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HomeMy WebLinkAboutSD-21-19 - Supplemental - 0600 Spear Street (15)478 Blair Park Road Williston, VT 05495 802 879 6331www.tcevt.com42 Mapleville Depot Road St. Albans, VT 05478 802 528 5116 Civil Engineering Environmental Services Land Surveying Landscape Architecture 19-268 March 18, 2022 Prepared By: Trudell Consulting Engineers STORMWATER MANAGEMENT PLAN 600 SPEAR STREET – SOUTH BURLINGTON, VERMONT 1.Project Description This project consists of a residential development located at 600 Spear Street in South Burlington, Vermont. The parcel is approximately 8.63 acres in size and is developed with a residential apartment building and a commercial warehouse building. This project proposes to add eight four-plex units to the parcel, one public street and four residential parking areas off of the public road. The existing apartment and commercial building will remain. Thirty-two (32) new units are proposed and two (2) units will remain for a total of thirty-four (34) residential units. This project will create approximately 4.78 acres of earth disturbance during construction including site work, redevelopment, and creation of new impervious surfaces. The project contains 0.46 acres of existing impervious surface of which some will remain, some will be redeveloped and some will be removed. The project proposes to add 1.85 acres of impervious surface such that the total resulting impervious surface on site will be 2.22 acres. The proposed treatment system has been designed to meet and exceed the provisions of the 2017 Vermont Stormwater Management Manual (VSMM) for up to the 10-year storm, and has been designed in accordance with the South Burlington City Ordinance: Stormwater Upgrade Feasibility Analysis which requires that stormwater treatment practices be designed up to the 25-year storm. 2.Receiving Waters For existing conditions, there is one discharge point in the northwest corner of the project site. The first discharge point is at the northwest corner of the site and the second is at the southern edge. The proposed project will have one discharge point, S/N 001, located at the northwest corner of the project site. All runoff from this project discharges into a Class II wetland which drains to a tributary of the Potash Brook. 3.Existing Conditions The parcel is currently developed with 0.55 acres of impervious surface including building coverage, a small paved driveway and a gravel driveway with parking area. Topography throughout the site is flat with slopes ranging from 0% to 5% in the area proposed to be developed. Topography surrounding the site is also flat in all directions except to the north where the site drops off at up to 35% slopes down towards an existing drainage ditch and the Class II wetlands. Soils within the developed project area are very well drained, loamy sands and transition within the wetland buffer to fine sandy loams. Three soils are mapped within the project area: 478 Blair Park Road Williston, VT 05495 802 879 6331www.tcevt.com42 Mapleville Depot Road St. Albans, VT 05478 802 528 5116 Civil Engineering Environmental Services Land Surveying Landscape Architecture Stormwater Management Plan Page 2 600 Spear Street – South Burlington, Vermont March 18, 2022 o AdA – Adams and Windsor sandy loams, Hydrologic Soil Group (HSG) A o AdD – Adams and Windsor sandy loams, HSG A o HnB – Hinesburg fine sandy loams, HSG A Soils on site have been field verified during soil excavations for environmental assessments and are included herein for reference. No ledge was encountered during test pit excavations. It should be noted that this site is considered disturbed and contaminated and therefore all drainage practices designed must take this into consideration. In general, the site is comprised of sands and gravels, slightly moist at depths around 7-8’ and some silts/clays are mixed in. 4.Existing Stormwater System There is no regulated existing stormwater system for the developed site. In general, the site naturally infiltrates most rain events. 5.Proposed Stormwater System Stormwater treatment will be provided by directing runoff from new buildings to roof drain downspouts where runoff can overland flow into bioretention treatment areas dispersed throughout the site. Sidewalk runoff will be disconnected where possible and where not feasible, runoff will overland flow through a peastone filter strip providing pre-treatment before discharging to a bioretention area. Road runoff will be pre-treated with deep sump catch basins and discharge to bioretention areas. Because the site is contaminated, the bioretention areas will be lined and all stormwater will be contained within a closed network. Runoff will not recharge the site except where as allowed with sidewalk disconnects. This system meets the water quality volume (WQv) standard, channel protection (CPv) standard and pre/post peak reduction (Qp10) requirements with disconnection, pre-treatment, and bioretention areas. This system also meets requirements set by the South Burlington Stormwater Utility (SBSU), which requires the project to meet State standards, as well as treat up to the 25-year storm event. Impervious Area The project proposes a total of 96,575 sf (2.22 ac) impervious surface. Refer to Sheets C4-01 and C4-02 for visual information as it relates to impervious for the project. This project was designed to meet the provisions of the Vermont Stormwater Management Manual 2017. Receiving Body One discharge point, S/N 001, has been established for this project. All runoff from this project discharges into a Class II wetland which drains to a tributary of the Potash Brook and is located at the northwest portion of the site. 478 Blair Park Road Williston, VT 05495 802 879 6331www.tcevt.com42 Mapleville Depot Road St. Albans, VT 05478 802 528 5116 Civil Engineering Environmental Services Land Surveying Landscape Architecture Stormwater Management Plan Page 3 600 Spear Street – South Burlington, Vermont March 18, 2022 Fish Habitat and Impaired Watershed This project discharges to warm water fisheries and discharges to waterbody VT05-11 which is impaired due to Chloride from road salt with a TMDL Priority of Low. Conformance with the 2017 Vermont Stormwater Management Manual Rule and Design Guidance ensures that discharges to an impaired watershed are permitted. Drainage Areas The site has been analyzed with one drainage area to model the pre- development stormwater conditions and five drainage areas to model the post- development stormwater conditions. The proposed drainage areas are summarized below: DA Discharge Point Total Area (ac)Impervious Area (ac) Proposed Treatment 1 S/N 001 1.028 0.672 Bioretention 2A S/N 001 0.522 0.231 Bioretention 2B S/N 001 0.353 0.102 Bioretention 3 S/N 001 1.223 0.769 Bioretention 4 S/N 001 0.441 0.240 Bioretention Demonstration of Compliance Compliance with the treatment standards are demonstrated for the site through HydroCAD modelling with supporting application materials and plans. The following sections show how each of the design criteria have been addressed. This project has been designed to reduce off-site runoff by capturing, treating, detaining, disconnecting and reducing runoff from new impervious surfaces. 5.E.i Post-Construction Soil Depth and Quality Standard Site details within the plan set provide overview information for the contractor on how to comply with the Post-Construction Soil Depth and Quality Standard. A very small portion of the site will be disturbed and not covered with an impervious surface or stormwater treatment area, therefore, this standard has minimal application. 5.E.ii Water Quality Treatment Standard (WQv) Water quality treatment ensures the removal of suspended solids and phosphorus typically found in stormwater. The water quality treatment standard for this project is met using pre-treatment via stone diaphragms that surround several of the bioretention areas, as well as deep sump catch basins. The bioretention practices provide 24-hour detention of runoff that is exfiltrated through the bioretention soil into a 6” HDPE perforated drain that conveys the runoff into an outlet structure and then to S/N 001. The hydrologic model of the 1”, 24-hr. rain event was performed to ensure conformance with the standard. 478 Blair Park Road Williston, VT 05495 802 879 6331www.tcevt.com42 Mapleville Depot Road St. Albans, VT 05478 802 528 5116 Civil Engineering Environmental Services Land Surveying Landscape Architecture Stormwater Management Plan Page 4 600 Spear Street – South Burlington, Vermont March 18, 2022 5.E.iii Groundwater Recharge Treatment Standard (Rev) The groundwater recharge treatment standard is important to achieve especially for well drained sites with Hydrologic Group A soils, however because this site is contaminated, the bioretention practices must be lined and therefore cannot infiltrate into the ground. Disconnection of sidewalk runoff will likely occur onsite and will provided 0.0293 ac-ft of the required 0.1007 ac-ft, however further disconnection is not feasible. 5.E.iv Channel Protection Standard (CPv) The channel protection volume standard is met by providing extended detention above the bioretention areas in each drainage area. Although the HydroCAD shows that the 24-hour extended detention is not met, all discharges are controlled either through a 1” orifice or are controlled through exfiltration through the soil into 6” HDPE perforated underdrains. Each bioretention area has a peak discharge rate ranging from 0.1 cfs to 0.3 cfs. 5.E.v Overbank Flood Protection Standard (Qp10) The Qp10 standard is met by detention above each of the bioretention areas with discharge via 8” horizontal orifices in outlet structures in each practice. Routing the runoff through management practices results in a reduced post-development stormwater discharge rate as compared to existing conditions, therefore this treatment standard is met. Pre-development runoff Rate: 0.67 cfs Pre-Routed post-development runoff Rate: 8.83 cfs Routed post-development runoff Rate: 0.21 cfs 5.E.vi SBSU Standard – 25-yr, 24-hr Storm The SBSU 25-yr storm event standard is met by detention above each of the bioretention areas with discharge via 8” horizontal orifices in outlet structures in each practice. Routing the runoff through management practices results in a reduced post-development stormwater discharge rate as compared to existing conditions, therefore this treatment standard is met. Pre-development runoff Rate: 0.81 cfs Pre-Routed post-development runoff Rate: 10.57 cfs Routed post-development runoff Rate: 0.61 cfs 478 Blair Park Road Williston, VT 05495 802 879 6331www.tcevt.com42 Mapleville Depot Road St. Albans, VT 05478 802 528 5116 Civil Engineering Environmental Services Land Surveying Landscape Architecture Stormwater Management Plan Page 5 600 Spear Street – South Burlington, Vermont March 18, 2022 5.E.vii Extreme Flood Protection Standard (Qp100) Not required as this development does not exceed 10 acres of impervious. Best Management Practices Water quality is achieved through utilization of five bioretention areas in lieu of a traditional large treatment pond. The bioretention areas modeled within five (5) nodes in HydroCAD were selected as the primary treatment component for the site. These treatment areas, also known as rain gardens, will provide a dynamic landscaping that is aesthetic and functional. Due to the HSG A soils, there is a possibility that runoff from rooftops will flow overland and infiltrate back into the earth. Where feasible, sidewalks are also disconnected and runoff is allowed to infiltrate into the ground surface. Finally, the heavily landscaped site includes a plethora of newly planted trees which will treat water that infiltrates into the ground. These plantings provide water quality for areas of the site which cannot be feasibly captured and treated through reforestation tree credits. Pre-treatment is achieved using deep sump catch basins (Bioretention Areas 4 and 5), as well as peastone diaphragms (Bioretention Areas 1, 2, 3, and 4). The bioretention areas near homes nestled into the front yards receive runoff from rooftops which do not require pretreatment. Wetland continues northwest Wetland continues southeast Unnamed tributary of Potash Brook 296295 294 293 292 291 290298299300301302303297289287304305288306286285284281283 300295 305296 297289 298299302285 304296 286 2963032 9 6 295297 303306290 2 9 3 300288 301298295 294 2993022942 8 7 30029430429329229829629 5 301 289291290 302298299 297 295288 Wetland C0.06 ac Wetland B0.03 ac Wetland D0.02 ac HnB AdD EwA AdA BlB ScA AdB An DdA HnB Location ^_ Copyright:© 2013 NationalGeographic Society, i-cubed Project Parcel (8.66 ac) Tax Parcel Boundary Existing Farm Swale Class II Wetland Buffer (50') TCE Wetland Delineation (0.18 ac)Class II (0.08 ac) Class III (0.1 ac) Contour (1') NRCS Soils NRCS Hydric Soils Ground Water SPA* Surface Water SPA VHD Stream VHD Open Water* River Corridor* Floodway* Class A Watershed* FEMA Flood Zone*A* AE* No Data* Deer Wintering Areas* Indiana Bat Hibernacula* Significant Natural Community* RTE Species* Uncommon Species* * = Layer does not occur within the map extent. ** = FEMA Flood Zone layer contains FEMA-digitized data only.Some locations may not have data. Sources: Aerial Imagery by Google Earth; Streams by VHD (2018); VTE911 Roads (2019); Soils by NRCS (2021); Contours by VCGI & CCRPC (Various dates); RTE Species and Natural Community by VT Fish & Wildlife (2020); Uncommon Species by VT Fish &Wildlife (2020). Tax Parcel Boundary compiled by VCGI; Deer Wintering Areaby ANR (2020); River Corridor by ANR (2019); Groundwater & SurfaceWater Protection Areas by ANR (2019); All other layers by TCE (2021). Disclaimer: The accuracy of information presented is determined by itssources.TCE is not responsible for any errors or omissions that may exist.Questions of on-the-ground location can be resolved by site inspections and/or surveys by a registered surveyor. This map is not a replacement for surveyed information or engineering studies. Legend 802.879.6331 www.tcevt.com [ 0 120 240 360 48060Feet 600 Spear StreetSouth Burlington, VT Natural Resources Map Project: 19-268Prepared By: SRK03/18/20221 inch = 120 feet Soil Key Soil Description Hydric Hydrogroup On Site KfactWS Prime Ag ValueAdAAdams and Windsor loamy sands, 0 to 5 percent slopes N A Ia .10 Statewide 6AdDAdams and Windsor loamy sands, 12 to 30 percent slopes N A Ib .10 NPSL 8HnBHinesburg fine sandy loam, 3 to 8 percent slopes N A IIh .17 Prime 3ScAScantic silt loam, 0 to 2 percent slopes Y C/D IVa .32 Statewide 6d 1STE DA 1 Existing 1STPm DA1 - MOD CN 2aSTPm DA2a MOD CN 2bSTPm DA2b MOD CN 3STPm DA3 - MOD CN 4STPm DA4 MOD CN 1 Bioretention Area 1 2 Bioretention Area 2 3 Bioretention Area 3 4 Bioretention Area 4 5 Bioretention Area 5 SN S/N 001 Routing Diagram for 19-268 600 Spear 2022 0119 Prepared by Trudell Consulting Engineers, Printed 3/18/2022 HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link 19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 2HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Rainfall Events Listing (selected events) Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 WQv Type II 24-hr Default 24.00 1 1.00 2 19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 3HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 0.271 98 Impervious (1STE) 2.251 96 MOD CN (1STPm, 3STPm) 0.522 93 MOD CN (2aSTPm) 0.353 90 MOD CN (2bSTPm) 0.441 95 MOD CN (4STPm) 3.295 32 Woods/grass comb., Good, HSG A (1STE) 7.133 66 TOTAL AREA 19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 4HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Soil Listing (selected nodes) Area (acres) Soil Group Subcatchment Numbers 3.295 HSG A 1STE 0.000 HSG B 0.000 HSG C 0.000 HSG D 3.838 Other 1STE, 1STPm, 2aSTPm, 2bSTPm, 3STPm, 4STPm 7.133 TOTAL AREA 19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 5HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Ground Covers (selected nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 0.000 0.000 0.271 0.271 Impervious 1STE 0.000 0.000 0.000 0.000 3.567 3.567 MOD CN 1STPm, 2aSTPm, 2bSTPm, 3STPm, 4STPm 3.295 0.000 0.000 0.000 0.000 3.295 Woods/grass comb., Good 1STE 3.295 0.000 0.000 0.000 3.838 7.133 TOTAL AREA 19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 6HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pipe Listing (selected nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Width (inches) Diam/Height (inches) Inside-Fill (inches) 11 291.25 291.00 22.4 0.0112 0.013 0.0 12.0 0.0 22 293.25 293.00 23.8 0.0105 0.013 0.0 12.0 0.0 33 293.25 293.00 12.7 0.0197 0.013 0.0 12.0 0.0 44 290.25 290.10 50.0 0.0030 0.013 0.0 12.0 0.0 55 291.25 290.25 96.7 0.0103 0.013 0.0 12.0 0.0 Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 7HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=3.566 ac 7.60% Impervious Runoff Depth=0.06"Subcatchment 1STE: DA 1 Existing Flow Length=370' Slope=0.0270 '/' Tc=27.5 min CN=WQ Runoff=0.19 cfs 0.018 af Runoff Area=1.028 ac 0.00% Impervious Runoff Depth=0.63"Subcatchment 1STPm: DA1 - MOD CN Flow Length=165' Slope=0.0180 '/' Tc=3.0 min CN=96 Runoff=1.26 cfs 0.054 af Runoff Area=0.522 ac 0.00% Impervious Runoff Depth=0.45"Subcatchment 2aSTPm: DA2a MOD CN Tc=0.0 min CN=93 Runoff=0.52 cfs 0.020 af Runoff Area=0.353 ac 0.00% Impervious Runoff Depth=0.32"Subcatchment 2bSTPm: DA2b MOD CN Flow Length=91' Slope=0.0140 '/' Tc=2.8 min CN=90 Runoff=0.23 cfs 0.009 af Runoff Area=1.223 ac 0.00% Impervious Runoff Depth=0.63"Subcatchment 3STPm: DA3 - MOD CN Flow Length=380' Slope=0.0200 '/' Tc=5.5 min CN=96 Runoff=1.37 cfs 0.064 af Runoff Area=0.441 ac 0.00% Impervious Runoff Depth=0.56"Subcatchment 4STPm: DA4 MOD CN Flow Length=179' Slope=0.0320 '/' Tc=2.5 min CN=95 Runoff=0.50 cfs 0.021 af Peak Elev=294.72' Storage=1,704 cf Inflow=1.26 cfs 0.054 afPond 1: Bioretention Area 1 Outflow=0.02 cfs 0.050 af Peak Elev=296.95' Storage=631 cf Inflow=0.52 cfs 0.020 afPond 2: Bioretention Area 2 Outflow=0.01 cfs 0.017 af Peak Elev=296.79' Storage=304 cf Inflow=0.23 cfs 0.009 afPond 3: Bioretention Area 3 Outflow=0.00 cfs 0.008 af Peak Elev=293.91' Storage=2,401 cf Inflow=1.37 cfs 0.064 afPond 4: Bioretention Area 4 Outflow=0.01 cfs 0.037 af Peak Elev=294.90' Storage=754 cf Inflow=0.50 cfs 0.021 afPond 5: Bioretention Area 5 Outflow=0.00 cfs 0.013 af Inflow=0.04 cfs 0.126 afPond SN: S/N 001 Primary=0.04 cfs 0.126 af Total Runoff Area = 7.133 ac Runoff Volume = 0.186 af Average Runoff Depth = 0.31" 96.20% Pervious = 6.862 ac 3.80% Impervious = 0.271 ac Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 8HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1STE: DA 1 Existing Runoff =0.19 cfs @ 12.19 hrs, Volume=0.018 af, Depth= 0.06" Routed to nonexistent node 3L Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr WQv Rainfall=1.00" Area (ac) CN Description *0.271 98 Impervious 3.295 32 Woods/grass comb., Good, HSG A 3.566 Weighted Average 3.295 92.40% Pervious Area 0.271 7.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 27.5 370 0.0270 0.22 Lag/CN Method, Lag Subcatchment 1STE: DA 1 Existing Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr WQv Rainfall=1.00" Runoff Area=3.566 ac Runoff Volume=0.018 af Runoff Depth=0.06" Flow Length=370' Slope=0.0270 '/' Tc=27.5 min CN=WQ 0.19 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 9HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1STPm: DA1 - MOD CN Runoff =1.26 cfs @ 11.94 hrs, Volume=0.054 af, Depth= 0.63" Routed to Pond 1 : Bioretention Area 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr WQv Rainfall=1.00" Area (ac) CN Description *1.028 96 MOD CN 1.028 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 3.0 165 0.0180 0.92 Lag/CN Method, Subcatchment 1STPm: DA1 - MOD CN Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr WQv Rainfall=1.00" Runoff Area=1.028 ac Runoff Volume=0.054 af Runoff Depth=0.63" Flow Length=165' Slope=0.0180 '/' Tc=3.0 min CN=96 1.26 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 10HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2aSTPm: DA2a MOD CN [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.52 cfs @ 11.90 hrs, Volume=0.020 af, Depth= 0.45" Routed to Pond 2 : Bioretention Area 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr WQv Rainfall=1.00" Area (ac) CN Description *0.522 93 MOD CN 0.522 100.00% Pervious Area Subcatchment 2aSTPm: DA2a MOD CN Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr WQv Rainfall=1.00" Runoff Area=0.522 ac Runoff Volume=0.020 af Runoff Depth=0.45" Tc=0.0 min CN=93 0.52 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 11HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2bSTPm: DA2b MOD CN Runoff =0.23 cfs @ 11.94 hrs, Volume=0.009 af, Depth= 0.32" Routed to Pond 3 : Bioretention Area 3 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr WQv Rainfall=1.00" Area (ac) CN Description *0.353 90 MOD CN 0.353 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 2.8 91 0.0140 0.55 Lag/CN Method, Subcatchment 2bSTPm: DA2b MOD CN Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr WQv Rainfall=1.00" Runoff Area=0.353 ac Runoff Volume=0.009 af Runoff Depth=0.32" Flow Length=91' Slope=0.0140 '/' Tc=2.8 min CN=90 0.23 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 12HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 3STPm: DA3 - MOD CN Runoff =1.37 cfs @ 11.97 hrs, Volume=0.064 af, Depth= 0.63" Routed to Pond 4 : Bioretention Area 4 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr WQv Rainfall=1.00" Area (ac) CN Description *1.223 96 MOD CN 1.223 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 5.5 380 0.0200 1.15 Lag/CN Method, Subcatchment 3STPm: DA3 - MOD CN Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr WQv Rainfall=1.00" Runoff Area=1.223 ac Runoff Volume=0.064 af Runoff Depth=0.63" Flow Length=380' Slope=0.0200 '/' Tc=5.5 min CN=96 1.37 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 13HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 4STPm: DA4 MOD CN Runoff =0.50 cfs @ 11.93 hrs, Volume=0.021 af, Depth= 0.56" Routed to Pond 5 : Bioretention Area 5 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr WQv Rainfall=1.00" Area (ac) CN Description *0.441 95 MOD CN 0.441 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 2.5 179 0.0320 1.19 Lag/CN Method, Subcatchment 4STPm: DA4 MOD CN Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr WQv Rainfall=1.00" Runoff Area=0.441 ac Runoff Volume=0.021 af Runoff Depth=0.56" Flow Length=179' Slope=0.0320 '/' Tc=2.5 min CN=95 0.50 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 14HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1: Bioretention Area 1 Inflow Area =1.028 ac, 0.00% Impervious, Inflow Depth = 0.63" for WQv event Inflow =1.26 cfs @ 11.94 hrs, Volume=0.054 af Outflow =0.02 cfs @ 17.76 hrs, Volume=0.050 af, Atten= 99%, Lag= 349.2 min Primary =0.02 cfs @ 17.76 hrs, Volume=0.050 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 294.72' @ 17.76 hrs Surf.Area= 3,103 sf Storage= 1,704 cf Plug-Flow detention time= 1,225.2 min calculated for 0.050 af (92% of inflow) Center-of-Mass det. time= 1,181.7 min ( 1,989.9 - 808.3 ) Volume Invert Avail.Storage Storage Description #1 294.00'7,418 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 294.00 1,613 0 0 295.00 3,676 2,645 2,645 296.00 5,870 4,773 7,418 Device Routing Invert Outlet Devices #1 Primary 291.25'12.0" Round Culvert L= 22.4' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 291.25' / 291.00' S= 0.0112 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 294.00'0.500 in/hr Exfiltration over Surface area from 294.00' - 296.00' Excluded Surface area = 1,613 sf #3 Device 1 295.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 295.60'8.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.02 cfs @ 17.76 hrs HW=294.72' (Free Discharge) 1=Culvert (Passes 0.02 cfs of 6.52 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.02 cfs) 3=CPv Orifice ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 15HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 1: Bioretention Area 1 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=1.028 ac Peak Elev=294.72' Storage=1,704 cf 1.26 cfs 0.02 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 16HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 2: Bioretention Area 2 Inflow Area =0.522 ac, 0.00% Impervious, Inflow Depth = 0.45" for WQv event Inflow =0.52 cfs @ 11.90 hrs, Volume=0.020 af Outflow =0.01 cfs @ 19.78 hrs, Volume=0.017 af, Atten= 99%, Lag= 472.7 min Primary =0.01 cfs @ 19.78 hrs, Volume=0.017 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 296.95' @ 19.78 hrs Surf.Area= 897 sf Storage= 631 cf Plug-Flow detention time= 1,325.1 min calculated for 0.017 af (88% of inflow) Center-of-Mass det. time= 1,265.4 min ( 2,097.4 - 832.0 ) Volume Invert Avail.Storage Storage Description #1 296.00'1,908 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 296.00 426 0 0 297.00 920 673 673 298.00 1,550 1,235 1,908 Device Routing Invert Outlet Devices #1 Primary 293.25'12.0" Round Culvert L= 23.8' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 293.25' / 293.00' S= 0.0105 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 296.00'0.500 in/hr Exfiltration over Surface area from 296.00' - 298.00' Excluded Surface area = 426 sf #3 Device 1 297.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 297.80'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.01 cfs @ 19.78 hrs HW=296.95' (Free Discharge) 1=Culvert (Passes 0.01 cfs of 6.77 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.01 cfs) 3=CPv Orifice ( Controls 0.00 cfs) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 17HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 2: Bioretention Area 2 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.522 ac Peak Elev=296.95' Storage=631 cf 0.52 cfs 0.01 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 18HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 3: Bioretention Area 3 Inflow Area =0.353 ac, 0.00% Impervious, Inflow Depth = 0.32" for WQv event Inflow =0.23 cfs @ 11.94 hrs, Volume=0.009 af Outflow =0.00 cfs @ 23.61 hrs, Volume=0.008 af, Atten= 99%, Lag= 700.5 min Primary =0.00 cfs @ 23.61 hrs, Volume=0.008 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 296.79' @ 23.61 hrs Surf.Area= 499 sf Storage= 304 cf Plug-Flow detention time= 1,322.7 min calculated for 0.008 af (87% of inflow) Center-of-Mass det. time= 1,257.7 min ( 2,114.3 - 856.5 ) Volume Invert Avail.Storage Storage Description #1 296.00'1,148 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 296.00 274 0 0 297.00 560 417 417 298.00 901 731 1,148 Device Routing Invert Outlet Devices #1 Primary 293.25'12.0" Round Culvert L= 12.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 293.25' / 293.00' S= 0.0197 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 296.00'0.500 in/hr Exfiltration over Surface area from 296.00' - 298.00' Excluded Surface area = 274 sf #3 Device 1 297.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 297.60'18.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.00 cfs @ 23.61 hrs HW=296.79' (Free Discharge) 1=Culvert (Passes 0.00 cfs of 6.59 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.00 cfs) 3=CPv Orifice ( Controls 0.00 cfs) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 19HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 3: Bioretention Area 3 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.353 ac Peak Elev=296.79' Storage=304 cf 0.23 cfs 0.00 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 20HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 4: Bioretention Area 4 Inflow Area =1.223 ac, 0.00% Impervious, Inflow Depth = 0.63" for WQv event Inflow =1.37 cfs @ 11.97 hrs, Volume=0.064 af Outflow =0.01 cfs @ 24.05 hrs, Volume=0.037 af, Atten= 99%, Lag= 725.3 min Primary =0.01 cfs @ 24.05 hrs, Volume=0.037 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 293.91' @ 24.05 hrs Surf.Area= 3,042 sf Storage= 2,401 cf Plug-Flow detention time= 1,630.1 min calculated for 0.037 af (58% of inflow) Center-of-Mass det. time= 1,520.1 min ( 2,330.7 - 810.6 ) Volume Invert Avail.Storage Storage Description #1 293.00'16,926 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 293.00 2,215 0 0 294.00 3,120 2,668 2,668 295.00 4,162 3,641 6,309 296.00 5,289 4,726 11,034 297.00 6,494 5,892 16,926 Device Routing Invert Outlet Devices #1 Primary 290.25'12.0" Round Culvert L= 50.0' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 290.25' / 290.10' S= 0.0030 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 293.00'0.500 in/hr Exfiltration over Surface area from 293.00' - 297.00' Excluded Surface area = 2,215 sf #3 Device 1 294.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 295.10'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.01 cfs @ 24.05 hrs HW=293.91' (Free Discharge) 1=Culvert (Passes 0.01 cfs of 6.03 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.01 cfs) 3=CPv Orifice ( Controls 0.00 cfs) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 21HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 4: Bioretention Area 4 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=1.223 ac Peak Elev=293.91' Storage=2,401 cf 1.37 cfs 0.01 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 22HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 5: Bioretention Area 5 Inflow Area =0.441 ac, 0.00% Impervious, Inflow Depth = 0.56" for WQv event Inflow =0.50 cfs @ 11.93 hrs, Volume=0.021 af Outflow =0.00 cfs @ 24.02 hrs, Volume=0.013 af, Atten= 99%, Lag= 725.3 min Primary =0.00 cfs @ 24.02 hrs, Volume=0.013 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 294.90' @ 24.02 hrs Surf.Area= 993 sf Storage= 754 cf Plug-Flow detention time= 1,583.6 min calculated for 0.013 af (65% of inflow) Center-of-Mass det. time= 1,475.8 min ( 2,293.4 - 817.7 ) Volume Invert Avail.Storage Storage Description #1 294.00'3,696 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 294.00 683 0 0 295.00 1,027 855 855 296.00 1,411 1,219 2,074 297.00 1,833 1,622 3,696 Device Routing Invert Outlet Devices #1 Primary 291.25'12.0" Round Culvert L= 96.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 291.25' / 290.25' S= 0.0103 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 294.00'0.500 in/hr Exfiltration over Surface area from 294.00' - 297.00' Excluded Surface area = 683 sf #3 Device 1 295.00'1.0" Vert. Cpv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 296.00'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.00 cfs @ 24.02 hrs HW=294.90' (Free Discharge) 1=Culvert (Passes 0.00 cfs of 5.65 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.00 cfs) 3=Cpv Orifice ( Controls 0.00 cfs) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 23HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 5: Bioretention Area 5 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.441 ac Peak Elev=294.90' Storage=754 cf 0.50 cfs 0.00 cfs Type II 24-hr WQv Rainfall=1.00"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 24HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond SN: S/N 001 [40] Hint: Not Described (Outflow=Inflow) Inflow Area =3.567 ac, 0.00% Impervious, Inflow Depth > 0.42" for WQv event Inflow =0.04 cfs @ 19.67 hrs, Volume=0.126 af Primary =0.04 cfs @ 19.67 hrs, Volume=0.126 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Pond SN: S/N 001 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.042 0.04 0.038 0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Inflow Area=3.567 ac0.04 cfs0.04 cfs 1STE DA 1 Existing 1STP DA1 2aSTP DA2a 2bSTP DA2b 3STP DA3 4STP DA4 1 Bioretention Area 1 2 Bioretention Area 2 3 Bioretention Area 3 4 Bioretention Area 4 5 Bioretention Area 5 SN S/N 001 Routing Diagram for 19-268 600 Spear 2022 0119 Prepared by Trudell Consulting Engineers, Printed 3/18/2022 HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link 19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 2HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Rainfall Events Listing (selected events) Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 1-Year Type II 24-hr Default 24.00 1 1.87 2 2 10-Year Type II 24-hr Default 24.00 1 3.20 2 3 25-Year Type II 24-hr Default 24.00 1 3.82 2 19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 3HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 1.553 39 >75% Grass cover, Good, HSG A (1STP, 2aSTP, 2bSTP, 3STP, 4STP) 2.285 98 Impervious (1STE, 1STP, 2aSTP, 2bSTP, 3STP, 4STP) 3.295 32 Woods/grass comb., Good, HSG A (1STE) 7.133 55 TOTAL AREA 19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 4HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Soil Listing (selected nodes) Area (acres) Soil Group Subcatchment Numbers 4.848 HSG A 1STE, 1STP, 2aSTP, 2bSTP, 3STP, 4STP 0.000 HSG B 0.000 HSG C 0.000 HSG D 2.285 Other 1STE, 1STP, 2aSTP, 2bSTP, 3STP, 4STP 7.133 TOTAL AREA 19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 5HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Ground Covers (selected nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 1.553 0.000 0.000 0.000 0.000 1.553 >75% Grass cover, Good 1STP, 2aSTP, 2bSTP, 3STP, 4STP 0.000 0.000 0.000 0.000 2.285 2.285 Impervious 1STE, 1STP, 2aSTP, 2bSTP, 3STP, 4STP 3.295 0.000 0.000 0.000 0.000 3.295 Woods/grass comb., Good 1STE 4.848 0.000 0.000 0.000 2.285 7.133 TOTAL AREA 19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 6HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pipe Listing (selected nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Width (inches) Diam/Height (inches) Inside-Fill (inches) 11 291.25 291.00 22.4 0.0112 0.013 0.0 12.0 0.0 22 293.25 293.00 23.8 0.0105 0.013 0.0 12.0 0.0 33 293.25 293.00 12.7 0.0197 0.013 0.0 12.0 0.0 44 290.25 290.10 50.0 0.0030 0.013 0.0 12.0 0.0 55 291.25 290.25 96.7 0.0103 0.013 0.0 12.0 0.0 Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 7HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=3.566 ac 7.60% Impervious Runoff Depth=0.13"Subcatchment 1STE: DA 1 Existing Flow Length=370' Slope=0.0270 '/' Tc=27.5 min CN=WQ Runoff=0.38 cfs 0.037 af Runoff Area=1.028 ac 65.37% Impervious Runoff Depth=1.08"Subcatchment 1STP: DA1 Flow Length=165' Slope=0.0180 '/' Tc=6.0 min CN=WQ Runoff=1.74 cfs 0.092 af Runoff Area=0.522 ac 44.25% Impervious Runoff Depth=0.73"Subcatchment 2aSTP: DA2a Flow Length=97' Slope=0.0130 '/' Tc=6.6 min CN=WQ Runoff=0.59 cfs 0.032 af Runoff Area=0.353 ac 28.90% Impervious Runoff Depth=0.48"Subcatchment 2bSTP: DA2b Flow Length=91' Slope=0.0140 '/' Tc=7.6 min CN=WQ Runoff=0.25 cfs 0.014 af Runoff Area=1.223 ac 62.88% Impervious Runoff Depth=1.03"Subcatchment 3STP: DA3 Flow Length=254' Slope=0.0220 '/' Tc=8.1 min CN=WQ Runoff=1.86 cfs 0.105 af Runoff Area=0.441 ac 54.42% Impervious Runoff Depth=0.90"Subcatchment 4STP: DA4 Flow Length=179' Slope=0.0320 '/' Tc=5.8 min CN=WQ Runoff=0.63 cfs 0.033 af Peak Elev=295.08' Storage=2,953 cf Inflow=1.74 cfs 0.092 afPond 1: Bioretention Area 1 Outflow=0.03 cfs 0.083 af Peak Elev=297.26' Storage=931 cf Inflow=0.59 cfs 0.032 afPond 2: Bioretention Area 2 Outflow=0.02 cfs 0.029 af Peak Elev=297.05' Storage=444 cf Inflow=0.25 cfs 0.014 afPond 3: Bioretention Area 3 Outflow=0.01 cfs 0.012 af Peak Elev=294.28' Storage=3,599 cf Inflow=1.86 cfs 0.105 afPond 4: Bioretention Area 4 Outflow=0.03 cfs 0.069 af Peak Elev=295.18' Storage=1,041 cf Inflow=0.63 cfs 0.033 afPond 5: Bioretention Area 5 Outflow=0.01 cfs 0.024 af Inflow=0.10 cfs 0.217 afPond SN: S/N 001 Primary=0.10 cfs 0.217 af Total Runoff Area = 7.133 ac Runoff Volume = 0.313 af Average Runoff Depth = 0.53" 67.97% Pervious = 4.848 ac 32.03% Impervious = 2.285 ac Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 8HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1STE: DA 1 Existing Runoff =0.38 cfs @ 12.19 hrs, Volume=0.037 af, Depth= 0.13" Routed to nonexistent node 3L Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1-Year Rainfall=1.87" Area (ac) CN Description *0.271 98 Impervious 3.295 32 Woods/grass comb., Good, HSG A 3.566 Weighted Average 3.295 92.40% Pervious Area 0.271 7.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 27.5 370 0.0270 0.22 Lag/CN Method, Lag Subcatchment 1STE: DA 1 Existing Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 1-Year Rainfall=1.87" Runoff Area=3.566 ac Runoff Volume=0.037 af Runoff Depth=0.13" Flow Length=370' Slope=0.0270 '/' Tc=27.5 min CN=WQ 0.38 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 9HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1STP: DA1 Runoff =1.74 cfs @ 11.97 hrs, Volume=0.092 af, Depth= 1.08" Routed to Pond 1 : Bioretention Area 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1-Year Rainfall=1.87" Area (ac) CN Description *0.672 98 Impervious 0.356 39 >75% Grass cover, Good, HSG A 1.028 Weighted Average 0.356 34.63% Pervious Area 0.672 65.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 6.0 165 0.0180 0.46 Lag/CN Method, Subcatchment 1STP: DA1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 1-Year Rainfall=1.87" Runoff Area=1.028 ac Runoff Volume=0.092 af Runoff Depth=1.08" Flow Length=165' Slope=0.0180 '/' Tc=6.0 min CN=WQ 1.74 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 10HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2aSTP: DA2a Runoff =0.59 cfs @ 11.97 hrs, Volume=0.032 af, Depth= 0.73" Routed to Pond 2 : Bioretention Area 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1-Year Rainfall=1.87" Area (ac) CN Description *0.231 98 Impervious 0.291 39 >75% Grass cover, Good, HSG A 0.522 Weighted Average 0.291 55.75% Pervious Area 0.231 44.25% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 6.6 97 0.0130 0.25 Lag/CN Method, Subcatchment 2aSTP: DA2a Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 1-Year Rainfall=1.87" Runoff Area=0.522 ac Runoff Volume=0.032 af Runoff Depth=0.73" Flow Length=97' Slope=0.0130 '/' Tc=6.6 min CN=WQ 0.59 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 11HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2bSTP: DA2b Runoff =0.25 cfs @ 11.98 hrs, Volume=0.014 af, Depth= 0.48" Routed to Pond 3 : Bioretention Area 3 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1-Year Rainfall=1.87" Area (ac) CN Description *0.102 98 Impervious 0.251 39 >75% Grass cover, Good, HSG A 0.353 Weighted Average 0.251 71.10% Pervious Area 0.102 28.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.6 91 0.0140 0.20 Lag/CN Method, Subcatchment 2bSTP: DA2b Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 1-Year Rainfall=1.87" Runoff Area=0.353 ac Runoff Volume=0.014 af Runoff Depth=0.48" Flow Length=91' Slope=0.0140 '/' Tc=7.6 min CN=WQ 0.25 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 12HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 3STP: DA3 Runoff =1.86 cfs @ 11.99 hrs, Volume=0.105 af, Depth= 1.03" Routed to Pond 4 : Bioretention Area 4 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1-Year Rainfall=1.87" Area (ac) CN Description *0.769 98 Impervious 0.454 39 >75% Grass cover, Good, HSG A 1.223 Weighted Average 0.454 37.12% Pervious Area 0.769 62.88% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 8.1 254 0.0220 0.52 Lag/CN Method, Subcatchment 3STP: DA3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)2 1 0 Type II 24-hr 1-Year Rainfall=1.87" Runoff Area=1.223 ac Runoff Volume=0.105 af Runoff Depth=1.03" Flow Length=254' Slope=0.0220 '/' Tc=8.1 min CN=WQ 1.86 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 13HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 4STP: DA4 Runoff =0.63 cfs @ 11.97 hrs, Volume=0.033 af, Depth= 0.90" Routed to Pond 5 : Bioretention Area 5 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1-Year Rainfall=1.87" Area (ac) CN Description *0.240 98 Impervious 0.201 39 >75% Grass cover, Good, HSG A 0.441 Weighted Average 0.201 45.58% Pervious Area 0.240 54.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 5.8 179 0.0320 0.51 Lag/CN Method, Subcatchment 4STP: DA4 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 1-Year Rainfall=1.87" Runoff Area=0.441 ac Runoff Volume=0.033 af Runoff Depth=0.90" Flow Length=179' Slope=0.0320 '/' Tc=5.8 min CN=WQ 0.63 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 14HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1: Bioretention Area 1 Inflow Area =1.028 ac, 65.37% Impervious, Inflow Depth = 1.08" for 1-Year event Inflow =1.74 cfs @ 11.97 hrs, Volume=0.092 af Outflow =0.03 cfs @ 15.81 hrs, Volume=0.083 af, Atten= 98%, Lag= 230.5 min Primary =0.03 cfs @ 15.81 hrs, Volume=0.083 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 295.08' @ 15.81 hrs Surf.Area= 3,856 sf Storage= 2,953 cf Plug-Flow detention time= 1,273.7 min calculated for 0.083 af (90% of inflow) Center-of-Mass det. time= 1,222.2 min ( 1,987.8 - 765.6 ) Volume Invert Avail.Storage Storage Description #1 294.00'7,418 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 294.00 1,613 0 0 295.00 3,676 2,645 2,645 296.00 5,870 4,773 7,418 Device Routing Invert Outlet Devices #1 Primary 291.25'12.0" Round Culvert L= 22.4' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 291.25' / 291.00' S= 0.0112 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 294.00'0.500 in/hr Exfiltration over Surface area from 294.00' - 296.00' Excluded Surface area = 1,613 sf #3 Device 1 295.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 295.60'8.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.03 cfs @ 15.81 hrs HW=295.08' (Free Discharge) 1=Culvert (Passes 0.03 cfs of 6.90 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.03 cfs) 3=CPv Orifice (Orifice Controls 0.01 cfs @ 0.97 fps) 4=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 15HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 1: Bioretention Area 1 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=1.028 ac Peak Elev=295.08' Storage=2,953 cf 1.74 cfs 0.03 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 16HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 2: Bioretention Area 2 Inflow Area =0.522 ac, 44.25% Impervious, Inflow Depth = 0.73" for 1-Year event Inflow =0.59 cfs @ 11.97 hrs, Volume=0.032 af Outflow =0.02 cfs @ 13.65 hrs, Volume=0.029 af, Atten= 97%, Lag= 100.3 min Primary =0.02 cfs @ 13.65 hrs, Volume=0.029 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 297.26' @ 13.65 hrs Surf.Area= 1,083 sf Storage= 931 cf Plug-Flow detention time= 1,007.0 min calculated for 0.029 af (91% of inflow) Center-of-Mass det. time= 959.6 min ( 1,725.7 - 766.1 ) Volume Invert Avail.Storage Storage Description #1 296.00'1,908 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 296.00 426 0 0 297.00 920 673 673 298.00 1,550 1,235 1,908 Device Routing Invert Outlet Devices #1 Primary 293.25'12.0" Round Culvert L= 23.8' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 293.25' / 293.00' S= 0.0105 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 296.00'0.500 in/hr Exfiltration over Surface area from 296.00' - 298.00' Excluded Surface area = 426 sf #3 Device 1 297.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 297.80'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.02 cfs @ 13.65 hrs HW=297.26' (Free Discharge) 1=Culvert (Passes 0.02 cfs of 7.08 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.01 cfs) 3=CPv Orifice (Orifice Controls 0.01 cfs @ 2.24 fps) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 17HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 2: Bioretention Area 2 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.522 ac Peak Elev=297.26' Storage=931 cf 0.59 cfs 0.02 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 18HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 3: Bioretention Area 3 Inflow Area =0.353 ac, 28.90% Impervious, Inflow Depth = 0.48" for 1-Year event Inflow =0.25 cfs @ 11.98 hrs, Volume=0.014 af Outflow =0.01 cfs @ 14.92 hrs, Volume=0.012 af, Atten= 98%, Lag= 176.2 min Primary =0.01 cfs @ 14.92 hrs, Volume=0.012 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 297.05' @ 14.92 hrs Surf.Area= 576 sf Storage= 444 cf Plug-Flow detention time= 1,288.5 min calculated for 0.012 af (87% of inflow) Center-of-Mass det. time= 1,225.5 min ( 1,992.5 - 767.1 ) Volume Invert Avail.Storage Storage Description #1 296.00'1,148 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 296.00 274 0 0 297.00 560 417 417 298.00 901 731 1,148 Device Routing Invert Outlet Devices #1 Primary 293.25'12.0" Round Culvert L= 12.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 293.25' / 293.00' S= 0.0197 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 296.00'0.500 in/hr Exfiltration over Surface area from 296.00' - 298.00' Excluded Surface area = 274 sf #3 Device 1 297.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 297.60'18.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.01 cfs @ 14.92 hrs HW=297.05' (Free Discharge) 1=Culvert (Passes 0.01 cfs of 6.87 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.00 cfs) 3=CPv Orifice (Orifice Controls 0.00 cfs @ 0.75 fps) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 19HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 3: Bioretention Area 3 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.353 ac Peak Elev=297.05' Storage=444 cf 0.25 cfs 0.01 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 20HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 4: Bioretention Area 4 Inflow Area =1.223 ac, 62.88% Impervious, Inflow Depth = 1.03" for 1-Year event Inflow =1.86 cfs @ 11.99 hrs, Volume=0.105 af Outflow =0.03 cfs @ 17.83 hrs, Volume=0.069 af, Atten= 99%, Lag= 350.3 min Primary =0.03 cfs @ 17.83 hrs, Volume=0.069 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 294.28' @ 17.83 hrs Surf.Area= 3,417 sf Storage= 3,599 cf Plug-Flow detention time= 1,339.3 min calculated for 0.069 af (65% of inflow) Center-of-Mass det. time= 1,239.0 min ( 2,006.5 - 767.5 ) Volume Invert Avail.Storage Storage Description #1 293.00'16,926 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 293.00 2,215 0 0 294.00 3,120 2,668 2,668 295.00 4,162 3,641 6,309 296.00 5,289 4,726 11,034 297.00 6,494 5,892 16,926 Device Routing Invert Outlet Devices #1 Primary 290.25'12.0" Round Culvert L= 50.0' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 290.25' / 290.10' S= 0.0030 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 293.00'0.500 in/hr Exfiltration over Surface area from 293.00' - 297.00' Excluded Surface area = 2,215 sf #3 Device 1 294.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 295.10'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.03 cfs @ 17.83 hrs HW=294.28' (Free Discharge) 1=Culvert (Passes 0.03 cfs of 6.42 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.01 cfs) 3=CPv Orifice (Orifice Controls 0.01 cfs @ 2.37 fps) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 21HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 4: Bioretention Area 4 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)2 1 0 Inflow Area=1.223 ac Peak Elev=294.28' Storage=3,599 cf 1.86 cfs 0.03 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 22HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 5: Bioretention Area 5 Inflow Area =0.441 ac, 54.42% Impervious, Inflow Depth = 0.90" for 1-Year event Inflow =0.63 cfs @ 11.97 hrs, Volume=0.033 af Outflow =0.01 cfs @ 14.78 hrs, Volume=0.024 af, Atten= 98%, Lag= 169.0 min Primary =0.01 cfs @ 14.78 hrs, Volume=0.024 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 295.18' @ 14.78 hrs Surf.Area= 1,094 sf Storage= 1,041 cf Plug-Flow detention time= 1,190.8 min calculated for 0.024 af (73% of inflow) Center-of-Mass det. time= 1,099.3 min ( 1,864.7 - 765.4 ) Volume Invert Avail.Storage Storage Description #1 294.00'3,696 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 294.00 683 0 0 295.00 1,027 855 855 296.00 1,411 1,219 2,074 297.00 1,833 1,622 3,696 Device Routing Invert Outlet Devices #1 Primary 291.25'12.0" Round Culvert L= 96.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 291.25' / 290.25' S= 0.0103 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 294.00'0.500 in/hr Exfiltration over Surface area from 294.00' - 297.00' Excluded Surface area = 683 sf #3 Device 1 295.00'1.0" Vert. Cpv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 296.00'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.01 cfs @ 14.78 hrs HW=295.18' (Free Discharge) 1=Culvert (Passes 0.01 cfs of 5.86 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.00 cfs) 3=Cpv Orifice (Orifice Controls 0.01 cfs @ 1.76 fps) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 23HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 5: Bioretention Area 5 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.441 ac Peak Elev=295.18' Storage=1,041 cf 0.63 cfs 0.01 cfs Type II 24-hr 1-Year Rainfall=1.87"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 24HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond SN: S/N 001 [40] Hint: Not Described (Outflow=Inflow) Inflow Area =3.567 ac, 56.46% Impervious, Inflow Depth > 0.73" for 1-Year event Inflow =0.10 cfs @ 15.17 hrs, Volume=0.217 af Primary =0.10 cfs @ 15.17 hrs, Volume=0.217 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Pond SN: S/N 001 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=3.567 ac0.10 cfs0.10 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 25HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=3.566 ac 7.60% Impervious Runoff Depth=0.23"Subcatchment 1STE: DA 1 Existing Flow Length=370' Slope=0.0270 '/' Tc=27.5 min CN=WQ Runoff=0.67 cfs 0.067 af Runoff Area=1.028 ac 65.37% Impervious Runoff Depth=1.94"Subcatchment 1STP: DA1 Flow Length=165' Slope=0.0180 '/' Tc=6.0 min CN=WQ Runoff=3.04 cfs 0.166 af Runoff Area=0.522 ac 44.25% Impervious Runoff Depth=1.31"Subcatchment 2aSTP: DA2a Flow Length=97' Slope=0.0130 '/' Tc=6.6 min CN=WQ Runoff=1.02 cfs 0.057 af Runoff Area=0.353 ac 28.90% Impervious Runoff Depth=0.86"Subcatchment 2bSTP: DA2b Flow Length=91' Slope=0.0140 '/' Tc=7.6 min CN=WQ Runoff=0.44 cfs 0.025 af Runoff Area=1.223 ac 62.88% Impervious Runoff Depth=1.87"Subcatchment 3STP: DA3 Flow Length=254' Slope=0.0220 '/' Tc=8.1 min CN=WQ Runoff=3.25 cfs 0.190 af Runoff Area=0.441 ac 54.42% Impervious Runoff Depth=1.62"Subcatchment 4STP: DA4 Flow Length=179' Slope=0.0320 '/' Tc=5.8 min CN=WQ Runoff=1.09 cfs 0.059 af Peak Elev=295.60' Storage=5,256 cf Inflow=3.04 cfs 0.166 afPond 1: Bioretention Area 1 Outflow=0.06 cfs 0.150 af Peak Elev=297.82' Storage=1,638 cf Inflow=1.02 cfs 0.057 afPond 2: Bioretention Area 2 Outflow=0.05 cfs 0.054 af Peak Elev=297.47' Storage=715 cf Inflow=0.44 cfs 0.025 afPond 3: Bioretention Area 3 Outflow=0.02 cfs 0.023 af Peak Elev=295.03' Storage=6,441 cf Inflow=3.25 cfs 0.190 afPond 4: Bioretention Area 4 Outflow=0.05 cfs 0.141 af Peak Elev=295.82' Storage=1,820 cf Inflow=1.09 cfs 0.059 afPond 5: Bioretention Area 5 Outflow=0.03 cfs 0.049 af Inflow=0.21 cfs 0.416 afPond SN: S/N 001 Primary=0.21 cfs 0.416 af Total Runoff Area = 7.133 ac Runoff Volume = 0.565 af Average Runoff Depth = 0.95" 67.97% Pervious = 4.848 ac 32.03% Impervious = 2.285 ac Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 26HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1STE: DA 1 Existing Runoff =0.67 cfs @ 12.19 hrs, Volume=0.067 af, Depth= 0.23" Routed to nonexistent node 3L Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10-Year Rainfall=3.20" Area (ac) CN Description *0.271 98 Impervious 3.295 32 Woods/grass comb., Good, HSG A 3.566 Weighted Average 3.295 92.40% Pervious Area 0.271 7.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 27.5 370 0.0270 0.22 Lag/CN Method, Lag Subcatchment 1STE: DA 1 Existing Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10-Year Rainfall=3.20" Runoff Area=3.566 ac Runoff Volume=0.067 af Runoff Depth=0.23" Flow Length=370' Slope=0.0270 '/' Tc=27.5 min CN=WQ 0.67 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 27HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1STP: DA1 Runoff =3.04 cfs @ 11.97 hrs, Volume=0.166 af, Depth= 1.94" Routed to Pond 1 : Bioretention Area 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10-Year Rainfall=3.20" Area (ac) CN Description *0.672 98 Impervious 0.356 39 >75% Grass cover, Good, HSG A 1.028 Weighted Average 0.356 34.63% Pervious Area 0.672 65.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 6.0 165 0.0180 0.46 Lag/CN Method, Subcatchment 1STP: DA1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)3 2 1 0 Type II 24-hr 10-Year Rainfall=3.20" Runoff Area=1.028 ac Runoff Volume=0.166 af Runoff Depth=1.94" Flow Length=165' Slope=0.0180 '/' Tc=6.0 min CN=WQ 3.04 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 28HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2aSTP: DA2a Runoff =1.02 cfs @ 11.97 hrs, Volume=0.057 af, Depth= 1.31" Routed to Pond 2 : Bioretention Area 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10-Year Rainfall=3.20" Area (ac) CN Description *0.231 98 Impervious 0.291 39 >75% Grass cover, Good, HSG A 0.522 Weighted Average 0.291 55.75% Pervious Area 0.231 44.25% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 6.6 97 0.0130 0.25 Lag/CN Method, Subcatchment 2aSTP: DA2a Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 10-Year Rainfall=3.20" Runoff Area=0.522 ac Runoff Volume=0.057 af Runoff Depth=1.31" Flow Length=97' Slope=0.0130 '/' Tc=6.6 min CN=WQ 1.02 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 29HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2bSTP: DA2b Runoff =0.44 cfs @ 11.98 hrs, Volume=0.025 af, Depth= 0.86" Routed to Pond 3 : Bioretention Area 3 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10-Year Rainfall=3.20" Area (ac) CN Description *0.102 98 Impervious 0.251 39 >75% Grass cover, Good, HSG A 0.353 Weighted Average 0.251 71.10% Pervious Area 0.102 28.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.6 91 0.0140 0.20 Lag/CN Method, Subcatchment 2bSTP: DA2b Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10-Year Rainfall=3.20" Runoff Area=0.353 ac Runoff Volume=0.025 af Runoff Depth=0.86" Flow Length=91' Slope=0.0140 '/' Tc=7.6 min CN=WQ 0.44 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 30HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 3STP: DA3 Runoff =3.25 cfs @ 11.99 hrs, Volume=0.190 af, Depth= 1.87" Routed to Pond 4 : Bioretention Area 4 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10-Year Rainfall=3.20" Area (ac) CN Description *0.769 98 Impervious 0.454 39 >75% Grass cover, Good, HSG A 1.223 Weighted Average 0.454 37.12% Pervious Area 0.769 62.88% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 8.1 254 0.0220 0.52 Lag/CN Method, Subcatchment 3STP: DA3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)3 2 1 0 Type II 24-hr 10-Year Rainfall=3.20" Runoff Area=1.223 ac Runoff Volume=0.190 af Runoff Depth=1.87" Flow Length=254' Slope=0.0220 '/' Tc=8.1 min CN=WQ 3.25 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 31HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 4STP: DA4 Runoff =1.09 cfs @ 11.97 hrs, Volume=0.059 af, Depth= 1.62" Routed to Pond 5 : Bioretention Area 5 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10-Year Rainfall=3.20" Area (ac) CN Description *0.240 98 Impervious 0.201 39 >75% Grass cover, Good, HSG A 0.441 Weighted Average 0.201 45.58% Pervious Area 0.240 54.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 5.8 179 0.0320 0.51 Lag/CN Method, Subcatchment 4STP: DA4 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 10-Year Rainfall=3.20" Runoff Area=0.441 ac Runoff Volume=0.059 af Runoff Depth=1.62" Flow Length=179' Slope=0.0320 '/' Tc=5.8 min CN=WQ 1.09 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 32HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1: Bioretention Area 1 Inflow Area =1.028 ac, 65.37% Impervious, Inflow Depth = 1.94" for 10-Year event Inflow =3.04 cfs @ 11.97 hrs, Volume=0.166 af Outflow =0.06 cfs @ 15.34 hrs, Volume=0.150 af, Atten= 98%, Lag= 202.3 min Primary =0.06 cfs @ 15.34 hrs, Volume=0.150 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 295.60' @ 15.34 hrs Surf.Area= 4,997 sf Storage= 5,256 cf Plug-Flow detention time= 1,179.2 min calculated for 0.150 af (90% of inflow) Center-of-Mass det. time= 1,127.1 min ( 1,879.6 - 752.5 ) Volume Invert Avail.Storage Storage Description #1 294.00'7,418 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 294.00 1,613 0 0 295.00 3,676 2,645 2,645 296.00 5,870 4,773 7,418 Device Routing Invert Outlet Devices #1 Primary 291.25'12.0" Round Culvert L= 22.4' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 291.25' / 291.00' S= 0.0112 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 294.00'0.500 in/hr Exfiltration over Surface area from 294.00' - 296.00' Excluded Surface area = 1,613 sf #3 Device 1 295.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 295.60'8.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.06 cfs @ 15.34 hrs HW=295.60' (Free Discharge) 1=Culvert (Passes 0.06 cfs of 7.42 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.04 cfs) 3=CPv Orifice (Orifice Controls 0.02 cfs @ 3.61 fps) 4=Orifice/Grate (Weir Controls 0.00 cfs @ 0.16 fps) Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 33HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 1: Bioretention Area 1 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)3 2 1 0 Inflow Area=1.028 ac Peak Elev=295.60' Storage=5,256 cf 3.04 cfs 0.06 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 34HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 2: Bioretention Area 2 Inflow Area =0.522 ac, 44.25% Impervious, Inflow Depth = 1.31" for 10-Year event Inflow =1.02 cfs @ 11.97 hrs, Volume=0.057 af Outflow =0.05 cfs @ 12.88 hrs, Volume=0.054 af, Atten= 95%, Lag= 54.5 min Primary =0.05 cfs @ 12.88 hrs, Volume=0.054 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 297.82' @ 12.88 hrs Surf.Area= 1,436 sf Storage= 1,638 cf Plug-Flow detention time= 806.5 min calculated for 0.054 af (94% of inflow) Center-of-Mass det. time= 770.2 min ( 1,523.4 - 753.1 ) Volume Invert Avail.Storage Storage Description #1 296.00'1,908 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 296.00 426 0 0 297.00 920 673 673 298.00 1,550 1,235 1,908 Device Routing Invert Outlet Devices #1 Primary 293.25'12.0" Round Culvert L= 23.8' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 293.25' / 293.00' S= 0.0105 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 296.00'0.500 in/hr Exfiltration over Surface area from 296.00' - 298.00' Excluded Surface area = 426 sf #3 Device 1 297.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 297.80'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.05 cfs @ 12.88 hrs HW=297.82' (Free Discharge) 1=Culvert (Passes 0.05 cfs of 7.63 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.01 cfs) 3=CPv Orifice (Orifice Controls 0.02 cfs @ 4.25 fps) 4=Overflow Grate (Weir Controls 0.02 cfs @ 0.46 fps) Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 35HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 2: Bioretention Area 2 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=0.522 ac Peak Elev=297.82' Storage=1,638 cf 1.02 cfs 0.05 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 36HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 3: Bioretention Area 3 Inflow Area =0.353 ac, 28.90% Impervious, Inflow Depth = 0.86" for 10-Year event Inflow =0.44 cfs @ 11.98 hrs, Volume=0.025 af Outflow =0.02 cfs @ 12.98 hrs, Volume=0.023 af, Atten= 95%, Lag= 59.9 min Primary =0.02 cfs @ 12.98 hrs, Volume=0.023 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 297.47' @ 12.98 hrs Surf.Area= 719 sf Storage= 715 cf Plug-Flow detention time= 822.9 min calculated for 0.023 af (92% of inflow) Center-of-Mass det. time= 778.8 min ( 1,532.9 - 754.2 ) Volume Invert Avail.Storage Storage Description #1 296.00'1,148 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 296.00 274 0 0 297.00 560 417 417 298.00 901 731 1,148 Device Routing Invert Outlet Devices #1 Primary 293.25'12.0" Round Culvert L= 12.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 293.25' / 293.00' S= 0.0197 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 296.00'0.500 in/hr Exfiltration over Surface area from 296.00' - 298.00' Excluded Surface area = 274 sf #3 Device 1 297.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 297.60'18.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.02 cfs @ 12.98 hrs HW=297.47' (Free Discharge) 1=Culvert (Passes 0.02 cfs of 7.29 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.01 cfs) 3=CPv Orifice (Orifice Controls 0.02 cfs @ 3.14 fps) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 37HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 3: Bioretention Area 3 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.353 ac Peak Elev=297.47' Storage=715 cf 0.44 cfs 0.02 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 38HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 4: Bioretention Area 4 Inflow Area =1.223 ac, 62.88% Impervious, Inflow Depth = 1.87" for 10-Year event Inflow =3.25 cfs @ 11.99 hrs, Volume=0.190 af Outflow =0.05 cfs @ 17.38 hrs, Volume=0.141 af, Atten= 98%, Lag= 323.3 min Primary =0.05 cfs @ 17.38 hrs, Volume=0.141 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 295.03' @ 17.38 hrs Surf.Area= 4,198 sf Storage= 6,441 cf Plug-Flow detention time= 1,284.5 min calculated for 0.141 af (74% of inflow) Center-of-Mass det. time= 1,193.6 min ( 1,948.0 - 754.5 ) Volume Invert Avail.Storage Storage Description #1 293.00'16,926 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 293.00 2,215 0 0 294.00 3,120 2,668 2,668 295.00 4,162 3,641 6,309 296.00 5,289 4,726 11,034 297.00 6,494 5,892 16,926 Device Routing Invert Outlet Devices #1 Primary 290.25'12.0" Round Culvert L= 50.0' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 290.25' / 290.10' S= 0.0030 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 293.00'0.500 in/hr Exfiltration over Surface area from 293.00' - 297.00' Excluded Surface area = 2,215 sf #3 Device 1 294.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 295.10'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.05 cfs @ 17.38 hrs HW=295.03' (Free Discharge) 1=Culvert (Passes 0.05 cfs of 7.13 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.02 cfs) 3=CPv Orifice (Orifice Controls 0.03 cfs @ 4.79 fps) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 39HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 4: Bioretention Area 4 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)3 2 1 0 Inflow Area=1.223 ac Peak Elev=295.03' Storage=6,441 cf 3.25 cfs 0.05 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 40HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 5: Bioretention Area 5 Inflow Area =0.441 ac, 54.42% Impervious, Inflow Depth = 1.62" for 10-Year event Inflow =1.09 cfs @ 11.97 hrs, Volume=0.059 af Outflow =0.03 cfs @ 13.95 hrs, Volume=0.049 af, Atten= 97%, Lag= 118.9 min Primary =0.03 cfs @ 13.95 hrs, Volume=0.049 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 295.82' @ 13.95 hrs Surf.Area= 1,340 sf Storage= 1,820 cf Plug-Flow detention time= 907.8 min calculated for 0.049 af (83% of inflow) Center-of-Mass det. time= 833.4 min ( 1,585.8 - 752.4 ) Volume Invert Avail.Storage Storage Description #1 294.00'3,696 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 294.00 683 0 0 295.00 1,027 855 855 296.00 1,411 1,219 2,074 297.00 1,833 1,622 3,696 Device Routing Invert Outlet Devices #1 Primary 291.25'12.0" Round Culvert L= 96.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 291.25' / 290.25' S= 0.0103 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 294.00'0.500 in/hr Exfiltration over Surface area from 294.00' - 297.00' Excluded Surface area = 683 sf #3 Device 1 295.00'1.0" Vert. Cpv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 296.00'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.03 cfs @ 13.95 hrs HW=295.82' (Free Discharge) 1=Culvert (Passes 0.03 cfs of 6.32 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.01 cfs) 3=Cpv Orifice (Orifice Controls 0.02 cfs @ 4.24 fps) 4=Overflow Grate ( Controls 0.00 cfs) Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 41HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 5: Bioretention Area 5 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=0.441 ac Peak Elev=295.82' Storage=1,820 cf 1.09 cfs 0.03 cfs Type II 24-hr 10-Year Rainfall=3.20"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 42HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond SN: S/N 001 [40] Hint: Not Described (Outflow=Inflow) Inflow Area =3.567 ac, 56.46% Impervious, Inflow Depth > 1.40" for 10-Year event Inflow =0.21 cfs @ 12.96 hrs, Volume=0.416 af Primary =0.21 cfs @ 12.96 hrs, Volume=0.416 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Pond SN: S/N 001 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=3.567 ac0.21 cfs0.21 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 43HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=3.566 ac 7.60% Impervious Runoff Depth=0.27"Subcatchment 1STE: DA 1 Existing Flow Length=370' Slope=0.0270 '/' Tc=27.5 min CN=WQ Runoff=0.81 cfs 0.081 af Runoff Area=1.028 ac 65.37% Impervious Runoff Depth=2.35"Subcatchment 1STP: DA1 Flow Length=165' Slope=0.0180 '/' Tc=6.0 min CN=WQ Runoff=3.64 cfs 0.202 af Runoff Area=0.522 ac 44.25% Impervious Runoff Depth=1.60"Subcatchment 2aSTP: DA2a Flow Length=97' Slope=0.0130 '/' Tc=6.6 min CN=WQ Runoff=1.23 cfs 0.070 af Runoff Area=0.353 ac 28.90% Impervious Runoff Depth=1.06"Subcatchment 2bSTP: DA2b Flow Length=91' Slope=0.0140 '/' Tc=7.6 min CN=WQ Runoff=0.53 cfs 0.031 af Runoff Area=1.223 ac 62.88% Impervious Runoff Depth=2.27"Subcatchment 3STP: DA3 Flow Length=254' Slope=0.0220 '/' Tc=8.1 min CN=WQ Runoff=3.90 cfs 0.231 af Runoff Area=0.441 ac 54.42% Impervious Runoff Depth=1.96"Subcatchment 4STP: DA4 Flow Length=179' Slope=0.0320 '/' Tc=5.8 min CN=WQ Runoff=1.31 cfs 0.072 af Peak Elev=295.69' Storage=5,679 cf Inflow=3.64 cfs 0.202 afPond 1: Bioretention Area 1 Outflow=0.23 cfs 0.184 af Peak Elev=297.90' Storage=1,763 cf Inflow=1.23 cfs 0.070 afPond 2: Bioretention Area 2 Outflow=0.27 cfs 0.066 af Peak Elev=297.62' Storage=826 cf Inflow=0.53 cfs 0.031 afPond 3: Bioretention Area 3 Outflow=0.06 cfs 0.029 af Peak Elev=295.17' Storage=7,029 cf Inflow=3.90 cfs 0.231 afPond 4: Bioretention Area 4 Outflow=0.18 cfs 0.180 af Peak Elev=296.03' Storage=2,113 cf Inflow=1.31 cfs 0.072 afPond 5: Bioretention Area 5 Outflow=0.07 cfs 0.061 af Inflow=0.57 cfs 0.520 afPond SN: S/N 001 Primary=0.57 cfs 0.520 af Total Runoff Area = 7.133 ac Runoff Volume = 0.687 af Average Runoff Depth = 1.15" 67.97% Pervious = 4.848 ac 32.03% Impervious = 2.285 ac Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 44HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1STE: DA 1 Existing Runoff =0.81 cfs @ 12.19 hrs, Volume=0.081 af, Depth= 0.27" Routed to nonexistent node 3L Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 25-Year Rainfall=3.82" Area (ac) CN Description *0.271 98 Impervious 3.295 32 Woods/grass comb., Good, HSG A 3.566 Weighted Average 3.295 92.40% Pervious Area 0.271 7.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 27.5 370 0.0270 0.22 Lag/CN Method, Lag Subcatchment 1STE: DA 1 Existing Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 25-Year Rainfall=3.82" Runoff Area=3.566 ac Runoff Volume=0.081 af Runoff Depth=0.27" Flow Length=370' Slope=0.0270 '/' Tc=27.5 min CN=WQ 0.81 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 45HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1STP: DA1 Runoff =3.64 cfs @ 11.97 hrs, Volume=0.202 af, Depth= 2.35" Routed to Pond 1 : Bioretention Area 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 25-Year Rainfall=3.82" Area (ac) CN Description *0.672 98 Impervious 0.356 39 >75% Grass cover, Good, HSG A 1.028 Weighted Average 0.356 34.63% Pervious Area 0.672 65.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 6.0 165 0.0180 0.46 Lag/CN Method, Subcatchment 1STP: DA1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)4 3 2 1 0 Type II 24-hr 25-Year Rainfall=3.82" Runoff Area=1.028 ac Runoff Volume=0.202 af Runoff Depth=2.35" Flow Length=165' Slope=0.0180 '/' Tc=6.0 min CN=WQ 3.64 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 46HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2aSTP: DA2a Runoff =1.23 cfs @ 11.97 hrs, Volume=0.070 af, Depth= 1.60" Routed to Pond 2 : Bioretention Area 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 25-Year Rainfall=3.82" Area (ac) CN Description *0.231 98 Impervious 0.291 39 >75% Grass cover, Good, HSG A 0.522 Weighted Average 0.291 55.75% Pervious Area 0.231 44.25% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 6.6 97 0.0130 0.25 Lag/CN Method, Subcatchment 2aSTP: DA2a Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 25-Year Rainfall=3.82" Runoff Area=0.522 ac Runoff Volume=0.070 af Runoff Depth=1.60" Flow Length=97' Slope=0.0130 '/' Tc=6.6 min CN=WQ 1.23 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 47HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2bSTP: DA2b Runoff =0.53 cfs @ 11.98 hrs, Volume=0.031 af, Depth= 1.06" Routed to Pond 3 : Bioretention Area 3 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 25-Year Rainfall=3.82" Area (ac) CN Description *0.102 98 Impervious 0.251 39 >75% Grass cover, Good, HSG A 0.353 Weighted Average 0.251 71.10% Pervious Area 0.102 28.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.6 91 0.0140 0.20 Lag/CN Method, Subcatchment 2bSTP: DA2b Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 25-Year Rainfall=3.82" Runoff Area=0.353 ac Runoff Volume=0.031 af Runoff Depth=1.06" Flow Length=91' Slope=0.0140 '/' Tc=7.6 min CN=WQ 0.53 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 48HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 3STP: DA3 Runoff =3.90 cfs @ 11.99 hrs, Volume=0.231 af, Depth= 2.27" Routed to Pond 4 : Bioretention Area 4 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 25-Year Rainfall=3.82" Area (ac) CN Description *0.769 98 Impervious 0.454 39 >75% Grass cover, Good, HSG A 1.223 Weighted Average 0.454 37.12% Pervious Area 0.769 62.88% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 8.1 254 0.0220 0.52 Lag/CN Method, Subcatchment 3STP: DA3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)4 3 2 1 0 Type II 24-hr 25-Year Rainfall=3.82" Runoff Area=1.223 ac Runoff Volume=0.231 af Runoff Depth=2.27" Flow Length=254' Slope=0.0220 '/' Tc=8.1 min CN=WQ 3.90 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 49HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 4STP: DA4 Runoff =1.31 cfs @ 11.96 hrs, Volume=0.072 af, Depth= 1.96" Routed to Pond 5 : Bioretention Area 5 Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 25-Year Rainfall=3.82" Area (ac) CN Description *0.240 98 Impervious 0.201 39 >75% Grass cover, Good, HSG A 0.441 Weighted Average 0.201 45.58% Pervious Area 0.240 54.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 5.8 179 0.0320 0.51 Lag/CN Method, Subcatchment 4STP: DA4 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 25-Year Rainfall=3.82" Runoff Area=0.441 ac Runoff Volume=0.072 af Runoff Depth=1.96" Flow Length=179' Slope=0.0320 '/' Tc=5.8 min CN=WQ 1.31 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 50HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1: Bioretention Area 1 Inflow Area =1.028 ac, 65.37% Impervious, Inflow Depth = 2.35" for 25-Year event Inflow =3.64 cfs @ 11.97 hrs, Volume=0.202 af Outflow =0.23 cfs @ 12.59 hrs, Volume=0.184 af, Atten= 94%, Lag= 37.2 min Primary =0.23 cfs @ 12.59 hrs, Volume=0.184 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 295.69' @ 12.59 hrs Surf.Area= 5,180 sf Storage= 5,679 cf Plug-Flow detention time= 1,009.9 min calculated for 0.184 af (91% of inflow) Center-of-Mass det. time= 962.7 min ( 1,713.4 - 750.7 ) Volume Invert Avail.Storage Storage Description #1 294.00'7,418 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 294.00 1,613 0 0 295.00 3,676 2,645 2,645 296.00 5,870 4,773 7,418 Device Routing Invert Outlet Devices #1 Primary 291.25'12.0" Round Culvert L= 22.4' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 291.25' / 291.00' S= 0.0112 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 294.00'0.500 in/hr Exfiltration over Surface area from 294.00' - 296.00' Excluded Surface area = 1,613 sf #3 Device 1 295.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 295.60'8.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.23 cfs @ 12.59 hrs HW=295.69' (Free Discharge) 1=Culvert (Passes 0.23 cfs of 7.50 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.04 cfs) 3=CPv Orifice (Orifice Controls 0.02 cfs @ 3.86 fps) 4=Orifice/Grate (Weir Controls 0.17 cfs @ 0.96 fps) Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 51HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 1: Bioretention Area 1 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)4 3 2 1 0 Inflow Area=1.028 ac Peak Elev=295.69' Storage=5,679 cf 3.64 cfs 0.23 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 52HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 2: Bioretention Area 2 Inflow Area =0.522 ac, 44.25% Impervious, Inflow Depth = 1.60" for 25-Year event Inflow =1.23 cfs @ 11.97 hrs, Volume=0.070 af Outflow =0.27 cfs @ 12.14 hrs, Volume=0.066 af, Atten= 78%, Lag= 9.8 min Primary =0.27 cfs @ 12.14 hrs, Volume=0.066 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 297.90' @ 12.14 hrs Surf.Area= 1,490 sf Storage= 1,763 cf Plug-Flow detention time= 693.3 min calculated for 0.066 af (95% of inflow) Center-of-Mass det. time= 661.2 min ( 1,414.9 - 753.8 ) Volume Invert Avail.Storage Storage Description #1 296.00'1,908 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 296.00 426 0 0 297.00 920 673 673 298.00 1,550 1,235 1,908 Device Routing Invert Outlet Devices #1 Primary 293.25'12.0" Round Culvert L= 23.8' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 293.25' / 293.00' S= 0.0105 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 296.00'0.500 in/hr Exfiltration over Surface area from 296.00' - 298.00' Excluded Surface area = 426 sf #3 Device 1 297.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 297.80'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.27 cfs @ 12.14 hrs HW=297.90' (Free Discharge) 1=Culvert (Passes 0.27 cfs of 7.71 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.01 cfs) 3=CPv Orifice (Orifice Controls 0.02 cfs @ 4.47 fps) 4=Overflow Grate (Weir Controls 0.23 cfs @ 1.06 fps) Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 53HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 2: Bioretention Area 2 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=0.522 ac Peak Elev=297.90' Storage=1,763 cf 1.23 cfs 0.27 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 54HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 3: Bioretention Area 3 Inflow Area =0.353 ac, 28.90% Impervious, Inflow Depth = 1.06" for 25-Year event Inflow =0.53 cfs @ 11.98 hrs, Volume=0.031 af Outflow =0.06 cfs @ 12.35 hrs, Volume=0.029 af, Atten= 89%, Lag= 21.7 min Primary =0.06 cfs @ 12.35 hrs, Volume=0.029 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 297.62' @ 12.35 hrs Surf.Area= 770 sf Storage= 826 cf Plug-Flow detention time= 724.6 min calculated for 0.029 af (93% of inflow) Center-of-Mass det. time= 685.1 min ( 1,443.9 - 758.8 ) Volume Invert Avail.Storage Storage Description #1 296.00'1,148 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 296.00 274 0 0 297.00 560 417 417 298.00 901 731 1,148 Device Routing Invert Outlet Devices #1 Primary 293.25'12.0" Round Culvert L= 12.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 293.25' / 293.00' S= 0.0197 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 296.00'0.500 in/hr Exfiltration over Surface area from 296.00' - 298.00' Excluded Surface area = 274 sf #3 Device 1 297.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 297.60'18.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.05 cfs @ 12.35 hrs HW=297.62' (Free Discharge) 1=Culvert (Passes 0.05 cfs of 7.43 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.01 cfs) 3=CPv Orifice (Orifice Controls 0.02 cfs @ 3.65 fps) 4=Overflow Grate (Weir Controls 0.03 cfs @ 0.40 fps) Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 55HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 3: Bioretention Area 3 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.353 ac Peak Elev=297.62' Storage=826 cf 0.53 cfs 0.06 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 56HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 4: Bioretention Area 4 Inflow Area =1.223 ac, 62.88% Impervious, Inflow Depth = 2.27" for 25-Year event Inflow =3.90 cfs @ 11.99 hrs, Volume=0.231 af Outflow =0.18 cfs @ 13.14 hrs, Volume=0.180 af, Atten= 95%, Lag= 68.8 min Primary =0.18 cfs @ 13.14 hrs, Volume=0.180 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 295.17' @ 13.14 hrs Surf.Area= 4,353 sf Storage= 7,029 cf Plug-Flow detention time= 1,123.8 min calculated for 0.180 af (78% of inflow) Center-of-Mass det. time= 1,037.8 min ( 1,790.7 - 752.9 ) Volume Invert Avail.Storage Storage Description #1 293.00'16,926 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 293.00 2,215 0 0 294.00 3,120 2,668 2,668 295.00 4,162 3,641 6,309 296.00 5,289 4,726 11,034 297.00 6,494 5,892 16,926 Device Routing Invert Outlet Devices #1 Primary 290.25'12.0" Round Culvert L= 50.0' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 290.25' / 290.10' S= 0.0030 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 293.00'0.500 in/hr Exfiltration over Surface area from 293.00' - 297.00' Excluded Surface area = 2,215 sf #3 Device 1 294.00'1.0" Vert. CPv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 295.10'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.18 cfs @ 13.14 hrs HW=295.17' (Free Discharge) 1=Culvert (Passes 0.18 cfs of 7.26 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.02 cfs) 3=CPv Orifice (Orifice Controls 0.03 cfs @ 5.11 fps) 4=Overflow Grate (Weir Controls 0.12 cfs @ 0.86 fps) Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 57HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 4: Bioretention Area 4 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)4 3 2 1 0 Inflow Area=1.223 ac Peak Elev=295.17' Storage=7,029 cf 3.90 cfs 0.18 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 58HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond 5: Bioretention Area 5 Inflow Area =0.441 ac, 54.42% Impervious, Inflow Depth = 1.96" for 25-Year event Inflow =1.31 cfs @ 11.96 hrs, Volume=0.072 af Outflow =0.07 cfs @ 12.80 hrs, Volume=0.061 af, Atten= 95%, Lag= 50.3 min Primary =0.07 cfs @ 12.80 hrs, Volume=0.061 af Routed to Pond SN : S/N 001 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 296.03' @ 12.80 hrs Surf.Area= 1,423 sf Storage= 2,113 cf Plug-Flow detention time= 849.4 min calculated for 0.061 af (85% of inflow) Center-of-Mass det. time= 780.1 min ( 1,531.7 - 751.6 ) Volume Invert Avail.Storage Storage Description #1 294.00'3,696 cf Ponding Area (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 294.00 683 0 0 295.00 1,027 855 855 296.00 1,411 1,219 2,074 297.00 1,833 1,622 3,696 Device Routing Invert Outlet Devices #1 Primary 291.25'12.0" Round Culvert L= 96.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 291.25' / 290.25' S= 0.0103 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 294.00'0.500 in/hr Exfiltration over Surface area from 294.00' - 297.00' Excluded Surface area = 683 sf #3 Device 1 295.00'1.0" Vert. Cpv Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 296.00'8.0" Horiz. Overflow Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.07 cfs @ 12.80 hrs HW=296.03' (Free Discharge) 1=Culvert (Passes 0.07 cfs of 6.47 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.01 cfs) 3=Cpv Orifice (Orifice Controls 0.03 cfs @ 4.78 fps) 4=Overflow Grate (Weir Controls 0.03 cfs @ 0.54 fps) Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 59HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Pond 5: Bioretention Area 5 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=0.441 ac Peak Elev=296.03' Storage=2,113 cf 1.31 cfs 0.07 cfs Type II 24-hr 25-Year Rainfall=3.82"19-268 600 Spear 2022 0119 Printed 3/18/2022Prepared by Trudell Consulting Engineers Page 60HydroCAD® 10.10-6a s/n 02645 © 2020 HydroCAD Software Solutions LLC Summary for Pond SN: S/N 001 [40] Hint: Not Described (Outflow=Inflow) Inflow Area =3.567 ac, 56.46% Impervious, Inflow Depth > 1.75" for 25-Year event Inflow =0.57 cfs @ 12.66 hrs, Volume=0.520 af Primary =0.57 cfs @ 12.66 hrs, Volume=0.520 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Pond SN: S/N 001 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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=3.567 ac0.57 cfs0.57 cfs