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HomeMy WebLinkAboutWPO202200052 Calculations 2022-12-27SHIMP ENGINEERING, P.C. Design Focused Engineering December 22, 2022 Engineering Review Albemarle County Department of Community Development 401 McIntire Road Charlottesville, VA 22902 r S MP a i . 183 l f2(22%2Z q� tiss�orvnl. Regarding: WPO 2022_ Bird St Subdivision — SWM Calculation Packet Dear Reviewer, Enclosed are the remaining stormwater calculations and data for the Bird St Subdivision VSMP plan. A full narrative, stormwater maps, VRRM data, and SWM plan are included in the full size VSMP plan sheets. Specifically, please reference sheets C11, C15-C19 This packet contains the supporting HydroCAD runoff modelling reports, sediment basin sizing nomographs, culvert nomographs, soil data, and rainfall data to support the subdivision VSMP design. If you have any questions about this calculation packet please do not hesitate to contact me at: keane@shimp- engineering.com or by phone at 434-299-9843. Regards, Keane Rucker Shimp Engineering, PC 912 E. High St. Charlottesville, VA 22902 1434.227.5140 1 shimp-engineering.com Contents: SWM Quantity Requirements: Pre-Dev HydroCAD Report Page 6 Post-Dev HydroCAD Report Page 22 Culvert Inlet Control Nomograph Page 63 Sediment Basin Design: Design Spreadsheet Page 65 Design Nomographs Page 67 Independent Reports: Excerpt from NRCS Soils Report Page 72 NOAA Precipitation Report Page 76 SWM Quantity Requirements: Pre-Dev HydroCAD Report Post-Dev HydroCAD Report Culvert Inlet Control Nomograph Bird St Subdivision PreDev Time of Concentration Calculations Postdev Onsite to POA 1 077 ft overland -forest 248 ft s. c. flow -grass 395 ft channel -natural Postdev Offsite to POA 1 100 ft overland -grass 262 ft s. c. flow -grass 1300 ft channel -natural 6.5% slope 0.25 C-value 9.4 min 8.9% slope 2.0 fps velocity 2.1 min. 6.0 ft height 4.0 min. TOC= 15.4 min. 3.5% slope 0.28 C-value 10.5 min 11.5% slope 2.3 fps velocity 1.9 min. 70.0ft height 6.2 min. TOC= 18.6 min. POA 2 100 ft overland -forest 6.0% slope 0.25 C-value 10.6 min 331 ft s. c. flow -forest 8.5% slope 1.5 fps velocity 3.8 min. 2005 ft channel -natural 72.0 ft height 10.0 min. TOC= 24.4 min. Predev Onsite to POA 3 2-acre steep developed drainage area, assumed: 5.0 min. TOC= 5.0 min. Predev to POA 4 370 ft s. c. flow -forest Predev Onsite to POA 5 086 ft overland -grass 459 ft s. c. flow -grass 169 ft channel -paved Predev Offsite to POA 5 100 ft overland -grass 397 ft s. c. flow -grass 600ft channel -natural Seelye Chart NEH Figure 15-4 Kirpich Chart Seelye Chart NEH Figure 15-4 Kirpich Chart Seelye Chart NEH Figure 15-4 Kirpich Chart 4.6% slope 1.0 fps velocity 6.2 min. NEH Figure 15-4 TOC= 6.2 min. 9.3% slope 0.28 C-value 8.2 min 8.7% slope 2.0fps velocity 3.8 min. 10.0 ft height 0.2 min. TOC= 12.3 min. 7.0% slope 0.28 C-value 9.2 min 17.6% slope 2.9 fps velocity 2.3 min. 28.0 ft height 3.7 min. TOC= 15.2 min. Seelye Chart NEH Figure 15-4 Kirpich Chart Seelye Chart NEH Figure 15-4 Kirpich Chart 4 Appendix 6D-1 Overland Flow Time - Seelye Chapter 16 1lme of Concentration Part 630 Natlaal Engineering Handbook 1992 Tc =0.225 LG a2 S-0. 19 i 1,0 Figurel5-4 Velocity versus slope for shallow concentrated flow T.- 0�11actl RM Time, m.+atee L -Lerym of Strip, head 35 IS- Sops. fee~0.70 1.00 o.so TRAVEL TIME FOR CHANNEL FLOW (Kirpich Chart) C = Raapnal'C' Value b Gmurd Chwaaet 0.60 600 30 - 090 H (feet) Soo Paved 0.9 0.30 x 500 Tr (min.) 2O0 400 0.6 25 - 300 0.7 - 0.6as Bare 20 - 2011 0.5 _ W cu w �\ Poor 0.4 lL Z _ W (�if999 LL Su >kC H 0.5 Average. 0.3 w 15 Grass 1.0 LLO -i J J AIII 4. OI eSS .`� 20 ~ /! O 70 0.2 = 60 �i� 10 50 \ 20 W F W 2� ~ 2 O 0.20 C 0.09 O.oB 0.07 0.05 0.09 US 0.02 0.01 0.006 - c s a - S, - ,�.._ .. 3 ,m 3° E° ! 6' - e '�¢� _ - 100 100 L (feet) 10D00 ek4 50 50 5000 ' (1) xith rotunl Meme « g 10 (2) T r pevM c multi PLY 10 t by 0.2 1 £ s £ 5 -- _ o 40 i K > f9 V 30 o a 9 K z F K 6 20 Q� S Awl.. -C" V.... for SslmatrxY Grau.0 Cirrraeter Oma Groan 0.219 f Pan+ 0.26 7 areru0e Green Sxrtaae 0.28 L. 0.30 Velocity (Ws) 00 1 1 TIME OF CONCENTRATION Or SMALL DRAINAGE BASINS NOTE: CHANNELS WITHIN TOC FLOW PATH ARE ALL MANMADE Table I5-3 Equations and assumptions developed from figure 15-0 Flow type Depth Mantdnglen Velocity equation (n) (We) Pavement and small upland guNes 0.2 0.025 V=20311g.r' Grassed waterways 0.4 0.050 V=16.135(s)ob Boor Oroee Svrfooe 0.36 'future 0.40 1Q Bare $oli 0.48 Nearly bare and untiBed(overland flow); and alluvial fans in western mountain 0.2 0.061 V=9.965(sfo regions PovtW G.so Cultivated straight row crops 0.2 0.058 V=8.762(s)o` short -grass pasture 0.2 0.073 V=6.962(sfo Source: VDOT Plate 5-3 OVERLAND FLOW TIME Minimum tillage cultivation, contour or stdpeeopped, and woodlands 0.2 0.101 V=5.032(.r' Forest with heavy ground biter and hay meadows 0.2 0202 V=2.516er5 LEGEND: PreDev Onsite to POA 1 Predev Offsite to POA 2 Predev Offsite to POA 2 Predev to POA 4 Bird St. Subdivision Predev Onsite to POA 5 Pre Development Predev Offsite to POA 5 ` Time of Concentration Nomographs 1S 2S O ONSITE TO P 1 OFFS E TO POA 1 3L Pt 1 4S ONSITE TO POA 2 6L rJS POA 2 OFFSITE TO POA 2 8S ONSITE t0 POA 3 Ex. Wet Pond POA 3 12S ONSITE TO POA 5 -D 14L 13S POA 5 OFFSITE TO POA 5 Subcat Reach Aon Llnk 10S ONSITE l�0 POA 4 OA 4 11S OFFSITE TO POA 4 6 PreDev Bird St Predev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paae 2 Time span=5.00-40.00 hrs, dt=0.05 hrs, 701 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: ONSITE TO POA 1 Runoff Area=4.480 ac 0.00% Impervious Runoff Depth=0.37" Tc=15.4 min CN=63 Runoff=1.37 cfs 0.137 of Subcatchment 2S: OFFSITE TO POA 1 Runoff Area=9.180 ac 4.36% Impervious Runoff Depth=0.71" Tc=18.6 min CN=72 Runoff=6.74 cfs 0.547 of Link 3L: POA 1 Inflow=8.09 cfs 0.684 of Primary=8.09 cfs 0.684 of Subcatchment 4S: ONSITE TO POA 2 Runoff Area=0.200 ac 10.00% Impervious Runoff Depth=0.43" Tc=5.0 min CN=65 Runoff=0.13 cfs 0.007 of Subcatchment 5S: OFFSITE TO POA 2 Runoff Area=49.380 ac 1.80% Impervious Runoff Depth=0.63" Tc=24.4 min CN=70 Runoff=25.48 cfs 2.581 of Link 6L: POA 2 Inflow=32.61 cfs 3.272 of Primary=32.61 cfs 3.272 of Pond 7S: Ex. Wet Pond Peak Elev=307.14' Inflow=32.61 cfs 3.272 of Outflow=32.61 cfs 3.272 of Subcatchment 8S: ONSITE TO POA 3 Runoff Area=2.380 ac 13.03% Impervious Runoff Depth=0.43" Tc=5.0 min CN=65 Runoff=1.56 cfs 0.086 of Link 9L: POA 3 Inflow=32.93 cfs 3.359 of Primary=32.93 cfs 3.359 of Subcatchment 111S: ONSITE TO POA 4 Runoff Area=0.950 ac 6.32% Impervious Runoff Depth=0.34" Tc=6.2 min CN=62 Runoff=0.40 cfs 0.027 of Subcatchment 11S: OFFSITE TO POA 4 Runoff Area=1.670 ac 7.19% Impervious Runoff Depth=0.34" Tc=6.2 min CN=62 Runoff=0.70 cfs 0.047 of Link 12L: POA 4 Inflow=33.22 cfs 3.432 of Primary=33.22 cfs 3.432 of Subcatchment 12S: ONSITE TO POA 5 Runoff Area=2.960 ac 3.04% Impervious Runoff Depth=0.34" Tc=12.3 min CN=62 Runoff=0.88 cfs 0.083 of Subcatchment 13S: OFFSITE TO POA 5 Runoff Area=8.190 ac 4.40% Impervious Runoff Depth=0.63" Tc=15.2 min CN=70 Runoff=5.72 cfs 0.428 of Link 14L: POA 5 Inflow=6.59 cfs 0.511 of Primary=6.59 cfs 0.511 of PreDev Bird St Predev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 1 S: ONSITE TO POA 1 Runoff = 1.37 cfs @ 12.12 hrs, Volume= 0.137 af, Depth= 0.37" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 1.040 55 Woods, Good, HSG B 1.080 77 Woods, Good, HSG D 2.360 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 4.480 63 Weighted Average 4.480 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.4 Direct Entry, Summary for Subcatchment 2S: OFFSITE TO POA 1 Runoff = 6.74 cfs @ 12.13 hrs, Volume= 0.547 af, Depth= 0.71" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.310 55 Woods, Good, HSG B 2.550 77 Woods, Good, HSG D 3.370 61 >75% Grass cover, Good, HSG B 2.550 80 >75% Grass cover, Good, HSG D 0.400 98 Paved parking, HSG B 9.180 72 Weighted Average 8.780 95.64% Pervious Area 0.400 4.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.6 Direct Entry, Summary for Link 3L: POA 1 Inflow Area = 13.660 ac, 2.93% Impervious, Inflow Depth = 0.60" for 1-YR event Inflow = 8.09 cfs @ 12.13 hrs, Volume= 0.684 of Primary = 8.09 cfs @ 12.13 hrs, Volume= 0.684 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs PreDev Bird St Predev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 4S: ONSITE TO POA 2 Runoff = 0.13 cfs @ 11.98 hrs, Volume= 0.007 af, Depth= 0.43" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.180 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.020 98 Paved parking, HSG B 0.200 65 Weighted Average 0.180 90.00% Pervious Area 0.020 10.00% Impervious Area Tc Length Description 5.0 Direct Entry, Summary for Subcatchment 5S: OFFSITE TO POA 2 Runoff = 25.48 cfs @ 12.21 hrs, Volume= 2.581 af, Depth= 0.63" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 8.050 55 Woods, Good, HSG B 21.130 77 Woods, Good, HSG D 14.170 61 >75% Grass cover, Good, HSG B 5.140 80 >75% Grass cover, Good, HSG D 0.890 98 Paved parking, HSG B 49.380 70 Weighted Average 48.490 98.20% Pervious Area 0.890 1.80% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 24.4 Direct Entry, Summary for Link 6L: POA 2 Inflow Area = 63.240 ac, 2.07% Impervious, Inflow Depth = 0.62" for 1-YR event Inflow = 32.61 cfs @ 12.19 hrs, Volume= 3.272 of Primary = 32.61 cfs @ 12.19 hrs, Volume= 3.272 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs PreDev Bird St Predev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 @ 2011 HydroCAD Software Solutions LLC Page 5 Summary for Pond 7S: Ex. Wet Pond Inflow Area = 63.240 ac, 2.07% Impervious, Inflow Depth = 0.62" for 1-YR event Inflow = 32.61 cfs @ 12.19 hrs, Volume= 3.272 of Outflow = 32.61 cfs @ 12.19 hrs, Volume= 3.272 af, Atten= 0%, Lag= 0.0 min Primary = 32.61 cfs @ 12.19 hrs, Volume= 3.272 of Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 307.14' @ 12.19 hrs Device Routing Invert Outlet Devices #1 Primary 306.00' 10.0' long x 10.0' breadth Broad -Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Primary 308.00' 50.0' long x 15.0' breadth Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max=32.41 cfs @ 12.19 hrs HW=307.13' (Free Discharge) �1=Broad-Crested Rectangular Weir (Weir Controls 32.41 cfs @ 2.86 fps) 2=Emergency Spillway ( Controls 0.00 cfs) Summary for Subcatchment 8S: ONSITE TO POA 3 Runoff = 1.56 cfs @ 11.98 hrs, Volume= 0.086 af, Depth= 0.43" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.340 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.730 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.310 98 Paved parking, HSG B 2.380 65 Weighted Average 2.070 86.97% Pervious Area 0.310 13.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 9L: POA 3 Inflow Area = 65.620 ac, 2.47% Impervious, Inflow Depth = 0.61" for 1-YR event Inflow = 32.93 cfs @ 12.19 hrs, Volume= 3.359 of Primary = 32.93 cfs @ 12.19 hrs, Volume= 3.359 af, Atten= 0%, Lag= 0.0 min rut PreDev Bird St Predev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 6 Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Summary for Subcatchment 10S: ONSITE TO POA 4 Runoff = 0.40 cfs @ 12.01 hrs, Volume= 0.027 af, Depth= 0.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.250 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.640 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.060 98 Paved parking, HSG B 0.950 62 Weighted Average 0.890 93.68% Pervious Area 0.060 6.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.2 Direct Entry, Summary for Subcatchment 11S: OFFSITE TO POA 4 Runoff = 0.70 cfs @ 12.01 hrs, Volume= 0.047 af, Depth= 0.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN 0.540 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.010 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.120 98 Paved Darkina. HSG B 1.670 62 Weighted Average 1.550 92.81 % Pervious Area 0.120 7.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.2 Direct Entry, 11 PreDev Bird St Predev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 7 Summary for Link 12L: POA 4 Inflow Area = 68.240 ac, 2.64% Impervious, Inflow Depth = 0.60" for 1-YR event Inflow = 33.22 cfs @ 12.19 hrs, Volume= 3.432 of Primary = 33.22 cfs @ 12.19 hrs, Volume= 3.432 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Summary for Subcatchment 12S: ONSITE TO POA 5 Runoff = 0.88 cfs @ 12.09 hrs, Volume= 0.083 af, Depth= 0.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Descriotion 0.270 55 Woods, Good, HSG B 0.110 77 Woods, Good, HSG D 2.490 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.090 98 Paved parking, HSG B 2.960 62 Weighted Average 2.870 96.96% Pervious Area 0.090 3.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.3 Direct Entry, Summary for Subcatchment 13S: OFFSITE TO POA 5 Runoff = 5.72 cfs @ 12.10 hrs, Volume= 0.428 af, Depth= 0.63" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Descriotion 0.930 55 Woods, Good, HSG B 1.430 77 Woods, Good, HSG D 3.060 61 >75% Grass cover, Good, HSG B 2.410 80 >75% Grass cover, Good, HSG D 0.360 98 Paved parking, HSG B 8.190 70 Weighted Average 7.830 95.60% Pervious Area 0.360 4.40% Impervious Area IN PreDev Bird St Predev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 8 Tc Length Description 15.2 Direct Entry, Summary for Link 14L: POA 5 Inflow Area = 11.150 ac, 4.04% Impervious, Inflow Depth = 0.55" for 1-YR event Inflow = 6.59 cfs @ 12.10 hrs, Volume= 0.511 of Primary = 6.59 cfs @ 12.10 hrs, Volume= 0.511 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs 13 PreDev Bird St Predev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HvdroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paae 9 Time span=5.00-40.00 hrs, dt=0.05 hrs, 701 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: ONSITE TO POA 1 Runoff Area=4.480 ac 0.00% Impervious Runoff Depth=1.64" Tc=15.4 min CN=63 Runoff=8.87 cfs 0.611 of Subcatchment 2S: OFFSITE TO POA 1 Runoff Area=9.180 ac 4.36% Impervious Runoff Depth=2.35" Tc=18.6 min CN=72 Runoff=24.73 cfs 1.800 of Link 3L: POA 1 Inflow=33.45 cfs 2.411 of Primary=33.45 cfs 2.411 of Subcatchment 4S: ONSITE TO POA 2 Runoff Area=0.200 ac 10.00% Impervious Runoff Depth=1.79" Tc=5.0 min CN=65 Runoff=0.64 cfs 0.030 of Subcatchment 5S: OFFSITE TO POA 2 Runoff Area=49.380 ac 1.80% Impervious Runoff Depth=2.19" Tc=24.4 min CN=70 Runoff=104.26 cfs 8.995 of Link 6L: POA 2 Inflow=134.41 cfs 11.436 of Primary=134.41 cfs 11.436 of Pond 7S: Ex. Wet Pond Peak Elev=308.41' Inflow=134.41 cfs 11.436 of Outflow=134.41 cfs 11.436 of Subcatchment 8S: ONSITE TO POA 3 Runoff Area=2.380 ac 13.03% Impervious Runoff Depth=1.79" Tc=5.0 min CN=65 Runoff=7.60 cfs 0.355 of Link 9L: POA 3 Inflow=135.69 cfs 11.790 of Primary=135.69 cfs 11.790 of Subcatchment 111S: ONSITE TO POA 4 Runoff Area=0.950 ac 6.32% Impervious Runoff Depth=1.56" Tc=6.2 min CN=62 Runoff=2.53 cfs 0.124 of Subcatchment 11S: OFFSITE TO POA 4 Runoff Area=1.670 ac 7.19% Impervious Runoff Depth=1.56" Tc=6.2 min CN=62 Runoff=4.45 cfs 0.218 of Link 12L: POA 4 Inflow=137.14 cfs 12.132 of Primary=137.14 cfs 12.132 of Subcatchment 12S: ONSITE TO POA 5 Runoff Area=2.960 ac 3.04% Impervious Runoff Depth=1.56" Tc=12.3 min CN=62 Runoff=6.24 cfs 0.386 of Subcatchment 13S: OFFSITE TO POA 5 Runoff Area=8.190 ac 4.40% Impervious Runoff Depth=2.19" Tc=15.2 min CN=70 Runoff=22.61 cfs 1.492 of Link 14L: POA 5 Inflow=28.72 cfs 1.877 of Primary=28.72 cfs 1.877 of 14 PreDev Bird St Predev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 1 S: ONSITE TO POA 1 Runoff = 8.87 cfs @ 12.09 hrs, Volume= 0.611 af, Depth= 1.64" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 1.040 55 Woods, Good, HSG B 1.080 77 Woods, Good, HSG D 2.360 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 4.480 63 Weighted Average 4.480 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.4 Direct Entry, Summary for Subcatchment 2S: OFFSITE TO POA 1 Runoff = 24.73 cfs @ 12.12 hrs, Volume= 1.800 af, Depth= 2.35" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.310 55 Woods, Good, HSG B 2.550 77 Woods, Good, HSG D 3.370 61 >75% Grass cover, Good, HSG B 2.550 80 >75% Grass cover, Good, HSG D 0.400 98 Paved parking, HSG B 9.180 72 Weighted Average 8.780 95.64% Pervious Area 0.400 4.36% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.6 Direct Entry, Summary for Link 3L: POA 1 Inflow Area = 13.660 ac, 2.93% Impervious, Inflow Depth = 2.12" for 10-YR event Inflow = 33.45 cfs @ 12.11 hrs, Volume= 2.411 of Primary = 33.45 cfs @ 12.11 hrs, Volume= 2.411 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs IN PreDev Bird St Predev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment 4S: ONSITE TO POA 2 Runoff = 0.64 cfs @ 11.96 hrs, Volume= 0.030 af, Depth= 1.79" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.180 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.020 98 Paved parking, HSG B 0.200 65 Weighted Average 0.180 90.00% Pervious Area 0.020 10.00% Impervious Area Tc Length Description 5.0 Direct Entry, Summary for Subcatchment 5S: OFFSITE TO POA 2 Runoff = 104.26 cfs @ 12.19 hrs, Volume= 8.995 af, Depth= 2.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 8.050 55 Woods, Good, HSG B 21.130 77 Woods, Good, HSG D 14.170 61 >75% Grass cover, Good, HSG B 5.140 80 >75% Grass cover, Good, HSG D 0.890 98 Paved parking, HSG B 49.380 70 Weighted Average 48.490 98.20% Pervious Area 0.890 1.80% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 24.4 Direct Entry, Summary for Link 6L: POA 2 Inflow Area = 63.240 ac, 2.07% Impervious, Inflow Depth = 2.17" for 10-YR event Inflow = 134.41 cfs @ 12.16 hrs, Volume= 11.436 of Primary = 134.41 cfs @ 12.16 hrs, Volume= 11.436 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs pry PreDev Bird St Predev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 12 Summary for Pond 7S: Ex. Wet Pond Inflow Area = 63.240 ac, 2.07% Impervious, Inflow Depth = 2.17" for 10-YR event Inflow = 134.41 cfs @ 12.16 hrs, Volume= 11.436 of Outflow = 134.41 cfs @ 12.16 hrs, Volume= 11.436 af, Atten= 0%, Lag= 0.0 min Primary = 134.41 cfs @ 12.16 hrs, Volume= 11.436 of Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 308.41' @ 12.16 hrs Device Routing Invert Outlet Devices #1 Primary 306.00' 10.0' long x 10.0' breadth Broad -Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Primary 308.00' 50.0' long x 15.0' breadth Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max=133.17 cfs @ 12.16 hrs HW=308.40' (Free Discharge) �1=Broad-Crested Rectangular Weir (Weir Controls 98.44 cfs @ 4.09 fps) 2=Emergency Spillway (Weir Controls 34.74 cfs @ 1.72 fps) Summary for Subcatchment 8S: ONSITE TO POA 3 Runoff = 7.60 cfs @ 11.96 hrs, Volume= 0.355 af, Depth= 1.79" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.340 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.730 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.310 98 Paved parking, HSG B 2.380 65 Weighted Average 2.070 86.97% Pervious Area 0.310 13.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 9L: POA 3 Inflow Area = 65.620 ac, 2.47% Impervious, Inflow Depth = 2.16" for 10-YR event Inflow = 135.69 cfs @ 12.16 hrs, Volume= 11.790 of Primary = 135.69 cfs @ 12.16 hrs, Volume= 11.790 af, Atten= 0%, Lag= 0.0 min IVA PreDev Bird St Predev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 13 Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Summary for Subcatchment 10S: ONSITE TO POA 4 Runoff = 2.53 cfs @ 11.98 hrs, Volume= 0.124 af, Depth= 1.56" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.250 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.640 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.060 98 Paved parking, HSG B 0.950 62 Weighted Average 0.890 93.68% Pervious Area 0.060 6.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.2 Direct Entry, Summary for Subcatchment 11S: OFFSITE TO POA 4 Runoff = 4.45 cfs @ 11.98 hrs, Volume= 0.218 af, Depth= 1.56" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN 0.540 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.010 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.120 98 Paved Darkina. HSG B 1.670 62 Weighted Average 1.550 92.81 % Pervious Area 0.120 7.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.2 Direct Entry, It.] PreDev Bird St Predev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 14 Summary for Link 12L: POA 4 Inflow Area = 68.240 ac, 2.64% Impervious, Inflow Depth = 2.13" for 10-YR event Inflow = 137.14 cfs @ 12.16 hrs, Volume= 12.132 of Primary = 137.14 cfs @ 12.16 hrs, Volume= 12.132 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Summary for Subcatchment 12S: ONSITE TO POA 5 Runoff = 6.24 cfs @ 12.05 hrs, Volume= 0.386 af, Depth= 1.56" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Descriotion 0.270 55 Woods, Good, HSG B 0.110 77 Woods, Good, HSG D 2.490 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.090 98 Paved parking, HSG B 2.960 62 Weighted Average 2.870 96.96% Pervious Area 0.090 3.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.3 Direct Entry, Summary for Subcatchment 13S: OFFSITE TO POA 5 Runoff = 22.61 cfs @ 12.08 hrs, Volume= 1.492 af, Depth= 2.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Descriotion 0.930 55 Woods, Good, HSG B 1.430 77 Woods, Good, HSG D 3.060 61 >75% Grass cover, Good, HSG B 2.410 80 >75% Grass cover, Good, HSG D 0.360 98 Paved parking, HSG B 8.190 70 Weighted Average 7.830 95.60% Pervious Area 0.360 4.40% Impervious Area 19 Bird St Subdivision PreDev Time of Concentration Calculations Postdev Onsite to Pomd 1 055 ft overland -grass 9.1% slope 0.28 C-value 6.8 min Seelye Chart 80 ft s. c. flow -pavement 2.5% slope 3.2 fps velocity 0.4 min. NEH Figure 15-4 246 ft channel -paved 5.0 ft height 0.5 min. Kirpich Chart TOC= 7.7 min. Postdev Offsite to Pond 1 100 ft overland -grass 3.5% slope 0.28 C-value 10.5 min Seelye Chart 262 ft s. c. flow -grass 11.5% slope 2.3 fps velocity 1.9 min. NEH Figure 15-4 950 ft channel -natural 54.0 ft height 4.6 min. Kirpich Chart 450 ft channel -paved 11.0 ft height 0.8 min. Kirpich Chart TOC= 17.8 min. Postdev Offsite to POA 2 100 ft overland -forest 6.0% slope 0.25 C-value 10.6 min Seelye Chart 331 ft s. c. flow -forest 8.5% slope 1.5 fps velocity 3.8 min. NEH Figure 15-4 2005 ft channel -natural 72.0 ft height 10.0 min. Kirpich Chart TOC= 24.4 min. Postdev Onsite to Pond 2 055 ft overland -grass 9.1% slope 0.28 C-value 6.8 min Seelye Chart 110 ft s. c. flow -grass 1.8% slope 2.6 fps velocity 0.7 min. NEH Figure 15-4 246 ft channel -paved 5.0 ft height 0.5 min. Kirpich Chart TOC= 8.0 min. Postdev Offsite to Pond 2 080 ft overland -grass 10.0% slope 0.28 C-value 7.8 min Seelye Chart 235 ft s. c. flow -woods 12.8% slope 1.6 fps velocity 2.4 min. NEH Figure 15-4 700ft channel -paved 23.0ft height 0.9 min. Kirpich Chart TOC= 11.2 min. 370 ft s. c. flow -forest 4.6% slope 1.0 fps velocity 6.2 min. NEH Figure 15-4 TOC= 6.2 min. Postdev Offsite to POA 5 100 ft overland -grass 7.0% slope 0.28 C-value 9.2 min Seelye Chart 397 ft s. c. flow -grass 17.6% slope 2.9 fps velocity 2.3 min. NEH Figure 15-4 600 ft channel -natural 28.0 ft height 3.7 min. Kirpich Chart TOC= 15.2 min. 20 w LL z a S ix 6D-1 Overland Flow Time - 600 Soo Paved 400 DA Bare 200 Soil \� Poor rS55 surirjkCE Averagt R . ESS 50 40 t) 30 p K u 20 qi U 10 TC = 0.225 LG 42 S-o 19 C -1.0 T. = 0v 111aoci Flo« nn», M.nrae L = Logth al Strip, had 35 S - slope. fee~ C = RaNpnal'C' Value b Grourtl Chasse[ 0.9 0.6 0.7 0.6 0.5 0.4 0.5 1,0 0.2 \ \ 10 \ 20 V J a Z O <F G 30 25 W W 15� ~ 2 H U z Z 61 LL��%Q* Awl.. -C" V.... for SRI BCtep GrWnO Crpppter Ots, a Oro.. 0.215 F Pee+ 0.26 A veroge Creel Svtooe 0.2E L. 0.30 Pow Oroee Svrfooe 0.36 Posture 0.40 Ewe $OI i 0.4E P.." G.so OVERLAND FLOW TIME LEGEND: Postdev Onsite to POA 1 Postdev Offsite to POA 2 Postdev Offsite to POA 2 Postdev to POA 4 Postdev Onsite to POA 5 Postdev Offsite to POA 5 Chapter 15 Time of Concentration Par1630 Natlaal Engineering Handbook Figure 15-1 Velocity versus slope for shallow concentrated flow 1.00 0.90 0.60 0.70 0.60 0.50 0.40 0.30 0.20 0.10 C: QGJ a 666 o.0s � mrfi `n u06 o.us "a 0.02 0.01 loll --_ /, / E aMEN nnne�e�� �llllll�lll■l� � � �111111��■ � �. � ammmm��■ �����onnnnm ��������1111111111 ��■■■■�■111111111 wool ■■■99 �_��� mom■ ��■■ ��■■ ��■ / r , I r . J �■11111■IIIII��■ � ������I������_�� iiiiiiliiiilQ=■ ■l �� 0 0 0 0000o Vlocity(Wo) 6 Table I5-3 Equations and assumptions developed from figure 154 Flow type Depth Mannwe n Velocity egentlon (ft) W.) 7 - Yavereentandsmallep1andguNes 0.2 0.025 V=20328le0b Grassed waterways 0.4 0.050 V=16.135(s)ob Yearly bare and untiBed(overiand flow); and alluvial farts in western mountain 0.2 0.061 V=9.965(sfo regions Gidtivat.d straight. crops 0.2 0.058 V=8.762(s)o` Shortgrasspasture 0.2 0.073 V=6.962(sfo Minimum tillage cultivation, contour or striperopped, and woodlands 0.2 0.101 V=5.032(.r' Forest with heavy ground Utter and hay meadows 0.2 0202 V=2.516ler5 Bird St. Subdivision Post Development Time of Concentration Nomographs 1992 TRAVEL TIME FOR CHANNEL FLOW (Kilpich Chart) H (feet) 500 Tr (min.) 200 00 100 L (feet) 10000 1.50 ♦ so0o No♦♦♦♦♦ a.Ith et.raNVels; m (2) For pave multi Pt` ♦ 10 10 Tt by p.2 1000 f e ♦♦ s 100 1 I TIME OF CONCENTRATION OF SMALL DRAINAGE BASINS NOTE: CHANNELS WITHIN TOC FLOW PATH ARE ALL MANMADE Source: VDOT Plate 5-3 2S 4S OFFS TO Pond i ONSrr UNMANAGED TO POA 1 1S ----fl 3P ----0 5L 1a5 VOLUMI ONSfrE TO Port t Detention Pond 1 PU5 / ONSITE FAR TO D 6S ONSITE TO POA 2 b $L 2 VIA "C" PIPES. VOLUME TO POA j� -p 14 J FOA3 12S SITE TO POND 2 VIA'D" PIPES. VOLUME TO POA5 21S 2OS O FSITE UNM GEDTO ONSITE UNM AGED 5 TO POA P 2 of Dete ion Pond 2 _ D 7S blll 22L ONSITE CLOSE TO POND 2 VIA'C" POA 5 OFFSITE TO POA2 PIPES. VOLUME TO � POA3 1$$ 9P �-0 16L LL }� OFFSITE Il0 POA 4 Ex. Wet Pond / POA 3 \ ONSITE UNMANAGED TO POA 3 Subcat Reach Aon Llnk ONSITE TO POA 4 POA 4 p% PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 2 Time span=5.00-40.00 hrs, dt=0.05 hrs, 701 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1S: ONSITE TO Pond 1 Runoff Area=1.360 ac 44.85% Impervious Runoff Depth=1.39" Tc=7.7 min CN=84 Runoff=3.12 cfs 0.157 of Subcatchment 2S: OFFSITE TO Pond 1 Runoff Area=8.960 ac 4.46% Impervious Runoff Depth=0.71" Tc=17.8 min CN=72 Runoff=6.78 cfs 0.534 of Pond 3P: Detention Pond 1 Peak EIev=311.40' Storage=6,544 cf Inflow=8.27 cfs 0.691 of Outflow=4.50 cfs 0.690 of Subcatchment 4S: ONSITE UNMANAGED Runoff Area=0.260 ac 0.00% Impervious Runoff Depth=0.55" Tc=5.0 min CN=68 Runoff=0.23 cfs 0.012 of Link 5L: POA 1 Inflow=4.54 cfs 0.702 of Primary=4.54 cfs 0.702 of Subcatchment 6S: ONSITE TO POA 2 Runoff Area=0.150 ac 0.00% Impervious Runoff Depth=0.31" Tc=5.0 min CN=61 Runoff=0.06 cfs 0.004 of Subcatchment 7S: OFFSITE TO POA 2 Runoff Area=49.380 ac 1.80% Impervious Runoff Depth=0.63" Tc=24.4 min CN=70 Runoff=25.48 cfs 2.581 of Link 8L: POA 2 Inflow=29.88 cfs 3.287 of Primary=29.88 cfs 3.287 of Pond 9P: Ex. Wet Pond Peak EIev=307.07' Inflow=29.88 cfs 3.287 of Outflow=29.88 cfs 3.287 of Subcatchment 10S: ONSITE FAR TO POND Runoff Area=2.370 ac 34.60% Impervious Runoff Depth=0.81" Tc=8.0 min CN=74 Runoff=3.03 cfs 0.160 of Subcatchment 11S: OFFSITE TO POND 2. Runoff Area=1.370 ac 0.00% Impervious Runoff Depth=0.22" Tc=11.2 min CN=58 Runoff=0.19 cfs 0.026 of Subcatchment 12S: ONSITE TO POND 2 Runoff Area=4.030 ac 35.98% Impervious Runoff Depth=0.86" Tc=8.2 min CN=75 Runoff=5.47 cfs 0.288 of Subcatchment 13S: ONSITE CLOSE TO Runoff Area=1.710 ac 39.18% Impervious Runoff Depth=0.86" Tc=6.0 min CN=75 Runoff=2.51 cfs 0.122 of Pond 14P: Detention Pond 2 Peak EIev=285.00' Storage=11,892 cf Inflow=11.02 cfs 0.596 of Primary=0.42 cfs 0.502 of Secondary=0.15 cfs 0.093 of Outflow=0.57 cfs 0.595 of Subcatchment 15S: ONSITE UNMANAGED Runoff Area=0.290 ac 0.00% Impervious Runoff Depth=0.22" Tc=6.1 min CN=58 Runoff=0.05 cfs 0.005 of Link 16L: POA 3 Inflow=30.30 cfs 3.795 of Primary=30.30 cfs 3.795 of 23 PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 3 Subcatchment 17S: ONSITE TO POA 4 Runoff Area=0.300 ac 0.00% Impervious Runoff Depth=0.31" Tc=6.2 min CN=61 Runoff=0.11 cfs 0.008 of Subcatchment 18S: OFFSITE TO POA 4 Runoff Area=1.690 ac 7.10% Impervious Runoff Depth=0.34" Tc=6.2 min CN=62 Runoff=0.71 cfs 0.047 of Link 19L: POA 4 Inflow=30.50 cfs 3.850 of Primary=30.50 cfs 3.850 of Subcatchment 20S: ONSITE UNMANAGED Runoff Area=0.170 ac 0.00% Impervious Runoff Depth=0.31" Tc=6.1 min CN=61 Runoff=0.06 cfs 0.004 of Subcatchment 21S: OFFSITE UNMANAGED Runoff Area=7.010 ac 5.14% Impervious Runoff Depth=0.71" Tc=15.2 min CN=72 Runoff=5.81 cfs 0.417 of Link 22L: POA 5 Inflow=5.92 cfs 0.515 of Primary=5.92 cfs 0.515 of 24 PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 1S: ONSITE TO Pond 1 Runoff = 3.12 cfs @ 11.99 hrs, Volume= 0.157 af, Depth= 1.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.290 61 >75% Grass cover, Good, HSG B 0.460 80 >75% Grass cover, Good, HSG D 0.110 98 Paved parking, HSG B 0.500 98 Paved parking, HSG D 1.360 84 Weighted Average 0.750 55.15% Pervious Area 0.610 44.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.7 Direct Entry, Summary for Subcatchment 2S: OFFSITE TO Pond 1 Runoff = 6.78 cfs @ 12.12 hrs, Volume= 0.534 af, Depth= 0.71" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN 0.120 55 Woods, Good, HSG B 2.520 77 Woods, Good, HSG D 3.370 61 >75% Grass cover, Good, HSG B 2.550 80 >75% Grass cover, Good, HSG D 0.400 98 Paved Darkina. HSG B 8.960 72 Weighted Average 8.560 95.54% Pervious Area 0.400 4.46% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 17.8 Direct Entry, 021 PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 5 Summary for Pond 3P: Detention Pond 1 Inflow Area = 10.320 ac, 9.79% Impervious, Inflow Depth = 0.80" for 1-YR event Inflow = 8.27 cfs @ 12.07 hrs, Volume= 0.691 of Outflow = 4.50 cfs @ 12.29 hrs, Volume= 0.690 af, Atten= 46%, Lag= 12.7 min Primary = 4.50 cfs @ 12.29 hrs, Volume= 0.690 of Routing by Dyn-Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 311.40' @ 12.29 hrs Surf.Area= 4,017 sf Storage= 6,544 cf Plug -Flow detention time= 47.7 min calculated for 0.689 of (100% of inflow) Center -of -Mass det. time= 47.9 min ( 921.4 - 873.5) Volume Invert Avail.Storage Storage Description #1 309.00' 19,302 cf Detention Pond Storage (Prismatic) Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic -feet) (cubic -feet) 309.00 710 0.0 0 0 309.49 710 40.0 139 139 309.50 2,430 100.0 16 155 310.00 3,120 100.0 1,388 1,542 312.00 4,400 100.0 7,520 9,062 314.00 5,840 100.0 10,240 19,302 Device Routina Invert Outlet Devices #1 Primary 309.00' 30.0" Round 30" RCP L= 60.0' Ke= 0.200 Inlet / Outlet Invert= 309.00' / 308.00' S= 0.0167'/' Cc= 0.900 n= 0.013 #2 Device 1 309.00' 6.0" Round underdrain L= 60.0' Ke= 0.900 Inlet / Outlet Invert= 309.00' / 309.00' S= 0.0000 7' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #3 Device 1 310.00' 1.0' long Sharp -Crested Rectangular Weir 2 End Contraction(s) #4 Device 1 312.00' 48.0" Horiz. standpipe rim C= 0.600 Limited to weir flow at low heads #5 Primary 313.00' 4.0' long x 20.0' breadth Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max=4.49 cfs @ 12.29 hrs HW=311.40' TW=0.00' (Dynamic Tailwater) 1-30" RCP (Passes 4.49 cfs of 29.97 cfs potential flow) 2=underdrain (Barrel Controls 0.60 cfs @ 3.05 fps) 3=Sharp-Crested Rectangular Weir (Weir Controls 3.89 cfs @ 3.87 fps) =standpipe rim ( Controls 0.00 cfs) =Emergency Spillway ( Controls 0.00 cfs) %zj PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 4S: ONSITE UNMANAGED TO POA 1 Runoff = 0.23 cfs @ 11.98 hrs, Volume= 0.012 af, Depth= 0.55" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.170 61 >75% Grass cover, Good, HSG B 0.090 80 >75% Grass cover, Good, HSG D 0.260 68 Weighted Average 0.260 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 5L: POA 1 Inflow Area = 10.580 ac, 9.55% Impervious, Inflow Depth = 0.80" for 1-YR event Inflow = 4.54 cfs @ 12.29 hrs, Volume= 0.702 of Primary = 4.54 cfs @ 12.29 hrs, Volume= 0.702 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs 100-YR Fixed water surface Elevation= 309.10' Summary for Subcatchment 6S: ONSITE TO POA 2 Runoff = 0.06 cfs @ 12.00 hrs, Volume= 0.004 af, Depth= 0.31" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.150 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved Darkina. HSG B 0.150 61 Weighted Average 0.150 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, OrA PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 7S: OFFSITE TO POA 2 Runoff = 25.48 cfs @ 12.21 hrs, Volume= 2.581 af, Depth= 0.63" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 8.050 55 Woods, Good, HSG B 21.130 77 Woods, Good, HSG D 14.170 61 >75% Grass cover, Good, HSG B 5.140 80 >75% Grass cover, Good, HSG D 0.890 98 Paved parking, HSG B 49.380 70 Weighted Average 48.490 98.20% Pervious Area 0.890 1.80% Impervious Area Tc Length Slope Velocity Capacity Description 24.4 Direct Entry, Summary for Link 8L: POA 2 Inflow Area = 60.110 ac, 3.16% Impervious, Inflow Depth = 0.66" for 1-YR event Inflow = 29.88 cfs @ 12.22 hrs, Volume= 3.287 of Primary = 29.88 cfs @ 12.22 hrs, Volume= 3.287 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Summary for Pond 9P: Ex. Wet Pond Inflow Area = 60.110 ac, 3.16% Impervious, Inflow Depth = 0.66" for 1-YR event Inflow = 29.88 cfs @ 12.22 hrs, Volume= 3.287 of Outflow = 29.88 cfs @ 12.22 hrs, Volume= 3.287 af, Atten= 0%, Lag= 0.0 min Primary = 29.88 cfs @ 12.22 hrs, Volume= 3.287 of Routing by Dyn-Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 307.07' @ 12.22 hrs Device Routing Invert Outlet Devices #1 Primary 306.00' 10.0' long x 10.0' breadth Broad -Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Primary 308.00' 50.0' long x 15.0' breadth Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 28 PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 8 Primary OutFlow Max=29.59 cfs @ 12.22 hrs HW=307.07' TW=0.00' (Dynamic Tailwater) �1=Broad-Crested Rectangular Weir (Weir Controls 29.59 cfs @ 2.77 fps) 2=Emergency Spillway ( Controls 0.00 cfs) Summary for Subcatchment 10S: ONSITE FAR TO POND 2 VIA "C" PIPES. VOLUME TO POA 3 Volume from this area Calculated as routed to POA 3 Runoff = 3.03 cfs @ 12.00 hrs, Volume= 0.160 af, Depth= 0.81" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.550 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.820 98 Paved parking, HSG B 0.000 98 Paved oarkina. HSG D 2.370 74 Weighted Average 1.550 65.40% Pervious Area 0.820 34.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, Summary for Subcatchment 11 S: OFFSITE TO POND 2. VOLUME TO POA 3 Volume from this area Calculated as routed to PGA 3 Runoff = 0.19 cfs @ 12.09 hrs, Volume= 0.026 af, Depth= 0.22" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.780 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.590 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 1.370 58 Weighted Average 1.370 100.00% Pervious Area .x1 PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 9 Tc Length Slope Velocity Capacity Description 11.2 Direct Entry, Summary for Subcatchment 12S: ONSITE TO POND 2 VIA "D" PIPES. VOLUME TO POA 5 Volume from this area Calculated as routed to POA 5 Runoff = 5.47 cfs @ 12.00 hrs, Volume= 0.288 af, Depth= 0.86" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 2.470 61 >75% Grass cover, Good, HSG B 0.110 80 >75% Grass cover, Good, HSG D 1.420 98 Paved parking, HSG B 0.030 98 Paved Darkina. HSG D 4.030 75 Weighted Average 2.580 64.02% Pervious Area 1.450 35.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.2 Direct Entry, Summary for Subcatchment 13S: ONSITE CLOSE TO POND 2 VIA "C' PIPES. VOLUME TO POA 3 Volume from this area Calculated as routed to POA 3 Runoff = 2.51 cfs @ 11.98 hrs, Volume= 0.122 af, Depth= 0.86" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.040 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.670 98 Paved parking, HSG B 0.000 98 Paved parking, HSG D 1.710 75 Weighted Average 1.040 60.82% Pervious Area 0.670 39.18% Impervious Area 01 PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Preoared by (enter vour comDanv name here) Printed 12/22/2022 Tc Length Slope Velocity Capacity Description 6.0 Direct Entry, Summary for Pond 14P: Detention Pond 2 Since Pond 2 has two spillways which discharge a mixed flow regime discharging to both POA 3 and POA 5, with mixed offsite and inflow runoffs, we have calulated that the runoff volume from each barrel is dictated by the runoff of the drainage system closest to each spillway system. The "C" storm sewer collection system discharges into the pond close to the riser which outlets to POA 3. Thus, for regulatory volume calculations, the runoff volume from 105, 11S, & 13S is assumed to discharge to POA 3. Similarly, since the "D" system storm sewer collection system discharges into the pond close to the riser which outlets to POA 5. Thus, for regulatory volume calculations, the runoff volume from 12S is assumed to discharge to POA 5. Inflow Area = 9.480 ac, 31.01% Impervious, Inflow Depth = 0.75" for 1-YR event Inflow = 11.02 cfs @ 12.00 hrs, Volume= 0.596 of Outflow = 0.57 cfs @ 13.85 hrs, Volume= 0.595 af, Atten= 95%, Lag= 110.8 min Primary = 0.42 cfs @ 13.85 hrs, Volume= 0.502 of Secondary = 0.15 cfs @ 13.85 hrs, Volume= 0.093 of Routing by Dyn-Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 285.00' @ 13.85 hrs Surf.Area= 11,028 sf Storage= 11,892 cf Plug -Flow detention time= 266.7 min calculated for 0.595 of (100% of inflow) Center -of -Mass det. time= 266.2 min ( 1,136.0 - 869.8) Volume Invert Avail.Storage Storage Description #1 283.20' 74,244 cf Detention Pond Storage (Prismatic) Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) M (cubic -feet) (cubic -feet) 283.20 1,900 0.0 0 0 283.70 1,900 40.0 380 380 284.00 8,840 100.0 1,611 1,991 286.00 13,230 100.0 22,070 24,061 288.00 17,875 100.0 31,105 55,166 289.00 20,280 100.0 19,078 74,244 31 PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 11 Device Routing Invert Outlet Devices #1 Primary 279.00' 30.0" Round 30" HDPE TO POA 3 L= 70.0' Ke= 0.200 Inlet / Outlet Invert= 279.00' / 276.50' S= 0.0357'/' Cc= 0.900 n= 0.012 #2 Secondary 283.50' 24.0" Round 24" RCP TO POA 5 L= 60.0' Ke= 0.200 Inlet / Outlet Invert= 283.50' / 282.80' S= 0.0117 7' Cc= 0.900 n= 0.013 #3 Device 1 283.20' 6.0" Round 6" Perf. Underdrain POA 3 L= 180.0' Ke= 0.900 Inlet / Outlet Invert= 283.20' / 282.00' S= 0.0067'/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #4 Device 2 284.30' 2.0" W x 3.0" H Vert. 1 yr 2x3 Orifice POA 5 C= 0.600 #5 Device 1 285.10' 18.0" Vert. 18" Orifice POA 3 C= 0.600 #6 Device 2 285.10' 18.0" Vert. 18" Orifice POA 5 C= 0.600 #7 Device 1 286.10' 60.0" Horiz. 60" Standpipe Rim POA 3 C= 0.600 Limited to weir flow at low heads #8 Device 2 286.10' 48.0" Horiz. 48" Standpipe Rim POA 5 C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.42 cfs @ 13.85 hrs HW=285.00' TW=0.00' (Dynamic Tailwater) t1=30" HDPE TO POA 3 (Passes 0.42 cfs of 64.37 cfs potential flow) 3=6" Perf. Underdrain POA 3 (Barrel Controls 0.42 cfs @ 2.13 fps) =18" Orifice POA 3 ( Controls 0.00 cfs) 7=60" Standpipe Rim POA 3 ( Controls 0.00 cfs) Secondary OutFlow Max=0.15 cfs @ 13.85 hrs HW=285.00' TW=0.00' (Dynamic Tailwater) 1--2=24" RCP TO POA 5 (Passes 0.15 cfs of 11.01 cfs potential flow) 1 yr 2x3 Orifice POA 5 (Orifice Controls 0.15 cfs @ 3.63 fps) =18" Orifice POA 5 ( Controls 0.00 cfs) 8=48" Standpipe Rim POA 5 ( Controls 0.00 cfs) Summary for Subcatchment 15S: ONSITE UNMANAGED TO POA 3 Runoff = 0.05 cfs @ 12.02 hrs, Volume= 0.005 af, Depth= 0.22" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.290 58 Meadow. non-arazed. HSG B 0.290 100.00% Pervious Area Tc Length Slope Velocity Capacity Description 6.1 Direct Entry, W PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 12 Summary for Link 16L: POA 3 Inflow Area = 69.880 ac, 6.93% Impervious, Inflow Depth = 0.65" for 1-YR event Inflow = 30.30 cfs @ 12.22 hrs, Volume= 3.795 of Primary = 30.30 cfs @ 12.22 hrs, Volume= 3.795 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs 100-YR Fixed water surface Elevation= 286.90' Summary for Subcatchment 17S: ONSITE TO POA 4 Runoff = 0.11 cfs @ 12.01 hrs, Volume= 0.008 af, Depth= 0.31" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.300 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 0.300 61 Weighted Average 0.300 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.2 Direct Entry, Summary for Subcatchment 18S: OFFSITE TO POA 4 Runoff = 0.71 cfs @ 12.01 hrs, Volume= 0.047 af, Depth= 0.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Description 0.540 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.030 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.120 98 Paved parking, HSG B 1.690 62 Weighted Average 1.570 92.90% Pervious Area 0.120 7.10% Impervious Area 33 PostDev Bird St Postdev Type 1124-hr 1-YR Rainfall=2.84" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 13 Tc Length Description 6.2 Direct Entry, Summary for Link 19L: POA 4 Inflow Area = 71.870 ac, 6.90% Impervious, Inflow Depth = 0.64" for 1-YR event Inflow = 30.50 cfs @ 12.22 hrs, Volume= 3.850 of Primary = 30.50 cfs @ 12.22 hrs, Volume= 3.850 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Summary for Subcatchment 20S: ONSITE UNMANAGED TO POA 5 Runoff = 0.06 cfs @ 12.01 hrs, Volume= 0.004 af, Depth= 0.31" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Descriotion 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.170 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 0.170 61 Weighted Average 0.170 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.1 Direct Entry, Summary for Subcatchment 21 S: OFFSITE UNMANAGED TO POA 5 Runoff = 5.81 cfs @ 12.09 hrs, Volume= 0.417 af, Depth= 0.71" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.84" Area (ac) CN Descriotion 0.330 55 Woods, Good, HSG B 1.430 77 Woods, Good, HSG D 2.470 61 >75% Grass cover, Good, HSG B 2.420 80 >75% Grass cover, Good, HSG D 0.300 98 Paved parking, HSG B 0.060 98 Paved Darkina. HSG D 7.010 72 Weighted Average 6.650 94.86% Pervious Area 0.360 5.14% Impervious Area 34 Bird St Postdev name Tc Length Slope Velocity Capacity Description (min) (feet) (ft/f0 (ft/sec) (cfs) 15.2 Direct Entry, PostDev Type 1124-hr 1-YR Rainfall=2.84" Printed 12/22/2022 Summary for Link 22L: POA 5 Inflow Area = 7.180 ac, 5.01% Impervious, Inflow Depth = 0.86" for 1-YR event Inflow = 5.92 cfs @ 12.09 hrs, Volume= 0.515 of Primary = 5.92 cfs @ 12.09 hrs, Volume= 0.515 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs 100-YR Fixed water surface Elevation= 286.80' starting at To= 1.00 hrs 35 PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 15 Time span=5.00-40.00 hrs, dt=0.05 hrs, 701 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1S: ONSITE TO Pond 1 Runoff Area=1.360 ac 44.85% Impervious Runoff Depth=3.45" Tc=7.7 min CN=84 Runoff=7.56 cfs 0.391 of Subcatchment 2S: OFFSITE TO Pond 1 Runoff Area=8.960 ac 4.46% Impervious Runoff Depth=2.35" Tc=17.8 min CN=72 Runoff=24.74 cfs 1.757 of Pond 3P: Detention Pond 1 Peak Elev=312.63' Storage=11,969 cf Inflow=28.61 cfs 2.148 of Outflow=28.20 cfs 2.148 of Subcatchment 4S: ONSITE UNMANAGED Runoff Area=0.260 ac 0.00% Impervious Runoff Depth=2.02" Tc=5.0 min CN=68 Runoff=0.95 cfs 0.044 of Link 5L: POA 1 Inflow=28.42 cfs 2.192 of Primary=28.42 cfs 2.192 of Subcatchment 6S: ONSITE TO POA 2 Runoff Area=0.150 ac 0.00% Impervious Runoff Depth=1.49" Tc=5.0 min CN=61 Runoff=0.39 cfs 0.019 of Subcatchment 7S: OFFSITE TO POA 2 Runoff Area=49.380 ac 1.80% Impervious Runoff Depth=2.19" Tc=24.4 min CN=70 Runoff=104.26 cfs 8.995 of Link 8L: POA 2 Inflow=129.93 cfs 11.205 of Primary=129.93 cfs 11.205 of Pond 9P: Ex. Wet Pond Peak EIev=308.39' Inflow=129.93 cfs 11.205 of Outflow=129.93 cfs 11.205 of Subcatchment 10S: ONSITE FAR TO POND Runoff Area=2.370 ac 34.60% Impervious Runoff Depth=2.52" Tc=8.0 min CN=74 Runoff=9.80 cfs 0.499 of Subcatchment 11S: OFFSITE TO POND 2. Runoff Area=1.370 ac 0.00% Impervious Runoff Depth=1.28" Tc=11.2 min CN=58 Runoff=2.36 cfs 0.146 of Subcatchment 12S: ONSITE TO POND 2 Runoff Area=4.030 ac 35.98% Impervious Runoff Depth=2.61" Tc=8.2 min CN=75 Runoff=17.10 cfs 0.877 of Subcatchment 13S: ONSITE CLOSE TO Runoff Area=1.710 ac 39.18% Impervious Runoff Depth=2.61" Tc=6.0 min CN=75 Runoff=7.69 cfs 0.372 of Pond 14P: Detention Pond 2 Peak EIev=286.29' Storage=27,977 cf Inflow=36.46 cfs 1.894 of Primary=10.27 cfs 1.214 of Secondary=9.19 cfs 0.680 of Outflow=19.46 cfs 1.894 of Subcatchment 15S: ONSITE UNMANAGED Runoff Area=0.290 ac 0.00% Impervious Runoff Depth=1.28" Tc=6.1 min CN=58 Runoff=0.62 cfs 0.031 of Link 16L: POA 3 Inflow=138.15 cfs 12.450 of Primary=138.15 cfs 12.450 of cW PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 16 Subcatchment 17S: ONSITE TO POA 4 Runoff Area=0.300 ac 0.00% Impervious Runoff Depth=1.49" Tc=6.2 min CN=61 Runoff=0.76 cfs 0.037 of Subcatchment 18S: OFFSITE TO POA 4 Runoff Area=1.690 ac 7.10% Impervious Runoff Depth=1.56" Tc=6.2 min CN=62 Runoff=4.50 cfs 0.220 of Link 19L: POA 4 Inflow=139.26 cfs 12.707 of Primary=139.26 cfs 12.707 of Subcatchment 20S: ONSITE UNMANAGED Runoff Area=0.170 ac 0.00% Impervious Runoff Depth=1.49" Tc=6.1 min CN=61 Runoff=0.43 cfs 0.021 of Subcatchment 21S: OFFSITE UNMANAGED Runoff Area=7.010 ac 5.14% Impervious Runoff Depth=2.35" Tc=15.2 min CN=72 Runoff=20.93 cfs 1.375 of Link 22L: POA 5 Inflow=29.91 cfs 2.076 of Primary=29.91 cfs 2.076 of ON PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 17 Summary for Subcatchment 1S: ONSITE TO Pond 1 Runoff = 7.56 cfs @ 11.99 hrs, Volume= 0.391 af, Depth= 3.45" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.290 61 >75% Grass cover, Good, HSG B 0.460 80 >75% Grass cover, Good, HSG D 0.110 98 Paved parking, HSG B 0.500 98 Paved parking, HSG D 1.360 84 Weighted Average 0.750 55.15% Pervious Area 0.610 44.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.7 Direct Entry, Summary for Subcatchment 2S: OFFSITE TO Pond 1 Runoff = 24.74 cfs @ 12.11 hrs, Volume= 1.757 af, Depth= 2.35" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN 0.120 55 Woods, Good, HSG B 2.520 77 Woods, Good, HSG D 3.370 61 >75% Grass cover, Good, HSG B 2.550 80 >75% Grass cover, Good, HSG D 0.400 98 Paved Darkina. HSG B 8.960 72 Weighted Average 8.560 95.54% Pervious Area 0.400 4.46% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 17.8 Direct Entry, 38 PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 18 Summary for Pond 3P: Detention Pond 1 Inflow Area = 10.320 ac, 9.79% Impervious, Inflow Depth = 2.50" for 10-YR event Inflow = 28.61 cfs @ 12.07 hrs, Volume= 2.148 of Outflow = 28.20 cfs @ 12.11 hrs, Volume= 2.148 af, Atten= 1%, Lag= 2.0 min Primary = 28.20 cfs @ 12.11 hrs, Volume= 2.148 of Routing by Dyn-Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 312.63' @ 12.11 hrs Surf.Area= 4,852 sf Storage= 11,969 cf Plug -Flow detention time= 28.3 min calculated for 2.145 of (100% of inflow) Center -of -Mass det. time= 28.5 min ( 869.3 - 840.8) Volume Invert Avail.Storage Storage Description #1 309.00' 19,302 cf Detention Pond Storage (Prismatic) Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic -feet) (cubic -feet) 309.00 710 0.0 0 0 309.49 710 40.0 139 139 309.50 2,430 100.0 16 155 310.00 3,120 100.0 1,388 1,542 312.00 4,400 100.0 7,520 9,062 314.00 5,840 100.0 10,240 19,302 Device Routina Invert Outlet Devices #1 Primary 309.00' 30.0" Round 30" RCP L= 60.0' Ke= 0.200 Inlet / Outlet Invert= 309.00' / 308.00' S= 0.0167'/' Cc= 0.900 n= 0.013 #2 Device 1 309.00' 6.0" Round underdrain L= 60.0' Ke= 0.900 Inlet / Outlet Invert= 309.00' / 309.00' S= 0.0000 7' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #3 Device 1 310.00' 1.0' long Sharp -Crested Rectangular Weir 2 End Contraction(s) #4 Device 1 312.00' 48.0" Horiz. standpipe rim C= 0.600 Limited to weir flow at low heads #5 Primary 313.00' 4.0' long x 20.0' breadth Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max=27.99 cfs @ 12.11 hrs HW=312.62' TW=0.00' (Dynamic Tailwater) 1-30" RCP (Passes 27.99 cfs of 43.33 cfs potential flow) 2=underdrain (Barrel Controls 0.77 cfs @ 3.91 fps) 3=Sharp-Crested Rectangular Weir (Weir Controls 6.95 cfs @ 5.30 fps) =standpipe rim (Weir Controls 20.27 cfs @ 2.58 fps) =Emergency Spillway ( Controls 0.00 cfs) M PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 4S: ONSITE UNMANAGED TO POA 1 Runoff = 0.95 cfs @ 11.96 hrs, Volume= 0.044 af, Depth= 2.02" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.170 61 >75% Grass cover, Good, HSG B 0.090 80 >75% Grass cover, Good, HSG D 0.260 68 Weighted Average 0.260 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 5L: POA 1 Inflow Area = 10.580 ac, 9.55% Impervious, Inflow Depth = 2.49" for 10-YR event Inflow = 28.42 cfs @ 12.10 hrs, Volume= 2.192 of Primary = 28.42 cfs @ 12.10 hrs, Volume= 2.192 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs 100-YR Fixed water surface Elevation= 309.10' Summary for Subcatchment 6S: ONSITE TO POA 2 Runoff = 0.39 cfs @ 11.97 hrs, Volume= 0.019 af, Depth= 1.49" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.150 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved Darkina. HSG B 0.150 61 Weighted Average 0.150 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Cro7 PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 7S: OFFSITE TO POA 2 Runoff = 104.26 cfs @ 12.19 hrs, Volume= 8.995 af, Depth= 2.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 8.050 55 Woods, Good, HSG B 21.130 77 Woods, Good, HSG D 14.170 61 >75% Grass cover, Good, HSG B 5.140 80 >75% Grass cover, Good, HSG D 0.890 98 Paved parking, HSG B 49.380 70 Weighted Average 48.490 98.20% Pervious Area 0.890 1.80% Impervious Area Tc Length Slope Velocity Capacity Description 24.4 Direct Entry, Summary for Link 8L: POA 2 Inflow Area = 60.110 ac, 3.16% Impervious, Inflow Depth = 2.24" for 10-YR event Inflow = 129.93 cfs @ 12.17 hrs, Volume= 11.205 of Primary = 129.93 cfs @ 12.17 hrs, Volume= 11.205 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Summary for Pond 9P: Ex. Wet Pond Inflow Area = 60.110 ac, 3.16% Impervious, Inflow Depth = 2.24" for 10-YR event Inflow = 129.93 cfs @ 12.17 hrs, Volume= 11.205 of Outflow = 129.93 cfs @ 12.17 hrs, Volume= 11.205 af, Atten= 0%, Lag= 0.0 min Primary = 129.93 cfs @ 12.17 hrs, Volume= 11.205 of Routing by Dyn-Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 308.39' @ 12.17 hrs Device Routing Invert Outlet Devices #1 Primary 306.00' 10.0' long x 10.0' breadth Broad -Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Primary 308.00' 50.0' long x 15.0' breadth Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 41 PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 21 Primary OutFlow Max=128.61 cfs @ 12.17 hrs HW=308.38' TW=0.00' (Dynamic Tailwater) �1=Broad-Crested Rectangular Weir (Weir Controls 96.96 cfs @ 4.07 fps) 2=Emergency Spillway (Weir Controls 31.65 cfs @ 1.66 fps) Summary for Subcatchment 10S: ONSITE FAR TO POND 2 VIA "C" PIPES. VOLUME TO POA 3 Volume from this area Calculated as routed to POA 3 Runoff = 9.80 cfs @ 12.00 hrs, Volume= 0.499 af, Depth= 2.52" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.550 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.820 98 Paved parking, HSG B 0.000 98 Paved oarkina. HSG D 2.370 74 Weighted Average 1.550 65.40% Pervious Area 0.820 34.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, Summary for Subcatchment 11 S: OFFSITE TO POND 2. VOLUME TO POA 3 Volume from this area Calculated as routed to PGA 3 Runoff = 2.36 cfs @ 12.05 hrs, Volume= 0.146 af, Depth= 1.28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.780 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.590 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 1.370 58 Weighted Average 1.370 100.00% Pervious Area EIN PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 22 Tc Length Slope Velocity Capacity Description 11.2 Direct Entry, Summary for Subcatchment 12S: ONSITE TO POND 2 VIA "D" PIPES. VOLUME TO POA 5 Volume from this area Calculated as routed to POA 5 Runoff = 17.10 cfs @ 12.00 hrs, Volume= 0.877 af, Depth= 2.61" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 2.470 61 >75% Grass cover, Good, HSG B 0.110 80 >75% Grass cover, Good, HSG D 1.420 98 Paved parking, HSG B 0.030 98 Paved Darkina. HSG D 4.030 75 Weighted Average 2.580 64.02% Pervious Area 1.450 35.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.2 Direct Entry, Summary for Subcatchment 13S: ONSITE CLOSE TO POND 2 VIA "C' PIPES. VOLUME TO POA 3 Volume from this area Calculated as routed to POA 3 Runoff = 7.69 cfs @ 11.97 hrs, Volume= 0.372 af, Depth= 2.61" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.040 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.670 98 Paved parking, HSG B 0.000 98 Paved parking, HSG D 1.710 75 Weighted Average 1.040 60.82% Pervious Area 0.670 39.18% Impervious Area 43 PostDev Bird St Postdev Type 1124-hr 10-YR Rainfall=5.20" Preoared by (enter vour comDanv name here) Printed 12/22/2022 Tc Length Slope Velocity Capacity Description 6.0 Direct Entry, Summary for Pond 14P: Detention Pond 2 Since Pond 2 has two spillways which discharge a mixed flow regime discharging to both POA 3 and POA 5, with mixed offsite and inflow runoffs, we have calulated that the runoff volume from each barrel is dictated by the runoff of the drainage system closest to each spillway system. The "C" storm sewer collection system discharges into the pond close to the riser which outlets to POA 3. Thus, for regulatory volume calculations, the runoff volume from 105, 11S, & 13S is assumed to discharge to POA 3. Similarly, since the "D" system storm sewer collection system discharges into the pond close to the riser which outlets to POA 5. Thus, for regulatory volume calculations, the runoff volume from 12S is assumed to discharge to POA 5. Inflow Area = 9.480 ac, 31.01% Impervious, Inflow Depth = 2.40" for 10-YR event Inflow = 36.46 cfs @ 11.99 hrs, Volume= 1.894 of Outflow = 19.46 cfs @ 12.11 hrs, Volume= 1.894 af, Atten= 47%, Lag= 7.0 min Primary = 10.27 cfs @ 12.11 hrs, Volume= 1.214 of Secondary = 9.19 cfs @ 12.11 hrs, Volume= 0.680 of Routing by Dyn-Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 286.29' @ 12.11 hrs Surf.Area= 13,901 sf Storage= 27,977 cf Plug -Flow detention time= 168.8 min calculated for 1.894 of (100% of inflow) Center -of -Mass det. time= 168.5 min ( 1,004.3 - 835.8) Volume Invert Avail.Storage Storage Description #1 283.20' 74,244 cf Detention Pond Storage (Prismatic) Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) M (cubic -feet) (cubic -feet) 283.20 1,900 0.0 0 0 283.70 1,900 40.0 380 380 284.00 8,840 100.0 1,611 1,991 286.00 13,230 100.0 22,070 24,061 288.00 17,875 100.0 31,105 55,166 289.00 20,280 100.0 19,078 74,244 C!I PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 24 Device Routing Invert Outlet Devices #1 Primary 279.00' 30.0" Round 30" HDPE TO POA 3 L= 70.0' Ke= 0.200 Inlet / Outlet Invert= 279.00' / 276.50' S= 0.0357'/' Cc= 0.900 n= 0.012 #2 Secondary 283.50' 24.0" Round 24" RCP TO POA 5 L= 60.0' Ke= 0.200 Inlet / Outlet Invert= 283.50' / 282.80' S= 0.0117 7' Cc= 0.900 n= 0.013 #3 Device 1 283.20' 6.0" Round 6" Perf. Underdrain POA 3 L= 180.0' Ke= 0.900 Inlet / Outlet Invert= 283.20' / 282.00' S= 0.0067'/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #4 Device 2 284.30' 2.0" W x 3.0" H Vert. 1 yr 2x3 Orifice POA 5 C= 0.600 #5 Device 1 285.10' 18.0" Vert. 18" Orifice POA 3 C= 0.600 #6 Device 2 285.10' 18.0" Vert. 18" Orifice POA 5 C= 0.600 #7 Device 1 286.10' 60.0" Horiz. 60" Standpipe Rim POA 3 C= 0.600 Limited to weir flow at low heads #8 Device 2 286.10' 48.0" Horiz. 48" Standpipe Rim POA 5 C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=9.85 cfs @ 12.11 hrs HW=286.28' TW=0.00' (Dynamic Tailwater) t1=30" HDPE TO POA 3 (Passes 9.85 cfs of 72.53 cfs potential flow) 3=6" Perf. Underdrain POA 3 (Barrel Controls 0.51 cfs @ 2.61 fps) =18" Orifice POA 3 (Orifice Controls 5.50 cfs @ 3.69 fps) 7=60" Standpipe Rim POA 3 (Weir Controls 3.84 cfs @ 1.38 fps) Secondary OutFlow Max=8.84 cfs @ 12.11 hrs HW=286.28' TW=0.00' (Dynamic Tailwater) 1--2=24" RCP TO POA 5 (Passes 8.84 cfs of 21.96 cfs potential flow) 1 yr 2x3 Orifice POA 5 (Orifice Controls 0.27 cfs @ 6.55 fps) =18" Orifice POA 5 (Orifice Controls 5.50 cfs @ 3.69 fps) 8=48" Standpipe Rim POA 5 (Weir Controls 3.07 cfs @ 1.38 fps) Summary for Subcatchment 15S: ONSITE UNMANAGED TO POA 3 Runoff = 0.62 cfs @ 11.99 hrs, Volume= 0.031 af, Depth= 1.28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.290 58 Meadow. non-arazed. HSG B 0.290 100.00% Pervious Area Tc Length Slope Velocity Capacity Description 6.1 Direct Entry, 01 PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 25 Summary for Link 16L: POA 3 Inflow Area = 69.880 ac, 6.93% Impervious, Inflow Depth = 2.14" for 10-YR event Inflow = 138.15 cfs @ 12.16 hrs, Volume= 12.450 of Primary = 138.15 cfs @ 12.16 hrs, Volume= 12.450 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs 100-YR Fixed water surface Elevation= 286.90' Summary for Subcatchment 17S: ONSITE TO POA 4 Runoff = 0.76 cfs @ 11.98 hrs, Volume= 0.037 af, Depth= 1.49" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.300 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 0.300 61 Weighted Average 0.300 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.2 Direct Entry, Summary for Subcatchment 18S: OFFSITE TO POA 4 Runoff = 4.50 cfs @ 11.98 hrs, Volume= 0.220 af, Depth= 1.56" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Description 0.540 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.030 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.120 98 Paved parking, HSG B 1.690 62 Weighted Average 1.570 92.90% Pervious Area 0.120 7.10% Impervious Area CS7 PostDev Bird St Postdev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 26 Tc Length 6.2 Description Direct Entry, Summary for Link 19L: POA 4 Inflow Area = 71.870 ac, 6.90% Impervious, Inflow Depth = 2.12" for 10-YR event Inflow = 139.26 cfs @ 12.16 hrs, Volume= 12.707 of Primary = 139.26 cfs @ 12.16 hrs, Volume= 12.707 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Summary for Subcatchment 20S: ONSITE UNMANAGED TO POA 5 Runoff = 0.43 cfs @ 11.98 hrs, Volume= 0.021 af, Depth= 1.49" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Descriotion 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.170 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 0.170 61 Weighted Average 0.170 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.1 Direct Entry, Summary for Subcatchment 21 S: OFFSITE UNMANAGED TO POA 5 Runoff = 20.93 cfs @ 12.08 hrs, Volume= 1.375 af, Depth= 2.35" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.20" Area (ac) CN Descriotion 0.330 55 Woods, Good, HSG B 1.430 77 Woods, Good, HSG D 2.470 61 >75% Grass cover, Good, HSG B 2.420 80 >75% Grass cover, Good, HSG D 0.300 98 Paved parking, HSG B 0.060 98 Paved Darkina. HSG D 7.010 72 Weighted Average 6.650 94.86% Pervious Area 0.360 5.14% Impervious Area CS1 Bird St Postdev name Tc Length Slope Velocity Capacity Description (min) (feet) (ft/f0 (ft/sec) (cfs) 15.2 Direct Entry, PostDev Type 1124-hr 10-YR Rainfall=5.20" Printed 12/22/2022 Summary for Link 22L: POA 5 Inflow Area = 7.180 ac, 5.01% Impervious, Inflow Depth = 3.47" for 10-YR event Inflow = 29.91 cfs @ 12.10 hrs, Volume= 2.076 of Primary = 29.91 cfs @ 12.10 hrs, Volume= 2.076 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs 100-YR Fixed water surface Elevation= 286.80' starting at To= 1.00 hrs Cfl PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 28 Time span=5.00-40.00 hrs, dt=0.05 hrs, 701 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1S: ONSITE TO Pond 1 Runoff Area=1.360 ac 44.85% Impervious Runoff Depth>6.60" Tc=7.7 min CN=84 Runoff=13.94 cfs 0.748 of Subcatchment 2S: OFFSITE TO Pond 1 Runoff Area=8.960 ac 4.46% Impervious Runoff Depth=5.16" Tc=17.8 min CN=72 Runoff=54.50 cfs 3.855 of Pond 3P: Detention Pond 1 Peak EIev=313.60' Storage=17,001 cf Inflow=61.86 cfs 4.602 of Outflow=57.26 cfs 4.602 of Subcatchment 4S: ONSITE UNMANAGED Runoff Area=0.260 ac 0.00% Impervious Runoff Depth=4.68" Tc=5.0 min CN=68 Runoff=2.18 cfs 0.101 of Link 5L: POA 1 Inflow=57.66 cfs 4.703 of Primary=57.66 cfs 4.703 of Subcatchment 6S: ONSITE TO POA 2 Runoff Area=0.150 ac 0.00% Impervious Runoff Depth=3.85" Tc=5.0 min CN=61 Runoff=1.04 cfs 0.048 of Subcatchment 7S: OFFSITE TO POA 2 Runoff Area=49.380 ac 1.80% Impervious Runoff Depth=4.92" Tc=24.4 min CN=70 Runoff=239.46 cfs 20.258 of Link 8L: POA 2 Inflow=296.35 cfs 25.010 of Primary=296.35 cfs 25.010 of Pond 9P: Ex. Wet Pond Peak EIev=309.10' Inflow=296.35 cfs 25.010 of Outflow=296.35 cfs 25.010 of Subcatchment 10S: ONSITE FAR TO POND Runoff Area=2.370 ac 34.60% Impervious Runoff Depth=5.40" Tc=8.0 min CN=74 Runoff=20.57 cfs 1.067 of Subcatchment 11S: OFFSITE TO POND 2. Runoff Area=1.370 ac 0.00% Impervious Runoff Depth=3.50" Tc=11.2 min CN=58 Runoff=6.95 cfs 0.400 of Subcatchment 12S: ONSITE TO POND 2 Runoff Area=4.030 ac 35.98% Impervious Runoff Depth=5.52" Tc=8.2 min CN=75 Runoff=35.41 cfs 1.855 of Subcatchment 13S: ONSITE CLOSE TO Runoff Area=1.710 ac 39.18% Impervious Runoff Depth=5.52" Tc=6.0 min CN=75 Runoff=15.89 cfs 0.787 of Pond 14P: Detention Pond 2 Peak EIev=288.04' Storage=55,796 cf Inflow=77.78 cfs 4.108 of Primary=31.50 cfs 0.984 of Secondary=20.09 cfs 2.312 of Outflow=51.59 cfs 3.296 of Subcatchment 15S: ONSITE UNMANAGED Runoff Area=0.290 ac 0.00% Impervious Runoff Depth=3.50" Tc=6.1 min CN=58 Runoff=1.76 cfs 0.085 of Link 16L: POA 3 Inflow=323.95 cfs 26.078 of Primary=323.95 cfs 26.078 of «: PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 29 Subcatchment 17S: ONSITE TO POA 4 Runoff Area=0.300 ac 0.00% Impervious Runoff Depth=3.85" Tc=6.2 min CN=61 Runoff=2.00 cfs 0.096 of Subcatchment 18S: OFFSITE TO POA 4 Runoff Area=1.690 ac 7.10% Impervious Runoff Depth=3.97" Tc=6.2 min CN=62 Runoff=11.62 cfs 0.559 of Link 19L: POA 4 Inflow=326.58 cfs 26.734 of Primary=326.58 cfs 26.734 of Subcatchment 20S: ONSITE UNMANAGED Runoff Area=0.170 ac 0.00% Impervious Runoff Depth=3.85" Tc=6.1 min CN=61 Runoff=1.14 cfs 0.055 of Subcatchment 21S: OFFSITE UNMANAGED Runoff Area=7.010 ac 5.14% Impervious Runoff Depth=5.16" Tc=15.2 min CN=72 Runoff=46.01 cfs 3.016 of Link 22L: POA 5 Inflow=66.67 cfs 5.382 of Primary=66.67 cfs 5.382 of *1 PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment 1S: ONSITE TO Pond 1 Runoff = 13.94 cfs @ 11.99 hrs, Volume= 0.748 af, Depth> 6.60" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.290 61 >75% Grass cover, Good, HSG B 0.460 80 >75% Grass cover, Good, HSG D 0.110 98 Paved parking, HSG B 0.500 98 Paved parking, HSG D 1.360 84 Weighted Average 0.750 55.15% Pervious Area 0.610 44.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.7 Direct Entry, Summary for Subcatchment 2S: OFFSITE TO Pond 1 Runoff = 54.50 cfs @ 12.10 hrs, Volume= 3.855 af, Depth= 5.16" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN 0.120 55 Woods, Good, HSG B 2.520 77 Woods, Good, HSG D 3.370 61 >75% Grass cover, Good, HSG B 2.550 80 >75% Grass cover, Good, HSG D 0.400 98 Paved Darkina. HSG B 8.960 72 Weighted Average 8.560 95.54% Pervious Area 0.400 4.46% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 17.8 Direct Entry, 51 PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 31 Summary for Pond 3P: Detention Pond 1 Inflow Area = 10.320 ac, 9.79% Impervious, Inflow Depth > 5.35" for 100-YR event Inflow = 61.86 cfs @ 12.07 hrs, Volume= 4.602 of Outflow = 57.26 cfs @ 12.13 hrs, Volume= 4.602 af, Atten= 7%, Lag= 3.7 min Primary = 57.26 cfs @ 12.13 hrs, Volume= 4.602 of Routing by Dyn-Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 313.60' @ 12.13 hrs Surf.Area= 5,549 sf Storage= 17,001 cf Plug -Flow detention time= 20.0 min calculated for 4.601 of (100% of inflow) Center -of -Mass det. time= 19.8 min ( 839.7 - 819.9) Volume Invert Avail.Storage Storage Description #1 309.00' 19,302 cf Detention Pond Storage (Prismatic) Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic -feet) (cubic -feet) 309.00 710 0.0 0 0 309.49 710 40.0 139 139 309.50 2,430 100.0 16 155 310.00 3,120 100.0 1,388 1,542 312.00 4,400 100.0 7,520 9,062 314.00 5,840 100.0 10,240 19,302 Device Routina Invert Outlet Devices #1 Primary 309.00' 30.0" Round 30" RCP L= 60.0' Ke= 0.200 Inlet / Outlet Invert= 309.00' / 308.00' S= 0.0167'/' Cc= 0.900 n= 0.013 #2 Device 1 309.00' 6.0" Round underdrain L= 60.0' Ke= 0.900 Inlet / Outlet Invert= 309.00' / 309.00' S= 0.0000 7' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #3 Device 1 310.00' 1.0' long Sharp -Crested Rectangular Weir 2 End Contraction(s) #4 Device 1 312.00' 48.0" Horiz. standpipe rim C= 0.600 Limited to weir flow at low heads #5 Primary 313.00' 4.0' long x 20.0' breadth Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max=56.80 cfs @ 12.13 hrs HW=313.57' TW=309.10' (Dynamic Tailwater) 1-30" RCP (Barrel Controls 52.12 cfs @ 10.62 fps) 2=underdrain (Passes < 0.88 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Passes < 11.04 cfs potential flow) =standpipe rim (Passes < 75.88 cfs potential flow) =Emergency Spillway (Weir Controls 4.68 cfs @ 2.04 fps) M PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment 4S: ONSITE UNMANAGED TO POA 1 Runoff = 2.18 cfs @ 11.96 hrs, Volume= 0.101 af, Depth= 4.68" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Description 0.170 61 >75% Grass cover, Good, HSG B 0.090 80 >75% Grass cover, Good, HSG D 0.260 68 Weighted Average 0.260 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 5L: POA 1 Inflow Area = 10.580 ac, 9.55% Impervious, Inflow Depth = 5.33" for 100-YR event Inflow = 57.66 cfs @ 12.13 hrs, Volume= 4.703 of Primary = 57.66 cfs @ 12.13 hrs, Volume= 4.703 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs 100-YR Fixed water surface Elevation= 309.10' Summary for Subcatchment 6S: ONSITE TO POA 2 Runoff = 1.04 cfs @ 11.96 hrs, Volume= 0.048 af, Depth= 3.85" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.150 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved Darkina. HSG B 0.150 61 Weighted Average 0.150 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, 53 PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment 7S: OFFSITE TO POA 2 Runoff = 239.46 cfs @ 12.18 hrs, Volume= 20.258 af, Depth= 4.92" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Description 8.050 55 Woods, Good, HSG B 21.130 77 Woods, Good, HSG D 14.170 61 >75% Grass cover, Good, HSG B 5.140 80 >75% Grass cover, Good, HSG D 0.890 98 Paved parking, HSG B 49.380 70 Weighted Average 48.490 98.20% Pervious Area 0.890 1.80% Impervious Area Tc Length Slope Velocity Capacity Description 24.4 Direct Entry, Summary for Link 8L: POA 2 Inflow Area = 60.110 ac, 3.16% Impervious, Inflow Depth = 4.99" for 100-YR event Inflow = 296.35 cfs @ 12.17 hrs, Volume= 25.010 of Primary = 296.35 cfs @ 12.17 hrs, Volume= 25.01Oaf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Summary for Pond 9P: Ex. Wet Pond Inflow Area = 60.110 ac, 3.16% Impervious, Inflow Depth = 4.99" for 100-YR event Inflow = 296.35 cfs @ 12.17 hrs, Volume= 25.010 of Outflow = 296.35 cfs @ 12.17 hrs, Volume= 25.01Oaf, Atten= 0%, Lag= 0.0 min Primary = 296.35 cfs @ 12.17 hrs, Volume= 25.010 of Routing by Dyn-Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 309.10' @ 12.17 hrs Device Routing Invert Outlet Devices #1 Primary 306.00' 10.0' long x 10.0' breadth Broad -Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Primary 308.00' 50.0' long x 15.0' breadth Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 54 PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 34 Primary OutFlow Max=293.42 cfs @ 12.17 hrs HW=309.09' TW=286.90' (Dynamic Tailwater) �1=Broad-Crested Rectangular Weir (Weir Controls 143.43 cfs @ 4.64 fps) 2=Emergency Spillway (Weir Controls 149.99 cfs @ 2.75 fps) Summary for Subcatchment 10S: ONSITE FAR TO POND 2 VIA "C" PIPES. VOLUME TO POA 3 Volume from this area Calculated as routed to POA 3 Runoff = 20.57 cfs @ 11.99 hrs, Volume= 1.067 af, Depth= 5.40" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.550 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.820 98 Paved parking, HSG B 0.000 98 Paved oarkina. HSG D 2.370 74 Weighted Average 1.550 65.40% Pervious Area 0.820 34.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, Summary for Subcatchment 11 S: OFFSITE TO POND 2. VOLUME TO POA 3 Volume from this area Calculated as routed to PGA 3 Runoff = 6.95 cfs @ 12.04 hrs, Volume= 0.400 af, Depth= 3.50" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Description 0.780 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.590 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 1.370 58 Weighted Average 1.370 100.00% Pervious Area M PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 35 Tc Length Slope Velocity Capacity Description 11.2 Direct Entry, Summary for Subcatchment 12S: ONSITE TO POND 2 VIA "D" PIPES. VOLUME TO POA 5 Volume from this area Calculated as routed to POA 5 Runoff = 35.41 cfs @ 11.99 hrs, Volume= 1.855 af, Depth= 5.52" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 2.470 61 >75% Grass cover, Good, HSG B 0.110 80 >75% Grass cover, Good, HSG D 1.420 98 Paved parking, HSG B 0.030 98 Paved Darkina. HSG D 4.030 75 Weighted Average 2.580 64.02% Pervious Area 1.450 35.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.2 Direct Entry, Summary for Subcatchment 13S: ONSITE CLOSE TO POND 2 VIA "C' PIPES. VOLUME TO POA 3 Volume from this area Calculated as routed to POA 3 Runoff = 15.89 cfs @ 11.97 hrs, Volume= 0.787 af, Depth= 5.52" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.040 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.670 98 Paved parking, HSG B 0.000 98 Paved parking, HSG D 1.710 75 Weighted Average 1.040 60.82% Pervious Area 0.670 39.18% Impervious Area �1y PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Preoared by (enter vour comDanv name here) Printed 12/22/2022 Tc Length Slope Velocity Capacity Description 6.0 Direct Entry, Summary for Pond 14P: Detention Pond 2 Since Pond 2 has two spillways which discharge a mixed flow regime discharging to both POA 3 and POA 5, with mixed offsite and inflow runoffs, we have calulated that the runoff volume from each barrel is dictated by the runoff of the drainage system closest to each spillway system. The "C" storm sewer collection system discharges into the pond close to the riser which outlets to POA 3. Thus, for regulatory volume calculations, the runoff volume from 105, 11S, & 13S is assumed to discharge to POA 3. Similarly, since the "D" system storm sewer collection system discharges into the pond close to the riser which outlets to POA 5. Thus, for regulatory volume calculations, the runoff volume from 12S is assumed to discharge to POA 5. Inflow Area = 9.480 ac, 31.01% Impervious, Inflow Depth = 5.20" for 100-YR event Inflow = 77.78 cfs @ 11.99 hrs, Volume= 4.108 of Outflow = 51.59 cfs @ 12.07 hrs, Volume= 3.296 af, Atten= 34%, Lag= 5.0 min Primary = 31.50 cfs @ 12.07 hrs, Volume= 0.984 of Secondary = 20.09 cfs @ 12.07 hrs, Volume= 2.312 of Routing by Dyn-Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Peak Elev= 288.04' @ 12.07 hrs Surf.Area= 17,960 sf Storage= 55,796 cf Plug -Flow detention time= 122.4 min calculated for 3.296 of (80% of inflow) Center -of -Mass det. time= 40.1 min (854.4 - 814.3) Volume Invert Avail.Storage Storage Description #1 283.20' 74,244 cf Detention Pond Storage (Prismatic) Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) M (cubic -feet) (cubic -feet) 283.20 1,900 0.0 0 0 283.70 1,900 40.0 380 380 284.00 8,840 100.0 1,611 1,991 286.00 13,230 100.0 22,070 24,061 288.00 17,875 100.0 31,105 55,166 289.00 20,280 100.0 19,078 74,244 57 PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 37 Device Routing Invert Outlet Devices #1 Primary 279.00' 30.0" Round 30" HDPE TO POA 3 L= 70.0' Ke= 0.200 Inlet / Outlet Invert= 279.00' / 276.50' S= 0.0357'/' Cc= 0.900 n= 0.012 #2 Secondary 283.50' 24.0" Round 24" RCP TO POA 5 L= 60.0' Ke= 0.200 Inlet / Outlet Invert= 283.50' / 282.80' S= 0.0117 7' Cc= 0.900 n= 0.013 #3 Device 1 283.20' 6.0" Round 6" Perf. Underdrain POA 3 L= 180.0' Ke= 0.900 Inlet / Outlet Invert= 283.20' / 282.00' S= 0.0067'/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #4 Device 2 284.30' 2.0" W x 3.0" H Vert. 1 yr 2x3 Orifice POA 5 C= 0.600 #5 Device 1 285.10' 18.0" Vert. 18" Orifice POA 3 C= 0.600 #6 Device 2 285.10' 18.0" Vert. 18" Orifice POA 5 C= 0.600 #7 Device 1 286.10' 60.0" Horiz. 60" Standpipe Rim POA 3 C= 0.600 Limited to weir flow at low heads #8 Device 2 286.10' 48.0" Horiz. 48" Standpipe Rim POA 5 C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=31.09 cfs @ 12.07 hrs HW=288.01' TW=286.90' (Dynamic Tailwater) t1=30" HDPE TO POA 3 (Inlet Controls 31.09 cfs @ 6.33 fps) 3=6" Perf. Underdrain POA 3 (Passes < 0.28 cfs potential flow) =18" Orifice POA 3 (Passes < 8.95 cfs potential flow) 7=60" Standpipe Rim POA 3 (Passes < 99.49 cfs potential flow) Secondary OutFlow Max=19.85 cfs @ 12.07 hrs HW=288.01' TW=286.80' (Dynamic Tailwater) 1--2=24" RCP TO POA 5 (Outlet Controls 19.85 cfs @ 6.32 fps) 1 yr 2x3 Orifice POA 5 (Passes < 0.22 cfs potential flow) =18" Orifice POA 5 (Passes < 9.35 cfs potential flow) 8=48" Standpipe Rim POA 5 (Passes < 66.49 cfs potential flow) Summary for Subcatchment 15S: ONSITE UNMANAGED TO POA 3 Runoff = 1.76 cfs @ 11.98 hrs, Volume= 0.085 af, Depth= 3.50" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Description 0.290 58 Meadow. non-arazed. HSG B 0.290 100.00% Pervious Area Tc Length Slope Velocity Capacity Description 6.1 Direct Entry, 0.1 PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 38 Summary for Link 16L: POA 3 Inflow Area = 69.880 ac, 6.93% Impervious, Inflow Depth = 4.48" for 100-YR event Inflow = 323.95 cfs @ 12.16 hrs, Volume= 26.078 of Primary = 323.95 cfs @ 12.16 hrs, Volume= 26.078 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs 100-YR Fixed water surface Elevation= 286.90' Summary for Subcatchment 17S: ONSITE TO POA 4 Runoff = 2.00 cfs @ 11.98 hrs, Volume= 0.096 af, Depth= 3.85" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Description 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.300 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 0.300 61 Weighted Average 0.300 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.2 Direct Entry, Summary for Subcatchment 18S: OFFSITE TO POA 4 Runoff = 11.62 cfs @ 11.98 hrs, Volume= 0.559 af, Depth= 3.97" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Description 0.540 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 1.030 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.120 98 Paved parking, HSG B 1.690 62 Weighted Average 1.570 92.90% Pervious Area 0.120 7.10% Impervious Area *1 PostDev Bird St Postdev Type 1124-hr 100-YR Rainfall=8.53" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 39 Tc Length 6.2 Description Direct Entry, Summary for Link 19L: POA 4 Inflow Area = 71.870 ac, 6.90% Impervious, Inflow Depth = 4.46" for 100-YR event Inflow = 326.58 cfs @ 12.16 hrs, Volume= 26.734 of Primary = 326.58 cfs @ 12.16 hrs, Volume= 26.734 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Summary for Subcatchment 20S: ONSITE UNMANAGED TO POA 5 Runoff = 1.14 cfs @ 11.98 hrs, Volume= 0.055 af, Depth= 3.85" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Descriotion 0.000 55 Woods, Good, HSG B 0.000 77 Woods, Good, HSG D 0.170 61 >75% Grass cover, Good, HSG B 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Paved parking, HSG B 0.170 61 Weighted Average 0.170 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.1 Direct Entry, Summary for Subcatchment 21 S: OFFSITE UNMANAGED TO POA 5 Runoff = 46.01 cfs @ 12.07 hrs, Volume= 3.016 af, Depth= 5.16" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs Type II 24-hr 100-YR Rainfall=8.53" Area (ac) CN Descriotion 0.330 55 Woods, Good, HSG B 1.430 77 Woods, Good, HSG D 2.470 61 >75% Grass cover, Good, HSG B 2.420 80 >75% Grass cover, Good, HSG D 0.300 98 Paved parking, HSG B 0.060 98 Paved Darkina. HSG D 7.010 72 Weighted Average 6.650 94.86% Pervious Area 0.360 5.14% Impervious Area :ru PostDev Bird St Postdev Type // 24-hr 100-YR Rainfall=8.53" Preoared by (enter vour comoanv name here) Printed 12/22/2022 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/f0 (ft/sec) (cfs) 15.2 Direct Entry, Summary for Link 22L: POA 5 Inflow Area = 7.180 ac, 5.01% Impervious, Inflow Depth = 9.00" for 100-YR event Inflow = 66.67 cfs @ 12.07 hrs, Volume= 5.382 of Primary = 66.67 cfs @ 12.07 hrs, Volume= 5.382 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs 100-YR Fixed water surface Elevation= 286.80' starting at To= 1.00 hrs 61 PreDev Bird St Predev Type //24-hr 10-YR Rainfall=5.20" Prepared by {enter your company name here} Printed 12/22/2022 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 15 Tc Length Description 15.2 Direct Entry, Summary for Link 14L: POA 5 Inflow Area = 11.150 ac, 4.04% Impervious, Inflow Depth = 2.02" for 10-YR event Inflow = 28.72 cfs @ 12.07 hrs, Volume= 1.877 of Primary = 28.72 cfs @ 12.07 hrs, Volume= 1.877 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-40.00 hrs, dt= 0.05 hrs :�a Chapter 8 - Culverts Appendix 8C-2 Inlet Control, Circular Corrugated Metal OCHART 2 eo w,000 16B (I) 8,000 EXAMPLE 136 6,000 one incM.1l.a r..tl B (2) 3,000 o•aacr. 3) la4 4,000 s. 6. Prr Irw q 2 s 3.000 D (.«ry 6. 120 In I.a 5.4 , 2.000 4. 08 a 131 e.: 6.4 '0 in for 3. 4. a 86 1,000 3, r BOO 3. 64 w 600 Y 300 TY 400 — — — — / Y• 2. 300 u 60 200 Z c 64 v W 1.35 - MITERED POND OUTLET w CULVERTS < e0/ o 025=187 cfs2 / 60 0 1.0 =9 CFS EACH a 42 / a 70 0 0 / 40 w 1.0 r 36 30 NW ENTRANCE u w SCALE D TYPE .e ao 33 20 11) naa..n c .B .B SO Ixl wit vo t. W", a i ro .loP .B_ c 2T 10 PI holoclina a c T T B a w 24 T 6 21 3 T. or ..ot. IYI w PI P•.I.ct 4 ..riunHllr to .o.l. (I). IN. B .n tlni�llr ,ecll n.e lin rba.9lr .6 3 0 of o mero, .r rorvo .. .6 B ill.rr r.M1l. 2 3 3 1.0 .3 — I � 12 HEADWATER DEPTH FOR C. M. PIPE CULVERTS WITH INLET CONTROL BYwEPU OF PuauG X040! .lnw. I%! NOTE: RUNOFF FLOW "0" RESULTS FROM SCS TR-55 Source: HD S-5 CALCULATIONS. SINCE TWO (2) CULVERTS WILL BE USED, TOTAL FLOW IS DIVIDED IN HALF FOR THIS NOMOGRAPH. 1 of 1 VDOT Drainage Manual 63 Sediment Basin Design: Design Spreadsheet Design Nomographs UL BIRD ST SUBDIVISION SEDIMENT BASIN SPREADSHEET Orange cells need input, white cells are calculations. Basin BASIN B Step I: Preliminary Design Top of Dam 289.3 Downstream Toe of Dam 278.0 Barrel length (it) 70.0 Slope of principal spillway barrel (%) 3.6% Step 2, Calculate Runoff Rational Method Drainage Area (ac) 8.0 C 0.75 12 4.3 125 6.6 Q2 (cfs) 25.8 Qn (cfs) 39.6 Required Spillway Capacity with emergency spillway (cfs) 39.6 Step 3: Principal Spillway From Plate 3.14-8 Riser Diameter (in) 48 Actual head (ft) 1.20 Achieved Standpipe Capacity Q,�, mac (cfs) 51 Step 4: Emergency Spillway From Table 334-C Achieved Emerg. Spillway Capacity 0.0 Bp 0.0 b - Bottom width (ft) 0 S - slope of exit channel (% ftlfoot) 0.0% X - minimum length of exit channel (it) 0 Achieved Total Spillway Capacity (cfs) 51.0 Step 5: Basin Sizing Design Parameters Required Wet +Dry Storage (cy) 1,072 Wet Storage Required Volume (cy) 536.00 Required Volume (cf) 14,472 Minimum Standpipe Invert 268 Cleanout Required Volume (cy) Cleanout Max. Volume (cf) 402 Design Elevation Area (sf) 282.0 6,140 Bottom of Wet Storage 283.0 7,450 Cleanout Elevation 284.0 8,840 Top of Wet Storage 252 Cleanout Achieved Volume (cy) Wet Storage Achieved Volume (cf) 14,940 Wet Storage Achieved Volume (cy) 553.33 Usi Basin BASIN B Dry Storage Required Volume try) 536.00 14,472 Required Volume left Maximum Top of Dry Storage 286.1 Design Elevation Area (sf) 284.0 8,840 Bottom of Dry Storage 285.0 11,000 286.0 13,230 Top of Dry Storage 22,035 Dry Storage Achieved Volume (cf) Dry Storage Achieved Volume (cy) 816.11 Step 6: Final Details Upstream Toe of Dam 282.0 Permanent Riser (Principle Spillway) Elevation 286.1 Emergency Spillway Elevation - Max. 25-Yr WSE 287.3 Conversion to Permanent Pond Notes Remove dewatering orifice Trash rack and anti -vortex device sizing From Wle 3.1: ,. Diameter (in) 72 Height (in) ? 1 Barrel Design From Retention Basin Design and Plate 3.14-B (RCP): Head on barrel (ft) 8.3 Outlet Pipe diameter (in) 74 Qvta (max) 44.1) ¢watering Orifice Design Riser Height 4.0 It (ft) 1.0 Dry Storage let) 22,035 Q (cfs) 1.02 A (sf) 0.212 d (it) 0.52 Dewatering Orifice Diameter (in) 6 Flexible Tubing Diameter (in) 8 Baffles Required? YES Baffle Calculation Required L=q(2*A) 40.00 Length of Flow (L) (it) A (sf) ( Surface area of the Normal Pool) 8940.0 Effective Width (Wd = Area/Length 221.0 Req L=�(2*A) 133.0 Anti -Seep Collar Design From Plate 3.1442 Slope of upstream embankment (:1) 3.0 Saturated length of barrel 15 Number of collars required 1 Dimensions 4' x 4' 1992 3.14 000--- - -i: 7 -.7 - -1-77 -71 7; 800, Riser Inflow Curves 600---- Legend 500 Weir flow, Qw=9.739 D,H 3/2 4001-1- ............. Orifice flow, QO=3.782 D2rH 3C)o 1 tM so . .. .... .. . J 4 u 30. --------- - o C; -------------- I. ... .. .. .. .. ........... ... ..... . ....... i, 10 Source: USDA-SCS 1.2' Head Plate 3.14-8 PROJECT: JOHNSTON & CO. SELF STORAGE 67 TABLE 3.14-B PIPE FLOW CHART, n = 0.013 CA n CD FOR REINFORCED CONCAeTR PIPE INLET � � Ae 4 I(t � 0.65 AND ]0 FEET OF NEINPORCFD CONCRETE PIPE CONDUIT (full flow N a ^�^ b W 4. A eaeomedl Note correction fmtore for pipe lengths other than JO feet diameter of pipe in inches N. n Feet 12• 15^ 16• 21^ 24 30" 36^ 13" dB" 54^ 60" 66" J2" JB" 84^ 90" 96" 302" 1 3.22 S.N S. 13.8 26.0 38.6 53.8 A.b 91.5 119 MI6] 19' 229 264 302 342 3 6.55 7.69 11.7 16.7 23.5 36.8 54.6 76.0 301 129 161 197 236 278 324 374 427 483 3 5.57 9.42 16.1 20.4 27.5 95.0 66.9 93.1 124 159 198 291 289 311 397 458 523 592 b 6.93 10.9 16.6 23.5 31.8 52.0 ]].3 108 143 183 228 278 334 394 459 529 604 683 5 7.19 12.3 18.5 36.3 35.5 58.1 86.4 130 160 205 355 311 373 440 513 591 675 764 6 7.88 13.3 20.3 28.8 18.9 63.7 94.6 132 175 220 280 341 609 482 5-2 647 739 837 J 8.51 16.6 21.9 31.1 a�.O 68.8 102 192 189 242 303 368 441 521 607 699 798 904 8 9.10 15.6 23.5 33.3 66.9 73.5 109 152 202 359 333 394 472 557 685 748 854 966 9.65 16.3 24.9 35.3 47.7 78.0 116 161 314 275 342 418 500 590 688 793 905 1025 30 10.2 17.3 36.2 37.3 50.2 82.2 122 170 226 289 361 440 527 622 725 836 954 1080 11 10.7 18.0 27.5 39.0 52.7 86.3 128 176 237 300 379 462 553 653 761 e]] 1001 1133 12 11.1 18.9 28.7 90.8 55.0 90.1 139 186 297 317 395 482 57e 682 796 916 1045 1184 13 11.6 19.6 29.9 62.4 57.3 93.7 139 394 257 330 411 502 601 710 827 953 3088 3232 14 12.0 20.4 31.0 44.1 59.1 97.3 145 201 267 342 427 521 624 736 858 989 1139 127E 15 33.5 21.1 32.1 45.6 61.5 101 150 208 2]] 354 443 539 646 762 888 3029 1169 1323 16 12.9 21.8 33.2 47.1 63.5 104 155 215 286 366 457 557 667 ]8] 917 1057 1207 1367 17 13.3 22.4 34.2 48.5 65.5 107 159 222 394 377 471 579 688 812 996 1090 1249 1409 18 13.7 23.1 35.2 49.9 67.4 110 164 228 303 388 484 591 708 835 973 1121 1280 1450 19 19.0 23.7 36.1 51.3 69.2 113 168 236 311 399 497 607 737 858 1000 1152 1315 1489 20 14.6 26.3 37.1 53.6 71.0 116 173 260 319 409 510 623 746 880 1026 1182 1350 1528 21 14.7 24.9 38.0 53.9 73.8 119 1]] 246 327 419 523 638 764 902 1051 1211 1383 1566 32 15.1 25.5 18.9 55.2 74.5 122 181 252 335 929 535 653 782 933 1076 1240 1915 1603 23 15.4 26.1 39.8 56.5 76.2 125 186 258 342 439 567 668 800 944 1100 1268 1647 1639 24 15.8 26.7 60.6 57.7 77.8 127 189 261 350 448 559 682 817 964 1123 1295 1478 1679 25 16.1 37.3 41.5 58.9 79.9 13D 193 269 357 958 571 696 834 989 1147 1322 1509 17O8 26 16.6 2].] 62.3 60.0 83.0 133 197 274 364 967 582 710 850 3004 1169 1398 1539 1792 27 16.7 28.3 43.1 61.2 83.5 135 201 279 371 476 593 723 867 3023 1192 1373 1568 1]]5 28 17.0 28.8 63.9 62.3 84.1 138 209 385 378 489 604 ]3] 883 1041 1214 1399 1597 1808 29 17.3 29.3 66.7 63.4 85.5 140 208 290 384 493 615 750 898 1060 1235 1423 1625 1890 30 17.6 29.8 65.6 66.5 87.0 142 212 294 391 501 625 763 913 1078 1256 1448 1653 1871 feet Correction Factors For other Pipe Lengths 20 1.30 3.39 1.21 1.18 1.15 1.12 1.10 1.08 1.07 1.06 1.05 1.05 1.09 1.04 1.03 1.03 .03 30 1.22 1.18 1.15 3.13 1.12 1.09 1.08 1.06 1.05 1.05 1.09 1.06 1.03 1.03 1.03 1.0� 1.02 1.02 40 1.15 1.13 1.11 1.30 1.08 1.O7 1.05 1.05 1.04 1.03 1.O1 1.03 1.02 1.02 1.02 1.02 1.02 1.02 50 1.09 1.08 1.O7 1.06 1.05 1.O4 1.06 1.03 3.03 1.02 1.02 1.02 1.02 1.01 1.01 1.01 1.01 1.01 60 1.09 1.06 1.03 1.03 1.03 1.02 1.03 1.02 1.01 1.01 1.01 1.01 1.01 1.01 1.01 1.01 1.01 1.01 70 1.00 1.00 1.00 1.00 3.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 80 .% .97 .97 .97 .98 .98 .98 .99 .99 .99 .99 .99 .99 .99 .99 .99 .99 .99 90 .93 .94 .94 .95 .95 .96 .97 .97 .98 .98 .98 .98 .98 .99 .99 .99 .99 .99 300 .90 .91 .92 .93 .93 .95 .95 .96 .97 .97 .97 .98 .98 .98 .98 .98 .98 .99 120 .84 .86 .BJ .89 .90 .91 .93 .94 .96 .95 .96 .96 .96 .97 .97 .97 .97 .98 160 .80 .82 .8I .BS .86 .88 .90 .91 .92 .93 .94 .94 .95 .95 .% .96 .96 .97 160 .76 .]B .BO .82 .83 .86 .BB .89 .90 .91 .92 .93 .94 .99 .95 .95 .95 .96 1992 PROJECT: JOHNSTON & CO. SELF STORAGE 3.14 TABLE 3.14-D CONCENTRIC TRASH RACK AND ANTI -VORTEX DEVICE DESIGN TABLE Riser Cylinder Minimum Top Diam., Height, Minimum Size in. Diameter, Thickness, inches Support Bar Thickness Stiffener inches gage 12 18 16 6 #6 Rebar or 11/2 x 16 ga. 11/2 x 3/16 angle (F&C) 15 21 16 7 " 18 27 16 8 " 21 30 16 11 16 ga.(C), 14 ga.(F) 24 36 16 13 " 27 42 16 15 " 36 54 14 17 #8 Rebar 14 ga.(C), 12 ga.(F) 42 60 16 19 " " - 48 72 16 21 11/4" pipe or 1'/4 x 14 ga.(C), 10 11/4 x'/a angle ga.(F) 54 78 16 25 " " " " 60 90 14 29 11/2" pipe or 11/2 x 12 ga.(C), 8 - 11/s x 1/4 angle ga.(F) 66 96 14 33 2" pipe or 2 x 2 x 12 ga.(C), 8 2 x 2 x 1/4 3/16 angle ga.(F) angle w/stiffener 72 102 14 36 21/2 x 21/2 x '/4 angle 78 114 14 39 21/2" pipe or 2 x 2 x " '/4 angle 84 120 12 42 21/2" pipe or 21/2 x 21/2 x 21/2 x 21/2 x %angle 5/16 angle Note,: The criterion for sizing the cylinder is that the area between the inside of the cylinder and the outside of the riser is equal to or greater than the area inside the riser. Therefore, the above table is invalid for use with concrete pipe risers. Note2: Corrugation for 12"-36" pipe measures 22/a" x'/2"; for 42" -84" the corrugation measures 5" x 1" or 8" x 1". Note3: C = corrugated; F = flat. Source: Adapted from USDA-SCS and Carl M. Henshaw Drainage Products Information. III - 104 go Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report 70 3A G GPN 37 4743 N 3 Hydrologic Soil Group —Albemarle County, Virginia 3 ME570 719M n9wo 7200!0 M10 721170 72M3O 3A 480' N `a 'a V 0. c 4 a e i be valid aift`his 5 ° <3A 4743"N 710310 Mm nssso ]XL50 T 10 72D TN133 3 3 Nap Sole: 1:2,490 iFpri*W mA poft t (8.5' x 11') sleet N Meters S 70 ,40 2,0 AFeet o ,ao 200 mo wo Map prgation: Nkb Ngofor Correrwordinat s: WGS84 Edge C6: U,M Zone 17N WGS84 USDA Natural Resources Web Soil Survey 11/16/2022 72 Conservation Service National Cooperative Soil Survey Page 1 of 4 MAPLEGEND Area of Interest (AOI) Area of Interest (AD[) Soils Soil Rating Polygons 0 A Q AID Q B Q B/D o C 0 CID 0 D O Not rated or not available Soil Rating Lines ~ A ~ AID N B �y B/D N C N C/D N D 0 Not rated or not available Soil Rating Points A e AID ❑ B ❑ B/D Hydrologic Soil Group —Albemarle County, Virginia ❑ C p CID D 0 Not rated or not available Water Features Streams and Canals Transportation H Rails N Interstate Highways ,.� US Routes Major Roads Background . Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: 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 16, Aug 23, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: May 19, 2022—jut 1, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. tlSDA Natural Resources Web Soil Survey 11/16/2022 78 011111111111 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 51 D Bugley channery silt loam, 15 to 25 percent slopes D 3.6 19.8% 51E D 0.0 0.0% 53B Danripple loam, 2 to 7 percent slopes B 4.8 26.3% 62B Buffstat silt loam, 2 to 7 percent slopes B 3.2 17.7% 62C Buffstat silt loam, 7 to 15 percent slopes B 6.3 34.6% 91 Urban land 0.3 1.5% Totals for Area of Interest 18.2 100.0% Natural Resources Web Soil Survey 11/162022 Conservation Service National Cooperative Soil Survey Page 3 of 4 74 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 Specked Tie -break Rule: Higher Natural Resources Web Soil Survey 11/162022 Conservation Service National Cooperative Soil Survey Page 4 of 4 75 NOAA Atlas 14, Volume 2, Version 3 Location name: Scottsville, Virginia, USA' '°✓�'"* Latitude: 37.797°, Longitude:-78.5017° Elevation: 317.55 ft" i " source: ESRI Maps -source USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. Bonnin, 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 inchl Average recurrence interval (years) Duration ��� 10 25 50 100 200 500 1000 0.338 0.395 0.457 0.523 0.589 0.642 0.690 0.733 0.781 0.823 5-min (0.305-0.376) (0.356-0.439) (0.412-0.508) (0.470-0.580) (0.527-0.651) (0.573-0.710) (0.612-0.762) (0.646-0.810) (0.682-0.865) (0.713-0.913) 0.541 0.632 0.732 0.837 0.938 1.02 1.10 1.16 1.24 1.30 10 mi -n (0.487-0.600) (0.570-0.702) (0.659-0.813) (0.752-0.928) (0.840-1.04) (0.912-1.13) (0.973-1.21 ) ( 1.02-129 ) ( 1.08-1.37 ) ( 1.12-1.44 ) 0.676 0.794 0.926 1.06 1.19 1.30 1.39 1.47 1.55 1.63 15-min (0.608-0.751) (0.716-0.883) (0.834-1.03) (0.951-1A7) 1 (1.07-1.32) 1 (1.164.43) 11 (1.23-1.53) (1.29-1.62) (1.364.72) 0.926 1.10 1.32 1.53 1.76 1.95 2.12 2.28 2.47 2.63 30-min (0.834-1.03) (0.989-1.22) 1 (1.19-1.46) 1 (1.38-1.70) 1 (1.58-1.95) 1 (1.74-2.15) 11 (1.88-2.35) (2.01-2.52) (2.16-2.74) (2.28-2.92) 1.16 1.38 1.69 2.00 2.35 2.64 2.92 3.20 3.55 3.84 60-min (1 .04-1.28) (1.24-1.53) (1.52-1.87) 1 (1.80-2.21) (2.10-2.59) 1 (2.36-2.92) 11 (2.59-3.23) (2.82-3.54) (3.10-3.93) (3.33-4.27) 1.38 1.65 2.03 2.42 2.87 3.27 3.66 4.06 4.57 5.01 2-hr (1.23-1.56) (1.47-1.85) (1.80-2.28) (2.15-2.71) (2.54-3.21) (2.88-3.66) (3.20-4.09) (3.52-4.53) (3.92-5.11 ) ( 4.26-5.62 ) 1.50 F 3.97 4.39 4.95 5.43 3-hr 1 (1.59-2.02) (1.95-2.49) (2.32-2.96) (2.74-3.50) (3.10-3.99) (3.45-4.46) (3.79-4.94) (4.22-5.57) (4.59-6.12) 1.90 2.26 2.76 3.30 3.95 4.55 5.15 5.79 6.64 7.42 6-hr 1 ( .69-2.16) (2.00-2.57) (2.44-3.14) (2.91 $.74) (3.46-4.47) (3.96-5.14) (4.44-5.81) 6.70 (4.93-6.53) (5.58-7.50) (6.15-8.38 ) 2.37 2.81 3.45 4.14 5.02 5.85 7.63 8.93 10.2 12-hr (2.11-2.70) (2.50-3.21) (3.06-3.93) (3.66-4.72) 1 (4.39-5.69) 1 (5.07-6.61) 1 (5.74-7.56) 8.53 1 (6.45-8.60) 1 (7.4140.1) (8.28-11.5) 2.84 3.44 4.39 5.20 6.39 7.41 9.77 11.6 13.2 24-hr 2 ( .56-3.18) (3.10-3.85) (3.95-4.92) (4.66-5.81) (5.69-7.12) (6.56-8.24) (7.49-9.48) 9.61 (8.49-10.8) (9.94-12.8) ( 11.1-14.6) 3.33 4.04 5.13 6.03 7.34 8.43 10.9 12.7 14.3 2 day (3.01-3.71) (3.65-4.49) (4.63-5.70) (5.44-6.70) (6.57-8.13) (7.51-9.32) (8.50-10.6) (9.56-12.0) ( 11.1-14.1) ( 12.3-15.9 ) 3-day 3.55 (3.23-3.93) F 4.29 (3.91-4.76) 5.46 (4.95-6.04) 6.41 (5.81-7.08) 7.79 (7.02-8.60) 8.95 (8.02-9.86) 10.2 ) (9.07-11.2 ( 11.5 ) 10.2-12.7 ( 13.5 ) 11.8-14.9 ( 15.1 ) 13.1-16.7 3.76 4.55 5.78 6.79 8.25 9.47 10.8 12.2 14.2 16.0 4 (3.44-4.16) (4.16-5.03) 5.23 (5.27-6.37) 6.54 (6.18-7.47) 7.61 (7.47-9.06) 9.15 (8.5240.4) 10.4 (9.64-11.8) 11.8 ( 10.8-13.4) ( 12.545.7) ( 13.9-17.6 ) 4.35 13.2 15.3 17.1 7 day (4 .00-4.74) (4.82-5.71) 5.91 (6.01-7.13) (6.98-8.30) (8.34-9.96) (9.45-11.4 ) (10.6-12.8) 12.7 (11.8-14.4) ( 13.5-16.7) (14.9-18.7) 4.93 7.29 8.42 10.0 11.3 14.1 16.1 17.8 10-day (4 .55-5.34) (5.46-6.41) (6.74-7.90) (7.75-9.11) (9.17-10.8) (10.3-12.2) (11.5-13.7) (12.7-15.3) (14.4-17.5) (15.7-19.3) 9.40 10.7 12.4 13.8 6.52 7.78 15.1 16.5 18.4 19.9 20-day (6.10-7.01) (7.27-8.35) (8.77-10.1) (9.94-11.4) (11.5-13.3) (12.7-14.7) (14.0-16.2) 16.9 (15.2-17.8) (16.8-19.9) (18.0-21.5) 8.03 9.52 11.3 12.6 14.3 15.6 18.1 19.7 21.0 30-day (7 .54-8.56) (8.95-10.1) (10.6-12.0) (11.8-13.4) (13.4-15.2) (14.6-16.6) 1 (15.7-18.0) 1 (16.8-19.3) 1 (18.2-21.1) 1 (19.3-22.4) 10.1 11.9 13.9 15.4 17.3 18.7 20.1 21.4 23.1 24.3 45-day (9.48-10.7) (11.2-12.6) (13.1-14.7) (14.5-16.3) (16.3-18.3) 1 (17.649.8) 1 (18.8-21.3) 22.7 1 (20.0-22.7) 1 (21.4-24.5) 1 (22.5-25.9) 11.9 13.9 16.1 17.7 19.7 21.2 24.0 25.7 27.0 60 day (11212.5) (13.2-14.7) (15.2-17.0) 1 (16.7-18.7) (18.6-20.8) (20.0-22.4) (21.3-24.0) (22.5-25.4) (24.0-27.3) j (25.1-28.6) 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 Atlas 14 document for more information. Back to Top PF graphical PDS-based depth -duration -frequency (DDF) curves Latitude: 37.79700, Longitude:-78.50170 25 c FIf a IN v O 15 i 2 10 5 711 .......... :............... :.... G C C G C >. T T A >. >. >. T T E E E L L L L t A -c A N M M -o m m m in N n5 vS n� a v v a M; v v v A o vi $ ^� A A r o 6 o uno a to Duration "0 25 5 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval (years) NOAA Atlas 14, Volume 2, Version 3 Created (GMT): Wed Nov 16 21:49:27 2022 Back to Top Maps & aerials Small scale terrain Average recurrence interval (years) — 1 2 5 10 — 25 50 100 200 500 — 1000 Duration — 5-min — 2-oay — 10inm — 3-day — 15-min — 4-day — 30-n1n — 7-day — 60-min — 10-day — 2-hr — 20-day — 3-hr — 30-day — Bfir — 45-day — 12-hr — 60-day — 24-hr F&A i. Scottsville Urn 2mi Large scale terrain \ Washington, D.C.'y' �At Harrisonburg. 5 taun ton VIRGINIA IA �•� Richmond � Lynchburg sburg 4 Roanoke ~ \ rl 1 mi .� Norfol 60mi Large scale map 0 © .4V. o ton ^r, 6rglnia Harrisonburg bL n u don Ilnla ' chmond ,Lynchburg Blacksburg ..Roanoke / Ofll �1�001km 66Omi Large scale aerial 78