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HomeMy WebLinkAboutMS 2024-0006; CARLSBAD BOULEVARD HOMES; HYDROLOGY STUDY; 2025-03-01 HYDROLOGY STUDY FOR CARLSBAD PARCEL (TENTATIVE MAP) / COASTAL DEVELOPMENT PERMIT / MINOR SUBDIVISION PERMIT CARLSBAD BOULEVARD HOMES PUD 2024-0006 / CDP 2024-0028 / MS 2024-0006 GR2025-0007 DWG 551-9A CITY OF CARLSBAD, CA APN: 210-062-09 PREPARED FOR: TIDES AT TERRAMAR LLC 2888 LOKER AVENUE EAST, SUITE 220 CARLSBAD, CA 92010 PH: (949) 678-4927 PREPARED BY: PASCO LARET SUITER & ASSOCIATES, INC. 1911 SAN DIEGO AVENUE, SUITE 100 SAN DIEGO, CA 92110 PH: (858) 259-8212 Prepared: March 2025 Revised: August 2025 __________________________________________________ BRYAN A. KNAPP, RCE 86542 DATE PLSA 4169 TABLE OF CONTENTS SECTION Executive Summary 1.0 Introduction 1.1 Existing Conditions 1.2 Proposed Project 1.3 Conclusions 1.4 References 1.5 Methodology 2.0 Introduction 2.1 County of San Diego Criteria 2.2 City of Carlsbad Standards 2.3 Runoff Coefficient Determination 2.4 Hydrology & Hydraulic Model Output 3.0 Pre-Developed Hydrologic Model Output (100-Year Event) 3.1 Post-Developed Hydrologic Model Output (100-Year Event) 3.2 Pre-Developed vs. Post-Developed Peak Flows (100-Year Event) 3.3 Detention Analysis (100-Year Event) 3.4 Storm Water Pollutant Control 3.5 Appendix 4.0 Appendix A: Hydrology Support Material Appendix B: 100-Year Storm Event Detention Analysis PLSA 4169 Page 1 of 13 1.0 EXECUTIVE SUMMARY 1.1 Introduction This Hydrology Study for the proposed development at 5211 Carlsbad Boulevard, Carlsbad has been prepared to analyze the hydrologic and hydraulic characteristics of the existing and proposed project site. This report intends to present both the methodology and the calculations used for determining the runoff from the project site in both the pre-developed (existing) conditions and the post-developed (proposed) conditions produced by the 100- year, 6-hour storm. 1.2 Existing Conditions The subject property is located on the western side of Carlsbad Boulevard between Cannon Road to the north, and Cerezo Drive to the south. The site is adjacent to residential lots to the north, south and west, and Carlsbad Boulevard to the east. The existing site is a vacant lot with vegetation. The project site is located within the Agua Hedionda Hydrologic Area, and, more specifically, the Los Monos Hydrologic Sub-Area (904.31) of the Carlsbad watershed. The existing site is comprised of approximately 0.138 acres. Currently, there is no existing storm drain infrastructure located onsite to convey drainage. In Carlsbad Boulevard, east of the site, there is an existing public 30” RCP storm drain main with an existing Q100 = 18.3 CFS that eventually discharges to Agua Hedionda per DWG 270-2 included in Appendix A. Based on a study of the existing topography, the site primarily drains from east to west, discharging across the west property line. The site accepts offsite run-on from the vegetated sloped area of the public right-of-way to the east of the site. There appears to be a swale at the top of slope at the edge of AC pavement on the west side of the public right-of-way to direct remaining public right-of-way runoff north along Carlsbad Boulevard away from the site. The lot adjacent to the west property line consists of a residential building with a pool and typical landscape improvements in the rear yard. In a storm event, surface runoff flows through the adjacent lot to the west and eventually makes its way to a public storm drain inlet in Shore Drive where it enters a buried pipe network. From here, drainage is routed directly to the Pacific Ocean. The analyzed watershed of the subject property can be categorized into one major drainage basin, EX-1. Basin EX-1 is approximately 0.173 acres in size and 0.0% impervious and includes offsite run-on areas from the public right-of-way east of the property. Per the Web Soil Survey application available through the United States Department of Agriculture, the area is generally categorized to have group B soils. Based upon soil type B and the amount of existing impervious area onsite, a runoff coefficient of 0.25 was calculated for Basin EX-1 using the methodology described in section 3.1.2 of the San Diego County Hydrology Manual and the formula provided therein. Using the Rational Method Procedure outlined in the San Diego County Hydrology Manual, a peak flow rate and time of concentration was calculated for the drainage basin for the 100-year, 6-hour storm event. Table 1 below summarizes the results of the Rational Method calculations. PLSA 4169 Page 2 of 13 EXISTING DRAINAGE FLOWS DRAINAGE AREA DRAINAGE AREA (ACRES) Q100 (CFS) I100 (IN/HR) EX-1 0.173 0.29 6.59 Table 1. Existing Condition Peak Drainage Flow Rates The peak flow rate for the 100-year, 6-hour storm was determined to be 0.29 cfs with a time of concentration of 5.0 minutes used to calculate the rainfall intensity of 6.59 in/hr for the drainage basin of this size and amount of impervious area; discharging to the western property line. Refer to pre-development hydrology calculations included in section 3.1 of this report for detailed analysis and the pre-development hydrology map in Appendix A of this hydrology report for existing drainage basin delineation and discharge locations. 1.3 Proposed Project The proposed project includes the clearing of all onsite existing vegetation and the construction of a duplex residential building. The project also proposes various hardscape and landscape improvements including two private driveways with portions to be pervious pavers, and walkways. Site grading along with drainage and utility improvements typical of this type of residential development will also be constructed. The runoff from the site will be collected by multiple roof downspouts and area drains around the building to then be routed to a gravel storage basin detention system at the rear of the property. The offsite run-on from the public right-of-way to the east will sheet flow to the site and flow to the two proposed pervious paver driveways. A perforated pipe at the bottom of the driveway paver section will collect runoff and routes to the gravel storage basin at the rear of the property. The discharge from the gravel storage basin is controlled by an orifice installed in the 12”x12” brooks box at the storage basin outlet and is then conveyed east to the 24”x24” brooks box at the east property line. The discharge then leaves the site and continues east via a private 18” RCP storm drain connecting to the existing public 30” RCP storm drain main in Carlsbad Boulevard per DWG 270-2. Once runoff enters the public storm drain system in Carlsbad Boulevard, it eventually makes its way to discharge at Agua Hedionda. A hydraulic study using Hydraflow Express is included in Appendix A that shows the pre and post construction flows in the existing public 30” RCP storm drain main downstream from the site. The additional mitigated flow of 0.29 CFS from the site has negligible impact on the drainage system capacities. An offsite basin exhibit is also included in Appendix A showing the upstream offsite basins contributing to the Carlsbad Boulevard storm drain main. PLSA 4169 Page 3 of 13 The analyzed watershed can be categorized into one major drainage basin PR-1. Drainage basin PR-1 has a discharge location to tie into the existing 30” RCP storm drain main in Carlsbad Boulevard. Basin PR-1 is approximately 0.173 acres in size and 62.5% impervious. Based upon soil type B and the amount of proposed impervious area onsite, a runoff coefficient for each sub basin was calculated using the methodology described in section 3.1.2 of the San Diego County Hydrology Manual and the formula provided therein. Using the Rational Method Procedure outlined in the San Diego County Hydrology Manual, a peak flow rate and time of concentration was calculated for the post- development 100-year, 6-hour storm event. Table 2 below summarizes the results of the Rational Method calculations. PROPOSED DRAINAGE FLOWS DRAINAGE AREA RUNOFF COEFF. DRAINAGE AREA (ACRES) Q100 UNMIT (CFS) I100 (IN/HR) PR-1 0.656 0.173 0.73 6.59 Table 2. Proposed Condition Peak Drainage Flow Rates The peak flow rate for the 100-year, 6-hour storm for the entire Basin PR-1 was determined to be 0.73 cfs. For an explanation of the mitigated output from the onsite detention please refer to Section 3.4 of this report. In an effort to comply with City of Carlsbad’s storm water standards required of Standard projects, the subject property will also implement various source control and site design BMP’s where feasible and applicable in accordance with the City of Carlsbad’s BMP Design Manual. The site will also implement minimized hardscape areas, minimize soil compaction where applicable, and promote runoff dispersion by draining new hardscape areas through landscaped swales. PLSA 4169 Page 4 of 13 1.4 Conclusions Based upon the analysis included in this report, the proposed onsite drainage system design is adequate to capture and convey runoff from the proposed project and discharge to the existing public 30” RCP storm drain main in Carlsbad Boulevard east of the property per DWG 270-2 while complying with local and state level water quality regulations. The stormwater detention system has been sized to mitigate the peak flows generated in the proposed condition, compared to the pre-project levels. The hydraulic study included in Appendix A shows the additional mitigated flow of 0.29 CFS added to Carlsbad Boulevard storm drain main has negligible impacts. Once runoff enters the public storm drain system in Carlsbad Boulevard, it makes its way north to discharge at Agua Hedionda. PROPOSED MITIGATED DRAINAGE FLOWS DRAINAGE AREA RUNOFF COEFF. DRAINAGE AREA (ACRES) Q100 UNMIT (CFS) Q100 MIT (CFS) I100 (IN/HR) PR-1 TOTAL 0.656 0.173 0.73 0.29 6.59 Table 3. Proposed Condition Mitigated Peak Drainage Flow Rates PLSA 4169 Page 5 of 13 1.5 References “San Diego County Hydrology Manual”, revised June 2003, County of San Diego, Department of Public Works, Flood Control Section. “San Diego County Hydraulic Design Manual”, revised September 2014, County of San Diego, Department of Public Works, Flood Control Section “Engineering Standards, Volume 5: Carlsbad BMP Design Manual”, revised February 2016, City of Carlsbad Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at http://websoilsurvey.nrcs.usda.gov. PLSA 4169 Page 6 of 13 METHODOLOGY 2.1 Introduction The hydrologic model used to perform the hydrologic analysis presented in this report utilizes the Rational Method (RM) equation, Q = CIA. The RM formula estimates the peak rate of runoff based on the variables of area, runoff coefficient, and rainfall intensity. The rainfall intensity (I) is equal to: I = 7.44 x P6 x D-0.645 Where: I = Intensity (in/hr) P6 = 6-hour precipitation (inches) D = duration (minutes – use Tc) Using the Time of Concentration (Tc), which is the time required for a given element of water that originates at the most remote point of the basin being analyzed to reach the point at which the runoff from the basin is being analyzed. The RM equation determines the storm water runoff rate (Q) for a given basin in terms of flow (typically in cubic feet per second (cfs) but sometimes as gallons per minute (gpm)). The RM equation is as follows: Q = CIA Where: Q = flow (in cfs) C = runoff coefficient, ratio of rainfall that produces storm water runoff (runoff vs. infiltration/evaporation/absorption/etc) I = average rainfall intensity for a duration equal to the Tc for the area, in inches per hour. A = drainage area contributing to the basin in acres. The RM equation assumes that the storm event being analyzed delivers precipitation to the entire basin uniformly, and therefore the peak discharge rate will occur when a raindrop that falls at the most remote portion of the basin arrives at the point of analysis. The RM also assumes that the fraction of rainfall that becomes runoff or the runoff coefficient C is not affected by the storm intensity, I, or the precipitation zone number. PLSA 4169 Page 7 of 13 2.2 County of San Diego Criteria As defined by the County Hydrology Manual dated June 2003, the rational method is the preferred equation for determining the hydrologic characteristics of basins up to approximately one square mile in size. The County of San Diego has developed its own tables, nomographs, and methodologies for analyzing storm water runoff for areas within the county. The County has also developed precipitation isopluvial contour maps that show even lines of rainfall anticipated from a given storm event (i.e. 100-year, 6-hour storm). One of the variables of the RM equation is the runoff coefficient, C. The runoff coefficient is dependent only upon land use and soil type and the County of San Diego has developed a table of Runoff Coefficients for Urban Areas to be applied to basin located within the County of San Diego. The table categorizes the land use, the associated development density (dwelling units per acre) and the percentage of impervious area. Each of the categories listed has an associated runoff coefficient, C, for each soil type class. The County has also illustrated in detail the methodology for determining the time of concentration, in particular the initial time of concentration. The County has adopted the Federal Aviation Agency’s (FAA) overland time of flow equation. This equation essentially limits the flow path length for the initial time of concentration to lengths under 100 feet, and is dependent on land use and slope. 2.3 City of Carlsbad Standards The City of Carlsbad has additional requirements for hydrology reports and drainage plans which are outlined in the Grading Ordinance. Please refer to this manual for further details. 2.4 Runoff Coefficient Determination As stated in section 2.2, the runoff coefficient is dependent only upon land use and soil type and the County of San Diego has developed a table of Runoff Coefficients for Urban Areas to be applied to basin located within the County of San Diego. The table, included at the end of this section, categorizes the land use, the associated development density (dwelling units per acre) and the percentage of impervious area. PLSA 4169 Page 8 of 13 3.0 HYDROLOGY MODEL OUTPUT 3.1 Pre-Developed Hydrologic Model Output (100-Year Event) Pre-Development: Q = CIA *Rational Method Equation P100 = 2.5 *100-Year, 6-Hour Rainfall Precipitation Basin EX-1 (Total Drainage Basin) Total Area = 7,518 sf  0.173 Acres Impervious Area = 0 sf  0.000 Ac Pervious Area = 7,518 sf  0.173 Ac Cn, Weighted Runoff Coefficient, - 0.25, Cn value for natural ground, Type B Soils *Per San Diego Hydrology Design Manual (SDHDM) Section 3.1.2 - 0.90, Cn value for developed/impervious surface *Per SDHDM Section 3.1.2 Cn = 0.9 x 0 sf + 0.25 x 7,518 sf = 0.25 7,518 sf Tc = 5.0 mins * Minimum Tc for Rainfall Intensity per SDCHM P6 = 2.5 I = 7.44 x P6 x D-0.645 *Rainfall Intensity Equation I = 7.44 x 2.5 x 5.0-0.645 ≈ 6.59 in/hr I100 ≈ 6.59 in/hr Q = Cn x I100 x A *Q based on flow to existing improvements Q100 = 0.25 x 6.59 in/hr x 0.173 Ac = 0.29 cfs PLSA 4169 Page 9 of 13 3.2 Post-Developed Hydrologic Model Output (100-Year Event) Post-Development (without considering BMP treatment): Q = CIA *Rational Method Equation P100 = 2.5 *100-Year, 6-Hour Rainfall Precipitation Basin PR-1 (Total Drainage Basin) Total Area = 7,518 sf  0.173 Acres Impervious Area = 4,698 sf  0.108 Acres Pervious Area = 2,820 sf  0.065 Acres Cn, Weighted Runoff Coefficient - 0.25, Cn value for natural ground, Type B soils * Per San Diego Hydrology Design Manual (SDHDM) Section 3.1.2 - 0.9, C value for developed / impervious surface * Per SDHDM Section 3.1.2 Cn = 0.9 x 4,698 sf + 0.25 x 2,820 sf = 0.656 7,518 sf Tc = 5.0 min *Minimum Tc for Rainfall Intensity per SDCHM P6 = 2.5 I = 7.44 x P6 x D-0.645 *Rainfall Intensity Equation I = 7.44 x 2.5 x 5.0-0.645 ≈ 6.59 in/hr I100 ≈ 6.59 in/hr Q100 = C*I*A Q100 = 0.656 x 6.59 in/hr x 0.173 Ac = 0.73 cfs PLSA 4169 Page 10 of 13 3.3 Pre-Developed vs. Post-Developed Peak Flows (100-Year Event) Total Pre-Development (Discharge Leaving Site) Basin EX-1 Q100 = 0.29 cfs *Discharging from the site at the western property boundary Total Post-Development (Discharge Leaving Site) Basin PR-1 Q100 = 0.73 cfs *Discharging from the site at the western property boundary Pre-Development vs. Post-Development (Discharge Leaving Site): Pre-Development Post-Development Delta Q100 = 0.29 cfs Q100 = 0.73 cfs 0.44 cfs increase *Total overall site runoff increased in proposed condition from pre-development site. Refer to the following section, Section 3.4, of this report for a discussion of detention system proposed to mitigate site to existing conditions. Also refer to the Appendix of this report for existing and proposed condition hydrology node maps showing discharge locations from the subject property. 3.4 Detention Analysis The onsite gravel storage basin detention system will provide mitigation of the 100-year, 6-hour storm event peak flow rate. A routing analysis was performed for the proposed gravel storage basin detention system to confirm peak flow will be detained and slowly released to match existing conditions. HydroCAD-10 has the ability to route the 100-year, 6-hour storm event inflow hydrograph (generated and modeled using RatHydro, which is a Rational Method Design Storm Hydrograph software that creates a hydrograph using the results of the Rational Method calculations) through the detention system. Based on the gravel storage basin cross-sectional geometry and outlet structure data, HydroCAD-10 has the ability to perform a dynamic / routing analysis and calculate the detained peak flow rate as well as detained time to peak. The results of this analysis can be found in Appendix B of this report. PLSA 4169 Page 11 of 13 DRAINAGE AREA DRAINAGE AREA (ACRES) Q100 (CFS) I100 (IN/HR) EX-1 0.173 0.29 6.59 PR-1 0.173 0.73 6.59 PR-1(MIT) 0.173 0.29 6.59 Table 3. Comparison of Peak Drainage Flow Rates – Detained Condition Table 3 above lists a summary of the results of the detention analysis as compared to the pre-project and post-project unmitigated peak flows. Based on the results of the HydroCAD-10 analysis, it was determined that the gravel storage basin detention system provides mitigation for the 100-year, 6-hour storm event peak flow rate by detaining the proposed condition to 0.29 cfs, which is equal to the EX-1 existing condition Q100 of 0.29 cfs leaving the property. For additional information, refer to Appendix A of this Hydrology Report for the pre-and- post-developed project hydrologic node maps. Lastly, refer to Appendix B of this report for the HydroCAD-10 detailed output, which shows the dynamic routing of the 100-year, 6-hour storm event through the biofiltration basins and the resulting mitigated peak discharge leaving the subject property. PLSA 4169 Page 12 of 13 4.0 APPENDIX A: HYDROLOGY SUPPORT MATERIAL Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/5/2025 Page 1 of 4 36 6 5 7 8 8 36 6 5 7 9 5 36 6 5 8 0 2 36 6 5 8 0 9 36 6 5 8 1 6 36 6 5 8 2 3 36 6 5 7 8 1 36 6 5 7 8 8 36 6 5 7 9 5 36 6 5 8 0 2 36 6 5 8 0 9 36 6 5 8 1 6 36 6 5 8 2 3 468778 468785 468792 468799 468806 468813 468820 468827 468834 468841 468778 468785 468792 468799 468806 468813 468820 468827 468834 468841 33° 7' 50'' N 11 7 ° 2 0 ' 5 ' ' W 33° 7' 50'' N 11 7 ° 2 0 ' 2 ' ' W 33° 7' 49'' N 11 7 ° 2 0 ' 5 ' ' W 33° 7' 49'' N 11 7 ° 2 0 ' 2 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 10 20 40 60Feet 0 4 8 16 24Meters Map Scale: 1:303 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. USDA = MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: San Diego County Area, California Survey Area Data: Version 20, Aug 30, 2024 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 14, 2022—Mar 17, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/5/2025 Page 2 of 4USDA = □ D D D D D D D D ,,..,,,. ,,..,,,. □ ■ ■ □ □ ,,..._., t-+-t ~ tllWI ,..,,. ~ • Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI MlC Marina loamy coarse sand, 2 to 9 percent slopes B 0.2 100.0% Totals for Area of Interest 0.2 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/5/2025 Page 3 of 4USDA = Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/5/2025 Page 4 of 4~ IL__·-----_--_I .L 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 ~ 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 W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W G G G G G G G G G G G G G G G G G G G G G G G G G G W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W E E E E E E E E E E E E E E E E E E E E E E E E E W W W W W W W W W W W W W W W W W W W W W W W W W S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S C S S C C X X X X X X X X X X X XXXXXXXXXX X X X 53. 9 5 R I M 52. 7 3 R I M 46. 5 3 F L 53. 5 9 53. 9 2 53. 2 2 53. 4 4 53. 7 7 53. 6 0 53. 8 6 52. 8 9 53. 3 4 44. 4 9 46. 3 0 44. 7 2 49. 4 9 49. 9 2 53. 4 0 53. 3 3 55 55 55 55 55 55 55 55 50 50 50 50 50 50 50 50 5 0 45 45 45 45 45 45 45 45 CARLSBAD BLVD LOT 34 MAP 2696 LOT 32 MAP 2696 LOT 27 MAP 2696 LOT 29 MAP 2696LOT 28 MAP 2696 LOT 33 MAP 2696 NODE 101 (52.7 FS) NODE 100 (44.0 FS) Q100 = 0.29 CFS L = 1 1 0 ' BASIN EX-1 AREA = 7,518 SF (0.173 AC) R/W R/W R/W EXISTING 30" RCP STORM DRAIN PER DWG 270-2 299 LF ; S = 0.5% EX. SD MH 52.57 RIM 37.07 FL EX. SD MH 54.33 RIM 38.53 FL GRAPHIC SCALE: 1" = 10' 0 10'20'30' J:\ACTIVE JOBS\4169 KMJ CARLSBAD BLVD\CIVIL\REPORTS\HYDROLOGY\DISCRETIONARY\Appendix PRE-DEVELOPMENT HYDROLOGY NODE MAP 5211 CARLBAD BOULEVARD CITY OF CARLSBAD SCALE : 1"=10' AREA CALCULATIONS - BASIN EX-1 (TOTAL) TOTAL BASIN AREA: 7,518 SF / 0.173 AC BASIN IMPERVIOUS AREA: 0 SF / 0.000 AC BASIN PERVIOUS AREA: 7,518 SF / 0.173 AC IMPERVIOUS %0.0% Cn 0.25 Tc:5.0 MINS I:6.59 IN/HR Q100:0.29 CFS LEGEND EXISTING PROPERTY BOUNDARY ADJACENT PROPERTY LINE / RIGHT-OF-WAY CENTERLINE OF ROAD ADJACENT LOT LINE EXISTING CONTOUR LINE EXISTING FLOW LINE EXISTING DIRECTION OF FLOW EXISTING DRAINAGE BASIN BOUNDARY EXISTING NODE BASIN BOUNDARY PLAN VIEW - EXISTING HYDROLOGY NODE MAP SCALE: 1" = 10' ___ __,, ' --------- ' ' -- ~- / ---- --✓ ................ _-- ..._ ..._ ' ........................ I --- -------- ...... ....... ....... ------... ........ ....... ___ ....... -- -------::::::::::::::= ---- ............... ----, ✓ ' ------=::..,:- ----- ' ' ' I I I \ -- ( \ \ / \ ~---✓ ..._ ..._ 7 17 f~- 17 1,/. I 'J ~ -le-- 17 I> . I I> -~ I I I I I I I I 17 I> I I \ '-r I J I I ____ ,/ I I ' I ---................ ______ _ ----------------- ----....... -' ...._ I ...._ ' ...._ '- .......... ,,_; ---..._ ...._ ...._ ...._ . ..._ ..._ ..._ ..._ ------...... ...._ ...._ ...._ ' I ' ------------~ --' ', ' ...._ -...__ _____ _ ------..._ ----- '-s::-:--- ' ..._ ...._ ' ...._ ' ..._ ' ..._ ,,,,,,............ ---------.... --....... ___ ,,.,, ---........ ...._ '- ...._ ' 1 ' \ \ I '-'\ \ \ I I I \ I I \ \ -- ---------r \ ..._ ..._ ------ \ \ -------- I> r-- 1. ~ •. I '7 . I • l 17 I I I I -✓ ✓ 17 I> " I> \ \ ' ' \ ' '-...._ ' ....._ ____ _ ' '- ...._ ..._ ---, ' ----........ \ \ \ \ '...._' ------- I I , I ....... _ r- • I',,: ii -I ., = ' -- ---------- -------- 17 -- ...... ___ _ -------- ---------------------- ' -- 64 - PASCO LARET SUITER I #l,SiS\ [))CC I ffe{lr IESi San Diego I Encinitas I Or~nge. County Phone 858.259.8212 I www.plsaengmeermg.com C C X X X X X X X X X X X XXXXXXXXXX X X 52. 7 3 R I M 46. 5 3 F L 53. 5 9 53. 9 2 53. 2 2 53. 4 4 53. 7 7 53. 6 0 53. 8 6 52. 8 9 53. 3 4 44. 4 9 46. 3 0 44. 7 2 49. 4 9 49. 9 2 53. 4 0 53. 3 3 55 55 55 55 55 55 55 50 50 50 50 50 50 50 5 0 45 45 45 45 45 45 45 45 SDSD SD SD SD SD SD SD W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W G G G G G G G G G G G G G G G G G G G G G G G W W W W W W W W W W W W W W W W W W W W W W W JT JT JT JT G G G G G G G G G W W W W E E E E E E E E E E E E E E E E E E E E E E EEEE E E E E SD W W W W W W W W W W W W W W W W W W W W W W W S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S SD SD SD SD SD SD SD SD SD SD SD SD SD SD C X X X X SD SD SD SD SD SD X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X CARLSBAD BLVD LOT 34 MAP 2696 LOT 32 MAP 2696 LOT 27 MAP 2696 LOT 29 MAP 2696LOT 28 MAP 2696 BASIN PR-1 AREA = 7,518 SF (0.173 AC) 47.2 TG 46.2 IE IN (W) 44.5 IE IN (S) 43.8 IE IN (N) 43.6 IE OUT (E) Q100 (UNMIT) = 0.73 Q100 (MIT) = 0.29 3" ORIFICE GRAVEL DETENTION SYSTEM A = 273 SF R/W R/W R/W (37.75) IE@MAIN 38.25 IE@LAT Q100 (UNMIT) = 0.73 Q100 (MIT) = 0.29 EXISTING 30" RCP STORM DRAIN PER DWG 270-2 299 LF ; S = 0.5% EX. SD MH 52.57 RIM 37.07 FL EX. SD MH 54.33 RIM 38.53 FL PROP. PVT. 18" RCP STORM DRAIN GRAPHIC SCALE: 1" = 10' 0 10'20'30' J:\ACTIVE JOBS\4169 KMJ CARLSBAD BLVD\CIVIL\REPORTS\HYDROLOGY\FINAL ENGINEERING\Appendix POST-DEVELOPMENT HYDROLOGY NODE MAP 5211 CARLBAD BOULEVARD CITY OF CARLSBAD SCALE : 1"=10' PLAN VIEW - PROPOSED HYDROLOGY NODE MAP SCALE: 1" = 10' AREA CALCULATIONS - BASIN PR-1 TOTAL BASIN AREA: 7,518 SF / 0.173 AC BASIN IMPERVIOUS AREA: 4,698 SF / 0.108 AC BASIN PERVIOUS AREA: 2,820 SF / 0.065 AC IMPERVIOUS %62.5% Cn 0.656 Tc:5.0 MINS I:6.59 IN/HR Q100 UNMIT:0.73 CFS Q100 MIT:0.29 CFS LEGEND EXISTING PROPERTY BOUNDARY ADJACENT PROPERTY LINE / RIGHT-OF-WAY CENTERLINE OF ROAD ADJACENT LOT LINE EXISTING CONTOUR LINE PROPOSED FLOW LINE PROPOSED DIRECTION OF FLOW PROPOSED DRAINAGE BASIN BOUNDARY PROPOSED IMPERVIOUS AREA PROPOSED GRAVEL DETENTION SYSTEM PROPOSED PERVIOUS PAVERS -✓- -- ' - ,.... -~ ,.... ----- ............. ----------- -- / ._ __ _ - :~~(il~t~!t.i.~~:1~~~~~~.~: ----- ---:11:>"' I I l I I ) ' J bl> \ , , I . ,,,✓'I'/ --b,-'>-, :) -I ----------- ----....... --- --------"'C-:...__. ___ .............................. ---------- ------' ------' ...__ ____ _ ---....... ___ _ --------------------- \ - I I J --/ \ -------- ------- --= ' --------~ ...._ ....... .,..,., ----------IL___ ----,. ---=t" -· ~~'?---------" -------- b -- ------ " ~ \ ---·---> • \ --- .. • \ ............. ____ , I \______ ------------ -- --- -------------------------- I ------------- , I b '-7, r- I ''I, ii SI ' -- 64 - vzzzzzzvz,a ~ ~ PREPARED BY: LARET s u ITER PASCO I #\,SiS\[)J(Ciffe:irlESi • Encinitas I Orange County San Diego I 8212 I www.plsaengineering.com Phone 858.259. Hydraflow Storm Sewers Extension for Autodesk® Civil 3D® Plan Project File: 4169-Hydraflow.stm Number of lines: 5 Date: 6/18/2025 Storm Sewers v2023.00 Storm Sewer Tabulation Page 1 Station Len Drng Area Rnoff Area x C Tc Rain Total Cap ~el Pipe Invert Elev HGL Elev Grnd / Rim Elev Line ID eoeff (I) flow full Line To Iner Total Iner Total Inlet Syst Size Slope Dn Up Dn Up Dn Up Line (ft) (ac) (ac) (C) (min) (min) (in/hr) (efs) (efs) (ft/s) (in) (%) (ft) (ft) (ft) (ft) (ft) (ft) 1 End 138.949 0.00 0.00 0.00 0.00 0.00 0.0 1.1 0.0 19.03 28.69 6.25 30 0.49 37.07 37.75 38.55 39.25 52.57 53.33 TIE IN 2 1 68.917 0.00 0.00 0.00 0.00 0.00 0.0 0.3 0.0 0.73 25.14 1.55 18 5.73 38.25 42.20 39.85 42.52 53.33 50.20 24X24 BOX 3 2 23.955 0.00 0.00 0.00 0.00 0.00 0.0 0.2 0.0 0.73 0.73 4.17 6 1.71 42.40 42.81 42.81 43.24 50.20 49.90 CLEANOUT 4 3 52.795 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.73 0.69 3.93 6 1.50 42.81 43.60 43.26 44.05 49.90 47.20 12X12 BOX 5 1 159.747 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 18.30 28.66 4.95 30 0.49 37.75 38.53 39.85 40.08 53.33 54.33 EX MH 1 Project File: New.stm Number of lines: 5 Run Date: 8/14/2025 NOTES:lntensity = 18.28 / (Inlet time+ 0.10) A 0.64; Return period =Yrs. 100 ; c = cir e = ellip b = box Storm Sewers v2023.00 PA S C O , L A R E T , S U I T E R & A S S O C I A T E S 19 1 1 S A N D I E G O A V E N U E , S A N D I E G O C A 9 2 1 1 0 PH : ( 8 5 8 ) 2 5 9 - 8 2 1 2 F A X : ( 8 5 8 ) 2 5 9 - 4 8 1 2 PLSA 4169 "AS BUILT" DATE INSPECTOR DATE REVIEWED BY: 2 GRAPHIC SCALE: 1" = 10' 0 10'20'30' J:\ACTIVE JOBS\4169 KMJ CARLSBAD BLVD\CIVIL\DRAWING\IMPROVEMENT PLANS\4169-CV-IP-01-PLAN AND PROFILE.DWG PLAN VIEW - PUBLIC IMPROVEMENTS SCALE: 1" = 10' PROFILE VIEW - CL CARLSBAD BLVD SCALE: 1" = 10' HORIZONTAL; 1" = 4' VERTICAL 36 CL 40 CL 44 CL 48 CL 52 CL 36 CL 40 CL 44 CL 48 CL 52 CL 11+00 11+50 12+00 UTILITIES ARE KNOWN TO EXIST IN THE AREA. INFORMATION SHOWN HEREON IS PER BEST AVAILABLE RECORD INFORMATION. EXACT HORIZONTAL AND VERTICAL LOCATION OF EXISTING UTILITIES UNKNOWN. CONTRACTOR TO FIELD VERIFY LOCATION OF EXISTING UTILITIES PRIOR TO ORDERING MATERIALS AND CONSTRUCTION. CONTRACTOR SHALL NOTIFY ENGINEER OF WORK OF ANY DISCREPANCIES BETWEEN ACTUAL LOCATION AND PLAN LOCATION OF UTILITIES UPON DISCOVERY OF DISCREPANCY ALL EXISTING MONUMENTS TO BE PROTECTED IN PLACE. ANY MONUMENTS DESTROYED DURING CONSTRUCTION SHALL BE REPLACED BY A LICENSED LAND SURVEYOR AND PROPER DOCUMENTATION SHALL BE FILED WITH THE COUNTY RECORDER. ADDITIONAL NOTES 1. ALL UTILITIES SHOWN HEREON PER BEST AVAILABLE RECORD INFORMATION. 2. ONSITE IMPROVEMENTS SHOWN HEREON FOR REFERENCE ONLY; REFER TO SEPARATE PRECISE GRADING PLAN DWG 551-9A FOR CONSTRUCTION 3. DRY UTILITIES BY SEPARATE PERMIT. SHOWN FOR REFERENCE ONLY. 4. PROPOSED SEWER LATERAL TO INCLUDE BACKWATER VALVE PER CITY OF CARLSBAD ENGINEER STANDARDS VOLUME 1 CHAPTER 6.3. 2 CONSTRUCTION NOTES EXISTING 4" WATER MAIN (ABANDONED) TO BE REMOVED ALONG PROJECT FRONTAGE AND CUT AND CAPPED AT EACH END. DISPOSE OF IN ACCORDANCE WITH SPECIFICATION 15000-3.12 OF THE CITY OF CARLSBAD ENGINEERING STANDARDS VOLUME 3. PROPOSED 2" DOMESTIC WATER SERVICE, 1.5" METER AND 1.5" BACKFLOW PER CMWD STANDARD W-4, W-6; TO BE CONSTRUCTED BY CONTRACTOR PROPOSED PRIVATE 18" RCP STORM DRAIN PIPE; SEE PROFILE VIEW THIS SHEET PROPOSED TRENCH RESURFACING OF AC PAVEMENT PER CITY OF CARLSBAD STANDARD GS-25, GS-28 LIMITS OF SAWCUT OF EXISTING AC PAVEMENT; SEE DETAIL THIS SHEET PROPOSED AC PAVEMENT (6" AC / 12" AB) PROPOSED 3" AC GRIND AND OVERLAY CONCRETE LUG CONNECTION PER SDRSD D-63 PORTIONS OF EXISTING RETAINING WALL ENCROACHING SUBJECT PROPERTY TO BE REMOVED PROPOSED CLEANOUT WITH 12" CAST IRON LID PER CITY OF CARLSBAD STANDARD S-7 PROPOSED 24"X24" BROOKS BOX SOLID PLATE COVER OR APPROVED EQUAL PER PRECISE GRADING PLAN DWG 551-9A PROPOSED 6" THICK PCC DRIVEWAY NOT TO SCALE TYPICAL DETAIL - AC PAVEMENT SAWCUT TYPICAL SECTION - CARLSBAD BLVD NOT TO SCALE 10+50 56 CL 56 CL 36 40 44 48 52 56 36 40 44 48 52 56 PROFILE VIEW - PRIVATE 18" SD LATERAL @ STA 10+97.12 SCALE: 1" = 10' HORIZONTAL; 1" = 4' VERTICAL SD PIPE DATA TABLE PIPE # SIZE MATERIAL UPSTREAM IE DOWNSTREAM IE LENGTH (FT) PIPE SLOPE 18"RCP 42.2 38.25 68 6.5%2 1+00 1+50 C C X X X X 55 55 55 55 55 55 55 55 50 50 50 50 50 50 50 50 W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W G G G G G G G G G G G G G G G G G G G G G G G G G G W W W W W W W W W W W W W W W W W W W W W W W W W W W JT JT JT G G G G G G G G G W W W E E E E E E E E E E E E E E E E E E E E E E E E E EEEE E E E E W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S WM SD SD SD SD SD SD SD C SD X X X X X ROW ROW ROW 49 51 52 53 53 52 51 50 9 EX. SEWER MH 53.95 RIM 43.55 FL EX. SD MH 52.57 RIM 37.07 FL EX. SD MH 54.33 RIM 38.53 FL EX. SEWER MH 52.73 RIM 46.53 FL 50 . 0 ' 10 0 . 0 ' R O W CARLSBAD BLVD (50.0 TW) (49.0 BW)50.5 FS50.3 FS (50.0 FS) (51.8 FS) EXISTING RETAINING WALL TO REMAIN EXISTING TRANSFORMER TO REMAIN EXISTING AT&T PEDESTAL TO REMAIN (52.7 FS) (51.7 BW) (52.7 FS) 52.3 FS 52.3 FS 2 1 4 6 5 7 52.4 FS ST A 1 1 + 3 2 . 9 2 ~ 2 8 . 0 0 ' R T 53 . 2 F S ST A 1 1 + 1 7 . 9 2 ~ 2 8 . 0 0 ' R T 53 . 2 F S 52.4 FS EXISTING SIGN TO BE RELOCATED EXISTING CHARTER PEDESTAL TO REMAIN (53.2 FS) WATER SERVICE TO CORE THROUGH SLURRY ENCASEMENT EXISTING 6" VCP SEWER MAIN PER DWG 141-5 EXISTING 30" RCP STORM DRAIN PER DWG 270-2 299 LF ; S = 0.5% CMWD 12" PVC WATER MAIN PER DWG 540-1 EXISTING 6" VCP SEWER MAIN PER DWG 141-5 342 LF; S = 0.8% EXISTING 6" ACP WATER MAIN PER DWG 18-AD EXISTING SDG&E CONDUIT BANK WITH SLURRY ENCASEMENT (53.3 FS) ST A 1 0 + 7 5 . 0 1 ~ 1 6 . 0 0 ' R T (5 2 . 9 F S ) (52.8 FS) 16 . 0 ' 28 . 0 ' 12 . 0 ' 53.2 FS53.1 FS 53.0 FS 53.0 FS (52.9 FS) EXISTING 4" CI WATER MAIN (ABANDONED) EXISTING 4" HP GAS PER DWG 270-2 EXISTING FIRE HYDRANT 50 . 0 ' 8. 0 % 8. 0 % 0. 5 % 1. 7 % 15 . 0 % 15 . 0 % (2 . 5 % ) (2 . 9 % ) (2 . 8 % ) (2 . 6 % ) (0 . 4 % ) (0 . 9 % ) 0.8%0.5% 1. 3 % 0. 8 % 0.7%0.5% ST A 1 1 + 3 9 . 4 2 ~ 4 . 9 2 ' L T CO N N E C T T O 1 2 " P V C W A T E R M A I N AS B U I L T P R O V I D E D U P O N PR O J E C T C O M P L E T I O N ST A 1 1 + 1 2 . 5 0 ~ 1 3 . 0 0 ' R T AP P R O X . L O C A T I O N O F E X . 4 " S E W E R L A T PE R D W G 1 4 1 - 5 T O R E M A I N (4 2 . 8 ) I E @ M A I N ; ( 4 3 . 0 ) I E @ L A T STA 11+14.50 ~39.00 LT CONNECT TO EXIST. GAS MAIN PER SEPARATE SDG&E WORK ORDER EXISTING SDG&E CONDUIT BANK WITH SLURRY ENCASEMENT EXISTING GRAVEL SHOULDER EXISTING AC PAVEMENT EDGE 11+00 12+00 ST A 1 0 + 9 2 . 0 7 ~ 2 8 . 0 0 ' R T 53 . 1 F S ST A 1 1 + 0 7 . 0 7 ~ 2 8 . 0 0 ' R T 53 . 1 F S ST A 1 1 + 5 1 . 7 5 ~ 1 6 . 0 0 ' R T (5 3 . 4 F S ) EX. SEWER MH 51.83 RIM 40.93 FL STA 10+97.12 ~15.00 LT = STA 1+00.00 18" SD LATERAL TIE INTO EX. 30" RCP SD PER DWG 270-2 (37.75) IE@MAIN 38.25 IE@LAT Q100 (UNMIT) = 0.56 CFS Q100 (MIT) = 0.23 CFS EXISTING 6" ACP WATER MAIN PER DWG 18-AD ST A 1 0 + 9 0 . 0 0 ~ 2 0 . 0 0 ' R T AP P R O X . L O C A T I O N O F E X . WA T E R L A T E R A L P E R D W G 1 8 - A D TO B E R E M O V E D B Y C O N T R A C T O R 4 4 (51.6 BW) STA 10+97.12 ~52.92 RT = STA 1+67.92 18" SD LATERAL 50.2 TG 42.4 IE IN (N) 42.2 IE OUT (E) 11 (50.0 FS) (50.3 FS) (49.0 TW) (49.0 BW) GB GB 3 8 (SEE DWG 551-9A FOR ONSITE IMPROVEMENTS) N30°04'01"W 75.00' LOT 34 MAP 2696 LOT 32 MAP 2696 ST A 1 0 + 9 9 . 5 7 ~ 2 8 . 0 0 ' R T 15 ' D W Y C L ST A 1 1 + 2 5 . 4 2 ~ 2 8 . 0 0 ' R T 15 ' D W Y C L 50.6 FS50.6 FS50.5 FS 50.6 RIM (43.8 IE)10 1 CL 0+ 0 0 1+ 0 0 1+ 5 0 20.2'20.2' 1212 CUT AND CAP CUT AND CAP 2 GU T T E R L I N E SA W C U T L I N E 3.0' MIN 2.0' MIN STRUCTURAL SECTION 6" AC OVER 12" CLASS II AB OVER NATIVE SUBGRADE COMPACTED TO 95% REL. COMP. COLD PLAN AND OVERLAY (3" MIN. DEPTH) TO PROVIDE SMOOTH TRANSITION EXISTING AC PAVEMENT CL (2-3%)(2-3%) 9.8' EX. TRAVEL LANE 8.0' EX. BIKE LANE 12.0' PROP. AC PAVEMENT 12.5' EX. CENTER TURN LANE 9.8' EX. TRAVEL LANE 9.0' EX. BIKE LANE 20.4' 22.0' PROP. PCC DRIVEWAY 50.0'50.0' 8%(2-4%) ROW 2-3% 15% PL EX. 6" VCP SEWER MAIN PER DWG 141-5 EX. 6" ACP WATER MAIN PER DWG 18-AD EX. 30" RCP STORM DRAIN PER DWG 270-2 EX. 6" VCP SEWER MAIN PER DWG 270-2 EX. 6" ACP WATER MAIN PER DWG 18-AD EX. 4" HP GAS MAIN PER DWG 270-2 SAWCUT AND GRIND & OVERLAY PER DETAIL THIS SHEET CMWD 12" PVC WATER MAIN PER DWG 540-1 *PAVEMENT SECTION TO BE VERIFIED BY PROJECT GEOTECHNICAL ENGINEER BASED ON FIELD TESTED R-VALUE 6" THICK PCC DRIVEWAY SUBGRADE TO BE COMPACTED TO AT LEAST 95% RELATIVE COMPACTION PER GEOTECH REPORT (5 3 . 2 7 F S ) ST A 1 0 + 5 0 . 0 0 (5 3 . 5 0 F S ) ST A 1 1 + 0 0 . 0 0 (5 3 . 8 1 F S ) ST A 1 1 + 5 0 . 0 0 (5 4 . 1 5 F S ) ST A 1 2 + 0 0 . 0 0 (0.5%) EX. 6" VCP SEWER MAIN PER DWG 141-5 342 LF; S = 0.8% (0.6%)(0.7%) EX. 6" VCP SEWER MAIN PER DWG 141-5 315 LF; S = 0.7% APPROX. EX. 6" ACP WATER MAIN PER DWG 18-AD APPROX. EX. 6" ACP WATER MAIN PER DWG 18-AD EX. 30" RCP STORM DRAIN PER DWG 270-2 299 LF; S = 0.5% APPROX. EX. 4" HP GAS MAIN PER DWG 270-2 APPROX. CMWD 12" PVC WATER MAIN PER DWG 540-1 EG @ CL ST A = 1 0 + 9 7 . 1 2 CO N C R E T E L U G C O N N E C T I O N PE R S D R S D D - 6 3 (3 7 . 7 5 I E ) @ M A I N 38 . 2 5 I E @ L A T ST A = 1 1 + 3 9 . 4 2 PR O P O S E D 2 " D O M E S T I C WA T E R S E R V I C E EXISTING GRADE PROP. SAWCUT LINE PL PROP. FINISHED GRADE ST A 1 0 + 9 7 . 1 2 ~ 1 5 . 0 0 L T = ST A 1 + 0 0 . 0 0 1 8 " S D L A T E R A L EX . 3 0 " R C P S T O R M D R A I N PE R D W G 2 7 0 - 2 ST A 1 0 + 9 7 . 1 2 ~ 5 2 . 9 2 R T = S T A 1 + 6 7 . 9 2 1 8 " S D L A T E R A L PR O P . 2 4 " X 2 4 " B R O O K S B O X 50 . 2 T G PR O P . 1 8 " S D 42 . 2 I E O U T PR O P . 6 " S D 42 . 4 I E I N PROP. 18" RCP SD PIPE 68 LF S = 0.065 Q100 IN (UNMIT) = 0.56 CFS V100 IN (UNMIT) = 1.41 FT/S PROP. 18" SD CONCRETE LUG CONNECTION 38.25 IE IN EX. 30" SD (37.75 IE) CMWD 12" PVC WATER MAIN PER DWG 540-1 EX. 6" ACP WATER MAIN PER DWG 18-AD EX. 6" VCP SEWER MAIN PER DWG 141-5 (~42.3 IE) 1. 0 ' M I N C L E A R A N C E CL CA R L S B A D B L V D . HGL 42.48 HGL CENTERLINE DATA TABLE LINE # / CURVE # 1 LENGTH 2049.88 BEARING/DELTA N30°04'01"W RADIUS +-+---+-+--1------+----+---+--+--+--+--+--+----14 r ___ __, -------------------------------------------...... ...... __________ _ ....... _______ ....... ✓-------~~----~ ---,,,,,,.. --- _J _,,-------------- --" -- " -.., ( \ \ / ---- ---+------,- ---1-------11----1 ---+------11----1 I I ------------,_ ------------------ -------..... --------------..,,-- V -__ [ t pl_ -----,--··- • --------------------- ------- ---- -~ -------PLSA I■~ PLSAENGINEERING.COM -'---" I ...-/ -I -------- - ------------------ ------------ ...... ------ ....._ ______ _ ------====--------=------d_ ---------- ------, --b -~ ~====----,-........._f ------i------- ? I ---- I I ) ----------...-...- r --------- ---------- --------' ? t (1 t .m. DAlE INITIAL ENGINEER OF WORK t i+ P------rr I t t t ' ' l l_ ---, -------r _______ ' t t t DATE INITIAL REVISION DESCRIPTION OlHER APPROVAL (D ® ® ® ® ® I +----+----+-----------,1 0 0 '?"Of ESS / OJII !SJ~ ~\'IDRtJji,t.;'-1( '<' 1,_~ !:?~ 'to~ Cl) Qj ""' ---z '-' No. 86542 ,.,, u.J Exp. 03/31 /27 ,.,, P.E. EXP. "' ;:t, * * J'~Ji CIV\\. ,s.;*'t- t OF Ci>.1.\' I SHEET I CITY OF CARLSBAD I SHEETS I ENGINEERING DEPARlMENT IMPROVEMENT PLANS FOR: CARLSBAD BOULEVARD HOMES CARLSBAD BOULEVARD MP2025-0009 IMPROVEMENTS APPROVED: TIMOTHY 0. CARROLL PRINCIPAL ENGINEER RCE55381 EXPIRES 12/;,1 /26 DATE DATE INITIAL CHKD BY: PROJECT NO. DRAWING NO. CllY APPROVAL RVWD BY: MS2024-0006 551-9 J:\ACTIVE JOBS\4169 KMJ CARLSBAD BLVD\CIVIL\STUDIES\Offsite Drainage . BASIN 1 EA= 0.32AC 0.45 OFFS/TE BASIN EXHIBIT CARLSBAD BOULEVARD HOMES CARLSBAD, CA PLSA JOB NUMBER: 4169 DATE: 03/13/2025 . - ~ 1111!!1111!!!!! ~ . -'·- - ., 49+00 50+00 --See sheet 14 .Por P r ot'i le. ' Ci:: 8 Type A-/ Cu r b Inle t "9 Sta 4 8 • 5 3 . -- - ---' -·- 51+00 ~: ~-* - 52+00 a - 53+00 V--Gas . -. ··- . -. - -. -.. - . - . - --I ·s - ~ ---t 54+00 55+00 56+00 PROFILE : CARLSBAD BOULEVARD SCALE : I " = 40' HORZ I" = 4 ' VERT See S1,,eet 14 .Por Pro.Pi le i 10' T~pe B-1 Curb In le t" 8 S+a.54 +54 - 57+00 't'* .. .-,,...i; ** 4* ** ** ~* *# ** -----,--- -. . - -... ~.., tu c · '" .. ce. t I -0 58+00 59+00 STORM DRAIN DATA NO. DELTA OR BRG. RADIUS LENGTH REMARKS [I] N. -57" zq '57"W 71.29' 3c;" RCP III Ll •. 29" IO' 28" qo• 45.83 30" R CP rn s. 24°48'44' £ ;;g,43 30" RC P I±] S 24 °48'44"£ J<:;1.7 3 30" RC P 157 5 24° 38'32" E 271..82 30' RC P ~ S 20°3/'54"£ 299.32' 30" R C P [Z] 522°1':l°2 3"E 14/i,. 72' 3.0" R C P Im N. roo· 3 q'oq" E Bto.03' 1'8" RCP [2] N &.7°39'41' E 72.75' • 18'' RCP . *" LEIJGTH .:5#011/,</ /.:5 FR"7N € .:5TRL/C!TVRE 1lJ € .:5TRVC'TVRE. ···.~ le . / PROP0.5ED CURB \ CR/W 3" Electric Conduit---....__ G/JTTC:R '{ ~i!?E:W.tll/< -.__, -----;:-' A -" ----------,,-' I I ' '---==-----------""""' ~~~~;.;:;~ /;(/.3/0E FAC'E "7F \ -------------- -, - -" I , ... I ,:;;;;;;;;;;;;;;;;;;;;;;;;;;:::::=:==---I---- ( L.----"" ' ' I I ) C) C) =-===--==-1 + Cl\ ,0 .---(3 _____ __,_ II) ' 1 JOw \ I ----------------...._ --.. - ----::.--- , -\....,./ \ _,,,,, -...,_ -\ ....________ I ___,,. L w -~., --,; --' ,......._ -------------= -----.: -/ ' '1'.:<! "' -..-I. \ 'hl,tp.,,.--A C 0 . !I 14 / Pfli:tJP066D CUl'UJ , QUTrt:R 7 / \ F?/W ·---=-- 1'-s._ ,,p a.c..,;ro~M Sta. 51+81,29' Rt. STD€WALI<. I '\.;'7, , STA. ""~05ef &ti~r/\Jff;;.:::----, • 1 'i?q '"l:r (i:;T!:jpeAC.O.#15 Sta, 50+19.3, 29' Rt ' ' i Mod ified Ty pe B Cu r b Inlet "IO, Sta 48•o,O x ( 5ee De ta; I on t1 Storm D rain l Profile and Details '' ,sheet fa) I ~ 1 _,_,,____,'s-,--x i -=::: I l X I Tvoe A Headw a ll St a . 4 8 •OO Note: Profile of Stor m Drain Laterals Shown on 11 S1brm Drain Profile and Deiail&11 sheet 14 . 5 I If I ca e : I = 40 ([ 20" Fue I L ine ~ 9G " Tuv,nel . Contractor to vec,·.P3 fop of' tunne l elevotloV1 prior t o storm droin cons+ructioVJ. i Tvoe. A C.O. "13 Sta 54 •54 , 2/b' Rt . RCE 39413 EXP. 12-31-19 '· 9-t1 ·M DATE NOTE : 4'. Tvne A C.O.11 12 Sta. 57•54, 27 'Rt. , FROM STA , 49+05.87 TO STA .64'"88 i OF STORM DRAIN WAS SHIFTED WEST TO • 51 FROM FACE OF CURB. DUE TO CONFLICT . W/ GAS LINE 3-1-• LT Asav11--r DFVIWJNbS fsii¥r'1 CITY OF CARLSBAD 1--1-+---------------,,-+----I ~ ENGINEERING DE PAR Tlli ENT 1--t-t---------=~ ,___.L .-<><, ,, t--+-+--------:,""", __ :---.'1:,_.,-:-..,. ,-.,,...,.""' ... ,+----1 CARLSBAD BOU LEVARD IMPROVEMENTS ' .. ,. .. 1--+--+--..-l.' - DATE BY DESCRIPTION APP'D REVISIONS STORM DRAIN PLAN 8 PROFILE STA 46+50, TO STA 59+00 RE . ,Z.~ CITY ENG INEER OWN.BY, ___ , CHKO. BY, ___ I FIELD BK , PRO JECT NO. 3 2 05 DATE DRAWING NO. 270-2 J.N.270 • " i "' 0 6 i I I ! r ; i ~ t • I 11 < • ,., ll C ~ ~ ~ I I • I Cl f]. :E z G) z C s: ID m JJ Cl I z G) z C s: ~ ·l • <F !/')c ct - 59+00 (J'I .... V " -C (/) -- ~,, '"~ El' 5 - -i"G 61 +00 STORM DRAIN DATA NO. DEL TA OR BRG. RADIUS LENGTH REMARKS [I] 5 22• 19 ' 23" E .. 98.87' 30" RCP 245.58' 30" RCP 1;31 5 35•15' 13" E 132.18' 3d' RCP 72. 75 ,-18'f<.C.P~ FUTURE 31-151 ,, " 11 ~ - ~ - 61+00 62+00 63+00 64+00 ' ( 8 Type B-1 Cu rb Inlet "7 st,, 04+ BB Ck Tupe A CO.# Ila Sto.59+98.3G, 2G.39 'L t . Proposed Curb, Gutter 4 Sidewalk I!;; TtJpe A C.O. "'II Sto.G2+43.57, 24.IG'R+. NOTE : FROM STA . 49+ 05. 87 TO STA . 64+ 8 8 Ct_ OF STORM DRAIN WAS SHIFTED WEST TO 5' FROM FACE OF CURB, DUE TO CONFLICT WITH EX. GAS LINE -'--------=:...._=--________ __J. Nole: Length shown ,e from (j; structure to £le sfruclure. Note: Profile of Storm Draon Lateral$ Shown on 11 Storrn Oro.in Profi le and Deto.il!::>11 sheet 14 ~ S 35°·15'!3"E 2.32.47' 30" RCP 1---=='--.j.._C=--=-.::.....c.::.....c-=-.:::__/ ___ _j____,c='..2.'.__J___::=-__:__:~__J_ ~ 5 25°22'Z0'E 245.58' 30" RCP -- - - -, . :: =I L. l:E :!) i1 .... 65+00 66+00 67+00 68+00 69+00 70+00 71+00 PROFILE: CAR.LSBAD BOULEVARD See f'or SCALE : 1·" = 40° HORZ I"= 4' VERT ~ Tvpe A C.O. "10 b Sta w4+88 , zr,,· Rt. Sheet 14 Pro.Pile --8'' VG P Sewer if: T~pe A C,O."' 10" S+a.G7 ➔-%,oq, 3.5' Lt FUf{Jf(c 8"TYf'E ''!3-1"/NlET I- •' -See Sheet 14 -Po r Pro.Pi le r . . :; ' . ~ CITY OF CARLSBAD ~ 1----11---1---------------+---I ~ ENGINEERING OE PART II ENT ~ 3·7·90 LT AS BUILT DRAWING~ 1----11---1---------------+---I 1---+--+------------1----1 CARLSBAD BOULEVARD IMPROVEMENTS ~\\OfESSf~ , , o'-v"' "~ v.. .--~ -' -,, • STORM DRAIN PLAN S PROFILE " . ,, -., ~,·~' ' ~ -~ ' ' ~1 "''<\,; ' ' ., -::(lt-3/;J'I' -~-1--1--1--------------1---1 STA 59 +00 JO STA 71400 ·~ ~0-v1, z • 1------1---1---------------+---I ~-~JI/Iii . $, APP •• u -~ • .,._,/,,/ ,,/4,{__ 9-/,5-<Yf ---------------.--·-------~-,I~~ ~::~\()~1!,: ~-t:::t:t::::::::::::::::::::::::::~:::::1 ~R~E=·:::::!"~-l~f~f':!§:"'~c~1'::t~Y~~E~N~G:::1=:NE~E~R::::::-=:::::!DA~TE~=::::! ENGINEER OF WORK'. •. OWN .BY, ___ , PROJECT NO. DRAWING NO. /1 DATE BY DESCRIPTION APP'0 CHK0.BY, ___ , 3205 270-2 ,di ./ £(~ .L -1-14-&l FIELDBK, '-/11"'."LcitEiifu:;v'icE 39413 -EX1P. 12-31-ee DATE REVISIONS J.N.270 -- I I I I I I I I , I ----- 0 ~-i G) z C s: ID m :n ' ' 0 I z G) z C s: ID !B I 91455 -- - -- - --,- -- - al -· --- I ~ ~I ----- - V I- 71 +00 72+00 ,.,i 73+00 " m 74+00 75+00 76+00 NO. [JJ rn @] 7 m " 1/) en 6c€ '7f-!€cT /4. FOR PRORC6--- FUTURE. ':!'TYPt"B"f/VlET- STORM DRAIN DATA DEL TA OR BRG. RADIUS LENGTH REMARKS S 30°4!'5&" E II 3 . I I ' 30" R CP 5 30°41 '5~' E 2 94,0' 30" -R,CP S 3 0" 41 ' 5/o E 300.0' 30" RC P 5 30°41' 5/o" E 300.0' 3 0" RC P 5 30'4 I ' 5(o' E 730' 30" RC P N 59• /8° 0 4 " E 23.5 '. 18" R:.C.P ~ FUTURE: S30°41' 5~• E 119-89' 30" RC P N 59"l8'04'' E 31 .75 ' it'>" i'i(.C.P~ FUTURE: N \j 01 " 10 V CP Se we r 10" AC Water A V FUTUR.€ fO'TYPE"/3·1" INLET I I a:: 0 w g§ :I: (/) q; Tvo e A c.o "a Sta 7w +27 1 /5 'lt N o te : L e n9+n s h o w n is -t'rom ~ s tru c ture +o <J;: s truc ture. - - 77+00 78+00 PROFILE: CARLSBAD SCALE: I"= 40' HORZ 111 = 4 1 VERT " p G VC Sewe r ~ !lL -, -- -- 79+00 80+00 BOULEVARD " w AC Water - 81 +00 Ci; Type I>, C 0 . "7 Sta 79+27 , 15 ' Lt -- - - .. - 82+00 a: Type A C.O. '"0 -Sta82+27, /5'Lt R/W ,.,-. ... --- -- - • 83+00 " lo VC P 5ewer . w > a:: 0 :I: wl-·o:: ::::> ,. .,.,. ,. 0 0 •:J'i :., ,.,.. .. ',Jf4'--z :.,, Sea le : I' .. ' =-4~or' --,----------~!;:=-:?:::;::::• ::-~~~~~,-=~-~--:~:~·= ,,..,;_'"'(/)=_ -;-=·~·;·====;:-;::::::==:;, -• ,n .=...-,,. -· - ~ CITY OF CARLSBAD ~ .·, ' ' '• -·- M. L. CRE~ RCE 39413' EXP. 12-31-19 1-14-88 DATE 1---1--+---------------;----; Lfl__j ENGINEERING DE PAR TM ENT ~ 1---1--+---------------;----; 1---+--+------------t----=-i· CARLSBAD BOULEVARD IMPROVEMENTS DATE IIY DESCRIPTION APP0 D REVISIONS STORM DRAIN PLAN B PROF! LE STl'y 71 + 00 TO STA ·CITY ENGINEER DWN.BY,~--1 CHKO.BY,_·~-1 FIELD BK , PROJECT NO. 3205 83+00 DATE DRAWING NO. 270 ·2 J.N.270 ., I I. I - '( I I I I _:_._I Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Mar 13 2025 EX. PUBLIC 30-IN RCP SD MAIN Circular Diameter (ft)= 2.50 Invert Elev (ft) = 100.00 Slope (%)= 0.50 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 18.30 Highlighted Depth (ft)= 1.44 Q (cfs)= 18.30 Area (sqft)= 2.93 Velocity (ft/s)= 6.24 Wetted Perim (ft) = 4.31 Crit Depth, Yc (ft) = 1.45 Top Width (ft)= 2.47 EGL (ft)= 2.05 0 1 2 3 4 5 Elev (ft)Depth (ft)Section 99.50 -0.50 100.00 0.00 100.50 0.50 101.00 1.00 101.50 1.50 102.00 2.00 102.50 2.50 103.00 3.00 Reach (ft) ---~ ~ --" --- f_ -~= ~ --- - - X -)_ --I " ~ -~ -_--7 --- Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Aug 14 2025 EX. PUBLIC 30-IN RCP SD MAIN Circular Diameter (ft)= 2.50 Invert Elev (ft) = 100.00 Slope (%)= 0.50 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 18.59 Highlighted Depth (ft)= 1.46 Q (cfs)= 18.59 Area (sqft)= 2.98 Velocity (ft/s)= 6.24 Wetted Perim (ft) = 4.35 Crit Depth, Yc (ft) = 1.47 Top Width (ft)= 2.46 EGL (ft)= 2.07 0 1 2 3 4 5 Elev (ft)Depth (ft)Section 99.50 -0.50 100.00 0.00 100.50 0.50 101.00 1.00 101.50 1.50 102.00 2.00 102.50 2.50 103.00 3.00 Reach (ft) - -------~ ~ / "'i-.. -/-~- 17= " \. --=\ ~ ---- - ~ ~ '\.... -/-~ ' ~ ,, -------- Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Mar 13 2025 EX. PUBLIC 30-IN RCP SD MAIN Circular Diameter (ft)= 2.50 Invert Elev (ft) = 100.00 Slope (%)= 0.50 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 28.87 Highlighted Depth (ft)= 2.04 Q (cfs)= 28.87 Area (sqft)= 4.29 Velocity (ft/s)= 6.73 Wetted Perim (ft) = 5.64 Crit Depth, Yc (ft) = 1.84 Top Width (ft)= 1.94 EGL (ft)= 2.74 0 1 2 3 4 5 Elev (ft)Depth (ft)Section 99.50 -0.50 100.00 0.00 100.50 0.50 101.00 1.00 101.50 1.50 102.00 2.00 102.50 2.50 103.00 3.00 Reach (ft) ---~ ~ ' V --- f_ -~= - - - - X -)_ --I " ~ -~ -_--7 --- Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Aug 14 2025 EX. PUBLIC 30-IN RCP SD MAIN Circular Diameter (ft)= 2.50 Invert Elev (ft) = 100.00 Slope (%)= 0.50 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 29.16 Highlighted Depth (ft)= 2.06 Q (cfs)= 29.16 Area (sqft)= 4.33 Velocity (ft/s)= 6.73 Wetted Perim (ft) = 5.70 Crit Depth, Yc (ft) = 1.84 Top Width (ft)= 1.90 EGL (ft)= 2.76 0 1 2 3 4 5 Elev (ft)Depth (ft)Section 99.50 -0.50 100.00 0.00 100.50 0.50 101.00 1.00 101.50 1.50 102.00 2.00 102.50 2.50 103.00 3.00 Reach (ft) - -------~ ~ / "'i-.. --L-V ~- I -... 17= -" \. --=\ - - ~ ~ '\.... -/-~ ' ~ ,, -------- Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Mar 13 2025 EX. PUBLIC 30-IN RCP SD MAIN Circular Diameter (ft)= 2.50 Invert Elev (ft) = 100.00 Slope (%)= 0.79 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 34.08 Highlighted Depth (ft)= 1.92 Q (cfs)= 34.08 Area (sqft)= 4.05 Velocity (ft/s)= 8.41 Wetted Perim (ft) = 5.35 Crit Depth, Yc (ft) = 1.99 Top Width (ft)= 2.11 EGL (ft)= 3.02 0 1 2 3 4 5 Elev (ft)Depth (ft)Section 99.50 -0.50 100.00 0.00 100.50 0.50 101.00 1.00 101.50 1.50 102.00 2.00 102.50 2.50 103.00 3.00 Reach (ft) ---~ ~ --" ---~ I .., ... t --~= - - - - - X -)_ --I " ~ -~ -_--7 --- Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Aug 14 2025 EX. PUBLIC 30-IN RCP SD MAIN Circular Diameter (ft)= 2.50 Invert Elev (ft) = 100.00 Slope (%)= 0.79 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 34.37 Highlighted Depth (ft)= 1.93 Q (cfs)= 34.37 Area (sqft)= 4.08 Velocity (ft/s)= 8.43 Wetted Perim (ft) = 5.38 Crit Depth, Yc (ft) = 2.00 Top Width (ft)= 2.09 EGL (ft)= 3.04 0 1 2 3 4 5 Elev (ft)Depth (ft)Section 99.50 -0.50 100.00 0.00 100.50 0.50 101.00 1.00 101.50 1.50 102.00 2.00 102.50 2.50 103.00 3.00 Reach (ft) - -------~ ~ / "'i-.. -/--~- I ..., ' --\. ---=\ - - ~ ~ '--/-~ ' ~ ,, -------- Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Mar 13 2025 EX. PUBLIC 30-IN RCP SD MAIN Circular Diameter (ft)= 2.50 Invert Elev (ft) = 100.00 Slope (%)= 1.10 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 37.46 Highlighted Depth (ft)= 1.81 Q (cfs)= 37.46 Area (sqft)= 3.82 Velocity (ft/s)= 9.81 Wetted Perim (ft) = 5.10 Crit Depth, Yc (ft) = 2.07 Top Width (ft)= 2.23 EGL (ft)= 3.31 0 1 2 3 4 5 Elev (ft)Depth (ft)Section 99.50 -0.50 100.00 0.00 100.50 0.50 101.00 1.00 101.50 1.50 102.00 2.00 102.50 2.50 103.00 3.00 Reach (ft) ---~ ~ --" --- / -'V ~ - l - ~--- - - - - \ -J -- " ~ -~ -___;:::/ --- Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Aug 14 2025 EX. PUBLIC 30-IN RCP SD MAIN Circular Diameter (ft)= 2.50 Invert Elev (ft) = 100.00 Slope (%)= 1.10 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 37.75 Highlighted Depth (ft)= 1.82 Q (cfs)= 37.75 Area (sqft)= 3.83 Velocity (ft/s)= 9.86 Wetted Perim (ft) = 5.11 Crit Depth, Yc (ft) = 2.08 Top Width (ft)= 2.22 EGL (ft)= 3.33 0 1 2 3 4 5 Elev (ft)Depth (ft)Section 99.50 -0.50 100.00 0.00 100.50 0.50 101.00 1.00 101.50 1.50 102.00 2.00 102.50 2.50 103.00 3.00 Reach (ft) - -------~ ~ / "'i-.. -/-~- f-/ V " ' I ---=\ - - - ~ ~ '\.... -/-~ ' ~ ,, -------- Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Mar 13 2025 EX. PUBLIC 36-IN RCP SD MAIN Circular Diameter (ft)= 3.00 Invert Elev (ft) = 100.00 Slope (%)= 0.50 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 44.20 Highlighted Depth (ft)= 2.31 Q (cfs)= 44.20 Area (sqft)= 5.85 Velocity (ft/s)= 7.55 Wetted Perim (ft) = 6.44 Crit Depth, Yc (ft) = 2.17 Top Width (ft)= 2.52 EGL (ft)= 3.20 0 1 2 3 4 5 Elev (ft)Depth (ft)Section 99.00 -1.00 100.00 0.00 101.00 1.00 102.00 2.00 103.00 3.00 104.00 4.00 Reach (ft) -~ -------- ~--V -I ... /· -·\ --- ( ' \--' \ --/ \. ~ --------~ Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Aug 14 2025 EX. PUBLIC 36-IN RCP SD MAIN Circular Diameter (ft)= 3.00 Invert Elev (ft) = 100.00 Slope (%)= 0.50 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 44.49 Highlighted Depth (ft)= 2.32 Q (cfs)= 44.49 Area (sqft)= 5.87 Velocity (ft/s)= 7.58 Wetted Perim (ft) = 6.45 Crit Depth, Yc (ft) = 2.18 Top Width (ft)= 2.51 EGL (ft)= 3.21 0 1 2 3 4 5 Elev (ft)Depth (ft)Section 99.00 -1.00 100.00 0.00 101.00 1.00 102.00 2.00 103.00 3.00 104.00 4.00 Reach (ft) -~ ---........... ~ -V---, /· -·\ --- ( ' \ --' i --1-~ V -------- PLSA 4169 Page 13 of 13 APPENDIX B: 100-YEAR STORM EVENT DETENTION ANALYSIS RATIONAL METHOD HYDROGRAPH PROGRAM COPYRIGHT 1992, 2001 RICK ENGINEERING COMPANY RUN DATE 8/14/2025 HYDROGRAPH FILE NAME Text1 TIME OF CONCENTRATION 5 MIN. 6 HOUR RAINFALL 2.5 INCHES BASIN AREA 0.173 ACRES RUNOFF COEFFICIENT 0.656 PEAK DISCHARGE 0.73 CFS TIME (MIN) = 0 DISCHARGE (CFS) = 0 TIME (MIN) = 5 DISCHARGE (CFS) = 0 TIME (MIN) = 10 DISCHARGE (CFS) = 0 TIME (MIN) = 15 DISCHARGE (CFS) = 0 TIME (MIN) = 20 DISCHARGE (CFS) = 0 TIME (MIN) = 25 DISCHARGE (CFS) = 0 TIME (MIN) = 30 DISCHARGE (CFS) = 0 TIME (MIN) = 35 DISCHARGE (CFS) = 0 TIME (MIN) = 40 DISCHARGE (CFS) = 0 TIME (MIN) = 45 DISCHARGE (CFS) = 0 TIME (MIN) = 50 DISCHARGE (CFS) = 0 TIME (MIN) = 55 DISCHARGE (CFS) = 0 TIME (MIN) = 60 DISCHARGE (CFS) = 0 TIME (MIN) = 65 DISCHARGE (CFS) = 0 TIME (MIN) = 70 DISCHARGE (CFS) = 0 TIME (MIN) = 75 DISCHARGE (CFS) = 0 TIME (MIN) = 80 DISCHARGE (CFS) = 0 TIME (MIN) = 85 DISCHARGE (CFS) = 0 TIME (MIN) = 90 DISCHARGE (CFS) = 0 TIME (MIN) = 95 DISCHARGE (CFS) = 0 TIME (MIN) = 100 DISCHARGE (CFS) = 0 TIME (MIN) = 105 DISCHARGE (CFS) = 0 TIME (MIN) = 110 DISCHARGE (CFS) = 0 TIME (MIN) = 115 DISCHARGE (CFS) = 0 TIME (MIN) = 120 DISCHARGE (CFS) = 0 TIME (MIN) = 125 DISCHARGE (CFS) = 0 TIME (MIN) = 130 DISCHARGE (CFS) = 0 TIME (MIN) = 135 DISCHARGE (CFS) = 0 TIME (MIN) = 140 DISCHARGE (CFS) = 0 TIME (MIN) = 145 DISCHARGE (CFS) = 0 TIME (MIN) = 150 DISCHARGE (CFS) = 0 TIME (MIN) = 155 DISCHARGE (CFS) = 0 TIME (MIN) = 160 DISCHARGE (CFS) = 0 TIME (MIN) = 165 DISCHARGE (CFS) = 0 TIME (MIN) = 170 DISCHARGE (CFS) = 0 TIME (MIN) = 175 DISCHARGE (CFS) = 0 TIME (MIN) = 180 DISCHARGE (CFS) = 0 TIME (MIN) = 185 DISCHARGE (CFS) = 0 TIME (MIN) = 190 DISCHARGE (CFS) = 0 TIME (MIN) = 195 DISCHARGE (CFS) = 0 TIME (MIN) = 200 DISCHARGE (CFS) = 0 TIME (MIN) = 205 DISCHARGE (CFS) = 0.1 TIME (MIN) = 210 DISCHARGE (CFS) = 0.1 TIME (MIN) = 215 DISCHARGE (CFS) = 0.1 TIME (MIN) = 220 DISCHARGE (CFS) = 0.1 TIME (MIN) = 225 DISCHARGE (CFS) = 0.1 TIME (MIN) = 230 DISCHARGE (CFS) = 0.1 TIME (MIN) = 235 DISCHARGE (CFS) = 0.1 TIME (MIN) = 240 DISCHARGE (CFS) = 0.2 TIME (MIN) = 245 DISCHARGE (CFS) = 0.73 TIME (MIN) = 250 DISCHARGE (CFS) = 0.1 TIME (MIN) = 255 DISCHARGE (CFS) = 0.1 TIME (MIN) = 260 DISCHARGE (CFS) = 0.1 TIME (MIN) = 265 DISCHARGE (CFS) = 0.1 TIME (MIN) = 270 DISCHARGE (CFS) = 0 TIME (MIN) = 275 DISCHARGE (CFS) = 0 TIME (MIN) = 280 DISCHARGE (CFS) = 0 TIME (MIN) = 285 DISCHARGE (CFS) = 0 TIME (MIN) = 290 DISCHARGE (CFS) = 0 TIME (MIN) = 295 DISCHARGE (CFS) = 0 TIME (MIN) = 300 DISCHARGE (CFS) = 0 TIME (MIN) = 305 DISCHARGE (CFS) = 0 TIME (MIN) = 310 DISCHARGE (CFS) = 0 TIME (MIN) = 315 DISCHARGE (CFS) = 0 TIME (MIN) = 320 DISCHARGE (CFS) = 0 TIME (MIN) = 325 DISCHARGE (CFS) = 0 TIME (MIN) = 330 DISCHARGE (CFS) = 0 TIME (MIN) = 335 DISCHARGE (CFS) = 0 TIME (MIN) = 340 DISCHARGE (CFS) = 0 TIME (MIN) = 345 DISCHARGE (CFS) = 0 TIME (MIN) = 350 DISCHARGE (CFS) = 0 TIME (MIN) = 355 DISCHARGE (CFS) = 0 TIME (MIN) = 360 DISCHARGE (CFS) = 0 TIME (MIN) = 365 DISCHARGE (CFS) = 0 1P Basin PR-1 - Gravel Detention 1L Basin PR-1 - Inflow Routing Diagram for 4169 - Detention Analysis Full Site Prepared by Pasco Laret Suiter & Associates, Printed 10/2/2025 HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Subcat Reach Pond Link0 D 6 [j .------___J San_Diego 6-hr Rainfall=6.59"4169 - Detention Analysis Full Site Printed 10/2/2025Prepared by Pasco Laret Suiter & Associates Page 17HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Summary for Link 1L: Basin PR-1 - Inflow Inflow = 0.73 cfs @ 244.78 mins, Volume= 0.014 af Primary =0.73 cfs @ 244.78 mins, Volume= 0.014 af, Atten= 0%, Lag= 0.0 min Routed to Pond 1P : Basin PR-1 - Gravel Detention Primary outflow = Inflow, Time Span= 0.00-365.00 mins, dt= 5.000 mins DISCHARGE = Imported from Basin PR-1 RatHydro.csv Link 1L: Basin PR-1 - Inflow Inflow Primary Hydrograph Time (minutes) 360340320300280260240220200180160140120100806040200 Fl o w ( c f s ) 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 DISCHARGE = Imported from Basin PR-1 RatHydro.csv 0.73 cfs 0.73 cfs I I I I I I I I I I I I I I I / --7 ---r---1---T ---1---7 ---r---1---r---1-----r---1---r---1---T I I I I I I I I I I I I I I I I --~---~---1---4 ---1---~---~---l---~---l-~--=-~J ~---~---l---~---l---4 D I I I I I I I I I __ I ___ I ______ I ______ I ___ I ___ I ___ I ___ I ___ I __ I ___ I ___ I ___ I ___ I ___ I I I I I I I I I I I I I I I I I I I I I I I I I I I I , --7---r--7---T---r--7---r--7---r---r--T --7---r--7---r---r--T I I I I I I I I I I I I I --4 ---~--~---+---~--4 ---~--~---~---~--+ -4 ---~--~---~---~--+ I I I I I I I I I I I I I I I I I --~---L--~---i ___ L __ ~---L--~---L ___ L __ i _J ___ L--~---L ___ L __ i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I , --7---r--7---T---r--,---r--7---r---r--T -,---r--7---r---r--T I I I I I I I I I I I I I I I I I --~---~--~---+---~--~---~--~---~---~--• -~---~--~---~---~--+ I I I I I I I I I I _ _ I ___ I ___ I_ _ _ I ___ I_ _ _ I ___ I ___ I ___ I ___ I_ _ _ _ I ___ I ___ I ___ I ___ I_ _ _ I I I I I I I I I I I I I I --I ---I ------I ------I ---I ---1---I ---1-----I ---I ---1---I ---1---I I I I I I I I I I I I I I I I I ,---4---~--~---+---~--4---~--~---~---~----4---~--~---~---~--+ I I I I I I I I I I I I I I I I _J ___ L--~---L---L --i I I I I I I I I I I I I I I I I I I I I I I I I I - -I - -I I I I ' I I I I I I I I I I I I I I I I I ,---~---r--7---~---r--~---r--~---r,-~~~~ San_Diego 6-hr Rainfall=6.59"4169 - Detention Analysis Full Site Printed 10/2/2025Prepared by Pasco Laret Suiter & Associates Page 18HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Hydrograph for Link 1L: Basin PR-1 - Inflow Time (minutes) Inflow (cfs) Elevation (feet) Primary (cfs) 0.00 0.00 0.00 0.00 5.00 0.00 0.00 0.00 10.00 0.00 0.00 0.00 15.00 0.00 0.00 0.00 20.00 0.00 0.00 0.00 25.00 0.00 0.00 0.00 30.00 0.00 0.00 0.00 35.00 0.00 0.00 0.00 40.00 0.00 0.00 0.00 45.00 0.00 0.00 0.00 50.00 0.00 0.00 0.00 55.00 0.00 0.00 0.00 60.00 0.00 0.00 0.00 65.00 0.00 0.00 0.00 70.00 0.00 0.00 0.00 75.00 0.00 0.00 0.00 80.00 0.00 0.00 0.00 85.00 0.00 0.00 0.00 90.00 0.00 0.00 0.00 95.00 0.00 0.00 0.00 100.00 0.00 0.00 0.00 105.00 0.00 0.00 0.00 110.00 0.00 0.00 0.00 115.00 0.00 0.00 0.00 120.00 0.00 0.00 0.00 125.00 0.00 0.00 0.00 130.00 0.00 0.00 0.00 135.00 0.00 0.00 0.00 140.00 0.00 0.00 0.00 145.00 0.00 0.00 0.00 150.00 0.00 0.00 0.00 155.00 0.00 0.00 0.00 160.00 0.00 0.00 0.00 165.00 0.00 0.00 0.00 170.00 0.00 0.00 0.00 175.00 0.00 0.00 0.00 180.00 0.00 0.00 0.00 185.00 0.00 0.00 0.00 190.00 0.00 0.00 0.00 195.00 0.00 0.00 0.00 200.00 0.00 0.00 0.00 205.00 0.10 0.00 0.10 210.00 0.10 0.00 0.10 215.00 0.10 0.00 0.10 220.00 0.10 0.00 0.10 225.00 0.10 0.00 0.10 230.00 0.10 0.00 0.10 235.00 0.10 0.00 0.10 240.00 0.20 0.00 0.20 245.00 0.73 0.00 0.73 250.00 0.10 0.00 0.10 255.00 0.10 0.00 0.10 Time (minutes) Inflow (cfs) Elevation (feet) Primary (cfs) 260.00 0.10 0.00 0.10 265.00 0.10 0.00 0.10 270.00 0.00 0.00 0.00 275.00 0.00 0.00 0.00 280.00 0.00 0.00 0.00 285.00 0.00 0.00 0.00 290.00 0.00 0.00 0.00 295.00 0.00 0.00 0.00 300.00 0.00 0.00 0.00 305.00 0.00 0.00 0.00 310.00 0.00 0.00 0.00 315.00 0.00 0.00 0.00 320.00 0.00 0.00 0.00 325.00 0.00 0.00 0.00 330.00 0.00 0.00 0.00 335.00 0.00 0.00 0.00 340.00 0.00 0.00 0.00 345.00 0.00 0.00 0.00 350.00 0.00 0.00 0.00 355.00 0.00 0.00 0.00 360.00 0.00 0.00 0.00 365.00 0.00 0.00 0.00 San_Diego 6-hr Rainfall=6.59"4169 - Detention Analysis Full Site Printed 10/2/2025Prepared by Pasco Laret Suiter & Associates Page 7HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Summary for Pond 1P: Basin PR-1 - Gravel Detention [92] Warning: Device #2 is above defined storage Inflow =0.73 cfs @ 244.78 mins, Volume= 0.014 af Outflow = 0.29 cfs @ 249.90 mins, Volume= 0.013 af, Atten= 61%, Lag= 5.1 min Primary = 0.29 cfs @ 249.90 mins, Volume= 0.013 af Routed to nonexistent node 24P Routing by Dyn-Stor-Ind method, Time Span= 0.00-365.00 mins, dt= 5.000 mins Peak Elev= 46.04' @ 249.91 mins Surf.Area= 273 sf Storage= 201 cf Plug-Flow detention time= 10.7 min calculated for 0.013 af (95% of inflow) Center-of-Mass det. time= 9.1 min ( 247.4 - 238.3 ) Volume Invert Avail.Storage Storage Description #1 44.20'218 cf Gravel Storage (Prismatic) Listed below (Recalc) 546 cf Overall x 40.0% Voids Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft) (cubic-feet) (cubic-feet) 44.20 273 0 0 46.20 273 546 546 Device Routing Invert Outlet Devices #1 Device 3 44.45'3.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #2 Device 3 46.20'6.0" Round Culvert Bypass L= 1.3' Box, headwall w/3 square edges, Ke= 0.500 Inlet / Outlet Invert= 46.20' / 46.19' S= 0.0077 '/' Cc= 0.900 n= 0.013, Flow Area= 0.20 sf #3 Primary 44.45'6.0" Round Culvert Outlet L= 10.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 44.45' / 40.00' S= 0.4450 '/' Cc= 0.900 n= 0.013, Flow Area= 0.20 sf Primary OutFlow Max=0.29 cfs @ 249.90 mins HW=46.03' (Free Discharge) 3=Culvert Outlet (Passes 0.29 cfs of 1.09 cfs potential flow) 1=Orifice (Orifice Controls 0.29 cfs @ 5.81 fps) 2=Culvert Bypass ( Controls 0.00 cfs) t_ t San_Diego 6-hr Rainfall=6.59"4169 - Detention Analysis Full Site Printed 10/2/2025Prepared by Pasco Laret Suiter & Associates Page 8HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Pond 1P: Basin PR-1 - Gravel Detention Inflow Primary Hydrograph Time (minutes) 360340320300280260240220200180160140120100806040200 Fl o w ( c f s ) 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Peak Elev=46.04' Storage=201 cf 0.73 cfs 0.29 cfs Pond 1P: Basin PR-1 - Gravel Detention Primary Stage-Discharge Discharge (cfs) 0.70.650.60.550.50.450.40.350.30.250.20.150.10.050 El e v a t i o n ( f e e t ) 46 45 Orifice + Culvert Outlet Culvert Bypass I I I I I I I I I I I --1---1 ______ I ______ 1---1 ------1 ______ I ______ 1---1 ------1 ------1 D _ _ I ___ I ___ I_ _ _ I ___ I_ _ _ I ___ I ___ I ___ I ___ I_ _ _ I __ _ _ I ___ I ___ I ___ I ___ I_ _ _ I I I I I I I I I I I I I I I I I I / I I I T I 7 I I I I T -7 ---I ---1---T ---1---T I I I I I I I I I I I I I I I I I --4 ---~--~---+---~--4 ---~--~---~---~--+---4 ---~--~---~---~--+ I I I I I I I I I I I I I I I I I __ J ___ L_-~ ___ i ___ L __ J ___ L--~---L ___ L __ i _ _J ___ L--~---L ___ L __ i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I , --,---r--7---T---r--,---r--7---r---r--T--,---r--7---r---r--T I I I I I I I I I I I I I I I I I --~---~--~---+---~--~---~--~---~---~--+--~---~--~---~---~--+ I I I I I I I I I I _ _ I ___ I ___ I_ _ _ I ___ I_ _ _ I ___ I __ -:-__ I __ -:--,.-.....e.l ~-......11---L=-..,-1 ___ I __ -:-__ I __ -:- _ _ I I I I I I I I I I --I ---I ------I ------I ---I ---1---I ---1-----I ---1---I ---1---I I I I I I I I I I I I I I ,---4---~--~---+---~--4---~--~---~---~--+- I I I I I I I I I I I I I __ J ___ L_-~ ___ i ___ L __ J ___ L--~---L---L --i _J ___ L--~---L---L --i I I I I I I I I I I I I I I I I I I I I I I I I I - -I - -I I I I ' I I I I I I I I I I I I I I I I I ,---,---r--7---T---r--,---r--7---r-- 1 I I I I □ - - -_1_ - - -_J _ - - - San_Diego 6-hr Rainfall=6.59"4169 - Detention Analysis Full Site Printed 10/2/2025Prepared by Pasco Laret Suiter & Associates Page 9HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Pond 1P: Basin PR-1 - Gravel Detention Surface Storage Stage-Area-Storage Storage (cubic-feet) 200180160140120100806040200 Surface/Horizontal/Wetted Area (sq-ft) 2702602502402302202102001901801701601501401301201101009080706050403020100 El e v a t i o n ( f e e t ) 46 45 Gravel Storage I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I - -_J -_I L .1 __ I _ L _ _I __ L l. ..l __ I ---1-I --1--I - I I I I I I I I I I I I I I I I I I I I I I I I I D I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I _ .1 __ I __ .L _J _I __ L _ _J __ L _ ...1 _J _I San_Diego 6-hr Rainfall=6.59"4169 - Detention Analysis Full Site Printed 10/2/2025Prepared by Pasco Laret Suiter & Associates Page 10HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Hydrograph for Pond 1P: Basin PR-1 - Gravel Detention Time (minutes) Inflow (cfs) Storage (cubic-feet) Elevation (feet) Primary (cfs) 0.00 0.00 0 44.20 0.00 5.00 0.00 0 44.20 0.00 10.00 0.00 0 44.20 0.00 15.00 0.00 0 44.20 0.00 20.00 0.00 0 44.20 0.00 25.00 0.00 0 44.20 0.00 30.00 0.00 0 44.20 0.00 35.00 0.00 0 44.20 0.00 40.00 0.00 0 44.20 0.00 45.00 0.00 0 44.20 0.00 50.00 0.00 0 44.20 0.00 55.00 0.00 0 44.20 0.00 60.00 0.00 0 44.20 0.00 65.00 0.00 0 44.20 0.00 70.00 0.00 0 44.20 0.00 75.00 0.00 0 44.20 0.00 80.00 0.00 0 44.20 0.00 85.00 0.00 0 44.20 0.00 90.00 0.00 0 44.20 0.00 95.00 0.00 0 44.20 0.00 100.00 0.00 0 44.20 0.00 105.00 0.00 0 44.20 0.00 110.00 0.00 0 44.20 0.00 115.00 0.00 0 44.20 0.00 120.00 0.00 0 44.20 0.00 125.00 0.00 0 44.20 0.00 130.00 0.00 0 44.20 0.00 135.00 0.00 0 44.20 0.00 140.00 0.00 0 44.20 0.00 145.00 0.00 0 44.20 0.00 150.00 0.00 0 44.20 0.00 155.00 0.00 0 44.20 0.00 160.00 0.00 0 44.20 0.00 165.00 0.00 0 44.20 0.00 170.00 0.00 0 44.20 0.00 175.00 0.00 0 44.20 0.00 180.00 0.00 0 44.20 0.00 185.00 0.00 0 44.20 0.00 190.00 0.00 0 44.20 0.00 195.00 0.00 0 44.20 0.00 200.00 0.00 0 44.20 0.00 205.00 0.10 15 44.34 0.00 210.00 0.10 41 44.57 0.03 215.00 0.10 54 44.70 0.08 220.00 0.10 58 44.73 0.09 225.00 0.10 59 44.74 0.10 230.00 0.10 60 44.75 0.10 235.00 0.10 60 44.75 0.10 240.00 0.20 72 44.86 0.13 245.00 0.73 156 45.63 0.24 250.00 0.10 201 46.04 0.29 255.00 0.10 152 45.60 0.24 San_Diego 6-hr Rainfall=6.59"4169 - Detention Analysis Full Site Printed 10/2/2025Prepared by Pasco Laret Suiter & Associates Page 11HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Hydrograph for Pond 1P: Basin PR-1 - Gravel Detention (continued) Time (minutes) Inflow (cfs) Storage (cubic-feet) Elevation (feet) Primary (cfs) 260.00 0.10 117 45.27 0.20 265.00 0.10 93 45.05 0.16 270.00 0.00 66 44.81 0.11 275.00 0.00 43 44.60 0.04 280.00 0.00 36 44.53 0.01 285.00 0.00 33 44.50 0.01 290.00 0.00 32 44.49 0.00 295.00 0.00 31 44.48 0.00 300.00 0.00 30 44.48 0.00 305.00 0.00 30 44.47 0.00 310.00 0.00 29 44.47 0.00 315.00 0.00 29 44.47 0.00 320.00 0.00 29 44.47 0.00 325.00 0.00 29 44.46 0.00 330.00 0.00 29 44.46 0.00 335.00 0.00 29 44.46 0.00 340.00 0.00 29 44.46 0.00 345.00 0.00 28 44.46 0.00 350.00 0.00 28 44.46 0.00 355.00 0.00 28 44.46 0.00 360.00 0.00 28 44.46 0.00 365.00 0.00 28 44.46 0.00 San_Diego 6-hr Rainfall=6.59"4169 - Detention Analysis Full Site Printed 10/2/2025Prepared by Pasco Laret Suiter & Associates Page 12HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Stage-Discharge for Pond 1P: Basin PR-1 - Gravel Detention Elevation (feet) Primary (cfs) 44.20 0.00 44.21 0.00 44.22 0.00 44.23 0.00 44.24 0.00 44.25 0.00 44.26 0.00 44.27 0.00 44.28 0.00 44.29 0.00 44.30 0.00 44.31 0.00 44.32 0.00 44.33 0.00 44.34 0.00 44.35 0.00 44.36 0.00 44.37 0.00 44.38 0.00 44.39 0.00 44.40 0.00 44.41 0.00 44.42 0.00 44.43 0.00 44.44 0.00 44.45 0.00 44.46 0.00 44.47 0.00 44.48 0.00 44.49 0.00 44.50 0.01 44.51 0.01 44.52 0.01 44.53 0.01 44.54 0.02 44.55 0.02 44.56 0.02 44.57 0.03 44.58 0.03 44.59 0.04 44.60 0.04 44.61 0.05 44.62 0.05 44.63 0.05 44.64 0.06 44.65 0.06 44.66 0.07 44.67 0.07 44.68 0.08 44.69 0.08 44.70 0.08 44.71 0.09 Elevation (feet) Primary (cfs) 44.72 0.09 44.73 0.09 44.74 0.10 44.75 0.10 44.76 0.10 44.77 0.10 44.78 0.11 44.79 0.11 44.80 0.11 44.81 0.11 44.82 0.12 44.83 0.12 44.84 0.12 44.85 0.12 44.86 0.13 44.87 0.13 44.88 0.13 44.89 0.13 44.90 0.13 44.91 0.14 44.92 0.14 44.93 0.14 44.94 0.14 44.95 0.14 44.96 0.15 44.97 0.15 44.98 0.15 44.99 0.15 45.00 0.15 45.01 0.16 45.02 0.16 45.03 0.16 45.04 0.16 45.05 0.16 45.06 0.16 45.07 0.17 45.08 0.17 45.09 0.17 45.10 0.17 45.11 0.17 45.12 0.17 45.13 0.18 45.14 0.18 45.15 0.18 45.16 0.18 45.17 0.18 45.18 0.18 45.19 0.19 45.20 0.19 45.21 0.19 45.22 0.19 45.23 0.19 Elevation (feet) Primary (cfs) 45.24 0.19 45.25 0.19 45.26 0.20 45.27 0.20 45.28 0.20 45.29 0.20 45.30 0.20 45.31 0.20 45.32 0.20 45.33 0.21 45.34 0.21 45.35 0.21 45.36 0.21 45.37 0.21 45.38 0.21 45.39 0.21 45.40 0.21 45.41 0.22 45.42 0.22 45.43 0.22 45.44 0.22 45.45 0.22 45.46 0.22 45.47 0.22 45.48 0.22 45.49 0.23 45.50 0.23 45.51 0.23 45.52 0.23 45.53 0.23 45.54 0.23 45.55 0.23 45.56 0.23 45.57 0.24 45.58 0.24 45.59 0.24 45.60 0.24 45.61 0.24 45.62 0.24 45.63 0.24 45.64 0.24 45.65 0.25 45.66 0.25 45.67 0.25 45.68 0.25 45.69 0.25 45.70 0.25 45.71 0.25 45.72 0.25 45.73 0.25 45.74 0.26 45.75 0.26 Elevation (feet) Primary (cfs) 45.76 0.26 45.77 0.26 45.78 0.26 45.79 0.26 45.80 0.26 45.81 0.26 45.82 0.26 45.83 0.26 45.84 0.27 45.85 0.27 45.86 0.27 45.87 0.27 45.88 0.27 45.89 0.27 45.90 0.27 45.91 0.27 45.92 0.27 45.93 0.28 45.94 0.28 45.95 0.28 45.96 0.28 45.97 0.28 45.98 0.28 45.99 0.28 46.00 0.28 46.01 0.28 46.02 0.28 46.03 0.29 46.04 0.29 46.05 0.29 46.06 0.29 46.07 0.29 46.08 0.29 46.09 0.29 46.10 0.29 46.11 0.29 46.12 0.29 46.13 0.29 46.14 0.30 46.15 0.30 46.16 0.30 46.17 0.30 46.18 0.30 46.19 0.30 46.20 0.30 46.21 0.30 46.22 0.30 46.23 0.31 46.24 0.31 46.25 0.31 46.26 0.31 46.27 0.32 San_Diego 6-hr Rainfall=6.59"4169 - Detention Analysis Full Site Printed 10/2/2025Prepared by Pasco Laret Suiter & Associates Page 14HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: Basin PR-1 - Gravel Detention Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 44.20 273 0 44.21 273 1 44.22 273 2 44.23 273 3 44.24 273 4 44.25 273 5 44.26 273 7 44.27 273 8 44.28 273 9 44.29 273 10 44.30 273 11 44.31 273 12 44.32 273 13 44.33 273 14 44.34 273 15 44.35 273 16 44.36 273 17 44.37 273 19 44.38 273 20 44.39 273 21 44.40 273 22 44.41 273 23 44.42 273 24 44.43 273 25 44.44 273 26 44.45 273 27 44.46 273 28 44.47 273 29 44.48 273 31 44.49 273 32 44.50 273 33 44.51 273 34 44.52 273 35 44.53 273 36 44.54 273 37 44.55 273 38 44.56 273 39 44.57 273 40 44.58 273 41 44.59 273 43 44.60 273 44 44.61 273 45 44.62 273 46 44.63 273 47 44.64 273 48 44.65 273 49 44.66 273 50 44.67 273 51 44.68 273 52 44.69 273 54 44.70 273 55 44.71 273 56 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 44.72 273 57 44.73 273 58 44.74 273 59 44.75 273 60 44.76 273 61 44.77 273 62 44.78 273 63 44.79 273 64 44.80 273 66 44.81 273 67 44.82 273 68 44.83 273 69 44.84 273 70 44.85 273 71 44.86 273 72 44.87 273 73 44.88 273 74 44.89 273 75 44.90 273 76 44.91 273 78 44.92 273 79 44.93 273 80 44.94 273 81 44.95 273 82 44.96 273 83 44.97 273 84 44.98 273 85 44.99 273 86 45.00 273 87 45.01 273 88 45.02 273 90 45.03 273 91 45.04 273 92 45.05 273 93 45.06 273 94 45.07 273 95 45.08 273 96 45.09 273 97 45.10 273 98 45.11 273 99 45.12 273 100 45.13 273 102 45.14 273 103 45.15 273 104 45.16 273 105 45.17 273 106 45.18 273 107 45.19 273 108 45.20 273 109 45.21 273 110 45.22 273 111 45.23 273 112 San_Diego 6-hr Rainfall=6.59"4169 - Detention Analysis Full Site Printed 10/2/2025Prepared by Pasco Laret Suiter & Associates Page 15HydroCAD® 10.20-7a s/n 10097 © 2025 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: Basin PR-1 - Gravel Detention (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 45.24 273 114 45.25 273 115 45.26 273 116 45.27 273 117 45.28 273 118 45.29 273 119 45.30 273 120 45.31 273 121 45.32 273 122 45.33 273 123 45.34 273 124 45.35 273 126 45.36 273 127 45.37 273 128 45.38 273 129 45.39 273 130 45.40 273 131 45.41 273 132 45.42 273 133 45.43 273 134 45.44 273 135 45.45 273 137 45.46 273 138 45.47 273 139 45.48 273 140 45.49 273 141 45.50 273 142 45.51 273 143 45.52 273 144 45.53 273 145 45.54 273 146 45.55 273 147 45.56 273 149 45.57 273 150 45.58 273 151 45.59 273 152 45.60 273 153 45.61 273 154 45.62 273 155 45.63 273 156 45.64 273 157 45.65 273 158 45.66 273 159 45.67 273 161 45.68 273 162 45.69 273 163 45.70 273 164 45.71 273 165 45.72 273 166 45.73 273 167 45.74 273 168 45.75 273 169 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 45.76 273 170 45.77 273 171 45.78 273 173 45.79 273 174 45.80 273 175 45.81 273 176 45.82 273 177 45.83 273 178 45.84 273 179 45.85 273 180 45.86 273 181 45.87 273 182 45.88 273 183 45.89 273 185 45.90 273 186 45.91 273 187 45.92 273 188 45.93 273 189 45.94 273 190 45.95 273 191 45.96 273 192 45.97 273 193 45.98 273 194 45.99 273 195 46.00 273 197 46.01 273 198 46.02 273 199 46.03 273 200 46.04 273 201 46.05 273 202 46.06 273 203 46.07 273 204 46.08 273 205 46.09 273 206 46.10 273 207 46.11 273 209 46.12 273 210 46.13 273 211 46.14 273 212 46.15 273 213 46.16 273 214 46.17 273 215 46.18 273 216 46.19 273 217 46.20 273 218 46.21 273 218 46.22 273 218 46.23 273 218 46.24 273 218 46.25 273 218 46.26 273 218 46.27 273 218