Appendix D - 8449 Garvey Hydraulic CalculationsCal Land Engineering, Inc.
dba Quartech Consultants
Geotechnical, Environmental, and Civil Engineering
HYDRAULIC CALCULATIONS
PROVIDES DATE 04/05/2017
JOB ADDRESS:
8449 Garvey Avenue,
Rosemead, CA
BY
CAL LAND ENGINEERING, INC.
Cal Land Engineering, Inc.
dba Quartech Consultants
Geotechnical, Environmental, and Civil Engineering
Introduction
The project site is located on Garvey Avenue, between Earle Avenue and Willard
Avenue, City of Rosemead.
The project is relatively flat, existing drainage flow drains to south direction from north.
Hydraulic calculation is based on 50-year storm event. There is no off-site drainage for
this project. The proposed development is to construct a mixed-use development.
Proposed Hydrology Study
A-1
Soil Type: 007
Total Area = 0.803 acres
Percent Impervious = 92.87 %
Average Rainfall Depth = 6.22 in.
Using Tc Calculator
Tc = 5 min.
Q1 = 2.6441 cfs
n = 0.009 for PVC pipe
V = (1.49/0.009) x (R) 2/3 x (S) 1/2 ft/sec
Q = V x Ap cfs
A = 0.196 R = 0.125 S = 0.005
V = (1.49/0.009) x (0.125) 2/3 x (0.005) 1/2 = 2.927
Q = 2.927 x 0.196
Q = 0.574 cfs
5xQ = 2.87 cfs > 2.6441 cfs for five (5) 6”PVC pipe with 0.5% min slope
A-2
Soil Type: 007
Total Area = 0.029 acres
Percent Impervious = 6.2 %
Average Rainfall Depth = 6.22 in.
Using Tc Calculator
Tc = 5 min.
Q2 = 0.0789 cfs
Q = Q1 + Q2 = 2.6441 + 0.0789 = 2.723 cfs
Parkway Drain
n = 0.013
V = (1.49/0.013) x (R) 2/3 x (S) 1/2 ft/sec
Q = V x Ab cfs
L = 2 x (W+0.333)
Ab = 0.333 x W = 0.666 R = Ab/L = 0.143 S = 0.02
V = (1.49/0.012) x (0.143) 2/3 x (0.02) 1/2 = 4.427
Q = 4.427 x 0.666 = 2.948 cfs
Q = 2.948 cfs > 2.723 cfs for W = 2’ Rarkway Drain with 2.0% slope
Peak Flow Hydrologic Analysis
File location: C:/Users/nam/Desktop/8449 Garvey Ave., Rosemead.pdf
Version: HydroCalc 0.3.0-beta
Input Parameters
Project Name 8449 Garvey Ave., Rosemead
Subarea ID A-1
Area (ac)0.803
Flow Path Length (ft)80.62
Flow Path Slope (vft/hft)0.01
50-yr Rainfall Depth (in)6.22
Percent Impervious 0.9287
Soil Type 7
Design Storm Frequency 50-yr
Fire Factor 0
LID False
Output Results
Modeled (50-yr) Rainfall Depth (in)6.22
Peak Intensity (in/hr)3.711
Undeveloped Runoff Coefficient (Cu)0.722
Developed Runoff Coefficient (Cd)0.8873
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)2.6441
Burned Peak Flow Rate (cfs)2.6441
24-Hr Clear Runoff Volume (ac-ft)0.3494
24-Hr Clear Runoff Volume (cu-ft)15220.7185
Peak Flow Hydrologic Analysis
File location: C:/Users/nam/Desktop/8449 Garvey Ave., Rosemead - A-2.pdf
Version: HydroCalc 0.3.0-beta
Input Parameters
Project Name 8449 Garvey Ave., Rosemead
Subarea ID A-2
Area (ac)0.029
Flow Path Length (ft)116.65
Flow Path Slope (vft/hft)0.01
50-yr Rainfall Depth (in)6.22
Percent Impervious 0.062
Soil Type 7
Design Storm Frequency 50-yr
Fire Factor 0
LID False
Output Results
Modeled (50-yr) Rainfall Depth (in)6.22
Peak Intensity (in/hr)3.711
Undeveloped Runoff Coefficient (Cu)0.722
Developed Runoff Coefficient (Cd)0.733
Time of Concentration (min)5.0
Clear Peak Flow Rate (cfs)0.0789
Burned Peak Flow Rate (cfs)0.0789
24-Hr Clear Runoff Volume (ac-ft)0.0029
24-Hr Clear Runoff Volume (cu-ft)127.381