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HomeMy WebLinkAboutWPO201700023 Certified Engineer's Report Minor Amendment 2018-03-26 APPROVED by the Albemarle County Community Development Department Date 3/26/Zm$ File L.4o?a700073 -,-/f,' S 4 P.-, I> A) Permeable Pavers Area 12" of#3 S ne under (14s) .)Permeable Pavement RioRoad •� D 10P D Oil UG-60" D.A. 60" CM SWQ Unit cis. D Ill Dev. Area A w/o SWM Point of Analysis (Storm A) _. �' 0' d1, _a CI'‘R, vim° ,/ tic. No.35326 • 8- i cl l' 1 . ;'',AL Reach on. Routing Diagram for OakleighMSPA-SCS-Area A-SPA-rev Prepared by Microsoft, Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 2 Area Listing (selected nodes) Area CN Description (sq-ft) (subcatchment-numbers) 45,128 61 >75% Grass cover, Good, HSG B (2S, 3S, 6S, 14S) 4,356 98 Impervious (6S) 47,480 98 Paved parking&roofs (2S) 12,981 98 Paved parking, HSG B (14S) 36,590 98 Permeable Pavers (3S) 20,473 58 Woods/grass comb., Good, HSG B (3S, 6S) 167,009 83 TOTAL AREA Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 3 Soil Listing (selected nodes) Area Soil Subcatchment (sq-ft) Group Numbers 0 HSG A 78,582 HSG B 2S, 3S, 6S, 14S 0 HSG C 0 HSG D 88,427 Other 2S, 3S, 6S 167,009 TOTAL AREA Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 4 Ground Covers (selected nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Su (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) Cover Nu 0 45,128 0 0 0 45,128 >75% Grass cover, Good 0 0 0 0 4,356 4,356 Impervious 0 12,981 0 0 0 12,981 Paved parking 0 0 0 0 47,480 47,480 Paved parking& roofs 0 0 0 0 36,590 36,590 Permeable Pavers 0 20,473 0 0 0 20,473 Woods/grass comb., Good 0 78,582 0 0 88,427 167,009 TOTAL AREA Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 5 Pipe Listing (selected nodes) Line# Node In-Invert Out-Invert Length Slope n Diam/Wdth Height Inside-Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 10P 543.10 543.00 10.0 0.0100 0.013 15.0 0.0 0.0 Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 2yr Alb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 6 Time span=1.00-20.00 hrs, dt=0.05 hrs, 381 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment2S: UG-60"D.A. Runoff Area=1.550 ac 70.32% Impervious Runoff Depth>2.11" Tc=5.0 min CN=87 Runoff=6.20 cfs 11,900 cf Subcatchment3S: Permeable Pavers Area Runoff Area=1.300 ac 64.62% Impervious Runoff Depth>1.87" Tc=5.0 min CN=84 Runoff=4.69 cfs 8,835 cf Subcatchment6S: Dev.Area A w/o SWM Runoff Area=0.640 ac 15.63% Impervious Runoff Depth>0.76" Tc=5.0 min CN=66 Runoff=0.93 cfs 1,765 cf Subcatchment14S: RioRoad Runoff Area=0.344 ac 86.63% Impervious Runoff Depth>2.66" Tc=5.0 min CN=93 Runoff=1.63 cfs 3,324 cf Pond 4P: 12"of#3 Stone under Permeable Peak EIev=559.38' Storage=0.116 of Inflow=4.69 cfs 8,835 cf Outflow=0.33 cfs 6,203 cf Pond 10P: 60"CMP Peak EIev=546.35' Storage=6,189 cf Inflow=7.99 cfs 21,427 cf Primary=1.68 cfs 9,836 cf Secondary=0.25 cfs 9,180 cf Outflow=1.93 cfs 19,017 cf Link 7L: Point of Analysis(Storm A) Inflow=2.55 cfs 20,782 cf Primary=2.55 cfs 20,782 cf Link 13L: SWQ Unit Inflow=0.25 cfs 9,180 cf Primary=0.25 cfs 9,180 cf Total Runoff Area = 167,009 sf Runoff Volume = 25,824 cf Average Runoff Depth = 1.86" 39.28% Pervious =65,601 sf 60.72% Impervious = 101,408 sf • Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 2yr Alb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 2S: UG-60" D.A. Permeable Paver Are Not Included [49] Hint: Tc<2dt may require smaller dt Runoff = 6.20 cfs @ 11.95 hrs, Volume= 11,900 cf, Depth> 2.11" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2yr Alb. Rainfall=3.60" Area (ac) CN Description 1.090 98 Paved parking & roofs 0.460 61 >75% Grass cover, Good, HSG B 1.550 87 Weighted Average 0.460 29.68% Pervious Area 1.090 70.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 2S: UG-60" D.A. Hydrograph ■Runoff 6- Type II 24-hr 2yr Alb. Rainfall=3.60" 5= Runoff Area=1.550 ac Runoff Volume=11,900 cf 4- Runoff Depth>2.11" LL 3- Tc=5.0 min CN=87 2- 1- o ,, ,,,, ,,,,,, , ,, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 2yr Alb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 3S: Permeable Pavers Area [49] Hint: Tc<2dt may require smaller dt Runoff = 4.69 cfs @ 11.96 hrs, Volume= 8,835 cf, Depth> 1.87" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2yr Alb. Rainfall=3.60" Area (ac) CN Description * 0.840 98 Permeable Pavers 0.210 61 >75% Grass cover, Good, HSG B 0.250 58 Woods/grass comb., Good, HSG B 1.300 84 Weighted Average 0.460 35.38% Pervious Area 0.840 64.62% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 3S: Permeable Pavers Area Hydrograph 7 54 _ II Runoff II - 4- Type 2yr Alb. Rain24hr fall=3.60" Runoff Area=1.300 ac Runoff Volume=8,835 cf 3 Runoff Depth>1.87" Tc=5.0 min 2. CN=84 1- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 2yr Alb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 sin 02893 ©2017 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 6S: Dev. Area A w/o SWM Developed area that does not drain to BMP Shown as hatched area on plan [49] Hint: Tc<2dt may require smaller dt Runoff = 0.93 cfs @ 11.97 hrs, Volume= 1,765 cf, Depth> 0.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2yr Alb. Rainfall=3.60" Area (ac) CN Description 0.320 61 >75% Grass cover, Good, HSG B 0.220 58 Woods/grass comb., Good, HSG B * 0.100 98 Impervious 0.640 66 Weighted Average 0.540 84.38% Pervious Area 0.100 15.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 6S: Dev. Area A w/o SWM Hydrograph z 1- ■Runoff Type II 24-hr 2yr Alb. Rainfall=3.60" Runoff Area=0.640 ac Runoff Volume=1,765 cf Runoff Depth>0.76" Tc=5.0 min CN=66 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) • . Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 2yr Alb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 14S: RioRoad [49] Hint: Tc<2dt may require smaller dt Runoff = 1.63 cfs @ 11.95 hrs, Volume= 3,324 cf, Depth> 2.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2yr Alb. Rainfall=3.60" Area (ac) CN Description 0.298 98 Paved parking, HSG B 0.046 61 >75% Grass cover, Good, HSG B 0.344 93 Weighted Average 0.046 13.37% Pervious Area 0.298 86.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 14S: RioRoad Hydrograph ■Runoff - Type II 24-hr 2yr Alb. Rainfall=3.60" Runoff Area=0.344 ac Runoff Volume=3,324 cf 1- Runoff Depth>2.66" - Tc=5.0 min CN=93 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 2yr Alb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 11 Summary for Pond 4P: 12" of#3 Stone under Permeable Pavement Inflow Area = 56,628 sf, 64.62% Impervious, Inflow Depth > 1.87" for 2yr Alb. event Inflow = 4.69 cfs @ 11.96 hrs, Volume= 8,835 cf Outflow = 0.33 cfs @ 12.59 hrs, Volume= 6,203 cf, Atten= 93%, Lag= 38.2 min Primary = 0.33 cfs @ 12.59 hrs, Volume= 6,203 cf Routing by Dyn-Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 559.38' @ 12.59 hrs Surf.Area= 0.770 ac Storage= 0.116 af Plug-Flow detention time= 197.4 min calculated for 6,203 cf(70% of inflow) Center-of-Mass det. time= 129.7 min ( 909.8- 780.1 ) Volume Invert Avail.Storage Storage Description #1 559.00' 0.308 af 12" of#3 under all permeables (Prismatic)Listed below (Recaic) 0.770 af Overall x 40.0% Voids #2 560.00' 0.102 af 4" of#57 under permeables (Prismatic)Listed below (Recalc) 0.254 af Overall x 40.0% Voids 0.410 af Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 559.00 0.770 0.000 0.000 560.00 0.770 0.770 0.770 Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 560.00 0.770 0.000 0.000 560.33 0.770 0.254 0.254 Device Routing Invert Outlet Devices #1 Primary 559.00' 6.0"Vert. 6" Perforated PVC C= 0.600 rimary OutFlow Max=0.33 cfs @ 12.59 hrs HW=559.38' TW=545.84' (Dynamic Tailwater) 1=6" Perforated PVC (Orifice Controls 0.33 cfs @ 2.09 fps) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type II 24-hr 2yr Alb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 12 Pond 4P: 12" of#3 Stone under Permeable Pavement Hydrograph / •Inflow 4.69 cfs ■Primary 5 Inflow Area=56,628 sf Peak Elev=559.38' 4_ Storage=0.116 of w 3- 3 o - U- 2-- 1- 0.33 cfs 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type ll 24-hr 2yr Alb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 13 Summary for Pond 10P: 60" CMP Inflow Area = 139,131 sf, 69.76% Impervious, Inflow Depth > 1.85" for 2yr Alb. event Inflow = 7.99 cfs @ 11.96 hrs, Volume= 21,427 cf Outflow = 1.93 cfs @ 12.12 hrs, Volume= 19,017 cf, Atten= 76%, Lag= 9.8 min Primary = 1.68 cfs @ 12.12 hrs, Volume= 9,836 cf Secondary = 0.25 cfs @ 11.20 hrs, Volume= 9,180 cf Routing by Dyn-Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 546.35' @ 12.12 hrs Surf.Area= 2,760 sf Storage= 6,189 cf Plug-Flow detention time= 73.6 min calculated for 19,017 cf(89°A) of inflow) Center-of-Mass det. time= 35.3 min ( 843.8 - 808.6 ) Volume Invert Avail.Storage Storage Description #1 543.20' 3,891 cf 24.00'W x 115.00'L x 6.00'H #57 Gravel Backfill 16,560 cf Overall - 6,833 cf Embedded = 9,727 cf x 40.0% Voids #2 543.20' 6,833 cf 60.0" Round 60" Perforated CMP Inside#1 L= 348.0' 10,724 cf Total Available Storage Device Routing Invert Outlet Devices #1 Secondary 543.20' Flow restricted by WQ Unit Head (feet) 0.00 0.10 5.00 Disch. (cfs) 0.000 0.250 0.250 #2 Primary 543.10' 15.0" Round 15" HDPE (SD A) L= 10.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 543.10'/543.00' S= 0.0100 '/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf #3 Device 2 544.62' 6.0"W x 7.0" H Vert. 6" x 6" Orifice in Wall C= 0.600 #4 Device 2 546.35' 25.0" W x 4.0" H Vert. 12" x 12" Orifice in Wall C= 0.600 #5 Device 2 548.20' 6.5' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 5.0' Crest Height Primary OutFlow Max=1.67 cfs @ 12.12 hrs HW=546.33' TW=0.00' (Dynamic Tailwater) tj=15" HDPE (SD A) (Passes 1.67 cfs of 9.54 cfs potential flow) -3=6" x 6" Orifice in Wall (Orifice Controls 1.67 cfs @ 5.73 fps) -4=12" x 12" Orifice in Wall ( Controls 0.00 cfs) -S=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Secondary OutFlow Max=0.25 cfs @ 11.20 hrs HW=543.30' TW=0.00' (Dynamic Tailwater) 1=Flow restricted by WQ Unit(Custom Controls 0.25 cfs) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type Il 24-hr 2yrAlb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 14 Pond 10P: 60" CMP Hydrograph 7.99 cfs ■inflow El Outflow Inflow Area=139,131 sf ■Primary El Secondary 8 Peak Elev=546.35' Storage=6,189 cf 7- 6: w 5- u 3 0 4- LL 3.= 1.93 cfs 1.68 cfs 0.25 cfs 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type ll 24-hr 2yr Alb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 15 Summary for Link 7L: Point of Analysis (Storm A) Discharge to Storm G (24" HDPE) Inflow Area = 167,009 sf, 60.72% Impervious, Inflow Depth > 1.49" for 2yr Alb. event Inflow = 2.55 cfs @ 12.01 hrs, Volume= 20,782 cf Primary = 2.55 cfs @ 12.01 hrs, Volume= 20,782 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Link 7L: Point of Analysis (Storm A) Hydrograph ■Inflow 9 cc rf III Primary Inflow Area=167,009 s��2.55 cfs �- 2 y V 3 O LL 1- Lmer' 0- 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 11 24-hr 2yr Alb. Rainfall=3.60" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 16 Summary for Link 13L: SWQ Unit Inflow = 0.25 cfs @ 11.20 hrs, Volume= 9,180 cf Primary = 0.25 cfs @ 11.20 hrs, Volume= 9,180 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Link 13L: SWQ Unit / Hydrograph 0.28J I CI 7ri rf ■Inflow ■Primary 0.26 0.25 cfs 0.24- 0.22= 0.18- 0.16- 3 0.14 2 0 0.12- 0.1- 0.08 0.06- 0.04 0.02 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 10yr Alb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 17 Time span=1.00-20.00 hrs, dt=0.05 hrs, 381 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment2S: UG-60"D.A. Runoff Area=1.550 ac 70.32% Impervious Runoff Depth>3.79" Tc=5.0 min CN=87 Runoff=10.70 cfs 21,305 cf Subcatchment3S: Permeable Pavers Area Runoff Area=1.300 ac 64.62% Impervious Runoff Depth>3.48" Tc=5.0 min CN=84 Runoff=8.44 cfs 16,439 cf Subcatchment6S: Dev.Area A w/o SWM Runoff Area=0.640 ac 15.63% Impervious Runoff Depth>1.89" Tc=5.0 min CN=66 Runoff=2.39 cfs 4,385 cf Subcatchment14S: RioRoad Runoff Area=0.344 ac 86.63% Impervious Runoff Depth>4.43" Tc=5.0 min CN=93 Runoff=2.61 cfs 5,527 cf Pond 4P: 12"of#3 Stone under Permeable Peak Elev=559.71' Storage=0.220 of Inflow=8.44 cfs 16,439 cf Outflow=0.64 cfs 12,816 cf Pond 10P: 60"CMP Peak Elev=548.17' Storage=9,583 cf Inflow=13.77 cfs 39,648 cf Primary=6.83 cfs 26,125 cf Secondary=0.25 cfs 10,656 cf Outflow=7.08 cfs 36,781 cf Link 7L: Point of Analysis(Storm A) Inflow=8.76 cfs 41,167 cf Primary=8.76 cfs 41,167 cf Link 13L: SWQ Unit Inflow=0.25 cfs 10,656 cf Primary=0.25 cfs 10,656 cf Total Runoff Area = 167,009 sf Runoff Volume =47,656 cf Average Runoff Depth =3.42" 39.28% Pervious = 65,601 sf 60.72% Impervious = 101,408 sf Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 10yr Alb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment 2S: UG-60" D.A. Permeable Paver Are Not Included [49] Hint: Tc<2dt may require smaller dt Runoff = 10.70 cfs @ 11.95 hrs, Volume= 21,305 cf, Depth> 3.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10yr Alb. Rainfall=5.50" Area (ac) CN Description 1.090 98 Paved parking & roofs 0.460 61 >75% Grass cover, Good, HSG B 1.550 87 Weighted Average 0.460 29.68% Pervious Area 1.090 70.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 2S: UG-60" D.A. Hydrograph ■Runoff 11- Type II 24-hr 10- 10yr Alb. Rainfall=5.50" 9_ Runoff Area=1.550 ac 8- Runoff Volume=21,305 cf Runoff Depth>3.79" 6= Tc=5.0 min LL 5 CN=87 4- 3. 2- 1- 0 , T. ..,. ,. ..,T.. , ,,,,•r 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 10yr Alb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 3S: Permeable Pavers Area [49] Hint: Tc<2dt may require smaller dt Runoff = 8.44 cfs @ 11.95 hrs, Volume= 16,439 cf, Depth> 3.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10yr Alb. Rainfall=5.50" Area (ac) CN Description * 0.840 98 Permeable Pavers 0.210 61 >75% Grass cover, Good, HSG B 0.250 58 Woods/grass comb., Good, HSG B 1.300 84 Weighted Average 0.460 35.38% Pervious Area 0.840 64.62% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 3S: Permeable Pavers Area Hydrograph z 981 III Runoff 8- Type II 24-hr 10yr Alb. Rainfall=5.50" = Runoff Area=1.300 ac 67 Runoff Volume=16,439 cf f - Runoff Depth>3.48" Tc=5.0 min a 4_ CN=84 3- 2- 1? 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) • Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 10yr Alb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 6S: Dev. Area A w/o SWM Developed area that does not drain to BMP Shown as hatched area on plan [49] Hint: Tc<2dt may require smaller dt Runoff = 2.39 cfs @ 11.96 hrs, Volume= 4,385 cf, Depth> 1.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10yr Alb. Rainfall=5.50" Area (ac) CN Description 0.320 61 >75% Grass cover, Good, HSG B 0.220 58 Woods/grass comb., Good, HSG B * 0.100 98 Impervious 0.640 66 Weighted Average 0.540 84.38% Pervious Area 0.100 15.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 6S: Dev. Area A w/o SWM Hydrograph ■Runoff - Type 1124-hr 10yr Alb. Rainfall=5.50" Runoff Area=0.640 ac Runoff Volume=4,385 cf - Runoff Depth>1.89" - Tc=5.0 min 1- CN=66 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) • Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 10yr Alb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 21 Summary for Subcatchment 14S: RioRoad [49] Hint: Tc<2dt may require smaller dt Runoff = 2.61 cfs @ 11.95 hrs, Volume= 5,527 cf, Depth> 4.43" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10yr Alb. Rainfall=5.50" Area (ac) CN Description 0.298 98 Paved parking, HSG B 0.046 61 >75% Grass cover, Good, HSG B 0.344 93 Weighted Average 0.046 13.37% Pervious Area 0.298 86.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 14S: RioRoad Hydrograph II Runoff - Type !! 24-hr 10yr Alb. Rainfall=5.50" 2_ Runoff Area=0.344 ac - Runoff Volume=5,527 cf - Runoff Depth>4.43" Tc=5.0 m i n CN=93 o 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 10yr Alb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD®10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 22 Summary for Pond 4P: 12" of#3 Stone under Permeable Pavement Inflow Area = 56,628 sf, 64.62% Impervious, Inflow Depth > 3.48" for 10yr Alb. event Inflow = 8.44 cfs @ 11.95 hrs, Volume= 16,439 cf Outflow = 0.64 cfs @ 12.52 hrs, Volume= 12,816 cf, Atten= 92%, Lag= 33.7 min Primary = 0.64 cfs @ 12.52 hrs, Volume= 12,816 cf Routing by Dyn-Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 559.71' @ 12.52 hrs Surf.Area= 0.770 ac Storage= 0.220 af Plug-Flow detention time= 194.5 min calculated for 12,782 cf(78% of inflow) Center-of-Mass det. time= 137.5 min ( 903.6- 766.1 ) Volume Invert Avail.Storage Storage Description #1 559.00' 0.308 af 12" of#3 under all permeables (PrismaticPsted below (Recalc) 0.770 af Overall x 40.0% Voids #2 560.00' 0.102 af 4"of#57 under permeables (Prismatic)Listed below (Recalc) 0.254 af Overall x 40.0% Voids 0.410 af Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 559.00 0.770 0.000 0.000 560.00 0.770 0.770 0.770 Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 560.00 0.770 0.000 0.000 560.33 0.770 0.254 0.254 Device Routing Invert Outlet Devices #1 Primary 559.00' 6.0"Vert. 6" Perforated PVC C= 0.600 Primary OutFlow Max=0.64 cfs @ 12.52 hrs HW=559.71' TW=546.44' (Dynamic Tailwater) 4L-1=6" Perforated PVC (Orifice Controls 0.64 cfs @ 3.28 fps) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type II 24-hr 10yr Alb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 23 Pond 4P: 12" of#3 Stone under Permeable Pavement Hydrograph Inflow 8.44 cfs , Primary Inflow Area=56,628 sf 8- Peak EIev=559.71 ' Storage=0.220 of 6- 13 5- 3 o LL 4 3- 1 2- 1- 0.64 cfs 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type 1124-hr 10yr Alb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 24 Summary for Pond 10P: 60" CMP Inflow Area = 139,131 sf, 69.76% Impervious, Inflow Depth > 3.42" for 10yr Alb. event Inflow = 13.77 cfs @ 11.95 hrs, Volume= 39,648 cf Outflow = 7.08 cfs @ 12.05 hrs, Volume= 36,781 cf, Atten= 49%, Lag= 6.0 min Primary = 6.83 cfs @ 12.05 hrs, Volume= 26,125 cf Secondary = 0.25 cfs @ 10.25 hrs, Volume= 10,656 cf Routing by Dyn-Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 548.17' @ 12.05 hrs Surf.Area= 2,760 sf Storage= 9,583 cf Plug-Flow detention time= 51.3 min calculated for 36,781 cf(93% of inflow) Center-of-Mass det. time= 25.2 min ( 827.8 - 802.5 ) Volume Invert Avail.Storage Storage Description #1 543.20' 3,891 cf 24.00'W x 115.00'L x 6.00'H #57 Gravel Backfill 16,560 cf Overall - 6,833 cf Embedded = 9,727 cf x 40.0% Voids #2 543.20' 6,833 cf 60.0" Round 60" Perforated CMP Inside#1 L= 348.0' 10,724 cf Total Available Storage Device Routing Invert Outlet Devices #1 Secondary 543.20' Flow restricted by WQ Unit Head (feet) 0.00 0.10 5.00 Disch. (cfs) 0.000 0.250 0.250 #2 Primary 543.10' 15.0" Round 15" HDPE (SD A) L= 10.0' RCP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 543.10' / 543.00' S= 0.0100 '/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf #3 Device 2 544.62' 6.0" W x 7.0" H Vert. 6" x 6" Orifice in Wall C= 0.600 #4 Device 2 546.35' 25.0" W x 4.0" H Vert. 12" x 12" Orifice in Wall C= 0.600 #5 Device 2 548.20' 6.5' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 5.0' Crest Height Primary OutFlow Max=6.80 cfs @ 12.05 hrs HW=548.15' TW=0.00' (Dynamic Tailwater) Li=15" HDPE (SD A) (Passes 6.80 cfs of 12.43 cfs potential flow) -3=6" x 6" Orifice in Wall (Orifice Controls 2.53 cfs @ 8.67 fps) -4=12" x 12" Orifice in Wall (Orifice Controls 4.28 cfs @ 6.16 fps) -S=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Secondary OutFlow Max=0.25 cfs @ 10.25 hrs HW=543.30' TW=0.00' (Dynamic Tailwater) 1=Flow restricted by WQ Unit(Custom Controls 0.25 cfs) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type ll 24-hr 10yr Alb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 25 Pond 10P: 60" CMP Hydrograph 13.77 cfs ■inflow Cl Outflow Inflow Area=139 131 sf II Primary 15-_ Secondary, 14 Peak Elev=548.17' 13 Storage=9,583 cf 12 11 10 y 9 7.08 cfs 2. 8 6.83 cfs 0 7 LL 6 5 4 3- _ j�./�il./r�.✓er�/f��.If//�i�/r�, 2' ,.fr�/�r/.I' / tii�./�� frf��rif%//.%//r/i + 1 0.25 cfs o 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type ll 24-hr 10yrAlb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 26 Summary for Link 7L: Point of Analysis (Storm A) Discharge to Storm G (24" HDPE) Inflow Area = 167,009 sf, 60.72% Impervious, Inflow Depth > 2.96" for 10yr Alb. event Inflow = 8.76 cfs @ 12.01 hrs, Volume= 41,167 cf Primary = 8.76 cfs @ 12.01 hrs, Volume= 41,167 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Link 7L: Point of Analysis (Storm A) Hydrograph R 7F rf •■Inflow ■Primary 9_ Inflow Area=167,009 8.76 cfs I 8 7- 6- N1 t) 5- 0 LL 4- 3- 2- 1- - 1- 0 r • r , 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Dev A- Revised OakleighMSPA-SCS-Area A-SPA-rev Type ll 24-hr 10yr Alb. Rainfall=5.50" Prepared by Microsoft Printed 3/7/2018 HydroCAD® 10.00-20 s/n 02893 ©2017 HydroCAD Software Solutions LLC Page 27 Summary for Link 13L: SWQ Unit Inflow = 0.25 cfs @ 10.25 hrs, Volume= 10,656 cf Primary = 0.25 cfs @ 10.25 hrs, Volume= 10,656 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 1.00-20.00 hrs, dt= 0.05 hrs Link 13L: SWQ Unit / Hydrograph 0.28- I fl 9c rf Inflow II 0.26-] 0.25 cfs Primary 0.24= 0.22- 0.18- H 0.16= 0.14- LL 0.12- 0.081 0.06- 0.04- 0.02- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours)