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Home My WebLink AboutCT 02-26; SEASHORE ON THE SAND; HYDROLOGY REPORT; 2006-07-14,- " .' ! . , , , -" , , -f , i , . j :. 1 . \ ; .~ : . i HYDROLOGY REPORT FOR Norine Sigafoose 2805 Ocean Street Carlsbad, CA 92008 PROJECT Seashore on the Sand 2805 Ocean Street Carlsbad, CA 92008 ,<>T:02~o PREPARED BY: Aquaterra Engineering Inc . 1843 Campesino Place Oceanside, CA 92054 tele: 760-439-2802 fax: 760-439-2866 July 14, 2006 / Hydrology & Hydraulics Report City of Carlsbad This Hydraullc~ and Hydrology Report was prepared using the following Manuals: l j Hydrology Mla.tllual, June 2003, County of San Diego Drainage of'4iklhway Pavements, u.s. Dept. of Transportation ~? ~ The Rationaf· W~ethod was used to determine the 100 yr. storm Q values . ." ' The RationatMethod uses the following formula to establish the flow: '-. ) Q=CIA where, : 1 .,. ! ~ 1 Q = the peak runoff in cubic feet per second C = Runoff coefficient representing the ratio of runoff to rainfall i ·1 I = time average intensity in inches per hour A = Area of the subbasin in acres . , , HYDROLOGY REPORT , I , ! POOR QUALITY ORIGINAL S /I , e e ~ ~ Aquaterrc'iEngineering Inc. l' ~ '--.-.----... -~ ,<.;.-:-. -.. :.~ ... :' :.:-: .. San Diego County Hydrology Manual Date: June 2003 Table 3 .. 1 Section: Page: RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use Runoff Coefficient "C" Soil TXEe . NRCS Elements Coun Elements %IMPER. A B C Undisturbed Natural Terrain (Natural) Permanent Open Space 0* 0.20 0.25 . 0.30 'low Density Residential (LDR) Residential, 1.0 DU/A or less 10 0.27 0.32 0.36 . Low Density Residential (LDR) Residential, 2.0 DU/A or less 20 0.34 0.38 0.42 Low Density Residential (LDR) Residential, 2.9 DUI A or less 25 0.38 0.41 0.45 Medium Density Residential (MDR) Residential, 4.3 DU/A or less 30 0.41 '0.45 0.48 Medium Density Residential (MDR) Residential, 7.3 DU/A or less 40 0.48 0.51 0.54 .Medium Density Residential (MDR) . Residential, 10.9 DU/A or less 45 0.52 0.54 0.57 Medium Density Residential (MDR) Residential, 14.5 DUIA or less 50 0.55 0.58 0.60 High Density Residential (HDR) Residential, 24.0 DUI A or less 65 0.66 0.67 0.69 High Density Residential (HDR) Residential, 43.0 DU/A or less 80 0.76 0.77 O.~8 Commercialllndustrial (N. Com) Neighborhood Commercial 80 0.76 0.77 0.78 .... ±Ot2 Ill_Ii""" ..,Aitg t tk lI_.;J , ~~ CommerciallIndustrial (G. Com) General Commercial 85 0.80 0.80 0.81 Commercial/lndustrial (O.P. Com) Offlce,ProfessionaVCommercial 90 0.a3 0.84 0.84 3 6 of 26 D 0.35 0.41 0.46 0.49 0.52 0.57 0.60 0.63 0.71 .. 0.79 0.79 0.82 0.85 2, 'e e .~~---_.----'~Oiih'1tlcroiallIndustrial.~~imited:J.}--T.im;ted.Jndl!strillL....-. __ ., 1.,.....,........9_Q,~ __ ~_0-'~3 __ ~~ __ O.84 0.84 0.85 '," -·~"'-";~''''''''M~~~~~¥..z:..'\:-. ~:',~";,,,..-'I'-:""'·!'"''''''''''':''''''t:'' "..-,,-~ .... ..::. ... ~ .... , .'.I-:~'!". __ ,_.:.r. __ >,;'J ".i': .Y'~;.;:,,,, ~-~ '. _ : v.~ 1..; ~ -'/00; .. ___ ' :: _. " _~~~~~~~"!'~~-~--~ ---Commerclal/Indust:rlaHGeneraliD--d -GeneraHnctustftal. :..-.: .::.--:::":::::":::'~"::~::'f -~:r.J.l--"_~-::",:~~::::-_~G;oq:--·:~:::--, "·,Q..s7-::':-'"~·~0.;g3~''''''.'~,:&C~-:~' !M~.qk:~-:":;::~:::::'::::-::-::-:::,,~ *Th~ valpes associatec;1 with 0% iinpervioUs may be used fQr direct 9alcutation of the runoff coefficient as described in Section 3.1.2 (representing the pervious runoff coefficient, Cp, for the soil type)~ or fo), areas thatwillremain-undisturbed in perpetuity. Justification must be given that the area wilhemain natural forever (e.g., the area is located in Cleveland National Forest). DU/A = dwelling units per acre mcs ;= National Resources Conservation Service 3·6 ( I" ? I 'If ! . ; I l t ( ___________ -------------IJr.i~----r ~i San Diego County Hydrology Manual . Date: June 2003 Section: Page: r; 3 12 of 26 , . Note that the Initial Time of Concentration should be reflective of the genef41and-use at the 1 '(; upstream end of a drainage basin. A single lot with an area of two or less a<:jr~~ does not have a significant effect wltere the drainage basin area is 2.0 to 6.0.0 acres. if i . i; , !, , f I Table 3-2 provides limits of the length (Maximum Length (L~) of sheet .fl~'o/ to "be used in hydtology studies. Initial Ti values bas~ on average C values f6I the Lan~ ~~se Element are also included. These values can be used in planning and design applicahG~ as described below. Exceptions may be approved by the '<:Regulating Agency" WhenJ $t~bmitted with a .. '" detailed study. It: 1: ! I; Table 3-2 ,~ MAXIMUM OVERLAND FLOW LENGTH (Itk 11 AI & INITIAL TIME OF CONCENTRATION ( !!)Ji Element* nUl .5% 1% 2% 3% ~ ~' 5%. ~~ Acre LM Ti LM Ti LM Ti LM Ti LM tli ltill . Natural 5.0 13.2 7.0 12.5 85 1.0.9 1.0.0 1.0.3 1.00 f"'l~ ,8.j7, LDR 1 50 12.2 7.0 11.5 85 1.0.0 10.0 9.5 100 tl t '8Al' LDR 2 5.0 11.3 7.0 1.0.5 85 9.2 10.0 8.8 1.0.0 11~~ LDR 2.9 5.0 10.7 7.0 10 • .0 . 85 8.8 95 8.1 1.00 l~'u tZ'r.Q MDR t~<tt 4.3 5.0 1.0.2 7.0 9.6 8.0 8.1 95 7.8 1.0.0 1:6:1'rt '-",~, MDR 7.3 5.0 9.2 65 8.4 80 7.4 95 7.0 100 f6:0 I ,~., MDR ,1< 10.9 50 8.7 65 7.9 80 6.9 90 6.4 100 r ,. $;~7 MDR 14.5 50 8.2 65 7.4 8.0 6.5 90 6 • .0 lOO t .-i514 BDR 24 5.0 6.7 65 6.1 75 5.1 9.0 . 4~9 95 IP t4i~ HDR 43 5.0 5.3 65 4.7 75 4 . .0 85 3.8 95 rr " :3:'4 , t. ~ _N.".Com 5.0 5.3 60 4.5 75 4.0 85 3.8 95 t'; I ", ';.~4 G.Com 5.0 4.7 6.0 4.1 75 3.6 85 3.4 9.0 I'f) I 2!.9 O.PJCom 5.0 4.2 60 3.7 7.0 3.1 80 2.9 9.0 rH Z~9 Limited!. 50 4.2 60 3.7 70 3.1 80 2.9, 90 1 'r-2;9 ; 1.0% LM Tj 1.00 6.9 1.0.0 6.4 10.0 5.8 1.0.0 5.6 1.0.0 ,5.3 1.0.0 4.8 10.0 4.5 100 4.3 100 3,5 10.0 2.7 100 2.7 , 100 2.4 10.0 2.2 100 2.2 f 2:.~ General I. 5.0 3.7 6.0 3.2 70 2.7 80 2.6 90 1.00 1.9 '* . . . 1f -\ ~ §ee T~le 3 1 for more detailed descnption . 3-12 --... I 1 ' I e e 1/ 0 !~ onta III .~ ~ 1 O~ ~ c Iii Ii I = .S! c = j ra~ :;. 19i zl U . .",.--. ..... ~ \C W ~ • lit It ti 00 Gil :: 'iJ ~ '" g ~!;! Ii~ fi C+-f > "iii o~ ::::: lla '5 ,!!~ j!a 1", :t "',. ~ <§, :! ::> . fiil. fi§ 11 'a .s 0 fg li Iii It II) a~ = .!5 S ~ ... ~q ; '# :; ~ =: );llll inn §£ ... :~ .: 41 \>I U .:: = ... 10.0 i"'t .... ... ~ I' "-i'oo 9.0 I' ~ ,.... N I IU III III II 1111 1111111111 11111 UJ 1I llUlllI1l ~;O~ '1''' ~1""'~f'~111111I1I1I1I\1I11II1II1111I11I1I1I1II1I11I1I'1II 1111 7.0" I'~ i' ",,":-0. EQUATION 6.0 • i'o ~ i" i"o J :::: 7.44 Pe 0.0.645 5.0"" "," " ' • ~ I :::: Intensity (ln/hr) I'i'o '" i'" ~ ~ .. Ps:::: a-Hour Preclpltatlon (in) 4.0~ """,., D = Duration (min) J 'I' I .... ". ~ i' ,I '" 1'" I" U"Io. il"lJ.I1.ll.rl'!!Ullllilllllllll 1.1 I.LLU IIII II i 1111111 3.0. "N. IIIUlllnu 1"1 'II 1111 1111111 ''',' ~ . , , . I 1~f;:IIIIIf't'ItIIIIIIII*flllltHttlrnllltK\.ltlIlI_I~IIIIIIIIIIIIIIIIIIIIIIII. 1:" ::I f 'fi r:1•O ~O.9 ·\!!O.8 J!I .50.7 O.S 0.5 0.4 I I I I I I I 1 I I I ! 1 1 II 1 III 11'111111111111111111 1 III 1 III II II III IIlImIW: 1 . , ' ... ~ ......... _ ...... . 0.3 2.0 0.2 'H--\-_. 1.0 -·-~-.-::-l:-kj;"~.: ':":" .. _~~'-,;!" ': . ~~ :.rr IflUtfllJf·" ~ 'N'!:'!" :1~H1 UlIIlU,'III""H_"·J+'"" I"un",:'.' JU;m II~ _. ~ .... -~'-'~'~"'~""-V;"":"'lf~"'·~·-"""'\'>; ~""l""!".,,~''(.. .. ~,,,,_ ~tll~~~_._, iff ~.r".:, \. ...,.,.ej'+..;' .... i:'i<...:c,f.._ .. ',l'I ::1 "';"_1'«,4: II ' . , "I" 'I III III' I ' . I . 'I' , 0.1t I I I r ill III . J -,I-++t+,i+HI-+H'I*I1+HHHlI 5 6 7 8 9 10 15 20 .30 40 50 1 2. 3 4, 5' 6 Minutes Hours ,DuranDn Intenslty·Duratl~n Design Chart. Template ( ( DirectIons for Application: (1) From precipitation maps determine 6 hr and 24 hr amounts , forthe selected frequency. These maps afe Included In the County Hydrology Manual (10, 50, and 100 yr maps Included in the Design and Procedure Manual). (2) Adjust S hr preolpltatlon (If necessary) so that it Is within the range of 45% to 65% of the 24 hr preolpitation (not appllcaple to Desert). (3) Plot 6 hr preclpltatlon on the right 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. Appllcatlon Form: (a) Selected frequency _ year , (b)PS= 2.5 In.,P24= ~'::4 = S$' %(~) (~) Adjusted PS(2) = ti in. (d) 1x = __ min. (e) I = _ in.lhr. Note: This chart replaces the Intensity-Duration-Frequency curves used since 1966. tit e ----.. , •• 1\.,. ": ~ ~ ...... F I'G U.R E 3 .. 1 \ <;'. ~ (' " " .6.E Feet Tc = SODD Tc == L = 4000 .6.E = 30DD 2000 10D AE EQUAll0N e~S)O.385 1 H Ii ~L i. j t Time of concentration (l1ourS) Watercourse Distance (mUss) Change in elevation ~lon9 effective slope fine (See Agure a..5)(feet) -! \: I ! Tc i.; L Miles Feet 0.5 L . 3000 , 2000 1800 1600 1400 1200 200 " , " Hours Minut~s 1 ~ 4 2401-'\'! . 1 ~ 1~O I " "-" Tc 11 120 -ll } ~; t I: i t ~ 60 I'll 50 t t; I ' j. ,\ t ~ I Ii ~ J ~! I I: ! ,I {I 'i t q ! t , I i; 0, -~ \ ! I 'jl :~ ~ \;1 ttl t . ~ , ;1; l j 1 , ,\: ~ -f.'. If, 1;' F ,1 ti f ~ I ~ ~ I Ii f ! j I 'j! SOURCE: Ca/ifbmia DivisIon of Highways (1~41) and Kirp/ch (1940) _ , ' ~~~~~~~~~~~~~~~~--~--~------------~t~~l-F---I-G---U--R~E Nomograph for Detenninafion of f, 1~. TIme of Concentration (Tc) or Travel nme (Tt) for Natural Wltersheds t:. ~-\ ~ ! ',. ' i' i j, 1", f ," o o I , , " , MAP (U.S.D.A.) QUADRANGLE e TABLE . If! e l~ 11.--lNTERPRETATIONS FOR LAND ~~AGEMENT--CQnttu~ed Map symbo Soil Lffi I.oas Flores-Urban land complex, 9 to :SO percent slopes: LpB LpC LpC2 Las Flores-------------------------------------------- Urban iand-------------------------------------------- Las Posas fine sandy loam~ 2 to 5· percent slopes---------- Las Posas fine sandy loam~ 5 to 9 percent s1opes---------- Las Posas fine sandy loam~ 5 to 9 percent slopes, eroded. LpD2 Las Posas fine sandy loam~ 9 to 15 percent slopes ~ eroded. LpE2 !Las Posas fine sandy loam, 15 to 30 percent slopes, eroded. LrE Las Posas stony fine sandy loam, 9 to 30 percent slopes. LrE2 Las Posas stony fine sandy loam, 9 to 30 percent slopes, eroded. LrG lLas Posas stony fine sandy loam, 30 to 65 percent slopes. LsE Linne clay loam. 9 to 30 percent slopes------------------ LsF Linne clay loam, 30 to 50 percent slopes----------------- Lu Loamy alluvial land-------------------------------------- LvF3 Loamy alluvial land-Huerhuero complex. 9 to 50 percent slopes, severely eroded: Loamy alluvial land------------------------------~--- Huerhuero-------------------------------------------- Md iade land-----------------------------------------------~ ltUC ~rina loamy coarse sand~ 2 to 9p'ercent sl0:2es---------- ""'''· ........ '''''&iIE'-~~a'i1'Ci7'9to 30 percent: slopes--------- MIlA . Mecca coarse sandy loam, 0 to 2 percent slopes----------- MnB Mecca coarse sandy loam, 2 to 5 percent slopes----------- MoA ~ecca sandy loam. saline, 0 to 2 percent slopes---------- ltfpA2 lMecca fine sandy loam. 0 to 2 percent slopes, eroded-----~~G ~etamo7phic rock land------------------------------------ MvA Mottsville loamy coarse sand~ 0 to 2 percent slopes------ MvC (ottsville loamy coarse sand~ 2 to 9 percent slopes------ MvD ~ottsville loamy coarse sand, 9 to 15 percent slopes----- MxA Mottsville loamy coarse sand, ''let, 0 to 2 percent OhC one OhF Oke slopes. Olivenhain cobbly loam, 2 to 9 percent slopes------------ 01ivenhain cobbly loam, 9 to 30 percent slopes----------- Olivenhain cobbly loam, 30 to 50 percent slopes---------- Olivenbain-Urban land complex, 2 to 9 percent slopes: Olivenhain---------------------------_______________ _ Urban land-------------------------------___________ _ OkE Plivenhain-Urban land complex, 9 to 30 percent slopes: Olivenhain-----------------------___ -_________ ~ _____ - PeA PeC Pee2 PeD2 PfA Urban land------------------------------------------- Placentia sandy loam. 0 to 2 percent slopes--------------- Placentia sandy loam, 2 to 9 percent s1opes-------------- Placentia sandy loam. 5 to 9 percent slopes. exoded------ Placentia sandy loam, 9 to 15 percent slopes, eroded----- Placentia sandy loam, thick surface, 0 to 2 percent slopes. PfC Placentia sandy loam, thick surface. 2 to 9 percent slopes. Py Playas--------------------------------------___________ -_ See footnotes at end of table. 36 f i ~ Hydro- logic group I f~~~clibility 1 J; D D D D D D D D D D c C B D D D A A B B B B D A A A o D D D D D D D D D D D D D D , \ ~ , ;~ . '}~oderate 2---- M{laerate 2---- ) fh6rierate 2----IT ' rl~oderate 2,..---r i 1 h;j'6derate 1---f .!. I! t l·lOderate 1---, "it I . t.{ IModerate 1--- : W' ! .' ! S~vere 1-----\. ,.! , I : l~~~.derate 2--- !q~;vere 1----- : St~ilere 16---- i L t .~ \ ;S~'vere 1-----:S~vere 1-----: " i ~ ; Sl~yere 2-----1l~ere 2-----, r.!~ ,.)\were 16 lSe~ere 16 'S~ilere 16 ,~~vere 16 S,~ve:re 1-----S,~\rere 2..,---- 'S,);vere 2-----S;~'\rere 2----- 1 S.~;vere 2-----: 'j. , ~; 5l.were , sr~vere ·'S;~vere I "'<j: ~ ~ . , . '. \ ,'5 , _,J " J. '~- 16-'--- 16----1----- ;; s,~yere 9----- I St~ilere .9-----:. S(~\re:re 9-----[S~~ere 9-----r $r~1rere 16---- I ',1 ~ I ~~{t i iS~vere 16---- Il· I 1It}~.i:lera:l:e 2 I t:.i 1 ~. 1; 'f; i; , )t, jt t . r I" t ,i\, J l.im.ta't::;::s con:'.-eZ'S:' z:: from =::-..::;: ;::.,.; -"-,.-i'-~ ... _= ... R E.i~~~ .. . S::'i.;-:~ " '. , I Slight. Slight. Modera1;e. ·Moderate. Mllderate. Moderate. Moderate. Slight. Severe. Severe. Sli~ Slight:_ Severe. Slight. 4 Slight. 4- Slight. 4 Slight. '4 Slight. Slight. Moderate. Slight. Slight. Slight. Slight. Slight. Slight. ~.