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HomeMy WebLinkAbout25 SITE 2 Drainage Report - 2025-04-18FULLER ENGINEERING & LAND SURVEYING, LLC 525 John Street  Second Floor Bridgeport, CT 06604 (203) 333-9465 (203) 336-1769 FAX FULLER ENGINEERING & LAND SURVEYING, LLC 525 JOHN STREET 2ND FLOOR BRIDGEPORT, CONNECTICUT 06604 PHONE (203)333-9465; FAX (203)336-1769 ENGINEERING REPORT Project Name: Madison Place Luxury Townhouse Development 18 Powerhouse Road & 145 CT Route 32 Montville, CT Information prepared for: JNE Holdings, LLC & Town of Montville Department of Public Works / Engineering Department Dated: January 11 February 2025 Revised 18 April 2025 TABLE OF CONTENTS (Stormwater Study) Introduction 1 Narrative 1 Modifications to this Report 1 Pre-Development Conditions 2 Proposed Post Development Conditions 2 Calculations 2 Basin ‘A’ 2 Basin ‘B’ 3 Summary Basin ‘A’ 4 Summary Basin ‘B’ 4 Conclusion 4 Soil Erosion and Sedimentation Control (All Phases) 5 Montville Precipitation Frequency (PF) Rainfall Data Appendix A NRCS Soil Map & Hydrologic Soil Group Rating Appendix B HydroCAD Analysis – Basin A Powerhouse Road Appendix C HydroCAD Analysis – Basin B Route 32 Appendix D Drainage Area Maps Appendix E Pipe Flow Calculations Appendix F Operations and Maintenance Plan Appendix G FULLER ENGINEERING & LAND SURVEYING, LLC 525 John Street – Second Floor – Bridgeport, CT 06604 Phone: (203) 333-9465 Fax: (203) 336-1769 FULLER ENGINEERING & LAND SURVEYING, LLC 525 JOHN STREET 2ND FLOOR BRIDGEPORT, CONNECTICUT 06604 PHONE (203)333-9465; FAX (203)336-1769 P a g e | 1 STORMWATER STUDY APPLICANT: JNE HOLDINGS, LLC PROJECT LOCATION: WILTONS WAY 18 Powerhouse Road & 145 Route 32, Montville, Connecticut INTRODUCTION The proposed project consists of the merger of two parcels into one lot consisting of 110,146 S.F.: 145 CT Route 23 Site Area: 59,415 S.F. One existing 4 family residential unit. 18 Powerhouse Road Site Area 50,731 S.F. One existing 2 family residential unit. The proposed project is anticipated to be constructed in three phases. DRAINAGE STUDY NARRATIVE The subject of this report is a 1.185 acre portion of a parcel located at 145 Route 32 in Monteville.. The purpose of this report is to determine the existing and proposed runoffs resulting from the proposed site improvements in order to design a stormwater management system. MODIFICATIONS TO THIS REPORT The previous drainage report revised through March 7, 2025 analyzed the drainage areas into two separate phases. Based on comments from the Town Engineer, this report has been restructured into two overall drainage basins: 1. Basin ‘A’ - The largest watershed area which flows to the east and consists primarily of the proposed development 2. Basin ‘B’ - The smaller watershed area flowing toward CT Route 32. The individual phase calculations have been eliminated from this report and replaced by analysis of Basins ‘A’, and ‘B’ individual watersheds. Basin ‘A’ now merges and analyzes Phase 1 and Phase 2 together through the ‘Combined’ portion of the analysis. Stormwater Study –Madision Place 11 February 2025 JNE Holdings, LLC Rev 18 April 2025 18 Powerhouse & 145 Route 32 Montville, CT P a g e | 2 FULLER ENGINEERING & LAND SURVEYING, LLC 525 JOHN STREET 2ND FLOOR BRIDGEPORT, CONNECTICUT 06604 PHONE (203)333-9465; FAX (203)336-1769 PRE-DEVELOPMENT CONDITIONS The subject parcel is located on the west side of Route 32, at its intersection with Powerhouse Road. The lot currently contains buildings and a driveway. There are two watershed basins on the property, one draining to the west and Route 32 and the other to the east. Existing soils at this location, as identified in the NRCS Soil Survey of Fairfield County, Connecticut, consist of Narragansett silt loam, 2 to 8 percent slopes, which has a Hydrologic classification of “B”. The existing runoff from a 100-Year rainfall event in Basin A is 8.00 c.f.s. The existing runoff from a 100-Year rainfall event in Basin B is 3.06 c.f.s. PROPOSED POST-DEVELOPMENT CONDITIONS The proposal for this phase is to construct a total of 11 residential units, with associated driveway. The area of Basin A increases by the same amount as Basin B decreases due to the proposed construction. The proposed runoff (prior to mitigation) from a 100-Year rainfall event in Basin A is 12.44 c.f.s. The proposed runoff (prior to mitigation) from a 100-Year rainfall event in Basin B is 2.95 c.f.s. CALCULATIONS The following computations of the existing and proposed conditions runoff flows were derived from the HydroCAD computer software. HydroCAD follows the NRCS TR-20 procedure for computing stormwater runoff. Computations were performed for a 50-year storm event, which has a 2% chance of occurring in any given 12 month period. BASIN ‘A’ Existing Conditions (Basin A): House 1,382 s.f. CN 98 Driveway 1,696 s.f. CN 98 Garage 764 s.f. CN 98 Concrete Slab 246 s.f. CN 98 Shed 373 s.f. CN 98 Walks 221 s.f. CN 98 House Basin B 200 s.f. CN 98 Driveway Basin B 1,169 s.f. CN 98 Lawn 82,223 s.f. CN 69 Total 88,274 s.f. Stormwater Study –Madision Place 11 February 2025 JNE Holdings, LLC Rev 18 April 2025 18 Powerhouse & 145 Route 32 Montville, CT P a g e | 3 FULLER ENGINEERING & LAND SURVEYING, LLC 525 JOHN STREET 2ND FLOOR BRIDGEPORT, CONNECTICUT 06604 PHONE (203)333-9465; FAX (203)336-1769 Weighted CN - 71 Proposed Conditions (Basin A): Buildings 14,182 s.f. CN 98 Driveway/Parking 16,150 s.f. CN 98 Lawn 58,665 s.f. CN 69 Total 88,997 s.f. Weighted CN - 79 Groundwater Recharge Volume (GWV) Basin A: Impervious area = 34.1 % WQV = (0.3569 * 2.043 ac)/12 x 1.3 = 0.0789908 ac-ft = 3,440.8 ft3 GWV = 3,440.8 * 0.25 = 860.2 ft3 BASIN ‘B’ Existing Conditions (Basin B): House 1,659 s.f. CN 98 Driveway 1,934 s.f. CN 98 Gravel 836 s.f. CN 85 Walks 196 s.f. CN 98 Lawn 16,768 s.f. CN 69 Total 21,393 s.f. Weighted CN - 75 Proposed Conditions (Basin B): House 1,659 s.f. CN 98 Building 1,046 s.f. CN 98 Driveway 1,271 s.f. CN 98 Lawn 16,694 s.f. CN 69 Total - 20,670 s.f. Weighted CN - 75 Stormwater Study –Madision Place 11 February 2025 JNE Holdings, LLC Rev 18 April 2025 18 Powerhouse & 145 Route 32 Montville, CT P a g e | 4 FULLER ENGINEERING & LAND SURVEYING, LLC 525 JOHN STREET 2ND FLOOR BRIDGEPORT, CONNECTICUT 06604 PHONE (203)333-9465; FAX (203)336-1769 SUMMARY Basin A: 100 Year 50 Year 25Yr. 10Yr. 5Yr. 2Yr. Existing Runoff : 8.00 6.73 c.f.s 5.48 3.93 2.86 1.68 Proposed Runoff : 12.44 10.72 c.f.s 9.04 6.85 5.30 3.49 Runoff Retained: 4.78 4.26 c.f.s 3.75 3.08 2.60 2.01 Areas Bypassing Retention Plus overflow: 7.60 6.41 c.f.s 5.24 3.78 2.76 1.64 SUMMARY Basin B: 100 Year 50 Year 25Yr. 10Yr. 5Yr. 2Yr. Existing Runoff : 3.06 2.61 c.f.s 2.17 1.61 1.21 0.76 Proposed Runoff : 2.95 2.52 c.f.s. 2.10 1.55 1.17 0.74 CONCLUSION: The increased runoff resulting from the proposed site improvements will be retained in an on- site retention system. The runoff from the driveway and the roof of the northern building in Basin A will be routed to a total of 352 linear feet of 48” concrete galleries. The galleries consisting of two sets, the 160 linear feet to mitigate the Phase 1 of construction and the set of 192 linear feet for the remainder in Basin A. The increase in stormwater runoff is mitigated on- site. This system will reduce the net peak run-off during a 100 Year (2%) rainfall event in Basin A to 7.60 c.f.s. from its current peak of 8.00 c.f.s. The bottom of the eastern set of concrete galleries will be at elevation 98.6. No restrictive layer was found to an elevation of 97.0. The bottom of the western set of concrete galleries will be at elevation 93.9. No restrictive layer was found to an elevation of 92.0. The proposed retention system in Basin A provides a total of 5,750 ft3 of storage, which will be adequate to maintain the net runoff during a 100 Year rainfall event, meets the Water Quality Volume and will provide groundwater recharge. Stormwater Study –Madision Place 11 February 2025 JNE Holdings, LLC Rev 18 April 2025 18 Powerhouse & 145 Route 32 Montville, CT P a g e | 5 FULLER ENGINEERING & LAND SURVEYING, LLC 525 JOHN STREET 2ND FLOOR BRIDGEPORT, CONNECTICUT 06604 PHONE (203)333-9465; FAX (203)336-1769 The maximum peak net runoff from the proposed conditions decrease compared to the peak runoff from the existing conditions for each of the rainfall events in Basin A from the 2 Year to the 100 Year rainfall events, as the table above illustrates. The runoff in Basin B conditions decrease compared to the peak runoff from the existing conditions for each of the rainfall events from the 2 Year to the 100 Year rainfall events, as the table above illustrates, due to a reduction of 74 square feet of impervious surfaces. The proposed improvements will have no adverse impact on surrounding properties. SOIL EROSION AND SEDIMENTATION CONTROL (All Phases) For temporary condition or during construction a silt fence shall be provided along the property lines. Anti-tracking aprons shall be provided at all access routes from the site to the public road. A temporary diversion berm with stone check dams @ 50 ft o.c. shall be maintained and relocated as required during construction. All planting areas shall be protected with slope stabilization measures. For permanent condition, all embankments, after being stabilized, shall be seeded to lawn or seed mixture as specified. Newly planted areas shall be covered with straw or erosion control blankets. APPENDIX “A” MONTVILLE PRECIPITATION FREQUENCY (PF) RAINFALL DATA #245 Norwich New London Road (CT State RTE. 32) Montville, CT APPENDIX “B” NRCS SOIL MAP AND HYDROLOGIC SOIL GROUP RATINGS Soil Map—State of Connecticut, Eastern Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/8/2025 Page 1 of 34590530459055045905704590590459061045906304590650459055045905704590590459061045906304590650741450741470741490741510741530741550741570741590741610741630 741450 741470 741490 741510 741530 741550 741570 741590 741610 741630 41° 25' 52'' N 72° 6' 37'' W41° 25' 52'' N72° 6' 28'' W41° 25' 48'' N 72° 6' 37'' W41° 25' 48'' N 72° 6' 28'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 40 80 160 240 Feet 0 10 20 40 60 Meters Map Scale: 1:894 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:12,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: State of Connecticut, Eastern Part Survey Area Data: Version 2, Aug 30, 2024 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 14, 2022—Oct 6, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Soil Map—State of Connecticut, Eastern Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/8/2025 Page 2 of 3 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 38C Hinckley loamy sand, 3 to 15 percent slopes 0.1 3.2% 66B Narragansett silt loam, 2 to 8 percent slopes 2.4 96.0% 68C Narragansett silt loam, 3 to 15 percent slopes, extremely stony 0.0 0.7% Totals for Area of Interest 2.5 100.0% Soil Map—State of Connecticut, Eastern Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/8/2025 Page 3 of 3 APPENDIX “C” HydroCAD Analysis Basin A Powerhouse Road 1S Existing Conditions Basin A Powerhouse Road Routing Diagram for 2578ExistingRev1 Prepared by Fairfield County Engineering LLC, Printed 4/17/2025 HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 2 Year Rainfall=3.54"2578ExistingRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 8HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff =1.68 cfs @ 12.27 hrs, Volume=0.183 af, Depth>1.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 2 Year Rainfall=3.54" Area (sf)CN Description *1,382 98 House *1,696 98 Driveway *764 98 Garage *246 98 Concrete Slab *373 98 Shed *221 98 Walks *200 98 House Basin B *1,169 98 Driveway Basin B 82,223 69 50-75% Grass cover, Fair, HSG B 88,274 71 Weighted Average 82,223 93.15% Pervious Area 6,051 6.85% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 15.8 162 0.0140 0.17 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.3 199 0.1390 2.61 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 17.1 361 Total Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 2 Year Rainfall=3.54" Runoff Area=88,274 sf Runoff Volume=0.183 af Runoff Depth>1.08" Flow Length=361' Tc=17.1 min CN=71 1.68 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 5 Year Rainfall=4.55"2578ExistingRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 9HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff =2.86 cfs @ 12.27 hrs, Volume=0.300 af, Depth>1.77" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 5 Year Rainfall=4.55" Area (sf)CN Description *1,382 98 House *1,696 98 Driveway *764 98 Garage *246 98 Concrete Slab *373 98 Shed *221 98 Walks *200 98 House Basin B *1,169 98 Driveway Basin B 82,223 69 50-75% Grass cover, Fair, HSG B 88,274 71 Weighted Average 82,223 93.15% Pervious Area 6,051 6.85% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 15.8 162 0.0140 0.17 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.3 199 0.1390 2.61 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 17.1 361 Total Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 NOAA 24-hr D 5 Year Rainfall=4.55" Runoff Area=88,274 sf Runoff Volume=0.300 af Runoff Depth>1.77" Flow Length=361' Tc=17.1 min CN=71 2.86 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 10 Year Rainfall=5.39"2578ExistingRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 10HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff =3.93 cfs @ 12.26 hrs, Volume=0.406 af, Depth>2.40" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 10 Year Rainfall=5.39" Area (sf)CN Description *1,382 98 House *1,696 98 Driveway *764 98 Garage *246 98 Concrete Slab *373 98 Shed *221 98 Walks *200 98 House Basin B *1,169 98 Driveway Basin B 82,223 69 50-75% Grass cover, Fair, HSG B 88,274 71 Weighted Average 82,223 93.15% Pervious Area 6,051 6.85% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 15.8 162 0.0140 0.17 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.3 199 0.1390 2.61 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 17.1 361 Total Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 NOAA 24-hr D 10 Year Rainfall=5.39" Runoff Area=88,274 sf Runoff Volume=0.406 af Runoff Depth>2.40" Flow Length=361' Tc=17.1 min CN=71 3.93 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 25 Year Rainfall=6.55"2578ExistingRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 11HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff =5.48 cfs @ 12.26 hrs, Volume=0.563 af, Depth>3.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 25 Year Rainfall=6.55" Area (sf)CN Description *1,382 98 House *1,696 98 Driveway *764 98 Garage *246 98 Concrete Slab *373 98 Shed *221 98 Walks *200 98 House Basin B *1,169 98 Driveway Basin B 82,223 69 50-75% Grass cover, Fair, HSG B 88,274 71 Weighted Average 82,223 93.15% Pervious Area 6,051 6.85% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 15.8 162 0.0140 0.17 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.3 199 0.1390 2.61 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 17.1 361 Total Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)6 5 4 3 2 1 0 NOAA 24-hr D 25 Year Rainfall=6.55" Runoff Area=88,274 sf Runoff Volume=0.563 af Runoff Depth>3.33" Flow Length=361' Tc=17.1 min CN=71 5.48 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 50 Year Rainfall=7.44"2578ExistingRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 12HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff =6.73 cfs @ 12.26 hrs, Volume=0.689 af, Depth>4.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 50 Year Rainfall=7.44" Area (sf)CN Description *1,382 98 House *1,696 98 Driveway *764 98 Garage *246 98 Concrete Slab *373 98 Shed *221 98 Walks *200 98 House Basin B *1,169 98 Driveway Basin B 82,223 69 50-75% Grass cover, Fair, HSG B 88,274 71 Weighted Average 82,223 93.15% Pervious Area 6,051 6.85% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 15.8 162 0.0140 0.17 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.3 199 0.1390 2.61 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 17.1 361 Total Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 NOAA 24-hr D 50 Year Rainfall=7.44" Runoff Area=88,274 sf Runoff Volume=0.689 af Runoff Depth>4.08" Flow Length=361' Tc=17.1 min CN=71 6.73 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 100 Year Rainfall=8.34"2578ExistingRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 13HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff =8.00 cfs @ 12.26 hrs, Volume=0.820 af, Depth>4.86" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 100 Year Rainfall=8.34" Area (sf)CN Description *1,382 98 House *1,696 98 Driveway *764 98 Garage *246 98 Concrete Slab *373 98 Shed *221 98 Walks *200 98 House Basin B *1,169 98 Driveway Basin B 82,223 69 50-75% Grass cover, Fair, HSG B 88,274 71 Weighted Average 82,223 93.15% Pervious Area 6,051 6.85% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 15.8 162 0.0140 0.17 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.3 199 0.1390 2.61 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 17.1 361 Total Subcatchment 1S: Existing Conditions Basin A Powerhouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 NOAA 24-hr D 100 Year Rainfall=8.34" Runoff Area=88,274 sf Runoff Volume=0.820 af Runoff Depth>4.86" Flow Length=361' Tc=17.1 min CN=71 8.00 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. 2S Proposed Conditions Basin A Powehouse Road Routing Diagram for 2578ProposedRev1 Prepared by Fairfield County Engineering LLC, Printed 4/17/2025 HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 2 Year Rainfall=3.54"2578ProposedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 15HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff =3.49 cfs @ 12.16 hrs, Volume=0.271 af, Depth>1.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 2 Year Rainfall=3.54" Area (sf)CN Description *14,182 98 Buildings *16,150 98 Driveway 58,665 69 50-75% Grass cover, Fair, HSG B 88,997 79 Weighted Average 58,665 65.92% Pervious Area 30,332 34.08% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 NOAA 24-hr D 2 Year Rainfall=3.54" Runoff Area=88,997 sf Runoff Volume=0.271 af Runoff Depth>1.59" Flow Length=361' Tc=8.2 min CN=79 3.49 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 5 Year Rainfall=4.55"2578ProposedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 16HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff =5.30 cfs @ 12.16 hrs, Volume=0.411 af, Depth>2.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 5 Year Rainfall=4.55" Area (sf)CN Description *14,182 98 Buildings *16,150 98 Driveway 58,665 69 50-75% Grass cover, Fair, HSG B 88,997 79 Weighted Average 58,665 65.92% Pervious Area 30,332 34.08% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 NOAA 24-hr D 5 Year Rainfall=4.55" Runoff Area=88,997 sf Runoff Volume=0.411 af Runoff Depth>2.41" Flow Length=361' Tc=8.2 min CN=79 5.30 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 10 Year Rainfall=5.39"2578ProposedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 17HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff =6.85 cfs @ 12.15 hrs, Volume=0.534 af, Depth>3.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 10 Year Rainfall=5.39" Area (sf)CN Description *14,182 98 Buildings *16,150 98 Driveway 58,665 69 50-75% Grass cover, Fair, HSG B 88,997 79 Weighted Average 58,665 65.92% Pervious Area 30,332 34.08% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 NOAA 24-hr D 10 Year Rainfall=5.39" Runoff Area=88,997 sf Runoff Volume=0.534 af Runoff Depth>3.13" Flow Length=361' Tc=8.2 min CN=79 6.85 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 25 Year Rainfall=6.55"2578ProposedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 18HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff =9.04 cfs @ 12.15 hrs, Volume=0.710 af, Depth>4.17" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 25 Year Rainfall=6.55" Area (sf)CN Description *14,182 98 Buildings *16,150 98 Driveway 58,665 69 50-75% Grass cover, Fair, HSG B 88,997 79 Weighted Average 58,665 65.92% Pervious Area 30,332 34.08% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)10 9 8 7 6 5 4 3 2 1 0 NOAA 24-hr D 25 Year Rainfall=6.55" Runoff Area=88,997 sf Runoff Volume=0.710 af Runoff Depth>4.17" Flow Length=361' Tc=8.2 min CN=79 9.04 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 50 Year Rainfall=7.44"2578ProposedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 19HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff =10.72 cfs @ 12.15 hrs, Volume=0.848 af, Depth>4.98" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 50 Year Rainfall=7.44" Area (sf)CN Description *14,182 98 Buildings *16,150 98 Driveway 58,665 69 50-75% Grass cover, Fair, HSG B 88,997 79 Weighted Average 58,665 65.92% Pervious Area 30,332 34.08% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)12 11 10 9 8 7 6 5 4 3 2 1 0 NOAA 24-hr D 50 Year Rainfall=7.44" Runoff Area=88,997 sf Runoff Volume=0.848 af Runoff Depth>4.98" Flow Length=361' Tc=8.2 min CN=79 10.72 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 100 Year Rainfall=8.34"2578ProposedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 20HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff =12.44 cfs @ 12.15 hrs, Volume=0.990 af, Depth>5.82" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 100 Year Rainfall=8.34" Area (sf)CN Description *14,182 98 Buildings *16,150 98 Driveway 58,665 69 50-75% Grass cover, Fair, HSG B 88,997 79 Weighted Average 58,665 65.92% Pervious Area 30,332 34.08% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 2S: Proposed Conditions Basin A Powehouse Road Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)13 12 11 10 9 8 7 6 5 4 3 2 1 0 NOAA 24-hr D 100 Year Rainfall=8.34" Runoff Area=88,997 sf Runoff Volume=0.990 af Runoff Depth>5.82" Flow Length=361' Tc=8.2 min CN=79 12.44 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. 3S Areas Routed to Retention 4S Areas Routed to Retention 5S Areas not Routed to Retention 1P 48" Concrete Galleries 2P 48" Concrete Galleries 1L Combined Hydrograph Routing Diagram for 2578CombinedRev1 Prepared by Fairfield County Engineering LLC, Printed 4/17/2025 HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 2 Year Rainfall=3.54"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 22HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Areas Routed to Retention Runoff =0.72 cfs @ 12.11 hrs, Volume=0.057 af, Depth>3.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 2 Year Rainfall=3.54" Area (sf)CN Description *9,067 98 Driveway/Parking 9,067 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 3S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 NOAA 24-hr D 2 Year Rainfall=3.54" Runoff Area=9,067 sf Runoff Volume=0.057 af Runoff Depth>3.30" Tc=5.0 min CN=98 0.72 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 2 Year Rainfall=3.54"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 23HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Areas Routed to Retention Runoff =1.29 cfs @ 12.11 hrs, Volume=0.103 af, Depth>3.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 2 Year Rainfall=3.54" Area (sf)CN Description *7,083 98 Parking/Driveway *5,245 98 Building Units 2-4 *4,017 98 Building Units 8-10 16,345 98 Weighted Average 16,345 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 4S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 2 Year Rainfall=3.54" Runoff Area=16,345 sf Runoff Volume=0.103 af Runoff Depth>3.30" Tc=5.0 min CN=98 1.29 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 2 Year Rainfall=3.54"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 24HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Areas not Routed to Retention Runoff =1.64 cfs @ 12.16 hrs, Volume=0.132 af, Depth>1.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 2 Year Rainfall=3.54" Area (sf)CN Description *4,920 98 Buildings 58,665 69 50-75% Grass cover, Fair, HSG B 63,585 71 Weighted Average 58,665 92.26% Pervious Area 4,920 7.74% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 5S: Areas not Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 2 Year Rainfall=3.54" Runoff Area=63,585 sf Runoff Volume=0.132 af Runoff Depth>1.09" Flow Length=361' Tc=8.2 min CN=71 1.64 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 2 Year Rainfall=3.54"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 25HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1P: 48" Concrete Galleries Inflow Area =0.583 ac,100.00% Impervious, Inflow Depth > 1.18" for 2 Year event Inflow =0.72 cfs @ 12.11 hrs, Volume=0.057 af Outflow =0.11 cfs @ 11.60 hrs, Volume=0.057 af, Atten= 85%, Lag= 0.0 min Discarded =0.11 cfs @ 11.60 hrs, Volume=0.057 af Primary =0.00 cfs @ 0.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 94.79' @ 12.62 hrs Surf.Area= 756 sf Storage= 612 cf Plug-Flow detention time= 34.0 min calculated for 0.057 af (100% of inflow) Center-of-Mass det. time= 33.3 min ( 788.0 - 754.7 ) Volume Invert Avail.Storage Storage Description #1 93.90'270 cf 18.00'W x 42.00'L x 4.00'H Stone 3,024 cf Overall - 2,349 cf Embedded = 675 cf x 40.0% Voids #2 93.90'2,349 cf 16.00'W x 40.00'L x 3.67'H 48" Concrete Galleries Inside #1 2,619 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 97.90'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 93.90'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.11 cfs @ 11.60 hrs HW=93.94' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=93.90' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) Pond 1P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.583 ac Peak Elev=94.79' Storage=612 cf 0.72 cfs 0.11 cfs 0.11 cfs 0.00 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 2 Year Rainfall=3.54"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 26HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 2P: 48" Concrete Galleries Inflow Area =0.375 ac,100.00% Impervious, Inflow Depth > 3.30" for 2 Year event Inflow =1.29 cfs @ 12.11 hrs, Volume=0.103 af Outflow =0.13 cfs @ 11.24 hrs, Volume=0.103 af, Atten= 90%, Lag= 0.0 min Discarded =0.13 cfs @ 11.24 hrs, Volume=0.103 af Primary =0.00 cfs @ 0.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 100.32' @ 13.03 hrs Surf.Area= 900 sf Storage= 1,415 cf Plug-Flow detention time= 74.5 min calculated for 0.103 af (100% of inflow) Center-of-Mass det. time= 73.8 min ( 828.5 - 754.7 ) Volume Invert Avail.Storage Storage Description #1 98.60'313 cf 18.00'W x 50.00'L x 4.00'H Stone 3,600 cf Overall - 2,819 cf Embedded = 781 cf x 40.0% Voids #2 98.60'2,819 cf 16.00'W x 48.00'L x 3.67'H 48" Concrete Galleries Inside #1 3,131 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 102.60'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 98.60'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.13 cfs @ 11.24 hrs HW=98.64' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.13 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=98.60' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) Pond 2P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.375 ac Peak Elev=100.32' Storage=1,415 cf 1.29 cfs 0.13 cfs 0.13 cfs 0.00 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 2 Year Rainfall=3.54"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 27HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Link 1L: Combined Hydrograph Inflow Area =2.043 ac,34.08% Impervious, Inflow Depth > 0.78" for 2 Year event Inflow =1.64 cfs @ 12.16 hrs, Volume=0.132 af Primary =1.64 cfs @ 12.16 hrs, Volume=0.132 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Link 1L: Combined Hydrograph Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=2.043 ac 1.64 cfs 1.64 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 5 Year Rainfall=4.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 28HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Areas Routed to Retention Runoff =0.93 cfs @ 12.11 hrs, Volume=0.075 af, Depth>4.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 5 Year Rainfall=4.55" Area (sf)CN Description *9,067 98 Driveway/Parking 9,067 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 3S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 5 Year Rainfall=4.55" Runoff Area=9,067 sf Runoff Volume=0.075 af Runoff Depth>4.31" Tc=5.0 min CN=98 0.93 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 5 Year Rainfall=4.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 29HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Areas Routed to Retention Runoff =1.67 cfs @ 12.11 hrs, Volume=0.135 af, Depth>4.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 5 Year Rainfall=4.55" Area (sf)CN Description *7,083 98 Parking/Driveway *5,245 98 Building Units 2-4 *4,017 98 Building Units 8-10 16,345 98 Weighted Average 16,345 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 4S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 5 Year Rainfall=4.55" Runoff Area=16,345 sf Runoff Volume=0.135 af Runoff Depth>4.31" Tc=5.0 min CN=98 1.67 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 5 Year Rainfall=4.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 30HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Areas not Routed to Retention Runoff =2.76 cfs @ 12.16 hrs, Volume=0.216 af, Depth>1.78" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 5 Year Rainfall=4.55" Area (sf)CN Description *4,920 98 Buildings 58,665 69 50-75% Grass cover, Fair, HSG B 63,585 71 Weighted Average 58,665 92.26% Pervious Area 4,920 7.74% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 5S: Areas not Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 NOAA 24-hr D 5 Year Rainfall=4.55" Runoff Area=63,585 sf Runoff Volume=0.216 af Runoff Depth>1.78" Flow Length=361' Tc=8.2 min CN=71 2.76 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 5 Year Rainfall=4.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 31HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1P: 48" Concrete Galleries Inflow Area =0.583 ac,100.00% Impervious, Inflow Depth > 1.54" for 5 Year event Inflow =0.93 cfs @ 12.11 hrs, Volume=0.075 af Outflow =0.11 cfs @ 11.40 hrs, Volume=0.075 af, Atten= 89%, Lag= 0.0 min Discarded =0.11 cfs @ 11.40 hrs, Volume=0.075 af Primary =0.00 cfs @ 0.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 95.24' @ 12.86 hrs Surf.Area= 756 sf Storage= 923 cf Plug-Flow detention time= 54.4 min calculated for 0.075 af (100% of inflow) Center-of-Mass det. time= 53.8 min ( 803.5 - 749.6 ) Volume Invert Avail.Storage Storage Description #1 93.90'270 cf 18.00'W x 42.00'L x 4.00'H Stone 3,024 cf Overall - 2,349 cf Embedded = 675 cf x 40.0% Voids #2 93.90'2,349 cf 16.00'W x 40.00'L x 3.67'H 48" Concrete Galleries Inside #1 2,619 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 97.90'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 93.90'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.11 cfs @ 11.40 hrs HW=93.94' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=93.90' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) Pond 1P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.583 ac Peak Elev=95.24' Storage=923 cf 0.93 cfs 0.11 cfs 0.11 cfs 0.00 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 5 Year Rainfall=4.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 32HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 2P: 48" Concrete Galleries Inflow Area =0.375 ac,100.00% Impervious, Inflow Depth > 4.31" for 5 Year event Inflow =1.67 cfs @ 12.11 hrs, Volume=0.135 af Outflow =0.13 cfs @ 10.96 hrs, Volume=0.135 af, Atten= 93%, Lag= 0.0 min Discarded =0.13 cfs @ 10.96 hrs, Volume=0.135 af Primary =0.00 cfs @ 0.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 101.16' @ 13.31 hrs Surf.Area= 900 sf Storage= 2,097 cf Plug-Flow detention time= 118.5 min calculated for 0.135 af (100% of inflow) Center-of-Mass det. time= 118.0 min ( 867.6 - 749.6 ) Volume Invert Avail.Storage Storage Description #1 98.60'313 cf 18.00'W x 50.00'L x 4.00'H Stone 3,600 cf Overall - 2,819 cf Embedded = 781 cf x 40.0% Voids #2 98.60'2,819 cf 16.00'W x 48.00'L x 3.67'H 48" Concrete Galleries Inside #1 3,131 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 102.60'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 98.60'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.13 cfs @ 10.96 hrs HW=98.64' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.13 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=98.60' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) Pond 2P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.375 ac Peak Elev=101.16' Storage=2,097 cf 1.67 cfs 0.13 cfs 0.13 cfs 0.00 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 5 Year Rainfall=4.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 33HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Link 1L: Combined Hydrograph Inflow Area =2.043 ac,34.08% Impervious, Inflow Depth > 1.27" for 5 Year event Inflow =2.76 cfs @ 12.16 hrs, Volume=0.216 af Primary =2.76 cfs @ 12.16 hrs, Volume=0.216 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Link 1L: Combined Hydrograph Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=2.043 ac 2.76 cfs 2.76 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 10 Year Rainfall=5.39"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 34HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Areas Routed to Retention Runoff =1.10 cfs @ 12.11 hrs, Volume=0.089 af, Depth>5.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 10 Year Rainfall=5.39" Area (sf)CN Description *9,067 98 Driveway/Parking 9,067 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 3S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 10 Year Rainfall=5.39" Runoff Area=9,067 sf Runoff Volume=0.089 af Runoff Depth>5.15" Tc=5.0 min CN=98 1.10 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 10 Year Rainfall=5.39"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 35HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Areas Routed to Retention Runoff =1.98 cfs @ 12.11 hrs, Volume=0.161 af, Depth>5.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 10 Year Rainfall=5.39" Area (sf)CN Description *7,083 98 Parking/Driveway *5,245 98 Building Units 2-4 *4,017 98 Building Units 8-10 16,345 98 Weighted Average 16,345 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 4S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 NOAA 24-hr D 10 Year Rainfall=5.39" Runoff Area=16,345 sf Runoff Volume=0.161 af Runoff Depth>5.15" Tc=5.0 min CN=98 1.98 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 10 Year Rainfall=5.39"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 36HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Areas not Routed to Retention Runoff =3.78 cfs @ 12.16 hrs, Volume=0.293 af, Depth>2.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 10 Year Rainfall=5.39" Area (sf)CN Description *4,920 98 Buildings 58,665 69 50-75% Grass cover, Fair, HSG B 63,585 71 Weighted Average 58,665 92.26% Pervious Area 4,920 7.74% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 5S: Areas not Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 NOAA 24-hr D 10 Year Rainfall=5.39" Runoff Area=63,585 sf Runoff Volume=0.293 af Runoff Depth>2.41" Flow Length=361' Tc=8.2 min CN=71 3.78 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 10 Year Rainfall=5.39"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 37HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1P: 48" Concrete Galleries Inflow Area =0.583 ac,100.00% Impervious, Inflow Depth > 1.84" for 10 Year event Inflow =1.10 cfs @ 12.11 hrs, Volume=0.089 af Outflow =0.11 cfs @ 11.24 hrs, Volume=0.089 af, Atten= 90%, Lag= 0.0 min Discarded =0.11 cfs @ 11.24 hrs, Volume=0.089 af Primary =0.00 cfs @ 0.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 95.67' @ 13.04 hrs Surf.Area= 756 sf Storage= 1,213 cf Plug-Flow detention time= 75.1 min calculated for 0.089 af (100% of inflow) Center-of-Mass det. time= 74.4 min ( 821.0 - 746.6 ) Volume Invert Avail.Storage Storage Description #1 93.90'270 cf 18.00'W x 42.00'L x 4.00'H Stone 3,024 cf Overall - 2,349 cf Embedded = 675 cf x 40.0% Voids #2 93.90'2,349 cf 16.00'W x 40.00'L x 3.67'H 48" Concrete Galleries Inside #1 2,619 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 97.90'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 93.90'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.11 cfs @ 11.24 hrs HW=93.94' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=93.90' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) Pond 1P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.583 ac Peak Elev=95.67' Storage=1,213 cf 1.10 cfs 0.11 cfs 0.11 cfs 0.00 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 10 Year Rainfall=5.39"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 38HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 2P: 48" Concrete Galleries Inflow Area =0.375 ac,100.00% Impervious, Inflow Depth > 5.15" for 10 Year event Inflow =1.98 cfs @ 12.11 hrs, Volume=0.161 af Outflow =0.13 cfs @ 10.76 hrs, Volume=0.161 af, Atten= 94%, Lag= 0.0 min Discarded =0.13 cfs @ 10.76 hrs, Volume=0.161 af Primary =0.00 cfs @ 0.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 101.90' @ 13.51 hrs Surf.Area= 900 sf Storage= 2,708 cf Plug-Flow detention time= 161.5 min calculated for 0.161 af (100% of inflow) Center-of-Mass det. time= 160.6 min ( 907.2 - 746.6 ) Volume Invert Avail.Storage Storage Description #1 98.60'313 cf 18.00'W x 50.00'L x 4.00'H Stone 3,600 cf Overall - 2,819 cf Embedded = 781 cf x 40.0% Voids #2 98.60'2,819 cf 16.00'W x 48.00'L x 3.67'H 48" Concrete Galleries Inside #1 3,131 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 102.60'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 98.60'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.13 cfs @ 10.76 hrs HW=98.64' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.13 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=98.60' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) Pond 2P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.375 ac Peak Elev=101.90' Storage=2,708 cf 1.98 cfs 0.13 cfs 0.13 cfs 0.00 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 10 Year Rainfall=5.39"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 39HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Link 1L: Combined Hydrograph Inflow Area =2.043 ac,34.08% Impervious, Inflow Depth > 1.72" for 10 Year event Inflow =3.78 cfs @ 12.16 hrs, Volume=0.293 af Primary =3.78 cfs @ 12.16 hrs, Volume=0.293 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Link 1L: Combined Hydrograph Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Inflow Area=2.043 ac 3.78 cfs 3.78 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 25 Year Rainfall=6.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 40HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Areas Routed to Retention Runoff =1.34 cfs @ 12.11 hrs, Volume=0.109 af, Depth>6.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 25 Year Rainfall=6.55" Area (sf)CN Description *9,067 98 Driveway/Parking 9,067 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 3S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 25 Year Rainfall=6.55" Runoff Area=9,067 sf Runoff Volume=0.109 af Runoff Depth>6.31" Tc=5.0 min CN=98 1.34 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 25 Year Rainfall=6.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 41HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Areas Routed to Retention Runoff =2.41 cfs @ 12.11 hrs, Volume=0.197 af, Depth>6.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 25 Year Rainfall=6.55" Area (sf)CN Description *7,083 98 Parking/Driveway *5,245 98 Building Units 2-4 *4,017 98 Building Units 8-10 16,345 98 Weighted Average 16,345 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 4S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 NOAA 24-hr D 25 Year Rainfall=6.55" Runoff Area=16,345 sf Runoff Volume=0.197 af Runoff Depth>6.31" Tc=5.0 min CN=98 2.41 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 25 Year Rainfall=6.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 42HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Areas not Routed to Retention Runoff =5.24 cfs @ 12.16 hrs, Volume=0.406 af, Depth>3.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 25 Year Rainfall=6.55" Area (sf)CN Description *4,920 98 Buildings 58,665 69 50-75% Grass cover, Fair, HSG B 63,585 71 Weighted Average 58,665 92.26% Pervious Area 4,920 7.74% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 5S: Areas not Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 NOAA 24-hr D 25 Year Rainfall=6.55" Runoff Area=63,585 sf Runoff Volume=0.406 af Runoff Depth>3.34" Flow Length=361' Tc=8.2 min CN=71 5.24 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 25 Year Rainfall=6.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 43HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1P: 48" Concrete Galleries Inflow Area =0.583 ac,100.00% Impervious, Inflow Depth > 2.47" for 25 Year event Inflow =1.34 cfs @ 12.11 hrs, Volume=0.120 af Outflow =0.11 cfs @ 11.00 hrs, Volume=0.120 af, Atten= 92%, Lag= 0.0 min Discarded =0.11 cfs @ 11.00 hrs, Volume=0.120 af Primary =0.00 cfs @ 0.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 96.94' @ 13.55 hrs Surf.Area= 756 sf Storage= 2,085 cf Plug-Flow detention time= 140.9 min calculated for 0.120 af (100% of inflow) Center-of-Mass det. time= 140.1 min ( 886.1 - 746.0 ) Volume Invert Avail.Storage Storage Description #1 93.90'270 cf 18.00'W x 42.00'L x 4.00'H Stone 3,024 cf Overall - 2,349 cf Embedded = 675 cf x 40.0% Voids #2 93.90'2,349 cf 16.00'W x 40.00'L x 3.67'H 48" Concrete Galleries Inside #1 2,619 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 97.90'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 93.90'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.11 cfs @ 11.00 hrs HW=93.94' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=93.90' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) Pond 1P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.583 ac Peak Elev=96.94' Storage=2,085 cf 1.34 cfs 0.11 cfs 0.11 cfs 0.00 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 25 Year Rainfall=6.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 44HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 2P: 48" Concrete Galleries Inflow Area =0.375 ac,100.00% Impervious, Inflow Depth > 6.31" for 25 Year event Inflow =2.41 cfs @ 12.11 hrs, Volume=0.197 af Outflow =0.57 cfs @ 12.56 hrs, Volume=0.188 af, Atten= 76%, Lag= 26.6 min Discarded =0.13 cfs @ 10.40 hrs, Volume=0.177 af Primary =0.45 cfs @ 12.56 hrs, Volume=0.011 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 102.83' @ 12.56 hrs Surf.Area= 900 sf Storage= 3,131 cf Plug-Flow detention time= 187.5 min calculated for 0.187 af (95% of inflow) Center-of-Mass det. time= 157.9 min ( 901.3 - 743.5 ) Volume Invert Avail.Storage Storage Description #1 98.60'313 cf 18.00'W x 50.00'L x 4.00'H Stone 3,600 cf Overall - 2,819 cf Embedded = 781 cf x 40.0% Voids #2 98.60'2,819 cf 16.00'W x 48.00'L x 3.67'H 48" Concrete Galleries Inside #1 3,131 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 102.60'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 98.60'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.13 cfs @ 10.40 hrs HW=98.64' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.13 cfs) Primary OutFlow Max=0.44 cfs @ 12.56 hrs HW=102.82' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.44 cfs @ 2.24 fps) Pond 2P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.375 ac Peak Elev=102.83' Storage=3,131 cf 2.41 cfs 0.57 cfs 0.13 cfs 0.45 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 25 Year Rainfall=6.55"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 45HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Link 1L: Combined Hydrograph Inflow Area =2.043 ac,34.08% Impervious, Inflow Depth > 2.39" for 25 Year event Inflow =5.24 cfs @ 12.16 hrs, Volume=0.406 af Primary =5.24 cfs @ 12.16 hrs, Volume=0.406 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Link 1L: Combined Hydrograph Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Inflow Area=2.043 ac 5.24 cfs 5.24 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 50 Year Rainfall=7.44"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 46HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Areas Routed to Retention Runoff =1.52 cfs @ 12.11 hrs, Volume=0.125 af, Depth>7.20" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 50 Year Rainfall=7.44" Area (sf)CN Description *9,067 98 Driveway/Parking 9,067 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 3S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 50 Year Rainfall=7.44" Runoff Area=9,067 sf Runoff Volume=0.125 af Runoff Depth>7.20" Tc=5.0 min CN=98 1.52 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 50 Year Rainfall=7.44"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 47HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Areas Routed to Retention Runoff =2.74 cfs @ 12.11 hrs, Volume=0.225 af, Depth>7.20" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 50 Year Rainfall=7.44" Area (sf)CN Description *7,083 98 Parking/Driveway *5,245 98 Building Units 2-4 *4,017 98 Building Units 8-10 16,345 98 Weighted Average 16,345 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 4S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 NOAA 24-hr D 50 Year Rainfall=7.44" Runoff Area=16,345 sf Runoff Volume=0.225 af Runoff Depth>7.20" Tc=5.0 min CN=98 2.74 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 50 Year Rainfall=7.44"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 48HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Areas not Routed to Retention Runoff =6.41 cfs @ 12.16 hrs, Volume=0.497 af, Depth>4.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 50 Year Rainfall=7.44" Area (sf)CN Description *4,920 98 Buildings 58,665 69 50-75% Grass cover, Fair, HSG B 63,585 71 Weighted Average 58,665 92.26% Pervious Area 4,920 7.74% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 5S: Areas not Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 NOAA 24-hr D 50 Year Rainfall=7.44" Runoff Area=63,585 sf Runoff Volume=0.497 af Runoff Depth>4.09" Flow Length=361' Tc=8.2 min CN=71 6.41 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 50 Year Rainfall=7.44"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 49HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1P: 48" Concrete Galleries Inflow Area =0.583 ac,100.00% Impervious, Inflow Depth > 3.13" for 50 Year event Inflow =1.94 cfs @ 12.28 hrs, Volume=0.152 af Outflow =0.47 cfs @ 12.72 hrs, Volume=0.152 af, Atten= 76%, Lag= 26.4 min Discarded =0.11 cfs @ 10.84 hrs, Volume=0.140 af Primary =0.36 cfs @ 12.72 hrs, Volume=0.012 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 98.07' @ 12.72 hrs Surf.Area= 756 sf Storage= 2,619 cf Plug-Flow detention time= 173.8 min calculated for 0.152 af (100% of inflow) Center-of-Mass det. time= 173.2 min ( 918.0 - 744.8 ) Volume Invert Avail.Storage Storage Description #1 93.90'270 cf 18.00'W x 42.00'L x 4.00'H Stone 3,024 cf Overall - 2,349 cf Embedded = 675 cf x 40.0% Voids #2 93.90'2,349 cf 16.00'W x 40.00'L x 3.67'H 48" Concrete Galleries Inside #1 2,619 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 97.90'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 93.90'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.11 cfs @ 10.84 hrs HW=93.94' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.36 cfs @ 12.72 hrs HW=98.07' (Free Discharge) 1=Orifice/Grate (Weir Controls 0.36 cfs @ 1.35 fps) Pond 1P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.583 ac Peak Elev=98.07' Storage=2,619 cf 1.94 cfs 0.47 cfs 0.11 cfs 0.36 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 50 Year Rainfall=7.44"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 50HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 2P: 48" Concrete Galleries Inflow Area =0.375 ac,100.00% Impervious, Inflow Depth > 7.20" for 50 Year event Inflow =2.74 cfs @ 12.11 hrs, Volume=0.225 af Outflow =1.57 cfs @ 12.28 hrs, Volume=0.210 af, Atten= 43%, Lag= 9.8 min Discarded =0.13 cfs @ 10.04 hrs, Volume=0.183 af Primary =1.44 cfs @ 12.28 hrs, Volume=0.027 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 104.92' @ 12.28 hrs Surf.Area= 900 sf Storage= 3,131 cf Plug-Flow detention time= 173.5 min calculated for 0.210 af (93% of inflow) Center-of-Mass det. time= 134.4 min ( 876.0 - 741.6 ) Volume Invert Avail.Storage Storage Description #1 98.60'313 cf 18.00'W x 50.00'L x 4.00'H Stone 3,600 cf Overall - 2,819 cf Embedded = 781 cf x 40.0% Voids #2 98.60'2,819 cf 16.00'W x 48.00'L x 3.67'H 48" Concrete Galleries Inside #1 3,131 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 102.60'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 98.60'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.13 cfs @ 10.04 hrs HW=98.64' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.13 cfs) Primary OutFlow Max=1.40 cfs @ 12.28 hrs HW=104.79' (Free Discharge) 1=Orifice/Grate (Orifice Controls 1.40 cfs @ 7.12 fps) Pond 2P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=0.375 ac Peak Elev=104.92' Storage=3,131 cf 2.74 cfs 1.57 cfs 0.13 cfs 1.44 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 50 Year Rainfall=7.44"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 51HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Link 1L: Combined Hydrograph Inflow Area =2.043 ac,34.08% Impervious, Inflow Depth > 2.99" for 50 Year event Inflow =6.41 cfs @ 12.16 hrs, Volume=0.510 af Primary =6.41 cfs @ 12.16 hrs, Volume=0.510 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Link 1L: Combined Hydrograph Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=2.043 ac 6.41 cfs 6.41 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 100 Year Rainfall=8.34"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 52HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Areas Routed to Retention Runoff =1.71 cfs @ 12.11 hrs, Volume=0.140 af, Depth>8.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 100 Year Rainfall=8.34" Area (sf)CN Description *9,067 98 Driveway/Parking 9,067 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 3S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 100 Year Rainfall=8.34" Runoff Area=9,067 sf Runoff Volume=0.140 af Runoff Depth>8.09" Tc=5.0 min CN=98 1.71 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 100 Year Rainfall=8.34"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 53HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: Areas Routed to Retention Runoff =3.07 cfs @ 12.11 hrs, Volume=0.253 af, Depth>8.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 100 Year Rainfall=8.34" Area (sf)CN Description *7,083 98 Parking/Driveway *5,245 98 Building Units 2-4 *4,017 98 Building Units 8-10 16,345 98 Weighted Average 16,345 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.0 Direct Entry, Direct Subcatchment 4S: Areas Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 NOAA 24-hr D 100 Year Rainfall=8.34" Runoff Area=16,345 sf Runoff Volume=0.253 af Runoff Depth>8.09" Tc=5.0 min CN=98 3.07 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 100 Year Rainfall=8.34"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 54HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Areas not Routed to Retention Runoff =7.60 cfs @ 12.15 hrs, Volume=0.592 af, Depth>4.87" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 100 Year Rainfall=8.34" Area (sf)CN Description *4,920 98 Buildings 58,665 69 50-75% Grass cover, Fair, HSG B 63,585 71 Weighted Average 58,665 92.26% Pervious Area 4,920 7.74% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 6.3 111 0.0650 0.29 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 1.9 250 0.1020 2.24 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 8.2 361 Total Subcatchment 5S: Areas not Routed to Retention Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 NOAA 24-hr D 100 Year Rainfall=8.34" Runoff Area=63,585 sf Runoff Volume=0.592 af Runoff Depth>4.87" Flow Length=361' Tc=8.2 min CN=71 7.60 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 100 Year Rainfall=8.34"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 55HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1P: 48" Concrete Galleries Inflow Area =0.583 ac,100.00% Impervious, Inflow Depth > 3.84" for 100 Year event Inflow =3.39 cfs @ 12.19 hrs, Volume=0.186 af Outflow =1.99 cfs @ 12.32 hrs, Volume=0.184 af, Atten= 41%, Lag= 8.1 min Discarded =0.11 cfs @ 10.72 hrs, Volume=0.145 af Primary =1.89 cfs @ 12.32 hrs, Volume=0.039 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 101.89' @ 12.32 hrs Surf.Area= 756 sf Storage= 2,619 cf Plug-Flow detention time= 154.1 min calculated for 0.184 af (98% of inflow) Center-of-Mass det. time= 143.9 min ( 887.4 - 743.5 ) Volume Invert Avail.Storage Storage Description #1 93.90'270 cf 18.00'W x 42.00'L x 4.00'H Stone 3,024 cf Overall - 2,349 cf Embedded = 675 cf x 40.0% Voids #2 93.90'2,349 cf 16.00'W x 40.00'L x 3.67'H 48" Concrete Galleries Inside #1 2,619 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 97.90'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 93.90'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.11 cfs @ 10.72 hrs HW=93.94' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=1.88 cfs @ 12.32 hrs HW=101.84' (Free Discharge) 1=Orifice/Grate (Orifice Controls 1.88 cfs @ 9.56 fps) Pond 1P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=0.583 ac Peak Elev=101.89' Storage=2,619 cf 3.39 cfs 1.99 cfs 0.11 cfs 1.89 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 100 Year Rainfall=8.34"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 56HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Pond 2P: 48" Concrete Galleries Inflow Area =0.375 ac,100.00% Impervious, Inflow Depth > 8.09" for 100 Year event Inflow =3.07 cfs @ 12.11 hrs, Volume=0.253 af Outflow =2.51 cfs @ 12.19 hrs, Volume=0.233 af, Atten= 18%, Lag= 4.7 min Discarded =0.13 cfs @ 9.80 hrs, Volume=0.187 af Primary =2.39 cfs @ 12.19 hrs, Volume=0.046 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Peak Elev= 108.70' @ 12.19 hrs Surf.Area= 900 sf Storage= 3,131 cf Plug-Flow detention time= 161.2 min calculated for 0.233 af (92% of inflow) Center-of-Mass det. time= 116.2 min ( 856.3 - 740.1 ) Volume Invert Avail.Storage Storage Description #1 98.60'313 cf 18.00'W x 50.00'L x 4.00'H Stone 3,600 cf Overall - 2,819 cf Embedded = 781 cf x 40.0% Voids #2 98.60'2,819 cf 16.00'W x 48.00'L x 3.67'H 48" Concrete Galleries Inside #1 3,131 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 102.60'6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 98.60'6.000 in/hr Exfiltration over Horizontal area Discarded OutFlow Max=0.13 cfs @ 9.80 hrs HW=98.68' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.13 cfs) Primary OutFlow Max=2.17 cfs @ 12.19 hrs HW=107.88' (Free Discharge) 1=Orifice/Grate (Orifice Controls 2.17 cfs @ 11.06 fps) Pond 2P: 48" Concrete Galleries Inflow Outflow Discarded Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 Inflow Area=0.375 ac Peak Elev=108.70' Storage=3,131 cf 3.07 cfs 2.51 cfs 0.13 cfs 2.39 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 100 Year Rainfall=8.34"2578CombinedRev1 Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 57HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Link 1L: Combined Hydrograph Inflow Area =2.043 ac,34.08% Impervious, Inflow Depth > 3.71" for 100 Year event Inflow =7.60 cfs @ 12.15 hrs, Volume=0.631 af Primary =7.60 cfs @ 12.15 hrs, Volume=0.631 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs Link 1L: Combined Hydrograph Inflow Primary Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=2.043 ac 7.60 cfs 7.60 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. APPENDIX “D” HYDROCAD ANALYSIS BASIN B CT ROUTE 32 1S Existing Conditions Basin B Route 32 Routing Diagram for 2578Existing Prepared by Fairfield County Engineering LLC, Printed 4/17/2025 HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 2 Year Rainfall=3.54"2578Existing Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 59HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff =0.76 cfs @ 12.13 hrs, Volume=0.054 af, Depth>1.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 2 Year Rainfall=3.54" Area (sf)CN Description *1,659 98 House *1,934 98 Driveway *836 85 Gravel *196 98 Walks 16,768 69 50-75% Grass cover, Fair, HSG B 21,393 75 Weighted Average 17,604 82.29% Pervious Area 3,789 17.71% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 NOAA 24-hr D 2 Year Rainfall=3.54" Runoff Area=21,393 sf Runoff Volume=0.054 af Runoff Depth>1.33" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 0.76 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 5 Year Rainfall=4.55"2578Existing Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 60HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff =1.21 cfs @ 12.12 hrs, Volume=0.085 af, Depth>2.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 5 Year Rainfall=4.55" Area (sf)CN Description *1,659 98 House *1,934 98 Driveway *836 85 Gravel *196 98 Walks 16,768 69 50-75% Grass cover, Fair, HSG B 21,393 75 Weighted Average 17,604 82.29% Pervious Area 3,789 17.71% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 5 Year Rainfall=4.55" Runoff Area=21,393 sf Runoff Volume=0.085 af Runoff Depth>2.09" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 1.21 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 10 Year Rainfall=5.39"2578Existing Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 61HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff =1.61 cfs @ 12.12 hrs, Volume=0.113 af, Depth>2.77" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 10 Year Rainfall=5.39" Area (sf)CN Description *1,659 98 House *1,934 98 Driveway *836 85 Gravel *196 98 Walks 16,768 69 50-75% Grass cover, Fair, HSG B 21,393 75 Weighted Average 17,604 82.29% Pervious Area 3,789 17.71% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 10 Year Rainfall=5.39" Runoff Area=21,393 sf Runoff Volume=0.113 af Runoff Depth>2.77" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 1.61 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 25 Year Rainfall=6.55"2578Existing Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 62HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff =2.17 cfs @ 12.12 hrs, Volume=0.154 af, Depth>3.75" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 25 Year Rainfall=6.55" Area (sf)CN Description *1,659 98 House *1,934 98 Driveway *836 85 Gravel *196 98 Walks 16,768 69 50-75% Grass cover, Fair, HSG B 21,393 75 Weighted Average 17,604 82.29% Pervious Area 3,789 17.71% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 NOAA 24-hr D 25 Year Rainfall=6.55" Runoff Area=21,393 sf Runoff Volume=0.154 af Runoff Depth>3.75" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 2.17 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 50 Year Rainfall=7.44"2578Existing Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 63HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff =2.61 cfs @ 12.12 hrs, Volume=0.186 af, Depth>4.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 50 Year Rainfall=7.44" Area (sf)CN Description *1,659 98 House *1,934 98 Driveway *836 85 Gravel *196 98 Walks 16,768 69 50-75% Grass cover, Fair, HSG B 21,393 75 Weighted Average 17,604 82.29% Pervious Area 3,789 17.71% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 NOAA 24-hr D 50 Year Rainfall=7.44" Runoff Area=21,393 sf Runoff Volume=0.186 af Runoff Depth>4.53" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 2.61 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 100 Year Rainfall=8.34"2578Existing Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 64HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff =3.06 cfs @ 12.12 hrs, Volume=0.219 af, Depth>5.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 100 Year Rainfall=8.34" Area (sf)CN Description *1,659 98 House *1,934 98 Driveway *836 85 Gravel *196 98 Walks 16,768 69 50-75% Grass cover, Fair, HSG B 21,393 75 Weighted Average 17,604 82.29% Pervious Area 3,789 17.71% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 1S: Existing Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 NOAA 24-hr D 100 Year Rainfall=8.34" Runoff Area=21,393 sf Runoff Volume=0.219 af Runoff Depth>5.34" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 3.06 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. 2S Proposed Conditions Basin B Route 32 Routing Diagram for 2578Proposed Prepared by Fairfield County Engineering LLC, Printed 4/17/2025 HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. NOAA 24-hr D 2 Year Rainfall=3.54"2578Proposed Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 66HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff =0.74 cfs @ 12.13 hrs, Volume=0.053 af, Depth>1.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 2 Year Rainfall=3.54" Area (sf)CN Description *1,659 98 House *1,046 98 Building *1,271 98 Driveway 16,694 69 50-75% Grass cover, Fair, HSG B 20,670 75 Weighted Average 16,694 80.76% Pervious Area 3,976 19.24% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 NOAA 24-hr D 2 Year Rainfall=3.54" Runoff Area=20,670 sf Runoff Volume=0.053 af Runoff Depth>1.33" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 0.74 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 5 Year Rainfall=4.55"2578Proposed Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 67HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff =1.17 cfs @ 12.12 hrs, Volume=0.083 af, Depth>2.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 5 Year Rainfall=4.55" Area (sf)CN Description *1,659 98 House *1,046 98 Building *1,271 98 Driveway 16,694 69 50-75% Grass cover, Fair, HSG B 20,670 75 Weighted Average 16,694 80.76% Pervious Area 3,976 19.24% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 5 Year Rainfall=4.55" Runoff Area=20,670 sf Runoff Volume=0.083 af Runoff Depth>2.09" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 1.17 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 10 Year Rainfall=5.39"2578Proposed Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 68HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff =1.55 cfs @ 12.12 hrs, Volume=0.109 af, Depth>2.77" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 10 Year Rainfall=5.39" Area (sf)CN Description *1,659 98 House *1,046 98 Building *1,271 98 Driveway 16,694 69 50-75% Grass cover, Fair, HSG B 20,670 75 Weighted Average 16,694 80.76% Pervious Area 3,976 19.24% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 NOAA 24-hr D 10 Year Rainfall=5.39" Runoff Area=20,670 sf Runoff Volume=0.109 af Runoff Depth>2.77" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 1.55 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 25 Year Rainfall=6.55"2578Proposed Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 69HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff =2.10 cfs @ 12.12 hrs, Volume=0.148 af, Depth>3.75" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 25 Year Rainfall=6.55" Area (sf)CN Description *1,659 98 House *1,046 98 Building *1,271 98 Driveway 16,694 69 50-75% Grass cover, Fair, HSG B 20,670 75 Weighted Average 16,694 80.76% Pervious Area 3,976 19.24% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 NOAA 24-hr D 25 Year Rainfall=6.55" Runoff Area=20,670 sf Runoff Volume=0.148 af Runoff Depth>3.75" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 2.10 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 50 Year Rainfall=7.44"2578Proposed Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 70HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff =2.52 cfs @ 12.12 hrs, Volume=0.179 af, Depth>4.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 50 Year Rainfall=7.44" Area (sf)CN Description *1,659 98 House *1,046 98 Building *1,271 98 Driveway 16,694 69 50-75% Grass cover, Fair, HSG B 20,670 75 Weighted Average 16,694 80.76% Pervious Area 3,976 19.24% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 NOAA 24-hr D 50 Year Rainfall=7.44" Runoff Area=20,670 sf Runoff Volume=0.179 af Runoff Depth>4.53" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 2.52 cfs This document was created by an application that isn’t licensed to use novaPDF. 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NOAA 24-hr D 100 Year Rainfall=8.34"2578Proposed Printed 4/17/2025Prepared by Fairfield County Engineering LLC Page 71HydroCAD® 10.00-26 s/n 06020 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff =2.95 cfs @ 12.12 hrs, Volume=0.211 af, Depth>5.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.04 hrs NOAA 24-hr D 100 Year Rainfall=8.34" Area (sf)CN Description *1,659 98 House *1,046 98 Building *1,271 98 Driveway 16,694 69 50-75% Grass cover, Fair, HSG B 20,670 75 Weighted Average 16,694 80.76% Pervious Area 3,976 19.24% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.2 100 0.0850 0.32 Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.54" 0.3 31 0.0850 2.04 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 5.5 131 Total Subcatchment 2S: Proposed Conditions Basin B Route 32 Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)3 2 1 0 NOAA 24-hr D 100 Year Rainfall=8.34" Runoff Area=20,670 sf Runoff Volume=0.211 af Runoff Depth>5.34" Flow Length=131' Slope=0.0850 '/' Tc=5.5 min CN=75 2.95 cfs This document was created by an application that isn’t licensed to use novaPDF. Purchase a license to generate PDF files without this notice. APPENDIX E WATERSHED MAPS FOR EXISTING & PROPOSED CONDITIONS LEGEND LIMITS OF EXISTING DRAINAGE AREA FLOW PATH PROPERTY LINE GENERAL NOTES 1.STORMWATER RUNOFF ANALYSIS WAS CALCULATED USING THE NRCS TR-20 METHODOLOGY. Job Number: Job Start Date: Checked By: Sheet Title: Drawn By: Sheet Number: Scale: 3/20/24 FE24-1889 THIS DRAWING IS THE PROPERTY OF THE ENGINEER. IT HAS BEEN SPECIFICALLY PREPARED FOR THE OWNER FOR THIS PROJECT AT THIS SITE AND IS NOT TO BE USED FOR ANY OTHER PURPOSE, LOCATION OR OWNER WITHOUT WRITTEN CONSENT OF THE ENGINEER.PREPARED FOR18 POWERHOUSE ROAD LUXURY TOWNHOUSE DEVELOPMENTD.R.R.J.E.Q.JNE HOLDINGS, LLC525 JOHN STREET BRIDGEPORT, CT. 06604 Office (203) 333-9465 fax (203) 336-1769 e-mail Info@FullerSurveyors MONTVILLE, CONNECTICUTAPPROVED BY THE MONTVILLE PLANNING AND ZONING COMMISSION CHAIRMAN DATE MADISON PLACE4/18/2025 11:39 AMAPPROVED BY THE MONTVILLE INLAND WETLAND COMMISSION CHAIRMAN DATE EXPIRATION DATE SEC PLAN APPROVAL DATE Submission 02/11/25 Staff Comments 02/21/25 Staff Comments 03/07/25 Staff Comments 03/18/25 Staff Comments 03/31/25 Staff Comments 04/16/25 Staff Comments 04/18/25 DA-EX 1" = 20' EXISTING DRAINAGE AREA EXISTING DRAINAGE AREA 'A' HYDROLOGIC SOIL GROUP B TOTAL DRAINAGE AREA = 2.0 AC TOTAL IMPERVIOUS AREA = 0.1 AC TOTAL PERVIOUS AREA = 1.9 AC CURVE NUMBER = 70 TIME OF CONCENTRATION = 17.1 MIN. SHEET FLOW PATH = 162' OHW OHW OHW OHW OHW OHW OHW OHW OHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWBIT. CONC. PAVEMENT 2 1/2 STORY WOOD FRAME HOUSE NORWICH NEW LONDON TNPK( ROUTE 32)STEEL HATCH GRAVEL WELL OIL FILL MAILBOX OHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWEM UTL BOX LAWN AREA LAWN AREA SNET 2741 S UP 7702 FRONT 2742 FRONT 2741 FRONT 2740 BIT. CONC. CURBBARBED WIRE FENCE BARBED WIRE FENCE STOCKADE FENCE STOCKADE FENCESTOCKADE FENCE1 STORYCONC. WALK CONC. WALKCONC. LANDING CONC. LANDING CURB CUTCONC.STEPSI PIN FNDI PIPE FND I PIN FND CONC. STEPS GUTTER LINECONC. WALK PLANTINGAREAOHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW HETL CO 2426 HELT CO 2506 POWERHOUSE ROAD WELL WELL CHAINLINK FENCEREMAINS OF CONC. FLOOR CONC. CURBCONC. CURBBIT. CONC. PAVEMENT CONC. WALKCONC. WALKCONC. WALK E.O.P. E.O.P. E.O.P. E.O.P. GRAVEL DRIVEWAY 1 STORY WOOD FRAME SHED 2 1/2 STORY WOOD FRAME HOUSE1 STORY WOOD FRAME GARAGE 20' SIDE BUILDING SETBACK40' REAR BUILDING SETBACK 20' SIDE BUILDING SETBACK40' FRONT BUILDING SETBACK FP. 1,382 S.F.FP. 760 S.F. FP. 373 S.F. FP. 1,536 S.F. MERESTONE HELD MON FND / HELD FIRE HYD D.H. FND EXISTING DRAINAGE AREA 'B' TOTAL DRAINAGE AREA = 21,393 TOTAL IMPERVIOUS AREA = 3,789 S.F. TOTAL PERVIOUS AREA = 17,604 S.F. CURVE NUMBER = 75 TIME OF CONCENTRATION = 5.5 MIN. FLOW PATH 122' SHALLOW CONCENTRATED FLOW PATH = 199' LEGEND LIMITS OF EXISTING DRAINAGE AREA FLOW PATH PROPERTY LINE GENERAL NOTES 1.THE STORMWATER MANAGEMENT PLAN AND DESIGN IS INTENDED TO BE IN COMPLIANCE WITH THE 2000 CONNECTICUT DEPARTMENT OF TRANSPORTATION (CTDOT) DRAINAGE MANUAL AND THE 2004 CONNECTICUT STORMWATER QUALITY MANUAL. 2.STORMWATER RUNOFF ANALYSIS WAS CALCULATED USING THE SCS TR-55 METHODOLOGY. Job Number: Job Start Date: Checked By: Sheet Title: Drawn By: Sheet Number: Scale: 3/20/24 FE24-1889 THIS DRAWING IS THE PROPERTY OF THE ENGINEER. IT HAS BEEN SPECIFICALLY PREPARED FOR THE OWNER FOR THIS PROJECT AT THIS SITE AND IS NOT TO BE USED FOR ANY OTHER PURPOSE, LOCATION OR OWNER WITHOUT WRITTEN CONSENT OF THE ENGINEER.PREPARED FOR18 POWERHOUSE ROAD LUXURY TOWNHOUSE DEVELOPMENTD.R.R.J.E.Q.JNE HOLDINGS, LLC525 JOHN STREET BRIDGEPORT, CT. 06604 Office (203) 333-9465 fax (203) 336-1769 e-mail Info@FullerSurveyors MONTVILLE, CONNECTICUTAPPROVED BY THE MONTVILLE PLANNING AND ZONING COMMISSION CHAIRMAN DATE MADISON PLACE4/18/2025 11:39 AMAPPROVED BY THE MONTVILLE INLAND WETLAND COMMISSION CHAIRMAN DATE EXPIRATION DATE SEC PLAN APPROVAL DATE Submission 02/11/25 Staff Comments 02/21/25 Staff Comments 03/07/25 Staff Comments 03/18/25 Staff Comments 03/31/25 Staff Comments 04/16/25 Staff Comments 04/18/25 DA-PR 1" = 20' PROPOSED DRAINAGE AREA AREA NOT ROUTED TO DETENTION PHASE 2 PROPOSED POND 2P SHEET FLOW PATH = 111' OHW OHW OHW OHW OHW OHW OHW OHW OHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWOHWBIT. CONC. PAVEMENT 2 1/2 STORY WOOD FRAME HOUSE NORWICH NEW LONDON TNPK( ROUTE 32)STEEL HATCH GRAVEL WELL OIL FILL MAILBOXOHW EM UTL BOX LAWN AREA LAWN AREA SNET 2741 S UP 7702 FRONT 2742 FRONT 2741 BIT. CONC. CURBBARBED WIRE FENCE BARBED WIRE FENCE STOCKADE FENCE STOCKADE FENCESTOCKADE FENCE1 STORYCONC. WALK CONC. WALKCONC. LANDING CONC. LANDING CURB CUTCONC.STEPSI PIN FNDI PIPE FND I PIN FND CONC. STEPS CONC. WALK PLANTINGAREAOHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW OHW I PIPE FND CLP 2445 HETL CO 2426 HELT CO 2506 POWERHOUSE ROAD WELL WELL CHAINLINK FENCEREMAINS OF CONC. FLOOR CONC. CURBCONC. CURBBIT. CONC. PAVEMENT CONC. WALKCONC. WALKCONC. WALK E.O.P. E.O.P. E.O.P. E.O.P. GRAVEL DRIVEWAY 1 STORY WOOD FRAME SHED 2 1/2 STORY WOOD FRAME HOUSE1 STORY WOOD FRAME GARAGE FP. 1,382 S.F.FP. 760 S.F. FP. 373 S.F. FP. 1,536 S.F. MERESTONE HELD MON FND / HELD FIRE HYD D.H. FND AREA 4S AREA 5S AREA 3S PHASE 1 PROPOSED POND 1P PROPOSED SUBCATCHMENT 2S TOTAL DRAINAGE AREA = 20,670 S.F. TOTAL IMPERVIOUS AREA = 3,973 S.F. TOTAL PERVIOUS AREA = 16,694 S.F. CURVE NUMBER = 75 TIME OF CONCENTRATION = 5.5 MIN. PROPOSED SUBCATCHMENT 5S NOT ROUTED TO RETENTION TOTAL DRAINAGE AREA = 63,585 S.F. TOTAL IMPERVIOUS AREA = 4,920 S.F. PERVIOUS AREA = 58,665 S.F. CURVE NUMBER = 71 TIME OF CONCENTRATION = 8.2 MIN. AREA 5S AREA 5S AREA 5S SHALLOW CONCENTRATED FLOW PATH = 250' PROPOSED SUBCATCHMENT 4S TOTAL DRAINAGE AREA = 16,345 S.F. TOTAL IMPERVIOUS AREA = 16,345 S.F. TOTAL PERVIOUS AREA = 0 S.F. CURVE NUMBER = 98 TIME OF CONCENTRATION = 5.0 MIN. PROPOSED SUBCATCHMENT 3S TOTAL DRAINAGE AREA = 9,067 S.F. TOTAL IMPERVIOUS AREA =9,067 S.F. TOTAL PERVIOUS AREA = 0 S.F. CURVE NUMBER = 98 TIME OF CONCENTRATION = 5.0 MIN. AREA 2S DRAINAGE BASIN 'A' DRAINAGE BASIN 'B' APPENDIX F PIPE FLOW CALCULATIONS FULLER ENGINEERING & LAND SURVEYING, LLC 525 John Street – Second Floor – Bridgeport, CT 06604 Phone: (203) 333-9465 Fax: (203) 336-1769 FULLER ENGINEERING & LAND SURVEYING, LLC 525 JOHN STREET 2ND FLOOR BRIDGEPORT, CONNECTICUT 06604 PHONE (203)333-9465; FAX (203)336-1769 P a g e | 1 PIPE FLOW CALCULATIONS Phase 1 8" pipe @ 1% = 1.43 cfs 10" pipe @ 0.5 % = 1.83 cfs Therefore, good for Phase 1; max flow 0.85 cfs Phase 2 8" pipe @ 3 % = 2.47 cfs 8" pipe @ 1.5 % = 1.74 cfs Therefore, good for Phase 2and 3 ; max flow 1.63 cfs APPENDIX “G” OPERATIONS AND MAINTENANCE PLAN Appendix O Operations and Maintenance Plan 145 Norwich New London Tpke. Route 32 & 18 Powerhouse Road Montville, CT February 11, 2025 Scope: The purpose of the Operations and Maintenance Plan is to ensure that the existing and proposed stormwater components installed at 145 Route 32, Norwich New London Turnpike and 18 Powerhouse Road, Montville, CT are maintained in operational condition throughout the life of the project. The service procedures associated with this plan shall be performed as required by the parties legally responsible for their maintenance. Recommended Frequency of Service: As further defined below, all stormwater components should be checked on a periodic basis and kept in full working order. Ultimately, the required frequency of inspection and service will depend on runoff quantities, pollutant loading, and clogging due to debris. At a minimum, we recommend that all stormwater components be inspected and serviced twice per year, once before winter begins and once during spring cleanup. Qualified Inspector: The inspections must be completed by an individual experienced in the construction and maintenance of stormwater drainage systems. Once every five years the inspections must be completed by a professional engineer. Service Procedures: 1. Catch Basins & Drainage Inlets: a. Catch basins and drainage inlets shall be completely cleaned of accumulated debris and sediments at the completion of construction. b. For the first year, catch basins and drainage inlets shall be inspected on a quarterly basis. c. Any accumulated debris within the catch basins/inlets shall be removed and any repairs as required. d. From the second year onward, visual inspections shall occur twice per year, once in the spring and once in the fall, after fall cleanup of leaves has occurred. e. Accumulated debris within the catch basins/inlets shall be removed and repairs made as required. f. Accumulated sediments shall be removed at which time they are within 12 inches of the invert of the outlet pipe. g. Any additional maintenance required per the manufacturer’s specifications shall also be completed. 2. Storm Drainage Piping and Manholes/Junction Boxes: a. All storm drainage piping shall be completely flushed of debris and accumulated sediment at the completion of construction. b. Manholes/Junction Boxes shall be inspected and repaired on an annual basis. c. Unless system performance indicates degradation of piping, comprehensive video inspection of storm drainage piping shall occur once every ten years. d. Any additional maintenance required per the manufacturer’s specifications shall also be completed. 3. Stormwater Inlet/Control Structures: a. All control structures (orifice, weir, etc.) shall be completely cleaned of accumulated debris and sediments at the completion of construction. Any repairs shall be performed. b. For the first year, control structures (orifice, weir, etc.) shall be inspected on a quarterly basis. c. Any accumulated debris shall be removed and any repairs made to the control structures (orifice, weir, etc.) as required. d. From the second year onward, visual inspections shall occur twice per year, once in the spring and once in the fall, after fall cleanup of leaves has occurred. e. Accumulated debris shall be removed and repairs made as required. f. Any additional maintenance required per the manufacturer’s specifications shall also be completed. 4. Drywells and Infiltration Systems: a. All drywells/infiltrators shall be completely cleaned of accumulated debris and sediments upon the completion of construction. b. For the first year, the drywells/infiltrators shall be inspected on a quarterly basis. c. Any accumulated debris within the drywells/infiltrators shall be removed and any repairs made to the units as required. d. From the second year onward, visual inspection shall occur twice per year, once in the spring and once in the fall, after fall cleanup of leaves has occurred. e. Accumulated debris within the units shall be removed and repairs made as required. f. Any additional maintenance required per the manufacturer’s specifications shall also be completed. 5. Roof Gutters: a. Remove accumulated debris and inspect for damage. Any damage should be repaired as required. Disposal of Debris and Sediment: All debris and sediment removed from the stormwater structures and bioretention/biofiltration basins shall be disposed of legally. There shall be no dumping of silt or debris into or in proximity to any inland or tidal wetlands. Maintenance Records: The Owners(s) must maintain all records (logs, invoices, reports, data, etc.) and have them readily available for inspection at all times. Operations and Maintenance Log (Page 1 of 3) #245 Route 32 Norwich New London Tpke. Montville, CT March 8, 2022 30, _________________________________________________________________________________ Type of Inspection:  Spring  Fall  Other Inspector’s Name:______________________________ Date of Inspection:___________________ Affiliation:_____________________________________ Phone #:___________________________ Catch Basins & Drainage Inlets: · Has accumulated debris been removed from grates?  Yes  No  N/A · Do any basins require additional repair? (identify below):  Yes  No  N/A · Have sumps been cleaned of sediment?  Yes  No  N/A Notes: Storm Drainage Piping and Manholes/Junction Boxes: · Has accumulated debris been removed?  Yes  No  N/A · Do any manholes require additional repair? (identify below):  Yes  No  N/A · Is there any evidence of stormwater piping failure?  Yes  No  N/A · Has a comprehensive video inspection been completed?  Yes  No  N/A Notes: Stormwater Control Structures: · Has accumulated debris been removed?  Yes  No  N/A · Are any repairs required? (identify below):  Yes  No  N/A · Have orifices and weirs been cleaned of debris?  Yes  No  N/A Notes: Operations and Maintenance Log (Page 2 of 3) #245 Route 32 Norwich New London Tpke., Montville, CT March 8, 2022 Drainage Outfalls/Splash Pads/Scour Holes/Level Spreaders: · Have all drainage outlets been cleared of debris?  Yes  No  N/A · Have all outlet protections been inspected/repaired?  Yes  No  N/A · Have all erosion issues been repaired?  Yes  No  N/A Notes: Drywells and Infiltration Systems: · Have units been cleared of debris/sediments?  Yes  No  N/A · Do units require additional repair? (identify below):  Yes  No  N/A · Has draining times of system been verified?  Yes  No  N/A Notes: Roof Gutters: · Has accumulated debris been removed from gutters?  Yes  No  N/A · Do any gutters require additional repair? (identify below):  Yes  No  N/A Notes: Operations and Maintenance Log (Page 3 of 3) #245 Route 32 Norwich New London Tpke. Montville CT March 8, 2022 Please make additional notes/observations and particular concerns below. Also record any additional maintenance that has been performed: __________________________________________________________ _____________________ Signature of Inspector: Date: