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Arbor Cove Stormwater Management Report 3-10-14 STORMWATER MANAGEMENT FOR ARBOR COVE Chanhassen, Minnesota March 10, 2014 Otto Project No. 13-0545 Prepared for: Dogwood Road, LLC Prepared by: Otto Associates, Engineers & Land Surveyors, Inc. 9 West Division Street, Buffalo, MN 55313 • 763-682-4727 • Fax 763-682-3522 • www.ottoassociates.com SUMMARY Runoff (cfs) 2 Year 10 Year 100 Year Existing Runoff 6.69 14.14 24.59 Proposed Runoff 5.77 11.54 24.54 1S E1 3S E2 4S E3 2R Exist. Ditch 5R Exist. offsite Routing Diagram for 13-0545 EXIST Prepared by Otto Associates, Engineers & Land Surveyors, Inc., Printed 3/10/2014 HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Subcat Reach Pond Link Type II 24-hr 2 yr Rainfall=2.80"13-0545 EXIST Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 2HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: E1 Runoff=0.55 cfs @ 12.31 hrs, Volume=0.054 af, Depth>0.94" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2 yr Rainfall=2.80" Area (ac)CNDescription 0.69079Woods/grass comb., Good, HSG D 0.690100.00% Pervious Area TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 33.53000.07000.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 0.6600.10001.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 34.1360Total Summary for Subcatchment 3S: E2 Runoff=1.54 cfs @ 12.36 hrs, Volume=0.162 af, Depth>0.99" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2 yr Rainfall=2.80" Area (ac)CNDescription 1.76079Woods/grass comb., Good, HSG D 0.10098Unconnected roofs, HSG D 0.10080>75% Grass cover, Good, HSG D 1.96080Weighted Average 1.86094.90% Pervious Area 0.1005.10% Impervious Area 0.100100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 36.93000.05500.14 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 1.01100.14501.90 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 37.9410Total Summary for Subcatchment 4S: E3 Runoff=4.66 cfs @ 12.35 hrs, Volume=0.483 af, Depth>0.94" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2 yr Rainfall=2.80" Type II 24-hr 2 yr Rainfall=2.80"13-0545 EXIST Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 3HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Area (ac)CNDescription 4.33079Woods/grass comb., Good, HSG D 0.20098Unconnected roofs, HSG D 0.90080>75% Grass cover, Good, HSG D 0.50078Meadow, non-grazed, HSG D *0.27078Wetland 6.20080Weighted Average, UI Adjusted CN = 79 6.00096.77% Pervious Area 0.2003.23% Impervious Area 0.200100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 34.53000.06500.14 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 2.41500.04501.06 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 36.9450Total Summary for Reach 2R: Exist. Ditch Inflow Area =6.200 ac,3.23% Impervious, Inflow Depth > 0.94" for 2 yr event Inflow=4.66 cfs @ 12.35 hrs, Volume=0.483 af Outflow=4.62 cfs @ 12.38 hrs, Volume=0.482 af, Atten= 1%, Lag= 2.1 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 4.93 fps, Min. Travel Time= 1.2 min Avg. Velocity = 2.20 fps, Avg. Travel Time= 2.6 min Peak Storage= 330 cf @ 12.36 hrs Average Depth at Peak Storage= 0.32' Bank-Full Depth= 2.00' Flow Area= 16.0 sf, Capacity= 220.10 cfs 2.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 14.00' Length= 350.0' Slope= 0.0686 '/' Inlet Invert= 1,008.00', Outlet Invert= 984.00' Type II 24-hr 2 yr Rainfall=2.80"13-0545 EXIST Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 4HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Reach 5R: Exist. offsite Inflow Area =8.850 ac,3.39% Impervious, Inflow Depth > 0.95" for 2 yr event Inflow=6.69 cfs @ 12.37 hrs, Volume=0.698 af Outflow=6.69 cfs @ 12.37 hrs, Volume=0.698 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=4.20"13-0545 EXIST Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 5HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: E1 Runoff=1.16 cfs @ 12.30 hrs, Volume=0.111 af, Depth>1.94" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=4.20" Area (ac)CNDescription 0.69079Woods/grass comb., Good, HSG D 0.690100.00% Pervious Area TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 33.53000.07000.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 0.6600.10001.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 34.1360Total Summary for Subcatchment 3S: E2 Runoff=3.19 cfs @ 12.35 hrs, Volume=0.329 af, Depth>2.01" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=4.20" Area (ac)CNDescription 1.76079Woods/grass comb., Good, HSG D 0.10098Unconnected roofs, HSG D 0.10080>75% Grass cover, Good, HSG D 1.96080Weighted Average 1.86094.90% Pervious Area 0.1005.10% Impervious Area 0.100100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 36.93000.05500.14 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 1.01100.14501.90 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 37.9410Total Summary for Subcatchment 4S: E3 Runoff=9.87 cfs @ 12.33 hrs, Volume=1.001 af, Depth>1.94" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr Rainfall=4.20" Type II 24-hr 10 yr Rainfall=4.20"13-0545 EXIST Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 6HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Area (ac)CNDescription 4.33079Woods/grass comb., Good, HSG D 0.20098Unconnected roofs, HSG D 0.90080>75% Grass cover, Good, HSG D 0.50078Meadow, non-grazed, HSG D *0.27078Wetland 6.20080Weighted Average, UI Adjusted CN = 79 6.00096.77% Pervious Area 0.2003.23% Impervious Area 0.200100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 34.53000.06500.14 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 2.41500.04501.06 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 36.9450Total Summary for Reach 2R: Exist. Ditch Inflow Area =6.200 ac,3.23% Impervious, Inflow Depth > 1.94" for 10 yr event Inflow=9.87 cfs @ 12.33 hrs, Volume=1.001 af Outflow=9.83 cfs @ 12.36 hrs, Volume=0.999 af, Atten= 0%, Lag= 1.7 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 6.11 fps, Min. Travel Time= 1.0 min Avg. Velocity = 2.53 fps, Avg. Travel Time= 2.3 min Peak Storage= 565 cf @ 12.35 hrs Average Depth at Peak Storage= 0.47' Bank-Full Depth= 2.00' Flow Area= 16.0 sf, Capacity= 220.10 cfs 2.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 14.00' Length= 350.0' Slope= 0.0686 '/' Inlet Invert= 1,008.00', Outlet Invert= 984.00' Type II 24-hr 10 yr Rainfall=4.20"13-0545 EXIST Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 7HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Reach 5R: Exist. offsite Inflow Area =8.850 ac,3.39% Impervious, Inflow Depth > 1.95" for 10 yr event Inflow=14.14 cfs @ 12.35 hrs, Volume=1.439 af Outflow=14.14 cfs @ 12.35 hrs, Volume=1.439 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.00"13-0545 EXIST Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 8HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: E1 Runoff=2.02 cfs @ 12.29 hrs, Volume=0.195 af, Depth>3.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.00" Area (ac)CNDescription 0.69079Woods/grass comb., Good, HSG D 0.690100.00% Pervious Area TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 33.53000.07000.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 0.6600.10001.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 34.1360Total Summary for Subcatchment 3S: E2 Runoff=5.49 cfs @ 12.34 hrs, Volume=0.569 af, Depth>3.48" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.00" Area (ac)CNDescription 1.76079Woods/grass comb., Good, HSG D 0.10098Unconnected roofs, HSG D 0.10080>75% Grass cover, Good, HSG D 1.96080Weighted Average 1.86094.90% Pervious Area 0.1005.10% Impervious Area 0.100100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 36.93000.05500.14 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 1.01100.14501.90 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 37.9410Total Summary for Subcatchment 4S: E3 Runoff=17.21 cfs @ 12.33 hrs, Volume=1.748 af, Depth>3.38" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr Rainfall=6.00" Type II 24-hr 100 yr Rainfall=6.00"13-0545 EXIST Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 9HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Area (ac)CNDescription 4.33079Woods/grass comb., Good, HSG D 0.20098Unconnected roofs, HSG D 0.90080>75% Grass cover, Good, HSG D 0.50078Meadow, non-grazed, HSG D *0.27078Wetland 6.20080Weighted Average, UI Adjusted CN = 79 6.00096.77% Pervious Area 0.2003.23% Impervious Area 0.200100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 34.53000.06500.14 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 2.41500.04501.06 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 36.9450Total Summary for Reach 2R: Exist. Ditch Inflow Area =6.200 ac,3.23% Impervious, Inflow Depth > 3.38" for 100 yr event Inflow=17.21 cfs @ 12.33 hrs, Volume=1.748 af Outflow=17.13 cfs @ 12.35 hrs, Volume=1.746 af, Atten= 0%, Lag= 1.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 7.11 fps, Min. Travel Time= 0.8 min Avg. Velocity = 2.83 fps, Avg. Travel Time= 2.1 min Peak Storage= 846 cf @ 12.34 hrs Average Depth at Peak Storage= 0.62' Bank-Full Depth= 2.00' Flow Area= 16.0 sf, Capacity= 220.10 cfs 2.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 14.00' Length= 350.0' Slope= 0.0686 '/' Inlet Invert= 1,008.00', Outlet Invert= 984.00' Type II 24-hr 100 yr Rainfall=6.00"13-0545 EXIST Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 10HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Reach 5R: Exist. offsite Inflow Area =8.850 ac,3.39% Impervious, Inflow Depth > 3.40" for 100 yr event Inflow=24.59 cfs @ 12.34 hrs, Volume=2.509 af Outflow=24.59 cfs @ 12.34 hrs, Volume=2.509 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs 1S P1 2S P2 3S P3 5R Prop offsite 8R Ditch 2P Fil. Basin Routing Diagram for 13-0545 PROPOSED Prepared by Otto Associates, Engineers & Land Surveyors, Inc., Printed 3/10/2014 HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Subcat Reach Pond Link Type II 24-hr 2 yr Rainfall=2.80"13-0545 PROPOSED Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 2HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: P1 Runoff=4.62 cfs @ 12.34 hrs, Volume=0.534 af, Depth=1.04" Runoff by SCS TR-20 method, UH=SCS, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs Type II 24-hr 2 yr Rainfall=2.80" Area (ac)CNDescription 4.76079Woods/grass comb., Good, HSG D 0.20098Unconnected roofs, HSG D 0.40080>75% Grass cover, Good, HSG D 0.50078Meadow, non-grazed, HSG D *0.27078Veg. Wetland 6.13080Weighted Average, UI Adjusted CN = 79 5.93096.74% Pervious Area 0.2003.26% Impervious Area 0.200100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 34.53000.06500.14 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 2.41500.04501.06 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 36.9450Total Summary for Subcatchment 2S: P2 Runoff=0.23 cfs @ 12.21 hrs, Volume=0.026 af, Depth=0.45" Runoff by SCS TR-20 method, UH=SCS, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs Type II 24-hr 2 yr Rainfall=2.80" Area (ac)CNDescription 0.05058Woods/grass comb., Good, HSG B 0.20098Unconnected roofs, HSG B 0.45061>75% Grass cover, Good, HSG B 0.70071Weighted Average, UI Adjusted CN = 66 0.50071.43% Pervious Area 0.20028.57% Impervious Area 0.200100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 8.0400.04500.08 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 14.72300.04500.26 Sheet Flow, Grass: Short n= 0.150 P2= 2.80" 22.7270Total Type II 24-hr 2 yr Rainfall=2.80"13-0545 PROPOSED Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 3HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: P3 Runoff=2.71 cfs @ 12.14 hrs, Volume=0.206 af, Depth=1.22" Runoff by SCS TR-20 method, UH=SCS, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs Type II 24-hr 2 yr Rainfall=2.80" Area (ac)CNDescription 0.50098Unconnected roofs, HSG D 1.02080>75% Grass cover, Good, HSG D 0.50079Woods/grass comb., Good, HSG D 2.02084Weighted Average, UI Adjusted CN = 82 1.52075.25% Pervious Area 0.50024.75% Impervious Area 0.500100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 18.81350.06000.12 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 1.01700.03502.81 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.41600.10006.42 Shallow Concentrated Flow, Paved Kv= 20.3 fps 20.2465Total Summary for Reach 5R: Prop offsite [40] Hint: Not Described (Outflow=Inflow) Inflow Area =8.850 ac,10.17% Impervious, Inflow Depth = 1.04" for 2 yr event Inflow=5.77 cfs @ 12.35 hrs, Volume=0.766 af Outflow=5.77 cfs @ 12.35 hrs, Volume=0.766 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs / 3 Summary for Reach 8R: Ditch Inflow Area =6.130 ac,3.26% Impervious, Inflow Depth = 1.04" for 2 yr event Inflow=4.62 cfs @ 12.34 hrs, Volume=0.534 af Outflow=4.60 cfs @ 12.36 hrs, Volume=0.534 af, Atten= 0%, Lag= 1.0 min Routing by Dyn-Stor-Ind method, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs / 3 Max. Velocity= 4.69 fps, Min. Travel Time= 1.4 min Avg. Velocity = 1.81 fps, Avg. Travel Time= 3.7 min Peak Storage= 392 cf @ 12.36 hrs Average Depth at Peak Storage= 0.33' Bank-Full Depth= 2.00' Flow Area= 16.0 sf, Capacity= 205.89 cfs Type II 24-hr 2 yr Rainfall=2.80"13-0545 PROPOSED Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 4HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC 2.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 14.00' Length= 400.0' Slope= 0.0600 '/' Inlet Invert= 1,008.00', Outlet Invert= 984.00' Summary for Pond 2P: Fil. Basin Inflow Area =2.020 ac,24.75% Impervious, Inflow Depth = 1.22" for 2 yr event Inflow=2.71 cfs @ 12.14 hrs, Volume=0.206 af Outflow=1.00 cfs @ 11.99 hrs, Volume=0.206 af, Atten= 63%, Lag= 0.0 min Primary=1.00 cfs @ 11.99 hrs, Volume=0.206 af Routing by Dyn-Stor-Ind method, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 982.67' @ 12.43 hrs Surf.Area= 2,704 sf Storage= 1,664 cf Plug-Flow detention time= 8.8 min calculated for 0.206 af (100% of inflow) Center-of-Mass det. time= 8.8 min ( 861.6 - 852.8 ) VolumeInvertAvail.StorageStorage Description #1982.00'9,833 cf Custom Stage Data (Prismatic) Listed below (Recalc) ElevationSurf.AreaInc.StoreCum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 982.002,25000 984.003,6005,8505,850 985.004,3653,9839,833 DeviceRouting InvertOutlet Devices #1Primary978.50'15.0" Round Culvert L= 33.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 978.50' / 978.00' S= 0.0152 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2Device 1983.70'27.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3Device 1982.00'1.00 cfs Exfiltration at all elevations Phase-In= 0.01' Primary OutFlow Max=1.00 cfs @ 11.99 hrs HW=982.04' TW=0.00' (Dynamic Tailwater) 1=Culvert (Passes 1.00 cfs of 10.09 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Exfiltration (Exfiltration Controls 1.00 cfs) Type II 24-hr 10 yr Rainfall=4.20"13-0545 PROPOSED Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 5HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: P1 Runoff=9.81 cfs @ 12.34 hrs, Volume=1.087 af, Depth=2.13" Runoff by SCS TR-20 method, UH=SCS, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs Type II 24-hr 10 yr Rainfall=4.20" Area (ac)CNDescription 4.76079Woods/grass comb., Good, HSG D 0.20098Unconnected roofs, HSG D 0.40080>75% Grass cover, Good, HSG D 0.50078Meadow, non-grazed, HSG D *0.27078Veg. Wetland 6.13080Weighted Average, UI Adjusted CN = 79 5.93096.74% Pervious Area 0.2003.26% Impervious Area 0.200100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 34.53000.06500.14 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 2.41500.04501.06 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 36.9450Total Summary for Subcatchment 2S: P2 Runoff=0.80 cfs @ 12.18 hrs, Volume=0.070 af, Depth=1.21" Runoff by SCS TR-20 method, UH=SCS, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs Type II 24-hr 10 yr Rainfall=4.20" Area (ac)CNDescription 0.05058Woods/grass comb., Good, HSG B 0.20098Unconnected roofs, HSG B 0.45061>75% Grass cover, Good, HSG B 0.70071Weighted Average, UI Adjusted CN = 66 0.50071.43% Pervious Area 0.20028.57% Impervious Area 0.200100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 8.0400.04500.08 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 14.72300.04500.26 Sheet Flow, Grass: Short n= 0.150 P2= 2.80" 22.7270Total Type II 24-hr 10 yr Rainfall=4.20"13-0545 PROPOSED Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 6HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: P3 Runoff=5.31 cfs @ 12.13 hrs, Volume=0.400 af, Depth=2.37" Runoff by SCS TR-20 method, UH=SCS, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs Type II 24-hr 10 yr Rainfall=4.20" Area (ac)CNDescription 0.50098Unconnected roofs, HSG D 1.02080>75% Grass cover, Good, HSG D 0.50079Woods/grass comb., Good, HSG D 2.02084Weighted Average, UI Adjusted CN = 82 1.52075.25% Pervious Area 0.50024.75% Impervious Area 0.500100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 18.81350.06000.12 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 1.01700.03502.81 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.41600.10006.42 Shallow Concentrated Flow, Paved Kv= 20.3 fps 20.2465Total Summary for Reach 5R: Prop offsite [40] Hint: Not Described (Outflow=Inflow) Inflow Area =8.850 ac,10.17% Impervious, Inflow Depth = 2.11" for 10 yr event Inflow=11.54 cfs @ 12.39 hrs, Volume=1.557 af Outflow=11.54 cfs @ 12.39 hrs, Volume=1.557 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs / 3 Summary for Reach 8R: Ditch Inflow Area =6.130 ac,3.26% Impervious, Inflow Depth = 2.13" for 10 yr event Inflow=9.81 cfs @ 12.34 hrs, Volume=1.087 af Outflow=9.78 cfs @ 12.35 hrs, Volume=1.087 af, Atten= 0%, Lag= 0.6 min Routing by Dyn-Stor-Ind method, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs / 3 Max. Velocity= 5.81 fps, Min. Travel Time= 1.1 min Avg. Velocity = 2.13 fps, Avg. Travel Time= 3.1 min Peak Storage= 673 cf @ 12.35 hrs Average Depth at Peak Storage= 0.49' Bank-Full Depth= 2.00' Flow Area= 16.0 sf, Capacity= 205.89 cfs Type II 24-hr 10 yr Rainfall=4.20"13-0545 PROPOSED Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 7HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC 2.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 14.00' Length= 400.0' Slope= 0.0600 '/' Inlet Invert= 1,008.00', Outlet Invert= 984.00' Summary for Pond 2P: Fil. Basin Inflow Area =2.020 ac,24.75% Impervious, Inflow Depth = 2.37" for 10 yr event Inflow=5.31 cfs @ 12.13 hrs, Volume=0.400 af Outflow=1.68 cfs @ 12.46 hrs, Volume=0.400 af, Atten= 68%, Lag= 19.8 min Primary=1.68 cfs @ 12.46 hrs, Volume=0.400 af Routing by Dyn-Stor-Ind method, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 983.80' @ 12.46 hrs Surf.Area= 3,462 sf Storage= 5,128 cf Plug-Flow detention time= 30.8 min calculated for 0.400 af (100% of inflow) Center-of-Mass det. time= 30.8 min ( 864.6 - 833.8 ) VolumeInvertAvail.StorageStorage Description #1982.00'9,833 cf Custom Stage Data (Prismatic) Listed below (Recalc) ElevationSurf.AreaInc.StoreCum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 982.002,25000 984.003,6005,8505,850 985.004,3653,9839,833 DeviceRouting InvertOutlet Devices #1Primary978.50'15.0" Round Culvert L= 33.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 978.50' / 978.00' S= 0.0152 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2Device 1983.70'27.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3Device 1982.00'1.00 cfs Exfiltration at all elevations Phase-In= 0.01' Primary OutFlow Max=1.68 cfs @ 12.46 hrs HW=983.80' TW=0.00' (Dynamic Tailwater) 1=Culvert (Passes 1.68 cfs of 12.77 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.68 cfs @ 1.01 fps) 3=Exfiltration (Exfiltration Controls 1.00 cfs) Type II 24-hr 100 yr Rainfall=6.00"13-0545 PROPOSED Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 8HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: P1 Runoff=17.07 cfs @ 12.34 hrs, Volume=1.880 af, Depth=3.68" Runoff by SCS TR-20 method, UH=SCS, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs Type II 24-hr 100 yr Rainfall=6.00" Area (ac)CNDescription 4.76079Woods/grass comb., Good, HSG D 0.20098Unconnected roofs, HSG D 0.40080>75% Grass cover, Good, HSG D 0.50078Meadow, non-grazed, HSG D *0.27078Veg. Wetland 6.13080Weighted Average, UI Adjusted CN = 79 5.93096.74% Pervious Area 0.2003.26% Impervious Area 0.200100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 34.53000.06500.14 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 2.41500.04501.06 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 36.9450Total Summary for Subcatchment 2S: P2 Runoff=1.73 cfs @ 12.16 hrs, Volume=0.142 af, Depth=2.44" Runoff by SCS TR-20 method, UH=SCS, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs Type II 24-hr 100 yr Rainfall=6.00" Area (ac)CNDescription 0.05058Woods/grass comb., Good, HSG B 0.20098Unconnected roofs, HSG B 0.45061>75% Grass cover, Good, HSG B 0.70071Weighted Average, UI Adjusted CN = 66 0.50071.43% Pervious Area 0.20028.57% Impervious Area 0.200100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 8.0400.04500.08 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 14.72300.04500.26 Sheet Flow, Grass: Short n= 0.150 P2= 2.80" 22.7270Total Type II 24-hr 100 yr Rainfall=6.00"13-0545 PROPOSED Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 9HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: P3 Runoff=8.85 cfs @ 12.12 hrs, Volume=0.671 af, Depth=3.99" Runoff by SCS TR-20 method, UH=SCS, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs Type II 24-hr 100 yr Rainfall=6.00" Area (ac)CNDescription 0.50098Unconnected roofs, HSG D 1.02080>75% Grass cover, Good, HSG D 0.50079Woods/grass comb., Good, HSG D 2.02084Weighted Average, UI Adjusted CN = 82 1.52075.25% Pervious Area 0.50024.75% Impervious Area 0.500100.00% Unconnected TcLengthSlopeVelocityCapacityDescription (min)(feet)(ft/ft)(ft/sec)(cfs) 18.81350.06000.12 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 1.01700.03502.81 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.41600.10006.42 Shallow Concentrated Flow, Paved Kv= 20.3 fps 20.2465Total Summary for Reach 5R: Prop offsite [40] Hint: Not Described (Outflow=Inflow) Inflow Area =8.850 ac,10.17% Impervious, Inflow Depth = 3.65" for 100 yr event Inflow=24.54 cfs @ 12.27 hrs, Volume=2.693 af Outflow=24.54 cfs @ 12.27 hrs, Volume=2.693 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs / 3 Summary for Reach 8R: Ditch Inflow Area =6.130 ac,3.26% Impervious, Inflow Depth = 3.68" for 100 yr event Inflow=17.07 cfs @ 12.34 hrs, Volume=1.880 af Outflow=17.04 cfs @ 12.34 hrs, Volume=1.880 af, Atten= 0%, Lag= 0.3 min Routing by Dyn-Stor-Ind method, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs / 3 Max. Velocity= 6.76 fps, Min. Travel Time= 1.0 min Avg. Velocity = 2.41 fps, Avg. Travel Time= 2.8 min Peak Storage= 1,008 cf @ 12.34 hrs Average Depth at Peak Storage= 0.64' Bank-Full Depth= 2.00' Flow Area= 16.0 sf, Capacity= 205.89 cfs Type II 24-hr 100 yr Rainfall=6.00"13-0545 PROPOSED Printed 3/10/2014Prepared by Otto Associates, Engineers & Land Surveyors, Inc. Page 10HydroCAD® 10.00 s/n 03113 © 2012 HydroCAD Software Solutions LLC 2.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 14.00' Length= 400.0' Slope= 0.0600 '/' Inlet Invert= 1,008.00', Outlet Invert= 984.00' Summary for Pond 2P: Fil. Basin Inflow Area =2.020 ac,24.75% Impervious, Inflow Depth = 3.99" for 100 yr event Inflow=8.85 cfs @ 12.12 hrs, Volume=0.671 af Outflow=6.97 cfs @ 12.23 hrs, Volume=0.671 af, Atten= 21%, Lag= 6.7 min Primary=6.97 cfs @ 12.23 hrs, Volume=0.671 af Routing by Dyn-Stor-Ind method, Time Span= 2.00-100.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 984.11' @ 12.23 hrs Surf.Area= 3,681 sf Storage= 6,235 cf Plug-Flow detention time= 25.7 min calculated for 0.671 af (100% of inflow) Center-of-Mass det. time= 25.7 min ( 844.7 - 819.0 ) VolumeInvertAvail.StorageStorage Description #1982.00'9,833 cf Custom Stage Data (Prismatic) Listed below (Recalc) ElevationSurf.AreaInc.StoreCum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 982.002,25000 984.003,6005,8505,850 985.004,3653,9839,833 DeviceRouting InvertOutlet Devices #1Primary978.50'15.0" Round Culvert L= 33.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 978.50' / 978.00' S= 0.0152 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2Device 1983.70'27.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3Device 1982.00'1.00 cfs Exfiltration at all elevations Phase-In= 0.01' Primary OutFlow Max=6.96 cfs @ 12.23 hrs HW=984.11' TW=0.00' (Dynamic Tailwater) 1=Culvert (Passes 6.96 cfs of 13.19 cfs potential flow) 2=Orifice/Grate (Weir Controls 5.96 cfs @ 2.08 fps) 3=Exfiltration (Exfiltration Controls 1.00 cfs) 1. E n t e r t h e a m o u n t o f n e w i m p e r v i o u s s u r f a c e s i n s q u a r e fe e t . ( C E L L ' C 3 ' ) Im p e r v i o u s A r e a ( S Q F T ) 35 , 5 0 0 To t a l T r e a t m e n t V o l u m e 3, 1 0 6 Vo l u m e t o b e R e t a i n e d 1, 4 7 9 Wa t e r Q u a l i t y V o l u m e 1, 6 2 7 Se l e c t B M P ( D r o p d o w n ) B M P D e t a i l s ( V o l u m e , A r e a ) U n i t s V o l u m e R e d u c t i o n T P T r e a t m e n t T S S T r e a t m e n t Bi o r e t e n t i o n ( C u b i c F e e t ) 2 , 4 0 0 Cu b i c F e e t 96 0 1 , 8 0 0 2 , 1 6 0 Up l a n d V e g e t a t i o n 34 , 9 1 9 Sq u a r e F e e t 1, 4 5 5 0 0 Se l e c t B M P 0 N/ A 0 0 0 Se l e c t B M P 0 N/ A 0 0 0 Se l e c t B M P 0 N/ A 0 0 0 Se l e c t B M P 0 N/ A 0 0 0 Se l e c t B M P 0 N/ A 0 0 0 Se l e c t B M P 0 N/ A 0 0 0 Se l e c t B M P 0 N/ A 0 0 0 Se l e c t B M P 0 N/ A 0 0 0 To t a l VolumePercentage of RequirementMeets Requirement? Vo l u m e 2,415163.26%YES TP 1,800110.63%YES TS S 2,160132.75%YES IN P U T C E L L S CA L C U L A T I O N C E L L S RE S U L T S C E L L S 2. S e l e c t B M P s b y c l i c k i n g a c e l l w i t h ' S e l e c t B M P ' a n d pi c k i n g a B M P o p t i o n f r o m t h e d r o p d o w n l i s t . 4. " Y E S " w i l l b e d i s p l a y e d i n t h e ' M e e t s R e q u i r e m e n t ? ' co l u m n w h e n t h e v o l u m e a n d p o l l u t a n t r e m o v a l a m o u n t s ha v e b e e n m e t . 1 0 0 % o f t h e v o l u m e r e q u i r e m e n t m u s t b e re t a i n e d . P o l l u t a n t T r e a t m e n t m u s t b e g r e a t e r t h a t 9 0 % o f th e W a t e r Q u a l i t y V o l u m e . 3. E n t e r t h e v o l u m e o r a r e a a s s o c i a t e d w i t h e a c h B M P i n t h e 'B M P D e t a i l s ' C o l u m n . V o l u m e s / A r e a s m u s t b e e n t e r e d i n th e u n i t s t h a t a r e d i s p l a y e d i n t h e a s s o c i a t e d ' U n i t s ' c o l u m n . Re d u c t i o n a m o u n t a r e c o m p u t e d b a s e d o n t h e r e m o v a l cr e d i t s g i v e n f o r e a c h B M P . S e e C a r v e r W M O B M P c r e d i t l i s t fo r m o r e i n f o r m a t i o n .