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HomeMy WebLinkAboutCT 15-07; OCEAN VIEW POINT; FINAL HYDROLOGY STUDY; 2024-04-01 FINAL HYDROLOGY STUDY FOR OCEAN VIEW POINT FINAL APPROVAL – GRADING PLAN, TWAIN AVENUE, CARLSBAD CA PLANNING CASE NO: CT-15-07 / CDP-15-53 / PUD-15-15 DWG. 534-6A, GR 2021-0043 CITY OF CARLSBAD, CA PREPARED FOR: SHEA HOMES LIMITED PARTNERSHIP 9990 MESA RIM ROAD SAN DIEGO, CA 92121 PH: (858) 526-6532 PREPARED BY: PASCO LARET SUITER & ASSOCIATES, INC. 535 N. HIGHWAY 101, SUITE A SOLANA BEACH, CA 92075 PH: (858) 259-8212 Prepared: October 2021 Final: April 2024 __________________________________________________ BRYAN A. KNAPP, RCE 86542 DATE PLSA 3657-01 TABLE OF CONTENTS SECTION Executive Summary 1.0 Introduction 1.1 Existing Conditions 1.2 Proposed Project 1.3 Conclusions 1.4 Mitigated/Unmitigated Comparison of Flows 1.5 References 1.6 Methodology 2.0 Introduction 2.1 County of San Diego Criteria 2.2 City of Carlsbad Standards 2.3 Runoff Coefficient Determination 2.4 AES Rational Method Computer Model 2.5 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 Detention Analysis (100-Year Event) 3.3 Hydromodification Analysis 3.4 Storm Water Pollutant Control 3.5 Hydraulic Calculations 4.0 Appendix 5.0 Appendix A: Hydrology Support Material Appendix B: Storm Water Pollutant Control and Detention Calculations PLSA 3657-01 Page 1 of 21 1.0 EXECUTIVE SUMMARY 1.1 Introduction This Final Hydrology Study for the proposed development at the Terminus of Twain Ave. 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. For hydromodification management and compliance including analysis up to the 10-year, 6-hour storm event, refer to the project Storm Water Quality Management Plan (SWQMP) prepared by Pasco, Laret, Suiter & Associates under separate cover. 1.2 Existing Conditions The subject property is located along the southern most cul-de-sac on Twain Avenue. The site is bordered by existing single-family developments to the north. To the east, west and south the property is bordered by undeveloped open space and Faraday Avenue. The property is zoned R-1 one-family residential zone (R-1, R-4) for the purpose of creating single-family residential land. The existing site mostly consists of open space with natural vegetation and a few small shed-like structures. Natural vegetation onsite is made up of several trees, low shrubs and bare soil. A loose trail is also contained within the site. The site is located within the Agua Hedionda Lagoon Hydrologic Area within the Carlsbad Watershed (904.31). The existing site is comprised of approximately 21.9 gross acres, but the project disturbance is limited to approximately 4.54 acres as over 75% of the project’s site area will be mapped as undisturbed open space in accordance with criteria outlined in the City’s Hillside Ordinance. Runoff through the site generally flows from north to south on the surface via sheet flow methods, and a study of the existing conditions and site topography shows that there does not appear to be any existing storm drain infrastructure located on the property. Although all drainage through the property ultimately flows south towards Faraday Avenue, the site can be categorized into four main existing drainage basins currently discharging to four main naturally formed streams leaving the project proposed disturbed area. The westernmost portion of the site flows toward the southwest headed offsite towards Faraday Avenue. The middle two existing basins drain south towards Faraday Avenue and make their way into existing storm drain structures that flow underneath Faraday Avenue and continue to sheet flow towards the southwest. Lastly, the existing basin to the east also follows a similar drainage path. All runoff leaving the subject property ultimately confluences south of Faraday Avenue. From this point, drainage continues to sheet flow southwest through a golf course on the south side of Faraday Avenue and eventually enters the existing Agua Hedionda Lagoon before ultimately outletting to the Pacific Ocean. PLSA 3657-01 Page 2 of 21 Per the Web Soil Survey application available through the United States Department of Agriculture, the area is generally categorized to have group A and D soils. However, as a result from site specific analysis and soil testing, the soils can be classified closer to a type D soil in accordance with letter titled Updated Geotechnical Evaluation Oceanview Project” prepared by Geotek, Inc. dated 11/02/21. Based upon soil type and the amount of existing impervious area onsite, a runoff coefficient of 0.35 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 analyzed basin for the 100-year, 6-hour storm event. Table 1 below summarizes the results of the Rational Method calculations. EXISTING DRAINAGE FLOWS DRAINAGE AREA DRAINAGE AREA (ACRES) Q100 (CFS) I100 (IN/HR) EX-1 1.17 Ac 1.81 4.58 EX-2 0.98 Ac 1.48 4.76 EX-3 0.89 Ac 1.48 4.32 EX-4 1.50 Ac 2.40 4.41 Table 1. Existing Condition Peak Drainage Flow Rates Table 1 above lists the peak flow rates for the project site in the existing condition for the respective rainfall events. The peak flow rate for the 100-year, 6-hour storm for the combined existing Basins was determined to be 7.17 cfs with a time of concentration of 10.2 minutes, discharging along the surface to the west before being conveyed southwest to sheet flow overland. Refer to pre-development hydrology calculations included in Section 3.1 of this report for a detailed analysis of the existing drainage basin, as well as a pre-development hydrology node map included in the appendix of this report for pre-development drainage basin delineation and discharge locations leaving the subject property. 1.3 Proposed Project The proposed project includes the demolition of a majority of the onsite structures (consisting mainly of what appear to be temporary / non-permitted sheds) and improvements and the construction of 13 new single-family lots and residences, along with a new private street, and various surface, grading, and utility improvements typical of this type of construction. . The proposed lot pad elevations range from elevation 324.83 for the highest northeasterly lot (lot1), gradually decreasing to 308.83 (lots 9 and 10) at the lowest point of the site, only to step back up to pad elevations 309.83 (lots 11-13) as can be seen on the project Precise Grading Plan submitted under separate cover. PLSA 3657-01 Page 3 of 21 Runoff from the proposed development will continue to discharge to the south of the proposed disturbed area to mimic existing drainage conditions and the existing onsite topography. Lots 1-7 will drain to the front of the properties into Twain Court to be collected in a series of private storm drain curb inlets that will be piped to the proposed biofiltration BMP 2 located within Lot 15. Lots 8-13 will also drain to the front of the properties and into Twain Court to be collected in a series of private inlets and storm drain piping to route to BMP 1 for treatment and flood control mitigation. The existing undisturbed open space behind the proposed residences will continue to drain from north to south down to Faraday Avenue as they do in the existing condition, bypassing any treatment as there is no proposed hardscape along those areas. As in the existing condition, the project site appears to accept some minor offsite runon from the adjacent property to the northwest at the trail location due to an existing manufactured slope located north of the property boundary at 2090 Twain Avenue. This drainage does not enter the project disturbed area and thus is not included in the drainage analysis. However, a cross lot drainage scenario from the subject property to the northeast is being mitigated by moving the existing top of slope to the property boundary. Unlike the existing condition, the majority of the analyzed watershed area is be broken down into three major drainage basins, but maintaining the same four separate discharge locations from the site. Basin PR-1 consists of the majority of the property and is approximately 4.21 acres in size and 44.4% impervious. This area of the site will be collected and conveyed to both the proposed biofiltration basin facilities then piped out to the southwest side of the property at two separate locations. Basin PR-2 consists of a remaining portion of the property including the developed hillside which consist of, graded slopes, and open space. It is approximately 0.21 acres and 0.00% impervious. Basin PR-2 will drain directly to the east of the property where it will be conveyed east to the analyzed point of compliance. Basin PR-3 consists of the remaining portion of the property including the developed hillside which consist of, graded slopes, and open space. It is approximately 0.13 acres and 0.00% impervious. Basin PR-3 will drain directly to the south of the property line where it will be conveyed south to the analyzed point of compliance. From here, all drainage will continue southwest as it does in the existing condition to enter the existing engineered systems below Faraday Avenue eventually to sheet flow west and ultimately discharge to the Pacific Ocean via the Agua Hedionda Lagoon. Based on the proposed land use and soil type of the subject property, runoff coefficients for this site were determined using Table 3-1 Runoff Coefficients for Urban Areas of the San Diego County Hydrology Manual. Refer to section 3.2 of this report, as well as the post-development hydrology map included in Appendix A, for additional analysis and a summary of runoff coefficients used. Using the Rational Method Procedure outlined in the San Diego County Hydrology Manual, a peak flow rate and time of concentration were calculated for the 100-year, 6-hour storm event for each of the drainage basins in the proposed condition. Table 2 below summarizes the results of the Rational Method calculations. PLSA 3657-01 Page 4 of 21 PROPOSED DRAINAGE FLOWS DRAINAGE AREA DRAINAGE AREA (ACRES) Q100 (CFS) I100 (IN/HR) PR-1(PR-208) 2.36 Ac 6.82 5.04 PR-1(PR-308) 1.85 Ac 4.88 4.54 PR-2 0.21 Ac 0.50 6.85 PR-3 0.13 Ac 0.31 6.85 Table 2. Proposed Condition Peak Drainage Flow Rates The two (2) streams within PR-1 were determined separately in the proposed condition, in order to compare to pre-developed conditions. This was determined to be 12.5 cfs of total runoff leaving the disturbed area and the area analyzed. Refer to post-development hydrology calculations included in Section 3.2 of this report for detailed analyses of the proposed drainage basins as well as a post-development hydrology node map included in Appendix A of this report for post-development drainage delineation and discharge locations. As this section of the report only serves to analyze the total, unmitigated peak runoff generated from the proposed project, refer to Section 3.3 of this report for a discussion of the detention components of the site. This analysis takes into account the proposed detention, pollutant removal, and hydromodification management facility proposed onsite. The results of the detention analysis provide a resultant, mitigated peak runoff leaving the site in addition to the detained time to peak (see Appendix B for results of the dynamic detention analysis performed using HydroCAD-10 software). In an effort to comply with the City of Carlsbad’s Stormwater standards, all runoff generated onsite will be conveyed to an onsite biofiltration facility on a dedicated BMP mapped lot located within lot 15. For a discussion regarding hydromodification management requirements and compliance, refer to the project Storm Water Quality Management Plan (SWQMP) under separate cover. An impermeable liner is proposed along the sides and bottom of the biofiltration basin as was deemed by the project geotechnical engineer. In an effort to comply with the City of Carlsbad’s storm water standards for all development projects, the project site will implement source control and site design BMP’s in addition to the proposed biofiltration treatment control BMP where feasible and applicable in accordance with the City of Carlsbad’s BMP Design Manual. All runoff generated from proposed roofs and hardscape areas will be directed to landscaped areas and grassy swales to disperse drainage onto pervious surfaces. Proposed impervious area and soil compaction are minimized to the greatest extent feasible, and dispersion is promoted as well. Partial infiltration and evapotranspiration in landscaped areas will assist in slowing peak discharges and in reducing total volume generated during storm events. PLSA 3657-01 Page 5 of 21 The onsite landscaped areas will remove sediment and particulate-bound pollutants from storm water prior to leaving the project site. 1.4 Conclusions Based upon the hydrology calculations performed for the project site, there is an increase in peak runoff in the post-developed condition compared to the existing condition due to the increase in proposed site hardscape. For a discussion on the detention analysis performed for the project site, refer to Section 3.3 below as well as the Appendix of this report. Based on the analysis included in Section 3.3, the proposed onsite detention facilities accommodate the increase in peak runoff generated in the proposed condition, mitigating peak flows to below pre-developed conditions. The site has been designed and graded in a way to minimize earthwork to the greatest extent feasible and maintain historic drainage patterns. Water leaving the subject property will continue to do so from the same points of discharge as in the existing condition. Thus, water will not be diverted away from existing drainage patterns, and the proposed development and resulting peak runoff will not have an adverse effect on the downstream watershed and existing infrastructure. 1.5 Mitigated/Unmitigated Comparison of Flows (Pre vs. Post Development) Pre-Development (Basin EX:1) Post-Development (PR-1) Delta EX-102: Q100 = 2.40 cfs PR-308: (UNMIT) Q100 = 4.88 cfs +2.48 cfs (MIT) Q100 = 0.19 cfs -2.21 cfs Pre-Development (Basin EX:2) Post-Development (PR-1) Delta EX-202: Q100 = 1.48 cfs PR-208: (UNMIT) Q100 = 6.82 cfs +5.34 cfs (MIT) Q100 = 0.16 cfs -1.32 cfs Pre-Development (Basin EX:3) Post-Development (PR-3) Delta EX-302: Q100 = 1.48 cfs PR-3: Q100 = 0.31 cfs -1.17 cfs Pre-Development (Basin EX:4) Post-Development (PR-2) Delta EX-402: Q100 = 1.81 cfs PR-2: Q100 = 0.50 cfs -1.31 cfs - - PLSA 3657-01 Page 6 of 21 1.6 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 “City of Carlsbad BMP Design Manual for Permanent Site Design, Storm Water Treatment and Hydromodification Management”, revised September 2021, 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 3657-01 Page 7 of 21 2.0 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 3657-01 Page 8 of 21 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 which are outlined in the Grading and Erosion Control Ordinance, Title 15 of the . Please refer to this manual for reference and 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. 2.5 AES Rational Method Computer Model The Rational Method computer program developed by Advanced Engineering Software (AES) satisfies the County of San Diego design criteria, therefore it is the computer model used for this study. The AES hydrologic model is capable of creating independent node-link models of each interior drainage basin and linking these sub-models together at confluence points to determine peak flow rates. The program utilizes base information input by the user to perform calculations for up to 15 hydrologic processes. The required base information includes drainage basin area, storm water facility locations and sizes, land PLSA 3657-01 Page 9 of 21 uses, flow patterns, and topographic elevations. The hydrologic conditions were analyzed in accordance with the 2003 County of San Diego Hydrology Manual criteria as follows: Design Storm 100-year, 6-hour 100-year, 6-hour Precipitation 2.7 inches Rainfall Intensity Based on the 2003 County of San Diego Hydrology Manual criteria Runoff Coefficient Weighted Runoff Coefficients per Section 3.1, 3.2 of this report and Table 3-2 of SDHDM 2.5.1 AES Computer Model Code Information 0: Enter Comment 2: Initial Subarea Analysis 3: Pipe/Box/Culvert Travel Time 5: Open Channel Travel Time 7: User-Specified hydrology data at Node 8: Addition of sub-area runoff to Main Stream 10: Copy Main Stream data onto a Memory Bank 11: Confluence Memory Bank data with Main Stream 13: Clear the Main Stream PLSA 3657-01 Page 10 of 21 3.0 HYDROLOGY MODEL OUTPUT 3.1 Pre-Developed Hydrologic Model Output (100 Year Event) Pre-Development: Q = CIA *Rational Method Equation P100 = 2.6 *100-Year, 6-Hour Rainfall Precipitation Basin EX-1, 2, 3 & 4 (Entire Drainage Basin) Total Area = 198,101 sf ➔ 4.55 Acres Impervious Area = 764 sf ➔ 0.02 Ac Pervious Area = 197,337 sf ➔ 4.53 Ac Cn, Weighted Runoff Coefficient, - 0.35, Cn value for natural ground, Type D 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 = 0.90 x 764 sf + 0.35 x 197,337 sf = 0.35 198,101 sf Basin EX-1 (Discharging to Southwest) Total Area = 65,456 sf ➔ 1.50 Acres Impervious Area = 0 sf ➔ 0.00 Ac Pervious Area = 65,456 sf ➔ 1.50 Ac Cn = 0.35 Tc = ti + tt ti @ 100’= 6.8% => 8.0 min from Table 3-2 of SDCHM for ~0 DU/Ac tt => L = 262’ ΔE = 30.7’ tt= [{11.9(L/5,280)^3}/ΔE]^0.385 from Figure 3-4 SDHDM Section 3.1.4.2 tt= [{11.9(262/5,280)^3}/30.7]^0.385 = 0.022 0.022 x 60 = 1.3 Min. Tc = 8.0 + 1.3 = 9.3 Min P6 = 2.6 I = 7.44 x P6 x D-0.645 I = 7.44 x 2.6 x 9.3-0.645 ≈ 4.58 in/hr I100 ≈ 4.58 in/hr PLSA 3657-01 Page 11 of 21 Q100 = C*I*A Q100 = 0.35 x 4.58 in/hr x 1.50 Ac = 2.40 cfs Basin EX-2 (Discharging to South) Total Area = 38,949 sf ➔ 0.89 Acres Impervious Area = 0 sf ➔ 0.00 Ac Pervious Area = 38,949 sf ➔ 0.89 Acres Cn = 0.35 Tc = ti + tt ti @ 100’= 7.0% => 8.0 min from Table 3-2 of SDCHM for ~0 DU/Ac tt => L = 187’ ΔE = 42.0’ tt= [{11.9(L/5,280)^3}/ΔE]^0.385 tt= [{11.9(187/5,280)^3}/42.0]^0.385 = 0.013 0.013 x 60 = 0.80 Min. Tc = 8.0 + 0.80 = 8.8 Min P6 = 2.6 I = 7.44 x P6 x D-0.645 I = 7.44 x 2.6 x 8.80-0.645 ≈ 4.76 in/hr I100 ≈ 4.76 in/hr Q100 = C*I*A Q100 = 0.35 x 4.76 in/hr x 0.89 Ac = 1.48 cfs Basin EX-3 (Discharging to South) Total Area = 42,878 sf ➔ 0.98 Acres Impervious Area = 316 sf ➔ 0.01 Ac Pervious Area = 42,562 sf ➔ 0.97 Ac Cn = 0.35 Tc = ti + tt ti @ 100’= 5.5% => 8.5 min from Table 3-2 of SDCHM for ~0 DU/Ac tt => L = 358’ ΔE = 37.5’ tt= [{11.9(L/5,280)^3}/ΔE]^0.385 tt= [{11.9(358/5,280)^3}/37.5]^0.385 = 0.029 0.029 x 60 = 1.7 Min. Tc = 8.5 + 1.7 = 10.2 Min P6 = 2.6 PLSA 3657-01 Page 12 of 21 I = 7.44 x P6 x D-0.645 I = 7.44 x 2.6 x 10.2-0.645 ≈ 4.32 in/hr I100 ≈ 4.32 in/hr Q100 = C*I*A Q100 = 0.35 x 4.32 in/hr x 0.98 Ac = 1.48 cfs Basin EX-4 (Discharging to East) Total Area = 50,818 sf ➔ 1.17 Acres Impervious Area = 449 sf ➔ 0.01 Ac Pervious Area = 50,369 sf ➔ 1.16 Ac Cn = 0.35 Tc = ti + tt ti @ 100’= 5.7% => 8.5 min from Table 3-2 of SDCHM for ~0 DU/Ac tt => L = 205’ ΔE = 20.8’ tt= [{11.9(L/5,280)^3}/ΔE]^0.385 tt= [{11.9(205/5,280)^3}/20.8]^0.385 = 0.019 0.020 x 60 = 1.4 Min. Tc = 8.5 + 1.4 = 9.9 Min P6 = 2.6 I = 7.44 x P6 x D-0.645 I = 7.44 x 2.6 x 9.9-0.645 ≈ 4.41 in/hr I100 ≈ 4.41 in/hr Q100 = C*I*A Q100 = 0.35 x 4.41 in/hr x 1.17 Ac = 1.81 cfs Total Q100 for Existing Development = EX-1 + EX-2 + EX-3 + EX-4 = 2.40 cfs + 1.48 cfs + 1.48 cfs + 1.81 cfs = 7.17 cfs PLSA 3657-01 Page 13 of 21 3.2 Post-Developed Hydrologic Model Output (100-Year Event) Post-Development: Q = CIA *Rational Method Equation P100 = 2.6 *100-Year, 6-Hour Rainfall Precipitation Basin PR-1 (Onsite Improvements) Total Area = 183,540 sf ➔ 4.21 Acres Impervious Area = 86,896 sf ➔ 1.99 Ac (Includes 15% hardscape contingency) Pervious Area = 96,644 sf ➔ 2.22 Ac (Includes 15% hardscape contingency) Cn, Weighted Runoff Coefficient, - 0.35, Cn value for natural ground, Type D 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 = 0.90 x 86,896 sf + 0.35 x 96,644 sf = 0.61 183,540 sf Basin PR-1: Node 208 (Drainage Basins PR-1.1, 1.2, 1.4, 1.5) Total Area = 101,553 sf ➔ 2.33 Acres Q = Cn x I100 x A *Q based on flow to proposed BMP Entering open space portion of site TC = 8.05 min (See attached AES calculations) Q100 = 6.82 cfs (See attached AES calculations) Basin PR-1: Node 308 (Drainage Basins PR-1.3, 1.6, 1.7) Total Area = 81,987 sf ➔ 1.88 Acres Q = Cn x I100 x A *Q based on flow to proposed BMP Entering open space portion of site TC = 9.47 min (See attached AES calculations) Q100 = 4.88 cfs (See attached AES calculations) Basin PR-1 (Entire Drainage Basin) Entering open space portion of site TC = 9.47 min (See attached AES calculations) Q100 = 6.82 cfs + 4.88 cfs Q100 = 11.70 cfs (See attached AES calculations) ____________________________________________________________________________ **************************************************************************** RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT 2003,1985,1981 HYDROLOGY MANUAL (c) Copyright 1982-2016 Advanced Engineering Software (aes) Ver. 23.0 Release Date: 07/01/2016 License ID 1452 Analysis prepared by: ************************** DESCRIPTION OF STUDY ************************** * PASCO LARET SUITER & ASSOCIATES * * 3657 POST DEVELOPMENT HYDRO STUDY * * BASIN PR-1 (UNMITIGATED) * ************************************************************************** FILE NAME: 3657POST.DAT TIME/DATE OF STUDY: 12:00 03/30/2023 ---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: ---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 100.00 6-HOUR DURATION PRECIPITATION (INCHES) = 2.600 SPECIFIED MINIMUM PIPE SIZE(INCH) = 3.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR NO. (FT) (FT) SIDE / SIDE/ WAY (FT) (FT) (FT) (FT) (n) === ===== ========= ================= ====== ===== ====== ===== ======= 1 17.0 12.0 0.018/0.018/0.020 0.50 1.50 0.0312 0.125 0.0150 GLOBAL STREET FLOW-DEPTH CONSTRAINTS: 1. Relative Flow-Depth = 0.50 FEET as (Maximum Allowable Street Flow Depth) - (Top-of-Curb) 2. (Depth)*(Velocity) Constraint = 10.0 (FT*FT/S) *SIZE PIPE WITH A FLOW CAPACITY GREATER THAN OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.* **************************************************************************** FLOW PROCESS FROM NODE 100.00 TO NODE 101.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 51.00 UPSTREAM ELEVATION(FEET) = 324.80 DOWNSTREAM ELEVATION(FEET) = 324.30 ELEVATION DIFFERENCE(FEET) = 0.50 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.340 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.877 SUBAREA RUNOFF(CFS) = 0.18 TOTAL AREA(ACRES) = 0.05 TOTAL RUNOFF(CFS) = 0.18 **************************************************************************** FLOW PROCESS FROM NODE 101.00 TO NODE 102.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 323.30 DOWNSTREAM(FEET) = 322.90 FLOW LENGTH(FEET) = 71.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 6.0 INCH PIPE IS 2.9 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 1.95 GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.18 PIPE TRAVEL TIME(MIN.) = 0.61 Tc(MIN.) = 6.95 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 102.00 = 122.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 102.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.541 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6100 SUBAREA AREA(ACRES) = 0.13 SUBAREA RUNOFF(CFS) = 0.44 TOTAL AREA(ACRES) = 0.2 TOTAL RUNOFF(CFS) = 0.61 TC(MIN.) = 6.95 **************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 103.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 322.90 DOWNSTREAM(FEET) = 321.80 FLOW LENGTH(FEET) = 87.00 MANNING'S N = 0.013 ASSUME FULL-FLOWING PIPELINE PIPE-FLOW VELOCITY(FEET/SEC.) = 3.10 PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.61 PIPE TRAVEL TIME(MIN.) = 0.47 Tc(MIN.) = 7.42 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 103.00 = 209.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 103.00 TO NODE 104.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>(STREET TABLE SECTION # 1 USED)<<<<< ============================================================================ UPSTREAM ELEVATION(FEET) = 321.80 DOWNSTREAM ELEVATION(FEET) = 315.43 STREET LENGTH(FEET) = 75.00 CURB HEIGHT(INCHES) = 6.0 STREET HALFWIDTH(FEET) = 17.00 DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 12.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018 OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018 SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1 STREET PARKWAY CROSSFALL(DECIMAL) = 0.020 Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.89 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW: STREET FLOW DEPTH(FEET) = 0.18 HALFSTREET FLOOD WIDTH(FEET) = 2.87 AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.61 PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.83 STREET FLOW TRAVEL TIME(MIN.) = 0.27 Tc(MIN.) = 7.69 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.191 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.610 SUBAREA AREA(ACRES) = 0.18 SUBAREA RUNOFF(CFS) = 0.57 TOTAL AREA(ACRES) = 0.4 PEAK FLOW RATE(CFS) = 1.14 END OF SUBAREA STREET FLOW HYDRAULICS: DEPTH(FEET) = 0.20 HALFSTREET FLOOD WIDTH(FEET) = 3.85 FLOW VELOCITY(FEET/SEC.) = 4.51 DEPTH*VELOCITY(FT*FT/SEC.) = 0.89 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 104.00 = 284.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 104.00 TO NODE 105.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 312.43 DOWNSTREAM(FEET) = 303.00 FLOW LENGTH(FEET) = 21.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 1.6 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 14.26 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 1.14 PIPE TRAVEL TIME(MIN.) = 0.02 Tc(MIN.) = 7.71 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 105.00 = 305.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 105.00 TO NODE 105.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 7.71 RAINFALL INTENSITY(INCH/HR) = 5.18 TOTAL STREAM AREA(ACRES) = 0.36 PEAK FLOW RATE(CFS) AT CONFLUENCE = 1.14 **************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 201.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 86.00 UPSTREAM ELEVATION(FEET) = 316.30 DOWNSTREAM ELEVATION(FEET) = 315.00 ELEVATION DIFFERENCE(FEET) = 1.30 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.552 WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 72.67 (Reference: Table 3-1B of Hydrology Manual) THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.754 SUBAREA RUNOFF(CFS) = 0.49 TOTAL AREA(ACRES) = 0.14 TOTAL RUNOFF(CFS) = 0.49 **************************************************************************** FLOW PROCESS FROM NODE 201.00 TO NODE 202.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 312.50 DOWNSTREAM(FEET) = 311.90 FLOW LENGTH(FEET) = 64.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 6.0 INCH PIPE IS 4.7 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 3.00 GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.49 PIPE TRAVEL TIME(MIN.) = 0.36 Tc(MIN.) = 6.91 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 202.00 = 150.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 202.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.562 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6100 SUBAREA AREA(ACRES) = 0.03 SUBAREA RUNOFF(CFS) = 0.10 TOTAL AREA(ACRES) = 0.2 TOTAL RUNOFF(CFS) = 0.58 TC(MIN.) = 6.91 **************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 203.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 311.90 DOWNSTREAM(FEET) = 311.05 FLOW LENGTH(FEET) = 57.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 6.0 INCH PIPE IS 4.4 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 3.75 GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.58 PIPE TRAVEL TIME(MIN.) = 0.25 Tc(MIN.) = 7.16 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 203.00 = 207.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 203.00 TO NODE 204.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>(STREET TABLE SECTION # 1 USED)<<<<< ============================================================================ UPSTREAM ELEVATION(FEET) = 311.05 DOWNSTREAM ELEVATION(FEET) = 306.58 STREET LENGTH(FEET) = 98.00 CURB HEIGHT(INCHES) = 6.0 STREET HALFWIDTH(FEET) = 17.00 DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 12.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018 OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018 SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1 STREET PARKWAY CROSSFALL(DECIMAL) = 0.020 Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.77 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW: STREET FLOW DEPTH(FEET) = 0.27 HALFSTREET FLOOD WIDTH(FEET) = 7.95 AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.04 PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 1.10 STREET FLOW TRAVEL TIME(MIN.) = 0.40 Tc(MIN.) = 7.56 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.245 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.610 SUBAREA AREA(ACRES) = 1.37 SUBAREA RUNOFF(CFS) = 4.38 TOTAL AREA(ACRES) = 1.5 PEAK FLOW RATE(CFS) = 4.93 END OF SUBAREA STREET FLOW HYDRAULICS: DEPTH(FEET) = 0.32 HALFSTREET FLOOD WIDTH(FEET) = 10.39 FLOW VELOCITY(FEET/SEC.) = 4.54 DEPTH*VELOCITY(FT*FT/SEC.) = 1.43 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 204.00 = 305.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 204.00 TO NODE 205.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 303.58 DOWNSTREAM(FEET) = 303.00 FLOW LENGTH(FEET) = 6.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 4.9 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 12.83 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 4.93 PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 7.57 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 205.00 = 311.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 206.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.241 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6100 SUBAREA AREA(ACRES) = 0.13 SUBAREA RUNOFF(CFS) = 0.42 TOTAL AREA(ACRES) = 1.7 TOTAL RUNOFF(CFS) = 5.34 TC(MIN.) = 7.57 **************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 206.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< >>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 7.57 RAINFALL INTENSITY(INCH/HR) = 5.24 TOTAL STREAM AREA(ACRES) = 1.67 PEAK FLOW RATE(CFS) AT CONFLUENCE = 5.34 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 1.14 7.71 5.180 0.36 2 5.34 7.57 5.241 1.67 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH/HOUR) 1 6.46 7.57 5.241 2 6.42 7.71 5.180 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 6.46 Tc(MIN.) = 7.57 TOTAL AREA(ACRES) = 2.0 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 206.00 = 311.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 207.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 294.25 DOWNSTREAM(FEET) = 292.70 FLOW LENGTH(FEET) = 150.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 10.4 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 6.08 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 6.46 PIPE TRAVEL TIME(MIN.) = 0.41 Tc(MIN.) = 7.98 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 207.00 = 461.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 207.00 TO NODE 208.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 292.60 DOWNSTREAM(FEET) = 280.00 FLOW LENGTH(FEET) = 65.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 4.7 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 17.75 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 6.46 PIPE TRAVEL TIME(MIN.) = 0.06 Tc(MIN.) = 8.05 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 208.00 = 526.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 208.00 TO NODE 208.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.041 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.5736 SUBAREA AREA(ACRES) = 0.33 SUBAREA RUNOFF(CFS) = 0.58 TOTAL AREA(ACRES) = 2.4 TOTAL RUNOFF(CFS) = 6.82 TC(MIN.) = 8.05 **************************************************************************** FLOW PROCESS FROM NODE 300.00 TO NODE 300.00 IS CODE = 10 ---------------------------------------------------------------------------- >>>>>MAIN-STREAM MEMORY COPIED ONTO MEMORY BANK # 1 <<<<< ============================================================================ **************************************************************************** FLOW PROCESS FROM NODE 300.00 TO NODE 301.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 76.00 UPSTREAM ELEVATION(FEET) = 309.80 DOWNSTREAM ELEVATION(FEET) = 309.10 ELEVATION DIFFERENCE(FEET) = 0.70 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 7.174 WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 62.63 (Reference: Table 3-1B of Hydrology Manual) THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.427 SUBAREA RUNOFF(CFS) = 0.20 TOTAL AREA(ACRES) = 0.06 TOTAL RUNOFF(CFS) = 0.20 **************************************************************************** FLOW PROCESS FROM NODE 301.00 TO NODE 302.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 308.55 DOWNSTREAM(FEET) = 308.10 FLOW LENGTH(FEET) = 45.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 6.0 INCH PIPE IS 2.5 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 2.52 GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.20 PIPE TRAVEL TIME(MIN.) = 0.30 Tc(MIN.) = 7.47 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 302.00 = 121.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 302.00 TO NODE 302.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.287 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6100 SUBAREA AREA(ACRES) = 0.01 SUBAREA RUNOFF(CFS) = 0.03 TOTAL AREA(ACRES) = 0.1 TOTAL RUNOFF(CFS) = 0.23 TC(MIN.) = 7.47 **************************************************************************** FLOW PROCESS FROM NODE 302.00 TO NODE 303.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 308.10 DOWNSTREAM(FEET) = 307.70 FLOW LENGTH(FEET) = 24.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 6.0 INCH PIPE IS 2.4 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 3.11 GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.23 PIPE TRAVEL TIME(MIN.) = 0.13 Tc(MIN.) = 7.60 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 303.00 = 145.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 303.00 TO NODE 304.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>(STREET TABLE SECTION # 1 USED)<<<<< ============================================================================ UPSTREAM ELEVATION(FEET) = 307.70 DOWNSTREAM ELEVATION(FEET) = 305.58 STREET LENGTH(FEET) = 187.00 CURB HEIGHT(INCHES) = 6.0 STREET HALFWIDTH(FEET) = 17.00 DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 12.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018 OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018 SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1 STREET PARKWAY CROSSFALL(DECIMAL) = 0.020 Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.31 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW: STREET FLOW DEPTH(FEET) = 0.31 HALFSTREET FLOOD WIDTH(FEET) = 10.11 AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.23 PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.69 STREET FLOW TRAVEL TIME(MIN.) = 1.40 Tc(MIN.) = 9.00 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.690 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.610 SUBAREA AREA(ACRES) = 1.45 SUBAREA RUNOFF(CFS) = 4.15 TOTAL AREA(ACRES) = 1.5 PEAK FLOW RATE(CFS) = 4.35 END OF SUBAREA STREET FLOW HYDRAULICS: DEPTH(FEET) = 0.37 HALFSTREET FLOOD WIDTH(FEET) = 13.20 FLOW VELOCITY(FEET/SEC.) = 2.59 DEPTH*VELOCITY(FT*FT/SEC.) = 0.95 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 304.00 = 332.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 304.00 TO NODE 305.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 303.20 DOWNSTREAM(FEET) = 303.00 FLOW LENGTH(FEET) = 7.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.2 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 7.99 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 4.35 PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 9.01 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 305.00 = 339.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 305.00 TO NODE 306.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.685 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6100 SUBAREA AREA(ACRES) = 0.13 SUBAREA RUNOFF(CFS) = 0.37 TOTAL AREA(ACRES) = 1.7 TOTAL RUNOFF(CFS) = 4.72 TC(MIN.) = 9.01 **************************************************************************** FLOW PROCESS FROM NODE 306.00 TO NODE 307.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 295.50 DOWNSTREAM(FEET) = 294.05 FLOW LENGTH(FEET) = 134.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 8.5 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 5.73 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 4.72 PIPE TRAVEL TIME(MIN.) = 0.39 Tc(MIN.) = 9.40 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 307.00 = 473.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 307.00 TO NODE 308.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 293.95 DOWNSTREAM(FEET) = 292.00 FLOW LENGTH(FEET) = 41.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.7 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 9.83 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 4.72 PIPE TRAVEL TIME(MIN.) = 0.07 Tc(MIN.) = 9.47 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 308.00 = 514.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 308.00 TO NODE 308.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.537 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.5819 SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.32 TOTAL AREA(ACRES) = 1.9 TOTAL RUNOFF(CFS) = 4.88 TC(MIN.) = 9.47 ============================================================================ END OF STUDY SUMMARY: TOTAL AREA(ACRES) = 1.9 TC(MIN.) = 9.47 PEAK FLOW RATE(CFS) = 4.88 ============================================================================ ============================================================================ END OF RATIONAL METHOD ANALYSIS PLSA 3657-01 Page 14 of 21 Basin PR-2 (Entire Drainage Basin) Total Area = 9,022 sf ➔ 0.21 Acres Impervious Area = 0 sf ➔ 0.00 Ac Pervious Area = 9,022 sf ➔ 0.21 Acres Cn, Weighted Runoff Coefficient, - 0.35, Cn value for natural ground, Type D 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 = 0.90 x 0 sf + 0.35 x 18,604 sf = 0.35 18,604 sf Tc = 5.0 Min * Minimum TC per SDCHM P6 = 2.6 I = 7.44 x P6 x D-0.645 I = 7.44 x 2.6 x 5.0-0.645 ≈ 6.85 in/hr I100 ≈ 6.85 in/hr Q = Cn x I100 x A Q100 = 0.35 x 6.85 in/hr x 0.21 Ac = 0.50 cfs Basin PR-3 (Entire Drainage Basin) Total Area = 10,188 sf ➔ 0.23 Acres Impervious Area = 0 sf ➔ 0.00 Ac Pervious Area = 10,188 sf ➔ 0.23 Ac Cn, Weighted Runoff Coefficient, - 0.35, Cn value for natural ground, Type D 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 = 0.90 x 0 sf + 0.35 x 10,188 sf = 0.35 10,188 sf PLSA 3657-01 Page 15 of 21 Tc = 5.0 Min * Minimum TC per SDCHM P6 = 2.6 I = 7.44 x P6 x D-0.645 I = 7.44 x 2.6 x 5.0-0.645 ≈ 6.85 in/hr I100 ≈ 6.85 in/hr Q = Cn x I100 x A Q100 = 0.35 x 6.85 in/hr x 0.13 Ac = 0.31 cfs 3.3 Detention Analysis (100-Year Event) The onsite biofiltration basins provide pollutant control as well as mitigation of the 100- year, 6-hour storm event peak flow rate. The 100-year storm event detention analysis was performed using HydroCAD-10 software as well as Advanced Engineering Software (A.E.S). HydroCAD-10 has the ability to route the 100-year, 6-hour storm event inflow hydrograph through the biofiltration facility, and based on the facility cross sectional geometry, stage-storage, and outlet structure data, calculate the detained peak flow rate and detained time to peak. The inflow runoff hydrograph to the biofiltration basin was modeled using RatHydro which is a Rational Method Design Storm Hydrograph software that creates a hydrograph using the results of the Rational Method calculations. The proposed biofiltration facilities consists of two basins with surface area square footage per plan, 18 inches of engineered soil, a two separate Stormtech MC-7200 and MC-3500 vault system storage layers along with an impermeable liner along the sides and bottom of the BMP to introduce a no infiltration condition. Runoff generated during high-frequency, low-intensity storm events will be biofiltered through the engineered soil and storage vault layers, then collected in a PVC subdrain pipe system and directed to an emergency overflow / outlet structure located in the biofiltration basin. Runoff will filter through the BMP cross-section and enter the Stormtech MC vault systems. The subdrain system will connect to the outlet structure before an outlet pipe conveys drainage offsite. In larger storm events, runoff not filtered through the engineered soil and vault systems to instead be conveyed via an overflow outlet structure consisting of a 3-foot by 3-foot grate located on top of the catch basin. Runoff conveyed via the outlet structure will bypass the soil layers and be conveyed directly to a proposed 18-inch RCP drainpipe to direct discharge offsite. PLSA 3657-01 Page 16 of 21 PROPOSED DRAINAGE FLOWS (MIT) DRAINAGE AREA DRAINAGE AREA (ACRES) Q100 (CFS) I100 (IN/HR) PR-1(PR-208) 2.36 0.14 0.88 PR-1(PR-308) 1.85 0.17 0.89 Table 3. Proposed Condition Peak Drainage Flow Rates (Mitigated) Table 3 above lists the peak flow rates for the project site in the proposed, mitigated condition after being routed through the biofiltration basin. Based on the results of the HydroCAD-10 analysis, the HMP biofiltration facilities and outlet structures provide mitigation for the 100-year, 6-hour storm event peak flow rate. Runoff leaving the site from basin PR-1 continues south off our property. The resulting total peak discharge leaving the site is 0.31 cfs, which when combined with the hillside area (PR-2 & PR-3) considered in the analysis results in a total discharge of 1.12 cfs. This below the pre-development Q100 of 7.17 cfs for the same drainage area. Refer to Appendix A of this Hydrology Report and also to Appendix B for the HydroCAD-10 detailed output, which shows the effect of the detention characteristics of the biofiltration basins on the resulting peak discharge and time of concentration leaving the subject property. 3.3.1 Proposed Detained Condition Output Summary (100-Year Event) Summary of Pre-Development Flows Pre-Development (Basin EX:1) Pre-Development (Basin EX:2) EX-102: Q100 = 2.40 cfs EX-202: Q100 = 1.48 cfs Pre-Development (Basin EX:3) Pre-Development (Basin EX:4) EX-302: Q100 = 1.48 cfs EX-402: Q100 = 1.81 cfs Summary of Post-Development Flows (Mitigated) Post-Development (PR-1) (PR-208) Post-Development (PR-1) (PR-308) (MIT) Q100 = 0.14 cfs (MIT) Q100 = 0.17 cfs PLSA 3657-01 Page 17 of 21 Peak Runoff Generated (Onsite) Mitigated/Unmitigated Comparison of Flows (Pre vs. Post Development) Pre-Development (Basin EX:1) Post-Development (PR-1) Delta EX-102: Q100 = 2.40 cfs PR-308: (UNMIT) Q100 = 4.88 cfs +2.48 cfs (MIT) Q100 = 0.17 cfs -2.23 cfs Pre-Development (Basin EX:2) Post-Development (PR-1) Delta EX-202: Q100 = 1.48 cfs PR-208: (UNMIT) Q100 = 6.82 cfs +5.34 cfs (MIT) Q100 = 0.14 cfs -1.34 cfs Pre-Development (Basin EX:3) Post-Development (PR-3) Delta EX-302: Q100 = 1.48 cfs PR-3: Q100 = 0.31 cfs -1.17 cfs Pre-Development (Basin EX:4) Post-Development (PR-2) Delta EX-402: Q100 = 1.81 cfs PR-2: Q100 = 0.50 cfs -1.31 cfs 3.4 Hydromodification Analysis Refer to the project Storm Water Quality Management Plan (SWQMP) prepared by Pasco, Laret, Suiter & Associates under separate cover for discussion of hydromodification management strategy and compliance to satisfy the requirements of the MS4 Permit. 3.5 Storm Water Pollutant Control To meet the requirements of the MS4 Permit, the HMP bioretention facility is designed to treat onsite storm water pollutants contained in the volume of runoff from a 24-hour, 85th percentile storm event by slowly infiltrating runoff through an engineered soil layer. Refer to the project Storm Water Quality Management Plan (SWQMP) prepared by Pasco, Laret, Suiter & Associates under separate cover for discussion of pollutant control. - - ____________________________________________________________________________ **************************************************************************** RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT 2003,1985,1981 HYDROLOGY MANUAL (c) Copyright 1982-2016 Advanced Engineering Software (aes) Ver. 23.0 Release Date: 07/01/2016 License ID 1452 Analysis prepared by: ************************** DESCRIPTION OF STUDY ************************** * PASCO LARET SUITER & ASSOCIATES * * 3657 POST DEVELOPMENT HYDRO STUDY * * BASIN PR-1 (MITIGATED / DETAINED) * ************************************************************************** FILE NAME: 3657MIT1.DAT TIME/DATE OF STUDY: 12:14 03/30/2023 ---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: ---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 100.00 6-HOUR DURATION PRECIPITATION (INCHES) = 2.600 SPECIFIED MINIMUM PIPE SIZE(INCH) = 3.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR NO. (FT) (FT) SIDE / SIDE/ WAY (FT) (FT) (FT) (FT) (n) === ===== ========= ================= ====== ===== ====== ===== ======= 1 17.0 12.0 0.018/0.018/0.020 0.50 1.50 0.0313 0.125 0.0150 GLOBAL STREET FLOW-DEPTH CONSTRAINTS: 1. Relative Flow-Depth = 0.50 FEET as (Maximum Allowable Street Flow Depth) - (Top-of-Curb) 2. (Depth)*(Velocity) Constraint = 10.0 (FT*FT/S) *SIZE PIPE WITH A FLOW CAPACITY GREATER THAN OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.* **************************************************************************** FLOW PROCESS FROM NODE 100.00 TO NODE 101.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 51.00 UPSTREAM ELEVATION(FEET) = 324.80 DOWNSTREAM ELEVATION(FEET) = 324.30 ELEVATION DIFFERENCE(FEET) = 0.50 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.340 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.877 SUBAREA RUNOFF(CFS) = 0.18 TOTAL AREA(ACRES) = 0.05 TOTAL RUNOFF(CFS) = 0.18 **************************************************************************** FLOW PROCESS FROM NODE 101.00 TO NODE 102.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 323.30 DOWNSTREAM(FEET) = 322.90 FLOW LENGTH(FEET) = 71.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 6.0 INCH PIPE IS 2.9 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 1.95 GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.18 PIPE TRAVEL TIME(MIN.) = 0.61 Tc(MIN.) = 6.95 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 102.00 = 122.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 102.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.541 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6100 SUBAREA AREA(ACRES) = 0.13 SUBAREA RUNOFF(CFS) = 0.44 TOTAL AREA(ACRES) = 0.2 TOTAL RUNOFF(CFS) = 0.61 TC(MIN.) = 6.95 **************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 103.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 322.90 DOWNSTREAM(FEET) = 321.80 FLOW LENGTH(FEET) = 87.00 MANNING'S N = 0.013 ASSUME FULL-FLOWING PIPELINE PIPE-FLOW VELOCITY(FEET/SEC.) = 3.10 PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.61 PIPE TRAVEL TIME(MIN.) = 0.47 Tc(MIN.) = 7.42 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 103.00 = 209.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 103.00 TO NODE 104.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>(STREET TABLE SECTION # 1 USED)<<<<< ============================================================================ UPSTREAM ELEVATION(FEET) = 321.80 DOWNSTREAM ELEVATION(FEET) = 315.43 STREET LENGTH(FEET) = 75.00 CURB HEIGHT(INCHES) = 6.0 STREET HALFWIDTH(FEET) = 17.00 DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 12.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018 OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018 SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1 STREET PARKWAY CROSSFALL(DECIMAL) = 0.020 Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.89 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW: STREET FLOW DEPTH(FEET) = 0.18 HALFSTREET FLOOD WIDTH(FEET) = 2.87 AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.61 PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.83 STREET FLOW TRAVEL TIME(MIN.) = 0.27 Tc(MIN.) = 7.69 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.191 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.610 SUBAREA AREA(ACRES) = 0.18 SUBAREA RUNOFF(CFS) = 0.57 TOTAL AREA(ACRES) = 0.4 PEAK FLOW RATE(CFS) = 1.14 END OF SUBAREA STREET FLOW HYDRAULICS: DEPTH(FEET) = 0.20 HALFSTREET FLOOD WIDTH(FEET) = 3.85 FLOW VELOCITY(FEET/SEC.) = 4.51 DEPTH*VELOCITY(FT*FT/SEC.) = 0.89 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 104.00 = 284.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 104.00 TO NODE 105.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 312.43 DOWNSTREAM(FEET) = 303.00 FLOW LENGTH(FEET) = 21.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 1.6 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 14.26 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 1.14 PIPE TRAVEL TIME(MIN.) = 0.02 Tc(MIN.) = 7.71 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 105.00 = 305.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 105.00 TO NODE 105.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 7.71 RAINFALL INTENSITY(INCH/HR) = 5.18 TOTAL STREAM AREA(ACRES) = 0.36 PEAK FLOW RATE(CFS) AT CONFLUENCE = 1.14 **************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 201.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 86.00 UPSTREAM ELEVATION(FEET) = 316.30 DOWNSTREAM ELEVATION(FEET) = 315.00 ELEVATION DIFFERENCE(FEET) = 1.30 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.552 WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 72.67 (Reference: Table 3-1B of Hydrology Manual) THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.754 SUBAREA RUNOFF(CFS) = 0.49 TOTAL AREA(ACRES) = 0.14 TOTAL RUNOFF(CFS) = 0.49 **************************************************************************** FLOW PROCESS FROM NODE 201.00 TO NODE 202.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 312.50 DOWNSTREAM(FEET) = 311.90 FLOW LENGTH(FEET) = 64.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 6.0 INCH PIPE IS 4.7 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 3.00 GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.49 PIPE TRAVEL TIME(MIN.) = 0.36 Tc(MIN.) = 6.91 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 202.00 = 150.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 202.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.562 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6100 SUBAREA AREA(ACRES) = 0.03 SUBAREA RUNOFF(CFS) = 0.10 TOTAL AREA(ACRES) = 0.2 TOTAL RUNOFF(CFS) = 0.58 TC(MIN.) = 6.91 **************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 203.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 311.90 DOWNSTREAM(FEET) = 311.05 FLOW LENGTH(FEET) = 57.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 6.0 INCH PIPE IS 4.4 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 3.75 GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.58 PIPE TRAVEL TIME(MIN.) = 0.25 Tc(MIN.) = 7.16 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 203.00 = 207.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 203.00 TO NODE 204.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>(STREET TABLE SECTION # 1 USED)<<<<< ============================================================================ UPSTREAM ELEVATION(FEET) = 311.05 DOWNSTREAM ELEVATION(FEET) = 306.58 STREET LENGTH(FEET) = 98.00 CURB HEIGHT(INCHES) = 6.0 STREET HALFWIDTH(FEET) = 17.00 DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 12.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018 OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018 SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1 STREET PARKWAY CROSSFALL(DECIMAL) = 0.020 Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.77 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW: STREET FLOW DEPTH(FEET) = 0.27 HALFSTREET FLOOD WIDTH(FEET) = 7.95 AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.04 PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 1.10 STREET FLOW TRAVEL TIME(MIN.) = 0.40 Tc(MIN.) = 7.56 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.245 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.610 SUBAREA AREA(ACRES) = 1.37 SUBAREA RUNOFF(CFS) = 4.38 TOTAL AREA(ACRES) = 1.5 PEAK FLOW RATE(CFS) = 4.93 END OF SUBAREA STREET FLOW HYDRAULICS: DEPTH(FEET) = 0.32 HALFSTREET FLOOD WIDTH(FEET) = 10.39 FLOW VELOCITY(FEET/SEC.) = 4.54 DEPTH*VELOCITY(FT*FT/SEC.) = 1.43 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 204.00 = 305.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 204.00 TO NODE 205.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 303.58 DOWNSTREAM(FEET) = 303.00 FLOW LENGTH(FEET) = 6.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 4.9 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 12.83 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 4.93 PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 7.57 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 205.00 = 311.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 206.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.241 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6100 SUBAREA AREA(ACRES) = 0.13 SUBAREA RUNOFF(CFS) = 0.42 TOTAL AREA(ACRES) = 1.7 TOTAL RUNOFF(CFS) = 5.34 TC(MIN.) = 7.57 **************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 206.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< >>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 7.57 RAINFALL INTENSITY(INCH/HR) = 5.24 TOTAL STREAM AREA(ACRES) = 1.67 PEAK FLOW RATE(CFS) AT CONFLUENCE = 5.34 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 1.14 7.71 5.180 0.36 2 5.34 7.57 5.241 1.67 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH/HOUR) 1 6.46 7.57 5.241 2 6.42 7.71 5.180 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 6.46 Tc(MIN.) = 7.57 TOTAL AREA(ACRES) = 2.0 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 206.00 = 311.00 FEET. +--------------------------------------------------------------------------+ | FLOW UPDATED PER MITIGATED Q100 FROM BMP | | TC UPDATED PER MITIGATED TC FROM BMP | | CONTINUE PROCESSING | +--------------------------------------------------------------------------+ **************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 206.00 IS CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<< ============================================================================ USER-SPECIFIED VALUES ARE AS FOLLOWS: TC(MIN) = 120.10 RAIN INTENSITY(INCH/HOUR) = 0.88 TOTAL AREA(ACRES) = 2.03 TOTAL RUNOFF(CFS) = 0.04 **************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 207.00 IS CODE = 41 ---------------------------------------------------------------------------- ** WARNING: Computed Flowrate is less than 0.1 cfs, Routing Algorithm is UNAVAILABLE. **************************************************************************** FLOW PROCESS FROM NODE 207.00 TO NODE 208.00 IS CODE = 41 ---------------------------------------------------------------------------- ** WARNING: Computed Flowrate is less than 0.1 cfs, Routing Algorithm is UNAVAILABLE. **************************************************************************** FLOW PROCESS FROM NODE 208.00 TO NODE 208.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 0.882 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.0682 SUBAREA AREA(ACRES) = 0.33 SUBAREA RUNOFF(CFS) = 0.10 TOTAL AREA(ACRES) = 2.4 TOTAL RUNOFF(CFS) = 0.14 TC(MIN.) = 120.10 **************************************************************************** FLOW PROCESS FROM NODE 300.00 TO NODE 300.00 IS CODE = 10 ---------------------------------------------------------------------------- >>>>>MAIN-STREAM MEMORY COPIED ONTO MEMORY BANK # 1 <<<<< ============================================================================ **************************************************************************** FLOW PROCESS FROM NODE 300.00 TO NODE 301.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< ============================================================================ *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 INITIAL SUBAREA FLOW-LENGTH(FEET) = 76.00 UPSTREAM ELEVATION(FEET) = 309.80 DOWNSTREAM ELEVATION(FEET) = 309.10 ELEVATION DIFFERENCE(FEET) = 0.70 SUBAREA OVERLAND TIME OF FLOW(MIN.) = 7.174 WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 62.63 (Reference: Table 3-1B of Hydrology Manual) THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.427 SUBAREA RUNOFF(CFS) = 0.20 TOTAL AREA(ACRES) = 0.06 TOTAL RUNOFF(CFS) = 0.20 **************************************************************************** FLOW PROCESS FROM NODE 301.00 TO NODE 302.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 308.55 DOWNSTREAM(FEET) = 308.10 FLOW LENGTH(FEET) = 45.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 6.0 INCH PIPE IS 2.5 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 2.52 GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.20 PIPE TRAVEL TIME(MIN.) = 0.30 Tc(MIN.) = 7.47 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 302.00 = 121.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 302.00 TO NODE 302.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.287 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6100 SUBAREA AREA(ACRES) = 0.01 SUBAREA RUNOFF(CFS) = 0.03 TOTAL AREA(ACRES) = 0.1 TOTAL RUNOFF(CFS) = 0.23 TC(MIN.) = 7.47 **************************************************************************** FLOW PROCESS FROM NODE 302.00 TO NODE 303.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 308.10 DOWNSTREAM(FEET) = 307.70 FLOW LENGTH(FEET) = 24.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 6.0 INCH PIPE IS 2.4 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 3.11 GIVEN PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.23 PIPE TRAVEL TIME(MIN.) = 0.13 Tc(MIN.) = 7.60 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 303.00 = 145.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 303.00 TO NODE 304.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>(STREET TABLE SECTION # 1 USED)<<<<< ============================================================================ UPSTREAM ELEVATION(FEET) = 307.70 DOWNSTREAM ELEVATION(FEET) = 305.58 STREET LENGTH(FEET) = 187.00 CURB HEIGHT(INCHES) = 6.0 STREET HALFWIDTH(FEET) = 17.00 DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 12.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018 OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018 SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1 STREET PARKWAY CROSSFALL(DECIMAL) = 0.020 Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.31 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW: STREET FLOW DEPTH(FEET) = 0.31 HALFSTREET FLOOD WIDTH(FEET) = 10.11 AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.23 PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.69 STREET FLOW TRAVEL TIME(MIN.) = 1.40 Tc(MIN.) = 9.00 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.690 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.610 SUBAREA AREA(ACRES) = 1.45 SUBAREA RUNOFF(CFS) = 4.15 TOTAL AREA(ACRES) = 1.5 PEAK FLOW RATE(CFS) = 4.35 END OF SUBAREA STREET FLOW HYDRAULICS: DEPTH(FEET) = 0.37 HALFSTREET FLOOD WIDTH(FEET) = 13.20 FLOW VELOCITY(FEET/SEC.) = 2.59 DEPTH*VELOCITY(FT*FT/SEC.) = 0.95 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 304.00 = 332.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 304.00 TO NODE 305.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 303.20 DOWNSTREAM(FEET) = 303.00 FLOW LENGTH(FEET) = 7.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.2 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 7.99 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 4.35 PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 9.01 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 305.00 = 339.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 305.00 TO NODE 306.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.685 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .6100 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.6100 SUBAREA AREA(ACRES) = 0.13 SUBAREA RUNOFF(CFS) = 0.37 TOTAL AREA(ACRES) = 1.7 TOTAL RUNOFF(CFS) = 4.72 TC(MIN.) = 9.01 +--------------------------------------------------------------------------+ | FLOW UPDATED PER MITIGATED Q100 FROM BMP | | TC UPDATED PER MITIGATED TC FROM BMP | | CONTINUE PROCESSING | +--------------------------------------------------------------------------+ **************************************************************************** FLOW PROCESS FROM NODE 306.00 TO NODE 306.00 IS CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<< ============================================================================ USER-SPECIFIED VALUES ARE AS FOLLOWS: TC(MIN) = 117.00 RAIN INTENSITY(INCH/HOUR) = 0.90 TOTAL AREA(ACRES) = 1.65 TOTAL RUNOFF(CFS) = 0.11 **************************************************************************** FLOW PROCESS FROM NODE 306.00 TO NODE 307.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 295.50 DOWNSTREAM(FEET) = 294.05 FLOW LENGTH(FEET) = 134.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 1.3 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 1.89 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.11 PIPE TRAVEL TIME(MIN.) = 1.18 Tc(MIN.) = 118.18 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 307.00 = 473.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 307.00 TO NODE 308.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 293.95 DOWNSTREAM(FEET) = 292.00 FLOW LENGTH(FEET) = 41.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 0.9 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 3.14 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.11 PIPE TRAVEL TIME(MIN.) = 0.22 Tc(MIN.) = 118.40 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 308.00 = 514.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 308.00 TO NODE 308.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< ============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 0.890 *USER SPECIFIED(SUBAREA): RESIDENTIAL (7.3 DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0 AREA-AVERAGE RUNOFF COEFFICIENT = 0.1042 SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.06 TOTAL AREA(ACRES) = 1.9 TOTAL RUNOFF(CFS) = 0.17 TC(MIN.) = 118.40 ============================================================================ END OF STUDY SUMMARY: TOTAL AREA(ACRES) = 1.9 TC(MIN.) = 118.40 PEAK FLOW RATE(CFS) = 0.17 ============================================================================ ============================================================================ END OF RATIONAL METHOD ANALYSIS PLSA 3657-01 Page 18 of 21 4.0 HYDRAULIC CALCULATIONS 4.1 Determination of Private Storm Drain Piping, Area Drain / Grate, and Curb Outlet Capacity Capacity and sizing for all drainage structures and facilities within each proposed lot were determined by each new parcel into sub-areas that would contribute to each drainage facility as shown in the Hydraulic Capacity Exhibit included in this section of the report. Lots 5, 6, and 7 were chosen to size drainage facilities on the remaining lots, assuming a worse-case scenario for each drainage facility that could be applied to the remaining homes. The maximum flow rate was calculated using the Rational Method for the several drainage scenarios as outlined below in Tables 4-6. Consideration was taken for lots with one (1) discharge location onto Twain Court, and lots with two (2) discharge locations onto Twain Court. Each condition was broken down into several different categories based on square footage of the usable pad areas for use in sizing onsite grated inlets, storm drain piping, as well as drainage outlet structures discharging from each lot to the Twain Court curb face. LOT GRATED INLET SIZING GRATED INLET LOT LOCATION Q100 (INLET) AREA (INLET) RAINFALL INTENSITY 1 5 0.49 CFS 0.14 AC 6.85 in / hr 2 6 0.38 CFS 0.09 AC 6.85 in / hr 3 7 0.31 CFS 0.075 AC 6.85 in / hr Table 4. Grated Inlet Peak Flow Rates The onsite grated inlet capacity was determined using the methodology from chapter 2 of the San Diego County Hydraulic Design Manual (September, 2014). The grate capacity was checked assuming 50 percent clogging in orifice and weir conditions as shown in this section of the report. Grated Inlet #1 was used to size all the proposed inlets on Lot 5, which has the largest usable pad area of 13,350 SF. Each inlet on Lot 5 is proposed to have a minimum of 7” of freeboard between the top of grate at the inlet location and either the building pad elevation or local high point within the side yards. Grated Inlet #2 and #3 were used to size the remaining inlets within the subject property. All remaining inlets have been designed to ensure a minimum of 6” of freeboard between the top of grate at the inlet location and building pad elevations in order to convey the 100-year, 6-hour storm peak flow rate assuming a 50% clogging factor. Based on the available head above each proposed inlet, it was determined the inlets at 50 percent clogging will convey peak flows generated without impacting the proposed building footprints. Additionally, the lots are proposed to be graded such that runoff will crest over a local high point and surface flow to Twain Court in the event the rear yard inlets are clogged and not functioning. PLSA 3657-01 Page 19 of 21 LOT PRIVATE STORM DRAIN PIPE SIZING PIPE FLOW LOT LOCATION Q100 (PIPING) AREA (PIPING) RAINFALL INTENSITY MIN PIPE SIZE / SLOPE 1 5 0.29 CFS 0.07 Ac 6.85 in / hr 4” PVC @ 2.0% 2 5 0.42 CFS 0.10 Ac 6.85 in / hr 6” PVC @ 0.6% 3 5 0.58 CFS 0.14 Ac 6.85 in / hr 6” PVC @ 1.0% 4 6 0.18 CFS 0.04 Ac 6.85 in / hr 4” PVC @ 1.0% 5 7 0.31 CFS 0.075 Ac 6.85 in / hr 6” PVC @ 0.6% 6 7 0.50 CFS 0.12 Ac 6.85 in / hr 6” PVC @ 0.6% Table 5. Private Storm Drain Peak Flow Rates A minimum time of concentration of 5.0 minutes was used in the rainfall intensity calculation to estimate a conservative value of the peak flow rate to each pipe stretch. The storm drain piping proposed on each lot has been proven to provide the minimum capacity to convey the 100-year, 6-hour storm peak flow rate. After determining the peak flows, a minimum pipe slope based on pipe size was calculated for each sub-area using the Civil 3D extension Hydraflow express as shown in this section of the report. Pipe Flow #1, 2, and 3 are applied to the stretches of Lot 5 as shown on the Hydraulic Capacity Exhibit. Pipe Flow #4 is applied to all piping on Lots 6, 10, 11, 12, and 13 that discharge from two different locations onto Twain Court. Curb outlets at each discharge location as described in the subsequent section. Pipe Flow #5 and #6 are applied to the initial two pipe runs for Lots 1, 2, 3, 4, 7, 8, and 9 as all these lots have similar usable pad areas, with Lot 7 used as the worst case scenario. Curb outlets at the single discharge location from each property as described in the subsequent section of this report. LOT CURB OUTLET SIZING CURB OUTLET LOT LOCATION Q100 (OUTLET) AREA (OUTLET) RAINFALL INTENSITY 1 5 1.04 CFS 0.31 5.5 in / hr 2 6 0.34 CFS 0.10 5.5 in / hr 3 7 0.70 CFS 0.21 5.5 in / hr Table 6. Curb Outlet Peak Flow Rates A time of concentration of 7.0 minutes was used in the rainfall intensity calculation to estimate peak flow rates received by the proposed curb outlet systems. The time of PLSA 3657-01 Page 20 of 21 concentration was calculated using AES for streams beginning in the rear yards of Lots 1 and 12 as can be seen in the separate post-project node map. This was determined to be over 7.0 minutes for both lots discharging out to Twain Court – as such, a time of concentration of 7.0 minutes can be conservatively assumed for all lots. Curb Outlet #1 is a standard curb outlet per SDRSD D-25A and is proposed for Lot 5, which has the largest usable pad area to convey to Twain Court. Curb Outlet #2 is applied to Lots 6, 10, 11, 12, and 13 as they all have similar usable pad areas, and will consist of 2x 3” PVC sidewalk under drain pipes sloped at 2.0% to core to the curb face (2x discharge locations from these lots). Curb Outlet #3 is applied to Lots 1, 2, 3, 4, 7, 8, and 9 as all these lots have similar usable pad areas, and will consist of a curb outlet per SDRSD D-25A, modified to a 1.5-ft wide channel sloped at 2.0% to the curb face. Additionally, hydraulic calculations for a number of other drainage facilities proposed on the project are included in this section. Refer to the attached exhibits and calculations for sizing for proposed curb inlet openings within Twain Court, storm drain outfall piping from the proposed BMP’s, brow ditch adjacent the BMP area, grated inlets within each BMP assuming 50 percent clogging to convey the unmitigated peak flow, and rock rip rap class based on velocities leaving the disturbed area. SHEDS SCATTERED BRUSH TREE DIRT DIRT DIRT BRUSH DENSE BRUSH AND TREES SCATTERED BRUSH BRUSH SCATTERED BRUSH SCATTERED BRUSH TREES TREES BRUSH SCATTERED BRUSH SCATTERED BRUSH SCATTERED BRUSH S S WW TRASHCAN ASPHALT CONC CONC CONC 6FT CONCRETE BLOCK WALL 325 325325 325 3 2 5 325 3 2 0 3 2 0 3 2 0 32 0 32 0 320 32 0 320 320 320 320 3 2 0 31 5 31 5 315 31 5 31 5 315 315 315 315 31 5 31 5 315 315 3 1 5 315 310 31 0 310 310 310 31 0 31 0 310 310 31 0 310 31 0 3 1 0 31 0 31 0 31 0 31 0 305 30 5 30 5 3 0 5 3 0 5 3 0 5 30 5 305 30 5 305 305 305 3 0 5 305 305 30 5 305 30 0 300 30 0 300 30 0 30 0 30 0 30 0 300 300 300 30 0 300 3 0 0 300 3 0 0 300 30 0 29 5 295 2 9 5 29 5 295 2 9 5 29 5 29 5 29 5 295 295 295 295 295 295 2 9 5 295 29 5 295 29 5 290 29 0 290 29 0 290 2 9 0 290 29 0 290 290 2 9 0 290 290 29 0 29 0 2 9 0 2 9 0 290 2 9 0 285 285 285 2 8 5 285 285 28 5 2 8 5 285 2 8 5 285 2 8 5 285 28 5 28 5 285 2 8 0 28 0 2 8 0 2 8 0 2 8 0 28 0 280 28 0 2 8 0 28 0 280 28 0 280 28 0 28 0 28 0 275 275 2 7 5 275 2 7 5 27 5 27 5 275 275 27 5 2 7 5 275 2 7 5 27 5 2 7 0 27 0 270 270 27 0 270 270 2 7 0 27 0 270 270 270 265 265 265 26 5 26 5 265 26 0 260 26 0 260 26 0 26 0 260 255 255 25 5 25 5 255 25 0 250 250 24 5 245 245 24 0 23 5 235 325 324 32 3 32 2 32 1 327.4322.1 322.1 321.9 327.9 328.1 328.7 327.8 TW=334.00 TW=334.66 TW=334.68 TW=334.62 TW=333.96 TW=333.95 320 315 325 324 321 320 319 316 31 5 314 31 6 31 5 316 3 1 4 31 5 31 4 313 310 308 312304 306 308 310 30 6 30 8 31 2 3 0 6 3 0 8 3 0 7 303 304 305 306 308 309 310 311 32 0 31 9 31 8 317 316 3 1 5 31 0 310 305 300 295 290 2 9 0 285 280 275 275 2 8 0 28 5 29 0 29 5 29 5 29 0 285 285 290 295 305 31 5 3 1 0 3 0 0 30 5 31 0 315 32 0 // // 326 // // ////// // // // // // // // //// 1+ 5 0 2 + 0 0 2 + 5 0 3 + 0 0 3+50 4+00 4+5 0 5 + 0 0 5 + 5 0 317 326 H H J J W W W W W W S S S SSSS S S S S SD S S G G G SD SD SD SD SD SD SD SD SD SD SD SD S S S W W W W XXXX 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 X X X X X X X X X X X X X X X X 280 275 290 285 290 295 305 300 310 3 0 5 3 1 0 3 1 5 3 0 5 3 1 0 300 295 290 305 3 1 5 320 315 3 1 0 325 305 300 295 LOT 1 10,356 S.F.0.238 AC. LOT 2 10,428 S.F.0.239 AC. LOT 3 12,508 S.F.0.287 AC. LOT 4 11,767 S.F.0.270 AC. LOT 5 19,660 S.F.0.451 AC. LOT 9 19,376 S.F.0.445 AC. LOT 13 10,899 S.F.0.250 AC. TW A I N A V E BMP #2 FG = 303.0 VE R N E V I E W (P R I V A T E R O A D ) BMP #1 FG = 303.0 GRATED INLET #1 *Q100 IN = 0.49 CFS 12"X12" INLET PIPE FLOW #1 A = 0.07 AC Q100 = 0.29 CFS PIPE FLOW #5 A = 0.075 AC Q100 = 0.31 CFS CURB OUTLET #2 A = 0.10 AC Q100 OUT= 0.4 CFS Q100 = 0.33 CFS 6" PVC @ 0.6% CURB INLET #2 ON GRADE Q100 = 4.93 CFS CURB INLET #1 ON GRADE Q100 = 1.14 CFS BMP #1 GRATED INLET 6" FREEBOARD Q100 UNMIT= 4.35 CFS LOT 2 PAD AREA ~ 7,750 SF LOT 1 PAD AREA ~ 8,500 SF LOT 3 PAD AREA ~ 8,250 SF LOT 4 PAD AREA ~ 8,150 SF LOT 5 PAD AREA ~ 13,350 SF LOT 8 PAD AREA ~ 7,400 SF RIP RAP LOCATION #7 RIP RAP LOCATION #2 RIP RAP LOCATION #1 RIP RAP LOCATION #6 RIP RAP LOCATION #4 CURB INLET #3 SAG INLET Q100 = 4.35 CFS RIP RAP LOCATION #3 RIP RAP LOCATION #5 LOT 6 PAD AREA ~ 8,700 SF LOT 7 PAD AREA ~ 9,050 SF LOT 9 PAD AREA ~ 8,700 SF LOT 10 PAD AREA ~ 6,400 SF LOT 11 PAD AREA ~ 6,350 SF LOT 13 PAD AREA ~ 8,200 SF LOT 12 PAD AREA ~ 8,700 SF Q100 = 0.33 CFS 6" PVC @ 0.6% GRATED INLET #1 0.14 AC PIPE FLOW #4 A = 0.04 AC Q100 = 0.17 CFS GRATED INLET #2 0.09 AC GRATED INLET #3 0.075 AC GRATED INLET #2 Q100 IN = 0.38 CFS 12"X12" INLET CURB OUTLET #1 A = 0.2 AC Q100 OUT= 0.6 CFS GRATED INLET #3 Q100 IN = 0.31 CFS 12"X12" INLET PIPE FLOW #6 A = 0.12 AC Q100 = 0.5 CFS PIPE FLOW #2 A = 0.10 AC Q100 = 0.42 CFS CURB OUTLET #3 A = 0.10 AC Q100 OUT= 0.4 CFS PIPE FLOW #3 A = 0.14 AC Q100 = 0.58 CFS RIP RAP #6 0.130 AC RIP RAP #7 0.130 AC 30 60 90 GRAPHIC SCALE 1" = 30' 030 PLAN VIEW - HYDRAULIC CAPACITY EXHIBIT INLETS AND PIPING SCALE: 1" = 30' HORIZONTAL PLSA 3657J:\ACTIVE JOBS\3657 RINCON OCEAN VIEW POINT\CIVIL\REPORTS\HYDROLOGY\HYDRAULICS\3657-CV-HYDRAULICS.DWG LEGEND PROPERTY BOUNDARY CENTERLINE OF ROAD RIGHT-OF-WAY ADJACENT PROPORTY LINE EXISTING CONTOUR LINE PROPOSED PATH OF TRAVEL PROPOSED HYDRAULIC ELEMENT BASIN BOUNDARY (GRATED INLET) PROPOSED HYDRAULIC ELEMENT BASIN BOUNDARY (PIPE FLOW) PROPOSED HYDRAULIC ELEMENT BASIN BOUNDARY (CURB OUTLET) PROPOSED MINOR DRAINAGE BASINBOUNDARY (SEE SEPARATE POST-PROJECT NODE MAP) PROPOSED MAJOR DRAINAGE BASIN BOUNDARY (SEE SEPARATE POST-PROJECT NODE MAP) SEE SEPARATE POST-PROJECT NODE MAP FOR PROPOSED IMPERVIOUSAREA 140 HYDRAULIC CAPACITY EXHIBIT TERMINUS OF TWAIN AVENUE CITY OF CARLSBAD - - ------- ------- ------- PASCO LARET SUITER ----• ~ ffe.$$«'.lllC!ffe.TIE$ San Diego I Solana Beach I Orange County Phone 858.259.82121 www.plsaengineering.com GRATED INLET #1: 12-in Grated Inlet in Sag (Assumed 50% Clogging) Cw 3 Unitless L 1 ft Pe 2.00 ft W 1 ft C0 0.67 Unitless Ae 0.5 *Pe assumes 50% clogging Weir Orifice Q (cfs)d (ft)Q (cfs)d (ft) 0.00 0.1 1.34 0.25 0.02 0.2 1.90 0.5 0.08 0.3 2.33 0.75 0.192 0.4 2.69 1 0.38 0.5 3.01 1.25 0.65 0.6 3.29 1.5 Step 1. Calculate the capacity of a grate inlet operating as a weir, using the w eir e,quation (Equation 2 -,]6) ,vith a length equivalent to p eri1nete.r· of th.e gn1te. When the grate is located n ext to a ,curb,. disregard the length of the grate against the curb. (2-16) whe:i-e ... Q Cw P e d inlet ,capacity of the grated mlet (ft3'/ ); w eir ,coeffici,ent (Cw=3.0 £or U.S. Traditional Units)· ,effective grate perimeter length. (ft); and flow depth approaching inlet (ft). To account for th e ,effects of clogging of a grated inlet operating as a w eir,. a dogging factoi-of fifty percent (CL-0.50) haU b e applied to the actual (undogged) p eri1nete.r· of the grate (P): Step 2. Calculate the capacity of a grate inlet operating as an orifi ce. Use the orifi ce equation (Equation 2-18), assuming the clear opening of the grate reduced by a clogging factor CA=0.50 (Equation 2-19). A San Diego Regiona l Standard No. D-l5 grate has an actual clear opening of A=4.7 ft2. The F ederal Highway Administration's Urban Drainage Desig n Manual (HEC-22) provides guidance for other grate types an d configurations. (2 -18) (2-19) where ... Q inlet capacity of the grated inlet (ft3/s); C0 orifice coefficient (C0 =0.67 for U.S. Traditional Units); g gravitational acceleration (ft/s2); d = flow depth above inlet (ft); Ae effective (clogged) grate area (ft2); CA area clogging factor (CA=0.50); and A actual opening area of the grate inlet (i.e., the total area less the area of bars or vanes). The actual opening area for a San Diego Regional Standard No. D-15 grate is A=4.7 ft2. The Federal Highway Administration's Urban Drainage D esign Manual (HEC-22) provides guidance for other grate types and configurations. GRATED INLET #2: 12-in Grated Inlet in Sag (Assumed 50% Clogging) Cw 3 Unitless L 1 ft Pe 2.00 ft W 1 ft C0 0.67 Unitless Ae 0.5 *Pe assumes 50% clogging Weir Orifice Q (cfs)d (ft)Q (cfs)d (ft) 0.00 0.1 1.34 0.25 0.02 0.2 1.90 0.5 0.08 0.3 2.33 0.75 0.192 0.4 2.69 1 0.38 0.5 3.01 1.25 0.65 0.6 3.29 1.5 Step 1. Calculate the capacity of a grate inlet operating as a weir, using the w eir e,quation (Equation 2 -,]6) ,vith a length equivalent to p eri1nete.r· of th.e gn1te. When the grate is located n ext to a ,curb,. disregard the length of the grate against the curb. (2-16) whe:i-e ... Q Cw P e d inlet ,capacity of the grated mlet (ft3'/ ); w eir ,coeffici,ent (Cw=3.0 £or U.S. Traditional Units)· ,effective grate perimeter length. (ft); and flow depth approaching inlet (ft). To account for th e ,effects of clogging of a grated inlet operating as a w eir,. a dogging factoi-of fifty percent (CL-0.50) haU b e applied to the actual (undogged) p eri1nete.r· of the grate (P): Step 2. Calculate the capacity of a grate inlet operating as an orifi ce. Use the orifi ce equation (Equation 2-18), assuming the clear opening of the grate reduced by a clogging factor CA=0.50 (Equation 2-19). A San Diego Regiona l Standard No. D-l5 grate has an actual clear opening of A=4.7 ft2. The F ederal Highway Administration's Urban Drainage Desig n Manual (HEC-22) provides guidance for other grate types an d configurations. (2 -18) (2-19) where ... Q inlet capacity of the grated inlet (ft3/s); C0 orifice coefficient (C0 =0.67 for U.S. Traditional Units); g gravitational acceleration (ft/s2); d = flow depth above inlet (ft); Ae effective (clogged) grate area (ft2); CA area clogging factor (CA=0.50); and A actual opening area of the grate inlet (i.e., the total area less the area of bars or vanes). The actual opening area for a San Diego Regional Standard No. D-15 grate is A=4.7 ft2. The Federal Highway Administration's Urban Drainage D esign Manual (HEC-22) provides guidance for other grate types and configurations. GRATED INLET #2: 12-in Grated Inlet in Sag (Assumed 50% Clogging) Cw 3 Unitless L 1 ft Pe 2.00 ft W 1 ft C0 0.67 Unitless Ae 0.5 *Pe assumes 50% clogging Weir Orifice Q (cfs)d (ft)Q (cfs)d (ft) 0.00 0.1 1.34 0.25 0.02 0.2 1.90 0.5 0.08 0.3 2.33 0.75 0.192 0.4 2.69 1 0.38 0.5 3.01 1.25 0.65 0.6 3.29 1.5 Step 1. Calculate the capacity of a grate inlet operating as a weir, using the w eir e,quation (Equation 2 -,]6) ,vith a length equivalent to p eri1nete.r· of th.e gn1te. When the grate is located n ext to a ,curb,. disregard the length of the grate against the curb. (2-16) whe:i-e ... Q Cw P e d inlet ,capacity of the grated mlet (ft3'/ ); w eir ,coeffici,ent (Cw=3.0 £or U.S. Traditional Units)· ,effective grate perimeter length. (ft); and flow depth approaching inlet (ft). To account for th e ,effects of clogging of a grated inlet operating as a w eir,. a dogging factoi-of fifty percent (CL-0.50) haU b e applied to the actual (undogged) p eri1nete.r· of the grate (P): Step 2. Calculate the capacity of a grate inlet operating as an orifi ce. Use the orifi ce equation (Equation 2-18), assuming the clear opening of the grate reduced by a clogging factor CA=0.50 (Equation 2-19). A San Diego Regiona l Standard No. D-l5 grate has an actual clear opening of A=4.7 ft2. The F ederal Highway Administration's Urban Drainage Desig n Manual (HEC-22) provides guidance for other grate types an d configurations. (2 -18) (2-19) where ... Q inlet capacity of the grated inlet (ft3/s); C0 orifice coefficient (C0 =0.67 for U.S. Traditional Units); g gravitational acceleration (ft/s2); d = flow depth above inlet (ft); Ae effective (clogged) grate area (ft2); CA area clogging factor (CA=0.50); and A actual opening area of the grate inlet (i.e., the total area less the area of bars or vanes). The actual opening area for a San Diego Regional Standard No. D-15 grate is A=4.7 ft2. The Federal Highway Administration's Urban Drainage D esign Manual (HEC-22) provides guidance for other grate types and configurations. Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Apr 18 2023 4-in PVC @ 1.0% Circular Diameter (ft)= 0.33 Invert Elev (ft) = 100.00 Slope (%)= 1.00 N-Value = 0.013 Calculations Compute by:Q vs Depth No. Increments = 20 Highlighted Depth (ft)= 0.31 Q (cfs)= 0.199 Area (sqft)= 0.08 Velocity (ft/s)= 2.37 Wetted Perim (ft) = 0.89 Crit Depth, Yc (ft) = 0.26 Top Width (ft)= 0.14 EGL (ft)= 0.40 0 1 Elev (ft)Section 99.75 100.00 100.25 100.50 100.75 101.00 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Apr 18 2023 4-in PVC @ 2.0% Circular Diameter (ft)= 0.33 Invert Elev (ft) = 100.00 Slope (%)= 2.00 N-Value = 0.013 Calculations Compute by:Q vs Depth No. Increments = 20 Highlighted Depth (ft)= 0.31 Q (cfs)= 0.281 Area (sqft)= 0.08 Velocity (ft/s)= 3.35 Wetted Perim (ft) = 0.89 Crit Depth, Yc (ft) = 0.30 Top Width (ft)= 0.14 EGL (ft)= 0.49 0 1 Elev (ft)Section 99.75 100.00 100.25 100.50 100.75 101.00 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Apr 18 2023 6-in PVC @ 0.6% Circular Diameter (ft)= 0.50 Invert Elev (ft) = 100.00 Slope (%)= 0.60 N-Value = 0.013 Calculations Compute by:Q vs Depth No. Increments = 20 Highlighted Depth (ft)= 0.48 Q (cfs)= 0.467 Area (sqft)= 0.19 Velocity (ft/s)= 2.42 Wetted Perim (ft) = 1.35 Crit Depth, Yc (ft) = 0.35 Top Width (ft)= 0.22 EGL (ft)= 0.57 0 1 Elev (ft)Section 99.75 100.00 100.25 100.50 100.75 101.00 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Apr 18 2023 6-in PVC @ 1.0% Circular Diameter (ft)= 0.50 Invert Elev (ft) = 100.00 Slope (%)= 1.00 N-Value = 0.013 Calculations Compute by:Q vs Depth No. Increments = 20 Highlighted Depth (ft)= 0.48 Q (cfs)= 0.602 Area (sqft)= 0.19 Velocity (ft/s)= 3.12 Wetted Perim (ft) = 1.35 Crit Depth, Yc (ft) = 0.40 Top Width (ft)= 0.22 EGL (ft)= 0.63 0 1 Elev (ft)Section 99.75 100.00 100.25 100.50 100.75 101.00 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Apr 18 2023 Modified D-25 Curb Outlet @ 2.0% Rectangular Bottom Width (ft) = 1.50 Total Depth (ft) = 0.25 Invert Elev (ft) = 100.00 Slope (%)= 2.00 N-Value = 0.015 Calculations Compute by:Q vs Depth No. Increments = 10 Highlighted Depth (ft)= 0.25 Q (cfs)= 1.720 Area (sqft)= 0.38 Velocity (ft/s)= 4.59 Wetted Perim (ft) = 2.00 Crit Depth, Yc (ft) = 0.25 Top Width (ft)= 1.50 EGL (ft)= 0.58 0 .5 1 1.5 2 2.5 Elev (ft)Depth (ft)Section 99.75 -0.25 100.00 0.00 100.25 0.25 100.50 0.50 100.75 0.75 101.00 1.00 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Apr 18 2023 3-in PVC Sidewalk Under Drain @ 2.0% Circular Diameter (ft)= 0.25 Invert Elev (ft) = 100.00 Slope (%)= 2.00 N-Value = 0.013 Calculations Compute by:Q vs Depth No. Increments = 8 Highlighted Depth (ft)= 0.22 Q (cfs)= 0.131 Area (sqft)= 0.05 Velocity (ft/s)= 2.88 Wetted Perim (ft) = 0.61 Crit Depth, Yc (ft) = 0.22 Top Width (ft)= 0.17 EGL (ft)= 0.35 0 1 Elev (ft)Section 99.75 100.00 100.25 100.50 100.75 101.00 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Apr 18 2023 D-25 Curb Outlet @ 2.0% Rectangular Bottom Width (ft) = 3.00 Total Depth (ft) = 0.25 Invert Elev (ft) = 100.00 Slope (%)= 2.00 N-Value = 0.015 Calculations Compute by:Q vs Depth No. Increments = 5 Highlighted Depth (ft)= 0.25 Q (cfs)= 3.761 Area (sqft)= 0.75 Velocity (ft/s)= 5.01 Wetted Perim (ft) = 3.50 Crit Depth, Yc (ft) = 0.25 Top Width (ft)= 3.00 EGL (ft)= 0.64 0 .5 1 1.5 2 2.5 3 3.5 4 Elev (ft)Depth (ft)Section 99.75 -0.25 100.00 0.00 100.25 0.25 100.50 0.50 100.75 0.75 101.00 1.00 Reach (ft) PLSA 3657 CURB INLET SIZING Hydraulic Calculations for Ocean View Point – Terminus of Twain Avenue Inlet Design – Curb Inlets on Grade Use equation (2-2) per San Diego County Drainage Design Manual (Inlet on Grade) Inlet capacity is lower of the two calculations, inlet as weir and inlet as orifice (Equation 2-2) Q/Lt= 0.7*(a+y)3/2 Q= interception capacity of the curb inlet (ft3/s) y= depth of flow approaching the curb inlet (ft) a = depth of depression of curb at inlet (ft) Lt= length of clear opening of inlet for total interception (ft) Inlet 1 (@ Pvt Road STA 2+55.08) Q100 = 1.14 cfs at curb inlet opening y = 0.16 ft (Flow Depth from Figure 2-4 of Hydraulic Design Manual for 6” curb/gutter) v = 6.1 ft/s (From Figure 2-4 of Hydraulic Design Manual for 6” curb/gutter) a= 0.17 ft (2-in depression) Lt = Q _ = 1.14 cfs _ _ = 8.6 ft 0.7*(a+y)3/2 0.7*(.17+.16)3/2 *Use Lt = 9.0 feet (10.0 feet total length of inlet including upstream and downstream face of curb inlet per SDRSD D-02 Type B inlet) *Using Lt of 9.0 feet intercepts 100% of flow for 100-year storm entering Inlet 1 2.3.2 Inlet Design 2.3.2.1 Curb Inlets Curb inlets on Grade Full Interception The capacity of a curb inlet on continuous grade depends on gutter slope, depth of flow in the gutter, the dimensions of the curb opening, and the amount of depression at the catch basin. Equation 2-2 describe the capacity (Q) of a curb inlet assuming full ( I 00 percent) interception. ( )J/2 Q/Lr:0.7 a+y (2-2) where ... Q interception capacity of the curb i1Jlet (ft3/s); y depth of flow approaching the curb inlet (fl); a depth of depression of curb at inlet (tl); Lr length of clear opening of inlet for total in terception (tl). Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Friday, Mar 24 2023 Q100 Into Inlet 1 Gutter Cross Sl, Sx (ft/ft) = 0.020 Cross Sl, Sw (ft/ft) = 0.083 Gutter Width (ft) = 1.50 Invert Elev (ft) = 315.40 Slope (%)= 7.00 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 1.14 Highlighted Depth (ft)= 0.16 Q (cfs)= 1.140 Area (sqft)= 0.19 Velocity (ft/s)= 6.06 Wetted Perim (ft) = 3.59 Crit Depth, Yc (ft) = 0.26 Spread Width (ft) = 3.43 EGL (ft)= 0.73 0 5 10 15 20 25 30 35 Elev (ft)Depth (ft)Section 315.00 -0.40 315.25 -0.15 315.50 0.10 315.75 0.35 316.00 0.60 Reach (ft) PLSA 3657 Inlet 2 (@ Pvt Road STA 4+08.78) Q100 = 1.14 cfs at curb inlet opening y = 0.31 ft (Flow Depth from Figure 2-4 of Hydraulic Design Manual for 6” curb/gutter) v = 4.2 ft/s (From Figure 2-4 of Hydraulic Design Manual for 6” curb/gutter) a= 0.17 ft (2-in depression) Lt = Q _ = 4.93 cfs _ _ = 21.2 ft 0.7*(a+y)3/2 0.7*(.17+.31)3/2 **Curb inlet opening length exceeds 20-ft; Use equation (2-2) per San Diego County Drainage Design Manual tonly capture 85% of 100-year event (meets Hydraulic Design Manual standards) E = 1 – [1-(L’/LT)]1/8 for L’<LT L’E-0.85 = 0.65*LT L’E-0.85 = 0.65*Lt = Q _ = 4.93 cfs _ = 0.65*21.2 ft 0.7*(a+y)3/2 0.7*(.17+.31)3/2 = 13.8 ft L’E-0.85 = 14.0 ft *Use Lt = 14.0 feet (15.0 feet total length of inlet including upstream and downstream face of curb inlet per SDRSD D-02 Type B inlet) *Using Lt of 14.0 feet intercepts 85% of flow for 100-year storm, and by-passes 15% downstream Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Friday, Mar 24 2023 Q100 Into Inlet 2 Gutter Cross Sl, Sx (ft/ft) = 0.020 Cross Sl, Sw (ft/ft) = 0.083 Gutter Width (ft) = 1.50 Invert Elev (ft) = 306.60 Slope (%)= 1.60 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 4.93 Highlighted Depth (ft)= 0.31 Q (cfs)= 4.930 Area (sqft)= 1.19 Velocity (ft/s)= 4.15 Wetted Perim (ft) = 10.89 Crit Depth, Yc (ft) = 0.39 Spread Width (ft) = 10.57 EGL (ft)= 0.57 0 5 10 15 20 25 30 35 Elev (ft)Depth (ft)Section 306.00 -0.60 306.50 -0.10 307.00 0.40 307.50 0.90 308.00 1.40 Reach (ft) PLSA 2186 CURB INLET SIZING Hydraulic Calculations for Ocean View Point – Terminus of Twain Avenue Inlet Design – Curb Inlets on Sag Use equation (2-8) per San Diego County Drainage Design Manual (Curb Inlet in Sag) Inlet capacity is lower of the two calculations, inlet as weir and inlet as orifice (Equation 2-8) Q= CW*LW*d3/2 Q= inlet capacity (ft3/s) CW= weir discharge coefficient (see Table2-1) LW = weir length (ft) d= flow depth (ft) Q100 = 4.35 cfs (Q100 from drainage basin) + 4.93 cfs*0.15 (Q100 bypass upstream inlet) = 5.09 cfs Inlet 3 (@ Pvt Road STA ) Q100 = 5.09 cfs (conservative estimate for each inlet in sag on site) CW = 3.0 (Weir Coefficient for Curb Opening Inlet per Table 2-1 of SDCHDM) d = 0.33 ft (Flow depth approaching inlet per Hydrology Calculations) Q= CW*LW*d3/2 5.09 cfs = 3.0*LW*0.333/2 LW = 8.95 ft *Use LW = 10.0 feet at sump inlet condition Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Friday, Mar 24 2023 Q100 Into Inlet 3 Gutter Cross Sl, Sx (ft/ft) = 0.020 Cross Sl, Sw (ft/ft) = 0.083 Gutter Width (ft) = 1.50 Invert Elev (ft) = 306.60 Slope (%)= 1.00 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 5.09 Highlighted Depth (ft)= 0.33 Q (cfs)= 5.090 Area (sqft)= 1.47 Velocity (ft/s)= 3.46 Wetted Perim (ft) = 12.16 Crit Depth, Yc (ft) = 0.40 Spread Width (ft) = 11.82 EGL (ft)= 0.52 0 5 10 15 20 25 30 35 Elev (ft)Depth (ft)Section 306.00 -0.60 306.50 -0.10 307.00 0.40 307.50 0.90 308.00 1.40 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Apr 13 2023 Modified Type B Brow Ditch Flow (Rip Rap) User-defined Invert Elev (ft) = 100.00 Slope (%)= 50.00 N-Value = 0.015 Calculations Compute by:Known Q Known Q (cfs) = 0.54 (Sta, El, n)-(Sta, El, n)... ( 0.00, 101.00)-(0.03, 100.75, 0.015)-(0.13, 100.50, 0.015)-(0.34, 100.25, 0.015)-(0.88, 100.00, 0.015)-(1.12, 100.00, 0.015)-(1.66, 100.25, 0.015) -(1.87, 100.50, 0.015)-(1.97, 100.75, 0.015)-(2.00, 101.00, 0.015) Highlighted Depth (ft)= 0.11 Q (cfs)= 0.540 Area (sqft)= 0.05 Velocity (ft/s)= 10.28 Wetted Perim (ft) = 0.76 Crit Depth, Yc (ft) = 0.28 Top Width (ft)= 0.72 EGL (ft)= 1.75 -.5 0 .5 1 1.5 2 2.5 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 Sta (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Apr 13 2023 Modified Type B Brow Ditch Flow User-defined Invert Elev (ft) = 100.00 Slope (%)= 1.00 N-Value = 0.015 Calculations Compute by:Known Q Known Q (cfs) = 0.54 (Sta, El, n)-(Sta, El, n)... ( 0.00, 101.00)-(0.03, 100.75, 0.015)-(0.13, 100.50, 0.015)-(0.34, 100.25, 0.015)-(0.88, 100.00, 0.015)-(1.12, 100.00, 0.015)-(1.66, 100.25, 0.015) -(1.87, 100.50, 0.015)-(1.97, 100.75, 0.015)-(2.00, 101.00, 0.015) Highlighted Depth (ft)= 0.26 Q (cfs)= 0.540 Area (sqft)= 0.21 Velocity (ft/s)= 2.59 Wetted Perim (ft) = 1.46 Crit Depth, Yc (ft) = 0.28 Top Width (ft)= 1.34 EGL (ft)= 0.36 -.5 0 .5 1 1.5 2 2.5 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 Sta (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Apr 13 2023 Modified Type D Brow Ditch Flow User-defined Invert Elev (ft) = 100.00 Slope (%)= 2.00 N-Value = 0.015 Calculations Compute by:Known Q Known Q (cfs) = 0.58 (Sta, El, n)-(Sta, El, n)... ( 0.00, 101.00)-(0.05, 100.60, 0.015)-(0.19, 100.35, 0.015)-(0.42, 100.15, 0.015)-(1.00, 100.00, 0.015)-(1.24, 100.00, 0.015)-(1.83, 100.15, 0.015) -(2.06, 100.35, 0.015)-(2.19, 100.60, 0.015)-(2.25, 101.00, 0.015) Highlighted Depth (ft)= 0.19 Q (cfs)= 0.580 Area (sqft)= 0.18 Velocity (ft/s)= 3.19 Wetted Perim (ft) = 1.57 Crit Depth, Yc (ft) = 0.24 Top Width (ft)= 1.50 EGL (ft)= 0.35 -.5 0 .5 1 1.5 2 2.5 3 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 Sta (ft) 36-in Grated Inlet in Sag (Assumed 50% Clogging) Cw 3 Unitless L 3 ft Pe 6.00 ft W 3 ft C0 0.67 Unitless Ae 4.5 *Pe assumes 50% clogging Weir Orifice Q (cfs)d (ft)Q (cfs)d (ft) 0.57 0.1 12.10 0.25 1.61 0.2 17.11 0.5 2.96 0.3 20.95 0.75 4.55 0.4 24.20 1 6.36 0.5 27.05 1.25 8.37 0.6 29.63 1.5 Step 1. Calculate the capacity of a grate inlet operating as a weir, using the weir equation (Equation 2-16) with a length equiYalent to perimeter of the grate. When the grate is located next to a curb, disregard the length of the grate against the curb. O=r Pd312 ----W e (2-16) where ... Q Cw Pe d inlet capacity of the grated inlet (ft3/s); weir coefficient (Cw=3.0 for U.S. Traditional Units); effectiYe grate perimeter length (ft); and fl.ow depth approaching inlet (ft). To account for the effects of clogging of a grated inlet operating as a weir, a clogging factor of fifty percent (CL=0.50) shall be applied to the actual (unclogged) perimeter of the grate (P): Step 2. where ... Q C:o ); d A, CA A Calculat.e the capaci1;y of a grate inlet operating as aJ1 orifice. Use Ui.e orifice t:9ualiun (Et1ualiun 2-18), assuming the. c,;lt:ar opening of the grnle n::duced by a clogging factor C.,=0.50 (Equation 2-19). A San Diego Regional Standard ;'Jo. D-15 grate has an actual clear opening of .11-4.7 ft'. The. Federal Highway Administration's Urban Drainage Design ,1.,fanual (HEC-22) provides guidance for other grate types and configurations. inlet capacity of the grated inlet (ft3/s); orifice coefficient (C0=0.67 for IJ.S. Traditional Units); grav itat.iorrnl acceleration (ft/s2); How <.lt:plh above inlt:l (l't); effective (dogged) grate area (ft2); area clogging factor (C:4=0.50); and (1-IX) (2-1 I}) actual opening area of the grate inlet (i.e., the total area less the area of bars or vanes ). The actual open ing area for a San Diego Regional Standard No. D-15 grate is A 4.7 ft2. The Federnl Highway Administration's Urhan I.Jrainage l)e.yigri A1anual (HEC-22) f.ll'OVidcs gui.danc.:: for other grate type~ and conligurnlion.s. 36-in Grated Inlet in Sag (Assumed 50% Clogging) Cw 3 Unitless L 3 ft Pe 6.00 ft W 3 ft C0 0.67 Unitless Ae 4.5 *Pe assumes 50% clogging Weir Orifice Q (cfs)d (ft)Q (cfs)d (ft) 0.57 0.1 12.10 0.25 1.61 0.2 17.11 0.5 2.96 0.3 20.95 0.75 4.55 0.4 24.20 1 6.36 0.5 27.05 1.25 8.37 0.6 29.63 1.5 Step 1. Calculate the capacity of a grate inlet operating as a weir, using the weir equation (Equation 2-16) with a length equiYalent to perimeter of the grate. When the grate is located next to a curb, disregard the length of the grate against the curb. O=r Pd312 ----W e (2-16) where ... Q Cw Pe d inlet capacity of the grated inlet (ft3/s); weir coefficient (Cw=3.0 for U.S. Traditional Units); effectiYe grate perimeter length (ft); and fl.ow depth approaching inlet (ft). To account for the effects of clogging of a grated inlet operating as a weir, a clogging factor of fifty percent (CL=0.50) shall be applied to the actual (unclogged) perimeter of the grate (P): Step 2. where ... Q C:o ); d A, CA A Calculat.e the capaci1;y of a grate inlet operating as aJ1 orifice. Use Ui.e orifice t:9ualiun (Et1ualiun 2-18), assuming the. c,;lt:ar opening of the grnle n::duced by a clogging factor C.,=0.50 (Equation 2-19). A San Diego Regional Standard ;'Jo. D-15 grate has an actual clear opening of .11-4.7 ft'. The. Federal Highway Administration's Urban Drainage Design ,1.,fanual (HEC-22) provides guidance for other grate types and configurations. inlet capacity of the grated inlet (ft3/s); orifice coefficient (C0=0.67 for IJ.S. Traditional Units); grav itat.iorrnl acceleration (ft/s2); How <.lt:plh above inlt:l (l't); effective (dogged) grate area (ft2); area clogging factor (C:4=0.50); and (1-IX) (2-1 I}) actual opening area of the grate inlet (i.e., the total area less the area of bars or vanes ). The actual open ing area for a San Diego Regional Standard No. D-15 grate is A 4.7 ft2. The Federnl Highway Administration's Urhan I.Jrainage l)e.yigri A1anual (HEC-22) f.ll'OVidcs gui.danc.:: for other grate type~ and conligurnlion.s. Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Apr 13 2023 18-in RCP Pipe BMP 1 Outflow Circular Diameter (ft)= 1.50 Invert Elev (ft) = 100.00 Slope (%)= 1.00 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 4.72 Highlighted Depth (ft)= 0.71 Q (cfs)= 4.720 Area (sqft)= 0.83 Velocity (ft/s)= 5.71 Wetted Perim (ft) = 2.28 Crit Depth, Yc (ft) = 0.84 Top Width (ft)= 1.50 EGL (ft)= 1.22 0 1 2 3 Elev (ft)Section 99.50 100.00 100.50 101.00 101.50 102.00 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Thursday, Apr 13 2023 18-in RCP Pipe BMP 2 Outflow Circular Diameter (ft)= 1.50 Invert Elev (ft) = 100.00 Slope (%)= 1.00 N-Value = 0.013 Calculations Compute by:Known Q Known Q (cfs) = 6.46 Highlighted Depth (ft)= 0.86 Q (cfs)= 6.460 Area (sqft)= 1.05 Velocity (ft/s)= 6.15 Wetted Perim (ft) = 2.58 Crit Depth, Yc (ft) = 0.99 Top Width (ft)= 1.48 EGL (ft)= 1.45 0 1 2 3 Elev (ft)Section 99.50 100.00 100.50 101.00 101.50 102.00 Reach (ft) Rip Rap Calculations Per Site Locations Velocities reference from AES / Hydraflow output. Site Velocities Located onsite do not require Special Designs per SDRSD D-40. (Shown Below) A B C D E Rip Rap Location 1 Rip Rap Location 1 Pipe Velocity per AES: 14.26 Ft/S Rip Rap Per Selection D on Table 7-1 Per SDRSD D-40 TABLE 7-1 {BELOW) PER JULY 2005 SAN DIEGO COU DRAI GE DESIGN MANUAL DESIG VELOCITY ROCK RIP-RAP THICKNESS {FT/SEC) * CLASS " ( I ) 6-10 NO. 2 BACKING 1.1 FT 10-12 1/4 TO 2.7 FT 12-14 1/2 TO 3.5 FT 14-16 1 TON 4.4 FT 16-18 2 TO 5.4 FT OVER 20 FT /SEC REQUIRES SPECIAL DESIGN ****************** ******* ********* * ******************* FLOW PROCESS FROM NODE 104.00 TO NODE 105.00 IS CODE= 41 >>>>>COMPUTE PIPE -FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER -SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ELEVATION DATA: UPSTREAM(FEET) = 312.43 DOWNSTREAM(FEET) = 303.00 FLOW LENGTH(FEET) = 21.00 MANNING'S N = 0 .013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 1.6 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 14.26 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES= 1 PIPE-FLOW(CFS) = 1.14 PIPE TRAVEL TIME(MIN.) = 0.02 Tc(MIN.) = 7.71 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 105.00 = 305.00 FEET. Rip Rap Location 2 Rip Rap Location 2 Pipe Velocity per AES: 12.83 Ft/S Rip Rap Per Selection C on Table 7-1 Per SDRSD D-40 Rip Rap Location 3 Rip Rap Location 3 Pipe Velocity per AES: 17.75 Ft/S Rip Rap Per Selection E on Table 7-1 Per SDRSD D-40 **************************************************************************** FLOW PROCESS FROM NODE 204.00 TO NODE 20S.00 IS CODE= 41 >>>>>COMPUTE PIPE -FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER -SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ELEVATION DATA: UPSTREAM{FEET) = 303.58 DOWNSTREAM(FEET) 303.00 FLOW LENGTH(FEET) = 6.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 4.9 INCHES PIPE-FLOW VELOCITY(FEET/SEC .) = 12.83 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW{CFS) = 4.93 PIPE TRAVEL TIME(MIN.) = 0.01 Tc{MIN.) = 7.57 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 205.00 = 311.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 207.00 TO NODE 208.00 IS CODE = 41 >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ELEVATION DATA: UPSTREAM(FEET) = 292.60 DOWNSTREAM(FEET) 280.00 FLOW LENGTH{FEET) = 65.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 4.7 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 17.75 GIVEN PIPE DIAMETER{INCH) = 18.00 NUMBER OF PIPES= 1 PIPE -FLOW{CFS) = 6.46 PIPE TRAVEL TIME{MIN.) = 0.06 Tc(MIN.) = 8.05 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 208.00 526 .00 FEET. Rip Rap Location 4 Rip Rap Location 4 Pipe Velocity per AES: 7.99 Ft/S Rip Rap Per Selection A on Table 7-1 Per SDRSD D-40 Rip Rap Location 5 Rip Rap Location 5 Pipe Velocity per AES: 9.83 Ft/S Rip Rap Per Selection B on Table 7-1 Per SDRSD D-40 **************** * ******** * ** *** ** * ******** * ********** ********* * FLOW PROCESS FROM NODE 304.00 TO NODE 305 .00 IS CODE= 41 ELEVATI ON DATA: UPSTREAM(FEET) = 303.20 DOWNSTREAM(FEET) = FLOW LENGTH(FEET) = 7.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.2 INCHES PIPE -FLOW VELOCITY(FEET/SEC.) = 7.99 GIVEN PIPE DIAMETER(INCH) = 18.00 PIPE -FLOW(CFS) = 4.35 NUMBER OF PIPES = PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 1 303.00 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 9.01 305.00 = 339 .00 FEET. ****** ********** ********** ********* ********** ********* ********* ***************** * ******** * ******** * ******** * ******************** * FLOW PROCESS FROM NODE 307.00 TO NODE 308.00 IS CODE = 41 >>>>>COMPUTE PIPE -FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ELEVATION DATA: UPSTREAM(FEET) = 293.95 DOWNSTREAM(FEET) = 292.00 FLOW LENGTH(FEET) = 41.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.7 I NCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 9.83 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES= PIPE-FLOW(CFS) = 4.72 PIPE TRAVEL TIME(MIN.) = 0.07 Tc(MIN.) = LONGEST FLOWPATH FROM NODE 300.00 TO NODE 9.47 308.00 = 1 514.00 FEET. **************************************************************************** Rip Rap Location 6 Total Area = 5,820 sf  0.13 Acres (Entirety of basin PR-1.6 used for calculation) Cn = 0.61 Taken from hydro report for all of basin PR-1 Tc = 5.0 min P6 = 2.6 I = 7.44 x P6 x D-0.645 I = 7.44 x 2.6 x 5.0-0.645 ≈ 6.85 in/hr I100 ≈ 6.85 in/hr Q100 = C*I*A Q100 = 0.61 x 6.85 in/hr x 0.13 Ac = 0.54 cfs Rip Rap Location 6 Pipe Velocity per Hydraflow Express: 3.82 Ft/S Rip Rap Per Selection A on Table 7-1 Per SDRSD D-40 Channel Report Hydraflow Express Extension for Autodesk® Civil 30® by Autodesk. Inc. 18-in RCP Pipe BMP 1 Inflow Circular Diameter (ft} Invert Elev (ft) Slope(%) N-Value Calculations Compute by: Known Q ( cfs) = 1.50 = 100.00 = 2.00 = 0.013 Known Q = 0.54 Highlighted Depth (ft} Q (cfs) Area (sqft) Velocity (ft/s) Wetted Perim (ft) Crit Depth, Ye (ft) Top Width (ft) EGL (ft) Thursday, Apr 13 2023 = 0.20 = 0.540 = 0.14 = 3.82 = 1.12 = 0.28 = 1.02 = 0.43 Rip Rap Location 7 Total Area = 5,539 sf  0.13 Acres (Entirety of basin PR-3 used for calculation) Cn = 0.61 Taken from hydro report for all of basin PR-1 Tc = 5.0 min P6 = 2.6 I = 7.44 x P6 x D-0.645 I = 7.44 x 2.6 x 5.0-0.645 ≈ 6.85 in/hr I100 ≈ 6.85 in/hr Q100 = C*I*A Q100 = 0.61 x 6.85 in/hr x 0.13 Ac = 0.54 cfs Rip Rap Location 6 Pipe Velocity per Hydraflow Express: 10.28 Ft/S See Channel Report next sheet per Hydraflow Output Rip Rap Per Selection B on Table 7-1 Per SDRSD D-40 Channel Report Hydranow Express Extension for Autodesk® Civil 30® by Autodesk. Inc. Modified Type B Brow Ditch Flow (Rip Rap) User-defined Invert Elev (ft) Slope(%) N-Value Calculations Compute by: Known Q (cfs) (Sta, El, n)-(Sta, El, n) ... = 100.00 = 50.00 = 0.015 Known Q = 0.54 Thursday, Apr 13 2023 Highlighted Depth (ft) = 0.11 Q (cfs) = 0.540 Area (sqft) = 0.05 Velocity (ft/s) = 10.28 Wetted Perim (ft) = 0.76 Grit Depth, Ye (ft) = 0.28 Top Width (ft) = 0.72 EGL (ft) = 1.75 ( 0.00. 101.00),(0.03, 100.75, 0.015)-(0.13, 100.50, 0.015)-(0.34, 100.25, 0.015)-(0.88, 100.00, 0.015)-(1.12, 100.00, 0.015)-(1.66, 100.25, 0.015) -(1.87, 100.50, 0.015)-(1.97, 100.75, 0.015)-(2.00, 101.00, 0.015) PLSA 3657-01 Page 21 of 21 5.0 APPENDIX IL__·-----_--_I .L 10.0 9.0 8,0 7.0 6.0 5.0 4.0 3.0 2.0 0.6 0,5 0.4 0.3 0.2 0,1 ' • ' ......... ' ""'I'-,, ' ' ..... 1, ..... ' • ' ...... , .......... ......... ""r-. I""._ I", .... .... "i--.. ...... r-,r-, ,'""' ....... ' ' .... ...... , ""'" ..... .. I' • ' """' --.... ~ .. ' • ""' ~" ' ..... ""'I'-,, "" ,., I', " I", ' ' .......... ! .. --~ ~ "" .... " ' ..... , I= 3.2 in/hr ...... "' " ' ~ ~" -,_ .... .... " ..... ......... I', .... .... " " ' ..... " .. l'o ~ ' ...... 'l'o, "~ ' ...... , I " ' "l'o "~ , ... 'l'o ......... ~" ...... " ... , .. .. "' " " tc = 20 min I I I I 11 I 111 ' 5 6 7 8 9 10 15 20 30 Minutes " .. "" "• " "• " ~ .. .. " ~ .. " " "• " " "· "• " " '" I 40 50 Duration EQUATION I = 7.44 P5 D-0.645 I = Intensity (in/hr) P5 = 6-Hour Precipitation (in) D = Duration (min) 'I',, .... ' ..... '' I'-,, , .... ... , ,, ... ' 1, ""' r-... ' .... ...... .. ~" l'r-..._ , .. ,, "" " 1, 'r-. ...... :--....., .. l'o " :--.I',, ,, " ·~ " ..... ... " .... , ....... :-,... ,., ", ~ :--., ' .. " ....... " 1, '"' " ' I'"" 1,._. " :-,...r-... I', :--....., " " 2 3 4 Hours I I 5 6 C)} ± 0 ~ -0 ~ s.o t 5.5 g, 5.0 :, 4.5 '§' 0 4.0 ~ 3.5 !!!.. 3,0 2.5 2.0 1.5 1.0 Intensity-Duration Design Chart -Example 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 (1 O, 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 = _3_ in., p24 ::;: ~ .~ ::;: ~ %(2) 24 (c) Adjusted p6(2) = _3_ in . (d) Ix= 20 min . {e) J = ~ in./hr. Note: This chart replaces the Intensity-Duration-Frequency curves used since 1965. 5-5.5 -6 ~ 1 1.5 r~ 2.5 J-3:-5 -4 4.5' I Ouralion 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 2.124 ~.18 _i.?415.3Q_ 6.36_U£ jl.48-9.54 J 0.60 11.:,6_6_ J.2.72 __ 10 1.68 2.53 3.37 4.21 5.0~5.90 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 1.00 I, .6212.,sfu~ 3.23 3.11 4.31 4.85 5.39 5.93 '5.45 --25 0.93 1 .40 1.87 2.33 2.80 3.27 3.73 4.20 4.67 5. ~ 5.60 --30 0.83 1.24 1.661 2,07 2.49 2,90 3,32 3.73 4.15 4.56 ,..i-98 --. -_-40 0.69-:-1.03 1.38 1.72 2.07 2.41 2.76 3.10 3.45 3.79 4.13 50 o.6_f o.oo T 19-1.49 I 1.19~()~ ..J,39 2.69 2.98 3.28 3.58 60 0.53 0.80 1.06 1.33 1.59 1.86 2,12 2.39 , 2.65 2.9~ 3.18 ~ o ::fi 0.61 0.02 1.02 123 1.43 1.63 1.84 2.04 2.25 ~2A5 ----rio 0.34 0.51 0.68 0.85 1.02 1.19 1.36 1.53 1.70 1fil 2.04 7 so 0.29 0.44 0.59 0.7310.88 1.03 1.18.....J.12 1.47 1.62 1.76 180 .9.26 ~9fo.5g_ 0.65 0.78 0.91 1.Q!J 1.18 1.31 1.44 1.57 240 0.22 0.33 0.43 0.540.651·0.76 0~87 j 0.98 1.08 1.~ 1.30 300 0.19 0.28 0.38 0.470:56 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 I 0.75 0.84 0.92 1.00 Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil SurveyNational Cooperative Soil Survey 6/23/2021Page 1 of 4 36 6 6 1 0 0 36 6 6 2 0 0 36 6 6 3 0 0 36 6 6 4 0 0 36 6 6 5 0 0 36 6 6 6 0 0 36 6 6 7 0 0 36 6 6 8 0 0 36 6 6 1 0 0 36 6 6 2 0 0 36 6 6 3 0 0 36 6 6 4 0 0 36 6 6 5 0 0 36 6 6 6 0 0 36 6 6 7 0 0 36 6 6 8 0 0 471500 471600 471700 471800 471900 472000 472100 472200 472300 472400 472500 472600 471500 471600 471700 471800 471900 472000 472100 472200 472300 472400 472500 472600 33° 8' 23'' N 11 7 ° 1 8 ' 2 0 ' ' W 33° 8' 23'' N 11 7 ° 1 7 ' 3 3 ' ' W 33° 7' 58'' N 11 7 ° 1 8 ' 2 0 ' ' W 33° 7' 58'' N 11 7 ° 1 7 ' 3 3 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 250 500 1000 1500Feet 0 50 100 200 300Meters Map Scale: 1:5,510 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 ServiceWeb 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, CaliforniaSurvey Area Data: Version 15, May 27, 2020 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jan 23, 2020—Feb 13, 2020 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 SurveyNational Cooperative Soil Survey 6/23/2021Page 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 DaE2 Diablo clay, 15 to 30 percent slopes, eroded, warm MAAT C 0.0 0.0% HrC Huerhuero loam, 2 to 9 percent slopes D 14.9 17.3% LeE Las Flores loamy fine sand, 15 to 30 percent slopes D 21.0 24.3% LeE2 Las Flores loamy fine sand, 15 to 30 percent slopes, eroded D 3.5 4.1% LvF3 Loamy alluvial land-Huerhuero complex, 9 to 50 percent slopes, severely eroded B 37.1 43.1% MlC Marina loamy coarse sand, 2 to 9 percent slopes B 8.5 9.9% SbC Salinas clay loam, 2 to 9 percent slopes C 1.0 1.1% VaC Visalia sandy loam, 5 to 9 percent slopes A 0.0 0.0% Totals for Area of Interest 86.1 100.0% Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil SurveyNational Cooperative Soil Survey 6/23/2021Page 3 of 4USDA = 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 Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil SurveyNational Cooperative Soil Survey 6/23/2021Page 4 of 4~ ,\'\'\'\'\"~"::...--=-----:::.__-==-----:::--==--"',\'),J l11,1l1 11 1 ~\\\II\ \\ --1-"'-"'"--::::__'-----.--;,--'z~'---"~------------>--------------:::..:::.~::::-"-":'-.;I ~-~ \ .__ ___ ____. \ \ "' \ \ ,"L \\ \\\\\ \\\ \ \\\ ~ \ '\' \ '\' ~ '.::: :::-==---=-~3---~'I\\//////;/// / / I// i'tW ~ \ \ \ ~ ~' -1' ~~:____":::. ~ ~-:=_ ~~--: BASIN EX-2 =~ ~ ~ "---" :::-~J:--_.:---:.__-=:--~-= '-"-. '"-\ ( ----\ \ \ \. \"'\ \\ \ \ \ \ \ \ \ l \ \ \ \ \ \ \ \ \ \ \ '--------, \' \ ) ,, I '11 I\ \ \ \ \ \ \ \ \ \" ---~~~-~ :::::: --------. -o.a9Ac "' \' \'--"" --~ -----------------------------" \ \ \ \ I r \ \ \ I SCALE: 1" = 30' HORIZONTAL 30 0 30 60 J:'ACTIVE JOBSl3657 RINCON OCEAN VIEW POINTCIVILIREPORTS'HYDROLOGY'APPENOIXl3657-CV-HYDE 4 BASIN CONFIG.DWG LEGEND PROPERTY BOUNDARY CENTERLINE OF ROAD RIGHT-OF-VIVIY ADJACENT PROPORTY LINE EXISTING CONTOUR LINE PROPOSED PATH OF TRAVEL PROPOSED MAJOR DRAINAGE BASIN BOUNDARY EXISTING IMPERVIOUS AREA - - 1777777771 BASIN EX-1-AREA CALCULATIONS TOTAL BASIN AREA BASIN EXISTING IMPERVIOUS AREA BASIN EXISTING PERVIOUS AREA % IMPERVIOUS Cn TIME OF CONCENTRATION 65,458 SF(1.50AC) 0SF(0.00AC) 65,458 SF(1.50AC) 0.00% 0.35 9.3 MINUTES (SEE HYDROLOGY REPORT) BASIN EX-2-AREA CALCULATIONS TOTAL BASIN AREA BASIN EXISTING IMPERVIOUS AREA BASIN EXISTING PERVIOUS AREA % IMPERVIOUS en TIME OF CONCENTRATION 38,949 SF (0.89 AC) 0SF(0.00AC) 38,949 SF (0.89 AC) 0.00% 0.35 8.8 MINUTES (SEE HYDROLOGY REPORT) BASIN EX-3-AREA CALCULATIONS TOTAL BASIN AREA BASIN EXISTING IMPERVIOUS AREA BASIN EXISTING PERVIOUS AREA % IMPERVIOUS Cn TIME OF CONCENTRATION 42,878 SF (0. 98 AC) 316 SF (0.01 AC) 42,562 SF (0. 98 AC) 0.74 % 0.35 10.2 MINUTES (SEE HYDROLOGY REPORT) BASIN EX-4-AREA CALCULATIONS TOTAL BASIN AREA BASIN EXISTING IMPERVIOUS AREA BASIN EXISTING PERVIOUS AREA % IMPERVIOUS en TIME OF CONCENTRATION 90 50,818 SF (1.17 AC) 449 SF (0.01 AC) 50,369SF(1.16AC) 0.88% 0.35 9.9 MINUTES (SEE HYDROLOGY REPORT) PRE-DEVELOPMENT HYDROLOGIC NODE MAP TERMINUS OF TWAIN AVENUE CITY OF CARLSBAD PASCO LARET SUITER ----• t fa\$$~tifa\'il'IE$ San Diego I Solana Beach I Orange County Phone 858.259.82121 www.plsaengineering.com PLSA3657 SHEDS SCATTERED BRUSH TREE DIRT DIRT DIRT BRUSH DENSE BRUSH AND TREES SCATTERED BRUSH BRUSH SCATTERED BRUSH SCATTERED BRUSH TREES TREES BRUSH SCATTERED BRUSH SCATTERED BRUSH SCATTERED BRUSH S S WW TRASHCAN ASPHALT CONC CONC CONC 6FT CONCRETE BLOCK WALL 325 325325 325 3 2 5 325 3 2 0 3 2 0 3 2 0 32 0 32 0 320 32 0 320 320 320 320 3 2 0 31 5 31 5 315 31 5 31 5 315 315 315 315 31 5 31 5 315 315 3 1 5 315 310 31 0 310 310 310 31 0 31 0 310 310 31 0 310 31 0 3 1 0 31 0 31 0 31 0 31 0 305 30 5 30 5 3 0 5 3 0 5 3 0 5 30 5 305 30 5 305 305 305 3 0 5 305 305 30 5 305 30 0 300 30 0 300 30 0 30 0 30 0 30 0 300 300 300 30 0 300 3 0 0 300 3 0 0 300 30 0 29 5 295 2 9 5 29 5 295 2 9 5 29 5 29 5 29 5 295 295 295 295 295 295 2 9 5 295 29 5 295 29 5 290 29 0 290 29 0 290 2 9 0 290 29 0 290 290 2 9 0 290 290 29 0 29 0 2 9 0 2 9 0 290 2 9 0 285 285 285 2 8 5 285 285 28 5 2 8 5 285 2 8 5 285 2 8 5 285 28 5 28 5 285 2 8 0 28 0 2 8 0 2 8 0 2 8 0 28 0 280 28 0 2 8 0 28 0 280 28 0 280 28 0 28 0 28 0 275 275 2 7 5 275 2 7 5 27 5 27 5 275 275 27 5 2 7 5 275 2 7 5 27 5 2 7 0 27 0 270 270 27 0 270 270 2 7 0 27 0 270 270 270 265 265 265 26 5 26 5 265 26 0 260 26 0 260 26 0 26 0 260 255 255 25 5 25 5 255 25 0 250 250 24 5 245 245 24 0 23 5 235 325 324 32 3 32 2 32 1 327.4322.1 322.1 321.9 327.9 328.1 328.7 327.8 TW=334.00 TW=334.66 TW=334.68 TW=334.62 TW=333.96 TW=333.95 W W W W W W S S S SSSS S S S S SD S S G G G SD SD SD SD SD SD SD SD SD SD SD S S S S S S S S S S S S S SD S S S W W W W S S S S S S S S S S S S S S S XXXX 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 X X X X X X X X X X X X X X X X 280 275 290 285 290 295 305 300 310 3 0 5 3 1 0 3 1 5 3 0 5 3 1 0 300 295 290 305 3 1 5 320 315 3 1 0 325 305 300 295 LOT 1 10,356 S.F.0.238 AC. LOT 2 10,428 S.F.0.239 AC. LOT 3 12,508 S.F.0.287 AC. LOT 4 11,767 S.F.0.270 AC. LOT 5 19,660 S.F.0.451 AC. LOT 9 19,376 S.F.0.445 AC. LOT 13 10,899 S.F.0.250 AC. 320 315 325 324 321 320 319 316 31 5 314 31 6 31 5 316 3 1 4 31 5 31 4 313 310 308 312304 306 308 310 30 6 30 8 31 2 3 0 6 3 0 8 3 0 7 303 304 305 306 308 309 310 311 32 0 31 9 31 8 317 316 3 1 5 31 0 310 305 300 295 290 2 9 0 285 280 275 275 2 8 0 28 5 29 0 29 5 29 5 29 0 285 285 290 295 305 31 5 3 1 0 3 0 0 30 5 31 0 315 32 0 // // 326 // // ////// // // // // // // // //// 317 326 H H J J TW A I N A V E BASIN PR-2 AREA = 9,022 SF = 0.21 AC BMP #2 A ~ 3,650 SF FG = 303.0 BASIN PR-1.3.3 AREA = 63,211 SF= 1.45 AC BASIN PR-1.1.3AREA = 7,841 SF= 0.18 AC L=71' L = 6 3 ' BASIN PR-1.5 AREA = 14,178 SF = 0.33 AC BASIN PR-3 AREA = 5,539 SF = 0.13 AC L=86 ' L=57' L=98' L= 7 2 ' L=187' L= 7 6 ' BASIN PR-1.3.1 AREA = 2,430 SF = 0.06 AC BASIN PR-1.1.1 AREA = 2,372 SF= 0.05 AC BASIN PR-1.2.3 AREA = 59,892 SF = 1.37 AC BASIN PR-1.2.1 AREA = 5,985 SF = 0.14 AC BASIN PR-1 AREA = 183,540 SF = 4.21 AC BASIN PR-1.2.2AREA = 997 SF= 0.03 AC BASIN PR-1.2 AREA = 66,874 SF = 1.54 AC BASIN PR-1.3.2AREA = 596 SF = 0.01 AC BASIN PR-1.3 AREA = 66,237 SF = 1.52 AC BASIN PR-1.1 AREA = 15,658 SF = 0.36 AC BASIN PR-1.6 AREA = 5,820 SF = 0.13 AC L=13 4 ' L=1 5 0 ' VE R N E V I E W (PRI V A T E R O A D ) BMP #1 A ~ 2,500 SF FG = 303.0 BASIN PR-1.4 AREA = 5,839 SF = 0.13 AC L= 6 4 NODE PR-100 324.8 FG NODE PR-101 324.3 TG 323.3 IE NODE PR-205 303.0 FG Q100 = 4.93 CFS NODE PR-103 321.8 FS NODE PR-102 324.2 TG 322.9 IE NODE PR-201 315.0 TG 312.5 IE NODE PR-203 311.05 FS NODE PR-302 309.0 TG308.1 IE NODE PR-303 307.7 FS NODE PR-305 303.0 FG Q100 = 4.35 CFS NODE PR-304 305.58 FS 303.2 IE NODE PR-204 306.58 FL/IE 303.58 IE NODE PR-104 315.43 FS 312.43 IE L=6' L=24' L=24' NODE PR-105 303.0 FG Q100 = 1.14 CFS NODE PR-301 309.1 TG 308.55 IE NODE PR-300 309.8 FG NODE PR-200 316.3 FG L=21' NODE PR-308 292.0 IE Q100 = 4.88 CFS (UNMIT) Q100 = 0.17 CFS (MIT) NODE PR-306 304.5 TG 295.50 IE Q100 = 4.72 CFS (UNMIT) Q100 = 0.11 CFS (MIT) NODE PR-206 304.42 TG 294.25 IE OUT Q100 = 6.46 CFS (UNMIT) Q100 = 0.04 CFS (MIT) NODE PR-208 280.0 IE Q100 = 6.82 CFS (UNMIT) Q100 = 0.14 CFS (MIT) L=7'NODE PR-2 (300.5 FG) Q100 = 0.50 CFS NODE PR-3 (284.0 FG) Q100 = 0.31 CFS NODE PR-202 315.0 TG 311.9 IE L=51' BASIN PR-1.7 AREA = 8,934 SF = 0.20 AC NODE PR-207 292.6 IE OUT Q100 = 6.46 CFS (UNMIT) Q100 = 0.04 CFS (MIT) NODE PR-307 293.95 IE OUT Q100 = 4.72 CFS (UNMIT) Q100 = 0.11 CFS (MIT) L=6 5 ' L=41 ' L=45' BASIN PR-1.1.2 AREA = 5,445 SF = 0.13 AC BASIN PR-1 - AREA CALCULATIONS TOTAL BASIN AREA 183,540 (4.21 AC) BASIN PROPOSED IMPERVIOUS AREA 75,562 SF (1.73 AC)BASIN PROPOSED PERVIOUS AREA 107,978 SF (2.48 AC) BASIN PROPOSED IMPERVIOUS AREA 86,896 SF (1.99 AC) (15% CONTINGENCY) BASIN PROPOSED PERVIOUS AREA 96,644 SF (2.22 AC) (15% CONTINGENCY) % IMPERVIOUS 47.3 % Cn 0.61 TIME OF CONCENTRATION 8.05 MINUTES (PR-208)9.47 MINUTES (PR-308) (SEE HYDROLOGY REPORT) 30 60 90 GRAPHIC SCALE 1" = 30' 030 PLAN VIEW - PROPOSED HYDROLOGY NODE MAP SCALE: 1" = 30' HORIZONTAL PLSA 3657J:\ACTIVE JOBS\3657 RINCON OCEAN VIEW POINT\CIVIL\REPORTS\HYDROLOGY\APPENDIX\3657-CV-HYDD.DWG LEGEND PROPERTY BOUNDARY CENTERLINE OF ROAD RIGHT-OF-WAY ADJACENT PROPORTY LINE EXISTING CONTOUR LINE PROPOSED PATH OF TRAVEL PROPOSED MINOR NODAL BASIN BOUNDARY PROPOSED MINOR DRAINAGE BASIN BOUNARY PROPOSED MAJOR DRAINAGE BASIN BOUNDARY IMPERVIOUS AREA 140 BASIN PR-2 - AREA CALCULATIONS TOTAL BASIN AREA 9,022 (0.21 AC) BASIN EXISTING IMPERVIOUS AREA 0 SF (0.00 AC)BASIN EXISTING PERVIOUS AREA 9,022 SF (0.21 AC) % IMPERVIOUS 0.00 % Cn 0.35 TIME OF CONCENTRATION 5.0 MINUTES (SEE HYDROLOGY REPORT) BASIN PR-3 - AREA CALCULATIONS TOTAL BASIN AREA 5,539 (0.13 AC) BASIN EXISTING IMPERVIOUS AREA 0 SF (0.00 AC)BASIN EXISTING PERVIOUS AREA 5,539 SF (0.13 AC) % IMPERVIOUS 0.00 % Cn 0.35 TIME OF CONCENTRATION 5.0 MINUTES (SEE HYDROLOGY REPORT) POST-DEVELOPMENTHYDROLOGIC NODE MAP TERMINUS OF TWAIN AVENUECITY OF CARLSBAD - - ------- 1½?7/2727ZVZZ/4/ZI PASCO LARET SUITER ----• ~ ffe.$$«'.lllC!ffe.TIE$ San Diego I Solana Beach I Orange County Phone 858.259.82121 www.plsaengineering.com 1L Inflow to BMP-1 OPT 2 1P BMP-1 OPT 2 2L Inflow to BMP-2 OPT 2 2P BMP-2 OPT 2 Routing Diagram for 3657 - Full BMP Prepared by Pasco Laret Suiter & Assoc, Printed 3/29/2023 HydroCAD® 10.20-2g s/n 10097 © 2022 HydroCAD Software Solutions LLC Subcat Reach Pond Link ----[> ___ ___;[> 0 D 6 [j .------___J 3657 - Full BMP Printed 3/29/2023Prepared by Pasco Laret Suiter & Assoc Page 2HydroCAD® 10.20-2g s/n 10097 © 2022 HydroCAD Software Solutions LLC Summary for Link 1L: Inflow to BMP-1 OPT 2 Inflow = 4.71 cfs @ 4.20 hrs, Volume= 9,729.00 cf Primary = 4.71 cfs @ 4.20 hrs, Volume= 9,729.00 cf, Atten= 0%, Lag= 0.0 min Routed to Pond 1P : BMP-1 OPT 2 Primary outflow = Inflow, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs DISCHARGE Imported from BMP-1 OPT 2 RatHydro.csv Link 1L: Inflow to BMP-1 OPT 2 Inflow Primary Hydrograph Time (hours) 6543210 Fl o w ( c f s ) 5 4 3 2 1 0 DISCHARGE Imported from BMP-1 OPT 2 RatHydro.csv 4.71 cfs 4.71 cfs D 3657 - Full BMP Printed 3/29/2023Prepared by Pasco Laret Suiter & Assoc Page 3HydroCAD® 10.20-2g s/n 10097 © 2022 HydroCAD Software Solutions LLC Summary for Pond 1P: BMP-1 OPT 2 Inflow = 4.71 cfs @ 4.20 hrs, Volume= 9,729.00 cf Outflow = 0.11 cfs @ 6.00 hrs, Volume= 1,301.38 cf, Atten= 98%, Lag= 108.0 min Primary = 0.11 cfs @ 6.00 hrs, Volume= 1,301.38 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Peak Elev= 304.10' @ 6.00 hrs Storage= 8,425.98 cf Plug-Flow detention time= 173.0 min calculated for 1,301.38 cf (13% of inflow) Center-of-Mass det. time= 23.5 min ( 240.7 - 217.2 ) Volume Invert Avail.Storage Storage Description #1 295.50' 10,677.86 cf Custom Stage Data Listed below 3657 - Full BMP Printed 3/29/2023Prepared by Pasco Laret Suiter & Assoc Page 4HydroCAD® 10.20-2g s/n 10097 © 2022 HydroCAD Software Solutions LLC Elevation Cum.Store (feet) (cubic-feet) 295.50 0.00 295.59 46.80 295.67 93.60 295.75 140.40 295.84 187.20 295.92 234.00 296.00 280.80 296.09 327.60 296.17 374.40 296.25 421.20 296.34 519.23 296.42 616.70 296.50 713.85 296.59 810.69 296.67 907.18 296.75 1,003.34 296.84 1,099.14 296.92 1,194.56 297.00 1,289.57 297.09 1,384.17 297.17 1,478.33 297.25 1,572.02 297.34 1,665.23 297.42 1,757.93 297.50 1,850.09 297.59 1,941.71 297.67 2,032.71 297.75 2,123.09 297.84 2,212.83 297.92 2,301.88 298.00 2,390.21 298.09 2,477.78 298.17 2,564.55 298.25 2,650.48 298.34 2,735.54 298.42 2,819.68 298.50 2,902.84 298.59 2,984.99 298.67 3,066.04 298.75 3,145.95 298.84 3,224.65 298.92 3,302.03 299.00 3,378.05 299.09 3,452.55 299.17 3,525.46 299.25 3,596.60 299.34 3,665.80 299.42 3,732.83 299.50 3,797.39 299.59 3,858.80 36 5 7 - F u l l B M P P r i n t e d 3 / 2 9 / 2 0 2 3 Pr e p a r e d b y P a s c o L a r e t S ui t e r & A s s o c Pa g e 5 Hy d r o C A D ® 1 0 . 2 0 -2 g s / n 1 0 0 9 7 © 2 0 2 2 H y d r o C A D S o f t w a r e S o l u t i o n s L L C 29 9 . 6 7 3, 9 1 5 . 4 1 29 9 . 7 5 3, 9 6 8 . 0 3 29 9 . 8 4 4, 0 1 9 . 0 7 29 9 . 9 2 4, 0 6 8 . 6 6 30 0 . 0 0 4, 1 1 6 . 2 6 30 0 . 0 9 4, 1 6 3 . 0 6 30 0 . 1 7 4, 2 0 9 . 8 6 30 0 . 2 5 4, 2 5 6 . 6 6 30 0 . 3 4 4, 3 0 3 . 4 6 30 0 . 4 2 4, 3 5 0 . 2 6 30 0 . 5 0 4, 3 9 7 . 0 6 30 0 . 5 9 4, 4 4 3 . 8 6 30 0 . 6 7 4, 4 9 0 . 6 6 30 0 . 7 5 4, 5 3 7 . 4 6 30 0 . 8 4 4, 5 8 4 . 2 6 30 0 . 9 2 4, 6 3 1 . 0 6 30 1 . 0 0 4, 6 7 7 . 8 6 30 3 . 0 0 5, 6 7 7 . 8 6 30 4 . 5 0 9, 4 2 7 . 8 6 30 5 . 0 0 1 0 , 6 7 7 . 8 6 De v i c e R o u t i n g I n v e r t O u t l e t D e v i c e s #1 P r i m a ry 2 9 5 . 5 0 ' 18 . 0 0 " R o u n d C u l v e r t L= 1 0 . 0 ' R C P , s q u a r e e d g e h e a d w a l l , K e = 0 . 5 0 0 In l e t / O u t l e t I n v e r t = 2 9 5 . 5 0 ' / 2 9 5 . 4 0 ' S = 0 . 0 1 0 0 ' / ' C c = 0 . 9 0 0 n= 0 . 0 1 3 , F l o w A r e a = 1 . 7 7 s f #2 D e v i c e 1 2 9 5 . 7 5 ' 1. 2 0 " V e r t . O r i f i c e C = 0 . 6 0 0 L i m i t e d t o w e i r f l o w a t l o w h e a d s #3 D e v i c e 1 3 0 4 . 5 0 ' 36 . 0 0 " x 3 6 . 0 0 " H o r i z . G r a t e C = 0 . 6 0 0 i n 3 6 . 0 0 " x 3 6 . 0 0 " G r a t e ( 1 0 0 % o p e n a r e a ) Li m i t e d t o w e i r f l o w a t l o w h e a d s #4 D e v i c e 2 2 9 5 . 5 0 ' 0. 2 9 c f s E x f i l t r a t i o n w h e n a b o v e 2 9 5 . 5 0 ' Pr i m a r y O u t F l o w M a x = 0 . 1 1 c f s @ 6 . 0 0 h r s H W = 3 0 4 . 1 0 ' ( F r e e D i s c h a r g e ) 1= C u l v e r t ( P a s s e s 0 . 1 1 c f s o f 2 3 . 8 4 c f s p o t e n t i a l f l o w ) 2= O r if i c e ( O r i f i c e C o n t r o l s 0 . 1 1 c f s @ 1 3 . 8 7 1 f p s ) 4= E x fi l t r a t i o n ( P a s s e s 0 . 1 1 c f s o f 0 . 2 9 c f s p o t e n t i a l f l o w ) 3= G r at e ( C o n t r o l s 0 . 0 0 c f s ) r ..--I ....... I~ r 3657 - Full BMP Printed 3/29/2023Prepared by Pasco Laret Suiter & Assoc Page 6HydroCAD® 10.20-2g s/n 10097 © 2022 HydroCAD Software Solutions LLC Pond 1P: BMP-1 OPT 2 Inflow Primary Hydrograph Time (hours) 6543210 Fl o w ( c f s ) 5 4 3 2 1 0 Peak Elev=304.10' Storage=8,425.98 cf 4.71 cfs 0.11 cfs D Total Volume Drawdown Calculation: BMP-1 Project Name Ocean View Point Project No 3657 Date 3/29/2023 Total Inflow Hydrograph Drawdown Time Through Orifice: 25.44 hrs BMP Surface Area 2500 sq ft Note: Drawdown time is calculated assuming an initial water surface depth equal to the invert of the lowest surface discharge opening in the outlet structure. Underdrain Orifice Diameter: 1.2 in C:0.6 Surface Ponding:1.5 ft Amended Soil Depth: 2 ft Storage Depth: 5.25 ft Volume (cf)Qorifice (cfs)∆T (hr)Total Time (hr) Total Inflow Hydrograph Volume 9729.00 0.111 0.000 0.0 0.00 0.101 25.440 25.44 I 3657 - Full BMP Printed 3/29/2023Prepared by Pasco Laret Suiter & Assoc Page 7HydroCAD® 10.20-2g s/n 10097 © 2022 HydroCAD Software Solutions LLC Summary for Link 2L: Inflow to BMP-2 OPT 2 Inflow = 6.45 cfs @ 4.13 hrs, Volume= 11,363.59 cf Primary = 6.45 cfs @ 4.13 hrs, Volume= 11,363.59 cf, Atten= 0%, Lag= 0.0 min Routed to Pond 2P : BMP-2 OPT 2 Primary outflow = Inflow, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs DISCHARGE Imported from BMP-2 OPT 2 RatHydro adj.csv Link 2L: Inflow to BMP-2 OPT 2 Inflow Primary Hydrograph Time (hours) 6543210 Fl o w ( c f s ) 7 6 5 4 3 2 1 0 DISCHARGE Imported from BMP-2 OPT 2 RatHydro adj.csv 6.45 cfs 6.45 cfs D 3657 - Full BMP Printed 3/29/2023Prepared by Pasco Laret Suiter & Assoc Page 8HydroCAD® 10.20-2g s/n 10097 © 2022 HydroCAD Software Solutions LLC Summary for Pond 2P: BMP-2 OPT 2 Inflow = 6.45 cfs @ 4.13 hrs, Volume= 11,363.59 cf Outflow = 0.04 cfs @ 6.00 hrs, Volume=491.52 cf, Atten= 99%, Lag= 112.1 min Primary = 0.04 cfs @ 6.00 hrs, Volume=491.52 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-6.00 hrs, dt= 0.01 hrs Peak Elev= 299.41' @ 6.00 hrs Storage= 10,869.22 cf Plug-Flow detention time= 216.1 min calculated for 490.70 cf (4% of inflow) Center-of-Mass det. time= 26.5 min ( 240.7 - 214.2 ) Volume Invert Avail.Storage Storage Description #1 294.25' 21,636.85 cf Custom Stage Data Listed below 3657 - Full BMP Printed 3/29/2023Prepared by Pasco Laret Suiter & Assoc Page 9HydroCAD® 10.20-2g s/n 10097 © 2022 HydroCAD Software Solutions LLC Elevation Cum.Store (feet) (cubic-feet) 294.25 0.00 294.33 100.73 294.42 201.47 294.50 302.20 294.58 402.93 294.67 503.67 294.75 604.40 294.83 705.13 294.92 805.87 295.00 906.60 295.08 1,120.41 295.17 1,333.56 295.25 1,546.33 295.33 1,758.68 295.42 1,970.51 295.50 2,181.89 295.58 2,392.86 295.67 2,603.33 295.75 2,813.25 295.83 3,022.60 295.92 3,231.35 296.00 3,439.45 296.08 3,646.91 296.17 3,853.50 296.25 4,059.52 296.33 4,264.75 296.42 4,469.18 296.50 4,672.77 296.58 4,875.41 296.67 5,077.21 296.75 5,278.07 296.83 5,477.95 296.92 5,676.68 297.00 5,874.41 297.08 6,071.04 297.17 6,266.52 297.25 6,460.80 297.33 6,653.85 297.42 6,845.59 297.50 7,035.99 297.58 7,224.99 297.67 7,412.54 297.75 7,598.58 297.83 7,782.98 297.92 7,965.85 298.00 8,147.05 298.08 8,326.52 298.17 8,504.19 298.25 8,680.00 298.33 8,853.84 3657 - Full BMP Printed 3/29/2023Prepared by Pasco Laret Suiter & Assoc Page 10HydroCAD® 10.20-2g s/n 10097 © 2022 HydroCAD Software Solutions LLC 298.42 9,025.64 298.50 9,195.28 298.58 9,362.67 298.67 9,527.67 298.75 9,690.22 298.83 9,850.14 298.92 10,007.30 299.00 10,161.55 299.08 10,312.64 299.17 10,460.36 299.25 10,604.36 299.33 10,744.21 299.42 10,879.32 299.50 11,008.64 299.58 11,128.82 299.67 11,241.70 299.75 11,351.91 299.83 11,459.95 299.92 11,565.72 300.00 11,668.05 300.08 11,768.78 300.17 11,869.51 300.25 11,970.25 300.33 12,070.98 300.42 12,171.71 300.50 12,272.45 300.58 12,373.18 300.67 12,473.91 300.75 12,574.65 300.83 12,675.38 300.92 12,776.11 301.00 12,876.85 303.00 14,336.85 304.42 19,519.85 305.00 21,636.85 Device Routing Invert Outlet Devices #1 Primary 294.25'18.00" Round Culvert L= 10.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 294.25' / 294.15' S= 0.0100 '/' Cc= 0.900 n= 0.013, Flow Area= 1.77 sf #2 Device 1 294.50'0.85" Vert. Orifice C= 0.600 Limited to weir flow at low heads #3 Device 1 304.42'36.00" x 36.00" Horiz. Grate C= 0.600 in 36.00" x 36.00" Grate (100% open area) Limited to weir flow at low heads #4 Device 2 294.25'0.42 cfs Exfiltration when above 294.25' Primary OutFlow Max=0.04 cfs @ 6.00 hrs HW=299.41' (Free Discharge) 1=Culvert (Passes 0.04 cfs of 17.88 cfs potential flow) 2=Orifice (Orifice Controls 0.04 cfs @ 10.634 fps) 4=Exfiltration (Passes 0.04 cfs of 0.42 cfs potential flow) 3=Grate ( Controls 0.00 cfs) 3657 - Full BMP Printed 3/29/2023Prepared by Pasco Laret Suiter & Assoc Page 11HydroCAD® 10.20-2g s/n 10097 © 2022 HydroCAD Software Solutions LLC Pond 2P: BMP-2 OPT 2 Inflow Primary Hydrograph Time (hours) 6543210 Fl o w ( c f s ) 7 6 5 4 3 2 1 0 Peak Elev=299.41' Storage=10,869.22 cf 6.45 cfs 0.04 cfs D Total Volume Drawdown Calculation: BMP-1 Project Name Ocean View Point Project No 3657 Date 3/29/2023 Total Inflow Hydrograph Drawdown Time Through Orifice: 55.14 hrs BMP Surface Area 3650 sq ft Note: Drawdown time is calculated assuming an initial water surface depth equal to the invert of the lowest surface discharge opening in the outlet structure. Underdrain Orifice Diameter: 0.85 in C:0.6 Surface Ponding:1.417 ft Amended Soil Depth: 2 ft Storage Depth: 6.5 ft Volume (cf)Qorifice (cfs)∆T (hr)Total Time (hr) Total Inflow Hydrograph Volume 11363.59 0.059 0.000 0.0 0.00 0.055 55.142 55.14 I