Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
WPO202200028 Calculations 2023-03-17
SHIMP ENGINEERING, P.C. Design Focused Engineering January 10, 2023 Regarding: Rivers Edge — SWM Calculation Packet Dear Reviewer, Enclosed is the stormwater calculation packet for the Rivers Edge Site Plan in Albemarle County, VA. The purpose of this project is to construct 34 new 3-story multifamily buildings with associated parking and travel ways. This project will disturb a total area of 9.31 acres. The conditions of subsection F of 9VAC25-870-65 Water Quality have been met for this site. The VRRM considers the total limits of disturbance for the project when calculating the required load reductions for the development. Using the DEQ VRRM Re -Development Compliance Spreadsheet, the TIP Load Reduction Required for this plan is 6.50 lb/yr. This requirement will be satisfied through dedication of 15.76 acres of ForesUOpenspace easement and the remaining required reduction of 2.07 Iblyr will be satisfied through the purchase of 2.07 nutrient credits. Two points of analysis were considered for the site Water Quantity (Channel Protection) and Flood Protection. POA1 The proposed stormwater design meets the Water Quantity requirements set forth in 9VAC25-870-66-8(3) for discharge to a natural stormwater conveyance system through the use of a new underground detention system that releases the 1-yr storm at rates compliant with the Energy Balance Equation. Note that since the 1-yr reduction of the total runoff (including offsite area) is greater than the reduction required by the Energy Balance Equation, runoff at this POA is compliant with the Energy Balance Equation. This runoff will be released directly into the North Fork Rivanna River. The proposed stormwater design meets the Flood Protection requirements set forth in 9VAC25-870-66-C(3)C where the stormwater conveyance system releases runoff to a mapped floodplain. POA 2 The proposed stormwater design meets the Water Quantity requirements set forth in 9VAC25-870.66-B(3) for discharge to a natural stormwater conveyance system through the use of a new dry detention pond that releases the 1-yr storm at rates compliant with the Energy Balance Equation. The proposed stormwater design meets the Flood Protection requirements set forth in 9VAC25-870-66-C(2)B through the use of a new dry detention pond that releases the 10-yr storm at rates below predevelopment. POA Predev [cfs] Omax [cfs] Postdev [cfs] 1-yr 10-y. I +-y, 1 2.97 42.29 2.06 2.04 57.38 2 3.22 20.95 1 2.03 2.02 1 20.34 If you have any questions please do not hesitate to contact me at: Justin@shimp-engineedng.com or 434-227-5140 ext. 3. Justin Shimp, P.E. Shimp Engineering, P.C. !. No. 45183 11 IbI23 Contents: Pre -Development Runoff Quantity Calculations: Pre-Dev Drainage Map Pre-Dev HydroCAD Report Post-Dev Runoff Quantity Calculations: Post-Dev Drainage Map Ditch Drainage Map LD-268 Ditch Calculations LD-229 Pipe Capacity Calculations Energy Balance Equation Summary Post-Dev HydroCAD Report Runoff Quality Calculations: VRRM Re -Development Spreadsheet Summary Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report Pre -Development Runoff Quantity Calculations: Pre-Dev Drainage Map Pre-Dev HydroCAD Report S DA Ar 1 899 2 339 Total 1,23 200 0 200 400 600 Pre -Development Drainage Area Summary SF AC SF AC SF AC SF AC SF AC min DA Area Area Impervious Impervious C Pervious Pervious Turf Turf Woods Woods TOC 1 899,243 20.64 23,285 0.53 0.32 875,958 20.11 24,500 0.5 851,458 19.55 7.00 2 339,357 7.79 60,887 1.40 0.41 278,470 6.39 115,854 2. 162,616 3.73 7.00 Total 1,238,600 28.43 84,172 1.93 - 1,154,428 26.50 140,354 3. 1,014,074 23.28 - Predevelopment HydroCAD Report Rivers Edge (6S (5S) DA 1 PREDEV DA1 PREDEV UNMANAGED DEVELOPMENT AREA 2L POA 1 Sub4 Reach X 4on Llnk i3S DA2 PREDEV 4L POA 2 Rivers Edge Pre Development - Rivers Edge Type 11 24-hr 1-yr Rainfall=2.96" Prepared by {enter your company name here} Printed 5/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 2 Time span=5.00-60.00 hrs, dt=0.05 hrs, 1101 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment3S: DA2 PREDEV Runoff Area=7.790 ac 17.97% Impervious Runoff Depth=0.35" Tc=7.0 min UI Adjusted CN=61 Runoff=3.22 cfs 0.227 of Subcatchment5S: DA1 PREDEV Runoff Area=4.880 ac 2.66% Impervious Runoff Depth=0.23" Tc=5.0 min CN=57 Runoff=1.04 cfs 0.095 of Subcatchment6S: DA 1 PREDEV Runoff Area=15.760 ac 2.54% Impervious Runoff Depth=0.21" Tc=7.0 min CN=56 Runoff=2.13 cfs 0.274 of Link 2L: POA 1 Inflow=2.97 cfs 0.369 of Primary=2.97 cfs 0.369 of Link 4L: POA 2 Inflow=3.22 cfs 0.227 of Primary=3.22 cfs 0.227 of Total Runoff Area = 28.430 ac Runoff Volume = 0.596 of Average Runoff Depth = 0.25" 93.21% Pervious = 26.500 ac 6.79% Impervious = 1.930 ac Rivers Edge Pre Development - Rivers Edge Type 11 24-hr 1-yr Rainfall=2.96" Prepared by {enter your company name here} Printed 5/11/2022 HVdroCAD® 9.10 s/n 07054 ©2010 HVdroCAD Software Solutions LLC Paoe 3 Summary for Subcatchment 3S: DA2 PREDEV Runoff = 3.22 cfs @ 12.01 hrs, Volume= 0.227 af, Depth= 0.35" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Rainfall=2.96" Area (ac) CN Description 1.400 98 Unconnected pavement, HSG B 2.660 61 Turf 3.730 55 Woods 7.790 65 Weighted Average, UI Adjusted CN = 61 6.390 82.03% Pervious Area 1.400 17.97% Impervious Area 1.400 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Subcatchment 5S: DA1 PREDEV DEVELOPMENT AREA Runoff = 1.04 cfs @ 12.01 hrs, Volume= 0.095 af, Depth= 0.23" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Rainfall=2.96" Area (ac) CN Description 0.130 98 Impervious 0.300 61 Turf 4.450 55 Woods 4.880 57 Weighted Average 4.750 97.34% Pervious Area 0.130 2.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6S: DA 1 PREDEV UNMANAGED Runoff = 2.13 cfs @ 12.04 hrs, Volume= 0.274 af, Depth= 0.21" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Type 11 24-hr 1-yr Rainfall=2.96" Rivers Edge Pre Development - Rivers Edge Type 11 24-hr 1-yr Rainfall=2.96" Prepared by {enter your company name here} Printed 5/11/2022 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 4 Area (ac) CN Description 0.400 98 Impervious 0.260 61 Turf 15.100 55 Woods 15.760 56 Weighted Average 15.360 97.46% Pervious Area 0.400 2.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Link 2L: PDA 1 Inflow Area = 20.640 ac, 2.57% Impervious, Inflow Depth = 0.21" for 1-yr event Inflow = 2.97 cfs @ 12.03 hrs, Volume= 0.369 of Primary = 2.97 cfs @ 12.03 hrs, Volume= 0.369 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Summary for Link 4L: PDA 2 Inflow Area = 7.790 ac, 17.97% Impervious, Inflow Depth = 0.35" for 1-yr event Inflow = 3.22 cfs @ 12.01 hrs, Volume= 0.227 of Primary = 3.22 cfs @ 12.01 hrs, Volume= 0.227 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Rivers Edge Pre Development - Rivers Edge Type 11 24-hr 10-yr Rainfall= 5.41 " Prepared by {enter your company name here} Printed 5/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 5 Time span=5.00-60.00 hrs, dt=0.05 hrs, 1101 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment3S: DA2 PREDEV Runoff Area=7.790 ac 17.97% Impervious Runoff Depth=1.62" Tc=7.0 min UI Adjusted CN=61 Runoff=20.95 cfs 1.053 of Subcatchment5S: DA1 PREDEV Runoff Area=4.880 ac 2.66% Impervious Runoff Depth=1.33" Tc=5.0 min CN=57 Runoff=11.12 cfs 0.541 of Subcatchment6S: DA 1 PREDEV Runoff Area=15.760 ac 2.54% Impervious Runoff Depth=1.26" Tc=7.0 min CN=56 Runoff=31.60 cfs 1.655 of Link 2L: POA 1 Inflow=42.29 cfs 2.195 of Primary=42.29 cfs 2.195 of Link 4L: POA 2 Inflow=20.95 cfs 1.053 of Primary=20.95 cfs 1.053 of Total Runoff Area = 28.430 ac Runoff Volume = 3.248 of Average Runoff Depth = 1.37" 93.21% Pervious = 26.500 ac 6.79% Impervious = 1.930 ac Rivers Edge Pre Development - Rivers Edge Type 11 24-hr 10-yr Rainfall= 5.41 " Prepared by {enter your company name here} Printed 5/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 6 Summary for Subcatchment 3S: DA2 PREDEV Runoff = 20.95 cfs @ 11.99 hrs, Volume= 1.053 af, Depth= 1.62" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Rainfall=5.41" Area (ac) CN Description 1.400 98 Unconnected pavement, HSG B 2.660 61 Turf 3.730 55 Woods 7.790 65 Weighted Average, UI Adjusted CN = 61 6.390 82.03% Pervious Area 1.400 17.97% Impervious Area 1.400 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Subcatchment 5S: DA1 PREDEV DEVELOPMENT AREA Runoff = 11.12 cfs @ 11.97 hrs, Volume= 0.541 af, Depth= 1.33" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Rainfall=5.41" Area (ac) CN Description 0.130 98 Impervious 0.300 61 Turf 4.450 55 Woods 4.880 57 Weighted Average 4.750 97.34% Pervious Area 0.130 2.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6S: DA 1 PREDEV UNMANAGED Runoff = 31.60 cfs @ 12.00 hrs, Volume= 1.655 af, Depth= 1.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Type 11 24-hr 10-yr Rainfall=5.41" Rivers Edge Pre Development - Rivers Edge Type 11 24-hr 10-yr Rainfall= 5.41 " Prepared by {enter your company name here} Printed 5/11/2022 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 7 Area (ac) CN Description 0.400 98 Impervious 0.260 61 Turf 15.100 55 Woods 15.760 56 Weighted Average 15.360 97.46% Pervious Area 0.400 2.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Link 2L: PDA 1 Inflow Area = 20.640 ac, 2.57% Impervious, Inflow Depth = 1.28" for 10-yr event Inflow = 42.29 cfs @ 11.99 hrs, Volume= 2.195 of Primary = 42.29 cfs @ 11.99 hrs, Volume= 2.195 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Summary for Link 4L: PDA 2 Inflow Area = 7.790 ac, 17.97% Impervious, Inflow Depth = 1.62" for 10-yr event Inflow = 20.95 cfs @ 11.99 hrs, Volume= 1.053 of Primary = 20.95 cfs @ 11.99 hrs, Volume= 1.053 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Rivers Edge Pre Development - Rivers Edge Type 11 24-hr 100-yr Rainfall=8.86" Prepared by {enter your company name here} Printed 5/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 8 Time span=5.00-60.00 hrs, dt=0.05 hrs, 1101 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment3S: DA2 PREDEV Runoff Area=7.790 ac 17.97% Impervious Runoff Depth=4.11" Tc=7.0 min UI Adjusted CN=61 Runoff=54.28 cfs 2.670 of Subcatchment5S: DA1 PREDEV Runoff Area=4.880 ac 2.66% Impervious Runoff Depth=3.63" Tc=5.0 min CN=57 Runoff=31.90 cfs 1.475 of Subcatchment6S: DA 1 PREDEV Runoff Area=15.760 ac 2.54% Impervious Runoff Depth=3.51" Tc=7.0 min CN=56 Runoff=93.55 cfs 4.606 of Link 2L: POA 1 Inflow=123.97 cfs 6.082 of Primary=123.97 cfs 6.082 of Link 4L: POA 2 Inflow=54.28 cfs 2.670 of Primary=54.28 cfs 2.670 of Total Runoff Area = 28.430 ac Runoff Volume = 8.752 of Average Runoff Depth = 3.69" 93.21% Pervious = 26.500 ac 6.79% Impervious = 1.930 ac Rivers Edge Pre Development - Rivers Edge Type 11 24-hr 100-yr Rainfall=8.86" Prepared by {enter your company name here} Printed 5/11/2022 HVdroCAD® 9.10 s/n 07054 ©2010 HVdroCAD Software Solutions LLC Paoe 9 Summary for Subcatchment 3S: DA2 PREDEV Runoff = 54.28 cfs @ 11.99 hrs, Volume= 2.670 af, Depth= 4.11" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Rainfall=8.86" Area (ac) CN Description 1.400 98 Unconnected pavement, HSG B 2.660 61 Turf 3.730 55 Woods 7.790 65 Weighted Average, UI Adjusted CN = 61 6.390 82.03% Pervious Area 1.400 17.97% Impervious Area 1.400 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Subcatchment 5S: DA1 PREDEV DEVELOPMENT AREA Runoff = 31.90 cfs @ 11.96 hrs, Volume= 1.475 af, Depth= 3.63" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Rainfall=8.86" Area (ac) CN Description 0.130 98 Impervious 0.300 61 Turf 4.450 55 Woods 4.880 57 Weighted Average 4.750 97.34% Pervious Area 0.130 2.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6S: DA 1 PREDEV UNMANAGED Runoff = 93.55 cfs @ 11.99 hrs, Volume= 4.606 af, Depth= 3.51" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Type 11 24-hr 100-yr Rainfall=8.86" Rivers Edge Pre Development - Rivers Edge Type 11 24-hr 100-yr Rainfall=8.86" Prepared by {enter your company name here} Printed 5/11/2022 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 10 Area (ac) CN Description 0.400 98 Impervious 0.260 61 Turf 15.100 55 Woods 15.760 56 Weighted Average 15.360 97.46% Pervious Area 0.400 2.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Link 2L: PDA 1 Inflow Area = 20.640 ac, 2.57% Impervious, Inflow Depth = 3.54" for 100-yr event Inflow = 123.97 cfs @ 11.98 hrs, Volume= 6.082 of Primary = 123.97 cfs @ 11.98 hrs, Volume= 6.082 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Summary for Link 4L: PDA 2 Inflow Area = 7.790 ac, 17.97% Impervious, Inflow Depth = 4.11" for 100-yr event Inflow = 54.28 cfs @ 11.99 hrs, Volume= 2.670 of Primary = 54.28 cfs @ 11.99 hrs, Volume= 2.670 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-60.00 hrs, dt= 0.05 hrs Post-Dev Runoff Quantity Calculations: Post-Dev Drainage Map Ditch Drainage Map LD-268 Ditch Calculations Storm Structure Drainage Map LD-204 Inlet Calculations LD-229 Pipe Capacity Calculations Energy Balance Equation Summary Post-Dev HydroCAD Report G DA-DA2 UNMANAGED === 6.14 AC C=0.38-� TOC=7 min DA-DEV TO DRY POND 1.70 AC C=0.54 TOC=5 min .w RIVER'S EDGE POSTDEVELOPMENT DRAINAGE AREA Rivers Edge Post -Development Drainage Area Summary POA Energy Balance Equation Summary For PDA 1 Rivers Edge POA 1 1.r.:4Hr Mwm [emPan:en. 0,_.<a5 F F[(OPm *RVc_,l/RVoaa_,, Oe..e,y.e5l0r�.we[RV,�nml/RV memm Pre Or¢Ile 0:!nege Are a = Pan anus Dreln•e• Are. _ Ooaa e 2 W LF. _ m0.awaowa•Ebel Max qy„ a iMlo this sold Is corn plated with SVAC268ID66-CQJb because the toi ratio :d by an mount succeeding the reduction Must by Ilse enteMy hue complies x11M1 9VAQ6870ti6C0)b became the 10yr peak ru Te 01 1 Energy 911-10 Romrvmems m , RetluFluxQ PCA by: (Op„an-Mix °,,,.) a r.,uiretl redb ticn @ POA 4.86 1.04 - 0.13 = 0.91 sn loathed 4.88 s ACMG 1, MUCTION AT PSo 1: 0.9 0.99 cEs A19 N ACHIEVED Energy Balance Equation Summary Rivers Edge POA 2 Dnvziecee<I f.=I@re.ervneen'RVr,e.ne.n,.n/Rv,ereimee Damewa5(QonnaeRVrmnaol/Marvr ww: PreOw DA= ].]9 ac Past-Dw Qwo... lwd = 3II RVw.oe,.:ucea = 0.II] sea gre.,a Ap9 n1 RVo:.ewe = 0.2BB ACM1icetl Pasl-0evMm Runongsw' 2.02cr•. Sile complies vi1M1 9VAC258I666(3JA Mmimun Olwr a 26.95c1e(oetleN Achiweal O10vr a 20.34cls SF AC SF AC AC SF ACISFAC AC (MIN) DA 1 Area Area Impervious Impervious C A Pervious Pervio Turf Woods TOC DETENTION (PIPE) 212,535 4.88 139,738 0.69 4.88 72,798 1.67 t5FF 1 00 5.00 DA I UNMANAGED 686,648 15.76 450 0.01 0.30 15.7fi 686,198 15.75 7.00 DA ITOTAL 899,183 20.64 140,188 3.22 0.99 20.64 758,995 17.42 SF AC SF AC AC SF AC SF AC 5F AC (MIN) DA 2 Area Area Impervious I Im ervious C A Pervious Pervious Turf Turf I Woods Woods TOC DETENTION (POND) 73,953 1.70 29,221 35,164 1 0.54 0.38 1.70 44,732 1.03 44,732 0 0.00 5.00 DA2Unmanaged 267,671 6.14 6.14 232,507 5.34 59,454 173052.3 3.97 7.00 DA2TOTAL 341,623 7.84 64,385 1.48 1 0.41 7.84 277,238 6.36 1 104,186 l 2M 173,052 l 3.97 Pntlev qs DA-DA1 UNMANAGED 15.76 AC C=0.30 TOC=7 min ,M o Achieved Total Runoff (Including Offsile) T1.�ftdMan POSMEV 01pas1= 2.M 0pae1= 692 01,W=5).96 10�YR ReOuation 45.09 Nate: Since the Lyrreduction MIM1eIMeI ninon Qncluding Mae mnis greelxlllm Ilia reduction 'equlretl by the Ens, Balance Equation, Rinof M this POA Is compound Win IM1e Energ) Balance DA-DEV 4.88 AC -----C=0.69 TOC=5 min 1 Rivers Edge Post -Development Drainage Area Summary SF AC SF AC AC SF AC SF AC SF AC (MIN) DA 1 Area Area Impervious Impervious C A Pervious Pervious Turf Turf Woods Woods TOC DETENTION (PIPE) 212,535 4.88 139,738 3.21 0.69 4.88 72,798 1.67 72,798 1.67 0 0.00 5.00 DA 1 UNMANAGED 686,648 15.76 450 0.01 0.30 15.76 686,198 15.75 92,770 2.13 593,428 13.62 7.00 DA 1 TOTAL 899,183 20.64 140,188 3.22 0.99 20.64 758,995 17.42 165,568 3.80 593,428 SF AC SF AC AC SF AC SF AC SF AC (MIN) DA2 Area Area Impervious I Impervious C A Pervious Pervious Turf Turf Woods Woods TOC DETENTION (POND) 73,953 1.70 29,221 0.67 0.54 1.70 44,732 1.03 44,732 1.03 0 5.00 DA2 Unmanaged 267,671 6.14 35,164 0.81 0.38 6.14 232,507 5.34 59,454 1.36 173052.3 7.00 DA 2 TOTAL 341,623 7.84 64,385 1.48 0.41 7.84 277,238 6.36 104,186 2.39 173,052 -- \ 1 ♦\\\ I \\I Wit lit '- _� `♦` \\ \`� 1\`III 1 1` 1♦ '� 1 9g 1 I \ \\�\\\` `\\`�\ \\�o\♦\"\x\\ __-__%-`.i\t\ i i%���( � i i't l'ji t`��ill�i i It ' ' 11`` `�`\��\\`\\•�\`I '�.0 11 i I I \ t m"AI``\ \ `\�V 1 `�` `♦ `�`PI ��\\`� `\\`♦ �`\� _ `♦ I I I I III \ A•£�• \t \ \ tl 1 `` t \tt\ J ttl I �`` `i \��ii: r /' I i i i III ` \\\\`\ \ .II 1 `t't \`���\ "t\'t I _` ♦ I r rr 1 1 I I I I \ \ \ \\\\ \ \ \ \`�``\`� t // i I\ \ III 1 �'t`\ t` ♦ t \ ♦\♦ 0`♦\ t ```t\frr( l 'It t'I\� t % ``I \ t`t `\ ``\�` `NIt`\`� "`� . \\\♦O\ " �\ '`. ♦ \ III r t I I r`1 l I \ ♦ q�\t . I\\III ♦11 �/ Ili r / I I � �\I I \ ♦ \\\ . `t\\ Itl It11 1`I l l \ 1V'\�.l I \ ` `♦; `•`:♦\\ � `♦ ♦ \ I \ I I Il `I l I `C , ` I y'(�y'�j I I I ` ' `�y�' �`` `` `\\`�♦\}`\�\I`I;I`♦ tl l�`�♦ /\"II`All�``tl\{ p` \`` Illi `�♦ \` 1\i ♦ \ ♦ t \ \\ t t I1 `\\�` �� ♦ / \ ♦` It \'t I � I \ I •w; ♦'♦ �1 \ � it i il\ ♦`�♦\\\\,\;`t`\`�\\ i \,'t'11\l )ilk �``� \ ♦ \ \ \ ` '\\ I i i I \```'\I `\ i' /`�♦`♦\ `V\1VO 1 ; t \ \ ♦}`\'t 1 l i ) '\ `�\� ( \`t\III\\\♦`t`li `'t11 ^♦♦`�; ♦ I I I I t \\IIII I I \♦ ` ``\� \ ` ` I\II`N\I ' \ �' I t 1 I I I t\ ♦II l 1 l t \♦`\ \` I I N I �i /1WMI I I 1 \tl If ♦` `\ I I I\♦\,`�\`.`♦`` _ \ II I Il I I Il1t\\I I `\♦1 \\♦ ♦ \ I \ it I I I 1 I I I 1111111\t l 1 ♦U\ )it �ji/\\ t/ 1 \\t``����� 1 l 1 I l i \ Ilii'li'1 i l <il) ♦ li \'i \ l \ i i III i i i `i lli nil it `I 1\ \ it 't,\�. V. _I i%\\�`♦``` ��\`.\�. \ C\ \ IWt`t t 11 `` '` \ \ ` `" `♦ `�`` \ �`♦ ` t`. \ `\ �`\ ♦\\ \\ �Il\\tl � }11j111/1 i \ 1 /`ii�' ` `\i �� :`: �` `♦\`. dt\` � i i l I i i I `Illli(/ I i i l \ ' ��'♦ I 1 � -_) ttt\ � `. \ \ � � ` '� I\1ll i i l i i i \/Milli f i i � f t``;`♦. ♦( \/� :Iti( ` `\`'\�\LA\\ `\ \M I III IIIII i lyltt t t t\J ♦J\t ` lOt t\I \\ 11 l\t\`t \t It t a`t \`;`\ ` Jill \ \ ` \ ``t' \\`♦` :` '.�\ r I , II II iliiilliii ilk � 11 % \\ : �i\�\ 1i1\ t % '` ♦♦```` \\``\ III\ IV I I(fJliilJif lull l l 1 \ (:�li i�� l/I !! JI I i i i i I � Il) i I i �/ i i 1\ ♦♦il ��li I`ii\` 1 I ` `t` \\ ' \� r i i l l i i i I) I f I f I 1 r i i / \ t\\ It ♦\\ I \ \` %i illi iiJ if ifi/iii i / l\�_�\`:�t \`t\\`♦ \t 1 tt � \`♦\i RIVER'S EDGE POST DEVELOPMENT DITCH DRAINAGE AREA MAP 1. `\t\t;I -, pr 111\II/r' / C Illlt 1t ;!I1; l` I W - I .a Illfll 1 tit, i 1. � "�� \ ' ' � t\`\`III\P\`\"•o�) \ SCC 5 DA=0.36AC Rivers Edge Modified LD-268 Roadside and Median Ditch Design Folm Side Slope Min. M. Earth Dtch A Tc 12 110 02 DID - :1 L - :1 R Slope Ft/Ft Slope FUR Atl altle Velocity n=.m Vel.• 2-yr NWecity 10-yr "Depth Matting Type Freenoare Ooo" Depth INCR ACC 1 0.1] 0.09 0.09 SO 5.39 7.05 0.46 0.60 2 2 0.03 0.w 4.0 1.76 OA2 EC-2 T PE1 0.58 1.00 2 i2:�: 0.13 a.08 0.08 SO 5.39 7.05 0.41 0.54 2 2 0.03 0.0d 4.0 1J1 0.41 EC-2 WPE1 0.60 1.00 3 0.05 0.03 0.03 5.0 5.39 ].05 0.18 0.24 2 2 0.03 0.03 4.0 1.25 0.30 EARTH 0.]0 1.00 9 0.68 0.36 0.36 5.0 5.39 ].OS 1.96 25] 2 2 0.01 0.11 9.0 3.T1 OAS EC-2 TWE1 0.11 1.00 5 0.% 0.22 0.22 SO 539 ).OS 1.20 L5] 2 2 0.01 0.11 40 3.2] 0.]4 EC-2 TWEI 0.26 1.00 2-yr Velocity calmledons pet m ed using steepest elope a 2-yr fm 16yr Depth calculdim pt f od using shallows[ slope 810.yr Iwr • elestsken fiom HytlmCADmatlel 110 �v SCC sf ac Imp (sf) Imp (ac) Turf (sf) Turf (ac) C 1 7463 0.17 2490 0.06 4973 0.11 0.50 2 5842 0.13 2634 0.06 3208 0.07 0.57 3 2322 0.05 1323 0.03 999 0.02 0.64 4 29626 0.68 11607 0.27 18019 0.41 0.54 5 15490 0.36 8430 0.19 7060 0.16 0.63 80 0 80 160 240 Scale: 1"=80' ----------------- _ - ----- ---- a Scale: 1' =80 Rivers Edge Modified LD-268 Roadside and Median Ditch Design Form Side Slope Min. Max Earth Ditch C A CA Tc 12 110 D2 010 :1 L y R Slope Ft/Ft Slope FVFt Allowable Velocity n=.03 Vel.' 2-yr *Velocity 10-yr "Depth Matting Type FreeboarE Channel Deem INCR ACC 1 0.50 0.17 0.09 0.09 5.0 5.39 7.05 0.46 0.60 2 2 0.03 0.04 4.0 1.76 0.42 EC-2 TYPE 1 0.58 1.00 2 0.57 0.13 0.08 0.08 5.0 5.39 7.05 0.41 0.54 2 2 0.03 0.04 4.0 1.71 0.41 EC-2 TYPE 1 0.60 1.00 3 0.64 0.05 0.03 0.03 5.0 5.39 7.05 0.18 0.24 2 2 0.03 0.03 4.0 1.25 0.30 EARTH 0.70 1.00 4 0.54 0.68 0.36 0.36 5.0 5.39 7.05 1.96 2.57 2 2 0.01 0.11 4.0 3.70 0.89 EC-2 TYPE 1 0.11 1.00 5 0.63 0.36 0.22 0.22 5.0 5.39 7.05 1.20 1.57 2 2 0.01 0.11 4.0 3.27 0.74 EC-2 TYPE 1 0.26 1.00 2-yr Velocity calculations performed using steepest slope 8 2-yr flow 10-yr Depth calculation performed using shallowest slope 8 10-yr flaw Flows ales taken from HydmCAD model --- - -_-__ = � ==_- RIVER'S EDGE=_ ----_-__==-__- - - ------------ --- --- _--= STORM STRUCTURE - ---- \ -`� - - \�\�,.�T� `_ _,__= -___ _ -_-`__ =_ - DRAINAGE AREA MAP :\\� ,` - `` '�„ <%'--,`_ 'r ,, ;,,_l�__-_==-�--- ----- IN IN IN I IN N.\\ \ ` \ \ \ \ `\ \ \ \ \ \\ \ ` \I 1 1 I i I \ ` \`\ \ jw ` I _ - \IN `\ IN IN IN k0.34 AU IN � / 1 � i i / i I / i/ / i r/ < Ir / I \�.. \\� �� m - - .� f� . / ,a 1 r � o / ' ♦� i / 7( �/,�. II \ � 1� i\ � \ 1 I IN IN \ \\ \\ \\ \ IN \\ \ \IN- L c' I IN IN Vic---- ♦Ft \ / i / /i l i 1 IN IN I IN I IN IN ----------- -/ IN IN IN `\\ \\ \`\\ ` \ \ \ �, `\,; \,; \ \ \ �, ` ,� - 'n'�...� ` 7" . "'� 77" __ �] \\ \ \ `\ \ 7t `\ `, `\ `\ ` \`\, `\, \NIN `\_- - - \�` \\\\ \ , ' ------------- IN IN IN IN IN, IN ♦ \ \ `` - ___------- -__ �` �`\ "IN \ — — — NIN \--------'': 1 �` `�- --_ ----' 200 400 600 Scale: 1"=200' 200 � Rivers Edge Storm Structure Drainage Area Summary Inlet Area (sf) Area (ac) Road (sf) Other Impervious (sf) Impervious (sf) Impervious (ac) Turf(sf) Turf (ac) c F7 7368 0.17 2777 0 2777 0.06 4591 0.11 0.53 F6 4214 0.10 3031 165 3196 0.07 1018 0.02 0.76 F5 14208 0.33 8196 1024 9220 0.21 4988 0.11 0.69 F4 14910 0.34 7126 1297 8423 0.19 6487 0.15 0.64 F3 10439 0.24 5126 0 5126 0.12 5313 0.12 0.59 F2B 20417 0.47 11371 1042 12413 0.28 8004 0.18 0.66 F2A 3473 0.08 2029 449 2478 0.06 995 0.02 0.73 F2 7506 0.17 3467 0 3467 0.08 4039 1 0.09 0.58 E3 14704 0.34 OIL- 7572 758 8330 0.19 6374 0.15 0.64 E2 14771 0.34 7397 1041 8438 0.19 6333 0.15 0.64 D2 8342 0.19 5033 611 5644 0.13 2698 0.06 0.71 C3 12988 0.30 5981 569 6550 0.15 6438 0.15 0.60 C2 16430 0.38 7388 1063 8451 0.19 7,979 0.18 0.61 B2 11506 0.26 5294 636 5930 0.14 5576 0.13 0.61 J4 36093 0.83 13712 0 13712 0.31 22381 0.51 0.53 J3 7330 0.17 3448 0 3448 0.08 3882 0.09 0.58 Rivers Edge LD-204 Stomlwater Inlet Computations Inlets on crave ony Sag InInls Only S. 8 o, c 0 F S P E y w� V u S c fi w -4c m SS a S 0 a a E rc a a o a" a a t 1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 In (a0 I (ao) Pnmr) NN (oral (ors) (1) ('r) CT) (n) (a) (ora) (aal (n) (a) (n) F7 DI-3C 8 7368 0.17 0.53 0.09 4.0 0.36 0.00 0.36 0.015 0.015 0.020 0.020 - - - - - 0.09 0.5 0.18 Z83 6.5 0.58 0.00 0.58 0.015 0.015 0.020 0.020 - - - - - 0.11 0.5 021 3.90 F6 DI-3B 10 4214 0.10 0.76 0.07 4.0 0.29 0.00 0.29 0.015 0.040 0.015 0.083 1.0 0.12 100.0% 0.29 0.00 - - - - 6.5 0.47 0.00 0.47 0.015 0.010 0.015 0.083 1.68 0.14 100.0% 0.47 0.00 - - - - F5 DI-3B 10 14208 0.33 0.69 0.22 4.0 0.90 0.00 0.90 0.015 0.040 0.015 0.083 2.78 0.18 100.0% 0.90 0.00 - - - - 6.5 1.46 0.00 1.46 0.015 0.010 0.015 0.083 4.82 0.21 100.0% 1.46 0.00 - - - - F4 DI-3B 10 14910 0.34 0.64 0.22 4.0 0.87 0.00 0.87 0.015 0.040 0.015 0.083 - - - - - 0.18 0.5 0.35 1.11 6.5 1.42 0.00 1.42 0.015 0.010 0.015 0.083 - - - - - 0.21 0.5 0.41 1.53 F3 DI-3B 12 10439 0.24 0.59 0.14 4.0 0.57 0.00 0.57 0.015 0.083 0.020 0.083 1.67 0.13 61.6% 0.35 0.22 - - - - 6.5 0.93 0.00 0.93 0.015 0.083 0.020 0.083 1.89 0.16 52.1% 0.48 0.44 - - - - F2 DI-3B 14 7506 0.17 0.58 0.10 4.0 0.40 0.00 0.40 0.015 0.100 0.020 0.020 3.24 0.06 100.0% 0.40 0.00 - - - - 6.5 0.65 0.00 0.66 0.015 0.100 0.020 0.020 1 3.89 0.08 100.0% 0.65 0.00 F2B DI-3B 14 20/17 0.47 0.66 0.31 4.0 1.25 0.00 1.25 0.015 0.030 0.010 0.010 - - - - - 0.10 0.5 Fig 9.60 6.5 2.03 0.00 2.03 0.015 0.030 0.010 0.010 - - - - - 0.12 0.5 0.23 13.27 F2 DI-313 10 3473 0.08 0.73 0.06 4.0 0.23 0.00 0.23 0.015 0.030 0.010 0.010 5.09 0.05 100.0% 0.23 0.00 - - - - w vFve IV wrV9 V.1 VD9 uee 4.0 aeo V.Vo V.ae V.Vm V.VVa VVoo VV*0 - - - 6.5 1.40 0.00 1.40 0.015 0.008 0.050 0.083 - - - F2 D1-3B 10 14771 0.38 0.64 0.24 4.0 0.97 0.00 0.97 0.015 0.008 0.050 0.083 - - - 0.28 0.5 0.56 1.62 0.24 0.5 0.49 1.19 6.5 0.88 0.00 0.88 0.015 0.008 0.050 0.083 3.40 0.m 100.0% 0.88 0.00 C3 C2 DI-3B DI-3B 10 10 12988 16430 0.30 0.38 0.60 0.61 0.18 0.23 4.0 6.5 4.0 6.5 0.72 1.17 0.92 1.49 0.00 0.00 0.00 0.08 0.72 1.17 0.92 1.57 0.015 0.015 0.015 0.015 0.008 0.008 0.008 0.008 0.050 0.050 0.050 0.050 0.083 0.083 0.083 0.083 - - - - - - - - - - - - - - 0.22 0.26 0.24 0.29 0.5 0.5 0.5 0.5 0." 0.52 0.48 0.58 0.98 I. 1.15 1.66 B2 D1-3B 10 115M 0.26 0.61 0.16 4.0 6.5 0.64 1.05 0.22 0.44 0.86 1.49 0.015 0.015 0.008 0.008 0.050 0.050 0.083 0.083 1 3.37 1 4.36 0.23 0.28 100.0% 94.5% 0.86 1.41 0.00 0.08 - - - - J4 DI-5 3X3 36093 0.83 0.53 0.44 4.0 1.75 0.00 1.75 0.015 0.034 0.020 - - - - - - 0.13 0.5 0.26 451 6.5 2.84 0.00 2.84 0.015 0.034 0.020 - - - - - 0.18 0.5 0.35 0.11 J3 DI-5 US 7330 0.17 0.58 0.10 4.0 0.39 0.00 0.39 0.015 0.034 0.020 - - - - - - 0.05 0.5 0.09 419 6.5 0.64 0.00 0.64 0.015 0.034 0.020 0.06 0.5 0.12 0.28 LD-229 Storm Drain Design Computations Rivers Edge From Structure To Structure Catch. Area ac Runoff Coef Increment AC ac ACCUm. AC ac wA m. with RD ac Total TOC min Total Intensity inthr Total Flow ofs Up Invert Elev. Down Invert Elev. Pipe Length ft Invert Slope % Pipe Diameter in Pipe Capacity cfs Velocity MIS) Flow time Increment min 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 J4 J3 0.83 0.51 0.42 0.42 0.42 5.0 6.81 2.88 388.75 388.51 24 1.00% 15 7.0 5.48 0.07 J3 J2 0.17 0.62 0.10 0.53 0.53 5.1 6.79 3.57 388.31 1 388.01 1 21.69 1.38% 15 8.2 6.46 0.06 J2 J1 0.00 0.00 0.00 0.53 0.53 5.1 6.77 3.56 387.81 1 386.00 1 156.09 1.16% 15 8.9 6.82 0.38 '1-14 H3 6.13 383.00 374.00 130.32 6.91% 15 18.4 13.48 0.16 'H3 H2 - - - - - - - 6.13 373.80 368.50 48.48 10.93% 15 23.1 15.93 0.05 'H2 H1 6.13 358.50 358.00 50.00 1.00% 15 7.0 6.43 0.13 F7 F6 0.17 0.53 0.09 0.09 0.09 5.0 6.81 0.61 437.56 434.56 118.46 2.53% 15 11.1 4.86 0.41 F6 F5 0.10 0.76 0.07 0.16 0.58 5.4 6.70 3.87 434.36 429.92 149.89 2.96% 15 12.0 8.7 0.29 F5 F4 0.33 0.69 0.22 0.80 1.64 5.7 6.62 10.82 429.72 424.91 151.35 3.18% 18 20.6 11.7 0.22 F4 F3 0.34 0.64 0.22 1.85 2.27 5.9 6.56 14.89 420.00 417.75 25.40 8.86% 18 33.9 18.6 0.02 F3 F2 0.24 0.59 0.14 2.41 2.41 5.9 6.55 15.81 417.55 412.57 57.25 8.70% 18 34.1 18.7 0.05 F2 F1 0.17 0.58 0.10 4.96 4.96 6.0 6.54 32.46 407.58 402.00 92.06 6.06% 24 72.2 22.4 0.07 F2C F2B 0.47 0.66 0.31 0.31 1.56 5.0 6.81 10.63 410.17 409.28 98.62 0.90% 24 23.3 7.2 0.23 F2B F2A 0.00 0.00 0.00 1.56 1.56 5.0 6.81 10.63 409.08 408.36 80.66 0.89% 24 23.1 7.2 0.19 F2A F2 0.08 0.73 0.06 1.62 2.45 5.2 6.76 16.56 408.16 407.78 75.00 0.51% 24 17.5 6.3 0.20 E4 E3 0.34 0.64 0.22 0.22 0.63 5.0 6.81 4.31 399.00 397.75 101.20 1.24% 15 7.8 6.5 0.26 E3 E2 0.00 0.00 0.00 0.63 0.63 5.0 6.81 4.31 397.55 397.00 31.66 1.74% 15 9.2 7.4 0.07 E2 E1 0.34 0.64 0.22 0.85 1.27 5.0 6.81 8.62 396.80 396.00 28.07 2.85% 18 19.5 10.6 0.04 D2 D1 0.19 0.71 0.14 0.14 0.97 5.0 6.81 6.59 398.00 396.00 23.44 8.53% 15 20.4 14.8 0.03 C3 C2 C2 C1 0.30 0.38 0.60 0.61 0.18 0.23 0.18 0.83 0.60 1.66 5.0 5.0 6.81 6.81 4.06 11.29 400.54 399.00 399.20 397.00 112.94 28.21 1.19% 7.09% 15 18 7.6 30.3 6.3 15.9 0.30 0.03 B2 B1 0.26 0.61 0.16 0.16 0.58 5.0 6.81 3.93 398.00 396.00 23.82 8.40% 15 20.3 12.8 0.03 `A4 A3 57.38 390.65 379.52 69.69 15.97% 36 288.8 31.8 0.04 `A3 A2 57.38 373.00 368.66 181.54 2.39% 36 111.7 15.9 0.19 `A2 At 57.38 359.59 359.21 37.72 1.01% 36 72.6 11.4 0.06 'Flow rate from detention taken from 10-yr HydroCAD model. ROOF DRAIN Computations Roof Drain Catch. Runoff Increment Accum. Total Total Total To Str # Area Coeff. AC AC TOC Intensity Flow Unit # (ac) (ac) (ac) (min) (in/hr) (cfs) 1 2 3 4 5 6 7 8 9 1 F6 0.03 0.90 0.03 0.03 5.00 6.81 0.21 2 F6 0.03 0.90 0.03 0.03 5.00 6.81 0.21 3 F5 0.03 0.90 0.03 0.03 5.00 6.81 0.21 4 F5 0.03 0.90 0.03 0.03 5.00 6.81 0.21 5 F5 0.03 0.90 0.03 0.03 5.00 6.81 0.21 6 F5 0.03 0.90 0.03 0.03 5.00 6.81 0.21 7 F4 0.03 0.90 0.03 0.03 5.00 6.81 0.21 8 F4 0.03 0.90 0.03 0.03 5.00 6.81 0.21 9 F2A 0.03 0.90 0.03 0.03 5.00 6.81 0.21 10 F2A 0.03 0.90 0.03 0.03 5.00 6.81 0.21 11 F213 0.03 0.90 0.03 0.03 5.00 6.81 0.21 12 F213 0.03 0.90 0.03 0.03 5.00 6.81 0.21 13 F2A 0.03 0.90 0.03 0.03 5.00 6.81 0.21 14 F2A 0.03 0.90 0.03 0.03 5.00 6.81 0.21 15 F213 0.03 0.90 0.03 0.03 5.00 6.81 0.21 16 F213 0.03 0.90 0.03 0.03 5.00 6.81 0.21 17 F213 0.03 0.90 0.03 0.03 5.00 6.81 0.21 18 F26 0.03 0.90 0.03 0.03 5.00 6.81 0.21 19 C3 0.03 0.90 0.03 0.03 5.00 6.81 0.21 20 C3 0.03 0.90 0.03 0.03 5.00 6.81 0.21 21 C2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 22 C2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 23 C2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 24 C2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 25 B2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 26 B2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 27 D2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 28 D2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 29 D2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 30 D2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 31 E2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 32 E2 0.03 0.90 0.03 0.03 5.00 6.81 0.21 33 E3 0.03 0.90 0.03 0.03 5.00 6.81 0.21 34 E3 0.03 0.90 0.03 0.03 5.00 6.81 0.21 Energy Balance Equation Summary For POA 1 Rivers Edge POA 1 1Yr.29Hrsmnnr mwrl:on: 1-YEAR STORM ANALYSIS: To mfei Ene gy Me. Requirements, I.F.'(QP__,'RV__,)/RV_, R¢Wce Hiss I PDA by: AchiwOd Total R000if(InclUdln Make p�c(Q 'In/si (pe,a,.,M. C.) = requlrelrelucLan®POA PREOEV POSTOEV Pre OIce11e Drainage Area = LBB as iM - 013 = 0.91 ch lequlred 1-YR pPre= ].9] pest- 2.9f Post Omlle Drainage Area = 488 as ACHIEVE31jr REOULTIOHATPOAI: 2-YR Qpre= 111M p.post= 6.92 le.e...p.e 1.W IF. = 0.8 9.93 cfa 1(1 Qpre= Q,N 011"- 5]39 RVe-n--t= 0.035 Nat ci•— • 0.13 eft RVo..a.Qe 0.02 ACHIEVED j 1.YR Reduction 10-YR Reduction 0.93 eares NMe: Since the EnereJuctlonM quidol mun at this PDAis area)I5greaters than iMre]udlon by the Enegy Ealance Equation, Runo%al this POA Is compliant vAtM1 Ne Ereryy Balanre E uallon. RumXto Nlsypoim an iscomment asevAtM19VAC2S8]Dn seemed by use eaidollame to this paint Is rMure!Uyanamount AG2M 7iM (2)b req t by Viee km eis equdlm. Site mmplleS vnIM1 9VAC258]O88C(2)G Mrause tM lDyr peak mno%Is 2]ucel. Energy Balance Equation Summary (� Rivers Edge POA 2 Qdeveloped� I.F. *(Cprre-develoWd�RVPre-Developed)/RVdeveloWd Qdevelowd2� (Qore to *RVforerted)/RVdevelowd Pre-Dev DA= 7.79 ac Post-Dev DA= 7.84 ac Qpre-developed = 3.22 RVPre-D..eloWd = 0.227 MaxOde,reir= 2.03cfs RVDeveloped = 0.288 Achieved Post-Dev Max Runoff 01yr = 2.02cfs. Site complies with 9VAC25-870-66-(3)A Maximum 010yr = 20.95cfs (predev) Achieved 010yr = 20.34cfs Flow Rates Flow Rates ~ev cfs Postdev cfs 1- r 3.22 1- r 2.02 z-yr 6.87 z-yr 4.68 E10-yr 20.95 10-yr 20.34 1 00-r 54.28 1 00-r 51.45 Post Development HydroCAD Report Rivers Edge 2S 18 6S 5S DA1 Unma aged :711, ipe Detention DA2 Unm aged Dev o Dry Pond 3P 7P DET TION SYSTEM ry Pond 4L 8L POA1 POA2 Sub4 Reach Aon Llnk Post -Development Post Development - Rivers Edge Type 11 24-hr 1-yr Rainfall=2.96" Prepared by {enter your company name here} Printed 11/21/2022 Time span=1.00-60.00 hrs, dt=0.05 hrs, 1181 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: Dev to Pipe Detention Runoff Area=4.880 ac 65.78% Impervious Runoff Depth=1.55" Tc=5.0 min CN=85 Runoff=13.61 cfs 0.632 of Subcatchment2S: DA1 Unmanaged Runoff Area=16.140 ac 0.06% Impervious Runoff Depth=0.18" Tc=7.0 min CN=55 Runoff=1.57 cfs 0.248 of Subcatchment5S: Dev to Dry Pond Runoff Area=1.700 ac 39.41% Impervious Runoff Depth=0.99" Tc=5.0 min CN=76 Runoff=3.00 cfs 0.140 of Subcatchment6S: DA2 Unmanaged Runoff Area=6.140 ac 13.19% Impervious Runoff Depth=0.29" Tc=7.0 min UI Adjusted CN=59 Runoff=1.77 cfs 0.148 of Pond 3P: DETENTION SYSTEM Peak Elev=395.73' Storage=0.342 of Inflow=13.61 cfs 0.632 of Outflow=0.53 cfs 0.632 of Pond 7P: Dry Pond Peak Elev=385.74' Storage=2,399 cf Inflow=3.00 cfs 0.140 of Outflow=0.28 cfs 0.140 of Link 4L: POA1 Inflow=2.04 cfs 0.880 of Primary=2.04 cfs 0.880 of Link 8L: POA2 Inflow=2.02 cfs 0.288 of Primary=2.02 cfs 0.288 of Total Runoff Area = 28.860 ac Runoff Volume = 1.168 of Average Runoff Depth = 0.49" 83.71% Pervious = 24.160 ac 16.29% Impervious = 4.700 ac Post -Development Post Development - Rivers Edge Type 11 24-hr 1-yr Rainfall=2.96" Prepared by {enter your company name here} Printed 11/21/2022 Runoff = Summary for Subcatchment 1S: Dev to Pipe Detention 13.61 cfs @ 11.96 hrs, Volume= 0.632 af, Depth= 1.55" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Rainfall=2.96" Area (ac) CN Description 3.210 98 Impervious 1.670 61 >75% Grass cover, Good, HSG B 4.880 85 Weighted Average 1.670 34.22% Pervious Area 3.210 65.78% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: DA1 Unmanaged Runoff = 1.57 cfs @ 12.05 hrs, Volume= 0.248 af, Depth= 0.18" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Rainfall=2.96" Area (ac) CN Description 0.010 98 Unconnected pavement, HSG B 2.130 58 Meadow, non -grazed, HSG B 14.000 55 Woods. Good. HSG B 16.140 55 Weighted Average 16.130 99.94% Pervious Area 0.010 0.06% Impervious Area 0.010 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Subcatchment 5S: Dev to Dry Pond Runoff = 3.00 cfs @ 11.96 hrs, Volume= 0.140 af, Depth= 0.99" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type 11 24-hr 1-yr Rainfall=2.96" Post -Development Post Development - Rivers Edge Type 11 24-hr 1-yr Rainfall=2.96" Prepared by {enter your company name here) Printed 11/21/2022 Area (ac) CN Description 0.670 98 Impervious 1.030 61 >75% Grass cover. Good. HSG B 1.700 76 Weighted Average 1.030 60.59% Pervious Area 0.670 39.41 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6S: DA2 Unmanaged Runoff = 1.77 cfs @ 12.02 hrs, Volume= 0.148 af, Depth= 0.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Rainfall=2.96" Area (ac) CN Description 0.810 98 Unconnected pavement, HSG B 1.360 61 >75% Grass cover, Good, HSG B 3.970 55 Woods, Good, HSG B 6.140 62 Weighted Average, UI Adjusted CN = 59 5.330 86.81 % Pervious Area 0.810 13.19% Impervious Area 0.810 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Pond 3P: DETENTION SYSTEM Inflow Area = 4.880 ac, 65.78% Impervious, Inflow Depth = 1.55" for 1-yr event Inflow = 13.61 cfs @ 11.96 hrs, Volume= 0.632 of Outflow = 0.53 cfs @ 13.62 hrs, Volume= 0.632 af, Atten= 96%, Lag= 99.8 min Primary = 0.53 cfs @ 13.62 hrs, Volume= 0.632 of Routing by Stor-Ind method, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 395.73' @ 13.62 hrs Surf.Area= 0.078 ac Storage= 0.342 of Plug -Flow detention time= 343.0 min calculated for 0.632 of (100% of inflow) Center -of -Mass det. time= 342.6 min ( 1,168.2 - 825.5 ) Volume Invert Avail.Storage Storage Description #1 390.65' 0.555 of 108.0" D x 380.01 Pipe Storage #2 390.65' 0.018 of 36.0" D x 113.01 Pipe Storage 0.573 of Total Available Storage Post -Development Post Development - Rivers Edge Type 11 24-hr 1-yr Rainfall=2.96" Prepared by {enter your company name here) Printed 11/21/2022 Device Routing Invert Outlet Devices #1 Primary 390.65' 36.0" Round Culvert L= 70.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 390.65' / 379.52' S= 0.1590 T Cc= 0.900 n= 0.012 #2 Device 1 390.65' 3.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 396.85' 12.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 398.15' 6.0' long x 6.26' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 7.5' Crest Height #5 Primary 405.57' 24.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.53 cfs @ 13.62 hrs HW=395.73' (Free Discharge) 1=Culvert (Passes 0.53 cfs of 56.85 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.53 cfs @ 10.72 fps) 3=Orifice/Grate ( Controls 0.00 cfs) =Sharp -Crested Rectangular Weir( Controls 0.00 cfs) S=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 7P: Dry Pond Inflow Area = 1.700 ac, 39.41 % Impervious, Inflow Depth = 0.99" for 1-yr event Inflow = 3.00 cfs @ 11.96 hrs, Volume= 0.140 of Outflow = 0.28 cfs @ 12.51 hrs, Volume= 0.140 af, Atten= 91 %, Lag= 33.0 min Primary = 0.28 cfs @ 12.51 hrs, Volume= 0.140 of Routing by Stor-Ind method, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Peak Elev= 385.74' @ 12.51 hrs Surf.Area= 1,742 sf Storage= 2,399 cf Plug -Flow detention time= 100.6 min calculated for 0.140 of (100% of inflow) Center -of -Mass det. time= 101.1 min ( 957.1 - 856.0 ) Volume Invert Avail.Storage Storage Description #1 384.00' 10,553 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 384.00 1,018 0 0 386.00 1,851 2,869 2,869 388.00 2,899 4,750 7,619 388.90 3,620 2,934 10,553 Device Routing Invert Outlet Devices #1 Primary 383.00' 15.0" Round Culvert L= 130.8' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 383.00' / 374.00' S= 0.0688 T Cc= 0.900 n= 0.012 #2 Device 1 384.00' 2.9" Vert. Orifice/Grate C= 0.600 #3 Device 1 387.10' 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Post Development - Rivers Edge Prepared by {enter your company name here) Post -Development Type 11 24-hr 1-yr Rainfall=2.96" Printed 11/21/2022 Primary OutFlow Max=0.28 cfs @ 12.51 hrs HW=385.74' (Free Discharge) tTCulvert (Passes 0.28 cfs of 7.58 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.28 cfs @ 6.12 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Summary for Link 4L: POA1 Inflow Area = 21.020 ac, 15.32% Impervious, Inflow Depth = 0.50" for 1-yr event Inflow = 2.04 cfs @ 12.05 hrs, Volume= 0.880 of Primary = 2.04 cfs @ 12.05 hrs, Volume= 0.880 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Summary for Link 8L: POA2 Inflow Area = 7.840 ac, 18.88% Impervious, Inflow Depth = 0.44" for 1-yr event Inflow = 2.02 cfs @ 12.02 hrs, Volume= 0.288 of Primary = 2.02 cfs @ 12.02 hrs, Volume= 0.288 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Post -Development Post Development - Rivers Edge Type/1 24-hr 2-yr Rainfall=3.58" Prepared by {enter your company name here} Printed 11/21/2022 Time span=1.00-60.00 hrs, dt=0.05 hrs, 1181 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: Dev to Pipe Detention Runoff Area=4.880 ac 65.78% Impervious Runoff Depth=2.09" Tc=5.0 min CN=85 Runoff=18.11 cfs 0.848 of Subcatchment2S: DA1 Unmanaged Runoff Area=16.140 ac 0.06% Impervious Runoff Depth=0.37" Tc=7.0 min CN=55 Runoff=6.40 cfs 0.502 of Subcatchment5S: Dev to Dry Pond Runoff Area=1.700 ac 39.41% Impervious Runoff Depth=1.42" Tc=5.0 min CN=76 Runoff=4.36 cfs 0.202 of Subcatchment6S: DA2 Unmanaged Runoff Area=6.140 ac 13.19% Impervious Runoff Depth=0.52" Tc=7.0 min UI Adjusted CN=59 Runoff=4.36 cfs 0.269 of Pond 3P: DETENTION SYSTEM Peak Elev=397.15' Storage=0.447 of Inflow=18.11 cfs 0.848 of Outflow=1.13 cfs 0.848 of Pond 7P: Dry Pond Peak Elev=386.47' Storage=3,799 cf Inflow=4.36 cfs 0.202 of Outflow=0.34 cfs 0.202 of Link 4L: POA1 Inflow=6.92 cfs 1.350 of Primary=6.92 cfs 1.350 of Link 8L: POA2 Inflow=4.66 cfs 0.470 of Primary=4.66 cfs 0.470 of Total Runoff Area = 28.860 ac Runoff Volume = 1.820 of Average Runoff Depth = 0.76" 83.71% Pervious = 24.160 ac 16.29% Impervious = 4.700 ac Post -Development Post Development - Rivers Edge Type/1 24-hr 2-yr Rainfall=3.58" Prepared by {enter your company name here} Printed 11/21/2022 Runoff = Summary for Subcatchment 1S: Dev to Pipe Detention 18.11 cfs @ 11.96 hrs, Volume= 0.848 af, Depth= 2.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 2-yr Rainfall=3.58" Area (ac) CN Description 3.210 98 Impervious 1.670 61 >75% Grass cover, Good, HSG B 4.880 85 Weighted Average 1.670 34.22% Pervious Area 3.210 65.78% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: DA1 Unmanaged Runoff = 6.40 cfs @ 12.02 hrs, Volume= 0.502 af, Depth= 0.37" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 2-yr Rainfall=3.58" Area (ac) CN Description 0.010 98 Unconnected pavement, HSG B 2.130 58 Meadow, non -grazed, HSG B 14.000 55 Woods. Good. HSG B 16.140 55 Weighted Average 16.130 99.94% Pervious Area 0.010 0.06% Impervious Area 0.010 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Subcatchment 5S: Dev to Dry Pond Runoff = 4.36 cfs @ 11.96 hrs, Volume= 0.202 af, Depth= 1.42" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type 11 24-hr 2-yr Rainfall=3.58" Post -Development Post Development - Rivers Edge Type/1 24-hr 2-yr Rainfall=3.58" Prepared by {enter your company name here) Printed 11/21/2022 Area (ac) CN Description 0.670 98 Impervious 1.030 61 >75% Grass cover. Good. HSG B 1.700 76 Weighted Average 1.030 60.59% Pervious Area 0.670 39.41 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6S: DA2 Unmanaged Runoff = 4.36 cfs @ 12.01 hrs, Volume= 0.269 af, Depth= 0.52" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 2-yr Rainfall=3.58" Area (ac) CN Description 0.810 98 Unconnected pavement, HSG B 1.360 61 >75% Grass cover, Good, HSG B 3.970 55 Woods, Good, HSG B 6.140 62 Weighted Average, UI Adjusted CN = 59 5.330 86.81 % Pervious Area 0.810 13.19% Impervious Area 0.810 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Pond 3P: DETENTION SYSTEM Inflow Area = 4.880 ac, 65.78% Impervious, Inflow Depth = 2.09" for 2-yr event Inflow = 18.11 cfs @ 11.96 hrs, Volume= 0.848 of Outflow = 1.13 cfs @ 12.73 hrs, Volume= 0.848 af, Atten= 94%, Lag= 46.4 min Primary = 1.13 cfs @ 12.73 hrs, Volume= 0.848 of Routing by Stor-Ind method, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 397.15' @ 12.73 hrs Surf.Area= 0.070 ac Storage= 0.447 of Plug -Flow detention time= 370.2 min calculated for 0.848 of (100% of inflow) Center -of -Mass det. time= 370.5 min ( 1,187.7 - 817.2 ) Volume Invert Avail.Storage Storage Description #1 390.65' 0.555 of 108.0" D x 380.01 Pipe Storage #2 390.65' 0.018 of 36.0" D x 113.01 Pipe Storage 0.573 of Total Available Storage Post -Development Post Development - Rivers Edge Type/1 24-hr 2-yr Rainfall=3.58" Prepared by {enter your company name here) Printed 11/21/2022 Device Routing Invert Outlet Devices #1 Primary 390.65' 36.0" Round Culvert L= 70.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 390.65' / 379.52' S= 0.1590 T Cc= 0.900 n= 0.012 #2 Device 1 390.65' 3.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 396.85' 12.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 398.15' 6.0' long x 6.26' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 7.5' Crest Height #5 Primary 405.57' 24.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=1.12 cfs @ 12.73 hrs HW=397.15' (Free Discharge) 1=Culvert (Passes 1.12 cfs of 67.14 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.60 cfs @ 12.16 fps) 3=Orifice/Grate (Orifice Controls 0.52 cfs @ 1.75 fps) =Sharp -Crested Rectangular Weir( Controls 0.00 cfs) S=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 7P: Dry Pond Inflow Area = 1.700 ac, 39.41 % Impervious, Inflow Depth = 1.42" for 2-yr event Inflow = 4.36 cfs @ 11.96 hrs, Volume= 0.202 of Outflow = 0.34 cfs @ 12.60 hrs, Volume= 0.202 af, Atten= 92%, Lag= 38.2 min Primary = 0.34 cfs @ 12.60 hrs, Volume= 0.202 of Routing by Stor-Ind method, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Peak Elev= 386.47' @ 12.60 hrs Surf.Area= 2,098 sf Storage= 3,799 cf Plug -Flow detention time= 129.5 min calculated for 0.202 of (100% of inflow) Center -of -Mass det. time= 128.9 min ( 973.9 - 844.9 ) Volume Invert Avail.Storage Storage Description #1 384.00' 10,553 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 384.00 1,018 0 0 386.00 1,851 2,869 2,869 388.00 2,899 4,750 7,619 388.90 3,620 2,934 10,553 Device Routing Invert Outlet Devices #1 Primary 383.00' 15.0" Round Culvert L= 130.8' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 383.00' / 374.00' S= 0.0688 T Cc= 0.900 n= 0.012 #2 Device 1 384.00' 2.9" Vert. Orifice/Grate C= 0.600 #3 Device 1 387.10' 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Post Development - Rivers Edge Prepared by {enter your company name here) Post -Development Type/1 24-hr 2-yr Rainfall=3.58" Printed 11/21/2022 Primary OutFlow Max=0.34 cfs @ 12.60 hrs HW=386.47' (Free Discharge) tTCulvert (Passes 0.34 cfs of 8.80 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.34 cfs @ 7.38 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Summary for Link 4L: POM Inflow Area = 21.020 ac, 15.32% Impervious, Inflow Depth = 0.77" for 2-yr event Inflow = 6.92 cfs @ 12.02 hrs, Volume= 1.350 of Primary = 6.92 cfs @ 12.02 hrs, Volume= 1.350 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Summary for Link 8L: POA2 Inflow Area = 7.840 ac, 18.88% Impervious, Inflow Depth = 0.72" for 2-yr event Inflow = 4.66 cfs @ 12.01 hrs, Volume= 0.470 of Primary = 4.66 cfs @ 12.01 hrs, Volume= 0.470 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Post -Development Post Development - Rivers Edge Type 11 24-hr 10-yr Rainfall= 5.41 " Prepared by {enter your company name here} Printed 11/21/2022 Time span=1.00-60.00 hrs, dt=0.05 hrs, 1181 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: Dev to Pipe Detention Runoff Area=4.880 ac 65.78% Impervious Runoff Depth=3.75" Tc=5.0 min CN=85 Runoff=31.69 cfs 1.525 of Subcatchment2S: DA1 Unmanaged Runoff Area=16.140 ac 0.06% Impervious Runoff Depth=1.19" Tc=7.0 min CN=55 Runoff=30.21 cfs 1.602 of Subcatchment5S: Dev to Dry Pond Runoff Area=1.700 ac 39.41% Impervious Runoff Depth=2.88" Tc=5.0 min CN=76 Runoff=8.77 cfs 0.408 of Subcatchment6S: DA2 Unmanaged Runoff Area=6.140 ac 13.19% Impervious Runoff Depth=1.47" Tc=7.0 min UI Adjusted CN=59 Runoff=14.81 cfs 0.754 of Pond 3P: DETENTION SYSTEM Peak Elev=399.31' Storage=0.567 of Inflow=31.69 cfs 1.525 of Outflow=27.52 cfs 1.517 of Pond 7P: Dry Pond Peak Elev=387.37' Storage=5,895 cf Inflow=8.77 cfs 0.408 of Outflow=6.13 cfs 0.408 of Link 4L: POA1 Inflow=57.38 cfs 3.119 of Primary=57.38 cfs 3.119 of Link 8L: POA2 Inflow=20.34 cfs 1.161 of Primary=20.34 cfs 1.161 of Total Runoff Area = 28.860 ac Runoff Volume = 4.288 of Average Runoff Depth = 1.78" 83.71% Pervious = 24.160 ac 16.29% Impervious = 4.700 ac Post -Development Post Development - Rivers Edge Type 11 24-hr 10-yr Rainfall= 5.41 " Prepared by {enter your company name here} Printed 11/21/2022 Runoff = Summary for Subcatchment 1S: Dev to Pipe Detention 31.69 cfs @ 11.95 hrs, Volume= 1.525 af, Depth= 3.75" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Rainfall=5.41" Area (ac) CN Description 3.210 98 Impervious 1.670 61 >75% Grass cover, Good, HSG B 4.880 85 Weighted Average 1.670 34.22% Pervious Area 3.210 65.78% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: DA1 Unmanaged Runoff = 30.21 cfs @ 12.00 hrs, Volume= 1.602 af, Depth= 1.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Rainfall=5.41" Area (ac) CN Description 0.010 98 Unconnected pavement, HSG B 2.130 58 Meadow, non -grazed, HSG B 14.000 55 Woods. Good. HSG B 16.140 55 Weighted Average 16.130 99.94% Pervious Area 0.010 0.06% Impervious Area 0.010 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Subcatchment 5S: Dev to Dry Pond Runoff = 8.77 cfs @ 11.96 hrs, Volume= 0.408 af, Depth= 2.88" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type 11 24-hr 10-yr Rainfall=5.41" Post -Development Post Development - Rivers Edge Type 11 24-hr 10-yr Rainfall= 5.41 " Prepared by {enter your company name here) Printed 11/21/2022 Area (ac) CN Description 0.670 98 Impervious 1.030 61 >75% Grass cover. Good. HSG B 1.700 76 Weighted Average 1.030 60.59% Pervious Area 0.670 39.41 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6S: DA2 Unmanaged Runoff = 14.81 cfs @ 11.99 hrs, Volume= 0.754 af, Depth= 1.47" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Rainfall=5.41" Area (ac) CN Description 0.810 98 Unconnected pavement, HSG B 1.360 61 >75% Grass cover, Good, HSG B 3.970 55 Woods, Good, HSG B 6.140 62 Weighted Average, UI Adjusted CN = 59 5.330 86.81 % Pervious Area 0.810 13.19% Impervious Area 0.810 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Pond 3P: DETENTION SYSTEM Inflow Area = 4.880 ac, 65.78% Impervious, Inflow Depth = 3.75" for 10-yr event Inflow = 31.69 cfs @ 11.95 hrs, Volume= 1.525 of Outflow = 27.52 cfs @ 12.01 hrs, Volume= 1.517 af, Atten= 13%, Lag= 3.5 min Primary = 27.52 cfs @ 12.01 hrs, Volume= 1.517 of Routing by Stor-Ind method, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 399.31' @ 12.01 hrs Surf.Area= 0.030 ac Storage= 0.567 of Plug -Flow detention time= 265.0 min calculated for 1.516 of (99% of inflow) Center -of -Mass det. time= 262.3 min ( 1,062.8 - 800.5 ) Volume Invert Avail.Storage Storage Description #1 390.65' 0.555 of 108.0" D x 380.01 Pipe Storage #2 390.65' 0.018 of 36.0" D x 113.01 Pipe Storage 0.573 of Total Available Storage Post -Development Post Development - Rivers Edge Type 11 24-hr 10-yr Rainfall= 5.41 " Prepared by {enter your company name here) Printed 11/21/2022 Device Routing Invert Outlet Devices #1 Primary 390.65' 36.0" Round Culvert L= 70.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 390.65' / 379.52' S= 0.1590 T Cc= 0.900 n= 0.012 #2 Device 1 390.65' 3.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 396.85' 12.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 398.15' 6.0' long x 6.26' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 7.5' Crest Height #5 Primary 405.57' 24.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=24.51 cfs @ 12.01 hrs HW=399.19' (Free Discharge) 1=Culvert (Passes 24.51 cfs of 79.67 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.69 cfs @ 13.97 fps) 3=Orifice/Grate (Orifice Controls 3.48 cfs @ 6.95 fps) =Sharp -Crested Rectangular Weir(Weir Controls 20.35 cfs @ 3.39 fps) S=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 7P: Dry Pond Inflow Area = 1.700 ac, 39.41 % Impervious, Inflow Depth = 2.88" for 10-yr event Inflow = 8.77 cfs @ 11.96 hrs, Volume= 0.408 of Outflow = 6.13 cfs @ 12.03 hrs, Volume= 0.408 af, Atten= 30%, Lag= 4.6 min Primary = 6.13 cfs @ 12.03 hrs, Volume= 0.408 of Routing by Stor-Ind method, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Peak Elev= 387.37' @ 12.03 hrs Surf.Area= 2,569 sf Storage= 5,895 cf Plug -Flow detention time= 127.4 min calculated for 0.407 of (100% of inflow) Center -of -Mass det. time= 127.8 min ( 952.3 - 824.6 ) Volume Invert Avail.Storage Storage Description #1 384.00' 10,553 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 384.00 1,018 0 0 386.00 1,851 2,869 2,869 388.00 2,899 4,750 7,619 388.90 3,620 2,934 10,553 Device Routing Invert Outlet Devices #1 Primary 383.00' 15.0" Round Culvert L= 130.8' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 383.00' / 374.00' S= 0.0688 T Cc= 0.900 n= 0.012 #2 Device 1 384.00' 2.9" Vert. Orifice/Grate C= 0.600 #3 Device 1 387.10' 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Post Development - Rivers Edge Prepared by {enter your company name here) Post -Development Type 11 24-hr 10-yr Rainfall=5.41 " Printed 11/21/2022 Primary OutFlow Max=5.73 cfs @ 12.03 hrs HW=387.36' (Free Discharge) tTCulvert (Passes 5.73 cfs of 10.07 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.40 cfs @ 8.66 fps) 3=Orifice/Grate (Weir Controls 5.33 cfs @ 1.66 fps) Summary for Link 4L: POA1 Inflow Area = 21.020 ac, 15.32% Impervious, Inflow Depth = 1.78" for 10-yr event Inflow = 57.38 cfs @ 12.01 hrs, Volume= 3.119 of Primary = 57.38 cfs @ 12.01 hrs, Volume= 3.119 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Summary for Link 8L: POA2 Inflow Area = 7.840 ac, 18.88% Impervious, Inflow Depth = 1.78" for 10-yr event Inflow = 20.34 cfs @ 12.01 hrs, Volume= 1.161 of Primary = 20.34 cfs @ 12.01 hrs, Volume= 1.161 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Post -Development Post Development - Rivers Edge Type 11 24-hr 100-yr Rainfall=8.86" Prepared by {enter your company name here} Printed 11/21/2022 Time span=1.00-60.00 hrs, dt=0.05 hrs, 1181 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: Dev to Pipe Detention Runoff Area=4.880 ac 65.78% Impervious Runoff Depth=7.05" Tc=5.0 min CN=85 Runoff=57.29 cfs 2.865 of Subcatchment2S: DA1 Unmanaged Runoff Area=16.140 ac 0.06% Impervious Runoff Depth=3.39" Tc=7.0 min CN=55 Runoff=92.40 cfs 4.556 of Subcatchment5S: Dev to Dry Pond Runoff Area=1.700 ac 39.41% Impervious Runoff Depth=5.95" Tc=5.0 min CN=76 Runoff=17.62 cfs 0.842 of Subcatchment6S: DA2 Unmanaged Runoff Area=6.140 ac 13.19% Impervious Runoff Depth=3.87" Tc=7.0 min UI Adjusted CN=59 Runoff=40.28 cfs 1.980 of Pond 3P: DETENTION SYSTEM Peak EIev=400.12' Storage=0.573 of Inflow=57.29 cfs 2.865 of Outflow=57.41 cfs 2.875 of Pond 7P: Dry Pond Peak EIev=388.32' Storage=8,600 cf Inflow=17.62 cfs 0.842 of Outflow=11.30 cfs 0.842 of Link4L: POA1 Inflow=144.38 cfs 7.431 of Primary=144.38 cfs 7.431 of Link 8L: POA2 Inflow=51.45 cfs 2.823 of Primary=51.45 cfs 2.823 of Total Runoff Area = 28.860 ac Runoff Volume = 10.244 of Average Runoff Depth = 4.26" 83.71% Pervious = 24.160 ac 16.29% Impervious = 4.700 ac Post -Development Post Development - Rivers Edge Type 11 24-hr 100-yr Rainfall=8.86" Prepared by {enter your company name here} Printed 11/21/2022 Runoff = Summary for Subcatchment 1S: Dev to Pipe Detention 57.29 cfs @ 11.95 hrs, Volume= 2.865 af, Depth= 7.05" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Rainfall=8.86" Area (ac) CN Description 3.210 98 Impervious 1.670 61 >75% Grass cover, Good, HSG B 4.880 85 Weighted Average 1.670 34.22% Pervious Area 3.210 65.78% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: DA1 Unmanaged Runoff = 92.40 cfs @ 11.99 hrs, Volume= 4.556 af, Depth= 3.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Rainfall=8.86" Area (ac) CN Description 0.010 98 Unconnected pavement, HSG B 2.130 58 Meadow, non -grazed, HSG B 14.000 55 Woods. Good. HSG B 16.140 55 Weighted Average 16.130 99.94% Pervious Area 0.010 0.06% Impervious Area 0.010 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Subcatchment 5S: Dev to Dry Pond Runoff = 17.62 cfs @ 11.95 hrs, Volume= 0.842 af, Depth= 5.95" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type 11 24-hr 100-yr Rainfall=8.86" Post -Development Post Development - Rivers Edge Type 11 24-hr 100-yr Rainfall=8.86" Prepared by {enter your company name here) Printed 11/21/2022 Area (ac) CN Description 0.670 98 Impervious 1.030 61 >75% Grass cover. Good. HSG B 1.700 76 Weighted Average 1.030 60.59% Pervious Area 0.670 39.41 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6S: DA2 Unmanaged Runoff = 40.28 cfs @ 11.99 hrs, Volume= 1.980 af, Depth= 3.87" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Rainfall=8.86" Area (ac) CN Description 0.810 98 Unconnected pavement, HSG B 1.360 61 >75% Grass cover, Good, HSG B 3.970 55 Woods, Good, HSG B 6.140 62 Weighted Average, UI Adjusted CN = 59 5.330 86.81 % Pervious Area 0.810 13.19% Impervious Area 0.810 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Pond 3P: DETENTION SYSTEM Inflow Area = 4.880 ac, 65.78% Impervious, Inflow Depth = 7.05" for 100-yr event Inflow = 57.29 cfs @ 11.95 hrs, Volume= 2.865 of Outflow = 57.41 cfs @ 11.95 hrs, Volume= 2.875 af, Atten= 0%, Lag= 0.0 min Primary = 57.41 cfs @ 11.95 hrs, Volume= 2.875 of Routing by Stor-Ind method, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 400.12' @ 11.95 hrs Surf.Area= 0.000 ac Storage= 0.573 of Plug -Flow detention time= 169.1 min calculated for 2.865 of (100% of inflow) Center -of -Mass det. time= 173.5 min ( 956.4 - 782.9 ) Volume Invert Avail.Storage Storage Description #1 390.65' 0.555 of 108.0" D x 380.01 Pipe Storage #2 390.65' 0.018 of 36.0" D x 113.01 Pipe Storage 0.573 of Total Available Storage Post -Development Post Development - Rivers Edge Type 11 24-hr 100-yr Rainfall=8.86" Prepared by {enter your company name here} Printed 11/21/2022 Device Routing Invert Outlet Devices #1 Primary 390.65' 36.0" Round Culvert L= 70.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 390.65' / 379.52' S= 0.1590 T Cc= 0.900 n= 0.012 #2 Device 1 390.65' 3.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 396.85' 12.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 398.15' 6.0' long x 6.26' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 7.5' Crest Height #5 Primary 405.57' 24.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=57.07 cfs @ 11.95 hrs HW=400.12' (Free Discharge) 1=Culvert (Passes 57.07 cfs of 84.76 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.72 cfs @ 14.72 fps) 3=Orifice/Grate (Orifice Controls 4.18 cfs @ 8.36 fps) =Sharp -Crested Rectangular Weir(Weir Controls 52.16 cfs @ 4.73 fps) S=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 7P: Dry Pond Inflow Area = 1.700 ac, 39.41 % Impervious, Inflow Depth = 5.95" for 100-yr event Inflow = 17.62 cfs @ 11.95 hrs, Volume= 0.842 of Outflow = 11.30 cfs @ 12.03 hrs, Volume= 0.842 af, Atten= 36%, Lag= 4.4 min Primary = 11.30 cfs @ 12.03 hrs, Volume= 0.842 of Routing by Stor-Ind method, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Peak Elev= 388.32' @ 12.03 hrs Surf.Area= 3,158 sf Storage= 8,600 cf Plug -Flow detention time= 94.2 min calculated for 0.842 of (100% of inflow) Center -of -Mass det. time= 94.6 min ( 898.5 - 803.9 ) Volume Invert Avail.Storage Storage Description #1 384.00' 10,553 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 384.00 1,018 0 0 386.00 1,851 2,869 2,869 388.00 2,899 4,750 7,619 388.90 3,620 2,934 10,553 Device Routing Invert Outlet Devices #1 Primary 383.00' 15.0" Round Culvert L= 130.8' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 383.00' / 374.00' S= 0.0688 T Cc= 0.900 n= 0.012 #2 Device 1 384.00' 2.9" Vert. Orifice/Grate C= 0.600 #3 Device 1 387.10' 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Post Development - Rivers Edge Prepared by {enter your company name here) Post -Development Type/1 24-hr 100-yr Rainfall=8.86" Printed 11/21/2022 Primary OutFlow Max=11.25 cfs @ 12.03 hrs HW=388.28' (Free Discharge) tCulvert (Inlet Controls 11.25 cfs @ 9.17 fps) 2=Orifice/Grate (Passes < 0.45 cfs potential flow) 3=Orifice/Grate (Passes < 52.96 cfs potential flow) Summary for Link 4L: POA1 Inflow Area = 21.020 ac, 15.32% Impervious, Inflow Depth = 4.24" for 100-yr event Inflow = 144.38 cfs @ 11.97 hrs, Volume= 7.431 of Primary = 144.38 cfs @ 11.97 hrs, Volume= 7.431 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Summary for Link 8L: POA2 Inflow Area = 7.840 ac, 18.88% Impervious, Inflow Depth = 4.32" for 100-yr event Inflow = 51.45 cfs @ 11.99 hrs, Volume= 2.823 of Primary = 51.45 cfs @ 11.99 hrs, Volume= 2.823 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 1.00-60.00 hrs, dt= 0.05 hrs Runoff Quality Calculations: VRRM Map Pre-Dev VRRM Map Post-Dev VRRM Re -Development Spreadsheet Summary Pre-ReDevelopment Land Cover (acres) I � I \ 1 I I \ rl \ I \ I LIMITS OF DISTURBANCE 9.31 AC PREDEVELOPMENT VRRM MAP 0 �2] \� / / A soils B Soils C Soils D Soils Totals % of Total Forest/Open (acres) 5.00 16.16 0.00 0.00 21.15 84 Managed Turf (acres) 0.22 2.04 0.00 0.00 2.26 9 Impervious Cover (acres) 0.24 1.43 0.00 0.00 1.67 7 25.07 100 1 i 1 \ 1 \ I 1 `\ 1 \ 1 \\ - - - - - - - - - - - - \ �\------------ COG � ♦ \ \ � tP' / y I 1 1 \ \ \ ♦ \ � ! M / t .F R t .t x t x + + + t #,# ••.�� \\\ \\ \ \♦ �� ,�.-.ate' .`'4� � w : ; #t : _ : • x ; x � {; x : • �'= `J' ; ' / .' � / fr ':/ �i�� //' Jam•, LIMITS OF DISTURBANCE 9.31 AC FOREST/OPENSPACE HSG B SOILS 10.96 AC RIVER'S EDGE POSTDEVELOPMENT VA la LIMA 9 Post-ReDevelopment Land Cover (acres) I / % / I / j 1 / / 1 / / 1 / / 1 A soils B Soils C Soils D Soils Totals % of Total Forest/Open (acres) 4.80 10.96 0.00 0.00 15.76 63 Managed Turf (acres) 0.40 4.72 0.00 0.00 5.12 20 Impervious Cover (acres) 0.26 3.94 0.00 0.00 4.19 17 * Forest/Open Space areas must he protected in accordance with the Virginia Runoff Reduction Method 25.07 100 / 1 I 1 \\ I 1 \ \ 1 1 \\ 1 \ 1 \\ Total Runoff Volume Reduction (W) 0 Total TP Load Reduction Achieved (lb/yr) 0.00 Total TN Load Reduction Achieved (lb/yr) 0.00 Remaining Post Development TP Load (lb/yr) 12.35 Remaining TP Load Reduction (lb/yr) 2.07 Required •-' \ '- \\ y� \ *Reduction below new development loodlimitation notrequired ---------------------------------------------- Ul DEDICATED IF DEDICATED FOREST/OPENSPACE \ \ • •.' " HSG A SOILS \` - 4.80 AC --- ' . 00 Ngno Runoff Reaudi'n MCNM WORaMm DEQ Virginia Runoff Reduction Method Re -Development COmpliaxe Spreadsheet - Version 3.0 BMP Design Sperifimtiws List 20B Draft Sods a Spea Site Summary Project Tide: River's Edge Date: 44893 Txal Rainfall llnl: 43 Total Disturbed Arxage: 9.31 Site Land Cover Summary Pre-ReDevelopment Land Cover (acres) A soils Bbili [Soli DSMIs Teu6 %of Tmal Forest/Open (acres) S.OD 16.16 0.00 0.00 21.15 84 Managed Turf (acres) 0.22 2.04 0.00 0.00 2.26 9 Impervious Cover (acres) 0.24 1.43 0.00 0.00 1.67 ] 25.0] 100 Post-ReDevelopment Land Cover (acres) A sous 1 Bsons 1 Cb1i 1 usage ToraB %ef Tmal Forest/Open (acres) 1 CAD 1 10.96 1 0.00 1 0.00 15J6 63 Managed Turf(arxs) I OAO 1 4.72 1 0.00 1 0.00 5.12 20 Impervious 1 0.26 1 3.90 1 0.00 1 0.00 4.19 17 'forest/Open Space areas must he prancand In xmrdanre MOL the Wglnue Runoff Reduction MnM1atl 25.07 100 Site Tv and Land Cover Nutrient Loads Final Post -Development Post- Adjusted Pre, RlDelebPment Development o,oem R New InoWndous) ft Site Rv o.22 D.13 11 Treatment volume(Re) 19,650 10,932 % P Lead(Ib/yr) 12.35 6.87 TT Bourne 1p Wd(lb/,): 9.24386' 'xedm'eu+hebwrewEeMoymmrkMBrrvrorvmnmreyuirM TOGI TP Load Reduction Required(lb/yr) 1 2.07 1 1.38 1 4.44 Final Pox-Developxmlead (Post-RdDevelo It New lmpervlau) Pre- RlDavlblxnent TN Load (Ib/yr) 88.32 42.54 Site Compliance Summary Pre- Re0eyebPon Final Post-Development Port-ReOerelopment TP TD Loadperxre Witted per ac Load per acre h ac r (Ib/acre/yr)re (lb/acre/yrl 0.26 D.49 0.30 Nowmum Is Reduction Requlred Below I 'Nate:%Fedu[tian will reduxpostdevebpmentnbad rokss@an arequoltO baseline bad oJ9.2416/yr (OAi lya /yrf PrcReBevebM Wad ems lA1.redr ...forPast-RR--Pos1.v1Plmd-bmeNriebadof9.2/38616Hrf,Mrelinebad=simoreax64lla/ar/yr Toral Runoff Volume Reduction (R') 0 Total TP lead Reduction Adneud(Ib/yr) O.OD T. TN bad Reduction A,Neved (lb/,) MOD Remaining Pat Development To bad 12.35 (Ib/yr) Remaining W bad Reduction(lb/yr) Z07 Required! 'RMurOonbebwmwdevebpmentlmdh=Mtimrmtrequir d Drainage Area Summary D.A.A D.A.B D.A.0 D.A.D DA.E Tood F-st/Open (acres) 000 0.00 0.00 0.00 DDO 0.00 Managed Turf(aueal 000 000 0.00 0.00 000 000 Impervious Cour(xresl 1 000 000 OOD 0.00 0.00 0.00 Tmal Area(acro) 1 0.00 O.00 O.00 O.00 DOO DOO Drainage Area Compliance Summary D.A.A D.A.B D.A.0 D.A.D D.A.E Total lP Load Reduced(lb/yr) ORO ODD O.00 O.00 0.00 0.00 TN bad Reduced(IIII ORO ODD O.00 DOD 0.00 0.00 Sundae, RrX Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report 76 //34E , 34D � 39 E- MAPLEGEND Area of Interest (A01) 0 Area of Interest A01) Solis Soil Rating Polygons 0 A Q AID o B Q BID o C 0 CID 0 D 0 Not rated or not available Soil Rating Lines . r A ,y AID rV B ram/ B/D N C N CID i D . . Not rated or not available Soil Rating Points A Q AID O B 0 BID Hydrologic Soil Group —Albemarle County, Virginia 0 C CID D 13 Not rated or not available Water Features Streams and Canals Transportation µ� Rails N Interstate Highways �y US Routes Major Roads Local Roads Background . Aerial Photography MAP INFORMATION The soil surveys that comprise your AC I were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Albemarle County, Virginia Survey Area Data: Version 13, Sep 17, 2019 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: May 20, 2019—Aug 1, 2019 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. USDA Natural Resources Web Soil Survey 121512019 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group —Albemarle County, Virginia Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 10 Ronda loamy sand, 0 to A 9.7 19.8% 2 percent slopes, frequently flooded 14D Chester loam, 15 to 25 B 0.2 0.4% percent slopes 16 Codorus silt loam, 0 to 2 B/D 0.2 0.3% percent slopes, occasionally flooded 34C Glenelg loam, 7 to 15 B 5.0 10.2% percent slopes 34D Glenelg loam, 15 to 25 B 8.4 17.0% percent slopes 34E Glenelg loam, 25 to 45 B 6.8 13.8% percent slopes 39E Hazel loam, 25 to 45 B 0.9 1.8% percent slopes 42133 Yadkin Gay loam, 15 to B 3.2 6.6% 25 percent slopes, severely eroded 47E Philomont sandy loam, A 0.1 0.2% 25 to 45 percent slopes 50E Manor loam, 25 to 45 B 0.2 0.5% percent slopes 76 Dan River loam, 0 to 2 B 3.3 6.7% percent slopes, occasionally flooded 83 Colvard fine sandy A 4.1 8.3% loam, 0 to 2 percent slopes, occasionally flooded W Water 7.1 14.4% Totals for Area of Interest 49.3 100.0% Natural Resources Web Soil Survey 12/52019 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group —Albemarle County, Virginia Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie -break Rule: Higher Natural Resources Web Soil Survey 12/5/2019 Conservation Service National Cooperative Soil Survey Page 4 of 4 NOAA Atlas 14, Volume 2, Version 3 Location name: Charlottesville, Virginia, USA*`r Latitude: 38.1528°, Longitude:-78.4168° Elevation: 433.69 ft** 'source: ESRI Maps iA -" source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. Bonin, D. Martin, B. Lin, T. Parzybok, M.Yekta. and D. Riley NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)t Average recurrence interval (years) Duretion 7 ������1 2 6 70 25 60 100 700 200 500 7000 s In (0.314 0 985) (0.307 0.459) (0.44 539) (04 960 607) (0.555-0 683) (0.02-0.0744) (0.645-0 801) (0.6840 857) (0.730-0 928) (07 66-0.987) 70-min (0.5020615) (0.6 0.736) (0.705-0.64) (07 9 -0971) (0.85-1.09) (0.958-1.18) (1.02127) (1.8-LO) (1. 5-31347) (1.21-4.55) 75-min (0.627--0.769) (0.766--0924) (0892--109) (1.00-1.23) (1. 2-21538) (1.21-31650) (1.3�61) 1 (1.37--11671) (1. 5-6L85) 1 (1.511695) 30-min (0. 60-1205) (1.04-1.28) (1.27�'55) (1.45-178) (1.62605) (1.832.26) (1.98-� 7) (2: 32.67) (2.31 2694) (24 5-3.16) 60-min (1.071931) (1.314.60) (1.63--61.99) 8 9 (1-2.32) (2.212772) (2.48-3.06) (2. 338 40) (2.99-3.74) (3.324.2) (3.58461) 2-hr (1.27�61) (1.541395) (1.93-2.44) (22 6-2.87) (2. 8342) (3.03-3.89) (3. 94936) (37 5487) (42 595.59) (4.666.22) 6 IF 6.07 S-hr40) (1.38--61..78) (1.67 2916) (2.08 2770) (2.44-3.16) (2. 0 3?77) (32 84.28) (3.67 4682) (4.0756 (4.61�20) (5.076.90) 6-hr (17 6 2825) (2. 2 2072) (2.62 3838) (3.8-3.98) (3. 8 4.78) (41 �47) (4. 2--r�6.2) (5.27-27A3) (6.05 8 20) (6.781 9.25) 7.16 72-hr (2. 02884) (2.653A2) (3. 9-4.26) (3.8-5.04) (4.68-6.11) (5.37-2738) (6. 08.13) (6.8-9.29) (8. 0111.0) (8.W12.6) 24-hr (F2.63.34) (3. 23104) (4. 0�15) (4.82608) (5. 8-7.44) (6.778061) (7.39689) (8.75- 1.3) (102-13.4) (115--15.3) 2-day (3.14 3990) (3.814372) (4.835799) (5.66-7 03) (6.84 8753) (7.80-9.79) (8.82-1.2) (9.93- 2.7) (11 5314.9) (127---16.8) F-3.711 IF 3-day (3.37-4.12) (4.8-44..99) (5. 86.33) (6.o6-743) (7.339.01) (8.36-10.3) (9.46-1.8) (10.6-13.4) (12.3-15.7) (137--197.7) 4-day (3. 0�35) (4.35-5.26) (5.52$68) (6.47-782) (7.82-99..50) (8.9310.9) (10.1-12.4) (114-14.1) (131- 6.5) (14.68.6) 7-day (4. 9�03) (5.05605) (6. 0-67956) (7.31 8?80) (8. 5-610.6) (9.92- 2.1) (111z 3.6) (12.4-15.4) (142617.9) (157a-20.0) IF 6.0 10dey (4.8-565) (5.746.78) (7.088.37) (8.ir9965) (9.64-11.5) (10.8 2.9) (12314.5) 1 (13.4-16.2) 1 (15.1-8.6) 1 (16.6 0.6) 8.15 1 20aay (6. 8-674.35) (7.61 8.76) (9. 8--1150.6) (10.4- 2.0) (120- 3.9) (13.3-5.4) (14.6-19.0) (15.9-18.6) (176- 0.9) (18.99)2.6) 30-0ay (7.878996) (9.34- 0.6) (11.0- 2.6) (12.314.0) (140415.9) (152-137.4) (16?4- 8.8) (176- 0.3) (19?0-22.2) (202� 3.6) 2.4 454ey (9.87---11.1) (117z 3.1) (13.6-15.3) (15.1--107.0) (16.9- 9.1) (18.3- 0.7) (196022.2) (20.8- 3.7) (22.3-25.7) (23.4-27.1) -24 60-0ay (11.6-13.0) (137 15.3) (15'8-17.6) (17 3 9.4) (1923--21.6) (2027z 3.3) T-1324.9) (23 326.4) (24?9-3.3) (26 P 9.7) t Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA AOas 14 document for more information. Back to Top