7/11/2018Prepared by Microsoft Page 6HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment EDA-2: Area in NE corner of existing site Runoff = 46.04 cfs @ 12.15 hrs, Volume= 3.854 af, Depth> 2.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.50" Area (ac) CN Description 2.800 61 >75% Grass cover, Good, HSG B 0.100 55 Woods, Good, HSG B 0.600 98 Paved parking & roofs 10.800 74 >75% Grass cover, Good, HSG C 5.300 70 Woods, Good, HSG C 3.000 98 Paved parking & roofs 22.600 75 Weighted Average 19.000 84.07% Pervious Area 3.600 15.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 50 0.0220 0.11 Sheet Flow, Flow to the east down dense grass hill Grass: Dense n= 0.240 P2= 3.20" 1.4 370 0.0780 4.50 Shallow Concentrated Flow, Flow to the east Unpaved Kv= 16.1 fps 1.1 260 0.0620 4.01 Shallow Concentrated Flow, Flow to control point Unpaved Kv= 16.1 fps 10.4 680 Total Summary for Reach DP-2: Control point for existing runoff Inflow Area = 22.600 ac, 15.93% Impervious, Inflow Depth > 2.05" for 10-yr event Inflow = 46.04 cfs @ 12.15 hrs, Volume= 3.854 af Outflow = 46.04 cfs @ 12.15 hrs, Volume= 3.854 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.25"Village Hill - Co-Housing - Pre-Development Printed 7/11/2018Prepared by Microsoft Page 7HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=22.600 ac 15.93% Impervious Runoff Depth>2.65"Subcatchment EDA-2: Area in NE corner Flow Length=680' Tc=10.4 min CN=75 Runoff=59.97 cfs 4.988 af Inflow=59.97 cfs 4.988 afReach DP-2: Control point for existing runoff Outflow=59.97 cfs 4.988 af Type III 24-hr 25-yr Rainfall=5.25"Village Hill - Co-Housing - Pre-Development Printed 7/11/2018Prepared by Microsoft Page 8HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment EDA-2: Area in NE corner of existing site Runoff = 59.97 cfs @ 12.15 hrs, Volume= 4.988 af, Depth> 2.65" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.25" Area (ac) CN Description 2.800 61 >75% Grass cover, Good, HSG B 0.100 55 Woods, Good, HSG B 0.600 98 Paved parking & roofs 10.800 74 >75% Grass cover, Good, HSG C 5.300 70 Woods, Good, HSG C 3.000 98 Paved parking & roofs 22.600 75 Weighted Average 19.000 84.07% Pervious Area 3.600 15.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 50 0.0220 0.11 Sheet Flow, Flow to the east down dense grass hill Grass: Dense n= 0.240 P2= 3.20" 1.4 370 0.0780 4.50 Shallow Concentrated Flow, Flow to the east Unpaved Kv= 16.1 fps 1.1 260 0.0620 4.01 Shallow Concentrated Flow, Flow to control point Unpaved Kv= 16.1 fps 10.4 680 Total Summary for Reach DP-2: Control point for existing runoff Inflow Area = 22.600 ac, 15.93% Impervious, Inflow Depth > 2.65" for 25-yr event Inflow = 59.97 cfs @ 12.15 hrs, Volume= 4.988 af Outflow = 59.97 cfs @ 12.15 hrs, Volume= 4.988 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.00"Village Hill - Co-Housing - Pre-Development Printed 7/11/2018Prepared by Microsoft Page 9HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=22.600 ac 15.93% Impervious Runoff Depth>4.14"Subcatchment EDA-2: Area in NE corner Flow Length=680' Tc=10.4 min CN=75 Runoff=93.89 cfs 7.801 af Inflow=93.89 cfs 7.801 afReach DP-2: Control point for existing runoff Outflow=93.89 cfs 7.801 af Type III 24-hr 100-yr Rainfall=7.00"Village Hill - Co-Housing - Pre-Development Printed 7/11/2018Prepared by Microsoft Page 10HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment EDA-2: Area in NE corner of existing site Runoff = 93.89 cfs @ 12.15 hrs, Volume= 7.801 af, Depth> 4.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.00" Area (ac) CN Description 2.800 61 >75% Grass cover, Good, HSG B 0.100 55 Woods, Good, HSG B 0.600 98 Paved parking & roofs 10.800 74 >75% Grass cover, Good, HSG C 5.300 70 Woods, Good, HSG C 3.000 98 Paved parking & roofs 22.600 75 Weighted Average 19.000 84.07% Pervious Area 3.600 15.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 50 0.0220 0.11 Sheet Flow, Flow to the east down dense grass hill Grass: Dense n= 0.240 P2= 3.20" 1.4 370 0.0780 4.50 Shallow Concentrated Flow, Flow to the east Unpaved Kv= 16.1 fps 1.1 260 0.0620 4.01 Shallow Concentrated Flow, Flow to control point Unpaved Kv= 16.1 fps 10.4 680 Total Summary for Reach DP-2: Control point for existing runoff Inflow Area = 22.600 ac, 15.93% Impervious, Inflow Depth > 4.14" for 100-yr event Inflow = 93.89 cfs @ 12.15 hrs, Volume= 7.801 af Outflow = 93.89 cfs @ 12.15 hrs, Volume= 7.801 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs PDA-2A Northern & Eastern Edges of Site PDA-2B TCB "Lot 13A" Project PDA-2C Southeast Corner of Site PDA-2D Future Co-Housing Site DP-2 Control Point for proposed drainage S1 Drainage Swale (Upper Segment) S2 Drainage Swale (Middle Segment) S3 Drainage Swale (Lower Segment) P2 Basin #2 (Survey) P4 Basin #4 (Survey) Routing Diagram for 17-058-Village Hill Co-Housing Prepared by Microsoft, Printed 7/23/2018 HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Subcat Reach Pond Link 17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 2HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 0.436 90 1/8 acre lots, 65% imp, HSG C (PDA-2B) 2.465 61 >75% Grass cover, Good, HSG B (PDA-2B, PDA-2C, PDA-2D) 15.450 74 >75% Grass cover, Good, HSG C (PDA-2A, PDA-2B, PDA-2C, PDA-2D) 0.171 98 Detention Basin (PDA-2D) 0.785 98 Detention Pond/Rain Garden (PDA-2C) 7.507 98 Paved parking & roofs (PDA-2C) 0.750 98 Paved parking & roofs (10% Extra) (PDA-2C) 3.546 98 Pavement & Roof (PDA-2A, PDA-2B, PDA-2D) 0.014 98 Pavement & Roof (SFH 10% Extra) (PDA-2D) 0.068 98 Pond/Rain Garden (PDA-2B) 2.754 70 Woods, Good, HSG C (PDA-2A, PDA-2D) Type III 24-hr 2-yr Rainfall=3.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 3HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=6.215 ac 5.25% Impervious Runoff Depth>0.91"Subcatchment PDA-2A: Northern & Eastern Tc=5.0 min CN=74 Runoff=6.23 cfs 0.470 af Runoff Area=3.509 ac 49.68% Impervious Runoff Depth>1.66"Subcatchment PDA-2B: TCB "Lot 13A" Tc=5.0 min CN=86 Runoff=6.85 cfs 0.486 af Runoff Area=16.045 ac 56.35% Impervious Runoff Depth>1.66"Subcatchment PDA-2C: Southeast Corner Tc=5.0 min CN=86 Runoff=31.30 cfs 2.221 af Runoff Area=8.177 ac 24.62% Impervious Runoff Depth>1.13"Subcatchment PDA-2D: Future Co-Housing Tc=5.0 min CN=78 Runoff=10.57 cfs 0.769 af Inflow=13.35 cfs 3.761 afReach DP-2: Control Point for proposed drainage Outflow=13.35 cfs 3.761 af Avg. Flow Depth=0.00' Max Vel=0.00 fps Inflow=0.00 cfs 0.000 afReach S1: Drainage Swale (Upper n=0.030 L=85.0' S=0.0141 '/' Capacity=62.64 cfs Outflow=0.00 cfs 0.000 af Avg. Flow Depth=0.38' Max Vel=2.61 fps Inflow=4.67 cfs 2.098 afReach S2: Drainage Swale (Middle n=0.030 L=235.0' S=0.0155 '/' Capacity=852.09 cfs Outflow=4.67 cfs 2.095 af Avg. Flow Depth=0.23' Max Vel=2.09 fps Inflow=4.67 cfs 2.095 afReach S3: Drainage Swale (Lower n=0.030 L=235.0' S=0.0155 '/' Capacity=71.42 cfs Outflow=4.67 cfs 2.091 af Peak Elev=188.27' Storage=19,023 cf Inflow=19.99 cfs 3.345 afPond P2: Basin #2 (Survey) Primary=9.21 cfs 3.291 af Secondary=0.00 cfs 0.000 af Outflow=9.21 cfs 3.291 af Peak Elev=201.57' Storage=48,053 cf Inflow=31.30 cfs 2.221 afPond P4: Basin #4 (Survey) Primary=4.67 cfs 2.098 af Secondary=0.00 cfs 0.000 af Tertiary=0.00 cfs 0.000 af Outflow=4.67 cfs 2.098 af Type III 24-hr 2-yr Rainfall=3.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 4HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment PDA-2A: Northern & Eastern Edges of Site Runoff = 6.23 cfs @ 12.09 hrs, Volume= 0.470 af, Depth> 0.91" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.00" Area (ac) CN Description * 0.326 98 Pavement & Roof 2.344 70 Woods, Good, HSG C 3.545 74 >75% Grass cover, Good, HSG C 6.215 74 Weighted Average 5.889 94.75% Pervious Area 0.326 5.25% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2B: TCB "Lot 13A" Project Runoff = 6.85 cfs @ 12.08 hrs, Volume= 0.486 af, Depth> 1.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.00" Area (ac) CN Description * 1.392 98 Pavement & Roof * 0.068 98 Pond/Rain Garden 0.028 61 >75% Grass cover, Good, HSG B 0.436 90 1/8 acre lots, 65% imp, HSG C 1.585 74 >75% Grass cover, Good, HSG C 3.509 86 Weighted Average 1.766 50.32% Pervious Area 1.743 49.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2C: Southeast Corner of Site Runoff = 31.30 cfs @ 12.08 hrs, Volume= 2.221 af, Depth> 1.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.00" Type III 24-hr 2-yr Rainfall=3.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 5HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Area (ac) CN Description 7.507 98 Paved parking & roofs * 0.785 98 Detention Pond/Rain Garden * 0.750 98 Paved parking & roofs (10% Extra) 1.298 61 >75% Grass cover, Good, HSG B 5.705 74 >75% Grass cover, Good, HSG C 16.045 86 Weighted Average 7.003 43.65% Pervious Area 9.042 56.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2D: Future Co-Housing Site Runoff = 10.57 cfs @ 12.08 hrs, Volume= 0.769 af, Depth> 1.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.00" Area (ac) CN Description * 1.828 98 Pavement & Roof * 0.171 98 Detention Basin * 0.014 98 Pavement & Roof (SFH 10% Extra) 1.139 61 >75% Grass cover, Good, HSG B 0.410 70 Woods, Good, HSG C 4.615 74 >75% Grass cover, Good, HSG C 8.177 78 Weighted Average 6.164 75.38% Pervious Area 2.013 24.62% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Reach DP-2: Control Point for proposed drainage Inflow Area = 33.946 ac, 38.66% Impervious, Inflow Depth > 1.33" for 2-yr event Inflow = 13.35 cfs @ 12.11 hrs, Volume= 3.761 af Outflow = 13.35 cfs @ 12.11 hrs, Volume= 3.761 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-yr Rainfall=3.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 6HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Reach S1: Drainage Swale (Upper Segment) Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 0.00 fps, Min. Travel Time= 0.0 min Avg. Velocity = 0.00 fps, Avg. Travel Time= 0.0 min Peak Storage= 0 cf @ 0.00 hrs Average Depth at Peak Storage= 0.00' Bank-Full Depth= 1.00' Flow Area= 15.0 sf, Capacity= 62.64 cfs 5.00' x 1.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 10.0 '/' Top Width= 25.00' Length= 85.0' Slope= 0.0141 '/' Inlet Invert= 202.20', Outlet Invert= 201.00' ‡ Summary for Reach S2: Drainage Swale (Middle Segment) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 1.57" for 2-yr event Inflow = 4.67 cfs @ 12.61 hrs, Volume= 2.098 af Outflow = 4.67 cfs @ 12.66 hrs, Volume= 2.095 af, Atten= 0%, Lag= 3.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 2.61 fps, Min. Travel Time= 1.5 min Avg. Velocity = 1.66 fps, Avg. Travel Time= 2.4 min Peak Storage= 420 cf @ 12.62 hrs Average Depth at Peak Storage= 0.38' Bank-Full Depth= 4.00' Flow Area= 84.0 sf, Capacity= 852.09 cfs 3.00' x 4.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 4.5 '/' Top Width= 39.00' Length= 235.0' Slope= 0.0155 '/' Inlet Invert= 198.15', Outlet Invert= 194.50' ‡ Type III 24-hr 2-yr Rainfall=3.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 7HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Reach S3: Drainage Swale (Lower Segment) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 1.57" for 2-yr event Inflow = 4.67 cfs @ 12.66 hrs, Volume= 2.095 af Outflow = 4.67 cfs @ 12.71 hrs, Volume= 2.091 af, Atten= 0%, Lag= 3.4 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 2.09 fps, Min. Travel Time= 1.9 min Avg. Velocity = 1.24 fps, Avg. Travel Time= 3.2 min Peak Storage= 524 cf @ 12.67 hrs Average Depth at Peak Storage= 0.23' Bank-Full Depth= 1.00' Flow Area= 15.0 sf, Capacity= 71.42 cfs 8.00' x 1.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 7.0 '/' Top Width= 22.00' Length= 235.0' Slope= 0.0155 '/' Inlet Invert= 198.15', Outlet Invert= 194.50' ‡ Summary for Pond P2: Basin #2 (Survey) Inflow Area = 27.731 ac, 46.15% Impervious, Inflow Depth > 1.45" for 2-yr event Inflow = 19.99 cfs @ 12.09 hrs, Volume= 3.345 af Outflow = 9.21 cfs @ 12.48 hrs, Volume= 3.291 af, Atten= 54%, Lag= 23.3 min Primary = 9.21 cfs @ 12.48 hrs, Volume= 3.291 af Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 186.29' Surf.Area= 7,457 sf Storage= 2,114 cf Peak Elev= 188.27' @ 12.48 hrs Surf.Area= 9,570 sf Storage= 19,023 cf (16,909 cf above start) Plug-Flow detention time= 41.5 min calculated for 3.243 af (97% of inflow) Center-of-Mass det. time= 21.8 min ( 917.4 - 895.6 ) Volume Invert Avail.Storage Storage Description #1 186.00' 63,502 cf Custom Stage Data (Prismatic) Listed below (Recalc) Type III 24-hr 2-yr Rainfall=3.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 8HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 186.00 7,120 0 0 187.00 8,281 7,701 7,701 188.00 9,296 8,789 16,489 189.00 10,317 9,807 26,296 190.00 11,482 10,900 37,195 191.00 12,823 12,153 49,348 192.00 15,486 14,155 63,502 Device Routing Invert Outlet Devices #1 Primary 186.29'36.0" Round Culvert L= 212.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet / Outlet Invert= 186.29' / 181.44' S= 0.0229 '/' Cc= 0.900 n= 0.013, Flow Area= 7.07 sf #2 Device 1 186.26'12.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 186.31'12.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 188.50'6.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #5 Secondary 191.60'Custom Weir/Orifice, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 Width (feet) 4.50 12.00 Primary OutFlow Max=9.21 cfs @ 12.48 hrs HW=188.27' (Free Discharge) 1=Culvert (Passes 9.21 cfs of 23.65 cfs potential flow) 2=Orifice/Grate (Orifice Controls 4.64 cfs @ 5.91 fps) 3=Orifice/Grate (Orifice Controls 4.56 cfs @ 5.81 fps) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=186.29' (Free Discharge) 5=Custom Weir/Orifice ( Controls 0.00 cfs) Summary for Pond P4: Basin #4 (Survey) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 1.66" for 2-yr event Inflow = 31.30 cfs @ 12.08 hrs, Volume= 2.221 af Outflow = 4.67 cfs @ 12.61 hrs, Volume= 2.098 af, Atten= 85%, Lag= 31.7 min Primary = 4.67 cfs @ 12.61 hrs, Volume= 2.098 af Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Tertiary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 199.44' Surf.Area= 15,569 sf Storage= 6,494 cf Peak Elev= 201.57' @ 12.61 hrs Surf.Area= 23,347 sf Storage= 48,053 cf (41,559 cf above start) Plug-Flow detention time= 171.6 min calculated for 1.945 af (88% of inflow) Center-of-Mass det. time= 98.6 min ( 922.6 - 824.0 ) Type III 24-hr 2-yr Rainfall=3.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 9HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 199.00' 115,492 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 199.00 13,951 0 0 200.00 17,629 15,790 15,790 201.00 21,260 19,445 35,235 202.00 24,892 23,076 58,311 203.00 28,524 26,708 85,019 204.00 32,422 30,473 115,492 Device Routing Invert Outlet Devices #1 Primary 199.44'12.0" Round Culvert L= 93.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet / Outlet Invert= 199.44' / 198.15' S= 0.0139 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #2 Secondary 202.20'8.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Tertiary 203.70'Custom Weir/Orifice, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 Width (feet) 4.00 12.00 Primary OutFlow Max=4.67 cfs @ 12.61 hrs HW=201.57' (Free Discharge) 1=Culvert (Barrel Controls 4.67 cfs @ 5.94 fps) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=199.44' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Tertiary OutFlow Max=0.00 cfs @ 0.00 hrs HW=199.44' (Free Discharge) 3=Custom Weir/Orifice ( Controls 0.00 cfs) Type III 24-hr 10-yr Rainfall=4.50"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 10HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=6.215 ac 5.25% Impervious Runoff Depth>1.97"Subcatchment PDA-2A: Northern & Eastern Tc=5.0 min CN=74 Runoff=14.26 cfs 1.021 af Runoff Area=3.509 ac 49.68% Impervious Runoff Depth>3.00"Subcatchment PDA-2B: TCB "Lot 13A" Tc=5.0 min CN=86 Runoff=12.31 cfs 0.878 af Runoff Area=16.045 ac 56.35% Impervious Runoff Depth>3.00"Subcatchment PDA-2C: Southeast Corner Tc=5.0 min CN=86 Runoff=56.29 cfs 4.013 af Runoff Area=8.177 ac 24.62% Impervious Runoff Depth>2.29"Subcatchment PDA-2D: Future Co-Housing Tc=5.0 min CN=78 Runoff=21.99 cfs 1.561 af Inflow=32.71 cfs 7.233 afReach DP-2: Control Point for proposed drainage Outflow=32.71 cfs 7.233 af Avg. Flow Depth=0.40' Max Vel=2.50 fps Inflow=8.99 cfs 0.490 afReach S1: Drainage Swale (Upper n=0.030 L=85.0' S=0.0141 '/' Capacity=62.64 cfs Outflow=8.96 cfs 0.490 af Avg. Flow Depth=0.68' Max Vel=3.58 fps Inflow=14.64 cfs 3.852 afReach S2: Drainage Swale (Middle n=0.030 L=235.0' S=0.0155 '/' Capacity=852.09 cfs Outflow=14.57 cfs 3.848 af Avg. Flow Depth=0.44' Max Vel=3.01 fps Inflow=14.57 cfs 3.848 afReach S3: Drainage Swale (Lower n=0.030 L=235.0' S=0.0155 '/' Capacity=71.42 cfs Outflow=14.49 cfs 3.843 af Peak Elev=189.28' Storage=29,261 cf Inflow=38.55 cfs 6.282 afPond P2: Basin #2 (Survey) Primary=23.96 cfs 6.213 af Secondary=0.00 cfs 0.000 af Outflow=23.96 cfs 6.213 af Peak Elev=202.75' Storage=78,038 cf Inflow=56.29 cfs 4.013 afPond P4: Basin #4 (Survey) Primary=5.69 cfs 3.362 af Secondary=8.99 cfs 0.490 af Tertiary=0.00 cfs 0.000 af Outflow=14.68 cfs 3.852 af Type III 24-hr 10-yr Rainfall=4.50"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 11HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment PDA-2A: Northern & Eastern Edges of Site Runoff = 14.26 cfs @ 12.08 hrs, Volume= 1.021 af, Depth> 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.50" Area (ac) CN Description * 0.326 98 Pavement & Roof 2.344 70 Woods, Good, HSG C 3.545 74 >75% Grass cover, Good, HSG C 6.215 74 Weighted Average 5.889 94.75% Pervious Area 0.326 5.25% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2B: TCB "Lot 13A" Project Runoff = 12.31 cfs @ 12.07 hrs, Volume= 0.878 af, Depth> 3.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.50" Area (ac) CN Description * 1.392 98 Pavement & Roof * 0.068 98 Pond/Rain Garden 0.028 61 >75% Grass cover, Good, HSG B 0.436 90 1/8 acre lots, 65% imp, HSG C 1.585 74 >75% Grass cover, Good, HSG C 3.509 86 Weighted Average 1.766 50.32% Pervious Area 1.743 49.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2C: Southeast Corner of Site Runoff = 56.29 cfs @ 12.07 hrs, Volume= 4.013 af, Depth> 3.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.50" Type III 24-hr 10-yr Rainfall=4.50"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 12HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Area (ac) CN Description 7.507 98 Paved parking & roofs * 0.785 98 Detention Pond/Rain Garden * 0.750 98 Paved parking & roofs (10% Extra) 1.298 61 >75% Grass cover, Good, HSG B 5.705 74 >75% Grass cover, Good, HSG C 16.045 86 Weighted Average 7.003 43.65% Pervious Area 9.042 56.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2D: Future Co-Housing Site Runoff = 21.99 cfs @ 12.08 hrs, Volume= 1.561 af, Depth> 2.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.50" Area (ac) CN Description * 1.828 98 Pavement & Roof * 0.171 98 Detention Basin * 0.014 98 Pavement & Roof (SFH 10% Extra) 1.139 61 >75% Grass cover, Good, HSG B 0.410 70 Woods, Good, HSG C 4.615 74 >75% Grass cover, Good, HSG C 8.177 78 Weighted Average 6.164 75.38% Pervious Area 2.013 24.62% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Reach DP-2: Control Point for proposed drainage Inflow Area = 33.946 ac, 38.66% Impervious, Inflow Depth > 2.56" for 10-yr event Inflow = 32.71 cfs @ 12.16 hrs, Volume= 7.233 af Outflow = 32.71 cfs @ 12.16 hrs, Volume= 7.233 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-yr Rainfall=4.50"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 13HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Reach S1: Drainage Swale (Upper Segment) Inflow = 8.99 cfs @ 12.45 hrs, Volume= 0.490 af Outflow = 8.96 cfs @ 12.46 hrs, Volume= 0.490 af, Atten= 0%, Lag= 1.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 2.50 fps, Min. Travel Time= 0.6 min Avg. Velocity = 1.32 fps, Avg. Travel Time= 1.1 min Peak Storage= 306 cf @ 12.46 hrs Average Depth at Peak Storage= 0.40' Bank-Full Depth= 1.00' Flow Area= 15.0 sf, Capacity= 62.64 cfs 5.00' x 1.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 10.0 '/' Top Width= 25.00' Length= 85.0' Slope= 0.0141 '/' Inlet Invert= 202.20', Outlet Invert= 201.00' ‡ Summary for Reach S2: Drainage Swale (Middle Segment) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 2.88" for 10-yr event Inflow = 14.64 cfs @ 12.46 hrs, Volume= 3.852 af Outflow = 14.57 cfs @ 12.50 hrs, Volume= 3.848 af, Atten= 1%, Lag= 2.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 3.58 fps, Min. Travel Time= 1.1 min Avg. Velocity = 1.91 fps, Avg. Travel Time= 2.1 min Peak Storage= 959 cf @ 12.48 hrs Average Depth at Peak Storage= 0.68' Bank-Full Depth= 4.00' Flow Area= 84.0 sf, Capacity= 852.09 cfs 3.00' x 4.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 4.5 '/' Top Width= 39.00' Length= 235.0' Slope= 0.0155 '/' Inlet Invert= 198.15', Outlet Invert= 194.50' ‡ Type III 24-hr 10-yr Rainfall=4.50"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 14HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Reach S3: Drainage Swale (Lower Segment) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 2.88" for 10-yr event Inflow = 14.57 cfs @ 12.50 hrs, Volume= 3.848 af Outflow = 14.49 cfs @ 12.54 hrs, Volume= 3.843 af, Atten= 1%, Lag= 2.3 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 3.01 fps, Min. Travel Time= 1.3 min Avg. Velocity = 1.46 fps, Avg. Travel Time= 2.7 min Peak Storage= 1,135 cf @ 12.51 hrs Average Depth at Peak Storage= 0.44' Bank-Full Depth= 1.00' Flow Area= 15.0 sf, Capacity= 71.42 cfs 8.00' x 1.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 7.0 '/' Top Width= 22.00' Length= 235.0' Slope= 0.0155 '/' Inlet Invert= 198.15', Outlet Invert= 194.50' ‡ Summary for Pond P2: Basin #2 (Survey) Inflow Area = 27.731 ac, 46.15% Impervious, Inflow Depth > 2.72" for 10-yr event Inflow = 38.55 cfs @ 12.08 hrs, Volume= 6.282 af Outflow = 23.96 cfs @ 12.22 hrs, Volume= 6.213 af, Atten= 38%, Lag= 8.6 min Primary = 23.96 cfs @ 12.22 hrs, Volume= 6.213 af Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 186.29' Surf.Area= 7,457 sf Storage= 2,114 cf Peak Elev= 189.28' @ 12.20 hrs Surf.Area= 10,647 sf Storage= 29,261 cf (27,148 cf above start) Plug-Flow detention time= 34.0 min calculated for 6.164 af (98% of inflow) Center-of-Mass det. time= 21.0 min ( 902.7 - 881.6 ) Volume Invert Avail.Storage Storage Description #1 186.00' 63,502 cf Custom Stage Data (Prismatic) Listed below (Recalc) Type III 24-hr 10-yr Rainfall=4.50"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 15HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 186.00 7,120 0 0 187.00 8,281 7,701 7,701 188.00 9,296 8,789 16,489 189.00 10,317 9,807 26,296 190.00 11,482 10,900 37,195 191.00 12,823 12,153 49,348 192.00 15,486 14,155 63,502 Device Routing Invert Outlet Devices #1 Primary 186.29'36.0" Round Culvert L= 212.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet / Outlet Invert= 186.29' / 181.44' S= 0.0229 '/' Cc= 0.900 n= 0.013, Flow Area= 7.07 sf #2 Device 1 186.26'12.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 186.31'12.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 188.50'6.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #5 Secondary 191.60'Custom Weir/Orifice, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 Width (feet) 4.50 12.00 Primary OutFlow Max=23.71 cfs @ 12.22 hrs HW=189.28' (Free Discharge) 1=Culvert (Passes 23.71 cfs of 41.61 cfs potential flow) 2=Orifice/Grate (Orifice Controls 6.00 cfs @ 7.65 fps) 3=Orifice/Grate (Orifice Controls 5.94 cfs @ 7.57 fps) 4=Broad-Crested Rectangular Weir (Weir Controls 11.76 cfs @ 2.51 fps) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=186.29' (Free Discharge) 5=Custom Weir/Orifice ( Controls 0.00 cfs) Summary for Pond P4: Basin #4 (Survey) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 3.00" for 10-yr event Inflow = 56.29 cfs @ 12.07 hrs, Volume= 4.013 af Outflow = 14.68 cfs @ 12.45 hrs, Volume= 3.852 af, Atten= 74%, Lag= 22.4 min Primary = 5.69 cfs @ 12.45 hrs, Volume= 3.362 af Secondary = 8.99 cfs @ 12.45 hrs, Volume= 0.490 af Tertiary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 199.44' Surf.Area= 15,569 sf Storage= 6,494 cf Peak Elev= 202.75' @ 12.45 hrs Surf.Area= 27,621 sf Storage= 78,038 cf (71,543 cf above start) Plug-Flow detention time= 158.5 min calculated for 3.695 af (92% of inflow) Center-of-Mass det. time= 107.3 min ( 914.4 - 807.2 ) Type III 24-hr 10-yr Rainfall=4.50"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 16HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 199.00' 115,492 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 199.00 13,951 0 0 200.00 17,629 15,790 15,790 201.00 21,260 19,445 35,235 202.00 24,892 23,076 58,311 203.00 28,524 26,708 85,019 204.00 32,422 30,473 115,492 Device Routing Invert Outlet Devices #1 Primary 199.44'12.0" Round Culvert L= 93.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet / Outlet Invert= 199.44' / 198.15' S= 0.0139 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #2 Secondary 202.20'8.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Tertiary 203.70'Custom Weir/Orifice, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 Width (feet) 4.00 12.00 Primary OutFlow Max=5.69 cfs @ 12.45 hrs HW=202.75' (Free Discharge) 1=Culvert (Barrel Controls 5.69 cfs @ 7.24 fps) Secondary OutFlow Max=8.97 cfs @ 12.45 hrs HW=202.75' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 8.97 cfs @ 2.04 fps) Tertiary OutFlow Max=0.00 cfs @ 0.00 hrs HW=199.44' (Free Discharge) 3=Custom Weir/Orifice ( Controls 0.00 cfs) Type III 24-hr 25-yr Rainfall=5.25"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 17HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=6.215 ac 5.25% Impervious Runoff Depth>2.56"Subcatchment PDA-2A: Northern & Eastern Tc=5.0 min CN=74 Runoff=18.67 cfs 1.328 af Runoff Area=3.509 ac 49.68% Impervious Runoff Depth>3.70"Subcatchment PDA-2B: TCB "Lot 13A" Tc=5.0 min CN=86 Runoff=15.06 cfs 1.082 af Runoff Area=16.045 ac 56.35% Impervious Runoff Depth>3.70"Subcatchment PDA-2C: Southeast Corner Tc=5.0 min CN=86 Runoff=68.87 cfs 4.946 af Runoff Area=8.177 ac 24.62% Impervious Runoff Depth>2.92"Subcatchment PDA-2D: Future Co-Housing Tc=5.0 min CN=78 Runoff=28.06 cfs 1.992 af Inflow=48.26 cfs 9.083 afReach DP-2: Control Point for proposed drainage Outflow=48.26 cfs 9.083 af Avg. Flow Depth=0.57' Max Vel=3.03 fps Inflow=18.28 cfs 1.028 afReach S1: Drainage Swale (Upper n=0.030 L=85.0' S=0.0141 '/' Capacity=62.64 cfs Outflow=18.23 cfs 1.028 af Avg. Flow Depth=0.86' Max Vel=4.09 fps Inflow=24.16 cfs 4.767 afReach S2: Drainage Swale (Middle n=0.030 L=235.0' S=0.0155 '/' Capacity=852.09 cfs Outflow=24.05 cfs 4.763 af Avg. Flow Depth=0.57' Max Vel=3.50 fps Inflow=24.05 cfs 4.763 afReach S3: Drainage Swale (Lower n=0.030 L=235.0' S=0.0155 '/' Capacity=71.42 cfs Outflow=23.96 cfs 4.758 af Peak Elev=189.71' Storage=33,959 cf Inflow=47.80 cfs 7.831 afPond P2: Basin #2 (Survey) Primary=37.74 cfs 7.755 af Secondary=0.00 cfs 0.000 af Outflow=37.74 cfs 7.755 af Peak Elev=203.06' Storage=86,620 cf Inflow=68.87 cfs 4.946 afPond P4: Basin #4 (Survey) Primary=5.92 cfs 3.740 af Secondary=18.28 cfs 1.028 af Tertiary=0.00 cfs 0.000 af Outflow=24.21 cfs 4.767 af Type III 24-hr 25-yr Rainfall=5.25"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 18HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment PDA-2A: Northern & Eastern Edges of Site Runoff = 18.67 cfs @ 12.08 hrs, Volume= 1.328 af, Depth> 2.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.25" Area (ac) CN Description * 0.326 98 Pavement & Roof 2.344 70 Woods, Good, HSG C 3.545 74 >75% Grass cover, Good, HSG C 6.215 74 Weighted Average 5.889 94.75% Pervious Area 0.326 5.25% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2B: TCB "Lot 13A" Project Runoff = 15.06 cfs @ 12.07 hrs, Volume= 1.082 af, Depth> 3.70" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.25" Area (ac) CN Description * 1.392 98 Pavement & Roof * 0.068 98 Pond/Rain Garden 0.028 61 >75% Grass cover, Good, HSG B 0.436 90 1/8 acre lots, 65% imp, HSG C 1.585 74 >75% Grass cover, Good, HSG C 3.509 86 Weighted Average 1.766 50.32% Pervious Area 1.743 49.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2C: Southeast Corner of Site Runoff = 68.87 cfs @ 12.07 hrs, Volume= 4.946 af, Depth> 3.70" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.25" Type III 24-hr 25-yr Rainfall=5.25"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 19HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Area (ac) CN Description 7.507 98 Paved parking & roofs * 0.785 98 Detention Pond/Rain Garden * 0.750 98 Paved parking & roofs (10% Extra) 1.298 61 >75% Grass cover, Good, HSG B 5.705 74 >75% Grass cover, Good, HSG C 16.045 86 Weighted Average 7.003 43.65% Pervious Area 9.042 56.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2D: Future Co-Housing Site Runoff = 28.06 cfs @ 12.08 hrs, Volume= 1.992 af, Depth> 2.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.25" Area (ac) CN Description * 1.828 98 Pavement & Roof * 0.171 98 Detention Basin * 0.014 98 Pavement & Roof (SFH 10% Extra) 1.139 61 >75% Grass cover, Good, HSG B 0.410 70 Woods, Good, HSG C 4.615 74 >75% Grass cover, Good, HSG C 8.177 78 Weighted Average 6.164 75.38% Pervious Area 2.013 24.62% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Reach DP-2: Control Point for proposed drainage Inflow Area = 33.946 ac, 38.66% Impervious, Inflow Depth > 3.21" for 25-yr event Inflow = 48.26 cfs @ 12.15 hrs, Volume= 9.083 af Outflow = 48.26 cfs @ 12.15 hrs, Volume= 9.083 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=5.25"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 20HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Reach S1: Drainage Swale (Upper Segment) Inflow = 18.28 cfs @ 12.35 hrs, Volume= 1.028 af Outflow = 18.23 cfs @ 12.36 hrs, Volume= 1.028 af, Atten= 0%, Lag= 0.9 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 3.03 fps, Min. Travel Time= 0.5 min Avg. Velocity = 1.54 fps, Avg. Travel Time= 0.9 min Peak Storage= 513 cf @ 12.35 hrs Average Depth at Peak Storage= 0.57' Bank-Full Depth= 1.00' Flow Area= 15.0 sf, Capacity= 62.64 cfs 5.00' x 1.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 10.0 '/' Top Width= 25.00' Length= 85.0' Slope= 0.0141 '/' Inlet Invert= 202.20', Outlet Invert= 201.00' ‡ Summary for Reach S2: Drainage Swale (Middle Segment) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 3.57" for 25-yr event Inflow = 24.16 cfs @ 12.36 hrs, Volume= 4.767 af Outflow = 24.05 cfs @ 12.39 hrs, Volume= 4.763 af, Atten= 0%, Lag= 1.8 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 4.09 fps, Min. Travel Time= 1.0 min Avg. Velocity = 1.98 fps, Avg. Travel Time= 2.0 min Peak Storage= 1,386 cf @ 12.37 hrs Average Depth at Peak Storage= 0.86' Bank-Full Depth= 4.00' Flow Area= 84.0 sf, Capacity= 852.09 cfs 3.00' x 4.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 4.5 '/' Top Width= 39.00' Length= 235.0' Slope= 0.0155 '/' Inlet Invert= 198.15', Outlet Invert= 194.50' ‡ Type III 24-hr 25-yr Rainfall=5.25"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 21HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Reach S3: Drainage Swale (Lower Segment) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 3.56" for 25-yr event Inflow = 24.05 cfs @ 12.39 hrs, Volume= 4.763 af Outflow = 23.96 cfs @ 12.42 hrs, Volume= 4.758 af, Atten= 0%, Lag= 2.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 3.50 fps, Min. Travel Time= 1.1 min Avg. Velocity = 1.53 fps, Avg. Travel Time= 2.6 min Peak Storage= 1,614 cf @ 12.41 hrs Average Depth at Peak Storage= 0.57' Bank-Full Depth= 1.00' Flow Area= 15.0 sf, Capacity= 71.42 cfs 8.00' x 1.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 7.0 '/' Top Width= 22.00' Length= 235.0' Slope= 0.0155 '/' Inlet Invert= 198.15', Outlet Invert= 194.50' ‡ Summary for Pond P2: Basin #2 (Survey) Inflow Area = 27.731 ac, 46.15% Impervious, Inflow Depth > 3.39" for 25-yr event Inflow = 47.80 cfs @ 12.08 hrs, Volume= 7.831 af Outflow = 37.74 cfs @ 12.39 hrs, Volume= 7.755 af, Atten= 21%, Lag= 18.6 min Primary = 37.74 cfs @ 12.39 hrs, Volume= 7.755 af Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 186.29' Surf.Area= 7,457 sf Storage= 2,114 cf Peak Elev= 189.71' @ 12.39 hrs Surf.Area= 11,149 sf Storage= 33,959 cf (31,845 cf above start) Plug-Flow detention time= 30.7 min calculated for 7.707 af (98% of inflow) Center-of-Mass det. time= 19.4 min ( 888.6 - 869.2 ) Volume Invert Avail.Storage Storage Description #1 186.00' 63,502 cf Custom Stage Data (Prismatic) Listed below (Recalc) Type III 24-hr 25-yr Rainfall=5.25"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 22HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 186.00 7,120 0 0 187.00 8,281 7,701 7,701 188.00 9,296 8,789 16,489 189.00 10,317 9,807 26,296 190.00 11,482 10,900 37,195 191.00 12,823 12,153 49,348 192.00 15,486 14,155 63,502 Device Routing Invert Outlet Devices #1 Primary 186.29'36.0" Round Culvert L= 212.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet / Outlet Invert= 186.29' / 181.44' S= 0.0229 '/' Cc= 0.900 n= 0.013, Flow Area= 7.07 sf #2 Device 1 186.26'12.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 186.31'12.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 188.50'6.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #5 Secondary 191.60'Custom Weir/Orifice, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 Width (feet) 4.50 12.00 Primary OutFlow Max=37.66 cfs @ 12.39 hrs HW=189.71' (Free Discharge) 1=Culvert (Passes 37.66 cfs of 47.19 cfs potential flow) 2=Orifice/Grate (Orifice Controls 6.50 cfs @ 8.27 fps) 3=Orifice/Grate (Orifice Controls 6.44 cfs @ 8.20 fps) 4=Broad-Crested Rectangular Weir (Weir Controls 24.72 cfs @ 3.40 fps) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=186.29' (Free Discharge) 5=Custom Weir/Orifice ( Controls 0.00 cfs) Summary for Pond P4: Basin #4 (Survey) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 3.70" for 25-yr event Inflow = 68.87 cfs @ 12.07 hrs, Volume= 4.946 af Outflow = 24.21 cfs @ 12.35 hrs, Volume= 4.767 af, Atten= 65%, Lag= 16.5 min Primary = 5.92 cfs @ 12.35 hrs, Volume= 3.740 af Secondary = 18.28 cfs @ 12.35 hrs, Volume= 1.028 af Tertiary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 199.44' Surf.Area= 15,569 sf Storage= 6,494 cf Peak Elev= 203.06' @ 12.35 hrs Surf.Area= 28,742 sf Storage= 86,620 cf (80,125 cf above start) Plug-Flow detention time= 143.1 min calculated for 4.618 af (93% of inflow) Center-of-Mass det. time= 97.9 min ( 899.2 - 801.3 ) Type III 24-hr 25-yr Rainfall=5.25"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 23HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 199.00' 115,492 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 199.00 13,951 0 0 200.00 17,629 15,790 15,790 201.00 21,260 19,445 35,235 202.00 24,892 23,076 58,311 203.00 28,524 26,708 85,019 204.00 32,422 30,473 115,492 Device Routing Invert Outlet Devices #1 Primary 199.44'12.0" Round Culvert L= 93.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet / Outlet Invert= 199.44' / 198.15' S= 0.0139 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #2 Secondary 202.20'8.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Tertiary 203.70'Custom Weir/Orifice, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 Width (feet) 4.00 12.00 Primary OutFlow Max=5.92 cfs @ 12.35 hrs HW=203.06' (Free Discharge) 1=Culvert (Barrel Controls 5.92 cfs @ 7.54 fps) Secondary OutFlow Max=18.27 cfs @ 12.35 hrs HW=203.06' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 18.27 cfs @ 2.67 fps) Tertiary OutFlow Max=0.00 cfs @ 0.00 hrs HW=199.44' (Free Discharge) 3=Custom Weir/Orifice ( Controls 0.00 cfs) Type III 24-hr 100-yr Rainfall=7.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 24HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=6.215 ac 5.25% Impervious Runoff Depth>4.04"Subcatchment PDA-2A: Northern & Eastern Tc=5.0 min CN=74 Runoff=29.45 cfs 2.092 af Runoff Area=3.509 ac 49.68% Impervious Runoff Depth>5.36"Subcatchment PDA-2B: TCB "Lot 13A" Tc=5.0 min CN=86 Runoff=21.48 cfs 1.568 af Runoff Area=16.045 ac 56.35% Impervious Runoff Depth>5.36"Subcatchment PDA-2C: Southeast Corner Tc=5.0 min CN=86 Runoff=98.22 cfs 7.170 af Runoff Area=8.177 ac 24.62% Impervious Runoff Depth>4.47"Subcatchment PDA-2D: Future Co-Housing Tc=5.0 min CN=78 Runoff=42.65 cfs 3.047 af Inflow=82.87 cfs 13.559 afReach DP-2: Control Point for proposed drainage Outflow=82.87 cfs 13.559 af Avg. Flow Depth=0.87' Max Vel=3.86 fps Inflow=46.07 cfs 2.425 afReach S1: Drainage Swale (Upper n=0.030 L=85.0' S=0.0141 '/' Capacity=62.64 cfs Outflow=45.94 cfs 2.425 af Avg. Flow Depth=1.23' Max Vel=4.99 fps Inflow=52.31 cfs 6.954 afReach S2: Drainage Swale (Middle n=0.030 L=235.0' S=0.0155 '/' Capacity=852.09 cfs Outflow=51.66 cfs 6.949 af Avg. Flow Depth=0.85' Max Vel=4.36 fps Inflow=51.66 cfs 6.949 afReach S3: Drainage Swale (Lower n=0.030 L=235.0' S=0.0155 '/' Capacity=71.42 cfs Outflow=51.11 cfs 6.942 af Peak Elev=191.53' Storage=56,483 cf Inflow=81.16 cfs 11.558 afPond P2: Basin #2 (Survey) Primary=65.80 cfs 11.467 af Secondary=0.00 cfs 0.000 af Outflow=65.80 cfs 11.467 af Peak Elev=203.67' Storage=105,025 cf Inflow=98.22 cfs 7.170 afPond P4: Basin #4 (Survey) Primary=6.37 cfs 4.528 af Secondary=46.07 cfs 2.425 af Tertiary=0.00 cfs 0.000 af Outflow=52.44 cfs 6.954 af Type III 24-hr 100-yr Rainfall=7.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 25HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment PDA-2A: Northern & Eastern Edges of Site Runoff = 29.45 cfs @ 12.08 hrs, Volume= 2.092 af, Depth> 4.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.00" Area (ac) CN Description * 0.326 98 Pavement & Roof 2.344 70 Woods, Good, HSG C 3.545 74 >75% Grass cover, Good, HSG C 6.215 74 Weighted Average 5.889 94.75% Pervious Area 0.326 5.25% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2B: TCB "Lot 13A" Project Runoff = 21.48 cfs @ 12.07 hrs, Volume= 1.568 af, Depth> 5.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.00" Area (ac) CN Description * 1.392 98 Pavement & Roof * 0.068 98 Pond/Rain Garden 0.028 61 >75% Grass cover, Good, HSG B 0.436 90 1/8 acre lots, 65% imp, HSG C 1.585 74 >75% Grass cover, Good, HSG C 3.509 86 Weighted Average 1.766 50.32% Pervious Area 1.743 49.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2C: Southeast Corner of Site Runoff = 98.22 cfs @ 12.07 hrs, Volume= 7.170 af, Depth> 5.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.00" Type III 24-hr 100-yr Rainfall=7.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 26HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Area (ac) CN Description 7.507 98 Paved parking & roofs * 0.785 98 Detention Pond/Rain Garden * 0.750 98 Paved parking & roofs (10% Extra) 1.298 61 >75% Grass cover, Good, HSG B 5.705 74 >75% Grass cover, Good, HSG C 16.045 86 Weighted Average 7.003 43.65% Pervious Area 9.042 56.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment PDA-2D: Future Co-Housing Site Runoff = 42.65 cfs @ 12.08 hrs, Volume= 3.047 af, Depth> 4.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.00" Area (ac) CN Description * 1.828 98 Pavement & Roof * 0.171 98 Detention Basin * 0.014 98 Pavement & Roof (SFH 10% Extra) 1.139 61 >75% Grass cover, Good, HSG B 0.410 70 Woods, Good, HSG C 4.615 74 >75% Grass cover, Good, HSG C 8.177 78 Weighted Average 6.164 75.38% Pervious Area 2.013 24.62% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Reach DP-2: Control Point for proposed drainage Inflow Area = 33.946 ac, 38.66% Impervious, Inflow Depth > 4.79" for 100-yr event Inflow = 82.87 cfs @ 12.11 hrs, Volume= 13.559 af Outflow = 82.87 cfs @ 12.11 hrs, Volume= 13.559 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-yr Rainfall=7.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 27HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Reach S1: Drainage Swale (Upper Segment) Inflow = 46.07 cfs @ 12.21 hrs, Volume= 2.425 af Outflow = 45.94 cfs @ 12.22 hrs, Volume= 2.425 af, Atten= 0%, Lag= 0.7 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 3.86 fps, Min. Travel Time= 0.4 min Avg. Velocity = 1.74 fps, Avg. Travel Time= 0.8 min Peak Storage= 1,016 cf @ 12.21 hrs Average Depth at Peak Storage= 0.87' Bank-Full Depth= 1.00' Flow Area= 15.0 sf, Capacity= 62.64 cfs 5.00' x 1.00' deep channel, n= 0.030 Stream, clean & straight Side Slope Z-value= 10.0 '/' Top Width= 25.00' Length= 85.0' Slope= 0.0141 '/' Inlet Invert= 202.20', Outlet Invert= 201.00' ‡ Summary for Reach S2: Drainage Swale (Middle Segment) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 5.20" for 100-yr event Inflow = 52.31 cfs @ 12.22 hrs, Volume= 6.954 af Outflow = 51.66 cfs @ 12.25 hrs, Volume= 6.949 af, Atten= 1%, Lag= 1.8 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 4.99 fps, Min. Travel Time= 0.8 min Avg. Velocity = 2.13 fps, Avg. Travel Time= 1.8 min Peak Storage= 2,461 cf @ 12.22 hrs Average Depth at Peak Storage= 1.23' Bank-Full Depth= 4.00' Flow Area= 84.0 sf, Capacity= 852.09 cfs 3.00' x 4.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 4.5 '/' Top Width= 39.00' Length= 235.0' Slope= 0.0155 '/' Inlet Invert= 198.15', Outlet Invert= 194.50' ‡ Type III 24-hr 100-yr Rainfall=7.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 28HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Summary for Reach S3: Drainage Swale (Lower Segment) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 5.20" for 100-yr event Inflow = 51.66 cfs @ 12.25 hrs, Volume= 6.949 af Outflow = 51.11 cfs @ 12.28 hrs, Volume= 6.942 af, Atten= 1%, Lag= 1.6 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 4.36 fps, Min. Travel Time= 0.9 min Avg. Velocity = 1.66 fps, Avg. Travel Time= 2.4 min Peak Storage= 2,793 cf @ 12.26 hrs Average Depth at Peak Storage= 0.85' Bank-Full Depth= 1.00' Flow Area= 15.0 sf, Capacity= 71.42 cfs 8.00' x 1.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 7.0 '/' Top Width= 22.00' Length= 235.0' Slope= 0.0155 '/' Inlet Invert= 198.15', Outlet Invert= 194.50' ‡ Summary for Pond P2: Basin #2 (Survey) Inflow Area = 27.731 ac, 46.15% Impervious, Inflow Depth > 5.00" for 100-yr event Inflow = 81.16 cfs @ 12.10 hrs, Volume= 11.558 af Outflow = 65.80 cfs @ 12.39 hrs, Volume= 11.467 af, Atten= 19%, Lag= 17.7 min Primary = 65.80 cfs @ 12.39 hrs, Volume= 11.467 af Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 186.29' Surf.Area= 7,457 sf Storage= 2,114 cf Peak Elev= 191.53' @ 12.39 hrs Surf.Area= 14,228 sf Storage= 56,483 cf (54,370 cf above start) Plug-Flow detention time= 26.5 min calculated for 11.395 af (99% of inflow) Center-of-Mass det. time= 17.6 min ( 866.3 - 848.7 ) Volume Invert Avail.Storage Storage Description #1 186.00' 63,502 cf Custom Stage Data (Prismatic) Listed below (Recalc) Type III 24-hr 100-yr Rainfall=7.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 29HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 186.00 7,120 0 0 187.00 8,281 7,701 7,701 188.00 9,296 8,789 16,489 189.00 10,317 9,807 26,296 190.00 11,482 10,900 37,195 191.00 12,823 12,153 49,348 192.00 15,486 14,155 63,502 Device Routing Invert Outlet Devices #1 Primary 186.29'36.0" Round Culvert L= 212.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet / Outlet Invert= 186.29' / 181.44' S= 0.0229 '/' Cc= 0.900 n= 0.013, Flow Area= 7.07 sf #2 Device 1 186.26'12.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 186.31'12.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 188.50'6.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #5 Secondary 191.60'Custom Weir/Orifice, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 Width (feet) 4.50 12.00 Primary OutFlow Max=65.76 cfs @ 12.39 hrs HW=191.52' (Free Discharge) 1=Culvert (Inlet Controls 65.76 cfs @ 9.30 fps) 2=Orifice/Grate (Passes < 8.25 cfs potential flow) 3=Orifice/Grate (Passes < 8.21 cfs potential flow) 4=Broad-Crested Rectangular Weir (Passes < 104.73 cfs potential flow) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=186.29' (Free Discharge) 5=Custom Weir/Orifice ( Controls 0.00 cfs) Summary for Pond P4: Basin #4 (Survey) Inflow Area = 16.045 ac, 56.35% Impervious, Inflow Depth > 5.36" for 100-yr event Inflow = 98.22 cfs @ 12.07 hrs, Volume= 7.170 af Outflow = 52.44 cfs @ 12.21 hrs, Volume= 6.954 af, Atten= 47%, Lag= 8.1 min Primary = 6.37 cfs @ 12.21 hrs, Volume= 4.528 af Secondary = 46.07 cfs @ 12.21 hrs, Volume= 2.425 af Tertiary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 199.44' Surf.Area= 15,569 sf Storage= 6,494 cf Peak Elev= 203.67' @ 12.21 hrs Surf.Area= 31,138 sf Storage= 105,025 cf (98,531 cf above start) Plug-Flow detention time= 119.5 min calculated for 6.804 af (95% of inflow) Center-of-Mass det. time= 83.2 min ( 874.1 - 791.0 ) Type III 24-hr 100-yr Rainfall=7.00"17-058-Village Hill Co-Housing Printed 7/23/2018Prepared by Microsoft Page 30HydroCAD® 10.00-12 s/n 00752 © 2014 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 199.00' 115,492 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 199.00 13,951 0 0 200.00 17,629 15,790 15,790 201.00 21,260 19,445 35,235 202.00 24,892 23,076 58,311 203.00 28,524 26,708 85,019 204.00 32,422 30,473 115,492 Device Routing Invert Outlet Devices #1 Primary 199.44'12.0" Round Culvert L= 93.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet / Outlet Invert= 199.44' / 198.15' S= 0.0139 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #2 Secondary 202.20'8.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Tertiary 203.70'Custom Weir/Orifice, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 Width (feet) 4.00 12.00 Primary OutFlow Max=6.37 cfs @ 12.21 hrs HW=203.67' (Free Discharge) 1=Culvert (Barrel Controls 6.37 cfs @ 8.11 fps) Secondary OutFlow Max=45.77 cfs @ 12.21 hrs HW=203.67' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 45.77 cfs @ 3.91 fps) Tertiary OutFlow Max=0.00 cfs @ 0.00 hrs HW=199.44' (Free Discharge) 3=Custom Weir/Orifice ( Controls 0.00 cfs) Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Appendix D – Water Quality Calculations Project:Village Hill Co-Housing Location:Northampton, MA Prepared For:Berkshire Design Group Purpose: Reference: Procedure: where: A = impervious surface drainage area (in square miles) WQV = water quality volume in watershed inches (1/2" in this case) Structure Name Impv. (acres) A (miles2) tc (min) tc (hr) WQV (in)qu (csm/in.)Q (cfs) SWTS 2.60 0.0040625 15.0 0.250 0.50 606.00 1.23 qu = the unit peak discharge, in csm/in. To calculate the water quality flow rate (WQF) over a given site area. In this situation the WQF is derived from the first 1/2" of runoff from the contributing impervious surface. Massachusetts Dept. of Environmental Protection Wetlands Program / United States Department of Agriculture Natural Resources Conservation Service TR-55 Manual Determine unit peak discharge using Figure 1 or 2. Figure 2 is in tabular form so is preferred. Using the tc, read the unit peak discharge (qu) from Figure 1 or Table in Figure 2. qu is expressed in the following units: cfs/mi2/watershed inches (csm/in). Compute Q Rate using the following equation: Q = (qu) (A) (WQV) Q = flow rate associated with first 1/2" of runoff Area 2.60 ac SWTS Weighted C 0.9 69 tc 15 min Particle size 0 CDS Model 2020-5 2.2 cfs CDS Hydraulic Capacitycfs Rainfall Intensity1 (in/hr) Percent Rainfall Volume1 Cumulative Rainfall Volume Total Flowrate (cfs) Treated Flowrate (cfs) Incremental Removal (%) 0.02 10.2%10.2%0.05 0.05 10.2 0.04 9.6%19.8%0.09 0.09 9.6 0.06 9.4%29.3%0.14 0.14 9.3 0.08 7.7%37.0%0.19 0.19 7.5 0.10 8.6%45.6%0.23 0.23 8.3 0.12 6.3%51.9%0.28 0.28 6.0 0.14 4.7%56.5%0.33 0.33 4.4 0.16 4.6%61.2%0.37 0.37 4.3 0.18 3.5%64.7%0.42 0.42 3.3 0.20 4.3%69.1%0.47 0.47 4.0 0.25 8.0%77.1%0.59 0.59 7.1 0.30 5.6%82.7%0.70 0.70 4.8 0.35 4.4%87.0%0.82 0.82 3.7 0.40 2.5%89.5%0.94 0.94 2.1 0.45 2.5%92.1%1.05 1.05 2.0 0.50 1.4%93.5%1.17 1.17 1.1 0.75 5.0%98.5%1.76 1.76 3.2 1.00 1.0%99.5%2.34 2.20 0.5 1.50 0.0%99.5%3.51 2.20 0.0 2.00 0.0%99.5%4.68 2.20 0.0 3.00 0.5%100.0%7.02 2.20 0.1 91.3 6.5% 93.2% 84.8% 1 - Based on 10 years of hourly precipitation data from NCDC Station 770, Boston WSFO AP, Suffolk County, MA 2 - Reduction due to use of 60-minute data for a site that has a time of concentration less than 30-minutes. Predicted Net Annual Load Removal Efficiency = Predicted % Annual Rainfall Treated = BASED ON THE RATIONAL RAINFALL METHOD BASED ON AN AVERAGE PARTICLE SIZE OF 110 MICRONS VILLAGE HILL CO-HOUSING Removal Efficiency Adjustment2 = CDS ESTIMATED NET ANNUAL SOLIDS LOAD REDUCTION Rainfall Station # NORTHAMPTON, MA Unit Site Designation CDS Treatment Capacity Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Appendix E – Outlet Protection Riprap Design Calculations Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Appendix F – Massachusetts Stormwater Checklist Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Appendix G – Stormwater Management System – Operation & Maintenance Plan Sunwood Builders – Co-Housing Development at Village Hill July 10, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 1 Stormwater Management System Operation & Maintenance Plan Co-Housing Development During Construction The Contractor shall be responsible for inspection and maintenance during construction. At all times, siltation fabric fencing, stakes and straw bales/wattles, sufficient to construct a sedimentation control barrier a minimum of 50 feet long, shall be stockpiled on the site in order to repair established barriers which may be damaged or breached. An inspection of all erosion control and stormwater management systems shall be conducted by the Contractor at least once a week and during all rain storms until the completion of construction. In case of any noted breach or failure, the Contractor shall immediately make appropriate repairs to any erosion control system and notify the engineer of any problems involving stormwater management systems. A rain storm shall be defined as any of the following: · A storm in which rain is predicted to last for twelve consecutive hours or more. · A storm for which a flash flood watch or warning is issued. · A single storm predicted to have a cumulative rainfall of greater than one-half inch. · A storm not meeting the previous three thresholds but which would mark a third consecutive day of measurable rainfall. The Contractor shall also inspect the erosion control and stormwater management systems at times of significant increase in surface water runoff due to rapid thawing when the risk of failure of erosion control measures is elevated. In such instances as remedial action is necessary, the Contractor shall repair any and all significant deficiencies in erosion control systems within two days. The Northampton Department of Public Works shall be notified of any significant failure of stormwater management systems or erosion and sediment control measures, and shall be notified of any release of pollutants to a water body (stream, brook, pond, etc.). The Contractor shall remove the sediment from behind the fence of the sedimentation control barrier when the accumulated sediment has reached one-half of the original installed height of the barrier. This project requires a NPDES General Permit for Stormwater Discharges from Constriction Activities. Contractor and Owner are responsible for finalizing a Stormwater Pollution Prevention Plan (SWPPP) and filing for the NDPES permit prior to the start of construction. All clearing, grading, drainage, construction, and development shall be conducted in strict accordance with the SWPPP. Sunwood Builders – Co-Housing Development at Village Hill July 10, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 2 Post-Construction Stormwater Management System Owner: Village Hill Co-Housing Homeowner’s Association (or similar legal entity TBD) Olander Drive Northampton, MA 01060 Party Responsible for Operation & Maintenance: Village Hill Co-Housing Homeowner’s Association (or similar legal entity TBD) Olander Drive Northampton, MA 01060 Inspection & Maintenance Schedule: 1) Deep-Sump Hooded Catch Basins & Yard Drains Catch basins should be inspected at least two times per year and cleaned annually or more often if required. Oil and sediments should be removed and disposed of in accordance with local, state and federal guidelines and regulations. In the case of an oil or bulk pollutant release, the system must be cleaned immediately following the spill and the proper authorities notified. 2) Stormwater Treatment Chamber The stormwater treatment chamber should be inspected at regular intervals and maintained when necessary to ensure optimum performance. The system shall be inspected at least four times during the first year and at least twice per year thereafter. If sediment accumulates fast enough to require removal more than once per year, the inspection frequency shall be increased. The visual inspection should ascertain that the system components are in working order and that there are no blockages or obstructions in the inlet and separation screen. The inspection should also quantify the accumulation of hydrocarbons, trash, and sediment in the system. Measuring pollutant accumulation can be done with a calibrated dipstick, tape measure or other measuring instrument. The CDS system should be cleaned when the level of sediment has reached 75% of capacity in the isolated sump or when an appreciable level of hydrocarbons and trash has accumulated. If absorbent material is used, it should be replaced when significant discoloration has occurred. Performance will not be impacted until 100% of the sump capacity is exceeded; however, it is recommended that the system be cleaned prior to that for easier removal of sediment. The level of sediment is easily determined by measuring from finished grade down to the top of the sediment pile. To avoid underestimating the level of sediment in the chamber, the measuring device must be lowered to the top of the sediment pile carefully. Particles at the top of the pile typically offer less resistance to the end of the rod than consolidated particles toward the bottom of the pile. Once this measurement is recorded, it should be compared to the as-built drawing for the unit to determine whether the height of the sediment pile off the bottom of the Sunwood Builders – Co-Housing Development at Village Hill July 10, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Page 3 sump floor exceeds 75% of the total height of isolated sump. Sediment shall be removed by a vacuum truck and disposed of in accordance with applicable regulations. 3) Storm Drain Outlet Protection The integrity of riprap outlet armoring shall be inspected twice per year for signs of dislodged stones or erosion at the perimeter of the apron. Any damage should be repaired to return the apron to the condition shown in the contract documents. While some growth of herbaceous plants is expected, regular trimming is required to prevent growth from restricting the free flow of water across the apron. 4) Street Sweeping Regular street sweeping will prevent sediment from reaching the stormwater treatment chamber. This will extend the life of stormwater treatment elements, and will reduce the effort and expense of cleaning those element. Street sweeping is not required under this plan; however, sweeping twice per year (including after the spring snow melt) is recommended. Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Appendix H – Storm Drain Sizing Calculations Village Hill Co-HousingStorm Drain Design Summary (25-Year Storm)7/11/2018Drainage Area Total Area(sf) Impervious Area(sf) Runoff CoefficientA3,109 928 C(Impervious)0.9B12,193 1,268 C(Vegetated)0.2C8,746 906 D2,780 310 Rainfall Intensity (in/hr)E3,972 1,862 I (25-year)7.2F16,693 5,042 G18,162 8,065 Manning "n" ValueH13,061 4,639 n0.013 I3,449 1,237 J5,924 1,942 K7,104 2,188 L14,496 2,918 M1,987 723 N22,101 5,661 O28,304 7,478 P21,784 8,266 Q1,027 1,027 R152,846 75,969 InletStructure IDOutletStructure ID Contributing Areas/Structures Total Area(sf) Impervious Area(sf) % ImperviousRunoff Coefficient 'C'RainfallIntensity 'I'(25-Year Storm)DrainageArea 'A'(acres)Flow RateQ=CIASize(in)Length(ft) Invert(Upstrm) Invert(Dwnstrm) Slope(%)Capacity(cfs)DesignCheckYD5YD6A3,109 928 30%0.417.20.070.21 826199.50 199.10 1.5%1.50 OKYD6FE7A3,109 928 30%0.417.20.070.21 846199.05 198.40 1.4%1.44 OKYD8YD9B12,193 1,268 10%0.277.20.280.55 847202.70 201.75 2.0%1.72 OKYD9YD10B,C20,939 2,174 10%0.277.20.480.94 8138201.65 198.70 2.1%1.77 OKYD10DMH13B,C,D23,719 2,484 10%0.277.20.541.07 12102198.60 197.60 1.0%3.54 OKDMH13DMH16B,C,D,E27,691 4,346 16%0.317.20.641.42 12107197.50 195.85 1.5%4.44 OKYD15DMH16F16,693 5,042 30%0.417.20.381.14 864197.00 196.05 1.5%1.48 OKDMH16DMH17B,C,D,E,F44,384 9,388 21%0.357.21.022.55 1231195.75 195.25 1.6%4.54 OKDMH17FE18B,C,D,E,F44,384 9,388 21%0.357.21.022.55 1280197.50 192.00 6.9%9.37 OKDMH19DMH24R152,846 75,969 50%0.557.23.5113.84 18223222.90 200.55 10.0%33.34 OKCB20CB21G18,162 8,065 44%0.517.20.421.53 1280204.55 203.35 1.5%4.38 OKCB21DMH24G,H31,223 12,704 41%0.487.20.722.50 12155203.25 200.10 2.0%5.09 OKYD22YD23I3,449 1,237 36%0.457.20.080.26 872203.00 201.55 2.0%1.72 OKYD23DMH24I,J9,373 3,179 34%0.447.20.220.68 1236201.45 200.70 2.1%5.16 OKDMH24STC30G,H,I,J,P,R215,226 100,118 47%0.537.24.9418.70 2440200.05 199.25 2.0%32.08 OKCB25DMH28N22,101 5,661 26%0.387.20.511.39 12191203.70 200.90 1.5%4.33 OKCB26DMH28O28,304 7,478 26%0.387.20.651.80 125202.50 202.00 10.0%11.30 OKYD27DMH28M1,987 723 36%0.457.20.050.15 846201.35 200.90 1.0%1.20 OKDMH28STC30M,N,O52,392 13,862 26%0.397.21.203.34 1847199.95 199.25 1.5%12.85 OKCB29STC30Q1,027 1,027 100%0.907.20.020.15 127203.00 202.25 10.7%11.69 OKSTC30FE31G,H,I,J,M,N,O,P,Q,R268,645 115,007 43%0.507.26.1722.19 24157199.00 192.00 4.5%47.90 OKYD36DMH39L14,496 2,918 20%0.347.20.330.82 1225195.85 195.35 2.0%5.05 OKYD38DMH39K7,104 2,188 31%0.427.20.160.49 849199.70 198.70 2.0%1.73 OKDMH39FE40K,L21,600 5,106 24%0.377.20.501.30 1298195.25 193.00 2.3%5.41 OKCB41DMH24P21,784 8,266 38%0.477.20.501.68 1245202.75 201.85 2.0%5.05 OKOutlet Pipe The Community Builders - Village HillStorm Drain Design Summary (100-Year Storm)7/11/2018Drainage Area Total Area(sf) Impervious Area(sf) Runoff CoefficientA3,109 928 C(Impervious)0.9B12,193 1,268 C(Vegetated)0.2C8,746 906 D2,780 310 Rainfall Intensity (in/hr)E3,972 1,862 I8.8F16,693 5,042 G18,162 8,065 Manning "n" ValueH13,061 4,639 n0.013 I3,449 1,237 J5,924 1,942 K7,104 2,188 L14,496 2,918 M1,987 723 N22,101 5,661 O28,304 7,478 P21,784 8,266 Q1,027 1,027 R152,846 75,969 InletStructure IDOutletStructure ID Contributing Areas/Structures Total Area(sf) Impervious Area(sf) % ImperviousRunoff Coefficient 'C'RainfallIntensity 'I'(25-Year Storm)DrainageArea 'A'(acres)Flow RateQ=CIASize(in)Length(ft) Invert(Upstrm) Invert(Dwnstrm) Slope(%)Capacity(cfs)DesignCheckYD5YD6A3,109 928 30%0.418.80.070.26 826199.50 199.10 1.5%1.50 OKYD6FE7A3,109 928 30%0.418.80.070.26 846199.05 198.40 1.4%1.44 OKYD8YD9B12,193 1,268 10%0.278.80.280.67 847202.70 201.75 2.0%1.72 OKYD9YD10B,C20,939 2,174 10%0.278.80.481.15 8138201.65 198.70 2.1%1.77 OKYD10DMH13B,C,D23,719 2,484 10%0.278.80.541.31 12102198.60 197.60 1.0%3.54 OKDMH13DMH16B,C,D,E27,691 4,346 16%0.318.80.641.73 12107197.50 195.85 1.5%4.44 OKYD15DMH16F16,693 5,042 30%0.418.80.381.39 864197.00 196.05 1.5%1.48 OKDMH16DMH17B,C,D,E,F44,384 9,388 21%0.358.81.023.12 1231195.75 195.25 1.6%4.54 OKDMH17FE18B,C,D,E,F44,384 9,388 21%0.358.81.023.12 1280197.50 192.00 6.9%9.37 OKDMH19DMH24R152,846 75,969 50%0.558.83.5116.92 18223222.90 200.55 10.0%33.34 OKCB20CB21G18,162 8,065 44%0.518.80.421.87 1280204.55 203.35 1.5%4.38 OKCB21DMH24G,H31,223 12,704 41%0.488.80.723.06 12155203.25 200.10 2.0%5.09 OKYD22YD23I3,449 1,237 36%0.458.80.080.31 872203.00 201.55 2.0%1.72 OKYD23DMH24I,J9,373 3,179 34%0.448.80.220.83 1236201.45 200.70 2.1%5.16 OKDMH24STC30G,H,I,J,P,R215,226 100,118 47%0.538.84.9422.85 2440200.05 199.25 2.0%32.08 OKCB25DMH28N22,101 5,661 26%0.388.80.511.69 12191203.70 200.90 1.5%4.33 OKCB26DMH28O28,304 7,478 26%0.388.80.652.20 125202.50 202.00 10.0%11.30 OKYD27DMH28M1,987 723 36%0.458.80.050.18 846201.35 200.90 1.0%1.20 OKDMH28STC30M,N,O52,392 13,862 26%0.398.81.204.08 1847199.95 199.25 1.5%12.85 OKCB29STC30Q1,027 1,027 100%0.908.80.020.19 127203.00 202.25 10.7%11.69 OKSTC30FE31M,N,O,P,Q,R228,049 99,124 43%0.508.85.2423.23 24157199.00 192.00 4.5%47.90 OKYD36DMH39L14,496 2,918 20%0.348.80.331.00 1225195.85 195.35 2.0%5.05 OKYD38DMH39K7,104 2,188 31%0.428.80.160.60 849199.70 198.70 2.0%1.73 OKDMH39FE40K,L21,600 5,106 24%0.378.80.501.59 1298195.25 193.00 2.3%5.41 OKCB41DMH24P21,784 8,266 38%0.478.80.502.05 1245202.75 201.85 2.0%5.05 OKOutlet Pipe Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Appendix I – Impervious Area Tabulation Summary Sunwood Builders – Co-Housing Development at Village Hill July 23, 2018 Northampton, Massachusetts Stormwater Management Report The Berkshire Design Group, Inc. Appendix J – Detention Basin #2 & #4 As-Built Survey