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Storm Water Report 4-1-09PRELIMINARY STORM WATER REPORT Powers Crossing Professional Center Chanhassen, MN Prepared for: Pope Associates, Inc. 1255 Energy Park Drive Chanhassen, MN 55108 Prepared by: Westwood Professional Services, Inc. 7699 Anagram Drive Eden Prairie, MN 55344 Phone 952-937-5150, Fax 952-937-5822 July 3, 2008 Revised September 3, 2008 Revised October 6, 2008 Revised April 1, 2009 ??? SUMMARY ??WESTWOOD PROFESSIONAL SERVICES, INC. (952) 937-5150 Project # 20061094.01 The attached storm water runoff and ponding calculations are based on Nationwide Urban Runoff Program (NURP) and The Soil Conservation Service Synthetic Unit Hydrograph Method incorporated into the software program HydroCAD Version 8.00; HydroCAD Software Solutions LLC. The goal of this report is to demonstrate that the proposed stormwater management facilities provide rate control and quality control for the storm water from the proposed Powers Crossing Professional Center project site. The rate control shall not exceed existing discharge rates for the 1, 2, 10 and 100-year storm events as stated in the CODE OF ORDINANCES City of CHANHASSEN, adopted September 24, 2007. The quality control shall obtain a total suspended solids removal of 90% and a phosphorus removal efficiency of 60% or greater using “PONDNET” by William Walker for the storm water contributed by the property. It will also meet the MPCA and NPDES Design Guidelines for Wet Sediment Basins. SITE BACKGROUND The proposed Powers Crossing Professional Center project site is located in Chanhassen, Minnesota, adjacent and east of Powers Boulevard and south of the intersection with Highway 312. The existing site was recently graded with a temporary pond located in the middle of the property. The undisturbed areas are mostly wooded. Elevations vary greatly throughout the site from 854 to 940. Approximately 18.4 acres, including the pond, drain south into a ditch located just east of Powers Boulevard. Of the 18.4 acres, 11.0 acres is onsite and the remaining 7.4 acres is offsite. 0.7 acres drain west directly onto Powers Boulevard and into its storm utility infrastructure. 2.1 acres drain north to a culvert that crosses underneath the Highway 312 on-ramp. Two remaining drainage areas drain 2.1 acres northeast to an existing larger ponding system and 3.7 acres to a separate pond to the east. (See the attached Existing Drainage Plan in the Appendices). The proposed site land land use is medical office which includes a large office building and parking ramp with other associated paved parking areas. 53% of the total area will be made up of impervious surfaces with the total disturbed area approximately equal to 12.0 acres. RATE & VOLUME CONTROL The existing site has been modeled assuming Type ‘C’ soils with curve numbers of 72 and 74 for wooded and pasture/prairie, respectively. The post-development curve numbers were obtained from “Technical Release 55: Urban Hydrology for Small Watersheds.” These were 100 for pond surfaces, 98 for impervious surfaces and 74 for areas with 75% or greater grass coverage. (See Appendix for curve numbers and drainage calculations.) A stormwater pond will be located in the southwestern corner of the property. Under the proposed conditions, 18.7 acres will drain south to the proposed pond and ultimately discharge into the ditch located east of Powers Boulevard. The 7.4 acre drainage area north of the building site will be directed to a bypass pipe that carries the drainage around the pond. No treatment for this area is provided in the proposed pond. 2.1 acres in the northeast corner of the site will drain northeast to the larger ponding system. 0.7 acres will drain west into the Powers Boulevard storm sewer system, 1.0 acres will drain northwest into the 312 storm sewer system, and 0.24 acres will drain offsite untreated to the south through the existing ditch. (See the attached Proposed Drainage Plan in the Appendices.) A summary of the existing and proposed drainage flows can be found in the following table. SUMMARY ?WESTWOOD PROFESSIONAL SERVICES, INC. (952) 937-5150 Existing Drainage Proposed Drainage Drainage Flows 1 yr (cfs) 2 yr (cfs) 10 yr (cfs) 100 yr (cfs) 1 yr (cfs) 2 yr (cfs) 10 yr (cfs) 100 yr (cfs) Southwest Drainage to Ditch 5.2 9.0 23.7 46.0 4.7 8.2 22.8 45.6 West Drainage to Powers Blvd 1.0 1.4 2.7 4.6 1.0 1.4 2.7 4.4 NE Drainage to NE Pond 1.3 2.0 5.0 9.5 1.7 2.6 5.8 10.4 East Drainage to Pond system 1.8 3.0 7.5 14.2 2.0 3.1 7.4 13.6 Drainage to Hwy 312 System 1.5 2.4 5.6 10.2 2.0 2.6 4.5 6.9 Total Site Runoff 10.8 17.8 44.5 84.5 11.4 17.9 43.2 80.9 WATER QUALITY The dead storage volumes were determined utilizing 2.5” runoff depth in accordance with NURP design guidelines. The provided dead storage volume can be found in the following table. The Walker Method target dead storage is 1.24 acre-ft. The HydroCAD stage storage data shows that the dead volume provided below the normal water level is 1.30 acre-ft (Refer to the attached Walker Design Spreadsheets and HydroCAD stage storage printout for design basis. Also, See 2.5” frequency NURP Storm volumes in the Appendix.) It should be noted that the water quality pond also provides enough live storage to treat the water quality volume as defined by the MPCA and NPDES program (1/2” of rainfall over new impervious surfaces and fewer than 5.66 cfs per acre of surface area of the pond of discharge). The water quality ponds provide skimming via the submerged outlet to the discharge and are designed such that the 100-Yr 24-Hr storm can pass through the outlet rather than overtopping the pond embankment. 1.5 feet of freeboard is provided between the 100-year high water level and the Emergency Overflow Elevation. One foot of freeboard is provided between the 100-year high water level and the top of the pond embankment. Other pond criteria can also be found in the following table. Drainage Area NWL Dead Storage 100-yr HWL Live Storage 100-yr Inflow 100-yr Discharge Overflow Elevation (ac.) (ft) (ac.-ft) (ft) (ac.-ft) (cfs) (cfs) (ft) Pond 12.5 866.4 1.30 870.1 870.1 1.8 75.5 45.6 871.6 The PONDNET model was used to determine the phosphorus removal efficiency of the proposed ponds. The required removal efficiency for the site is a 60% per the City of Chanhassen CODE OF ORDINANCES. Using typical phosphorus loadings for urban runoff which amount to around 78 lbs/yr for the development, the proposed overall development has a removal efficiency of 65.7%. (See the PondNet model in the Appendix.) EROSION CONTROL Silt fence, riprap, sediment filters at all inlets, seeding, and fiber blanket placement are some of the erosion control measures being proposed. Rock construction entrances are also standard. (See the grading and erosion control plan for additional information.) SUMMARY ?WESTWOOD PROFESSIONAL SERVICES, INC. (952) 937-5150 Appendix Appendix A Existing Conditions Appendix B Proposed Conditions Appendix C Water Quality Appendix D Details SUMMARY ?WESTWOOD PROFESSIONAL SERVICES, INC. (952) 937-5150 APPENDIX A EXISTING CONDITIONS EXDRA-11 Onsite Drainage South to ditch EXDRA-12 Drainage to Hwy 312 Storm Sewer EXDRA-13 NE Drainage to NE ponding systemEXDRA-14 Offsite Drainage South to ditch EXDRA-15 East Drainage to east ponding system EXDRA-17 West Drainage to Powers Blvd Storm Infrastructure 2L Existing site area 3L Southwest ditch Drainage Diagram for 08-10-02 Existing Conditions Prepared by {enter your company name here}, Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Subcat Reach Pond Link 08-10-02 Existing Conditions Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 2 Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 5.300 70 Woods, Good, HSG C (EXDRA-11) 13.220 72 Woods/grass comb., Good, HSG C (EXDRA-13,EXDRA-14,EXDRA-15) 0.510 74 >75% Grass cover, Good, HSG C (EXDRA-17) 7.830 74 Pasture/grassland/range, Good, HSG C (EXDRA-11,EXDRA-12) 0.200 98 Paved parking & roofs (EXDRA-17) 27.060 TOTAL AREA 08-10-02 Existing Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 3 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method -Pond routing by Stor-Ind method Subcatchment EXDRA-11: Onsite Drainage Runoff Area=11.010 ac 0.00% Impervious Runoff Depth>0.39" Tc=20.0 min CN=72 Runoff=4.42 cfs 0.362 af Subcatchment EXDRA-12: Drainage to Hwy Runoff Area=2.120 ac 0.00% Impervious Runoff Depth>0.46" Tc=10.0 min CN=74 Runoff=1.53 cfs 0.082 af Subcatchment EXDRA-13: NE Drainage to Runoff Area=2.100 ac 0.00% Impervious Runoff Depth>0.40" Tc=10.0 min CN=72 Runoff=1.25 cfs 0.069 af Subcatchment EXDRA-14: Offsite Drainage Runoff Area=7.420 ac 0.00% Impervious Runoff Depth>0.39" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 Runoff=2.48 cfs 0.243 af Subcatchment EXDRA-15: East Drainage to Runoff Area=3.700 ac 0.00% 0.00% Impervious Runoff Depth>0.40" Tc=15.0 min CN=72 Runoff=1.78 cfs 0.122 af Subcatchment EXDRA-17: West Drainage Runoff Area=0.710 ac 28.17% Impervious Runoff Depth>0.76" Tc=7.0 min CN=81 Runoff=1.00 cfs 0.045 af Link 2L: Existing site area delayed by 10.0 min Inflow=2.48 cfs 0.243 af Primary=2.46 cfs 0.241 af Link 3L: Southwest ditch Inflow=5.23 cfs 0.603 af Primary=5.23 cfs 0.603 af Total Runoff Area = 27.060 ac Runoff Volume = 0.922 af Average Runoff Depth = 0.41" 99.26% Pervious = 26.860 ac 0.74% Impervious = 0.200 ac 08-10-02 Existing Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment EXDRA-11: Onsite Drainage South to ditch Runoff = 4.42 cfs @12.16 hrs, Volume= 0.362 af, Depth> 0.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 5.710 74 Pasture/grassland/range, Good, HSG C 5.300 70 Woods, Good, HSG C 11.010 72 Weighted Average 11.010 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 20.0 Direct Entry, Subcatchment EXDRA-11: Onsite Drainage South to ditch Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 43210 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=11.010 ac Runoff Volume=0.362 af Runoff Depth>0.39" Tc=20.0 min CN=72 4.42 cfs 08-10-02 Existing Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment EXDRA-12: Drainage to Hwy 312 Storm Sewer Runoff = 1.53 cfs @12.03 hrs, Volume= 0.082 af, Depth> 0.46" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 2.120 74 Pasture/grassland/range, Good, HSG C 2.120 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment EXDRA-12: Drainage to Hwy 312 Storm Sewer Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 10 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=2.120 ac Runoff Volume=0.082 af Runoff Depth>0.46" Tc=10.0 min CN=74 1.53 cfs 08-10-02 Existing Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment EXDRA-13: NE Drainage to NE ponding system Runoff = 1.25 cfs @12.04 hrs, Volume= 0.069 af, Depth> 0.40" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 2.100 72 Woods/grass comb., Good, HSG C 2.100 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment EXDRA-13: NE Drainage to NE ponding system Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 10 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=2.100 ac Runoff Volume=0.069 af Runoff Depth>0.40" Tc=10.0 min CN=72 1.25 cfs 08-10-02 Existing Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment EXDRA-14: Offsite Drainage South to ditch Runoff = 2.48 cfs @12.24 hrs, Volume= 0.243 af, Depth> 0.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 7.420 72 Woods/grass comb., Good, HSG C 7.420 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.0 650 0.0120 0.42 Lag/CN Method, Subcatchment EXDRA-14: Offsite Drainage South to ditch Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 210 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=7.420 ac Runoff Volume=0.243 af Runoff Depth>0.39" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 2.48 cfs 08-10-02 Existing Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment EXDRA-15: East Drainage to east ponding system Runoff = 1.78 cfs @12.10 hrs, Volume= 0.122 af, Depth> 0.40" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 3.700 72 Woods/grass comb., Good, HSG C 3.700 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment EXDRA-15: East Drainage to east ponding system Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 10 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=3.700 ac Runoff Volume=0.122 af Runoff Depth>0.40" Tc=15.0 min CN=72 1.78 cfs 08-10-02 Existing Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment EXDRA-17: West Drainage to Powers Blvd Storm Infrastructure Runoff = 1.00 cfs @11.99 hrs, Volume= 0.045 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 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 0.510 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking & roofs 0.710 81 Weighted Average 0.510 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment EXDRA-17: West Drainage to Powers Blvd Storm Infrastructure Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 10 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=0.710 ac Runoff Volume=0.045 af Runoff Depth>0.76" Tc=7.0 min CN=CN=81 1.00 cfs 08-10-02 Existing Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 10 Summary for Link 2L: Existing site area Inflow Area = 7.420 ac, 0.00% Impervious, Inflow Depth > 0.39" for 1-yr Storm Event event Inflow = 2.48 cfs @12.24 hrs, Volume= 0.243 af Primary = 2.46 cfs @12.41 hrs, Volume= 0.241 af, Atten= 1%, Lag= 10.1 min Primary outflow = Inflow delayed by 10.0 min, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 2L: Existing site area Inflow Primary Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 210 Inflow Area=7.420 ac delayed by 10.0 min 2.24.84 6c fcsfs 08-10-02 Existing Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 11 Summary for Link 3L: Southwest ditch Inflow Area = 18.430 ac, 0.00% Impervious, Inflow Depth > 0.39" for 1-yr Storm Event event Inflow = 5.23 cfs @12.23 hrs, Volume= 0.603 af Primary = 5.23 cfs @12.23 hrs, Volume= 0.603 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 3L: Southwest ditch Inflow Primary Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 543210 Inflow Area=18.430 ac 5.23 cfs 08-10-02 Existing Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 12 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method -Pond routing by Stor-Ind method Subcatchment EXDRA-11: Onsite Drainage Runoff Area=11.010 ac 0.00% Impervious Runoff Depth>0.61" Tc=20.0 min CN=72 Runoff=7.45 cfs 0.561 af Subcatchment EXDRA-12: Drainage to Hwy Runoff Area=2.120 ac 0.00% Impervious Runoff Depth>0.70" Tc=10.0 min CN=74 Runoff=2.40 cfs 0.124 af Subcatchment EXDRA-13: NE Drainage to Runoff Area=2.100 ac 0.00% Impervious Runoff Depth>0.61" Tc=10.0 min CN=72 Runoff=2.05 cfs 0.108 af Subcatchment EXDRA-14: Offsite Drainage Runoff Area=7.420 ac 0.00% Impervious Runoff Depth>0.61" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 Runoff=4.20 cfs 0.377 af Subcatchment EXDRA-15: East Drainage to Runoff Area=3.700 ac 0.00% Impervious Runoff Depth>0.61" Tc=15.0 min CN=72 Runoff=2.97 cfs 0.189 af Subcatchment EXDRA-17: West Drainage Runoff Area=0.710 ac 28.17% Impervious Runoff Depth>1.06" Tc=7.0 min CN=81 Runoff=1.40 cfs 0.063 af Link 2L: Existing site area delayed by 10.0 min Inflow=4.20 cfs 0.377 af Primary=4.17 cfs 0.374 af Link 3L: Southwest ditch Inflow=9.02 cfs 0.935 af Primary=9.02 cfs 0.935 af Total Runoff Area = 27.060 ac Runoff Volume = 1.420 af Average Runoff Depth = 0.63" 99.26% Pervious = 26.860 ac 0.74% Impervious = 0.200 ac 08-10-02 Existing Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 13 Summary for Subcatchment EXDRA-11: Onsite Drainage South to ditch Runoff = 7.45 cfs @12.15 hrs, Volume= 0.561 af, Depth> 0.61" 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 Storm Event Rainfall=2.80" Area (ac) CN Description 5.710 74 Pasture/grassland/range, Good, HSG C 5.300 70 Woods, Good, HSG C 11.010 72 Weighted Average 11.010 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 20.0 Direct Entry, Subcatchment EXDRA-11: Onsite Drainage South to ditch Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 876543210 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=11.010 ac Runoff Volume=0.561 af Runoff Depth>0.61" Tc=20.0 min CN=72 7.45 cfs 08-10-02 Existing Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 14 Summary for Subcatchment EXDRA-12: Drainage to Hwy 312 Storm Sewer Runoff = 2.40 cfs @12.03 hrs, Volume= 0.124 af, Depth> 0.70" 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 Storm Event Rainfall=2.80" Area (ac) CN Description 2.120 74 Pasture/grassland/range, Good, HSG C 2.120 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment EXDRA-12: Drainage to Hwy 312 Storm Sewer Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 210 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=2.120 ac Runoff Volume=0.124 af Runoff Depth>0.70" Tc=10.0 min CN=74 2.40 cfs 08-10-02 Existing Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 15 Summary for Subcatchment EXDRA-13: NE Drainage to NE ponding system Runoff = 2.05 cfs @12.03 hrs, Volume= 0.108 af, Depth> 0.61" 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 Storm Event Rainfall=2.80" Area (ac) CN Description 2.100 72 Woods/grass comb., Good, HSG C 2.100 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment EXDRA-13: NE Drainage to NE ponding system Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 210 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=2.100 ac Runoff Volume=0.108 af Runoff Depth>0.61" Tc=10.0 min CN=72 2.05 cfs 08-10-02 Existing Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 16 Summary for Subcatchment EXDRA-14: Offsite Drainage South to ditch Runoff = 4.20 cfs @12.23 hrs, Volume= 0.377 af, Depth> 0.61" 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 Storm Event Rainfall=2.80" Area (ac) CN Description 7.420 72 Woods/grass comb., Good, HSG C 7.420 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.0 650 0.0120 0.42 Lag/CN Method, Subcatchment EXDRA-14: Offsite Drainage South to ditch Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 43210 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=7.420 ac Runoff Volume=0.377 af Runoff Depth>0.61" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 4.20 cfs 08-10-02 Existing Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 17 Summary for Subcatchment EXDRA-15: East Drainage to east ponding system Runoff = 2.97 cfs @12.09 hrs, Volume= 0.189 af, Depth> 0.61" 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 Storm Event Rainfall=2.80" Area (ac) CN Description 3.700 72 Woods/grass comb., Good, HSG C 3.700 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment EXDRA-15: East Drainage to east ponding system Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 3210 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=3.700 ac Runoff Volume=0.189 af Runoff Depth>0.61" Tc=15.0 min CN=72 2.97 cfs 08-10-02 Existing Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment EXDRA-17: West Drainage to Powers Blvd Storm Infrastructure Runoff = 1.40 cfs @11.99 hrs, Volume= 0.063 af, Depth> 1.06" 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 Storm Event Rainfall=2.80" Area (ac) CN Description 0.510 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking & roofs 0.710 81 Weighted Average 0.510 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment EXDRA-17: West Drainage to Powers Blvd Storm Infrastructure Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 10 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=0.710 ac Runoff Volume=0.063 af Runoff Depth>1.06" Tc=7.0 min CN=81 1.40 cfs 08-10-02 Existing Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 19 Summary for Link 2L: Existing site area Inflow Area = 7.420 ac, 0.00% Impervious, Inflow Depth > 0.61" for 2-yr Storm Event event Inflow = 4.20 cfs @12.23 hrs, Volume= 0.377 af Primary = 4.17 cfs @12.40 hrs, Volume= 0.374 af, Atten= 1%, Lag= 10.2 min Primary outflow = Inflow delayed by 10.0 min, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 2L: Existing site area Inflow Primary Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 43210 Inflow Area=7.420 ac delayed by 10.0 min 4.42.01 7c fcsfs 08-10-02 Existing Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 20 Summary for Link 3L: Southwest ditch Inflow Area = 18.430 ac, 0.00% Impervious, Inflow Depth > 0.61" for 2-yr Storm Event event Inflow = 9.02 cfs @12.21 hrs, Volume= 0.935 af Primary = 9.02 cfs @12.21 hrs, Volume= 0.935 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 3L: Southwest ditch Inflow Primary Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 109876543210 Inflow Area=18.430 ac 9.02 cfs 08-10-02 Existing Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 21 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method -Pond routing by Stor-Ind method Subcatchment EXDRA-11: Onsite Drainage Runoff Area=11.010 ac 0.00% Impervious Runoff Depth>1.45" Tc=20.0 min CN=72 Runoff=18.99 cfs 1.328 af Subcatchment EXDRA-12: Drainage to Hwy Runoff Area=2.120 ac 0.00% Impervious Runoff Depth>1.59" Tc=10.0 min CN=74 Runoff=5.58 cfs 0.281 af Subcatchment EXDRA-13: NE Drainage to Runoff Area=2.100 ac 0.00% Impervious Runoff Depth>1.45" Tc=10.0 min CN=72 Runoff=5.05 cfs 0.254 af Subcatchment EXDRA-14: Offsite Drainage Runoff Area=7.420 ac 0.00% Impervious Runoff Depth>1.44" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 Runoff=10.88 cfs 0.893 af Subcatchment EXDRA-15: East Drainage to Runoff Area=3.700 ac 0.00% Impervious Runoff Depth>1.45" Tc=15.0 min CN=72 Runoff=7.46 cfs 0.447 af Subcatchment EXDRA-17: West Drainage Runoff Area=0.710 ac 28.17% Impervious Runoff Depth>2.12" Tc=7.0 min CN=81 Runoff=2.74 cfs 0.125 af Link 2L: Existing site area delayed by 10.0 min Inflow=10.88 cfs 0.893 af Primary=10.76 cfs 0.889 af Link 3L: Southwest ditch Inflow=23.68 cfs 2.217 af Primary=23.68 cfs 2.217 af Total Runoff Area = 27.060 ac Runoff Volume = 3.329 af Average Runoff Depth = 1.48" 99.26% Pervious = 26.860 ac 0.74% Impervious = 0.200 ac 08-10-02 Existing Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment EXDRA-11: Onsite Drainage South to ditch Runoff = 18.99 cfs @12.14 hrs, Volume= 1.328 af, Depth> 1.45" 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 Storm Event Rainfall=4.20" Area (ac) CN Description 5.710 74 Pasture/grassland/range, Good, HSG C 5.300 70 Woods, Good, HSG C 11.010 72 Weighted Average 11.010 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 20.0 Direct Entry, Subcatchment EXDRA-11: Onsite Drainage South to ditch Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 21 20 19 18 17 16 15 14 13 12 11 109876543210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=11.010 ac Runoff Volume=1.328 af Runoff Depth>1.45" Tc=20.0 min CN=72 72 18.99 cfs 08-10-02 Existing Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment EXDRA-12: Drainage to Hwy 312 Storm Sewer Runoff = 5.58 cfs @12.02 hrs, Volume= 0.281 af, Depth> 1.59" 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 Storm Event Rainfall=4.20" Area (ac) CN Description 2.120 74 Pasture/grassland/range, Good, HSG C 2.120 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment EXDRA-12: Drainage to Hwy 312 Storm Sewer Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 6543210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=2.120 ac Runoff Volume=0.281 af Runoff Depth>1.59" Tc=10.0 min CN=74 5.58 cfs 08-10-02 Existing Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 24 Summary for Subcatchment EXDRA-13: NE Drainage to NE ponding system Runoff = 5.05 cfs @12.02 hrs, Volume= 0.254 af, Depth> 1.45" 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 Storm Event Rainfall=4.20" Area (ac) CN Description 2.100 72 Woods/grass comb., Good, HSG C 2.100 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment EXDRA-13: NE Drainage to NE ponding system Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 543210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=2.100 ac Runoff Volume=0.254 af Runoff Depth>1.45" Tc=10.0 min CN=72 5.05 cfs 08-10-02 Existing Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 25 Summary for Subcatchment EXDRA-14: Offsite Drainage South to ditch Runoff = 10.88 cfs @12.21 hrs, Volume= 0.893 af, Depth> 1.44" 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 Storm Event Rainfall=4.20" Area (ac) CN Description 7.420 72 Woods/grass comb., Good, HSG C 7.420 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.0 650 0.0120 0.42 Lag/CN Method, Subcatchment EXDRA-14: Offsite Drainage South to ditch Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 12 11 109876543210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=7.420 ac Runoff Volume=0.893 af Runoff Depth>1.44" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 10.88 cfs 08-10-02 Existing Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 26 Summary for Subcatchment EXDRA-15: East Drainage to east ponding system Runoff = 7.46 cfs @12.08 hrs, Volume= 0.447 af, Depth> 1.45" 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 Storm Event Rainfall=4.20" Area (ac) CN Description 3.700 72 Woods/grass comb., Good, HSG C 3.700 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment EXDRA-15: East Drainage to east ponding system Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 876543210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=3.700 ac Runoff Volume=0.447 af Runoff Depth>1.45" Tc=15.0 min CN=72 7.46 cfs 08-10-02 Existing Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 27 Summary for Subcatchment EXDRA-17: West Drainage to Powers Blvd Storm Infrastructure Runoff = 2.74 cfs @11.98 hrs, Volume= 0.125 af, Depth> 2.12" 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 Storm Event Rainfall=4.20" Area (ac) CN Description 0.510 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking & roofs 0.710 81 Weighted Average 0.510 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment EXDRA-17: West Drainage to Powers Blvd Storm Infrastructure Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 3210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=0.710 ac Runoff Volume=0.125 af Runoff Depth>2.12" Tc=7.0 min CN=81 2.74 cfs 08-10-02 Existing Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 28 Summary for Link 2L: Existing site area Inflow Area = 7.420 ac, 0.00% Impervious, Inflow Depth > 1.44" for 10-yr Storm Event event Inflow = 10.88 cfs @12.21 hrs, Volume= 0.893 af Primary = 10.76 cfs @12.38 hrs, Volume= 0.889 af, Atten= 1%, Lag= 10.0 min Primary outflow = Inflow delayed by 10.0 min, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 2L: Existing site area Inflow Primary Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 12 11 109876543210 Inflow Area=7.420 ac delayed by 10.0 min 101.08.87 6c fcsfs 08-10-02 Existing Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 29 Summary for Link 3L: Southwest ditch Inflow Area = 18.430 ac, 0.00% Impervious, Inflow Depth > 1.44" for 10-yr Storm Event event Inflow = 23.68 cfs @12.19 hrs, Volume= 2.217 af Primary = 23.68 cfs @12.19 hrs, Volume= 2.217 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 3L: Southwest ditch Inflow Primary Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 109876543210 Inflow Area=18.430 ac 23.68 cfs 08-10-02 Existing Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 30 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method -Pond routing by Stor-Ind method Subcatchment EXDRA-11: Onsite Drainage Runoff Area=11.010 ac 0.00% Impervious Runoff Depth>2.74" Tc=20.0 min CN=72 Runoff=36.34 cfs 2.515 af Subcatchment EXDRA-12: Drainage to Hwy Runoff Area=2.120 ac 0.00% Impervious Runoff Depth>2.94" Tc=10.0 min CN=74 Runoff=10.22 cfs 0.519 af Subcatchment EXDRA-13: NE Drainage to Runoff Area=2.100 ac 0.00% Impervious Runoff Depth>2.75" Tc=10.0 min CN=72 Runoff=9.52 cfs 0.481 af Subcatchment EXDRA-14: Offsite Drainage Runoff Area=7.420 ac 0.00% Impervious Runoff Depth>2.73" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 Runoff=20.94 cfs 1.691 af Subcatchment EXDRA-15: East Drainage to Runoff Area=3.700 ac ac 0.00% Impervious Runoff Depth>2.75" Tc=15.0 min CN=72 Runoff=14.21 cfs 0.847 af Subcatchment EXDRA-17: West Drainage Runoff Area=0.710 ac 28.17% Impervious Runoff Depth>3.62" Tc=7.0 min CN=81 Runoff=4.55 cfs 0.214 af Link 2L: Existing site area delayed by 10.0 min Inflow=20.94 cfs 1.691 af Primary=20.77 cfs 1.684 af Link 3L: Southwest ditch Inflow=45.95 cfs 4.199 af Primary=45.95 cfs 4.199 af Total Runoff Area = 27.060 ac Runoff Volume = 6.267 af Average Runoff Depth = 2.78" 99.26% Pervious = 26.860 ac 0.74% Impervious = 0.200 ac 08-10-02 Existing Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 31 Summary for Subcatchment EXDRA-11: Onsite Drainage South to ditch Runoff = 36.34 cfs @12.13 hrs, Volume= 2.515 af, Depth> 2.74" 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 Storm Event Rainfall=6.00" Area (ac) CN Description 5.710 74 Pasture/grassland/range, Good, HSG C 5.300 70 Woods, Good, HSG C 11.010 72 Weighted Average 11.010 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 20.0 Direct Entry, Subcatchment EXDRA-11: Onsite Drainage South to ditch Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 1086420 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=11.010 ac Runoff Volume=2.515 af Runoff Depth>2.74" Tc=20.0 20.0 min CN=72 36.34 cfs 08-10-02 Existing Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment EXDRA-12: Drainage to Hwy 312 Storm Sewer Runoff = 10.22 cfs @12.02 hrs, Volume= 0.519 af, Depth> 2.94" 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 Storm Event Rainfall=6.00" Area (ac) CN Description 2.120 74 Pasture/grassland/range, Good, HSG C 2.120 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment EXDRA-12: Drainage to Hwy 312 Storm Sewer Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 11 109876543210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=2.120 ac Runoff Volume=0.519 af Runoff Depth>2.94" Tc=10.0 min CN=74 10.22 cfs 08-10-02 Existing Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment EXDRA-13: NE Drainage to NE ponding system Runoff = 9.52 cfs @12.02 hrs, Volume= 0.481 af, Depth> 2.75" 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 Storm Event Rainfall=6.00" Area (ac) CN Description 2.100 72 Woods/grass comb., Good, HSG C 2.100 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment EXDRA-13: NE Drainage to NE ponding system Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 109876543210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=2.100 ac Runoff Volume=0.481 af Runoff Depth>2.75" Tc=10.0 min CN=72 9.52 cfs 08-10-02 Existing Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 34 Summary for Subcatchment EXDRA-14: Offsite Drainage South to ditch Runoff = 20.94 cfs @12.20 hrs, Volume= 1.691 af, Depth> 2.73" 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 Storm Event Rainfall=6.00" Area (ac) CN Description 7.420 72 Woods/grass comb., Good, HSG C 7.420 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.0 650 0.0120 0.42 Lag/CN Method, Subcatchment EXDRA-14: Offsite Drainage South to ditch Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 23 22 21 20 19 18 17 16 15 14 13 12 11 109876543210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=7.420 ac Runoff Volume=1.691 af Runoff Depth>2.73" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 20.94 cfs 08-10-02 Existing Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 35 Summary for Subcatchment EXDRA-15: East Drainage to east ponding system Runoff = 14.21 cfs @12.07 hrs, Volume= 0.847 af, Depth> 2.75" 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 Storm Event Rainfall=6.00" Area (ac) CN Description 3.700 72 Woods/grass comb., Good, HSG C 3.700 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment EXDRA-15: East Drainage to east ponding system Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 15 14 13 12 11 109876543210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=3.700 ac Runoff Volume=0.847 af Runoff Depth>2.75" Tc=15.0 min CN=72 14.21 cfs 08-10-02 Existing Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 36 Summary for Subcatchment EXDRA-17: West Drainage to Powers Blvd Storm Infrastructure Runoff = 4.55 cfs @11.98 hrs, Volume= 0.214 af, Depth> 3.62" 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 Storm Event Rainfall=6.00" Area (ac) CN Description 0.510 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking & roofs 0.710 81 Weighted Average 0.510 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment EXDRA-17: West Drainage to Powers Blvd Storm Infrastructure Runoff Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 543210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=0.710 ac Runoff Volume=0.214 af Runoff Depth>3.62" Tc=Tc=7.0 min CN=81 4.55 cfs 08-10-02 Existing Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 37 Summary for Link 2L: Existing site area Inflow Area = 7.420 ac, 0.00% Impervious, Inflow Depth > 2.73" for 100-yr Storm Event event Inflow = 20.94 cfs @12.20 hrs, Volume= 1.691 af Primary = 20.77 cfs @12.37 hrs, Volume= 1.684 af, Atten= 1%, Lag= 10.0 min Primary outflow = Inflow delayed by 10.0 min, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 2L: Existing site area Inflow Primary Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 23 22 21 20 19 18 17 16 15 14 13 12 11 109876543210 Inflow Area=7.420 ac delayed by 10.0 min 202.09.47 7c fcsfs 08-10-02 Existing Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 38 Summary for Link 3L: Southwest ditch Inflow Area = 18.430 ac, 0.00% Impervious, Inflow Depth > 2.73" for 100-yr Storm Event event Inflow = 45.95 cfs @12.18 hrs, Volume= 4.199 af Primary = 45.95 cfs @12.18 hrs, Volume= 4.199 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 3L: Southwest ditch Inflow Primary Hydrograph Time (hours) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Flow (cfs) 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 1086420 Inflow Area=18.430 ac 45.95 cfs SUMMARY ?WESTWOOD PROFESSIONAL SERVICES, INC. (952) 937-5150 APPENDIX B PROPOSED CONDITIONS DRA 12 Drainage to 312 Storm Sewer DRA-11 Developed Site Drainage to Pond DRA-11A Offsite Southern Drainage to Pond DRA-13 NE Drainage to NE ponding system DRA-14 Offsite Southern Drainage to Bypass Pipe DRA-15 East Drainage to East Pond System DRA-16 Untreated Drainage to Ditch DRA-17 Western Drainage to Powers Infrastructure Pond Pond to ditch 1L Bypass Pipe 2L Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to Ditch Drainage Diagram for 08-10-02 Proposed Conditions Prepared by {enter your company name here}, Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Subcat Reach Pond Link 08-10-02 Proposed Conditions Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 2 Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 14.510 72 Woods/grass comb., Good, HSG C (DRA-11,DRA-11A,DRA-14,DRA-15) 5.070 74 >75% Grass cover, Good, HSG C (DRA 12,DRA-11,DRA-13,DRA-16,D A-17) 6.900 98 Paved parking & roofs (DRA 12,DRA-11,DRA-13,DRA-17) 0.200 98 Paved roads w/curbs & sewers (DRA-15) 0.400 98 Water Surface (DRA-11A) 27.080 TOTAL AREA 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 3 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method -Pond routing by Stor-Ind method Subcatchment DRA 12: Drainage to 312 Runoff Area=1.020 ac 60.78% Impervious Runoff Depth>1.32" Tc=10.0 min CN=89 Runoff=2.04 cfs 0.112 af Subcatchment DRA-11: Developed Site Runoff Area=8.920 ac 67.49% Impervious Runoff Depth>1.39" Tc=10.0 min CN=90 Runoff=18.75 cfs 1.037 af Subcatchment DRA-11A: Offsite Southern Runoff Area=3.370 ac 11.87% Impervious Runoff Depth>0.56" Tc=15.0 min CN=75 Runoff=2.19 cfs 0.158 af Subcatchment DRA-13: NE Drainage to NE Runoff Area=2.100 ac 2.86% Impervious Runoff Depth>0.56" Tc=10.0 min CN=75 Runoff=1.66 cfs 0.099 af Subcatchment DRA-14: Offsite Southern Runoff Area=7.420 ac 0.00% Impervious Runoff Depth>0.45" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 Runoff=2.48 cfs 0.277 af Subcatchment DRA-15: East Drainage to Runoff Area=3.320 ac 6.02% Impervious Runoff Depth>0.52" Tc=15.0 min CN=74 Runoff=1.97 cfs 0.145 af Subcatchment DRA-16: Untreated Drainage Runoff Area=0.240 ac 0.00% Impervious Runoff Depth>0.52" Tc=10.0 min CN=74 Runoff=0.17 cfs 0.010 af Subcatchment DRA-17: Western Drainage Runoff Area=0.690 ac 28.99% Impervious Runoff Depth>0.84" Tc=7.0 min CN=81 Runoff=0.97 cfs 0.048 af Pond Pond: Pond to ditch Peak Elev=867.80' Storage=83,122 cf Inflow=20.48 cfs 1.195 af Outflow=2.27 cfs 0.922 af Link 1L: Bypass Pipe delayed by 10.0 min Inflow=2.48 cfs 0.277 af Primary=2.46 cfs 0.276 af Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to Ditch Inflow=4.72 cfs 1.208 af Primary=4.72 cfs 1.208 af Total Runoff Area = 27.080 ac Runoff Volume = 1.886 af Average Runoff Depth = 0.84" 72.30% Pervious = 19.580 ac 27.70% Impervious = 7.500 ac 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment DRA 12: Drainage to 312 Storm Sewer Runoff = 2.04 cfs @12.01 hrs, Volume= 0.112 af, Depth> 1.32" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 0.620 98 Paved parking & roofs 0.400 74 >75% Grass cover, Good, HSG C 1.020 89 Weighted Average 0.400 Pervious Area 0.620 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA 12: Drainage to 312 Storm Sewer Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 210 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=1.020 ac Runoff Volume=0.112 af Runoff Depth>1.32" Tc=10.0 min CN=89 2.04 cfs 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment DRA-11: Developed Site Drainage to Pond Runoff = 18.75 cfs @12.01 hrs, Volume= 1.037 af, Depth> 1.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 6.020 98 Paved parking & roofs 1.900 74 >75% Grass cover, Good, HSG C 1.000 72 Woods/grass comb., Good, HSG C 8.920 90 Weighted Average 2.900 Pervious Area 6.020 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-11: Developed Site Drainage to Pond Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 21 20 19 18 17 16 15 14 13 12 11 109876543210 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=8.920 ac Runoff Volume=1.037 af Runoff Depth>1.39" Tc=10.0 min CN=90 18.75 cfs 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment DRA-11A: Offsite Southern Drainage to Pond Runoff = 2.19 cfs @12.09 hrs, Volume= 0.158 af, Depth> 0.56" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 2.970 72 Woods/grass comb., Good, HSG C 0.400 98 Water Surface 3.370 75 Weighted Average 2.970 Pervious Area 0.400 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment DRA-11A: Offsite Southern Drainage to Pond Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 210 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=3.370 ac Runoff Volume=0.158 af Runoff Depth>0.56" Tc=15.0 min CN=75 2.19 cfs 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment DRA-13: NE Drainage to NE ponding system Runoff = 1.66 cfs @12.03 hrs, Volume= 0.099 af, Depth> 0.56" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 2.040 74 >75% Grass cover, Good, HSG C 0.060 98 Paved parking & roofs 2.100 75 Weighted Average 2.040 Pervious Area 0.060 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-13: NE Drainage to NE ponding system Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 10 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=2.100 ac Runoff Volume=0.099 af Runoff Depth>0.56" Tc=10.0 min CN=75 1.66 cfs 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment DRA-14: Offsite Southern Drainage to Bypass Pipe Runoff = 2.48 cfs @12.24 hrs, Volume= 0.277 af, Depth> 0.45" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 7.420 72 Woods/grass comb., Good, HSG C 7.420 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.0 650 0.0120 0.42 Lag/CN Method, Subcatchment DRA-14: Offsite Southern Drainage to Bypass Pipe Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 210 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=7.420 ac Runoff Volume=0.277 af Runoff Depth>0.45" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 2.48 cfs 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment DRA-15: East Drainage to East Pond System Runoff = 1.97 cfs @12.09 hrs, Volume= 0.145 af, Depth> 0.52" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 0.200 98 Paved roads w/curbs & sewers 3.120 72 Woods/grass comb., Good, HSG C 3.320 74 Weighted Average 3.120 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment DRA-15: East Drainage to East Pond System Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 210 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=3.320 ac Runoff Volume=0.145 af Runoff Depth>0.52" Tc=15.0 min CN=74 74 1.97 cfs 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment DRA-16: Untreated Drainage to Ditch Runoff = 0.17 cfs @12.03 hrs, Volume= 0.010 af, Depth> 0.52" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 0.240 74 >75% Grass cover, Good, HSG C 0.240 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-16: Untreated Drainage to Ditch Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.010 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=0.240 ac Runoff Volume=0.010 af Runoff Depth>0.52" Tc=10.0 min CN=74 0.17 cf s08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment DRA-17: Western Drainage to Powers Infrastructure Runoff = 0.97 cfs @11.99 hrs, Volume= 0.048 af, Depth> 0.84" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Storm Event Rainfall=2.35" Area (ac) CN Description 0.490 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking & roofs 0.690 81 Weighted Average 0.490 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment DRA-17: Western Drainage to Powers Infrastructure Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 10 Type II 24-hr 1-yr Storm Event Rainfall=2.35" Runoff Area=0.690 ac Runoff Volume=0.048 af Runoff Depth>0.84" Tc=7.0 min CN=81 0.97 cfs 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 12 Summary for Pond Pond: Pond to ditch Inflow Area = 12.290 ac, 52.24% Impervious, Inflow Depth > 1.17" for 1-yr Storm Event event Inflow = 20.48 cfs @12.02 hrs, Volume= 1.195 af Outflow = 2.27 cfs @12.57 hrs, Volume= 0.922 af, Atten= 89%, Lag= 33.1 min Primary = 2.27 cfs @12.57 hrs, Volume= 0.922 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 866.40' Surf.Area= 17,315 sf Storage= 56,826 cf Peak Elev= 867.80' @12.57 hrs Surf.Area= 20,334 sf Storage= 83,122 cf (26,296 cf above start) Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass det. time= 135.6 min ( 962.7 -827.1 ) Volume Invert Avail.Storage Storage Description #1 856.80' 189,244 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 856.80 208 0 0 858.00 1,322 918 918 860.00 3,122 4,444 5,362 862.00 5,439 8,561 13,923 864.00 8,330 13,769 27,692 865.00 9,991 9,161 36,853 866.00 16,450 13,221 50,073 868.00 20,773 37,223 87,296 870.00 25,404 46,177 133,473 872.00 30,367 55,771 189,244 Device Routing Invert Outlet Devices #1 Primary 866.40' V-Notch Weir, C= 2.62 Head (feet) 0.00 4.00 4.00 10.00 Width (feet) 0.00 3.00 6.00 6.00 Primary OutFlow Max=2.27 cfs @12.57 hrs HW=867.80' (Free Discharge) 1=V-Notch Weir (Weir Controls 2.27 cfs @3.10 fps) 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 13 Pond Pond: Pond to ditch Inflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 22 21 20 19 18 17 16 15 14 13 12 11 109876543210 Inflow Area=12.290 ac Peak Elev=867.80' Storage=83,122 cf 20.48 cfs 2.27 cfs 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 14 Summary for Link 1L: Bypass Pipe Inflow Area = 7.420 ac, 0.00% Impervious, Inflow Depth > 0.45" for 1-yr Storm Event event Inflow = 2.48 cfs @12.24 hrs, Volume= 0.277 af Primary = 2.46 cfs @12.41 hrs, Volume= 0.276 af, Atten= 1%, Lag= 10.1 min Primary outflow = Inflow delayed by 10.0 min, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 1L: Bypass Pipe Inflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 210 Inflow Area=7.420 ac delayed by 10.0 min 22.4.486 c cfsfs 08-10-02 Proposed Conditions Type II 24-hr 1-yr Storm Event Rainfall=2.35" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 15 Summary for Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to Ditch Inflow Area = 19.950 ac, 32.18% Impervious, Inflow Depth > 0.73" for 1-yr Storm Event event Inflow = 4.72 cfs @12.42 hrs, Volume= 1.208 af Primary = 4.72 cfs @12.42 hrs, Volume= 1.208 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to DitchInflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 543210 Inflow Area=19.950 ac 4.72 cfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 16 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method -Pond routing by Stor-Ind method Subcatchment DRA 12: Drainage to 312 Runoff Area=1.020 ac 60.78% Impervious Runoff Depth>1.72" Tc=10.0 min CN=89 Runoff=2.63 cfs 0.146 af Subcatchment DRA-11: Developed Site Runoff Area=8.920 ac 67.49% Impervious Runoff Depth>1.80" Tc=10.0 min CN=90 Runoff=23.98 cfs 1.336 af Subcatchment DRA-11A: Offsite Southern Runoff Area=3.370 ac 11.87% Impervious Runoff Depth>0.83" Tc=15.0 min CN=75 Runoff=3.40 cfs 0.233 af Subcatchment DRA-13: NE Drainage to NE Runoff Area=2.100 ac 2.86% Impervious Runoff Depth>0.83" Tc=10.0 min CN=75 Runoff=2.55 cfs 0.145 af Subcatchment DRA-14: Offsite Southern Runoff Area=7.420 ac 0.00% Impervious Runoff Depth>0.69" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 Runoff=4.20 cfs 0.424 af Subcatchment DRA-15: East Drainage to Runoff Area=3.320 ac 6.02% Impervious Runoff Depth>0.78" Tc=15.0 min CN=74 Runoff=3.12 cfs 0.216 af Subcatchment DRA-16: Untreated Drainage Runoff Area=0.240 ac 0.00% Impervious Runoff Depth>0.78" Tc=10.0 min CN=74 Runoff=0.27 cfs 0.016 af Subcatchment DRA-17: Western Drainage Runoff Area=0.690 ac 28.99% Impervious Runoff Depth>1.16" Tc=7.0 min CN=81 Runoff=1.36 cfs 0.067 af Pond Pond: Pond to ditch Peak Elev=868.15' Storage=90,464 cf Inflow=26.77 cfs 1.569 af Outflow=3.99 cfs 1.275 af Link 1L: Bypass Pipe delayed by 10.0 min Inflow=4.20 cfs 0.424 af Primary=4.17 cfs 0.422 af Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to Ditch Inflow=8.21 cfs 1.712 af Primary=8.21 cfs 1.712 af Total Runoff Area = 27.080 ac Runoff Volume = 2.582 af Average Runoff Depth = 1.14" 72.30% Pervious = 19.580 ac 27.70% Impervious = 7.500 ac 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 17 Summary for Subcatchment DRA 12: Drainage to 312 Storm Sewer Runoff = 2.63 cfs @12.01 hrs, Volume= 0.146 af, Depth> 1.72" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-yr Storm Event Rainfall=2.80" Area (ac) CN Description 0.620 98 Paved parking & roofs 0.400 74 >75% Grass cover, Good, HSG C 1.020 89 Weighted Average 0.400 Pervious Area 0.620 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA 12: Drainage to 312 Storm Sewer Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 210 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=1.020 ac Runoff Volume=0.146 af Runoff Depth>1.72" Tc=10.0 min CN=89 2.63 cfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment DRA-11: Developed Site Drainage to Pond Runoff = 23.98 cfs @12.01 hrs, Volume= 1.336 af, Depth> 1.80" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-yr Storm Event Rainfall=2.80" Area (ac) CN Description 6.020 98 Paved parking & roofs 1.900 74 >75% Grass cover, Good, HSG C 1.000 72 Woods/grass comb., Good, HSG C 8.920 90 Weighted Average 2.900 Pervious Area 6.020 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-11: Developed Site Drainage to Pond Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 109876543210 Type II 24-hr 2-yr Storm Event Rainfall=Rainfall=2.80" Runoff Area=8.920 ac Runoff Volume=1.336 af Runoff Depth>1.80" Tc=10.0 min CN=90 23.98 cfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment DRA-11A: Offsite Southern Drainage to Pond Runoff = 3.40 cfs @12.09 hrs, Volume= 0.233 af, Depth> 0.83" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-yr Storm Event Rainfall=2.80" Area (ac) CN Description 2.970 72 Woods/grass comb., Good, HSG C 0.400 98 Water Surface 3.370 75 Weighted Average 2.970 Pervious Area 0.400 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment DRA-11A: Offsite Southern Drainage to Pond Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 3210 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=3.370 ac Runoff Volume=0.233 af Runoff Depth>0.83" Tc=15.0 min CN=75 3.40 cfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment DRA-13: NE Drainage to NE ponding system Runoff = 2.55 cfs @12.03 hrs, Volume= 0.145 af, Depth> 0.83" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-yr Storm Event Rainfall=2.80" Area (ac) CN Description 2.040 74 >75% Grass cover, Good, HSG C 0.060 98 Paved parking & roofs 2.100 75 Weighted Average 2.040 Pervious Area 0.060 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-13: NE Drainage to NE ponding system Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 210 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=2.100 ac Runoff Volume=0.145 af Runoff Depth>0.83" Tc=10.0 min CN=75 2.55 cfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 21 Summary for Subcatchment DRA-14: Offsite Southern Drainage to Bypass Pipe Runoff = 4.20 cfs @12.23 hrs, Volume= 0.424 af, Depth> 0.69" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-yr Storm Event Rainfall=2.80" Area (ac) CN Description 7.420 72 Woods/grass comb., Good, HSG C 7.420 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.0 650 0.0120 0.42 Lag/CN Method, Subcatchment DRA-14: Offsite Southern Drainage to Bypass Pipe Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 43210 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=7.420 ac Runoff Volume=0.424 af Runoff Depth>0.69" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 4.20 cfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment DRA-15: East Drainage to East Pond System Runoff = 3.12 cfs @12.09 hrs, Volume= 0.216 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-yr Storm Event Rainfall=2.80" Area (ac) CN Description 0.200 98 Paved roads w/curbs & sewers 3.120 72 Woods/grass comb., Good, HSG C 3.320 74 Weighted Average 3.120 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment DRA-15: East Drainage to East Pond System Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 3210 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=3.320 ac Runoff Volume=0.216 af Runoff Depth>0.78" Tc=15.0 min CN=74 3.12 cfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment DRA-16: Untreated Drainage to Ditch Runoff = 0.27 cfs @12.03 hrs, Volume= 0.016 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-yr Storm Event Rainfall=2.80" Area (ac) CN Description 0.240 74 >75% Grass cover, Good, HSG C 0.240 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-16: Untreated Drainage to Ditch Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.020 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=0.240 ac Runoff Volume=0.016 af Runoff Depth>0.78" Tc=10.0 min CN=74 0.27 cfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 24 Summary for Subcatchment DRA-17: Western Drainage to Powers Infrastructure Runoff = 1.36 cfs @11.99 hrs, Volume= 0.067 af, Depth> 1.16" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-yr Storm Event Rainfall=2.80" Area (ac) CN Description 0.490 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking & roofs 0.690 81 Weighted Average 0.490 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment DRA-17: Western Drainage to Powers Infrastructure Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 10 Type II 24-hr 2-yr Storm Event Rainfall=2.80" Runoff Area=0.690 ac Runoff Volume=0.067 af Runoff Depth>1.16" Tc=7.0 min min CN=81 1.36 cfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 25 Summary for Pond Pond: Pond to ditch Inflow Area = 12.290 ac, 52.24% Impervious, Inflow Depth > 1.53" for 2-yr Storm Event event Inflow = 26.77 cfs @12.02 hrs, Volume= 1.569 af Outflow = 3.99 cfs @12.42 hrs, Volume= 1.275 af, Atten= 85%, Lag= 24.1 min Primary = 3.99 cfs @12.42 hrs, Volume= 1.275 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 866.40' Surf.Area= 17,315 sf Storage= 56,826 cf Peak Elev= 868.15' @12.42 hrs Surf.Area= 21,123 sf Storage= 90,464 cf (33,638 cf above start) Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass det. time= 118.7 min ( 938.9 -820.1 ) Volume Invert Avail.Storage Storage Description #1 856.80' 189,244 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 856.80 208 0 0 858.00 1,322 918 918 860.00 3,122 4,444 5,362 862.00 5,439 8,561 13,923 864.00 8,330 13,769 27,692 865.00 9,991 9,161 36,853 866.00 16,450 13,221 50,073 868.00 20,773 37,223 87,296 870.00 25,404 46,177 133,473 872.00 30,367 55,771 189,244 Device Routing Invert Outlet Devices #1 Primary 866.40' V-Notch Weir, C= 2.62 Head (feet) 0.00 4.00 4.00 10.00 Width (feet) 0.00 3.00 6.00 6.00 Primary OutFlow Max=3.98 cfs @12.42 hrs HW=868.15' (Free Discharge) 1=V-Notch Weir (Weir Controls 3.98 cfs @3.47 fps) 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 26 Pond Pond: Pond to ditch Inflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 28 26 24 22 20 18 16 14 12 1086420 Inflow Area=12.290 ac Peak Elev=868.15' Storage=90,464 cf 26.77 cfs 3.99 cfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 27 Summary for Link 1L: Bypass Pipe Inflow Area = 7.420 ac, 0.00% Impervious, Inflow Depth > 0.69" for 2-yr Storm Event event Inflow = 4.20 cfs @12.23 hrs, Volume= 0.424 af Primary = 4.17 cfs @12.40 hrs, Volume= 0.422 af, Atten= 1%, Lag= 10.2 min Primary outflow = Inflow delayed by 10.0 min, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 1L: Bypass Pipe Inflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 43210 Inflow Area=7.420 ac delayed by 10.0 min 44.2.107 c cfsfs 08-10-02 Proposed Conditions Type II 24-hr 2-yr Storm Event Rainfall=2.80" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 28 Summary for Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to Ditch Inflow Area = 19.950 ac, 32.18% Impervious, Inflow Depth > 1.03" for 2-yr Storm Event event Inflow = 8.21 cfs @12.40 hrs, Volume= 1.712 af Primary = 8.21 cfs @12.40 hrs, Volume= 1.712 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to DitchInflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 9876543210 Inflow Area=19.950 ac 8.21 cfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 29 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method -Pond routing by Stor-Ind method Subcatchment DRA 12: Drainage to 312 Runoff Area=1.020 ac 60.78% Impervious Runoff Depth>3.01" Tc=10.0 min CN=89 Runoff=4.50 cfs 0.255 af Subcatchment DRA-11: Developed Site Runoff Area=8.920 ac 67.49% Impervious Runoff Depth>3.10" Tc=10.0 min CN=90 Runoff=40.37 cfs 2.307 af Subcatchment DRA-11A: Offsite Southern Runoff Area=3.370 ac 11.87% Impervious Runoff Depth>1.81" Tc=15.0 min CN=75 Runoff=7.80 cfs 0.509 af Subcatchment DRA-13: NE Drainage to NE Runoff Area=2.100 ac 2.86% Impervious Runoff Depth>1.81" Tc=10.0 min CN=75 Runoff=5.77 cfs 0.317 af Subcatchment DRA-14: Offsite Southern Runoff Area=7.420 ac 0.00% Impervious Runoff Depth>1.59" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 Runoff=10.88 cfs 0.983 af Subcatchment DRA-15: East Drainage to Runoff Area=3.320 ac 6.02% Impervious Runoff Depth>1.74" Tc=15.0 min CN=74 Runoff=7.35 cfs 0.481 af Subcatchment DRA-16: Untreated Drainage Runoff Area=0.240 ac 0.00% Impervious Runoff Depth>1.74" Tc=10.0 min CN=74 Runoff=0.63 cfs 0.035 af Subcatchment DRA-17: Western Drainage Runoff Area=0.690 ac 28.99% Impervious Runoff Depth>2.29" Tc=7.0 min CN=81 Runoff=2.66 cfs 0.132 af Pond Pond: Pond to ditch Peak Elev=869.16' Storage=112,994 cf Inflow=47.10 cfs 2.815 af Outflow=12.46 cfs 2.468 af Link 1L: Bypass Pipe delayed by 10.0 min Inflow=10.88 cfs 0.983 af Primary=10.76 cfs 0.979 af Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to Ditch Inflow=22.86 cfs 3.482 af Primary=22.86 cfs 3.482 af Total Runoff Area = 27.080 ac Runoff Volume = 5.018 af Average Runoff Depth = 2.22" 72.30% Pervious = 19.580 ac 27.70% Impervious = 7.500 ac 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment DRA 12: Drainage to 312 Storm Sewer Runoff = 4.50 cfs @12.01 hrs, Volume= 0.255 af, Depth> 3.01" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Storm Event Rainfall=4.20" Area (ac) CN Description 0.620 98 Paved parking & roofs 0.400 74 >75% Grass cover, Good, HSG C 1.020 89 Weighted Average 0.400 Pervious Area 0.620 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA 12: Drainage to 312 Storm Sewer Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 543210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=1.020 ac Runoff Volume=0.255 af Runoff Depth>3.01" Tc=10.0 min CN=89 4.50 cfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 31 Summary for Subcatchment DRA-11: Developed Site Drainage to Pond Runoff = 40.37 cfs @12.01 hrs, Volume= 2.307 af, Depth> 3.10" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Storm Event Rainfall=4.20" Area (ac) CN Description 6.020 98 Paved parking & roofs 1.900 74 >75% Grass cover, Good, HSG C 1.000 72 Woods/grass comb., Good, HSG C 8.920 90 Weighted Average 2.900 Pervious Area 6.020 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-11: Developed Site Drainage to Pond Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 1086420 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=8.920 ac Runoff Volume=2.307 af Runoff Depth>3.10" Tc=10.0 min CN=90 40.37 cfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment DRA-11A: Offsite Southern Drainage to Pond Runoff = 7.80 cfs @12.08 hrs, Volume= 0.509 af, Depth> 1.81" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Storm Event Rainfall=4.20" Area (ac) CN Description 2.970 72 Woods/grass comb., Good, HSG C 0.400 98 Water Surface 3.370 75 Weighted Average 2.970 Pervious Area 0.400 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment DRA-11A: Offsite Southern Drainage to Pond Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 876543210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=3.370 ac Runoff Volume=0.509 af Runoff Depth>1.81" Tc=15.0 min CN=75 7.80 cfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment DRA-13: NE Drainage to NE ponding system Runoff = 5.77 cfs @12.02 hrs, Volume= 0.317 af, Depth> 1.81" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Storm Event Rainfall=4.20" Area (ac) CN Description 2.040 74 >75% Grass cover, Good, HSG C 0.060 98 Paved parking & roofs 2.100 75 Weighted Average 2.040 Pervious Area 0.060 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-13: NE Drainage to NE ponding system Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 6543210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=2.100 ac Runoff Volume=0.317 af Runoff Depth>1.81" Tc=10.0 min CN=75 5.77 cfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 34 Summary for Subcatchment DRA-14: Offsite Southern Drainage to Bypass Pipe Runoff = 10.88 cfs @12.21 hrs, Volume= 0.983 af, Depth> 1.59" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Storm Event Rainfall=4.20" Area (ac) CN Description 7.420 72 Woods/grass comb., Good, HSG C 7.420 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.0 650 0.0120 0.42 Lag/CN Method, Subcatchment DRA-14: Offsite Southern Drainage to Bypass Pipe Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 12 11 109876543210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=7.420 ac Runoff Volume=0.983 af Runoff Depth>1.59" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 10.88 cfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 35 Summary for Subcatchment DRA-15: East Drainage to East Pond System Runoff = 7.35 cfs @12.08 hrs, Volume= 0.481 af, Depth> 1.74" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Storm Event Rainfall=4.20" Area (ac) CN Description 0.200 98 Paved roads w/curbs & sewers 3.120 72 Woods/grass comb., Good, HSG C 3.320 74 Weighted Average 3.120 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment DRA-15: East Drainage to East Pond System Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 876543210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=3.320 ac Runoff Volume=0.481 af Runoff Depth>1.74" Tc=15.0 15.0 min CN=74 7.35 cfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 36 Summary for Subcatchment DRA-16: Untreated Drainage to Ditch Runoff = 0.63 cfs @12.02 hrs, Volume= 0.035 af, Depth> 1.74" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Storm Event Rainfall=4.20" Area (ac) CN Description 0.240 74 >75% Grass cover, Good, HSG C 0.240 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-16: Untreated Drainage to Ditch Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.050 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=0.240 ac Runoff Volume=0.035 af Runoff Depth>1.74" Tc=10.0 min CN=74 0.63 cfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 37 Summary for Subcatchment DRA-17: Western Drainage to Powers Infrastructure Runoff = 2.66 cfs @11.98 hrs, Volume= 0.132 af, Depth> 2.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Storm Event Rainfall=4.20" Area (ac) CN Description 0.490 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking & roofs 0.690 81 Weighted Average 0.490 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment DRA-17: Western Drainage to Powers Infrastructure Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 210 Type II 24-hr 10-yr Storm Event Rainfall=4.20" Runoff Area=0.690 ac Runoff Volume=0.132 af Runoff Depth>2.29" Tc=7.0 7.0 min CN=81 2.66 cfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 38 Summary for Pond Pond: Pond to ditch Inflow Area = 12.290 ac, 52.24% Impervious, Inflow Depth > 2.75" for 10-yr Storm Event event Inflow = 47.10 cfs @12.02 hrs, Volume= 2.815 af Outflow = 12.46 cfs @12.25 hrs, Volume= 2.468 af, Atten= 74%, Lag= 14.2 min Primary = 12.46 cfs @12.25 hrs, Volume= 2.468 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 866.40' Surf.Area= 17,315 sf Storage= 56,826 cf Peak Elev= 869.16' @12.25 hrs Surf.Area= 23,463 sf Storage= 112,994 cf (56,168 cf above start) Plug-Flow detention time= 362.8 min calculated for 1.163 af (41% of inflow) Center-of-Mass det. time= 90.2 min ( 895.4 -805.2 ) Volume Invert Avail.Storage Storage Description #1 856.80' 189,244 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 856.80 208 0 0 858.00 1,322 918 918 860.00 3,122 4,444 5,362 862.00 5,439 8,561 13,923 864.00 8,330 13,769 27,692 865.00 9,991 9,161 36,853 866.00 16,450 13,221 50,073 868.00 20,773 37,223 87,296 870.00 25,404 46,177 133,473 872.00 30,367 55,771 189,244 Device Routing Invert Outlet Devices #1 Primary 866.40' V-Notch Weir, C= 2.62 Head (feet) 0.00 4.00 4.00 10.00 Width (feet) 0.00 3.00 6.00 6.00 Primary OutFlow Max=12.44 cfs @12.25 hrs HW=869.16' (Free Discharge) 1=V-Notch Weir (Weir Controls 12.44 cfs @4.35 fps) 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 39 Pond Pond: Pond to ditch Inflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 52 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 1086420 Inflow Area=12.290 ac Peak Elev=869.16' Storage=112,994 cf 47.10 cfs 12.46 cfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 40 Summary for Link 1L: Bypass Pipe Inflow Area = 7.420 ac, 0.00% Impervious, Inflow Depth > 1.59" for 10-yr Storm Event event Inflow = 10.88 cfs @12.21 hrs, Volume= 0.983 af Primary = 10.76 cfs @12.38 hrs, Volume= 0.979 af, Atten= 1%, Lag= 10.0 min Primary outflow = Inflow delayed by 10.0 min, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 1L: Bypass Pipe Inflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 12 11 109876543210 Inflow Area=7.420 ac delayed by 10.0 min 1100.8.786 c cfsfs 08-10-02 Proposed Conditions Type II 24-hr 10-yr Storm Event Rainfall=4.20" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 41 Summary for Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to Ditch Inflow Area = 19.950 ac, 32.18% Impervious, Inflow Depth > 2.09" for 10-yr Storm Event event Inflow = 22.86 cfs @12.36 hrs, Volume= 3.482 af Primary = 22.86 cfs @12.36 hrs, Volume= 3.482 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to DitchInflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 109876543210 Inflow Area=19.950 ac 22.86 cfs 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 42 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method -Pond routing by Stor-Ind method Subcatchment DRA 12: Drainage to 312 Runoff Area=1.020 ac 60.78% Impervious Runoff Depth>4.73" Tc=10.0 min CN=89 Runoff=6.91 cfs 0.402 af Subcatchment DRA-11: Developed Site Runoff Area=8.920 ac 67.49% Impervious Runoff Depth>4.84" Tc=10.0 min CN=90 Runoff=61.32 cfs 3.596 af Subcatchment DRA-11A: Offsite Southern Runoff Area=3.370 ac 11.87% Impervious Runoff Depth>3.27" Tc=15.0 min CN=75 Runoff=14.20 cfs 0.918 af Subcatchment DRA-13: NE Drainage to NE Runoff Area=2.100 ac 2.86% Impervious Runoff Depth>3.27" Tc=10.0 min CN=75 Runoff=10.42 cfs 0.573 af Subcatchment DRA-14: Offsite Southern Runoff Area=7.420 ac 0.00% Impervious Runoff Depth>2.97" Flow Length=650' Slope=0.0120 '/' Tc=26.0 min CN=72 Runoff=20.94 cfs 1.838 af Subcatchment DRA-15: East Drainage to Runoff Area=3.320 ac 6.02% Impervious Runoff Depth>3.17" Tc=15.0 min CN=74 Runoff=13.58 cfs 0.878 af Subcatchment DRA-16: Untreated Drainage Runoff Area=0.240 ac 0.00% Impervious Runoff Depth>3.18" Tc=10.0 min CN=74 Runoff=1.16 cfs 0.064 af Subcatchment DRA-17: Western Drainage Runoff Area=0.690 ac 28.99% Impervious Runoff Depth>3.88" Tc=7.0 min CN=81 Runoff=4.42 cfs 0.223 af Pond Pond: Pond to ditch Peak Elev=870.20' Storage=138,598 cf Inflow=73.83 cfs 4.514 af Outflow=27.68 cfs 4.110 af Link 1L: Bypass Pipe delayed by 10.0 min Inflow=20.94 cfs 1.838 af Primary=20.77 cfs 1.832 af Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to Ditch Inflow=45.64 cfs 6.006 af Primary=45.64 cfs 6.006 af Total Runoff Area = 27.080 ac Runoff Volume = 8.492 af Average Runoff Depth = 3.76" 72.30% Pervious = 19.580 ac 27.70% Impervious = 7.500 ac 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 43 Summary for Subcatchment DRA 12: Drainage to 312 Storm Sewer Runoff = 6.91 cfs @12.01 hrs, Volume= 0.402 af, Depth> 4.73" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Storm Event Rainfall=6.00" Area (ac) CN Description 0.620 98 Paved parking & roofs 0.400 74 >75% Grass cover, Good, HSG C 1.020 89 Weighted Average 0.400 Pervious Area 0.620 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA 12: Drainage to 312 Storm Sewer Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 76543210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=1.020 ac Runoff Volume=0.402 af Runoff Depth>4.73" Tc=10.0 min CN=89 6.91 cfs cfs08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 44 Summary for Subcatchment DRA-11: Developed Site Drainage to Pond Runoff = 61.32 cfs @12.01 hrs, Volume= 3.596 af, Depth> 4.84" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Storm Event Rainfall=6.00" Area (ac) CN Description 6.020 98 Paved parking & roofs 1.900 74 >75% Grass cover, Good, HSG C 1.000 72 Woods/grass comb., Good, HSG C 8.920 90 Weighted Average 2.900 Pervious Area 6.020 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-11: Developed Site Drainage to Pond Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 65 60 55 50 45 40 35 30 25 20 15 1050 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=8.920 ac Runoff Volume=3.596 af Runoff Depth>4.84" Tc=10.0 min CN=90 61.32 cfs 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 45 Summary for Subcatchment DRA-11A: Offsite Southern Drainage to Pond Runoff = 14.20 cfs @12.07 hrs, Volume= 0.918 af, Depth> 3.27" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Storm Event Rainfall=6.00" Area (ac) CN Description 2.970 72 Woods/grass comb., Good, HSG C 0.400 98 Water Surface 3.370 75 Weighted Average 2.970 Pervious Area 0.400 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment DRA-11A: Offsite Southern Drainage to Pond Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 15 14 13 12 11 109876543210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=3.370 ac Runoff Volume=0.918 af Runoff Depth>3.27" Tc=15.0 min CN=75 14.20 cfs 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 46 Summary for Subcatchment DRA-13: NE Drainage to NE ponding system Runoff = 10.42 cfs @12.02 hrs, Volume= 0.573 af, Depth> 3.27" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Storm Event Rainfall=6.00" Area (ac) CN Description 2.040 74 >75% Grass cover, Good, HSG C 0.060 98 Paved parking & roofs 2.100 75 Weighted Average 2.040 Pervious Area 0.060 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-13: NE Drainage to NE ponding system Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 11 109876543210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=2.100 ac Runoff Volume=0.573 af Runoff Depth>3.27" Tc=10.0 10.0 min CN=75 10.42 cfs 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 47 Summary for Subcatchment DRA-14: Offsite Southern Drainage to Bypass Pipe Runoff = 20.94 cfs @12.20 hrs, Volume= 1.838 af, Depth> 2.97" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Storm Event Rainfall=6.00" Area (ac) CN Description 7.420 72 Woods/grass comb., Good, HSG C 7.420 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.0 650 0.0120 0.42 Lag/CN Method, Subcatchment DRA-14: Offsite Southern Drainage to Bypass Pipe Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 23 22 21 20 19 18 17 16 15 14 13 12 11 109876543210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=7.420 ac Runoff Volume=1.838 af Runoff Depth>2.97" Flow Length=650' 650' Slope=0.0120 '/' Tc=26.0 min CN=72 20.94 cfs 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 48 Summary for Subcatchment DRA-15: East Drainage to East Pond System Runoff = 13.58 cfs @12.07 hrs, Volume= 0.878 af, Depth> 3.17" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Storm Event Rainfall=6.00" Area (ac) CN Description 0.200 98 Paved roads w/curbs & sewers 3.120 72 Woods/grass comb., Good, HSG C 3.320 74 Weighted Average 3.120 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Subcatchment DRA-15: East Drainage to East Pond System Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 15 14 13 12 11 109876543210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=3.320 ac Runoff Volume=0.878 af Runoff Depth>3.17" Tc=15.0 min CN=74 13.58 cfs 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 49 Summary for Subcatchment DRA-16: Untreated Drainage to Ditch Runoff = 1.16 cfs @12.02 hrs, Volume= 0.064 af, Depth> 3.18" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Storm Event Rainfall=6.00" Area (ac) CN Description 0.240 74 >75% Grass cover, Good, HSG C 0.240 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment DRA-16: Untreated Drainage to Ditch Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 10 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=0.240 ac Runoff Volume=0.064 af Runoff Depth>3.18" Tc=10.0 min CN=74 1.16 cfs 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 50 Summary for Subcatchment DRA-17: Western Drainage to Powers Infrastructure Runoff = 4.42 cfs @11.98 hrs, Volume= 0.223 af, Depth> 3.88" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-yr Storm Event Rainfall=6.00" Area (ac) CN Description 0.490 74 >75% Grass cover, Good, HSG C 0.200 98 Paved parking & roofs 0.690 81 Weighted Average 0.490 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment DRA-17: Western Drainage to Powers Infrastructure Runoff Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 43210 Type II 24-hr 100-yr Storm Event Rainfall=6.00" Runoff Area=0.690 ac Runoff Volume=0.223 af Runoff Depth>3.88" Tc=7.0 min CN=81 4.42 cfs 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 51 Summary for Pond Pond: Pond to ditch Inflow Area = 12.290 ac, 52.24% Impervious, Inflow Depth > 4.41" for 100-yr Storm Event event Inflow = 73.83 cfs @12.02 hrs, Volume= 4.514 af Outflow = 27.68 cfs @12.20 hrs, Volume= 4.110 af, Atten= 63%, Lag= 10.9 min Primary = 27.68 cfs @12.20 hrs, Volume= 4.110 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Starting Elev= 866.40' Surf.Area= 17,315 sf Storage= 56,826 cf Peak Elev= 870.20' @12.20 hrs Surf.Area= 25,900 sf Storage= 138,598 cf (81,772 cf above start) Plug-Flow detention time= 244.4 min calculated for 2.805 af (62% of inflow) Center-of-Mass det. time= 73.4 min ( 866.6 -793.2 ) Volume Invert Avail.Storage Storage Description #1 856.80' 189,244 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 856.80 208 0 0 858.00 1,322 918 918 860.00 3,122 4,444 5,362 862.00 5,439 8,561 13,923 864.00 8,330 13,769 27,692 865.00 9,991 9,161 36,853 866.00 16,450 13,221 50,073 868.00 20,773 37,223 87,296 870.00 25,404 46,177 133,473 872.00 30,367 55,771 189,244 Device Routing Invert Outlet Devices #1 Primary 866.40' V-Notch Weir, C= 2.62 Head (feet) 0.00 4.00 4.00 10.00 Width (feet) 0.00 3.00 6.00 6.00 Primary OutFlow Max=27.64 cfs @12.20 hrs HW=870.20' (Free Discharge) 1=V-Notch Weir (Weir Controls 27.64 cfs @5.11 fps) 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 52 Pond Pond: Pond to ditch Inflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 80 75 70 65 60 55 50 45 40 35 30 25 20 15 1050 Inflow Area=12.290 ac Peak Elev=870.20' Storage=138,598 cf 73.83 cfs 27.68 cfs 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 53 Summary for Link 1L: Bypass Pipe Inflow Area = 7.420 ac, 0.00% Impervious, Inflow Depth > 2.97" for 100-yr Storm Event event Inflow = 20.94 cfs @12.20 hrs, Volume= 1.838 af Primary = 20.77 cfs @12.37 hrs, Volume= 1.832 af, Atten= 1%, Lag= 10.0 min Primary outflow = Inflow delayed by 10.0 min, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 1L: Bypass Pipe Inflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 23 22 21 20 19 18 17 16 15 14 13 12 11 109876543210 Inflow Area=7.420 ac delayed by 10.0 min 2200.9.747 c cfsfs 08-10-02 Proposed Conditions Type II 24-hr 100-yr Storm Event Rainfall=6.00" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 54 Summary for Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to Ditch Inflow Area = 19.950 ac, 32.18% Impervious, Inflow Depth > 3.61" for 100-yr Storm Event event Inflow = 45.64 cfs @12.32 hrs, Volume= 6.006 af Primary = 45.64 cfs @12.32 hrs, Volume= 6.006 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 2L: Pond Discharge (+) Bypass Pipe (+) Untreated Drainage to DitchInflow Primary Hydrograph Time (hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (cfs) 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 1086420 Inflow Area=19.950 ac 45.64 cfs SUMMARY ?WESTWOOD PROFESSIONAL SERVICES, INC. (952) 937-5150 APPENDIX C WATER QUALITY PONDNET 2.1 FLOW AND PHOSPHORUS ROUTING IN PON W. Walker March 1989 Press ALT-G for Graph TITLE--> Chanhassen Pond INPUT VARIABLES.... UNITS case labels NURP Pond 1 Pond 2 watershed area acres 100 11.89 0 runoff coefficient -0.2 0.65 0 pond surface area acres 1 0.41 0 pond mean depth feet 4.9 0 upstream pond p load lbs/yr 0 0 0 upstream pond outflow ac-ft/yr 0 0 0 OUTPUT VARIABLES........ outflow p load lbs/yr 43.64625 15.61117 #DIV/0! outflow volume ac-ft/yr 66.66667 25.76167 0 outflow p conc ppb 240.8734 222.9523 #DIV/0! pond removal % 62.94452 65.70146 #DIV/0! total removal % 62.94256 65.69964 #DIV/0! ASSUMED EXPORT FACTORS............. period length yrs 0.5 0.5 0.5 period precipitation inches 20 20 20 runoff total p ppb 650 650 650 runoff ortho p/total p -0.3 0.3 0.3 relative decay rate -1 1 1 unit runoff in/yr 8 26 0 unit export lbs/ac-y 1.177862 3.828053 0 POND WATER BUDGETS...................... runoff ac-ft/yr 66.66667 25.76167 0 upstream pond ac-ft/yr 0 0 0 total inflow ac-ft/yr 66.66667 25.76167 0 0 outflow ac-ft/yr 66.66667 25.76167 0 POND PHOSPHORUS BUDGETS................... runoff lbs/yr 117.7862 45.51555 0 upstream pond lbs/yr 0 0 0 total inflow lbs/yr 117.7862 45.51555 0 net sedimentation lbs/yr 74.13999 29.90438 #DIV/0! outflow lbs/yr 43.64625 15.61117 #DIV/0! HYDRAULIC PARAMETERS............ pond volume acre-ft 4.166667 2.009 0 vlawmo pond volume acre-ft 4.166667 1.610104 0 relative volume inches 2.5 3.119363 #DIV/0! residence time years 0.0625 0.077984 #DIV/0! residence time days 22.8125 28.46419 #DIV/0! overflow rate ft/yr 66.66667 62.83333 #DIV/0! inflow phos conc ppb 650.0344 650.0344 #DIV/0! outflow phos conc ppb 240.8734 222.9523 #DIV/0! p reaction rate -4.58409 5.585006 #DIV/0! 1-rp -0.370555 0.342985 #DIV/0! PONDSIZ -Version 2.1 -W. Walker INPUT VARIABLE UNITS VALUES NOTES case title ---------------> Chanhassen Pond watershed area acres 11.89 pervious curve number -85 from SCS tables, for AMC=2 impervious fraction -0.5 design storm inches 2.5 VLAWMO criterion = 2.5 inches antecedent moisture cond. 2 (1,2,or 3), VLAWMO criterion = 2 pond maximum depth feet 10 <= 10 ft bench width bc feet 10 >= 10 ft bench slope bc ft/ft 10 >= 10 ft horiz /ft vertical side slope ab ft/ft 3 >= 3 ft horiz /ft vertical pond shape factor 3 1=triangle,2=rectangle,3=ellipse length/width ratio -3 >= 3 top length c feet 290.00 adjust to achieve target volume OUTPUT VARIABLE UNITS VALUE target volume acre-ft 1.24 = design storm runoff volume 08-10-02 Proposed Conditions Type II 24-hr 2.5" Storm Event Rainfall=2.50" Prepared by {enter your company name here} Printed 10/6/2008 HydroCAD® 8.50 s/n 003363 © 2007 HydroCAD Software Solutions LLC Page 3 Stage-Area-Storage for Pond Pond: Pond to ditch Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 856.80 208 0 857.00 394 60 857.20 579 157 857.40 765 292 857.60 951 463 857.80 1,136 672 858.00 1,322 918 858.20 1,502 1,200 858.40 1,682 1,519 858.60 1,862 1,873 858.80 2,042 2,264 859.00 2,222 2,690 859.20 2,402 3,152 859.40 2,582 3,651 859.60 2,762 4,185 859.80 2,942 4,756 860.00 3,122 5,362 860.20 3,354 6,010 860.40 3,585 6,703 860.60 3,817 7,444 860.80 4,049 8,230 861.00 4,281 9,063 861.20 4,512 9,943 861.40 4,744 10,868 861.60 4,976 11,840 861.80 5,207 12,858 862.00 5,439 13,923 862.20 5,728 15,040 862.40 6,017 16,214 862.60 6,306 17,447 862.80 6,595 18,737 863.00 6,885 20,085 863.20 7,174 21,491 863.40 7,463 22,954 863.60 7,752 24,476 863.80 8,041 26,055 864.00 8,330 27,692 864.20 8,662 29,391 864.40 8,994 31,157 864.60 9,327 32,989 864.80 9,659 34,888 865.00 9,991 36,853 865.20 11,283 38,980 865.40 12,575 41,366 865.60 13,866 44,010 865.80 15,158 46,912 866.00 16,450 50,073 866.20 16,882 53,406 866.40 17,315 56,826 866.60 17,747 60,332 866.80 18,179 63,925 867.00 18,612 67,604 867.20 19,044 71,369 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 867.40 19,476 75,221 867.60 19,908 79,160 867.80 20,341 83,185 868.00 20,773 87,296 868.20 21,236 91,497 868.40 21,699 95,790 868.60 22,162 100,177 868.80 22,625 104,655 869.00 23,089 109,227 869.20 23,552 113,891 869.40 24,015 118,647 869.60 24,478 123,497 869.80 24,941 128,439 870.00 25,404 133,473 870.20 25,900 138,603 870.40 26,397 143,833 870.60 26,893 149,162 870.80 27,389 154,590 871.00 27,886 160,118 871.20 28,382 165,744 871.40 28,878 171,470 871.60 29,374 177,296 871.80 29,871 183,220 872.00 30,367 189,244 872.20 30,367 189,244 872.40 30,367 189,244 872.60 30,367 189,244 872.80 30,367 189,244 873.00 30,367 189,244 873.20 30,367 189,244 873.40 873.40 30,367 189,244 873.60 30,367 189,244 873.80 30,367 189,244 874.00 30,367 189,244 874.20 30,367 189,244 874.40 30,367 189,244 874.60 30,367 189,244 874.80 30,367 189,244 875.00 30,367 189,244 875.20 30,367 189,244 875.40 30,367 189,244 875.60 30,367 189,244 875.80 30,367 189,244 876.00 30,367 189,244 876.20 30,367 189,244 876.40 30,367 189,244 SUMMARY ?WESTWOOD PROFESSIONAL SERVICES, INC. (952) 937-5150 APPENDIX D DETAILS