HomeMy WebLinkAboutTract Map 20879-1 Lot 71 Hydro ReportAPPROVED BY
CITY OF TEMECULA
PUBLIC WORKS
david.pina 11/07/2024
11/07/2024 11/07/2024
11/07/20
Hydrology Report
for
The Shine Residence
31920 Vineyard Ave
Temecula CA 92591-4921
Table of Contents
Project Description 3
Project Setting 3
Pre-Project 3
Post Project 3
Interim Condition 3
Hydrology 4
Purpose 4
Description of Watershed 4
Methodology 4
Summary of Findings 5
Project Description
The resident of 31920 Vineyard Ave in Temecula,California,is proposing installing a swimming pool
and terrace area on their property.The pool and terrace area will be located in the back of the
property.
Project Setting
The project is located in a predominantly residential area of Temecula.Most of the area is composed
of single-family homes.
Pre-Project
The site is flat around the existing single-family residence.It also has a small hill towards the back of
the property.The property elevation goes from 1,240 feet in the front to 1,256 feet in the back.The
majority of the property is flat.Most of the property is landscaped and covered with grass,with the
rest covered in hardscape and concrete.
The property's current drainage pattern goes from the back toward the front street.The property
sheet flows from the northeast corner toward the southwest corner.
Post Project
When the proposed pool and terrace construction is complete,the property will have approximately
2750 square feet of additional concrete surfaces.Additionally,4"drainage pipes will be installed to
help convey flows through the property.However,with the additional concrete surfaces and the
installation of the drainage pipes within the property,there will not be a significant increase in the
amount of flow from the property.
Interim Condition
For the construction of the proposed swimming pool and the proposed terrace area,the existing hill
will be graded to accommodate the installation.The existing embankment will be excavated
approximately 15.5 feet,and a 6-foot tall retaining wall will be constructed.Another 17.5 feet of the
embankment will be excavated and graded to form the raised terrace area,and an 8-foot tall retaining
will be built abutting the adjacent property.
Currently,there are no known drainage issues on the property.
Hydrology
Purpose
The purpose of this report and analysis is to discuss the before and after conditions of the project.
Description of Watershed
The project is located within one residential property.The project site in the pre project condition has a C value
of 0.3.This was determined since the majority,about 90%,of the project site is of landscaped character.In
the post project condition the C value of the project was determined to be 0.5.The site changed from a
landscape mainly composed of grass to a more paved landscape.
The C values of 0.3 to 0.5 are values that fit within the description of the project.The project site is
characterized as a residential;single family areas.
Methodology
The determination of the flow rates of the project site were done using the rational method.Given the project
site size of 0.25 acres,this method was appropriate.The rational method is based on the following:
Q =CIA where,
Q =peak discharge -cubic feet per second (cfs)
C =Coefficient of Runoff
I =Rainfall Intensity (inches /hour)corresponding to the time of concentration
A =Area (acres)
The time of concentration of the project was assumed to be 5 minutes.And the storm events used for the
analysis of the project was for the 10 year and 100 year storm events.Which yielded the following intensities
respectively;2.94 inches /hour and 4.94 inches /hour.
The area of the project was determined through map measurements and found to be 0.25 acres.
Summary of Findings
Pre Project Post Project Difference
10 Year -Q (cfs)0.2205 0.3675 0.147
100 Year -Q (cfs)0.3705 0.6175 0.247
The analysis shows that there was less run off in the pre-project condition.This was due to the project being
mainly landscape.In the post project condition was an increase of 0.147 cfs in the 10 year storm event and an
increase of 0.247 cfs in the 100 year storm event.The increase in run off is due in part that landscape of the
project increasing impervious areas with the addition of the pool area and the raised terraces.The increases
in runoff from the property to the improve are not significant increases that would cause an adverse effect on
any adjacent properties or road infrastructure.
NOAA Atlas 14, Volume 6, Version 2
Location name: Temecula, California, USA*
Latitude: 33.5159°, Longitude: -117.1029°
Elevation: 1242 ft**
* source: ESRI Maps
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
Sanja Perica, Sarah Dietz, Sarah Heim, Lillian Hiner, Kazungu Maitaria, Deborah Martin, Sandra
Pavlovic, Ishani Roy, Carl Trypaluk, Dale Unruh, Fenglin Yan, Michael Yekta, Tan Zhao, Geoffrey
Bonnin, Daniel Brewer, Li-Chuan Chen, Tye Parzybok, John Yarchoan
NOAA, National Weather Service, Silver Spring, Maryland
PF_tabular | PF_graphical | Maps_&_aerials
PF tabular
AMS-based point precipitation frequency estimates with 90% confidence intervals (in
inches/hour)1
Duration Annual exceedance probability (1/years)
1/2 1/5 1/10 1/25 1/50 1/100 1/200 1/500 1/1000
5-min 1.58
(1.33-1.91)
2.39
(2.00-2.88)
2.94
(2.44-3.58)
3.70
(2.96-4.67)
4.31
(3.37-5.56)
4.94
(3.77-6.55)
5.63
(4.16-7.68)
6.59
(4.67-9.41)
7.38
(5.04-10.9)
10-min 1.14
(0.954-1.37)
1.71
(1.43-2.06)
2.11
(1.75-2.56)
2.65
(2.12-3.34)
3.08
(2.41-3.98)
3.55
(2.70-4.70)
4.03
(2.98-5.50)
4.73
(3.35-6.74)
5.29
(3.61-7.82)
15-min 0.916
(0.768-1.10)
1.38
(1.16-1.66)
1.70
(1.41-2.07)
2.14
(1.71-2.70)
2.49
(1.94-3.21)
2.86
(2.18-3.78)
3.25
(2.40-4.44)
3.81
(2.70-5.44)
4.26
(2.91-6.31)
30-min 0.702
(0.588-0.844)
1.06
(0.884-1.27)
1.30
(1.08-1.58)
1.63
(1.31-2.06)
1.90
(1.49-2.46)
2.19
(1.67-2.90)
2.49
(1.84-3.39)
2.91
(2.06-4.16)
3.26
(2.23-4.83)
60-min 0.539
(0.452-0.649)
0.811
(0.679-0.979)
0.998
(0.829-1.22)
1.26
(1.00-1.58)
1.46
(1.14-1.88)
1.68
(1.28-2.22)
1.91
(1.41-2.61)
2.24
(1.58-3.19)
2.50
(1.71-3.70)
2-hr 0.386
(0.324-0.465)
0.576
(0.482-0.695)
0.704
(0.584-0.857)
0.876
(0.701-1.10)
1.01
(0.791-1.30)
1.15
(0.877-1.52)
1.30
(0.960-1.77)
1.50
(1.06-2.14)
1.66
(1.14-2.46)
3-hr 0.313
(0.263-0.377)
0.466
(0.390-0.562)
0.568
(0.471-0.691)
0.703
(0.563-0.888)
0.809
(0.633-1.04)
0.918
(0.700-1.22)
1.03
(0.763-1.41)
1.19
(0.842-1.70)
1.31
(0.897-1.94)
6-hr 0.225
(0.189-0.271)
0.334
(0.280-0.403)
0.406
(0.337-0.494)
0.501
(0.401-0.632)
0.574
(0.449-0.741)
0.649
(0.495-0.861)
0.727
(0.538-0.993)
0.834
(0.590-1.19)
0.918
(0.626-1.36)
12-hr 0.149
(0.125-0.180)
0.222
(0.186-0.268)
0.270
(0.224-0.329)
0.333
(0.266-0.420)
0.381
(0.298-0.492)
0.430
(0.328-0.570)
0.480
(0.355-0.656)
0.550
(0.389-0.784)
0.604
(0.412-0.893)
24-hr 0.097
(0.085-0.112)
0.146
(0.129-0.169)
0.178
(0.156-0.208)
0.221
(0.187-0.266)
0.253
(0.210-0.312)
0.287
(0.232-0.361)
0.321
(0.253-0.416)
0.368
(0.279-0.496)
0.405
(0.297-0.564)
2-day 0.057
(0.050-0.066)
0.089
(0.078-0.103)
0.111
(0.097-0.129)
0.140
(0.118-0.169)
0.163
(0.135-0.201)
0.188
(0.152-0.237)
0.214
(0.169-0.277)
0.250
(0.190-0.337)
0.280
(0.205-0.389)
3-day 0.040
(0.035-0.046)
0.064
(0.056-0.074)
0.081
(0.070-0.094)
0.104
(0.088-0.125)
0.123
(0.102-0.151)
0.143
(0.116-0.180)
0.165
(0.130-0.213)
0.196
(0.149-0.264)
0.222
(0.163-0.309)
4-day 0.033
(0.029-0.038)
0.053
(0.046-0.061)
0.067
(0.059-0.078)
0.087
(0.074-0.105)
0.104
(0.086-0.128)
0.122
(0.099-0.153)
0.141
(0.111-0.183)
0.170
(0.129-0.229)
0.194
(0.142-0.269)
7-day 0.022
(0.019-0.025)
0.035
(0.031-0.041)
0.045
(0.040-0.053)
0.059
(0.050-0.072)
0.071
(0.059-0.087)
0.084
(0.068-0.105)
0.097
(0.077-0.126)
0.118
(0.089-0.159)
0.135
(0.099-0.188)
10-day 0.016
(0.014-0.019)
0.027
(0.024-0.031)
0.035
(0.030-0.041)
0.046
(0.039-0.055)
0.055
(0.045-0.067)
0.065
(0.052-0.081)
0.075
(0.059-0.098)
0.091
(0.069-0.123)
0.105
(0.077-0.146)
20-day 0.010
(0.009-0.012)
0.017
(0.015-0.020)
0.022
(0.019-0.026)
0.029
(0.025-0.035)
0.035
(0.029-0.044)
0.042
(0.034-0.053)
0.049
(0.039-0.064)
0.060
(0.045-0.081)
0.069
(0.051-0.096)
30-day 0.008
(0.007-0.009)
0.014
(0.012-0.016)
0.018
(0.015-0.021)
0.024
(0.020-0.029)
0.029
(0.024-0.035)
0.034
(0.027-0.043)
0.040
(0.031-0.052)
0.049
(0.037-0.066)
0.056
(0.041-0.078)
45-day 0.006
(0.005-0.007)
0.011
(0.009-0.012)
0.014
(0.012-0.016)
0.019
(0.016-0.022)
0.022
(0.019-0.028)
0.027
(0.022-0.034)
0.031
(0.025-0.041)
0.038
(0.029-0.052)
0.044
(0.032-0.062)
60-day 0.005
(0.005-0.006)
0.009
(0.008-0.011)
0.012
(0.010-0.014)
0.016
(0.013-0.019)
0.019
(0.016-0.024)
0.023
(0.019-0.029)
0.027
(0.021-0.035)
0.033
(0.025-0.044)
0.038
(0.028-0.053)
1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of annual maxima series (AMS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency
estimates (for a given duration and annual exceedance probability) will be greater than the upper bound (or less than the lower bound) is 5%.
Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid
PMP values.
Please refer to NOAA Atlas 14 document for more information.
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Maps & aerials
Small scale terrain
Large scale terrain
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Large scale aerial
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US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring, MD 20910
Questions?: HDSC.Questions@noaa.gov
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Project Location
Project Location