PC - Item 3A - SPA 22-01 & ZC 22-02 - Exhibit E - Appendix D - Drainage Study Strathmore GarveyGarvey & Strathmore Apartments
Drainage Study
7849 Garvey Avenue
Rosemead, CA 91770
Date Prepared:
August 11, 2022
Prepared for:
Green Park Property, LLC
Attn.: Cindy Lau
120 E. Valley Blvd.
San Gabriel, CA 91776
(626) 307-0062
Prepared By:
4340 Viewridge Ave, Suite B
San Diego, CA 92113
Ph: (858) 634-8620
Declaration of Responsible Charge:
I hereby declare that I am the engineer of work for this project, that I have exercised responsible
charge over the design of the project as defined in section 6703 of the business and professions
code, and that the design is consistent with current standards. I understand that the check of the
project drawings and specifications by the City of Rosemead is confined to a review only and does
not relieve me, as an engineer of work, of my responsibilities for project design.
_______________________________
Patric T. de Boer RCE 83583
Registration Expires 3-31-2023
______________________________
Patric T de Boer RCE 835
Table of Contents
Site & Project Description ....................................................................................................... 1
Methodology ............................................................................................................................ 1
Existing Conditions ................................................................................................................. 1
Proposed Conditions ............................................................................................................... 2
Existing HydroCalc Analysis................................................................................................... 2
Proposed HydroCalc Analysis ................................................................................................. 3
Results and Conclusions .......................................................................................................... 3
Site Vicinity Map ..................................................................................................................... 4
Existing Hydrology Exhibit .................................................................................................... 5
Proposed Hydrology Exhibit .................................................................................................. 6
Pipe Sizing ............................................................................................................................... 7
HydroCalc Analysis Exhibits .................................................................................................. 8
Appendices
50-Year 24-Hour Isopluvial ...................................................................................... Appendix 1
Soil Type Map ......................................................................................................... Appendix 2
1
Site & Project Description
This drainage study has been prepared for the proposed project located at 7849 Garvey Avenue in
the City of Rosemead. The project site is located 0.65 south of Interstate 10 at the northwest corner
of the intersection of Garvey Avenue and Strathmore Avenue. See figure No.1 for a Vicinity Map.
The site is currently occupied by a paved parking lot and three commercial buildings. No existing
storm drains or inlets are known to exist on the project site.
The proposed project involves the demolition and removal of all existing improvements and
structures. A seven story apartment with an integrated parking garage will be constructed. The
single building will cover the majority of the site.
Methodology
This drainage report has been prepared in accordance with current County of Los Angeles
regulations and procedures.
The analyses of the existing and proposed conditions were performed using HydroCalc (Version
1.02) to calculate runoff flowrates and volumes. Given the area, length of flow path, average slope,
design storm depth, imperviousness, and soil type, HydroCalc generates a hydrograph for the
existing and proposed conditions. Soil and rainfall inputs were determined using the GIS data
provided by maps the Los Angeles Flood Control District.
This report analyzes the flow generated by the 25, 50 and 100-year storm events for storm drain
sizing and flood control purposes.
The following references were used in this report
(1) Handbook of Hydraulics, E.F. Brater & H.W. King, 6th Ed., 1976.
(2) Los Angeles County Department of Public Works Hydrology Manual, 2006
Existing Conditions
The existing 1.21 acre site is 100% impervious and underlain by soil type # 7. The site accepts
offsite runoff from the alley and the properties west of the site. The offsite areas surface flow to the
site and confluence with the on-site flow before draining to Strathmore Avenue. The entire site and
the offsite areas drain east via surface flow to the gutter on Strathmore Ave., thence south to the
existing curb inlet, and ultimately to the existing 24” pipe on the public storm drain system. This
point is referred to as Discharge Point # 1 in this report.
2
Proposed Conditions
The proposed improvements consist of a seven-story apartment building, hardscape and on-site
storm drain system. The proposed development will grade the entire site but will keep the same
discharge point as the existing conditions. The proposed site will be 100% impervious. The
majority of the site will be covered by the building.
Catch basins will be installed along the west end of the building and the westerly alley to accept the
offsite runoff generated from the westerly properties and bypass via pipe flow to a connection
point to the 24” storm drain in Strathmore Avenue. The roof drains of the building will drain
directly to storm drain pipes in the ground level parking lot that will be connected to a proposed
8’x16’ Modular Wetland System vault for treatment. Following treatment, the stormwater will drain
out via pipe flow to a proposed storm drain pipe that will connect to the existing 24” RCP pipe on
Strathmore. This point is referred to as Discharge Point # 1 in this report.
Existing HydroCalc Analysis
The existing condition was modeled as a single on-site basin and three off-site basins, referred to as
E-1, O-1, O-2 and O-3 in this report. Below is a summary of the HydroCalc calculations for the
existing conditions.
The output data sheets from HydroCalc can be found at the end of this report.
Basin # Area
(ac)
Soil
Type
Imperv.
(%)
I25
(in/hr)
I50
(in/hr)
I100
(in/hr)
Q25
(cfs)
Q50
(cfs)
Q100
(cfs)
E-1 1.21 7 100 3.25 3.70 4.15 3.54 4.03 4.52
O-1 0.36 7 100 3.25 3.70 4.15 1.05 1.20 1.35
O-2 0.17 7 100 3.25 3.70 4.15 0.50 0.57 0.64
O-3 0.29 7 45 3.25 3.70 4.15 0.85 0.97 1.08
Total Combined Flow 5.93 6.76 7.58
3
Proposed HydroCalc Analysis
The proposed site was modeled as a single on-site basin and three offsite basins, referred to as P-1,
O-1, O-2 and O-3 in this report.
Below is a summary of the HydroCalc calculations for the proposed conditions.
The output data sheets from HydroCalc can be found at the end of this report.
Results and Conclusions
The proposed improvements result in no change to the peak runoff flowrate for the 25, 50 and
100-year storm events. This is because the site is 100 % impervious for both the existing and
proposed conditions. The onsite flowpath was modified, but the time of concentration in both the
existing and proposed conditions is below the 5.0 minute minimum allowed by the Rational
Method. The offsite flowpath is modified in that runoff from the site will discharge directly to a
new connection to the 24” storm drain in Strathmore Ave, rather than flowing to the existing curb
inlet first.
It is the opinion of Omega Engineering Consultants that the project will not cause adverse effects
to the downstream drainage facilities or receiving waters. A separate LID Plan has been prepared to
discuss the water quality impacts of the proposed development.
Basin # Area
(ac)
Soil
Type
Imperv.
(%)
I25
(in/hr)
I50
(in/hr)
I100
(in/hr)
Q25
(cfs)
Q50
(cfs)
Q100
(cfs)
P-1 1.21 7 100 3.25 3.70 4.15 3.54 4.03 4.52
O-1 0.36 7 100 3.25 3.70 4.15 1.05 1.20 1.35
O-2 0.17 7 100 3.25 3.70 4.15 0.50 0.57 0.64
O-3 0.29 7 45 3.25 3.70 4.15 0.85 0.97 1.08
Total Combined Flow 5.93 6.76 7.58
10
CONDUIT SIZING CALCULATIONS
The following chart details the sizing parameters and for conduits that convey runoff on the site.
K'= Discharge factor =(Q*n)/(d8/3*s1/2 )
n= Mannings coefficient =0.013 for PVC & HDPE
d=diameter of conduit (ft)=per chart
Q= Discharge =based off portions of basins tributary to outlet
s=Minimum Pipe Slope (ft/ft)=per chart
D=depth of flow =From table 7-4 See right
Ca= Flow factor = From table 7-14 See right
A=Cross sectional area of flow =Ca*d2
V=Velocity =Q/A
Pipe Flow
Pipe Tributary Areas Q (cfs)S (%)d (in)K'D/d Ca A (sf)V (fps)
1 Half of proposed building roof 2.26 0.5 12 0.4155 0.73 0.614 0.614 3.68
2 Half of proposed building roof 2.26 0.5 12 0.4155 0.73 0.614 0.614 3.68
3 Basin O-1 1.35 0.5 12 0.2482 0.52 0.413 0.413 3.27
4 Basin O-2 0.64 0.5 12 0.1177 0.34 0.236 0.236 2.72
5 Basin O-3 1.08 0.5 12 0.1986 0.45 0.343 0.343 3.15
6 Entire proposed building roof and
offsite basns 7.58 0.5 18 0.4727 0.83 0.697 1.568 4.83
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER/H&H/Calculations/25-Year/Strathmore - 25 Year - E-1.1.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 25 Year
Subarea ID E-1.1
Area (ac)1.21
Flow Path Length (ft)235.0
Flow Path Slope (vft/hft)0.0241
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 25-yr
Fire Factor 0
LID False
Output Results
Modeled (25-yr) Rainfall Depth (in)5.4436
Peak Intensity (in/hr)3.2478
Undeveloped Runoff Coefficient (Cu)0.6837
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)3.5369
Burned Peak Flow Rate (cfs)3.5369
24-Hr Clear Runoff Volume (ac-ft)0.4899
24-Hr Clear Runoff Volume (cu-ft)21341.0961
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER/H&H/Calculations/Proposed/25-Year/Strathmore - 25 Year - P-1.1.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 25 Year
Subarea ID P-1.1
Area (ac)1.21
Flow Path Length (ft)100.0
Flow Path Slope (vft/hft)0.005
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 25-yr
Fire Factor 0
LID False
Output Results
Modeled (25-yr) Rainfall Depth (in)5.4436
Peak Intensity (in/hr)3.2478
Undeveloped Runoff Coefficient (Cu)0.6837
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)3.5369
Burned Peak Flow Rate (cfs)3.5369
24-Hr Clear Runoff Volume (ac-ft)0.4899
24-Hr Clear Runoff Volume (cu-ft)21341.0961
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER REPORTS/H&H/Calculations/Offsite/25-Year/Strathmore - 25 Year - O-1.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 25 Year
Subarea ID O-1
Area (ac)0.36
Flow Path Length (ft)130.0
Flow Path Slope (vft/hft)0.0154
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 25-yr
Fire Factor 0
LID False
Output Results
Modeled (25-yr) Rainfall Depth (in)5.4436
Peak Intensity (in/hr)3.2478
Undeveloped Runoff Coefficient (Cu)0.6837
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)1.0523
Burned Peak Flow Rate (cfs)1.0523
24-Hr Clear Runoff Volume (ac-ft)0.1458
24-Hr Clear Runoff Volume (cu-ft)6349.417
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER REPORTS/H&H/Calculations/Offsite/25-Year/Strathmore - 25 Year - O-2.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 25 Year
Subarea ID O-2
Area (ac)0.17
Flow Path Length (ft)80.0
Flow Path Slope (vft/hft)0.025
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 25-yr
Fire Factor 0
LID False
Output Results
Modeled (25-yr) Rainfall Depth (in)5.4436
Peak Intensity (in/hr)3.2478
Undeveloped Runoff Coefficient (Cu)0.6837
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)0.4969
Burned Peak Flow Rate (cfs)0.4969
24-Hr Clear Runoff Volume (ac-ft)0.0688
24-Hr Clear Runoff Volume (cu-ft)2998.3358
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER REPORTS/H&H/Calculations/Offsite/25-Year/Strathmore - 25 Year - O-3.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 25 Year
Subarea ID O-3
Area (ac)0.29
Flow Path Length (ft)90.0
Flow Path Slope (vft/hft)0.0444
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 25-yr
Fire Factor 0
LID False
Output Results
Modeled (25-yr) Rainfall Depth (in)5.4436
Peak Intensity (in/hr)3.2478
Undeveloped Runoff Coefficient (Cu)0.6837
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)0.8477
Burned Peak Flow Rate (cfs)0.8477
24-Hr Clear Runoff Volume (ac-ft)0.1174
24-Hr Clear Runoff Volume (cu-ft)5114.8082
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER/H&H/Calculations/50-Year/Strathmore - 50 Year - E-1.1.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 50 Year
Subarea ID E-1.1
Area (ac)1.21
Flow Path Length (ft)235.0
Flow Path Slope (vft/hft)0.0241
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 50-yr
Fire Factor 0
LID False
Output Results
Modeled (50-yr) Rainfall Depth (in)6.2
Peak Intensity (in/hr)3.6991
Undeveloped Runoff Coefficient (Cu)0.721
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)4.0283
Burned Peak Flow Rate (cfs)4.0283
24-Hr Clear Runoff Volume (ac-ft)0.558
24-Hr Clear Runoff Volume (cu-ft)24306.4876
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER/H&H/Calculations/Proposed/50-Year/Strathmore - 50 Year - P-1.1.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 50 Year
Subarea ID P-1.1
Area (ac)1.21
Flow Path Length (ft)100.0
Flow Path Slope (vft/hft)0.005
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 50-yr
Fire Factor 0
LID False
Output Results
Modeled (50-yr) Rainfall Depth (in)6.2
Peak Intensity (in/hr)3.6991
Undeveloped Runoff Coefficient (Cu)0.721
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)4.0283
Burned Peak Flow Rate (cfs)4.0283
24-Hr Clear Runoff Volume (ac-ft)0.558
24-Hr Clear Runoff Volume (cu-ft)24306.4876
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER REPORTS/H&H/Calculations/Offsite/50-Year/Strathmore - 50 Year - O-1.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 50 Year
Subarea ID O-1
Area (ac)0.36
Flow Path Length (ft)130.0
Flow Path Slope (vft/hft)0.0154
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 50-yr
Fire Factor 0
LID False
Output Results
Modeled (50-yr) Rainfall Depth (in)6.2
Peak Intensity (in/hr)3.6991
Undeveloped Runoff Coefficient (Cu)0.721
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)1.1985
Burned Peak Flow Rate (cfs)1.1985
24-Hr Clear Runoff Volume (ac-ft)0.166
24-Hr Clear Runoff Volume (cu-ft)7231.6823
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER REPORTS/H&H/Calculations/Offsite/50-Year/Strathmore - 50 Year - O-2.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 50 Year
Subarea ID O-2
Area (ac)0.17
Flow Path Length (ft)80.0
Flow Path Slope (vft/hft)0.025
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 50-yr
Fire Factor 0
LID False
Output Results
Modeled (50-yr) Rainfall Depth (in)6.2
Peak Intensity (in/hr)3.6991
Undeveloped Runoff Coefficient (Cu)0.721
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)0.566
Burned Peak Flow Rate (cfs)0.566
24-Hr Clear Runoff Volume (ac-ft)0.0784
24-Hr Clear Runoff Volume (cu-ft)3414.9611
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER REPORTS/H&H/Calculations/Offsite/50-Year/Strathmore - 50 Year - O-3.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 50 Year
Subarea ID O-3
Area (ac)0.29
Flow Path Length (ft)90.0
Flow Path Slope (vft/hft)0.0444
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 50-yr
Fire Factor 0
LID False
Output Results
Modeled (50-yr) Rainfall Depth (in)6.2
Peak Intensity (in/hr)3.6991
Undeveloped Runoff Coefficient (Cu)0.721
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)0.9655
Burned Peak Flow Rate (cfs)0.9655
24-Hr Clear Runoff Volume (ac-ft)0.1337
24-Hr Clear Runoff Volume (cu-ft)5825.5218
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER/H&H/Calculations/100-Year/Strathmore - 100 Year - E-1.1.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 100 Year
Subarea ID E-1.1
Area (ac)1.21
Flow Path Length (ft)235.0
Flow Path Slope (vft/hft)0.0241
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 100-yr
Fire Factor 0
LID False
Output Results
Modeled (100-yr) Rainfall Depth (in)6.9564
Peak Intensity (in/hr)4.1504
Undeveloped Runoff Coefficient (Cu)0.7543
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)4.5198
Burned Peak Flow Rate (cfs)4.5198
24-Hr Clear Runoff Volume (ac-ft)0.6261
24-Hr Clear Runoff Volume (cu-ft)27271.8791
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER/H&H/Calculations/Proposed/100-Year/Strathmore - 100 Year - P-1.1.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 100 Year
Subarea ID P-1.1
Area (ac)1.21
Flow Path Length (ft)100.0
Flow Path Slope (vft/hft)0.005
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 100-yr
Fire Factor 0
LID False
Output Results
Modeled (100-yr) Rainfall Depth (in)6.9564
Peak Intensity (in/hr)4.1504
Undeveloped Runoff Coefficient (Cu)0.7543
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)4.5198
Burned Peak Flow Rate (cfs)4.5198
24-Hr Clear Runoff Volume (ac-ft)0.6261
24-Hr Clear Runoff Volume (cu-ft)27271.8791
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER REPORTS/H&H/Calculations/Offsite/100-Year/Strathmore - 100 Year - O-1.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 100 Year
Subarea ID O-1
Area (ac)0.36
Flow Path Length (ft)130.0
Flow Path Slope (vft/hft)0.0154
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 100-yr
Fire Factor 0
LID False
Output Results
Modeled (100-yr) Rainfall Depth (in)6.9564
Peak Intensity (in/hr)4.1504
Undeveloped Runoff Coefficient (Cu)0.7543
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)1.3447
Burned Peak Flow Rate (cfs)1.3447
24-Hr Clear Runoff Volume (ac-ft)0.1863
24-Hr Clear Runoff Volume (cu-ft)8113.9475
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER REPORTS/H&H/Calculations/Offsite/100-Year/Strathmore - 100 Year - O-2.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 100 Year
Subarea ID O-2
Area (ac)0.17
Flow Path Length (ft)80.0
Flow Path Slope (vft/hft)0.025
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 100-yr
Fire Factor 0
LID False
Output Results
Modeled (100-yr) Rainfall Depth (in)6.9564
Peak Intensity (in/hr)4.1504
Undeveloped Runoff Coefficient (Cu)0.7543
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)0.635
Burned Peak Flow Rate (cfs)0.635
24-Hr Clear Runoff Volume (ac-ft)0.088
24-Hr Clear Runoff Volume (cu-ft)3831.5863
Peak Flow Hydrologic Analysis
File location: P:/DWG OMEGA/0713 Strathmore and Garvey/STORMWATER REPORTS/H&H/Calculations/Offsite/100-Year/Strathmore - 100 Year - O-3.pdf
Version: HydroCalc 1.0.3
Input Parameters
Project Name Strathmore - 100 Year
Subarea ID O-3
Area (ac)0.29
Flow Path Length (ft)90.0
Flow Path Slope (vft/hft)0.0444
50-yr Rainfall Depth (in)6.2
Percent Impervious 1.0
Soil Type 7
Design Storm Frequency 100-yr
Fire Factor 0
LID False
Output Results
Modeled (100-yr) Rainfall Depth (in)6.9564
Peak Intensity (in/hr)4.1504
Undeveloped Runoff Coefficient (Cu)0.7543
Developed Runoff Coefficient (Cd)0.9
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)1.0832
Burned Peak Flow Rate (cfs)1.0832
24-Hr Clear Runoff Volume (ac-ft)0.1501
24-Hr Clear Runoff Volume (cu-ft)6536.2355
3
Appendix 1
Esri, NASA, NGA, USGS, FEMA | Esri Community Maps Contributor
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−
LA County Hydrology Map
Layers
Hydrology GIS
50yr Two Tenths (Rainfall)
DPA Zones
Soils 2004
Final 85th Percentile, 24-hrRainfall
1-year, 1-hour RainfallIntensity
Final 95th Percentile, 24-hrRainfall
LA County Parcels
About Legend Layers
Appendix 2
E
+
−
LA County Hydrology Map
Layers
Hydrology GIS
50yr Two Tenths (Rainfall)
DPA Zones
Soils 2004
Final 85th Percentile, 24-hrRainfall
1-year, 1-hour RainfallIntensity
Final 95th Percentile, 24-hrRainfall
LA County Parcels
About Legend Layers
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