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HomeMy WebLinkAboutCT 00-13; TABATA PROPERTY; HYDROLOGY STUDY; 2013-06-30HYDROLOGY STUDY FOR TABATA PROPERTY TENTATIVE MAP JOB NO. 00-1003 JUNE 30, 2000 BY O'DAY CONSULTANTS 5900 PASTEUR CT. SUITE 100 CARLSBAD, CALIFORNIA 92008 TIM CARROLL PROJECT MANAGER Existing Site Description The project site is located easterly of and adjoining Black Rail Road approximately 1400' southerly of Poinsettia Lane. The entire site consists of approximately 5 acres, which was used for agriculture. The natural drainage pattem of the site to be developed is split with approximately 4 acres draining west toward Black Rail Road and the remaining area draining to a brow ditch to the east. Proposed Project There are 17 single family residential homes proposed on the site. The westerly 12 of the 17 lots will drain to one of the two proposed cul-de-sac streets and be transported to Black Rail Road by gutter. The easterly five lots will drain to the cul-de- sac street and then be transported east by a brow ditch located in the southeast comer of the site. This brow ditch will connect to the existing brow ditch running adjacent to Cabela Place in the Aviara property. a) IT " 3*7' • ' V V ^ /ll.'lf.o^^J^V^^l ' \ 5" '/ " ^•<J'3/^= ZJ fc/lliVJ +/0 MIN) - IQ., I^/Ai rr^ j^./il^i-pi, kl/VTu^Au WA^^^*^^^=^i ® X0%-7.^11> tsipoiAJ iM-rr^ p-L^5f/U d) jl^nrnS^E^ ^nfOKt-^n/vl^ ^OM^Si-rr-^ L-M^ FT ' ——^——————— 2-70 FT V= ,^ f-r/c / — — — 1 u - / -^:^9r) j a i -ft Q-o'i - i ^1. 1 ! ! X^,A^-^IJ3/A C.-10 <:i^.--1 0 /uw I ^ 1 1 s n h Ui — , a) L-= 1^0 FT A' |.Z Ac. .Xv...!-'- 27P/^J'-'2'7s^c; /.'^- 7^ P^^iAj p,r7^ f^U^ J -^"^V,. __a-?_.2-a:.-C;,p-iL„^ _ . . —-— y''A^ .^r/^j-zi__-.„ ^. —-— 1 . „ _ , , .. " , -2_ - - _ _ _ _ (3 tLAr^k: i^ML. RnM^ /f^^f fl>btFl T^t^r^Rir/^ X'/g,o f=^-r 1 \ / T J - 3^0 FT / A- Lo At^/ 3 AAiAj Tc- --14--^ ' / \ / X'?>.5 -x t X:/7/ '%A ^ Q4 \ L-'- 7^^ ^ ,C ^ ? .9V A - ^ . ^ \/^ 4l-c^s T- 470/4 ^- IIS se?.-- 1.^^,/ X, r (44-f- f.q ^ |(. ^ A4,^J X-?>.2. 'i ; 1 . . -,.U 1 \ ! i!i ^^^ \ \ \ ~~~ — -— A^3 ^ X X^..,- /(i?.^ MIAJ -^-"^•^ Tx-3. ) 01.' r. c.« RUNOFF COEFFICIENTS CRATIONAL METHOD) I? LAND USE Coe f ficient. C -So il Group (1) Undeveloped Residential: A .50 . 35 C .40 D .45 .Rural .50 . 35 .40 . -iS Single Family .40 .43 .50^ V,;,_55 Multi-Units .45 .50 .60 . 70 -Mobile Homes (2) .45 .30 .53 . 63 Commercial (2) 80% Impervious .70 .75 .80 .33 Industrial (2) 90-» Impervious .80 .85 .90 .95 -WES; (1) Obtain soil group, from maps on file with the Department of Sanitation and Flood Control. (2) Where actual conditions deviate significantly from the tabulated imperviousness. 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: Considei commercial property on D soil group. Actual imperviousness =50% Tabulated imperviousness = 30% Revised C = |0 X 0.85 = 0.53 .\PPE.NDI.X :.\ RESIOeNTIAL STREET ONE SIDE ONUY EXAMPLE: "r-T~T'X[ r 5 6 7 a 9 10 DISCHARGE (CFS.) 1 20 30 40 50 Given > C.= 10 3=^5% Chart giw: Depth = a4, Velocity = 4.4 f.p.s. SAN OIEGO cou^f^r DEPARTMENT CF SPECIAL DISTRICT SERVICES DESIGN MAMUAL APPROVED /i.iJi/if^yy^'^^^rt^ GUTTER AND ROADWAY DISCHARGE-VELOCITY CHART DATE _Z2/3£4j. APPENDIX X-0 l_6(LI-c)rD_ SAN OIEGO COUNTY DEPARTMENT OF SPECIAL DISTRICT SERVICES DESIGN MANUAL URBAN AREAS OVERLAND TIME OF FLOW CURVES DATE APPENDIX X-C INTENSITV-DUMTION DtSIGN CHART Tininiir=i-ri » i i.iu.illiMiniihni 7.44 D 15 20 30 10 50 1 Minutes 2 . 3 Hours Directions for Application: , 1) From precipitation naps determine 6 hr. and 24 hr. amounts for the selected frequency. These maps are printed In the County Hydrolofiy Manual (10, 50 and 100 yr. maps Included in th Design and Procedure Manual). ?.) Adjust 6 hr. precipitation (If necessary) so that It Is within the ranfle of 45X to 65?; of the 24 hr. precipitation. (Not npplicahle to Desert) 3) Plot 6 hr. precipitation on the ribht side of the chart. 4) Draw a line through the point parallel to the plotted lines. 5) This line is the Intensity-duration curve for the location being analyzed. Application Form: 0) Selected Frequency /OO yr. 1) Ps - aA_in., P24- S.o . " 2) Adjusted *Pg« 3) t. 24 in. JO min. 4) I In/hr. *Not Applicable to Desert Region APPHNniX XI IV-A-14 Revised 1/8.S COUNTY OF SAN DIEGO DEPARTMENT OF SANITATION 5- FLOOD CONTftOL 33" '•5' 30« 15' fur" U.S. DtPARTMtN NATIONAL OCI;AMC AMD AT:. SPtCIAL HUUItS UKANCII. OH ICK Of 11 30' lOO-YEAR 24-HOl (I PRECIPITATION -20^ISOPLUVIALS OF 100 -YEAR 24-liOUn PnECIPITATIOIl IM EMTIIS OF AM IMCII '<i tor r OF COMMERCE U^tl-llCHIC AUMIKUrilATION UliOUOGY, NATIONAL WtATIIER SEWVICE iiir /I'j' .10' II' 117' .10' 116- "liy ISOPLUVIALS PnECiFlTATIOn IM OF 100-YEAn 6-HOUR rEMTliS or AM liiCII 33* U.S. DEPARTMEN NATIO.NAL OCEANIC AND ATrjoSI'IIEItlC ADkilNISTKATION f PECIAL (TUDieS URANCH, omCC OF II 30' _ zo i .saaa .4aaa .Zaaa j\ .Jas -) £Qa/?r/OA/ Te * 77/7re a/ eoncen/ra/forr // * Di/fere/tes m ff/ffva/za/r a/an^ e/feef/re s/aoa /ine (See Appendix 1'8) -r L ^ /O — ./aaa 8oa 700 'SOO •40O .300 .200 •/oo 4- J- 2- \ \ - \ /^ 'Saoo -\—4<^o -\-~J0O0 •so ¥0 .JO za as— NOTE jFOR NATURAL WATERSHEDS] J AOO TEN MINUTES TO \ I COMPUTED TIME OF CON- \ \ CENTRATION- J /O \ 2000 /SOO — /600 — /4fao — /200 . /ooo 900 — aoo — TOO — SOO -SOO — f(30 — 100 200 \ /BO /2a ./oo '30 .80 . 70 ^eo so — 40 — sa -20 /o ./6 ./4 \-/2 - /o 9 a 7 — 4 — J H SAN DIEGO COUNTY DEPARTMENT OF SPECIAL DISTRICT SERVICES APPROVED DESIGN MANUAL '0. //. /i4-'^-A~^ <lJLAy^ NOMOGRAPH FOR DETERMINATTON QF TIME OF CONCENTRATION (Tc) FOR NATURAL WATERSHEDS DATE /^A/^? APPENDIX X-A —————— , n_.. c/01 Averig* V<luc> of Roughntil Cocfflclenc (Hannlng'f n) H I ro ? r Type of W»terv<«y 1. Closed Conduits^') Steel (not lined) . Cast Iron Corrugated Hetil (not lined) Corrugated Metal(') (smooch asphalt quarccrlIning) Corrugated Hetal'^' (smooch asphalt half lining) Corrugiced HeCal (smooth asphalt full lining) Concrete Clay (sewer) Asbestos Cement Drain Tile (terra cotta) 2. Open ChannetiC) Unlined Clay Loam Sand Revettsd Gravel Rock Pipe and Wi re Sacked Concrete b. Lined Concrete (poured) Ai r Blown hlotarlS) Asphdicic Concrete ur Bituminous Plane Vegetated (small channel, shallow depths) Berir.uda, Kentucky Bluejrass, Buffalo Mowed CO 2 in. Length l< - 6 i n. Good stand a.iy grass Length 12 in. t Length 211 in. + Falr stand any grass Length 12 in. + Length 2't In. T ]. Pavement and Cutters (') Concrete Bituminous (plant-mixed) Roughness Coefficient (n) 0.015 O.OIS O.OJit 0.021 0.016 O.OIZ O.OIZ 0.013 O.OII O.OIS 023 .020 0.030 O.OliO O.OIS 0.02S 0.0|l< 0.016 0.018 0.050 0.060 0.120 0.200 100 170 CIS 016 Type of Waterway it. Depressed Hadlant (10:1 slopesC) Earth (without growth) Earth (with growth) Gravel t S.- Natural StreamsC*) .t, HInor icroam (lurfac* width at flood itagi < 100 fc) (1) Fairly regular section (a) Sone grass and weeds, llttia or no brush (b) Dense growth of weeds, depth of flow •laterlilly greater than weed height (c) Some weeds, light brush on banks ' (d) Som* weeds, heavy brush on banks (e) For trees within channel with brtnchet submerged ac high stage. Increase all above values by 0.015 (2) Irregular section, with pools, slight channel meander Channels (a) to (e) above. Increase alt ^ values by 0.015 ^ (]) Houncain strt<.iis; no vegetation In channel, bank^ usually steep, trees and brush along banks submerged at high stage (a) Bottom, gravel, cobbles and few boulders (b) Bottom, cobbles with large boulders Roughncs i Coefficient (n) I b. Flood plains (adjacent co natural streams) (I) Pasture, no brush (a) Short grass (b) High grass Cultlvsccd areas (a) No crop (b) Mature row crops (c) Mature fleld crops Heavy weeds, scattered brush Light brush and trees Medium to dense brush Dense wlI lows Cleared land with tree stumps, 100-150 pi;r acre Heavy stand of timber, little undergrowth (a) Flood depth below branches (b) Flood depth reaches branches (2) (3) (M (5) (6) (7) (8) 0.0<i0 0.050 0.05S 0.030 O.CliO O.OltO 0.060 0.050 0.060 0.030 O.OdO ,o<.a .OdO .050 .050 060 090 170 0.060 O.IIO 0.11(0 (1) (2) (3) (M NOTES Based on materials and workmanship required lo th* Standard Specifications. For pipe flowing full. Use value of 0.012 If trowled and 0.025 If purposely roughened. These values are offered as .-guide. For Important work and where accurac* determination of wac*r surface profile Is per.esjary. the designer should consulc Che Flood Concrot Discrlec office to obtain daca regarding n values applicable to specific streams. H td to to •