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Home My WebLink AboutMS 2018-0002; PRELIMINARY HYDROLOGY AND HYDRAULIC STUDY; 2020-04-22Preliminary Hydrology and Hydraulic Study 4 1391 Oak Avenue Carlsbad, CA 92008 Oak Avenue Parcel Map MS 2018-0002 DEV 2018-0048 Prepared for: Temujin and Summer Matsubara 1391 Oak Avenue Carlsbad, CA 92008 RECEIVED APR Z4 2020 LAND DEVELOPMENT ENGINEERING Prepared By: John P. Strohminger RCE 55187 dba Pacific Overland Engineering & Surveying 635 Via Columbia Vista, CA 92081 Date: April 22, 2020 co \o. 055187 LU \ Exp. 6130/Zc) ) . CM LOFC John P. Strohminger RCE 55187 Date 1 1 TABLE OF CONTENTS 2 Project Description................................................................................................................................2 2.1 Existing Condition .........................................................................................................................2 2.2 Proposed Condition ......................................................................................................................3 2.3 Soil Characteristics........................................................................................................................3 3 Rational Method Description................................................................................................................3 4 Hydrology Analysis ................................................................................................................................ 4 5 Rip Rap Pad Sizing.................................................................................................................................4 6 Water Quality........................................................................................................................................4 7 Hydromodification ................................................................................................................................ S 8 Conclusion ............................................................................................................................................. 5 9 Attachments..........................................................................................................................................5 10 References ........................................................................................................................................5 2 PROJECT DESCRIPTION This project is a 0.507 acre residential parcel located at 1391 Oak Avenue in the City of Carlsbad. Oak Avenue is a public street that connects with Pio Pico Drive to the west and Highland Drive to the east. The existing site was previously graded; there is one single family structure onsite. The project proposes to split, the existing lot into two parcels. The existing house will remain on one parcel and a new house will be constructed on a pan handle parcel. No Street improvements are proposed as Oak Avenue is exempt from the requirement for curb, gutter and sidewalk. The site's APN number is 205-20-18-00. The legal description is a portion of Tract 120 of Map 1661. A Vicinity Map is in the attachments. 2.1 ExIsTING CONDITION The exsting site has been graded with a pad for a single-family residence and driveway with carport at an average elevation of 150 feet above Mean Sea Level (MSL). The elevation of the street fronting the property is at 145 feet MSL. Oak Avenue is paved but has not been improved with curbs, gutters, or sidewalks. There are two properties to the east. Of those the southernmost property drains onto and through the subject property. To the south is an existing single-family residence at the same elevation as the subject property. To the west are two existing single family residences eight feet lower than the proposed house finished floor. Most of the subject property drains west across the lot line onto the properties to the west. Flows cross at five locations. From there water finds its way from the rear of the neighbor's yard out to Oak Avenue or to Pine Avenue. 2 Storm water from the front of the existing house of the subject property surface flows onto Oak Avenue and continues on the surface, along the road way to inlets at the intersection of Oak and Pio Pico. 2.2 PROPOSED CONDITION The proposed project calls for the existing house to remain and creates a new single-family residence with attached garage and a driveway on a panhandle parcel. Only the garage portion of the new structure will be slab on grade. The living portion will be on posts and will have a crawl space. The improvements and grading will disturb 6,765 square feet of area. The amount of new and replaced impervious surface will be 4,629 square feet. The project is a Standard Development Project. The new drainage pattern maintains cross lot drainage in accepting water from the east, and outfiowing water onto the property to the west. Flows from the front of the existing house will continue to run onto Oak Avenue. 2.3 SOIL CHARACTERISTICS The following soil group definitions come from Technical Release 55 (TR-55) by the United States Department of Agriculture: Group A soils have low runoff potential and high infiltration rates even when thoroughly wetted. They consist chiefly of deep, well to excessively drained sand or gravel and have a high rate of water transmission (greater than 0.30 in/hr). Group B soils have moderate infiltration rates when thoroughly wetted and consist chiefly of moderately deep to deep, moderately well to well drained soils with moderately fine to moderately course textures. These soils have a moderate rate of water transmission (0.15-0.30 in/hr). Group C soils have low infiltration rates when thoroughly wetted and consist chiefly of soils with a layer that impedes downward movement of water and soils with moderately fine to fine texture. These soils have a low rate of water transmission (0.05-0.15 in/hr). Group D soils have high runoff potential. They have very low infiltration rates when thoroughly wetted and consist chiefly of clay soils with a high swelling potential, soils with a permanent high water table, soils with a clay pan or clay layer at or near the surface, and shallow soils over nearly impervious material. These soils have a very low rate of water transmission (0-0.05 in/hr). The conservative approach is assuming Group D soils for the site. 3 RATIONAL METHOD DESCRIPTION The rational method, as described in the 2003 San Diego County Hydrology Manual, was used to generate surface runoff flows, which were then used to size the drainage facilities. The basic equation: Q = CIA Q = Peak Flow of Storm Water in Cubic Feet per Second (cfs) C = runoff coefficient (varies with land use) = Intensity (in/hr) A = Area (acres) The 6 hour and 24 hour rainfall isopluvial maps are found in the 2003 San Diego County Hydrology Manual. Adjusted P6 calculations can be found in the Attachments. Initial travel time calculations (Ti) are set on a: minimum 5 minutes as prescribed by the City and County. 4 HYDROLOGY ANALYSIS The table below summarizes the pre- and post-construction 100-year flows. The outfall points are shown on the Existing and Proposed Drainage Exhibits included in this report. Description Q-Exist (cfs) Q-Prop (cfs) Q-Change (cfs) Exist Node #102, Proposed Node # 202 0.67 0.58 -0.17 Exist Node #112, Proposed Node# 215 0.93 0.81 -0.12 Total 1.60 1.39 -0.29 Exist Node #141, Proposed Node #241 0.16 0.16 0.00 Table 1 Summary of existing and proposed stormwater runoff. The pre-development 100 year flow total that crosses the lot line to the west is 1.60 cfs. The total post- development 100 year flow is 1.39 cfs. This is a reduction of peak flow of 0.29 cfs. The pre and post development flows out to Oak Avenue are the same. 5 RIP RAP PAD SIZING The storm water at node 202 flows onto a proposed rip rap pad. The velocity of the flow at that point is 2.4 fps. The width of flow is 2.3 feet. Based on SDRSD D-40 the pad has been sized at 7 feet by 10 feet with No. 2 Backing. 6 WATER QUALITY This project is a Standard Development Project per the completed Storm Water Standards Questionnaire (E-34) provided in the attachments. This project is therefore not required to submit a Storm Water Quality Management Plan (SWQMP). 4 7 HYDROMODIFICATION This project is exempt from hydromodification requirements since it is not a Priority Development Project. 8 CoNcLusioN The existing condition discharges a total peak flow of 1.60 cubic feet per second of storm water across the property line to the west. The proposed project reduces that peak flow amount to 1.39 cubic feet per second and proposes a cDncrete wall with slots that disperses the flow to several outlets. This dispersal system matches the historical cross lot drainage concentration points. 9 ATTACHMENTS Includes: Vicinity Map Existing Drainage Map Existing Drainage Spreadsheet Analysis Proposed Drainage Map S. Proposed Drainage Spreadsheet Analysis Proposed Channel (3) and Pipe Flow analysis (1) Table 3-1, Runoff Coefficients for Urban Areas 100 Year 6 Hour Isooluvial 100 Year 24 Hour lsopluvial Figure 3-1, lntensit\j-Duration Design Chart E-34, Storm Water Standards Questionnaire E-36, Standard Project Requirement Checklist 10 REFERENCES City of Carlsbad Engineering Design Manual by the City of Carlsbad San Diego County Drainage Design Manual by the County of San Diego, May 2005. San Diego County Hydrology Manual by the County of San Diego, June 2003. Urban Hydrology for Small Watersheds TR-55 by the United States Department of Agriculture, June 1986. Low Impact Development Handbook by the County of San Diego, December 31, 2007. Water Quality Control Plan for the San Diego Basin by the California Regional Water Quality Control Board San Diego Region, April 25, 2007. Stormwater Best Management Practice Handbook by California Stormwater Quality Association, September 30, 2004. 5 Lutheran C Ii IL 9 Wort Montessori dsbid Carlsbad Village arden NCHS Carlsbad HeaUhCetitei rary lop I_p V V Packrd Dental 1*14 (010 9City of Carlsbad Oak Avenue at on I tus Thai Bistro. In iglerRealiy V Vicinity Map for 1391 Oak Avenue wood Ave 15. RasnwoodAve 4 0 SkateXSnc H V gNrm Coast I N- \$r\> / \ / )- // 1~. S, IV 141 ry Foo 011 5-1 L i/T 7-1 Ij 42 41 ' \ \ 4 - 3 &VEET111ZE Existing 4'fctsubcrc Oak Avenue Parcel Map _____ Drainage 1391 Oak Avenue, Carlsbad, CA 92008 Pre-Development Hydrology 1391 Oak Avenue, Carlsbad, Ca, 92008, April 23, 2019, John P. Strohrninger Engineering Nodes Incr. Area ac. Total Area ac Soil Gp Land Use C Incr. C*A Total C*A Flow Path, ft. Slope % Over- land Ti, mm Kirpich Ti mm. Manning Ti mm. To mm, cum. I In/hr Q=CIA Q, cfs. Notes 100-101 0.144 0.144 0 MDR 0.52 0.075 0.075 5 6.85 0.51 Initial Tc 5 minutes 101-102 0.087 0.231 0 NAT 035 0.030 0.105 98 8.9 0.63 5.6 635 0.67 Total Flow at Node 102 0.67 CFS 110-111 0.145 0.145 0 MDR 0.52 0.075 0.075 5 6.85 0.52 Initial Tc 5 minutes 111-112 0.207 0.352 D NAT 035 0.072 0.148 1011 9.4 0.681 5.7 631 0.93 Total Flow at Node 112 0.93 CFS 140-141 0.044 0.044 D MDR 052 0.023 0.023 5 685 0.16 Initial Tc 5 minutes Total Flow at Node 141 0.16 CFS lsopluvial_Data: P6= 1 2.6 Adjusted P6= 2.6 P24= 4.6 P6/P24= 57% _____ _____ _____ _____ ____ _______ ________ N \ \ \ Cb 00, 51 cW> '416 — 13 lee 01 Xi If N \ — / \ \ Proposed 4'fctsubcrc Oak Avenue Parcel /fap I Drainage 1391 Oak Avenue, Carlsbad, CA 92008 Post-Development Hydrology 1391 Oak Avenue, Carlsbad, Ca, 92008, April 23, 2019, John P. Strohminger Engineering Nodes Incr. Area ac. Total Area ac. Soil Gp Land Use Incr. C*A Total C*A Flow Path, ft. Slope % Over- land Ti, mm Kirpich Ti mm. Manning Ti mm. Tc mm, cum. I in/hr QCIA Q, cfs. Notes 200-201 0144 0.144 0 MDR 0.52 0.075 0.075 5 6.85 0.51 Initial Tc 5 minutes 201-202 0.0461 0.190 0 EQ3-5 038 0.017 0.092 107 8.4 0.74 5.71 6.27 0.58 Total Flow at Node 202 0.58 CFS 210-211 0.145 0.145 D MDR 0.52 0.075 0.075 5 6.85 0.52 Initial Tc 5 minutes 211-212 0.012 0.157 0 MDR 0.52 0.006 0.082 43 1.5 1.70 6.7 5.67 0.46 Vegetated Swale@1.5% 212-213 0 0.157 0 IMDR 052 0.000 0.082 171 1.0 0.08 6.8 563 0.46 6" PVC @1% 213-214 0.016 0.173 0 MDR 0.52 0.008 0.090 79 8.4 1.60 8.4 4.91 0.44 Vegetated Swale@8.4% 214-215 0.2181 0.391 D MDR 0.52 0.113 0.203 46 0.5 3.101 11.5 4.01 0.81 Vegetated Swale.5% Total Flow at Node 241 0.81 CFS 240-241 0.044 0.044 D MDR 0.521 0.023 0.023 1 J 51 6.85 0.16 Initial Tc 5 minutes Total Flow at Node 241 0.16 CFS Isopluval Data: P6 = - 2.6 - Adjusted P6 = 2.6 P24= 1 4.6 P6/P24= 57% Highlighted Depth (ft) = 0.52 0 (cfs) = 0.440 Area (sqft) = 0.54 Velocity (ft/s) = 0.81 Wetted Perim (if) = 2.33 Grit Depth, Yc (ft) = 0.32 Top Width (ft) = 2.08 EGL(ft) = 0.53 Channel Report Hydraf low Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Vegetated Swale @ 8.4% Triangular Side Slopes (z:1) = 2.00, 2.00 Total Depth (if) = 1.00 Invert Elev (if) = 100.00 Slope (%) = 8.40 N-Value = 0.200 Calculations Compute by: Known 0 Known 0 (cfs) = 0.44 Wednesday, Apr 24 2019 Elev (if) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 100.00 'SI 99.50 _n £fl 0 .5 1 1.5 2 2.5 3 3.5 4 4.5 5 Reach (ft) Highlighted Depth (ft) = 0.67 Q (cfs) = 0.460 Area (sqft) = 1.12 Velocity (ft/s) = 0.41 Wetted Perim (ft) = 3.62 Crit Depth, Yc (ft) = 0.30 Top Width (ft) = 3.35 EGL(ft) = 0.67 Channel Report - Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Vegetated Swale @1.52% Triangular Side Slopes (z:1) = 3.00, 2.00 Total Depth (ft) = 1.00 Invert Elev (ft) 100.00 Slope (%) = 1.52 N-Value = 0.200 Calculations Compute by: Known Q Known 0 (cfs) = 0.46 Wednesday, Apr 242019 Section Elev (ft) 102.00 101.50 101.00 100.50 100.00 99.50 Depth (ft) 2.00 1.50 1.00 0.50 -0.50 0 1 2 3 4 5 6 7 Reach (ft) Channel Report Hydraf low Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Tuesday, Apr 21 2020 <Name> \Ief ) trzze . - 6,-du- Triangular Highlighted Side Slopes (z:1) = 2.00, 2.00 Depth (ft) = 0.58 Total Depth (ft) = 1.00 Q (cfs) = 0.580 Area (sqft) = 0.67 Invert Elev (ft) = 100.00 Velocity (ft/s) = 0.86 Slope (%) = 8.40 Wetted Perim (ft) = 2.59 N-Value = 0.200 Grit Depth, Yc (ft) = 0.35 .. Top Width (ft) = 2.32 Calculations EGL (ft) = 0.59 Compute by: Known Q Known 0 (cfs) = 0.58 Elev (ft) Section 102.00 Depth (ft) 2.00 .101.50 1.50 101.00 100.50 0.50 100.00 Is' 99.50 _n ;n 0 .5 1 1.5 2 2.5 3 3.5 4 4.5 5 Reach (ft) Channel Report Hydraf low Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Wednesday, Apr 242019 Dispersal Structure @ 0.5% Triangular Highlighted Side Slopes (z:1) 0.00, 14.00 Depth (ft) = 0.69 Total Depth (ft) = 1.00 Q (cfs) = 0.810 Area (sqft) = 3.33 Invert Elev (ft) = 100.00 Velocity (ft/s) = 0.24 Slope (%) = 0.50 Wetted Perim (ft) = 10.37 N-Value = 0.200 Crit Depth, Yc (ft) = 0.25 Top Width (ft) = 9.66 Calculations EGL (ft) = 0.69 Compute by: Known Q Known 0 (cfs) = 0.81 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 100.00 SI' 99.50 - -0.50 0 2 4 6 8 10 12 14 16 18 Reach (ft) 6 Inch PVC @1% Circular Diameter (ft) = 0.50 Invert Elev (ft) = 100.00 Slope (%) = 1.00 N-Value = 0.011 Calculations Compute by: Known 0 Known 0 (cfs) = 0.46 Depth (ft) = 0.31 Q (cfs) = 0.460 Area (sqft) = 0.13 Velocity (ft/s) = 3.59 Wetted Perim (ft) = 0.91 Crit Depth, Yc (ft) = 0.35 Top Width (ft) = 0.49 EGL(ft) = 0.51 Highlighted Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodosk, Inc. Wednesday, Apr 24 2019 Elev (ft) Section 101.00 100.75 100.50 100.25 100.00 99.75 0 1 Reach (ft) San Diego County Hydrology Manual Section: 3 Date: June 2003 Page: •6of26 Table 3-1 RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use I Runoff Coefficient "C" Soil Type NRCS Elements County Elements % IMPER. A B C D Undisturbed Natural Terrain (Natural) Permanent Open Space 0* 0.20 0.25 0.30 0.35 Low Density Residential (LDR) Residential, 1.0 DU/A or less 10 0.27 0.32 0.36 0.41 Low Density Residential (LDR) Residential, 2.0 DU/A or less 20 0.34 0.38 0.42 0.46 Low Density Residential (LDR) Residential, 2.9 DU/A or less 25 0.38 0.41 0.45 0.49 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 0.57 Medium Density Residential (MDR) Residential, 10.9 DU/A or less 45 0.52 0.54 0.57 0.60 Medium Density Residential (MDR) Residential, 14.5 DU/A or less 50 0.55 0.58 0.60 0.63 High Density Residential (HDR) Residential, 24.0 DU/A or less 65 0.66 0.67 0.69 0.71 High Density Residential (HDR) Residential, 43.0 DU/A or less 80 0.76 0.77 0.78 0.79 Commercialllndustrial (N. Corn) Neighborhood Commercial 80 0.76 0.77 0.78 0.79 Commercial/Industrial(G. Corn) General Commercial 85 0.80 0.80 0.81 0.82 Commercialllndustrial (O.P. Corn) Office Professional/Commercial 90 0.83 0.84 0.84 0.85 Commercial/Industrial (Limited I.) Limited Industrial 90 0.83 0.84 0.84 0.85 Commercial/Industrial. (General I.) General Industrial 1 95 0.87 0.87 0.87 0.87 *The 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 areas that will 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 County of San Diego 44-ttôran- 33'___ J_ 1_4 ______ EIt1 1 ___ L4-H I Hydrology Manual -County1j I L4'+ L 4. 4.1 t H + -r r r—r Riv2rsideCounty m r + L44L HIuJJi w tTht 4 J. 4- 4- 4- r1 + I 30 4 -- + I L --- -- CL k —_ Rainfailsopluvials ___________ • 33-15 '•••-'--•• '-4 ----r1; ----- -.1. ..i41 ?' 7.4 - , 100 Year Rainfall Event -6 Hours CEANSDE j _f . . ,$2;-•. .+ -. _.L 2I6• 4 r r + -, — - -.. -i # r - IsopuvIal (inches) '' tt ' ifr -k------ __CNLSBAIf 4 QI _L 4— 41 4--r-i 4------ I I L t 11 Ll '+-- + +4-' H, T 4I+ 1 H:3OO' - - - 4- 4 SOLONA 4 - 4 Q 1 H 4-4 4-- 4-+t' 4-+44 -.#-. - -• '•\-•- 1-4-- --'--i--'---i- r I-''' t' j't 4-r 4 '." -. -- - -4-: 14-4 i-'-H--- ------------ •-1 •.- -4-4..,i.i-•-----i: 4- L- 4. t. - 4- -, -4-\I•; i_•__ • +--4---4--I--+--.-1-4--+ 1 -H' 4-4- ___ _ L 11 r--•i--r--------- I l -I I t -1----j-+--r-!.--,--'-- +_4..f_*#4l4-.L,...._ .4-. ' -•'-t--' 'i --77. -'•-' 4--4 ;.----i---ri-f+41 -4-i-1 4- 44-4-#+ TTW2)' - I -# -4 -- —4- + I 4 ¶4- r I SY DPW -.(IS Sa.itii(-1[S 4 1-I- - I - ++ -, \Vc I-la S'- Di goC utd 1. I 4- 1 _- i 1ERNL IfA 4- 1 I r N 04 --H ,- - - ___ - M e X t C 4- 1t ---------------------------- t. E 3230 S - ** - 1 - I - ..- 4 4- I -------------------I 4-4- - 4 4- I -------------------------------------------------------- 3230' 1 -i * - 4, 3 0 3 Miles -• ,4. ?---- WI H-HH-H-HJf L4 r Ti~_HH Ji 4LLpiT2Tp4JifLrr r1iJTfJTrTTJTrfrF TJ 1 I i -H County of San Diego Orange I Hydrology Manual rt __________ r I _J_ _•____ - - 333 H-4 rt.Gôunty -I4 1L il H ____________ - - t rt4 it -L - ± T L, t4 l0 - + +4 ..i_1 t : '.- t .4 I, H H Rainfall Isopluvials - --- 4 / - 100 Year Rainfall Event -24 Hours - t ocEANSIo()c'4--4---- - Isopluvial (inches) rijH Ltr% h1H f± -+— L:44T ... .44_........ F- ENCIN + t + 4_1144_i..I i. 44 L 4 * t F- 33OO----- .•-.,. 4t4tt+j..i4.:L ,.1 ++I -F 3 SO1PJA -4-_f -f---_4__-- 'DEL 44-'• f 5 ) 4 *4- 4 t 4- - 4- * - C) 1 4- -,- ' 4 -4-. -,- - _*- - CD - r 4 4 4- + - - (7" + ~-'- - f 4 C) - j 0-- i _-44.4 A. lL-4-._---.--.---4 4--.--. /. ...,-, 4--•..:------.-.-4--1 245' 4- 4- 4. . - . '.' ,' "..4.. ./'4-4-,'........- -. -'--:-.+ 4.•'"• 'tt' -I-li /3_i Sb- I DPW Sã'G11S It 1 -GIS j -41r n' - I - 4 4 4 \X H.. .-m1) C( (4*41 Ii4*-,- - --------------------------- ' • 4 1 04- : - W 4- • 4- 4 • - - %# . - -+ ,,t .--, , + --•'- V - 12*301 - - - . ______________________ + . - ' 1 4 • - - ' - - 4- ...I-i ti 32°30' 4 3 0 3MlIes 4--'- PA Directions for Application: 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). Adjust 6 hr precipitation (if necessary) so that it is within the range of 45% to 65% of the 24 hr precipitation (not applicaple to Desert). Plot 6 hr precipitation on the right side of the chart. Draw a line through the point parallel to the plotted lines. This line is the intensity-duration curve for the location being analyzed. Application Form: ____ Selected frequencyj 100 1year P6 = J 2.6 [in., P24 = f 4.6 f I %() 24 Adjusted p6(2) = 2.6 in. (d)tx 5 mm. (e) I = 6.85 in/hr. Note: This chart replaces the Intensity-Duration-Frequency curves used since 1965. P6 Ouralion. 5 i 1 15 2 2.5'-3 35 4 45 5 55 6 i I I I I I I I • I 263 13.95527 6.59 7.90.922:1054:11.86 13.17 14.49 15.81 7 2.12 3.18.4.24. 53o6 3 ? 42:8.48 9.54 10.60 11.651272 - 10 1,§§_i2I 317 1 0 390 bi 4 758 842921 1(311 324 .35454 5,19 649 713 15 1.30 .1.95.2.59 20 108 1622.15.26932337: 431 4.85 5:39' 5.93 .7 6.46 :5 25 30 093 1.40 1.87 2.33280 3.27. 3.734.20. 467 13 .5.60 083 1.24 16612072492.9(3 3.32: :1.73. 415 4.56 4.98 069 103 1,3811-1, 40 50 .38 1.722072.4112.76 310 060 0.90:1.19 I 49 I 79 209 2.39 2.69 2.98: 3.28 3.58 60 053 080!I 06;l 33:l59:t.86 2.12 ...39265 2.92 3.18 90 041 0.61:082, 1.02) 23. i.43 163 18420.1225 245 120 150 0.3.3 .0.51 068 0-85,1 102.1.19; 136 1.63 110 t 1.87 i 2.04 0.29 0441050 0.73 088 103, 1.18 132 1.47 :162 1.76 180 026;0.390,52 0.65:078 0.91 104 118 I 144 1,67 022 0.330430.61 41 065 0.76: 087 0.98 1.08 119 1.30 300 0.190.280.38.0470.56066 0750.85094 1.03 1.13 360 017 •025033 0.120.50 0.58._067 0.75 0.&4 0.92 0•3 I 0 C C) 6.0 V. 5.5 5.0 0 4.5 C) 4.0 3.5 . 3.0 2.5 2.0 1.5 1.0 6.1 ai _ ______11111111 _• .• = 6-Hour Precipitation (in) ' Duration UllftI IMM119412JIM004 q_5 1-1190 0 111 M 111401m,W011 amp 11111b.. K0 ..11199 q1i W q 11M lull I r1l .1'rrh 1,011m..' hn wlqlq 11L I ~t q I h 100 '~'q I KIN 01111i Z4 IIIIIIIIIIIUIlIIIII1Illh1IIIllhIllhIII!!IIOhIIIllllIllh1!IIlliI!iIiiIIIj!!Ih!!ii HhIIIIIIIIIIIHllh1HHhIIIllhIIIllhI11IIIillIHIOOtHIIIiI!iIIi!!IIIi!1bil!!!I 1IIIIIIIH1II1IllHIllOhIUff1011hIII1IIllhIIIIIhhfflJI1IIIiiI!!IIIii!lllhillI IIII1IIIIII1 11111 1111111111 IMlilill 1111111111 IiI1llllu1HhIi 111111 I1flI!!llffi .uilmnlatlllfl - iirn.ii;auuiiu.ii *.flfl.IflflIflfl1.fll000flflflh.tflfl,fl 1.21101 ..fl.su.I..:*aI,I UI...iuiiTh.'H •••• .U.II.IIUIIWUIIHI...lUmllvl,UU1*IHJI1U •. q1USIIIIlIUgIThi BEWES • *NSNIUIJ RIIUU uiuuw,.a.a.uiu. UflIUI*1U*NII1UI i RI MtIIlIuuI*IiI)IIIl usini,u ..'I. U*..UNM USUUNI1!ItI .II.galllllu 101111 IRUlIuRUPIflhIRNINE IIIflflhI *uIRa*• I*IIII•IUU1I uauunuui UWIUII IauIIUfl mwnmu,Iu....1Ifl uIuluufl amasiaiiuiimrninu uivauuiumiuuuznsiuju ua.u.•iiui IuIIillHhI - ••iiiuiii,iu Irnm,n uii11u1i1i11aiiuu1insoj ..•.i.au. uIaiuiiJ1i WINE u.aiaiainhiuirnuiu .uiiiuui Illifil WUuhlH a.a.igiu uIIIIIILh .uauauuuiun uiuuauiiiuiwiiwii a•asmi ;;a:;:;::#w;llIff,101. au•uaiuuiniiuwuirniuuuniiiwiinum iaisuuaiiiiiuiiii iiuRIIHu$Hh1IIftlllfllHlHIIII1IIHIUlIlItlllIW IH UuIIIluI1IIII1HuhIIlllUR•iuiuiiiuiaiiiuuiuiiitnnsuiuuiunuuwnwnimiiiuiiiiuninnnniinn - . 7 : • I is 20 30 40 so Minutes Hours Duration FIG U R E Intensity-Duration Design Chart - Template (City of STORM WATER STANDARDS Development Services Carlsbad QUESTIONNAIRE Land Development Engineering 1635 Faraday Avenue E-34 (760) 602-2750 www.carlsbadca.gov To address post-development pollutants that may be generated from development projects, the city requires that new development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices (BMPs) into the project design per Carlsbad BMP Design Manual (BMP Manual). To view the BMP Manual, refer to the Engineering Standards (Volume 5). This questionnaire must be completed by the applicant in advance of submitting for a development application (subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of storm water standards that must be applied to a proposed development or redevelopment project. Depending on the outcome, your project will either be subject to 'STANDARD PROJECT' requirements or be subject to 'PRIORITY DEVELOPMENT PROJECT' (PDP) requirements. Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City staff has responsibility, for making the final assessment after submission of the development application. If staff determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than initially assessed by you, this will result in the return of the development application as incomplete. In this case, please make the changes to the questionnaire and resubmit to the city. If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the questions, please seek assistance from Land Development Engineering staff. A completed and signed questionnaire must be submitted with each development project application. Only one completed and signed questionnaire is required when multiple development applications for the same project are submitted concurrently. PROJECT INFORMATION PROJECT NAME: Oak Avenue Parcel Map PROJECT ID: MS2018-0002 ADDRESS: 1391 Oak Avenue, Carlsbad, Ca 92008 APN: 205-020-18-00 The project is (check one): EZ New Development El Redevelopment The total proposed disturbed area is: 6,765 ft2 (_0.15 ) acres The total proposed newly created and/or replaced impervious area is: 4,629 ft2g.106) acres If your project is covered by an approved SWQMP as part of a larger development project, provide the project ID and the SWQMP # of the larger development project: Project ID SWQMP#: Then, go to Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your application to the city. E-34 Page 1 of 4 REV 02/16 STEP I TO BE COMPLETED FOR ALL PROJECTS To determine if your project is a "development project", please answer the following question: YES NO Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building o i or structure that do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)? If you answered "yes" to the above question, provide justification below then go to Step 5, mark the third box stating "my project is not a 'development project' and not subject to the requirements of the BMP manual" and complete applicant information. Justification/discussion: (e.g. the project includes only interior remodels within an existing building): If you answered "no" to the above question, the project is a 'development project', go to Step 2. STEP TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS To determine if your project is exempt from POP requirements pursuant to MS4 Permit Provision E.3.b.(3), please answer the following questions: Is your project LIMITED to one or more of the following: YES NO 1. Constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria: Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non- erodible permeable areas; Designed and constructed to be hydraulically disconnected from paved streets or roads; C) Designed and constructed with permeable pavements or surfaces in accordance with USEPA Green Streets guidance? 2. Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in o i accordance with the USEPA Green Streets guidance? 3. Ground Mounted Solar Array that meets the criteria provided in section 1.4.2 of the BMP manual? 0 If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark the second box stating "my project is EXEMPT from PDP . ." and complete applicant information. Discussion to justify exemption (e.g. the project redeveloping existing road designed and constructed in accordance with the USEPA Green Street guidance): If you answered "no" to the above questions, your project is not exempt from POP, go to Step 3. E-34 Page 2of4 REV 04/17 STEP 3 TO BE COMPLETED FOR ALL NEW OR REDEVELOPMENT PROJECTS To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1)): YES NO Is your project a new development that creates 10,000 square feet or more of impervious surfaces collectively over the entire project site? This includes commercial, industrial, residential, mixed-use, LI IXI and public development projects or public or private land. Is your project a redevelopment project creating and/or replacing 5,000 square feet or more of impervious surface collectively over the entire project site on an existing site of 10,000 square feet or El 0 more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface collectively over the entire project site and supports a restaurant? A restaurant is a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and 0 E refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial Classification (SIC) code 5812). Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface collectively over the entire project site and supports a hillside development project? A hillside 0 E development on_ any twenty-five greater. _project _includes _development _natural _slope _that _is_ _percent _or Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface collectively over the entire project site and supports a parking lot? A parking lot is a land area or facility for the temporary parking or storage of motor vehicles used personally for business or for commerce. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious street, road, highway, freeway or driveway surface collectively over the entire project El IN site?- A street, road, highway, freeway or driveway is any paved impervious surface used for the transportation of automobiles, other vehicles. _trucks, _motorcycles, _and Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more of impervious surface collectively over the entire site, and discharges directly to an Environmentally Sensitive Area (ESA)? "Discharging Directly to" includes flow that is conveyed overland a distance of 0 I 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).* Is your project a new development or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface that supports an automotive repair shop? An automotive repair shop is a facility that is categorized in any one of the following Standard Industrial Classification (SIC) codes: 5013, 5014, 5541, 7532-7534, or 7536-7539. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious area that supports a retail gasoline outlet (RGO)? This category includes El Im RGO'S that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily Traffic (AD T) of 100 or more vehicles per day. Is your project a new or redevelopment project that results in the disturbance of one or more acres of land and are expected to generate pollutants post construction? El X Is your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of impervious surface or (2) increases impervious surface on the property by more than 10%? (CMC 0 tI 21.203.040) If you answered "yes" to one or more of the above questions, your project is a POP. If your project is a redevelopment project, go to step 4. If your project is a new project, go to step 5, check the first box stating "My project is a PDP. and complete applicant information. If you answered "no" to all of the above questions, your project is a 'STANDARD PROJECT.' Go to step 5, check the second box stating "My project is a 'STANDARD PROJECT'..." and complete applicant information. E-34 ' Page 3 of 4 REV 04/17 STEP TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS (PDP) ONLY Complete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b.(2)): YES NO Does the redevelopment project result in the creation or replacement of impervious surface in an amount of less than 50% of the surface area of the previously existing development? Complete the percent impervious calculation below: Existing impervious area (A) = sq. ft. 0 0 Total proposed newly created or replaced impervious area (B) = sq. ft. Percent impervious area created or replaced (B/A)*100 = % If you answered "yes", the structural BMPs required for PDP apply only to the creation or replacement of impervious surface and not the entire development. Go to step 5, check the first box stating "My project is a PDP ..." and complete applicant information. If you answered "no," the structural BMP's required for PDP apply to the entire development Go to step 5, check the check the first box stating "My project is a PDP ..." and complete applicant information. STEPS CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION O My project is a PDP and must comply with PDP stormwater requirements of the BMP Manual. I understand I must prepare a Storm Water Quality Management Plan (SWQMP) for submittal at time of application. EZ My project is a 'STANDARD PROJECT' OR EXEMPT from PDP and must only comply with STANDARD PROJECT' stormwater requirements of the BMP Manual. As part of these requirements, I will submit a "Standard Project Requirement Checklist Form E-36" and incorporate low impact development strategies throughout my project. Note: For projects that are close to meeting the PDP threshold, staff may require detailed impervious area calculations and exhibits to verify if 'STANDARD PROJECT' stormwater requirements apply. O My Project is NOT a 'development project' and is not subject to the requirements of the BMP Manual. Applicant Information and Signature Box Applicant Name: John P. Strohminger Applicant Title: Project Civil Engineer Applicant Signature: Date: 4-22-2020 1nv1r0nmen1auy bensitive Areas include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); areas designated as preserves or their equivalent under the Mufti Species Conservation Program within the Cities and County of San Diego; Habitat Management Plan; and any other equivalent environmentally sensitive areas which have been identified by the City. This Box for Cliv Use Only City Concurrence: YES NO . El By: Date: Project ID: E-34 Page 4 of 4 REV 04/17 I C(` City of Carlsbad STANDARD PROJECT REQUIREMENT CHECKLIST E-36 Development Services Land Development Engineering 1635 Faraday Avenue (760) 602-2750 www.carlsbadca.gov Project Information Project Name: Oak Avenue Tentative Parcel Map Project ID: MS 2018-0002 DWG No. or Building Permit No.: Source Control BMPs All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See Chapter 4 and Appendix EA of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to implement source control BMPs shown in this checklist. Answer each category below pursuant to the following. "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix EA of the Model BMP Design Manual. Discussion/justification is not required. 'No" means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be provided. Please add attachments if more space is needed. "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project has no outdoor materials storage areas). Discussion/justification may be provided. Source Control -Requirement Applied? SC-1 Prevention of Illicit Discharges into the MS4 0 Yes 0 No 0 N/A Discussion/justification if SC-i not implemented: SC-2 Storm Drain Stenciling or Signage 0 Yes 0 No lii N/A Discussion/justification if SC-2 not implemented: There are no storm drains associated with this project. SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal 0 Yes 0 No 9 N/A Discussion/justification if SC-3 not implemented: There are no outdoor material storage areas proposed with this project. E-36 Page 1 of 4 Revised 09/16 Source Controtjirement (continued) Applied? SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and Wind Dispersal es 0 N N/A Discussion/justification if SC4 not implemented: There are no outdoor work areas proposed with this project. SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal II Yes 0 No 0 N/A Discussion/justification if SC-5 not implemented: SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and identify additional BMPs. (See Table in Appendix E.1 of BMP Manual for guidance). On-site storm drain inlets 0 Yes 0 No lI N/A Interior floor drains and elevator shaft sump pumps 0 Yes 0 No ll N/A Interior parking garages 0 Yes 0 No III N/A Need for future indoor & structural pest control III Yes 0 No 0 N/A O Landscape/Outdoor Pesticide Use 0 Yes 0 No III N/A C1 Pools, spas, ponds, decorative fountains, and other water features 0 Yes 0 No ll N/A Food service 0 Yes 0 No lI N/A Refuse areas 0 Yes 0 No !l N/A Industrial processes 0 Yes 0 No ii N/A Outdoor storage of equipmentor materials 0 Yes 0 No III N/A Vehicle and Equipment Cleaning 0 Yes 0 No Ii N/A Vehicle/Equipment Repair and Maintenance 0 Yes 0 No L1 N/A Fuel Dispensing Areas 0 Yes 0 No iJ N/A Loading Docks 0 Yes 0 No II N/A Fire Sprinkler Test Water IUI Yes 0 No 0 N/A Miscellaneous Drain or Wash Water 0 Yes 0 No IJ N/A Plazas, sidewalks, and parking lots 0 Yes 0 No II N/A For "Yes" answers, identify the additional BMP per Appendix E.1. Provide justification for "No answers. Structural lumber to be treated for pests. Fire Sprinkler test to be routed to sanitary sewer. E-36 Page 2 of 4 Revised 09/16 1 Site Design BMPs L__J All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to implement site design BMPs shown in this checklist. Answer each category below pursuant to the following. "Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of the Model BMP Design Manual. Discussion/justification is not required. "No" means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be provided. Please add attachments if more space is needed. "N/A" means the BMPs is not applicable at the project site because the project does not include the feature that is addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be provided. Site Design Requirement Applied? SD-I Maintain Natural Drainage Pathways and Hydrologic Features 0 Yes I 0 No I III N/A Discussion/justification if SD-1 not implemented: The entire site has been previously graded, so there are no natural drainage pathways or hydrologic features. SD-2 Conserve Natural Areas, Soils, and Vegetation I 0 Yes 0 No I 11 N/A Discussion/justification if SD-2 not implemented: There are no natural areas, soils or vegetation on this project site. SD-3 Minimize Impervious Area I li Yes I 0 No I 0 N/A Discussion/justification if SD-3 not implemented: SD-4 Minimize Soil Compaction ' Yes I 0 No I 0 N/A Discussion/justification if SD-4 not implemented: SD-5 Impervious Area Dispersion I l$l Yes I 0 No I 0 N/A Discussion/justification if SD-5 not implemented: E-36 Page 3 of 4 Revised 09/16 Site Design RLément (continued) Applied? SD-6 Runoff Collection I I ll Yes 0 No 0 N/A Discussion/justification if SD-6 not implemented: SD-7 Landscaping with Native or Drought Tolerant Species I 0 Yes I 0 No I L!1 N/A Discussion/justification if SD-7 not implemented: There is no landscaping proposed with the project except for the vegetated swales that require a non-native grass that provides a high runoff coefficient and must be regularly watered. SD-8 Harvesting and Using Precipitation I HYes I 0 No 0 N/A Discussion/justification if SD-8 not implemented: E-36 Page 4 of 4 Revised 09/16