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Home My WebLink AboutRiverlakes Park - Drainage StudyW.O. 156-09 DRAINAGE STUDY For Riverlakes Community Park Bakersfield, CA Prepared for: North of the River Recreation and Park District 405 Galaxy Avenue Bakersfield, CA 93308 June 13, 2011 Revised October 21, 2011 Tory R. Walker, R.C.E. 45005 President 122 Civic Center Drive, Suite 206, Vista, CA 92084 Ph: 760.414.9212 Fx: 760.414.9277 www.Trwengineering.Com Addendum to Drainage Study Report October 21, 2011 Mr. Manny Behl City of Bakersfield Public Works Dept. Bakersfield, CA 93301 Re: Drainage Study Report Addendum, in Response to City Comment Letter Dated August 11, 2011. Dear Manny: We are writing to summarize corrections and agreements made with you on the drainage study comments dated August 11, 2011. We are also supplementing those comments with supporting calculations for the retention basin (sump) changes made on October 18. 1. We have signed the drainage study, with a copy emailed to you, including this addendum. 2. Through email correspondence of 9-20-11, and phone conversation on same day, the area-wide study is not required, and it was noted that the runoff contribution from our project (0.49 acres into 342 acres) is insignificant and produces no HGL increase above Bakersfield standards. 3. C-value verification was provided and approved via phone. Copy provided with this addendum. 4. Overflow storm drain will be removed from project drawings. 5. The sump (retention basin) will be fenced - to be added to project drawings. 6. One sump is acceptable, with the note "City of Bakersfield not responsible for maintenance. North of the River Parks and Recreation Dept. will provide maintenance." 7. A change to the depth of basin was not required , no additional borings or revisions needed. The City will issue a conditional letter of approval that will note recommendations on the basin. Note - the basin bottom was lowered to elevation 390.0 with the October 18 change. This improves the drawdown ability of the basin. October 18, 2011 Update to Detention Basin: The detention basin (sump) configuration and bottom elevation was revised due to request by the North of the River Parks and Recreation Department. The following facts apply to the revised basin and potential changes to the drainage report needed: Referring to the proposed conditions hydrology map - Subarea E (0.38AC) is unchanged from previous. The entire area is landscaped and drains into the modified retention basin. The inflow hydrographs calculations in the Appendix C, (Retention Basin Calculations) are unchanged, as none of the inflow hydrographs are in need of revision. The interim basin calculations (hydrograph # 2) for both 10-year and 100-year have been rerun with the updated pond and hydrograph report provided directly following this section of addendum letter/report. Note the 100-year water surface is at 394.8, and the 10-year water surface is now at 390.44 (was 392.16 previously). Freeboard is provided for the basin perimeter at one foot above the water surface elevation (minimum). Pipeflow Changes: The 10-year criteria is unchanged from previous for the revised storm drains entering the basin (two). The lower reach of each pipe has lengthened, with the invert elevation at the outlet over 1.5 feet deeper. See pipeflow check for these revised reaches directly following the hydrograph calculations in this letter addendum. Thank You, TORY R. WALKER ENGINEERING, INC. Tory R. Walker, P.E. President DRAINAGE STUDY REPORT Riverlakes Community Park Page 1 Introduction The proposed Riverlakes Community Park is located in NW Bakersfield, north of Highway 58, East of Highway 99, and just northeast of the Friant-Kern Canal. Riverlakes Drive and Coffee Road are the major roadways to the north and east of the project. The project location is shown in Figure 1. The total park project area is approximately 27 acres, and the site is currently vacant. The Riverlakes Community Park is the first phase of the total park project. The proposed community center will include a central building and extensive landscaping/park area. The first phase will develop approximately 7 acres of the site for the community center and park, while the remaining 20 acres will be developed at a later time, possibly as a water park. The existing topography is relatively flat, with the highest elevations at the northeast and northwest portions of the site around elevation 397 feet, sloping to the southeast and southwest corners of the site, to an approximate elevation of 393 feet. This drainage report is intended to supplement the grading plan submittal to be reviewed by City staff. The purpose is to identify drainage basin areas, calculate peak flow rates, and size a retention basin to meet the City’s drainage design standards. Methodology City of Bakersfield methods are employed in the calculations for runoff and retention. Chapter 2.1 of the City of Bakersfield Standards for Drainage provides the design guidelines and data. Methods for calculating runoff coefficients, times-of-concentration, and frequency-year storm events are all described in that manual. The project site area is less than one square mile, therefore the 10-year frequency recurrence interval storm is used to for runoff calculations. For the retention basin on the site, the storage volume needed is based on the 100-year 24-hour storm, and the volume is based on average runoff coefficient and total tributary drainage area. The needed volumes, in acre-feet, are noted in the retention basin calculation section of this report, with supporting methodology in the appendices. DRAINAGE STUDY REPORT Riverlakes Community Park Page 2 Figure 1. Project Location Map (No Scale) Proposed Development Runoff Patterns and Storm Drain Design The proposed development has been divided into drainage basin areas, designated as A through M on the Hydrology Map, which is attached in Appendix A. Runoff from the drainage areas is discharged to the proposed retention basin, with a small portion of the site entrance draining to Riverlakes Road. In addition to the 7 acres of onsite area, 1.4 acres of offsite area from the Friant-Kern Canal drains onto the site from the west, and N Project Location DRAINAGE STUDY REPORT Riverlakes Community Park Page 3 6.2 acres of offsite area drains towards the site from the south. The drainage from the west is a permanent condition, while the drainage from the south is a temporary condition until the remainder of the park parcel is developed. When the remainder of the park is developed, the runoff from the 6.2 acre offsite area (M on the attached map) will be routed to a separate offsite retention basin. A summary of areas is shown in Table 1, below. Table 1. Summary of Drainage Subareas Subarea Drainage Area (ac) C Value Drain Location Retention Vol. (ac-ft) A 0.49 0.36 Offsite (Riverlakes Rd) N/A B to L 7.56 0.52 Retention Basin 0.589 M (Interim) 6.22 0.10 Retention Basin 0.093 M (Ultimate) 6.22 N/A Offsite N/A Interim Total (B to M) 13.78 0.68 Ultimate Total (B to L) 7.56 0.59 Storm drains at the site will be constructed using HDPE storm drain pipe, or similar, since the site gradient will require relatively flat, shallow, pipes. Storm drain calculations at the site were prepared using the Hydraflow Storm Sewers Extension from Autodesk. Hydraflow calculates runoff using the Rational Method and also calculates the HGL in the storm drain pipes. The drainage system was designed so that there was at least 0.5 feet of freeboard at each catch basin during a 10-year storm. The Hydraflow results are attached in Appendix B. The calculations were prepared for the storm drain system that drains the parking lot. The laterals draining the park were modeled as two discharge points into the trunk system. The starting water surface in the storm drain was set at normal depth, since for a 10-year storm, the water surface in the basin never exceeds 0.2 feet (See Retention Basin calculations for 10-year storm). Retention Basin Design A site-specific permeability test was performed to determine the capability of the soils at the site to drain within the required one week time period. Two borings were taken from the retention basin location. The measured percolation rates for the retention basin were 10.0 and 4.5 inches per hour. The design permeability of 2.4 inches per hour was determined by adjusting the average of the measured rates (7.25 in/hr) by a factor of safety. A factor of safety of 3.0 was used to account for reduction in permeability over time, as silt might collect in the basin between maintenance activities. DRAINAGE STUDY REPORT Riverlakes Community Park Page 4 Hydraflow Hydrographs Extension from Autodesk was used to size the retention basin. The inflow hydrograph was determined using the 100-year 24-hour precipitation total of 2.8 inches from the NOAA Atlas. A Type I SCS storm was used for the hydrograph, and the curve numbers for the interim and ultimate conditions were adjusted so the total inflow volumes were equal to the volumes from the Rational Method approach, as listed in Table 1. Outflow hydrographs were determined in Hydraflow Hydrographs using the geometry of the basin and the design percolation rate of 2.4 inches per hour. For the interim condition when Subarea M drains to the retention basin, a maximum depth of 0.98 feet was calculated for the 100-year 24-hour storm. For the ultimate condition, when Subarea M is routed to a different location, the maximum basin depth is 0.89 feet for the 100-year 24-hour storm. In both the interim and ultimate conditions, the basins will drain within 12 hours of the end of the 24-hour SCS design storm. The results are summarized in Table 2 and the output from Hydraflow Hydrographs, for the 10-year and 100-year storms, is included in Appendix C. Table 2. Summary of Retention Analysis Condition Drainage Area (ac) CN Value* Inflow Volume (ac-ft) Max Elevation (ft) Max Stage (ft) Interim 13.78 70.5 0.70 392.98 0.98 Ultimate 7.56 77.5 0.59 392.89 0.89 (*) Note: CN Adjusted so inflow volume matches Rational Method volume in Table 1. To allow maximum use of the retention basin area for the park, we have designed the basin so that the depth for a 100-year storm is less than 18 inches. Since the total basin depth is approximately 4 feet, we are proposing an overflow storm drain connection from the retention basin to the existing storm drain in Riverlakes Drive. While the project area was not included in the Riverlakes Area Drainage Plan (ADP), the storm drain between the site and the sump north of Hageman Road has a minimum of 2.1 feet of freeboard and a maximum of 12 feet of freeboard. This site would only be draining to the storm drain under the worst case scenario of the basin not being maintained and severe storms occurring back to back. The basin is in a prominent location next to the community center, so it is anticipated that it will be well maintained by the Parks District staff, making the probability of an overflow to the storm drain very low. Even if the site did spill, there is capacity in the Riverlakes storm drain to handle the additional runoff for a single event until the permeability of the basin can be restored. Excerpts from the ADP are included in Appendix D. DRAINAGE STUDY REPORT Riverlakes Community Park Page 5 Conclusion The project storm drains and retention basin have been designed to meet City of Bakersfield standards for the conservative case of the interim condition. When the full park parcel is developed, the performance of the retention basin and storm drain will improve, since 6.2 acres of tributary area will no longer contribute to this drainage system. DRAINAGE STUDY REPORT Riverlakes Community Park Appendix A: HYDROLOGY MAPS  Existing Condition Topography Map  Proposed Condition Hydrology Map DRAINAGE STUDY REPORT Riverlakes Community Park APPENDIX B: RATIONAL METHOD AND HGL CALCULATIONS 123 45 6 7 8 9 10 11 12 13Outfall Riverlakes Community CenterProject File: Riverlakes SD.stm Number of lines: 13Date: 06-09-2011Hydraflow Storm Sewers Extension v6.052 Storm Sewer Inventory Report Page 1 LineAlignmentFlow Data Physical Data Line ID No. DnstrLineDeflJuncKnownDrngRunoffInletInvertLineInvertLineLineNJ-lossInlet/linelengthangletypeQareacoefftimeEl DnslopeEl Upsiz eshapevaluecoeffRim ElNo.(ft)(deg)(cfs)(ac)(C)(min)(ft)(%)(ft)(in)(n)(K)(ft) 1End25.3000.000MH0.000.000.000.092.000.5192.1318Cir 0.0131.0095.802123.0000.000MH0.000.000.000.092.130.3992.2218Cir0. 0131.0095.80 3295.9000.000MH0.000.000.000.092.220.4892.6818Cir0. 0131.0094.40 436.600-90.000MH0.000.000.000.092.680.7692.7312Cir0 .0131.0094.40 5469.1000.000Grate0.000.650.8210.092.730.7793.2612Cir0.0131.0095.26G643.90090.000Grate0.000.570.8210.092.731.7992.8012C ir0.0131.0094.14H 7261.400-90.000Grate0.000.470.8210.092.471.0793.131 2Cir0.0131.0095.13F83252.1000.000Grate0.000.400.3615.092.680.3893.6412 Cir0.0131.0096.80K 9342.00090.000Grate0.001.100.3615.092.680.4892.8812 Cir0.0131.0095.50J101155.600-90.000MH0.000.000.000.092.380.3992.9912Cir0.0131.0096.60 111099.00090.000Grate0.006.220.1015.092.990.3993.38 12Cir0.0131.0094.50M 1210119.1000.000Grate0.000.370.8210.092.990.3493.39 12Cir0.0131.5095.16D 131266.000-90.000Grate0.000.300.8210.093.640.6194.0 46Cir0.0131.0095.04C Riverlakes Community Center Number of lines: 13Date: 06-09-2011Hydraflow Storm Sewers Extension v6.052 Storm Sewer Summary Report Page 1 LineLine IDFlowLineLineLineInvertInvertLineHGLHGLMi norHGLDnsJunction No. ratesizeshapelengthEL DnEL UpslopedownuplossJunctli neType(cfs)(in)(ft)(ft)(ft)(%)(ft)(ft)(ft)(ft)No. 1 2.6218Cir25.30092.0092.130.51492.6292.750.2292.97En dManhole 2 1.6418Cir23.00092.1392.220.39192.9792.980.0593.031Manhole 3 1.3518Cir95.90092.2292.680.48093.0393.140.1393.272Manhole 4 1.7012Cir6.60092.6892.730.75893.2793.28n/a93.51 j3Manhole 5G 0.9512Cir69.10092.7393.260.76793.5193.67n/a93.67 j4 Grate 6H 0.8312Cir3.90092.7392.801.79593.5193.510.0393.544Gr ate 7F 0.6912Cir61.40092.4793.131.07593.0393.48n/a93.48 j2 Grate 8K 0.2012Cir252.10092.6893.640.38193.2793.840.0693.893 Grate 9J 0.5612Cir42.00092.6892.880.47693.2793.300.0593.353G rate 10 1.5612Cir155.60092.3892.990.39293.0093.610.1593.751 Manhole 11M 0.8812Cir99.00092.9993.380.39493.7593.870.0893.9510 Grate 12D 0.9512Cir119.10092.9993.390.33693.7593.910.1394.031 0Grate 13C 0.446Cir66.00093.6494.040.60694.0594.450.1094.5512G rate Riverlakes Community Center Number of lines: 13Run Date: 06-09-2011 NOTES: Return period = 10 Yrs. ; j - Line contains hyd. jump. Hydraflow Storm Sewers Extension v6.052 Storm Sewer Tabulation Page 1 StationLenDrng AreaRnoffArea x CTcRainTotalCapVelPi peInvert ElevHGL ElevGrnd / Rim ElevLine ID coeff (I)flowfull LineToIncrTotalIncrTotalInletSyst SizeSlopeDnUpDnUpDnUp Line (ft)(ac)(ac)(C)(min)(min)(in/hr)(cfs)(cfs)(ft/s)(in )(%)(ft)(ft)(ft)(ft)(ft)(ft) 1End25.3000.0010.080.000.003.100.032.90.82.627.533. 80180.5192.0092.1392.6292.7594.0095.802123.0000.003.190.000.001.930.032.60.81.646.571.711 80.3992.1392.2292.9792.9895.8095.80 3295.9000.002.720.000.001.540.031.20.91.357.272.161 80.4892.2292.6893.0393.1495.8094.40436.6000.001.220.000.001.000.011.01.71.703.103.6412 0.7692.6892.7393.2793.2894.4094.40 5469.1000.650.650.820.530.5310.010.01.80.953.122.27 120.7792.7393.2693.5193.6794.4095.26G643.9000.570.570.820.470.4710.010.01.80.834.771.341 21.7992.7392.8093.5193.5194.4094.14H 7261.4000.470.470.820.390.3910.010.01.80.693.692.15 121.0792.4793.1393.0393.4895.8095.13F 83252.1000.400.400.360.140.1415.015.01.40.202.201.1 5120.3892.6893.6493.2793.8494.4096.80K9342.0001.101.100.360.400.4015.015.01.40.562.461.48 120.4892.6892.8893.2793.3094.4095.50J 101155.6000.006.890.000.001.170.016.51.31.562.233.0 7120.3992.3892.9993.0093.6195.8096.60 111099.0006.226.220.100.620.6215.015.01.40.882.241. 84120.3992.9993.3893.7593.8796.6094.50M 1210119.1000.370.670.820.300.5510.010.51.70.952.061 .91120.3492.9993.3993.7593.9196.6095.16D131266.0000.300.300.820.250.2510.010.01.80.440.442. 5360.6193.6494.0494.0594.4595.1695.04C Riverlakes Community Center Number of lines: 13Run Date: 06-09-2011 NOTES: Intensity = 14.49 / (Inlet time + 4.40) ^ 0. 79; Return period = 10 Yrs. ; c = cir e = el lip b = box Hydraflow Storm Sewers Extension v6.052 Hydraulic Grade Line Computations Page 1 LineSizeQDownstreamLenUpstreamCheckJLMinorcoeffloss InvertHGLDepthAreaVelVelEGLSfInvertHGLDepthAreaVelV elEGLSfAveEnrgyelevelevheadelevelevelevheadelevSfloss(in)(cfs)(ft)(ft)(ft)(sqft)(ft/s)(ft)(ft)(%)(ft)(ft)(ft)(ft)(sqft)(ft/s)(ft)(ft)(%)(%)(ft)(K)(ft)(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) (16)(17)(18)(19)(20)(21)(22)(23)(24) 1182.6292.0092.620.620.693.820.2392.840.49325.30092 .1392.750.62**0.693.790.2292.970.4820.4870.1231.000 .22 2181.6492.1392.970.841.021.600.0493.010.06623.00092 .2292.980.760.901.820.0593.030.0930.0790.0181.000.05 3181.3592.2293.030.810.981.380.0393.060.05195.90092 .6893.140.460.462.930.1393.270.3940.2220.2131.000.13 4121.7092.6893.270.590.493.490.1993.460.5196.60092. 7393.28 j0.55**0.453.790.2293.510.6430.5810.0381.00 0.22 5120.9592.7393.510.780.661.450.0393.540.07969.10093 .2693.67 j0.41**0.313.100.1593.820.5560.317n/a1.00n /a 6120.8392.7393.510.780.661.270.0393.530.0613.90092. 8093.510.710.591.410.0393.540.0770.0690.0031.000.03 7120.6992.4793.030.560.451.510.0493.070.10161.40093 .1393.48 j0.35**0.252.790.1293.600.5300.316n/a1.000 .12 8120.2092.6893.270.590.490.420.0093.280.007252.10093.6493.840.20**0.111.880.0693.890.4690.2380.6011.00 0.06 9120.5692.6893.270.590.491.150.0293.290.05642.00092 .8893.300.420.311.810.0593.350.1890.1220.0511.000.05 10121.5692.3893.000.62*0.513.070.1593.140.392155.60 092.9993.610.620.513.070.1593.750.3920.3920.6101.00 0.15 11120.8892.9993.750.760.641.370.0393.780.07099.0009 3.3893.870.490.382.310.0893.950.2670.1680.1671.000. 08 12120.9592.9993.750.760.641.480.0393.790.083119.100 93.3993.910.520.412.330.0893.990.2580.1700.2031.500 .13 1360.4493.6494.050.41*0.172.530.1094.150.60666.0009 4.0494.450.410.172.530.1094.550.6050.6050.4001.000. 10 Riverlakes Community Center Number of lines: 13Run Date: 06-09-2011 Notes: * Normal depth assumed.; ** Critical depth.; j-Line contains hyd. jump. ; c = cir e = ellip b = box Hydraflow Storm Sewers Extension v6.052 Hydraflow HGL Computation Procedure Page 1 General Procedure: Hydraflow computes the HGL using the Bernoulli ener gy equation. Manning's equation is used to determine energy losses due to pipe friction. In a standard step, iterative procedure, Hydraflow assumes upstream HGLs until the energy equation bal ances. If the energy equation cannot balance, supercritical flow exists and criti cal depth is temporarily assumed at the upstream end. A supercritical flow Profile is then computed using the same procedure in a downstream direction using momentum principles. Col. 1 The line number being computed. Calculations begin at Line 1 and proceed upstream. Col. 2 The line size. In the case of non-circular pipes, the line rise is printed above the span. Col. 3 Total flow rate in the line.Col. 4 The elevation of the downstream invert.Col. 5 Elevation of the hydraulic grade line at the downstream end. This is computed as the upstream HGL + Minor loss of this line's downstream line. Col. 6 The downstream depth of flow inside the pipe (HGL - Invert elevation) but not greater than the line size. Col. 7 Cross-sectional area of the flow at the downstream end.Col. 8 The velocity of the flow at the downstream end, (Col. 3 / Col. 7). Col. 9 Velocity head (Velocity squared / 2g).Col. 10 The elevation of the energy grade line at the downstream end, HGL + Velocity head, (Col. 5 + Col. 9). Col. 11 The friction slope at the downstream end (the S or Slope term in Manning's equation). Col. 12 The line length.Col. 13 The elevation of the upstream invert.Col. 14 Elevation of the hydraulic grade line at the upstream end.Col. 15 The upstream depth of flow inside the pipe (HGL - Invert elevation) but not greater than the line size. Col. 16 Cross-sectional area of the flow at the upstream end.Col. 17 The velocity of the flow at the upstream e nd, (Col. 3 / Col. 16). Col. 18 Velocity head (Velocity squared / 2g).Col. 19 The elevation of the energy grade line at the upstream end, HGL + Velocity head, (Col. 14 + Col. 18) . Col. 20 The friction slope at the upstream end (the S or Slope term in Manning's equation).Col. 21 The average of the downstream and upstream friction slopes. Col. 22 Energy loss. Average Sf/100 x Line Length (Col. 21/100 x Col. 12). Equals (EGL upstream - EGL downstream) +/- tolerance. Col. 23 The junction loss coefficient (K).Col. 24 Minor loss. (Col. 23 x Col. 18). Is added to upstream HGL and used as the starting HGL for the next upstream line(s). DRAINAGE STUDY REPORT Riverlakes Community Park APPENDIX C: RETENTION BASIN CALCULATIONS  Interim Condition  Ultimate Condition Hydraflow Table of Contents Bakersfield Comm Hydro.gpw Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Watershed Model Schematic ...................................................................................1 10 - Year Hydrograph Reports .................................................................................................................2 Hydrograph No. 1, SCS Runoff, Interim to W. Basin ..............................................................2 Hydrograph No. 2, Reservoir, Interim West Basin .................................................................3 Pond Report - Interim West Basin .....................................................................................4 Hydrograph No. 3, SCS Runoff, Ultimate to W. Basin ...........................................................5 Hydrograph No. 4, Reservoir, Ultimate West Basin ...............................................................6 Pond Report - Ultimate West Basin ...................................................................................7 100 - Year Hydrograph Reports .................................................................................................................8 Hydrograph No. 1, SCS Runoff, Interim to W. Basin ..............................................................8 Hydrograph No. 2, Reservoir, Interim West Basin .................................................................9 Hydrograph No. 3, SCS Runoff, Ultimate to W. Basin .........................................................10 Hydrograph No. 4, Reservoir, Ultimate West Basin .............................................................11 1 2 3 4 1 Watershed Model Schematic Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052 Project: Bakersfield Comm Hydro.gpwThursday, Jun 9, 2011 Hyd.OriginDescription Legend 1SCS RunoffInterim to W. Basin 2ReservoirInterim West Basin 3SCS RunoffUltimate to W. Basin 4ReservoirUltimate West Basin Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Hyd. No. 1 Interim to W. Basin Hydrograph type= SCS RunoffPeak discharge= 0.130 cfs Storm frequency= 10 yrsTime to peak= 12.87 hrs Time interval= 2 minHyd. volume= 5,602 cuft Drainage area= 13.780 acCurve number= 70.5 Basin Slope= 0.0 %Hydraulic length= 0 ft Tc method= USERTime of conc. (Tc)= 15.00 min Total precip.= 1.59 inDistribution= Type I Storm duration= 24 hrsShape factor= 484 2 02468101214161820222426 Q (cfs) 0.000.00 0.050.05 0.100.10 0.150.15 0.200.20 0.250.25 0.300.30 0.350.35 0.400.40 0.450.45 0.500.50 Q (cfs) Time (hrs) Interim to W. Basin Hyd. No. 1 -- 10 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Hyd. No. 2 Interim West Basin Hydrograph type= ReservoirPeak discharge= 0.118 cfs Storm frequency= 10 yrsTime to peak= 19.13 hrs Time interval= 2 minHyd. volume= 5,594 cuft Inflow hyd. No.= 1 - Interim to W. BasinMax. Elevation= 392.13 ft Reservoir name= Interim West BasinMax. Storage= 1,015 cuft Storage Indication method used. Outflow includes exfiltration. 3 04812162024283236 Q (cfs) 0.000.00 0.050.05 0.100.10 0.150.15 0.200.20 0.250.25 0.300.30 0.350.35 0.400.40 0.450.45 0.500.50 Q (cfs) Time (hrs) Interim West Basin Hyd. No. 2 -- 10 Year Hyd No. 2 Hyd No. 1 Total storage used = 1,015 cuft Pond Report 4 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Pond No. 1 - Interim West Basin Pond Data Contours - User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 392.00 ft Stage / Storage Table Stage (ft)Elevation (ft)Contour area (sqft)Incr. Storage (cuft)Total storage (cuft) 0.00392.007,57700 0.50392.508,3543,9813,981 1.00393.009,1584,3768,357 1.50393.509,9874,78413,141 Culvert / Orifice StructuresWeir Structures [A][B][C][PrfRsr][A][B][C][D] Rise (in)= 0.000.000.000.00 Span (in)= 0.000.000.000.00 No. Barrels= 0000 Invert El. (ft)= 0.000.000.000.00 Length (ft)= 0.000.000.000.00 Slope (%)= 0.000.000.00n/a N-Value= .013.013.013n/a Orifice Coeff.= 0.600.600.600.60 Multi-Stage= n/aNoNoNo Crest Len (ft)= 0.000.000.000.00 Crest El. (ft)= 0.000.000.000.00 Weir Coeff.= 3.333.333.333.33 Weir Type= ------------ Multi-Stage= NoNoNoNo Exfil.(in/hr)= 2.400 (by Contour) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table StageStorageElevationClv AClv BClv CPrfRsrWr AWr BWr CWr DExfilUserTotal ftcuftftcfscfscfscfscfscfscfscfscfscfscfs 0.000392.00------------------------0.000---0.000 0.503,981392.50------------------------0.464---0.464 1.008,357393.00------------------------0.509---0.509 1.5013,141393.50------------------------0.555---0.555 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Hyd. No. 3 Ultimate to W. Basin Hydrograph type= SCS RunoffPeak discharge= 0.547 cfs Storm frequency= 10 yrsTime to peak= 10.10 hrs Time interval= 2 minHyd. volume= 6,967 cuft Drainage area= 7.560 acCurve number= 77.5 Basin Slope= 0.0 %Hydraulic length= 0 ft Tc method= USERTime of conc. (Tc)= 15.00 min Total precip.= 1.59 inDistribution= Type I Storm duration= 24 hrsShape factor= 484 5 02468101214161820222426 Q (cfs) 0.000.00 0.100.10 0.200.20 0.300.30 0.400.40 0.500.50 0.600.60 0.700.70 0.800.80 0.900.90 1.001.00 Q (cfs) Time (hrs) Ultimate to W. Basin Hyd. No. 3 -- 10 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Hyd. No. 4 Ultimate West Basin Hydrograph type= ReservoirPeak discharge= 0.149 cfs Storm frequency= 10 yrsTime to peak= 13.50 hrs Time interval= 2 minHyd. volume= 6,958 cuft Inflow hyd. No.= 3 - Ultimate to W. BasinMax. Elevation= 392.16 ft Reservoir name= Ultimate West BasinMax. Storage= 1,274 cuft Storage Indication method used. Outflow includes exfiltration. 6 04812162024283236 Q (cfs) 0.000.00 0.100.10 0.200.20 0.300.30 0.400.40 0.500.50 0.600.60 0.700.70 0.800.80 0.900.90 1.001.00 Q (cfs) Time (hrs) Ultimate West Basin Hyd. No. 4 -- 10 Year Hyd No. 4 Hyd No. 3 Total storage used = 1,274 cuft Pond Report 7 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Pond No. 2 - Ultimate West Basin Pond Data Contours - User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 392.00 ft Stage / Storage Table Stage (ft)Elevation (ft)Contour area (sqft)Incr. Storage (cuft)Total storage (cuft) 0.00392.007,57700 0.50392.508,3543,9813,981 1.00393.009,1584,3768,357 1.50393.509,9874,78413,141 Culvert / Orifice StructuresWeir Structures [A][B][C][PrfRsr][A][B][C][D] Rise (in)= 0.000.000.000.00 Span (in)= 0.000.000.000.00 No. Barrels= 0000 Invert El. (ft)= 0.000.000.000.00 Length (ft)= 0.000.000.000.00 Slope (%)= 0.000.000.00n/a N-Value= .013.013.013n/a Orifice Coeff.= 0.600.600.600.60 Multi-Stage= n/aNoNoNo Crest Len (ft)= 0.000.000.000.00 Crest El. (ft)= 0.000.000.000.00 Weir Coeff.= 3.333.333.333.33 Weir Type= ------------ Multi-Stage= NoNoNoNo Exfil.(in/hr)= 2.400 (by Contour) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table StageStorageElevationClv AClv BClv CPrfRsrWr AWr BWr CWr DExfilUserTotal ftcuftftcfscfscfscfscfscfscfscfscfscfscfs 0.000392.00------------------------0.000---0.000 0.503,981392.50------------------------0.464---0.464 1.008,357393.00------------------------0.509---0.509 1.5013,141393.50------------------------0.555---0.555 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Hyd. No. 1 Interim to W. Basin Hydrograph type= SCS RunoffPeak discharge= 3.560 cfs Storm frequency= 100 yrsTime to peak= 10.07 hrs Time interval= 2 minHyd. volume= 30,574 cuft Drainage area= 13.780 acCurve number= 70.5 Basin Slope= 0.0 %Hydraulic length= 0 ft Tc method= USERTime of conc. (Tc)= 15.00 min Total precip.= 2.80 inDistribution= Type I Storm duration= 24 hrsShape factor= 484 8 02468101214161820222426 Q (cfs) 0.000.00 1.001.00 2.002.00 3.003.00 4.004.00 Q (cfs) Time (hrs) Interim to W. Basin Hyd. No. 1 -- 100 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Hyd. No. 2 Interim West Basin Hydrograph type= ReservoirPeak discharge= 0.507 cfs Storm frequency= 100 yrsTime to peak= 15.90 hrs Time interval= 2 minHyd. volume= 30,566 cuft Inflow hyd. No.= 1 - Interim to W. BasinMax. Elevation= 392.98 ft Reservoir name= Interim West BasinMax. Storage= 8,203 cuft Storage Indication method used. Outflow includes exfiltration. 9 04812162024283236 Q (cfs) 0.000.00 1.001.00 2.002.00 3.003.00 4.004.00 Q (cfs) Time (hrs) Interim West Basin Hyd. No. 2 -- 100 Year Hyd No. 2 Hyd No. 1 Total storage used = 8,203 cuft Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Hyd. No. 3 Ultimate to W. Basin Hydrograph type= SCS RunoffPeak discharge= 3.919 cfs Storm frequency= 100 yrsTime to peak= 10.07 hrs Time interval= 2 minHyd. volume= 25,728 cuft Drainage area= 7.560 acCurve number= 77.5 Basin Slope= 0.0 %Hydraulic length= 0 ft Tc method= USERTime of conc. (Tc)= 15.00 min Total precip.= 2.80 inDistribution= Type I Storm duration= 24 hrsShape factor= 484 10 02468101214161820222426 Q (cfs) 0.000.00 1.001.00 2.002.00 3.003.00 4.004.00 Q (cfs) Time (hrs) Ultimate to W. Basin Hyd. No. 3 -- 100 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2008 by Autodesk, Inc. v6.052Thursday, Jun 9, 2011 Hyd. No. 4 Ultimate West Basin Hydrograph type= ReservoirPeak discharge= 0.499 cfs Storm frequency= 100 yrsTime to peak= 13.20 hrs Time interval= 2 minHyd. volume= 25,719 cuft Inflow hyd. No.= 3 - Ultimate to W. BasinMax. Elevation= 392.89 ft Reservoir name= Ultimate West BasinMax. Storage= 7,392 cuft Storage Indication method used. Outflow includes exfiltration. 11 04812162024283236 Q (cfs) 0.000.00 1.001.00 2.002.00 3.003.00 4.004.00 Q (cfs) Time (hrs) Ultimate West Basin Hyd. No. 4 -- 100 Year Hyd No. 4 Hyd No. 3 Total storage used = 7,392 cuft DRAINAGE STUDY REPORT Riverlakes Community Park APPENDIX D: SUPPORTING DATA  NOAA Precipitation Data  Riverlakes ADP Excerpts