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HomeMy WebLinkAboutMS 01-07; CHARLES JACOBS PROPERTY; DRAINAGE STUDY FOR THE CREST ESTATES; 2002-05-08DRAINAGE STUDY RECEIVED SEP 05.2002 FOR ENGINEERING DEPARTMENT THE CREST ESTATES DECEMBER 7, 2000 REVISED: MAY 7, 2001 REVISED: OCTOBER 2, 2001 REVISED: MAY 8, 2002 J.N. 00-1031/5 OVLOF lq- SIR co \\55187 Exp. 6130104 Li - IJ c,vn.../JJ (AA V JtrrfP StTrohminc RCE NO. C55187 EXP. 6/30/2004 PREPARED BY: O'DAY CONSULTANTS 5900 PASTEUR COURT, SUITE 100 CARLSBAD, CA 92008 (760) 931-7700 ms ovo'7 TABLE OF CONTENTS SECTION 1 INTRODUCTION Purpose of Study......................................1 Conclusions...........................................1 Scope...................................................1 STUDY AREA SoilGroups ............................................1 LandUses .............................................2 HYDROLOGY AND HYDRAULICS Rational Method Description...........................2 ProgramProcess .......................................3 Inlet Sizing Calculation Formulas .....................4 SECTION 2 VicinityMap..........................................5 SoilMap ............................................. ..6 Runoff Coefficients ...................................7 Isopluvial Maps .......................................8 10-Year, 6-Hour ........................................ 8 10-Year, 24-Hour ...................................... 9 Intensity Duration Chart .............................10 Urban areas time of flow curves ......................11 SECTION 3 Summary of existing & proposed calculations ........... 12 RATIONAL METHOD COMPUTER RUNS Existing Condition Hydrology Proposed Condition Hydrology and Hydraulics MAP POCKETS Existing Condition Drainage Map Proposed Condition Drainage Map G:\jobs\jps.com\00 1031 \drainage\drainage study cover.doc DRAINAGE STUDY FOR THE CREST ESTATES INTRODUCTION Purpose of Study This drainage study determines the required drainage facilities for the ultimate development of the Seacrest Ridge property. Conclusions In the existing condition, this site delivers 1.68 cubic feet per second (cfs) of runoff water to Ridgecrest Drive and 1.24 cfs to Seacrest Drive. In the proposed condition, these amounts will decrease to 1.64 and 1.23 cfs respectively. Scope This study analyses the 10-year flow for both the existing and the drainage proposed condition for Seacrest Ridge. The existing condition is analyzed to study the existing flows and routing that are currently present. The proposed condition is analyzed to determine that existing drainage structures are adequate to handle future runoff. This analysis takes into account the future development of the four proposed lots on the property. STUDY AREA The location of The Crest Estates is shown on the vicinity map in this report. The proposed condition of this site is the development for single-family housing on the 1.38 acre site. The existing condition of this property is unconstrained developed land. The topography of the property is relatively flat with approximately 20 feet of fall across the entire site. Soil Groups The County/USGS Soil Map indicates that the property consists of type C soils. Therefore, soil type C is used in this report for all of the calculations. 1 Land Uses The Crest Estates lies in the middle of a fully developed subdivision in the City of Carlsbad. Single-family homes adjoin the property to the East and West with residential streets fronting the property to the North and South. HYDROLOGY & HYDRAULICS The rational method for storm water runoff was used for this study according to the County of San Diego Hydrology Manual. The CivilCADD Computer Program was used to model the basins and is described in this report. Rational Method Description The rational method was described in the 1985 San Diego County Flood Control/Hydrology manual, was used to generate surface runoff flows, which were then used to size the drainage facilities. The basic equation: Q = CIA C = runoff coefficient (varies with surface) I = intensity (varies with time of concentration) A = Area in acres The design storm for this project is the 10-year event; the corresponding 6-hour rainfall amount is 1.6 inches. A computer program developed by CivilCADD/Civildesign Engineering Software, © 1993 Version 3.2, is used to determine the times of concentration and corresponding intensities and flows for the various hydrological processes performed in this model. This program also determines the street flow and pipeflow characteristics for each segment modeled. Program Process The rational method program is a computer aided design program where the user develops a node link model of the watershed. The node link model is created by developing independent node link models of each interior watershed and linking these sub- models together at confluence points. 2 The program has the capability of performing calculations for eleven different hydrologic and hydraulic processes. These processes are assigned and printed in the output. They are as follows: Initial sub-area input, top of stream Street flow through sub-area. Includes sub-area runoff. Addition of runoff from sub-area to stream. Street inlet and parallel Street and pipef low and area. Pipeflow travel time (program estimated pipe size) Pipeflow travel time (user specified pipe size). Improved channel time - Area add option. Irregular channel travel time - Area add option. User specified entry of data at a point. Cdnfluence at downstream point in current stream. Confluence of main streams. G:\jobs\jps.com\001031\drainage\drainage study text.doc 3 SECTION 2 SOIL MAP San Diego County Soils Interpretation Study HYDROLOGIC SOIL GROUPS - RUNOFF POTENTIAL Coefficient, C Soil Group (1) A B C 0 .40 .45 .1+5 .30 .70 • 45 .50 .50 35 .75 .55 .70 .65 145 .85 TABLE 2 RUNOFF COEFFICIENTS (RATIoML METHOD) DEVELOPED AREAS (URBAN) Land Use Residential: Single Family Multi-Units Mobile homes Rural (lots greater than 1/2 acre) Commercial(Z) 80% Impervious Industrial (2) 90% Impervious .80 .85 90 .95 NOTES: Soil Group mans are available at the offices of the Department of Public Works. (2)Where actual conditions deviate significantly from the tabulated impervious- ness values of 80% or 90%, the values given for coefficient C. may be revised by multiplying 80% or 90% by the ratio of actual imperviousness to the tabulated imperviousness. However, in no case shall the final coefficient be less than 0.50. For example: Consider coirunercial property on 0 soil ,group. Actual imperviousness - 50% Tabulated imperviousness 80% Revised c . x0.85 a 053 80 IV-A-9 APPENDIX TX-8 Rev. 5/81 COUNTY OF SAN DIEGO DEPARTMENT OF SANITATION & FLOOD CONTROL 451 10-YEAR 6-1,10UR PRECIPITATION "16-' S5PLUVIfLS OF 10-YFJU 0-10 PUEC!PITMIO11 i III JEWPIS OF All INCH 30' 15' 330 45 1 prop 1,. I U.S. DEPARTMEJh' NATIONAL OCEANIC AND AI WO SPECIAL STUDIES ORANCII, OFEICL OF I VLP 30' 118° 45' 30' 15' ))70 1151 301 . 15' 116' COUNTY OF SAN DIEGO . I FLOOD CONTROL DEPARTMENT OF SANITATION & 10-YEAR 24-1-10UR PRECIPITATION 201 ISOPLUVIILS F 10-YEAR 24-HOUR - ________ - PECIPITATWJ RI EIThIS OF AN RCH IV )Sic, V40 Cc 301 SAN CL MENTE ju 35 - - ( : uu -25 339 c \, 40 .) .. •6 1 ,25 70 - 45'.. ______ _ _____ ___ 1wu, I, • / SPCIA1. STUDIES URANCII, 0 Fj'I CF OFIYUII.OY. NATIONAL WEATHER SRVICJ YSIPP 302. 301_ tj 1)89 451 30' 15' I170 11 51 30' 15' -. 110 0 1 -u 1 (0 -a. -U 1. rP . A rP 6 5 0 p5.0 4.0 3.0 .. 2. 5 3. tV' Co INTENSITYrDUMT!ON D1S1GI4 CIArT S. Directions for Application: From precipitation naps determine 6 hr. and 24 hr. amounts for the selected frequency. These maps are printed in the County Hydrology Manual (10, 50 and 100 yr. maps Included in the Design and Procedure Manual). Adjust 6 hr. precipitation (if necessary) so that it is within the range of 45% to 65% of the 24 hr. precipitation. (Not applicable to Desert) Plot 6 hr. precipitation on the right side of the chart. Draw a line through the point parallel to the plotted lines. This line is the Intensity-duration curve for the location being analyzed. Application Form: 0) Selected Frequency /0 _yr. 1) P6 Jtn., P 24= p P24 2) Adjusted *6... J.p in. 3) t = mm. 4) I = in/hr. -- 1.0 *Not Applicable to Desert Region 15 20 30 40 50 1 2 3 4 5 6 -____ Miniitnc Hours Revised 1/85 ADIcwnTY YT_A SECTION 3 SUMMARY OF DRAINAGE CALCS EXISTING -10 YEAR BASIN "A" TOTAL RUNOFF = 1.68 CFS PROPOSED -10 YEAR BASIN "C" TOTAL RUNOFF = 1.64 CFS BASIN "B" TOTAL RUNOFF = 1.24 CFS BASIN "D" TOTAL RUNOFF = 1.23 CFS San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c) 1993 Version 3.2 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 05/07/02 ----------------------------------------------------------------------- Charles Jacobs Property. Basin "A" (Existing Conditions) File-Char].l.out ********* Hydrology Study Control Information O'Day Consultants, San Deigo, California - S/N 10125 ------------------------------------------------------------------------ Rational hydrology study storm event year is 10.0 Map data precipitation entered: 6 hour, precipitation(inches) = 1.600 24 hour precipitation(inches) = 2.800 Adjusted 6 hour precipitation (inches) = 1.600 P6/P24 = 57.1% San Diego hydrology manual 'C' values used Runoff coefficients by rational method Process from Point/Station 1000.000 to Point/Station 1001.000 '"' INITIAL AREA EVALUATION **** User specified 'C' value of 0.950 given for subarea Initial subarea flow distance = 40.00(Ft.) Highest elevation = 340.00(Ft.) Lowest elevation = 338.00(Ft.) Elevation difference = 2.00(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 1.00 mm. TC = [1.8*(1.1_C)*distanceA.5)/(% slope"(1/3)] TC= [1.8*(1.1_0.9500)*(40.00A.5)/( 5.00'(1/3)]= 1 .00 Setting time of concentration to 5 minutes Rainfall intensity (I) = 4.216 for a 10.0 year storm Effective runoff coefficient. used for area (Q=KCIA) is C = 0.950 Subarea runoff = 0.140(CFS) Total initial stream area = 0.035 (Ac.) Process from Point/Station 1001.000 to Point/Station 1002.000 IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 324.00(Ft.) Downstream point elevation = 314.00(Ft.) Channel length thru subarea = 115.00(Ft.) Channel base width = 50.000(Ft.) Slope or 'Z' of left channel bank = 25.000 Slope or 'Z' of right channel bank = 25.000 Estimated mean flow rate at midpoint of channel = 0.841(CFS) Manning's 'N' = 0.020 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.841(CFS) Depth of flow = 0.014(Ft.), Average velocity = 1.237(Ft/s) Channel flow top width = 50.675(Ft.) Flow Velocity = 1.24 (Ft/s) Travel time = 1.55 mm. Time of concentration = 6.55 mm. Critical depth = 0.021(Ft.) Adding area flow to channel User specified 'C' value of 0.540 given for subarea Rainfall intensity = 3.542(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.540 Subarea runoff = 0.669(CFS) for 0.350(Ac.) Total runoff = 0.810(CFS) Total area = 0.39(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1002.000 to Point/Station 1003.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 314.000(Ft.) End of street segment elevation = 30.8.200(Ft.) Length of street segment = 170.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 16.000(Ft.) Distance from crown to crossfall grade break = 14.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 9.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(m.) Manning's N in gutter = 0.0130 Manning's N from gutter to grade break = 0.0130 Manning's N from grade break to crown = 0.0130 Estimated mean flow rate at midpoint of street = 1.346(CFS) Depth of flow = 0.208(Ft.), Average velocity = 3.464(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 5.633(Ft.) Flow velocity = 3.46(Ft/s) Travel time = 0.82 min. TC = 7.37 mm. Adding area flow to street User specified 'C' value of 0.520 given for subarea Rainfall intensity = 3.283(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.520 Subarea runoff = 0.871(CFS) for 0.510(Ac.) Total runoff = 1.680(CFS) Total area = 0.90(Ac.) Street flow at end of street = 1.680(CFS) Half street flow at end of street = 1.680(CFS) Depth of flow = 0.220(Ft.), Average velocity = 3.632(Ft/s) Flow width (from curb towards crown)= 6.256(Ft.) End of computations, total study area = 0.90 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c) 1993 Version 3.2 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 05/07/02 ------------------------------------------------------------------------ Charles Jacobs Property. Basin "B" (Existing Condition) File-Char12.out ------------------------------------------------------------------------ ********* Hydrology Study Control Information ------------------------------------------------------------------------ O'Day Consultants, San Deigo, California - SIN 10125 ------------------------------------------------------------------------ Rational hydrology study storm event year is 10.0 Map data precipitation entered: 6 hour, precipitation (inches) = 1.600 24 hour precipitation (inches) = 2.800 Adjusted 6 hour precipitation (inches) = 1.600 P6/P24 = 57.1% San Diego hydrology manual 'C' values used Runoff coefficients by rational method +++++ +++ + +++++ +++++++ +++++++++++ ++++++++++ + +++++++ +++++++++++ ++ ++++ + ++ Process from Point/Station 2000.000 to Point/Station 2001.000 INITIAL AREA EVALUATION User specified 'C' value of 0.950 given for subarea Initial subarea flow distance = 50.00(Ft.) Highest elevation = 340.00(Ft.) Lowest elevation = 338.00(Ft.) Elevation difference = 2.00(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 1.20 mm. TC = [1.8*(1.1_C)*distance".5)/C% slopeA(1/3)] TC= [1.8*(1.1_0.9500)*(50.00%.5)/( 4.00A(1/3)1= 1.20 Setting time of concentration to 5 minutes Rainfall intensity (I) = 4.216 for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.950 Subarea runoff = 0.160(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 2001.000 to Point/Station 2002.000 IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 327.50(Ft.) Downstream point elevation = 308.00(Ft.) Channel length thru subarea = 170.00(Ft.) Channel base width = 75.000(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 = 1.342(CFS) Manning's 'N' = 0.020 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 1.342(CFS) Depth of flow = 0.013(Ft.), Average velocity = 1.376(Ft/s) Channel flow top width = 76.289(Ft.) Flow Velocity = 1.38(Ft/s) Travel time = 2.06 mm. Time of concentration = 7.06 mm. Critical depth = 0.021(Ft.) Adding area flow to channel User specified 'C' value of 0.540 given for subarea Rainfall intensity = 3.375(In/}Ir) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.540 Subarea runoff = 1.075(CFS) for 0.590(Ac.) Total runoff = 1.235(CFS) Total area = 0.63(Ac.) End of computations, total study area = 0.63 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c) 1993 Version 3.2 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 05/07/02 ------------------------------------------------------------------------ Charles Jacobs Property. Basin "C" (Proposed Conditions) File-draini . out ------------------------------------------------------------------------ Hydrology Study Control Information ------------------------------------------------------------------------ O'Day Consultants, San Deigo, California - S/N 10125 ------------------------------------------------------------------------ Rational hydrology study storm event year is 10.0 Map data precipitation entered: 6 hour, precipitation(inches) = 1.600 24 hour precipitation(inches) = 2.800 Adjusted 6 hour precipitation (inches) = 1.600 P6/P24 = 57.1% San Diego hydrology manual 'C' values used Runoff coefficients by rational method ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 113.000 to Point/Station 114.000 INITIAL AREA EVALUATION **** User specified 'C' value of 0.950 given for subarea Initial subarea flow distance = 20.00(Ft.) Highest elevation = 330.00(Ft.) Lowest elevation = 328.00(Ft.) Elevation difference = 2.00(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 0.56 mm. TC = (1.8*(1.1_C)*distance.5)/(% slopeA(1/3)) TC=[1.8*(1.1_0.9500)*(20.00.5)/(10.00#%(1/3))= 0.56 Setting time of concentration to 5 minutes Rainfall intensity (I) = 4.216 for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.950 Subarea runoff = 0.056(CFS) Total initial stream area = 0.014 (Ac.) Process from Point/Station 114.000 to Point/Station 115.000 '' IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 317.00(Ft.) Downstream point elevation = 314.90(Ft.) Channel length thru subarea = 240.00(Ft.) Channel base width = 0.500(Ft.) Slope or 'Z' of left channel bank = 2.000 Slope or 'Z' of right channel bank = 2.000 Estimated mean flow rate at midpoint of channel 0.737(CFS) Manning's 'N' = 0.060 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.737(CFS) Depth of flow = 0.501(Ft.), Average velocity = 0.980(Ft/s) !!Warning: Water is above left or right bank elevations Channel flow top width = 2.500(Ft.) Flow Velocity = 0.98 (Ft/s) Travel time = 4.08 mm. Time of concentration = 9.08 mm. Critical depth = 0.283(Ft.) ERROR - Channel depth exceeds maximum allowable depth Adding area flow to channel User specified 'C' value of 0.480 given for subarea Rainfall intensity = 2.868(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.480 Subarea runoff = 0.468(CFS) for 0.340(Ac.) Total runoff = 0.524(CFS) Total area = 0.35 (Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 115.000 to Point/Station 116.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 314.900(Ft.) End of street segment elevation = 308.200(Ft.) Length of street segment = 190.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 16.000(Ft.) Distance from crown to crossfall grade break = 14.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 9.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(In.) Manning's N in gutter = 0.0130 Manning's N from gutter to grade break = 0.0130 Manning's N from grade break to crown = 0.0130 Estimated mean flow rate at midpoint of street = 0.643(CFS) Depth of flow = 0.169(Ft.), Average velocity = 3.061(Ft/s) Streetfiow hydraulics at midpoint of street travel: Halfstreet flow width = 3.724(Ft.) Flow velocity = 3.06(Ft/s) Travel time = 1.03 mm. TC = 10.12 mm. Adding area flow to street User specified 'C' value of 0.800 given for subarea Rainfall intensity = 2.675(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.800 Subarea runoff = 0.342(CFS) for 0.160(Ac.) Total runoff = 0.867(CFS) Total area 0.51 (Ac.) Street flow at end of street = 0.867(CFS) Half street flow at end of street = 0.867(CFS) Depth of flow = 0.184(Ft.), Average velocity = 3.218(Ft/s) Flow width (from curb towards crown)= 4.451(Ft.) +++++++++++++++++++++++++++++++++++++++++++++++.++++++++++++++++++++++ Process from Point/Station 116.000 to Point/Station 116.000 **** CONFLUENCE OF MINOR STREAMS Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.514(Ac.) Runoff from this stream = 0.867(CFS) Time of concentration = 10.12 mm. Rainfall intensity = 2.675(In/Hr) Process from Point/Station 109.000 to Point/Station 110.000 INITIAL AREA EVALUATION User specified 'C' value of 0.950 given for subarea Initial subarea flow distance = 20.00(Ft.) Highest elevatiàn = 339.50(Ft.) Lowest elevation = 337.50(Ft.) Elevation difference = 2.00(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 0.56 mm. TC = (1.8*(1.1_C)*distanceA.5)/(% slope"(1/3)) TC = [1.8*(1.1_0.9500)*( 20.00.5)/( 10.00"(1/3)1= 0.56 Setting time of concentration to 5 minutes Rainfall intensity (I) = 4.216 for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.950 Subarea runoff = 0.056(CFS) Total initial stream area = 0.014 (Ac.) Process from Point/Station 110.000 to Point/Station 111.000 IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 326.50(Ft.) Downstream point elevation = 324.70(Ft.) Channel length thru subarea = 190.00(Ft.) Channel base width = 0.500(Ft.) Slope or 'Z' of left channel bank = 2.000 Slope or 'Z' of right channel bank = 2.000 Estimated mean flow rate at midpoint of channel = 0.697(CFS) Manning's 'N' = 0.060 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.697(CFS) Depth of flow = 0.480(Ft.), Average velocity = 0.994(Ft/s) Channel flow top width = 2.420(Ft.) Flow Velocity = 0.99(Ft/s) Travel time = 3.19 mm. Time of concentration = 8.19 mm. Critical depth = 0.275(Ft.) Adding area flow to channel User specified 'C' value of 0.480 given for subarea Rainfall intensity = 3.067(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.480 Subarea runoff = 0.471(CFS) for 0.320 (Ac.) Total runoff = 0.527(CFS) Total area = 0.33(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++..++++++ Process from Point/Station 111.000 to Point/Station 112.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 324.70(Ft.) Downstream point elevation = 315.80(Ft.) Channel length thru subarea = 120.00(Ft.) Channel base width = 20.000(Ft.) Slope or 'Z' of left channel bank = 25.000 Slope or 'Z' of right channel bank = 25.000 Estimated mean flow rate at midpoint of channel = 0.614(CFS) Manning's 'N' = 0.015 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.614(CFS) Depth of flow = 0.017(Ft.), Average velocity = 1.763(Ft/s) Channel flow top width = 20.853(Ft.) Flow Velocity = 1.76(Ft/s) Travel time = 1.13 mm. Time of concentration = 9.32 mm. Critical depth = 0.030(Ft.) Adding area flow to channel User specified 'C' value of 0.850 given for subarea Rainfall intensity = 2.821(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.850 Subarea runoff = 0.264(CFS) for 0.110(Ac.) Total runoff = 0.791(CFS) Total area = 0.44 (Ac.) Process from Point/Station 112.000 to Point/Station 116.000 STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 315.800(Ft.) End of street segment elevation = 308.200(Ft.) Length of street segment = 210.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 16.000(Ft.) Distance from crown to crossfall grade break = 14.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 9.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(In.) Manning's N in gutter = 0.0130 Manning's N from gutter to grade break = 0.0130 Manning's N from grade break to crown = 0.0130 Estimated mean flow rate at midpoint of Street = 0.791(CFS) Depth of flow = 0.179(Ft.), Average velocity = 3.200(Ft/s) Streetfiow hydraulics at midpoint of street travel: Halfstreet flow width = 4.195(Ft.) Flow velocity = 3.20(Ft/s) Travel time = 1.09 mm. TC = 10.41 mm. Adding area flow to street User specified 'C' value of 0.950 given for subarea Rainfall intensity = 2.626(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.950 Subarea runoff = 0.000(CFS) for 0.000(Ac.) Total runoff = 0.791(CFS) Total area = 0.44 (Ac.) Street flow at end of street = 0.791(CFS) Half street flow at end of street = 0.791(CFS) Depth of flow = 0.179(Ft.), Average velocity = 3.200(Ft/s) Flow width (from curb towards crown)= 4.195(Ft.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 116.000 to Point/Station 116.000 CONFLUENCE OF MINOR STREAMS k Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.444 (Ac.) Runoff from this stream = 0.791(CFS) Time of concentration = 10.41 mm. Rainfall intensity = 2.626(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (mm) (In/Hr) 1 0.867 10.12 2.675 2 0.791 10.41 2.626 Qrnax(1) = 1.000 * 1.000 * 0.867) + 1.000 * 0.972 * 0.791) + = 1.635 Qmax(2) = 0.982 * 1.000 * 0.867) + 1.000 * 1.000 * 0.791) + = 1.642 Total of 2 streams to confluence: Flow rates before confluence point: 0.867 0.791 Maximum flow rates at confluence using above data: 1.635 1.642 Area of streams before confluence: 0.514 0.444 Results of confluence: Total flow rate = 1.642(CFS) Time of concentration = 10.414 mm. Effective stream area after confluence = 0.958 (Ac.) End of computations, total study area = 0.96 (Ac.) LI San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c) 1993 Version 3.2 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 05/07/02 ------------------------------------------------------------------------ Charles Jacobs Property. Basin "D" (Proposed Conditions) File-drain2.out ------------------------------------------------------------------------ ******** Hydrology Study Control Information ------------------------------------------------------------------------ O'Day Consultants, San Deigo, California - SIN 10125 ------------------------------------------------------------------------ Rational hydrology study storm event year is 10.0 Map data precipitation entered: 6 hour, precipitation(inches) = 1.600 24 hour precipitation(inches) = 2.800 Adjusted 6 hour precipitation (inches) = 1.600 P6/P24 = 57.1% San Diego hydrology manual 'C' values used Runoff coefficients by rational method Process from Point/Station 100.000 to Point/Station 101.000 INITIAL AREA EVALUATION User specified 'C' value of 0.950 given for subarea Initial subarea flow distance = 25.00(Ft.) Highest elevation = 332.40(Ft.) Lowest elevation = 330.40(Ft.) Elevation difference = 2.00(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 0.68 mm. TC = [1.8*(l.1_C)*distance'.5)/(% slope'(1/3)] TC= [1.8*(1.1_0.9500)*(25.00#.5)/( 8.00'(1/3)1= 0.68 Setting time of concentration to 5 minutes Rainfall intensity (I) = 4.216 for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.950 Subarea runoff = 0.064(CFS) Total initial stream area = 0.016(Ac.) Process from Point/Station 101.000 to Point/Station 102.000 IMPROVED CHANNEL TRAVEL TIME Upstream point elevation = 319.40(Ft.) Downstream point elevation = 318.10(Ft.) Channel length thru subarea = 140.00(Ft.) Channel base width = 0.500(Ft.) Slope or 'Z' of left channel bank = 2.000 Slope or 'Z' of right channel bank = 2.000 Estimated mean flow rate at midpoint of channel = 0.425(CFS) Manning's 'N' = 0.030 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.425(CFS) Depth of flow = 0.277(Ft.), Average velocity = 1.453(Ft/s) Channel flow top width = 1.608(Ft.) Flow Velocity = 1.45(Ft/s) Travel time = 1.61 mm. Time of concentration = 6.61 mm. Critical depth = 0.213(Ft.) Adding area flow to channel User specified 'C' value of 0.470 given for subarea Rainfall intensity = 3.522(In/}lr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.470 Subarea runoff = 0.298(CFS) for 0.180(Ac.) Total runoff = 0.362(CFS) Total area = 0.20(Ac.) Process from Point/Station 102.000 to Point/Station 108.000 IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 318.10(Ft.) Downstream point elevation = 312.00(Ft.) Channel length thru subarea = 140.00(Ft.) Channel base width = 12.000(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 = 0.445(CFS) Manning's 'N' = 0.015 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.445(CFS) Depth of flow = 0.022(Ft.), Average velocity = 1.541(Ft/s) Channel flow top width = 14.205(Ft.) Flow Velocity = 1.54 (Ft/s) Travel time = 1.51 mm. Time of concentration = 8.12 mm. Critical depth = 0.033(Ft.) Adding area flow to channel User specified 'C' value of 0.850 given, for subarea Rainfall intensity = 3.083(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.850 Subarea runoff = 0.236(CFS) for 0.090(Ac.) Total runoff = 0.598(CFS) Total area 0.29(Ac.) Process from Point/Station 108.000 to Point/Station 108.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.286(Ac.) Runoff from this stream = 0.598(CFS) Time of concentration = 8.12 mm. Rainfall intensity = 3.083(In/Hr) Process from Point/Station 105.000 to Point/Station 106.000 INITIAL AREA EVALUATION **** User specified 'C' value of 0.950 given for subarea Initial subarea flow distance = 20.00(Ft.) Highest elevation = 329.00(Ft.) Lowest elevation = 327.00(Ft.) Elevation difference = 2.00(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 0.56 mm. TC = (1.8*(l.1_C)*distance#.5)/(% slopeA(1/3)] TC = [1.8*(1.1_0.9500)*( 20.00".5)/( 10.0O(1/3)]= 0.56 Setting time of concentration to 5 minutes Rainfall intensity (I) = 4.216 for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.950 Subarea runoff = 0.060(CFS) Total initial stream area = 0.015(Ac.) Process from Point/Station 106.000 to Point/Station 107.000 '" IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 316.00(Ft.) Downstream point elevation = 314.50(Ft.) Channel length thru subarea = •160.00(Ft.) Channel base width = 0.500(Ft.) Slope or 'Z' of left channel bank = 2.000 Slope or 'Z' of right channel bank = 2.000 Estimated mean flow rate at midpoint of channel = 0.561(CFS) Manning's 'N' = 0.030 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.561(CFS) Depth of flow = 0.316(Ft.), Average velocity = 1.568(Ft/s) Channel flow top width = 1.764 (Ft.) Flow Velocity = 1.57(Ft/s) Travel time = 1.70 mm. Time of concentration = 6.70 mm. Critical depth = 0.246(Ft.) Adding area flow to channel User specified 'C' value of 0.470 given for subarea Rainfall intensity = 3.490(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.470 Subarea runoff 0.410(CFS) for 0.250(Ac.) Total runoff = 0.470(CFS) Total area = 0.27(Ac.) Process from Point/Station 107.000 to Point/Station 108.000 IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 314.50(Ft.) Downstream point elevation= 312.00(Ft.) Channel length thru subarea = 130.00(Ft.) Channel base width = 12.000(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 = 0.501(CFS) Manning's 'N' = 0.015 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.501(CFS) Depth of flow = 0.030(Ft.), Average velocity = 1.237(Ft/s) Channel flow top width = 15.002(Ft.) Flow Velocity = 1.24(Ft/s) Travel time = 1.75 mm. Time of concentration = 8.45 mm. Critical depth = 0.036(Ft.) Adding area flow to channel User specified 'C' value of 0.900 given for subarea Rainfall intensity = 3.005(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.900 Subarea runoff = 0.095(CFS) for 0.035(Ac.) Total runoff = 0.565(CFS) Total area = 0.30(Ac.) Process from Point/Station 108.000 to Point/Station 108.000 CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.300(Ac.) Runoff from this stream = 0.565(CFS) Time of concentration = 8.45 mm. Rainfall intensity = 3.005(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (mm) (In/Hr) 1 0.598 8.12 3.083 2 0.565 8.45 3.005 Qmax(1) = 1.000 * 1.000 0.598) + 1.000 * 0.961 * 0.565) + = 1.141 Qmax(2) = 0.974 * 1.000 * 0.598) + 1.000 * 1.000 * 0.565) + = 1.147 Total of 2 streams to confluence: flow rates before confluence point: 0.598 0.565 Maximum flow rates at confluence using above data: 1.141 1.147 Area of streams before confluence: 0.286 0.300 Results of confluence: Total flow rate = 1.147(CFS) Time of concentration = 8.453 mm. Effective stream area after confluence = 0.586(Ac.) Process from Point/Station 108.000 to Point/Station 109.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 312.000(Ft.) End of street segment elevation = 308.000(Ft.) Length of street segment = 50.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 8.000(Ft.) Distance from crown to crossfall grade break = 6.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 9.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(In.) Manning's N in gutter = 0.0130 Manning's N from gutter to grade break = 0.0130 Manning's N from grade break to crown = 0.0130 Estimated mean flow rate at midpoint of street = 1.182(CFS) Depth of flow = 0.179(Ft.), Average velocity = 4.761(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 4.206(Ft.) Flow velocity = 4.76(Ft/s) Travel time = 0.18 mm. TC = 8.63 mm. Adding area flow to street User specified 'C' value of 0.830 given for subarea Rainfall intensity = 2.965(In/Hr) for a 10.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.830 Subarea runoff = 0.086(CFS) for 0.035(Ac.) Total runoff = 1.234(CFS) Total area = 0.62(Ac.) Street flow at end of street = 1.234(CFS) Half street flow at end of street = 1.234(CFS) Depth of flow = 0.181(Ft.), Average velocity = 4.798(Ft/s) Flow width (from curb towards crown)= 4.311 (Ft.) End of computations, total study area = 0.62 (Ac.) THE CREST ES TA TES PROPOSED CONDITION SHEET 1 OF 1 SHEET DRA INA GE S TUD Y I I PREPARED APRIL 17, 2000 REkYSED MA Y 4 2002 DESIGNED BY: C.J.S. DATE: MAY 2002 DRAWN BY: B.H. SCALE: AS SHOWN 0 PROJECT MGR.:J.P.S. 99-1021 CONSULT/ TS 5900 Pasteur Court Civil Engineering ENGINEER OF WORK: Suite 100 Planning Carlsbad, California 92008 Processing 760-931-7700 Surveying Fax: 760-931-8680 DATE: RCE: 2002 O'Day Consultants, Inc, I r'. Ir11ThC'\ n C'V)l\ fThCv)I ThTh fl\ ICT O1 Th_ñD 'DDDfl rm Ec'T LI \ .) Li .1) '.) \ V V.1 V _) .L \ V V -i J. Li Li 'Li 'iv '.-J -d .3. .' 'd CRES T ES TA TES EXIS T/NC C ONDI TION DRA INA CE MA P N 11,600 1EGEM BASIN BOUNDRY LINE SUB BASIN BOUNDRY LINE X 1000 NODE NUMBER I© 2002 O'Day Consultants, Inc. H 0' 5' 20' 10' 40' SCALE: i" = 20' PREPARED APRIL /Z 2000 REfr1SED MA Y 4, 2002 DESIGNED BY; C.J.S. DATE: MAY 2002 DRAWN BY: B.H. SCALE: AS SHOWN 0/ PROJECT MGR.: J.P.S. JOB NO,:- 99-1021 ENGINEER QE WORK: C 0 N S U L T N T S 5900 Pasteur Court CMI Engineering Suite 100 Planning Carlsbad, California 92008 Processing 760-931 —7700 Surveying DATE- Fox: 760-931-8680 RCE: O:\J0BS\001031\0031DDEX.IJVG 8-19-02 32435 pm XREFS992 YHC, 9,921-EX-DRAIN