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HomeMy WebLinkAboutSDP 2018-0004; ROMERIA POINTE APARTMENTS; DRAINAGE STUDY; 2023-01-03ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 Drainage Study for Romeria Pointe Apartments Prepared for: BNR INVESTMENT & DEVELOPMENT, LLC 23800 VIA DEL RIO YORBA LINDA, CA 92887 (714) 692-9120 Project Site Address 7527 Romeria Street, Carlsbad, CA Prepared by: Michael L. Benesh, R.C.E. 37893 Date: January 3, 2023 ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 1 Contents Section 1. Certification ............................................................................................... 2 Section 2. Discussion ................................................................................................. 3 Section 2.01 Purpose .......................................................................................... 3 Section 3. Project ........................................................................................................ 4 Section 3.01 Description ..................................................................................... 4 Section 3.02 Topography and Land Use .......................................................... 4 Section 3.03 Off-Site Drainage .......................................................................... 4 Section 4. Methodology .............................................................................................. 5 Section 4.01 Rational Method ........................................................................... 5 Section 4.02 Unit Hydograph ............................................................................. 6 Section 4.03 Hydraulics ...................................................................................... 6 Section 5. Summary .................................................................................................... 8 Section 5.01 Post Construction Storm Runoff Impacts .................................... 8 5.01.1 Storm Runoff Entering the Site ........................................................... 8 5.01.2 Storm Runoff .................................................................................... 8 Attachment A - Vicinity Map ............................................................................................. A-1 Attachment B - Hydrology Map .......................................................................................... B-1 Attachment C - San Diego County Soils Group Map ...................................................... C-1 Attachment D - San Diego County Hydrology Manual Excerpts ................................... D-1 Attachment E - San Diego County Point Rainfall Maps .................................................... E-1 Attachment F - TC Calculations .......................................................................................... F-1 Attachment G - Rational Method Calculations ................................................................ G-1 Attachment H - Unit Hydrograph and BMP Basin Inflow/Outflow ....................................H-1 Attachment I - Hydraulic Calculations. .............................................................................. I-1 ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 2 Section 1. Certification Declaration of Responsible Charge I hereby declare that I a m the engineer of work for this project as defined in Section 6703 of the Business and Professions Code, and that the design is consistent with current standards. I understand that the check of project drawing and specifications by the City of Carlsbad is confined to a review only and does not relieve me, as engineer of work, of my responsibilities for project design. 1/3/23 Michael L Benesh, RCE 37893 Date ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 3 Section 2. Discussion Section 2.01 Purpose The purpose of this study is to determine the existing and anticipated 100-year storm runoff and required size of hydraulic structures to protect the proposed and existing slopes and structures on the site, and to identify existing drainage problems that may be caused, or aggravated, by project development. The project is required to meet the County of San Diego Hydromodification Mitigation requirement that the Post-project runoff conditions (flow rates and durations) must not exceed pre-development runoff conditions by more than 10 percent for storms in the range of 0.1 Q2 up to to the Q10 storm event. The SWQMP for the project contains the hydromodification management plan and supporting calculations. The project is also required to demonstrate that the increased runoff from a 100-year storm event will not adversely affect the downstream properties. ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 4 Section 3. Project Section 3.01 Description The project is a 0.7 acre site located in the City of Carlsbad, California. The site is bordered by Romeria Drive to the east, Gibraltar Drive to the north and multi-family residential developments to the south and west. The site does not contain any natural drainage channels or significant natural vegetation. The project has previously been graded and consists of two building pads and manufactured 2:1 slopes. The proposed project includes the construction of a 16 unit apartment complex in 2 buildings. The project parking will be inside the covered parking structure at the lowest level of each building. The construction will include driveways, buildings and the extension of utilities from Romeria Street and Gibraltar Street into the site. The proposed activities will be typical attached residential living. A detailed vicinity map is included in Attachment A. Section 3.02 Topography and Land Use The majority of the runoff from the site drains overland to Romeria Street to the east and Gibraltar Street to the north. The runoff in the streets are picked up in a catch basin on Gibraltar Street just west of the project site. From there it is conveyed to San Marcos Creek by means of a city storm drain system, and a concrete lined watercourse through the golf course north of the project site. A westerly facing slope drains to the property to the west of the project, which in turn drains out to Gibraltar Street and San Marcos Creek. Section 3.03 Off-Site Drainage There does not appear to be any runoff entering the project site from the adjoining properties. There are public streets on the north and east sides of the site and the property to the west is much lower than the site. The property to the south is higher than the project site, but there is an existing berm at the top of the slope and a drain system that conveys the runoff to Romeria Street that would prevent stormwater run-on. ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 5 Section 4. Methodology Section 4.01 Rational Method The Rational Method as described in the San Diego County Hydrology Manual, Section 3, (Revised June 2003) shall be used to determine storm runoff. The Rational Method formula is expressed as follows: Q = C I A Where: Q = peak discharge, in cubic feet per second (cfs) C = runoff coefficient, proportion of the rainfall that runs off the surface. The coefficient C has no units and is based on the soil group and the development type for the drainage sub-area. Attachment F includes calculations for the runoff coefficient for each drainage sub-area. I = average rainfall intensity for a duration equal to the Tc for the area, (in/Hr.) A = drainage area contributing to the design location, in acres The following values are used in the calculations: Soil Group D from San Diego County Soils Group Map. See Attachment C. C (Coefficient of Runoff) from Table 3-1. See Attachment D. 100 year 6 Hr. Rainfall = 2.7” See Attachment E. 100 year 24 Hr. Rainfall =4.8" See Attachment E. The site is first divided into drainage sub-areas. See the On-Site Hydrology Maps in Attachment B. The time of concentration, Tc, for each sub-area along the drainage path is computed based on the initial time of concentration for the initial area and the travel time to reach each succeeding node. Based on the time of concentration, the rainfall intensity is determined using Figure 3-2 (See Attachment D ). Then applying the rational method equation, the peak runoff is determined at each node along the drainage path. Q’s are tabulated for each sub-area along the drainage path. ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 6 The rational method calculations are in Attachment G. Section 4.02 Unit Hydograph The Rational Method Unit Hydrograph procedure as described in the San Diego County Hydrology Manual, Section 6, shall be used to determine time based storm inflowand outflow from the biofilter BMPs. Using this information, the effect of the BMPs on the peak outflow can be determined. For the creation of the Rational Method Hydrograph, a 100 year, 6-hour storm event and a Time of Concentration, Tc, approximately equivalent to the Tc determined in the rational method calculations is used. Peak flow is assumed to occur four hours into the storm. The incremental flows for each time period are then arranged in descending order, two thirds before and one third after, around the peak flow to construct the hydrograph. The water depth/baisin outflow for the BMPs is taken from the results of the San Diego Hydrology Model Software (SDHM 3.1) used for determining the hydromodification control results of the BMPs. The full output of the SDHM program is inculded in the SWQMP for the project. The hydrograph calculations are in Attachment H. Section 4.03 Hydraulics Hydraulic Capacity is determined by use of the Mannings Equation. The Mannings formula is expressed as follows: V = 1.49(R 2/3 s1/2 )/n Where: V = velocity (ft./sec.) R = hydraulic radius which h is determined by dividing the area of flow by the wetted perimeter (ft.) s = slope of conduit or channel (ft./ft.) n= Mannings roughness factor for the conduit or channel Autocad Hydraflow Express is used to determine the flow in the parkway culverts. Inlet Capacity is determined using the weir equation. Q=3Lh3/2 or h=(Q/3L)2/3 ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 7 Where: Q = flow (cfs) L = perimeter of the inlet (ft.) h = depth of water at the grate (ft.) The calculations are included in Attachment I. ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 8 Section 5. Summary Section 5.01 Post Construction Storm Runoff Impacts The proposed project will substantially alter the drainage patterns on the site, but will not alter the off- site or the surrounding area drainage patterns. The Storm water discharge points after development will not divert runoff from existing conditions. The potential pollutants generated by the additional impervious areas will be mitigated by directing the flows through biofiltration BMPs prior to draining to Gibraltar Street. These biofiltration BMPs will be sized to both treat the storm runoff from the site and provide flow control per the County of San Diego Hydromodification Management Plan. The detention volume provided in the biofiltration BMPs will be sized to both treat the runoff from the site and provide flow control, and therefore the project will not increase the rate or amount of surface runoff in a manner which would result in flooding on- or off-site. The proposed project will not alter the course of a stream or river, in a manner which would result in erosion or siltation either on-site or off-site. The project will not place housing within a 100-year flood hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or County Floodplain Maps as the site to be developed is not within a floodplain. The proposed project will not create or contribute runoff water which would exceed the capacity of existing or planned storm water drainage systems. The potential increases in runoff flows flow from the site will be mitigated by the inclusion of flood control facilities in the site drainage system. 5.01.1 Storm Runoff Entering the Site The project is not subject to storm run-on. The existing drainage pattern keeps water from entering the property. 5.01.2 Storm Runoff The amount of driveway and parking exposed to storm runoff has been kept to a minimum through the use of parking garages located under the proposed residences, but there will still be an increase to the amount of impervious area predominantly due to the construction of the buildings. This increase in impervious area will cause an increase in storm runoff from the project drainage area. Prior to development the project site has minimal impervious areas ( 1% +/-) as it is graded pads and slopes. After the site is developed, the impervious area will increase to 0.506 acres (22,054 sf), or 71% of the site area. ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 9 The storm runoff from DA-10 drains to BMP-1. The storm runoff from DA-11 drains to BMP-2. The storm runoff from DA-12 drains to BMP-4. The outflow from BMP-1, BMP-2 and BMP-4 will be directed via an on-site storm drain system to the easterly Parkway Culvert on Gibraltar. The storm runoff from DA-16 & DA-18 is collected in an on-site storm drain system that drains to BMP-3. The flow from BMP-3 will be direted to the westerly parkway culvert on Gibraltar. All the folws from the site will collect in the catch basin on Gibraltar located near the northwest corner of the site. A comparison of pre- and post-construction runoff for the site drainage basin is included in the table below. Node Area (Ac.) Pre- Const. % Imp Post- Const. % Imp Net Change Pre-Const. Runoff, Q100(CFS) Post Const. Runoff, Q100(CFS) Net Change A 0.71 1 71 70% 1.4 3.3 1.9 cfs The storm drain downstream of the project is a 48” diameter RCP at a slope of 0.010. The capacity of the pipe flowing full is 143.6 cfs. (Assuming a Mannings n=0.013.) The 1.9 cfs increase in peak runoff from the site is 1.32 percent of the capacity of the storm drain. The results above do not take into account the effect of the bio-filtration BMPs included the site design. The BMPs have a combined storage capacity of 3,610 cf which will delay the runoff from the site, reducing the peak runoff rate and mitigating the increase in runoff. BMP Storage: BMP Name Dimensions Surface Area (s.f.) Ponding Depth (inches) Media Depth (inches) Gravel Depth (inches) Effective Depth (inches) Storage Volume (c.f.) BMP-1 65’x5’ 325 10 21 48 36.55 990 BMP-2 50’x5’ 250 10 21 48 36.55 761 BMP-3 112’x6.5’ 560 10 21 48 36.55 2,217 BMP-4 8.23’x4’ 33 6 21 24 22.95 63 Total 1,168 4,031 ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 10 The Unit Hydrograph and Basin Inflow/Outflow calculations in Attachment H demonstrate that after development the peak runoff flow from a 100-year 6-hour storm will be less than it is currently. The table below includes the results of the calculations. The Q100 from the site in its existing condition is 1.4 cfs. After development, Qmit (Q100 adjusted for the mitigating effects of the biofilter basins), is 0.9 cfs. A reduction of 0.5 cfs or 36 perrcent. Qmit does not include adjustments for different times of concentration of the flows. That adjustment could only further reduce the Qmit values. BMP Runoff: BMP Q100 ignoring basin storage Q100 adjusted for basin storage Net Change % Difference BMP-1 (DA-10) 0.8 0.07 -0.73 -91% BMP-2 (DA-11) 0.4 0.03 -0.37 -92% BMP-3 (DA-16 & 18) 2.2 0.43 -1.77 -80% BMP-4 (DA-12) 0.1 0.04 -0.06 -85% Total 3.5 0.57 -2.93 -84% Total Site Runoff Comparison (Not adjusted for Tc): DA Q100 Existing (No Impervious Surfaces) Q100 Developed (Adjusted for basin storage) Net Change % Difference DA-10 (BMP-1) 0.33 0.07 -0.26 -79% DA-11 (BMP-2) 0.15 0.03 -0.12 -80% DA-12 (BMP-4) 0.03 0.04 +0.01 +33% DA-14 0.03 0.04 +0.01 +33% DA-15 0.19 0.19 - 0% ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 11 DA-16 & 18 (BMP-3) 0.95 0.43 -0.52 -55% DA-17 0.09 0.09 - 0% DA-19 & 20 0.01 0.02 +0.01 +100 Total 1.78 0.91 -0.87 -49% The hydraulic calculations in Attachment I indicate that the proposed storm drain structures are adequate to protect the site during a 100-year storm event. ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 A-1 Attachment A - Vicinity Map VICINITY CITY OF OCEANSIDE PACIFIC OCEAN /fJ MAP CITY OF ENCINITAS NOT TO SCALE CITY OF VISTA Y OF MARCOS Site ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 B-1 Attachment B - Hydrology Map Attachment B-1: Existing Condition Hydrology Map The full size map is included in folder at back of report. Attachment B-2: Proposed Condition Hydrology Map. The full size map is included in folder at back of report. EX. SEW E R M H E X . 8 " S E W E R P E R D W G 1 6 9 - 4 E X . 8 " W A T E R P E R D W G 1 6 9 - 4 E X . C U R B , G U T T E R & S I D E W A L K P E R D W G 6 9 - 4 85.70 TG Ex 1.5" S E R V I C E W / 1 " M E T E R (IRRIG . ) EX. CUR B , G U T T E R & SIDE W A L K EX . T R A N S F O R M E R EX . U T I L . B O X E S 66.5 0 TG 66.9 0 TG 66.9 0 TG 66.9 0 TG E X . C U R B , G U T T E R & S I D E W A L K E X . S T . L T . E X . 2 4 " S D P E R D W G 1 6 9 - 4 85.70 TG 85.70 TG 85 . 0 4 TG P I P E F D 3 P I P E F D 3 P I P E F D 3 P I P E F D 3 N9 0 ° 0 0 ' 0 0 " W 1 4 5 . 0 ' N00° 00' 00"E 90.0' N34° 4 5 ' 2 3 " W 6 6 . 0 ' D = 1 2 ° 3 6 ' 3 4 ", L = 1 3 4 . 2 ', R = 6 1 0 . 0 0 ' D=97°19'27", L=34.0', R = 2 0 . 0 0 ' D =4 0 °0 2'2 8 ",L =1 5 3 .7 ',R =2 2 0 .0 0 ' N00° 00' 00"E 90.0' 1 0.623 AC (0 SF IMP) 0% IMP 2 0.089 AC (376 SF IMP) 10% IMP Node A Q100=1.4 cfs Notes: ·Underlying Hydrologic Soils Group for the entire project is Soils Group D. ·There are no wells, springs or watercourses on the developed project site. ·The existing site is previously graded but has no impervious surfaces. Attachment B1 Drainage Study Romeria Pointe Existing Condition Hydrology Map SHEET 1 OF 1 Legend: Drainage Area # Area Impervios Cover % Impervious Drainage Area Boundary Scale: 1"=10' Feet 20 10 0 10 0.00 AC (10 SF IMP) 10.0% IMP PREPARED BY: ROBIN B. HAMERS & ASSOC., INC. CIVIL ENGINEERS 234 E. 17TH STREET, SUITE 205 COSTA MESA, CA 92627 (949) 548-1192 MICHAEL BENESH, R.C.E. 37893 DATE HBR 1/ 3/23 LIVIC RE E N I G N E LANOISSEFORPDERETSIGER Existing 42" storm drain flows northerly to the catch basin on Gibraltar at Node A. Existing terrace drain flows southerly to an inlet on the 42" storm drain that crosses the property to the west. Existing catch basin on Gibraltar at Node A. Existing berm and drainage system directs drainage from southerly site to Romeria . SITE BOUNDARY SITE BOUNDARY SITE BOUNDARY SITE BOUNDARY SITE BOUNDARY ----<:--_ ~~ "'--== -- ----------- ■ --- I I I I I I I I I I ~ l G APARTMENTS EXISTIN --------- I I --. ~ I Romeria / - L / / ""' / / / ""' - / I 1 I -, I .__ / -ci\ / i:-2' \ i:::, / lj~, / I •: ---~ ---' ' -'------------_./ I I / I I I I I \ I I \ \ \ ,, C / / , , , / , , , / / \ \ ------ \ 0 RCE 37893 / , , / , , , / , , 67 . 5 0 FS 85.00 T C 84.50 F S 8 8 . 0 0 T C 8 7 . 5 0 F S (81 . 8 ) EG (96.1) EG 86 . 0 0 FS (79 . 1 0 ) FS/ B W EX. SE W E R M H E X . 8 " S E W E R P E R D W G 1 6 9 - 4 E X . 8 " W A T E R P E R D W G 1 6 9 - 4 E X . C U R B , G U T T E R & S I D E W A L K P E R D W G 6 9 - 4 64.8 T W 63.8 F G C2 E2 68 . 0 TC 67.9 FS 60.0 TOE 67.4 T W 61.9 FG 1" LIP 66.70 FS 67 . 4 0 FS (78 . 0 7 ) FS/ B W 81 . 0 6 FS 87 . 6 7 T C 87.1 7 F S 85 . 5 0 T C 85.0 0 F S 86.2 5 FS86 . 5 0 FS 87 . 0 0 FS (96.5) EG 86.1 0 FS86 . 5 0 FS (96.5) EG 86.1 0 FS86 . 5 0 FS (96.1) EG 86.0 0 FS 86 . 5 0 FS (94.0) EG 86.0 0 FS86 . 5 0 FS 86. 3 0 FS 86.8 0 FS (78. 1 ) EG 86 . 3 0 FS 86.0 0 FS 86 . 0 0 FS 86.5 0 FS 86 . 0 0 FS 86 . 0 0 FS 86.5 0 FS 86 . 0 0 F S 81. 1 6 FS 86.50 FS 81. 2 5 FS 86.30 FS (77. 0 ) EG 80.66 FS 81 . 0 5 FS 65.1 FS 1" LIP 67.30 FS 67.50 FS 67.20 FS 67.50 FS 67.20 FS 67.40 FS 67.20 FS 67.40 FS 67.20 FS 67 . 4 0 FS 81.2 5 FS 81. 2 5 FS 67.40 FS 67.20 FS 67.20 FS 67.40 FS 6 7 . 2 0 F S 67 . 4 0 FS 67.20 FS 67.40 FS 67.20 FS 67.40 FS 67.20 FS 67.40 FS 67 . 4 0 FS 67.30 FS 75 . 5 0 FS 75 . 5 0 FS 75.50 FS 7 5 . 5 0 F S 81.25 FS 81.5 0 FS 85.70 TG 86.0 0 FL/H P 86 . 0 0 FL/H P 86.3 0 FL/H P 97 . 0 0 F S 9 0 . 5 8 F S 81.25 FS 84.50 TS 81.25 FS 86 . 5 0 FS 84.50 T W 81.25 F S 86.43 TG 81.28 FS 81.50 FS 81 . 5 T W 80 . 3 F G 81.5 TW 78.2 FG 78 . 5 T W 78 . 2 F G 81 . 5 T W 78 . 6 F G 78. 5 T W 75.1 F G 72 . 0 FG 67 . 0 FG 86 . 0 T W 83 . 2 F G 81. 1 6 FS (5 6 . 1 0 ) FS 70.50 TW 6 7 . 2 0 F S 71.5 T W 67.2 0 F S 7 1 . 5 T W 6 7 . 5 0 F S 7 1 . 5 T W 7 1 . 0 0 F S 80.96 TG 6 1 6 2 62 64.5 T W 63.0 F G 636465 6667 6365 64 67 67 . 1 FG Ex 1.5" S E R V I C E W / 1 " M E T E R (IRRIG . ) EX. CU R B , G U T T E R & SIDE W A L K EX . T R A N S F O R M E R EX . U T I L . B O X E S 66.5 0 TG 66. 9 0 TG 66.9 0 TG 66 . 9 0 TG 58.3 INV 5 6 . 0 I N V 81.0 TG84.0 TG 84.0 TG 81.0 TG 81.0 TG 81.15 TG 75.3 TG 81.1 5 TG 75 . 4 4 T G 7 0 . 9 6 T G 67. 0 0 TG 6 5 . 5 T G 5 6 . 5 I N V 78.5 TG 7 8 . 0 0 T G E X . C U R B , G U T T E R & S I D E W A L K F2 E X . S T . L T . (59.80) BW 64 . 6 TC 6 7 6 6 6 5 6 4 6 3 6 2 6 1 6 0 5 9 5 8 5 7 E X . 2 4 " S D P E R D W G 1 6 9 - 4 (4 1 . 9 ) ) I N V EX . 8 " S E W E R (6 4 . 1 ) ) I N V EX . 8 " S E W E R (78. 0 ) EG 85.70 TG 85.70 TG 85 . 0 4 T G 86. 2 0 FS 96 . 9 0 F S 90.6 8 FS 86.5 0 FS (5 6 . 2 0 ) FS56 . 1 8 FS 56 . 2 8 FS 63 . 4 6 FS 63.56 FS 6 3 . 5 4 F S 63.64 FS 67 . 3 0 FS 67.30 FS67.22 FS 67.50 FS 71.5 T W 67.0 8 F S 7 1 . 1 6 F S 71.00 FS 71.16 F S 81 . 2 5 FS 81. 2 5 FS81.25 FS 67.40 FS 86.50 FS 86 . 0 0 FS 7 5 7 2 86. 5 5 FS 81.12 FS 81. 1 6 FS 81 . 3 3 F S 81.42 FS81.5 0 FS 81. 5 0 FS 81 . 4 7 F S 81.33 FS 80 . 9 0 FS 81.10 TG 81. 2 0 TG 81.20 FS 81.42 FS 81.42 FS 81. 4 2 FS 81. 1 8 FL/ H P 81. 2 8 FL/ H P 81. 5 0 FS 81.28 FS 8 0 . 7 5 F S 80.86 FS 78. 2 5 FS 78.5 4 FS 79.0 4 FS 79.85 FS 81.50 FS 81.42 FS 80.7 FL/H P 79.6 FL 78.7 0 FS 79. 1 4 FS 79.95 FS 8 0 . 7 6 F S 78. 3 FL/ H P 67 . 3 0 FS 67.20 FS 67 . 3 0 FS 67.20 FS 81. 0 7 FS 80.2 FL/H P 79.1 FL (62.25) BW 87. 7 5 TC 8 3 . 9 5 T C W W W W W W 8 6 . 5 0 F S 86. 5 0 FS 84.50 TW 80.50 FS SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD S D SD BMP-4 O U T L E T 64.60 T . G . 59.03 IN V BMP-2 O U T L E T 85.83 T . G . 78.82 I N V SD SD SD SD SD SD SD SD SD SD SD S D SD SD SD SD SD SD SD SD SD BMP 3 O U T L E T 66.80 T . G . 58.65 I N V P I P E F D 3 P I P E F D 3 SD S D S D SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD SD S D SD BMP-4 O U T L E T 64.60 T . G . 59.03 IN V SD BMP-2 O U T L E T 85.83 T . G . 78.82 I N V SD SD SD SD SD SD SD SD SD SD SD S D SD SD SD SD SD SD SD SD SD BMP 3 O U T L E T 66.80 T . G . 58.65 I N V P I P E F D 3 P I P E F D 3 SD S D S D D2 N9 0 ° 0 0 ' 0 0 " W 1 4 5 . 0 ' N00° 00' 00"E 90.0' N34° 4 5 ' 2 3 " W 6 6 . 0 ' D = 1 2 ° 3 6 ' 3 4 ", L = 1 3 4. 2 ', R = 6 1 0 . 0 0 ' D=97°19'27", L=34. 0', R = 2 0 . 0 0 ' D =4 0 °0 2'2 8 ",L =1 5 3 .7 ',R =2 2 0 .0 0 ' N00° 00' 00"E 90.0' 84.7 5 FL 83 . 5 FL 81.5 FL 60 65.5 FG 66 . 0 FG 65.7 FG 66 78 . 0 0 TG 8 7 . 0 0 T G SD SD SDSD 90 . 5 8 TG Node A Q100=3.3 cfs Qmit = 0.9 cfs 10 0.133 AC (5023 SF IMP) 87% IMP 15 0.076 AC (86 SF IMP) 3% IMP 14 0.010 AC (0 SF IMP) 0% IMP 19 0.003 AC (0 SF IMP) 0% IMP Q100 = 1.1 cfs Qmit = 0.14 cfs Q100 = 0.8 cfs Qmit = 0.07 cfs 17 0.033 AC (83 SF IMP) 6% IMP 11 0.061 AC (2336 SF IMP) 89% IMP Q100 = 0.1 cfs Q100 = 0.4 cfs Qmit = 0.03 cfs Q100 = 2.2 cfs Qmit = 0.43 cfs Q100 = 0.1 cfs Qmit = 0.04 cfs 16 0.381 AC (14123 SF IMP) 85% IMP 20 0.001 AC (0 SF IMP) 0% IMP 18 0.001 AC (60 SF IMP) 100% IMP 12 0.012 AC (343 SF IMP) 66% IMP SD SD Notes: ·Underlying Hydrologic Soils Group for the entire project is Soils Group D. ·There are no wells, springs or watercourses on the developed project site. SHEET 1 OF 1 Legend: Impervious Surface (Parking, building, sidewalk) Storm Drain Drain Inlet Drainage Area # Area Impervios Cover % Impervious Drainage Area Boundary Scale: 1"=10' Feet 20 10 0 10 0.00 AC (10 SF IMP) 10.0% IMP Attachment B2 Drainage Study Romeria Pointe Developed Condition Hydrology Map PREPARED BY: ROBIN B. HAMERS & ASSOC., INC. CIVIL ENGINEERS 234 E. 17TH STREET, SUITE 205 COSTA MESA, CA 92627 (949) 548-1192 MICHAEL BENESH, R.C.E. 37893 DATE HBR 1/ 3/23 LIVIC RE EN I G N E LANOISSEFORPDERETSIGER Existing 42" storm drain flows northerly to the catch basin on Gibraltar at Node A. Existing terrace drain flows southerly to an inlet on the 42" storm drain that crosses the property to the west. Existing catch basin on Gibraltar at Node A. Existing berm and drainage system directs drainage from southerly site to Romeria . SITE BOUNDARY SITE BOUNDARY SITE BOUNDARY SITE BOUNDARY SITE BOUNDARY BMP-3 BMP-4 BMP-2 BMP-1 == = -l •-• ,,-'-.,II,.._·. • • • --· ',,, ~---'--',,, • - ~l • j om e • r I a Dr . . '' ·. \~ ... ,t , .... , -~ ', ',·"" '' ,Y1· ~' . ..__ ~°', ' '. •. / ~'·. ~' ' ' ' -V, ---,--- 1:y' ' ' ~·. ··· .. ~,··. ' I ~!•''~ , ' ;·· .. \,,. ',, .. , , X ''.. / I' \. ' .# /1/. . . ·~ . X . ' . . ' . . . . . • 0. ·:~ ---"~" ~'::;' ~ - TT--..-L ~ • ~ . "'· ' . -- . ~ ~ •.•...... 1 ---•~'f . . . . ~' ·. . '' '' ~~·· .. · .. . . " . ·~ -------== -~ --------- ------------------- \ \ \ ------ \ \ \ \ \ \ \ \ \ \ ------ \ • •• \ \ \ \ \ \ \ \ \ \ \ ' :.n \ \ \ \ • •• ',, ' •• • . • •• •• • • • • • • • \iS' \ ,,. \ <S \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 0 l ------ ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 C-1 Attachment C - San Diego County Soils Group Map Soils Group Map SITE -r---+-----1-----1 t Soil Groups i===J GroupA -Groupl:L i===J Group C i===J GroupO [=:] Undetc:an~ed i===J Data, u-.. prp,.-,::::3~~,;:~ ~"----:'C"r'~~-----,•-- ... _r RO B I N B . H A M E R S & A S S O C . , I N C . 23 4 E . 1 7 TH ST . , S U I T E 2 0 5 CI V I L E N G I N E E R S PL A N N E R S SU R V E Y O R S CO S T A M E S A , C A 9 2 6 2 7 .. . si n c e 1 9 8 1 Ph o n e 9 4 9 / 5 4 8 -11 9 2 D-1 At t a c h m e n t D - Sa n D i e g o C o u n t y H y d r o l o g y M a n u a l E x c e r p t s Table J-1 RU.i\OrF COEFFICIE~TS FOR URllA.i\ AREAS Land Use Runoff Coefficient "C'' SoilT~ NRCS Elemenis Counry ElemenlS %IMPER. A B C D UndL~lu1'bed Natural Terrain (Nalurol) Permanent Open Space o• 0.20 0.25 0 30 0.35 Low Density Res1dent1al (LDR) Re.~1denual, 1.0 DU/A or less 10 027 0.32 036 0.41 Low Density Residential (LDR) Res1denual, 2.0 DU/A or less 20 0.34 0.38 0.42 0.46 Low Density Res1dem1al (LDR) Res1dei1ual, 2.9 DU/A or less 25 0.38 0.41 0.45 0.49 Medtum Density Residenual (MOR) Res1denual, 4.3 DU/A or less JO 041 0.45 0.48 0.52 Medium Density Residential (J\IIDR) Res1denual, 7.3 DU/A or less 40 048 0.51 0.54 0.57 Med1111n Density Residential (MDR) Res1dei1ual, 10.9 DU/A or less 45 0.52 0.54 0.57 0.60 Med1111n Density Residen11al (MDR) Res1denual, 14.5 DU/A or less 50 0 55 0.58 0.60 0.63 High Density Reside@al (MDR) Res1denual, 24.0 DU/A or less 65 066 0.67 0.69 0.71 H,gh Density Residenual (I-IDR) Res1denual, 43.0 DU/A or less 80 076 0.77 0.78 079 Commerc,alilndustnal (N. Com) Ne1ghbo111ood Commercml 80 076 0.77 0.78 0.79 Commercialilndustnal (0. Com) General Commercial 85 080 0.80 0.81 0 82 Commerc,alJfodusmal (0. P. Com) Office Proressional/Comnierci1d 90 0.83 0.84 0.84 0.85 Comrnercmlilndustnal (Limited I.) Lunited Industrial 90 083 0.84 0.84 0 85 Commercialilndustnal {General I.) General Industrial 95 087 0.87 0.87 0 87 •The values associated with 0% irnperv1ous ,nay be used ror direct calculat,on of the runoff coeffic1em as described in Sec11on 3.1.2 (representing the perv1ous runoff coenicient, Cp, for the soil l)'Pe), or for areas that will remarn undisturbed in pet'petu,ty. Jus11fica.11on must be given that the area will remam natural forever (e.g., the area ,s located m Cleveland Na11onal Forest). DU/A• dwelling units per acre NRCS • Nnuonal Resources Consen.•at,on Service ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 D-2 Element* \Jatural LOR LOR LOR MOR MDR MOR MOR HOR HOR \I.Com G.Com O.P./Co m Limited I. Genera l I. Table 3-2 l\iAXIMUM OVERLAND FLO\\/ LENGl H (Lj\1) & INITIAL TllVIE OF CONCENTRA'I'ION (T;) DU/ .5% 1% 2% 3% 5% Acre LM Ti LM Ti LM T; LM Ti Ll\,1 Ti 50 13.2 70 12.5 85 10.9 100 10.3 100 8.7 I 50 12.2 70 11.5 85 10.0 100 9.5 100 8.0 2 50 11.3 70 10.5 85 9.2 100 8.8 100 7.4 2.9 50 10.7 70 10.0 85 8.8 95 8.1 100 7.0 4.3 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 7.3 50 9.2 65 8.4 80 7.4 95 7.0 100 6.0 10.9 50 8.7 65 7.9 80 6.9 90 6.4 100 5.7 14.5 50 8.2 65 7.4 80 6.5 90 6.0 100 5.4 24 50 6.7 65 6.1 75 5.1 90 4.9 95 4.3 43 50 5.3 65 4.7 75 4.0 85 3.8 95 3.4 so 5.3 60 4.5 75 4.0 85 3.8 95 3.4 50 4.7 60 4.1 75 3.6 85 3.4 90 2.9 so 4.2 60 3.7 70 3.1 80 2.9 90 2.6 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 50 3.7 60 3.2 70 2.7 80 2.6 90 2.3 *. ec Table 3-1 for more detailed description 10% LM Ti 100 6.9 100 6.4 100 5.8 100 5.6 100 5.3 100 4.8 100 4.5 100 4.3 100 3.5 100 2.7 100 2.7 100 2.4 100 2.2 100 2.2 100 1.9 RO B I N B . H A M E R S & A S S O C . , I N C . 23 4 E . 1 7 TH ST . , S U I T E 2 0 5 CI V I L E N G I N E E R S PL A N N E R S SU R V E Y O R S CO S T A M E S A , C A 9 2 6 2 7 .. . si n c e 1 9 8 1 Ph o n e 9 4 9 / 5 4 8 -11 9 2 D-3 100 90 a.o 70 l'-, " i',. i',.' !>.O ~o I ...._ ~ ,._i', ~ .... i',. .... ' :--. ... ..... ~ :::~i ' ~ ' ~ ~ ....... ' ~ '-' ~ ~ 40 :, '~ r-...' "~ ~ I 3-0 I 2.0 I I )10 , ;:os1 ~oa! lo11 .,. . I 06 05 I i I O• I OJ 02 ! I'-.. ....... - i- .... I' i', ..... , .... "'• --. .... "r-... ' I I ·-. ._._ ->-- ,---. ·---. ' I 01 , , , , 5 6 7 8 9 10 ....... ~' ~ ~ ~ ~- "~ ' ' ~,~ '"" H= 1·s llilfli I 11111111 I I I I I I I ' I 11 l ~ ·~ I I~ ,, I I l~I ml, 't' ' ' I I~ I I ' ~ l1 I ' II lj I I I I I I , 11 ' I I I I I 1 1) I ~ 1 1 • - lill I Ill I I I I I Ill I I 1111111 I Ill I EQUATION I I = 7.44 Ps o-0-645 I = Intensity (In/IV) I Pe = 6-Hour Preclpltltion (In) ~ ~ I D = Durabon (min) ... ◄ I .... r-..., I ..... r-...1 t-..... ) ~ I r-. ·' ' ..... .. ..... N"i-. .~ ~1 1 ~: ', l R: -~ I ' .. , N-:i ... ... I ~II .... ......:. ... .._i r....!. ' I II I , ...... .N-... '! I "r-- , .... ....... r-... I" ... ~ . II f" ......... I ~ I I ..... ', . I', ... ... "' M ·l : . + . ' . t b ... - H- ....... --..w I I I I I I I I I I I ... I ..,_ I ~ I ~ ' I +- l 4 4 I I Ml 5S !It! 5.0 9 •.s-:, ◄.0 i 35 !:- J.O 1-2.7 2.5 2.0 1.5 1.0 20 JO .io 60 1 2 3 • i; ii Minutes Hou11i Du~cn Intensity-Duration Design Chart• Template Directions for AppUcir:lon: ( 1) From precipll;llion ITl3')S de:emwne 6 hr and 2• tT amounts for the selected lr~ncy. These maps are lrduded In tho County ~ogyM81Ual (10, 50, and 100yrrrepe lnctuded In the Design and Plooe<lure Manual). (2) Adjust 6 hr preclpila'ion (ir necessary) so 1ha-II is withm the ronge ol 45"4 1065% of tho 24 hr praclpll:lltion (nol applicaple to Dosertr. (3) Plot 6 hr preoipitatio, on the right side or the chart. (4) Draw a line through lhe point parale l to the r'otted lines. (5) This fine is the 111temity-<luration curve for lhe location being analyzed. Appllcatlon Form: (a) Selected frequency JQQ_ year (b) P6 = 2,7 In P,4 : 4.8 ~ = ---• ' ---'P24 56 %12) (c) Adjusted p6<2> • ~ In. (d) lx • ___ min. (e) I " ___ ln./hr Note: This c;t,art replaoes the lntensily-Duration-Frequency curves used sine& 1965. P6 I I.II 2 u 3 i .5 • u I 5,5 • Dun,Jia,, I I I I I I I I I I I 5 263 3" S.27 G!)9 790 9.22 10.54 11.811 1117 14.49 16.tl 7 2 12 3 18 • 24 53(111,311 742 S •• 8 S< 1060 11 811 12 72 10 168 ~$3 3:J7 4~1 !,Ill, !>110 6/4 1 !,8 8'2 821 10 II 15 130 IQ!.2£!132•3.19454 Sl8 S.84 6 •9 7 13 7 78 20 1.()8 162 2 15 21111 '3.23 3.TT 4 31 •.15 5.38 593 SAS 25 093 I 40 187 233 280 327 3 TJ • 20 •P 513 560 JO 033 I 24 16G 207 14'1 l,O 3.32 373 •1$ ·~ •se 40 008 IIXI 1311 172 207 2•1 US 310 315 379 4 13 50 0 60 0.90 I 19 149 1.711 2.09 2 36 2.69 2.98 3211 3.58 SO Os.3 090 106 133 169 1$6 212 2.39 "' 292 3 18 10 041 OSI 082 102 123 143 1.63 1.IM 2..04 226 2 45 120 o:u 051 068 oes,102 11u 136 15,3 IJO 1 87 204 150 0'9 0 "'4.1.0MI 073088103 118 I 32 1<7 1 62 116 110 0211-0!9 0~ 06S~0.7a-091 1.04 1.18 1.31 144--,-S7 240 0.22 033043 054 065076 OIJ7 0INI 1.J& 118 130 :,00 019 028038 0•7 000066 0~ 0&) 0.94 103 I 13 HO 0.17 0.25 0,33 042 0..60 0..58 0.87 0.75 0.!◄ 0.92 1.00 ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 D-4 20 111 16 14 12 tel 9 ' ! J (/) ! (/) 'ls 2 ';f!. 18 16 I~ 10 DV D.8 07 oe 05 -- - - 1 -,,=.0t~~~ --2% --n =.0175 ------=..::.....___ :l'll, concrolG Gutter RESIDENTIAL STREET ONE SIDE ONLY I I ~ v,.. -,-.. !,~ I L I j .......... 10 , I -......!...<r L -~ ·P ' -...., ' -~ I ........ ........ I ]'...._ I I I ) ~ ~b1 I " I ,.._ ' , ~ I J ....... I ----.. I j 7--.. I _,ll I r---... I I ............ I _o°tf-I ...... -V.,B I 'I-._ J I/ -:.~ I ~ .f;P.& I " I ---r-..... j ....... , -1 ri/4 ~ "5' ~ I ....... I J I ---. r -rt'~ ~ ..... I ----i I !i ........... ~ .. I,,. , J I I •,h , ... ~~ " J i---_ / I ....... -r:,'t ~ ...... I r--.... I ~, ....... l i ,......... I ....... a' -...r:;,'J ... j '-.. J i---I J ...... J f l "'-"-'' I ~J (o_., I ---....... r--... I I'-<JI ~~./ t ' I r'~<sl I ........ I'-,. I ll/ ''bV f.D I I r-,...& -......1 I fl ....... I ......._ I r--J , ............ I i:fl -.... r-- ...... ..... / ........ / ........... , , v~ I -......:_<rh .... I I'--.. J -ti. v I ~ I ~, r ........... ~ I ........._ I I' ~I ...... , .... , ..... ~ I 7 I t 10 :NJ :Ill 4D 10 □lcclinro-(C i: S ) U:Ar.lPLE· cruen: a ■ 10 s ■ 2.,% Cha.11 pas O■plh = O·~•-Vltlocily =-4,4 tp,5, SOURCE San l>ego Counly Department or Special Dislroct Sen/Ices Oes,gn Manual f I , Gullv1 IUIIJ f\u111Jw11y Diwclitllyu • Vuluclly Chllfl 3-6 ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 E-1 Attachment E - San Diego County Point Rainfall Maps 100 Year – 6 Hour Rainfall SITE r , .. !,, ., .. ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 E-2 100 Year – 24 Hour Rainfall SITE l I _1_l 1 1~ '.J_,-, I I I --Y--11 I I ~ ~ -+ +-+-H1TTf 7 I ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 F-1 Attachment F - TC Calculations Existing Condition Tc, Initial Area 1 Total Area = 0.623 Acres % Imp = 0% Use Natural L=231’ Initial Slope >10% Ti=6.9 Min., Lm=100’ L=131’, h=25’ Tt=(11.9(L/5280)3/h)0.385 = 0.011hrs = 0.6 min Overland Flow Tc=6.9 + 0.6 = 7.5 min. The other existing area on the site is assumed to have a Tc=5 min. due to the short travel lengths and small areas. The proposed areas are also assumed to have a Tc=5.0 minutes due to the short travel lengths and small areas. ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 G-1 Attachment G - Rational Method Calculations The Rational Method as described in the San Diego County Hydrology Manual, Section 3, (Revised June 2003) shall be used to determine storm runoff. The Rational Method formula is expressed as follows: Q = C I A Where: Q = peak discharge, in cubic feet per second (cfs) C = runoff coefficient, proportion of the rainfall that runs off the surface. The coefficient C has no units and is based on the soil group and the development type for the drainage sub-area. Attachment F includes calculations for the runoff coefficient for each drainage sub-area. I = average rainfall intensity for a duration equal to the Tc for the area, (in/Hr.) A = drainage area contributing to the design location, in acres The following values are used in the calculations: Soil Groups from San Diego County Soils Group Maps. See Attachment C. C (Coefficient of Runoff) from Table 3-1. See Attachment D. 100 year 6 Hr. Rainfall = 2.7” See Attachment E. 100 year 24 Hr. Rainfall =4.8" See Attachment E. See calculations on the folowing pages. Rational Method Calculation Form Project: Romeria Pointe Frequency 100 Year Existing Condition P6=2.7 in./hr. Page G-2 Calculated by MB Date: 1/3/2023 Drainage Soil % Imp A C CA ΣCA I Q Slope Section V L Tt Tc Remarks Area Type Area Acres In./Hr.CFS '/Sec.Ft.Min.Min. D 0%0.35 D 10%0.41 0.35Confl A 0.712 0.260 0.03 1.4 7.55.48 2 0.089 0.040 0.040 7.11 0.3 5.0 Assumed - Small Areapipe & gut.19 240 0.2 5.2 To Confl A 7.5 See Attachment F0.623 0.220 0.220 5.48 1.2 1 Rational Method Calculation Form Project: Romeria Pointe Frequency 100 Year Developed Condition P6=2.7 in./hr. Page G-3 Calculated by MB Date: 1/3/2023 Drainage Soil % Imp A C CA ΣCA I Q Slope Section V L Tt Tc Remarks Area Type Area Acres In./Hr.CFS '/Sec.Ft.Min.Min. 0.35 0.35 0.35 Add-In Area 6.3 5.4 5.7 5.3 To Confl Add-In Area 5.0 Assumed - Small Area 0.03 0.2 5.0 To Confl A 8" pipe Assumed - Small Area5.0 7.11 0.134 7.11 0.15 0.0210.061 7.11 0.0470.133 0.134 0.95 16 & 18 0.382 87% D 0.4 0.0 1.1 6.13 2.2 0.007 0.205 0.177 0.002 6.39 7.11 0.170 0.4 6" pipe 0.021.1 6.77 0.67 0.12 0.8 0.110 7.11 0.161 0.133 0.061 0.005 20 & 19 14 0.051 0.004 0.83 0.400.012 11 89%0.84 0.48 12 D 66%0.012 0.71 0.009 D10 0.110 89% 17 16 & 18 12 0.012 0.004 D D 6% 0.84 0.013 0.82 D 0% 0.021D11 12 0.028150.076 0.222 11 Inlet 0.061 0.051 0.033 Confl 90 1.1 6" pipe Street 4 7 9 pipe & gut. 3.3 1.3 0.03 Street Street 7 155 6" pipe 10 75 150 19 0.04 0.382 7.11 To Confl A 0.002 0.0 5.9 7.11 6.85 150 0.4 90 0.4 3.5 0.14 0.1 To Confl A5.0 0.013 5.0 Assumed - Small Area5.0 5.0 Assumed - Small Area 5.9 5.0 0.1 0.38 24% 85%0.313 6.46 0.12 20 7.11 0.313 7.11 To Confl Assumed - Small Area Add-In Area Assumed - Small Area 5.2 5.0 5.0 Assumed - Small Area5.0 5.8 Assumed - Small Area Assumed - Small Area Assumed - Small Area5.0 0.3 D D 9% D 3%0.37 BMP Runoff with no improvements for comparison to Mitigated Flows. 0.80 0.531 - 240 0.33 0.4 0.051 7.11 0.047 12 Inlet D 66%0.012 0.71 0.009 0.009 Confl A 0.713 0.74 0.004 7.11 0.03 D 0.1 10 0% D 0% D 0% 0.35 Rational Method Calculation Form Project: Romeria Pointe Frequency 100 Year Developed Condition P6=2.7 in./hr. Page G-4 Calculated by MB Date: 1/3/2023 Drainage Soil &A C CA ΣCA I Q Slope Section V L Tt Sum T Remarks Area Acres In./Hr.In./Hr.CFS '/Sec.Ft.Min. 0.076 0.35 0.19 7.11 7.11 5.0 0.09 5.00.004 7.11 0.004140.012 0.35 15 5.0 0.027 17 0.033 0.35 0.012 0.012 0.027 5.0 D 0% D 0% 18 0.35 0.01 D 0% Note: Mitigated flows are not adjusted for Time of Concentration. Adjusting for Time of Concentration would reduce the total mitigated runoff from the site. 0.002 0.002 7.11 0.91 0.04 0.09 5.0 5.00.20 5.0 5.0 5.0 5.0 0.005 0.005 0.07 7.11 7.11 0.028 0.028 From Attachment H - BMP-2 Hydrograph From Attachment H - BMP-4 Hydrograph From Attachment H - BMP-3 Hydrograph 9% D 3% 5.0 5.0 20 & 19 0.004 Development 11 0.04 0.48 0.43 0.002 7.11 0.01 0.03 16 & 18 12 10 0.002 14 D 24% D From Attachment H - BMP-1 Hydrograph Mitigated Flows. D 6% 0.012 15 0.076 0.37 0.40 7.11 0.013 0.013 0.006 0.03 0.38170.033 D 0% DAM Runoff with no improvements for comparison to Mitigated Flows. Total Mitigated Flow ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 H-1 Attachment H - Unit Hydrograph and BMP Basin Inflow/Outflow The Rational Method Unit Hydrograph procedure as described in the San Diego County Hydrology Manual, Section 6, shall be used to determine time based storm inflow into the detention tanks. Using this information, and the capacity of the tanls, the effect of the storage tanks on the peak outflow can be determined. For the creation of the Rational Method Hydrograph the following information is used: 100 year, 6-hour rainfall, P6= 2.7” from Attachment E. Time of Concentration, Tc = 6 min. from Rational Method Calculations-developed site, Attachment G. CA from Rational Method Calculations for developed site, Attachment G. Rainfall intensity, I=7.44P6T-0.645 The Unit Hydrograph calculations on on the following pages. The storage capacities of the four BMP Planters when the water surface is at the top of the riser pipes are listed in the table below. BMP Storage: BMP Name Dimensions Surface Area (s.f.) Ponding Depth (inches) Media Depth (inches) Gravel Depth (inches) Effective Depth (inches) Storage Volume (c.f.) BMP-1 65’x5’ 325 10 21 48 36.55 990 BMP-2 50’x5’ 250 10 21 48 36.55 761 BMP-3 112’x6.5’ 560 10 21 48 36.55 2,217 BMP-4 8.23’x4’ 33 6 21 24 22.95 63 Total 1,168 4,031 The underdrains for the BMPs have small orifice openings to limit the runoff rate leaving the planters. The water depth outflow rate for the BMPs are determined using the SDHM 3.1 software. A copy of the outflow tables for each BMP are included herein. The calculations for the unit hydrographs and the basin water depth and runoff are included on the following pages. Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-1 Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-2 Calculated by MB Date: 3/14/2022 Tc=5 min.990 cf CA=0.11 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 1 5 7.11 0.59 1 0.08 0.01 0.017 5 5 - 0.000 2 10 4.55 0.17 2 0.17 0.01 0.017 5 - 10 0.08 0.001 3 15 3.50 0.12 3 0.25 0.01 0.020 6 - 16 0.16 0.001 4 20 2.91 0.09 4 0.33 0.01 0.020 6 - 22 0.16 0.001 5 25 2.52 0.08 5 0.42 0.01 0.020 6 - 28 0.23 0.002 6 30 2.24 0.07 6 0.50 0.01 0.020 6 - 34 0.31 0.002 7 35 2.03 0.06 7 0.58 0.01 0.020 6 1 39 0.39 0.002 8 40 1.86 0.06 8 0.67 0.01 0.020 6 1 44 0.39 0.002 9 45 1.72 0.05 9 0.75 0.02 0.020 6 1 49 0.47 0.002 10 50 1.61 0.05 10 0.83 0.02 0.020 6 1 54 0.54 0.002 11 55 1.51 0.05 11 0.92 0.02 0.020 6 1 59 0.54 0.002 12 60 1.43 0.04 12 1.00 0.02 0.020 6 1 64 0.62 0.003 13 65 1.36 0.04 13 1.08 0.02 0.023 7 1 70 0.70 0.003 14 70 1.30 0.04 14 1.17 0.02 0.023 7 1 76 0.78 0.003 15 75 1.24 0.04 15 1.25 0.02 0.023 7 1 82 0.78 0.003 16 80 1.19 0.04 16 1.33 0.02 0.023 7 1 88 0.86 0.003 17 85 1.14 0.03 17 1.42 0.02 0.023 7 1 94 0.93 0.003 18 90 1.10 0.03 18 1.50 0.02 0.023 7 1 100 1.01 0.003 19 95 1.06 0.03 19 1.58 0.02 0.023 7 1 106 1.09 0.004 20 100 1.03 0.03 20 1.67 0.02 0.023 7 1 112 1.09 0.004 21 105 1.00 0.03 21 1.75 0.02 0.027 8 1 119 1.17 0.004 22 110 0.97 0.03 22 1.83 0.02 0.027 8 1 126 1.24 0.004 23 115 0.94 0.03 23 1.92 0.02 0.027 8 1 133 1.32 0.004 24 120 0.92 0.03 24 2.00 0.02 0.027 8 1 140 1.40 0.004 25 125 0.89 0.03 25 2.08 0.02 0.030 9 1 148 1.48 0.004 26 130 0.87 0.03 26 2.17 0.02 0.030 9 1 156 1.56 0.004 27 135 0.85 0.03 27 2.25 0.02 0.030 9 1 164 1.63 0.004 Basin Storage Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-1 Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-3 Calculated by MB Date: 3/14/2022CA=0.11 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 28 140 0.83 0.02 28 2.33 0.02 0.030 9 1 172 1.71 0.004 29 145 0.81 0.02 29 2.42 0.02 0.033 10 1 181 1.79 0.005 30 150 0.79 0.02 30 2.50 0.02 0.033 10 1 190 1.87 0.005 31 155 0.78 0.02 31 2.58 0.03 0.033 10 1 199 1.95 0.005 32 160 0.76 0.02 32 2.67 0.03 0.037 11 1 209 2.02 0.005 33 165 0.75 0.02 33 2.75 0.03 0.037 11 1 219 2.10 0.005 34 170 0.73 0.02 34 2.83 0.03 0.040 12 1 230 2.18 0.005 35 175 0.72 0.02 35 2.92 0.03 0.040 12 1 241 2.26 0.005 36 180 0.71 0.02 36 3.00 0.03 0.043 13 2 252 2.33 0.005 37 185 0.69 0.02 37 3.08 0.03 0.047 14 2 264 2.41 0.005 38 190 0.68 0.02 38 3.17 0.04 0.047 14 2 276 2.49 0.005 39 195 0.67 0.02 39 3.25 0.04 0.053 16 2 290 2.57 0.005 40 200 0.66 0.02 40 3.33 0.04 0.053 16 2 304 2.72 0.006 41 205 0.65 0.02 41 3.42 0.05 0.060 18 2 320 2.80 0.006 42 210 0.64 0.02 42 3.50 0.05 0.067 20 2 338 2.96 0.006 43 215 0.63 0.02 43 3.58 0.06 0.077 23 2 359 3.11 0.006 44 220 0.62 0.02 44 3.67 0.06 0.083 25 2 382 3.27 0.006 45 225 0.61 0.02 45 3.75 0.08 0.107 32 2 412 3.50 0.006 46 230 0.60 0.02 46 3.83 0.09 0.127 38 2 448 3.73 0.007 47 235 0.59 0.02 47 3.92 0.17 0.220 66 2 512 4.20 0.007 48 240 0.59 0.02 48 4.00 0.59 0.790 237 2 747 5.83 0.073 49 245 0.58 0.02 49 4.08 0.12 0.157 47 22 772 5.91 0.073 50 250 0.57 0.02 50 4.17 0.07 0.093 28 22 778 5.91 0.073 51 255 0.56 0.02 51 4.25 0.05 0.070 21 22 777 5.91 0.073 52 260 0.56 0.02 52 4.33 0.04 0.057 17 22 772 5.91 0.073 53 265 0.55 0.02 53 4.42 0.04 0.050 15 22 765 5.91 0.073 54 270 0.54 0.02 54 4.50 0.03 0.043 13 22 756 5.83 0.073 55 275 0.54 0.02 55 4.58 0.03 0.040 12 22 746 5.83 0.073 56 280 0.53 0.02 56 4.67 0.03 0.037 11 22 735 5.75 0.073 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-1 Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-4 Calculated by MB Date: 3/14/2022CA=0.11 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 57 285 0.52 0.02 57 4.75 0.03 0.033 10 22 723 5.75 0.073 58 290 0.52 0.02 58 4.83 0.02 0.030 9 22 710 5.68 0.056 59 295 0.51 0.02 59 4.92 0.02 0.030 9 17 702 5.68 0.056 60 300 0.51 0.02 60 5.00 0.02 0.027 8 17 693 5.60 0.040 61 305 0.50 0.01 61 5.08 0.02 0.027 8 12 689 5.52 0.026 62 310 0.50 0.01 62 5.17 0.02 0.027 8 8 689 5.52 0.026 63 315 0.49 0.01 63 5.25 0.02 0.023 7 8 688 5.52 0.026 64 320 0.49 0.01 64 5.33 0.02 0.023 7 8 687 5.52 0.026 65 325 0.48 0.01 65 5.42 0.02 0.023 7 8 686 5.52 0.026 66 330 0.48 0.01 66 5.50 0.02 0.020 6 8 684 5.52 0.026 67 335 0.47 0.01 67 5.58 0.02 0.020 6 8 682 5.52 0.026 68 340 0.47 0.01 68 5.67 0.02 0.020 6 8 680 5.45 0.015 69 345 0.46 0.01 69 5.75 0.01 0.020 6 5 681 5.52 0.026 70 350 0.46 0.01 70 5.83 0.01 0.020 6 8 679 5.45 0.015 71 355 0.46 0.01 71 5.92 0.01 0.020 6 5 680 5.45 0.015 72 360 0.45 0.01 72 6.00 0.01 0.017 5 5 680 5.45 0.015 5 675 5.45 0.015 total 2.7 total 2.71 1,080 405 Unit Hydrograph Calculation Form Project: Romeria Pointe Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-5 Calculated by MB Date: 3/14/2022 0.000 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800 0.900 0 . 0 8 0 . 1 7 0 . 2 5 0 . 3 3 0 . 4 2 0 . 5 0 0 . 5 8 0 . 6 7 0 . 7 5 0 . 8 3 0 . 9 2 1 . 0 0 1 . 0 8 1 . 1 7 1 . 2 5 1 . 3 3 1 . 4 2 1 . 5 0 1 . 5 8 1 . 6 7 1 . 7 5 1 . 8 3 1 . 9 2 2 . 0 0 2 . 0 8 2 . 1 7 2 . 2 5 2 . 3 3 2 . 4 2 2 . 5 0 2 . 5 8 2 . 6 7 2 . 7 5 2 . 8 3 2 . 9 2 3 . 0 0 3 . 0 8 3 . 1 7 3 . 2 5 3 . 3 3 3 . 4 2 3 . 5 0 3 . 5 8 3 . 6 7 3 . 7 5 3 . 8 3 3 . 9 2 4 . 0 0 4 . 0 8 4 . 1 7 4 . 2 5 4 . 3 3 4 . 4 2 4 . 5 0 4 . 5 8 4 . 6 7 4 . 7 5 4 . 8 3 4 . 9 2 5 . 0 0 CF S Time (hours) Inflow Tank Outflow Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-1 Basin Outflow Data from SDHM 3.1 Page H-6 Calculated by MB Date: 3/14/2022BMP-1 Depth-Outflow Data from SDHM 3.1 Depth (ft)Storage (A-F)Storage (CF)Outflow (cfs)WS Elev (ft) 0.00 0 0 0.0000 89.58 0.08 0.000174 8 0.0009 89.66 0.16 0.000348 15 0.0013 89.74 0.23 0.000522 23 0.0016 89.81 0.31 0.000697 30 0.0019 89.89 0.39 0.000871 38 0.0021 89.97 0.47 0.001045 46 0.0023 90.05 0.54 0.001219 53 0.0025 90.12 0.62 0.001393 61 0.0027 90.20 0.70 0.001567 68 0.0028 90.28 0.78 0.001741 76 0.0030 90.36 0.86 0.001916 83 0.0031 90.44 0.93 0.00209 91 0.0033 90.51 1.01 0.002264 99 0.0034 90.59 1.09 0.002438 106 0.0035 90.67 1.17 0.002612 114 0.0037 90.75 1.24 0.002786 121 0.0038 90.82 1.32 0.00296 129 0.0039 90.90 1.40 0.003135 137 0.0040 90.98 1.48 0.003309 144 0.0041 91.06 1.56 0.003483 152 0.0042 91.14 1.63 0.003657 159 0.0043 91.21 1.71 0.003831 167 0.0044 91.29 1.79 0.004072 177 0.0045 91.37 1.87 0.004313 188 0.0046 91.45 1.95 0.004554 198 0.0047 91.53 2.02 0.004795 209 0.0048 91.60 2.10 0.005036 219 0.0049 91.68 2.18 0.005277 230 0.0050 91.76 2.26 0.005517 240 0.0051 91.84 2.33 0.005758 251 0.0052 91.91 2.41 0.005999 261 0.0053 91.99 2.49 0.00624 272 0.0053 92.07 2.57 0.006481 282 0.0054 92.15 2.65 0.006722 293 0.0055 92.23 2.72 0.006963 303 0.0056 92.30 2.80 0.007204 314 0.0057 92.38 2.88 0.007445 324 0.0057 92.46 2.96 0.007686 335 0.0058 92.54 3.03 0.007926 345 0.0059 92.61 3.11 0.008167 356 0.0060 92.69 3.19 0.008408 366 0.0060 92.77 3.27 0.008649 377 0.0061 92.85 3.35 0.00889 387 0.0062 92.93 3.42 0.009131 398 0.0063 93.00 3.50 0.009372 408 0.0063 93.08 3.58 0.009613 419 0.0064 93.16 3.66 0.009854 429 0.0065 93.24 3.73 0.010095 440 0.0065 93.31 3.81 0.010335 450 0.0066 93.39 3.89 0.010576 461 0.0067 93.47 3.97 0.010817 471 0.0067 93.55 4.05 0.011058 482 0.0068 93.63 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-1 Basin Outflow Data from SDHM 3.1 Page H-7 Calculated by MB Date: 3/14/2022BMP-1 Depth-Outflow Data from SDHM 3.1 Depth (ft)Storage (A-F)Storage (CF)Outflow (cfs)WS Elev (ft) 4.12 0.011299 492 0.0069 93.70 4.20 0.01154 503 0.0069 93.78 4.28 0.011781 513 0.0070 93.86 4.36 0.012022 524 0.0071 93.94 4.43 0.012263 534 0.0071 94.01 4.51 0.012504 545 0.0072 94.09 4.59 0.012744 555 0.0072 94.17 4.67 0.012985 566 0.0073 94.25 4.75 0.013226 576 0.0074 94.33 4.82 0.013467 587 0.0074 94.40 4.90 0.013708 597 0.0075 94.48 4.98 0.013949 608 0.0075 94.56 5.06 0.01419 618 0.0076 94.64 5.13 0.014431 629 0.0077 94.71 5.21 0.014672 639 0.0077 94.79 5.29 0.014913 650 0.0078 94.87 5.37 0.015153 660 0.0083 94.95 5.45 0.015394 671 0.0152 95.03 5.52 0.015635 681 0.0262 95.10 5.60 0.015876 692 0.0399 95.18 5.68 0.016117 702 0.0557 95.26 5.75 0.016335 712 0.0732 95.33 5.83 0.016916 737 0.0732 95.41 5.91 0.017496 762 0.0732 95.49 5.98 0.018077 787 0.0732 95.56 6.06 0.018657 813 0.0732 95.64 6.14 0.019238 838 0.0732 95.72 6.22 0.019818 863 0.0732 95.80 6.29 0.020398 889 0.0732 95.87 6.37 0.020979 914 0.0732 95.95 6.45 0.021559 939 0.0732 96.03 6.53 0.02214 964 0.0732 96.11 6.61 0.02272 990 0.0881 96.19 6.68 0.023301 1015 0.7070 96.26 6.76 0.023881 1040 1.6323 96.34 6.84 0.024462 1066 2.7663 96.42 6.92 0.025042 1091 4.0422 96.50 6.99 0.025623 1116 5.3956 96.57 7.07 0.026203 1141 6.7602 96.65 7.08 0.026784 1167 8.0699 96.66 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-2 Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-8 Calculated by MB Date: 3/14/2022 Tc=5 min.761 cf CA=0.05 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 1 5 7.11 0.59 1 0.08 0.01 0.010 3 3 - 0.000 2 10 4.55 0.17 2 0.17 0.01 0.010 3 - 6 0.08 0.000 3 15 3.50 0.12 3 0.25 0.01 0.010 3 - 9 0.08 0.000 4 20 2.91 0.09 4 0.33 0.01 0.010 3 - 12 0.16 0.000 5 25 2.52 0.08 5 0.42 0.01 0.010 3 - 15 0.16 0.000 6 30 2.24 0.07 6 0.50 0.01 0.010 3 - 18 0.23 0.000 7 35 2.03 0.06 7 0.58 0.01 0.010 3 - 21 0.23 0.000 8 40 1.86 0.06 8 0.67 0.01 0.010 3 - 24 0.31 0.000 9 45 1.72 0.05 9 0.75 0.02 0.010 3 - 27 0.31 0.000 10 50 1.61 0.05 10 0.83 0.02 0.010 3 - 30 0.39 0.000 11 55 1.51 0.05 11 0.92 0.02 0.010 3 - 33 0.39 0.000 12 60 1.43 0.04 12 1.00 0.02 0.010 3 - 36 0.47 0.000 13 65 1.36 0.04 13 1.08 0.02 0.010 3 - 39 0.47 0.000 14 70 1.30 0.04 14 1.17 0.02 0.010 3 - 42 0.54 0.000 15 75 1.24 0.04 15 1.25 0.02 0.010 3 - 45 0.54 0.000 16 80 1.19 0.04 16 1.33 0.02 0.010 3 - 48 0.62 0.000 17 85 1.14 0.03 17 1.42 0.02 0.010 3 - 51 0.62 0.000 18 90 1.10 0.03 18 1.50 0.02 0.010 3 - 54 0.70 0.000 19 95 1.06 0.03 19 1.58 0.02 0.010 3 - 57 0.70 0.000 20 100 1.03 0.03 20 1.67 0.02 0.010 3 - 60 0.78 0.000 21 105 1.00 0.03 21 1.75 0.02 0.013 4 - 64 0.86 0.000 22 110 0.97 0.03 22 1.83 0.02 0.013 4 - 68 0.86 0.000 23 115 0.94 0.03 23 1.92 0.02 0.013 4 - 72 0.93 0.000 24 120 0.92 0.03 24 2.00 0.02 0.013 4 - 76 1.01 0.000 25 125 0.89 0.03 25 2.08 0.02 0.013 4 - 80 1.01 0.000 26 130 0.87 0.03 26 2.17 0.02 0.013 4 - 84 1.09 0.000 27 135 0.85 0.03 27 2.25 0.02 0.013 4 - 88 1.17 0.000 Basin Storage Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-2 Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-9 Calculated by MB Date: 3/14/2022CA=0.05 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 28 140 0.83 0.02 28 2.33 0.02 0.013 4 - 92 1.17 0.000 29 145 0.81 0.02 29 2.42 0.02 0.013 4 - 96 1.24 0.000 30 150 0.79 0.02 30 2.50 0.02 0.017 5 - 101 1.32 0.000 31 155 0.78 0.02 31 2.58 0.03 0.017 5 - 106 1.40 0.000 32 160 0.76 0.02 32 2.67 0.03 0.017 5 - 111 1.48 0.001 33 165 0.75 0.02 33 2.75 0.03 0.017 5 - 116 1.48 0.001 34 170 0.73 0.02 34 2.83 0.03 0.017 5 - 121 1.56 0.001 35 175 0.72 0.02 35 2.92 0.03 0.020 6 - 127 1.63 0.001 36 180 0.71 0.02 36 3.00 0.03 0.020 6 - 133 1.71 0.001 37 185 0.69 0.02 37 3.08 0.03 0.020 6 - 139 1.79 0.001 38 190 0.68 0.02 38 3.17 0.04 0.023 7 - 146 1.87 0.001 39 195 0.67 0.02 39 3.25 0.04 0.023 7 - 153 1.95 0.001 40 200 0.66 0.02 40 3.33 0.04 0.027 8 - 161 2.02 0.001 41 205 0.65 0.02 41 3.42 0.05 0.030 9 - 170 2.10 0.001 42 210 0.64 0.02 42 3.50 0.05 0.030 9 - 179 2.18 0.001 43 215 0.63 0.02 43 3.58 0.06 0.037 11 - 190 2.26 0.001 44 220 0.62 0.02 44 3.67 0.06 0.040 12 - 202 2.41 0.001 45 225 0.61 0.02 45 3.75 0.08 0.050 15 - 217 2.57 0.001 46 230 0.60 0.02 46 3.83 0.09 0.057 17 - 234 2.72 0.001 47 235 0.59 0.02 47 3.92 0.17 0.103 31 - 265 2.96 0.002 48 240 0.59 0.02 48 4.00 0.59 0.367 110 - 375 4.05 0.002 49 245 0.58 0.02 49 4.08 0.12 0.073 22 1 396 4.28 0.002 50 250 0.57 0.02 50 4.17 0.07 0.043 13 1 408 4.36 0.003 51 255 0.56 0.02 51 4.25 0.05 0.033 10 1 417 4.43 0.003 52 260 0.56 0.02 52 4.33 0.04 0.027 8 1 424 4.51 0.003 53 265 0.55 0.02 53 4.42 0.04 0.023 7 1 430 4.59 0.003 54 270 0.54 0.02 54 4.50 0.03 0.020 6 1 435 4.67 0.003 55 275 0.54 0.02 55 4.58 0.03 0.020 6 1 440 4.67 0.003 56 280 0.53 0.02 56 4.67 0.03 0.017 5 1 444 4.75 0.003 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-2 Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-10 Calculated by MB Date: 3/14/2022CA=0.05 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 57 285 0.52 0.02 57 4.75 0.03 0.017 5 1 448 4.75 0.003 58 290 0.52 0.02 58 4.83 0.02 0.013 4 1 451 4.82 0.003 59 295 0.51 0.02 59 4.92 0.02 0.013 4 1 454 4.82 0.003 60 300 0.51 0.02 60 5.00 0.02 0.013 4 1 457 4.82 0.003 61 305 0.50 0.01 61 5.08 0.02 0.013 4 1 460 4.90 0.003 62 310 0.50 0.01 62 5.17 0.02 0.013 4 1 463 4.90 0.003 63 315 0.49 0.01 63 5.25 0.02 0.010 3 1 465 4.90 0.003 64 320 0.49 0.01 64 5.33 0.02 0.010 3 1 467 4.98 0.003 65 325 0.48 0.01 65 5.42 0.02 0.010 3 1 469 4.98 0.003 66 330 0.48 0.01 66 5.50 0.02 0.010 3 1 471 4.98 0.003 67 335 0.47 0.01 67 5.58 0.02 0.010 3 1 473 4.98 0.003 68 340 0.47 0.01 68 5.67 0.02 0.010 3 1 475 5.06 0.003 69 345 0.46 0.01 69 5.75 0.01 0.010 3 1 477 5.06 0.003 70 350 0.46 0.01 70 5.83 0.01 0.010 3 1 479 5.06 0.003 71 355 0.46 0.01 71 5.92 0.01 0.010 3 1 481 5.06 0.003 72 360 0.45 0.01 72 6.00 0.01 0.007 2 1 482 5.06 0.003 1 481 5.06 0.003 total 2.7 total 2.71 506 25 Unit Hydrograph Calculation Form Project: Romeria Pointe Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-11 Calculated by MB Date: 3/14/2022 0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0.400 0 . 0 8 0 . 1 7 0 . 2 5 0 . 3 3 0 . 4 2 0 . 5 0 0 . 5 8 0 . 6 7 0 . 7 5 0 . 8 3 0 . 9 2 1 . 0 0 1 . 0 8 1 . 1 7 1 . 2 5 1 . 3 3 1 . 4 2 1 . 5 0 1 . 5 8 1 . 6 7 1 . 7 5 1 . 8 3 1 . 9 2 2 . 0 0 2 . 0 8 2 . 1 7 2 . 2 5 2 . 3 3 2 . 4 2 2 . 5 0 2 . 5 8 2 . 6 7 2 . 7 5 2 . 8 3 2 . 9 2 3 . 0 0 3 . 0 8 3 . 1 7 3 . 2 5 3 . 3 3 3 . 4 2 3 . 5 0 3 . 5 8 3 . 6 7 3 . 7 5 3 . 8 3 3 . 9 2 4 . 0 0 4 . 0 8 4 . 1 7 4 . 2 5 4 . 3 3 4 . 4 2 4 . 5 0 4 . 5 8 4 . 6 7 4 . 7 5 4 . 8 3 4 . 9 2 5 . 0 0 CF S Time (hours) Inflow Tank Outflow Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-2 Outflow Data From SDHM 3.1 Page H-12 Calculated by MB Date: 3/14/2022BMP-2 Depth-Outflow Data from SDHM 3.1 Depth (ft)Storage (A-F)Storage (CF)Outflow (cfs)WS Elev (ft) 0.00 0 0 0.0000 79.25 0.08 0.000134 6 0.0000 79.33 0.16 0.000268 12 0.0000 79.41 0.23 0.000402 18 0.0000 79.48 0.31 0.000536 23 0.0000 79.56 0.39 0.00067 29 0.0000 79.64 0.47 0.000804 35 0.0000 79.72 0.54 0.000938 41 0.0000 79.79 0.62 0.001072 47 0.0000 79.87 0.70 0.001206 53 0.0000 79.95 0.78 0.00134 58 0.0000 80.03 0.86 0.001474 64 0.0000 80.11 0.93 0.001607 70 0.0000 80.18 1.01 0.001741 76 0.0000 80.26 1.09 0.001875 82 0.0002 80.34 1.17 0.002009 88 0.0003 80.42 1.24 0.002143 93 0.0004 80.49 1.32 0.002277 99 0.0004 80.57 1.40 0.002411 105 0.0005 80.65 1.48 0.002545 111 0.0006 80.73 1.56 0.002679 117 0.0006 80.81 1.63 0.002813 123 0.0007 80.88 1.71 0.002947 128 0.0007 80.96 1.79 0.003132 136 0.0007 81.04 1.87 0.003318 145 0.0008 81.12 1.95 0.003503 153 0.0008 81.20 2.02 0.003688 161 0.0008 81.27 2.10 0.003874 169 0.0009 81.35 2.18 0.004059 177 0.0009 81.43 2.26 0.004244 185 0.0009 81.51 2.33 0.00443 193 0.0010 81.58 2.41 0.004615 201 0.0010 81.66 2.49 0.0048 209 0.0011 81.74 2.57 0.004985 217 0.0012 81.82 2.65 0.005171 225 0.0012 81.90 2.72 0.005356 233 0.0013 81.97 2.80 0.005541 241 0.0014 82.05 2.88 0.005727 249 0.0015 82.13 2.96 0.005912 258 0.0016 82.21 3.03 0.006097 266 0.0016 82.28 3.11 0.006283 274 0.0017 82.36 3.19 0.006468 282 0.0018 82.44 3.27 0.006653 290 0.0018 82.52 3.35 0.006839 298 0.0019 82.60 3.42 0.007024 306 0.0019 82.67 3.50 0.007209 314 0.0020 82.75 3.58 0.007394 322 0.0021 82.83 3.66 0.00758 330 0.0021 82.91 3.73 0.007765 338 0.0022 82.98 3.81 0.00795 346 0.0022 83.06 3.89 0.008136 354 0.0023 83.14 3.97 0.008321 362 0.0023 83.22 4.05 0.008506 371 0.0024 83.30 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-2 Outflow Data From SDHM 3.1 Page H-13 Calculated by MB Date: 3/14/2022BMP-2 Depth-Outflow Data from SDHM 3.1 Depth (ft)Storage (A-F)Storage (CF)Outflow (cfs)WS Elev (ft) 4.12 0.008692 379 0.0024 83.37 4.20 0.008877 387 0.0025 83.45 4.28 0.009062 395 0.0025 83.53 4.36 0.009247 403 0.0025 83.61 4.43 0.009433 411 0.0026 83.68 4.51 0.009618 419 0.0026 83.76 4.59 0.009803 427 0.0027 83.84 4.67 0.009989 435 0.0027 83.92 4.75 0.010174 443 0.0028 84.00 4.82 0.010359 451 0.0028 84.07 4.90 0.010545 459 0.0028 84.15 4.98 0.01073 467 0.0029 84.23 5.06 0.010915 475 0.0029 84.31 5.13 0.011101 484 0.0030 84.38 5.21 0.011286 492 0.0030 84.46 5.29 0.011471 500 0.0030 84.54 5.37 0.011656 508 0.0031 84.62 5.45 0.011842 516 0.0031 84.70 5.52 0.012027 524 0.0031 84.77 5.60 0.012212 532 0.0032 84.85 5.68 0.012398 540 0.0032 84.93 5.75 0.012565 547 0.0040 85.00 5.83 0.013012 567 0.0040 85.08 5.91 0.013459 586 0.0040 85.16 5.98 0.013905 606 0.0040 85.23 6.06 0.014352 625 0.0040 85.31 6.14 0.014798 645 0.0040 85.39 6.22 0.015245 664 0.0040 85.47 6.29 0.015691 683 0.0014 85.54 6.37 0.016138 703 0.0024 85.62 6.45 0.016584 722 0.0030 85.70 6.53 0.017031 742 0.0036 85.78 6.61 0.017477 761 0.0921 85.86 6.68 0.017924 781 0.7114 85.93 6.76 0.01837 800 1.6372 86.01 6.84 0.018817 820 2.7715 86.09 6.92 0.019263 839 4.0477 86.17 6.99 0.01971 859 5.4014 86.24 7.07 0.020156 878 6.7664 86.32 7.08 0.020603 897 8.0763 86.33 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-3 Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-2 Calculated by MB Date: 1/3/2023 Tc=5 min.2,217 cf CA=0.313 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 1 5 7.11 0.59 1 0.08 0.01 0.050 15 15 - 0.000 2 10 4.55 0.17 2 0.17 0.01 0.053 16 - 31 0.08 0.000 3 15 3.50 0.12 3 0.25 0.01 0.053 16 - 47 0.16 0.000 4 20 2.91 0.09 4 0.33 0.01 0.053 16 - 63 0.23 0.000 5 25 2.52 0.08 5 0.42 0.01 0.053 16 - 79 0.31 0.000 6 30 2.24 0.07 6 0.50 0.01 0.053 16 - 95 0.39 0.000 7 35 2.03 0.06 7 0.58 0.01 0.057 17 - 112 0.47 0.000 8 40 1.86 0.06 8 0.67 0.01 0.057 17 - 129 0.54 0.000 9 45 1.72 0.05 9 0.75 0.02 0.057 17 - 146 0.62 0.000 10 50 1.61 0.05 10 0.83 0.02 0.060 18 - 164 0.70 0.000 11 55 1.51 0.05 11 0.92 0.02 0.060 18 - 182 0.78 0.000 12 60 1.43 0.04 12 1.00 0.02 0.060 18 - 200 0.86 0.000 13 65 1.36 0.04 13 1.08 0.02 0.063 19 - 219 0.93 0.000 14 70 1.30 0.04 14 1.17 0.02 0.063 19 - 238 1.09 0.001 15 75 1.24 0.04 15 1.25 0.02 0.063 19 - 257 1.17 0.001 16 80 1.19 0.04 16 1.33 0.02 0.067 20 - 277 1.24 0.001 17 85 1.14 0.03 17 1.42 0.02 0.067 20 - 297 1.32 0.001 18 90 1.10 0.03 18 1.50 0.02 0.067 20 - 317 1.40 0.001 19 95 1.06 0.03 19 1.58 0.02 0.070 21 - 338 1.48 0.001 20 100 1.03 0.03 20 1.67 0.02 0.070 21 - 359 1.63 0.002 21 105 1.00 0.03 21 1.75 0.02 0.073 22 - 381 1.71 0.002 22 110 0.97 0.03 22 1.83 0.02 0.073 22 1 402 1.79 0.002 23 115 0.94 0.03 23 1.92 0.02 0.077 23 1 424 1.87 0.002 24 120 0.92 0.03 24 2.00 0.02 0.077 23 1 446 1.95 0.002 25 125 0.89 0.03 25 2.08 0.02 0.080 24 1 469 2.02 0.002 26 130 0.87 0.03 26 2.17 0.02 0.083 25 1 493 2.10 0.002 27 135 0.85 0.03 27 2.25 0.02 0.087 26 1 518 2.18 0.002 Basin Storage Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-3 Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-3 Calculated by MB Date: 1/3/2023CA=0.313 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 28 140 0.83 0.02 28 2.33 0.02 0.087 26 1 543 2.26 0.002 29 145 0.81 0.02 29 2.42 0.02 0.093 28 1 570 2.33 0.002 30 150 0.79 0.02 30 2.50 0.02 0.093 28 1 597 2.41 0.003 31 155 0.78 0.02 31 2.58 0.03 0.100 30 1 626 2.49 0.003 32 160 0.76 0.02 32 2.67 0.03 0.100 30 1 655 2.57 0.003 33 165 0.75 0.02 33 2.75 0.03 0.107 32 1 686 2.72 0.003 34 170 0.73 0.02 34 2.83 0.03 0.110 33 1 718 2.80 0.004 35 175 0.72 0.02 35 2.92 0.03 0.117 35 1 752 2.96 0.004 36 180 0.71 0.02 36 3.00 0.03 0.120 36 1 787 3.03 0.004 37 185 0.69 0.02 37 3.08 0.03 0.130 39 1 825 3.19 0.004 38 190 0.68 0.02 38 3.17 0.04 0.137 41 1 865 3.27 0.005 39 195 0.67 0.02 39 3.25 0.04 0.150 45 1 909 3.42 0.005 40 200 0.66 0.02 40 3.33 0.04 0.157 47 1 955 3.58 0.005 41 205 0.65 0.02 41 3.42 0.05 0.173 52 2 1,005 3.73 0.006 42 210 0.64 0.02 42 3.50 0.05 0.187 56 2 1,059 3.97 0.006 43 215 0.63 0.02 43 3.58 0.06 0.217 65 2 1,122 4.12 0.006 44 220 0.62 0.02 44 3.67 0.06 0.240 72 2 1,192 4.36 0.007 45 225 0.61 0.02 45 3.75 0.08 0.303 91 2 1,281 4.67 0.007 46 230 0.60 0.02 46 3.83 0.09 0.357 107 2 1,386 5.06 0.007 47 235 0.59 0.02 47 3.92 0.17 0.627 188 2 1,572 5.60 0.008 48 240 0.59 0.02 48 4.00 0.59 2.247 674 2 2,244 6.61 0.426 49 245 0.58 0.02 49 4.08 0.12 0.443 133 128 2,249 6.61 0.426 50 250 0.57 0.02 50 4.17 0.07 0.267 80 128 2,201 6.53 0.316 51 255 0.56 0.02 51 4.25 0.05 0.200 60 95 2,166 6.53 0.316 52 260 0.56 0.02 52 4.33 0.04 0.163 49 95 2,120 6.45 0.291 53 265 0.55 0.02 53 4.42 0.04 0.143 43 87 2,076 6.37 0.265 54 270 0.54 0.02 54 4.50 0.03 0.127 38 79 2,035 6.29 0.236 55 275 0.54 0.02 55 4.58 0.03 0.113 34 71 1,998 6.29 0.236 56 280 0.53 0.02 56 4.67 0.03 0.103 31 71 1,958 6.22 0.202 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-3 Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-4 Calculated by MB Date: 1/3/2023CA=0.313 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 57 285 0.52 0.02 57 4.75 0.03 0.097 29 61 1,926 6.14 0.162 58 290 0.52 0.02 58 4.83 0.02 0.090 27 49 1,904 6.14 0.162 59 295 0.51 0.02 59 4.92 0.02 0.083 25 49 1,880 6.14 0.162 60 300 0.51 0.02 60 5.00 0.02 0.080 24 49 1,855 6.06 0.107 61 305 0.50 0.01 61 5.08 0.02 0.077 23 32 1,846 6.06 0.107 62 310 0.50 0.01 62 5.17 0.02 0.073 22 32 1,836 6.06 0.107 63 315 0.49 0.01 63 5.25 0.02 0.070 21 32 1,825 6.06 0.107 64 320 0.49 0.01 64 5.33 0.02 0.067 20 32 1,813 5.98 0.016 65 325 0.48 0.01 65 5.42 0.02 0.063 19 5 1,827 6.06 0.107 66 330 0.48 0.01 66 5.50 0.02 0.060 18 32 1,813 5.98 0.016 67 335 0.47 0.01 67 5.58 0.02 0.060 18 5 1,826 6.06 0.107 68 340 0.47 0.01 68 5.67 0.02 0.057 17 32 1,811 5.98 0.016 69 345 0.46 0.01 69 5.75 0.01 0.057 17 5 1,823 6.06 0.107 70 350 0.46 0.01 70 5.83 0.01 0.053 16 32 1,807 5.98 0.016 71 355 0.46 0.01 71 5.92 0.01 0.053 16 5 1,818 5.98 0.016 72 360 0.45 0.01 72 6.00 0.01 0.050 15 5 1,828 6.06 0.107 32 1,796 5.98 0.016 total 2.7 total 2.71 3,074 1,278 Unit Hydrograph Calculation Form Project: Romeria Pointe Frequency 100 Year 6-Hour Storm P6=2.7 in./hr. Page H-5 Calculated by MB Date: 1/3/2023 0.000 0.500 1.000 1.500 2.000 2.500 0 . 0 8 0 . 1 7 0 . 2 5 0 . 3 3 0 . 4 2 0 . 5 0 0 . 5 8 0 . 6 7 0 . 7 5 0 . 8 3 0 . 9 2 1 . 0 0 1 . 0 8 1 . 1 7 1 . 2 5 1 . 3 3 1 . 4 2 1 . 5 0 1 . 5 8 1 . 6 7 1 . 7 5 1 . 8 3 1 . 9 2 2 . 0 0 2 . 0 8 2 . 1 7 2 . 2 5 2 . 3 3 2 . 4 2 2 . 5 0 2 . 5 8 2 . 6 7 2 . 7 5 2 . 8 3 2 . 9 2 3 . 0 0 3 . 0 8 3 . 1 7 3 . 2 5 3 . 3 3 3 . 4 2 3 . 5 0 3 . 5 8 3 . 6 7 3 . 7 5 3 . 8 3 3 . 9 2 4 . 0 0 4 . 0 8 4 . 1 7 4 . 2 5 4 . 3 3 4 . 4 2 4 . 5 0 4 . 5 8 4 . 6 7 4 . 7 5 4 . 8 3 4 . 9 2 5 . 0 0 CF S Time (hours) Inflow Tank Outflow Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-3 Basin Outflow Data From SDHM Page H-6 Calculated by MB Date: 1/3/2023BMP-3 Depth-Outflow Chart from SDHM 3.1 Depth (ft)Storage (A-F)Storage (CF)Outflow (cfs)WS Elev (ft) 0.00 0 0 0.0000 60.05 0.08 0.00039 17 0.0000 60.13 0.16 0.00078 34 0.0000 60.21 0.23 0.00117 51 0.0000 60.28 0.31 0.00156 68 0.0000 60.36 0.39 0.00195 85 0.0000 60.44 0.47 0.00234 102 0.0000 60.52 0.54 0.002731 119 0.0000 60.59 0.62 0.003121 136 0.0000 60.67 0.70 0.003511 153 0.0000 60.75 0.78 0.003901 170 0.0000 60.83 0.86 0.004291 187 0.0000 60.91 0.93 0.004681 204 0.0000 60.98 1.01 0.005071 221 0.0000 61.06 1.09 0.005461 238 0.0005 61.14 1.17 0.005851 255 0.0008 61.22 1.24 0.006241 272 0.0009 61.29 1.32 0.006631 289 0.0011 61.37 1.40 0.007021 306 0.0012 61.45 1.48 0.007412 323 0.0014 61.53 1.56 0.007802 340 0.0015 61.61 1.63 0.008192 357 0.0017 61.68 1.71 0.008582 374 0.0017 61.76 1.79 0.009121 397 0.0019 61.84 1.87 0.009661 421 0.0019 61.92 1.95 0.010201 444 0.0021 62.00 2.02 0.01074 468 0.0021 62.07 2.10 0.01128 491 0.0022 62.15 2.18 0.01182 515 0.0023 62.23 2.26 0.012359 538 0.0024 62.31 2.33 0.012899 562 0.0025 62.38 2.41 0.013438 585 0.0027 62.46 2.49 0.013978 609 0.0028 62.54 2.57 0.014518 632 0.0030 62.62 2.65 0.015057 656 0.0032 62.70 2.72 0.015597 679 0.0034 62.77 2.80 0.016136 703 0.0036 62.85 2.88 0.016676 726 0.0038 62.93 2.96 0.017216 750 0.0040 63.01 3.03 0.017755 773 0.0042 63.08 3.11 0.018295 797 0.0043 63.16 3.19 0.018834 820 0.0045 63.24 3.27 0.019374 844 0.0047 63.32 3.35 0.019914 867 0.0048 63.40 3.42 0.020453 891 0.0050 63.47 3.50 0.020993 914 0.0051 63.55 3.58 0.021533 938 0.0053 63.63 3.66 0.022072 961 0.0054 63.71 3.73 0.022612 985 0.0055 63.78 3.81 0.023151 1008 0.0057 63.86 3.89 0.023691 1032 0.0058 63.94 3.97 0.024231 1056 0.0059 64.02 4.05 0.02477 1079 0.0060 64.10 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-3 Basin Outflow Data From SDHM Page H-7 Calculated by MB Date: 1/3/2023BMP-3 Depth-Outflow Chart from SDHM 3.1 Depth (ft)Storage (A-F)Storage (CF)Outflow (cfs)WS Elev (ft) 4.12 0.02531 1103 0.0062 64.17 4.20 0.025849 1126 0.0063 64.25 4.28 0.026389 1150 0.0064 64.33 4.36 0.026929 1173 0.0065 64.41 4.43 0.027468 1197 0.0066 64.48 4.51 0.028008 1220 0.0067 64.56 4.59 0.028548 1244 0.0068 64.64 4.67 0.029087 1267 0.0069 64.72 4.75 0.029627 1291 0.0071 64.80 4.82 0.030166 1314 0.0072 64.87 4.90 0.030706 1338 0.0073 64.95 4.98 0.031246 1361 0.0074 65.03 5.06 0.031785 1385 0.0075 65.11 5.13 0.032325 1408 0.0076 65.18 5.21 0.032864 1432 0.0077 65.26 5.29 0.033404 1455 0.0077 65.34 5.37 0.033944 1479 0.0078 65.42 5.45 0.034483 1502 0.0079 65.50 5.52 0.035023 1526 0.0080 65.57 5.60 0.035563 1549 0.0081 65.65 5.68 0.036102 1573 0.0082 65.73 5.75 0.036591 1594 0.0102 65.80 5.83 0.037891 1651 0.0122 65.88 5.91 0.039191 1707 0.0142 65.96 5.98 0.040492 1764 0.0162 66.03 6.06 0.041792 1820 0.10742 66.11 6.14 0.043092 1877 0.161884 66.19 6.22 0.044392 1934 0.202172 66.27 6.29 0.045693 1990 0.235671 66.34 6.37 0.046993 2047 0.264968 66.42 6.45 0.048293 2104 0.291334 66.50 6.53 0.049593 2160 0.315504 66.58 6.61 0.050894 2217 0.426045 66.66 6.68 0.052194 2274 1.065959 66.73 6.76 0.053494 2330 2.011182 66.81 6.84 0.054795 2387 3.164031 66.89 6.92 0.056095 2443 4.457941 66.97 6.99 0.057395 2500 5.828645 67.04 7.07 0.058695 2557 7.209909 67.12 7.08 0.059996 2613 8.535565 67.13 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-4 Frequency 100 Year P6=2.7 in./hr. Page H-20 Calculated by MB Date: 3/14/2022 Tc=5 min.69 cf CA=0.009 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 1 5 7.11 0.59 1 0.08 0.01 0.000 0.00 - - 0.000 2 10 4.55 0.17 2 0.17 0.01 0.000 0.00 - - - 0.000 3 15 3.50 0.12 3 0.25 0.01 0.000 0.00 - - - 0.000 4 20 2.91 0.09 4 0.33 0.01 0.000 0.00 - - - 0.000 5 25 2.52 0.08 5 0.42 0.01 0.000 0.00 - - - 0.000 6 30 2.24 0.07 6 0.50 0.01 0.000 0.00 - - - 0.000 7 35 2.03 0.06 7 0.58 0.01 0.000 0.00 - - - 0.000 8 40 1.86 0.06 8 0.67 0.01 0.000 0.00 - - - 0.000 9 45 1.72 0.05 9 0.75 0.02 0.000 0.00 - - - 0.000 10 50 1.61 0.05 10 0.83 0.02 0.003 1.00 - 1 0.10 0.000 11 55 1.51 0.05 11 0.92 0.02 0.003 1.00 - 2 0.21 0.000 12 60 1.43 0.04 12 1.00 0.02 0.003 1.00 - 3 0.26 0.000 13 65 1.36 0.04 13 1.08 0.02 0.003 1.00 - 4 0.37 0.000 14 70 1.30 0.04 14 1.17 0.02 0.003 1.00 - 5 0.47 0.000 15 75 1.24 0.04 15 1.25 0.02 0.003 1.00 - 6 0.52 0.000 16 80 1.19 0.04 16 1.33 0.02 0.003 1.00 - 7 0.63 0.000 17 85 1.14 0.03 17 1.42 0.02 0.003 1.00 - 8 0.73 0.000 18 90 1.10 0.03 18 1.50 0.02 0.003 1.00 - 9 0.78 0.000 19 95 1.06 0.03 19 1.58 0.02 0.003 1.00 - 10 0.89 0.000 20 100 1.03 0.03 20 1.67 0.02 0.003 1.00 - 11 0.99 0.000 21 105 1.00 0.03 21 1.75 0.02 0.003 1.00 - 12 1.04 0.000 22 110 0.97 0.03 22 1.83 0.02 0.003 1.00 - 13 1.15 0.000 23 115 0.94 0.03 23 1.92 0.02 0.003 1.00 - 14 1.25 0.000 24 120 0.92 0.03 24 2.00 0.02 0.003 1.00 - 15 1.36 0.000 25 125 0.89 0.03 25 2.08 0.02 0.003 1.00 - 16 1.41 0.000 26 130 0.87 0.03 26 2.17 0.02 0.003 1.00 - 17 1.51 0.000 27 135 0.85 0.03 27 2.25 0.02 0.003 1.00 - 18 1.62 0.000 Basin Storage Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-4 Frequency 100 Year P6=2.7 in./hr. Page H-21 Calculated by MB Date: 3/14/2022CA=0.009 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 28 140 0.83 0.02 28 2.33 0.02 0.003 1.00 - 19 1.67 0.000 29 145 0.81 0.02 29 2.42 0.02 0.003 1.00 - 20 1.77 0.001 30 150 0.79 0.02 30 2.50 0.02 0.003 1.00 - 21 1.83 0.001 31 155 0.78 0.02 31 2.58 0.03 0.003 1.00 - 22 1.88 0.001 32 160 0.76 0.02 32 2.67 0.03 0.003 1.00 - 23 1.93 0.001 33 165 0.75 0.02 33 2.75 0.03 0.003 1.00 - 24 1.98 0.001 34 170 0.73 0.02 34 2.83 0.03 0.003 1.00 - 25 2.09 0.001 35 175 0.72 0.02 35 2.92 0.03 0.003 1.00 - 26 2.14 0.001 36 180 0.71 0.02 36 3.00 0.03 0.003 1.00 - 27 2.19 0.001 37 185 0.69 0.02 37 3.08 0.03 0.003 1.00 - 28 2.24 0.001 38 190 0.68 0.02 38 3.17 0.04 0.003 1.00 - 29 2.30 0.001 39 195 0.67 0.02 39 3.25 0.04 0.003 1.00 - 30 2.40 0.001 40 200 0.66 0.02 40 3.33 0.04 0.003 1.00 - 31 2.45 0.001 41 205 0.65 0.02 41 3.42 0.05 0.007 2.00 - 33 2.56 0.001 42 210 0.64 0.02 42 3.50 0.05 0.007 2.00 - 35 2.71 0.001 43 215 0.63 0.02 43 3.58 0.06 0.007 2.00 - 37 2.82 0.001 44 220 0.62 0.02 44 3.67 0.06 0.007 2.00 - 39 2.98 0.002 45 225 0.61 0.02 45 3.75 0.08 0.010 3.00 - 42 3.13 0.002 46 230 0.60 0.02 46 3.83 0.09 0.010 3.00 1 44 3.29 0.002 47 235 0.59 0.02 47 3.92 0.17 0.017 5.00 1 48 3.55 0.002 48 240 0.59 0.02 48 4.00 0.59 0.063 19.00 1 66 4.12 0.004 49 245 0.58 0.02 49 4.08 0.12 0.013 4.00 1 69 4.22 0.004 50 250 0.57 0.02 50 4.17 0.07 0.007 2.00 1 70 4.22 0.004 51 255 0.56 0.02 51 4.25 0.05 0.007 2.00 1 71 4.27 0.035 52 260 0.56 0.02 52 4.33 0.04 0.003 1.00 10 62 4.01 0.004 53 265 0.55 0.02 53 4.42 0.04 0.003 1.00 1 62 4.01 0.004 54 270 0.54 0.02 54 4.50 0.03 0.003 1.00 1 62 4.01 0.004 55 275 0.54 0.02 55 4.58 0.03 0.003 1.00 1 62 4.01 0.004 56 280 0.53 0.02 56 4.67 0.03 0.003 1.00 1 62 4.01 0.004 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-4 Frequency 100 Year P6=2.7 in./hr. Page H-22 Calculated by MB Date: 3/14/2022CA=0.009 P6=2.70 in UH Elapsed Effective BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 Time Tc I P Time Time Rainfall Inflow Inflow Outflow Storage Depth Discharge Period Min.in/hr.in Period Hrs.in.Rate cfs Volume cf Volume cf CF Ft cfs 57 285 0.52 0.02 57 4.75 0.03 0.003 1.00 1 62 4.01 0.004 58 290 0.52 0.02 58 4.83 0.02 0.003 1.00 1 62 4.01 0.004 59 295 0.51 0.02 59 4.92 0.02 0.003 1.00 1 62 4.01 0.004 60 300 0.51 0.02 60 5.00 0.02 0.003 1.00 1 62 4.01 0.004 61 305 0.50 0.01 61 5.08 0.02 0.003 1.00 1 62 4.01 0.004 62 310 0.50 0.01 62 5.17 0.02 0.003 1.00 1 62 4.01 0.004 63 315 0.49 0.01 63 5.25 0.02 0.003 1.00 1 62 4.01 0.004 64 320 0.49 0.01 64 5.33 0.02 0.003 1.00 1 62 4.01 0.004 65 325 0.48 0.01 65 5.42 0.02 0.003 1.00 1 62 4.01 0.004 66 330 0.48 0.01 66 5.50 0.02 0.003 1.00 1 62 4.01 0.004 67 335 0.47 0.01 67 5.58 0.02 0.003 1.00 1 62 4.01 0.004 68 340 0.47 0.01 68 5.67 0.02 0.000 0.00 1 61 3.96 0.004 69 345 0.46 0.01 69 5.75 0.01 0.000 0.00 1 60 3.96 0.004 70 350 0.46 0.01 70 5.83 0.01 0.000 0.00 1 59 3.91 0.003 71 355 0.46 0.01 71 5.92 0.01 0.000 0.00 1 58 3.91 0.003 72 360 0.45 0.01 72 6.00 0.01 0.000 0.00 1 57 3.85 0.003 1 56 3.85 0.003 total 2.7 total 2.71 93.00 37 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-4 Frequency 100 Year P6=2.7 in./hr. Page H-23 Calculated by MB Date: 3/14/2022 0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0 . 0 8 0 . 1 7 0 . 2 5 0 . 3 3 0 . 4 2 0 . 5 0 0 . 5 8 0 . 6 7 0 . 7 5 0 . 8 3 0 . 9 2 1 . 0 0 1 . 0 8 1 . 1 7 1 . 2 5 1 . 3 3 1 . 4 2 1 . 5 0 1 . 5 8 1 . 6 7 1 . 7 5 1 . 8 3 1 . 9 2 2 . 0 0 2 . 0 8 2 . 1 7 2 . 2 5 2 . 3 3 2 . 4 2 2 . 5 0 2 . 5 8 2 . 6 7 2 . 7 5 2 . 8 3 2 . 9 2 3 . 0 0 3 . 0 8 3 . 1 7 3 . 2 5 3 . 3 3 3 . 4 2 3 . 5 0 3 . 5 8 3 . 6 7 3 . 7 5 3 . 8 3 3 . 9 2 4 . 0 0 4 . 0 8 4 . 1 7 4 . 2 5 4 . 3 3 4 . 4 2 4 . 5 0 4 . 5 8 4 . 6 7 4 . 7 5 4 . 8 3 4 . 9 2 5 . 0 0 CF S Time (hours) Inflow Outflow Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-4 Outflow from SDHM Output Page H-24 Calculated by MB Date: 3/14/2022BMP-4 Depth-Outflow Chart from SDHM 3.1 Depth (ft)Storage (A-F)Storage (CF)Outflow (cfs)WS Elev (ft) 0.00 0 0 0.0000 60.45 0.05 0.000014 1 0.0000 60.50 0.10 0.000027 1 0.0000 60.55 0.16 0.000041 2 0.0000 60.61 0.21 0.000055 2 0.0000 60.66 0.26 0.000068 3 0.0000 60.71 0.31 0.000082 4 0.0000 60.76 0.37 0.000096 4 0.0000 60.82 0.42 0.000109 5 0.0000 60.87 0.47 0.000123 5 0.0000 60.92 0.52 0.000137 6 0.0000 60.97 0.57 0.00015 7 0.0000 61.02 0.63 0.000164 7 0.0000 61.08 0.68 0.000178 8 0.0000 61.13 0.73 0.000191 8 0.0000 61.18 0.78 0.000205 9 0.0000 61.23 0.84 0.000219 10 0.0000 61.29 0.89 0.000232 10 0.0000 61.34 0.94 0.000246 11 0.0000 61.39 0.99 0.00026 11 0.0000 61.44 1.04 0.000273 12 0.0000 61.49 1.10 0.000287 13 0.0000 61.55 1.15 0.000301 13 0.0000 61.60 1.20 0.000314 14 0.0000 61.65 1.25 0.000328 14 0.0000 61.70 1.30 0.000342 15 0.0000 61.75 1.36 0.000355 15 0.0000 61.81 1.41 0.000369 16 0.0001 61.86 1.46 0.000382 17 0.0002 61.91 1.51 0.000396 17 0.0003 61.96 1.57 0.00041 18 0.0003 62.02 1.62 0.000423 18 0.0004 62.07 1.67 0.000437 19 0.0004 62.12 1.72 0.000451 20 0.0005 62.17 1.77 0.00047 20 0.0005 62.22 1.83 0.000489 21 0.0006 62.28 1.88 0.000507 22 0.0006 62.33 1.93 0.000526 23 0.0006 62.38 1.98 0.000545 24 0.0006 62.43 2.04 0.000564 25 0.0007 62.49 2.09 0.000583 25 0.0007 62.54 2.14 0.000602 26 0.0007 62.59 2.19 0.000621 27 0.0008 62.64 2.24 0.00064 28 0.0008 62.69 2.30 0.000659 29 0.0008 62.75 2.35 0.000678 30 0.0009 62.80 2.40 0.000696 30 0.0010 62.85 2.45 0.000715 31 0.0010 62.90 2.51 0.000734 32 0.0011 62.96 2.56 0.000753 33 0.0012 63.01 2.61 0.000772 34 0.0012 63.06 2.66 0.000791 34 0.0013 63.11 2.71 0.00081 35 0.0013 63.16 Unit Hydrograph Calculation Form Project: Romeria Pointe BMP-4 Outflow from SDHM Output Page H-25 Calculated by MB Date: 3/14/2022BMP-4 Depth-Outflow Chart from SDHM 3.1 Depth (ft)Storage (A-F)Storage (CF)Outflow (cfs)WS Elev (ft) 2.77 0.000829 36 0.0014 63.22 2.82 0.000848 37 0.0015 63.27 2.87 0.000867 38 0.0015 63.32 2.92 0.000885 39 0.0016 63.37 2.98 0.000904 39 0.0016 63.43 3.03 0.000923 40 0.0016 63.48 3.08 0.000942 41 0.0017 63.53 3.13 0.000961 42 0.0017 63.58 3.18 0.00098 43 0.0018 63.63 3.24 0.000999 44 0.0018 63.69 3.29 0.001018 44 0.0019 63.74 3.34 0.001037 45 0.0019 63.79 3.39 0.001056 46 0.0019 63.84 3.45 0.001074 47 0.0020 63.90 3.50 0.001093 48 0.0020 63.95 3.55 0.001112 48 0.0021 64.00 3.60 0.001131 49 0.0021 64.05 3.65 0.00115 50 0.0021 64.10 3.71 0.001169 51 0.0022 64.16 3.75 0.001185 52 0.0032 64.20 3.80 0.00123 54 0.0033 64.25 3.85 0.001276 56 0.0034 64.30 3.91 0.001321 58 0.0035 64.36 3.96 0.001367 60 0.0036 64.41 4.01 0.001412 62 0.0037 64.46 4.06 0.001458 64 0.0038 64.51 4.12 0.001504 66 0.0039 64.57 4.17 0.001549 67 0.0040 64.62 4.22 0.001595 69 0.0041 64.67 4.27 0.00164 71 0.0346 64.72 4.32 0.001686 73 0.2137 64.77 4.38 0.001731 75 0.4712 64.83 4.43 0.001777 77 0.7756 64.88 4.48 0.001822 79 1.0991 64.93 4.53 0.001868 81 1.4136 64.98 4.59 0.001913 83 1.6924 65.04 4.64 0.001959 85 1.9155 65.09 4.69 0.002004 87 2.0761 65.14 4.74 0.00205 89 2.1878 65.19 4.75 0.002096 91 2.3230 65.20 ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 I-1 Attachment I - Hydraulic Calculations. BMP Overflow Drains: The biofilter BMPs include overflow inlets that allow the larger strom events to be drained without overflowing the basins. BMP-3 has the largest Q100 peak flow at 2.2 cfs. The riser is a 24” diameter with a grate located 6” above the basin bottom and 6” below the top of the basin. The weir equation for determining the capacity of the inlet is: Q=3Lh3/2 or h=(Q/3L)2/3 Wher: L = 6.28’ Q = 2.2 cfs h =(2.2/(3*6.28))2/3 = 0.24’ < 0.5’ ✓OK Parkway Culverts: Autocad Hydraflow Express is used to determine the flow in the parkway culverts. The culvert below BMP-3 will have the highest flow of 2.2 cfs. The culverts dimensions are: Width= 2.0’ Height = 4” Slope = 0.02 Peak Q100 = 2.2 cfs The results are on the following page. ROBIN B. HAMERS & ASSOC., INC. 234 E. 17TH ST., SUITE 205 CIVIL ENGINEERSPLANNERSSURVEYORS COSTA MESA, CA 92627 ... since 1981 Phone 949/548-1192 I-2 Channel Re port Hydra!low E,\press Extension for Autode~k® AutoCADl!I Cfllil 30® by Autodesk, Inc.. Gibraltar Street Parkway Cu lverts Rectangular Bottom Width (fl} Total Depth (ft) Invert Elev (ft) Slope(%) N-Value Calculations Compute by: Known Q (ds} Elev (fl) 01.00 00.75 00.25 00.00 99.75 0 .5 = 2.00 = 0.33 = 100.00 = 2.00 = 0.015 Known Q = 2.20 Section "17 ..... 1.5 Reach (fl} Highlighted Depth (fl) Q (cfs) Area (sqft) Velocity (ft/s) Wetted Perim (fl) Crit Depth, Ye (ft) Top Width (fl) EGL (fl) 2 2.5 Thursday, Aug 16 2018 = 0 .24 = 2 .2 00 = 0.48 = 4 .58 = 2.48 = 0 .33 = 2 .00 = 0 .57 3 Depth (fl) 1.00 0.75 0.50 0.25 0.00 -0.25 Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Monday, Mar 14 2022 PVC s=0.005 d=10 in Circular Diameter (ft) = 0.83 Invert Elev (ft) = 60.00 Slope (%) = 0.50 N-Value = 0.013 Calculations Compute by: Known Depth Known Depth (ft) = 0.83 Highlighted Depth (ft) = 0.83 Q (cfs) = 1.532 Area (sqft) = 0.54 Velocity (ft/s) = 2.83 Wetted Perim (ft) = 2.61 Crit Depth, Yc (ft) = 0.56 Top Width (ft) = 0.00 EGL (ft) = 0.95 0 1 Elev (ft)Section 59.75 60.00 60.25 60.50 60.75 61.00 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Monday, Mar 14 2022 PVC s=0.020 d=10 in Circular Diameter (ft) = 0.83 Invert Elev (ft) = 60.00 Slope (%) = 2.00 N-Value = 0.013 Calculations Compute by: Known Depth Known Depth (ft) = 0.83 Highlighted Depth (ft) = 0.83 Q (cfs) = 3.064 Area (sqft) = 0.54 Velocity (ft/s) = 5.66 Wetted Perim (ft) = 2.61 Crit Depth, Yc (ft) = 0.76 Top Width (ft) = 0.00 EGL (ft) = 1.33 0 1 Elev (ft)Section 59.75 60.00 60.25 60.50 60.75 61.00 Reach (ft)