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HomeMy WebLinkAboutPD 2021-0034; TREHAN RESIDENCE; HYDROLOGY / DRAINAGE STUDY FOR TREHAN RESIDENCE; 2024-06-14 Snipes-Dye associates HYDROLOGY / DRAINAGE STUDY FOR TREHAN RESIDENCE 2436 LA COSTA AVENUE CARLSBAD, CA 92009 (Vacant Land) CITY OF CARLSBAD PROJECT NO. PD2021-0034 ASSESSOR'S PARCEL NUMBER(S): 216-160-10-00 ENGINEER OF WORK: ______________________________________________________________ WILLIAM A. SNIPES, RCE 50477 PREPARED FOR: Prime Land Developer LLC / Sameer Trehan 10547 Darella Way San Diego, CA 92126 (619) 261-7456 PREPARED BY: Snipes-Dye Associates civil engineers and land surveyors 8348 Center Drive, Suite G La Mesa, CA 91942 (619) 697-9234 CA1611 Dated: August 4, 2022 Revised: June 14, 2024 CA1611 Trehan Residence Hydrology / Drainage Study HYDROLOGY REPORT FOR TREHAN RESIDENCE The following hydrology and hydraulic calculations were prepared for the future development of a single-family residence located at a vacant parcel of land on La Costa Avenue, on the intersection with Sitio Del Mar in Carlsbad, California. The subject site is known as Assessor’s Parcel Number 216-160-10-00 consisting of 0.24-acre gross. The scope of work consists of the grading of land for the creation of the residential lot and its associated utilities, street improvements (including sidewalk and driveway), and the construction of a private storm drainage system that will convey runoff into a proposed detention pond without negatively impacting downstream drainage facilities and/or properties. The total area of disturbance of the project site will be equal to 0.22 acre. The purpose of this drainage study analysis is to demonstrate that the existing hydrologic conditions will not be negatively impacted by the proposed development’s grading and creation of new impervious surfaces. The area of the drainage analysis will encompass approximately 0.26 acre, which includes the site street frontage along La Costa Avenue. Runoff from the upstream properties will not enter the site, since the site is situated above all adjacent properties and La Costa Avenue. The hydrology analysis is based on the 100-year, 6-hour storm event. Modified Rational Method hydrology calculations were performed using AES Software and County of San Diego Hydrology Manual (2003 Edition) criteria. Runoff coefficients were based and weighted on the percentage of impervious area and the soil type for each drainage basin. The underlying site soil type was determined to be “D” soil. Detention routing analysis was prepared using the design procedure from San Diego County Hydraulic Design Manual Section 6.3. Inflow hydrographs for detention analysis were prepared according to the Rational Method Hydrograph Procedure in Section 6 of San Diego Hydrology Manual and inputted into Hydraflow Hydrographs Software for storage routing calculations. PRE-DEVELOPMENT CONDITIONS: The existing site is located in a City of Carlsbad designated low density residential area, and consists of a vacant parcel of land. The site consists of moderate to steep sloping land. Elevations within the site range from 100 feet M.S.L at the higher elevation near the southeast corner of the site to 75 feet M.S.L. near the northwest corner of the site. The site is predominantly covered with vegetation consisting of native grasses with trees and shrubs mainly along the north and east property lines. The existing site drainage is divided into three main drainage basins (denoted as Basins 1, 2, and 3 in the Pre-Development Drainage Map). Basin 1 is comprised of easterly half of the site approximately 0.12 acre in size. Runoff from Basin 1 begins near the southeast corner of the site as sheet flow in a general northerly direction traversing the site that eventually discharges onto the neighboring property along the north towards then towards the neighboring golf course. The 100-year peak discharge from Basin 1 is 0.26 cfs. Basin 2 consists mainly of the westerly portion of the site, where runoff sheet flows in a general northerly direction and discharges near the northwest corner of the site. The runoff from Basin 2 will also flow towards the neighboring golf course. The 100-year peak discharge from Basin 2 is 0.24 cfs. Basin 3 consists of the southwesterly portion of the site and the site street frontage along La CA1611 Trehan Residence Hydrology / Drainage Study Costa Avenue, with runoff consisting of sheet flow draining southwesterly towards the street gutter then into the existing public storm drain system. The 100-year peak discharge from Basin 3 is 0.11 cfs. Therefore, the total 100-year peak discharge for the area of analysis is equal to 0.61 cfs. POST-DEVELOPMENT CONDITIONS: The proposed development of the site will maintain similar drainage patterns and discharge locations as in the current condition. The post-development drainage will also be divided into 3 main drainage basins, where Basin 1 is comprised of subbasins 1A, 1B, and 1C. Based on the post-development drainage calculations, the overall site 100-year peak discharge will be 1.22 cfs with no mitigation which represents an increase of approximately 0.61 cfs. The increase in runoff is mainly attributed to the creation of impervious surfaces due to the development of the site. The increase in post-developed Basin 1 will be collected in a proposed detention basin that will have the capacity to provide peak flow mitigation to be approximately that of the onsite pre-developed condition. Refer to Detention Calculations section of this report for detention analysis provided for the proposed detention basin. The overall 100-year peak site discharge after mitigation will be 0.81 cfs. By comparing the mitigated post-developed runoff from Basins 1 and 2 to those in the pre-developed condition, their runoff is equivalent to 0.53 cfs which is a negligible 0.03 cfs higher than the pre-developed flow of 0.50 cfs. Post-developed runoff from Basin 3 (0.28 cfs) is slightly higher than the predeveloped condition (0.11 cfs). This increase of 0.17 cfs will not present a significant impact to the downstream existing drainage facilities, properties, and/or waterways, since La Costa Avenue has the capacity to carry this additional flow all the way to the existing private curb inlet past the Camino Alberto cul- de-sac (approximately a quarter mile west from the site. Table 1 below is a summary of the 100-year peak discharges for the pre- and post-development conditions of the project site: Table 1: Summary of 100-year, 6- hour Storm Event Basin ID Pre- Development Post-Development “C” TC (min.) I (in/hr) Area (ac.) Q100 (cfs) “C” TC (min.) I (in/hr) Area (ac.) Q100 (cfs) Mitigated Q100 (cfs) 1 0.35 6.27 6.264 0.12 0.26 0.67 5.00 7.246 0.17 0.82 0.36 2 0.35 6.27 6.264 0.11 0.24 0.55 5.00 7.246 0.04 0.17 0.17 3 0.54 5.65 6.697 0.03 0.11 0.76 5.00 7.246 0.05 0.28 0.28 SUM - - - 0.26 0.61 - - - 0.26 1.22 0.81 CA1611 Trehan Residence Hydrology / Drainage Study CONCLUSION: 1. The proposed discharge of surface drainage is generally consistent with the existing drainage patterns of the site. Site drainage is conveyed in the northerly direction toward the golf course and towards an existing storm drain inlet further west on La Costa Avenue, similar to pre-conditions. The runoff will be conveyed into San Marcos Creek and then Batiquitos Lagoon. 2. The proposed development of this project will not have a significant impact to the downstream drainage facilities and/or any downstream streams or rivers in a manner which would result in substantial erosion or siltation. 3. The site is not located within a 100-year flood hazard area or within the influence of flooding as a result of the failure of a levee or dam, therefore the proposed development will not expose people or structures to a significant risk of loss, injury or death. DECLARATION OF RESPONSIBLE CHARGE: I, hereby declare that I am the civil 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 responsibility for project design. __ 6-14-24 __ WILLIAM A. SNIPES Date R.C.E. 50477 Exp. 06-30-25 VICINITY CITY OF OCEANSIDE PACIFIC OCEAN 78 MAP CITY OF ENCINITAS NOT TO SCALE Y OF N MARCOS 100 2.75 4.9 56 2.75 P6=2.75 5.0 7.25 TREHAN RESIDENCE, 2436 LA COSTA AVENUE CARLSBAD, CA 92009 10.0 9.0 8.0 7.0 :5 0 .c vi Q) .c 6.0 5.0 4.0 3.0 2.0 g 1.0 ~09 -~08 Q) E o 1 0.6 0.5 0.4 0.3 0.2 0.1 r--.. 'r--. "'""'-, ........... ~ .... ~r-,.. .... "'""'-~r,.. ' 'r--. ~r--.. .... , .... , I..,.._ .... I', -., ~ ' ~ ......... .... ' r-..' ,, i-. .... ' i-.... ,, '~ ..... r--.. ..... .. ~ r-.., ... ~ ... , .... "" .. ~ .... ... ' ' ... ' .... ..._ .... , .. ,, .. ' ,t-.... , .... I', .. ~ " ' r-.. ' , .... .... " I"-._ ..... , .. ', ' ....... ... , ~ 'i-.... r-..' I-.._ .... I', ~ .... .. .... .... r-.. .... .. i--... , .... ~ ..... r--.. ....... ,, ' .... "" ~ i-.... 'r-.. ..... r--.. .. 'r-.. .... ... , ~ .. .. ..... r-.. .. ~ ', ...... ....... .. 5 6 7 8 9 10 15 20 30 Minutes .. .... .... .. .. ~ .... .. .. .. ~ ~~ .... ~~ .. .... .... .. .. ...... 40 50 Duration I = I = p6 = D = EQUATION 7.44 P6 D-0.645 Intensity (in/hr) 6-Hour Precipitation (in) Duration (min) " r-.. ... ' ~, .... .. r-.., .... ' r-.. r-.., r-.. • ', r-.. .. ' r-.. ... r-... r-. r-.. ........ I"-., , ... '-r-.. ' r-.. ' r-....._ r-.. 2 ,, ,, ' ........ I', ~ 'i-. ,, ,, ~ .. ,, "'i-. .. . ..... , :-- ..... , ,, ' .. ..,r--, "'r--~ ... '"" I" I" 3 Hours ~ .. ~ II, ~ ~ .. ~ .. ~ .. 4 5 6 O> i 0 ~ 7J ro 0 6.o -g; 5.5 ~ 5.0 g 4.5 5' 0 4.0 ~ 3.5 ~ 3.0 2.5 2.0 1.5 1.0 Intensity-Duration Design Chart -Template Directions for Application: (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 precipitation (not applicaple to Desert). (3) Plot 6 hr precipitation on the right side of the chart . (4) Draw a line through the point parallel to the plotted lines. (5) This line is the intensity-duration curve for the location being analyzed. Application Form: (a) Selected frequency ___ year p (b) p6 = ---in., P24 = ---'P 6 = %(2J 24 (c) Adjusted p6<2l = ___ in . (d) tx = __ min . (e) I = __ in./hr. Note: This chart replaces the Intensity-Duration-Frequency curves used since 1965. I I I I P6 1 1.5 2 2.5 3 3.5 4 I 4.5 5 5.5 6 Duration I I I I I I I I I I I 5 2.63 3.95 5.27 6.59 7.90 9.22 10.54 11.86 13.17 14.49 15.81 7 2.12 3.18 4.24 5.30 6.36 7.42 8.48 9.54 10.60 11.66 12.72 1.68 2.53 3.37 4.21 5.05 5.90 6.74 -8.42 -10.11 10 7.58 9.27 15 1.30 1.95 2.59 3.24 3.89 4.54 5.19 5.84 6.49 7.13 7.78 20 1.08 1.62 2.15 2.69 3.23 3.77 4.31 4.85 5.39 5.93 6.46 ~ 25 0.93-1.40 1.87 2.33 2.80 3.27 3.73 4.20 4.67 5.13 5.60 30 0.83 1.24 1.66 2.07 2.49 2.90 3.32 '3.73 4.15 4.56 4.98 ~ 0.69 1.03 1.38 1.72 2.07 2.41 2.76 3.10 3.45 3.79 4.13 50 0.60 0.90 1.19 1.49 1.79 2.09 2.39-2.69-2.98 3.28 3.58 60 0.53 0.80 1.06 1.33 1.59 1.86 2.12 2.39 2.65 2.92 3.18 90 0.41 0.61 0.82 1.02 TI3 1 .43 1.63 1.84 2.04 2.25 '2.45 120 0.34 0.51 0.68 0.85 1.02 1.19 1.36 1.53 1.70 1.87 2.04 150 0.29 0.44 0.59 0.73 0.88 1.03 -1.18 1.32 1.47 7 .62 1.76 180 0.26 0.39 0.52 0.65 0.78 0.91 1.04 1.18 1.31 1.44 1.57 240 0.22 0.33 0.43 0.54 0.65 0.76 0.87 0.98 1.08 1.19 1.30 300 0.19 0.28 0.38 0.47 0.56 0.66 0.75 0.85 0.94 1.03 1.13 360 0.17 0.25 0.33 0.42 0.50 0.58 0.67 0.75 0.84 0.92 1.00 F IG URE ~ SITE 2.75 TREHAN RESIDENCE VACANT LAND, 2436 LA COSTA AVE. CARLSBAD, CA 92009 ~-7 1 33'115' j O' 3 "t:, CD ::!. Q1.. County of San Diego Hydrology Manual • Co Rainfall Jsop/uvials 100 year Rainfall Event -6 Hours lsopluvial (inches) SITE 4.9 TREHAN RESIDENCE VACANT LAND, 2436 LA COSTA AVE. CARLSBAD, CA 92009 0 r 33'30' 33'15' --0 c;)) (') .,,. -33'00' .,,. (') 32'45' 32'30' 0 (') {Q c;)) ~ [o ,._ [o ~ g [o ,:.. ~ 0 ~ "' 1o e X C [o 1o County of San Diego Hydrology Manual 33'30' , • Rainfall Isopluvials 100 year Rainfall Event 24 H -ours lsopluvial (inches) J r ri ::::!. ~ DPW ~ *GIS S~ ~,,::=~.. anGIS We Have San Dicgc, C:n,md! 32'30' +N ~fM~JPROVIOEDWITHOOTWARRANTY ~. MERCHANT.· IN~~r-:r:~BOUT.Fl~S~IM.ITEDTO~,!'H~~s~~~PRESS Sa!GIS. AU Rig1M ~. FORA PARTIClJLAR PURPOSE. ES ~~~m~.:::'~ln:mlhes.AAOAG~I 'Miltlln p,ilffllnion d SANDAG be rapvdl.lc:ad wtlhDIA tt... Tiisprodu<;t rnayccnlaininformatilln S pormisaiongrantedbylhomas~:::.st,,ae,,repro(l.lcu(lwith [o 3 0 3 Miles !e 8/5/2021 ArcGIS - BMP Sizing Calculator https://www.arcgis.com/home/webmap/viewer.html?webmap=d164cb4d94654acc8da5067187cdba93&extent=-117.2737,33.177,-117.271,33.1786 1/1 About  Content  Legend  Legend BMP Sizing A B C D n/a + − 0 100 200ft   BMP Sizing Calculator HYDRO UNIT NAME CARLSBAD HYDRO AREA NAME San Marcos HYDRO SUBAREA NAME Batiquitos HYDRO BASIN NUMBER 904.51 HYDRO SOIL GROUP D RAIN GAUGE BASIN Oceanside Basin Zoom to Details Basemap BMP Sizing CalculatorArcGISTREHAN RESIDENCE, 2436 LA COSTA AVENUE CARLSBAD, CA 92009 SITE TREHAN RESIDENCE, 2436 LA COSTA AVENUE CARLSBAD, CA 92009 San Diego County Hydrology Manual Date: June 2003 Table 3-1 Section: Page: RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use Runoff Coefficient "C'' Soil Tvoe NRCS Elements County Elements ¾IMPER. A B Undisturbed Natural Terrain (Natural) Permanent Open Space 0* 0.20 0.25 Low Density Residential (LOR) Residential, 1.0 DU/A or less 10 0.27 0.32 Low Density Residential (LOR) Residential, 2.0 DU/A or less 20 0.34 0.38 Low Density Residential (LOR) 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 (MOR) Residential, 7.3 DU/A or less 40 0.48 0.51 Medium 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 (HOR) Residential, 24.0 DU/A or less 65 0.66 0.67 High Density Residential (HOR) Residential, 43.0 DU/A or less 80 0.76 0.77 Commercial/Industrial (N. Com) Neighborhood Commercial 80 0.76 0.77 Commercial/Industrial (G. Com) General Commercial 85 0.80 0.80 Commercial/Industrial (O.P. Com) Office Professional/Commercial 90 0.83 0.84 Commercial/Industrial (Limited I.) Limited Industrial 90 0.83 0.84 Commercial/Industrial <General I.) General Industrial 95 0.87 0.87 3 6 of26 C n 0.30 0.35 0.36 0.41 0.42 0.46 0.45 0.49 0.48 0 52 0.54 0.57 0.57 0.60 0.60 0.63 0.69 0.71 0.78 0.79 0.78 0.79 0.81 0.82 0.84 0.85 0.84 0.85 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 JOB NO. SHEET NO.1 OF 2 CALCULATED BY ND DATE 8/4/22 CHECKED BY DATE DESCRIPTION % IMP = Percent of impervious surface C p = (Soil 1*(Area1 /Area p)) + (Soil 2*(Area2 /Area p) Soil Group for Undisturbed Natural Terrain in Table 3-1 C p = Pervious runoff coefficient Soil 1 = Soil Group of area Area 1 = Area of Soil Group Area p = Total pervious area C =0.90(% IMP) + Cp(1 - % IMP) San Diego County Hydrology Manual (June 2003) C = Runoff Coefficient FROM TO 1.00 1.10 0.00 0.12 D 0.00 N/A 0.12 0.00 0.35 0.35 2.00 2.10 0.00 0.11 D 0.00 N/A 0.11 0.00 0.35 0.35 1.00 3.10 0.01 0.02 D 0.00 N/A 0.03 0.35 0.35 0.54 Total 0.26 C Soil Type 1 Soil Type 2 Total Area (Ac.) % IMP Cp TREHAN RESIDENCE, CARLSBAD Pre-Development CA1611 DETERMINE WEIGHTED RUNOFF COEFFICIENT "C" SNIPES-DYE ASSOCIATES 8348 CENTER DR., SUITE G LA MESA, CA 91942 (619) 697-9234 FAX (619) 460-2033 Per. Area Soil 2 (Ac.) Per. Area Soil 1 (Ac.) Imp. Area (Ac.)Study Node SDA PROJECT NO. JOB NO. SHEET NO.2 OF 2 CALCULATED BY ND DATE 8/4/22 CHECKED BY DATE DESCRIPTION % IMP = Percent of impervious surface C p = (Soil 1*(Area1 /Area p)) + (Soil 2*(Area2 /Area p) Soil Group for Undisturbed Natural Terrain in Table 3-1 C p = Pervious runoff coefficient Soil 1 = Soil Group of area Area 1 = Area of Soil Group Area p = Total pervious area C =0.90(% IMP) + Cp(1 - % IMP) San Diego County Hydrology Manual (June 2003) C = Runoff Coefficient FROM TO 1.00 1.05 0.05 0.04 D 0.00 N/A 0.09 0.57 0.35 0.66 1.05 1.10 0.00 0.02 D 0.00 N/A 0.02 0.00 0.35 0.35 1.15 1.20 0.05 0.01 D 0.00 N/A 0.06 0.77 0.35 0.77 2.00 2.10 0.02 0.02 D 0.00 N/A 0.04 0.44 0.35 0.59 1.00 3.10 0.04 0.01 D 0.00 N/A 0.05 0.74 0.35 0.76 Total 0.26 % IMP Cp C SDA PROJECT NO. CA1611 DETERMINE WEIGHTED RUNOFF COEFFICIENT "C" Study Node Imp. Area (Ac.) Per. Area Soil 1 (Ac.) Soil Type 1 Per. Area Soil 2 (Ac.) Soil Type 2 Total Area (Ac.) Post-Development SNIPES-DYE ASSOCIATES TREHAN RESIDENCE, CARLSBAD 8348 CENTER DR., SUITE G LA MESA, CA 91942 (619) 697-9234 FAX (619) 460-2033 TREHAN RESIDENCE, CARLSBAD DRAINAGE MAPS 83 4 8 C E N T E R D R I V E , S U I T E G , L A M E S A , C A 9 1 9 4 2 - 2 9 1 0 ( 6 1 9 ) 6 9 7 - 9 2 3 4 , F A X ( 6 1 9 ) 4 6 0 - 2 0 3 3 SN I P E S - D Y E A S S O C I A T E S -- L01 . rJ D J\;JJ-\P s--J7 LOT APNo 216-160 • • • • 97,,;75 • • • • 99.47 • • • • • 3.10 33 X 3.66 I X 8. 1 0.11 AC c-0.35 98.22 X 1 "" 98. 77 X 99.07 I t 99.4 • • • 98, 45 X 9 X \ 88. 78 X 98. 3 0.03AC C • 0.54 X BJ. 78 X 0.12AC C • 0.35 I 1.00 99.49 X 99 .. 76 LA COSTA A VE. 4 97.5 X 98. X •• 1.10 81.0 83.48 X X 86.92 91.57 X I • 80.99 I I 92.31 I I I 98.39J 100,42 ..... ·x 100, 67 • • . . • • • • , • • • . • . . . • • • . ' 4 &a • . • . • . ::-. --~-8~5----'1 • • • • • • . • • • ,:l ... • • • • • • - • • ,i. "'., .. . • • . . ' • • ;f_ ,1 ., • • • • • • • ' . • • • • • • • • . • ...-<'.I • • ., . . ' ' . • • • BASIN 1 2 3 SUM • LEGEND DRAINAGE BASIN _______ _ DRAINAGE SLB-BASIN_ ____ _ ----- DRAINAGE BASIN IQ_ _____ _ (I} DRAINAGE AREA_ _______ _ 0.12AC RUNOFF FACTOR C • 0.35 NODE ID ___________ _ B.EVATION (FEET) 100-YR PEAK DISCI-IARGE _____ _ FLOW PATl-l _________ _ R.OW LENGTl-l _________ _ L • 138" DIRECTION OF R.OW ______ _ PRE & POST DEVELOPMENT 100-YR. PEAK DISCHARGES PRE-DEVELOPMENT TIME OF AREA RUNOFF DISCHARGE CONCENTRATION Tc A FACTOR QlOO (IN MINUTES) (IN ACRES) "C" (IN CFS) 6.27 0.12 0.35 0.26 6.27 0.11 0,35 0.24 5.65 0.03 0.54 0.11 --0.26 --0.61 POST-DEVELOPMENT TIME OF AREA RUNOFF CONCENTRATION Tc A FACTOR (IN MINUTES) (IN ACRES) "C" 5.00 0.17 0.66 5.00 0.04 0.42 5.00 0.05 0.76 --0.26 -- 10 I DISCHARGE QlOO (IN CFS) 0.82 0.17 0.28 -- MITIGATION DETENTION QlOO (IN CFS) 0.46 0,00 0.00 -- N -EiD- 1 MITIGATED DISCHARGE QlOO (IN CFS) 0.36 0.17 0.28 0.81 PRE-DEVELOPMENT DRAINAGE MAP TREHAN RESIDENCE 2436 LA COST A AVE. CARSLBAD, CA 92009 ,. ., 1 !i! OF 2 SHEElS ~ '° ~ 83 4 8 C E N T E R D R I V E , S U I T E G , L A M E S A , C A 9 1 9 4 2 - 2 9 1 0 ( 6 1 9 ) 6 9 7 - 9 2 3 4 , F A X ( 6 1 9 ) 4 6 0 - 2 0 3 3 SN I P E S - D Y E A S S O C I A T E S J\_;JJ-\P 8117 ~ ~ , LOT B I 89.5 J\_;JJ-\P 8117 • . LOT 9 APN, 216-166 -09 . • • • . • 97,;75 • • • . • • R/W . ,, • • • • • • • • • • • • 3.10 97.75 . . • • • • . JJ ~ \ 99.07 99.4 • • • 1 98.31 "b' l)l !I:,· • 0) ' • ~ "' ~ £! • --' e DECK 97.63 FS 2.00 POOL R SEPARATE PERMIT) I PROPOSEd 2-STORY RESIDllNCE 2ND LEVEL t= 111.75 F.F. 1ST LEVEL 1100.75 F.F. •~ 100.30 PAD = 1100.0 ~63_· _ ~ETACHED ~ES 86.17 .F. 0,09 AC 0.06 AC p AD -85. C -0.66 c-0.11 I GARAGE 100.25 G.F. ri,PAD = 99.7 ,p 63. n,":> ~ ,(9' 1.15 100.25 0.05 AC I I LA COSTA A VE. • X 10' 4 . . 4 • • • ' • • PVC ~c. •• • • . . • • . 4 • • • • • • • t . . • • • • 4 • l . • . •• ® .. •• • .• • •• 0.02AC c-0.35 • • • • IE • • . • • IQO 93 . R✓W 100. 41 .. •• b • .• • .. 4 • • • • . • • • •• . • ' • • • • 100.67 . . • • . . • • • • • • • • . . • • • •· • . . • • • I I I I I I I • • • • • • • BASIN 1 2 3 SUM ., • . • •. LEGEND DRAINAGE BASIN _______ _ DRAINAGE SLB-BASIN_ ____ _ DRAINAGE BASIN IQ_ _____ _ DRAINAGE AREA_ _______ _ RUNOFF FACTOR NODE ID ___________ _ B.EVATION (FEET) 100-YR PEAK DISCI-IARGE _____ _ 100-YR PEAK DISCI-IARGE (MITIGATED> FLOW PATl-l _________ _ R.0W LENGTI-L ________ _ DIRECTION OF R.0W ______ _ ----- 0.15AC C • 0.66 L • 117 PRE & POST DEVELOPMENT 100-VR. PEAK DISCHARGES PRE-DEVELOPMENT POST-DEVELOPMENT MITIGATION MITIGATED TIME OF AREA RUNOFF DISCHARGE TIME OF AREA RUNOFF DISCHARGE DETENTION DISCHARGE CONCENTRATION Tc A FACTOR Ql00 CONCENTRATION Tc A FACTOR QlO0 QlO0 QlO0 (IN MINUTES) (IN ACRES) "C" (IN CFS) (IN MINUTES) (IN ACRES) "C" (IN CFS) (IN CFS) (IN CFS) 6.27 0.12 0.35 0.26 5.00 0.17 0.66 0.82 0.46 0.36 6.27 0.11 0.35 0.24 5.00 0.04 0.42 0.1 7 0.00 0.17 5.65 0.03 0.54 0.11 5.00 0.05 0.76 0.28 0.00 0.28 --0.26 --0.61 --0.26 ------0.81 N -EiD- I 10 10 I I SCALE• 1"•10' POST-DEVELOPMENT DRAINAGE MAP TREHAN RESIDENCE 2436 LA COST A AVE. CARSLBAD, CA 92009 30 I I\! ~ I\! lli ii ~ ,_ ., z 0 I < !5 J!! z "' " ~ el z: .. ii: !ii ; !! C ~ i!i ~ ~ I!; "' I: a lli .. ! ~ ~ .J. C 0 .I 0 z - SHEET fil "' !il i5 J!! i5 " " 8 el ,. w "' 0 ili I ... 0 I: a ~ ~ z: "' .., N !ii ~ s N 2 ;:::; ~ t ~ OF 2 SHEElS '° <{ u d z ~ PRE-DEVELOPMENT DRAINAGE CALCULATIONS ____________________________________________________________________________ **************************************************************************** RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT 2003,1985,1981 HYDROLOGY MANUAL (c) Copyright 1982-2016 Advanced Engineering Software (aes) Ver. 23.0 Release Date: 07/01/2016 License ID 1305 Analysis prepared by: Snipes-Dye associates civil engineers & land surveyors 8348 Center Drive, Suite G, La Mesa, CA 91942 (619) 697-9234 (619) 460-2033 fax www.snipesdye.com ************************** DESCRIPTION OF STUDY ************************** * TREHAN RESIDENCE, CARLSBAD, CA 92009 * * POST-DEVELOPMENT DRAINAGE CALCULATIONS * * 100-YEAR, 6-HOUR STORM EVENT * ************************************************************************** FILE NAME: CA1611.DAT TIME/DATE OF STUDY: 11:27 08/04/2022 ---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: ---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 100.00 6-HOUR DURATION PRECIPITATION (INCHES) = 2.750 SPECIFIED MINIMUM PIPE SIZE(INCH) = 3.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *SIZE PIPE WITH A FLOW CAPACITY GREATER THAN OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.* DRAINAGE BASIN I **************************************************************************** FLOW PROCESS FROM NODE 1.00 TO NODE 1.10 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 138.00 UPSTREAM ELEVATION(FEET) = 100.25 DOWNSTREAM ELEVATION(FEET) = 81.00 ELEVATION DIFFERENCE(FEET) = 19.25 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.267 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.264 SUBAREA RUNOFF(CFS) = 0.26 TOTAL AREA(ACRES) = 0.12 TOTAL RUNOFF(CFS) = 0.26 DRAINAGE BASIN II **************************************************************************** FLOW PROCESS FROM NODE 2.00 TO NODE 2.10 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 143.00 UPSTREAM ELEVATION(FEET) = 99.47 DOWNSTREAM ELEVATION(FEET) = 75.13 ELEVATION DIFFERENCE(FEET) = 24.34 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.267 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.264 SUBAREA RUNOFF(CFS) = 0.24 TOTAL AREA(ACRES) = 0.11 TOTAL RUNOFF(CFS) = 0.24 DRAINAGE BASIN III **************************************************************************** FLOW PROCESS FROM NODE 3.00 TO NODE 3.10 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .5400 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 72.00 UPSTREAM ELEVATION(FEET) = 100.25 DOWNSTREAM ELEVATION(FEET) = 97.75 ELEVATION DIFFERENCE(FEET) = 2.50 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 5.649 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.697 SUBAREA RUNOFF(CFS) = 0.11 TOTAL AREA(ACRES) = 0.03 TOTAL RUNOFF(CFS) = 0.11 ============================================================================ END OF STUDY SUMMARY: TOTAL AREA(ACRES) = 0.0 TC(MIN.) = 5.65 PEAK FLOW RATE(CFS) = 0.11 ============================================================================ ============================================================================ END OF RATIONAL METHOD ANALYSIS Page 2 of 2 POST-DEVELOPMENT DRAINAGE CALCULATIONS ____________________________________________________________________________ **************************************************************************** RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT 2003,1985,1981 HYDROLOGY MANUAL (c) Copyright 1982-2016 Advanced Engineering Software (aes) Ver. 23.0 Release Date: 07/01/2016 License ID 1305 Analysis prepared by: Snipes-Dye associates civil engineers & land surveyors 8348 Center Drive, Suite G, La Mesa, CA 91942 (619) 697-9234 (619) 460-2033 fax www.snipesdye.com ************************** DESCRIPTION OF STUDY ************************** * TREHAN RESIDENCE, CARLSBAD, CA 92009 * * POST-DEVELOPMENT DRAINAGE CALCULATIONS * * 100-YEAR, 6-HOUR STORM EVENT * ************************************************************************** FILE NAME: CA1611P4.DAT TIME/DATE OF STUDY: 08:32 08/09/2022 ---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: ---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 100.00 6-HOUR DURATION PRECIPITATION (INCHES) = 2.750 SPECIFIED MINIMUM PIPE SIZE(INCH) = 3.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *SIZE PIPE WITH A FLOW CAPACITY GREATER THAN OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.* DRAINAGE BASIN I **************************************************************************** FLOW PROCESS FROM NODE 1.00 TO NODE 1.05 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .6600 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 117.00 UPSTREAM ELEVATION(FEET) = 100.25 DOWNSTREAM ELEVATION(FEET) = 82.00 ELEVATION DIFFERENCE(FEET) = 18.25 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.676 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 7.246 ******* 1.05 ------- 1.05A NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE. SUBAREA RUNOFF(CFS) = 0.43 TOTAL AREA(ACRES) = 0.09 TOTAL RUNOFF(CFS) = 0.43 **************************************************************************** FLOW PROCESS FROM NODE 1.05 TO NODE 1.10 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 82.00 DOWNSTREAM(FEET) = 81.00 FLOW LENGTH(FEET) = 6.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 3.0 INCH PIPE IS 1.7 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 7.55 GIVEN PIPE DIAMETER(INCH) = 3.00 NUMBER OF PIPES = 2 PIPE-FLOW(CFS) = 0.43 PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 3.69 LONGEST FLOWPATH FROM NODE 1.00 TO NODE 1.10 = 123.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.10 TO NODE 1.10 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 3.69 RAINFALL INTENSITY(INCH/HR) = 7.25 TOTAL STREAM AREA(ACRES) = 0.09 PEAK FLOW RATE(CFS) AT CONFLUENCE = 0.43 **************************************************************************** FLOW PROCESS FROM NODE 1.15 TO NODE 1.20 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .7700 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 122.00 UPSTREAM ELEVATION(FEET) = 100.25 DOWNSTREAM ELEVATION(FEET) = 82.00 ELEVATION DIFFERENCE(FEET) = 18.25 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 2.757 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 7.246 NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE. SUBAREA RUNOFF(CFS) = 0.33 TOTAL AREA(ACRES) = 0.06 TOTAL RUNOFF(CFS) = 0.33 **************************************************************************** FLOW PROCESS FROM NODE 1.20 TO NODE 1.10 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ******* 1.05 ------- 1.05B ******* 1.10 ------- 1.10A ******** 1.10 -------- 1.10B ******** 1.10 -------- 1.10B ******** 1.10 -------- 1.10B ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 82.00 DOWNSTREAM(FEET) = 81.00 FLOW LENGTH(FEET) = 6.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 3.0 INCH PIPE IS 1.5 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 6.94 GIVEN PIPE DIAMETER(INCH) = 3.00 NUMBER OF PIPES = 2 PIPE-FLOW(CFS) = 0.33 PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 2.77 LONGEST FLOWPATH FROM NODE 1.15 TO NODE 1.10 = 128.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.10 TO NODE 1.10 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< >>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 2.77 RAINFALL INTENSITY(INCH/HR) = 7.25 TOTAL STREAM AREA(ACRES) = 0.06 PEAK FLOW RATE(CFS) AT CONFLUENCE = 0.33 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 0.43 3.69 7.246 0.09 2 0.33 2.77 7.246 0.06 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH/HOUR) 1 0.66 2.77 7.246 2 0.77 3.69 7.246 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 0.77 Tc(MIN.) = 3.69 TOTAL AREA(ACRES) = 0.2 LONGEST FLOWPATH FROM NODE 1.15 TO NODE 1.10 = 128.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.10 TO NODE 1.10 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 7.246 NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE. *USER SPECIFIED(SUBAREA): RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6624 ******** 1.10 -------- 1.10B ******** 1.10 -------- 1.10B ******** 1.10 -------- 1.10B ******** 1.10 -------- 1.10B SUBAREA AREA(ACRES) = 0.02 SUBAREA RUNOFF(CFS) = 0.05 TOTAL AREA(ACRES) = 0.2 TOTAL RUNOFF(CFS) = 0.82 TC(MIN.) = 3.69 DRAINAGE BASIN II **************************************************************************** FLOW PROCESS FROM NODE 2.00 TO NODE 2.10 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .5900 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 78.00 UPSTREAM ELEVATION(FEET) = 100.30 DOWNSTREAM ELEVATION(FEET) = 75.13 ELEVATION DIFFERENCE(FEET) = 25.17 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.763 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 7.246 NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE. SUBAREA RUNOFF(CFS) = 0.17 TOTAL AREA(ACRES) = 0.04 TOTAL RUNOFF(CFS) = 0.17 DRAINAGE BASIN III **************************************************************************** FLOW PROCESS FROM NODE 3.00 TO NODE 3.10 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .7600 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 72.00 UPSTREAM ELEVATION(FEET) = 100.25 DOWNSTREAM ELEVATION(FEET) = 97.75 ELEVATION DIFFERENCE(FEET) = 2.50 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.430 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 7.246 NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE. SUBAREA RUNOFF(CFS) = 0.28 TOTAL AREA(ACRES) = 0.05 TOTAL RUNOFF(CFS) = 0.28 ============================================================================ END OF STUDY SUMMARY: TOTAL AREA(ACRES) = 0.1 TC(MIN.) = 3.43 PEAK FLOW RATE(CFS) = 0.28 ============================================================================ ============================================================================ END OF RATIONAL METHOD ANALYSIS ******** 3.00 -------- 1.00 DRAINAGE BASIN 1A DETENTION BASIN ± PROPOSED DETENTION BASIN Q OUTFLOW = 0.36 CFS Q OUTFLOW = 0.82 CFS -- PROPOSED JlJIJCUS PANTENS AT AND ON SLOPE PER APPROVED LANDSCAPE PLANS LPC2022-0003, DWG. NO. 533-5L 1.5' 6" 5' 0 .70' Y ____ w.s. • a212 ~-3"-4" DIA ROCKS NATIVE MATERIAL TO BE---- COMPACTED e OBSEl<VED DURING CONSTRUCTION BY SOIL ENGll'EEI< IMPERMEABLE LINER <30 MIL PVC GEOMEMBRANE> O-C-2500 ONCRETE '\----\ -:-rv ,,,,, ~ UV-0:! ,~.~ SMALL CONC. co L ... <520-C-2500> /f 1-EADWALL ~/ ~ \~TIVE MATERIAL TO BE ,,r COMPACTED e OBSEl<VED ' 4" PVC PEl<FOl<A TED PIPE / DURING CONSTRUCTION BY \. WI~ 3/4" ~ED GRAVEL (-]-SOIL ENGll'EEI< 21 MIN. _J I FOOT MIN. INTO )= - - -APPROXIMATE KEYWAY -------=-----.1 ~~~~ [5 FOOT MIN. FOi< SLOPES < 10' 1-IIGI-I 12 FOOT MIN. FOi< SLOPES > 10' I-IIGI-I ®SECTION -NO SCALE HYDRAULIC CAPACITY ANALYSIS **************************************************************************** >>>>PIPEFLOW HYDRAULIC INPUT INFORMATION<<<< ---------------------------------------------------------------------------- PIPE DIAMETER(FEET) = 0.330 FLOWDEPTH(FEET) = 0.330 PIPE SLOPE(FEET/FEET) = 0.0350 MANNINGS FRICTION FACTOR = 0.013000 >>>>> NORMAL DEPTH FLOW(CFS) = 0.35 ============================================================================ **************************************************************************** >>>>PIPEFLOW HYDRAULIC INPUT INFORMATION<<<< ---------------------------------------------------------------------------- PIPE DIAMETER(FEET) = 0.330 PIPE SLOPE(FEET/FEET) = 0.0350 PIPEFLOW(CFS) = 0.33 MANNINGS FRICTION FACTOR = 0.013000 ============================================================================ CRITICAL-DEPTH FLOW INFORMATION: ---------------------------------------------------------------------------- CRITICAL DEPTH(FEET) = 0.31 CRITICAL FLOW AREA(SQUARE FEET) = 0.083 CRITICAL FLOW TOP-WIDTH(FEET) = 0.168 CRITICAL FLOW PRESSURE + MOMENTUM(POUNDS) = 2.79 CRITICAL FLOW VELOCITY(FEET/SEC.) = 3.981 CRITICAL FLOW VELOCITY HEAD(FEET) = 0.25 CRITICAL FLOW HYDRAULIC DEPTH(FEET) = 0.49 CRITICAL FLOW SPECIFIC ENERGY(FEET) = 0.55 ============================================================================ NORMAL-DEPTH FLOW INFORMATION: ---------------------------------------------------------------------------- NORMAL DEPTH(FEET) = 0.26 FLOW AREA(SQUARE FEET) = 0.07 FLOW TOP-WIDTH(FEET) = 0.274 FLOW PRESSURE + MOMENTUM(POUNDS) = 3.16 FLOW VELOCITY(FEET/SEC.) = 4.613 FLOW VELOCITY HEAD(FEET) = 0.330 HYDRAULIC DEPTH(FEET) = 0.26 FROUDE NUMBER = 1.590 SPECIFIC ENERGY(FEET) = 0.59 ============================================================================ 4-INCH PVC PIPE AT 3.5% SLOPE **************************************************************************** >>>>PIPEFLOW HYDRAULIC INPUT INFORMATION<<<< ---------------------------------------------------------------------------- PIPE DIAMETER(FEET) = 0.330 FLOWDEPTH(FEET) = 0.330 PIPE SLOPE(FEET/FEET) = 0.1460 MANNINGS FRICTION FACTOR = 0.013000 >>>>> NORMAL DEPTH FLOW(CFS) = 0.71 ============================================================================ **************************************************************************** >>>>PIPEFLOW HYDRAULIC INPUT INFORMATION<<<< ---------------------------------------------------------------------------- PIPE DIAMETER(FEET) = 0.330 PIPE SLOPE(FEET/FEET) = 0.1460 PIPEFLOW(CFS) = 0.43 MANNINGS FRICTION FACTOR = 0.013000 ============================================================================ CRITICAL-DEPTH FLOW INFORMATION: ---------------------------------------------------------------------------- CRITICAL DEPTH(FEET) = 0.32 CRITICAL FLOW AREA(SQUARE FEET) = 0.085 CRITICAL FLOW TOP-WIDTH(FEET) = 0.107 CRITICAL FLOW PRESSURE + MOMENTUM(POUNDS) = 4.54 CRITICAL FLOW VELOCITY(FEET/SEC.) = 5.065 CRITICAL FLOW VELOCITY HEAD(FEET) = 0.40 CRITICAL FLOW HYDRAULIC DEPTH(FEET) = 0.80 CRITICAL FLOW SPECIFIC ENERGY(FEET) = 0.72 ============================================================================ NORMAL-DEPTH FLOW INFORMATION: ---------------------------------------------------------------------------- NORMAL DEPTH(FEET) = 0.19 FLOW AREA(SQUARE FEET) = 0.05 FLOW TOP-WIDTH(FEET) = 0.327 FLOW PRESSURE + MOMENTUM(POUNDS) = 7.42 FLOW VELOCITY(FEET/SEC.) = 8.677 FLOW VELOCITY HEAD(FEET) = 1.169 HYDRAULIC DEPTH(FEET) = 0.15 FROUDE NUMBER = 3.930 SPECIFIC ENERGY(FEET) = 1.35 ============================================================================ 4-INCH PVC PIPE AT 14.6% SLOPE DETENTION CALCULATIONS 1 - Manual - 100 Yr - Qp = 0.82 cfs Hyd. 1 Q c f s Time (hrs) 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.6 1.2 1.8 2.4 3.0 3.6 4.2 4.8 5.4 6.0 Hydrograph Plot Hydraflow Hydrographs by Intelisolve Hyd. No. 1 DMA #1A Hydrograph type = Manual Peak discharge = 0.82 cfs Storm frequency = 100 yrs Time interval = 3 min Hydrograph Volume = 1,006 cuft Qpeak = 0.82 cfs Hydrograph Report Page 1 Hydraflow Hydrographs by Intelisolve Hyd. No. 1 DMA #1A Hydrograph type = Manual Peak discharge = 0.82 cfs Storm frequency = 100 yrs Time interval = 3 min Hydrograph Volume = 1,006 cuft Hydrograph Discharge Table Time -- Outflow (min cfs) 3 0.02 6 0.02 9 0.02 12 0.02 15 0.02 18 0.02 21 0.02 24 0.02 27 0.02 30 0.02 33 0.02 36 0.02 39 0.02 42 0.02 45 0.02 48 0.02 51 0.02 54 0.02 57 0.02 60 0.02 63 0.02 66 0.02 69 0.02 72 0.02 75 0.02 78 0.02 81 0.02 84 0.02 87 0.02 90 0.02 93 0.02 96 0.02 99 0.02 102 0.02 Time -- Outflow (min cfs) 105 0.02 108 0.02 111 0.02 114 0.02 117 0.02 120 0.02 123 0.02 126 0.03 129 0.03 132 0.03 135 0.03 138 0.03 141 0.03 144 0.03 147 0.03 150 0.03 153 0.03 156 0.03 159 0.03 162 0.03 165 0.03 168 0.03 171 0.03 174 0.04 177 0.04 180 0.04 183 0.04 186 0.04 189 0.04 192 0.05 195 0.05 198 0.05 201 0.05 204 0.05 Time -- Outflow (min cfs) 207 0.05 210 0.06 213 0.06 216 0.06 219 0.07 222 0.08 225 0.09 228 0.10 231 0.12 234 0.14 237 0.19 240 0.41 243 0.82 << 246 0.35 249 0.11 252 0.08 255 0.06 258 0.06 261 0.05 264 0.04 267 0.04 270 0.04 273 0.04 276 0.03 279 0.03 282 0.03 285 0.03 288 0.03 291 0.03 294 0.03 297 0.03 300 0.02 303 0.02 306 0.02 Time -- Outflow (min cfs) 309 0.02 312 0.02 315 0.02 318 0.02 321 0.02 324 0.02 327 0.02 330 0.02 333 0.02 336 0.02 339 0.02 342 0.02 345 0.02 348 0.02 351 0.02 354 0.02 357 0.02 360 0.02 363 0.02 ...End Peak inflow = 0.82 cfs 2 - Reservoir - 100 Yr - Qp = 0.36 cfs Hyd. 1 Hyd. 2 Q c f s Time (hrs) 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.7 1.4 2.1 2.8 3.5 4.2 4.9 5.6 6.3 7.0 Hydrograph Plot Hydraflow Hydrographs by Intelisolve Hyd. No. 2 BMP #1 Hydrograph type = Reservoir Peak discharge = 0.36 cfs Storm frequency = 100 yrs Time interval = 3 min Inflow hyd. No. = 1 Reservoir name = BMP #1 Max. Elevation = 82.72 ft Max. Storage = 176 cuft Storage Indication method used.Hydrograph Volume = 1,005 cuft Qin = 0.82 cfs Qout = 0.36 cfs Hydrograph Report Page 1 Hydraflow Hydrographs by Intelisolve Hyd. No. 2 BMP #1 Hydrograph type = Reservoir Peak discharge = 0.36 cfs Storm frequency = 100 yrs Time interval = 3 min Inflow hyd. No. = 1 Reservoir name = BMP #1 Max. Elevation = 82.72 ft Max. Storage = 176 cuft Storage Indication method used.Outflow hydrograph volume = 1,005 cuft Hydrograph Discharge Table Time Inflow Elevation Clv A Clv B Clv C Clv D Wr A Wr B Wr C Wr D Exfil Outflow (min) cfs ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 6 0.02 82.02 0.00 ----- ----- ----- ----- ----- ----- ----- ----- 0.00 9 0.02 82.03 0.01 ----- ----- ----- ----- ----- ----- ----- ----- 0.01 12 0.02 82.04 0.01 ----- ----- ----- ----- ----- ----- ----- ----- 0.01 15 0.02 82.05 0.01 ----- ----- ----- ----- ----- ----- ----- ----- 0.01 18 0.02 82.06 0.01 ----- ----- ----- ----- ----- ----- ----- ----- 0.01 21 0.02 82.06 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 24 0.02 82.06 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 27 0.02 82.06 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 30 0.02 82.06 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 33 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 36 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 39 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 42 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 45 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 48 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 51 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 54 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 57 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 60 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 63 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 66 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 69 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 72 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 75 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 78 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 81 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 84 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 87 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 90 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 93 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 96 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 99 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ----- ----- 0.02 102 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 105 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 108 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 111 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 114 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 117 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 Continues on next page... BMP #1 Page 2 Hydrograph Discharge Table Time Inflow Elevation Clv A Clv B Clv C Clv D Wr A Wr B Wr C Wr D Exfil Outflow (min) cfs ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 120 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 123 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 126 0.03 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 129 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 132 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 135 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 138 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 141 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 144 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 147 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 150 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 153 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 156 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 159 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 162 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 165 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 168 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 171 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 174 0.04 82.09 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 177 0.04 82.09 0.04 ----- ----- ----- ----- ----- ----- ---------- 0.04 180 0.04 82.10 0.04 ----- ----- ----- ----- ----- ----- ---------- 0.04 183 0.04 82.10 0.04 ----- ----- ----- ----- ----- ----- ---------- 0.04 186 0.04 82.10 0.04 ----- ----- ----- ----- ----- ----- ---------- 0.04 189 0.04 82.10 0.04 ----- ----- ----- ----- ----- ----- ---------- 0.04 192 0.05 82.10 0.04 ----- ----- ----- ----- ----- ----- ---------- 0.04 195 0.05 82.11 0.05 ----- ----- ----- ----- ----- ----- ---------- 0.05 198 0.05 82.11 0.05 ----- ----- ----- ----- ----- ----- ---------- 0.05 201 0.05 82.11 0.05 ----- ----- ----- ----- ----- ----- ---------- 0.05 204 0.05 82.11 0.05 ----- ----- ----- ----- ----- ----- ---------- 0.05 207 0.05 82.11 0.05 ----- ----- ----- ----- ----- ----- ---------- 0.05 210 0.06 82.12 0.05 ----- ----- ----- ----- ----- ----- ---------- 0.05 213 0.06 82.12 0.06 ----- ----- ----- ----- ----- ----- ---------- 0.06 216 0.06 82.12 0.06 ----- ----- ----- ----- ----- ----- ---------- 0.06 219 0.07 82.13 0.06 ----- ----- ----- ----- ----- ----- ---------- 0.06 222 0.08 82.13 0.07 ----- ----- ----- ----- ----- ----- ---------- 0.07 225 0.09 82.15 0.08 ----- ----- ----- ----- ----- ----- ---------- 0.08 228 0.10 82.16 0.09 ----- ----- ----- ----- ----- ----- ---------- 0.09 231 0.12 82.17 0.10 ----- ----- ----- ----- ----- ----- ---------- 0.10 234 0.14 82.19 0.12 ----- ----- ----- ----- ----- ----- ---------- 0.12 237 0.19 82.22 0.14 ----- ----- ----- ----- ----- ----- ---------- 0.14 240 0.41 82.32 0.21 ----- ----- ----- ----- ----- ----- ---------- 0.21 243 0.82 << 82.58 0.32 ----- ----- ----- ----- ----- ----- ----- ----- 0.32 246 0.35 82.72 << 0.36 ----- ----- ----- ----- ----- ----- ----- ----- 0.36 << 249 0.11 82.65 0.34 ----- ----- ----- ----- ----- ----- ---------- 0.34 252 0.08 82.52 0.30 ----- ----- ----- ----- ----- ----- ---------- 0.30 255 0.06 82.37 0.23 ----- ----- ----- ----- ----- ----- ---------- 0.23 258 0.06 82.25 0.17 ----- ----- ----- ----- ----- ----- ---------- 0.17 261 0.05 82.18 0.11 ----- ----- ----- ----- ----- ----- ---------- 0.11 264 0.04 82.14 0.07 ----- ----- ----- ----- ----- ----- ---------- 0.07 267 0.04 82.12 0.06 ----- ----- ----- ----- ----- ----- ---------- 0.06 270 0.04 82.11 0.05 ----- ----- ----- ----- ----- ----- ---------- 0.05 Continues on next page... Peak outflow = 0.36 cfs Peak inflow = 0.82 cfs BMP #1 Page 3 Hydrograph Discharge Table Time Inflow Elevation Clv A Clv B Clv C Clv D Wr A Wr B Wr C Wr D Exfil Outflow (min) cfs ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 273 0.04 82.10 0.04 ----- ----- ----- ----- ----- ----- ---------- 0.04 276 0.03 82.10 0.04 ----- ----- ----- ----- ----- ----- ---------- 0.04 279 0.03 82.09 0.04 ----- ----- ----- ----- ----- ----- ---------- 0.04 282 0.03 82.09 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 285 0.03 82.09 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 288 0.03 82.09 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 291 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 294 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 297 0.03 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 300 0.02 82.08 0.03 ----- ----- ----- ----- ----- ----- ---------- 0.03 303 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 306 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 309 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 312 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 315 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 318 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 321 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 324 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 327 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 330 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 333 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 336 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 339 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 342 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 345 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 348 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 351 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 354 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 357 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 360 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 363 0.02 82.07 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 366 0.00 82.06 0.02 ----- ----- ----- ----- ----- ----- ---------- 0.02 369 0.00 82.05 0.01 ----- ----- ----- ----- ----- ----- ---------- 0.01 372 0.00 82.04 0.01 ----- ----- ----- ----- ----- ----- ---------- 0.01 375 0.00 82.03 0.01 ----- ----- ----- ----- ----- ----- ---------- 0.01 378 0.00 82.03 0.01 ----- ----- ----- ----- ----- ----- ---------- 0.01 381 0.00 82.02 0.00 ----- ----- ----- ----- ----- ----- ---------- 0.00 384 0.00 82.02 0.00 ----- ----- ----- ----- ----- ----- ---------- 0.00 ...End Reservoir Report Page 1 Hydraflow Hydrographs by IntelisolveReservoir No. 1 - BMP #1 Pond Data Pond storage is based on known contour areas. Average end area method used. Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 82.00 163 0 0 0.50 82.50 263 107 107 1.00 83.00 363 157 263 Culvert / Orifice Structures Weir Structures [A] [B] [C] [D] [A] [B] [C] [D] Rise in = 3.0 0.0 0.0 0.0 Span in = 3.0 0.0 0.0 0.0 No. Barrels = 2 0 0 0 Invert El. ft = 82.00 0.00 0.00 0.00 Length ft = 0.0 0.0 0.0 0.0 Slope %= 0.00 0.00 0.00 0.00 N-Value = .013 .000 .000 .000 Orif. Coeff.= 0.60 0.00 0.00 0.00 Multi-Stage = n/a No No No Crest Len ft = 0.00 0.00 0.00 0.00 Crest El. ft = 0.00 0.00 0.00 0.00 Weir Coeff.= 3.33 3.33 0.00 0.00 Weir Type = --- --- --- --- Multi-Stage = No No No No Exfiltration Rate = 0.00 in/hr/sqft Tailwater Elev. = 0.00 ft Note: All outflows have been analyzed under inlet and outlet control. Stage / Storage / Discharge Table Stage Storage Elevation Clv A Clv B Clv C Clv D Wr A Wr B Wr C Wr D Exfil Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 82.00 0.00 --- --- --- --- --- --- --- --- 0.00 0.05 11 82.05 0.01 --- --- --- --- --- --- --- --- 0.01 0.10 21 82.10 0.04 --- --- --- --- --- --- --- --- 0.04 0.15 32 82.15 0.08 --- --- --- --- --- --- --- --- 0.08 0.20 43 82.20 0.13 --- --- --- --- --- --- --- --- 0.13 0.25 53 82.25 0.17 --- --- --- --- --- --- --- --- 0.17 0.30 64 82.30 0.20 --- --- --- --- --- --- --- --- 0.20 0.35 75 82.35 0.22 --- --- --- --- --- --- --- --- 0.22 0.40 85 82.40 0.25 --- --- --- --- --- --- --- --- 0.25 0.45 96 82.45 0.27 --- --- --- --- --- --- --- --- 0.27 0.50 107 82.50 0.29 --- --- --- --- --- --- --- --- 0.29 0.55 122 82.55 0.31 --- --- --- --- --- --- --- --- 0.31 0.60 138 82.60 0.33 --- --- --- --- --- --- --- --- 0.33 0.65 153 82.65 0.34 --- --- --- --- --- --- --- --- 0.34 0.70 169 82.70 0.36 --- --- --- --- --- --- --- --- 0.36 0.75 185 82.75 0.37 --- --- --- --- --- --- --- --- 0.37 0.80 200 82.80 0.39 --- --- --- --- --- --- --- --- 0.39 0.85 216 82.85 0.40 --- --- --- --- --- --- --- --- 0.40 0.90 232 82.90 0.42 --- --- --- --- --- --- --- --- 0.42 0.95 247 82.95 0.43 --- --- --- --- --- --- --- --- 0.43 1.00 263 83.00 0.44 --- --- --- --- --- --- --- --- 0.44 2-3" PVC drains