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HomeMy WebLinkAboutPUD 2018-0006; BREAKERS VIEW BEACH HOMES; PRELIMINARY DRAINAGE STUDY; 2019-07-10--.. --- ------------.. -.. -- --.. --... - -.. -- PRELIMINARY DRAINAGE STUDY TENTATIVE PARCEL MAP BREAKERS VIEW CONDOMINIUMS CITY OF CARLSBAD APN: 204-232-12 JUL l ~ 2019 CITY OF CL\f~LSBAO PLANNli\JG DIVlSION Prepared for: Jason Ianni 2337 Catalina Avenue Vista, CA 92084 Prepared by: bl-tA, Inc land planriing, civil engineering, surveyin[J 5115 Avenida Encinas, Suite L Carlsbad, CA 92008-4387 (760) 931-8700 July 10, 2019 w.o. 1013-1369-400 --- ---------------- -- --- .. -... - --- TABLE OF CONTENTS I. DISCUSSION .............................................................................. 3 V1c1n1ty Map ........................................................... 3 Purpose and Scope .................................................. 4 Project Description ................................................ .4 Study Method ......................................................... 5 Hydrology and Hydraulic Calculations ........................ 6 Conclusion ........................................................... 8 Declaration of Responsible Charge .............................. 9 II. EXHIBITS ................................................................................. 10 Existing Hydrology Map and Proposed Hydrology Map ... 10 III. HYDRAULIC CALCULATIONS .................................................... 11 . ----··•-·., , Flow-Through Planter Storage and Outflow Calculations ........................................................... 12 Flow-Through Planter Detail .................................... 16 IV. REFERENCES ............................................................................. 17 Breakers View Condominiums Preliminary Drainage Study Methodology -San Diego County Hydrology Manual bl-IA, Inc. land planning, civil engineering, surveying - ----- ------ - ---------- --.. -.. .. -- VICINITY MAP: Breakers View Condominiums Preliminary Drainage Study I. DISCUSSION ~ VICINITY MAP NTS bl-IA, Inc. land planning, civil engineering, surveying 3 L__ -- - --------- ---- - - --- --- .. -- PURPOSE AND SCOPE: The purpose of this report is to publish the results of a hydrology and hydraulic analysis for the proposed condominium project at 3648 Carlsbad Boulevard, City of Carlsbad. The proposed project is a 0.158 acre site. The scope is to study the existing and proposed hydrology and hydraulics as it influences the surrounding properties during a 100-year frequency storm event, and make recommendations to intercept, contain and convey QlO0 to the historic point of discharge. PROJECT DESCRIPTION: The project is located at 3648 Carlsbad Boulevard, near the southwest corner of the intersection of Cherry Avenue and Carlsbad Boulevard, in the City of Carlsbad. The project proposes the development of two condominiums with parking areas. The disturbed area is 0.16 acres; the existing site is 31 % impervious pre-redevelopment (2,018 square feet) and 72% impervious post- development (4,938 square feet). The proposed drainage basin matches the existing drainage basin in terms of overall area and basin limits. Storm flows affecting the site are limited to the rainfall that lands directly on this property. The following table summarizes the existing condition runoff information from the site. Please refer to the Existing Condition Hydrology Map for existing drainage area. TABLE I-Summary of Existing Condition Peak Flows Carlsbad Boulevard 0.158 0.59 The proposed drainage pattern will be similar as the existing drainage pattern with some modifications to incorporate the Low Impact Development (LID) Best Management Practices (BMPs) into the project design to mimic the impacts on storm water runoff and quality. The proposed runoff from the project is divided into three separate basin areas. DMA 1 ). Runoff from the condominium roofs will be captured and conveyed via roof drains to the proposed flow-through planters for storm water treatment. Runoff will be filtered through the media layer and aggregate storage layer before draining via underdrain pipe to a sidewalk underdrains at the southwest and northwest corners of the property. The sidewalk underdrains will direct flow southwesterly into the Carlsbad Boulevard curb and gutter. Flow will then be intercepted by the existing curb inlet in Carlsbad Boulevard, south of the Cherry Avenue . DMA 2). Runoff from the landscape, concrete sidewalk, and permeable pavement areas in the westerly portion of the project will flow towards Carlsbad Boulevard in the curb and gutter. Flow Breakers View Condominiums Preliminary Drainage Study bl-tA, Inc. land planning, civil engineering, surveying ---------------------------------------' 4 ---- - -------- ----.. ----.. - - All! will then be intercepted by the existing curb inlet in Carlsbad Boulevard, south of the Cherry Avenue. The permeable pavement areas and landscaping area swill provide pollutant control treatment of the storm water before discharging onto Carlsbad Boulevard. DMA 3). Runoff from the landscape, concrete sidewalk, and permeable pavement areas in the easterly portion of the project will flow towards a existing concrete swale in the alley near the northeast comer of the project. The table below summarizes the expected cumulative 100-year peak flow rate. Please refer to the Proposed Hydrology Map. Per the San Diego County Rainfall Isopluvial maps, the design 100-year rainfall depth for the site area is 2. 7 inches. TABLE 2-Summary of Developed Conditions Peak Flows Carlsbad Boulevard 0.158 0.79 STUDY METHOD: The method of analysis was based on the Rational Method according to the San Diego County Hydrology Manual (SDHM). Drainage basin areas were determined from the proposed shown on the tentative parcel map. Initial time of concentration of 5 minutes is used for P6 for 100 year storm, see References. Rainfall Intensity= I = 7.44*(P6)*(Tcr·0·645 P6 for 100 year storm= 2.7" In accordance with the County of San Diego standards, runoff coefficients were based on land use and soil type. The runoff coefficient is calculated from the impervious percentage for a given area using the formula from the SDHM . Where: C = 0.9 x (¾Impervious)+ Cp x (1 -¾Impervious) = Pervious Coefficient Runoff Value for the soil type (shown in Table 3-1 as Undisturbed Natural Terrain/Permanent Open Space, 0% Impervious). Soil type is Type B for this project determined from the Web Soil Survey in Appendix soil type map in the References. All landscaping (including raised planters) and permeable paver areas were considered 0% impervious because there is no impermeable liner to reduce the infiltration of water into the soil. Breakers View Condominiums bliA, Inc. Preliminary Drainage Study land planning, civil engineering, surveying ---------------------------------------~ 5 L ------------ --- ----------.. - ---- All roof and concrete areas were considered 100% impeivious. For the existing condition, all landscape and concrete areas were tabulated and the total existing site was calculated to be 41 % impeivious. A runoff coefficient of 0.52 was assigned for the existing hydrology. For the proposed condition, DMA 1, which encompasses the roof area draining to the LID planter (flow-through planters will have a impermeable liner to prevent infiltration), is considered 98% impeivious. A runoff coefficient of 0.88 was calculated for DMA 1. DMA 2, which encompasses the landscaping, concrete sidewalk, and peivious pavement areas in the westerly portion of the project that drains towards Carlsbad Boulevard in the curb and gutter is considered 8% impeivious. A runoff coefficient of 0.31 was calculated for DMA 2. D MA 3, which encompasses the landscaping, concrete sidewalk, and peivious pavement areas in the easterly portion of the project that drains towards a concrete swale in the alley is considered 38% impeivious. A runoff coefficient of 0.50 calculated for DMA 3. See the runoff coefficients and impeivious area percentages in the Hydrology and Hydraulic Calculations on the following pages. HYDROLOGY AND HYDRAULIC CALCULATIONS: EXISTING CONDITION HYDROLOGY TOTAL AREA (acres)= 0.158 IMPERVIOUS AREA (acres)= 0.066 PERCENT IMPERVIOUS 41.4% la=c1A Tc=5 MIN C = 0.9 x (%Impervious)+ CP x (1 -%Impervious), CP = 0.25 PERCENT IMPERVIOUS 41% C I (in/hr) A (ac) Q (cfs) 0.52 7.11 0.158 0.59 bl-tA, Inc. Breakers View Condominiums Preliminary Drainage Study land planning, civil engineering, surveying 6 ---- ----- -- ------------.. --- ----- DEVELOPED CONDITION HYDROLOGY DMA 1-ROOF DRAINING DIRECTLYTO LID PLANTERS TOTAL AREA (acres)= 0.102 IMPERVIOUS AREA (acres)= PERCENT IMPERVIOUS lo=c1A 0.099 97.7% C = 0.9 x (%Impervious)+ Cp x (1-%Impervious), CP = 0.25 PERCENT IMPERVIOUS C I (in/hr) 0.88 7.11 97.7% A (ac) 0.102 0.32 CFS DRAINS TO EACH LID PLANTER ON EACH SIDE OF THE FRONT PATIO. DMA 2 -AREAS DRAINING TO CARLSBAD BLVD TOTAL AREA (acres)= IMPERVIOUS AREA (acres)= PERCENT IMPERVIOUS lo=c1A 0.024 0.002 8.7% C = 0.9 x (%Impervious)+ Cp x (1-%Impervious), CP = 0.25 PERCENT IMPERVIOUS C I (in/hr) 0.31 7.11 DMA 3 -AREAS DRAINING DIRECTLY TOWARD ALLEY TOTAL AREA (acres)= IMPERVIOUS AREA (acres)= PERCENT IMPERVIOUS lo=c1A 0.032 0.012 38.0% C = 0.9 x (%Impervious)+ CP x (1-%Impervious), CP = 0.25 PERCENT IMPERVIOUS C I (in/hr) 0.50 7.11 bl-tA, Inc. 8.7% A (ac) 0.024 38.0% A (ac) 0.032 Tc=5 MIN Q (cfs) 0.63 Tc=5 MIN Q (cfs) 0.05 Tc=5 MIN Q (cfs) 0.11 Breakers View Condominiums Preliminary Drainage Study land planning, civil engineering, surveying 7 - - --- -- -.. - - • .. .. .. 11 .. • TABLE 3-Summary of Existing and Developed Condition Peak Flows SUMMARY OF PEAKS FLOWS AREA (ac) EXISTING PEAK DEVELOPED PEAK FLOW (cfs) FLOW (cfs) DIFFERENCE (cfs) 0.158 0.59 0.79 0.20 CONCLUSION: As shown in Table 3, the development of the proposed Breakers View Condominium Project will result in a net increase of peak flow discharged from the project site by approximately 0.20 cfs. This increase is considered negligible to the overall drainage discharged into the existing public storm drain downstream where an existing curb inlet located along Carlsbad Boulevard south of Cherry Avenue. Existing City of Carlsbad Improvement Drawing 273-8 (See References) shows an existing 18-inch storm system in Carlsbad Boulevard. Landscape, permeable pavers and impervious dispersion areas will slow runoff discharges, and reduce runoff. These small collection techniques foster opportunities to maintain the existing hydrology and provide a much greater range of retention practices . The developed site will also implement source control and site design BMPs in accordance with the "Standard Project" stormwater requirements . Peak flow rates listed above were generated based on criteria set forth in "San Diego County Hydrology Manual" (methodology presented in Chapter 4 of this report). Rational method output is located in Chapter 3. The hydraulic calculations show that the proposed onsite storm drain facilities can sufficiently convey the anticipated QlO0 flowrate without any adverse effects. Based on this conclusion, runoff released from the proposed project site will be unlikely to cause any adverse impact to downstream water bodies or existing habitat integrity. Sediment will likely be reduced upon site development . Breakers View Condominiums Preliminary Drainage Study bl-IA, Inc. land planning, civil engineering, surveying ______________________________ !8L__ -- --- ----------------- ------- ---- DECLARATION OF RESPONSIBLE CHARGE I hereby declare that I am the Engineer of Work for this project, that I have exercised responsible charge over the design of the project as defined in section 6703 of the business and professions code, and that the design is consistent with current standards. I understand that the check of project drawings and specifications by the City of Carlsbad is confined to a review only and does not relieve me, as Engineer of Work, of my responsibilities for project design. Breakers View Condominiums Preliminary Drainage Study 7-//-/;J Date bl-IA, Inc. land planning, civil engineering, surveying 9 L ------- -- --- ----------- ------- Breakers View Condominiums Preliminary Drainage Study II. EXHIBITS EXISTING HYDROLOGY MAP And PROPOSED HYDROLOGY MAP bl-IA, Inc. land planning, civil engineering, surveying 10 L-....... LEGEND: SURFACE NODE SURFACE FLOW, 100 YEAR (CFS) BASIN AREA BASIN LIMIT FLOW DIRECTION K:\Civil 3D\1369\DWG\HYDRO&SWMP\1013-1369-EX HYDRO.dwg, 7/10/2019 8:19:19 AM EXISTING HYDROLOGY MAP ERE ___________ RS VIEW CONDOMINIUMS \ 0 PROJECT CHARACTERISTICS APN 204-232-12 SOIL TYPE B 0 · 10 20 30 , 'iiiiiiiiiiiiiiiiiiiiiiiiiiiiii I~~~; PROJECT AREA 0.158 ACRES SCALE: 1" = 10' \ \ \ X 48.3 / bl-lA,lnc. \ \ \ \ As'ph. \ \ land plannlng, civll englnee~ng, surveying 5115 AVENIDA ENCINAS SUllE "L" CARLSBAD, CA. 92008-4387 (760) 931-8700 \ \ \ \ EXISTING HYDROLOGY MAP BREAKERS VIEW CONDOMINIUMS CITY OF CARLSBAD PROPOSED HYDROLOGY MAP PROJECT CHARACTERISTICS BRE ______ .JIIJ,,...,ll,,RS VIEW CONDOMINIUMS APN 204-232-12 SOIL TYPE B PROJECT AREA 0.158 ACRES DISTURBED AREA 0.158 ACRES PROPOSED IMPERVIOUS AREA 4,938 SF (0.113 AC) PROPOSED PERVIOUS AREA 1,944 SF (0.045 AC) 50.50 TG 24"X24" BROOKS PCC CATCH BASIN W/ GRATED INLET 2" MULCH 4"-DIA LID ORIFICE IMPERMEABLE LINER ON VERTICAL WALLS AND BOTTOM, PER SOILS REPORT---... 4" PVC WITH 3" PVC REDUCER SIDEWALK UNDERDRAIN EXISTING SIDEWALK SIDEWALK UNDERDRAIN *ENGINEERED SOIL MIX SHALL PROVIDE A MINIMUM SUSTAINED INFILTRATION RA TE OF 5"/HR. MIX SHALL BE SANDY LOAM TOP SOIL CONSISTING OF 50% SAND, 30% PLANTING SOIL, 20% SHREDDED HARDWOOD MULCH. R/W DEEP ROOTED, DENSE, DROUGHT TOLERANT PLANTING SUITABLE FOR WELL DRAINED SOIL 51.5 TW 50.34 FG ~6 ·, \\ 18" ENGINEERED SOIL MIX* {PERMEABLE \ 48. 7 FS 2" PEA GRAVEL PAVERS. \ CARLSBADB':L~VD~-~~~~~~~=;~~iir=~~ \ /1,-',JL...U-~T ;-TF=-'"""'----IO:,, ::R::RATED PVC PIPE W/ ,-..__\\\\\ 3" PVC PIPE 47.53 FL OUT-_, 47.55 FL IN-~ 6" HDPE 1":-84 FL MIN. 3" AGGREGATE BELOW \'--~ >-\. OUTLET 47_67 FL PLACEPIPEWJTH ~. '\ \ PIPE PERFORATIONS ~ , EXISTING AND PROPOSED~EXISTING GROUND OUT AT THE INVERT \\ 'r \_ \ \ SEWER LATERALS SHALL ~ • BE A MINIMUM OF 5 FT ,,.---::::o,,.-'2~%~M'.!'.'.'.lc::N·:,__ ______ 7 '\._ . \ \ BELOW GRADE AT \}__ __________ , __ ~{) "?J> PROPERTY LINE ~ ~ \\\~8 ,7 \ TYPICALBASINOUTLETDETAIL "~) \\ \ \ NOT TO SCALE \ NOTES: 7) ROOF DRAINS TO FLOW-THROUGH PLANTER. 2) LANDSCAPING, CONCRETE SIDEWALK, AND PERMEABLE PAVEMENT AREAS DRAIN TO CARLSBAD BOULEVARD AND REAR ALLEY. 3) ROOF SYSTEM TO INCORPORATE A SYSTEM TO CAPTURE THE FIRST WASH/OFF OF SEDIMENT, DEBRIS DURING A RAINFALL EVENT. SUMMARY OF DEVELOPED \ \ \ ~\\ \ \\\ c \ \ \ ~\ ~\\ ~H '0\\ L \, \ \N \\ ~\\\ \\ \\ \, ~\ \' \ '....J \ \ \\ '\ \ \\ \\ \\ ,\8, 6 LEGEND: OMA 7 -ROOF AREAS DRAINING TO LID PLANTER (0=0.64 CFS, AREA=0.102 AC} \ \ / R '£CT BO ---Wllllli!J CONDITION RESULTS 100-YEAR DEVELOPED FLOW-THROUGH PLANTER --------[ ~: ~: ~ :1 AREA (AC) DISCHARGE LOCATION PEAK FLOW (CFS) DMA 7 0.702 0.63 PERVIOUS PA VERS ------------I: i: i:;::: ~::: i :1 DMA 2 0.024 0.05 CONCRETE SIDEWALK ---------1 .. ~-.. _ .. ] DMA 3 0.032 0.17 DMA BOUNDARY--------------------------- TOTAL 0.158 0.79 K:\Civil 3D\1369\DWG\HYDRO&SWMP\1013-1369· PROP HYDRO.dwg, 7/10/2019 8:19:42 AM bliA,lnc. land planning, cM engineering, suNeylng 5115 AVENIDA ENCINAS SUl1E "L" CARLSBAD, CA. 92008-4387 (760) 931-8700 1..E A R EA 10 5 0 10 20 30 SCALE: 1" = 70' PROPOSED HYDROLOGY MAP BREAKERS VIEW CONDOMINIUMS CITY OF CARLSBAD C Breakers View Condominiums Preliminary Drainage Study III. HYDRAULIC CALCULATIONS bl-IA, Inc. land planning, civil engineering, surveying 11 L FLOW-THROUGH PLANTER BASIN STORAGE AND OUTFLOW CALCULATIONS NORTH SIDE (UNIT A) FLOW THROUGH PLANTER Table 2.A, Overflow Capacity of 24"x24" Brooks Catch Basin Outlet Using Broad Crested Weir Formula equation (6-10) Q=CLH1·5 where Coefficient C is 3.3. Basin Elev Coefficient Weir Length H (ft) a (cfs) (ft) 0.17 3.3 8 0 0.00 0.37 3.3 8 0.20 2.36 0.57 3.3 8 0.40 6.68 0.77 3.3 8 0.60 12.27 0.97 3.3 8 0.80 18.89 1.17 3.3 8 1.00 26.40 Table 2.B, Capacity of (3) 4"-dia Draindown Orifice Plate Assume downstream 3" PVC sidewalk underdrain controls orifice flow1 Using standard submerged Orifice Flow Equation (6-12) Q=CoA(2gH)0 5 Orifice Size 1 Diameter Invert of 4" Delta Area (sf) Coefficient Head (ft) Odrain ( cfs) PVC Orifice Elewtion Based on (3) (ft) (ft) Dia. (ft) 3" PVC Pipes 0.17 0.00 0.2500 0.14726 0.62 2.91 0.00 0.37 0.20 0.2500 0.14726 0.62 3.11 1.29 0.57 0.40 0.2500 0.14726 0.62 3.31 1.33 0.77 0.60 0.2500 0.14726 0.62 3.51 1.37 0.97 0.80 0.2500 0.14726 0.62 3.71 1.41 1.17 1.00 0.2500 0.14726 0.62 3.91 1.45 bliA, Inc. Breakers View Condominiums Preliminary Drainage Study land planning, civil engineering, surveying 12 L C NORTH SIDE (UNIT A) FLOW THROUGH PLANTER Table 2.C-Main Basin Depth vs. Storage and Discharge Information Bottom Basin Area (sf) = 51 Elev Depth Volume CF Volume acre-ft Outflow 0.17 0.00 38.25 0.0009 0.00 0.37 0.20 48.45 0.0011 1.29 0.57 0.40 58.65 0.0013 1.33 0.77 0.60 68.85 0.0016 1.37 0.97 0.80 79.05 0.0018 1.41 1.17 1.00 89.25 0.0020 1.45 ***assuming 25% Void Ratio in Engineered S01I Layer and 40% Void Ratio in Gra\tel Layer Drawdown calculator: Flow through orifice plate go\terns drain-down flow Basin Volume @ 3" Depth (ft3): Total Storage in Soil Media*** Q of (3) 3" orifices plate at 1" Head O\terflow on 24" x 24" Catch Basin Outlet (cfs) Drawdown time (hrs)< 24 hrs ✓ Breakers View Condominiums Preliminary Drainage Study bl-IA, Inc. land planning, civil engineering, surveying 13 L C SOUTH SIDE (UNIT B) FLOW THROUGH PLANTER Table 2.A, Overflow Capacity of 24"x24" Brooks Catch Basin Outlet Using Broad Crested Weir Formula equation (6-10) Q=CLH1·5 where Coefficient C is 3.3. Basin Elev Coefficient Weir Length H (ft) Q (cfs) (ft) (ft) 0.17 3.3 8 0 0.00 0.37 3.3 8 0.20 2.36 0.57 3.3 8 0.40 6.68 0.77 3.3 8 0.60 12.27 0.97 3.3 8 0.80 18.89 1.17 3.3 8 1.00 26.40 Table 2.8, Capacity of (3) 4"-dia Draindown Orifice Plate Assume downstream 3" PVC sidewalk underdrain controls orifice flow1 Using standard submerged Orifice Flow Equation (6-12) Q=CoA(2gH)0 5 Orifice Size 1 Diameter lmert of4" Delta Area (sf) Coefficient PVC Orifice Elevation Based on (3) (ft) (ft) Dia. (ft) 3" PVC Pipes 0.17 0.00 0.2500 0.14726 0.62 0.37 0.20 0.2500 0.14726 0.62 0.57 0.40 0.2500 0.14726 0.62 0.77 0.60 0.2500 0.14726 0.62 0.97 0.80 0.2500 0.14726 0.62 1.17 1.00 0.2500 0.14726 0.62 Head (ft) 2.91 3.11 3.31 3.51 3.71 3.91 bl-IA, Inc. Odrain (cfs) 0.00 1.29 1.33 1.37 1.41 1.45 Breakers View Condominiums Preliminary Drainage Study land planning, civil engineering, surveying 14 L C SOUTH SIDE (UNIT B) FLOW THROUGH PLANTER Table 2.C-Main Basin Depth vs. Storage and Discharge Information Bottom Basin Area (sf) = 60 Elev (ft) Depth (ft) Volume (cf) Volume (acre-ft Outflow (cfs) 0.17 0.00 45.00 0.0010 0.00 0.37 0.20 57.00 0.0013 1.29 0.57 0.40 69.00 0.0016 1.33 0.77 0.60 81 .00 0.0019 1.37 0.97 0.80 93.00 0.0021 1.41 1.17 1.00 105.00 0.0024 1.45 ***assuming 25% Void Ratio in Engineered Soil Layer and 40% Void Ratio in Gra\tel Layer Drawdown calculator: Flow through orifice plate go\terns drain-down flow Basin Volume @ 3" Depth (ft3): Total Storage in Soil Media*** Q of (3) 3" orifices plate at 1" Head O\terflow on 24" x 24" Catch Basin Outlet (cfs) Drawdown time (hrs) < 24 hrs ✓ Breakers View Condominiums Preliminary Drainage Study M-tA, Inc. land planning, civil engineering, surveying 1s L C 50.50 TG FLOW-THROUGH PLANTER DETAIL Not to Scale •ENGINEERED SOIL MIX SHALL PROVIDE A MINIMUM SUSTAINED INFIL TRA 770N RA TE: OF s•/HR. MIX SHALL 8E SANOY LOAM TOP SOIL CONSISTTNC OF SOX SANO, 30:f PLANTINC SOIL, 201¥ SHREDDED HARDWOOD MULCH. 24~X24' BROOKS PCC CATCH BASIN W/ CRATED INLET DEEP ROOTED, DENS£. DROUGHT TOLERANT PLANT1NG SUITABLE: 4• PVC WITH 3• P\IC REDUCER SIDEWALK f.lNOERORAIN EXIST1NG SIDEWALK SIDEWALK UNOeRORAIN 2• MULCH FOR Ml"LL DRAINcD SOIL ::--;a;:--'----5• PERFORA TE:D P\11'.; PIP£ IV/ 6. HOPE OUTLET PIPE PIPE MIN. J" ACGREGA TE" BEZ.OW tl,A~PJl'e.wmt l'ERFORATIONII EXIS77NG AND PROPOSED ---::;;EXISTING GROUND SEWER LATERALS SHAU BE A MINIMUM OF 5 FT -u.::::::::::2:X::M:l:N::. ::::::::::::::::Du BELOW GRADE AT - AT THE INVERT PROPERTY LINE Breakers View Condominiums Preliminary Drainage Study TYPICALBASINOUTLBTDETAIL NOT TO SCALE NOTES: 1) ROOF DRAINS 7V FLOW-THROUGH PLANTER. 2) LANDSCAPING, CONCRE:TE SIDEWALK, AND PERMEABLE PA Vf:MENT AREAS DRAIN TO CARLS8AO BOULEVARD ANO REAR ALL£Y. 3) ROOF' SYSTEM 7V INCORPORA T£ A SYSTEM 7V CAPTURE THE FIRST WASH/OFF OF SEDIMENT. DEBRIS DURING A RAINFALL £'/£NT. bliA, Inc. land planning, civil engineering, surveying 16 L C Breakers View Condominiums Preliminary Drainage Study IV. REFERENCES bliA, Inc. land planning, civil engineering, surveying 17 L C METHODOLOGY -SAN DIEGO COUNTY HYDROLOGY MANUAL Breakers View Condominiums Preliminary Drainage Study bl-IA, Inc. land planning, civil engineering, surveying 18 L C 0 ~'a ·~ s Oca ~~ c:/l 613 t+-t 0 0,--.! f~ 8t Breakers View Condominiums Preliminary Drainage Study i I: " 0 ·~ i:c .., I -::: ' ~ t -1:: : t;:; Jill l .g. = ,:! 1 ~ ~ & .. ! ! V")"I ~ I 1-1} ,ijl 11, J. ., ft 1 Qj j I 111 11 11 ~ V"); ~ fflil~~ z ~ 0 ~Cl)JI I c:: "'l 8: 4 ~tsii , .. I ,I . , :1 U "; N 0,11 ~ ?i' ~ t, lf lf z bl-I A, Inc. land planning, civil engineering, surveying 19 L IJ 0 --0 CD 3· :5· Ill '< 0 iil :5· Ill (C CD S!? C: a. '< OJ CD Ill :><"" CD en < c5· :E () 0 ::::, a. 0 ~-::::, c:· 3 en oi" 0- ::::i ::r-0.. ;i.. -o , oi" -::i ::i ::i 0 s· co 0 ~: Cl) ::i co =i Cl) ~ s· co (J) C < ~ s· co ! '. n ~ r:1_! -, ' 1 ~J Fl i n=t! ~,, 1: l I .. , '~ t• ' r, r1 j 1-i-Lt ' J bJ _L ~-.W :WJ ➔ }· t' PROJECT SITE LOCATION County of San Diego Hydrology Manual Rainfall lsopluvials 100 Yearltainrall Event• 24 Roan I --·" l~~nd,e,) GPS COORDINATES: P24=4.8" P6/P24= 56% ~tfs ~ SaiiGIS ~-==-'f.."c 11,1.,, \#l lh..~ <:...tJ..-t H ._:----.---...-~ ----.......--~,...------~--.,,, ... ~,,..4~,ulll'g( ~ ... -________ .. --.:...,..· -~-.... -~---._..,..,.,. _____ ..,.._ _ __,.,,...",,..,.__~- 3 ,O 3 MIies ~ l.J ""O CD CD CD -· Ql 3 :;,,:- -· CD ::::, -, Ql en "< < o ro· ii3 ::e 3 · () Ql 0 <O ::::, CD C.. (./) 0 ..... 3 C: -· ~ ~- 3 en OJ C"" :::J ::r- 0,_ ;i;;,, -0 .... OJ -:::J :::J :::J 0 s· co 0 ~: (t) :::J co :::J (t) ~ 5 co (f) C < ~ s· co San Diego C-0uuty Hydrology Manual. Date: · June 2003 · Table3-1 Section: Page: RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use I Runoff Coefficient "C'' Soil Type NRCS Elements Coun Elements % J},.,fPER. A B lJnd1!iturbed Natural Terrain (Nlltllral) Permanent Open Space o• 0.20 0.25 Low Density Residential (LOR) Residential, 1.0 DU/A or less JO 0.27 0.32 Low Density Residential (LDR) Residential, 2.0 DU/A or less 20 0.34 OJS Low Density Residential (LDR) Residential, 2.9 DU/A or less 25 0.38 0,41 Medium Density Residential (MOR) Residential, 4.3 DU/A or less 30 0.41 0.45 Medium Density Residential (MDR) Residcntia~ 7.3 DU!A or less 40 0.48 0,51 Mediu.rn Density Residential (MOR) Residential, 10.9 DU/A or less 45 0.52 0.54 Medium Density Residential (MOR} Residential, 14.5 DU/ A or less 50 0.55 0,58 High Density Residential (HDR) Residential, 24.0 DU/A or less 65 0.66 0.67 High Density Residential (HDR) Residential, 43.0 DU/A or less 80 0.76 0.77 Commercial/lndustrial (N, Com) Neighborhood Commercial 80 0.76 0,77 Commercial/lndustrial (O. Com) General Commercial 85 0.80 0.80 Commercia!/Tndustrial (O.P. Com} Office Pro fo:ssional/Commercial 90 0.83 0,84 Commercial/lndustrial (Limited I.) Limited Industrial 90 0.83 0.84 Commercial/Industria{ (General l.) General Industrial 95 0.87 0.87 C 0.30 0.36 0.42 0.45 0.48 0.54 0.57 0.60 0.69 0.78 0.78 0.81 0.84 0.84 0.87 3 6 of26 D 0.35 0.4) 0.46 0.49 0.52 0.57 0.60 0.63 0.7l 0.79 0.79 0.82 0.8.5 0.85 0.87 '11le values associated with 0% impervious may be used for direct calculation of the runoff coefficient as described in Section 3.1.2 (representing the pervious runoff coefficient, Cp, for the soil type}, or for area.~ that will remain undisturbed in perpetuity. Justification must be given that the area will remain natural furever (e.g., the area is J()()ated in Cleveland National Forest). DU/A "" dwelling units per a.ere NRCS = National Resources Conservation Service 3·6 C San Ditigo County Hydrolo1:-,y Munual Dll-tc: ·June 2003 Section; Page-; 3 · 5of26 C = 0 .90 x (% Impe.rvious) + Cp x (1 • % lmpervious) Where: Cp "" Pei:vious Coefficient Runoff Value for the soil type (shown in Table 3-1 as Undisturbed Natural Terrain/Permanent Open Space, 0% Impervious). SoH type can be detennined from the soil type map provided in Appendix A. The values in Table 3-1 are typical for most urban areas. However, if the basin conmins rural or agricultural land use, parks, golf courses, or other types of nonurban land use that are expected to be pennanent, the appropriate value should be selected based upon the soil and cover and approved by the local agency. Breakers View Condominiums Preliminary Drainage Study 3.:5 bl-tA, Inc. land planning, civil engineering, surveying L IJ '-.,J ""Cl OJ -, -, (t) (t) = Q) 3 :><"" -· (t) ::::, -, n> en "< $ 0 (t) ~-~ ::::, 0 Q) :::, <O a. (t) 0 SQ ~-I 100 C :::, a. -· '< C !,Ill" ; >!' ✓I :A' 130 .i I o3" C"" ::::, ::r- 0.. ;i;a. -cJ ' pi" s ::::, ::::, 0 s·. cp 0 ~ (D ::::, (0 ::::, (D ~ s· (0 en C < (D '< s· I co Iii w u. 0 ~ w (.) z ~ Ch i5 w Cl) Q:'; :::> ~ w ~ ~ ~ :::) z ~ l '1;;;,lf/ ::/f Y' I ~I I ~20:'l ~ w :; i== ~ u. 10 -~ er: w 6 -0 EXAMPLE: Given: Watercourse •Distance (D) => 70 Feet Slope (s)=1.3% Runoff Coefficient (C) = 0 .41 Overland Flow Time (T) = 9.5 Minutes T = 1.8 (1 .1-C) Vo ~rs SOURCE: Airport Drainage, Federal Aviation Administration, 1965 FIGURE Rational Formula -Overfand Time of Flow Nomograph I 3-3 I L!.E Feet 3000 Tc Tc L A.E EQUATION (1 ;_;:~ ')°'385 • Time of com::entration .(hours) .. w,iercour4t Dl$~C· (mlkl$) = Chal\lle in elevati0Mllon9 ~otive .$lof>e tine !See A9ure 3-S)!tcetl Tc Hou!'$ Mlnlltiu, 2001) 0 ' SQI>'-' 400 ' '~ ',?'?.! 300 ~ ' ' ' ' ' '-L , Miles Feet ' ,, o.s 3000 ' ' 21)()(1 ', 1800 , 1600 ' 30 ·14-00 ..... 20 10 200 AE L re SOURCE: Caiifornla Division of Highways (1941) and Kitpich (1940) Nomograph for Determination of 40 30 2.0 7 6 5 3 Time of Concentration (Tc) or Travel Time (Tt) for Natural Watersheds bl-IA, Inc, F 1 -G U R E ~ Breakers View Condominiums Preliminary Drainage Study land planning, civil engineeri ng, surveying L 1-1B-I l-,i=.01S...-~---------..!2~%:.._ __ _J _ -n=.0175 2% CollCtete Gutter 0.13 Paved RESIDENTW. STRE!i.T ONE SID£ 0NL Y 20 +-----1---+--+-1---!r+--+-+-+-d-.------1-·-..... ,.,,..i---1--4-.... e +-----+-,,__'-+--1--h~'-1-!-l-1-f.....:::,,.,"" v ____ ....,..,_.p..;__v,. I 1------+---JEC::::::jF=:-"""""b-----¥-/~-l--l-t.f.' I--~...:::::::.."' :j!_10t 7 ~~ r.,, L e-I r--. ~ I ~ •-+-----1#---+---+--+F->--st::---t--t-ll--t------=-+..,..,,_-,f--+-~-+ , I --.r---.l ,.::::_ I 12 -+-----lt---+--+.f-+--+-+--i""""I:'."". I I j ,-..t--.."',,.,. I I'--,... , 10 -+-----,..--+---+---,j~--+--l--~+--+-1-1__; ~':::.8.:.;t'-P I ·---......_ L_ ' , "'Z J ,--......... 9-¼---~-l-==:J;;==-=--l---A--~-+--l-~--1--+---...::::~~---l--'r.+--:::::..il-.J- 8 --1---7 ---r--...., ' "'1-... 7 ll 1-......1 l'----1 2 3 S 6 7 8 9 10 20 90 ◄0 SO Discharge (C.F.S.} EXAMPU::: Givan: Q = 10 S • 2.5% Chait givu: l><!pth • 0.4, Velocity • 4.4 t.1>.a. SOURCE: San Diego Couniy Oepartmont of $pedal Oiurict Servica>l OoSlgn Manual FI GU.RE Gutter and Roadway Discharge• Velocity Chart ~ bl-tA, Inc. Breakers View Condominiums Preliminary Drainage Study land planning, civil engineering, surveying 25 0.2 0.16 0.10 0.09 0.00 0.01 .0.06 O.OI, .0.04 0.03 0.02 0.002 0.001 0.0009 0.0008 o.00()7 0.0000 l).0005 0.0004 0.0003 !:;QUA710N: V = 1.49 R½ s'"' n 0.2 Q.4 0.5 s 6 7 a 9 10 20 > /' // 1 a; 0. ',_:-·,. j ~ .E ~ "-8 ..J w > GENERAL SOLUTION SOURCE, USOOT. FHWA, HDS-3 (1961} Manning's Equation Nomograph bliA, Inc. 30 20 10 < (; 7 6 5 4 3 1.0 0.9 0.8 0.7 0.6 0.5 o!)'l-/ 0.02 p C 0.03 . 0.04 (/l (/l o.os UJ ~ (!) 0.06 ::> 0 !'.I'.: 0.07 0.08 0.09 o.,o 0.2 0.3 0.4 1"~_:; ·1 Breakers View Condominiums Preliminary Drainage Study land planning, civil engineering, suNeying 26 L C ·20 ·30 40 SQ t Minutes OOraUon e o-0.645 ily(lrl/hr) r PreclpitaUon ( n (min) -+N-++++-~,..i.;.W4,!,!4.l#llll-3.o -t-1-H-N+H+Hfff,~H-ffl-2.5 2.0 1.5 2 3 4 5 6 Hours lntenslty-Ouratlon Design Chart -Template Breakers View Condominiums Preliminary Drainage Study Dlractlon_. for Appllcatlon: (1) From precipitation maps cfetermine ah( and 24 hr amoonts for th!} $&!ect.ed frequency, These maps are included lo the County Hydrology Manual (10, 50, end 100 yr maps Included in the Design and Procedure Manual). · (2) Adjust 6 hr preefprtaHon (if necessary) so that itis within the range of 45% to 65% of the 24 hr precipitation (not appfic:apfe to Desert). (3) Plot 6 hr precipitation on Iha right Side of the ~art. (4) Draw a line through the point parallel to ll'!e plotted tinn. (5) Thm line is the lntenslty..(luration curve for the location being analyzed. Application Form: (a) Selected frequency _!QQ_ year (b) Pe= 2.7 in., P24 = 4.8 ~ = 56 %(2) ---'P24 -- (c) Adjusted P6<2l: __ In. (d) Ix"' _5 __ min. (e) I ,. 2.:lL inJhr. Note: This chart replaces the lritenslty•Duration-Frequency curves used since 1965. PG.. . -.,,_._ -' ![~' ...,.;,....._::.-4-'~ =:,,.,..,,,.:....,~ . bliA, Inc. land planning, civil engineering, suNeying '2 7 L San Diego County Hydrology Manual Date; JUJlC 2003 3.2 DEVELOl'lNG INPUT DATA FOR THE RATlONAL METHOD Section: Page: 3 20of26 Thi section describes the development of the necessary data to perform RM calo\)Jations. Section 3.3 describes the RM calculation process. Input data for calculating peak flows and Tc's with the RM should be developed as.follows: 1. On a topographic base map, outline the overall drainage area boundary, showm,g adjacent drains, existing and proposed drains, and overland flow paths. 2. Verify the accuracy of the drainage map in the field. 3. Divide the drainage area into subareas by locating signincanl points of interest. These divisions should be based on topography, soil type, and land use. Ensure that an appropriate first subarea is delineated. For natural areas, the first subarea flow path length should be less than or equal to 4,000 feet plus the overland flow length (fable 3-2). For developed areas, the initial subarea flow path length should be consistent with Table 3-2. The topography and slope within the initial subarea should be generally unifo.1m. 4. Working from upstream to downstream, assign a number repxesenth1g each suba1-ea in the drainage system to each point of interest. Figure 3-8 provides guidelines for node numbel's for geographic information system (GJS)-based studies. 5. Measure each subarea in the drainage area to detennioe its size in acres (A). 6. Determine the length and effective slope of the flow path in each subarea. 7. lderttify the soil type for each subarea. Breakers View Condominiums Preliminary Drainage Study 3-20 bl-IA, Inc. land planning, civil engineering, surveying 28 7J OJ cil cil = Ql 3 ;;,,:- -· CD :::, ..., Ql en '< < a,· 0 iil 5· Ql (0 CD ~ 0.. '< i:u" ::E () 0 :::, 0.. 0 3 5· c:· 3 en er :::i Q. ::r- "O ~ i:u" s :::i :::i 0 s· Cf) () r (D :::i (0 s (D ~ s· Cf) (f) C < (D '< s· (0 ,) -0 Study Area SC ,.r··( ( ~1 l_.. : ( / ·, ,/ l,. Study Area LA 0 Define Study Areas (Two-Letter ID) © Define Maps (or Subregion$ on Region Basis) 0 Define Model Subareas on Map Basis 9'.,/ \ .... ' .· ! ........... -->11 • ., ........ ' .. \····/ \ .. ~ ,.// )' -·· 0 Define Major Flowpaths in Study Area © Define Regions on Study Area Basis Subarea ID= (LA010112) Region# N~:::_ l ..,.,,~,,,o,, l L l © Define Model Nodes (Intersection of Subarea Boundaries with Flowpath Lines) GIS/Hydrologic Model Data Ba.se Linkage Setup: Nodes, Subareas, Links LA 01 01 03 0 Number Nodes I' l~-~R •1 Sun Dtego County Hydrology Manual .D<\te: June 2003 Section: Page: 3 22of26 8. 'Determine th.e runoff coeffici.ent (C) for each subarea based on Table 3~1. [f the subarea contains more than one type of development cl.assification, use a proportionate average for C. In determining C for the subarea, use future land use taken from the applicable community plan, Multiple Species Conservation Plan, National Forest land use plan, etc. 9. Calculate the CA value for the subarea. 10. Calculate the :E(CA) value(s) for the subareas upstream oft.he point(s) of interest. 11. Detennine P6 and P.24 for the study using the isopluvial maps provided in Appendix B. If necessary, adjust the vaiue for l:6 to be within 45% to 65% of the value for P24. See Section 3.3 for a description of the RM calculation process. 3.3 PERFORMING RATIONALMETJ{O}) CALCULA'fIONS This section de-scribes the RM calcu.lation process. Using th.e input data. calculation of peak flows and Tc's should be performed as fullows: l. Determine T1 for the first subarea. Use Table 3-2 or Figure 3.3 as discussed in Section 3. l.4. If the watershed ls natural, the travel time to the downstream end of the fast subarea can be added to T; to obtain the Tc. Refer to paragraph 3. I .42 (a). 2. Detetmine I for the subarea using Figure 3-1. If T, was less than 5 minutes, us.e the 5 minute time to detenn.ine intensity for calcu.lating the flow. 3. C.alculate the peak discharge flow rate for the subarca, where Qp= L(CA) I. In case that the downstream flow rate is less than the upstream flow rate, due to the long travel time that is not offset by the additional subarea runoff, use the upstream peak flow for design purposes until downstream flows increase again. Breakers View Condominiums Preliminary Drainage Study bJ.tA, Inc. land planning, civil engineering, surveying 30 San Diego Coumy .liydrQ!ogy Manual Date: June 2003 4. Estimate the l'i to the next point of interest. 5. Add the T1 to the previous Tc to obtain a new Tc. Section: Page: 6. Continue with step 2, above, until the final point of interest is reached. 3 23of26 Note: TI1e MRM should be used to calculate the peak discharge when there is a junction from independent subareas into the drainage system. 3.4 MODIFIED .RATlONAL METHOD (FOR JUNCTION ANALYSIS) The purpose of this section is to describe the steps necessary to develop a hydrology repo1i for a small watershed using the MRM. It is necessary to use the MRM if the watershed contains junctions of independent drainage systems. The process is based on the design manuals of the City/C,,ounty of San Diego. The general process description for using this method, including an example of the application ofthi~ method, is described below. The engineer should only use the MRM for drainage areas up to-approximately I square mile in size. If the watershed will significantly exceed l square mile then the NRCS method described in Section 4 should be used. The engineer may choose to use either the RM or the 1v1RM for calculations for up to an approximately l •square-mile area and then transition the study to the JRCS method for additional downstream areas that exceed approximately 1 square mile. The transition process is described in Section 4. 3.4.l Modified Ration al Method General Process Description The general process for the MRM differs from the RM only when a junction of independent drainage systems is reacl1-ed. The peak Q, Tc, and I for each of the independent drainage systems at the point of the junction are calculated by the RM. The independent drainage- systems are then combined using the MRM procedure described below. The peak Q, T,;;, and 1 for each of the independent drainage systems at the point of the junction must be calculated prior to using the .MRM procedure to combine the independent drainage systems. as these Breakers View Condominiums Preliminary Drainage Study 3-23 b~A, Inc. land planning, civil engineering, surveying 31 San Diego County Hydrnlogy M;mual. Date; June 2003 Section: Page: 3 24of26 values will be used for the MRM calculations. After the independent drainage systems have been combined, RM calculations are continued to the next point of interest. 3.4.2 Procedure for Combining Independent Drainage Systems a.t ,a J IUlction Calculate the peak Q, Tc, and I for each of the independent drainage systems at the point of the junction. These values will be used for the MRM calculations. At the junction of two or more independent drainage systems, the respective peak flows are combined to obtain the maximum flow out of the junction at Te. Based on tbe approximation that total ninoff increases directly in proportion to time, a general equation may be written to detennine the maximum Q and its corresponding Tc using the peak Q -Tc, and I for each of the independent drainage systems at the point immediately before the junction. The general equation requi_res that contributing Q's be numbered in order of increasing Tc. Let Qi, T1, and 11 correspond to the tributary area with the shortest T,. Likewise, let Q2, T2, ilnd 11 correspond to the tributary area with the ne>..1: longer Te; Q3, T3, and h correspond to the tributary area with the next longer Tc; and so on. When only two in.dependent drainage systems are combined, leave Q:i, T3, and r3 out of the equation. Combine the independent drainage systems using the junction equation below: Breakers View Condominiums Preliminary Drainage Study Junctio11 Equation: T 1 < T 2 < T3 3-24 bHA, Inc. land planning, civil engineering, suNeying 32 Sim Piego County Hydrology Manual. Date; June 2003 Section: Page: 3 25of26 Calculate Qn, Qn, and Qn. elect the largest Q and use the Tc associated with that Q for further calculations (see the three Notes for options). If the largest calculated Q's are equal (e.g., Qn = Qn > Qr,), use the shorter of the Tc's associated with that Q. This equation may be expanded for a junction of more than three lndependel)t drainage systems using the same concept. The concept is that when Q from a selected subarea (e.g., Q2) is combined with Q from another subarea with a shorter Tc (e.g., Q1), the Q from the subarea with the shorter Tc is reduced by the ratio of the l's (h/T1); and when Q from a selected subarea (e.g., Qi) is combined with Q from another subarea with a longer T., (e.g., Q3), the Q from the subarea with the longer Te is reduced by the ratio of the Tc's (T2/f3). Note #1: At a junction of two independent drainage systems that have the same Tc. the tributary flows may be added to obtain the Qp- This can be verified by using the junction equation above. Let Q3, T,, and h = 0. When T1 and T1 are the same, lt and hare also the same, and Ti/f2 and Ji/1 1 = I. T1ff2 and Ii/Ir are cancelled front the equations. At this point, Qn = Qn = Qi + Q2. 01·e #2: 1n the upstream part of a watershed, a conservative computation is acceptable. When the times of concentration {Tc's) are relatively close in magnitude (within I 0%), use the shorter Tc for the intensity and the equation Q = l:(CA)I. Note #3: . An optional method of determining the Tc is to use the equation Tc = [(L (CA)7.44 PG)/QJ us This equation is from Q = !(CA)I = !(CA)(7.44 Peffe 645 ) and solving for Tc. The advantage in. this option is that the Tc is consistent with the peak flow Q, and avoids inappropriate fluctuation in dowustream flows in some cases. Breakers View Condominiums Preliminary Drainage Study 3-25 bl-IA, Inc. land planning, civil engineering, surveying 33 M.Ollt 11(11 I j ! J 1 I t t ,.. •• .a, -a b • • Breakers View Condominiums Preliminary Drainage Study ---- M.o«,n I 11 ,d A j I ~ I ., I • I 5' i ·I a I ◄ Ii • J l ,J i . • ·I I II l •• l z~ ,,,,..-•• m I --' -~ bHA, Inc. land planning, civil engineering, suNeying 3.1 'JJ '.J, "1J CD CD CD = DJ 3 :><"" -· <l> ::, ..., DJ CJ) '< < (1). 0 iil 5 · DJ (0 <l> en 2' a. -< ::E () 0 ::, a. 0 3 5 · c 3 CJ) 0) r:::r ::, ::r- 0. l> -0 ... 0) -::, ::, ::, () s· (0 () ~ CD ::, (0 5· CD ~ s· (0 U> C < ~ s· (0 !II ~dogie Sci Gftup,-Sen [logo County Ana. Celfonlo MAP LEGEND MAP INFORMATION ---~ □ "'-"'-~ -____ ...,,.... □ A C NO ■ I • Ml □ C c::I 01) CJ 0 □ ------•-.u... -A -NO -. -Ml -C -01) -0 •• NatfMNcwNI~ -----■ A ■ NO ■ • ■ Ml Nat\rllll- ~lenl« • C • 01) • 0 D -----__ ,_ -...i~ -----~ -us•--....,._ -L-----. _............., -Scll&lrwy -~Sol!Mwy The 901 ~ 11111 ~-N::A wtrt ,,..pped tt 1:24,000 Wlminf: Sol Mtp mty nat be Yll!d et lhis tc1N. Ell~dlllllPS beycnd flt -d ~ con -te ml __ .trig d flt dllol d ffllSll)irlg ond ecco,xy oltol bi,lec«Mnt. The,_.clonat_tlle ..... tr-d ccnlrHGng 901s 11111-h-bMn st,-, 111 mcn dlllil«I --Pin• rcty en.,. bar ICON on -fflllP thMI fer map --•-Seo.rte d ._,: _,,.t Resoun:es~ s..-.ic. -Sdl&irwyURl: Coodinll• Sy,ltm: Wob -.. .... (EJ>SG:3457) MIIPs ~ Ille -Sol Sllrwy .. based on the -Mtn:11<>r prcjeclicn, wHc:11 pt-lYIS dndlon end th ope but chtofb ~--•·A p,qeclion "81 pteMNes wee. 1llCII HIiie Alben*"'.,._ conic prCljodlon, lllculd be used f more •ccw• celcullliont d chtanc. or .... ,.~ Tllis prOG>d Is gen«Wd tcm Ille USM-NRCS ctrtiltd -es offl•-dlllt(s)lhltd-. Sol a,,wy ARI: Sen Oltgo Counly-. Celtornit Surwy ,,,_ 0...: lloniol 13, Sep 12, 2018 Sol ,,_,....,.,.la_(es--., fcrmep 1Cllts 1:50.000 or lergo, Ollt(s) etrlal l!Ngtt w«e p,at~lllled: No¥ 3. 2014-Nov 22.2014 Thecr1hclploloarce.besel!IIC)onwhldltlledllMswwe ccni,led-cl!illad pn,blbtf-. tcm Ille bec:lrlJ'Ol.lld lmeglry ~ on thest 11111PS Ase ntul, tcmt -thi9ngdmep111I -•mtybe-L 6118/2019 Plge2d4 -- .. .. .. -.. -.. .. .. -.. - .. -.. --.. -.. -.. ---- Hydrologic Soil Gr(ll.lp,-San Diego county Are11. Clllifomi11 Hydrologic Soil Group Totals for Area of lntere!i\t 0.2 Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long.duration storms . The soils in the United states are assigned to four groups (A, B, C, and D) and three dual classes (AID, BID, and CID). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet These consist chiefly of moderately deep or deei>i moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission . Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (AID, BID, or CID), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation MethOd: Dominant Condition Natural RMources Conswvatlon Service Web SOIi survey National COCl!)erattve Soil Survey bl-IA, Inc. 100.0% 6/16/2019 Page3r:/4 Breakers View Condominiums Preliminary Drainage Study land planning, civil engineering, surveying -C-----------------------------------------------~ 36 ----------.. - -... -.. .. - --.. -----.. .. --- - H)'drologic Sclil Groui>-$an Diego County Alea. Cillifomia Component Percent Cutoff: None Specified Tie-break Rule: Higher Nature! RHOUA:H Conservation Servlc• Web SOIi survey National Cooperative Soil Survey bl-IA, Inc. 6/18/2019 Page4 of 4 Breakers View Condominiums Preliminary Drainage Study land planning, civil engineering, surveying -------------------------------------------------~ 37 -i f \ ' \ ' \ ~---------------------------------------\ --- ' \ \ ' ' \ ' ' \ \ \ \ ' ' \ \ ' \ \ \ \ PACIFIC OCEAN A-1 \ \ \-------;-- MAGNOLIA AV \ \ ' \ \ \ \ \ \ \ \ \ AGUA HEDIONDA LAGOON AGUA HEDIONDA LAGOON \ \ \ \ \ I \ \ \ .. \ \ ;-------------------------------------------------------------------------------------------------------------MATCH LINE ________________________ '\---- ' \ \ BA IN I I I I \ \ \ ' \ ' ' \ \ ' I I \ \ :µ I I \ \ \ \ I \ I ' \ ' L-r: '-BCB Y)_ ""---30" RCP ~ ' ' ~S,s 'l' . ''b -~ ---. AGUA HEDIONDA LAGOON ' ' ' ' ' ' '~ ' ' HILL ... PLATE INDEX ~ ------------,-------------------------.------------.., ' ' ' .-< --__.,---. --_...-I ' r .t:5asin : A '-:-, .--, I A-1 : A-2 : _,. At 3 A-4 :,)-: : '\ ' I I ------------~ -----J ------,_ -----------...! ' '\ Basin : B L_/\: ,: -1 B-2 B-3 L B-4 \ : I \ 1 , I , \ -----------; ------------:--L--~ r ---~ \ 'L : : I : C-1 , C-2 , C-3 , C-1, , : ,: Basin: C : J : I \ ' ' I ~ ------------\-----------: -----------• :_ --• ---~T" --~ : : , : Basin : D \, : I I \ I I 1 ' D-1 ' \ D-2 ' D-3 ' D-4 1 ' ' ' I I ' . . , , 7· t I I I I < ' \ \ I I ' ~ ------------:----Y--: -~ ~ -:-.~" ------:------------:~ r' _r : l!:-3 E-4 1 E-1 E-2 -.--. , I '-~, ' 0 500 SCAIE IN Fl!1!T IliG1fflD Ei1S"IIN(; STORM DRAINS UNDER 12" 30• TO 45• .ABOVE 48" ------DITCH ---------PROPOSl!:D STORM DRAIN OR DRAINAGE FACIUTY LAKE, RESEVOIR. OR POND -----RIVER OR S'l'l!EAII Basin A BUENA vmA wArERSHED Basin B AGUA mmroNDA WATERSHED Basin C ENCINAS CREEK wA'f:JsRSBED Bas in D BATIQU1Tos WATERSHED WATERSHED DIVIDE BM FACIUTY DESIGNATION First letter la BASIN DESIGNATOR Following letter(•) ere the FAC!UTY DESIGNATOR -----PROPOSl!:D PLANNED LOCAL DRAINAGE (PID) AREA BOUNDARY ENHANCED NATURAL CHANNEL PROPOSl!:D ENHANCED 114TIJRAL CHANNEL IIAJOR CRnK FLOW 0 EX!St!N(; DETENTION BASIN PROPOSl!:D SEDIMENTATION BASIN Ei1S"IIN(; SEDIIIENTATION BASIN CITY OF CARlSIIAll BOUND.ARY PLATE B-1 PRO.£CT LOCATION MASTER PLAN OF DRAINAGE FACILITIES DATE PRQ..ECT PMrl8ER NOV 2007 128290 CITY OF CARLSBAD C-1 'L-----------------------------------------------------------~~:_ __________________________________________________________________ __:~~~~:_ __ L __________ .l...!SAN~,!D:!;!O:~GO:!!:,_,_!Cil!PO~~RNLl.~!.....J I ~ BROWN AND CALDWELL m ~ -~ ' -~ ' IQ ~ ~ 133 ~ 25-t-OO 24-t-OO 23t-OO \,___ 4', 15" RCP STUB STORM DRAIN HYDRAULIC' TABLE STATION PIPE Q(IOOyr) DEPTH V 12 T 60.00 TO 15 T 12.00 30" RCP 32.7 CFS FULL PIPE '6.66 FPS (5 t-12.00 TO 19 t-01.86 30" RCP 31.0 CFS FULL PIPE 6.32 FPS 19 -r 01.86 TO 19 i" 92 :oo 30" RCP 29.1 CFS FULL PIPE 5.93 FPS l~ t-92.00 TO 24 T 18.84 30° RCP 27.9 CFS FULL PIPE . 5.68 FPS ~ ~~ ~ ffl ~ ~ ~ ~ 22-tOO IJl!I 21-tOO DESIGNED DRAWN CHECKED ~ DSW RLK AO I 7-86 7-86 7-86 DATE ~ WILSON ENGINEERING CONSULTING ENGINEERS 3138 ROOSEVELT ST. CARLSBAD. CA. 454'--7019 SUBMITTED BY• ~'q, ' .:.: J 1 . 7-23-86 DEXTER S. WILSON R.C.E. 33692 EXP. 6/30/90 DATE ~ ~ ~ ~ ~ -~ ~ ~ I . • I ~ I ~ ' j ~ 0 jSHiE'fl CITY OF CA·RLSBAO !SHEETS! t--+-+--------------+---1 ~ ENGINEERING OE PAR TM ENT 5 1---+--+---------------+---1 DATE BY OESCRI PTION APP'O REVISIONS I PLANS FOR THE CONSTRUCTION OF C.ARLSBAD BLVD. ST.ORM DRAIN I · _STA. 12 -t 60.00 TO. STA., 24 + 18.84 APPROVED:,{)_ ,~ · RE . .37oj I CITY ENGINEER OWN.BY,,----1 CHKO.BY, ___ 1 FIELD BK, PROJECT NO . 3229 DATE I DRAWING NO. _ 275-8 I I I I I ____ L 1 j ! I I i: · 1 I ' • I !l ! I . I I ,