Storm Water Management Plan 11-29-06
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STORM WATER MANAGEMENT PLAN
FOR
ARBOR VIEW
Chanhassen, Minnesota
November 29, 2006
Otto Project No. 2-06-0135
Prepared for:
Carlson Custom Homes
Prepared by:
Otto Associates, Engineers & Land Surveyors, Inc.
ITO
SSOC1ATES
CITY OF CHANHASSEN
RECEIVED
DEe 0 1 2006
Engineers and Land Surveyors I Inc.
C'11.,t'''r!'''-
'''~', ....::vdlPLAJJNII.'Q D3'T
9 WEST DNISION STREET - BUFFALO, MN 55313 - (763) 682-4727 - FAX (763) 682-3522
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SUMMARY
Runoff (cfs)
AREA TO SOUTHWEST '<"':' ...:'n ", ,i/ " ",/to'Year'\< '.,',' tOO.Year' ,
+,:.
Existing (El) 2.59 10.07 24.97
Proposed (pI, P2, P3) 2.41 7.31 13.98
AREA TO NORTHEAST
Existing (E2)
Proposed (P4)
f~l'O,Yeat
3.71
2.89
, ,:100Year:(
10.07
7.32
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06-0135 EXISTING
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @ 2005 HydroCAD Software Solutions LLC
Type II 24-hr 2 yr Rainfal/=2.80"
Page 1
11/2912006
Runoff =
Subcatchment 1S: Existing Area E1
2.59 cfs @ 12.16 hrs, Volume=
0.253 af, Depth> 0.30"
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"
Tc Length Slope Velocity Capacity Description
(min) (feet) ( ftlft) (ftlsec) (cfs)
17.5 300 0.0500 0.3 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
0.8 200 0.0800 4.2 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
18.3 500 Total
Area (ac)
0.440
6.440
3.000
0.290
10.170
Runoff =
CN Description
98 Paved parking & roofs
61 Pasture/grassland/range, Good, HSG B
61 >75% Grass cover, Good, HSG B
58 Woods/grass comb., Good, HSG B
63 Weighted Average
Subcatchment 2S: Existing Area E2
0.81 cfs @ 12.46 hrs, Volume=
0.142 af, Depth> 0.24"
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)
0.080
0.160
4.840
2.000
7.080
CN Description
98 Paved parking & roofs
78 Wetland
61 Pasture/grassland/range, Good, HSG B
58 Woods/grass comb., Good, HSG B
61 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
36.3 280 0.0500 0.1 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 2.80"
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06-0135 EXISTING
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @ 2005 HydroCAD Software Solutions LLC
Type II 24-hr 10 yr Rainfa//=4.10"
Page 2
11/2912006
Runoff =
Subcatchment 1S: Existing Area E1
10.07 cfs @ 12.13 hrs, Volume=
0.727 af, Depth> 0.86"
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=4.10"
Area (ac)
0.440
6.440
3.000
0.290
10.170
CN Description
98 Paved parking & roofs
61 Pasture/grassland/range, Good, HSG B
61 >75% Grass cover, Good, HSG B
58 Woods/grass comb., Good, HSG B
63 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
17.5 300 0.0500 0.3 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
0.8 200 0.0800 4.2 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
18.3 500 Total
Runoff =
Subcatchment 2S: Existing Area E2
3.71 cfs @ 12.38 hrs, Volume=
0.442 af, Depth> 0.75"
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=4.10"
Area (ac)
0.080
0.160
4.840
2.000
7.080
CN Description
98 Paved parking & roofs
78 Wetland
61 Pasture/grassland/range, Good, HSG B
58 Woods/grass comb., Good, HSG B
61 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftIft) (ftIsec) (cfs)
36.3 280 0.0500 0.1 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 2.80"
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06-0135 EXISTING
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @2005 HydroCAD Software Solutions LLC
Type II 24-hr 100 yr Rainfal/=6.00"
Page 3
11/2912006
Runoff =
Subcatchment 1S: Existing Area E1
24.97 cfs @ 12.12 hrs, Volume=
1.664 af, Depth> 1.96"
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)
0.440
6.440
3.000
0.290
10.170
CN Description
98 Paved parking & roofs
61 Pasture/grassland/range, Good, HSG B
61 >75% Grass cover, Good, HSG B
58 Woods/grass comb., Good, HSG B
63 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) ( ftlft) (ftlsec) (cfs)
17.5 300 0.0500 0.3 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
0.8 200 0.0800 4.2 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
18.3 500 Total
Runoff =
Subcatchment 2S: Existing Area E2
10.07 cfs @ 12.35 hrs, Volume=
1.054 af, Depth> 1.79"
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)
0.080
0.160
4.840
2.000
7.080
CN Description
98 Paved parking & roofs
78 Wetland
61 Pasture/grassland/range, Good, HSG B
58 Woods/grass comb., Good, HSG B
61 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
36.3 280 0.0500 0.1 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 2.80"
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Existing Area E1
Existi ng Area E2
@B~~
Drainage Diagram for 06-0135 EXISTING
Prepared by Otto Associates, Inc. 11/29/2006
HydroCAD@7.10 sin 003215 @2005 HydroCAD Software Solutions LLC
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<1S;~
Proposed Area P1
\"'2"'S"""""")"""..-"
";">":':-""O"':':"";:::7,:+:;:,..h>
>,<"",:,,;:,:::,\.<,"
Proposed Area P2
<"3""S-'-""'.""'>."'.~"
-\'"":",-"",:,.,.'-::,,
,,'.,:'..-...;.>'...,....:.c.,-'.
Proposed Area P3
(4.$;;
-.,:":':"-:"'::-.;.;"':
Proposed Area P4
@B~~
~
Area to SW
Drainage Diagram for 06-0135 PROPOSED
Prepared by Otto Associates. Inc. 11/29/2006
HydroCAOO 7.10 sin 003215 @ 2005 HydroCAD Software Solutions LLC
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06-0135 PROPOSED
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @ 2005 HydroCAD Software Solutions LLC
Type 1/ 24-hr 2 yr Rainfal/=2.80"
Page 1
11/29/2006
Runoff =
Subcatchment 1S: Proposed Area P1
0.18 cfs @ 12.01 hrs, Volume=
0.011 af, Depth> 0.25"
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)
0.560
CN Description
61 > 75% Grass cover, Good, HSG B
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
6.2 130 0.1231 0.3 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
Runoff =
Subcatchment 2S: Proposed Area P2
8.04 cfs @ 12.10 hrs, Volume=
0.536 af, Depth> 0.57"
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)
2.800
8.050
0.200
0.200
11.250
CN Description
98 Paved parking & roofs
61 >75% Grass cover, Good, HSG B
100 Surface water
58 Woods/grass comb., Good, HSG B
71 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) ( ftlft) (ftlsec) (cfs)
14.3 300 0.0833 0.4 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
1.0 245 0.0408 4.1 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
0.6 270 0.0185 7.2 8.79 Circular Channel (pipe),
Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013 Concrete pipe, straight & clean
15.9 815 Total
Runoff =
Subcatchment 3S: Proposed Area P3
0.40 cfs @ 12.01 hrs, Volume=
0.021 af, Depth> 0.33"
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"
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06-0135 PROPOSED
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @2005 HydroCAD Software Solutions LLC
Type 1/24-hr 2 yr Rainfal/=2.80"
Page 2
11/2912006
Area (ac)
0.060
0.720
0.780
CN Description
98 Paved parking & roofs
61 > 75% Grass cover, Good, HSG B
64 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
6.8 155 0.1419 0.4 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
Runoff =
Subcatchment 45: Proposed Area P4
0.74 cfs @ 12.43 hrs, Volume=
0.114 af, Depth> 0.29"
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)
0.350
2.450
0.160
1.700
4.660
CN Description
98 Paved parking & roofs
61 >75% Grass cover, Good, HSG B
78 Wetland
58 Woods/grass comb., Good, HSG B
63 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
36.3 280 0.0500 0.1 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 2.80"
Inflow Area =
Inflow =
Outflow =
Reach 1 R: Area to SW
12.590 ac, Inflow Depth> 0.49" for 2 yr event
2.14 cfs @ 12.47 hrs, Volume= 0.509 af
2.14 cfs @ 12.47 hrs, Volume= 0.509 af, Atten= 0%, Lag= 0.0 min
Routing by Stor-Ind+ Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Inflow Area =
Inflow =
Outflow =
Primary =
Pond 2P: Area P2 Pond
11.250 ac, Inflow Depth> 0.57"
8.04 cfs @ 12.10 hrs, Volume=
2.04 cfs @ 12.50 hrs, Volume=
2.04 cfs @ 12.50 hrs, Volume=
for 2 yr event
0.536 af
0.476 af, Atten= 75%, Lag= 23.6 min
0.476 af
Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Peak Elev= 997.78' @ 12.50 hrs Surf.Area= 10,746 sf Storage= 7,860 cf
Plug-Flow detention time= 85.7 min calculated for 0.475 af (89% of inflow)
Center-of-Mass del. time= 49.9 min ( 880.3 - 830.3 )
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06-0135 PROPOSED
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @ 2005 HydroCAD Software Solutions LLC
Type II 24-hr 2 yr Rainfal/=2.80"
Page 3
11/2912006
Volume
#1
Avail.Storage Storage Description
70,830 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Invert
997.00'
Elevation
(feet)
997.00
998.00
1,000.00
1,002.00
Inc.Store
(cubic-feet)
o
10,250
26,025
34,555
Cum.Store
(cubic-feet)
o
10,250
36,275
70,830
Surf.Area
(sq-ft)
9,370
11,130
14,895
19,660
Device
#1
Invert Outlet Devices
997.00' 18.0" x 27.0' long Culvert RCP, square edge headwall, Ke= 0.500
Outlet Invert= 996.86' S= 0.0052 'f Cc= 0.900 n= 0.013
Routing
Primary
Primary OutFlow Max=2.04 cfs @ 12.50 hrs HW=997.78' (Free Discharge)
"t....1=Culvert (Barrel Controls 2.04 cfs @ 3.2 fps)
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06-0135 PROPOSED
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @2005 HydroCAD Software Solutions LLC
Type II 24-hr 10 yr Rainfal/=4.10"
Page 4
11/2912006
Runoff =
Subcatchment 1 S: Proposed Area P1
0.78 cfs @ 11.99 hrs, Volume=
0.036 af, Depth> 0.76"
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=4.10"
Area (ac)
0.560
CN Description
61 >75% Grass cover, Good, HSG B
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
6.2 130 0.1231 0.3 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
Runoff =
Subcatchment 2S: Proposed Area P2
19.99 cfs @ 12.09 hrs, Volume=
1.238 af, Depth> 1.32"
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=4.10"
Area (ac)
2.800
8.050
0.200
0.200
11.250
CN Description
98 Paved parking & roofs
61 >75% Grass cover, Good, HSG B
100 Surface water
58 Woods/grass comb., Good, HSG B
71 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) ( ftlft) (ftlsec) (cfs)
14.3 300 0.0833 0.4 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
1.0 245 0.0408 4.1 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
0.6 270 0.0185 7.2 8.79 Circular Channel (pipe),
Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013 Concrete pipe, straight & clean
15.9 815 Total
Runoff =
Subcatchment 3S: Proposed Area P3
1.31 cfs @ 11.99 hrs, Volume=
0.060 af, Depth> 0.92"
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=4.10"
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06-0135 PROPOSED
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @ 2005 HydroCAD Software Solutions LLC
Type 1/24-hr 10 yr Rainfa//=4.10"
Page 5
11/2912006
Area (ac)
0.060
0.720
0.780
CN Description
98 Paved parking & roofs
61 >75% Grass cover, Good, HSG B
64 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
6.8 155 0.1419 0.4 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
Runoff =
Subcatchment 4S: Proposed Area P4
2.89 cfs @ 12.37 hrs, Volume=
0.330 af, Depth> 0.85"
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=4.10"
Area (ac)
0.350
2.450
0.160
1.700
4.660
CN Description
98 Paved parking & roofs
61 > 75% Grass cover, Good, HSG B
78 Wetland
58 Woods/grass comb., Good, HSG B
63 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
36.3 280 0.0500 0.1 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 2.80"
Inflow Area =
Inflow =
Outflow =
Reach 1 R: Area to SW
12.590 ac, Inflow Depth> 1.19" for 10 yr event
7.31 cfs @ 12.34 hrs, Volume= 1.251 af
7.31 cfs @ 12.34 hrs, Volume= 1.251 af, Atten= 0%, Lag= 0.0 min
Routing by Stor-Ind+ Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Inflow Area =
Inflow =
Outflow =
Primary =
Pond 2P: Area P2 Pond
11.250 ac, Inflow Depth> 1.32"
19.99 cfs @ 12.09 hrs, Volume=
6.99 cfs @ 12.35 hrs, Volume=
6.99 cfs @ 12.35 hrs, Volume=
for 10 yr event
1.238 af
1.156 af, Atten= 65%, Lag= 15.4 min
1.156 af
Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Peak Elev= 998.69' @ 12.35 hrs Surf.Area= 12,428 sf Storage= 18,371 cf
Plug-Flow detention time= 60.9 min calculated for 1.152 af (93% of inflow)
Center-of-Mass del. time= 38.1 min ( 850.0 - 811.9 )
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06-0135 PROPOSED
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @2005 HydroCAD Software Solutions LLC
Type II 24-hr 10 yr Rainfal/=4.10"
Page 6
11/2912006
Volume
#1
Avail.Storage Storage Description
70,830 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Invert
997.00'
Elevation
(feet)
997.00
998.00
1,000.00
1,002.00
Surf.Area
(sq-ft)
9,370
11,130
14,895
19,660
Cum .Store
( cubic-feet)
o
10,250
36,275
70,830
Inc.Store
(cubic-feet)
o
10,250
26,025
34,555
Device
#1
Invert Outlet Devices
997.00' 18.0" x 27.0' long Culvert RCP, square edge headwall, Ke= 0.500
Outlet Invert= 996.86' S= 0.0052 'f Cc= 0.900 n= 0.013
Routing
Primary
Primary OutFlow Max=6.99 cfs @ 12.35 hrs HW=998.69' (Free Discharge)
't-1=Culvert (Barrel Controls 6.99 cfs @ 4.4 fps)
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06-0135 PROPOSED
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @2005 HydroCAD Software Solutions LLC
Type II 24-hr 100 yr Rainfal/=6.00"
Page 7
11/2912006
Runoff =
Subcatchment 1S: Proposed Area P1
1.93 cfs @ 11.98 hrs, Volume=
0.085 af, Depth> 1.81"
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)
0.560
CN Description
61 >75% Grass cover, Good, HSG B
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
6.2 130 0.1231 0.3 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
Runoff =
Subcatchment 2S: Proposed Area P2
40.62 cfs @ 12.08 hrs, Volume=
2.489 af, Depth> 2.65"
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)
2.800
8.050
0.200
0.200
11.250
CN Description
98 Paved parking & roofs
61 >75% Grass cover, Good, HSG B
100 Surface water
58 Woods/grass comb., Good, HSG B
71 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) ( ftlft) (ftlsec) (cfs)
14.3 300 0.0833 0.4 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80"
1.0 245 0.0408 4.1 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
0.6 270 0.0185 7.2 8.79 Circular Channel (pipe),
Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013 Concrete pipe, straight & clean
15.9 815 Total
Runoff =
Subcatchment 3S: Proposed Area P3
3.00 cfs @ 11.99 hrs, Volume=
0.134 af, Depth> 2.06"
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"
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06-0135 PROPOSED
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @ 2005 HydroCAD Software Solutions LLC
Type II 24-hr 100 yr Rainfal/=6.00"
Page 8
11/2912006
Area (ac)
0.060
0.720
0.780
CN Description
98 Paved parking & roofs
61 >75% Grass cover, Good, HSG B
64 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
6.8 155 0.1419 0.4 Sheet Flow,
Grass: Short n= 0.150 P2= 2.80" .
Runoff =
Subcatchment 45: Proposed Area P4
7.32 cfs @ 12.34 hrs, Volume=
0.756 af, Depth> 1.95"
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)
0.350
2.450
0.160
1.700
4.660
CN Description
98 Paved parking & roofs
61 >75% Grass cover, Good, HSG B
78 Wetland
58 Woods/grass comb., Good, HSG B
63 Weighted Average
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ftlsec) (cfs)
36.3 280 0.0500 0.1 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 2.80"
Inflow Area =
Inflow =
Outflow =
Reach 1 R: Area to SW
12.590 ac, Inflow Depth> 2.48" for 100 yr event
13.98 cfs @ 12.32 hrs, Volume= 2.599 af
13.98 cfs @ 12.32 hrs, Volume= 2.599 af, Atten= 0%, Lag= 0.0 min
Routing by Stor-Ind+ Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Inflow Area =
Inflow =
Outflow =
Primary =
Pond 2P: Area P2 Pond
11.250 ac, Inflow Depth> 2.65"
40.62 cfs @ 12.08 hrs, Volume=
13.30 cfs @ 12.35 hrs, Volume=
13.30 cfs @ 12.35 hrs, Volume=
for 100 yr event
2.489 af
2.380 af, Atten= 67%, Lag= 15.9 min
2.380 af
Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Peak Elev= 1,000.19' @ 12.35 hrs Surf.Area= 15,359 sf Storage= 39,224 cf
Plug-Flow detention time= 53.6 min calculated for 2.380 af (96% of inflow)
Center-of-Mass del. time= 37.6 min ( 835.0 - 797.4 )
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06-0135 PROPOSED
Prepared by Otto Associates, Inc.
HydroCAOO 7.10 sIn 003215 @2005 HydroCAD Software Solutions LLC
Type II 24-hr 100 yr Rainfal/=6.00"
Page 9
11/29/2006
Volume
#1
Avail.Storage Storage Description
70,830 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Invert
997.00'
Elevation
(feet)
997.00'
998.00
1,000.00
1,002.00
Surf.Area
(sq-ft)
9,370
11 ,130
14,895
19,660
Cum.Store
( cubic-feet)
o
10,250
36,275
70,830
Inc.Store
(cubic-feet)
o
10,250
26,025
34,555
Device
#1
Invert Outlet Devices
997.00' 18.0" x 27.0'long Culvert RCP, square edge headwall, Ke= 0.500
Outlet Invert= 996.86' S= 0.0052 'f Cc= 0.900 n= 0.013
Routing
Primary
Primary OutFlow Max=13.30 cfs @ 12.35 hrs HW=1,000.19' (Free Discharge)
't...-1=Culvert (Inlet Controls 13.30 cfs @ 7.5 fps)
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