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Home My WebLink AboutCT 08-06; Highland James Subdivision; Hydrology and Hydraulic Report; 2014-11-06- --- ---------• -• --- .... - - - ---- CITY OF CARLSBAD PREPARED BY: Aquaterra Engineering Inc. 1843 Campesino Place Oceanside, CA 92054 tele: 760-439-2802 fax: 760-439-2866 NOVEMBER 6, 2014 Prepared under the supervision of: -- TABLE OF CONTENTS SHEET DESCRIPTION -2 Project description 3 Hydrology Report 16 Hydraulic Calculations -20 Drainage Map Exhibits - -• ---.. -- - - - ----- ------- - -• --- ----- - - - - Hydrology & Hydraulics Report City of Carlsbad This Hydraulics and Hydrology Report was prepared using the following Manuals: Hydrology Manual, June 2003 edition, County of San Diego Drainage of Highway Pavements, U.S. Dept. of Transportation The Rational Method was used to determine the 100 yr. storm Q values. The Rational Method uses the following formula to establish the flow: where, Q=CIA Q = the peak runoff in cubic feet per second C = Runoff coefficient representing the ratio of runoff to rainfall I= time average intensity in inches per hour A = Area of the subbasin in acres ----- --- --------- - ----- - - Project Name, Location, Description Project Name: Highland James Subdivision, Lots 1-3 Project Address: James Drive, Carlsbad, CA 92008 Project Size: 0.52 Acres Area Disturbed: 0.47 Acres The site is located on James Drive, in the City of Carlsbad. This project, lots 1, 2 & 3, is the first phase of a 5 unit subdivision. The subject lots (1-3) are downstream of the lots in the later phase and accepts their drainage water. Existing Site Features and Conditions The site is currently vacant. The site is bordered on the north by Highland Drive on the west side and James Drive on the east. The land slopes in a northeasterly direction toward James drive. The site ultimately drains into the Aqua Hedionda Lagoon. The San Diego County's Hydrologic Soil Maps describe the onsite soil as being in Group A and having "low Runoff Potential". A site specific geological investigation is being conducted and the results will be contained in a report with findings and recommendations. Proposed Development Parameters The proposed site development includes the grading of pads only. No impervious surfaces such as buildings are not proposed at this time. However, the site accepts offsite drainage from partially developed land located westerly of the site. This offsite land is currently own by the owner/ developer. The results of the attached calculations show the following discharge rates: BASINA+B BASINA&B PRECONSTRUCTION INFLOW I OUTFLOW 1.46 cfs POST-CONSTRUCTION FLOW CONTROL INFLOW OUTFLOW 1.20cfs 1.20 cfs The post-development outflow is 0.26 cfs less than the pre-development outflow condition. Conclusion There is no historical evidence that the downstream water courses are inadequate to handle the storm flows. Due to the minimal modification of the site development, we do not believe that any downstream properties will be adversely impacted by the proposed development.. The project site is not located near a floodway or floodplain or a water course plotted on any official floodway map. As a result of the site drainage features and proposed modifications, we do not anticipate any negative impacts to downstream properties or drainage systems. -.. --- -HYDROLOGY CALCULATIONS .. --... - --... • - ----- - - - ~) ---Aquatet·ra Engineering Inc. -----... - ·-•• -•• --- - ----- --- -- --Aquate1·ra Engineering Inc. -- ---.. -----.. ----· • ----------·---I I 1--i I I I ! -j -I ! I / I I i I l -------------I L. I I i l ! ' t ----··---·-·-····-·-~ .. -• Aquaterra Engineering Inc. -.. -PROJECT .. ,_J -c-----~ --.. -• -L ! __,____.,_JJ_J ! l ,. - ·111111 -----i ,. .. I -- --I -+--f--i--f--1--+---+---l--i---l I_. - - !:-----!---l--4--+--· --+---.-I ---__,_---+--_,_-+--- L_ ___ . . '"' l~LL_l --Aquate1,·ra Engineerirg Inc. ---. - - - -I ,,_~~_,_J__LJ - ! I i --+--+---1-+--_I I,__,___,__ I I _1 --+--+--+--+--frL ! -.----,.--1---1---1---+___,_'--l-4---1-'-: =--4---F-'-.i---!'-""'0"""""'---!-'--+---"---+--i---i---"+----r--t----t--,L I I • - - - ..... -... ---I I i I I ! i i I i I i -J - --Aquate,,·ra Engineering Inc. - ' I ~=~± ~) i I I: I I i i i I i I I f I I I I t t I I I I I I I I I I I i j, t I San Diego County Hydrology Manual Date: June 2003 Table 3-1 Section: Page: RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use ,. Runoff Coefficient "C" Soil TXBe . NRCS Elements Coun Elements %IMPER. A B C Undisturbed Natural Terrain (Natural) Pennanent Open Space o• 0.20 0.25 . 0.30 Low De11sity Resid~ntial (LDR) llesidentiat, .1.0 DU/A.or less JO 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 (LOR) Residentia~ 2,9 DU/ A or less 25 0.38 0.41 OAS Medium Densij:yJleside11tial (ty{Qll) Resi4~nt111l, 4.3 DU/A. or le.ss 30 c.. ' -•. . . · .• .0 .. 41 ·o.4S 0.48 Medium Density Residential (MDR) Residential, 7.3 DU/A or less 40 0.48 0.51 O.S4 ,-,~ Medium Density Residential (MDR) · Residential, 10.9 DU/A or less 45 O.S2 O.S4 0.57 Medium Density Residential (MOR) Residential, 14.S DU/A or less so 0.55 0.58 0.60 High Density Residential (HDR) Residential, 24.0 DU/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. 0.;t8 Commercia11Industrlal (N. Com) Neighborhood Commercial 80 0.76 0.77 0.78 CommerciaVIndustrial (0, Com) General Cormnercial 85 0.80 0.80 0.81 Commercial/Industrial (O.P. Com) Office Professional/Commercial 90 0.83 0.84 0.84 CommerciaVIndustrial (Limited I.) Limited Industrial 90 0.83 0.84 0.84 Commercial/Industrial (General 1.) General Industrial 95 0.87 0.87 0.87 3 6of26 D 0.35 0.41 0.46 0.49 0.52 O.S1 0.60 0.63 0.71 ,, 0.79 0.79 0.82 0.85 0.85 0.87 *The values associated with 0% impervious may be used for direct calculation of the runoff coefficient as descn'bed in Section 3.1.2 (representing the pervious runoff coefficient. Cp, for the soil type), or for areas that wilt 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: Page: 3 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 w.pere 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 T; 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. · Table3-2 MAXIMUM OVERLAND FLOW LENGTH CLM) & INITIAL TIME OF CONCENTRATION (Tj) -Element* DU/ .5% 1% 2% 3% 5% 10% Acre LM Ti LM Ti 4f Ti LM Ti LM Ti 4t Ti Natural 50 13.2 70 12.5 85 J0.9 100 10.3 100 8.7 100 6.9 LDll 1 5() 12.2 70 l.L5 85 10.0 100 9.5 100 8.0 100 6.4 ·-· LDR 2 50 11.3 70 10.5 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 95 7.8 100 6,7 . . JOO 5.3 MDR 7.3 50 9.2 65 8.4 80 7.4 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 NIDR 14.5 so 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 90 4.9 95 4.3 100 3.5 HDR 43 50 53 65 4.7 75 4.0 85 3.8 95 3.4 100 2.7 N.Com 50 5.3 60 4.5 75 4.0 85 3.8 95 3.4 100 2.7 G.Com l 50 4.7 60 4.1 75 3.6 85 3.4 90 2.9 100 2.4 O.P./Com 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 Limited I. 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 l ' i General I. 50 3.7 60 3.2 70 2.7 80 2.6 90 2.3 100 1.9 ··~·*See Table 3-1 for more detailed description . ---------------~ r-'1 ~/ I•• 11 11 If 11 I 11 II II II 1111 II II Ii ll 11 10 9 8 'i e., 6 4 3 2 I 51. I~:: o. o. o. o .. o. I ) '' ) ' ,, ' >'-..-.. ) .. ' r,... )~ ' • ) ', ) ) J I ' ! I I I 0.2 ! 0.1 i...- ( "' ... "'" ....... ' ... •"'I ~ ' ' ....... Ii, "' ...~ ... IL .... ... ... -,"' "'~ ..... "' .... ..... ... '-i,,, ....... It " ' .. ... '~ "' .. ~~ , .... "' " ... ~ . ... ~ .. ~ ~i,,, '~ '~ "' ... ... .... "°'i,,, 'i,,, ". '~ .... loo h.. ........ "' 'i... .... ~ ..., """" ~ "'~ ~~ •. ,1 . . ' . ~ --"'. . r 8 9 10 11! 20 so 40 801 Minutes Durallon EQUATION l = 7.44 Pe o-<>,845 I = Intensity (In/hr) I, Pe = 8-Hour Precipitation (In) D = Duration (min) ~ Ill ', ' .. .... ~ ' ...,i... "', .. ,.. "' ·~ i... ~ .... "" ... .. ~ ~ ~ i"I"" 1~ "" ... '°"I' ~ ~~ ~ ", "' "~ ~ ~ ~ "'~ • "" ~ .... r,~ .... 1, ~~ ~ .... ... ~ r,11, 1, "' " r, 11111.11 :, ' ""'"" ~ i,,..i... -i-,-... ,.., ... -I I I 2 3 4 · 6 6 Hours i e.oj 5.5 • 6.0 4,ll '§1 4.0 i 3.6 ..... 3.0 2,5 2,0 1,5 1.0 Dtrect1ons for Appllcatlon: (1) From precipitation maps determine 6 hr and 24 hr amounts for the selected frequency. These maps are Included In the County Hydrology Manual (10, 50, and 100 yr maps Included In the Design and Procedure Manual). (2) Adjust 6 hr precipitation (If necessary) so that It Is within the range of 45% to 65% of the 24 hr preolpllatlon (not appllcaple to Desert). (3) Plot 6 hr precipitation on the right side or the chart. (4) Draw a line through the point parallel to the plotted lines. (5) This line Is the lnten61lty-duratlon curve for the looaHon being analyzed. Application Fonn: (a) Selected frequency _ year . c P .C/, {b) Pa= 1..tS:: In •• P24 = _L_ ,.3.p = ~ %(2} . 24 · (c) Adjusted P612l = Z;S_ in. (d) tx = _ min . (e) I= _ inJhr • Note: This chart replaces the lntenslty-Ouratlon·Frequenoy curves used since 1965. lntanalty•Duratlon Design Chart• Template ~~-i,• 3-1 ·~ :_: ( ,., eanslde. .. -... Mic CARLSBAD .. ... j> --z... -A -->" - - -. --. ")7 \ MIC ~\1'~ (s,j l j i I i i l I i f I • ) l I I t I I l I I I I I ) . I I . , 1 1 a • .. ,,I' County of San Diego Hydrology Manual Ral1ifall lsopluvials 100 Yenr Rnl11fnll Eve11t N 24 Hours \ ........ laopluvlal (l11ch1111) \ f)]}'JV ..,·"..,;.··G1\"S .in,,,., ell .~?·rr-11"(\".'." . .. . : \\JT .1h:v ~-:~\fo.f.-:-i~1\'ht.Lt,IJ(.:&1\Ut.Jt ~=n~,. \II s O' II. ~M"°'\MflfJI0.111&tMlltlWAMA1"1U '[1'"'11"""°"'-"'''UN.., ... lm<l•UfAI\I ~ ·=,. ~9't~fG"-""'tr.u.J.Af'OOfOU. tl•lf"l..-.111U1«rill'WIHftU<.,,,1,yt1e.atAJ"'>ll1t..,-fl'ILI !! w..-,r,,,,...,.,""'.,.'"'i.n,"'_.. .. """'"' ,1 -.r.1t'\t,IUIOHCAdClt.,10. 11o,,,1111.w .... 1unl>lrt~.u,,•111H11l,c,;.."'.:tS'-"·" ,,~1,a\c,rtltr"'"""'~"'"' 0 3 MIies c:::::l ~ - §>o~ t5 ~ ... ~ .. = ~ 0 ::z:: ta~ ..t! ,0 .. ' ii a-.. (I) @ 6 C ~ = ~ 'S t.H :::: ;;; oo ..g, i % D ......-1 -E = .!! ~\~ I;:; -;i e::: C: ... g£ C: ... ?-" = u C - --- - .. -- , . .:.. 11,-..,...-,----·-t--_. _ _.:_; -t·\···:. ""\ ...... .J.-~'-''-+;r.'--,>'-.:-;--,c-;;,,-+_.,..1' ~~'.~.~-t.;---c--'-1-~~ ;~t;~~~~~~~i~~.~~~~-?'f'=:...,;f.::;:f:i.;~:;Jtl::i!:~~~~r:t;:::~qt:~+=1~~ -... - • - .. .~~-~.,_I_LJ ~~+-rli-i"""? - EQUATION -A.E (1~~3)0.385 Tc = Feet 5000 Tc = Time of concentration (hows) L ::,; Watetcourse Distance (miles) 4000 JSE = Change in elewtion along effective slope fin~ {See Figure 3-5)(feet} 3000 4 240 -20D0 • a 180 --·- 1 60 50 40 L Miles Feet 30 - .l 20 ·-' 18 3000 16 0.5 ' ' 14 -' ' 12 ' ·-30 ' 10 ' 9 8 20 7 6 -5 10 4 -3 -5 -200 L Tc SOURCE: catlfomia Division of Highways (1941} and Kupich.(1940) -FIGURE Nomograph fot Determination of Time of Concen1ratlon (Tc) or Travel Time (ff} for Natural W:lfersheds ~ - --- HYDRAULIC CALCULATIONS - .. ------ --- -.. - - - -- - -.. Select Channel Type: Circle : b : I :~.::: T,::id _ .-1 --D-e-pt_h_f_ro_m_Q _______ .-ls_e_le_c_t_un_i_t_s_ys-t-em_:_F_e-et-(ft_) __________________ _ • jchannel slope: .5 ft/ft jwater depth(y): 0:09 ft I Radi~s (r) 1 ft -jFlow velocity 12.0529~ ft/s .-jL-eft_S_l-op-e-(Z-1 )-: ____ ft/_ft _____ /RightS1ope(Z2): ft/ft • !Flow discharge .57 ftA3/s j.-In_p_u_t_n_v_al_u_e_·_o_-0-13 ___ or_s_e_le_c_t _n _______________ _ • j Calculate! jstatus: Calculation finished Reset ,. jwetted perimeter 0.85 ft /Flow area 0.05 w2/ ~Ti_o_p_WI ___ dth-(T_)_o ___ 82 ___ ft ___ _ -jspecific energy;2.34 ft jFroude number:8.72 /Flow status;S~p~r~riticalflow • \critical depth\0:26 · ··· , !ft .-,C-n-.tl-.c-al_s_l_op_e_\0"""··~=00=·4=9'""'-,·~=iftl=ft,.,..,.,,,,=----,Velocity head;2:26 ·· · :ft - Copyright 2000 Dr. Xing Fang, Department of Civil Engineering, Lamar University. - -• - - - -.. - .. --- )pen Channel Flow Calculator http://www.eng.auburn.edu/-xzfUOOl/Handbook/Channels.htm - - - -• - - .. - - - - , ... Tofl B 11 Ou Pi~),:, . ···"") The open channel flow calculator Select Channel Type: Circle j Depth from Q /select unit system: Feet(ft) jchannel slope: J:01 --~ jwater depth(y): fo.48 ftt'"- ~F-lo_w_v_e_lo-ci_ty_f3-~-8-.7-82--_Jw_s __ ::::-ILeftSlope(Zl ): r--fwit- Flow dischargej1 .02 ltr3/s :• Input n value!o.013 ·· or select n clean.uncoated castiron:0.014 / Calculate! /status:fc;ic·ul~tio~--fini;hed -- ~~--e-tt-_ e_d_p_e-ri_rn_e-te-n=f1=·~=~5=----1Flow are~ltt" 2 -- 1ft I !specific energyj0.71 r IFroude nurnbe~----· 'jc_n_· ti-. c-al_d_e_p-thJ'f'=o .=4=9==,.ltt==£.,.,-. · -\Critical slopefo.ciogs jftlft /!Radius (r) ___ ~--!fl·-- RightS1ope(Z2): r-· · f wtt ' Reset \Flow status~~ritical fl~~·- /velocity heaclj0.23 .m,.= ~--- Copyright 2000 Dr. Xing Fang, Department of Civil Engineering, Lamar University . 6/22/2014 3:16 Pl i\o) \~ ·-• The open channel flow calculator JS 12C (? 6vJ r~~ ~ - 11111 Select Channel Type: Circle -I -I Rectangle Trapezoid Triangle -I Depth from a I !select unit system: Feet(ft) -/channel slope: 0.01 ft/ft /water depth(y): 0.61 ft j Radi~s (r) .625 ft .. jFiow velocity 5.2 ~------ft/-s ---~,L-eft_S_l-op-e-(Z_l_)_: ___ ft/_ft _____ jRightS1ope(Z2): ft/ft .. )Flow discharge 3.06 ft"3/s ~jln_p_u_t_n_v_a_l_ue-.-0.-0-13 ___ or_s_e_le_c_t_n _______________ _ ... I Calculate! --------------jstatus: Calculation finished I Reset .. jwetted perimeter 1.93 ----------- 1 Flow area 0.59 ft"2 jTop width(T) 1.25 ft ft ... jspecific energy 1.03 __________ ft ____ lFroude number 1.33 !Flow status Supercritical flow • !critical depth 0.71 !~c-n-·t1-·c_al_s_l_op_e_o ___ oo_6 ___ ft/_ft _____ lvelocity head0.42. ft ft --Copyright 2000 Dr. Xing Fang, Department of Civil Engineering, Lamar University. - 1111 ------ .. - - .... -- SYMBOL LEGEND DESCRIPTION SYMBOL ELEVATION, TOP OF STRUCTURE~TOP ELEVATION, TOP OF WALL TW ELEVATION, TOP OF CURB TC ELEVATION, FINISH FLOOR FF ELEVATION , FINISH SURFACE FS ELEVATION, FINISH GRADE FG ELEVATION , TOP OF GRATE TG ELEVATION, HIGH POINT HP ELEVATION, LOW POINT LP ELEVATION, FLOW LINE FL 0:__ __ ----=20 40 Seo.le• l' ~ 20' CITY HIGHWAY OF OCEANSIDE 78 CTASSWOOD AVE. ~-..,( ;;, j_ ~ SITE~ 7cJ '\ VICINITY MAP DRAINAGE MAP-POST CONSTRUCT/ON SCALE: 1 "=20' ---v-'l ~ : I I I CITY OF VISTA L---°L p p..LOll>/>.f'-AIRPORT ROAD NOT TI> 50ALE HIGHLAND-JAMES SUBDIVISION CT 08-06/ CDP 08-17 / HDP 08-03/ zc 08-01 SUPERVISION OF• ---). ___ _ GARI LIPSKA _____ DATELJ/..b.}11-- RCE 23080 EXPIRES 12/31/15 PLOT DATE• 11-06-14 I I t -1-' 'ss __l ____ ·S--, 20 SYMBOL LEGEND DESCRIPIIPN SYMBOL ELEVATION, TOP OF STRUCTURE_TOP ELEVATION, TOP OF WALL TW ELEVATION , TOP OF CURB TC ELEVATION, FINISH FLOOR FF ELEVATION, FINISH SURFACE FS ELEVATION, FINISH GRADE FG ELEVATION , TOP OF GRATE TG ELEVATION, HIGH POINT HP ELEVATION, LOW POINT LP ELEVATION, FLOW LINE FL 0 20 40 ----. Scole• 1 • = 20' CIVIL ENGINEERING * LAND PLANNING & §ie,gterra Engineerina Inc. ~ 1843 Campesino Pfuce ~ Oceanside, CA 92054 ~ Tele: (760) 439-2802 Fax: (760) 439-2868 CITY HIGHWAY OF OCEANSIDE 78 CTASSWOOD A\IE, 1- ~ SITE~ ~ VICINITY MAP ' i . I I I I I I I I ~ I I I I I I I I I I I I I I I ~ I I I I I I I I ~ DRAINAGE MAP-PRE-CONSTRUCTION --~ p : -I NOT 10 SCALE I I I CITY OF VISTA ~--°L SCALE: 1 "=20' ·-----·-------------~ ~- i I I I HIGHLAND-JAMES SUBDIVI 1 I . I I I I I I I . I I I -J \ ) UPERVISIDN OF• PLOT DATE• 11-06-14