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Home My WebLink AboutSDP 12-01; Vista La Costa Apartments; Site Development Plan (SDP) (5)DRAINAGE STUDY Vista La Costa JN 121004 For Vista La Costa SDP xx-xx February 15, 2012 JN 12-1004 Prepared For: SJ Assets Management, Inc. In care of Diversified Development, Inc 7668 El Camino Real Carlsbad, CA 92009 Ste. 104-280 Prepared By: O'DAY CONSULTANTS 2710 Loker Avenue West, Suite 100 Carlsbad, CA 92010 Nichole Fine Exp. 9/30/12 C 70035 G:\031060\Drainage\Hydrology\Drainage Study.doc Vista La Costa JN 121004 Section Description Page No. Introduction and Description B. Hydrologic Calculations Existing Conditions Appendix A Existing Hydrologic Conditions C. Hydrologic Calculations Proposed Conditions 5 6-8 Appendix B Proposed Conditions (Developed) 100-year hydrology for Vista La Costa 9-26 D. Hydraulic Calculations Developed Conditions Appendix C Hydraulics Analysis of Grate Capacity 27-29 EXHIBITS Exhibit A Exhibit B Exhibit C Exhibit D Exhibit E Exhibit F Exhibit G Exhibit H Exhibit I Exhibit J Exhibit K Vicinity Map Table 3-1 Runoff Coefficients For Urban Areas (Rational Method) Soil Group Map 100-year 6-hour precipitation map 100-year 24-hour precipitation map Figure 3-3 Urban Areas Overland Time of Flow Nomograph Figure 3-1 Intensity Duration Design Chart Capacity of Grate Inlet Chart from Bureau of Public Works Table A-3 Manning's Roughness Coefficients from San Diego County Drainage Design Manual 20-Scale Existing Conditions Hydrologic Map (Map Pocket) 10-Scale Proposed Conditions Hydrologic Map (Map Pocket) G:\031060\Drainage\Hydrology\Drainage Study.doc Vista La Costa JN 121004 Declaration of Responsible Charge I hereby declare that I am the Engineer of Work for this project, that I have exercised responsible charge over the design of this project as defined in section 6703 of the Business and Professions Code, and that the design is consistent with current standards. I understand that the check of project drawings and specifications by the City of Carlsbad is confined to a review only and does not relieve me, as the Engineer of Work, of my responsibilities for the project design. O'Day Consultants, Inc. 2710 Loker Avenue West, Suite 100 Carlsbad, CA 92010 (760) 931-7700 Date: Nichole A. Fine C 70035 Exp. 09/30/12 G:\031060\Drainage\Hydrology\Drainage Study.doc Vista La Costa JN 121004 A. Introduction and Description This Drainage Study was prepared to support the Site Development Plan for Vista La Costa, located 1.5 miles east of El Camino Real, north of Gibraltar Street in between Jerez Court and Romeria Street in the City of Carlsbad (See Vicinity Map, Exhibit 'A'). The existing site is Parcel 2 of Certificate of Compliance, recorded on August 27, 1984 as file number 84-325375. The site lies southerly of the La Costa Resort and Spa and is 0.88 gross acres. A Preliminary Storm Water Management Plan was prepared for Vista La Costa on February 10, 2012 by O'Day Consultants and will be referred to hereon as Reference 1. The existing site is mass graded per Grading Plans IM Costa South, Unit No. 5, County of San Diego Dwg. L-5548 (Reference 2). Existing Conditions: Currently, the site is mass-graded per Reference 2. The upper pad is at about elevation 61.0 and the lower pad is at elevation 55.5. On the northerly edge of the site a 1.4:1 slope daylights into the La Costa Golf Course and Spa to the north. The site drains at 0.5% towards Gibraltar Street, to a curb inlet located on the south side of the site. The curb inlet drains to a 48" RCP pipe, that runs along the easterly boundary of the site. The storm drain outlets to the north, to a PCC lined drainage swale in the La Costa Golf Course and ultimately outlets to the Batiquitos Lagoon. For the 100-year storm event see Appendix 'A'. Proposed Conditions: 19 Multi-Family residential units are proposed for Vista La Costa: two main buildings, and a parking lot. A private driveway will be constructed between the two buildings and lead into underground parking garages. The drive aisle and the parking lot will be constructed of pervious pavement or pavers. The roof will drain to various bioretention areas located at the southwest and north sides of the site. Each bioretention area will have an underground detention facility to limit the outflow for hydromodification. The detention facilities will limit the outflow to the lower flow threshold 0.1Q2. A plate will be placed over the outlet structure for the detention pipe. A small orifice opening will be at the bottom of the plate and a 6" diameter orifice will be at the top of the plate for overflows. The catch basin within the bioretention areas will be 10" above the finish grade. This will act as a secondary overflow if stormwater flows exceed capacity of detention facility. The trench drain at the bottom of Private Drive 'A' will pick-up water from the driveway and will connect to the private storm drain system. See Reference 1 for calculations for the treatment and hydromodification of storm water at the site. See Appendix B for the proposed 100 year hydrologic calculations. See Exhibit K for the drainage map. G:\031060\Drainage\Hydrology\Drainage Study.doc Vista La Costa JN 121004 B. Hydrologic Calculations The Hydrologic calculations were performed utilizing the San Diego County Rational Method as described in the San Diego County Hydrology Manual, June 2003. Pertinent exhibits from the San Diego County Hydrology Manual are enclosed for reference, as follows: Exhibit B - Table 3-1 Runoff Coefficients For Urban Areas (Rational Method) Exhibit C - Soil Group Map Exhibit D - 100-year 6-hour precipitation map Exhibit E - 100-year 24-hour precipitation map Exhibit F - Figure 3-3 Urban Areas Overland Time of Flow Nomograph Exhibit G - Figure 3-1 Intensity Duration Design Chart Exhibit J - 20-Scale Existing Conditions Hydrologic Map (Map Pocket) Exhibit K - 10-Scale Proposed Conditions Hydrologic Map (Map Pocket) G:\031060\Drainage\Hydrology\Drainage Study.doc Vista La Costa JN 121004 APPENDIX A 100 Year Calculations for Existing Conditions (See Exhibit 'J') G:\031060\Drainage\Hydrology\Drainage Study.doc Vista La Costa JN 121004 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 04/23/07 Existing 100-Yr Storm Hydrology Vista La Costa JN 03-1060 Prepared By: NF 4/23/07 g:\accts\031060\03 60e.out ********* Hydrology Study Control Information ********** Program License Serial Number 5014 Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 2.800 24 hour precipitation(inches) = 5.000 P6/P24 = 56.0% San Diego hydrology manual 'C values used -H-l--)--H-H-H-l--(--l--H-H-l--H-H-l--H-H-l--H-l- + -l--H-l--f- + -l--l--H-l--t--(--(--t- + -)--H-H-(- + -H-F-l--l- + Process from Point/Station 100.000 to Point/Station 101.000 **** INITIAL AREA EVALUATION **** 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 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.3 50 Initial subarea total flow distance = 153.500(Ft.) Highest elevation = 63.800(Ft.) Lowest elevation = 57.600(Ft.) Elevation difference = 6.200(Ft.) Slope = 4.039 % Top of Initial Area Slope adjusted by User to 0.500 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.50 %, in a development type of Permanent Open Space In Accordance With Figure 3-3 Initial Area Time of Concentration = 12.03 minutes G:\031060\Drainage\Hydrology\Drainage Study.doc Vista La Costa JN 121004 TC = [1. 8* (1.1-C) *distance(Ft. )-".5) / (% slope'"(l/3)] TC = [1.8*(1.1-0.3500)*( 50.000".5)/( 0.500^(1/3)]= 12.03 Rainfall intensity (I) = 4.188(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.381(CFS) Total initial stream area = 0.260(Ac.) -H-l--l--H-h-l--H-f-F-h-H-h-H-F-l--l--l--l--H-h-H-H-H-H-l--H-H-l--H-l--H-H-H-l--H + + -h-h-H-H-H-l- + -f--l- Process from Point/Station 102.000 to Point/Station 103.000 ^ **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** tm Estimated mean flow rate at midpoint of channel = 0.799(CFS) Depth of flow = 0.194(Ft.), Average velocity = 2.493(Ft/s) ******* Irregular Channel Data *********** Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 0.70 «i 2 10.00 0.50 3 10.17 0.00 « 4 11.50 0.12 5 30.00 0.49 Manning's 'N' friction factor = 0.015 ^ Sub-Channel flow = 0.799(CFS) g| ' ' flow top width = 5.086(Ft.) velocity= 2.493(Ft/s) ^ ' ' area = 0.321(Sg.Ft) ' ' Froude number = 1.750 ii Upstream point elevation = 56.900(Ft.) Downstream point elevation = 53.100(Ft.) ^ Flow length = 145.000(Ft.) Travel time = 0.97 min. Time of concentration = 13.00 min. " Depth of flow = 0.194(Ft.) m Average velocity = 2.493(Ft/s) Total irregular channel flow = 0.799(CFS) im Irregular channel normal depth above invert elev. = 0.194(Ft.) Average velocity of channel(s) = 2.493(Ft/s) Adding area flow to channel 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 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.3 50 Rainfall intensity = 3.984(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA = 0.290 Subarea runoff = 0.776(CFS) for 0.570(Ac.) Total runoff = 1.157(CFS) Total area = 0.830(Ac.) Depth of flow = 0.213(Ft.), Average velocity = 2.696(Ft/s) End of computations, total study area = 0.830 (Ac.) il G:\031060\Drainage\Hydrology\Drainage Study.doc Vista La Costa JN 121004 a APPENDIX B 100 Year Hydrologic Calculations for Proposed Conditions (See Exhibit'K') I I I I G:\031060\Drainage\Hydrology\Drainage Study.doc I Vista La Costa JN 121004 TC = [1.8*(1.1-0.7100)*( 100.000-^.5) / ( 12 . 500" (1/3) ] = 3.02 Rainfall intensity (I) = 10.202(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.362(CFS) Total initial stream area = 0.050(Ac.) -l--l--^-l--(- + -H-(--H-K-l-H--l-4--l--l--F-H-H-H-F-l--H-f-H-^-h-l--l--H-l--f-l--H-l--l--l--H-l--H-H-l--H + -H Process from Point/Station 200.000 to Point/Station 201.000 **** 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 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 3.02 min. Rainfall intensity = 10.202{In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.078 Subarea runoff = 0.435(CFS) for 0.060(Ac.) Total runoff = 0.797(CFS) Total area = 0.110(Ac.) -l- + -l--(--^-^-^-^-^--(--h-^-^-^-l--l--^-^-l--l--^-^-l--^-l--^--^-l--^-^-^-^-^-^-^--^+-^-^-l--^--l--t--^-^-^ Process from Point/Station 201.000 to Point/Station 202.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 59.200(Ft.) Downstream point/station elevation = 58.600(Ft.) Pipe length = 55.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.797(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.797(CFS) Normal flow depth in pipe = 4.29(In.) Flow top width inside pipe = 8.99(In.) Critical Depth = 4.89(In.) Pipe flow velocity = 3.83(Ft/s) Travel time through pipe = 0.24 min. Time of concentration (TC) = 3.2 6 min. Process from Point/Station 203.000 to Point/Station 204.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 57.900(Ft.) Downstream point elevation = 57.600 (Ft.) Channel length thru subarea = 44.000(Ft.) Channel base width = 7.000 (Ft.) Slope or 'Z' of left channel hank = 2.000 Slope or 'Z' of right channel bank = 2.000 Estimated mean flow rate at midpoint of channel = 0.861(CFS) Manning's 'N' =0.03 5 G:\031060\Drainage\HydroIogy\Drainage Study.doc 11 Vista La Costa JN 121004 0.888(Ft/s) Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.861(CFS) Depth of flow = 0.133(Ft.), Average velocity = Channel flow top width = 7.534(Ft.) Flow Velocity = 0.89(Ft/s) Travel time = 0.83 min. Time of concentration = 4.09 min. Critical depth = 0.077(Ft.) Adding area flow to channel 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 [HIGH DENSITY RESIDENTIAL (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 8.399(In/Hr) Effective runoff coefficient used for (Q=KCIA) is C = 0.710 CA = 0.099 Subarea runoff = 0.038(CFS) for 0.030(Ac.) Total runoff = 0.835(CFS) Total area = 0.140(Ac.; Depth of flow = 0.131(Ft.), Average velocity = 0.878(Ft/s) Critical depth = 0.075(Ft.) ] for a 100. total area 0 year storm -H-H-t--t--l--H-l- + -h + -h-H-h-h-H-H-l--H-l- + -H-)--h-h-H-f-h-H-l--l--l--H-f-l--h-t- + H-H--l--H-HH--H-l--l- + Process from Point/Station 204.000 to Point/Station 205.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 48.100(Ft.) Downstream point/station elevation = 47.400(Ft.) Pipe length = 66.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.83 5(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.835(CFS) Normal flow depth in pipe = 4.45(In.) Flow top width inside pipe = 9.00(In.) Critical Depth = 5.01(In.) Pipe flow velocity = 3.84(Ft/s) Travel time through pipe = 0.29 min. Time of concentration (TC) = 4.38 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 205.000 to Point/Station 205.000 **** 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 [HIGH DENSITY RESIDENTIAL (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 4.3 8 min. G:\031060\Drainage\Hydrology\Drainage Study.doc 12 Vista La Costa JN 121004 Rainfall intensity = 8.040(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.114 Subarea runoff = 0.078(CFS) for 0.020(Ac.) Total runoff = 0.913(CFS) Total area = 0.160(Ac.) -H-H-l--H-^-l- + -(--l- + + -H-H-l--l--l--t--H-f-l--l--^-h-H + -h-h-H-l--h-H-H-l--(--H-f-H-l--H-l--^-F-l--l--H + Process from Point/Station 205.000 to Point/Station 206.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 47.400(Ft.) Downstream point/station elevation = 47.000(Ft.) Pipe length = 37.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.913(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.913(CFS) Normal flow depth in pipe = 4.66(In.) Flow top width inside pipe = 8.99(In.) Critical Depth = 5.25(In.) Pipe flow velocity = 3.95(Ft/s) Travel time through pipe = 0.16 min. Time of concentration (TC) = 4.53 min. -l--h-hH--(--h-(--l--h-H-H-H-h-l--l--h-l--f--F-(--h-f-H-h-l--H-H-H-(--l--l--l--l--(--F-(--H-H-l--l--H-l--l- + Process from Point/Station 205.000 to Point/Station 206.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.160(Ac.) Runoff from this stream = 0.913(CFS) Time of concentration = 4.53 min. Rainfall intensity = 7.860(In/Hr) Program is now starting with Main Stream No. 2 -f-(--f-H-(--(--F-^-H-l--H-h-H-l--H-(--f-H-H-(--F-F-(--H-H-H-f--H-H-H-(--H-l--H-l--H + -H-H-f-l--H-H-l--H-^ Process from Point/Station 207.000 to Point/Station 208.000 **** INITIAL AREA EVALUATION **** 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 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 51.000(Ft.) Highest elevation = 55.000(Ft.) Lowest elevation = 54.400(Ft.) Elevation difference = 0.600(Ft.) Slope = 1.176 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 1.18 %, in a development type of G:\031060\Drainage\Hydrology\Drainage Study.doc 13 Vista La Costa JN 121004 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = TC = [1. 8* (1.1-C) *distance(Ft. ) ^^.5) / (% TC = [1.8*(1.1-0.7100) *( 65.000^^.5) / ( Rainfall intensity (I) = 7.052(In/Hr) Effective runoff coefficient used for area Subarea runoff = 0.150(CFS) Total initial stream area = 0.030(Ac.) 5.3 6 minutes slope'^ (1/3) ] 1.176'^ (1/3) ] = for a 100, (Q=KCIA) is 5.36 year storm = 0.710 -f-t--t--h + -(--^-l--h-l--H-F-H-l--H-(--F-H-f-(--H-H-H-l--h-l--t- + + -H-H-|--l--H-H-F-l--H-h-t--H-H-f-^-h-l- Process from Point/Station 208.000 to Point/Station 206.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 49.200(Ft.) Downstream point/station elevation = 47.000(Ft.) Pipe length = 11.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.150(CFS) Nearest computed pipe diameter = 3.00(In.) Calculated individual pipe flow = 0.150(CFS) Normal flow depth in pipe = 1.28(In.) Flow top width inside pipe = 2.97(In.) Critical Depth = 2.72(In.) Pipe flow velocity = 7.50(Ft/s) Travel time through pipe = 0.02 min. Time of concentration (TC) = 5.39 min. -^-^-^-(--^-^-(--^-^-l--)--^-^+-^-^-l--^-^-^--l--l--^-^-l--l--^-l--^-^-^--(--^-^-^-^--^-t--(--^-^-^-^--^-^ Process from Point/Station 208.000 to Point/Station 206.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.03 0(Ac.) Runoff from this stream = 0.150(CFS) Time of concentration = 5.39 min. Rainfall intensity = 7.031(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) = 0.913 0.150 Qmax(2) = 000 000 0. 895 1.000 4.53 5.39 1.000 * 0.841 * 1.000 * 1.000 * 7.860 7.031 0.913) -I- 0.150) -1- 0.913) + 0.150) + 1.040 0.967 Total of 2 main streams to confluence: Flow rates before confluence point: 0.913 0.150 G:\031060\Drainage\Hydrology\Drainage Study.doc 14 Vista La Costa JN 121004 Maximum flow rates at confluence using above data: 1.040 0.967 Area of streams before confluence: 0.160 0.030 Results of confluence: Total flow rate = 1.040(CFS) Time of concentration = 4.532 min. Effective stream area after confluence = 0.190(Ac.) -^-^•^-^-^-H-^ + -l--l--l--l--^-^-(--^•-^-^-(-++-^-^-^-^-(--^-^ + -^-l--^-l--^-(--^-l--^-^-^-^-^-l--^-^-^-^-^ Process from Point/Station 206.000 to Point/Station 209.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 47.000(Ft.) Downstream point/station elevation = 45.400(Ft.) Pipe length = 85.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.040(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 1.040(CFS) Normal flow depth in pipe = 4.28(In.) Flow top width inside pipe = 8.99(In.) Critical Depth = 5.62(In.) Pipe flow velocity = 5.03(Ft/s) Travel time through pipe = 0.2 8 min. Time of concentration (TC) = 4.81 min. -l--l--H-(- + + -h + -h-H-l--f-H-H-f-H-H-l--(--H-^-l--l--f-f-t- + -l--(--H-l--f-l--l--l--H-f-l--l--l--l--h + -H-(--h Process from Point/Station 206.000 to Point/Station 209.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.190(Ac.) Runoff from this stream = 1.040(CFS) Time of concentration = 4.81 min. Rainfall intensity = 7.560(In/Hr) Program is now starting with Main Stream No. 2 + -F-l--(--H + -l--l--t--h-h-^-l--F-H-h-H-h-H-h-H-h-H-l--H-t--f--(--f--)--H-(--t--H-l--F-t--l--l--l--(- + -l--F-^ Process from Point/Station 210.000 to Point/Station 211.000 **** INITIAL AREA EVALUATION **** 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 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 48.000(Ft.) Highest elevation = 56.200(Ft.) G:\031060\Drainage\Hydrology\Drainage Study.doc 15 Vista La Costa JN 121004 Lowest elevation = 53.200(Ft.) Elevation difference = 3.000(Ft.) Slope = 6.250 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 95.00 (Ft) for the top area slope value of 6.25 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.71 minutes TC = [1.8* (1.1-C) *distance(Ft.) ".5) / (% slope^^ (1/3) ] TC = [1.8* (1.1-0.7100) * ( 95.000-^.5) / ( 6 . 250^^ (1/3 ) ] = 3.71 Rainfall intensity (I) = 8.936(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.254(CFS) Total initial stream area = 0.040(Ac.) -H-H-f-F-H-H-H-(--(--f-H-H-l--l--f-(--l--H-f-H-f-l--(--f-f-h + -t--H-H-H-H-H-H-l--H-^-H-H4--H-H-H-f-F-l--^ Process from Point/Station 211.000 to Point/Station 209.000 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** Estimated mean flow rate at midpoint of channel = 0.444(CFS) Depth of flow = 0.133(Ft.), Average velocity = 4.241(Ft/s) ******* Irregular Channel Data *********** Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 0.33 2 10.50 0.12 3 11.83 0.00 4 12.00 0.50 Manning's 'N' friction factor = 0.015 Sub-Channel flow = 0.444(CFS) flow top width = 2.035(Ft.) velocity= 4.241(Ft/s) area = 0.105(Sq.Ft) ' ' Froude number = 3.2 95 Upstream point elevation = 53.200(Ft.) Downstream point elevation = 48.400(Ft.) Flow length = 47.000(Ft.) Travel time = 0.18 min. Time of concentration = 3.90 min. Depth of flow = 0.133(Ft.) Average velocity = 4.241(Ft/s) Total irregular channel flow = 0.444(CFS) Irregular channel normal depth above invert elev. = 0.133(Ft.) Average velocity of channel(s) = 4.241(Ft/s) Adding area flow to channel 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 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 G:\031060\Drainage\HydrologyVDrainage Study.doc 16 Vista La Costa JN 121004 Rainfall intensity = 8.661(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.071 Subarea runoff = 0.361 (CFS) for 0.060(Ac.) Total runoff = 0.615(CFS) Total area = 0.100(Ac. Depth of flow = 0.150(Ft.), Average velocity = 4.225(Ft/s) -l--|- + -^-^-l--l--l--l--^-^-l--l-+-l--l-++-^--l--^-(--^-^-^-^-l--^-l--^-l--^-^-^-+-^-^-|--^-|--^-^-t--^+-^ Process from Point/Station 211.000 to Point/Station 209.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.100(Ac.) Runoff from this stream = 0.615(CFS) Time of concentration = 3.90 min. Rainfall intensity = 8.661(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 1 1.040 4.81 7.560 2 0.615 3.90 8.661 Qmax(1) = 1.000 * 1.000 * 1.040) + 0.873 * 1.000 * 0.615) + = 1.576 Qmax(2) = 1.000 * 0.810 * 1.040) + 1.000 * 1.000 * 0.615) + = 1.457 Total of 2 main streams to confluence: Flow rates before confluence point: 1.040 0.615 Maximum flow rates at confluence using above data: m 1.576 1.457 Area of streams before confluence: mt 0.190 0.100 Results of confluence: Total flow rate = 1.576(CFS) Time of concentration = 4.814 min. Effective stream area after confluence = 0.290(Ac. Process from Point/Station 209.000 to Point/Station 212.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 45.400(Ft.) Downstream point/station elevation = 44.700 (Ft.) Pipe length = 70.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.576(CFS) Nearest computed pipe diameter = 9.00(In.) G:\031060\Drainage\Hydrology\Drainage Study.doc 17 Vista La Costa JN 121004 Calculated individual pipe flow = 1.576(CFS) Normal flow depth in pipe = 7.02(In.) Flow top width inside pipe = 7.46(In.) Critical Depth = 6.93(In.) Pipe flow velocity = 4.26(Ft/s) Travel time through pipe = 0.27 min. Time of concentration (TC) = 5.09 min. -l--l- + -H-l--l--l--H-h-f + -l--l- + -l--H-F-(--l--l--H-H-H-H-l--h-(--^-H-^-H-H-H-l- + + -l--H-l--l--l- + -H-(--H + Process from Point/Station 209.000 to Point/Station 212.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.290(Ac.) Runoff from this stream = 1.576(CFS) Time of concentration = 5.09 min. Rainfall intensity = 7.295(In/Hr) Program is now starting with Main Stream No. 2 -^^--^-(--^+-^-^-l--^-^--l--(--l--^--^--l--l--^--^-4--^-^-^-^-l--l--^-l--l--l--(--^-l--^-l--l--^--^-l--^-l-++-l-+ Process from Point/Station 200.000 to Point/Station 213.000 **** INITIAL AREA EVALUATION **** 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 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 40.000(Ft.) Highest elevation = 96.200(Ft.) Lowest elevation = 91.200(Ft.) Elevation difference = 5.000 (Ft.) Slope = 12.500 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 12.50 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.02 minutes TC = [1.8*(l.l-C)*distance(Ft.)".5)/(% slope'-(1/3 ) ] TC = [1.8*(1.1-0.7100)*( 100.000-^.5) / ( 12.500^^(1/3)]= 3.02 Rainfall intensity (I) = 10.202(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.362(CFS) Total initial stream area = 0.050(Ac.) -H-l--H-F-l--f-^-l--(--F-(--l--F-H-F-F-H-(- + -t--H + -h-(--l--f-l- + -F-F-h-h-l--l--l--l--F-f-f-l--f-l--H-H-H-H Process from Point/Station 214.000 to Point/Station 214.000 **** SUBAREA FLOW ADDITION **** Decimal fraction soil group A = 0.000 G:\031060\Drainage\Hydrology\Drainage Study.doc 18 Vista La Costa JN 121004 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 3.02 min. Rainfall intensity = 10.202(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.078 Subarea runoff = 0.435(CFS) for 0.060(Ac.) Total runoff = 0.797(CFS) Total area = 0.110(Ac.) Process from Point/Station 213.000 to Point/Station 214.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 57.400(Ft.) Downstream point/station elevation = 56.800(Ft.) Pipe length = 57.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.797(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.797(CFS) Normal flow depth in pipe = 4.34(In.) Flow top width inside pipe = 8.99(In.) Critical Depth = 4.89(In.) Pipe flow velocity = 3.78(Ft/s) Travel time through pipe = 0.25 min. Time of concentration (TC) = 3.28 min. -l--l--H-F-H-F-F-H-H-H-l--l--H-^-H-l--H-f-H-l--l--K-H-F-f-f-l--h-l--H-(--H-F-F-H-H-H-F-(--l--f--F-)--h-H-l- + Process from Point/Station 215.000 to Point/Station 216.000 **** IMPROVED CHANNEL TRAVEL TIME **** 55.800(Ft.) 55.400(Ft.) 70.000(Ft.) 4.000(Ft.) bank = 2.000 0 Upstream point elevation = Downstream point elevation = Channel length thru subarea Channel base width = Slope or 'Z' of left channel Slope or 'Z' of right channel bank = 2.000 Estimated mean flow rate at midpoint of channel = Manning's 'N' =0.035 Maximum depth of channel Flow(q) thru subarea = Depth of flow = 0.195(Ft. Channel flow top width = Flow Velocity = 1.01(Ft/s) Travel time = 1.16 min. Time of concentration = 4.43 min. Critical depth = 0.111(Ft.) Adding area flow to channel Decimal fraction soil group A = 0. Decimal fraction soil group B = 0. Decimal fraction soil group C = 0. 1.000(Ft.) 863(CFS) , Average velocity = 4.781(Ft.) 0.863(CFS) 1.007(Ft/s) .000 , 000 ,000 G:\031060\Drainage\Hydrology\Drainage Study.doc 19 Vista La Costa JN 121004 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (43.0 DU/A or Less ) Impervious value, Ai = 0.800 Sub-Area C Value = 0.79 0 Rainfall intensity = 7.971(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.731 CA = 0.110 Subarea runoff = 0.078(CFS) for 0.040(Ac.) Total runoff = 0.874(CFS) Total area = Depth of flow = 0.197(Ft.), Average velocity = 1 Critical depth = 0.111(Ft.) 0.150(Ac.) 012(Ft/s) Process from Point/Station 216.000 to Point/Station 212.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 46.900 (Ft.) Downstream point/station elevation = 44.700(Ft.) Pipe length = 39.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.874(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.874(CFS) Normal flow depth in pipe = 3.54(In.) Flow top width inside pipe = 5.90(In.) Critical Depth = 5.48(In.) Pipe flow velocity = 7.24(Ft/s) Travel time through pipe = 0.09 min. Time of concentration (TC) = 4.52 min. Process from Point/Station 216.000 to Point/Station 212.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.150(Ac.) Runoff from this stream = 0.874(CFS) Time of concentration = 4.52 min. Rainfall intensity = 7.869(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) 1.576 0.874 1.000 * 0.927 * Qmax(2) = 000 000 5.09 4.52 1.000 * 1.000 * 0.889 * 1.000 * 7 .295 7.869 1.576) + 0.874) -I- 1.576) + 0.874) -H 2 .387 2.276 G:\031060\Drainage\Hydrology\Drainage Study.doc 20 Vista La Costa JN 121004 Total of 2 main streams to confluence: Flow rates before confluence point: 1.576 0.874 Maximum flow rates at confluence using above data: 2.387 2.276 Area of streams before confluence: 0.290 0.150 Results of confluence: Total flow rate = 2.387(CFS) Time of concentration = 5.088 min. Effective stream area after confluence = 0.440(Ac.) -l--t--H-H-H-l--H-^-F-l--F-H-H-l--H-H-H-l--h-l--^-H-l--(--H-l--l--H-l--)--l- + -H-F-H-l--l--(--l--H-l--l--H-H + Process from Point/Station 212.000 to Point/Station 217.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 44.700(Ft.) Downstream point/station elevation = 42.100(Ft.) Pipe length = 76.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 2.387(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 2.387(CFS) Normal flow depth in pipe = 5.98(In.) Flow top width inside pipe = 8.50(In.) Critical Depth = 8.21(In.) Pipe flow velocity = 7. 66(Ft/s) Travel time through pipe = 0.17 min. Time of concentration (TC) = 5.25 min. -)--l--h-(--|--l- + -(--l--l--l--l--l--l--H + -)--t--l--(--K-|--l--l--H-H-H-l--h-l--l--H-l-H--h + -l--h + -(--l--h-^-f + Process from Point/Station 212.000 to Point/Station 217.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.440(Ac.) Runoff from this stream = 2.387(CFS) Time of concentration = 5.25 min. Rainfall intensity = 7.146(In/Hr) Program is now starting with Main Stream No. 2 +++++++++++++++++++++++++++++++++-^++++++++++++++++++++++++++++++++++++ Process from Point/Station 218.000 to Point/Station 219.000 **** INITIAL AREA EVALUATION **** 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 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 G:\031060\Drainage\Hydrology\Drainage Study.doc 21 Vista La Costa JN 121004 Sub-Area C Value = 0.710 Initial subarea total flow distance = 60.000(Ft.) Highest elevation = 93.500(Ft.) Lowest elevation = 88.500(Ft.) Elevation difference = 5.000(Ft.) Slope = 8.333 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 8.33 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.46 minutes TC = [1.8*(l.l-C)*distance(Ft.)'^.5)/(% slope'^ (1/3) ] TC = [1.8* (1.1-0.7100) * ( 100.000^^.5) / ( 8.333^(1/3)]= 3.46 Rainfall intensity (I) = 9.350(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.332(CFS) Total initial stream area = 0.050(Ac.) -^+-^-^-^-l-•^-^-^-l--^-f-l--^-^-^-^-^-^-l--l--l--^-^-^-^-l--^-l--^-(--^-l--(--l--^-^-+-l--l--l--l-+-l--^-^ Process from Point/Station 219.000 to Point/Station 220.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 54.900(Ft.) Downstream point/station elevation = 54.200(Ft.) Pipe length = 70.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.332(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.332(CFS) Normal flow depth in pipe = 3.32(In.) Flow top width inside pipe = 5.97(In.) Critical Depth = 3.50(In.) Pipe flow velocity = 2.98(Ft/s) Travel time through pipe = 0.39 min. Time of concentration (TC) = 3.85 min. -t- + -t--t--F-)--^-(--(--l-4--h-h-H-l--H-l--H-l--l--l--l--l--H-H-l--l--F-l--l--l--F-l--l--l--l--l--H-H-F-h + -(--f + Process from Point/Station 220.000 to Point/Station 220.000 **** 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 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 3.85 min. Rainfall intensity = 8.725(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.085 Subarea runoff = 0.411(CFS) for 0.070(Ac.) Total runoff = 0.743(CFS) Total area = 0.120(Ac.) G:\031060\Drainage\Hydrology\Drainage Study.doc 22 Vista La Costa JN 121004 -H-l--H-F + -f-t--h-l--t--H-l--t--(--f-)--l--F-h-l--h-H-l--h-l--(--f-H-f-F-(- + -H-l--l--H-l--l--H-H-f-l--)--F-^ Process from Point/Station 220.000 to Point/Station 221.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 54.200(Ft.) Downstream point/station elevation = 53.500(Ft.) Pipe length = 125.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.743(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.743(CFS) Normal flow depth in pipe = 5.03(In.) Flow top width inside pipe = 8.94(In.) Critical Depth = 4.72(In.) Pipe flow velocity = 2.93(Ft/s) Travel time through pipe = 0.71 min. Time of concentration (TC) = 4.57 min. -^-(--^-^-l--l--^-^-l--^-l--l--l--^-l--^-l--l--l--^-^-l--^-l--^-^-^-^-^-^-^-^-t--^-l--l--l--^-f--(--^-^-l- + Process from Point/Station 221.000 to Point/Station 221.000 **** 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 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 4.57 min. Rainfall intensity = 7.822(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.135 Subarea runoff = 0.312(CFS) for 0.070(Ac.) Total runoff = 1.055(CFS) Total area = 0.190(Ac.) -f-H-l--F-h-h + -H-h-l--f-H-F-l--h-t--f-f-f-l--l--l--l--l--h-l--l--(--K-l-H--h-H-h-h-^-H-h-h + -h-H-h-H-)--F Process from Point/Station 221.000 to Point/Station 222.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.500(Ft.) Downstream point/station elevation = 53.300(Ft.) Pipe length = 50.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.055(CFS) Nearest computed pipe diameter = 12.00(In.) Calculated individual pipe flow = 1.055(CFS) Normal flow depth in pipe = 5.78(In.) Flow top width inside pipe = 11.99(In.) Critical Depth = 5.18(In.) Pipe flow velocity = 2.82(Ft/s) Travel time through pipe = 0.30 min. Time of concentration (TC) = 4.86 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ G:\031060\Drainage\Hydrology\Drainage Study.doc 23 Vista La Costa JN 121004 Process from Point/Station 222.000 to Point/Station **** SUBAREA FLOW ADDITION **** 222.000 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 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 4.86 min. Rainfall intensity = 7.513(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.170 Subarea runoff = 0.225(CFS) for 0.050(Ac.) Total runoff = 1.280(CFS) Total area = 0.240(Ac.) -^-^-l--f-^-l--^-^-l-+-l--^+-^•-^ + -^-^-^-l--^-^-^-^-^--^-^-^-t-+-^--^-^-^-^ + + -^-^-^-^-^-^-^-^ + -^-(- + Process from Point/Station 223.000 to Point/Station 224.000 **** IMPROVED CHANNEL TRAVEL TIME **** 52 .300(Ft.) 51.900(Ft.) 85.000(Ft. 6.000(Ft.) bank = 2.000 1.000(Ft.) .494(CFS) Average velocity .905(Ft.) Upstream point elevation = Downstream point elevation = Channel length thru subarea Channel base width = Slope or 'Z' of left channel Slope or 'Z' of right channel bank = 2.000 Estimated mean flow rate at midpoint of channel Manning's 'N' =0.03 5 Maximum depth of channel = Flow(q) thru subarea = 1 Depth of flow = 0.226(Ft.), Channel flow top width = 6 Flow Velocity = 1.02 (Ft/s) Travel time = 1.3 8 min. Time of concentration = 6.25 Critical depth = 0.123(Ft. Adding area flow to channel Decimal fraction soil group A = Decimal fraction soil group B = Decimal fraction soil group C = Decimal fraction soil group D = [HIGH DENSITY RESIDENTIAL (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 6.391(In/Hr) Effective runoff coefficient used for (Q=KCIA) is C = 0.710 CA = 0.256 Subarea runoff = 0.353(CFS) for 0.120(Ac Total runoff = 1.634(CFS) Total area = Depth of flow = 0.239(Ft.), Average velocity = Critical depth = 0.131(Ft.) 1.494(CFS) 1.023(Ft/s) 000 000 000 000 for a 100. total area 0 year storm ) 0.360{Ac.) 1.057(Ft/s) G:\031060\Drainage\Hydrology\Drainage Study.doc 24 Vista La Costa JN 121004 -^-^--l--(--^-l--^-^-^-)--l--^-^-l--^-l--^-^-^--l--l--^+-^-^-^-^-^-^-l--^•^-^--^--^-l--^-^+-l--^-^-^-l--^+ Process from Point/Station 224.000 to Point/Station 217.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 42.600(Ft.) Downstream point/station elevation = 42.100(Ft.) Pipe length = 85.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.634(CFS) Nearest computed pipe diameter = 12.00(In.) Calculated individual pipe flow = 1.634(CFS) Normal flow depth in pipe = 6.69(In.) Flow top width inside pipe = 11.92(In.) Critical Depth = 6.52(In.) Pipe flow velocity = 3.63(Ft/s) Travel time through pipe = 0.39 min. Time of concentration (TC) = 6.64 min. -f-H-H-H-H + -H-l- + -h + + -f-H-l--H-l--l--H-(--l--(--l--H-l--l--H-H-(--t--H-l--H-(--H-(--l- + H--H-H-H-h-t--H-l- Process from Point/Station 224.000 to Point/Station 217.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.360(Ac.) Runoff from this stream = 1.634(CFS) Time of concentration = 6.64 min. Rainfall intensity = 6.146(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) Qmax(2) .387 .634 . 000 .000 0. 860 1. 000 5.25 6.64 1.000 * 0.792 * 1.000 * 1.000 * 7.146 6.146 2.387) + 1.634) + 2.387) + 1.634) -I- 3 . 680 3.687 Total of 2 main streams to confluence: Flow rates before confluence point: 2.387 1.634 Maximum flow rates at confluence using above data: 3.680 3.687 Area of streams before confluence: 0.440 0.360 Results of confluence: Total flow rate = 3.687(CFS) Time of concentration = 6.635 min. Effective stream area after confluence 0.800(Ac.) G:\031060\Drainage\Hydrology\Drainage Study.doc 25 Vista La Costa JN 121004 -F-h + -H-l--h-l--l--h-h-h-l--H-l- + -F-t--l--l--H-l- + + -l--l--l--f + + -l--l--l--h-H-H-h-h-f-(--h-t--t--(--f-l--l- Process from Point/Station 217.000 to Point/Station 225.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 42.100(Ft.) Downstream point/station elevation = 34.000(Ft.) Pipe length = 49.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 3.687(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 3.687(CFS) Normal flow depth in pipe = 4.75(In.) Flow top width inside pipe = 8.99(In.) Critical depth could not be calculated. Pipe flow velocity = 15.57 (Ft/s) Travel time through pipe = 0.05 min. Time of concentration (TC) = 6.69 min. End of computations, total study area = 0.800 (Ac.) 100 Year Flowrate for the Parking Lot (Pervious Pavement to Gibraltar) A= 0.05 AC C= 0.71 (See Exhibit 'B') 1= 7.37 in/hr (See Exhibit 'G' Tc=5 min.) 0= 0.26 cfs G:\031060\Drainage\Hydrology\Drainage Study.doc 26 Vista La Costa JN 121004 APPENDIX C Calculations for Grates (See Exhibit 'K') G:\031060\Drainage\Hydrology\Drainage Study.doc 27 Vista La Costa JN 121004 24"x 24" Catch Basin Qmax/P = 3.0 * H'^3/2 (Bureau of Public Roads Chart - See attached exhibiO Q - Storm runoff P - Perimeter of catch basin grate (24" x 24" Area Drain P=24"-i-24"-i-24"-i-24"=8.0') H - Head (assume 6" depression, H=0.5') Assuming grate is half clogged: (P=8.0/2=4.0') Qmax = (3.0 * 0.5''^3/2)*4.0' = 4.24 cfs 24' 24' 24" X 24" AREA DRAIN GRATE Capacity Calculations for 3' Diameter Round Grate Qmax/P = 3.0 * H^3/2 (Bureau of Public Roads Chart - See attached exhibit 'H') Q - Storm runoff P - Perimeter of catch basin grate (2*n*(1.5') = 9.42 ft^ H - Head (assume 2" depression, H=0.17') (Freeboard in bioretention area is 2") Assuming grate is half clogged: (P=9.42/2)= 4.71 ft^ Qmax = (3.0 * 0.17'^3/2)*4.71 = 0.99 cfs Node 204: 0.84 cfs OK Node 216: 0.87 cfs OK G:\031060\Drainage\Hydrology\Drainage Study.doc 28 Vista La Costa JN 121004 Node 224: 1.63 cfs (2~Inlets 0.99*2= 1.98 cfs) OK G:\031060\Drainage\Hydrology\Drainage Study.doc 29 EXHIBIT 'A cm OF OCEAHSnX cmr or SAN UMCOS PACtnc OCEAN PROJECT SITE aiYOF BHMTAS VICINITY MAP NO SCALE i i I i I I i I I I I i I i I I i I i I I I i k 1 San Diego County Hydrology Manual Date: June 2003 Section: Page: 3 6 of 26 Table 3-1 RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use Runoff Coefficient "C" Soil Type NRCS Elements County Elements % IMPER. A B C D Undisturbed Natural Terrain (Natural) Permanent Open Space 0* 0.20 0.25 0.30 0.35 Low Density Residential (LDR) Residential, 1.0 DU/A or less 10 0.27 0.32 0.36 0.41 Low Density Residential (LDR) Residential, 2.0 DU/A or less 20 0.34 0.38 0.42 0.46 Low Density Residential (LDR) Residential, 2.9 DU/A or less 25 0.38 0.41 0.45 0.49 Medium Density Residential (MDR) Residential, 4.3 DU/A or less 30 0.41 0.45 0.48 0.52 Medium Density Residential (MDR) Residendal, 7.3 DU/A or less 40 0.48 0.51 0.54 0.57 Medium Density Residential (MDR) Residential. 10.9 DU/A or less 45 0.52 0.54 0.57 0.60 Medium Density Residential (MDR) Residential, 14.5 DU/A or less 50 0.55 0.58 0.60 0.63 High Density Residential (HDR) Residential, 24.0 DU/A or less 65 0.66 0.67 0.69 0.71.^\ High Density Residential (HDR) Residential, 43.0 DU/A or less 80 0.76 0.77 0.78 0.79 ( Commercial/Industrial (N. Com) Neighborhood Conraiercial 80 0.76 0.77 0.78 0.79 Conunercial/lndustrial (G. Com) General Commercial 85 0.80 0.80 0.81 0.82 Conunercial/lndustrial (O.P. Com) Office Professional/Commercial 90 0.83 0.84 0.84 0.85 Commercial/Industrial (Limited I.) Limited Industrial 90 0.83 0.84 0.84 0.85 Commercial/Industrial (General I.) General Industrial 95 0.87 0.87 0.87 0.87 *The values associated with 0% impervious may be used for direct calculation of the coefficient, Cp, for the soil type), or for areas that will remain undisturbed in perpetuity. is located in Cleveland Nadonal Forest). DU/A = dwelling units per acre NRCS = National Resources Conservation Service runoff coefficient as described in Section 3.1.2 (representing the pervious runoff Justificadon must be given that the area will remain natural forever (e.g., the area 3-6 IIII I I t 1 i i i I /^ IIII I 1 i 1 1 i I I i i t i 33?30' County of San Diego Hydrology Manual Rainfall Isopluvials 100 Year Rainfall Event - 6 Hours isopluvial (Inches) -^GIS GIS ••XV H,!V'.,-.'^'J:I r'KY-' f .''i'Vv.T:'^- -im MAP IS PBCMMD WHIHOUI WAnnANTY OF AMT MK). HTHf" e>P«BS OBKMIED. wauDWQ. BUI NOT IMTBD TO. TMB iMPlW W*««MmS Of wcRcwiNTMaurT wm mNess FOR * pwiicuiAfi puwost 3 0 3 Miles lift, I 1 I I I 1 i i I I I. I 1 I i I 1 t 1 1 1 t I 33'30' County of San Diego Hydrology Manual Rainfall Isopluvials 100 Year Rainfall Event - 24 Hours Isopluvial (inches) DPW CIS t*n « PBovntia wrHout MMWAKTI of MND. fTivCRKuFHEBs on MPlKD. tNClUOING. Bur NOT UMTEOTD. THi M>lCO MARIUmK9 or MERCWMTAMUTY AND Ftness Fof> A pMrncuuo PUNKtse. 3 0 3 Miles Illlllliitliilllllll I i I 1 i I I i I i I 1 I 1 t 100 LU LU O 2 W O LU CO cc o O Q: LU I EXAMPLE: Given: Watercourse Distance (D) = 70 Feet Slope (s) =1.3% Runoff Coefficient (C) = 0.41 Overland Flow Time (T) = 9.5 Minutes SOURCE: Aiiport Drainage, Federal Aviation Administration. 1965 j_^.6{\.i-C)\fo Rational Formula - Overland Time of Flow Nomograph F I G U R E -r I I i I II II 11 II ftl I I i f 1 i I f E I I i I f I i I I i I i 7 8 9 10 20 30 40 50 1 Minutes Duration 3 4 Hours Diractlons for Application: (1) From precipitation maps determine 6 hr and 24 hr amounts fbr the selected fi-eqtjency. These maps are included in the County Hydrology Manual (10,50, and 100 yr maps included in the Design and Procedure Manual). (2) Adjust 6 hr precipitation (if necessary) so that it is within the range of 45% to 65% of tfie 24 hr precipitation (not applicaple to Desert). (3) Plot 6 hr precipitation on fhe right side of the chart. (4) Draw a tine through the point parallel to the plotted lines. (5) This line is the Intensity-duration curve fbr the location being analyzed. 50 year 5.5 ,_6 = 54.5 %(2) •P 24 Application Fonn: (a) Selected frequency (b) P6= 3 In.. Po^ (c) Adjusted Pg'^* = _J_ (d) t3j= 20 min. (e) I = 3.2 in./hr. Note: This chart replaces the Intenstty-Duration-Frequency curves used since 1965. PB 1 i.s 2 „ "* 'is ^ 5 6 iltiraaon ... 1 T ~ i' " 1 ! 1 1 1 i i 5 2.63 3.95 659 7.90:9.22 10.54; 11.86 13.17 14.49115.81 7 2.12 ai8 4>i 6.30X6.3617.42 8.48 : 9.iM 10.60 11.06 12.72 10 1.60 3.37 4.21 i5.0Sr 5.90 6.74 7.56 8.42 9^7 iail 15 1.30 1.95 ZS9 3.24 3.89] 4.54 5.19 5.84 6:40 7.13 fM 20 1XW 1.62 2.15 2.69 'i23{3.77] 4.31 4.861 5.39 6.93 B.46 35 6S3 1.40 1.87 2.3312J0l357 3.73 4.20 4.67 5.13 5.60 30 6l3 ii4 1.66 2.07 2.49r2.g0 3.SC '3.73 ~4.is 4.56 4:ge 40 0.69 'i.03j i.38 2.07; 2.41 2.76 3.10 3.45 ,3.79 4.13 SO 0.60 0.901 T19 1.4911.7912.09 l39 2.69 i98 3.28 ass 60 033 O.flO 1.06 1.33 1.59! 1.88 2.12 "2.39 2.65' 2.92 3.18 Hi o;4i o:oi 0.82 102 15311.43 1,63 1.8« 204 2i5 2.4S 120 oM 0.51 6.68 085 1.02U[.19i 1.36 ,1.53 0.8811.63ri."l8M.'32' 0.78! 6.91 i 1.04 1 1.18 1.70 , 1.87 2.04 iBO .„ ViM 0.59 073" 1.02U[.19i 1.36 ,1.53 0.8811.63ri."l8M.'32' 0.78! 6.91 i 1.04 1 1.18 1.47 1.62 i>8 " ISO OM 6.39 0.52 6.65 1.02U[.19i 1.36 ,1.53 0.8811.63ri."l8M.'32' 0.78! 6.91 i 1.04 1 1.18 i.31 1.44 isi 240 022 0.33 0.43 "0.54 0.65 0.76 0.87 0^98 i.b8 1.19 1.30 300 019 bis 0.38 6.47 6.56 i 0.661 0 75 0".50T0.5«i 6.«7 0 85 r 0.94 '1.63 i.l3 360 0.17 0.2S 0.33 a42 6.56 i 0.661 0 75 0".50T0.5«i 6.«7 0.75 i 0.84 0.92 1.00 Intenslty-Duration Design Chart - Example FIGURE - 3-2 1 -I •"I Willi' 41 •Jjj 1073.02 1—0—1 P » 2 (QT b) l=-. 1 1 1 i |< 1 •• lui ti" f"'| ' "' f"jl"'l "•>C.u^".| 1 1 I 1 1 •/• t till! g Mill I 1 / = lli IIII III /\ 4 i M II m / 1 = t I/-.• — ^ • 1 11 llillll/ r 1 11 llllll./ i IMM I-. ) . I .ni.i.|-..-||.»| 111, j.m)"i.)ii'-|—fl IIII I I I I M ' I 111 I t I I I I T7^\ ill .A I I I i I t I I I /I t IIII i I I I I I I I 111 ^jr-- i' l II 1/11 I I I 11 f Vi I I foil l >fl I IIII I i^t I TT I I 1/ 1/ I TT I I. \ Ml MM I llli I I i I I I I IIII I I I I I j I I I I I 111 I t I I I I I I £ H-:;05 Ul? 7.0 iD.j^.baaVEHffll hn^ilES I I I | I I Mill io/i . is. 3 TIW^* MIM llli I I I -I I I I I I I 1 I IIIII I HEAPS 3j-T\V£LN 6.^£ fTrjA^bljTION | \ £gcrOR IS Or;ia£.Tl)ON l!Sl iW iD^Tr'^JITr I | | | I I MM llllll I I IIM tf i- M Cr.f ri I I IMM • 3 • 11,1. ml... , III..1.1.,..1.., IL ~i till 111 1 III I.: .,!.„,Wll. ?12 3URSAU OF PUBLIC ROADS .CAPACITY Or GRATE I g ? FLJT i.i..t.tiiti<. ...L.. 1 1 I I VTi .> a a 7 c c ts Y INLET IN SUM? DIVJSIOW TWO WASH, p.C. VVATER PONDED ON GRATE EXHIBIT "I" Table A-3 Table A-3 Average Manning Roughness Coefflcients for Small Open Channels Conveying Less than 50 cfs* Dosign Flow Depth Lining Type 0-0.5 ft O.S-2.0fl > 2.0 It Concrete (Poured) . 0.015 0.013 0.013 Air Blown Concrete 0.023 0.019 0.016 Grouted Riprap 0.040 0.030 0.028 Stone Maeoniy 0.042 0.032 0.030 Soli Cement 0.025 0.022 0.020 Bare Soli 0.023 0.020 0.020 RoeliCut 0.045 0.035 0.025 Rocit Riprap Based on Rodt Size (See Section 5.7.2) Table A-4 Table A-4 Average Manning Roughness Coefficients for Larger Open Channels Unlined Channels Clay Loam.....' 0.023 Sand 0.020 Lined Channels Grass Lined (Well-Maintained) 0.035 Grass Lined (Not Maintained) 0.045 Wetland-Bottom Channels (New Channel) 0.023 Wetland-Bottom Channels (Mature Channel) See Table A-5 RIprap-UneO Channels See Section 5.7.2 Concrete (Poured) 0.014 Air Blown Mortar (Gunite or Shotcrete)' 0 016 Asphaltic Concrete or Bituminous Plant Mix 0.018 For channala with ravalmaiUs or muKipIt lining types, ust composXi Manning roughntat (xefUcitnt bastd on componant lining matwfaM. * Based on materials and workmanship required by standard specifications. ' For air-blown concrete, use »-0.012 (if troweled) and fl=0.025 if puiposely rougiiened. San Diego County Drainage Design Manual (May 2005) Page A-5