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Home My WebLink About440-001; James Canyon Estates Tentative Map; James Canyon Estates; 1998-12-01PRELIMINARY HYDROLOGIC AND HYDRAULIC REPORT JAMES CANYON ESTATES TENTATIVE MAP NO. CT- CITY OF CARLSBAD Job No. 440-001 DECEMBER 1998 Prepared By: Crosby Mead Sen (on & Associates 5650 El Camino Real, Suite 200 Carlsbad, CA 92008 (760)438-1210 Engineer of Work: George L. Benton R.C.E. No. 14594 Exp. 3/31/01 TABLE OF CONTENTS I. ON-SITE HYDROLOGY II. OFF-SITE HYDROLOGY HI. MAPS PART I - ON SITE INVESTIGATION I la^tf, £| RATIONAL METHOD Watersheds Less than Q.5 Square Mile Method of Computing Hunoff Dae the Rational Formula Q = CIA where: Q is the peak rule of How in cubic feet per second. C is a runoff coefficient expressed as that percentage of rainfall which ETecomes surface runoff. fc 1 ib the average rainfall intensity in inches per hour for a storm duration equal to the time of concentration (T\) of the contributing drainage aren. A^ is the drainage area in acres tributary to design point. (l) Kunoff Coefficient, C Appendix I-A lists the estimated coefficients for urban areas. For urban areas select an appropriate coefficient for each type of land use from Table, 2, Appendix 1-A. Multiply thU coefficient by the percentage of the total area Included in that class. The bum of the products for all land uses In San Diego County is the weighted runoff coefficient. (2) Rainfall Intensity. I Intensity - duration - frequency curves applicable to all areas within San Diego County are given in Appendix 1-ii. (3) Time of Concentration. Tc The time of concentration is the time required for runoff to flow from the most remote part of the watershed to the outlet point under consideration. v.JlJTY OF SAN DIEGO DEPARTMENT OF SANITATION FLOOD COiTTflOL 100-YEAR 6-HOin PRECtPlTATiOIJ «»5 ~2(U ISOPLUVIALS PRECIPITATION IN OF 100-YEAR 6-HOUR Kirns OF AN i;:c» zws^m^— ».\ f\v A \ V>/3 , DVOLOGY. NATIONAL rtATHIl BtKVICI *•** U.S. DEPARTWEh OCtAKIC . orrict or i 30'. 118 -our"' OF r-- DEPARTMENT OF SANITATION t- FLOOt) CONTROL *5 33* 30' 15' «i5 fttff U.S. DEPARTlltN HATIOKAL DCkAMC AMD AV ITVO11I »KA.-4CU. Of HCK OP II 30' 1ud-W,\R 24-n ^(MSOPLUVIALS Or 100 -YEAR 24-HOUR PRECIPITATION IN IMTHS OF AN INCH ?T^^\ \CCRC i>v4(rtr: iT.I 116 t ii i Lr\* i i i ~3v;^ n * • • • . i i ~n - i n i i rr n i ilii^. Jill! Equation: I - 7.44 PA D "'64S TiTr. . 6 I • Intensity (In./Hr.) P, • 6 Hr. Preclpitttion (In.) D • Duration ON Directions for Application: } Froai precipitation naps determine 6 hr. and 24 hr. amounts for th« selected frequency. These maps are printed in the County Hydrolog Manual (10. 50 And 100 yr. maps included in t Design and Procedure Manual). 2} Adjust 6 hr. precipitation (if necessary) so that it is within the range of 451 to 651 of the 24 hr. precipitation. (Not applicable to Desert) 3) P"bt 6 hr. precipitation on the riQht si of the chart. 4) Draw & line through the point parallel to th plotted lines. 5) This line 1s the intensity-duration curve fc the location being analyzed. Application Form: 0) Selected Frequency \0e> yr. 2) Adjusted *Pfi- 3) tc-^ 4) I •_ 24 in.•/ Not Applicable to Desert Regicn 30 40 50 1 n ..Duration 56 APPENDIX XI IV-A-14 Revised 1/85 PROJECT. CALC DATE -SHT__ CHKD OF STATION. AREA AREA REFERENCE D« .057 (SO scale) X .918 (200 scale)ACRES 91.6 (2000) COEFFICIENT OF RyNQFF: C (consider probable development) . Developed Areas (Urban) % Land Use Residential: Single Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 00% Impervious Industrial (2) 90% Impervious TIME OF CONCENTRATION /C (Chart B-U HUPt. Lo.pt. H. RUNOFF: Q " I x Qfr Altitude Factor - I » x C » min hr (10 min. minimum) (Chart C) Coefficient " C A .40 .45 .45 .30 .70 .00 Soil £ .45. .50 .50 .35 .75 .05 Typed) £ .50 .60 .55 .40 .80 .do £ ( * oDy*1 .70 - .65- f. .45 - .05 - .95 - c.S.tt CA . P.CPG Tc - (\\ 9(L3]\ H Tc- Time in Hours L* Distance in Mile* H- Height in (actor 100- cfs USE CFS /hr CA USE QlQtf- 1 46:CFS Reteience: San Diego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C 1 thru IX-C4 7t PROJECT. wot CALC JS:^ DATE .SHT__ CHKD OF CKTE STATION, AREA^ AREA REFERENCE QM .057 (50 scale) X .918 (200 scale) -CRES 91.8 (2000) COEFFICIENT OF RUNQFFj_C (consider probable development) • Developed Areas (Urban) A .40 .45 .45 .30 .70 .80 Residential: Single Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious TIME OF (Chart B-l) HUPt. Lo.Pt. H. L. ftUNQFF: Q -.1 x CA Altitude Factor * C - _ ^min _ hr (10 mln. minimum) (Chart C) " " Soil Type ( 1) £ .44 .50 .50 .35 .75 .85 £ .50 .60 .55 ,40 ,80 90 Tc " (H^ Tc- Time in Hours L* Distance in Miles H- Height in Feet I "Ar factor 100 cfs CA USE Q_ - USE Q10rr Reference: San Diego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C 1 thru IX-C4 .55 * .70 » .65 - .45 « .85 • .95 - CA CFS _CFS £>, PROJECT, WO* \ CALC CATE CHKD OF ' CATE STATION.AREA REFERENCE .057 (SO scale) X .918 (200 scale) 91. a (2000) COEFFICIENT OF RUNOFF: C (consider probable development) Developed Areas (Urban) % Land Use ACRES Residential: Single Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious OF CONCENTRATION *C (Chart B-l) Hl*Pt. Lo.Pt. H. L. RUNQfF: Q - 1 x CA Altitude Factor » C * min hr (10 mln. minimum) (Chart C) goefflcient " C Soil Type ( 1) iactor 100 » x "/hr CA cfs A .40 .45 .45 .30 .70 .80 £ .50 ,50 .35 .75 .85 £ .50 .60 .55 .40 .80 .90 Tc-185 Tc- Time in Hours L- Distance in Miles H* Height in Feet USE Q - USE Q10(T Reference; San Diego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C 1 thru IX-C4 .70 - .65 - .45 - .85 » .95 - CFS PROJECT. wot CALC DATE SHT__ CHKD. OF _CATE STATION. AREA AREA REFERENCE p» .05? (SO scale) X .918 (200 scale)ACRES OEFFIINT OF Developed Area a (Urban) use 91.8 (2000) ; C (consider probable development) Residential: Single Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious TIME OF CONCENTRATION AC (Chart B-l) HUPl. H. Lo.Pt.L. ftUNOFF: Q « 1 x CA Altitude Factor * C - _ min _ hr (10 mln. minimum) (Chart C) Coefficient " C " Soil Type ( 1) A .40 .45 .45 .30 .70 I .4* .50 .50 .35 .75 £ .50 .60 .55 .40 .80 £ .55 - .70 - .65 - .45 - .85 - .80 .85 .90 Tc- H Tc* Time in Hours L* Distance In Miles H- Height in Feet I M/hr cfs (actor 100 CA USE Q__ - USE Qlo<r Reference: San Diego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C1 thru IX-C4 .95 - CA - _CFS ere PROJECT. wot CALC or CATE CHID STATION. AREA AREA REFERENCE n« .057 (SO scale) X .918 (200 scale) •ACRES 91.8 (2000) COEFFICIENT OF RUNOFF: C (consider probable development) 1 Developed Areas (Urban) % Land Use Residential: Single Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious TIME OF CONCENTJV\TjQN (Chart B-l) Lo. H. L. RUNOFF: Q_ - J x O\ Altitude factor - C - min hr (10 min. minimum) (Chart C) Coefficient " C " A .40 .45 .45 .30 .70 Soil £ .4* .50 .50 .35 .75 Typ*(l) £ .50 .60 .55 .40 .80 £ i^Tsy <?-ss .70 - .65- .45- .85* .60 .85 .90 Tc - /M 9<li3 V "Tc« Time in Hours L- Distance in Miles H- Height (u. .95- CA - bo 100- cfs CA CFS era Reference: San Diego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C 1 thru IX-C4 PROJECT. wot CALC X EATE SHT_ CHKD OP STATION. AREA_ AREA REFERENCE .057 (50 scale) X .918 (200 scale) 91.8 (2000) COEFFICIENT OF RUNOFF: C (consider probable development) t Developed Areas (Urban) % Land Use Residential: Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious ACRES TIME OF CONCENTRATION *C (Chart B-l) HUPt. H. U>.Pt.L. RUNOFF: O «= I x CA Altitude Factor » I » x = min hr (10 min. minimum) (Chart C) Coefficient " C A .40 .45 .45 .30 .70 .80 Soil I .50 .50 .35 .75 .85 Typo(l) £ .50 .60 .55 .40 .80 .90 * .70 - .65 - .45 - .85 - .95 - C • HA • ^.4O *•** • am^Simm Tc Tc- Time in Hours L* Distance in Miles H* Height in Feat id c tor 100 cU USE Q__ - CA Retire nee: San Diego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C1 thru IX-C4 ..CFS era wo*_ CALC"CKTE . SHT__ CHKD OF , ^CATE STATION. AREA AREA REFERENCE Q« .057 (50 scale) X .918 (200 scale)ACRES 91.8 (2000) COEFFICIENT OF RUNOFF: C (consider probable development) • Developed Areas (Urban) Use .40 .45 Residential: . Single Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious JIME OF CONCENTRATION Ag (Chart B-l) HUPt. H. Lo.Pt. L. RUNOFF: Q « 1 x Altitude Factor C » _ min _ hr (10 mln. minimum) (Chart C) Qoefflcient " C Soil Type ( 1) .45 ,30 ,70 80 .4^ .50 .50 .35 .75 .85 £ .50 .60 .55 .40 .60 .90 - /ii-9(L3lyv H ;Tc Tc* Time in L* Distance in Miles H- Height in Feet factor c£s 00 /hr CA USE Q__ - USE Reference: San Diego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C 1 thru IX-C4 2 .55 .70 .65 .45 .85 .95 *- C CA _CFS CFS PROJECT. WOt CALC DATE SHT CHKD OP J»TE. STATION. AREA AREA REFERENCE .057 (50 scale) X .918 (200 scale) 91.8 (2000) COEFFICIENT OF RUNOFF: .C (consider probable development) Developed Areas (Urban) % Land Use ACRES Residential: Single Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious TIME OF CONCENTRATION *C (Chart B-l) HUPt. H. Lo.Pt.L. HUNQFF: O - 1 x CA Altitude Factor * C » mln hr (10 mtn. minimum) (Chart C) Coefficient * C Soil Type( 1) '/hr (actor CA cfs A .40 .45 .45 .30 .70 .80 I .50 .50 .35 .75 .85 .50 .60 .55 .40 .80 .90 Tc Tc- Time in Hours L» Distance in Miles H* Height in Feet USE Q_ - USE Qiotf- Reference: San Dtego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C1 thru IX-C4 .70 - .65 - .45 • .85 « ,95 - C • CA • .CFS CFS PROJECT. wo# CALC DATE SHT_ CHKD OF LATE STATION. AREA AREA REFERENCE J -14- .057 (50 scale) X .918 (200 scale) 91.8 (2000) COEFFICIENT OF RUNOFF: C (consider probable development) Developed Areas (Urban) Use A .40 .45 .45 .30 .70 ACRES Coefficient " C " Soil Typ*( 1) Residential: . Single Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious .80 i .4^ .50 .50 .35 .75 .85 £ .50 .60 .55 .40 .80 .90 TIME OF CONCENTRATION AC (Chart B-l) HUPt. H. L. Tc - /II.9tL3Y85 in Hours I* Duiance in Mil«a H- Height in Feet RUNOFF: Q._• 1 x Cft Altitude Factor » I - x I C * min hr (10 mln. minimum) (Chart C) factor "Ar ct§USE Q_ - USE Ql0tf" Reference: San Diego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C1 thru IX-C4 .55 » .70- .65 - .45 - .85 - .95 - CA - _CFS era STATION, AREA AREA REFERENCE PROJECT WO#_ CALCo .057 (50 scale) X .918 (200 scale) 91.8 (2000) 2O ACRES COEFFICIENT OF RUNOFF: C (consider probable development) Developed Areas (Urban) % Land Use AResidential: Single Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious TIME OF CONCENTRATION *C (Chart B-l) Hi.Pt. H Lo.Pt. ___ L. mln hr . minimum) RUNQFF: Q - I x C A Altitude Factor *(Chart C) Coefficient " C " Soil Type( 1) .40 B .45 .50 Tc /11.9(L3)VV H ;85 Tc« Time In Hours L= Distance in Miles H« Height in Feet I factor •100 "/hr "/hr CA cfs USE Q__ = USE OioO= Reference: San Diego County Flood Control Design and Procedure Manual (1) Obtain 30il type from Appendices IX-C 1 thru TX-C4 .45 .45 ,30 .70 .80 ^^— - . . — , ,50 .60 .70 = .50 .55 .65 = .35 .40 .45 =• .75 .80 .85* .85 .90 .95 » C » -^S^ CA -<2>,// .CFS CFS PROJECT CALC DATE -SHT__ CHKD OF EATE STATION, AREA AREA REFERENCE .057 (50 scale) X .918 (200 scale) 91.8 (2000) COEFFICIENT OF RUNOFF: C (consider probable development) Developed Areas (Urban) % Land Use Residential: Single Family Multi-Units ACRES Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious TIME OF CONCENTRATION XC (Chart B-l) Hl.Pt. H. Lo.Pt.L. RUNOFF: Q - I x CA Altitude Factor - C - mln hr (10 mln. minimum) (Chart C) Coefficient " C " A .40 .45 .45 .30 ,70 ,80 Soil B .45 .50 .50 .35 .75 .85 Type ( 1 ) c .50 .60 .55 .40 .80 .90 D .55 = .70 = .65 - .45 - .85 - .95 =• ,PXT -<S§~ C =• CA =£>,ZC> Tc 185 Tc= Time In Hours L= Distance In Miles H- Height In Feet I factor •100 "/hr "/hr CA cfs USE Q__ USE Q100= /> Reference: San Diego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C l thru IX-C4 CFS CFS PROJECT. WO* SHT OP CALC LATE CHKO CATE__ STATION AREA REFERENCE ^ Q- .057 (50 scale) AREA X .918 (200 scale) * 91.8 (2000) COEFFICIENT OF RUNOFF: C (consider probable Developed Areas (Urban) % k^nd Use Residential: \&O fa single Family Multi-Units Mobile Homes Rural (lots greater than 1/2 acre) Commercial (2) 80% Impervious Industrial (2) 90% Impervious TIME OF CONCENTIWTPN7^ (Chart B-l) 6 Lo.Pt. ^1'— - L. ^>&° |/25 ACRES development) Coefficient " C " Soil Type ( 1 ) A £ £ 2 .40 .4i ,50 (-5)* #S5 .45 .50 .60 .70 » .45 .50 .55 .65 - .30 .35 .40 .45 - .70 .75 .80 .85 - .80 .85 .90 .95- C - 0*>S cL-&ua Tc " ( \ 1 9 (L 3 \\3fl 5 Tc« Time in Hours .. ^ / S3? \ H- Haluht in Feet L— ^& B13NQFF: Q •= \ x CA Altitude Factor » C » ^min hr (10 mln. minimum) (Chart C) tactor 100 "/hr 3 "Ar CA cfs CF3 USE CFS Reference: San Diego County Flood Control Design and Procedure Manual (1) Obtain soil type from Appendices IX-C 1 thru IX-C4 STQRM SEWER DESIGN CALCULATIONS AREA DESIGNED BY »DATE*PAGE >OF LOCATION LINE U bPQTlTPPn j 8 TIM£ OfONCENTRATIONMtNUTCS (mm.)MITVhr.o •n nO • >M O i •Q £CHAMCTCT Orwpt (inchELOCITYwiNO ruuP.3.)II ITY Or»c• 1I o.\\ \-S age ** i-n •5°'&.0 4-5 m -!&7-9 J47 3.55 4-5?30.0 II ING ENGINEERS AND PLANNtR, DATE ipSyl CHECKED .CLIENT DATE JOB SHEET NO..OF JOB NO. COSULTING ENGINEERS AND PLANNERS BY s 7 DATE CLIENT .SHEET NO..OF CHECKED DATE JOB JOB NO. = g4J Pt' •gp^sp f ffl GJLJ. oat g^cfe^x ENGINEERS AND PL-ANN^R ri.IF.NT .SHEET NO..OF CHECKED DATE JOB JOB NO. PART II - OFF SITE INVESTIGATION CONSUL-TING ENGINEERS AND PLANNERS, BY DATE CLIENT CHECKED £.'.2:. DATE JOB . SHEET NO. _ JOB NO. .OF //. 4 f - SW - -9- /ffif^A^*-<V£ rCUc£^> <ro ENGINEERS AND PLANN >ATE 0/IW^ rilF.NT _.SHEET NO..OF DATE JOB JOB NO. B.A "£yvigw .x^feyfl^NJ A-A 25? OF ING ENGINEERS AND PUANN DATE-/ cx4^^< This plate applies only when the grate is located in a low point or sump where the water will pond at tha grata. The capacity of the grate depends upon the area of the openings and the depth of water at the grate. Recent experiments have determined that a grate will act as a weir and follow the weir formula for depths (heads) on the grate up to 0.4 ft. It will act as an orifice and follow the ori- fice formula for heads of 1.4 ft. and over. For heads between 0.4 ft. and 1-4 ft. the operation is indefinite because of vortices and eddies over the grate. In the usual problem the following are given: 1. A particular design of grate with dimensions. 2. A design discharge (Q) or information as to drainage area, rainfall intensities and runoff coefficients from which a discharge can be estimated. Procedure: 1. Compute the perimeter of the grate opening (P) ignoring the bars and omitting any side over which the water does not enter, such as when one side is against the face of a curb. Divide the result by 2. This allows for partial clogging of the grate by assuming that only half of the perimeter will be effective. 2. Compute the Q/P ratio. 3- Compute the total area of clear opening (A), excluding area taken up by bars, and divide by 2. This allows for partial clogging of the grate by assuming that only half of the area will be effective. 4. Compute the Q/A. ratio. 5. Enter the chart at the bottom scale using line (a) with the Q/P value and line (b) with the Q/A value and read the re- quired head in feet at the left margin. 6. If the required head falls below 0.4 ft., (a) only will apply. This is the usual case. ?. If the required head falls above 1.4 ft., (b) only will apply. 8. If the required head falls between 0.4 ft. and 1.4 ft. the actual head may be anywhere between (a) and (b). Use the value that gives the most conservative result, being sure to use line (a) with Q/P and line (b) with Q/*- IX the inlet is a combination type with grate and curb open- ing the recommended procedure is the same as with a grate alone except the perimeter and area are not divided by 2. The reason for this is that the curb opening will serva as a relief in event the grate becomes clogged. With the grate operating freely it is questionable whether much water will get to the curb opening until the discharge is sufficient to submerge the entire grate. 10. If the grate has an appreciable cross slope so the sida away from the curb is higher than that next to the curb the inflow over the side should be determined separately from that over the ends. Use the depth at the middle of the grate for end inflow and depth at edge away from the curb for side inflow. INLET CAPACITY OF GRATE AT SAG Plate 2.6-0658 p » 2 (a + b) A • e aw 0.0 1 1 f t i i I I (a) UJ o<ttl C/P OHM O.I HEAi s u 10 0. \CUPVC HEADS A 30 \.\CUR (V HEADS B •TVEE^ l»ai. o oiactJ_LI PIR FOOT Of 0.1 .» .4 .ft tf »ES tf »|.IEST 4 31 TlOtJ 1N1TE PjER M|Eill BP(Q/FIJ.J .« .r .•.•i.o ISDHJRG PE FOQ AfCA.i • • T • • 10 10 INLET CAPACITY OF GRATE AT SAG Plate 2.6-0658 PART III - MAPS