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HomeMy WebLinkAboutSDP 14-01; RACEWAY BUSINESS PARK LOT 17; HYDROLOGY STUDY; 2014-06-30FILE COPY Hydrology Study RE CE WE1fl FOR JUL 18 2014 LOT 17 LAru UtVtLJrdMEN I ENGINEERING CARLSBAD RACEWAY BUSINESS PARK PRECISE GRADING PLAN June 30, 2014 Prepared By: O'DAY CONSULTANTS 2710 Loker Avenue, Suite 100 Carlsbad, CA 92010 (760) 931-7700 1 0. 0 J.N. 12-1001 (( /,4 %CIVIL Timothy 0. Carroll RCE 55381 Exp. 12/31/14 SO 14-0 t P L A M. C =Cc -H a Q, Table of Contents Section Description Page No. Introduction and Project Description 3 Existing Hydrology Basin Areas And Hydrology Calculations 4 Proposed Hydrology Basin Areas And Hydrology Calculations 4 Exhibits Exhibit A - Vicinity Map Exhibit B - 20-Scale Existing Project Conditions Hydrologic Map (Map Pocket) Exhibit C - 20-Scale Proposed Project Conditions Hydrologic Map (Map Pocket) Appendices Appendix A Appendix B Appendix C - Hydrologic Calculations - Existing Project Conditions for 100-year Storm - Hydrologic Calculations - Proposed Project Conditions for 100-year Storm - County of San Diego Hydrology Manual References PA 4 Introduction and Project Description Lot 17 of Carlsbad Raceway Business Park project is located north of Lionshead Avenue and east of Melrose Drive in the City of Carlsbad, California (see Vicinity Map below). The entire site is approximately 4.8 acres. Lot 17 is an existing mass graded lot per approved grading plan Drawing 409-1A. The purpose of this Hydrology Study is to support a Precise Grading Plan which proposes the development of the site for industrial use. The site will include approximately 76,326 s.f. of building permit area (includes truck docks and trash enclosures) and approximately 177 parking spaces. The remainder of the site will be landscaping. Under existing conditions, there is a single location where runoff from the lot discharges to, as indicated on City of Carlsbad Grading Plans Drawing No. 409-1A, sheet 14 and Drawing No. 409-1, sheet 23. Runoff from the site drains to an existing desilting basin that is connected to a 54-inch storm drain that traverses the site and then discharges into an existing downstream detention basin west of Lot 17. The 54-inch storm drain is part of the existing drainage infrastructure serving the surrounding Carlsbad Raceway Business Park. The controlled discharge from the downstream detention basin eventually discharges to Agua Hedionda Creek. Since the lot is part of the mass grading plans for the Carlsbad Raceway Business Park, a runoff coefficient of 0.85 (Office Professional) is used in the existing hydrology calculations. Under proposed conditions, the majority of the site will drain into separate bioretention basins located along the southerly property line/right-of-way of Lionshead Avenue and the northeasterly corner of the property. The remaining area in the vicinity of the southwest corner of the property will be intercepted by a Urban Green biofiltration catch basin, and two other areas will drain into truck loading docks that are 4.5 feet below the finished floor of the proposed building. All proposed drainage facilities will connect to the existing drainage infrastructure located on-site. A runoff coefficient of 0.85 (Office Professional) is used in the proposed hydrology calculations. Hydrologic Calculations Hydrologic calculations were performed utilizing the San Diego County Rational Method as described in the San Diego County Hydrology Manual, June 2003. Pertinent references from the San Diego County Hydrology Manual are enclosed in Appendix "C" as follows: 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 3-1 Intensity Duration Design Chart In the Rational Method, Q= Flowrate =CIA, and C = Runoff coefficient, soil type 'C' = 7.44 P6t 645, Exhibit H 3 P6= Precipitation for the 6 hour, 100-year storm, Exhibit 'F' = 5 minutes minimum and calculated using methodology described in hydrology manual A = Drainage area in acres, Exhibit 'B' Existing hydrology basin areas and hydrology calculations are shown on Exhibit"B" and in Appendix "A". A summary of the existing hydrology is shown in the table below. Table 1. Q100 flow rates for Existing Project Condition Existing Project Hydrology Results• Basin Area (acres) Q (cfs) A 4.50 29.9 Total* 4.5 29.9 Proposed hydrology basin areas and hydrology calculations are shown on Exhibit "C" and in Appendix "B". A summary of the proposed hydrology is shown in the table below. Table 2. Q100 flow rates for Proposed Conditions Proposed Project Hydrology Results Basin Area (acres) 0 (cfs) A 2.71 15.9 B 1.98 11.3 C 0.14 0.9 Total 4.83 28.1 4 Comparison of existing hydrology and proposed hydrology is shown in the table below. Table 3. Q100 flow rates for Existing and Proposed Conditions Comparison of Existing Hydrology and Proposed Hydrology Basin Existing Project Hydrology (cfs) Proposed Project Hydrology (cfs) Total 29.9 28.1 There is an decrease in the storm water runoff from the proposed project conditions compared to the existing project conditions with a similar runoff coefficient. The decrease can be attributed to the longer time of concentration associated with the proposed site plan and reduced drainage area. 5 EXHIBITS CITY OF OCEANSIDE SITE BUSINESS PARK DR. LIONSHEAD AVE. OF MARCOS CITY OF ENCINITAS fr7C/MTY 444P NOT TO SCALE D081 T ' 4" APPENDIX A Hydrologic Calculations - Existing Project Conditions for 100-year storm San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c)1991-2006 Version 7.7 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 09/04/13 LOT 17 CARLSBAD RACEWAY 13102 0EF1 EXISTING HYDROLOGY ********* Hydrology Study Control Information Program License Serial Number 6218 Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 3.000 24 hour precipitation(inches) 5.500 P6/P24 = 54.5% San Diego hydrology manual 'C' values used ++ ++ + ++++++++++++++++++++ ++ + ++ ++++++ + + +++++++++++++ +++ ++++ ++ Process from Point/Station 100.000 to Point/Station 110.000 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 [COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Initial subarea total flow distance = 50.000(Ft.) Highest elevation = 404.000(Ft.) Lowest elevation = 403.000(Ft.) Elevation difference = 1.000(Ft.) Slope = 2.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 70.00 (Ft) for the top area slope value of 2.00 %, in a development type of Office Professional In Accordance With Table 3-2 Initial Area Time of Concentration = 3.10 minutes (for slope value of 2.00 %) Calculated TC of 3.100 minutes is less than 5 minutes, resetting PC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.904(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.850 Subarea runoff = 0.356(CFS) Total initial stream area = 0.053 (Ac.) + +++ +++++ ++ ++++++++ + + ++++++++ +++++++ + ++++++++++++++++++ ++ +++++ ++ Process from Point/Station 110.000 to Point/Station 120.000 IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 403.000(Ft.) Downstream point elevation = 389.000(Ft.) Channel length thru subarea = 490.000(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z' of left channel bank = 50.000 Slope or 'Z' of right channel bank = 50.000 Estimated mean flow rate at midpoint of channel = 15.305(CFS) Manning's 'N' = 0.015 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 15.305(CFS) Depth of flow = 0.265(Ft.), Average velocity = 4.353(Ft/s) Channel flow top width = 26.517(Ft.) Flow Velocity = 4.35(Ft/s) Travel time = 1.88 mm. Time of concentration = 4.98 mm. Critical depth = 0.357 (Ft.) Adding area flow to channel Calculated TC of 4.976 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.904(In/Hr) for a 100.0 year storm 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 [COMMERCIAL area type (Office Professional Impervious value, Al = 0.900 Sub-Area C Value = 0.850 Rainfall intensity = 7.904(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.850 CA = 3.828 Subarea runoff = 29.898(CFS) for 4.450(Ac.) Total runoff = 30.254(CFS) Total area = 4.503(Ac.) Depth of flow = 0.342(Ft.), Average velocity = 5.162(Ft/s) Critical depth = 0.469(Ft.) End of computations, total study area = 4.503 (Ac.) APPENDIX B Hydrologic Calculations - Proposed Project Conditions for 100-year storm San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c)1991-2006 Version 7.7 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 03/11/14 ------------------------------------------------------------------------ LOT 17 CARLSBAD RACEWAY 13].O2OSF1 PROPOSED HYDROLOGY - BASIN A ********* Hydrology Study Control Information ********** Program License Serial Number 6218 Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 3.000 24 hour precipitation(inches) = 5.500 P6/P24 = 54.5% San Diego hydrology manual 'C' values used Process from Point/Station 10.000 to Point/Station 20.000 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 [COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Initial subarea total flow distance = 50.000(Ft.) Highest elevation = 397.780(Ft.) Lowest elevation = 395.500(Ft.) Elevation difference = 2.280(Ft.) Slope = 4.560 % 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 Office Professional In Accordance With Table 3-2 Initial Area Time of Concentration = 4.20 minutes (for slope value of 0.50 %) Calculated TC of 4.200 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.904(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.850 Subarea runoff = 0.605(CFS) Total initial stream area = 0.090(Ac.) Process from Point/Station 20.000 to Point/Station 30.000 IMPROVED CHANNEL TRAVEL TIME Upstream point elevation = 397.500(Ft.) Downstream point elevation = 396.320(Ft.) Channel length thru subarea = 188.000(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z' of left channel bank = 33.000 Slope or 'Z' of right channel bank = 33.000 Estimated mean flow rate at midpoint of channel = 3.026(CFS) Manning's 'N' = 0.015 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 3.026(CFS) Depth of flow = 0.224(Ft.), Average velocity = 1.824(Ft/s) Channel flow top width = 14.798(Ft.) Flow Velocity = 1.82(Ft/s) Travel time = 1.72 mm. Time of concentration = 5.92 mm. Critical depth = 0.221(Ft.) Adding area flow to channel Rainfall intensity (I) = 7.090(In/Hr) for a 100.0 year storm 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 [COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Rainfall intensity = 7.090(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.850 CA = 0.757 Subarea runoff = 4.759(CFS) for 0.800(Ac.) Total runoff = 5.364(CFS) Total area = 0.890(Ac.) Depth of flow = 0.278(Ft.), Average velocity = 2.105(Ft/s) Critical depth = 0.277 (Ft.) +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-4- Process from Point/Station 30.000 to Point/Station 30.000 SUBAREA FLOW ADDITION Rainfall intensity (I) = 7.090(In/Hr) for a 100.0 year storm 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 [COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Time of concentration = 5.92 mm. Rainfall intensity = 7.090(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.850 CA = 1.139 Subarea runoff = 2.712(CFS) for 0.450(Ac.) Total runoff = 8.076(CFS) Total area = 1.340(Ac.) Process from Point/Station 30.100 to Point/Station 60.100 PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 388.700(Ft.) Downstream point/station elevation = 386.730(Ft.) Pipe length = 192.20(Ft.) Slope = 0.0102 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 8.076(CFS) Given pipe size = 18.00(In.) Calculated individual pipe flow = 8.076(CFS) Normal flow depth in pipe = 11.73(In.) Flow top width inside pipe = 17.15(In.) Critical Depth = 13.20(In.) Pipe flow velocity = 6.62(Ft/s) Travel time through pipe = 0.48 mm. Time of concentration (TC) = 6.40 mm. +++++++++++++++++4-++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 30.100 to Point/Station 60.100 CONFLUENCE OF MINOR STREAMS Along Main Stream number: 1 in normal stream number 1 Stream flow area = 1.340 (Ac.) Runoff from this stream = 8.076(CFS) Time of concentration = 6.40 mm. Rainfall intensity = 6.740(In/Hr) ++++++++++++.+++++++++++++++++++++++++++++++.+++++++++++++++++++++++++ Process from Point/Station 40.000 to Point/Station 50.000 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 [COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Initial subarea total flow distance = 100.000(Ft.) Highest elevation = 397.800(Ft.) Lowest elevation = 397.200(Ft.) Elevation difference = 0.600(Ft.) Slope = 0.600 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.60 %, in a development type of Office Professional In Accordance With Table 3-2 Initial Area Time of Concentration = 4.20 minutes (for slope value of 0.50 %) Calculated TC of 4.200 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.904(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.850 Subarea runoff = 3.964(CFS) Total initial stream area = 0.590(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-1-+ Process from Point/Station 50.000 to Point/Station 60.000 IMPROVED CHANNEL TRAVEL TIME Upstream point elevation = 397.200(Ft.) Downstream point elevation = 396.240(Ft.) Channel length thru subarea = 110.000(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z' of left channel bank = 50.000 Slope or 'Z' of right channel bank = 50.000 Estimated mean flow rate at midpoint of channel = Manning's 'N' = 0.015 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 5.408(CFS) Depth of flow = 0.224(Ft.), Average velocity = Channel flow top width = 22.422 (Ft.) Flow Velocity = 2.15(Ft/s) Travel time = 0.85 mm. Time of concentration = 5.05 mm. Critical depth = 0.236(Ft.) Adding area flow to channel Rainfall intensity (I) = 7.852(In/Hr) for a 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 [COMMERCIAL area type (Office Professional Impervious value, Al = 0.900 Sub-Area C Value = 0.850 5. 408 (CFS) 2.151(Ft/s) 100.0 year storm Rainfall intensity = 7.852(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.850 CA = 0.867 Subarea runoff = 2.843(CFS) for 0.430(Ac.) Total runoff = 6.807(CFS) Total area = 1.020 (Ac.) Depth of flow = 0.244(Ft.), Average velocity = 2.279(Ft/s) Critical depth = 0.258(Ft.) Process from Point/Station 60.000 to Point/Station 60.000 SUBAREA FLOW ADDITION **** Rainfall intensity (I) = 7.852(In/Hr) for a 100.0 year storm 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 [COMMERCIAL area type (Office Professional Impervious value, Al = 0.900 Sub-Area C Value = 0.850 Time of concentration = 5.05 mm. Rainfall intensity = 7.852(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.850 CA = 1.063 Subarea runoff = 1.535(CFS) for 0.230(Ac.) Total runoff = 8.342(CFS) Total area = 1.250 (Ac.) ++++++++++++.+..++++++++.++++++++++++++.+++++++++++++..+++++++++++++++ Process from Point/Station 60.000 to Point/Station 60.000 CONFLUENCE OF MINOR STREAMS Along Main Stream number: 1 in normal stream number 2 Stream flow area = 1.250(Ac.) Runoff from this stream = 8.342(CFS) Time of concentration = 5.05 mm. Rainfall intensity = 7.852(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (mm) (In/Hr) 1 8.076 6.40 6.740 2 8.342 5.05 7.852 Qmax(1) = 1.000 * 1.000 * 8.076) + 0.858 * 1.000 * 8.342) + = 15.237 Qmax(2) = 1.000 * 0.789 * 8.076) + 1.000 * 1.000 * 8.342) + = 14.716 Total of 2 streams to confluence: Flow rates before confluence point: 8.076 8.342 Maximum flow rates at confluence using above data: 15.237 14.716 Area of streams before confluence: 1.340 1.250 Results of confluence: Total flow rate = 15.237(CFS) Time of concentration = 6.402 mm. Effective stream area after confluence = 2.590(Ac.) Process from Point/Station 60.100 to Point/Station 60.200 k PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 386.480(Ft.) Downstream point/station elevation = 382.810(Ft.) Pipe length = 99.80(Ft.) Slope = 0.0368 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 15.237(CFS) Given pipe size = 18.00(In.) Calculated individual pipe flow = 15.237(CFS) Normal flow depth in pipe = 11.70(In.) Flow top width inside pipe = 17.17(In.) Critical Depth = 16.92(In.) Pipe flow velocity = 12.53(Ft/s) Travel time through pipe = 0.13 mm. Time of concentration (TC) = 6.53 mm. Process from Point/Station 60.100 to Point/Station 60.200 r PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 386.480(Ft.) Downstream point/station elevation = 382.810(Ft.) Pipe length = 99.80(Ft.) Slope = 0.0368 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 15.237(CFS) Given pipe size = 18.00(In.) Calculated. individual pipe flow = 15.237(CFS) Normal flow depth in pipe = 11.70(In.) Flow top width inside pipe = 17.17(In.) Critical Depth = 16.92(In.) Pipe flow velocity = 12.53(Ft/s) Travel time through pipe = 0.13 mm. Time of concentration (TC) = 6.67 mm. Process from Point/Station 60.200 to Point/Station 80.100 PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 382.560(Ft.) Downstream point/station elevation = 378.970(Ft.) Pipe length = 37.00(Ft.) Slope = 0.0970 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 15.237(CFS) Given pipe size = 18.00(In.) Calculated individual pipe flow = 15.237(CFS) Normal flow depth in pipe = 8.64.(In.) Flow top width inside pipe = 17.99(In.) Critical Depth = 16.92(In.) Pipe flow velocity = 18.19(Ft/s) Travel time through pipe = 0.03 mm. Time of concentration (TC) = 6.70 mm. Process from Point/Station 80.100 to Point/Station 80.100 CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 1 Stream flow area = 2.590 (Ac.) Runoff from this stream = 15.237(CFS) Time of concentration = 6.70 mm. Rainfall intensity = 6.544(In/Hr) +++++++++++++++++.+..++++++++++..++++++++++++++++++++++++++++++++....+ Process from Point/Station 70.000 to Point/Station 80.000 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 (COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Initial subarea total flow distance = 80.000(Ft.) Highest elevation = 397.300(Ft.) Lowest elevation = 393.700(Ft.) Elevation difference = 3.600(Ft.) Slope = 4.500 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 90.00 (Ft) for the top area slope value of 4.50 %, in a development type of Office Professional In Accordance With Table 3-2 Initial Area Time of Concentration = 2.60 minutes (for slope value of 5.00 %) Calculated TC of 2.600 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.904(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.850 Subarea runoff = 0.806(CFS) Total initial stream area = 0.120(Ac.) Process from Point/Station 80.000 to Point/Station 80.100 PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 390.700(Ft.) Downstream point/station elevation = 377.970(Ft.) Pipe length = 47.10(Ft.) Slope = 0.2703 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.806(CFS) Given pipe size = 8.00(In.) Calculated individual pipe flow = 0.806(CFS) Normal flow depth in pipe = 1.94(In.) Flow top width inside pipe = 6.85(In.) Critical Depth = 5.09(In.) Pipe flow velocity = 12.37(Ft/s) Travel time through pipe = 0.06 mm. Time of concentration (TC) = 2.66 mm. ++++++++++.++++++++++++++++++++++++++++.+.++++++++++++.++.++++++++++++ Process from Point/Station 80.100 to Point/Station 80.100 CONFLUENCE OF MINOR STREAMS Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.120(Ac.) Runoff from this stream = 0.806(CFS) Time of concentration = 2.66 mm. Rainfall intensity = 7.904(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (mm) (In/Hr) 1 15.237 6.70 6.544 2 0.806 2.66 7.904 Qmax(1) = 1.000 * 1.000 * 15.237) + 0.828 * 1.000 * 0.806) + = 15.904 Qmax(2) = 1.000 * 0.397 * 15.237) + 1.000 * 1.000 * 0.806) + = 6.862 Total of 2 streams to confluence: Flow rates before confluence point: 15.237 0.806 Maximum flow rates at confluence using above data: 15.904 6.862 Area of streams before confluence: 2.590 0.120 Results of confluence: Total flow rate = 15.904(CFS) Time of concentration = 6.701 mm. Effective stream area after confluence = 2.710(Ac.) + +++ ++ + + +++ +++ ++++.++ + ++ ++ ++++ +++ +++++ ++ + + +++++ ++ ++ ++ ++ + ++++ ++ ++ ++++++ + Process from Point/Station 80.100 to Point/Station 80.100 PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 377.970(Ft.) Downstream point/station elevation = 376.770(Ft.) Pipe length = 10.10(Ft.) Slope = 0.1188 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 15.904(CFS) Given pipe size = 18.00(In.) Calculated individual pipe flow = 15.904(CFS) Normal flow depth in pipe = 8.34 (In.) Flow top width inside pipe = 17.95(In.) Critical Depth = 17.08(In.) Pipe flow velocity = 19.82(Ft/s) Travel time through pipe = 0.01 mm. Time of concentration (TC) = 6.71 mm. End of computations, total study area = 2.710 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c)1991-2006 Version 7.7 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 03/11/14 ------------------------------------------------------------------------ LOT 17 CARLSBAD RACEWAY 13 102 OSF2 PROPOSED HYDROLOGY - BASIN B ------------------------------------------------------------------------ ********* Hydrology Study Control Information Program License Serial Number 6218 ------------------------------------------------------------------------ Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 3.000 24 hour precipitation(inches) = 5.500 P6/P24 = 54.5% San Diego hydrology manual 'C' values used +++++++++++-1++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 90.000 to Point/Station 100.000 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 [COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Initial subarea total flow distance = 50.000(Ft.) Highest elevation = 395.700(Ft.) Lowest elevation = 395.500(Ft.) Elevation difference = 0.200(Ft.) Slope = 0.400 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.40 %, in a development type of Office Professional In Accordance With Table 3-2 Initial Area Time of Concentration = 4.20 minutes (for slope value of 0.50 %) Calculated TC of 4.200 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.904.(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.850 Subarea runoff = 0.672(CFS) Total initial stream area = 0.100(Ac.) +++++++++++++++++++++++++++++++++++++.4-+++++++++++++++++++++++++++++++. Process from Point/Station 100.000 to Point/Station 110.000 STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 395.500(Ft.) End of street segment elevation = 394.300(Ft.) Length of street segment = 150.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 30.000(Ft.) Distance from crown to crossfall grade break = 28.490(Ft.) Slope from gutter to grade break (v/hz) = 0.033 Slope from grade break to crown (v/hz) = 0.033 Street flow is on [1] side(s) of the Street Distance from curb to property line = 10.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 0.125(In.) Manning's N in gutter = 0.0140 Manning's N from gutter to grade break = 0.0140 Manning's N from grade break to crown = 0.0330 Estimated mean flow rate at midpoint of street = 2.195(CFS) Depth of flow = 0.299(Ft.), Average velocity = 1.288(Ft/s) Streetfiow hydraulics at midpoint of street travel: Halfstreet flow width = 10.249(Ft.) Flow velocity = 1.29(Ft/s) Travel time = 1.94 mm. TC = 6.14 mm. Adding area flow to street Rainfall intensity (I) = 6.923(In/Hr) for a 100.0 year storm 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 [COMMERCIAL area type I (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Rainfall intensity = 6.923(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.850 CA = 0.527 Subarea runoff = 2.977(CFS) for 0.520(Ac.) Total runoff = 3.648(CFS) Total area = 0. 620 (Ac . Street flow at end of street = 3.648(CFS) Half street flow at end of street = 3.648(CFS) Depth of flow = 0.371(Ft.), Average velocity = 1.452(Ft/s) Flow width (from curb towards crown)= 12.414(Ft.) Process from Point/Station 110.000 to Point/Station 110.000 CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.620(Ac.) Runoff from this stream = 3.648(CFS) Time of concentration = 6.14 mm. Rainfall intensity = 6.923(In/Hr) Process from Point/Station 120.000 to Point/Station 130.000 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 [COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Initial subarea total flow distance = 50.000(Ft.) Highest elevation = 397.780(Ft.) Lowest elevation = 397.460(Ft.) Elevation difference = 0.320(Ft.) Slope = 0.640 % 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 Office Professional In Accordance With Table 3-2 Initial Area Time of Concentration = 4.20 minutes (for slope value of 0.50 %) Calculated TC of 4.200 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.904(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.850 Subarea runoff = 0.605(CFS) Total initial stream area = 0.090 (Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.+++++++ Process from Point/Station 130.000 to Point/Station 140.000 r IMPROVED CHANNEL TRAVEL TIME Upstream point elevation = 397.460(Ft.) Downstream point elevation = 393.600(Ft.) Channel length thru subarea = 311.000(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z' of left channel bank = 50.000 Slope or 'Z' of right channel bank = 50.000 Estimated mean flow rate at midpoint of channel = 4.231(CFS) Manning's 'N' = 0.015 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 4.231(CFS) Depth of flow = 0.191(Ft.), Average velocity = 2.309(Ft/s) Channel flow top width = 19.143(Ft.) Flow Velocity = 2.31(Ft/s) Travel time = 2.24 mm. Time of concentration = 6.44 mm. Critical depth = 0.213(Ft.) Adding area flow to channel Rainfall intensity (I) = 6.710(In/Hr) for a 100.0 year storm 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 [COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Rainfall intensity = 6.710(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.850 CA = 1.156 Subarea runoff = 7.153(CFS) for 1.270(Ac.) Total runoff = 7.757(CFS) Total area = 1.360 (Ac.) Depth of flow = 0.240(Ft.), Average velocity = 2.687(Ft/s) Critical depth = 0.271(Ft.) Process from Point/Station 140.000 to Point/Station 140.000 CONFLUENCE OF MINOR STREAMS Along Main Stream number: 1 in normal stream number 2 Stream flow area = 1.360 (Ac.) Runoff from this stream = 7.757(CFS) Time of concentration = 6.44 mm. Rainfall intensity = 6.710(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (mm) (In/Hr) 1 3.648 6.14 6.923 2 7.757 6.44 6.710 Qmax(1) = 1.000 * 1.000 * 3.648) + 1.000 * 0.953 * 7.757) + = 11.040 Qmax(2) = 0.969 * 1.000 * 3.648) + 1.000 * 1.000 * 7.757) + = 11.294 Total of 2 streams to confluence: Flow rates before confluence point: 3.648 7.757 Maximum flow rates at confluence using above data: 11.040 11.294 Area of streams before confluence: 0.620 1.360 Results of confluence: Total flow rate = 11.294(CFS) Time of concentration = 6.445 mm. Effective stream area after confluence = 1.980(Ac.) Process from Point/Station 140.000 to Point/Station 180.200 PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 387.800(Ft.) Downstream point/station elevation = 385.000(Ft.) Pipe length = 66.00(Ft.) Slope = 0.0424 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 11.294(CFS) Given pipe size = 18.00(In.) Calculated individual pipe flow = 11.294(CFS) Normal flow depth in pipe = 9.23(In.) Flow top width inside pipe = 17.99(In.) Critical Depth = 15.40(m.) Pipe flow velocity = 12.38(Ft/s) Travel time through pipe = 0.09 mm. Time of concentration (TC) = 6.53 mm. End of computations, total study area = 1.980 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c)1991-2006 Version 7.7 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 03/11/14 ------------------------------------------------------------------------ LOT 17 CARLSBAD RACEWAY 131020SF3 PROPOSED HYDROLOGY - BASIN C ********* Hydrology Study Control Information ********** Program License Serial Number 6218 Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 3.000 24 hour precipitation(inches) = 5.500 P6/P24 = 54.5% San Diego hydrology manual 'C' values used +++++++++++++++++++++++++++++++++-1-++++++++++++++++++++++++++++++++++++ Process from Point/Station 150.000 to Point/Station 160.000 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 [COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Initial subarea total flow distance = 50.000(Ft.) Highest elevation = 398.000(Ft.) Lowest elevation = 393.800(Ft.) Elevation difference = 4.200(Ft.) Slope = 8.400 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 8.40 %, in a development type of Office Professional In Accordance With Table 3-2 Initial Area Time of Concentration = 2.20 minutes (for slope value of 10.00 %) Calculated TC of 2.200 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.904(In/Hr) for a 10.0.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.850 Subarea runoff = 0.464(CFS) Total initial stream area = 0.069(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 160.000 to Point/Station 160.100 PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 391.800(Ft.) Downstream point/station elevation = 391.600(Ft.) Pipe length = 25.82(Ft.) Slope = 0.0077 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.464(CFS) Given pipe size = 6.00(In.) Calculated individual pipe flow = 0.464(CFS) Normal flow depth in pipe = 4.62 (In.) Flow top width inside pipe = 5.05(In.) Critical Depth = 4.17(In.) Pipe flow velocity = 2.86(Ft/s) Travel time through pipe = 0.15 mm. Time of concentration (TC) = 2.35 mm. Process from Point/Station 160.100 to Point/Station 160.200 r PIPEFLOW TRAVEL TIME (User specified size) Upstream point/station elevation = 391.600(Ft.) Downstream point/station elevation = 389.400(Ft.) Pipe length = 236.70(Ft.) Slope = 0.0093 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.464(CFS) Given pipe size = 6.00(In.) Calculated individual pipe flow = 0.464(CFS) Normal flow depth in pipe = 4.28 (In.) Flow top width inside pipe = 5.43(In.) Critical Depth = 4.17(In.) Pipe flow velocity = 3.10(Ft/s) Travel time through pipe = 1.27 mm. Time of concentration (TC) = 3.62 mm. Process from Point/Station 160.200 to Point/Station 180.100 PIPEFLOW TRAVEL TIME (User specified size) Upstream point/station elevation = 389.400(Ft.) Downstream point/station elevation = 388.800(Ft.) Pipe length = 74.70(Ft.) Slope = 0.0080 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.464(CFS) Given pipe size = 6.00(In.) Calculated individual pipe flow = 0.464(CFS) Normal flow depth in pipe = 4.55(In.) Flow top width inside pipe = 5.14(In.) Critical Depth = 4.17.(In.) Pipe flow velocity = 2.91(Ft/s) Travel time through pipe = 0.43 mm. Time of concentration (TC) = 4.05 mm. Process from Point/Station 180.100 to Point/Station 180.100 CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.069(Ac.) Runoff from this stream = 0.464(CFS) Time of concentration = 4.05 mm. Rainfall intensity = 7.904(In/Hr) Process from Point/Station 170.000 to Point/Station 180.000 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 [COMMERCIAL area type (Office Professional Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Initial subarea total flow distance = 50.000(Ft.) Highest elevation = 397.500(Ft.) Lowest elevation = 393.800(Ft.) Elevation difference = 3.700(Ft.) Slope = 7.400 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 90.00 (Ft) for the top area slope value of 7.40 %, in a development type of Office Professional In Accordance With Table 3-2 Initial Area Time of Concentration = 2.60 minutes (for slope value of 5.00 %) Calculated TC of 2.600 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.904(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.850 Subarea runoff = 0.464(CFS) Total initial stream area = 0.069(Ac.) Process from Point/Station 180.000 to Point/Station 180.100 PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 392.300(Ft.) Downstream point/station elevation = 388.800(Ft.) Pipe length = 73.00(Ft.) Slope = 0.0479 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.464(CFS) Given pipe size = 6.00(In.) Calculated individual pipe flow = 0.464(CFS) Normal flow depth in pipe = 2.55(In.) Flow top width inside pipe = 5.93(In.) Critical Depth = 4.17(In.) Pipe flow velocity = 5.82(Ft/s) Travel time through pipe = 0.21 mm. Time of concentration (TC) = 2.81 mm. +++++++++++++++++++++++++++++++++++++++++++4-++++++++++++++++++++++++++ Process from Point/Station 180.100 to Point/Station 180.100 CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.069(Ac.) Runoff from this stream = 0.464(CFS) Time of concentration = 2.81 mm. Rainfall intensity = 7.904(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (mm) (In/Hr) 1 0.464 4.05 7.904 2 0.464 2.81 7.904 Qmax(1) = 1.000 * 1.000 * 0.464) + 1.000 * 1.000 * 0.464) + = 0.927 Qmax(2) = 1.000 * 0.693 * 0.464) + 1.000 * 1.000 * 0.464) + = 0.785 Total of 2 streams to confluence: Flow rates before confluence point: 0.464 0.464 Maximum flow rates at confluence using above data: 0.927 0.785 Area of streams before confluence: 0.069 0.069 Results of confluence: Total flow rate = 0.927(CFS) Time of concentration = 4.053 mm. Effective stream area after confluence = 0.138(Ac.) Process from Point/Station 180.100 to Point/Station 180.200 PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 388.800(Ft.) Downstream point/station elevation = 385.000(Ft.) Pipe length = 59.00(Ft.) Slope = 0.0644 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.927(CFS) Given pipe size = 12.00(In.) Calculated individual pipe flow = 0.927(CFS) Normal flow depth in pipe = 2.59(Iri.) Flow top width inside pipe = 9.88(In.) Critical Depth = 4.85(In.) Pipe flow velocity = 7.41(Ft/s) Travel time through pipe = 0.13 mm. Time of concentration (TC) = 4.19 mm. End of computations, total study area = 0.138 (Ac.) APPENDIX C County of San Diego Hydrology Manual References San Diego County Hydrology Manual Section: 3 Date: June 2003 Page: 6of26 Table 3-1 RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use I Runoff Coefficient "C" Soil Type NRCS Elements County Elements % IMPER. A B C D Undisturbed Natural Terrain (Natural) Low Density Residential (LDR) Low Density Residential (LDR) Low Density Residential (LDR) Medium Density Residential (MDR) Medium Density Residential (MDR) Medium Density Residential (MDR) Medium Density Residential (MDR) High Density Residential (Hl)R) High Density Residential (HDR) Commercial/Industrial (N. Com) Commercial/Industrial (G. Com) Commercial/Industrial (O.P. Corn) Commercial/Industrial (Limited I.) - Commercial/Industrial (General I.) Permanent Open Space 0 0.20 0.25 0.30 0.35 Residential, 1.0 DU/A or less 10 0.27 0.32 0.36 0.41 Residential, 2.0 DU/A or less 20 0.34 0.38 0.42 0.46 Residential, 2.9 DU/A or less 25 0.38 0.41 0.45 0.49 Residential, 4.3 DU/A or less 30 0.41 0.45 0.48 0.52 Residential, 7.3 DU/A or less 40 0.48 0.51 0.54 0.57 Residential, 10.9 DU/A or less 45 0.52 0.54 0.57 0.60 Residential, 14.5 DU/A or less 50 0.55 0.58 0.60 0.63 Residential, 24.0 DU/A or less 65 0.66 0.67 0.69 0.71 Residential, 43.0 DU/A or less 80 0.76 0.77 0.78 0.79 Neighborhood Commercial 80 0.76 0.77 0.78 0.79 General Commercial 85 0.80 0.80 0.81 0.82 Office Professional/Commercial 90 0.83 0.84 0.84 0.85 Limited Industrial 90 0.83 0.84 0.84 0.85 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 runoff coefficient as described in Section 3.1.2 (representing the pervious runoff coefficient, Cp, for the soil type), or for areas that will remain undisturbed in perpetuity. Justification must be given that the area will remain natural forever (e.g., the area is located in Cleveland National Forest). DU/A = dwelling units per acre NRCS = National Resources Conservation Service 3-6 San Diego County Hydrology Manual Date: June 2003 Section: 3 Page: 12of26 Note that the Initial Time of Concentration should be reflective of the general land-use at the upstream end of a drainage basin. A single lot with an area of two or less acres does not have a significant effect where the drainage basin area is 20 to 600 acres. Table 3-2 provides limits of the length (Maximum Length (LM)) of sheet flow to be used in hydrology studies. Initial Tj values based on average C values for the Land Use Element are also included. These values can be used in planning and design applications as described below. Exceptions may be approved by the "Regulating Agency" when submitted with a detailed study. Table 3-2 MAXIMUM OVERLAND FLOW LENGTH (LM) & INITIAL TIME OF CONVNTRATION (T) Element* DU/ Acre .5% 1% 2% 3% 5% 10% LM Ti LM Ti LM Ti LM Ti LM TiLM T Natural 50 13.2 70 12.5 85 10.9 100 10.3 100 8.7 100 6.9 LDR 1 50 12.2 70 11.5 85 10.0 100 9.5 100 8.0 100 6.4 LDR 2 50 11.3 70 10.5 1 85 9.2 100 8.8 100 7.4 100 5.8 LDR 2.9 50 10.7 70 10.0 85 8.8 95 8.1 100 7.0 100 5.6 MDR 4.3 50 10.2 70 9.6 80 8.1 1 95 7.8 1 100 6.7 1 100 5.3 MDR 7.3 50 9.2 65 8.4 80 7.41 95 7.0 100 6.0 100 4.8 MDR 10.9 50 8.7 65 7.9 80 6.9 90 6.4 100 5.7 100 4.5 MDR 14.5 50 8.2 65 7.4 80 6.5 90 6.0 100 5.4 100 4.3 HDR 24 50 6.7 65 6.1 75 5.1 901 4.9 95 4.3 100 3.5 HDR 43 501. 5.3 65 4.7 75 4.0 85 3.8 95 3.41 100 2.7 N. Corn 50 5.3 60 4.5 75 4.0 85 3.8 1 . 95 3.4 100 2.7 G. Corn 50 4.7 60 4.1 75 3.6 85 3.4 90 2.9 100 2.4 O.P./Corn 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 Limited!. 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 General 1. 50 3.7 60 3.2 70 2.7 80 2.6 90 2.3 1 100 1 1.9 *See Table 3-1 for more detailed description 3-12 EQUATION E /11.9L3 O.3OS Feet Ic = It EaE ) 5000 Ic = Time of concentration (hours) I = Watercourse Distance (mires) ..4000 áE = Change in elevation along effective slope line (See Figure 3-5)(feet) 1-3000 Ic I-. Hours Minutes 2000 4 240 —1000 900 800 2 120 .T0 60\ 100 I _500\\ 80 —400 \ 70 1__60 —300 50 —200 S 40 I Miles Feet —30 —100 4000 20 300 16 -50 5 0. 14 -40 2000 12 1800 1600 10 -30 1400 \ 9 1200 8 -20 1000 7 900 800 & 700 600 5 -10 500 4 400 3 300 —5 I 1-200 AE L Tc SOURCE: California Division of Highways (1941) and l<Irpich (1940) Nomograph for Determination of Time of Concentration (Tc) or Travel Time (TI) for Natural Vtersheds I FIGURE 3..4 Watershed Divide Design Point L Watershed Divide Area "A" Effective Slope Line Stream Profile Area "B' Design Point (Watershed Outlet) L .1 Area "A" = Area "B" SOURCE: California Division of Highways (1941) and kirplch (1940) FIGURE Computation of Effective Slope for Natural Watersheds 35 VA•!!4VMMFIAMAN WMIUI WY tAUIi _ W1!JIWA_ WA - 1h VAUII&M•!A_ h - Ii LI A•VAU I A - - I NOWSWA All 7 ___ AN - ___ WIN 6qmm - lU WP 4UlI W - III,MIM FAR 4,101 FAMOVIA !__ IIA PA•lUi IWUI 0 A S IN 9 1 WA hW.,A E IN 0 FIGURE Gutter and Roadway Discharge - Velocity Chart 3-6 SLOPE in feet per foot-s a a' a QQOO4 - A a . ----.,---., C3 8 HYDRAULIC RADIUS in feet - R - ------------------------------------I-.. - ID C) -a 'C) u C2 Q 01CC) C) CA w -I ' 1 0 \ / 46 7 \ /.b -o co Pr \ / Cn \/ 9 /\ \ / VELOCITY in feet per second - V a p p pp .3 (.1 . UI 0) C)- v- in - 0) C) CD 0 a a ROUGHNESS Coefficient - n 0 p a ZD County of San Diego co Hydrology Manual Soil Hydrologic Group Legend — Major Roads Incorporated City Bdy HYDROLOGIC SOIL GROUP Hydrologic Group Undefined - Hydrologic Group A Hydrologic Group B Hydrologic Group C Hydrologic Group D No Soil Data GIS gIGJS THIS MAP IS PROVIDED WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Copyright SanGIS. All Rights Reserved. This product may contain information from the SANDAG Regional Information System which cannot be reproduced without the written permission of SANDAG. This product may contain information which has been reproduced with permission granted by Thomas Brothers Maps. 11 7'30'0'W 11T150W 11 7'0'0"W 116°450W 11630'0W 116'1 5'0'VV --------------------------- VA ra IF Or IN CEANSIDE —j ENC!NITAS DEL MAR 0 C-) CD c3) .'dJUiJ 14g ( _ CARLSBAD 1i r 1! • jr I,r C A .fl! • - L f,/k( i ?' F I w - ill 1 - /;.-•.- r1' I. I, - \SAN DIEc;o P.1P Ic$4iIIIIl;t1!I1 Jrtx '(rill i 11T300W 117'150W 11T00"W 116°450W 116°30'OW 116°150W H IMPERIAL BEACH yLJSA I -. - b ION. (:ITY 01 Or ro VISTA I £ I I I I Note: Soil Data Source USDAINRCS SSURGO Soils 2007 z 0 0 A 31.50 3MiIes WI 2/ OPEN SPA & MAP 1V01 I09 LEGEND Og POINT ID .NO OF PL US iôO.2 ________________________________________ BS/N . 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DIRECTION OF FLOW (3 EXISTING HYDROLOGY EXHIBI T B -0/ CONSULT NTS 0' 60' 30' SCALE: 1" = 30' 2710 Loker Ave West Civil Engineering Suite 100 Planning Carlsbad, California 92010 Processing 760-931-7700 Surveying Fax: 760-931-8680 oday©odayconsultants.com [] I: \131020\Stormwa ter—Site \Drainage\1320—Hydro Exist. dwg Jul 14, 2014 2:27pm Xrefs: 1 32OAMAP; 1320A07D; 1 32OAUTL; 1 32OAPIP—TXT; 1 320P1P; 1 3201P01