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Home My WebLink AboutCT 2018-0002; AVIARA APARTMENTS WEST; DRAINAGE STUDY; 2023-07-12Drainage Report A VIARA APARTMENTS -WEST CT2018-0002 GR 202 1-0050 I DWG 535-lA City of Carlsbad, CA ~ County of San Diego PREPARED FOR: WERMERS PROPERTIES 5120 Shoreham Place, Suite 150 San Diego, CA 92122 858-535-1475 PREPARED BY: BB&D~ PLANNING ENGINEERING SURVEYING SB&O, INC. 3990 RUFFIN ROAD, SUITE 120 SAN DIEGO, CA 92123 (858) 560-1141 SB&O JOB NO. 76582.90 Allen L. Butche , PE C4 7107 Original: /4mber 22, 2022 Addendum July 12, 2023 Vl. l Addendum #1 Corporate Office: 3990 Ruffin Road, Suite 120 ■ San Diego, CA. 92123 ■ Phone (858) 560-1141 ■ Fax (858) 560-8157 41689 Enterprise Circle North, Suite 126■ Temecula, CA. 92590 ■ Phone (951) 695-8900 ■ (95 1) 695-890 I TABLE OF CONTENTS Vicinity Map .................................................................................................................................... 1 1. Scope of Report ................................................................................................................. 2 2. Existing Site ....................................................................................................................... 2 3. Project Description ........................................................................................................... 2 4. Hydrology .......................................................................................................................... 3 4.1 Design Criteria ......................................................................................................................................... 3 4.2 Soils ........................................................................................................................................................... 3 4. 3 Runoff Coefficient CC-Factors) .................................................................................................................. 3 4. 4 Rainfall ...................................................................................................................................................... 3 4. 5 Time of Concentration ............................................................................................................................... 4 4. 6 Peak Flow Rates ........................................................................................................................................ 4 5. Post-Development Hydrology .......................................................................................... 4 6. Inlet & Ditch Sizing Sizing ............................................................................................... 5 7. Rational Method Hydrographs ........................................................................................ 5 8. Detention ........................................................................................................................... 6 9. Conclusion ......................................................................................................................... 6 EXHIBITS A. Rational Method Hydrology B. Inlet Sizing C. Rational Method Hydrograph D. Detention Routing, Storage Indication Outflow Table E. Velocity Calculations F. Hydraulic Grade Line for Bypass Storm Drain APPENDIX San Diego County June 2003 Hydrology Manual References EXISTING DRAINAGE EXHIBIT PROPOSED DRAINAGE EXHBIT D:176S82 Aviara Apts\13 Rcpons\Hydrology\Aviara West DRAINAGE REPORT Addi 2023-0510.docx Map Pocket #1 Map Pocket #2 Page i CITY OF OCEANSIDE ?s CITY OF VISTA PACIFIC OCEAN CITY OF VfC/NlTY MAP NOT TO SCALE THOMAS GUIDE PG. 1127, GRID A3 57TH EDITION D:\76582 Aviara Apts\13 Reports\llydrology\Aviara West DRAINAGE REPORT Addi 2023-0510.docx Y OF MARCOS Page I 1. Scope of Addendum The scope of this addendum is limited to providing detention routing for the revised linear underground storage system (UDB). The project hydrology and tributary stonn drain system has not changed. A construction change has been provided for the revised system. A separate SWQMP repo1i (SB&O, Inc. -October 2022) was prepared for the project, which documents the HMP mitigation for the developed project. A separate addendum to document the revised SWMM modeling has been prepared. 2. Existing Site The project site is located west of Aviara Parkway, south of Palomar Airp01i Road and Encinas Creek, in the City of Carlsbad. The site drains southeast to n01ihwest with overland flow to the existing graded channel in the n01ihwestern portion of the site, with runoff directed to the watercourse in Canyon De Las Encinas. The existing site includes a Warehouse building, storage yard and paved entry driveway and parking lot areas. Pervious areas consist of unvegetated graded areas and landscape areas at the margins of the development area The developed portion of the site (E-1) receives rnn-on from the "natural" slopes located south and west of the development areas. These areas will generally remain undisturbed by the re- development and will be intercepted by the future brow ditches above the retaining walls or toe of slope. There are four (4) run-on areas shown on the exhibits, denoted as E2, E3, E4 and ES. Runoff from these areas will be used for the sizing the proposed bypass st01m drains and ditches and added to the discharge location at the n01ihwest corner of the site. See Existing Drainage Exhibit in Map Pocket #1. 3. Project Description The proposed 5.48 ac development project area is a multi-story residential development. The development will include a single large building, surface parking, recreational pool and outdoor cmmnon areas. The proposed site improvements will include private stonn drain systems in the private driveway around the central building. Runoff will be directed to multiple biofiltration basins, which discharge to the HMP (UDB) facility. The central and western portions of the site and a portion of the northerly driveway, (drainage areas basins Nl & N2) are directed to Biofiltration Basin BMP-1, located near the northeast corner of the site The southerly portions of the developed site and the easterly portion of the building, and the southerly main driveway entry and slopes (Drainage Basin N3) are tiibutary to Biofiltration Basin BMP-2 (split into north and south pmiions). Outflows from BMP-1 & BMP-2 discharge to the Underground Detention Basin (UDB), which discharges at the northwest comer of the development area. Run-on from the westerly and southerly slopes will D:176582 Aviara Apts\13 Reports\Hydrology\Aviara West DRAINAGE REPORT Addi 2023-0407.docx Page 2 be intercepted using a bypass storm drain system including drainage ditches, inlets, and stonn drains along the southerly and westerly limits of development, discharging at the northern limits of the site, near the outlet of the post-development storm drain system See Proposed Drainage (DMA) Exhibit in Map Pocket #2. 4. Hydrology 4.1 Design Criteria Drainage systems will be designed in accordance with the City of Carlsbad's "Engineering Standards," Chapter 5. The Rational Method as defined in the San Diego County Hydrology Manual (June 2003 edition) is used to calculate peak flow rates for 100-year storm events. (See Appendix for Reference Materials, Charts & Tables). 4.2 Soils The soil mapping for the site includes hydrologic soil classification Type "A' in the central development area, and Type "D" along the western slopes and northeast limits. A portion of the existing westerly slope has been mapped as a Potential Critical Coarse Sediment Yield Area, which will be affected by the development. See project SWQMP report for additional details. 4.3 Rtmoff Coefficient (C-Factors) The runoff coefficients for this project, according to the San Diego County Hydrology Manual (2003) Table 3-1, includes the following; ' Surface Condition % Impervious Runoff Coefficient TypeA TypeD Pavement 95 0,87 0.87 Slopes 0-10 0.20 0.35 Existing (E-1 only) 62 0,651 Proposed Development 84 0.81 The runoff coefficients for the individual drainage areas will be calculated based upon the actual amounts of soil area. 4.4 Rainfall Rainfall intensities are calculated using the rainfall data from the County 6-Hour and 24-Hour Isopluvial Maps as follows; Storm 6-Hour 24-Hour Ratio Adjusted Event Rainfall Rainfall P6/P24 P6 (in) (in) (in) 100-Year 2.75 4.5 61% 2.7 See Appendix for Isopluvial Maps and Figure 3-1 to determine the adjusted 6-hour rainfall. D:\76582 Aviarn Apts\13 Rcpo11s\Hydrology\Aviara West DRAINAGE REPORT Addi 2023-0510.docx Page3 4.5 Time of Concentration Rainfall intensities were calculated using times of concentration in accordance with the procedures noted in the June 2003 Hydrology manual. This includes the limitations as noted in Table 3-2, which restricts the initial overland times of concentration (To) based upon the Land Use/ Density(% Impervious) and slope. 4.6 Peak Flow Rates Peak flow rates are estimated using the Rational Method (Q=CIA). Rainfall intensities are based upon the following fonnula; I= 7.44 P6 Tc-·645 Where; P6 is the local 6-hour rainfall total (inches) for a given storm frequency. Tc is the time of concentration (minutes) at the design location in the drainage system. Note: When calculating intensity, the minimum Tc is 5 minutes. 5, Hydrology In accordance with Table 3-2 of County Hydrology Manual, the initial time of concentration is limited to 6.9 minutes for "natural land uses", when slopes are greater than 10%. For Industrial land uses (roof) and paved areas (95% Impervious), the initial times of concentration are limited to 3.2 minutes for mild slopes (1.0%). Based upon these constraints, the initial time of concentration for both the existing and proposed site runoff will be limited by the natural steep slopes. The development areas will be governed by the overland flow lengths for paved and roof areas. The pealc flow rates for the developed portion of the site in the existing condition is detailed in Exhibit C and shown on the Existing Drainage Exhibit in Map Pocket 1. The peak flow rate for the proposed condition is closely tied to the travel time in the proposed storm drain system. Condition Vl00 Tc Intensity Area Composite Ql00 (fps) (min) (in/hr.) (ac) Runoff (cfs) Coefficient Existing (E-1 on! y) 1.67* 7.12 5.67 5.48 0.651 20.22 Proposed (unmitigated) 4.99* 14.08 3.83 5.48 0.505 10.28 *See Exhibit E for Velocity calculations. Note: The above table illustrates that the proposed redevelopment of the site reduces the 100- year peak runoff primarily due to the increased time of concentration. The 100-year rational method hydrology was calculated for all of the main storm drain runs, using San Diego County CivilD program node-to-node analysis. For purposes of these calculations, we have conservatively assumed that the 100-year flows through the water-quality basins. See Exhibit "A" for Rational Method Calculations, as shown on the node map in Map Pocket 1. D:\76582 AviaraApts\13 Reports\Hydrology\Avilll'a West DRAINAGE REPORT Addl 2023-0510.docx Page4 D:\76582 Aviara Apts\13 Reports\Hydrology\Aviara West DRAINAGE REPORT Add1 2023-0712.docx Page 5 6. Inlet and Ditch Sizing The project proposes private curb inlets Inlet openings in sump conditions are estimated using a two cfs per lineal foot of opening per Carlsbad City Standards chapter 5.4.A (excerpt included in Appendix). Proposed curb openings shall have an opening width of at least 4 feet for maintenance purposes. Brow ditches are located around the perimeter of the project and at the top/toe of internal slopes. Ditches are typically specified as San Diego Regional Standard D-75 (round bottom). A brow ditch capacity calculation has been provided in Exhibit B. The project ditches are typically designed with a slope of 2% and a minimum of 1%. The capacity is calculated using a 50%-full 24” pipe at a slope of 1%, therefore providing the maximum allowable Q, which is not exceeded by any of the project drainage areas. See Exhibit “B” for Inlet & Ditch Calculations. 7. Rational Method Hydrographs The County of San Diego Hydrology Manual includes a procedure to develop a time-based runoff series. The methodology assumes a simple triangular runoff hydrograph, and is based the 6-hour rainfall total, and the Rational Method input variables. The methodology provides runoff values at time intervals equal to multiples of the time of concentration. Details related to the procedure to develop the hydrograph are provided in Chapter 6 of the County of San Diego Hydrology Manual (See Appendix for details). Rational method hydrographs for a range of 6-hour storms were prepared for the area tributary to the underground detention/HMP tank (UDB). See Exhibit “C” for the 6-hour Rational Method Hydrograph calculations & inflow time series. Note: The Rational Method Hydrograph is based upon the Rational Method data inputs. However, the runoff estimates are adjusted during the confluence procedure of the CivilD program. In order to maintain continuity, an adjusted C factor (0.505) was calculated for the hydrograph input. Proposed P6 Rainfall (in) Tc (min) Intensity (in/hr.) Area (ac) Composite Runoff Coefficient Q100 (cfs) CivilD - Confluence 2.70 14.08 3.83 5.48 0.505 10.28 RM – Continuity 2.70 14.08 3.65 5.48 0.505 10.10 RM Hydrograph Input 2.70 15.0 3.50 5.48 0.505 9.70 The above table illustrates the potential discrepancies in using the rational method, which is highly sensitive to changes in the time of concentration. The use of the confluencing methodology (formerly known as the Modified Rational Method) violates continuity and distorts the peak flow rates. In order for Q = CIA, the runoff coefficient must be adjusted. D:\76582 Aviara Apts\13 Reports\Hydrology\Aviara West DRAINAGE REPORT Add1 2023-0712.docx Page 6 The Rational Method Hydrograph maintains continuity and is a volume based procedure. Flow rates are calculated using different rainfall intensities at multiples of time of concentration. The procedure requires a time of concentration as a whole minute, typically rounded up. The hydrograph methodology provides runoff time series from the 6-hour rainfall distribution, with the peak intensity occurring at 4-hours. Runoff volume equals the 6-hour rainfall total multiplied by the runoff coefficient and the area. Since the detention modeling is based upon volume rather than flow rates, minor differences in the peak flow rates has little impact on the routing procedure. 8. Detention The detention model is based upon the storage volumes, low flow orifice size and overflow weir dimensions, and excludes infiltration. The gross storage volume of UDB and the rock voids is 27,127 cubic feet, including 965 cubic feet of rock void space below the pipe flow line and low flow orifice outlet elevation. This volume is assumed to be saturated in a large storm event. In addition, the volume of the upstream basins (BMP-1 and BMP-2) are ignored for detention routing. An incremental Storage-Indication-Outflow table was prepared using the adjusted UDB volume and control structure openings. The 6-hour hydrographs were routed to determine the attenuated peak outflow and storage depth. Modeled value are summarized as follows; UDB (Pipe) / HMP-1 Adjusted Storage 26,162 cf. @ 7.5’ Depth Elevation Description Size Comment Rock Subgrade Excluded 77.85 Bottom of Pipe 77.85 Orifice – Low Flow 1.25” diameter 83.10 Overflow Weir 5’ Wide x 6” tall 5.25’ depth 84.85 Top of Pipe 7’ pipe depth 85.35 Top of Rock Backfill 7.5’ A review of the results indicates a peak outflow to the storm drain is 2.04 cfs, with a maximum storage depth of 5.5’ (1.5’ freeboard from top of pipe). The Storage Indication Outflow table and routing analyses for HMP-1 are in Exhibit “D”. Mitigated Discharge from Development Area Area (ac) Runoff Coefficient Q100 (cfs) Existing (E-1 only) 5.48 0.651 20.22 Proposed (excludes bypass) 5.48 0.505 2.04 The mitigated comparison shows a significant reduction in the Q100 peak discharge compared to the existing condition. I I D:\76582 Aviara Apts\13 Reports\Hydrology\Aviara West DRAINAGE REPORT Add1 2023-0712.docx Page 7 9. Conclusion The existing site includes a building and paved parking area with large slopes to the south and west, with limited storm drain facilities The proposed project has similar impervious area. The proposed private onsite system includes a bypass storm drain system to intercept and route flows beyond the development area. The proposed site storm drain conveys runoff to the onsite basins and an underground storage system to achieve HMP mitigation and attenuation of larger storms. As expected, project discharge is significantly reduced compared to the existing condition. The private storm drain systems adequately conveys the 100-year post development flows and the bypass flows. EXHIBIT A D:\76582 Aviara Apts\13 Reporls\Hydrology\Aviara West DRAINAGE REPORT Addi 2023-05 I0.docx I soil Type -Mix of A & D IA VIARA APARTMENTS -WEST 5/7/20231 P6= 2.7 Proposed DMA Portion Area lmperv C (A) C (D) C CxA Tc 1100 Ql00 Description ID Soil A (ac) {%) (ac) (min) (in/hr) (cfs) West BMP-1 NlA 1.10 95% 0.80 -0.88 NlD 0.47 95% 0.81 0.38 Nl 1.57 95% 0.803 1.26 Central BMP-1 N2A 1.68 95% 0.80 -1.35 N2D 0.18 40% 0.37 0.07 N2 1.87 90% 0.758 1.41 East BMP-2 N3A 1.39 80% 0.76 1.05 N3D 0.66 50% 0.63 0.41 N3 2.04 70% 0.718 1.47 0.756 4.14 Site Runoff -CivilD 5.48 84% a.sos 2.77 14.08 3.65 10.28 5.48 a.sos 2.77 14.1 3.65 10.10 5.48 a.sos 2.77 15.0 3.50 9.70 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2005 Version 6.5 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 08/12/22 ********* Hydrology Study Control Information********** Program License Serial Number 6334 Rational hydrology study storm event year is English (in-lb) input data Units used English (in) rainfall data used Map data precipitation entered: 6 hour, precipitation(inches) = 2.750 24 hour precipitation(inches) = 4.500 Adjusted 6 hour precipitation (inches)= 2.750 P6/P24 = 61.1% San Diego hydrology manual 'C' values used Runoff coefficients by modified rational method 100.0 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 101.000 to Point/Station 102.000 fJf1 **** INITIAL AREA EVALUATION**** 1!2.J User specified 'C' value of 0.350 given for subarea Time of concentration computed by the natural watersheds nomograph (App X-A) TC= [11.9*length(Mi)A3)/(elevation change(Ft.))JA.385 *60(min/hr) + 5 min. (City of Oceanside) Initial subarea flow distance = 418.000(Ft.) Highest elevation= 165.000(Ft.) Lowest elevation= 88.000(Ft.) Elevation difference= 77.000(Ft.) TC=[(11.9*0.0792A3)/( 77.00)]A.385= 1.56 + 5 min. = 6.56 min. Rainfall intensity (I)= 6.080(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff= 4.086(CFS) Total initial stream area= 1.920(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 102.000 to Point/Station 103.000 [)-7!> **** PIPEFLOW TRAVEL TIME (User specified size)**** O/'fCl;t Upstream point/station elevation= 86.900(Ft.) Downstream point/station elevation= 84.250(Ft.) Pipe length = 140.00(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 4.086(CFS) Given pipe size= 24.00(In.) Calculated individual pipe flow = 4.086(CFS) Normal flow depth in pipe= 5.87(In.) -~ Flow top width inside pipe= 20.63(In.) ~ Critical Depth= 8.49(In.) Pipe flow velocity= 6.86(Ft/s) Travel time through pipe= 0.34 min. Time of concentration (TC)= 6.90 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 103.000 to Point/Station 104.000 **** SUBAREA FLOW ADDITION**** User specified 'C' value of 0.350 given for subarea Time of concentration= 6.90 min. Rainfall intensity= 5,885(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA= 0.983 Subarea runoff= 1.702(CFS) for 0.890(Ac.) Total runoff= 5.788(CFS) Total area= 2.810(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 103.000 to Point/Station 104.000 **** PIPEFLOW TRAVEL TIME (User specified size)**** ®- Upstream point/station elevation= 79.610(Ft.) Downstream point/station elevation= 78.960(Ft.) Pipe length = 222.23(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 5.788(CFS) Given pipe size= 18.00(In.) Calculated individual pipe flow = 5.788(CFS) Normal flow depth in pipe= 18.00(In.) Flow top width inside pipe= 0.00(In.) Critical Depth= 11.15(In.) Pipe flow velocity= 3.21(Ft/s) Travel time through pipe= 1.15 min. Time of concentration (TC)= 8.05 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station **** SUBAREA FLOW ADDITION**** 105.000 f c..,J User specified 'C' value of 0.350 given for subarea Time of concentration= 8.05 min. Rainfall intensity= 5.327(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA= 1.743 Subarea runoff= 3.498(CFS) for 2.170(Ac.) Total runoff= 9.285(CFS) Total area= 4.980(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105.000 **** SUBAREA FLOW ADDITION**** ill User specified 'C' value of 0.350 given for subarea Time of concentration= 8.05 min. Rainfall intensity= 5.327(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA= 2.019 Subarea runoff= 1.473(CFS) for 0.790(Ac.) Total runoff= 10.758(CFS) Total area= 5.770(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105.000 ft::1 **** SUBAREA FLOW ADDITION**** l,_E::::-l User specified 'C' value of 0,350 given for subarea Time of concentration= 8.05 min. Rainfall intensity= 5.327(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA= 2.093 Subarea runoff= 0.392(CFS) for 0.210(Ac.) Total runoff= 11.150(CFS) Total area= 5.980(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105.000 rn **** SUBAREA FLOW ADDITION**** U-J User specified 'C' value of 0.350 given for subarea Time of concentration= 8.05 min. Rainfall intensity= 5.327(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA= 2.142 Subarea runoff= 0.261(CFS) for 0.140(Ac.) Total runoff= 11.411(CFS) Total area= 6.120(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105.000 **** PIPEFLOW TRAVEL TIME (User specified size)**** Upstream point/station elevation= 78.940(Ft.) Downstream point/station elevation= 77.990(Ft.) Pipe length = 317.23(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 11.411(CFS) Given pipe size= 18.00(In.) NOTE: Normal flow is pressure flow in user selected pipe size. The approximate hydraulic grade line above the pipe invert is 3.763(Ft.) at the headworks or inlet of the pipe(s) Pipe friction loss= 3.742(Ft.) Minor friction loss= 0.971(Ft.) K-factor= 1.50 Pipe flow velocity= 6.46(Ft/s) Travel time through pipe= 0.82 min. Time of concentration (TC)= 8.87 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 105.000 to Point/Station 106.000 **** PIPEFLOW TRAVEL TIME (User specified size)**** Upstream point/station elevation= 77.980(Ft.) Downstream point/station elevation= 77.720(Ft.) Pipe length = 85.93(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 11.411(CFS) Given pipe size= 18.00(In.) NOTE: Normal flow is pressure flow in user selected pipe size. The approximate hydraulic grade line above the pipe invert is 1.725(Ft.) at the headworks or inlet of the pipe(s) Pipe friction loss= 1.014(Ft.) Minor friction loss= 0.971(Ft.) K-factor= 1.50 Pipe flow velocity= 6.46(Ft/s) Travel time through pipe= 0.22 min. Time of concentration (TC)= 9.10 min. End of computations, total study area= 6.120 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2005 Version 6.5 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 08/05/22 ********* Hydrology Study Control Information********** Program License Serial Number 6334 Rational hydrology study storm event year is English (in-lb) input data Units used English (in) rainfall data used Map data precipitation entered: 6 hour, precipitation(inches) = 2.750 24 hour precipitation(inches) = 4.500 Adjusted 6 hour precipitation (inches)= 2.750 P6/P24 = 61.1% San Diego hydrology manual 'C' values used Runoff coefficients by modified rational method 100.0 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 201.000 to Point/Station 202.000 **** INITIAL AREA EVALUATION **** ~ User specified 'C' value of 0.800 given for subarea Initial subarea flow distance = 187.500(Ft.) Highest elevation= 87.890(Ft.) Lowest elevation= 87.100(Ft.) Elevation difference= 0.790(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 9.86 min. TC= [1.8*(1.1-C)*distance(Ft.)A .5)/(% slopeA(l/3)) TC= [1 .8*(1.1-0.8000)*( 187.500A.5)/( 0.421A(l/3))= 9.86 Rainfall intensity (I)= 4.675(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.800 Subarea runoff= 0.550(CFS) Total initial stream area= 0.147(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 202.000 to Point/Station **** SUBAREA FLOW ADDITION**** Decimal fraction soil group A= 0.080 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.920 [MULTI -UNITS area type Time of concentration= 9.86 min . 203.000 Rainfall intensity= 4.675(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.736 CA= 0.230 Subarea runoff= 0.528(CFS) for 0 .166(Ac.) Total runoff= 1.077(CFS) Total area= 0.313(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 202.000 to Point/Station 203.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation= 84 .500(Ft.) Downstream point/station elevation= 84.480(Ft.) Pipe length = 15.95(Ft.) Manning's N = 0.013 No. of pipes= 2 Required pipe flow = 1.077(CFS) Given pipe size= 12.00(In.) Calculated individual pipe flow = 0.539(CFS) Normal flow depth in pipe= 5.47(In.) Flow top width inside pipe= 11.95(In.) Critical Depth= 3.66(In.) Pipe flow velocity= 1.54(Ft/s) Travel time through pipe= 0.17 min. Time of concentration (TC)= 10.04 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 209.000 to Point/Station 203 .000 f tl **** SUBAREA FLOW ADDITION**** ~ Decimal fraction soil group A= 0.740 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.260 [MULTI -UNITS area type ] Time of concentration= 10.04 min . Rainfall intensity= 4.623(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.585 CA= 0.577 Subarea runoff= 1.588(CFS) for 0 .672(Ac.) Total runoff= 2.665(CFS) Total area= 0.985(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 203.000 to Point/Station 204.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation= 84.470(Ft.) Downstream point/station elevation= 84.140(Ft.) Pipe length = 111.71(Ft.) Manning's N = 0.013 No. of pipes= 2 Required pipe flow = 2.665(CFS) Given pipe size= 12.00(In.) Calculated individual pipe flow = 1.333(CFS) Normal flow depth in pipe= 7.31(In.) Flow top width inside pipe= ll.71(In.) Critical Depth= 5.86(In.) Pipe flow velocity= 2.66(Ft/s) Travel time through pipe= 0.70 min. Time of concentration (TC)= 10.74 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 210.000 to Point/Station 204.000 **** SUBAREA FLOW ADDITION**** Decimal fraction soil group A= 0.990 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.010 [MULTI -UNITS area type ] Time of concentration= 10.74 min. Rainfall intensity= 4.426(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.535 CA= 0.844 Subarea runoff= 1.072(CFS) for 0.592(Ac.) Total runoff= 3.737(CFS) Total area= 1.577(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 204.000 to Point/Station 205.000 **** PIPEFLOW TRAVEL TIME (User specified size)**** Upstream point/station elevation= 84.130(Ft.) Downstream point/station elevation= 83 .950(Ft.) Pipe length = 53.33(Ft.) Manning's N = 0.013 No. of pipes= 2 Required pipe flow = 3.737(CFS) Given pipe size= 12.00(In.) Calculated individual pipe flow = 1.869(CFS) Normal flow depth in pipe= 8 .93(In.) Flow top width inside pipe= 10.47(In.) Critical Depth= 6.98(In.) Pipe flow velocity= 2.98(Ft/s) Travel time through pipe= Time of concentration (TC)= 0.30 min. 11.03 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 205.000 to Point/Station 206.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation= 83.940(Ft.) Downstream point/station elevation= 83.710(Ft.) Pipe length = 49.77(Ft.) Manning 's N = 0.013 No. of pipes= 1 Required pipe flow = 3.737(CFS) Given pipe size= 24.00(In.) Calculated individual pipe flow = 3.737(CFS) Normal flow depth in pipe= 8 .06(In.) Flow top width inside pipe= 22.67(In.) Critical Depth= 8.12(In.) Pipe flow velocity= 4.04(Ft/s) Travel time through pipe= 0.21 min. Time of concentration (TC)= 11.24 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 206.000 to Point/Station 207.000 "71 **** SUBAREA FLOW ADDITION**** ~ Decimal fraction soil group A= 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [MULTI -UNITS area type Time of concentration= 11 .24 min. Rainfall intensity= 4.297(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.529 CA= 0.903 Subarea runoff= 0.143(CFS) for 0.130(Ac.)- Total runoff= 3.880(CFS) Total area= 1.707(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 206 .000 to Point/Station 207.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation= 83.700(Ft.) Downstream point/station elevation= 83.030(Ft.) Pipe length = 248.16(Ft.) Manning 's N = 0.013 No. of pipes= 1 Required pipe flow = 3.880(CFS) Given pipe size= 24.00(In.) Calculated individual pipe flow = 3.880(CFS) Normal flow depth in pipe= 9.49(In.) Flow top width inside pipe= 23.47(In.) Critical Depth= 8.27(In.) Pipe flow velocity= 3.36(Ft/s) Travel time through pipe= 1.23 min . Time of concentration (TC)= 12.47 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 211.000 to Point/Station 207.000 **** SUBAREA FLOW ADDITION**** ITT Decimal fraction soil group A= 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [MULTI -UNITS area type ] Time of concentration= 12.47 min . Rainfall intensity= 4.018(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.514 CA= 1.078 Subarea runoff= 0.450(CFS) for 0.388(Ac.) Total runoff= 4.330(CFS) Total area= 2.095(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 207.000 to Point/Station 208.000 1M7 **** SUBAREA FLOW ADDITION**** ~ Decimal fraction soil group A= 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [MULTI -UNITS area type ] Time of concentration= 12.47 min . Rainfall intensity= 4.018(In/Hr) for a 100 .0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.493 CA= 1.552 Subarea runoff= 1 .908(CFS) for 1.055(Ac.) Total runoff= 6.237(CFS) Total area= 3.150(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 207.000 to Point/Station 208.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation= 82.940(Ft.) Downstream point/station elevation= 82.400(Ft.) Pipe length = 204.12(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 6.237(CFS) Given pipe size= 24.00(In.) flow = 6.237(CFS) Calculated individual pipe Normal flow depth in pipe= Flow top width inside pipe= Critical Depth= 10.59(In.) 12.50(In.) 23.98(In.) Pipe flow velocity= 3.77(Ft/s) Travel time through pipe= 0.90 min. Time of concentration (TC)= 13.37 min. End of computations, total study area= 3.150 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)l991-2005 Version 6.5 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 08/05/22 ********* Hydrology Study Control Information********** Program License Serial Number 6334 Rational hydrology study storm event year is English (in-lb) input data Units used English (in) rainfall data used Map data precipitation entered: 6 hour, precipitation(inches) = 2.750 24 hour precipitation(inches) = 4.500 Adjusted 6 hour precipitation (inches)= 2.750 P6/P24 = 61.1% San Diego hydrology manual 'C' values used Runoff coefficients by modified rational method 100.0 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 301.000 to Point/Station 302.000 ,.;:;:;-,0 **** INITIAL AREA EVALUATION**** ~ Decimal fraction soil group A= 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [MULTI -UNITS area type ] Initial subarea flow distance = 136.000(Ft.) Highest elevation= 88.800(Ft.) Lowest elevation= 86.730(Ft.) Elevation difference= 2.070(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 11.86 min. TC= [l.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC= [l.8*(1.1-0.4500)*( 136.000A.5)/( 1.522A(l/3)]= 11 .86 Rainfall intensity (I)= 4 .150(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.450 Subarea runoff= 0.261(CFS) Total initial stream area= 0.140(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 302.000 to Point/Station 303 .000 JNf **** SUBAREA FLOW ADDITION**** ~ Decimal fraction soil group A= 0.420 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.580 [MULTI -UNITS area type ] Time of concentration= 11.86 min. Rainfall intensity= 4.150(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.533 CA= 0.176 Subarea runoff= 0.469(CFS) for 0.190(Ac.) Total runoff= 0.731(CFS) Total area= 0.330(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 302.000 to Point/Station 303.000 fol\ O **** SUBAREA FLOW ADDITION**** ll..-J_ Decimal fraction soil group A= 0.890 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.110 [MULTI -UNITS area type Time of concentration= 11 .86 min . Rainfall intensity= 4.150(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.491 CA= 0.654 Subarea runoff= 1.982(CFS) for 1.000(Ac.) Total runoff= 2.712(CFS) Total area= 1.330(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 302.000 to Point/Station 303.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation= 86.000(Ft.) Downstream point/station elevation= 85.000(Ft.) Pipe length = 326.86(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 2.712(CFS) Given pipe size= 15.00(In.) Calculated individual pipe flow = 2.712(CFS) Normal flow depth in pipe= 9.77(In.) Flow top width inside pipe= 14.29(In.) Critical Depth= 7.93(In.) Pipe flow velocity= Travel time through pipe= Time of concentration (TC) End of computations, total 3.20(Ft/s) 1. 70 min. = 13.56 min. study area= 1.330 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2005 Version 6.5 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 08/08/22 ------------------------------------------------------------------------ ********* Hydrology Study Control Information ********** ------------------------------------------------------------------------ Program License Serial Number 6334 ------------------------------------------------------------------------ Rational hydrology study storm event year is English (in-lb) input data Units used English (in) rainfall data used Map data precipitation entered: 6 hour, precipitation(inches) = 2.750 24 hour precipitation(inches) 4.500 Adjusted 6 hour precipitation (inches) = 2.750 P6/P24 = 61.1% San Diego hydrology manual 'C' values used Runoff coefficients by modified rational method 100.0 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 401.000 to Point/Station 402 .000 c\~] **** INITIAL AREA EVALUATION**** I _ Decimal fraction soil group A Decimal fraction soil group B Decimal fraction soil group C Decimal fraction soil group D [MULTI -UNITS area type 0.200 0.000 0.000 0.800 Initial subarea flow distance Highest elevation= 110 .500(Ft.) Lowest elevation= 88.900(Ft.) ] 275.000(Ft.) Elevation difference 21.600(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 6.76 min. TC = [1.8*(1.l -C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC= [1.8*(1 .1-0.6500)*( 275.000A.5)/( 7.855A (1/3)]= 6.76 Rainfall intensity (I)= 5 .966(In/Hr) for a 100 .0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0 .650 Subarea runoff= 0.970(CFS) Total initial stream area= 0.250(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 402.000 to Point/Station 403.000 **** CONFLUENCE OF MINOR STREAMS**** Along Main Stream number: 1 in normal stream number 1 Stream flow area= 0.250(Ac.) Runoff from this stream= 0.970(CFS) Time of concentration 6.76 min. Rainfall intensity= 5.966(In/Hr) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 303.000 to Point/Station 403.000 **** USER DEFINED FLOW INFORMATION AT A POINT**** Decimal fraction soil group A 0.830 Decimal fraction soil group B 0.000 Decimal fraction soil group C 0.000 Decimal fraction soil group D 0.170 [MULTI -UNITS area type ] Rainfall intensity (I)= 3.807(In/Hr) for a 100 .0 year storm User specified values are as follows : TC= 13.56 min. Rain intensity= 3.81(In/Hr) Total area= 1 .330(Ac.) Total runoff= 2.712(CFS) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 303.000 to Point/Station 403.000 **** CONFLUENCE OF MINOR STREAMS**** Along Main Stream number: 1 in normal stream number 2 Stream flow area= 1.330 (Ac.) Runoff from this stream 2.712(CFS) Time of concentration= 13.56 min. Rainfall intensity= 3.807(In/Hr) Summary of stream data : Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 1 0.970 6.76 5.966 2 2.712 13.56 3.807 Qmax(l) = 1.000 * 1.000 * 0.970) + 1.000 * 0.498 * 2.712) + = 2.321 Qmax(2) 0.638 * 1.000 * 0.970) + 1.000 * 1.000 * 2.712) + 3.331 Total of 2 streams to confluence: Flow rates before confluence point: 0.970 2.712 Maximum flow rates at confluence using above data: 2.321 3.331 Area of streams before confluence: 0.250 1.330 Results of confluence: Total flow rate= 3.331(CFS) Time of concentration 13.560 min . Effective stream area after confluence 1.580(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 403 .000 to Point/Station 404.000 **** PIPEFLOW TRAVE L TIME (User specified size) **** Upstream point/station elevation = 81.420(Ft.) Downstream point/station elevation 80.560(Ft.) Pipe length 86 .04(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow 3.331(CFS) Given pipe size= 18.00(In.) Calculated individual pipe flow = 3.331(CFS) Normal flow depth in pipe= 6.97(In.) Flow top width inside pipe= 17.53(In .) Critical Depth= 8.34(In.) Pipe flow velocity= 5.27(Ft/s) Travel time through pipe= 0.27 min. Time of concentration (TC)= 13.83 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 403 .000 to Point/Station 404.000 **** CONFLUENCE OF MINOR STREAMS**** Along Main Stream number: 1 in normal stream number 1 Stream flow area= 1.580(Ac.) Runoff from this stream 3.331(CFS) Time of concentration 13.83 min. Rainfall intensity= 3.759(In/Hr) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 406.000 to Point/Station 405.000 IIJ1 **** INITIAL AREA EVALUATION**** ~ Decimal fraction soil group A Decimal fraction soil group B Decimal fraction soil group C = Decimal fraction soil group D 0.810 0.000 0.000 0.190 [MULTI -UNITS area type Initial subarea flow distance Highest elevation= 107.000(Ft.) Lowest elevation= 86.940(Ft.) l 270.000(Ft.) Elevation difference= 20.060(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 9.13 min. TC= [1.8*(1.1-C)*distance(Ft.)'.5)/(% slope'(l/3)] TC= [1.8*(1.1-0.4975)*( 270.000'.5)/( 7.430'(1/3)]= 9.13 Rainfall intensity (I)= 4.913(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.498 Subarea runoff= 1.149(CFS) Total initial stream area= 0.470(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 405.000 to Point/Station 404.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation= 81.800(Ft.) Downstream point/station elevation= 80.630(Ft.) Pipe length = 21.71(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 1,149(CFS) Given pipe size= 18.00(In,) Calculated individual pipe flow = 1.149(CFS) Normal flow depth in pipe = 2. 66(In.) Flow top width inside pipe= 12.77(In.) Critical Depth= 4.80(In.) Pipe flow velocity= 7.06(Ft/s) Travel time through pipe= 0.05 min. Time of concentration (TC)= 9.18 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 405.000 to Point/Station 404.000 **** CONFLUENCE OF MINOR STREAMS**** Along Main Stream number: 1 in normal stream number 2 Stream flow area= 0.470(Ac.) Runoff from this stream= 1.149(CFS) Time of concentration= 9.18 min. Rainfall intensity= 4.895(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 1 3.331 13.83 3.759 2 1.149 9.18 4.895 Qrnax(l) 1.000 * 1.000 * 3.331) + 0.768 * 1.000 * 1.149) + 4 .213 Qmax(2) 1.000 * 0.664 * 3.331) + 1.000 * 1.000 * 1.149) + 3.360 Total of 2 streams to confluence: Flow rates before confluence point: 3.331 1.149 Maximum flow rates at confluence using above data: 4.213 3.360 Area of streams before confluence: 1.580 0.470 Results of confluence: Total flow rate= 4.213(CFS) Time of concentration 13.832 min. Effective stream area after confluence 2.050(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 404 .000 to Point/Station 407.000 **** PIPEFLOW TRAVEL TIME (User specified size)**** Upstream point/station elevation= 80.230(Ft.) Downstream point/station elevation 79.390(Ft.) Pipe length 83.54(Ft.) Manning's N = 0 .013 No. of pipes= 1 Required pipe flow 4.213(CFS) Given pipe size= 18.00(In.) Calculated individual pipe flow 4.213(CFS) Normal flow depth in pipe= 7.92(In.) Flow top width i nside pipe= 17.87(In.) Critical Depth = 9.44(In.) Pipe flow velocity= 5.63(Ft/s) Travel time through pipe= 0.25 min . Time of concentration (TC)= 14.08 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 404.000 to Point/Station 407.000 **** CONFLUENCE OF MINOR STREAMS**** Along Main Stream number: 1 in normal stream number 1 Stream flow area= 2.050(Ac.) Runoff from this stream 4.213(CFS) Time of concentration 14.08 min . Rainfall intensity= 3.716(In/Hr) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 208.000 to Point/Station 408.000 **** USER DEFINED FLOW INFORMATION AT A POINT**** ~ l"'"~p 1.--,~16 \3> Decimal fraction soil group A 0.000 Decimal fraction soil group B 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D 1.000 [MULTI -UNITS area type ] Ra i nfall intensity (I)= 3.842(In/Hr) for a 100.0 year storm User specified values are as follows: TC= 13.37 min. Rain intensity= 3.84(In/Hr) Total area= 3.150(Ac.) Total runoff= 6.237(CFS) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 408.000 to Point/Station 407.000 •l\l7y **** SUBAREA FLOW ADDITION**** V..:L Decimal fraction soil group A Decimal fraction soil group B Decimal fraction soil group C Decimal fraction soil group D [MULTI -UNITS area type 0.500 0.000 0.000 0.500 The area added to the existing stream causes a a lower flow rate of Q = 2.368(CFS) therefore the upstream flow rate of Q = 6.237(CFS) is being used Time of concentration= 13.37 min. Rainfall intensity= 3.842(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.190 CA = 0.616 Subarea runoff 0.000(CFS) for 0.100(Ac.) Total runoff= 6.237(CFS) Total area= 3.250(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 408.000 to Point/Station 407.000 'f7h1 **** SUBAREA FLOW ADDITION**** L::::Ll- Decimal fraction soil group A Decimal fraction soil group B Decimal fraction soil group C Decimal fraction soil group D [MULTI -UNITS area type 0.000 0.000 0.000 1.000 The area added to t he existing st ream causes a a lower flow rate of Q = 2.637(CFS) therefore the upstream flow rate of Q = 6.237(CFS) is being used Time of concentration= 13.37 min. Rainfall intensity= 3.842(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.205 CA= 0.686 Subarea runoff 0.000(CFS) for 0.100(Ac.) Total runoff= 6.237(CFS) Total area= 3.350(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 408.000 to Point/Station 407.000 rol+lkl **** SUBAREA FLOW ADDITION**** i!::J. 1.:::J.. Decimal fraction soil group A Decimal fraction soil group B Decimal fraction soil group C 0.680 0.000 0.000 Decimal fraction soil group D 0.320 [MULTI -UNITS area type The area added to the existing stream causes a a lower flow rate of Q = 2.800(CFS) therefore the upstream flow rate of Q = 6.237(CFS) is being used Time of concentration = 13.37 min . Rainfall intensity= 3.842(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.212 CA= 0.729 Subarea runoff 0.000(CFS) for 0.080(Ac.) Total runoff= 6.237(CFS) Total area= 3.430(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 408.000 to Point/Station 407 .000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation= 79 .100(Ft .) Downstream point/station elevation 79.040(Ft.) Pipe length 25.50(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow 6.237(CFS) Given pipe size= 24.00(In.) Calculated individual pipe flow = 6 .237(CFS) Normal flow depth in pipe = 12.96(In.) Flow top width inside pipe= 23.92(In.) Critical Depth= 10.59(In.) Pipe flow velocity= 3.60(Ft/s) Travel time through pipe= 0.12 min. Time of concentration (TC)= 13.49 min . ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 408.000 to Point/Station 407 .000 **** CONFLUE NCE OF MINOR STREAMS **** Along Main Stream number : 1 in normal stream number 2 Stream flow area= 3.430(Ac .) Runoff from this stream 6.237(CFS) Time of concentration= 13 .49 min. Rainfall intensity= 3.820(In/Hr) Summary of stream data: Stream Flow rate TC Rainfal l Intensity No, (CFS) (min) (In/Hr) 1 4.213 14.08 3.716 2 6.237 13.49 3.820 Qmax(l) 1.000 * 1.000 * 4.213) + 0.973 * 1.000 * 6.237) + 10.279 Qmax(2) 1.000 * 0.958 * 4.213) + 1.000 * 1.000 * 6.237) + 10.273 Total of 2 streams to confluence: Flow rates before confluence point: 4.213 6.237 Maximum flow rates at confluence using above data: 10.279 10.273 Area of streams before confluence: 2.050 3.430 Results of confluence: Total flow rate= 10.279(CFS) Time of concentration 14.079 min. Effective stream area after confluence 5.480(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 407.000 to Point/Station 409.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation= 79.060(Ft.) Downstream point/station elevation 78.640(Ft.) Pipe length = 41.90(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 10.279(CFS) Given pipe size= 24.00(In.) Calculated individual pipe flow = 10.279(CFS) Normal flow depth in pipe= 11.34(In.) Flow top width inside pipe= 23.96(In.) Critical Depth= 13.78(In.) Pipe flow velocity= 7.04(Ft/s) Travel time through pipe= 0.10 min. Time of concentration (TC)= 14.18 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 409.000 to Point/Station 410.000 **** PIPEFLOW TRAVEL TIME (User specified size)**** Upstream point/station elevation= 78.310(Ft.) Downstream point/station elevation= 77.850(Ft.) Pipe length = 50.29(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 10.279(CFS) Given pipe size= 24.00(In.) Calculated individual pipe flow 10.279(CFS) Normal flow depth in pipe= 11.65(In.) Flow top width inside pipe= 23.99(In.) Critical Depth= 13.78(In.) Pipe flow velocity= 6.80(Ft/s) Travel time through pipe= 0.12 min. Time of concentration (TC)= 14.30 min. End of computations, total study area= 5.480 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2005 Version 6.5 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date : 08/05/22 ********* Hydrology Study Control Information ********** Program License Serial Number 6334 Rational hydrology study storm event year is English (in-lb) input data Units used English (in) rainfall data used Map data precipitation entered: 6 hour, precipitation(inches) = 2.750 24 hour precipitation(inches) = 4.500 Adjusted 6 hour precipitation (inches)= 2.750 P6/P24 = 61.1% San Diego hydrology manual 'C' values used Runoff coefficients by modified rational method 100.0 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 501.000 to Point/Station 502.000 @ **** INITIAL AREA EVALUATION **** CR Decimal fraction soil group A= 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [MULTI -UNITS area type ] Initial subarea flow distance = 165.000(Ft.) Highest elevation= 110.000(Ft.) Lowest elevation= 87.280(Ft.) Elevation difference= 22.720(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 3.86 min . TC= [1.8*(1.1-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC= [1.8*(1.1-0.7000)*( 165.000A.5)/( 13.770A(1/3)]= 3.86 Setting time of concentration to 5 minutes Rainfall intensity (I)= 7.246(In/Hr) for a 100 .0 year storm Effective runoff coefficient used for area (Q=KCIA) is c = 0.700 Subarea runoff= 0.507(CFS) Total initial stream area= 0.100(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 502.000 to Point/Station 503.000 **** PIPEFLOW TRAVEL TIME (User specified size)**** Upstream point/station elevation= 82.950(Ft.) Downstream point/station elevation= 82.400(Ft.) Pipe length = 7.97(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 0.507(CFS) Given pipe size= 18.00(In.) Calculated individual pipe flow = 0.507(CFS) Normal flow depth in pipe= 1.70(In.) Flow top width inside pipe= 10.Sl(In.) Critical Depth= 3.lS(In.) Pipe flow velocity= 6.03(Ft/s) Travel time through pipe= 0.02 min. Time of concentration (TC) -5.02 min. End of computations, total study area= 0.100 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2005 Version 6.5 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 08/05/22 ********* Hydrology Study Control Information ********** Program License Serial Number 6334 Rational hydrology study storm event year is English (in-lb) input data Units used English (in) rainfall data used Map data precipitation entered : 6 hour, precipitation(inches) = 2.750 24 hour precipitation(inches) = 4.500 Adjusted 6 hour precipitation (inches)= 2.750 P6/P24 = 61.1% San Diego hydrology manual 'C' values used Runoff coefficients by modified rational method 100.0 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 601.000 to Point/Station 602.000 r;;l **** INITIAL AREA EVALUATION**** J,.C:...l Decimal fraction soil group A= Decimal fraction soil group B = Decimal fraction soil group C 1.000 0.000 0.000 Decimal fraction soil group D = 0.000 [MULTI -UNITS area type ] Initial subarea flow distance = 65 .000(Ft.) Highest elevation= 88.500(Ft.) Lowest elevation= 86.390(Ft.) Elevation difference= 2.110(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 6.37 min. TC= [1.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC= [l.8*(1.1-0.4500)*( 65.000A.5)/( 3.246A(l/3)]= 6.37 Rainfall intensity (I)= 6.197(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0 .450 Subarea runoff= 0.139(CFS) Total initial stream area= 0.050(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 602.000 to Point/Station 603.000 r:z:-1 **** SUBAREA FLOW ADDITION**** ~ Decimal fraction soil group A= 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [MULTI -UNITS area type Time of concentration= 6.37 min. Rainfall intensity= 6.197(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.544 CA= 0.043 Subarea runoff= 0.130(CFS) for 0.030(Ac.) Total runoff= 0.270(CFS) Total area= 0.080(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 602.000 to Point/Station 603.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation= 82.510(Ft.) Downstream point/station elevation= 82.400(Ft.) Pipe length = 5.97(Ft.) Manning's N = 0.013 No. of pipes= 1 Required pipe flow = 0.270(CFS) Given pipe size= 18.00(In.) Calculated individual pipe flow = 0.270(CFS) Normal flow depth in pipe= 1.72(In.) Flow top width inside pipe= 10.57(In.) Critical depth could not be calculated. Pipe flow velocity= 3.14(Ft/s) Travel time through pipe= 0.03 min. Time of concentration (TC)= 6.40 min. End of computations, total study area= 0.080 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2005 Version 6.5 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 08/12/22 ------------------------------------------------------------------------ ********* Hydrology Study Control Information ********** ------------------------------------------------------------------------ Program License Serial Number 6334 ------------------------------------------------------------------------ Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used English (in) rainfall data used Map data precipitation entered: 6 hour, precipitation(inches) = 2.750 24 hour precipitation(inches) = 4.500 Adjusted 6 hour precipitation (inches) = 2.750 P6/P24 = 61.1% San Diego hydrology manual 'C' values used Runoff coefficients by modified rational method ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 101.000 to Point/Station 102.000 **** INITIAL AREA EVALUATION **** ______________________________________________________________________ User specified 'C' value of 0.350 given for subarea Time of concentration computed by the natural watersheds nomograph (App X-A) TC = [11.9*length(Mi)^3)/(elevation change(Ft.))]^.385 *60(min/hr) + 5 min. (City of Oceanside) Initial subarea flow distance = 418.000(Ft.) Highest elevation = 165.000(Ft.) Lowest elevation = 88.000(Ft.) Elevation difference = 77.000(Ft.) TC=[(11.9*0.0792^3)/( 77.00)]^.385= 1.56 + 5 min. = 6.56 min. Rainfall intensity (I) = 6.080(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 4.086(CFS) Total initial stream area = 1.920(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 102.000 to Point/Station 103.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________ Upstream point/station elevation = 86.900(Ft.) Downstream point/station elevation = 84.250(Ft.) Pipe length = 140.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 4.086(CFS) Given pipe size = 24.00(In.) 1 Calculated individual pipe flow = 4.086(CFS) Normal flow depth in pipe = 5.87(In.) Flow top width inside pipe = 20.63(In.) Critical Depth = 8.49(In.) Pipe flow velocity = 6.86(Ft/s) Travel time through pipe = 0.34 min. Time of concentration (TC) = 6.90 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 103.000 to Point/Station 104.000 **** SUBAREA FLOW ADDITION **** ______________________________________________________________________ User specified 'C' value of 0.350 given for subarea Time of concentration = 6.90 min. Rainfall intensity = 5.885(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA = 0.983 Subarea runoff = 1.702(CFS) for 0.890(Ac.) Total runoff = 5.788(CFS) Total area = 2.810(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 103.000 to Point/Station 104.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________ Upstream point/station elevation = 79.610(Ft.) Downstream point/station elevation = 78.960(Ft.) Pipe length = 222.23(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 5.788(CFS) Given pipe size = 18.00(In.) Calculated individual pipe flow = 5.788(CFS) Normal flow depth in pipe = 18.00(In.) Flow top width inside pipe = 0.00(In.) Critical Depth = 11.15(In.) Pipe flow velocity = 3.21(Ft/s) Travel time through pipe = 1.15 min. Time of concentration (TC) = 8.05 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105.000 **** SUBAREA FLOW ADDITION **** ______________________________________________________________________ User specified 'C' value of 0.350 given for subarea Time of concentration = 8.05 min. Rainfall intensity = 5.327(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA = 1.743 Subarea runoff = 3.498(CFS) for 2.170(Ac.) Total runoff = 9.285(CFS) Total area = 4.980(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105.000 **** SUBAREA FLOW ADDITION **** ______________________________________________________________________ User specified 'C' value of 0.350 given for subarea Time of concentration = 8.05 min. 2 Rainfall intensity = 5.327(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA = 2.019 Subarea runoff = 1.473(CFS) for 0.790(Ac.) Total runoff = 10.758(CFS) Total area = 5.770(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105.000 **** SUBAREA FLOW ADDITION **** ______________________________________________________________________ User specified 'C' value of 0.350 given for subarea Time of concentration = 8.05 min. Rainfall intensity = 5.327(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA = 2.093 Subarea runoff = 0.392(CFS) for 0.210(Ac.) Total runoff = 11.150(CFS) Total area = 5.980(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105.000 **** SUBAREA FLOW ADDITION **** ______________________________________________________________________ User specified 'C' value of 0.350 given for subarea Time of concentration = 8.05 min. Rainfall intensity = 5.327(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA = 2.142 Subarea runoff = 0.261(CFS) for 0.140(Ac.) Total runoff = 11.411(CFS) Total area = 6.120(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________ Upstream point/station elevation = 78.940(Ft.) Downstream point/station elevation = 77.990(Ft.) Pipe length = 317.23(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 11.411(CFS) Given pipe size = 18.00(In.) NOTE: Normal flow is pressure flow in user selected pipe size. The approximate hydraulic grade line above the pipe invert is 3.763(Ft.) at the headworks or inlet of the pipe(s) Pipe friction loss = 3.742(Ft.) Minor friction loss = 0.971(Ft.)K-factor = 1.50 Pipe flow velocity = 6.46(Ft/s) Travel time through pipe = 0.82 min. Time of concentration (TC) = 8.87 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 105.000 to Point/Station 106.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________ Upstream point/station elevation = 77.980(Ft.) Downstream point/station elevation = 77.720(Ft.) Pipe length = 85.93(Ft.) Manning's N = 0.013 3 No. of pipes = 1 Required pipe flow = 11.411(CFS) Given pipe size = 18.00(In.) NOTE: Normal flow is pressure flow in user selected pipe size. The approximate hydraulic grade line above the pipe invert is 1.725(Ft.) at the headworks or inlet of the pipe(s) Pipe friction loss = 1.014(Ft.) Minor friction loss = 0.971(Ft.)K-factor = 1.50 Pipe flow velocity = 6.46(Ft/s) Travel time through pipe = 0.22 min. Time of concentration (TC) = 9.10 min. End of computations, total study area = 6.120 (Ac.) 4 EXHIBITB D:\76582 AviaraApts\13 Reports\Hydro\ogy\Aviara West DRAINAGE REPORT Addi 2023-0510.docx EXHIBITC D:\76582 Avian1Apts\13 Reports\Hydrology\Aviara West DRAINAGE REPORT Addi 2023-0510.docx Final Design 7-May-23 AVIARA APARTMENTS -WEST UDB Post Development Condition HMP-N Rational Method Unit Hydrograph 6 hr Storm County of San Diego Hydrology Manual -Chapter 6 Area 5.480 ac P6 1.24 in C 0.505 Storm 2 year Tc= 14.08 Tc= 15 minutes 12= 1.60 in/hr 7.44 P6 Tc A.0.645 02 a 4.43 cfs 1100= 3.50 in/hr 0100= 9.70 cfs 12,406 N= 24 Number of Precipitation Blocks Vol 12,330 0.62 P6 2.70 in Storm 100 year 0100= 9.70 (77) 0.62% 15 Minute Hydrograph AVIARA APARTMENTS-WEST 360 7-May-23 Qn = 60 CA PnfTc UDB Pt(n) = 0.124 P6 (n Tc)A0.355 Pn = Pt(n)-Pt(n-1) N Pt(n) Pn Q(n) Q(n) N Time Time Qn N Time Time On (min) (hrs) (cfs) (min) (hrs) (cfs) 1 0.40 0.40 4.433 4.433 2 0.51 0.11 1.237 1.237 1 255 4.25 4.433 4 270 4.50 0.000 3 0.59 0.08 0.878 0.878 2 240 4.00 1.237 7 285 4.75 0.471 4 0.66 0.06 0.704 0.704 3 225 3.75 0.878 10 300 5.00 0.369 5 0.71 0.05 0.598 0.598 5 210 3.50 0.598 13 315 5.25 0.309 6 0.76 0.05 0.525 0.525 6 195 3.25 0.525 16 330 5.50 0.269 7 0.80 0.04 0.471 0.471 8 180 3.00 0.429 19 345 5.75 0.240 8 0.84 0.04 0.429 0.429 9 165 2.75 0.396 22 360 6.00 0.218 9 0.87 0.04 0.396 0.396 11 150 2.50 0.346 10 0.91 0.03 0.369 0.369 12 135 2.25 0.326 11 0.94 0.03 0.346 0.346 14 120 2.00 0.294 12 0.97 0.03 0.326 0.326 15 105 1.75 0.281 13 1.00 0.03 0.309 0.309 17 90 1.50 0.258 14 1.02 0.03 0.294 0.294 18 75 1.25 0.248 15 1.05 0.03 0.281 0.281 20 60 1.00 0.232 16 1.07 0.02 0.269 0.269 21 45 0.75 0.224 17 1.09 0.02 0.258 0.258 23 30 0.50 0.211 18 1.12 0.02 0.248 0.248 24 15 0.25 0.205 19 1.14 0.02 0.240 0.240 20 1.16 0.02 0.232 0.232 21 1.18 0.02 0.224 0.224 22 1.20 0.02 0.218 0.218 23 1.22 0.02 0.211 0.211 24 1.24 0.02 0.205 0.205 25 1.26 0.02 0.200 0.000 AVIARAAPARTMENTS-WEST Final Design 7-May-23 UDB Post Development Hydrographs w 6 Hour Rational Method Ratio X/2 1.255 1.417 1.700 2.024 2.188 P6 1.235 1.55 1.75 2.1 2.5 2.702 PrewDeve 9.242 11.599 13.096 15.715 18.708 20.219 Peak 4.433 5.564 6.282 7.539 8.974 9.700 2 Year Return /Yr 2 5 10 25 50 100 N Time Time Qn Vol Time Q(n) Q(n) Q(n) Q(n) Q(n) Q(n) (min) (hrs) (els) (cf) (hrs) 0 0.00 0.000 0 0.00 0.000 0.000 0.000 0.000 0.000 0.000 24 15 0.25 0.205 92 0.25 0.205 0.258 0.291 0.349 0.416 0.449 23 30 0.50 0.211 188 0.50 0.211 0.265 0.299 0.359 0.428 0.462 21 45 0.75 0.224 196 0.75 0.224 0.282 0.318 0.381 0.454 0.491 20 60 1.00 0.232 205 1.00 0.232 0.291 0.328 0.394 0.469 0.507 18 75 1.25 0.248 216 1.25 0.248 0.312 0.352 0.422 0.503 0.544 17 90 1.50 0.258 228 1.50 0.258 0.324 0.366 0.439 0.522 0.565 15 105 1.75 0.281 242 1.75 0.281 0.352 0.398 0.477 0.568 0.614 14 120 2.00 0.294 258 2.00 0.294 0.369 0.416 0.500 0.595 0.643 12 135 2.25 0.326 279 2.25 0.326 0.409 0.462 0.554 0.660 0.713 11 150 2.50 0.346 302 2.50 0.346 0.434 0.490 0.588 0.699 0.756 9 165 2.75 0.396 334 2.75 0.396 0.497 0.561 0.673 0.802 0.867 8 180 3.00 0.429 371 3.00 0.429 0.539 0.608 0.730 0.869 0.940 6 195 3.25 0.525 429 3.25 0.525 0.659 0.744 0.893 1.063 1.148 5 210 3.50 0.598 505 3.50 0.598 0.750 0.847 1.017 1.210 1.308 3 225 3.75 0.878 664 3.75 0.878 1.102 1.244 1.493 1.777 1.921 2 240 4.00 1.237 952 4.00 1.237 1.552 1.753 2.103 2.504 2.706 1 255 4.25 4.433 21552 4.25 4.433 5.564 6.282 7.539 8.974 9.700 4 270 4.50 0.704 2,312 4.50 0.704 0.884 0.998 1.197 1.425 1.540 7 285 4.75 0.471 529 4.75 0.471 0.591 0.668 0.801 0.954 1.031 10 300 5.00 0.369 378 5.00 0.369 0.463 0.522 0.627 0.746 0.806 13 315 5.25 0.309 305 5.25 0.309 0.387 0.437 0.525 0.625 0.675 16 330 5.50 0.269 260 5.50 0.269 0.337 0.381 0.457 0.544 0.588 19 345 5.75 0.240 229 5.75 0.240 0.301 0.340 0.408 0.485 0.524 22 360 6.00 0.218 206 6.00 0.218 0.273 0.308 0.370 0.440 0.476 25 375 6.25 0.000 98 6.25 0.000 0.000 0.000 0.000 0.000 0.000 AVIARA APARTMENTS – WEST Addendum #1 UDB Final Design 12-Jul-23 Pipe Alternative HMP 1 6-Hour Rational Method Hydrograph Total Area 5.480 ac Elev Storage Storage Depth (cf) (ac-ft)(ft) Bottom of Pipe Storage 77.85 0 0.00 Low Flow Orifice 77.85 0 0.00 0.00 Overflow Weir 83.10 18,581 0.43 5.25 Top Of Pipe 84.85 24,707 0.57 7.00 Top of Rock 85.35 26,162 0.60 7.50 Storm Qexist Qin Qout WSEL Depth Frequency (cfs) (cfs) (cfs) (ft) (ft) 2 YEAR 9.24 4.43 0.08 80.95 3.1 5 YEAR 11.60 5.56 0.09 81.85 4.0 10 YEAR 13.10 6.28 0.09 82.25 4.4 25 YEAR 15.71 7.54 0.10 83.05 5.2 50 YEAR 18.71 8.97 1.00 83.25 5.4 100 YEAR 20.22 9.70 2.04 83.35 5.5 Outlet Control Structure Overflow Weir Opening #1 #2 #3 Overflow Elevation 77.85 83.1 0.0 N/A Width (in)1.250 60.00 0 Height (in)Dia 6.000 0 Detention Volume Excludes Rock Volume below Low Flow Outlet Detention Modeling Excludes Infiltration See Section 7 of the Drainage Report for discussion of Rational Method continuity issues. EXHIBITD D:\76582 Aviara Apts\13 Reports\Hydrology\Aviara West DRAINAGE REPORT Addl 2023-0407.docx AVIARA APARTMENTS – WEST Addendum #1 UDB Final Design 12-Jul-23 Pipe Alternative HMP 1 6-Hour Rational Method Hydrograph Total Area 5.480 ac Elev Storage Storage Depth (cf) (ac-ft)(ft) Bottom of Pipe Storage 77.85 0 0.00 Low Flow Orifice 77.85 0 0.00 0.00 Overflow Weir 83.10 18,581 0.43 5.25 Top Of Pipe 84.85 24,707 0.57 7.00 Top of Rock 85.35 26,162 0.60 7.50 Storm Qexist Qin Qout WSEL Depth Frequency (cfs) (cfs) (cfs) (ft) (ft) 2 YEAR 9.24 4.43 0.08 80.95 3.1 5 YEAR 11.60 5.56 0.09 81.85 4.0 10 YEAR 13.10 6.28 0.09 82.25 4.4 25 YEAR 15.71 7.54 0.10 83.05 5.2 50 YEAR 18.71 8.97 1.00 83.25 5.4 100 YEAR 20.22 9.70 2.04 83.35 5.5 Outlet Control Structure Overflow Weir Opening #1 #2 #3 Overflow Elevation 77.85 83.1 0.0 N/A Width (in)1.250 60.00 0 Height (in)Dia 6.000 0 Detention Volume Excludes Rock Volume below Low Flow Outlet Detention Modeling Excludes Infiltration See Section 7 of the Drainage Report for discussion of Rational Method continuity issues. UDB DETENTION BASIN ROUTING 20.22 Allowable 9.70 2.087 Qout 100 YEAR EVENT ~ 6 Hour STORM 83.35 Max WSEL 15 Min N/A hrs Drain Time Interval T QIN 2S/dT+O 2S/dT-O 0 Basin (HRS) (CFS) (CFS) (CFS) WSEL 1 0.25 0.000 0.00 0.00 0.0000 77.85 2 0.50 0.462 0.46 0.46 0.0000 77.85 3 0.75 0.491 1.42 1.37 0.0237 78.05 4 1.00 0.507 2.37 2.29 0.0372 78.25 5 1.25 0.544 3.34 3.26 0.0423 78.35 6 1.50 0.565 4.37 4.26 0.0511 78.55 7 1.75 0.614 5.44 5.33 0.0549 78.65 8 2.00 0.643 6.59 6.46 0.0620 78.85 9 2.25 0.713 7.82 7.69 0.0652 78.95 10 2.50 0.756 9.16 9.02 0.0712 79.15 11 2.75 0.867 10.64 10.48 0.0767 79.35 12 3.00 0.940 12.29 12.13 0.0819 79.55 13 3.25 1.148 14.22 14.04 0.0867 79.75 14 3.50 1.308 16.50 16.31 0.0935 80.05 15 3.75 1.921 19.54 19.34 0.0999 80.35 16 4.00 2.706 23.97 23.75 0.1097 80.85 17 4.25 9.700 36.15 35.89 0.1333 82.25 18 4.50 1.540 47.13 42.95 2.0867 83.35 19 4.75 1.031 45.52 43.43 1.0483 83.25 20 5.00 0.806 45.26 43.17 1.0483 83.25 21 5.25 0.675 44.65 44.01 0.3197 83.15 22 5.50 0.588 45.27 43.18 1.0483 83.25 23 5.75 0.524 44.29 43.65 0.3197 83.15 24 6.00 0.476 44.65 44.01 0.3197 83.15 25 6.25 0.000 44.49 43.85 0.3197 83.15 26 6.50 0.000 43.85 43.21 0.3197 83.15 27 6.75 0.000 43.21 42.92 0.1450 83.05 28 7.00 0.000 42.92 42.63 0.1450 83.05 29 7.25 0.000 42.63 42.34 0.1450 83.05 30 7.50 0.000 42.34 42.05 0.1436 82.95 31 7.75 0.000 42.05 41.76 0.1436 82.95 32 8.00 0.000 41.76 41.48 0.1422 82.85 33 8.25 0.000 41.48 41.19 0.1422 82.85 34 8.50 0.000 41.19 40.91 0.1422 82.85 35 8.75 0.000 40.91 40.63 0.1407 82.75 36 9.00 0.000 40.63 40.35 0.1407 82.75 37 9.25 0.000 40.35 40.07 0.1407 82.75 38 9.50 0.000 40.07 39.79 0.1393 82.65 39 9.75 0.000 39.79 39.51 0.1393 82.65 40 10.00 0.000 39.51 39.23 0.1393 82.65 41 10.25 0.000 39.23 38.95 0.1393 82.65 42 10.50 0.000 38.95 38.68 0.1378 82.55 43 10.75 0.000 38.68 38.40 0.1378 82.55 44 11.00 0.000 38.40 38.12 0.1378 82.55 D:\76582 Aviara Apts\13 Reports\Hydrology\UDB\Detention Arch Pipe.xlsx Pipe Alternative 45 11.25 0.000 38.12 37.85 0.1363 82.45 46 11.50 0.000 37.85 37.58 0.1363 82.45 47 11.75 0.000 37.58 37.31 0.1363 82.45 48 12.00 0.000 37.31 37.04 0.1348 82.35 49 12.25 0.000 37.04 36.77 0.1348 82.35 50 12.50 0.000 36.77 36.50 0.1348 82.35 51 12.75 0.000 36.50 36.23 0.1333 82.25 52 13.00 0.000 36.23 35.97 0.1333 82.25 53 13.25 0.000 35.97 35.70 0.1333 82.25 54 13.50 0.000 35.70 35.44 0.1317 82.15 55 13.75 0.000 35.44 35.17 0.1317 82.15 56 14.00 0.000 35.17 34.91 0.1317 82.15 57 14.25 0.000 34.91 34.65 0.1317 82.15 58 14.50 0.000 34.65 34.39 0.1301 82.05 59 14.75 0.000 34.39 34.12 0.1301 82.05 60 15.00 0.000 34.12 33.86 0.1301 82.05 61 15.25 0.000 33.86 33.61 0.1286 81.95 62 15.50 0.000 33.61 33.35 0.1286 81.95 63 15.75 0.000 33.35 33.09 0.1286 81.95 64 16.00 0.000 33.09 32.84 0.1270 81.85 65 16.25 0.000 32.84 32.59 0.1270 81.85 66 16.50 0.000 32.59 32.33 0.1270 81.85 67 16.75 0.000 32.33 32.08 0.1270 81.85 68 17.00 0.000 32.08 31.83 0.1253 81.75 69 17.25 0.000 31.83 31.58 0.1253 81.75 70 17.50 0.000 31.58 31.33 0.1253 81.75 71 17.75 0.000 31.33 31.07 0.1253 81.75 72 18.00 0.000 31.07 30.83 0.1237 81.65 73 18.25 0.000 30.83 30.58 0.1237 81.65 74 18.50 0.000 30.58 30.33 0.1237 81.65 75 18.75 0.000 30.33 30.09 0.1220 81.55 76 19.00 0.000 30.09 29.84 0.1220 81.55 77 19.25 0.000 29.84 29.60 0.1220 81.55 78 19.50 0.000 29.60 29.36 0.1220 81.55 79 19.75 0.000 29.36 29.12 0.1203 81.45 80 20.00 0.000 29.12 28.87 0.1203 81.45 81 20.25 0.000 28.87 28.63 0.1203 81.45 82 20.50 0.000 28.63 28.40 0.1186 81.35 83 20.75 0.000 28.40 28.16 0.1186 81.35 84 21.00 0.000 28.16 27.92 0.1186 81.35 85 21.25 0.000 27.92 27.69 0.1186 81.35 86 21.50 0.000 27.69 27.45 0.1169 81.25 87 21.75 0.000 27.45 27.22 0.1169 81.25 88 22.00 0.000 27.22 26.98 0.1169 81.25 89 22.25 0.000 26.98 26.75 0.1169 81.25 90 22.50 0.000 26.75 26.52 0.1151 81.15 91 22.75 0.000 26.52 26.29 0.1151 81.15 92 23.00 0.000 26.29 26.06 0.1151 81.15 93 23.25 0.000 26.06 25.83 0.1151 81.15 94 23.50 0.000 25.83 25.60 0.1133 81.05 95 23.75 0.000 25.60 25.38 0.1133 81.05 96 24.00 0.000 25.38 25.15 0.1133 81.05 D:176582 Aviara Apts\13 Reports\Hydrology\UDB\Detention Arch Pipe.xlsx Pipe Alternative 27,000 24,000 21,000 18,000 C' ~ '-' 4.1 5 15,000 = ~ ~ 12,000 c-= i. 0 ..... 00 9,000 6,000 3,000 0 Aviara West UDB Pipe Alternative --storage -•-Outflow r-----------------------------------------------~---:==,-18 f----------------------------------~--------;1------------+ 12 I ■ I I 10 1-------------------------~e..._ _____________ •~--------------+ 8 , , I ■ 1----------------------.,IC------------------':'---------------+ 6 , " I 1------------------"'---------------------------t-----------------+ 4 I ■ I I l-------------,,fl'=----------------------------'111------------------+2 I " .C'J~:::Dl:UUlllll..;:!lll■Clll...-..:lllm!IIIBIIB::~~;;,_......,,:~--------------1 o 77.00 78.00 79.00 80.00 81.00 82.00 83.00 84.00 85.00 86.00 Elevation UDB DETENTION BASIN ROUTING 20.22 Allowable 9.70 2.041 Qout 100 YEAR EVENT ~ 6 Hour STORM 83.35 Max WSEL 15 Min N/A hrs Drain Time Interval T QIN 2S/dT+O 2S/dT-O 0 Basin (HRS) (CFS) (CFS) (CFS) WSEL 1 0.25 0.000 0.00 0.00 0.0000 77.85 2 0.50 0.462 0.46 0.46 0.0000 77.85 3 0.75 0.491 1.42 1.38 0.0190 78.05 4 1.00 0.507 2.38 2.32 0.0268 78.25 5 1.25 0.544 3.37 3.31 0.0300 78.35 6 1.50 0.565 4.42 4.35 0.0358 78.55 7 1.75 0.614 5.53 5.45 0.0384 78.65 8 2.00 0.643 6.71 6.62 0.0433 78.85 9 2.25 0.713 7.98 7.88 0.0455 78.95 10 2.50 0.756 9.35 9.25 0.0496 79.15 11 2.75 0.867 10.88 10.77 0.0535 79.35 12 3.00 0.940 12.58 12.46 0.0570 79.55 13 3.25 1.148 14.55 14.43 0.0604 79.75 14 3.50 1.308 16.89 16.76 0.0651 80.05 15 3.75 1.921 19.98 19.84 0.0695 80.35 16 4.00 2.706 24.47 24.32 0.0763 80.85 17 4.25 9.700 36.72 36.53 0.0948 82.25 18 4.50 1.540 47.77 43.69 2.0412 83.35 19 4.75 1.031 46.26 44.26 1.0032 83.25 20 5.00 0.806 46.09 44.09 1.0032 83.25 21 5.25 0.675 45.57 43.56 1.0032 83.25 22 5.50 0.588 44.83 42.82 1.0032 83.25 23 5.75 0.524 43.93 43.73 0.1008 83.05 24 6.00 0.476 44.73 42.72 1.0032 83.25 25 6.25 0.000 43.20 43.00 0.1008 83.05 26 6.50 0.000 43.00 42.80 0.1008 83.05 27 6.75 0.000 42.80 42.60 0.1008 83.05 28 7.00 0.000 42.60 42.39 0.1008 83.05 29 7.25 0.000 42.39 42.19 0.1008 83.05 30 7.50 0.000 42.19 41.99 0.0988 83.05 31 7.75 0.000 41.99 41.80 0.0988 83.05 32 8.00 0.000 41.80 41.60 0.0988 83.05 33 8.25 0.000 41.60 41.40 0.0988 83.05 34 8.50 0.000 41.40 41.20 0.0988 83.05 35 8.75 0.000 41.20 41.01 0.0988 82.85 36 9.00 0,000 41.01 40.81 0.0988 82.85 37 9.25 0.000 40.81 40.61 0.0988 82.85 38 9.50 0.000 40.61 40.41 0.0988 82.85 39 9.75 0.000 40.41 40.22 0.0988 82.65 40 10.00 0.000 40.22 40.02 0.0988 82.65 41 10.25 0.000 40.02 39.82 0.0988 82.65 42 10.50 0.000 39.82 39.62 0.0988 82.65 43 10.75 0.000 39.62 39.43 0.0968 82.65 44 11.00 0.000 39.43 39.24 0.0968 82.65 D:\76582 Aviara Apts\13 Reports\Hydrology\UDB\Detention Arch Pipe.xlsx Pipe Alternative 45 11.25 0.000 39.24 39.04 0.0968 82.65 46 11.50 0.000 39.04 38.85 0.0968 82.65 47 11.75 0.000 38.85 38.65 0.0968 82.65 48 12.00 0.000 38.65 38.46 0.0968 82.45 49 12.25 0.000 38.46 38.27 0.0968 82.45 50 12.50 0.000 38.27 38.07 0.0968 82.45 51 12.75 0.000 38.07 37.88 0.0968 82.45 52 13.00 0.000 37.88 37.69 0.0948 82.45 53 13.25 0.000 37.69 37.50 0.0948 82.45 54 13.50 0.000 37.50 37.31 0.0948 82.45 55 13.75 0.000 37.31 37.12 0.0948 82.45 56 14.00 0.000 37.12 36.93 0.0948 82.45 57 14.25 0.000 36.93 36.74 0.0948 82.25 58 14.50 0.000 36.74 36.55 0.0948 82.25 59 14.75 0.000 36.55 36.36 0.0948 82.25 60 15.00 0.000 36.36 36.17 0.0948 82.25 61 15.25 0.000 36.17 35.98 0.0948 82.25 62 15.50 • 0.000 35.98 35.80 0.0926 82.25 63 15.75 0.000 35.80 35.61 0.0926 82.25 64 16.00 0.000 35.61 35.43 0.0926 82.25 65 16.25 0.000 35.43 35.24 0.0926 82.25 66 16.50 0.000 35.24 35.06 0.0905 82.05 67 16.75 0.000 35.06 34.88 0.0905 82.05 68 17.00 0.000 34.88 34.70 0.0905 82.05 69 17.25 0.000 34.70 34.52 0.0905 82.05 70 17.50 0.000 34.52 34.34 0.0905 82.05 71 17.75 0.000 34.34 34.16 0.0905 82.05 72 18.00 0.000 34.16 33.98 0.0905 82.05 73 18.25 0.000 33.98 33.80 0.0905 82.05 74 18.50 0.000 33.80 33.61 0.0905 82.05 75 18.75 0.000 33.61 33.43 0.0905 82.05 76 19.00 0.000 33.43 33.26 0.0883 82.05 77 19.25 0.000 33.26 33.08 0.0883 82.05 78 19.50 0.000 33.08 32.90 0.0883 82.05 79 19.75 0.000 32.90 32.73 0.0883 82.05 80 20.00 0.000 32.73 32.55 0.0883 82.05 81 20.25 0.000 32.55 32.37 0.0883 81.85 82 20.50 0.000 32.37 32.20 0.0883 81.85 83 20.75 0.000 32.20 32.02 0.0883 81.85 84 21.00 0.000 32.02 31.84 0.0883 81.85 85 21.25 0.000 31.84 31.67 0.0883 81.85 86 21.50 0.000 31.67 31.49 0.0883 81.65 87 21.75 0.000 31.49 31.31 0.0883 81.65 88 22.00 0.000 31.31 31.14 0.0883 81.65 89 22.25 0.000 31.14 30.96 0.0883 81.65 90 22.50 0.000 30.96 30.79 0.0883 81.65 91 22.75 0.000 30.79 30.61 0.0860 81.65 92 23.00 0.000 30.61 30.44 0.0860 81.65 93 23.25 0.000 30.44 30.27 0.0860 81.65 94 23.50 0.000 30.27 30.10 0.0860 81.65 95 23.75 0.000 30.10 29.93 0.0860 81.65 96 24.00 0.000 29.93 29.75 0.0860 81.65 D:\76582 Aviara Apts\13 Reports\Hydrology\UDB\Detention Arch Pipe.xlsx Pipe Alternative Pl o t t e d : 7/ 1 0 / 2 0 2 3 1 2 : 2 1 P M D : \ 7 6 5 8 2 A V I A R A A P T S \ 0 3 D W G \ D X \ 7 6 5 8 2 D X 0 5 - P R O P O S E D D R A I N A G E . D W G - m g u a r i n DMA TOTAL AREA IMPERVIOUS IMPERVIOUS PERVIOUS EFFECTIVE IMPERVIOUS DCV SURFACE AREA REQUIRED * SURFACE AREA PROVIDED BMP TYPE / STANDARD BMP NO (SF)(SF)(%)(SF)(SF)(CF)(SF)(SF)ID N1A 47,818 45,427 95% 2,391 41,123 1,988 1,234 BIOFILTRATION PARTIAL PR-1 BMP-1 N1D 20,548 19,521 95% 1,027 17,877 864 536 BIOFILTRATION PARTIAL PR-1 BMP-1 N2A 73,343 69,676 95% 3,667 63,075 3,049 1,892 BIOFILTRATION PARTIAL PR-1 BMP-1 N2D 8,002 3,201 40% 4,801 4,321 209 130 BIOFILTRATION PARTIAL PR-1 BMP-1 149,711 137,824 92% 11,887 126,396 6,109 3,792 3,797 BIOFILTRATION PARTIAL PR-1 BMP-1 N3A 60,335 48,268 80% 12,067 44,648 2,158 1,339 BIOFILTRATION PARTIAL PR-1 BMP-2 N3D 28,606 14,303 50% 14,303 17,164 830 515 BIOFILTRATION PARTIAL PR-1 BMP-2 88,941 62,571 70% 26,370 61,812 2,988 1,854 2,195 BIOFILTRATION PARTIAL PR-1 BMP-2 - - - - - - - TOTAL 238,652 200,395 84% 38,257 188,208 9,097 Existing DMA Portion Area Imperv C (A) C (D)C C x A Description ID Soil A (ac) (%)(ac) Existing Warehouse / Lot E-1 0.7 5.48 85.0 0.80 0.81 0.803 4.40 Slope West E-2 0.0 1.29 0.0 0.20 0.35 0.350 0.45 Slope Southwest E-3 0.0 2.16 0.0 0.20 0.35 0.350 0.76 Slope Southwest E-4 0.1 2.81 0.0 0.20 0.35 0.335 0.94 Slope North E-5 1.0 0.35 0.0 0.20 0.35 0.200 0.07 TOTALS 12.09 38.53 0.548 6.62 Proposed DMA Portion Area Imperv C (A) C (D)C C x A Description ID Soil A (ac) (%)(ac) West BMP-1 N1A 1.00 1.10 95% 0.80 0.800 0.88 N1D 0.47 95% 0.81 0.38 N1 0.70 1.57 95% 0.803 1.26 Central BMP-1 N2A 1.00 1.68 95% 0.80 0.800 1.35 N2D 0.18 40% 0.37 0.07 N2 0.90 1.87 90% 0.758 1.41 East BMP-2 N3A 1.00 1.39 80% 0.76 1.05 N3D 0.66 50% 0.63 0.41 N3 0.7 2.04 70% 0.718 1.47 4.14 Site Runoff -CivilD 5.48 84% 0.755 4.14 EXIST. DRAINAGE AREA SUMMARY A VIARA WEST DMA AND BMP SUMMARY TABLE PROP. DRAINAGE AREA SUMMARY A VIARA WEST I I GRAPHIC SCALE 30' 0 30' 60' LEGEND DESCRIPT10N PROPERTY LINE/PROJECT BOUNDARY PROPOSED CURB AND GUTTER EXISDNG CONTOUR PROPOSED OMA LIMITS SOILS AREA DIRECDON OF DRAINAGE STORM DRAIN PIPE SIZE PER PLAN UNDERGROUND DETENDON BASIN SYMBOL ~ 6.!D ---______/ ------------ -so-so-so,- UDB OMA IDENDFIER •1DMA fl DMA AREA (AC.) ----------I--• 1.9600 90' PROPOSED DMA EXHIBIT FOR: AV/ARA APARTMENTS CARLSBAD, CALIFORNIA PLANNING ENGINEERING SURVEYING 3880 Ruffin Rosd, Suite 1 20 San Diego, Ca. !32123 858-560-11 41 858-560-8157 Fax 76582.25