HomeMy WebLinkAboutTechDrainage(Sept.2001)
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RECEIVED
SEP 2 0 2001
CITY OF TEMECULA
ENGINEERING DEPARTMENT
TECHNICAL DRAINAGE STUDY
FOR
CROWNE HILL
TRACTS 23143-F-6-7-8-9-10-11
15-100245.001
September 20001
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Prepared for:
Communities Southwest, Inc.
181 Old Springs Road
Anaheim, Ca. 92808
Phone: (714) 279-6555
Fax: (714) 279-6556
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TABLE OF CONTENTS
Page
II. INTRODUCTION _ _ _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
III. LOCATION AND DESCRIPTION ......................................... 2
.11I. FEDERAL EMERGENCY MANAGEMENT AGENCY (FEMA)
FLOOD HAZARD ANALYSIS ............................................ 2
: IV. STORM WATER QUALITY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
. V. HYDROLOGIC METHODOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
. VI. HYDRAULIC METHODOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
'VII. EXISTING AND PROPOSED HYDRAULIC FACILITIES
PER ASSESSMENT DISTRICT 159 ......................................5
'VIII. EXISTING CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
IX. PROPOSED CONDITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
. X. REVISIONS (STORM DRAIN LINES A, B C, L, & M) ........................ 26
XI. CONCLUSIONS AND RECOMMENDATIONS .............................. 27
XII. REFERENCES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
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LIST OF TABLES
No.
Description
Page
TABLE 1
EXISTING STORM DRAIN APPURTENANCES
BUTTERFIELD STAGE ROAD & PAUBA ROAD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
TABLE 2
SUMMARY - CATCH BASIN CAPACITIES -10-YEAR . . . . . . . . . . . . . . . . . . . . . . . . 23
TABLE 3
SUMMARY - CATCH BASIN CAPACITIES -100-YEAR. . . . . . . . . . . . . . . . . . . . . . . 25
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LIST OF FIGURES
No. Description Following Page
FIGURE 1 - VICINITY MAP ................................................... 2
FIGURE 2 - FIRM ........................................................... 2
FIGURE 3 - SOILS MAP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
FIGURE 4 - HYDROLOGY MAP- PROPOSED DEVELOPMENT. . . . . . . . . . . . . . . . . . . . . 10
i FIGURE 5 - PROPOSED AND EXISTING STORM DRAIN SYSTEMS. . . . . . . . . . . . . . . . . 10
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
I. INTRODUCTION
Communities Southwest, Inc. is proposing the residential development otTracts 23143-F-6-
7-8-9-10- & 11 located southeast of the Butterfield Stage Road/Pauba Road intersection
in the City of Temecula, California. Identified as Crowne Hill, this project consists of 683
lots. Tracts 23143-2, 3 & 4, comprising the southern portion of this site, have been
developed by others and are not a part of this project. Similarly, the northwest portion of
this site has been recorded as Tract 23143-1. Although under the same ownership, Tract
23143-1 will be developed by others and is not a part of this project.
The purpose of this report is to accompany the grading plan for this project in support of
obtaining a grading permit for final map recording. This study specifically accomplishes the
following tasks:
.:. Identify FEMA designation for this site.
.:. Address peak pre-developed onsite 10-year and 100-year runoff
-:. Determine the peak post-developed onsite 1 O-year and 100-year runoff
.:. Identify existing hydraulic facilities that affect the site.
-:. Propose storm drain systems to convey the onsite flows
-:. Address downstream impacts.
.:. Propose first flush mitigation facilities in accordance with the policies set
forth in the San Diego Regional Water Quality Control Board
(SDRWQCB ). National Pollutant Discharge Elimination System (NPDES)
Storm Water Permit (Reference 1) for discharging into existing hydraulic
facilities
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
II. LOCATION AND DESCRIPTION
The site is currently bounded on the north by Pauba Road, on the east by scattered single
family residences, on the southeast by vacant land, on the southwest by the residential
development comprising Tract 23143-2, 3, & 4, and on the west by Butterfield Stage Road.
Figure 1 shows the location of this project.
With the exception of Tracts 23143-2, 3 & 4, this project is currently undeveloped. The
property, covered with grasses and scattered brush, is situated on a ridge, aligned in a
general northwest-southeast direction.
III. FEDERAL EMERGENCY MANAGEMENT AGENCY (FEMA)
FLOOD HAZARD ANALYSIS
Figure 2 is a Geographic Information Systems (GIS) composite of portions of the Federal
Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) Panel Nos.
060245 2765A, 06024527770 B, 060245 3355 C, 060245 3360B (Reference 2). As shown
on this figure, the project site is not located in a FEMA designated Zone A Special Flood
Hazard Area.
IV. STORM WATER QUALITY
This project is located within the Murrieta Creek Temecula Valley Drainage District, which
requires all proposed developments to be in compliance with the policy of the National
Pollutant Discharge Elimination System (NPDES) Storm Water Permit issued by the San
Diego Regional Water Quality Control Board (SDRWQCB).
As with most urban developments, this project has potential for long term impacts on water
quality with the addition of pollutants. Some possible causes of volatile solids in urban
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PROJECT SITE
~ S~i\Il-GO
HI'IY. 79
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TO SAN DIEGO
VICINITY MAP
NOT TO SCALE
FIGURE
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. - - Crowne Hill
d Zones for
Floo
y:-:
o
1250 Feet
Flood Plain
Hazard Areas . Ide 100 year Flood Plain
Flood zon~.termiMd to ~ ~~~ye.r and SOQ-~~~ Plain
· ~:..n the limIts 0 be Outside SOQ-year
~ ~ea Oetennined to
FIGURE 2
. _-=.:':::'E
I@: -.,,-. .._._
-. ...-.
CO...U..T..... ........
. . . GI., ~_,.1I11W1
11;_11_
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
runoff are the following:
. Accidental spills or deliberate dumping of oil-based materials.
. Engine emissions during normal operations.
. Atmospheric particulates associated with rainfall or dustfall.
. Spilling of crude or refined petroleum products.
. Leached or eroded pavement.
. Natural seepage on land.
. Natural biogenic sources.
Post-developed storm water flows from this project will be subject to the NPDES permit
process. Through this permit process, the current policy of both Riverside County and the
City of Temecula is the requirement that the developer has the responsibility of identifying
and implementing a program of Best Management Practices (BMPs) to minimize the
potential for pollution.
Water Quality Mitigation Basins are proposed at all locations which discharge to existing
hydraulic facilities. These basins were designed in accordance in the following policies set
forth by the San Diego Regional Water Quality Control Board (SDRWQCB):
1. To contain the volume generated by 0.6-inch of rainfall over the tributary
area times the Coefficient of Runoff (Rational Hydrology) plus an additional
10 percent of this volume for sediment.
2.. To contain the maximum runoff produced by a rainfall intensity of 0.2-inches
of rain per hour
3. The basin should be stored for a period between 24 and 40 hours.
All outflow storm drains in the water quality mitigation basins include a standpipe (diameter
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Crowne Hill
Tracts 23143-F-6-7-8-9-10
Technical Drainage Study
varies), whose elevation is determined based on the above storage requirements and an
orifice plate to drain the basin. The proposed Water Quality Mitigation Basins are further
discussed in Section IX of this report. All calculations are included in Appendix A.
v. HYDROLOGIC METHODOLOGY
The methodology presented in this study is in compliance with the Riverside Flood Control
District and Water Conservation District (RCFC& WCD) 1978 Hydrology Manual (Reference
3, hereinafter referred to as the Manual).
Model Descriptions -
The Integrated Rational Method Hydrology System Model Version 8.0, dated January 1,
2000, (Reference 4) within the Advanced Engineering Systems Software (AES) was used
to generate the peak 1 O-year and 1 OO-year onsite flows.
Soil Type - The Manual utilizes the Soil Conservation Service (SCS) soil classification
system, which classifies soils into four (4) types: A through D, with D being the least
impervious. A composite soils map for this project was assembled by scanning portions
of Hydrologic Soils Group Plates C-1.53 and C-1.61 of the Manual onto an AutoCad file
containing the boundary of this site. The soils map, superimposed with the boundary of this
project, is presented as Figure 3 in this report. According to this figure, the project is
located within a mixture of the above-mentioned soil types.
Development Type- The proposed development was based on single-family homes with
a density of 4 lots per acre. For undeveloped areas, the study was based on natural ground
with fair cover.
Intensity- The1 O-minute 160-minute intensity values (inches/hour) for the 1 O-year and 100-
year storm events, obtained from Plate D-4.1 (4 of 6) of the Manual, are 2.36/0.88 and
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I PROJECT
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F I\~~GURE 3
SOILS MAP
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
3.48/1.30, respectively.
Drainage Areas and Flow Patterns - The drainage areas and flow patterns were
determined using 40 scale grading plans. The areas were measured using the computer
capabilities of AutoCAD.
VI. HYDRAULIC METHODOLOGY
The Hydraulic Elements Program Package (HELE1) Version 8.0 dated January 1, 2000,
(Reference 5) within the Advanced Engineering Systems Software (AES) was used to
determine the street flow characteristics and to size the proposed catch basins. The
RCFC&WCD's hydrologic criteria (1 O-year storm flow and 1 OO-year storm flow be contained
within the curb and street right-of-way, respectively) was used in the determination of the
catch basin locations. An entrance loss of 0.20 was to describe the catch basin entrance
loss.
The Los Angeles County Flood Control District's Water Surface Pressure Gradient(WSPG)
computer model (Reference 6) was used to generate the 100-year Hydraulic Grade Line
(HGL) in the storm drain systems. An entrance loss of 0.20 was to describe the catch basin
entrance loss at the upstream terminus of the storm drain systems.
The U.S Army Corps of Engineers' HEC-1 Flood Hydrograph computer program was used
to determine the peak stage and volume in the proposed Water Quality Mitigation Basins.
VI. EXISTING AND PROPOSED HYDRAULIC FACILITIES PER
ASSESSMENT DISTRICT 159
A substantial portion of the runoff from this project will be directed to the existing storm
drain systems in Butterfield Stage Road and in Pauba Road. These facilities, as well as the
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Crowne Hill
Tracts 23143-F-6-7-8-9-10
Technical Drainage Study
proposed storm drain systems in Crowne Hill Drive, were designed in the approved
Hydrology Study - Mass Grading With Assessment District 159 For Tract 23143 Crowne
Hill (Reference 7). The existing and proposed storm drains, associated with Assessment
District 159, depicted on Figure 4, are summarized in Table 1.
TABLE 1
EXISTING AND PROPOSED STORM DRAINS
ASSESSMENT DISTRICT 159
BUTTERFIELD STAGE ROADIPAUBA ROAD/CROWNE HILL DRIVE
BUTTERFIELD STAGE ROAD
EXISTING LINES D, E, F, G, H, I, & J
Line Description
Line D 36" RCP with Upstream Concrete Bulkhead
Line E 36" RCP with Upstream Apron
Line F 36" RCP with Upstream Concrete Bulkhead
Line G 48" RCP with Upstream Apron
Line H 48" RCP with Upstream Concrete Bulkhead
Line H-1 42" RCP with Upstream Headwall
Line I 18" RCP with Upstream Catch Basin(L=14')
Line J 18"-24" RCP with Upstream Catch
Basin(L=14')
PAUBA ROAD
EXISTING LINES AA, BB, CC, DD, D1, D2 & EE
Line Description
AA 24" RCP with Flared Upstream End
SB 18" RCP
CC 18" RCP with Upstream Catch Basin(L=14')
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
DD 27" -30" RCP
D1 18" RCP with Upstream Catch Basin
(L=14')
D2 18" RCP with Bulkhead at Upstream End
EE 30" RCP with Upstream Catch Basin
(L=14')
CROWNE HILL DRIVE
PROPOSED LINES D, DD, E & E-1
Line Description
D 18" - 36" RCP
Joins Line D (Butterfield Stage Road)
DD Catch Basin(L=13.3')
Joins Line DD (Pauba Road)
E 27" RCP with Upstream Catch Basin(L=28')
E-1 18" RCP with Upstream Catch Basin(L=28')
ROYAL CREST PLACE
PROPOSED LINES H, H-2, H-3, H-4, H-5 & H-6
Line Description
H 48' RCP
Joins Existing Line H in
Butterfield Stage Road
H-2 (North) 18" RCP with Upstream Catch Basin(L=14')
H-2 (South) 18" RCP with Upstream Catch Basin(L=21 ')
H-3 (North & South) 18" RCP with Upstream Catch Basin(L=21')
H-4 24"-30" RCP with Upstream Concrete
Bulkhead
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
H-5
H-6
24" RCP with Upstream Catch Basin(L=21')
18" RCP with Upstream Concrete Bulkhead
VIII. HYDROLOGY - EXISTING CONDITIONS
The existing hydrology for the entire site, including Tracts 23143-1,2,3,& 4), was addressed
in the approved Undeveloped Hydrology Study for Tract 23143 Crowne Hill (Reference 8)
and will not be repeated in this report. Copies of referenced material are included in
Appendix C.
IX. HYDROLOGY - PROPOSED CONDITIONS
The hydrology of this site was previously studied in numerous reports by Trans-Pacific
Consultants (TPC), formerly known as RANPAC Engineering Corporation. A review of
these reports indicated that the 10-year and 100-year flows used in the design of the
existing storm drain facilities in Butterfield Stage Road and in Pauba Road, constructed with
the above-mentioned Mass Grading of Assessment District 159 For Tract 23143, were
obtained from the Hydrology/Hydraulic Calculations (Ultimate Conditions) for Butterfield
Stage Road Rancho Villages Assessment District 159 (Reference 9). Portions of pertinent
information from Reference 9 are included in Appendix C.
The proposed development, covering approximately -- acres, includes the construction of
the following facilities.
. 683 single family lots
. School site
. Interior private streets, with a 60-foot right-of-way, normal crown sections, L-type
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Crowne Hill
Tracts 23143-F-6-7-8.9-10
Technical Drainage Study
curb and gutter, and 5-foot sidewalks on both sides. It is noted that the main interior
streets, Crowne Hill Drive and Royal Crest Place, will be constructed as part of
Assessment District No. 159.
Sidewalks in the perimeter streets (Butterfield Stage Road and Pauba Road).
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The hydrologic analyses in the TPC studies were used as guidelines in establishing the
onsite hydrologic models in this report. This analysis is in compliance with RCFC&WCD
criteria (1 O-year storm flow and 1 OO-year storm flow be contained within the curb and street
right-of-way, respectively).
The Rational program was used to determine furthest upstream location in the drainage
basin where either the 1 O-year flow exceeded top of curb or the tOO-year flow exceeded
right-of-way. At that location, catch basin(s) were sized so that the bypasses did not
exceed the above criteria to the next proposed set of catch basins. The bypasses were
routed downstream in an open conveyance system (usually a street) This procedure was
repeated downstream to the last set of catch basins. All catch basins located in a sump
condition were designed to intercept the entire 1 OO-year flow. EmerQency overflow paths
have been [lrovig.!'ctaLallsump 10cat[Q.ns. Upon completing the catch basin bypass flows,
the Rational program was modeled to reflect the storm drain flows. The storm drain
plan/profiles were used in determining the locations of junctions, changes in pipe slope and
changes in pipe size for the Rational model. The hydrologic data for the intercepted flows
at the furthest upstream catch basin were recalled into the model using Option 7. The
intercepted flows were routed downstream to the next point of impact to the storm drain
Uunction, change in pipe slope, size, etc.) using Option 4 of the Rational program. At a
junction, the tributary flows were recalled into the system using Option 7 and confluenced
with the mainline flows using Option 1. The combined flows were routed downstream using
Option 4. This procedure was repeated downstream to the discharge point of the storm
drain. Rock Energy Dissipaters, as shown on San Diego Regional Standard Drawing No.
D-40.1 (Reference 10), are proposed at the outlets of all storm drains, which discharge into
natural watercourses. All supporting hydrologic and hydraulic calculations are included in
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Technical Drainage Study Crowne Hill
Tracts 23143-F-6-7-8-9-10
Appendices A and B, respectively. All referenced information is included,inAppendix C.
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The proposed onsite drainage patterns (drainage basins and nodes) and the proposed
storm drain systems for this project are presented on Figure 4 and Figure 5, respectively.
The site has been divided into 15 drainage basins, identified in numbers ranging from 100
to 1500. The nodes were located as closely as possible to those in the previous TPC
reports. The 1 O-year and 1 OO-year catch basin capacities are summarized in Tables 2 and
3, respectively. The 15 drainage basins are discussed as follows.
DRAINAGE BASIN 100 (Nodes 101 -109)/
STORM DRAIN LINE "M"
The 1 O-year and 1 OO-year flows concentrating at the low point (Node 107) in Sage
Court cul-de-sac are 10.5 cfs and 15.8 cfs, respectively (See Rational Output
Files:10L 100.DAT and 100L 100.DAT, Appendix A). A 7-foot long catch basin is
""--'--o,~ .0'_.__.
proposed at the above sump to intercept the total 1 OO-year flow to an 18-inch storm
drain which will daylight in one of the natural washes as shown on Figure 5. Erosion
protection in conformance with Reference 10 has been provided at the outlet.
DRAINAGE BASIN 200 (Nodes 201 - 234)/
STORM DRAIN LINES. "L,"L 1 ," "L2," & "L3"
The discharge from this drainage basin will be conveyed in the existing storm drain
system (Lines DD and EE) in the Pauba Road right-of-way (See Table 1, page -).
This system includes a temporary onsite 30-inch RCP (Node 223) approximately 20-
foot long, which connects to the existing 14-foot long catch basin at the low point
in Pauba Road (Node 230).
The majority of the flows in this drainage basin will be intercepted in the proposed
28-foot long catch basins in the Northshire Court/Crowne Hill Drive intersection
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
(Nodes 217 and 220). The intercepted flow will be conveyed in a 24-inch storm
drain (Line L), which extends to the low point (Nodes 204, 210) in Sage Court. At
this location, this storm drain be joined by laterals extending from the set of 7 -foot
long catch basins at the low point in Sage Court. A 30-inch storm drain will convey
the total 10-year and 1 OO-year flows of 37.3 cfs and 51.8 cfs, respectively to the
Water Quality Mitigation Basin. (See Rational Output Files:10L200.DAT and
100L200.DAT, Appendix A). This water quality basin was designed not only to
store a minimum volume as required by the SDRWQCB but also not to discharge
more than the 30 cfs, which is the capacity of the above-mentioned 30-inch RCP.
This capacity, determined using the WSPG computer program, is in agreement
with 29.6 cfs as shown on the "AS-BUILT" plans (Reference 11).
As previously mentioned, the HEC-1 program was used to route the flows through
this basin. The inflow hydrograph was determined by the triangular method with
the peak 100-yearflow (57.6 cfs) and time of concentration (10.4 minutes) obtained
from the above-mentioned Rational output. The stage-volume curve was obtained
from measuring the surface areas of specific contours with AutoCad. A
spreadsheet, assembled using the orifice and weir equations, provided the stage-
discharge relationship. The results of the HEC-1 program indicate a maximum
storage volume, outflow and stage of 2.0 acre-feet,19 cfs, and 1274.83 feet,
respectively. A 6-inch orifice plate will drain this basin in approximately 31.3 hours
(See orifice control sizing equation in Appendix A)
Downstream of this water quality basin, there are three existing catch basins
forming the form the upstream ends of Lines D-1, DD, and EE. Only nuisance
flows were assumed to be intercepted in the 14-foot long catch basin (Line D-1)
located near the high point in Pauba Road. A portion of the bypass at Node 217
will be intercepted downstream by the existing 13.3-foot long catch basin in Crowne
Hill Drive (Node 226) and conveyed in Line DD. The remaining bypass, along with
the flows generated in the Pauba Road right-of-way will be intercepted in the 14-foot
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Technical Drainage Study
Crowne Hill
Tracts 23143.F.6-7.8-9-10
long catch basin (Node 230)at the low point in Pauba Road. The total combined
100-year flow discharging this system (Node 234) is 28.7 cfs. This value is
considerably less than the existing 1 OO-year flow of 58.4 cfs (Reference 8) and the
44.6 cfs as shown on Reference 11. Therefore, no adverse downstream hydraulic
impacts are expected. The A.D. 159 storm drain plan/profile for the above-
mentioned storm drain lines are included in Appendix C.
DRAINAGE BASIN 300 (Nodes 301 - 331)/
STORM DRAIN LINES: "A," "A1," "A2," "A3," & "M"
The low point of Wyandotte Street is located at Nodes 323 and 324. Although,
catch basins (L=14') are proposed at this location, an additional set of basins are
proposed in Wyandotte Street at the Faber Court intersection (Nodes 310 and 311).
These upstream basins are necessary as the slope of Wyandotte Street is milder
downstream of the above intersection, which would result in the 1 O-year flow depth
exceeding the curb height. These 7-foot long catch basins have been designed to
insure that the 1 O-year bypass do not exceed the top of curb. The intercepted flows
will be conveyed in an 18-inch storm drain to the sump catch basins. The combined
100-year flow of 66.7 cfs will be conveyed in a 36-inch storm drain, which will
daylight into one of the natural washes. Erosion protection has been provided at
the outlet. The 1 O-year and 100-year Rational output files for Drainage Basin 300
are 1 OL300.DAT, and L300.DAT, respectively, included in Appendix A.
DRAINAGE BASIN 400 (Nodes 401 - 421)/
STORM DRAIN LINE "B3"(L1NE "E-1" A.D. 159)
This drainage basin comprises the tributary area to the reach of Crowne Hill Drive
between Royal Crest Place and Paoli Court, The 1 O-year flow depth exceeds the
top of curb downstream of Node 417. However, there is a proposed 28-foot catch
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
basin at the northwest corner of the Crowne Hill Drive/Royal Crest Place
intersection (Node 417), designed under Assessment District No. 159 Crowne Hill
Drive & Calle Las Mariposas Phase /I (Reference 12). This catch basin intercepts
the majority of the tributary 1 O-year and 1 OO-year flows (See Tables 2 and 3). The
bypasses are directed westerly onto Royal Crest Place within Drainage Basin 1000.
The flows in the east side of Crowne Hill Drive are conveyed easterly onto Royal
Crest Place within Drainage Basin 600. The 1 O-year and 1 OO-year Rational output
files for Drainage Basin 400 are 10L400.DAT, and 100L400.DAT, respectively,
included in Appendix A.
DRAINAGE BASIN 500 (Nodes 500 - 509):
STORM DRAIN LINE "B" (LINE "E" A.D. 159)
This drainage basin comprises the tributary area to the reach of Crowne Hill Drive
between Royal Crest Place and Fox Road Court. The 1 O-year flow depth exceeds
the top of curb in the reach between Nodes 501and 506. However, there is a 28-
foot catch basin at the southwest corner of the Crowne Hill Drive/Royal Crest Place
intersection (Node 506) which was designed under Reference 12. This catch basin
intercepts the majority of the the 1 O-year and 1 OO-year tributary flows (See Tables
2 and 3). The bypasses are directed westerly onto Royal Crest Place within
Drainage Basin 1000. The flows in the east side of Crowne Hill Drive are conveyed
easterly onto Royal Crest Place within Drainage Basin 600. The 1 O-year and 100-
year Rational output files for Drainage Basin 500 are 1 OL500.DA T, and 500L.DA T,
respectively, included in Appendix A.
DRAINAGE BASIN 600 (Nodes 601 - 609):
STORM DRAIN LINE "B" (LINE "E" A.D. 159), LINE "B1" & LINE "B2."
This basin includes the proposed 27-inch RCP storm drain system (LINES "E," &
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
"E-1"in the Crowne Hill Drive I Royal Crest Place intersection (Reference 12). This
system includes a set of 28-foot long catch basins (Nodes 417, 506) at the above-
mentioned intersection. This project proposes to extended the storm drain as a 36-
inch RCP downstream to the proposed set of 10-foot long catch basins at the low
point in Wyandotte Road (Nodes 602 & 605). The total 1 OO-yearflow (77.8 cfs) will
be conveyed in the 36-inch storm drain, which will discharge into one of the natural
watercourses. Erosion protection has been provided at the outlet. The 1 O-year and
100-year Rational output files for Drainage Basin 600 are 10L600.DAT, and
100L600.DAT, respectively, included in Appendix A.
DRAINAGE BASIN 700 (Nodes 201 - 222):
This drainage basin comprises the tributary area to Crowne Hill Drive north of the
high point at the Paoli Court intersection. The nodes have been renumbered as this
drainage basin has been combined with Drainage Basin 200.
DRAINAGE BASIN 800 (Nodes 801 - 842):
STORM DRAIN LINES "F, " "F1 ," "F2," "F3, "F4," "G," "G1 ," "G2," & "T."
The 1 O-year street flows begin to exceed the top of curb in the reach of Larry Lee
Street between Nodes 821 and 825. Hence, this report proposes a 7-foot long
catch basin at Node 821. The intercepted flows will be conveyed in a 18-inch storm
drain to the next set catch basins at Nodes 835 and 840. These 21-foot long catch
basins have been designed to insure the 10-year bypasses remain below top of
curb downstream to the last set of catch basins. A 36-inch storm drain will convey
the combined flows to the last set of catch basins at the tract boundary. The 21-foot
long catch basins at Nodes 841 and 842 have been designed to intercept the
majority of the 1 OO-year flow. The 1 OO-year flow (61.5 cfs), conveyed in the 36-inch
storm drain, will discharge into one of the natural watercourses. Erosion protection
has been provided at the outlet. The total 1 OO-year bypass (0.5 cfs) to the existing
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
adjacent development ,Tract 23143-4, is insignificant (See Drainage Basin 1400).
The 10-year and 100-year Rational output files for Drainage Basin 800 are
10LN800.DAT, and 800.DAT, respectively, included in Appendix A.
DRAINAGE BASIN 900 (Nodes 901 -910):
This project proposes a parkway drain at the low points in Sparks Court (Node 903)
and in DuPont Street (Node 909). The flows will be conveyed in a natural swale to
the existing 42-inch lateral (Node 910) of the Royal Crest storm drain (See
Drainage Basin 1000, following). The 1 O-year and 1 OO-year Rational output files for
Drainage Basin 900 are 10L 1300.DAT, and 100L 1300.DAT, respectively, included
in Appendix A.
DRAINAGE BASIN 1000 (Nodes 1001 - 1024):
This drainage basin comprises Tract23143-1, which has been recorded but not yet
constructed. In the Royal Crest/Butterfield Stage intersection, there is an existing
storm drain system Comprising Line "H" and Laterals "H-1," "I," & "J." The
southeast corner of the above-mentioned intersection has been graded to create
a depressed area which drains directly to Lateral "H-1." This study utilized the
hydrologic data presented in the following approved documents:
. Hydrology/Hydraulic Calculations (Ultimate Conditions) for Butterfield
Stage Road Rancho Villages Assessment District 159 (Reference 9)
. City of Temecula Developed Conditions Hydrology Study for Tract
23143-1 (Reference 13).
. "As-Built" Assessment District plan/profiles for Lines "H, " "I, " and "J"
(Reference 14) for the reach of storm drain between Stations
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Tracts 23143-F-6-7-8-9-10
8+61.03 to 12+45.60.
. Assessment District 159 storm drain plan/profiles for Lines "H,"
through "H-7,""I, "and "J"(Reference 15) for the reach of storm drain
between Stations 12+45.60 and 25+60.92.
. Tract 23143-1 City of Temecula Schedule "A" Storm Drain
Improvement Plans (Reference 16) for the reach of storm drain
between Stations 25+60.92 to 28+09.63.
The flows in this drainage basin will be conveyed in Assessment District 159
extension of Line "H" in Royal Crest Place to the intersection of Harwick Lane in
Tract 23143-1 (References 15 and 16). Although the hydrology of this storm drain
extension was addressed in Reference 13, there are several changes impacting the
hydrology/hydraulics. These changes are summarized as follows:
1. Different bypasses from the proposed 28-foot long catch basins in
the Crowne Hill/Royal Crest intersection (Nodes 417 and 506).
2. A reduction of the drainage area impacting the proposed catch
basins in Harwick Lane (Nodes 103 and 107).
3. Different tributary flows to the proposed catch basins in Royal Crest
Place (Nodes 109, 114, 115, 118, 120 and 121).
The above revisions have been incorporated in this report. The 1 O-year and 100-
year Rational output files for Drainage Basin 1000 are 10L1000.DAT, and
1000.DAT, respectively, included in Appendix A. The revised 100-year hydraulic
grade line (HGL) has been plotted on the Royal Crest/Butterfield Stage. All
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Technical Drainage Study
Crowne Hill
Tracts 23143-F-6-7-8-9-10
supporting hydrologic and hydraulic calculations are included in Appendices A and
B, respectively.
DRAINAGE BASIN 1100 (Nodes 1101 - 1140 & 1151 -1153)
STORM DRAIN LINES "F," "F1," "F2,"IlF3,""F4,""G,""G1," & "G2," & "T."
The flows generated in this basin will be conveyed in three separate storm drains
(Lines "F," "G" & 'T') to the Water Quality Mitigation Basin adjacent to San Juan
Court. Originally, this drainage basin included a fourth storm drain system which
conveyed the flows intercepted at the sump catch basins (L=10') in Fox Road
(Nodes 1141& 1148) to the above-mentioned Water Quality Mitigation Basin.
However, the resulting 100-year water surface elevation (1241.27') in the basin
exceeded the top of curb elevations at the above-mentioned sump. In order to be
hydraulically feasible, this storm drain would require a considerably lower water
surface elevation in the Water Quality Mitigation Basin. This, in turn, would result
in a larger basin and the loss of additional lots.
As an alternative solution, the storm drain system (Lines "S2" & "S4") was realigned
to discharge into the Water Quality Mitigation Basin adjacent to the Paraguay
Drive/Fox Road knuckle The hydraulic results indicate that the additional flows
from Lines "S2" & "S4" would not require the loss of more lots (See Drainage Basin
1200, following).
Line "F" begins at the two proposed 28-foot catch basins in Fox Road,
approximately 2 lots downstream of the intersection with Swoboda Court (Nodes
1104 & 1116). Although, the 1 O-year street flows in Fox Road begin to exceed the
normal6-inch curbface at the intersection with Swoboda Court, it was not practical
to place catch basins immediately downstream of this intersection due to the limited
lot frontage. To comply with RCFC&WCD criteria this study proposes an 8-inch
curb in Fox Road extending from the intersection with Swoboda Court to the above-
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Crowne Hill
Tracts 23143-F-6-7-8-9-10
mentioned catch basins. The intercepted flows will be conveyed in a 36-inch storm
drain to the next set catch basins (L=28') at Nodes 1123 and 1126. These catch
basins were designed to intercept most of the 1 OO-year flow so as to minimize the
bypasses to the sump catch basins at Nodes 1141 and 1148. The 1 O-year and 100-
year discharges in Line "F" are 53.1 cfs and 77.4 cis, respectively (summation of
peak flows at catch basins). The 1 O-year and 1 OO-year Rational output files for Line
"F" are 10L 1100.DAT, and 1001100.DAT, respectively, included in Appendix A.
Line G begins at the proposed 28-foot catch basin in Hussar Court (Node 1135) The
intercepted flows will be conveyed in an 18-inch storm drain to the next set of catch
basins (L=10') at Nodes 1136 and 1140. The total100-year flow of 24.8 cfs will
be conveyed in a 30-inch storm drain which enters the Water Quality Mitigation
Basin adjacent to Line "F." The reason for not joining the two storm drains is to
avoid the large hydraulic head losses that would result.
The proposed 7 -foot catch basin at the end of San Juan Court intercepts a 100-year
flow of 3.2 cfs, which is also conveyed to the Water Quality Mitigation Basin in an
18-inch storm drain (Line "T"). The10-year and 100-year Rational output files for
Lines "F" and 'T' are 101100.DAT, and 1100.DAT, respectively, included in
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Appendix A.
This Water Quality Mitigation Basin was designed to store a minimum volume of
1.92 acre-feet to be in conformance with the SDRWQCB criteria. The flows will
discharge in the existing 48-inch storm drain (Line "G"), which was constructed as
part of A.D 159. The inlet apron will be replaced with a manhole and the 48-inch
pipe will be extended approximately 40 feet into the basin. A 48-inch diameter
standpipe will be placed at the upstream end of this storm drain, which is identified
as Line "SJC" in the improvement plans (See Sheet 9, Tract 23143-8). The top of
the standpipe is at an elevation of 1239.9 feet, which corresponds to the1.92 acre-
feet of volume in the basin. A 4-inch orifice plate, located at the upstream end of
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Tracts 23143-F-6-7-8-9-10
the standpipe will drain this basin in approximately 31.8 hours which is in
conformance with SDRWQCB criteria (See orifice control sizing equation in
Appendix A). The above outlet structure is shown as Detail 4, Sheet 11, Tract
23143-8.
The HEC-1 computer model was used to determine the peak stage, volume and
discharge in this basin. Rational computer model (file - 11 OOSD.DA T) was used to
determine the total100-year inflow to this Water Quality Mitigation Basin. The
inflow hydrograph was determined by the triangular method with the peak 100-year
flow (99.0 cfs) and time of concentration (9.4 minutes) obtained from the above-
mentioned Rational file. The stage-volume data (measured through AutoCad) and
the stage-discharge relationship (weir and orifice spreadsheet) are included in
Appendix A. The results of the HEC-1 program indicate a maximum storage
volume, outflow and stage of 2.0 acre-feet, 62.0 cfs, and 1241.27 feet respectively.
The 62.0 cfs is significantly less than both the interim 1 OO-year flow (84.7 cfs) and
ultimate 100-yearflow (146.8 cfs) as determined in A.D. 159 (Reference 7). This
discharge is also considerably less than the existing 1 OO-yearflow of 131.46 cfs as
determined in Reference 8. Hence, no adverse downstream impacts are
anticipated.
DRAINAGE BASIN 1200 (Nodes 1201 - 1231 & 1140-1150)..
STORM DRAIN LINES "S," "S1," "S2,""S3,""S4," & "U."
The flows generated in this basin will be conveyed in two separate storm drains
(Lines "S," & "U"), which discharge in the Water Quality Mitigation Basin at the
Paraguay Drive/Fox Road knuckle. The lines are aligned adjacent to each other
as they enter the basin since their connection would result in large hydraulic head
losses.
Line "S" begins at the set of catch basins in Paraguay Drive downstream of the
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Tracts 23143-F-6-7-8-9-10
intersection with Jolle Court (Nodes 1218 & 1225). The intercepted flows will be
conveyed in a 30-inch storm drain to the junction with Line "S2." As previously
mentioned, this storm drain system conveys the flows intercepted at the sump
catch basins in Fox Road (Nodes 1141 & 1148). The combined flows will be
conveyed in a 36-inch storm drain downstream to the junction with Line "S1" (Node
1227) Only one catch basin is proposed at this location to minimize the size of the
sump catch basin located further downstream (Node 1231, Line "U") on the same
side of the knuckle. The reason to minimize the catch basin length is to lessen the
chance of conflict with the existing underground utilities. The total 100-year
discharge from the 36-inch Line "s" is 70.3 cfs..
Line "u" begins atthe 14-footcatch basin at the low point (Node 1230) in the above-
mentioned knuckle. A 36-inch storm drain connects this catch basin to the 7-foot
catch basin at the low point (Node 1231) on the opposite side of the knuckle. Both
catch basins were designed to intercept the total tributary flows in Paraguay Drive
as well as the 1 OO-year bypasses from the nearby 21-foot long catch basins (Nodes
1317 & 1318) constructed with Tract 23414-3 (See Drainage Basin 1300, following).
The total 1 OO-year discharge from the 36-inch Line "u" is 42.0 cfs. The 10-year
and 100-year Rational files for both Lines "s" & "u" are 10L 12.DAT and
R1200.DA T, respectively. The 1 O-year and 1 OO-year Rational files for Line "S2" are
10S2.DAT and 100S2.DAT, respectively.
This Water Quality Mitigation Basin was designed to store a minimum volume of
1.54 acre-feet to be in conformance with the SDRWQCB criteria. The flows will
discharge in the existing 36-inch storm drain (Line "E"), which was constructed as
part of A.D 159. The inlet apron will be replaced with a manhole and the 36-inch
pipe will be extended approximately 30 feet into the basin. A 48-inch diameter
standpipe will be placed at the upstream end of this storm drain, which is identified
as Line "PKB" in the improvement plans (See Sheet 10, Tract 23143-6). The top
of the standpipe is at an elevation of 1225.9 feet, which corresponds to the1.54
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Tracts 23143-F-6-7-8-9-10
acre-feet of volume in the basin. A 4-inch orifice plate, located at the upstream end
of the standpipe, will drain this basin in approximately 28.3 hours which is in
conformance with SDRWQCB criteria (See orifice control sizing equation in
Appendix A). The above outlet structure is shown as Detail --, Sheet xx, Tract
23143-6.
The HEC-1 computer model was used to determine the peak stage, volume and
discharge in this basin. Rational computer model (file -SD12.DAT) was used to
determine the total100-year inflow (78.4 cfs) to this Water Quality Mitigation Basin.
The inflow hydrograph was determined by the triangular method with the peak 100-
year flow (78.4 cfs) and time of concentration (9.7 minutes) obtained from the
above-mentioned Rational file. The stage-volume data (measured through
AutoCad) and the stage-discharge relationship (weir and orifice spreadsheet) are
included in Appendix A. The results of the HEC-1 program indicate a maximum
storage volume, outflow and stage of 2.0 acre-feet, 54.0 cfs, and 1227.58 feet
respectively. The total flows from basins 1200 and 1300 are 87.4 cfs (54 cfs + 33.4
cfs). This value is significantly less than the existing both the interim 1 OO-year flow
(99.7 cfs) and ultimate 100-year flow (116.6 cfs) as determined in A.D. 159
(Reference 7). This discharge is also considerably less than the existing 100-year
flow of 114.71 cfs as determined in Reference 8. Hence, no adverse downstream
impacts are anticipated.
DRAINAGE BASIN 1300 (Nodes 1301 -1318):
This drainage basin comprises a portion of Tract 23143-3, which has been
constructed. The high point in Fox Road at the intersection with Maidstone Court
forms the upstream drainage boundary. The flows are directed to the existing set
of 21-foot long catch basins (one on side of the street) at Nodes 1317 and 1318 in
Fox Road. These catch basins intercept a total100-year flow of 33.6 cfs and the
bypass 16.2 cfs) to the sump catch basins (Nodes 1230 and 1231). The 10-year
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and 100-year Rational files are 10L 1300.DAT and 1300.DAT, respectively.
DRAINAGE BASIN 1400 (Nodes 1401 - 1417):
This drainage basin, comprising portions ofTract 23413-7 and existing Tract 23413-
40, drains to the existing set of catch basins in Fox Road at the intersection with Old
Kent Road (Nodes 1408 and 417). As indicated in the approved City of Temecula
Hydrology/Hydraulic Study for Tracts 23143-3 & 23143-4 (Reference 17), the
total100-year flow at the above catch basins is 38.8 cfs. Since this flow is slightly
higher than the 38.4 cfs calculated in this report, no adverse hydraulic impacts are
anticipated. The 100-year Rational file is 1400.DAT. All referenced information is
included in Appendix C.
DRAINAGE BASIN 1500 (Nodes 1501 - 1542)
This drainage basin comprises portions of Tract 23413-6, and existing Tracts
23413-2,23413-3,23413-4. The flows generated within this drainage basin are
conveyed in the existing storm drain in Crowne Hill Drive. At the intersection with
Butterfield Stage Road, this storm drain joins the 36-inch storm drain constructed
as part of Assessment District 159. The hydrologic model for this drainage basin
incorporated the Assessment District No. 159 Crowne Hill Drive & Calle Las
Mariposas Phase II and the City of Temecula Rough Grading Plans for Tract 2314-
2, -3 and -4. The 100-year flow at the downstream end of the Crowne Hill Drive
storm drain (Node 1538) is 75.7 cfs. This value is less than the 100-year of 92.6
cfs, as determined in Reference 7. The 100-year Rational file is 1500UDAT
(Nodes 1501-1523) and Line DD.DAT (Nodes 1523-1542).
The following tables summarize the 1 O-year and 1 OO-year capacities of the proposed catch
basins.
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TABLE 2-
SUMMARY
CAPACITIES OF PROPOSED CATCH BASINS
10- YEAR
\c Slope Depth Q(lnl) Q(bYPass) Catch Basin Length
Q "'
(100)
t7
CB No.lNode (cfs) l'!o) 1ft) lets) Icfs) 1ft)
1/107 10.5 Sump <0.83 10.5 0.0 7.0
2/310 16.4 1.60 0.50 5.1 11.3 7.0
3/311 16.4 1.60 0.57 5.1 11.3 7.0
TABLE 2-
SUMMARY
CAPACITIES OF PROPOSED CATCH BASINS
10-YEAR
Q(10) Slope Depth Q(inl) Q(bYPaSS) Catch Basin Length
CB NO.lNode lets) l'!o) 1ft) Icfs) Icfs) 1ft)
4/323 19.5 Sumo <0.83 19.5 0.0 14.0
5/324 14.7 Sump <0.83 14.7 0.0 14.0
4171A.D. 159) 17.3 0.92 0.56 16.4 0.9 28.0
5061A.D.159) 18.6 1.60 0.52 16.3 2.3 28.0
6/602 10.4 Sump <0.83 10.4 0.0 10.0
7/605 10.4 Sumo <0.83 10.4 0.0 10.0
8/821 8.0 0.50 0.52 4.6 3.4 7.0
9/835 16.8 0.50 0.58 14.3 2.5 21.0 -
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1 0/840 16.8 0.50 0.58 14.3 2.5 21.0
11/842 6.0 0.50 0.44 6.0 0.0 21.0
12/841 4.7 0.50 0.41 4.7 0.0 21.0
13/1218 24.9 0.52 0.48 17.0 7.9 28.0
14/1225 14.4 5.0 0.41 7.5 6.9 14.0
15/1141 8.9 Sump <0.83 8.9 0.0 10.0
16/1148 8.9 Sump <0.83 8.9 0.0 10.0
17/1227 8.2 4.9 0.35 5.7 2.5 14.0
18/1230 9.2 Sump <0.83 9.2 0.0 14.0
19/1231 6.0 Sump <0.83 6.0 0.0 7.0
1317(Tr.-3) 16.2 1.00 0.53 13.2 3.0 21.0
13181Tr.-31 16.2 1.00 0.53 13.2 3.0 21.0
20/1104 18.6 1.00 0.55 16.9 1.7 28.0
21/1116 18.6 1.00 0.55 16.9 1.7 28.0
22/1123 14.7 1.60 0.47 13.7 1.0 28.0
23/1126 5.6 1.60 0.35 5.6 0.0 28.0
24/1135 13.4 4.10 0.43 12.4 1.0 28.0
25/1136 7.4 5.00 0.34 4.2 3.2 10.0
26/1140 3.0 4.65 0.26 2.6 0.4 10.0
27/1153 2.0 Sump <0.83 2.0 0.0 7.0
28/220 20.7 5.00 0.55 17.7 3.0 28.0
29/217 9.1 8.20 0.34 9.1 0.0 28.0
30/204 7.4 Sump <0.83 7.4 0.0 7.0
31/211 7.4 Sumo <0.83 7.4 0.0 7.0
. See Figure 4.
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TABLE 3-
SUMMARY
CAPACITIES OF PROPOSED CATCH BASINS
100-YEAR
Q(1001 Slope Depth Qc;"l Q(bypass) Catch Basin Length
CB No./Node (efs) (0/0) (ft) (cfs) (efs) (ft)
1/107 15.8 Sumo <0.83 15.8 0.0 7.0
2/310 24.80 1.60 0.57 6.2 18.6 7.0
3/311 24.80 1.60 0.57 6.2 18.6 7.0
4/323 27.4 Sumo <0.83 27.4 0.0 14.0
5/324 27.4 Sumo <0.83 27.4 0.0 14.0
417(A.D. 159) 17.3 0.92 0.56 16.4 0.9 28.0
506(A.D.159) 22.9 1.60 0.56 18.7 4.2 28.0
6/602 22.4 Sumo <0.83 22.4 0.0 10.0
7/605 22.4 Sumo <0.83 22.4 0.0 10.0
8/821 10.0 0.50 0.52 5.1 4.9 7.0
9/835 26.1 0.50 0.68 19.1 7.0 21.0
1 0/840 26.1 0.50 0.68 19.1 7.0 21.0
11/842 11.5 0.50 0.53 11.2 0.3 21.0
12/841 11.5 0.50 0.53 11.2 0.3 21.0
13/1218 31.6 0.52 0.52 19.3 12.3 28.0
14/1225 27.5 5.0 0.50 10.1 17.4 14.0
15/1141 16.7 Sumo <0.83 16.7 0.0 10.0
16/1148 16.7 Sumo <0.83 16.7 0.0 10.0
17/1227 14.2 4.9 0.41 7.5 6.7 14.0
18/1230 27.2 Sumo <0.83 27.2 0.0 14.0
19/1231 14.8 Sumn <0.83 14.8 0.0 7.0
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TABLE 3'
SUMMARY
CAPACITIES OF PROPOSED CATCH BASINS
100-YEAR
Q(100) Slope Depth Q(intl Q(bypaSS) Catch Basin Length
CB No.lNode (cfs) 1%) 1ft) lefs) Icfs) (ft)
1317!Tr.-3) 24.9 1.00 0.60 16.8 8.1 21.0
1318ITr.-3) 24.9 1.00 0.60 16.8 8.1 21.0
20/1104 28.4 1.00 0.62 22.0 6.4 28.0
21/1116 28.4 1.00 0.62 22.0 6.4 28.0
22/1123 19.1 1.60 0.53 16.7 2.4 28.0
23/1126 19.1 1.60 0.53 16.7 2.4 28.0
24/1135 20.2 4.10 0.49 16.1 4.1 28.0
25/1136 13.6 5.00 0.40 5.4 8.2 10.0
26/1140 4.4 4.65 0.30 3.3 1.1 10.0
27/1153 3.2 Sumo <0.83 3.2 0.0 7.0
28/220 31.9 5.00 0.62 22.9 9.0 28.0
29/217 17.7 8.20 0.40 13.2 4.2 28.0
30/204 11.2 Sump <0.83 11.2 0.0 7.0
31/211 11.2 Sumo <0.83 11.2 0.0 7.0
Note: At all sump locations, the depth is less than the height of the sump catch basin (0.83')
, See Figure 4.
x. REVISIONS (STORM DRAIN LINES A, B C, L & M )
Since the original submittal, a portion of the site has been lowered to provide a more
equitable earth balance. The hydrology and hydraulics for the above-mentioned storm
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drain lines have been revised The hydrologic impacts are insignificant as the revised
flows have changed only a few cfs. . The revised storm drain plan/profiles for Lines A,
B, C, L, M, and associated laterals are included in this submittal. The revised Rational
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and WSPG calculations are included in Appendix D.
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XI. CONCLUSIONS AND RECOMMENDATIONS
1. Methodology used in this report is in compliance with the Riverside County Flood
Control and Water Conservation District (RCFC&WCD) criteria and the San Diego
Regional Water Quality Control Board (SDRWQCB).
2. This project is not mapped in a FEMA Special Flood Hazard Area.
3. The drainage patterns in this report are generally consistent with those presented
in the Hydrology Study - Mass Grading With Assessment District 159 For Tract
23143 Crowne Hill (Reference 1).
4. There are no anticipated negative downstream impacts.
5. Since this project exceeds 5 acres, an application for a storm water discharge
permit (NPDES) will be required. The NPDES permit application will be filed upon
approval of the this study from the City of Temecula.
XII. REFERENCES
1. San Diego Regional Water Quality Control Board (RWQCB ), National Pollutant
Discharge Elimination System (NPDES) Storm Water Permit
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2. Federal Emergency Management Agency (FEMA) , Flood Insurance Rate Maps
Panel Nos. 0602452765A, 060245 2770 B, 0602453355C, and 0602453360B.
3. Riverside Flood Control District and Water Conservation District (RCFC&WCD)
Hydrology Manual, 1978.
4. Advanced Engineering Systems Software (AES), Rational Method Hydrology
System Model Version 8.0, January 1, 2000.
5. Advanced Engineering Systems Software (AES), Hydraulic Elements Program
Package (HELE1) Version 8.0, January 1, 2000.
6. Los Angeles County Flood Control District, Water Surface Pressure Gradient
(WSPG), Version 2.4.
7. RAN PAC Engineering Corporation, Hydrology Study - Mass Grading With
Assessment District 159 For Tract 23143 Crowne Hill, January 1992, updated
January 1995 and February 1995.
8. RANPAC Engineering Corporation, Undeveloped Hydrology Study for Tract 23143
Crowne Hill, December 20, 1991.
9. RANPAC Engineering Corporation, Hydrology/Hydraulic Calculations (Ultimate
Conditions) for Butterfield Stage Road Rancho Villages Assessment District,
January 1990, Revised February 22,1990.
10. San Diego Regional Standard Drawing No. D-40.1
11. RANPAC Engineering Corporation, "AS-BUILT" plan/profile, Pauba Road, October
10,1994.
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12. RAN PAC Engineering Corporation, Assessment District No. 159 Crowne Hill Drive
& Calle Las Mariposas Phase /I plan/profile, 1989
13. Trans-Pacific Consultants, City of Temecula Developed Conditions Hydrology Study
for Tract 23143-1, June 1992.
14. RAN PAC Engineering Corporation, Assessment District No. 159 Butterfield Stage
Road Lines "H," "H-1, " "I," & "J," April 1990.
15. RANPAC Engineering Corporation, Assessment District No. 159 Royal Crest Place
Lines "H-4, " & "H-5, " March 1990.
16. RANPAC Engineering Corporation, Tract 23143-1 City of Temecula Schedule '~"
Storm Drain Improvement Plans, January 1992.
17. Trans-Pacific Consultants, City of Temecula Developed Conditions Hydrology Study
for Tract 23143-3 and 23143-4, June 14, 1995.
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