Loading...
HomeMy WebLinkAboutPD 2024-0009; 3771 SKYLINE RD; HYDROLOGY REPORT; 2025-01-24 Planning • Civil • Survey • Structural Rancho Coastal Engineering and Surveying, Inc. Mailing Address: 310 S. Twin Oaks Valley Rd., #107-297, San Marcos, CA 92078 Physical Address: 310 Via Vera Cruz, #205, San Marcos, CA 92078 Phone (760) 510-3152 / Fax: (760) 510-3153 / www.rcesd.com HYDROLOGY REPORT VECK RESIDENCE 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 APN: 207-053-13 LEGAL: PORTION OF LOT 20 PER MAP 3019 PD 2024-0009, GR 2024-0013, DWG 548-2A PREPARED FOR: VECK INVESTMENT PROPERTIES, LLC C/O ELZABETH TEMPLE 3276 HIGHLAND DRIVE CARLSBAD, CALIFORNIA 92008 PREPARED BY: RANCHO COASTAL ENGINEERING, INC. 310 S. TWIN OAKS ROAD #107-297 SAN MARCOS, CALIFORNIA 92078 (760) 510-3152 Revision 2: January 24, 2025 Revision 1: October 11, 2024 Original Date: August 12, 2024 I hereby declare that I am the engineer of work for this project, that I have exercised responsible charge over the design of the project as defined in Section 6703 of the Business and Professions code, and that the design is consistent with current standards. _____________________________ ______________ DOUGLAS E. LOGAN DATE R.C.E. NO. 39726 EXPIRES 12/31/25 1/24/25 RANCHO COASTAL ENGINEERING Single Source Development Consul tan t HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 Rev2: 1/24/25, Rev1: 10/11/24 8157 Veck Residence - i - Original: 8/12/24 TABLE OF CONTENTS DESCRIPTIONS PAGE COVER SHEET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i TABLE OF CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii 1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2.0 LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3.0 METHODOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4.0 RUNOFF COEFFICIENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5.0 EXISTING CONDITIONS CALCULATIONS . . . . . . . . . . . . . . . . . . . . . . . . 2 6.0 PROPOSED CONDITIONS CALCULATIONS . . . . . . . . . . . . . . . . . . . . . . 2 7.0 COMPARISON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 8.0 CONCLUSION AND ENGINEER’S STATEMENT . . . . . . . . . . . . . . . . . . . 4 9.0 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 10.0 DECLARATION OF RESPONSIBLE CHARGE . . . . . . . . . . . . . . . . . . . . . 5 11.0 ATTACHMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 11.1 ATTACHMENT 1: STANDARDS EXCERPTS . . . . . . . . . . . . . . . . 5 11.2 ATTACHMENT 2: EXISTING CONDITIONS CALCULATIONS . . . 5 11.3 ATTACHMENT 3: PROPOSED CONDITIONS CALCULATIONS . . 5 11.4 ATTACHMENT 4: STUDY EXHIBITS . . . . . . . . . . . . . . . . . . . . . 5 ATTACHMENT 1: STANDARDS EXCERPTS ATTACHMENT 2: EXISTING CONDITIONS CALCULATIONS ATTACHMENT 3: PROPOSED CONDITIONS CALCULATIONS ATTACHMENT 4: STUDY EXHIBITS HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 Rev2: 1/24/25, Rev1: 10/11/24 8157 Veck Residence - 1 - Original: 8/12/24 1.0 INTRODUCTION The purpose of this report is to calculate the pre-development and post development drainage analysis for the proposed redevelopment of the single-family residence on the project site. The existing house will be demolished and a new one with additional improvements will be constructed. New improvements include patios, a pool and a permeable driveway. 2.0 LOCATION The project site is located at 3771 Skyline Road, 92008 on APN 207-053-13. A vicinity map for the project site is included for reference in Attachment 4. 3.0 METHODOLOGY For ease of reference, this report calculates the 100-Year Design Storm Event discharge rates based on the San Diego County Hydrology Manual (June 2003 Edition) rational methodology and routing calculations. In addition, this manual will be referred to as the ‘Standards’ throughout this report. Excerpts from the standards have been included in Attachment 1: Standards Excerpts for reference. The calculations have been evaluated using CIVILCADD/CIVILDESIGN Engineering Software. A copy of the project site’s hydrologic soils type is provided for reference in Attachment 1. The existing condition calculations are provided in Attachment 2. The proposed conditions are provided in Attachments 3. The exhibits used in these calculations are provided in Attachment 4. 4.0 RUNOFF COEFFICIENTS The project’s existing and proposed conditions subareas have had their individual impervious areas calculated. The subareas have then be compared to the values in Table 3-1 from the standards. Then, the value is coordinated with Type B Soils and the land use has been used in the calculations. A summary of values used is as follows: EXISTING CONDITIONS PROPOSED CONDITIONS SUBAREA ID IMP % LAND USE SUBAREA ID IMP % LAND USE 1.1 27.8% MDR-4.3 1.1 78.2% HDR-43 1.2 28.6% MDR-4.3 1.2 78.8% HDR-43 1.3 77.2% HDR-43 1.3 88.2% COMM/OFFICE 1.4 18.2% LDR-2.0 1.4 51.2% MDR-14.5 1.5 34.1% MDR-4.3 1.5 85.8% COMM/NBHD 2.1 0% NATURAL 1.6 0% NATURAL 2.2 0% NATURAL 1.7 22.4% LDR-2.0 2.3 0% NATURAL 1.8 0% NATURAL 1.9 0% NATURAL 1.10 0% NATURAL 2.1 0% NATURAL 2.2 0% NATURAL 2.3 0% NATURAL HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 Rev2: 1/24/25, Rev1: 10/11/24 8157 Veck Residence - 2 - Original: 8/12/24 5.0 EXISTING CONDITIONS CALCULATIONS The project site is split into two drainage areas. The existing single-family residence shall drain to the curb and gutter of Skyline Road and shall be called Compliance Point 1 and shall remain the same in the existing and proposed conditions. The second drainage area is natural areas and slopes that drain out to the back side of the project site and shall be Compliance Point 2. A summary of the compliance point data follows on the next page as follows: EXISTING CONDITIONS SUMMARY COMPLIANCE POINT 1 DATA 100-YEAR INTENSITY (IN/HR) 6.778 TOTAL DISCHARGE (CFS) 0.77 TIME OF CONCENTRATION (MIN) 5.24 AREA (ACRES) 0.275 EXISTING CONDITIONS SUMMARY COMPLIANCE POINT 2 DATA 100-YEAR INTENSITY (IN/HR) 6.561 TOTAL DISCHARGE (CFS) 0.05 TIME OF CONCENTRATION (MIN) 5.51 AREA (ACRES) 0.032 6.0 PROPOSED CONDITIONS CALCULATIONS The project site is split into two drainage areas. The existing single-family residence shall drain to the curb and gutter of Skyline Road and shall be called Compliance Point 1 and shall remain the same in the existing and proposed conditions. The second drainage area is natural areas and slopes that drain out to the back side of the project site and shall be Compliance Point 2. A summary of the compliance point data follows on the next page as follows: PROPOSED CONDITIONS SUMMARY COMPLIANCE POINT 1 DATA 100-YEAR INTENSITY (IN/HR) 4.172 TOTAL DISCHARGE (CFS) 0.89 TIME OF CONCENTRATION (MIN) 7.94 AREA (ACRES) 0.279 HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 Rev2: 1/24/25, Rev1: 10/11/24 8157 Veck Residence - 3 - Original: 8/12/24 PROPOSED CONDITIONS SUMMARY COMPLIANCE POINT 2 DATA 100-YEAR INTENSITY (IN/HR) 6.018 TOTAL DISCHARGE (CFS) 0.13 TIME OF CONCENTRATION (MIN) 7.51 AREA (ACRES) 0.085 Pressurized Pipe Note: Proposed Node Run 1.54 – 1.81 is comprised of (3) ~ 3-inch PVC pipes that exit at the gutter line of Skyline Road. This pipe run is under pressure in the 100-Year Design Storm Event. The HGL in the pipe places the elevation at the upstream Node of 1.54 at 281.9 ft. The finished grade at Node 1.54 is 282.5 ft. This means that the pipe is under pressure but is not overflowing at Node 1.54. This is an acceptable condition of flow. 7.0 COMPARISON A summary and comparison of the overall compliance point data from the existing to the proposed conditions at each of the compliance points are as follows: COMPLIANCE POINT 1 DATA SUMMARY AND COMPARISON DATA EXISTING PROPOSED COMPARISON INTENSITY (IN/HR) 6.778 4.172 - 2.606 TOTAL DISCHARGE (CFS) 0.77 0.89 + 0.12 TIME OF CONCENTRATION (MIN) 5.24 7.94 + 2.70 AREA (ACRES) 0.275 0.279 + 0.004 COMPLIANCE POINT 2 DATA SUMMARY AND COMPARISON DATA EXISTING PROPOSED COMPARISON INTENSITY (IN/HR) 6.561 5.998 - 0.563 TOTAL DISCHARGE (CFS) 0.05 0.04 - 0.01 TIME OF CONCENTRATION (MIN) 5.51 7.55 + 2.04 AREA (ACRES) 0.032 0.024 - 0.008 HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 Rev2: 1/24/25, Rev1: 10/11/24 8157 Veck Residence - 4 - Original: 8/12/24 8.0 CONCLUSION AND ENGINEER’S STATEMENTS Through the inclusion of the proposed single-family residence’s improvements and through routing, the site will increase the peak discharge runoff during the 100-Year Design Strom Event at Compliance Point 1 by 0.12 cfs and will decrease the peak discharge rate at Compliance Point 2 by 0.01 cfs. The increase and decrease should be considered negligible over the areas acreage. In addition, the following statements apply to the project site: Drainage Pattern Alteration Statement: The proposed project does not substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, in a manner which would result in substantial erosion or siltation on- or off-site. This project site will continue to discharge at the same discharge points from the site in the existing adjacent streets. Flooding Statement: The proposed project does not substantially alter the existing drainage pattern of the site or area including through the alteration of the course of a stream or river or substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or off-site as this report outlines each compliance point’s peak discharge rate in the 100-Year Design Storm Event. Housing in a 100-Year Flood Hazard Statement: The project is the redevelopment of a single-family residence with a new single-family residence. The project site is listed by FEMA as being in Zone X per Panel 06073C0762G effective 5/16/2012 and will not have any flood hazards. A copy of the project site’s FEMA Map is provided for reference in Attachment 1. 9.0 REFERENCES The following references were utilized in the creation of this hydrology report: Brater & King, Handbook of Hydraulics, 6th ed. San Diego Area Regional Standard Drawings, Standard Drawings for Agencies in the San Diego Region, Maintained and Published by the County of San Diego, Department of Public Works April 2006 San Diego County Hydrology Manual, Prepared for the County of San Diego, Department of Public Works, Flood Control Section June 2003. San Diego County Drainage Design Manual, Prepared for the County of San Diego, Department of Public Works, Flood Control Section September 2014. HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 Rev2: 1/24/25, Rev1: 10/11/24 8157 Veck Residence - 5 - Original: 8/12/24 10.0 DECLARATION OF RESPONSIBLE CHARGE I hereby declare that I am the engineer of work for this project, that I have exercised responsible charge over the design of the project as defined in Section 6703 of the Business and Professions code, and that the design is consistent with current standards. I understand that the check of this report by the County of San Diego is confined to a review only and does not relieve me, as engineer of work, of my responsibilities for project design. 1/24/25 __________________________ ________________ Douglas E. Logan Date 11.0 ATTACHMENTS The following attachment sections are provided for reference: 11.1 ATTACHMENT 1: STANDARD EXCERPTS This attachment contains excerpts from the standards used to perform this drainage analysis. 11.2 ATTACHMENT 2: EXISTING CONDITIONS CALCULATIONS This attachment contains the existing conditions calculations. 11.3 ATTACHMENT 3: PROPOSED CONDITIONS CALCULATIONS This attachment contains the proposed conditions calculations. 11.4 ATTACHMENT 4: STUDY EXHIBITS This attachment contains the study exhibits used in these calculations. A vicinity map and hydrology maps are provided in this attachment. HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 ATTACHMENT 1: STANDARDS EXCERPTS Please see the attached excerpts from the Standards. !"^$ !"_$ Aù %&s( !"a$!"^$ !"^$ A© %&s( ?z Aª A¨ Aª Aª AÀ A¨ A¨ A© A© !"a$ !"_$ !"_$ !"_$ A© AÀ %&s(?j ?jA×AÀ ?h ?h AÀ AÀ AÛ !"_$ ?z !"_$?z !"a$ A¨ !"a$ !"^$ VISTA POWAY SANTEE LA MESA DEL MAR CORONADO EL CAJON CARLSBAD OCEANSIDE ENCINITAS SAN DIEGO ESCONDIDOSAN MARCOS CHULA VISTA LEMON GROVE SOLANA BEACH NATIONAL CITY IMPERIAL BEACH 116°15'0"W 116°15'0"W 116°30'0"W 116°30'0"W 116°45'0"W 116°45'0"W 117°0'0"W 117°0'0"W 117°15'0"W 117°15'0"W 117°30'0"W 117°30'0"W 33 ° 3 0 '0 " N 33 ° 3 0 '0 " N 33 ° 1 5 '0 " N 33 ° 1 5 '0 " N 33 ° 0 ' 0" N 33 ° 0 ' 0" N 32 ° 4 5 '0 " N 32 ° 4 5 '0 " N County of San DiegoHydrology ManualSoil Hydrologic Group Legend Major Roads Incorporated City Bdy HYDROLOGIC SOIL GROUP Hydrologic Group Undefined Hydrologic Group A Hydrologic Group B Hydrologic Group C Hydrologic Group D No Soil Data THIS MAP IS PROVIDED WITHOUT WARRANTY OF ANY KIND,EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITEDTO, THE IMPLIED WARRANTIES OF MERCHANTABILITY ANDFITNESS FOR A PARTICULAR PURPOSE.Copyright SanGIS. All Rights Reserved. This product may contain information from the SANDAG Regional Information System which cannot be reproduced without the written permission of SANDAG. This product may contain information which has been reproduced with permission granted by Thomas Brothers Maps. Note: Soil Data Source USDA/NRCSSSURGO Soils 2007 ±3 0 31.5 Miles Riverside County P a c i f i c O c e a n Impe ri a l C oun ty M exico Orange County - - D DPW *GIS ~~,..~""~'"~"-':-"-• ..... .,.. ...................... ~.-._... 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 0.5 0.4 0.3 0.2 0.1 ' ' " .... ' "r-.. ' ' .... i, .... .... ' • ' .... , ........ .... I'-,. 'r-. r-,, ' ... ... 'r-.. ' ' ..... .... , .... ,. ... • ' ' ' .... "r-,. ' ' ' ... ' .... , ' ' • ' 'r-.. ... ..... ' .... ,. ' ' .... , ' , .. ' 5 6 7 8 9 10 ·, .... • r-.., ·, ... , ·, .... , r-.r-. .. r-' ' ~ .. .. I" I'-"-""" , .. .. ~ ~ r-.r-, "'i-. '~ ~ .. .. .. , ... , .. 'i-. ~ ~ r-.,. '~ .. .. r-. I", .. .. "r-~ ....... .. ,. 'r-.. ... .. ~ .. 1'-i-,. ,, "", .. 15 20 30 Minutes .. .. '"" .... .. .... .. ~r-.. .. ~ ~ .. .. .. .. ~ .. ~ ~ ~ '"" ~ .. .. .. ""~ 40 50 Duration I = I = p6 = D = EQUATION 7.44 P6 D-0.645 Intensity (in/hr) 6-Hour Precipitation (in) Duration (min) 'i', ... ' ... , .... i', ,i-.. ' ~ i', .... 'i-.. 1, 'i-.. 'r-- Ir-. ... , , ... 'i-.. ' I'-, 'i' '-i-.. 2 ', '' .. ' .... '' ' .. .. ""· ', ', ' ~ "" '' . .... , . .... , .. , ' I" .. ', '"" I" I" 3 Hours .. .. .. .. .. .. .. ~ ~ .. .. .. 4 5 6 O> i 0 ~ 7J ro 0 6.0 R 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 P6 1 1.5 2 2.5 3 3.5 4 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 10 1.68 2.53 3.37 4.21 5.05 5.90 6.74 7.58 8.42 9.27 10.11 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 2.0~ 2.41 2.76_ 3.10 3.45 3.79 c---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 ,_~ 1.33 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 0.613_ 0.85 ~ 1.19 1.36 1.53 1.70 1.87 2.04 --f--150 0.29 0.44 0.59 0.73 0.88 1.03 1.18 1.32 1.47 1.62 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 FIGURE ~ IL__·-----_--_I .L I I I I I . . . . . . . . • . -) . ,-. ' ' . : . . . ,, .,,. . . -... ·, "~ ~ ~ . I I I I I · . --- . . -~ . . . . . . . . ,=' ·- --. . . . . . . . ' ~ e,a\H'1'Y 0 ~i.NDIEc;o • I -······_--___JI DPW ~GIS [lep:I.J""iJ7ient Di P11Mc Works Grn,r,..•pfll/,; /11furrr,.itiw1 &rv,t r.i-:; 3-3 f-w w LL 0 ~ w (_) z <( f-(/) 0 w (/) a:: ::::> 0 (_) a:: w i EXAMPLE: Given: Watercourse Distance (D) = 70 Feet Slope (s) = 1.3% Runoff Coefficient (C) = 0.41 Overland Flow Time (T) = 9.5 Minutes SOURCE: Airport Drainage, Federal Aviation Administration, 1965 C.:: o.95 T= 1.8(1.1-C)VD 3\fs (/) w f-::::> z 20 ~ ~ w ~ i== ~ 0 _J LL Cl 10 z <( _J a:: w > 0 FIGURE Rational Formula -Overland Time of Flow Nomograph San Diego County Hydrology Manual Section: 3 Date: June 2003 Page: 6 of 26 Table 3-1 RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use 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 0.52 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 Commercial/Industrial (N. Com) Neighborhood Commercial 80 0.76 0.77 0.78 0.79 Commercial/Industrial (G. Com) General Commercial 85 0.80 0.80 0.81 0.82 Commercial/Industrial (O.P. Com) 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 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 San Diego County Hydrology Manual Section: 3 Date: June 2003 Page: 12 of 26 Note that the Initial Time of Concentration should be reflective of the general land-use at the upstream end of a drainage basin. A single lot with an area of two or less acres does not have a significant effect where the drainage basin area is 20 to 600 acres. Table 3-2 provides limits of the length (Maximum Length (LM)) of sheet flow to be used in hydrology studies. Initial Ti values based on average C values for the Land Use Element are also included. These values can be used in planning and design applications as described below. Exceptions may be approved by the “Regulating Agency” when submitted with a detailed study. Table 3-2 MAXIMUM OVERLAND FLOW LENGTH (LM) & INITIAL TIME OF CONCENTRATION (Ti) .5% 1% 2% 3% 5% 10% Element* DU/ Acre LM Ti LM Ti LM Ti LM Ti LM Ti LM Ti Natural 50 13.2 70 12.5 85 10.9 100 10.3 100 8.7 100 6.9 LDR 1 50 12.2 70 11.5 85 10.0 100 9.5 100 8.0 100 6.4 LDR 2 50 11.3 70 10.5 85 9.2 100 8.8 100 7.4 100 5.8 LDR 2.9 50 10.7 70 10.0 85 8.8 95 8.1 100 7.0 100 5.6 MDR 4.3 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 100 5.3 MDR 7.3 50 9.2 65 8.4 80 7.4 95 7.0 100 6.0 100 4.8 MDR 10.9 50 8.7 65 7.9 80 6.9 90 6.4 100 5.7 100 4.5 MDR 14.5 50 8.2 65 7.4 80 6.5 90 6.0 100 5.4 100 4.3 HDR 24 50 6.7 65 6.1 75 5.1 90 4.9 95 4.3 100 3.5 HDR 43 50 5.3 65 4.7 75 4.0 85 3.8 95 3.4 100 2.7 N. Com 50 5.3 60 4.5 75 4.0 85 3.8 95 3.4 100 2.7 G. Com 50 4.7 60 4.1 75 3.6 85 3.4 90 2.9 100 2.4 O.P./Com 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 Limited I. 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 General I. 50 3.7 60 3.2 70 2.7 80 2.6 90 2.3 100 1.9 *See Table 3-1 for more detailed description 3-12 San Diego County Drainage Design Manual (July 2005) Page A-3 Table A-1 Average Manning Roughness Coefficients for Pavement and Gutters1 Concrete Gutter2 ......................................................................................................................0.015 Concrete Pavement Float Finish .........................................................................................................................0.014 Broom Finish.......................................................................................................................0.016 Concrete Gutter with Asphalt Pavement Smooth Finish.....................................................................................................................0.013 Rough Texture....................................................................................................................0.015 Asphalt Pavement Smooth Finish.....................................................................................................................0.013 Rough Texture....................................................................................................................0.016 Based on FHWA HEC-22. 1 Based on materials and workmanship required by standard specifications. 2 Increase roughness coefficient in gutters with mild slopes where sediment might accumulate by 0.020. Table A-1 San Diego County Drainage Design Manual (July 2005) Page A-4 Table A-2 Average Manning Roughness Coefficients for Closed Conduits3 Reinforced Concrete Pipe (RCP) .............................................................................................0.013 Corrugated Metal Pipe and Pipe Arch 2-3/8 x 1/2 inch Corrugations Unlined ........................................................................................................................0.024 Half Lined Full Flow ...............................................................................................................0.018 d/D>=0.60 .............................................................................................................0.016 d/D<0.60 ...............................................................................................................0.013 Fully Lined ...................................................................................................................0.013 3 x 1 inch Corrugations ......................................................................................................0.027 6 x 2 inch Corrugations ......................................................................................................0.032 Spiral Rib Pipe ...................................................................................................................0.013 Helically Wound Pipe 18-inch .........................................................................................................................0.015 24-inch .........................................................................................................................0.017 30-inch .........................................................................................................................0.019 36-inch .........................................................................................................................0.021 42-inch .........................................................................................................................0.022 48-inch .........................................................................................................................0.023 Plastic Pipe (HPDE and PVC) Smooth ..............................................................................................................................0.013 Corrugated .........................................................................................................................0.024 Vitrified Clay Pipe .....................................................................................................................0.014 Cast-Iron Pipe (Uncoated) .......................................................................................................0.013 Steel Pipe .................................................................................................................................0.011 Brick .........................................................................................................................................0.017 Cast-In-Place Concrete Pipe Rough Wood Forms ..........................................................................................................0.017 Smooth Wood or Steel Forms ...........................................................................................0.014 3 Based on materials and workmanship required by standard specifications. Table A-2 San Diego County Drainage Design Manual (July 2005) Page A-5 Table A-3 Average Manning Roughness Coefficients for Small Open Channels Conveying Less than 50 cfs4 Design Flow Depth Lining Type 0 – 0.5 ft 0.5 – 2.0 ft > 2.0 ft Concrete (Poured) 0.015 0.013 0.013 Air Blown Concrete 0.023 0.019 0.016 Grouted Riprap 0.040 0.030 0.028 Stone Masonry 0.042 0.032 0.030 Soil Cement 0.025 0.022 0.020 Bare Soil 0.023 0.020 0.020 Rock Cut 0.045 0.035 0.025 Rock Riprap Based on Rock Size (See Section 5.7.2) Table A-4 Average Manning Roughness Coefficients for Larger Open Channels Unlined Channels Clay Loam...........................................................................................................................0.023 Sand ...................................................................................................................................0.020 Lined Channels Grass Lined (Well-Maintained) ..........................................................................................0.035 Grass Lined (Not Maintained) ............................................................................................0.045 Wetland-Bottom Channels (New Channel)........................................................................0.023 Wetland-Bottom Channels (Mature Channel)............................................................ See Table A-5 Riprap-Lined Channels ......................................................................................... See Section 5.7.2 Concrete (Poured).....................................................................................................................0.014 Air Blown Mortar (Gunite or Shotcrete)5 ..................................................................................0.016 Asphaltic Concrete or Bituminous Plant Mix.............................................................................0.018 For channels with revetments or multiple lining types, use composite Manning roughness coefficient based on component lining materials. 4 Based on materials and workmanship required by standard specifications. 5 For air-blown concrete, use n=0.012 (if troweled) and n=0.025 if purposely roughened. Table A-3 Table A-4 San Diego County Drainage Design Manual (July 2005) Page A-6 Table A-5 Average Manning Roughness Coefficients for Natural Channels Minor Streams (Surface Width at Flood Stage < 100 ft) Fairly Regular Section (A) Some Grass and Weeds, Little or No Brush .........................................................0.030 (B) Dense Growth of Weeds, Depth of Flow Materially Greater Than Weed Height ....................................................................................................................0.040 (C) Some Weeds, Light Brush on Banks.....................................................................0.040 (D) Some Weeds, Heavy Brush on Banks ..................................................................0.060 (E) For Trees within Channel with Branches Submerged at High Stage, Increase All Above Values By ..............................................................................................0.015 Irregular Section, with Pools, Slight Channel Meander Channels (A) to (E) Above, Increase All Values By.....................................................0.015 Mountain Streams; No Vegetation in Channel, Banks Usually Steep, Trees and Brush along Banks Submerged at High Stage (A) Bottom, Gravel, Cobbles and Few Boulders..........................................................0.050 (B) Bottom, Cobbles with Large Boulders....................................................................0.060 Flood Plains (Adjacent To Natural Streams) Pasture, No Brush (A) Short Grass ............................................................................................................0.030 (B) High Grass .............................................................................................................0.040 Cultivated Areas (A) No Crop..................................................................................................................0.040 (B) Mature Row Crops .................................................................................................0.040 (C) Mature Field Crops.................................................................................................0.050 Heavy Weeds, Scattered Brush .........................................................................................0.050 Light Brush and Trees ........................................................................................................0.060 Medium To Dense Brush....................................................................................................0.090 Dense Willows ....................................................................................................................0.170 Cleared Land with Tree Stumps, 100-150 Per Acre...........................................................0.060 Heavy Stand of Timber, Little Undergrowth (A) Flood Depth below Branches.................................................................................0.110 (B) Flood Depth Reaches Branches ............................................................................0.140 Table A-5 National Flood Hazard Layer FIRMette FEMA 117°19'42"W 33°9'54"N 0 250 500 1,000 1,500 Basemap Imagery Source: USGS National Map 2023 Legend SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V, A99 With BFE or Depth Zone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile Zone x Future Conditions 1% Annual Chance Flood Hazard zone x Area with Reduced Flood Risk due to Levee. See Notes. zone x OTHER AREAS OF FLOOD HAZARD I" ,I .,J//J Area with Flood Risk due to Levee zone o OTHER AREAS NO SCREEN Area of Minimal Flood Hazard Zone X c:::::::J Effective LOM Rs Area of Undetermined Flood Hazard Zone o GENERAL 1-- - -Channel, Culvert, or Storm Sewer STRUCTURES I I I I I I I Levee, Dike, or Floodwall OTHER FEATURES MAP PANELS Cross Sections with 1% Annual Chance Water Surface Elevation , - - -Coastal Transect -m-Base Flood Elevation Line (BFE) = Limit of Study ---Jurisdiction Boundary C Coastal Transect Baseline Profile Baseline Hydrographic Feature Digital Data Available N r No Digital Data Available + fx Unmapped The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. This map complies with FEM A's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 8/7/2024 at 4:13 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: base map imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 2-1 ATTACHMENT 2: EXISTING CALCULATIONS Please see the attached existing conditions calculations. HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 2-2 EXISTING CONDITIONS – 100-YEAR DESIGN STORM EVENT COMPLIANCE POINT 1 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2014 Version 9.0 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 01/13/25 ------------------------------------------------------------------------ ********* Hydrology Study Control Information ********** ------------------------------------------------------------------------ Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 2.650 24 hour precipitation(inches) = 4.600 P6/P24 = 57.6% San Diego hydrology manual 'C' values used ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.110 to Point/Station 1.210 **** INITIAL AREA EVALUATION **** ______________________________________________________________________ Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [MEDIUM DENSITY RESIDENTIAL ] (4.3 DU/A or Less ) Impervious value, Ai = 0.300 Sub-Area C Value = 0.450 Initial subarea total flow distance = 50.000(Ft.) Highest elevation = 290.000(Ft.) Lowest elevation = 285.800(Ft.) Elevation difference = 4.200(Ft.) Slope = 8.400 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 8.40 %, in a development type of 4.3 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 5.76 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)] TC = [1.8*(1.1-0.4500)*( 100.000^.5)/( 8.400^(1/3)]= 5.76 Rainfall intensity (I) = 6.376(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.450 Subarea runoff = 0.023(CFS) Total initial stream area = 0.008(Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 2-3 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.210 to Point/Station 1.520 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** ______________________________________________________________________ Estimated mean flow rate at midpoint of channel = 0.166(CFS) Depth of flow = 0.046(Ft.), Average velocity = 3.199(Ft/s) ******* Irregular Channel Data *********** ----------------------------------------------------------------- Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 0.50 2 0.00 0.00 3 17.00 0.35 Manning's 'N' friction factor = 0.013 ----------------------------------------------------------------- Sub-Channel flow = 0.166(CFS) ' ' flow top width = 2.248(Ft.) ' ' velocity= 3.199(Ft/s) ' ' area = 0.052(Sq.Ft) ' ' Froude number = 3.706 Upstream point elevation = 285.800(Ft.) Downstream point elevation = 274.200(Ft.) Flow length = 95.000(Ft.) Travel time = 0.49 min. Time of concentration = 6.25 min. Depth of flow = 0.046(Ft.) Average velocity = 3.199(Ft/s) Total irregular channel flow = 0.166(CFS) Irregular channel normal depth above invert elev. = 0.046(Ft.) Average velocity of channel(s) = 3.199(Ft/s) Adding area flow to channel Rainfall intensity (I) = 6.046(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [MEDIUM DENSITY RESIDENTIAL ] (4.3 DU/A or Less ) Impervious value, Ai = 0.300 Sub-Area C Value = 0.450 Rainfall intensity = 6.046(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.450 CA = 0.049 Subarea runoff = 0.271(CFS) for 0.100(Ac.) Total runoff = 0.294(CFS) Total area = 0.108(Ac.) Depth of flow = 0.057(Ft.), Average velocity = 3.688(Ft/s) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 2-4 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.110 to Point/Station 1.520 **** CONFLUENCE OF MINOR STREAMS **** ______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.108(Ac.) Runoff from this stream = 0.294(CFS) Time of concentration = 6.25 min. Rainfall intensity = 6.046(In/Hr) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.310 to Point/Station 1.410 **** INITIAL AREA EVALUATION **** ______________________________________________________________________ Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [HIGH DENSITY RESIDENTIAL ] (43.0 DU/A or Less ) Impervious value, Ai = 0.800 Sub-Area C Value = 0.770 Initial subarea total flow distance = 45.000(Ft.) Highest elevation = 289.000(Ft.) Lowest elevation = 287.800(Ft.) Elevation difference = 1.200(Ft.) Slope = 2.667 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 85.00 (Ft) for the top area slope value of 2.67 %, in a development type of 43.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.95 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)] TC = [1.8*(1.1-0.7700)*( 85.000^.5)/( 2.667^(1/3)]= 3.95 Calculated TC of 3.949 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 6.982(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.770 Subarea runoff = 0.108(CFS) Total initial stream area = 0.020(Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 2-5 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.410 to Point/Station 1.510 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** ______________________________________________________________________ Estimated mean flow rate at midpoint of channel = 0.226(CFS) Depth of flow = 0.035(Ft.), Average velocity = 1.464(Ft/s) ******* Irregular Channel Data *********** ----------------------------------------------------------------- Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 0.50 2 6.00 0.00 3 10.00 0.00 4 16.00 0.50 Manning's 'N' friction factor = 0.025 ----------------------------------------------------------------- Sub-Channel flow = 0.226(CFS) ' ' flow top width = 4.838(Ft.) ' ' velocity= 1.464(Ft/s) ' ' area = 0.154(Sq.Ft) ' ' Froude number = 1.444 Upstream point elevation = 287.800(Ft.) Downstream point elevation = 283.900(Ft.) Flow length = 65.000(Ft.) Travel time = 0.74 min. Time of concentration = 4.69 min. Depth of flow = 0.035(Ft.) Average velocity = 1.464(Ft/s) Total irregular channel flow = 0.226(CFS) Irregular channel normal depth above invert elev. = 0.035(Ft.) Average velocity of channel(s) = 1.464(Ft/s) Adding area flow to channel Calculated TC of 4.689 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 6.982(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [LOW DENSITY RESIDENTIAL ] (2.0 DU/A or Less ) Impervious value, Ai = 0.200 Sub-Area C Value = 0.380 Rainfall intensity = 6.982(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.479 CA = 0.038 Subarea runoff = 0.157(CFS) for 0.059(Ac.) Total runoff = 0.264(CFS) Total area = 0.079(Ac.) Depth of flow = 0.038(Ft.), Average velocity = 1.548(Ft/s) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 2-6 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.510 to Point/Station 1.520 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** ______________________________________________________________________ Estimated mean flow rate at midpoint of channel = 0.411(CFS) Depth of flow = 0.093(Ft.), Average velocity = 2.594(Ft/s) ******* Irregular Channel Data *********** ----------------------------------------------------------------- Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 0.30 2 6.00 0.00 3 11.00 0.30 Manning's 'N' friction factor = 0.025 ----------------------------------------------------------------- Sub-Channel flow = 0.411(CFS) ' ' flow top width = 3.409(Ft.) ' ' velocity= 2.594(Ft/s) ' ' area = 0.159(Sq.Ft) ' ' Froude number = 2.120 Upstream point elevation = 283.900(Ft.) Downstream point elevation = 274.200(Ft.) Flow length = 85.000(Ft.) Travel time = 0.55 min. Time of concentration = 5.24 min. Depth of flow = 0.093(Ft.) Average velocity = 2.594(Ft/s) Total irregular channel flow = 0.411(CFS) Irregular channel normal depth above invert elev. = 0.093(Ft.) Average velocity of channel(s) = 2.594(Ft/s) Adding area flow to channel Rainfall intensity (I) = 6.778(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [MEDIUM DENSITY RESIDENTIAL ] (4.3 DU/A or Less ) Impervious value, Ai = 0.300 Sub-Area C Value = 0.450 Rainfall intensity = 6.778(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.464 CA = 0.077 Subarea runoff = 0.261(CFS) for 0.088(Ac.) Total runoff = 0.525(CFS) Total area = 0.167(Ac.) Depth of flow = 0.102(Ft.), Average velocity = 2.757(Ft/s) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 2-7 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.310 to Point/Station 1.520 **** CONFLUENCE OF MINOR STREAMS **** ______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.167(Ac.) Runoff from this stream = 0.525(CFS) Time of concentration = 5.24 min. Rainfall intensity = 6.778(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 1 0.294 6.25 6.046 2 0.525 5.24 6.778 Qmax(1) = 1.000 * 1.000 * 0.294) + 0.892 * 1.000 * 0.525) + = 0.762 Qmax(2) = 1.000 * 0.838 * 0.294) + 1.000 * 1.000 * 0.525) + = 0.771 Total of 2 streams to confluence: Flow rates before confluence point: 0.294 0.525 Maximum flow rates at confluence using above data: 0.762 0.771 Area of streams before confluence: 0.108 0.167 Results of confluence: Total flow rate = 0.771(CFS) Time of concentration = 5.235 min. Effective stream area after confluence = 0.275(Ac.) End of computations, total study area = 0.275 (Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 2-8 EXISTING CONDITIONS – 100-YEAR DESIGN STORM EVENT COMPLIANCE POINT 2 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2014 Version 9.0 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 01/13/25 ------------------------------------------------------------------------ ********* Hydrology Study Control Information ********** ------------------------------------------------------------------------ Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 2.650 24 hour precipitation(inches) = 4.600 P6/P24 = 57.6% San Diego hydrology manual 'C' values used ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 2.110 to Point/Station 2.210 **** INITIAL AREA EVALUATION **** ______________________________________________________________________ Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.250 Initial subarea total flow distance = 20.000(Ft.) Highest elevation = 296.000(Ft.) Lowest elevation = 290.500(Ft.) Elevation difference = 5.500(Ft.) Slope = 27.500 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 27.50 %, in a development type of Permanent Open Space In Accordance With Figure 3-3 Initial Area Time of Concentration = 5.07 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)] TC = [1.8*(1.1-0.2500)*( 100.000^.5)/( 27.500^(1/3)]= 5.07 Rainfall intensity (I) = 6.921(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.250 Subarea runoff = 0.005(CFS) Total initial stream area = 0.003(Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 2-9 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 2.210 to Point/Station 2.310 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** ______________________________________________________________________ Estimated mean flow rate at midpoint of channel = 0.011(CFS) Depth of flow = 0.071(Ft.), Average velocity = 2.201(Ft/s) ******* Irregular Channel Data *********** ----------------------------------------------------------------- Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 1.00 2 1.00 0.00 3 2.00 1.00 Manning's 'N' friction factor = 0.013 ----------------------------------------------------------------- Sub-Channel flow = 0.011(CFS) ' ' flow top width = 0.143(Ft.) ' ' velocity= 2.201(Ft/s) ' ' area = 0.005(Sq.Ft) ' ' Froude number = 2.052 Upstream point elevation = 290.500(Ft.) Downstream point elevation = 289.000(Ft.) Flow length = 30.000(Ft.) Travel time = 0.23 min. Time of concentration = 5.30 min. Depth of flow = 0.071(Ft.) Average velocity = 2.201(Ft/s) Total irregular channel flow = 0.011(CFS) Irregular channel normal depth above invert elev. = 0.071(Ft.) Average velocity of channel(s) = 2.201(Ft/s) Adding area flow to channel Rainfall intensity (I) = 6.728(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.250 Rainfall intensity = 6.728(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.250 CA = 0.003 Subarea runoff = 0.012(CFS) for 0.007(Ac.) Total runoff = 0.017(CFS) Total area = 0.010(Ac.) Depth of flow = 0.083(Ft.), Average velocity = 2.434(Ft/s) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 2-10 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 2.310 to Point/Station 2.320 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** ______________________________________________________________________ Estimated mean flow rate at midpoint of channel = 0.035(CFS) Depth of flow = 0.040(Ft.), Average velocity = 2.372(Ft/s) ******* Irregular Channel Data *********** ----------------------------------------------------------------- Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 0.50 2 6.40 0.00 3 9.50 0.50 Manning's 'N' friction factor = 0.025 ----------------------------------------------------------------- Sub-Channel flow = 0.035(CFS) ' ' flow top width = 0.752(Ft.) ' ' velocity= 2.372(Ft/s) ' ' area = 0.015(Sq.Ft) ' ' Froude number = 2.972 Upstream point elevation = 289.000(Ft.) Downstream point elevation = 280.000(Ft.) Flow length = 30.000(Ft.) Travel time = 0.21 min. Time of concentration = 5.51 min. Depth of flow = 0.040(Ft.) Average velocity = 2.372(Ft/s) Total irregular channel flow = 0.035(CFS) Irregular channel normal depth above invert elev. = 0.040(Ft.) Average velocity of channel(s) = 2.372(Ft/s) Adding area flow to channel Rainfall intensity (I) = 6.561(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.250 Rainfall intensity = 6.561(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.250 CA = 0.008 Subarea runoff = 0.036(CFS) for 0.022(Ac.) Total runoff = 0.052(CFS) Total area = 0.032(Ac.) Depth of flow = 0.046(Ft.), Average velocity = 2.619(Ft/s) End of computations, total study area = 0.032 (Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-1 ATTACHMENT 3: PROPOSED CALCULATIONS Please see the attached proposed conditions calculations. HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-2 PROPOSED CONDITIONS – 100-YEAR DESIGN STORM EVENT COMPLIANCE POINT 1 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2014 Version 9.0 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 01/24/25 ------------------------------------------------------------------------ Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 2.650 24 hour precipitation(inches) = 6.600 P6/P24 = 40.2% Adjusted 6 hour precipitation (inches) = 2.970 Adjusted P6/P24 = 45.0% San Diego hydrology manual 'C' values used ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.110 to Point/Station 1.120 **** INITIAL AREA EVALUATION **** ______________________________________________________________________ Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.670 Initial subarea total flow distance = 12.000(Ft.) Highest elevation = 287.600(Ft.) Lowest elevation = 287.500(Ft.) Elevation difference = 0.100(Ft.) Slope = 0.833 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 0.83 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 6.63 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)] TC = [1.8*(1.1-0.6700)*( 65.000^.5)/( 0.833^(1/3)]= 6.63 Rainfall intensity (I) = 6.522(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.670 Subarea runoff = 0.061(CFS) Total initial stream area = 0.014(Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-3 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.120 to Point/Station 1.220 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________ Upstream point/station elevation = 286.500(Ft.) Downstream point/station elevation = 284.100(Ft.) Pipe length = 115.00(Ft.) Slope = 0.0209 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.061(CFS) Given pipe size = 6.00(In.) Calculated individual pipe flow = 0.061(CFS) Normal flow depth in pipe = 1.12(In.) Flow top width inside pipe = 4.67(In.) Critical Depth = 1.45(In.) Pipe flow velocity = 2.43(Ft/s) Travel time through pipe = 0.79 min. Time of concentration (TC) = 7.42 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.210 to Point/Station 1.220 **** SUBAREA FLOW ADDITION **** ______________________________________________________________________ Rainfall intensity (I) = 6.066(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [HIGH DENSITY RESIDENTIAL ] (43.0 DU/A or Less ) Impervious value, Ai = 0.800 Sub-Area C Value = 0.770 Time of concentration = 7.42 min. Rainfall intensity = 6.066(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.755 CA = 0.072 Subarea runoff = 0.374(CFS) for 0.081(Ac.) Total runoff = 0.435(CFS) Total area = 0.095(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.220 to Point/Station 1.320 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________ Upstream point/station elevation = 284.100(Ft.) Downstream point/station elevation = 283.700(Ft.) Pipe length = 45.00(Ft.) Slope = 0.0089 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.435(CFS) Given pipe size = 6.00(In.) Calculated individual pipe flow = 0.435(CFS) Normal flow depth in pipe = 4.15(In.) Flow top width inside pipe = 5.54(In.) Critical Depth = 4.03(In.) Pipe flow velocity = 3.01(Ft/s) Travel time through pipe = 0.25 min. Time of concentration (TC) = 7.67 min. HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-4 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.310 to Point/Station 1.320 **** SUBAREA FLOW ADDITION **** ______________________________________________________________________ Rainfall intensity (I) = 5.939(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.840 Time of concentration = 7.67 min. Rainfall intensity = 5.939(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.772 CA = 0.091 Subarea runoff = 0.106(CFS) for 0.023(Ac.) Total runoff = 0.541(CFS) Total area = 0.118(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.320 to Point/Station 1.530 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________ Upstream point/station elevation = 283.700(Ft.) Downstream point/station elevation = 282.500(Ft.) Pipe length = 12.00(Ft.) Slope = 0.1000 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.541(CFS) Given pipe size = 6.00(In.) Calculated individual pipe flow = 0.541(CFS) Normal flow depth in pipe = 2.27(In.) Flow top width inside pipe = 5.82(In.) Critical Depth = 4.50(In.) Pipe flow velocity = 7.93(Ft/s) Travel time through pipe = 0.03 min. Time of concentration (TC) = 7.69 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.110 to Point/Station 1.530 **** CONFLUENCE OF MINOR STREAMS **** ______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.118(Ac.) Runoff from this stream = 0.541(CFS) Time of concentration = 7.69 min. Rainfall intensity = 5.926(In/Hr) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-5 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.410 to Point/Station 1.520 **** INITIAL AREA EVALUATION **** ______________________________________________________________________ Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [MEDIUM DENSITY RESIDENTIAL ] (14.5 DU/A or Less ) Impervious value, Ai = 0.500 Sub-Area C Value = 0.580 Initial subarea total flow distance = 45.000(Ft.) Highest elevation = 291.000(Ft.) Lowest elevation = 287.500(Ft.) Elevation difference = 3.500(Ft.) Slope = 7.778 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 7.78 %, in a development type of 14.5 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 4.72 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)] TC = [1.8*(1.1-0.5800)*( 100.000^.5)/( 7.778^(1/3)]= 4.72 Calculated TC of 4.724 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.825(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.580 Subarea runoff = 0.100(CFS) Total initial stream area = 0.022(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.510 to Point/Station 1.520 **** SUBAREA FLOW ADDITION **** ______________________________________________________________________ Calculated TC of 4.724 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.825(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [COMMERCIAL area type ] (Neighborhod Commercial ) Impervious value, Ai = 0.800 Sub-Area C Value = 0.770 Time of concentration = 4.72 min. Rainfall intensity = 7.825(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.697 CA = 0.040 Subarea runoff = 0.211(CFS) for 0.035(Ac.) Total runoff = 0.311(CFS) Total area = 0.057(Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-6 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.520 to Point/Station 1.530 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________ Upstream point/station elevation = 286.200(Ft.) Downstream point/station elevation = 282.500(Ft.) Pipe length = 50.00(Ft.) Slope = 0.0740 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.311(CFS) Given pipe size = 4.00(In.) Calculated individual pipe flow = 0.311(CFS) Normal flow depth in pipe = 2.23(In.) Flow top width inside pipe = 3.97(In.) Critical Depth = 3.63(In.) Pipe flow velocity = 6.20(Ft/s) Travel time through pipe = 0.13 min. Time of concentration (TC) = 4.86 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.410 to Point/Station 1.530 **** CONFLUENCE OF MINOR STREAMS **** ______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.057(Ac.) Runoff from this stream = 0.311(CFS) Time of concentration = 4.86 min. Rainfall intensity = 7.825(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 1 0.541 7.69 5.926 2 0.311 4.86 7.825 Qmax(1) = 1.000 * 1.000 * 0.541) + 0.757 * 1.000 * 0.311) + = 0.776 Qmax(2) = 1.000 * 0.631 * 0.541) + 1.000 * 1.000 * 0.311) + = 0.652 Total of 2 streams to confluence: Flow rates before confluence point: 0.541 0.311 Maximum flow rates at confluence using above data: 0.776 0.652 Area of streams before confluence: 0.118 0.057 Results of confluence: Total flow rate = 0.776(CFS) Time of concentration = 7.694 min. Effective stream area after confluence = 0.175(Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-7 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.530 to Point/Station 1.540 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________ Upstream point/station elevation = 282.500(Ft.) Downstream point/station elevation = 280.400(Ft.) Pipe length = 11.00(Ft.) Slope = 0.1909 Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.776(CFS) Given pipe size = 6.00(In.) Calculated individual pipe flow = 0.776(CFS) Normal flow depth in pipe = 2.32(In.) Flow top width inside pipe = 5.84(In.) Critical Depth = 5.27(In.) Pipe flow velocity = 11.07(Ft/s) Travel time through pipe = 0.02 min. Time of concentration (TC) = 7.71 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.540 to Point/Station 1.810 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________ Upstream point/station elevation = 280.400(Ft.) Downstream point/station elevation = 280.000(Ft.) Pipe length = 15.00(Ft.) Slope = 0.0267 Manning's N = 0.013 No. of pipes = 3 Required pipe flow = 0.776(CFS) Given pipe size = 3.00(In.) NOTE: Normal flow is pressure flow in user selected pipe size. The approximate hydraulic grade line above the pipe invert is 1.532(Ft.) at the headworks or inlet of the pipe(s) Pipe friction loss = 1.285(Ft.) Minor friction loss = 0.647(Ft.) K-factor = 1.50 Pipe flow velocity = 5.27(Ft/s) Travel time through pipe = 0.05 min. Time of concentration (TC) = 7.76 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.110 to Point/Station 1.810 **** CONFLUENCE OF MINOR STREAMS **** ______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.175(Ac.) Runoff from this stream = 0.776(CFS) Time of concentration = 7.76 min. Rainfall intensity = 5.894(In/Hr) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-8 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.610 to Point/Station 1.710 **** INITIAL AREA EVALUATION **** ______________________________________________________________________ Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.250 Initial subarea total flow distance = 25.000(Ft.) Highest elevation = 291.000(Ft.) Lowest elevation = 288.800(Ft.) Elevation difference = 2.200(Ft.) Slope = 8.800 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 8.80 %, in a development type of Permanent Open Space In Accordance With Figure 3-3 Initial Area Time of Concentration = 7.41 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)] TC = [1.8*(1.1-0.2500)*( 100.000^.5)/( 8.800^(1/3)]= 7.41 Rainfall intensity (I) = 6.071(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.250 Subarea runoff = 0.005(CFS) Total initial stream area = 0.003(Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-9 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.710 to Point/Station 1.810 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** ______________________________________________________________________ Estimated mean flow rate at midpoint of channel = 0.029(CFS) Depth of flow = 0.024(Ft.), Average velocity = 1.985(Ft/s) ******* Irregular Channel Data *********** ----------------------------------------------------------------- Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 0.50 2 0.00 0.00 3 17.00 0.35 Manning's 'N' friction factor = 0.013 ----------------------------------------------------------------- Sub-Channel flow = 0.029(CFS) ' ' flow top width = 1.188(Ft.) ' ' velocity= 1.985(Ft/s) ' ' area = 0.015(Sq.Ft) ' ' Froude number = 3.163 Upstream point elevation = 288.800(Ft.) Downstream point elevation = 280.000(Ft.) Flow length = 80.000(Ft.) Travel time = 0.67 min. Time of concentration = 8.08 min. Depth of flow = 0.024(Ft.) Average velocity = 1.985(Ft/s) Total irregular channel flow = 0.029(CFS) Irregular channel normal depth above invert elev. = 0.024(Ft.) Average velocity of channel(s) = 1.985(Ft/s) Adding area flow to channel Rainfall intensity (I) = 5.741(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [LOW DENSITY RESIDENTIAL ] (2.0 DU/A or Less ) Impervious value, Ai = 0.200 Sub-Area C Value = 0.380 Rainfall intensity = 5.741(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.369 CA = 0.013 Subarea runoff = 0.070(CFS) for 0.032(Ac.) Total runoff = 0.074(CFS) Total area = 0.035(Ac.) Depth of flow = 0.035(Ft.), Average velocity = 2.513(Ft/s) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-10 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.610 to Point/Station 1.810 **** CONFLUENCE OF MINOR STREAMS **** ______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.035(Ac.) Runoff from this stream = 0.074(CFS) Time of concentration = 8.08 min. Rainfall intensity = 5.741(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 1 0.776 7.76 5.894 2 0.074 8.08 5.741 Qmax(1) = 1.000 * 1.000 * 0.776) + 1.000 * 0.960 * 0.074) + = 0.847 Qmax(2) = 0.974 * 1.000 * 0.776) + 1.000 * 1.000 * 0.074) + = 0.830 Total of 2 streams to confluence: Flow rates before confluence point: 0.776 0.074 Maximum flow rates at confluence using above data: 0.847 0.830 Area of streams before confluence: 0.175 0.035 Results of confluence: Total flow rate = 0.847(CFS) Time of concentration = 7.758 min. Effective stream area after confluence = 0.210(Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-11 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.810 to Point/Station 1.102 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** ______________________________________________________________________ Estimated mean flow rate at midpoint of channel = 0.886(CFS) Depth of flow = 0.090(Ft.), Average velocity = 4.542(Ft/s) ******* Irregular Channel Data *********** ----------------------------------------------------------------- Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 0.50 2 0.00 0.00 3 17.00 0.35 Manning's 'N' friction factor = 0.013 ----------------------------------------------------------------- Sub-Channel flow = 0.886(CFS) ' ' flow top width = 4.352(Ft.) ' ' velocity= 4.542(Ft/s) ' ' area = 0.195(Sq.Ft) ' ' Froude number = 3.782 Upstream point elevation = 280.000(Ft.) Downstream point elevation = 274.900(Ft.) Flow length = 50.000(Ft.) Travel time = 0.18 min. Time of concentration = 7.94 min. Depth of flow = 0.090(Ft.) Average velocity = 4.542(Ft/s) Total irregular channel flow = 0.886(CFS) Irregular channel normal depth above invert elev. = 0.090(Ft.) Average velocity of channel(s) = 4.542(Ft/s) Adding area flow to channel Rainfall intensity (I) = 5.806(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.250 Rainfall intensity = 5.806(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.648 CA = 0.148 Subarea runoff = 0.015(CFS) for 0.019(Ac.) Total runoff = 0.862(CFS) Total area = 0.229(Ac.) Depth of flow = 0.089(Ft.), Average velocity = 4.511(Ft/s) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-12 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.110 to Point/Station 1.102 **** CONFLUENCE OF MINOR STREAMS **** ______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.229(Ac.) Runoff from this stream = 0.862(CFS) Time of concentration = 7.94 min. Rainfall intensity = 5.806(In/Hr) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.910 to Point/Station 1.101 **** INITIAL AREA EVALUATION **** ______________________________________________________________________ Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.250 Initial subarea total flow distance = 65.000(Ft.) Highest elevation = 284.000(Ft.) Lowest elevation = 283.000(Ft.) Elevation difference = 1.000(Ft.) Slope = 1.538 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 85.00 (Ft) for the top area slope value of 1.54 %, in a development type of Permanent Open Space In Accordance With Figure 3-3 Initial Area Time of Concentration = 12.22 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)] TC = [1.8*(1.1-0.2500)*( 85.000^.5)/( 1.538^(1/3)]= 12.22 Rainfall intensity (I) = 4.397(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.250 Subarea runoff = 0.019(CFS) Total initial stream area = 0.017(Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-13 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.101 to Point/Station 1.102 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** ______________________________________________________________________ Estimated mean flow rate at midpoint of channel = 0.037(CFS) Depth of flow = 0.038(Ft.), Average velocity = 1.368(Ft/s) ******* Irregular Channel Data *********** ----------------------------------------------------------------- Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 0.30 2 6.00 0.00 3 11.00 0.30 Manning's 'N' friction factor = 0.025 ----------------------------------------------------------------- Sub-Channel flow = 0.037(CFS) ' ' flow top width = 1.405(Ft.) ' ' velocity= 1.368(Ft/s) ' ' area = 0.027(Sq.Ft) ' ' Froude number = 1.742 Upstream point elevation = 283.000(Ft.) Downstream point elevation = 274.200(Ft.) Flow length = 85.000(Ft.) Travel time = 1.04 min. Time of concentration = 13.26 min. Depth of flow = 0.038(Ft.) Average velocity = 1.368(Ft/s) Total irregular channel flow = 0.037(CFS) Irregular channel normal depth above invert elev. = 0.038(Ft.) Average velocity of channel(s) = 1.368(Ft/s) Adding area flow to channel Rainfall intensity (I) = 4.172(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.250 Rainfall intensity = 4.172(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.250 CA = 0.013 Subarea runoff = 0.033(CFS) for 0.033(Ac.) Total runoff = 0.052(CFS) Total area = 0.050(Ac.) Depth of flow = 0.044(Ft.), Average velocity = 1.492(Ft/s) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-14 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 1.910 to Point/Station 1.102 **** CONFLUENCE OF MINOR STREAMS **** ______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.050(Ac.) Runoff from this stream = 0.052(CFS) Time of concentration = 13.26 min. Rainfall intensity = 4.172(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 1 0.862 7.94 5.806 2 0.052 13.26 4.172 Qmax(1) = 1.000 * 1.000 * 0.862) + 1.000 * 0.599 * 0.052) + = 0.893 Qmax(2) = 0.719 * 1.000 * 0.862) + 1.000 * 1.000 * 0.052) + = 0.671 Total of 2 streams to confluence: Flow rates before confluence point: 0.862 0.052 Maximum flow rates at confluence using above data: 0.893 0.671 Area of streams before confluence: 0.229 0.050 Results of confluence: Total flow rate = 0.893(CFS) Time of concentration = 7.941 min. Effective stream area after confluence = 0.279(Ac.) End of computations, total study area = 0.279 (Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-15 PROPOSED CONDITIONS – 100-YEAR DESIGN STORM EVENT COMPLIANCE POINT 2 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2014 Version 9.0 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 01/24/25 ------------------------------------------------------------------------ ********* Hydrology Study Control Information ********** ------------------------------------------------------------------------ Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 2.650 24 hour precipitation(inches) = 6.600 P6/P24 = 40.2% Adjusted 6 hour precipitation (inches) = 2.970 Adjusted P6/P24 = 45.0% San Diego hydrology manual 'C' values used ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 2.110 to Point/Station 2.120 **** INITIAL AREA EVALUATION **** ______________________________________________________________________ Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.250 Initial subarea total flow distance = 25.000(Ft.) Highest elevation = 290.400(Ft.) Lowest elevation = 288.000(Ft.) Elevation difference = 2.400(Ft.) Slope = 9.600 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 9.60 %, in a development type of Permanent Open Space In Accordance With Figure 3-3 Initial Area Time of Concentration = 7.20 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)] TC = [1.8*(1.1-0.2500)*( 100.000^.5)/( 9.600^(1/3)]= 7.20 Rainfall intensity (I) = 6.186(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.250 Subarea runoff = 0.006(CFS) Total initial stream area = 0.004(Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-16 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 2.120 to Point/Station 2.210 **** IMPROVED CHANNEL TRAVEL TIME **** ______________________________________________________________________ Upstream point elevation = 288.000(Ft.) Downstream point elevation = 286.500(Ft.) Channel length thru subarea = 10.000(Ft.) Channel base width = 0.500(Ft.) Slope or 'Z' of left channel bank = 3.000 Slope or 'Z' of right channel bank = 3.000 Manning's 'N' = 0.037 Maximum depth of channel = 0.750(Ft.) Flow(q) thru subarea = 0.006(CFS) Depth of flow = 0.014(Ft.), Average velocity = 0.840(Ft/s) Channel flow top width = 0.582(Ft.) Flow Velocity = 0.84(Ft/s) Travel time = 0.20 min. Time of concentration = 7.40 min. Critical depth = 0.016(Ft.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 2.210 to Point/Station 2.220 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** ______________________________________________________________________ Estimated mean flow rate at midpoint of channel = 0.022(CFS) Depth of flow = 0.032(Ft.), Average velocity = 2.163(Ft/s) ******* Irregular Channel Data *********** ----------------------------------------------------------------- Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 0.00 0.50 2 6.40 0.00 3 9.50 0.50 Manning's 'N' friction factor = 0.025 ----------------------------------------------------------------- Sub-Channel flow = 0.022(CFS) ' ' flow top width = 0.617(Ft.) ' ' velocity= 2.163(Ft/s) ' ' area = 0.010(Sq.Ft) ' ' Froude number = 2.992 Upstream point elevation = 286.500(Ft.) Downstream point elevation = 280.000(Ft.) Flow length = 20.000(Ft.) Travel time = 0.15 min. Time of concentration = 7.55 min. Depth of flow = 0.032(Ft.) Average velocity = 2.163(Ft/s) Total irregular channel flow = 0.022(CFS) Irregular channel normal depth above invert elev. = 0.032(Ft.) Average velocity of channel(s) = 2.163(Ft/s) Adding area flow to channel HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 3-17 Rainfall intensity (I) = 5.998(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.250 Rainfall intensity = 5.998(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.250 CA = 0.006 Subarea runoff = 0.030(CFS) for 0.020(Ac.) Total runoff = 0.036(CFS) Total area = 0.024(Ac.) Depth of flow = 0.039(Ft.), Average velocity = 2.456(Ft/s) End of computations, total study area = 0.024 (Ac.) HYDROLOGY REPORT VECK RESIDENCE PD2024-0009, GR 2024-0013, DWG 548-2A 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 ATTACHMENT 4: STUDY EXHIBITS Please see the attached exhibits. VICINITY MAP VICINITY MAP T.B, PG. 1106-H5 NOT TO SCALE CITY Of' OCEANSIDE C\-IE.S1N A.P.N. 207-053-13 ADDRESS 3771 SKYLINE ROAD CARLSBAD, CALIFORNIA 92008 la LEGAL DESCRIPTION PORTION OF LDT 20 PER MAP 3019 N Of' cos -~// / \ ~' "-r ~ 10 5 0 10 20 SCALE IN FEET SCALE: 1' = 10' <ORIGINAL EXHIBIT SIZE IS 24X36) LEGEND ->-->-- EXISTING CONDITIONS SUBAREA IMP LAND 11 / 'Yo l)S~: 1.1 '27.8% MDR 4.3 1.2 '28.()% MDR-4.3 1.3 77.20/c, 111)1~-4:J 1.4 18.2% U W-'2.0 l, ,., :.l-1.1% .M.DH. 1,:_l 2.1 0% NATUl>!AL 2.2 (l°l'c, NATlJI-./AI, '2.3 (l°f'i, N!\TlJl-.//\1, EXISTING CONDITIONS SUMMARY COMPLIANCE POINT 1 DATA INTENSITI (IN/IIR) TOTAL l)ISCHARGE (CFSl TTMF: OF CONCENTRi\TTON (MTN) AHJ::A (ACH.J::.Sl EXISTING CONDITIONS SUMMARY COMPLIANCE POINT 2 DATA INTENSI1Y i'IN IHR) ·ro'l'AL l)ISCH/\RGE (U'S\ TIM:C OF CONCENTRATION fMINl J\REA (-\CREf;) RANCHO COASTAL ENGINEERING & SURVEYING SINGLE SOURCE DEVELOPMENT CONSULTANT 310 VIA VERA CRUZ, 11205 SAN MARCOS, CA. 92078 (760) 510-3152 Ph / (760) 510-3153 F o.x EB CE:> 100 YEAR G.778 0.7 ! "· '24 /J.27G 100-YEAR 6.361 (_l.0,-i 0.Gl 0.032 DRAINAGE AREA SUB BOUNDARY, NUMBER, AND ACREAGE FLOW PA TH, DIRECTION, LENGTH (OVERLAND) STUDY NOD£ NUMBER (2 ELEVATIONS AT NODE) NODE ELEVATION (FG) COMPLIANCE POINT EXISTING IMPERVIOUS AREAS PDS2024-0009, GR 2024-0013, DWG 548-2A CITY OF CARLSBAD HYDROLOGY EXHIBIT -EXISTING CONDITIONS FOR, VECK FEBIC ace 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 APN: 207-053-13 POR. LOT 20 PER MAP 3019 286.0 1W 282.5 BW (TYP.) . '·i'.'1 _'_.;."[ :::11~ ~. 4 :::1:11 : . · . • t j. l : 4 . ' ' ' p~ ' • • . 6 (TYP.) ard .0 IE 4 •· • ' ... I ,.. '\>."'1-1-}'I::f.i co <E,-----,--: " . . . b-"' •• ·• •• /·.·,·. . . ' ' ., " () I ' I • I ) 7 ) / • . . , 'I.AWN• 1 .1 , z ''--,;nFi"-ii""'B'rii 291.25 1W 286.0 BW 2.1 ' 4 7 7 • :,;··, 1 i ' •:__..,1-----1 (' =J~· I AC ) 71 I ' ' ' • 4 I ., • > 1~ ) I~ I<,: <t• ) + ➔ \: ) . ) \. 10 5 0 10 SCALE IN FEET SCALE• 1' = 10' <ORIGINAL EXHIBIT SIZE IS 24X36) 20 LEGEND ------EB ->-->--CJ::> ->-->-CJ::> A fil l'R(WOSl-rn CONl)ITIONS SlJRAREA IMP LAND ID % USE 11 78,2%i HDR-1J 1 ' 78.84(, 111)1\-43 LJ 88,2% COMM/OFHCL 11 51.:2':'rr.i MDH-11 . .S 1 d 8ii.8% COMM/NRHD 1. 6 0'}•() NATURAL 1 7 22.1'% UW-'1.0 1 8 0% Ni\TLJRAL 1 0 ("Ji% NATURAL 1.10 001,, N1\'rlJh'/\L 2.1 no, ,o NATURAL 2.:2 O'Yo NATURAL 2.3 0% N.!\TURJ\L PROPOSED CONDITIONS SUMMARY COMPLIANCE POINI' 1 DATA 100-YEAR lN'l'.l!.:NSrfY llN/llE ·1.l'IL TOT/\T, nTSCH/\R\rR (c:FS) (UN TThiE or CONCENTRATION fMIN) 7.91 AREA (ACRES) 0.:279 PROPOSED CONDITIONS SUMMARY COMPLIANCE POINT 2 DATA 100-YEAR INTl-(NSITY (IN/HR\ (i.()18 TOTAL DISCILA.RGE (CFS) 0.13 TIM~; OF CONC~:NTRATION (MIN.I 7.!':-1 ARE.'\. fACRES'1 0,03G DRAINAGE AREA SUB BOUNDARY, NUMBER, AND ACREAGE FLOW PA TH, DIRECTION, LENGTH (OVERLAND) FLOW PATH, DIRECTION, LENGTH (PIPED) STIJDY NODE NUMBER (2 ELEVA 11ONS AT NODE) NODE ELEVATION (FG) NODE ELEVA 11ON (IE) PIPE COMPLIANCE POINT PROPOSED IMPER\/IOUS AREAS COMPLIANC-E POINI' 1 DATA SUMMARY AND COMPARISON DATA EXISTING PROPOSED COMPARISON lNTENSlTY (lN/Hk) 6.778 4,172 -2,606 TOTAL DTSCTTARGE (CFS) 0.77 0.8CJ + 0.1'2 TTM"R OF CONCENTRATTON (\flN) ,).')4 7.04 + ').70 AREA (ACRES) 0.:275 0.279 + 0.00,1 COMPLIANCE POINI' 2 DATA SUMMARY AND COMPARISON DATA INT~:NSITY (IN/HR) TOTAL DTSCHARGE (CFS) TIME OF cnNCENTRATION (:\1:IN) illiEf\ (AC.l{.t::S) RANCHO COASTAL ENGINEERING & SURVEYING SINGLE SOURCE DEVELOPMENT CONSULTANT 310 VIA VERA CRUZ, 11205 SAN MARCOS, CA. 92078 (760) 510-3152 Ph / (760) 510-3153 F o.x EXISTING PROPOSED COMPARISON (J.-J(i 1 !J.998 -O.-Jb3 o.o,=-:. 0.04 -0.01 5.51 7.55 + 2 .0°1 O.O'.:l2 0,024 -(.l.008 PDS2024-0009, GR 2024-0013, DWG 548-2A CITY OF CARLSBAD HYDROLOGY EXHIBIT -PROPOSED CONDlllONS FOR: VECK FEBIC ace 3771 SKYLINE ROAD, CARLSBAD, CALIFORNIA 92008 APN: 207-053-13 POR. LOT 20 PER MAP 3019