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HomeMy WebLinkAbout02-00500141- 00074110DRIVE RELOCATION Drainage Report page 1 DRIVE RELOCATION ONE LINCOLN PLACEIWHEELER SUBD. DRAINAGE REPORT Prepared By: Urban Design Group 2700 Earl Rudder Freeway South, Suite 4300 College Station, Texas 77845 (409) 696-9653 ph (409) 696-9752' fax dkeating@udgcs.com Prepared for: Spirit Development 1 7502 Greenville Avenue, Suite 500 Dallas, Texas 75231 July 2002 JOB # 00-365 DRIVE RELOCATION Drainage Report page 2 TABLE OF CONTENTS 1. Certification II. General Location and Description III. Drainage Basins IV. Drainage Design Criteria V. Drainage Facility Design APPENDIX A. Watershed Map & FIRM Map APPENDIX B. Drainage Area Map (Existing Conditions) APPENDIX C. Drainage Area Map (Developed Conditions) APPENDIX D. Computations/Results (Existing Conditions) APPENDIX E. Computations/Results (Improved Conditions) JOB # 00-365 DRIVE RELOCATION Drainage Report page 3 1. CERTIFICATION I hereby certify that this report for the drainage design of improvements for Driveway Relocation on University Drive , was prepared by me in accordance with the provisions of the City of College Station Drainage Policy and Design Standards, for the owners thereof. . lot N AL E~ '9, 1-7. ©2 Registered Professional Engineer State of Texas No. 68243 JOB # 00-365 DRIVE RELOCATION Drainage Report page 4 II. GENERAL LOCATION AND DESCRIPTION A. Location Primary drainage system identified This project is located within the Carter Creek Watershed. The area of the new joint drive drains to Burton Creek and ultimately empties into Carter Creek. Surrounding developments shown The new joint drive would be partially located on Lot 3, Block 1, of the One Lincoln Place Subdivision, and partially located on Lot 1, Block 1, of the Wheeler Phase Two Subdivision. The new drive location lines up with the recently constructed median opening on University Drive. Surrounding developments include the Quality Suites Hotel to the southeast, an undeveloped pad site to the west, and the undeveloped Wheeler tract to the east. The recently constructed University Park development is to the north. Local streets, drainage systems shown Adjacent streets include University Drive to the north. Drainage systems include the existing storm sewer in University Drive and a tributary to Burton Creek to the south. B. Description of Property Acreage of project The area of the joint drive access easement is only 0.13 acres. However, in looking at the construction of the drive, (at a low point on the Quality Suites side), the entire upstream drainage area was considered in the design of the new joint drive. Acreages for each drainage area are shown on the accompanying maps. Land cover described A portion of the area is vacant land with grassland cover, and the remaining portion has parking and drive. Primary/secondary systems within property shown No existing primary or secondary systems are currently on the subject tract. The project will include the installation of storm sewer (secondary system) improvements. General description The new joint drive will replace the existing right in right out only drive currently serving the Quality Suites hotel. The new joint drive will serve the existing hotel, future development on the hotel pad site, as well as future JOB 9 00-365 DRIVE RELOCATION Drainage Report page 5 development of the Wheeler Subdivision. Without the new drive at that location, traffic traveling from the east will have to make a U-turn to enter either the hotel, pad site, or Wheeler Subdivision. Furthermore, traffic leaving each of those tracts would have to make a U-turn to travel west on University Drive. The new joint drive will provide a portion of detention for the development of the pad site in front of the existing hotel. (This pad site is shown as Lot 3B on the recently submitted replat of the One Lincoln Place Subdivision). The design of the new joint drive includes one area drain inlet, which is being used for detention. This surface pond A will provide some detention but is not sufficient for full development of lot 3B. Additional detention will be required for lot 3B when the site drainage is designed. A pipe has been stubbed out for use by lot 3B when it develops to prevent removal of the new drive. III. DRAINAGE BASINS AND SUB-BASINS A. Drainage Basins References to FIRMS if applicable The subject tract is located in FIRM # 48041 C0142C. Secondary system flow patterns and impact of development on existing system Because detention is required, no increase in runoff is expected to Burton Creek downstream. Approval from TxDOT is being sought for the connection to their storm sewer (secondary system). Proposed pathways to Primary system shown or described The proposed pathway to the primary system (tributary to Carter Creek) is via proposed storm sewer (onsite) and existing storm sewer within University Drive. IV. DRAINAGE DESIGN CRITERIA Any deviation from standards being requested? None that we are aware of. Discussion of site constraints and capacities (streets, existing structures etc.) Because there is no pathway to Burton Creek (to the south), connection to TxDOT's system is desired. Detention for the hotel was provided at the time of the hotel development. A portion of the detention for the development of the pad site is being proposed with this drive relocation, since the drive is at the location of the low point for the pad site. The location of the drive is set JOB # 00-365 DRIVE RELOCATION Drainage Report page 6 (by median placement), and the topography of the two tracts make other alternatives unfeasible. Discussion of any applicable previous drainage studies and how this plan will affect it A drainage study for the Quality Suites Hotel (UDG) was approved previously. As mentioned, detention for the hotel has already been provided. A drainage study for the Burton Creek Floodplain (UDG) was approved previously as well. A flood study for reclamation of the floodplain (prepared by Kling) includes the installation of channel improvements (detention) on the Wheeler property. However, to our knowledge this study has not been approved by FEMA. Hydrologic Criteria Rainfall/runoff calculation method described and calculations provided The Rational Method was used to determine the runoff rates. C values were estimated using Table III-1 of the City's Drainage Policy & Design Standards (DPDS). A minimum time of concentration of ten minutes was used in the calculations. Rainfall intensities were computed using coefficients appropriate for Brazos County, for a duration equal to the time of concentration. The results (hydrographs) for the 100 yr peak runoff for the pre- and post- developed areas are included in the appendix. Detention discharge/storage calculation method/calculations The rating tables for reservoir storage/elevation (reservoir routing) procedure is provided below. Storage volumes computed are shown in the printouts contained in the appendix. Storm recurrence intervals used Return periods used in the analysis include the 100 year storm events. Discussion of other drainage facility design criteria used if not referenced in Rtnnrinrric The program used for hydrologic computations of the runoff hydrographs and the modeling (routing) of the hydrographs through the detention pond is HydroCAD, a hydrologic modeling tool for civil engineers. The detention pond modeled is the drive area immediately surrounding the grate inlet located within the joint use drive proposed. The outlet works consist of a grate inlet sized to limit the post developed flows to the pre-developed flow from the upstream area. JOB # 00-365 DRIVE RELOCATION Drainage Report page 7 Hydraulic Criteria Identify capacity of systems used The 100 yr flow exiting Pond A is 3.16 cfs. The maximum capacity of the 18" RCP connecting to TxDOT's storm system is 8.05 cfs at a velocity of 4.55 ft/sec. Specify velocities at critical points in system The velocity of the 18"" RCP (100 yr event) is 4.07 ft/sec which is acceptable (15 ft/sec max) in concrete pipe. Other grassed and landscaped areas that drain to the detention area have slopes and velocities similar to that pre- developed. Slopes on the paved areas are minimal (1% - 4%). Runoff velocities from these areas do not exceed that allowable for paved areas. Identify detention/retention outlet and routing The detention outlet for Pond A consists of a surface grate inlet. The rating table for this grate inlet is shown below. The orifice equation (pg. 39 of DPDS, Section V.D.b) was used to calculate the outflow from the inlet for varying heads. Elev Head Outflow (ft) (cfs) 304.00 0.0 0.00 304.10 0.1 1.52 304.20 0.2 2.16 304.30 0.3 2.64 304.40 0.4 3.05 304.45 0.45 3.23 V. DRAINAGE FACILITY DESIGN Discuss drainage patterns/flows (pre vs.post) Existing and proposed drainage patterns are shown on the map provided in this report. Are they draininq water onto another propertv owner?-if so. is it where the water flowed before? and is it not more than what flowed there before? and not faster than it flowed before? The pre-developed runoff enters Burton Creek and empties into the Carter Creek ultimately. With the proposed improvements, the post developed flow will enter Burton Creek via TxDOT storm sewer. Discuss erosion control measures employed During the construction, temporary erosion control measures include placement of silt fencing around the perimeter of the downstream end of the JOB # 00-365 DRIVE RELOCATION Drainage Report page 8 property to prevent erosion until permanent structures have been constructed and sufficient vegetation has been established. Discuss detention pond design (sideslope, low flow channels, outlet works, freeboard, emergency spillway) Surface Detention Pond A is located on concrete areas with mild slopes to the grate inlet. In flooding conditions, the maximum depth of water is 0.41 feet (less than the 0.83' allowed). In emergency conditions, any flows exceeding the 100 yr capacity of the pond would top the curb and enter Burton Creek to the south (as it does today). Discuss maintenance access and responsibilities Maintenance responsibilities of Detention Pond A would be jointly with the two property owners. Maintenance responsibilities would transfer to any new landowners should the facility change ownership. JOB # 00-365 DRIVE RELOCATION Drainage Report page 9 Conclusions Verify compliance with DPDS (signed and sealed certification) Provided at beginning of report Explain effectiveness of improvements with regard to controlling discharges of 5-100 year storm by a) Detaining b) Accommodating runoff in existing/proposed easements or ROW discharging into primary system c) Combination of a & b The relocation of the existing drive does not require detention. However, the location of the proposed area grate drain will inherently provide some detention. The calculations in this report are an estimate only as the final design of lot 3B has not been determined. Using the developed flows for drainage area A (shown on the drainage area maps), the proposed discharges will be controlled with the area drain private property and within the joint drive access easement. The site discharges before and after development are summarized below. Storm QPRE QPOST (yr) (cfs) (cfs) 2 2.77 2.04 5 3.37 2.29 10 3.78 2.45 25 4.32 2.70 50 4.89 3.11' 100 5.10 3.16 In each storm frequency, the post-developed flow is below the pre-developed rates. Additional restricting structures (grates in the parking for Lot 3B) could be added at the time of site development). References 'City of College Station, Drainage Policy & Design Criteria 2Burton Creek Flood Study, Urban Design Group 3Qualitiy Suites Hotel Drainage Report, Urban Design Group 4Burton Creek Flood Study, Kling Engineering JOB # 00-365 ~ ~ J 1 11 n I D I ~ 1 0 n1 ~ 01 m ml m1 y -n n O H D C ~ '~1 of cmi n M ZI G) b ; yl Z I r. I D r )I O Z `J TRI SOOTH FORK i i ® II. ~ I r r O O Z C! H u ~ A ♦ 0 + el Cal n~ oz) m x CITY LIMI a'S W C m n y m 0 M X D 0 w cD1l Z m z D D { r Z -Di ~ z z -mac m 0 c 2 ° v D Z n D M m = 0 D m - -c 0 m m cn m z r c m fi7 m -4 ~ 3 m m 0 m z a 3 m u I ( r T Oa I ~ I e~Rro I j I COLLEGE -1 I \40 p I rn V AT. • SF- I a EE® F. M. I r I OEAcvn O C i COLLEGE STATION, a 1 E?I ~I A I ;I z :;I D % Cal G7 .m w I K p i a 0 ^y~ SR~ F fl UP \ D~ = D MINIK, DR. r HWY WOLFPEN i o \ RF f~ 'KWAY ~ ♦ I \ y O I I~ ~ \1 1 I 1 r r----~ BFI ♦ o I ~ - CREEK I COLLEGE STATION CITY LIMITg~ 1 ~ I L----~ FOXF~Rf i I I \flj 'C17- ZONE X ZONE X ONE X ZONE A r # r_ / J i , s_ ZONE AE X s} 1 r . „l ZONE X I 1 ~k 1 ZONE A ZONE X 5,4~,r / I G / 0 Lo -.No II S \ 11 c>-~nn mmm \ \ \ 0tnNIn \ \ F4o cl -u X, 1 ~ n< \ \ 1 (AZ 'XI A \ I ~ N \ ' ~ Its / \ / o rn ~vAv CO \ / DIZZ :70"3: rrl m o zt rn \ / Ap, / C-J cri-Lo /il I II aaa O / nOr) \ \ / wcnomm~ \ -4 (A \ \ \ \ \ / !o co \ \ / / \ \ (A z \ \ ' (71 \ _O C). . . \ \ \ ~n OD (A \ \ ' ~ \ \ I II II aaa C)0n \ \ \ \ \ \ mmm (A (A o cr 67 -u ma \ \ \ NZ \ \ \ \ , 8 r y rg ` loo~ T \ rri r T / e / m e u z \ \ / a m / / 2 YR EXISTING Rainfall Duration= 10 min, Inten=6.33 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Hydrograph Plot 10 Runoff 11 N w V 3 0 LL 3 Time (hours) EXISTING Rainfall Duration= 10 min, Inten=6.33 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Runoff = 3.83 cfs @ 0.17 hrs, Volume= 0.054 of Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Rainfall Duration=10 min, Inten=6.33 in/hr Area (ac) C Description 1.090 0.56 Existing Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, developed 5 YR EXISTING Rainfall Duration= 10 min, Inten=7.69 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Hydrograph Plot 10 Runoff N w V 3 0 UL 3 Time (hours) EXISTING Rainfall Duration= 10 min, Inten=7.69 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Runoff = 4.65 cfs @ 0.17 hrs, Volume= 0.065 of Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Rainfall Duration=10 min, Inten=7.69 in/hr Area (ac) C Description 1.090 0.56 Existing Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, developed 10 YR EXISTING Rainfall Duration= 10 min, Inten=8.63 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Hydrograph Plot D Runoff rn w U 3 0 U- 3 Time (hours) EXISTING Rainfall Duration= 10 min, Inten=8.63 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Runoff = 5.22 cfs @ 0.17 hrs, Volume= 0.073 of Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Rainfall Duration=10 min, Inten=8.63 in/hr Area (ac) C Description 1.090 0.56 Existing Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, developed 25 YR EXISTING Rainfall Duration= 10 min, Inten=9.86 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Hydrograph Plot D Runoff N w V 3 0 LL 3 Time (hours) EXISTING Rainfall Duration=10 min, Inten=9.86 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Runoff = 5.96 cfs @ 0.17 hrs, Volume= 0.084 of Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Rainfall Duration=10 min, Inten=9.86 in/hr Area (ac) C Description 1.090 0.56 Existing Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, developed 50 YR EXISTING Rainfall Duration= 10 min, Inten=11.15 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Hydrograph Plot 10 Runoff N w V 3 0 LL 3 4 Time (hours) EXISTING Rainfall Duration= 10 min, Inten=11.15 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Runoff = 6.74 cfs @ 0.17 hrs, Volume= 0.094 of Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Rainfall Duration= 10 min, Inten=11.15 in/hr Area (ac) C Description 1.090 0.56 Existing Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, developed 100 YR EXISTING Rainfall Duration= 10 min, Inten=11.65 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Hydrograph Plot 10 Runoff N w V 3 O LL 3 Time (hours) EXISTING Rainfall Duration= 10 min, Inten=11.65 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Subcatchment EX: EXISTING AREA Runoff = 7.04 cfs @ 0.17 hrs, Volume= 0.099 of Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Rainfall Duration= 10 min, Inten=11.65 in/hr Area (ac) C Description 1.090 0.56 Existing Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, developed 2 YR POND A Rainfall Duration= 10 min, Inten=6.33 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Pond POND A: POND A Hydrograph Plot Inflow Primary w w U 3 O LL 3 Time (hours) POND A Rainfall Duration= 10 min, Inten=6.33 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Pond POND A: POND A [85] Warning: Oscillations may require Finer Routing>1 Inflow = 2.77 cfs @ 0.17 hrs, Volume= 0.039 of Outflow = 2.04 cfs @ 0.21 hrs, Volume= 0.039 af, Atten= 26%, Lag= 2.7 min Primary = 2.04 cfs @ 0.21 hrs, Volume= 0.039 of Routing by Stor-Ind method, Time Span= 0.00-6.00 hrs , dt= 0.01 hrs Peak Elev= 304.18' Storage= 0.005 of Plug-Flow detention time= (not calculated: outflow precedes inflow) Storage and wetted areas determined by Irregular sections Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (acres) (feet) (acre-feet) (acre-feet) (acres) 304.00 0.000 0.0 0.000 0.000 0.000 304.10 0.004 67.4 0.000 0.000 0.008 304.20 0.156 100.7 0.006 0.006 0.019 304.30 0.032 165.1 0.009 0.015 0.050 304.35 0.043 186.5 0.002 0.017 0.064 304.45 0.060 239.0 0.005 0.022 0.104 Primary OutFlow (Free Discharge) t-1=grate/orifice # Routing Invert Outlet Devices 1 Primary 304.00' grate/orifice Head (feet) 0.00 0.10 0.20 0.30 0.35 0.45 Disch. (cfs) 0.00 1.52 2.16 2.64 3.05 3.23 5 YR POND A Rainfall Duration= 10 min, Inten=7.69 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Pond POND A: POND A Hydrograph Plot 0 Inflow Primary y w V 3 0 LL 3 Time (hours) POND A Rainfall Duration= 10 min, Inten=7.69 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcom puter Systems 7/19/02 Pond POND A: POND A Inflow = 3.37 cfs @ 0.17 hrs, Volume= 0.047 of Outflow = 2.29 cfs @ 0.22 hrs, Volume= 0.047 af, Atten= 32%, Lag= 3.3 min Primary = 2.29 cfs @ 0.22 hrs, Volume= 0.047 of Routing by Stor-Ind method, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Peak Bev= 304.23' Storage= 0.009 of Plug-Flow detention time= 1.6 min calculated for 0.047 of (100% of inflow) Storage and wetted areas determined by Irregular sections Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (acres) (feet) (acre-feet) ( acre-feet) (acres) 304.00 0.000 0.0 0.000 0.000 0.000 304.10 0.004 67.4 0.000 0.000 0.008 304.20 0.156 100.7 0.006 0.006 0.019 304.30 0.032 165.1 0.009 0.015 0.050 304.35 0.043 186.5 0.002 0.017 0.064 304.45 0.060 239.0 0.005 0.022 0.104 Primary OutFlow (Free Discharge) t-1=grate/orifice # Routinq Invert Outlet Devices 1 Primary 304.00' grate/orifice Head (feet) 0.00 0.10 0.20 0.30 0.35 0.45 Disch. (cfs) 0.00 1.52 2.16 2.64 3.05 3.23 10 YR POND A Rainfall Duration= 10 min, Inten=8.63 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Pond POND A: POND A Hydrograph Plot Inflow Primary N w V 3 0 U- 3 Time (hours) POND A Rainfall Duration=10 min, Inten=8.63 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcom puter Systems 7/19/02 Pond POND A: POND A Inflow = 3.78 cfs @ 0.17 hrs, Volume= 0.053 of Outflow = 2.45 cfs @ 0.23 hrs, Volume= 0.053 af, Atten= 35%, Lag= 3.6 min Primary = 2.45 cfs @ 0.23 hrs, Volume= 0.053 of Routing by Stor-Ind method, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Peak Elev= 304.26' Storage= 0.011 of Plug-Flow detention time= 2.0 min calculated for 0.053 of ( 100% of inflow) Storage and wetted areas determined by Irregular sections Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (acres) (feet) (acre-feet) (acre-feet) (acres) 304.00 0.000 0.0 0.000 0.000 0.000 304.10 0.004 67.4 0.000 0.000 0.008 304.20 0.156 100.7 0.006 0.006 0.019 304.30 0.032 165.1 0.009 0.015 0.050 304.35 0.043 186.5 0.002 0.017 0.064 304.45 0.060 239.0 0.005 0.022 0.104 Primary OutFlow (Free Discharge) L1=grate/orifice # Routing Invert Outlet Devices 1 Primary 304.00' grate/orifice Head (feet) 0.00 0.10 0.20 0.30 0.35 0.45 Disch. (cfs) 0.00 1.52 2.16 2.64 3.05 3.23 25 YR POND A Rainfall Duration= 10 min, Inten=9.86 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Pond POND A: POND A Hydrograph Plot Inflow 0 Primary N w V 3 0 LL 3 Time (hours) POND A Rainfall Duration= 10 min, Inten=9.86 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcom puter Systems 7/19/02 Pond POND A: POND A Inflow = 4.32 cfs @ 0.17 hrs, Volume= 0.061 of Outflow = 2.70 cfs @ 0.23 hrs, Volume= 0.061 af, Atten= 37%, Lag= 3.8 min Primary = 2.70 cfs @ 0.23 hrs, Volume= 0.061 of Routing by Stor-Ind method, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Peak Elev= 304.31' Storage= 0.015 of Plug-Flow detention time= 2.6 min calculated for 0.061 of (100% of inflow) Storage and wetted areas determined by Irregular sections Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (acres) (feet) (acre-feet) ( acre-feet) (acres) 304.00 0.000 0.0 0.000 0.000 0.000 304.10 0.004 67.4 0.000 0.000 0.008 304.20 0.156 100.7 0.006 0.006 0.019 304.30 0.032 165.1 0.009 0.015 0.050 304.35 0.043 186.5 0.002 0.017 0.064 304.45 0.060 239.0 0.005 0.022 0.104 Primary OutFlow (Free Discharge) t1=grate/orifice # Routing Invert Outlet Devices 1 Primary 304.00' grate/orifice Head (feet) 0.00 0.10 0.20 0.30 0.35 0.45 Disch. (cfs) 0.00 1.52 2.16 2,64 3.05 3.23 50 YR POND A Rainfall Duration= 10 min, Inten=11.15 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Pond POND A: POND A Hydrograph Plot E3 Inflow Primary 5 4 N 3 3 0 U- 2 0 0 1 2 3 4 5 6 Time (hours) POND A Rainfall Duration= 10 min, Inten=11.15 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcom puter Systems 7/19/02 Pond POND A: POND A Inflow = 4.89 cfs @ 0.17 hrs, Volume= 0.068 of Outflow = 3.11 cfs @ 0.23 hrs, Volume= 0.069 af, Atten= 36%, Lag= 3.7 min Primary = 3.11 cfs @ 0.23 hrs, Volume= 0.069 of Routing by Stor-Ind method, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Peak Elev= 304.38' Storage= 0.018 of Plug-Flow detention time= 2.9 min calculated for 0.068 of ( 100%0 of inflow) Storage and wetted areas determined by Irregular sections Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (acres) (feet) (acre-feet) (acre-feet) (acres) 304.00 0.000 0.0 0.000 0.000 0.000 304.10 0.004 67.4 0.000 0.000 0.008 304.20 0.156 100.7 0.006 0.006 0.019 304.30 0.032 165.1 0.009 0.015 0.050 304.35 0.043 186.5 0.002 0.017 0.064 304.45 0.060 239.0 0.005 0.022 0.104 Primary OutFlow (Free Discharge) L1=grate/orifice # Routina Invert Outlet Devices 1 Primary 304.00' grate/orifice Head (feet) 0.00 0.10 0.20 0.30 0.35 0.45 Disch. (cfs) 0.00 1.52 2.16 2,64 3.05 3.23 100 YR POND A Rainfall Duration= 10 min, Inten=11.64 in/hr Prepared by Urban Design Group Page 1 HydroCAD® 6.00 s/n 001705 © 1986-2001 Applied Microcomputer Systems 7/19/02 Pond POND A: POND A Hydrograph Plot 0 Inflow 0 Primary y w V 3 O U. 3 Time (hours) POND A Rainfall Duration= 10 min, Inten=11.64 in/hr Prepared by Urban Design Group Page 1 HydroCADO 6.00 s/n 001705 © 1986-2001 Applied Microcom puter Systems 7/19/02 Pond POND A: POND A Inflow = 5.10 cfs @ 0.17 hrs, Volume= 0.072 of Outflow = 3.16 cfs @ 0.23 hrs, Volume= 0.072 af, Atten= 38%, Lag= 3.9 min Primary = 3.16 cfs @ 0.23 hrs, Volume= 0.072 of Routing by Stor-Ind method, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Peak Elev= 304.41' Storage= 0.020 of Plug-Flow detention time= 3.0 min calculated for 0.072 of ( 100% of inflow) Storage and wetted areas determined by Irregular sections Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (acres) (feet) (acre-feet) (acre-feet) (acres) 304.00 0.000 0.0 0.000 0.000 0.000 304.10 0.004 67.4 0.000 0.000 0.008 304.20 0.156 100.7 0.006 0.006 0.019 304.30 0.032 165.1 0.009 0.015 0.050 304.35 0.043 186.5 0.002 0.017 0.064 304.45 0.060 239.0 0.005 0.022 0.104 Primary OutFlow (Free Discharge) t-1=grate/orifice # Routina Invert Outlet Devices 1 Primary 304.00' grate/orifice Head (feet) 0.00 0.10 0.20 0.30 0.35 0.45 Disch. (cfs) 0.00 1.52 2.16 2.164 3.05 3.23