Loading...
Pond Calculations 2-28-08 Engineering · Planning · Surveying , CITY OF CHANHASSEN RECEIVED February 28, 2008 PEB 2 9 2008 CHANHASSEN PLANNING DEPT Joe Shamla, P.E. City of Chanhassen 7700 Market Blvd Chanhassen, MN 55317 RE: 1011 Stockdale pond calculations Revised 2-28-08 Dear Joe, The following is a summary of the calculations used to size the expansion of the existing Chanhassen Lakes stormwater pond onto the proposed 101 site, as well as a conceptual pond for the future project on the north lot. IDI Pond Expansion The existing stormwater pond serving Lots 1, 2 & 3 of Block 1 in Chanhassen Lakes Business Park ih Addition will be expanded to west in order to accommodate the additional runoff from the proposed 101 project. The existing pond has a NWL of 938.6, and a bottom elevation of approximately 933.0, and the expansion will continue use of these elevations. The pond expansion involves moving the NWL of the pond west to the retaining wall around the truck loading area, and then sloping down at a 3: 1 slope to match the pond bottom elevation at 933.0. The expansion volume was calculated as the difference between the existing pond contours, which were interpolated based on a combination of the Chanhassen Lakes Business Park ih Addition original design plans dated 6-29-1999 & the stormwater management plan dated 6-1-1999, and the proposed contours. A table of the pond areas at each elevation is as follows: Pond Area from Proposed Total Area Contour SMP (sf) expansion (sf) Elevation area (sf) 933 9600 5256 14856 934 12100 5504 17604 935 14400 5763 20163 936 16900 6008 22908 937 19600 6269 25869 938 27000 7232 34232 939 28000 7437 35437 940 29200 7626 36826 941 31800 7762 39562 942 48800 7570 56370 14800 28th Avenue North, Suite 140 . Plymouth, Minnesota. 55447 phone 763/476-6010 . fax 763/476-8532 . website mfra.com I Using these areas, the proposed dead pool of the new expanded pond comes out to 131,844 cf, an expansion of 33,747 cf from the existing condition (98,097 ct). The proposed runoff from the 101 site during the 2.5" rainfall event (NURP design storm) is 25,700 cf, which is less than the amount of the proposed pond expansion. The storage volume target determined using the Walker method is 29,500 cf, and the proposed expansion satisfies this requirement as well. Concept North Lot Pond The conceptual pond for the north lot was designed using assumed elevations and impervious/pervious areas based on the latest site sketch. The most recent site sketch for this lot calls for 41,000 sf of impervious surface, leaving approximately 34,361 sf of pervious surface that won't flow directly into the wetland; this area is modeled as node S1. The pond was also sized based on the 2.5" NURP design storm, which produces 8,232 cf of runoff over the tributary area. The proposed dead pool of the conceptual pond was therefore sized to meet or exceed this number, and 9,854 cf of dead storage is provided. The storage volume target determined using the Walker method is 9,700 cf, and the conceptual pond satisfies this requirement as well. Oue to the fact that a finalized site plan & use of the site have not been determined, it is very likely that the shape, size & tributary of the conceptual pond will change when the site is developed. Runoff Rate Control Runoff rate control for the existing Chanhassen Lakes Business Park pond tributary area, the 101 site & the north lot conceptual site were modeled as a whole using the SCS TR-20 runoff method for the 24-hour 2, 10 & 100-year design storms. Oetails on the existing pond, outlet structure & tributary area were pulled from the original design data contained in the 6-1-1999 stormwater management plan; the existing tributary area is modeled as X2/S3, and contains 5.03 ac of impervious (CN 98), 3.10 ac of Lawn/Neutral (CN 60), and 0.5 acres of Pond (CN 80). The pond was modeled as described above in the 101 Pond Expansion section. A summary of the runoff rates is as follows; please refer to the HydroCAO report for further detail. Maximum Rate of Runoff (efs) 24-Hour Storm ExistinQ Proposed 2-Year 7.73 4.06 10-Year 16.88 7.96 100-Year 32.11 12.19 Conclusion The proposed stormwater management improvements on the 101 site & north lot will meet water quality requirements by providing sufficient dead pool volume in the expanded/new ponds to meet NURP design standards, and will meet water quantity requirement by providing sufficient live storage volume to retain & release runoff at a rate less than existing conditions. If you have any questions or comments regarding the proposed improvement, please contact me directly at 763- 746-1608 or iiones@mfra.com. Sincerely, McCOMBS FRANK ROOS ASSOCIATES J; ~C/ Jared Jones, E.I.T. G ~ Total Existing G 79 Chan Lakes ~ ~ Existing Pond G concePtNo~~otto Pond \ ~ Concept p\ jnded Pond ~~ o e e IDI Site to \ 79 Chan Lakes ~ IDI Lot to Offsite North Lot Wetland ~UbC1 B ~ ~ Drainage Diagram for Stockdale Site Rev 2-28-08 Prepared by MFRA 2/28/2008 HydroCAOO 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 2- Year Rainfal/=2.80" Page 2 2/28/2008 Runoff = Subcatchment 51: Concept North lot to Pond 4.09 cfs @ 12.01 hrs, Volume= 0.225 af, Depth> 1.56" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.80" Area (sf) 41,000 34,361 75,361 34,361 41,000 Tc Length (min) (feet) 10.0 Runoff = CN Description 98 Paved parking & roofs 74 >75% Grass cover, Good, HSG C 87 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (fUft) (ftIsec) (cfs) Direct Entry, Subcatchment 52: 101 Site to Pond 11.78 cfs @ 12.01 hrs, Volume= 0.680 af, Depth> 2.15" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.80" Area (sf) 135,870 29,278 165,148 29,278 135,870 Tc Length (min) (feet) 10.0 Runoff = CN Description 98 Paved parking & roofs 74 >75% Grass cover, Good, HSG C 94 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (ftIft) (ftIsec) (cfs) Direct Entry, Subcatchment 53: Existing Chan lakes 12.97 cfs @ 12.11 hrs, Volume= 0.921 af, Depth> 1.28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.80" Area (ac) 5.030 0.500 3.100 8.630 3.600 5.030 CN Description 98 Roof / Parking Lot 80 Pond 60 Lawn / Natural 83 Weighted Average Pervious Area Impervious Area Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sin 001876 @2006 HydroCAD Software Solutions LLC Type /I 24-hr 2- Year Rainfal/=2.80" Page 3 2/28/2008 Tc Length (min) (feet) 18.0 Runoff = Slope Velocity Capacity Description (fUft) (fUsee) (cfs) Direct Entry, Subcatchment S4: 101 Lot to Offsite 0.64 cfs @ 12.03 hrs, Volume= 0.037 af, Depth> 0.78" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.80" Area (sf) 24,658 24,658 Tc Length (min) (feet) 10.0 Rurroff = CN Description 74 Grass & Wetland Areas Pervious Area Slope Velocity Capacity Description (fUft) (fUsee) (cfs) Direct Entry, . Subcatchment S5: North Lot Wetland 0.25 cfs @ 12.02 hrs, Volume= 0.014 af, Depth> 0.93" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.80" Area (sf) 8,018 8,018 Tc Length (min) (feet) 10.0 Runoff = CN Description 77 Brush, Poor, HSG C Pervious Area Slope Velocity Capacity Description (fUft) (fUsee) (cfs) Direct Entry, Subcatchment X1: Existing Stockdale Property 7.10 cfs @ 12.03 hrs, Volume= 0.408 af, Depth> 0.78" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.80" Area (sf) 273,185 273,185 CN Description 74 >75% Grass cover, Good, HSG C Pervious Area Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 2- Year Rainfal/=2.80" Page 4 2/28/2008 Tc Length (min) (feet) 10.0 Runoff Slope Velocity Capacity Description (fUft) (ftlsec) (cfs) Direct Entry, Subcatchment X2: Existing Chan lakes = 12.97 cfs @ 12.11 hrs, Volume= 0.921 af, Depth> 1.28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.80" Area (ac) 5.030 0.500 3.100 8.630 3.600 5.030 Tc Length (min) (feet) 18.0 Inflow Area = Inflow = Outflow = Primary = CN Description 98 Roof / Parking Lot 80 Pond 60 Lawn I Natural 83 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (fUft) (ftlsec) (cfs) Direct Entry, Pond P1: Expanded Pond 12.421 ac, Inflow Depth> 1.55" 22.62 cfs @ 12.05 hrs, Volume= 2.71 cfs @ 12.72 hrs, Volume= 2.71 cfs @ 12.72 hrs, Volume= for 2-Year event 1.602 af 1.323 af, Atten= 88%, Lag= 40.5 min 1.323 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 938.60' Surf.Area= 34,955 sf Storage= 131,844 cf Peak Elev= 939.61' @ 12.72 hrs Surf.Area= 36,283 sf Storage= 167,771 cf (35,927 cf above start) Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass det. time= 145.9 min ( 967.5 - 821.7 ) Volume #1 Invert 933.00' Avail.Storage Storage Description 268,214 cf Custom Stage Data (Prismatic)...isted below (Recalc) Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 2- Year Rainfal/=2.80" Page 5 2/28/2008 Elevation (feet) 933.00 934.00 935.00 936.00 937.00 938.00 939.00 940.00 941.00 942.00 Device #1 Routing Primary #2 #3 Device 1 Device 1 Surf.Area (sq-ft) 14,856 17,604 20,163 22,908 25,869 34,232 35,437 36,826 39,562 56,370 Inc.Store (cubic-feet) o 16,230 18,884 21,536 24,389 30,051 34,835 36,132 38,194 47,966 Cum.Store (cubic-feet) o 16,230 35,114 56,649 81,038 111,088 145,923 182,054 220,248 268,214 Invert Outlet Devices 938.00' 12.0" x 25.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 937.80' S= 0.0080 'J' Cc= 0.900 n= 0.012 Concrete pipe, finished 940.10' 48.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 938.60' 12.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=2.70 cfs @ 12.72 hrs HW=939.61' (Free Discharge) L1=Culvert (Passes 2.70 cfs of 3.85 cfs potential flow) t2=orifice/Grate (Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 2.70 cfs @ 3.44 fps) Inflow Area = Inflow = Outflow = Primary = Pond P2: Concept Pond 1.730 ac, Inflow Depth> 1.56" for 2-Year event 4.09 cfs @ 12.01 hrs, Volume= 0.225 af 1.51 cfs @ 12.18 hrs, Volume=' 0.213 af, Atten= 63%, Lag= 9.6 min 1.51 cfs @ 12.18 hrs, Volume= 0.213 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 940.00' Surf.Area= 5,052 sf Storage= 9,854 cf Peak Elev= 940.66' @ 12.18 hrs Surf.Area= 5,694 sf Storage= 13,390 cf (3,537 cf above start) Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass det. time= 47.8 min ( 871.6 - 823.9 ) Volume #1 Invert 934.00' Avail.Storage Storage Description 29,539 cf Custom Stage Data (Prismatic).Jsted below (Recalc) Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sin 001876 @2006 HydroCAD Software Solutions LLC Type /I 24-hr 2-Year Rainfal/=2.80" Page 6 2/28/2008 Elevation (feet) 934.00 935.00 936.00 937.00 938.00 939.00 940.00 941.00 942.00 943.00 Device #1 Surf.Area (sq-ft) 465 713 1,013 1,367 1,773 2,229 5,052 6,027 7,059 8,147 Inc.Store (cubic-teet) o 589 863 1,190 1,570 2,001 3,641 5,540 6,543 7,603 Cum.Store (cubic-feet) o 589 1 ,452 2,642 4,212 6,213 9,854 15,393 21,936 29,539 Routing Primary Invert Outlet Devices 940.00' 12.0" x 100.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 939.00' S= 0.0100 'I' Cc= 0.900 n= 0.012 Concrete pipe, finished Primary OutFlow Max=1.51 cfs @ 12.18 hrs HW=940.66' -(Free Discharge) L1=Culvert (Inlet Controls 1.51 cfs @ 2.76 fps) Inflow Area = Inflow = Outflow = Primary = Pond XP: Existing Pond 8.630 ac, Inflow Depth> 1.28" 12.97 cfs @ 12.11 hrs, Volume= 1.64 cfs @ 12.80 hrs, Volume= 1.64 cfs @ 12.80 hrs, Volume= for 2-Year event 0.921 af 0.752 at, Atten= 87%, Lag= 41.3 min 0.752 at Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 938.60' Surf.Area= 0.635 ac Storage= 2.252'at Peak Elev= 939.29' @ 12.80 hrs Surf.Area= 0.652 ac Storage= 2.697 af (0.445 af above start) Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-ot-Mass del. time= 131.2 min ( 975.6 - 844.4 ) Volume #1 Elevation (feet) 933.00 937.00 938.00 940.00 941.00 942.00 Device #1 Invert 933.00' Avail.Storage Storage Description 4.790 at Custom Stage Data (Prismatic}..isted below (Recalc) Surf.Area (acres) 0.220 0.450 0.620 0.670 0.730 1.120 Inc.Store (acre-teet) 0.000 1.340 0.535 1.290 0.700 0.925 Cum.Store (acre-feet) 0.000 1.340 1.875 3.165 3.865 4.790 Routing Primary Invert Outlet Devices 938.00' 12.0" x 25.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 937.80' S= 0.0080 'I' Cc= 0.900 n= 0.012 Concrete pipe, finished Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sin 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 2-Year Rainfal/=2.80" Page 7 2/28/2008 #2 Device 1 #3 Device 1 940.1 A' 48.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 938.60' 12.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=1.64 cfs @ 12.80 hrs HW=939.29' (Free Discharge) "L.1 =Culvert (Passes 1.64 cfs of 3.13 cfs potential flow) t2=orifice/Grate (Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 1.64 cfs @ 2.83 fps) Link TP: Total Proposed Inflow Area = Inflow = Primary = 14.901 ac, Inflow Depth> 1.28" for 2-Yearevent 4.06 cfs @ 12.28 hrs, Volume= 1.587 af 4.06 cfs @ 12.28 hrs, Volume= 1.587 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link TX: Total Existing Inflow Area = Inflow = Primary = 14.901 ac, Inflow Depth> 0.93" for 2-Year event 7.37 cfs @ 12.03 hrs, Volume= 1.160 af 7.37 cfs @ 12.03 hrs, Volume= 1.160 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAO@ 8.00 sin 001876 @ 2006 HydroCAO Software Solutions LLC Type /I 24-hr 10- Year Rainfal/=4. 10" Page 8 2/28/2008 Runoff = Subcatchment 51: Concept North lot to Pond 7.01 cfs @ 12.01 hrs, Volume= 0.393 af, Depth> 2.72" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.10" Area (sf) 41,000 34,361 75,361 34,361 41,000 Tc Length (min) (feet) 10.0 Runoff = CN Description 98 Paved parking & roofs 74 >75% Grass cover, Good, HSG C 87 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (fUft) (ftIsec) (cfs) Direct Entry, Subcatchment 52: 101 Site to Pond 18.18 cfs @ 12.01 hrs, Volume= 1.079 af, Depth> 3.42" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10- Year Rainfall=4.10" Area (sf) 135,870 29,278 165,148 29,278 135,870 Tc Length (min) (feet) 10.0 Runoff = CN Description 98 Paved parking & roofs 74 >75% Grass cover, Good, HSG C 94 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (fUft) (ftIsec) (cfs) Direct Entry, Subcatchment 53: Existing Chan lakes 24.02 cfs @ 12.10 hrs, Volume= 1.700 af, Depth> 2.36" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.10" Area (ac) 5.030 0.500 3.100 8.630 3.600 5.030 CN Description 98 Roof / Parking Lot 80 Pond 60 Lawn I Natural 83 Weighted Average Pervious Area Impervious Area Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 1 0- Ye~r Rainfal/=4. 10" Page 9 2/28/2008 Tc Length (min) (feet) 18.0 Runoff = Slope Velocity Capacity Description (fUft) (ftlsec) (cfs) Direct Entry, Subcatchment S4: 101 Lot to Offsite 1.42 cfs @ 12.02 hrs, Volume= 0.079 af, Depth> 1.67" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.10" Area (sf) 24,658 24,658 Tc Length (min) (feet) 10.0 Runoff = CN Description 74 Grass & Wetland Areas Pervious Area Slope Velocity Capacity Description (fUft) (fUsee) (cfs) Direct Entry, Subcatchment S5: North Lot Wetland 0.53 cfs @ 12.02 hrs, Volume= 0.029 af, Depth> 1.89" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.10" . Area (sf) 8,018 8,018 Tc Length (min) (feet) 10.0 Runoff = CN Description 77 Brush, Poor, HSG C Pervious Area Slope Velocity Capacity Description (fUft) (ftlsec) (cfs) Direct Entry, Subcatchment X1: Existing Stockdale Property 15.79 cfs @ 12.02 hrs, Volume= 0.871 af, Depth> 1.67" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.10" Area (sf) 273,185 273,185 CN Description 74 >75% Grass cover, Good, HSG C Pervious Area Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sin 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 10- Year Rainfal/=4. 10" Page 1 0 2/28/2008 Tc Length (min) (feet) 10.0 Runoff Slope Velocity Capacity Description (ft/ft) (ftIsec) (cfs) Direct Entry, Subcatchment X2: Existing Chan lakes = 24.02 cfs @ 12.10 hrs, Volume= 1.700 af, Depth> 2.36" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.10" Area (ac) 5.030 0.500 3.100 8.630 3.600 5.030 Tc Length (min) (feet) 18.0 Inflow Area = Inflow = Outflow = Primary = CN Description 98 Roof I Parking Lot 80 Pond 60 Lawn I Natural 83 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (ftIft) (ftIsec) (cfs) Direct Entry, Pond P1: Expanded Pond 12.421 ac, Inflow Depth> 2.68" 38.89 cfs @ 12.05 hrs, Volume= 5.14 cfs @ 12.65 hrs, Volume= . 5.14 cfs @ 12.65 hrs, Volume= for 10-Year event 2.779 af 2.423 af, Atten= ,87%, 2.423 af Lag= 36.0 min Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 938.60' Surf.Area= 34,955 sf Storage= 131,844 cf Peak Elev= 940.34' @ 12.65 hrs Surf.Area= 37,769 sf Storage= 194,915 cf (63,071 cfabove start) Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass det. time= 149.4 min ( 957.7 - 808.2 ) Volume #1 Invert 933.00' Avail.Storage Storage Description 268,214 cf Custom Stage Data (PrismaticJ-isted below (Recalc) Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 10- Year Rainfal/=4. 10" Page 11 2/28/2008 Elevation (feet) 933.00 934.00 935.00 936.00 937.00 938.00 939.00 940.00 941.00 942.00 Device #1 Routing Primary #2 #3 Device 1 Device 1 Surf.Area (sq-ft) 14,856 17,604 20,163 22,908 25,869 34,232 35,437 36,826 39,562 56,370 Inc.Store (cubic-feet) o 16,230 18,884 21,536 24,389 30,051 34,835 36,132 38,194 47,966 Cum.Store (cubic-feet) o 16,230 35,114 56,649 81,038 111,088 145,923 182,054 220,248 268,214 Invert Outlet Devices 938.00' 12.0" x 25.0'long Culvert Rep, sq.cut end projecting, Ke= 0.500 Outlet Invert= 937.80' S= 0.0080 'I' Cc= 0.900 n= 0.012 Concrete pipe, finished 940.10' 48.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 938.60' 12.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=5.14 cfs @ 12.65 hrs HW=940.34' (Free Discharge) L1=Culvert (Inlet Controls 5.14 cfs @ 6.54 fps) t2=orifice/Grate (Passes < 4.98 cfs potential flow) 3=Orifice/Grate (Passes < 4.22 cfs potential flow) Inflow Area = Inflow = Outflow = Primary = Pond P2: Concept Pond 1.730 ac, Inflow Depth> 2.72" 7.01 cfs @ 12.01 hrs, Volume= 2.80 cfs @ 12.17 hrs, Volume= 2.80 cfs @ 12.17 hrs, Volume= for 10-Year event 0.393 af 0.377 af, Atten= 60%, Lag= 9.2 min 0.377 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 940.00' Surf.Area= 5,052 sf Storage= 9,854 cf Peak Elev= 941.05' @ 12.17 hrs Surf.Area= 6,077 sf Storage= 15,684 cf (5,830 cf above start) Plug-Flow detention time= 326.4 min calculated for 0.151 af (38% of inflow) Center-of-Mass deL time= 40.7 min ( 848.8 - 808.2 ) Volume #1 Invert 934.00' Avail.Storage Storage Description 29,539 cf Custom Stage Data (PrismaticJ-jsted below (Recalc) Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 10- Year Rainfal/=4. 10" Page 12 2/28/2008 Elevation (feet) 934.00 935.00 936.00 937.00 938.00 939.00 940.00 941.00 942.00 943.00 Device Routing #1 Primary Surf.Area (sq-ft) 465 713 1,013 1,367 1,773 2,229 5,052 6,027 7,059 8,147 Inc.Store (cubic-feet) o 589 863 1,190 1,570 2,001 3,641 5,540 6,543 7,603 Cum.Store (cubic-feet) o 589 1 ,452 2,642 4,212 6,213 9,854 15,393 21,936 29,539 Invert Outlet Devices 940.00' 12.0" x 100.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 939.00' S= 0.0100 'I' Cc= 0.900 n= 0.012 Concrete pipe, finished Primary OutFlow Max=2.79 cfs @ 12.17 hrs HW=941.04' (Free Discharge) 'L.1=Culvert (Inlet Controls 2.79 cfs @ 3.55 fps) Inflow Area = Inflow = Outflow = Primary = Pond XP: Existing Pond 8.630 ac, Inflow Depth> 2.36" 24.02 cfs @ 12.10 hrs, Volume= 3.37 cfs @ 12.70 hrs, Volume= 3.37 cfs @ 12.70 hrs, Volume= for 10-Year event 1.700 af 1.485 af, Atten= 86%, Lag= 35.5 min 1 .485 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 938.60' Surf.Area= 0.635 ac Storage= 2.252 af Peak Elev= 939.89' @ 12.70 hrs Surf.Area= 0.667 ac Storage= 3.094 af (0.843 af above start) . Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass del. time= 123.6 min ( 950.8 - 827.1 ) Volume #1 Elevation (feet) 933.00 937.00 938.00 940.00 941.00 942.00 Device #1 Invert 933.00' Avail.Storage Storage Description 4.790 af Custom Stage Data {PrismaticJ-isted below (Recalc) Surf.Area (acres) 0.220 0.450 0.620 0.670 0.730 1.120 Routing Primary Inc.Store (acre-feet) 0.000 1.340 0.535 1.290 0.700 0.925 Cum.Store (acre-feet) 0.000 1.340 1.875 3.165 3.865 4.790 Invert Outlet Devices 938.00' 12.0" x 25.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 937.80' S= 0.0080 'I' Cc= 0.900 n= 0.012 Concrete pipe, finished Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAO@ 8.00 sIn 001876 @ 2006 HydroCAO Software Solutions LLC Type /I 24-hr 10- Year Rainfal/=4. 10" Page 13 2/28/2008 #2 Device 1 #3 Device 1 940.10' 48.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 938.60' 12.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=3.37 cfs @ 12.70 hrs HW=939.89' (Free Discharge) L1=Culvert (Passes 3.37 cfs of 4.47 cfs potential flow) t2=orifiCe/Grate (Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 3.37 cfs @ 4.29 fps) Link TP: Total Proposed Inflow Area = Inflow = Primary = 14.901 ac, Inflow Depth> 2.34" for 10-Year event 7.96 cfs @ 12.31 hrs, Volume= 2.908 af 7.96 cfs @ 12.31 hrs, Volume= 2.908 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link TX: Total Existing Inflow Area = Inflow = Primary = 14.901 ac, Inflow Depth> 1.90" for 1 O-Year event 16.88 cfs @ 12.03 hrs, Volume= 2.355 af 16.88 cfs @ 12.03 hrs, Volume= 2.355 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00hrs, dt= 0.05 hrs Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 100-Year Rainfal/=5.90" Page 14 2/28/2008 Runoff = Subcatchment S1: Concept North Lot to Pond 11.10 cfs @ 12.01 hrs, Volume= 0.636 af, Depth> 4.41" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.90" Area (sf) 41,000 34,361 75,361 34,361 41,000 Te Length (min) (feet) 10.0 Runoff = CN Description 98 Paved parking & roofs 74 >75% Grass cover, Good, HSG C 87 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (fUft) (fUsee) (cfs) Direct Entry, Subcatchment S2: 101 Site to Pond 26.92 cfs @ 12.01 hrs, Volume= 1.639 af, Depth> 5.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.90" . Area (sf) 135,870 29,278 165,148 29,278 135,870 Te Length (min) (feet) 10.0 Runoff = CN Description 98 Paved parking & roofs 74 >75% Grass cover, Good, HSG C 94 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (fUft) (fUsee) (cfs) Direct Entry, Subcatchment S3: Existing Chan Lakes 40.04 cfs @ 12.10 hrs, Volume= 2.865 af, Depth> 3.98" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.90" Area (ac) 5.030 0.500 3.100 8.630 3.600 5.030 CN Description 98 Roof / Parking Lot 80 Pond 60 Lawn / Natural 83 Weighted Average Pervious Area Impervious Area Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 100- Year Rainfal/=5.90" Page 15 2/28/2008 T c Length (min) (feet) 18.0 Runoff = Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) Direct Entry, Subcatchment S4: 101 Lot to Offsite 2.66 cfs @ 12.02 hrs, Volume= 0.146 af, Depth> 3.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.90" Area (sf) 24,658 24,658 Tc Length (min) (feet) 10.0 Runoff = CN Description 74 Grass & Wetland Areas Pervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) Direct Entry, Subcatchment S5: North Lot Wetland 0.94 cfs @ 12.01 hrs, Volume= 0.052 af, Depth> 3.38" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year . Rainfall=5.90" Area (sf) 8,018 8,018 Tc Length (min) (feet) 10.0 Runoff = CN Description 77 Brush, Poor, HSG C Pervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) Direct Entry, Subcatchment X1: Existing Stockdale Property 29.44 cfs @ 12.02 hrs, Volume= 1.617 af, Depth> 3.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.90" Area (sf) 273,185 273,185 CN Description 74 >75% Grass cover, Good, HSG C Pervious Area Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 100-Year Rainfal/=5.90" Page 16 2/28/2008 Tc Length (min) (feet) 10.0 Runoff Slope Velocity Capacity Description (fUft) (fUsec) (cfs) Direct Entry, Subcatchment X2: Existing Chan lakes = 40.04 cfs @ 12.10 hrs, Volume= 2.865 af, Depth> 3.98" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.90" Area (ac) 5.030 0.500 3.100 8.630 3.600 5.030 Tc Length (min) (feet) 18.0 Inflow Area = Inflow = Outflow = Primary = CN Description 98 Roof / Parking Lot 80 Pond 60 Lawn / Natural 83 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (fUft) (fUsec) (cfs) Direct Entry, Pond P1: Expanded Pond 12.421 ac, Inflow Depth> 4.35" 62.10 cfs @ 12.05 hrs, Volume= 6.45 cfs..@12.77hrs,Volume= . " ,. 6.45 cfs @ 12.77 hrs, Volume= for 100-Year event 4.504 af 4.031 af, Atten= 90%, Lag= 43.1 min 4.031 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 938.60' Surf.Area= 34,955 sf Storage= 131,844 cf Peak Elev= 941.41' @ 12.77 hrs Surf.Area= 46,376 sf Storage= 237,669 cf (105,825 cf above start) Plug-Flow detention time= 611.7 min calculated for 1.002 af (22% of inflow) Center-of-Mass del. time= 171.2 min (967.5 -796.3) Volume #1 Invert 933.00' Avail.Storage Storage Description 268,214 cf Custom Stage Data (Prismatic)..Jsted below (Recalc) Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@8.00 sIn 001876 @2006 HydroCAD Software Solutions LLC Type /I 24-hr tOO-Year Rainfal/=5.90" Page 17 2/28/2008 Elevation (feet) 933.00 934.00 935.00 936.00 937.00 938.00 939.00 940.00 941.00 942.00 Device #1 Routing Primary #2 #3 Device 1 Device 1 Surf.Area (sq-ft) 14,856 17,604 20,163 22,908 25,869 34,232 35,437 36,826 39,562 56,370 Inc.Store (cubic-feet) o 16,230 18,884 21,536 24,389 30,051 34,835 36,132 38,194 47,966 Cum.Store (cubic-feet) o 16,230 35,114 56,649 81,038 111,088 145,923 182,054 220,248 268,214 Invert Outlet Devices 938.00' 12.0" x 25.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 937.80' S= 0.0080 '/' Cc= 0.900 n= 0.012 Concrete pipe, finished 940.10' 48.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 938.60' 12.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=6.45 cfs @ 12.77 hrs HW=941.41' (Free Discharge) "L-1=Culvert (Inlet Controls 6.45 cfs @ 8.21 fps) t2=orifiCe/Grate (Passes < 61.27 cfs potential flow) 3=Orifice/Grate (Passes < 5.74 cfs potential flow) Inflow Area = Inflow = Outflow = Primary = Pond P2: Concept Pond 1.730 ac, Inflow Depth> 4.41" 11.10 cfs @ 12.01 hrs, Volume= ! 3.89 cfs @ 12.18 hrs, Volume= 3.89 cfs @ 12.18 hrs, Volume= for 100-Year event 0.636 af 0.618 af, Atten= 65%, 0.618 af Lag=10.0 min Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 940.00' Surf.Area= 5,052 sf Storage= 9,854 cf Peak Elev= 941.59' @ 12.18 hrs Surf.Area= 6,637 sf Storage= 19,133 cf (9,279 cf above start) Plug-Flow detention time= 216.4 min calculated for 0.392 af (62% of inflow) Center-of-Mass del. time= 38.7 min ( 833.3 - 794.6 ) Volume #1 Invert 934.00' Avail.Storage Storage Description 29,539 cf Custom Stage Data (Prismatic)...isted below (Recalc) Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @2006 HydroCAD Software Solutions LLC Type /I 24-hr 100-Year Rainfal/=5.90" Page 18 2/28/2008 Elevation (feet) 934.00 935.00 936.00 937.00 938.00 939.00 940.00 941.00 942.00 943.00 Device #1 Surf.Area (sq-ft) 465 713 1,013 1,367 1,773 2,229 5,052 6,027 7,059 8,147 Inc.Store (cubic-feet) o 589 863 1,190 1,570 2,001 3,641 5,540 6,543 7,603 Cum.Store (cubic-feet) o 589 1 ,452 2,642 4,212 6,213 9,854 15,393 21,936 29,539 Routing Primary Invert Outlet Devices 940.00' 12.0" x 100.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 939.00' S= 0.0100 'I' Cc= 0.900 n= 0.012 Concrete pipe, finished Primary OutFlow Max=3.89 cfs @ 12.18 hrs HW=941.59'(Free Discharge) L1=Culvert (Barrel Controls 3.89 cfs @ 4.95 fps) Inflow Area = Inflow = Outflow = Primary = Pond XP: Existing Pond 8.630 ac, Inflow Depth> 3.98" 40.04 cfs @ 12.10 hrs, Volume= 5.70 cfs @ 12.67 hrs, Volume= 5.70 cfs @ 12.67 hrs, Volume= for 100-Year event 2.865 af 2.597 af, Atten= 86%, Lag= 33.9 min 2.597 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 938.60' Surf.Area= 0.635 ac ' Storage= 2.252 af Peak Elev= 940.77' @ 12.67 hrs Surf.Area= 0.716 ac Storage= 3.698 af (1.446 af above start) Plug-Flow detention time= 665.0 min calculated for 0.344 af (12% of inflow) Center-of-Mass del. time= 128.2 min (940.7 - 812.5 ) Volume #1 Elevation (feet) 933.00 937.00 938.00 940.00 941.00 942.00 Device #1 Invert 933.00' Avail.Storage Storage Description 4.790 af Custom Stage Data (Prismatic}..isted below (Reeale) Surf.Area (acres) 0.220 0.450 0.620 0.670 0.730 1.120 Routing Primary Inc.Store (acre-feet) 0.000 1.340 0.535 1.290 0.700 0.925 Cum.Store (acre-feet) 0.000 1.340 1.875 3.165 3.865 4.790 Invert Outlet Devices 938.00' 12.0" x 25.0' long Culvert RCP, sq.eut end projecting, Ke= 0.500 Outlet Invert= 937.80' S= 0.0080 'I' Cc= 0.900 n= 0.012 Concrete pipe, finished Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr 100-Year Rainfal/=5.90" Page 19 2/28/2008 #2 Device 1 #3 Device 1 940.10' 48.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 938.60' 12.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=5.70 cfs @ 12.67 hrs HW=940.77' (Free Discharge) L1=Culvert (Inlet Controls 5.70 cfs @ 7.25 fps) t2=orifice/Grate (Passes < 22.44 cfs potential flow) 3=Orifice/Grate (Passes < 4.88 cfs potential flow) Link TP: Total Proposed Inflow Area = Inflow = Primary = 14.901 ac, Inflow Depth> 3.90" for 100-Year event 12.19 cfs @ 12.07 hrs, Volume= 4.847 af 12.19 cfs @ 12.07 hrs, Volume= 4.847 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link TX: Total Existing Inflow Area = Inflow = Primary = 14.901 ac, Inflow Depth> 3.39" for 100-Year event 32.11 cfs @ 12.02 hrs, Volume= 4.213 af 32.11 cfs @ 12.02 hrs, Volume= 4.213 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr NURP Rainfal/=2.50" Page 20 2/28/2008 Runoff = Subcatchment S1: Concept North Lot to Pond 3.43 cfs @ 12.02 hrs, Volume= 0.189af, Depth> 1.31" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr NURP Rainfall=2.50" Area (sf) 41,000 34,361 75,361 34,361 41,000 Tc Length (min) (feet) 10.0 Runoff = CN Description 98 Paved parking & roofs 74 >75% Grass cover, Good, HSG C 87 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (ftlft) (ftlsec) (cfs) Direct Entry, Subcatchment S2: 101 Site to Pond 10.29 cfs @ 12.01 hrs, Volume= 0.590 af, Depth> 1.87" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr NURP Rainfall=2.50" Area (sf) 135,870 29,278 165,148 29,278 135,870 Tc Length (min) (feet) 10.0 Runoff = CN Description 98 Paved parking & roofs 74 >75% Grass cover, Good, HSG C 94 Weighted Average Pervious Area Impervious Area Slope Velocity Capacity Description (ftlft) (ftlsec) ( cfs) Direct Entry, Subcatchment S3: Existing Chan Lakes 10.57 cfs @ 12.11 hrs, Volume= 0.756 af, Depth> 1.05" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr NURP Rainfall=2.50" Area (ac) 5.030 0.500 3.100 8.630 3.600 5.030 CN Description 98 Roof / Parking Lot 80 Pond 60 Lawn / Natural 83 Weighted Average Pervious Area Impervious Area Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @2006 HydroCAD Software Solutions LLC Type /I 24-hr NURP Rainfal/=2.50" Page 21 2/28/2008 Tc Length (min) (feet) 18.0 Runoff = Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) Direct Entry, Subcatchment S4: 101 Lot to Offsite 0.48 cfs @ 12.03 hrs, Volume= 0.029 af, Depth> 0.61" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr NURP Rainfall=2.50" Area (sf) 24,658 24,658 Tc Length (min) (feet) 10.0 Runoff = CN Description 74 Grass & Wetland Areas Pervious Area Slope Velocity Capacity Description (ftlft) (ft/sec) ( cfs) Direct Entry, Subcatchment S5: North Lot Wetland 0.20 cfs @ 12.03 hrs, Volume= 0.011 af, Depth> 0.74" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr NURP Rainfall=2.50" Area (sf) 8,018 8,018 T c Length (min) (feet) 10.0 Runoff = CN Description 77 Brush, Poor, HSG C Pervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) Direct Entry, Subcatchment X1: Existing Stockdale Property 5.36 cfs @ 12.03 hrs, Volume= 0.317 af, Depth> 0.61" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr NURP Rainfall=2.50" Area (sf) 273,185 273,185 CN Description 74 >75% Grass cover, Good, HSG C Pervious Area Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr NURP Rainfal/=2.50" Page 22 2/28/2008 Tc Length (min) (feet) 10.0 Runoff Slope Velocity Capacity Description (ftIft) (ftIsec) (cfs) Direct Entry, Subcatchment X2: Existing Chan lakes = 10.57 cfs @ 12.11 hrs, Volume= 0.756 af, Depth> 1.05" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr NURP Rainfall=2.50" Area (ac) 5.030 0.500 3.100 8.630 3.600 5.030 Tc Length (min) (feet) 18.0 Inflow Area = Inflow = Outflow = Primary = CN Description 98 Roof / Parking Lot 80 Pond 60 Lawn / Natural 83 Weighted Average Pervious Area Impervious Area . Slope Velocity Capacity Description (ftIft) (ftIsec) ( cfs) Direct Entry, Pond P1: Expanded Pond 12.421 ac, Inflow Depth> 1.30" 19.01 cfs @ 12.05 hrs, Volume= 2.22 cfs @ 12.75 hrs, Volume= 2.22 cfs @ 12.75 hrs, Volume= for NURP event 1.345 af 1.085 af, Atten= 88%, Lag= 42.2 min 1.085 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 938.60' Surf.Area= 34,955 sf Storage= 131,844 cf Peak Elev= 939.45' @ 12.75 hrs Surf.Area= 36,057 sf Storage= 161,891 cf (30,047 cf above start) Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass del. time= 148.2 min ( 974.0 - 825.9 ) Volume #1 Invert 933.00' Avail.Storage Storage Description 268,214 cf Custom Stage Data (Prismatic)...isted below (Recalc) Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr NURP Rainfal/=2.50" Page 23 2/28/2008 Elevation (feet) 933.00 934.00 935.00 936.00 937.00 938.00 939.00 940.00 941.00 942.00 Device #1 Routing Primary #2 #3 Device 1 Device 1 Surf.Area (sq-ft) 14,856 17,604 20,163 22,908 25,869 34,232 35,437 36,826 39,562 56,370 Inc.Store (cubic-feet) o 16,230 18,884 21,536 24,389 30,051 34,835 36,132 38,194 47,966 Cum.Store (cubic-feet) o 16,230 35,114 56,649 81,038 111,088 145,923 182,054 220,248 268,214 Invert Outlet Devices 938.00' 12.0" x 25.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 937.80' S= 0.0080 'I' Cc= 0.900 n= 0.012 Concrete pipe, finished 940.10' 48.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 938.60' 12.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=2.22 cfs @ 12.75 hrs HW=939.45' (Free Discharge) L1 =Culvert (Passes 2.22 cfs of 3.44 cfs potential flow) t2=orifiCe/Grate (Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 2.22 cfs @ 3.13 fps) Inflow Area = . Inflow = Outflow = Primary = Pond P2: Concept Pond 1.730 ac, Inflow Depth> 1.31" 3.43 cfs @ 12.02 hrs, Volume= 1.18 cfs @ 12.19 hrs, Volume= 1.18cfs@ 12.19hrs, Volume= for NURP event 0.189 af 0.178 af, Atten= 66%, Lag= 10.5 min 0.178 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 940.00' Surf.Area= 5,052 sf Storage= 9,854 cf Peak Elev= 940.57' @ 12.19 hrs Surf.Area= 5,604 sf Storage= 12,869 cf (3,016 cf above start) Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass del. time= 51.6 min ( 880.5 - 828.9 ) Volume #1 Invert 934.00' Avail.Storage Storage Description 29,539 cf Custom Stage Data (Prismatic)...isted below (Recalc) Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@8.00 sIn 001876 @2006 HydroCAD Software Solutions LLC Type /I 24-hr NURP Rainfal/=2.50" Page 24 2/28/2008 Elevation (feet) 934.00 935.00 936.00 937.00 938.00 939.00 940.00 941.00 942.00 943.00 Device #1 Surf.Area (sq-ft) 465 713 1,013 1,367 1,773 2,229 5,052 6,027 7,059 8,147 Inc.Store (cubic-feet) o 589 863 1,190 1,570 2,001 3,641 5,540 6,543 7,603 Cum.Store (cubic-feet) o 589 1 ,452 2,642 4,212 6,213 9,854 15,393 21,936 29,539 Routing Primary Invert Outlet Devices 940.00' 12.0" x 100.0'long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 939.00' S= 0.0100 'I' Cc= 0.900 n= 0.012 Concrete pipe, finished Primary OutFlow Max=1.17 cfs @ 12.19 hrs HW=940.57' (Free Discharge) "L.1=Culvert (Inlet Controls 1.17 cfs @ 2.56 fps) Inflow Area = Inflow = Outflow = Primary = Pond XP: Existing Pond 8.630 ac, Inflow Depth> 1.05" 10.57 cts @ 12.11 hrs, Volume= 1.19 cfs @ 12.92 hrs, Volume= 1.19 cfs @ 12.92 hrs, Volume= for NURP event 0.756 af 0.597 at, Atten= 89%, Lag= 48.4 min 0.597 at Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hI's . Starting Elev= 938.60' Surf.Area= 0.635 ac Storage= 2.252 af Peak Elev= 939.17' @ 12.92 hrs Surf.Area= 0.649 ac Storage= 2.617 af (0.365 af above start) Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass det. time= 138.2 min ( 988.2 - 850.0 ) Volume #1 Elevation (feet) 933.00 937.00 938.00 940.00 941.00 942.00 Device #1 Invert 933.00' Avail.Storage Storage Description 4.790 af Custom Stage Data (Prismatic}.Jsted below (Recalc) Surf.Area (acres) 0.220. 0.450 0.620 0.670 0.730 1.120 Routing Primary Inc.Store (acre-feet) 0.000 1.340 0.535 1.290 0.700 0.925 Cum.Store (acre-feet) 0.000 1.340 1.875 3.165 3.865 4.790 Invert Outlet Devices 938.00' 12.0" x 25.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 937.80' S= 0.0080 'I' Cc= 0.900 n= 0.012 Concrete pipe, finished Stockdale Site Rev 2-28-08 Prepared by MFRA HydroCAD@ 8.00 sIn 001876 @ 2006 HydroCAD Software Solutions LLC Type /I 24-hr NURP Rainfal/=2.50" Page 25 2/28/2008 #2 Device 1 #3 Device 1 940.10' 48.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 938.60' 12.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=1.19 cfs @ 12.92 hrs HW=939.17' (Free Discharge) L1 =Culvert (Passes 1.19 cfs of 2.89 cfs potential flow) t2=orifiCe/Grate (Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 1.19 cfs @ 2.57 fps) Link TP: Total Proposed Inflow Area = Inflow = Primary = 14.901 ac, Inflow Depth> 1.05" for NURP event 3.21 cfs @ 12.36 hrs, Volume= 1.303 af 3.21 cfs @ 12.36 hrs, Volume= 1.303 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link TX: Total Existing Inflow Area = Inflow = Primary = 14.901 ac, Inflow Depth> 0.74" for NUR.P event 5.51 cfs @ 12.04 hrs, Volume= 0.914 af 5.51 cfs @ 12.04 hrs, Volume= 0.914 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs