HomeMy WebLinkAboutLD23-0519Permit Number: LD23-0519
LD - Offsite Improvements/ Street & Storm Drain Improvements
Issued: 03/25/2025
Expired: 09/22/2025
Job Address: Tract Map 36483
Legal Description:
City of Temecula - Land Development Division
41000 Main Street - Temecula, CA 92590
Mailing Address: P.O. Box 9033 Temecula, CA 92589-9033
Phone: (951) 308-6395 Fax: (951) 694-6475
Ed Lenth
17320 Redhill Ave. Ste. 350 35 Snowdrop Tree, 350
Irvine, CA 92614
Applicant:
Contractor:
Description:
Tract Map 36483 Villages at Paseo Del Sol (Elderberry) Street and Storm Drain Improvement Plans
The following separate permits will be required:
1. Encroachment permit for ALL work within the City right-of-way
2. Haul Route Permit for the import/export of material
3. Private utilities
Maximum 2:1 slopes. All grading and erosion & sediment control improvements shall be as specified on the
approved plans and per the preliminary soils report.
Page 1 of 2*****See Page 2 of this Permit for Permittee Responsibilities*****
Permit Number: LD23-0519
LD - Offsite Improvements/ Street & Storm Drain Improvements
Permittee Responsibilities
This Permittee agrees to indemnify, defend and save the City, its authorized agents, officers, representatives and employees,
harmless from and against any and all penalties, liabilities or loss resulting from claims or court action and arising out of any
accident, loss or damage to persons or property happening or occurring as a proximate result of any work undertaken under
the permit granted pursuant to this application.
Trench repair shall be pursuant to City of Temecula Standard Drawing No. 407.
3.Traffic control devices shall be utilized to protect and control pedestrian and vehicular traffic in the construction
area in accordance with the latest revision of the “Manual of Uniform Traffic Control Devices for Streets and
Highways” (MUTCD). The contractor shall submit a specific traffic control plan for review and approval by the
City in accordance with City “Traffic Control Plan Guidelines” for all work within Major Circulation Element
streets.
2.BEFORE YOU DIG - CALL (TOLL FREE) 800-422-4133
A pre-construction meeting is required two (2) business days prior to any scheduled work. Permittee
shall contact LDInspections@TemeculaCA.gov to schedule a meeting.
1.
4.
Water Quality: Contractor shall remain in compliance with the City Water Pollution Control Ordinance.
Contractor is required to provide protection of the City storm drain system.
5.
Work hours shall be limited between 7:30 AM and 4:30 PM, Monday through Friday, unless otherwise noted.
No work shall be allowed during City-recognized holidays."
6.
THIS PERMIT IS ISSUED AND ACCEPTED SUBJECT TO THE FOLLOWING CONDITIONS AND ANY ATTACHED
PROVISIONS:
All U.S.A. mark outs shall be removed prior to completion of project.7.
8.All contractors and subcontractors shall have a valid City of Temecula business license and valid Certificate of
Liability prior to start of work.
9.Should there be any claim against the City and the property owner with the encroachment being the proximate
cause, the property owner shall be notified in writing to remove the encroachment within 30 days or the City will
remove and bill the owner.
10.Permission is hereby requested to encroach into public right of way to perform work as set forth above. It is
understood that this permit is limited to the work described herein and that all work is to be done in compliance
with the provisions attached to this permit and with all other applicable rules. Permittee shall be responsible
for said compliance, for acceptability of the work, for repair or replacement thereof if defective, and for repair or
replacement of any existing improvement damaged by the doing of the work
I hereby certify and agree on behalf of the Permittee that all laws, regulations and ordinances of the City of
Temecula and the State of California and the terms and conditions of the Permit shall be complied with whether
herein stated or not.
11.
12.I hereby warrant and represent to the City that I am authorized to execute this Permit Application on behalf of
the Permittee and bind the Permittee to the agreements contained herein and any conditions of the Permit.
******Contractor and all subcontractors shall be present at the pre-construction
meeting; otherwise, the meeting will be rescheduled to a later date******
Any work commencing within the City right-of-way before permit issuance or a pre-construction meeting shall
be subject to a 72-Hour suspension of said work and an assessment of double permit fees.13.
Permitee Date
City Engineer or Authorized Representative Date
03/25/2025
Page 2 of 2
FINAL HYDROLOGY AND
HYDRAULICS STUDY FOR THE
VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA
CALIFORNIA
PREPARED FOR:
MDS CONSULTING
17320 REDHILL AVENUE, SUITE 350
IRVINE, CA 92614
(949) 251-8821
PREPARED BY:
36263 CALLE DE LOBO
MURRIETA, CA 92562
(951) 304-9552 • FAX (951) 304-3568
DATE PREPARED:
MARCH 23, 2023
DATE REVISED:
MAY 23, 2023
JULY 19, 2023
SEPTEMBER 18, 2023
JANUARY 15, 2024
JUNE 20, 2024
SEPTEMBER 20, 2024
DECEMBER 12, 2024
APPROVED BY
CITY OF TEMECULA
PUBLIC WORKS
valerie.caragan 01/06/2025
01/06/2025 01/06/2025
01/06/20
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
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This report has been prepared by or under the direction of the following registered civil
engineer who attests to the technical information contained herein. The registered civil
engineer has also judged the qualifications of any technical specialists providing
engineering data upon which recommendations, conclusions, and decisions are based.
12/12/2024
Joseph L. Castaneda RCE 59835 Date Seal
Registered Civil Engineer
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
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TABLE OF CONTENTS
I. INTRODUCTION .................................................................................................. 1
II. Project Site and Drainage Area Overview ....................................................... 1
III. Hydrology Analysis .......................................................................................... 2
IV. Hydraulic Analysis ........................................................................................... 3
V. Conclusions ..................................................................................................... 8
VI. References ...................................................................................................... 8
FIGURES
FIGURE 1: VICINITY MAP
FIGURE 2: OPEN SPACE HYDROLOGY AND HYDRAULICS MAP
APPENDICES
APPENDIX A: POST-PROJECT CONDITION ONSITE RATIONAL METHOD HYDROLOGY
ANALYSIS
APPENDIX A.1: AREA A
APPENDIX A.2: AREA B
APPENDIX A.3: AREA C
APPENDIX A.4: AREA D
APPENDIX A.5: AREA E
APPENDIX A.6: AREA F
APPENDIX A.7: AREA OPEN
APPENDIX B: HYDRAULIC STORM DRAIN ANALYSIS
APPENDIX B.1: STREET CAPACITY CALCULATIONS
APPENDIX B.2: CATCH BASIN FLOW-BY SUMMARY TABLE
APPENDIX B.3: CATCH BASIN SIZING CALCULATIONS
APPENDIX B.4: DROP INLET CALCULATIONS
APPENDIX B.5: STORM DRAIN WSPG CALCULATIONS
APPENDIX B.6: DIVERSION STRUCTURE WEIR CALCULATION
APPENDIX B.7: BASIN OUTLET STRUCTURE CALCULATION
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
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EXCERPTS
EXCERPT A: LINE S STORM DRAIN PLANS DWG NO. 7-245
EXCERPT B: PALOMA DEL SOL ALCOBA DRIVE STORM DRAIN TRACT NO. 24185 LINE
A STORM DRAIN PLANS DWG NO. 7-263
EXCERPT C: VESTING TENTATIVE TRACT NO. 24185, THE MEADOWS AT RANCHO
CALIFORNIA ROAD CORRECTION MAP PA10
EXHIBITS
EXHIBIT A: POST-PROJECT CONDITION ONSITE RATIONAL METHOD HYDROLOGY
MAP
EXHIBIT B: DRAINAGE FACILITIES MAP
EXHIBIT C: HYDROLOGIC SOILS MAP
EXHIBIT D: RAINFALL MAPS
EXHIBIT E: SLOPE OF INTENSITY DURATION CURVES
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
O:\298.01.21\Engineering\Hydrology_Plan\Reports\PA 4 Final Hydro Report.docx
1
I. INTRODUCTION
The Villages at Paseo Del Sol is a Specific Plan (Specific Plan No. 219, Amendment
No. 8) which is located in the City of Temecula. This report is specifically for
Planning Area 4A of the Specific Plan, also referred to as Tentative Tract Map
36483. Planning area 4A proposes to construct approximately 43 acres of medium-
high density residential development. The scope of this report includes:
• Determine the peak 100-year peak flow rates for post-project conditions for
onsite areas using the Riverside County Flood Control and Water
Conservation District (RCFC & WCD) Rational Method.
• Determine the required storm drain improvements to flood protect the site.
• Preparation of a hydrology and hydraulic report, which consists of
hydrological and analytical results and exhibits
II. PROJECT SITE AND DRAINAGE OVERVIEW
The Villages at Paseo Del Sol – TTM 36483 – Planning Area 4A, is a proposed
medium-high density residential development located in the City of Temecula. The
project site is roughly bounded by De Portola Road to the north, Butterfield Stage
Road to the east, Temecula Parkway to the south, and residential development to
the west.
The project site has been previously graded, and incorporates fill, earthen drainage
ditches, and minor erosion control for the fill area. Currently, the project site
discharges into the existing Line “S” Storm Drain system located within Temecula
Parkway. The Line “S” Storm Drain is an 84” – 96” MS4 Facility maintained by
Riverside County Flood Control and Water Conservation District. The Line “S”
Storm Drain discharges directly into the Temecula Creek Channel (see Line “S”
storm drain plans in Excerpt “A”). The offsite storm drain improvements have been
analyzed as part of a separate report. This report supports the calculations and
analyses for the onsite area only. The post-project onsite area will discharge into
the proposed Line “A” Storm Drain system, which connects to the existing Line “A”
Storm Drain (see Excerpt B) at De Portola Road and traverses the project site to the
south. The Line A Storm Drain runoff will flow along an earthen channel and into
the existing Line “S” Storm Drain.
The project site will construct medium-high density residential homes, a biofiltration
basin, a subsurface basin and a modular wetlands for water quality treatment. The
project site will also address hydromodifications as required by the Water Quality
Management Plan. The water quality treatment has been discussed in the Water
Quality Management Plan, and the hydromodification analyses has been included
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
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in a separate study.
The project did not require a pre-project condition analyses since the project is
draining to existing MDP facilities, and have been designed for the ultimate build out
of the tributary area. Any minor increase in flow rates will not adversely impact the
design of the MDP system. The project is not within a 100-year flood hazard.
III. HYDROLOGY ANALYSIS
The RCFC & WCD Hydrology Manual (Reference 1) was used to develop
the hydrological parameters for the rational method. The calculations were
performed using the computer program developed by Civil Cadd/Civil Design.
The existing soil types are Soils A and D, and is shown in Exhibit C. Exhibit C is
a Hydrologic Soils Map which was obtained from the United States Department of
Agriculture, Natural Resources Conservation Service (NRCS) WebSoil Survey.
The following rainfall depths (in inches) were utilized in the hydrology analyses, which were obtained from the RCFC & WCD Hydrology Manual's lsohyetal Maps:
Table 1: Rainfall Data
Storm Event 1-Hour Duration
2-Year 0.55
100-Year 1.30
The slope value used for the rational method value is 0.55. The rainfall maps
have been included Exhibit D, and the slope of intensity duration curves have
been included as Exhibit E .
The onsite watershed areas have been designated as areas A and B. Area A is
tributary to the Line A1 and A2 systems, and Area B is the area tributary to the Line
B systems. The onsite area was analyzed as condominium development, since this
project site is medium-high density residential. The average lot size ranges from
5,200 sq. ft. to 7,000 sq. ft., which is smaller than the smallest lots for single family
residential (1/4 acre residential). Therefore, the next higher impervious cover is
associated with condominiums, per the RCFC&WCD Hydrology Manual.
Area A hydrology model was broken into two separate watershed areas based on
the flows tributary to the diversion structure and Node 114 as shown on Exhibit A
Post-Project Hydrology Map and Exhibit B Drainage Facilities Map. The second
hydrology model incorporates a command defined as a user defined condition to
input the runoff that by-passes the diversion structure at Node 114. This was done
in order to hydraulically assess the diversion structure, and then provide a
representation of the flow through the diversion structure that flows directly into the
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
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Line A1 storm drain system downstream of the diversion structure. Both hydrology
models have been included in Appendix A.
The Line A flows have been summarized in Table 2 below.
Table 2: Line A Flow Rate Summary
Storm Drain System Added Flow Rate (CFS) Total Flow Rate (CFS)
Line A Upstream End 295.8 295.8
Line B – Reach 1 11.6 307.4
Lateral A 8.9 316.3
Areas C through E are the offsite street areas. Butterfield Stage Road and De Portola
Road are tributary to existing catch basins, and Temecula Parkway flows continue to
the south west to a catch basin approximately 280 feet downstream of the project
site. The existing catch basins have all been sized for the ultimate tributary flow rate.
Please note that the Open Space hydrology in Appendix A.7 utilizes user defined
nodes to account for the confluence and travel time of offsite flows as they comingle
with onsite flows prior to entering the Line E/Line S storm drain system. Since the
flows tributary to the open space area that arrive through Line A, with a total inflow
of 316.3 ft3/s , include an offsite area that is not explicitly part of this study, the onsite
area B, and part of the onsite area A , it is difficult to characterize the tributary area
for the user defined node in the hydrology program CivilD. This is because the runoff
from the part of onsite Area A that is tributary to the Later al A is not fully captured.
The user defined node, therefore, conservatively models the tributary area as 141.76
ac. This is the sum of the tributary area to the Line A system which includes 124 ac
of tributary area from offsite area to the north (Tract No. 24185, see Excerpt C), 3.91
ac from onsite area B, and 13.85 ac from onsite area A. Note that not all of the runoff
generated by the 13.85 ac of area A is captured by Line A due to the diversion
structure diverting flows past Line A.
The rational method hydrology calculations have been included in Appendix A, and
the rational method hydrology map has been included as Exhibit A.
IV. HYDRAULIC ANALYSIS
The proposed project will incorporate subsurface storm drain to convey the flows
generated from the onsite area. During final engineering, the storm drain systems
that are shown on Exhibit B were analyzed using the Water Surface Pressure
Gradient Program and downstream water surface elevations obtained from the Line
A system. The catch basins were sized using normal depth calculations, and detailed
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
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catch basin flow by analyses were calculated to determine the intercepted flows and
corresponding pipe flow rates.
Street capacity calculations were performed to assess the flooding within the streets,
and ensure that the flows meet the following street design criteria:
• 10-year storm event flows shall be contained within the top of curb elevation
• 100-year storm event flows shall be contained within the right-of-way elevation
The street design criteria controlled the location in which catch basins were required.
For locations other than low points, catch basins were provided when the above
mentioned street criteria was exceeded. Due to the street section being a 60’ width
right-of-way to right-of-way, the centerline depth is 0.55 feet above the gutter flow
line, and the top of curb is 0.50 feet above the gutter flow line, therefore the 10 -year
flows will be contained within one side of the street. Rating tables for the street
capacity calculations for various slopes have been included in Appendix B.
Once the location of the catch basins were determined, the catch basin sizing
calculations were performed, and a spreadsheet summarizing the intercepted vs. by-
pass flows was prepared. The street capacity and catch basin sizing calculations
have been included in Appendix B . Table 3 provides a summary of the catch basin
interception and bypass flow rates.
Table 3: Catch Basin Summary Table
Catch
Basin
Q
Hydrology
(CFS)
Upstream
Bypass
CB1
Q Total
(CFS)
Q Intercepted
(CFS)
Q Bypass
(CFS)
15 5.47 N/A 5.47 4.66 0.81
1 11.30 CB 15 12.11 8.112 4.00
2 3.13 CB 1 7.13 6.36 0.77
3 5.30 CB 2 6.07 5.65 0.42
4 6.26 N/A 6.26 5.77 0.49
5 5.51 CB 3, 7 6.92 6.92 0
6 3.69 CB 4 4.18 4.18 0
7 5.23 N/A 5.23 4.24 0.99
8 4.98 N/A 4.98 3.77 1.21
9 7.15 N/A 7.15 5.89 1.26
10 2.41 CB 8, 9 4.88 4.88 0
11 14.06 N/A 14.06 13.22 0.84
12 2.23 N/A 2.23 2.23 0
13 4.43 CB 16 5.12 5.12 0
14 2.31 CB 19 2.54 2.54 0
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
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16 3.14 N/A 3.14 2.45 0.69
17 0.27 CB 11 1.11 0.78 0.333
18 1.17 CB 12 1.17 0.80 0.374
19 2.15 N/A 2.15 1.92 0.23
1. The “Upstream Bypass CB” column provides the bypass flows the current catch basin receives. For example,
CB 1 receives the bypass flows from CB 15.
2. The half street capacity at Catch Basin #1 is 8.11 ft3/s, therefore an additional 4 ft3/s will overtop the centerline
to Catch Basin #2.
3-4. The bypass flows from CB 17 and CB 18 go offsite. Approved through discussions with City.
A more in depth catch basin flow by summary table has been provided in Appendix
B.
The downstream water surface elevation within bioretention basin A was obtained
from a weir equation that utilized a 16 foot weir with a flow line elevation of 1103.00
(which was obtained from the storm drain improvement plans). The Technical
Memorandum: SWMM Modeling for Hydromodification Compliance of: Villas at
Paseo del Sol, Temecula, CA, prepared by REC Consultants, has be en included as
an attachment to the Water Quality Management Plan. The SWMM modelled a basin
that had a bottom elevation of 1101 and a weir of 1104. The final design implemented
the same design and storage volume, with the exception that the basin bottom
elevation is 1100. This revision occurred during the final engineering process as part
of finalizing the grading of the project site. This required the basin outlet structure to
lower the weir to elevation 1103 to ensure compliance with the SWMM Model. Please
note Table 4 provides the design summary between the SWMM Model and the final
engineering design.
Table A – Design Parameter Comparison
Comparison Location SWMM Model Final Engineering
Basin Bottom Area 21,534 ft2 21,778 ft2
Basin Bottom Elevation 1101 ft 1100 ft
Outlet Weir Elevation 1104 ft 1103 ft
Basin Side Slopes 3:1 3:1
Available Depth 5 ft 5 ft
Based on the final engineering design, the water quality basins is consistent with the
SWMM model.
The 100 year flow rate into the basin is 67.1 ft3/s which results in a maximum 100-
year water surface elevation over the 16 foot long weir of 1104.25.
Due to the elevations of the storm drain and the design constraints, Line A1 had to
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
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incorporate a reinforced concrete box system for Line A1. This was due to cover
issues and crossing the main Line A system that convey the offsite flows through the
project. The flow rates within the systems were based upon the hydrology flow rates
for the mainlines (systems with more than one reach) and the intercepted flow rates
for the laterals (one reach systems).
The elevations of the site and the requirement for the crossing of Line A resulted in
the design of a diversion structure that would allow for flow rate less than the 10 year
to flow to the biofiltration basin, and for flows in excess to pass to Lateral A and
discharge directly into the Line A system. To determine that the 10 year flow rate,
which is equal to 21.2 ft3/s at Node 114, would flow into the system an iterative
calculation process was used with the WSPG program. The analysis used the 100
year flow rate. The iteration process was performed by balancing the flow rate with
the weir elevation to ensure that 21.2 ft3/s would flow through Line A1. Based on the
100 year hydraulic analyses, it was determined that a flow rate of 23 ft 3/s would flow
through Line A1 if the baffle wall inside the diversion structure was place at elevation
1104.70, see Figure below.
Figure A – Diversion Structure
The design in Figure A ensures that the 10 year flow rate of 21.6 ft 3/s always flows to
the basin in order to meet the hydromodification criteria. The total flow rate at the
diversion structure (Node 114) which excludes the flows by-passing catch basins #3
and #4 is 31.93 ft3/s. The top of weir elevation was designed to be equivalent to the
WSE for the flow rate of 23.0 ft3/s. This allows flows exceeding 23.0 ft3/s to overtop
the weir. This total flow rate overtopping the weir would be 8.93 ft3/s (31.93 ft3/s minus
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
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23.00 ft3/s). Using an 8 foot weir length, the resulting ponded depth o ver the weir is
0.52 feet. The weir invert elevation is 1104.70, resulting in a water surface elevation
of 1105.22. As previously stated, the 23.00 ft3/s was added to the flow rates within
the pipe downstream of the diversion structure directly.
The Lateral A bypass storm drain was designed to convey 8.93 ft3/s into Line A. The
Line A water surface elevation at downstream end of Lateral A is 1098.15. This will
not impact the operation of the diversion weir since the water surface elevation is well
below the weir elevation of 1104.70. Therefore, the diversion structure will function
in the 100-year condition. The downstream water surface ele vation for the Line B
system was also obtained from the Line A improvement plans . The water surface
elevation at the Line B junction is 1102.91.
In addition to assessing the onsite storm drain, the proposed Line A storm drain was
analyzed to determine the hydraulic impacts to the system upstream of DePortola
Road. The downstream control for Line A was determined by hydraulically modeling
the open space channel between the Line S headwall and the Line A outlet. The open
space was modeled as a trapezoidal channel with 2.5:1 side slopes. Figure 2
provides the cross sections used for the hydraulic model along with the hydrology
which yielded a total flow rate of 329.3 CFS through the channel. The open channel
flow enters Line S and confluences with Line C for a total of 382.7 CFS. This flow rate
is less than the design flow rate of 395.8 CFS per Dwg No. 7-245. The Line S water
surface elevation of 1099.37 was utilized as the downstream control for the hydraulic
model. The downstream control of 1099.37 in the open space model was computed
by modeling the water surface elevation in Line S. This WSPG model is called Line
E since the alignment Line S is referred to as both Line E and Line S in various storm
drain plans. Note that the alignment is called Line S in the RCFC&WCD Storm Drain
plans. The model of Line S/Line E resulted in the downstream control for the open
space area of 1099.37 (see WSPG output). This model is based on the known
flowrate and geometry of Line S/Line E. The downstream control in the Line E WSPG
is derived from the documented Water Surface Elevation in the RCFC&WCD storm
drain plans. Sheet 4 of the RCFC&WCD plans (Excerpt A; DWG 7 -245) show a
downstream WSE of 1095.42 at Station 40+74.37. The WSPG model relabels Station
40+74.32 as 10+00.00. This point was picked as the downstream control since this
is the station at which the proposed Storm Drain improvement plans begin for Line
S/Line E. As a result, the model calculated a water surface elevation of 1099.406 for
the open channel which was then used as the downstream co ntrol for the Line A
hydraulic model.
The Line A hydraulic model was extended beyond Station 19+43.60 shown on the
plans to assess impacts to the existing storm drain system. Based on the final
engineering plans Station 19+43.60 is equal to Station 25+00 .00 and Station
FINAL HYDROLOGY AND HYDRAULICS STUDY
FOR THE VILLAGES AT PASEO DEL SOL
TTM 36483 – PLANNING AREA 4
CITY OF TEMECULA, CALIFORNIA
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19+58.22 is equal to Station 25+14.16 as shown on the Line A Plans per Dwg No. 7 -
263, included as Excerpt B. An EQ card was used for the hydraulic model at Station
19+43.60 so that the WSPG stationing matched the Line A as -built plans per Dwg
No. 7-263. The hydraulic model resulted in a water surface elevation of 1102.05 at
Station 25+14.16 which is equivalent to 1102.05 water surface elevation of the Line
A as-built plans at the same location.
The street capacity calculations, catch basin sizing calculations, catch basin flow-by
summary table, and storm drain sizing calculations have been included in Appendix
B. The Drainage Facilities Map has been included as Exhibit B.
V. CONCLUSIONS
The hydrology and hydraulic analyses performed for the Villages at Paseo Del Sol –
TTM 36483 – Planning Area 4A provide results that demonstrate that the storm drain
will provide the required flood protection for the site and meet the street flooding
criteria. The following can be concluded:
1. The proposed Line A Storm Drain will convey the offsite flows through the
project site without impacting the existing storm drain. The results indicate
that the pre-project and post-project have the same water surface elevation of
1102.05 at Station 25+14.16.
2. The Line A1 system and the Diversion Structure can convey the 10 year flow
through the downstream system to ensure project is meeting the
hydromodification criteria.
3. The proposed water quality basin will treat runoff emanating from the project
site. Additionally, a 16 feet weir has been placed in the basin to ensure that
project is consistent with the SWMM Model.
4. The proposed storm drain systems will adequately convey the proposed 100 -
year flow rates.
VI. REFERENCES
1. Riverside County Flood Control and Water Conservation District Hydrology
Manual, April 1978.
2. Los Angeles County Flood Control Design Manual, March 1982
FIGURES
FIGURE 1: VICINITY MAP
41660 IVY STREET, SUITE A
MURRIETA, CA 92562
PH. 951.304.9552 FAX 951.304.3568
Engineering & Consulting, Inc.
FIGURE 2: Open Space Hydrology and Hydraulics Map
OPEN SPACE/DRAINAGE CHANNEL
W.Q. BASIN
OPEN SPACE/DRAINAGE CHANNEL
19
20
21
22
23242526
27
28
29
65
57
55
54
53 52
51
30
31
32
33 34 35 36
38
39
40
41
42434445
46
47
48
49
50
838488899091
99 121
92
122
82
6968
67
168
167
164
15
3
152
151
150
148
147
146
145
149
166
858687
56
189
179
37
169
939495969798
175
182
TR
A
C
T
N
O
.
2
4
1
8
2
-
2
165 66
NOT A PART
OPEN SPACE/DRAINAGE CHANNEL
W.Q. BASIN
OPEN SPACE/DRAINAGE CHANNEL
19
20
21
22
23242526
27
28
29
65
57
55
54
53 52
51
30
31
32
33 34 35 36
38
39
40
41
42434445
46
47
48
49
50
838488899091
99 121
92
122
82
6968
67
168
167
164
15
3
152
151
150
148
147
146
145
149
166
858687
56
189
179
37
169
939495969798
175
182
TR
A
C
T
N
O
.
2
4
1
8
2
-
2
165 66
NOT A PART
41660 IVY STREET, SUITE A
MURRIETA, CA 92562
PH. 951.304.9552 FAX 951.304.3568
Engineering & Consulting, Inc.
APPENDICES
APPENDIX A: POST-PROJECT CONDITION ONSITE RATIONAL METHOD
HYDROLOGY ANALYSIS
APPENDIX A.1: AREA A
100-YEAR
1
Riverside County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software,(c) 1989 - 2001 Version 6.4
Rational Hydrology Study Date: 03/02/22 File:ARA1100.out
------------------------------------------------------------------------
298.01.21
100-YEAR RATIONAL TABLING METHOD
POST PROJECT CONDITION FOR AREA A1
ARA1100.RRV
------------------------------------------------------------------------
********* Hydrology Study Control Information **********
English (in-lb) Units used in input data file
------------------------------------------------------------------------
TRI-8 Builders - S/N 615
------------------------------------------------------------------------
Rational Method Hydrology Program based on
Riverside County Flood Control & Water Conservation District
1978 hydrology manual
Storm event (year) = 100.00 Antecedent Moisture Condition = 2
2 year, 1 hour precipitation = 0.550(In.)
100 year, 1 hour precipitation = 1.300(In.)
Storm event year = 100.0
Calculated rainfall intensity data:
1 hour intensity = 1.300(In/Hr)
Slope of intensity duration curve = 0.5500
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 101.000 to Point/Station 102.000
**** INITIAL AREA EVALUATION ****
______________________________________________________________________
Initial area flow distance = 728.000(Ft.)
Top (of initial area) elevation = 1121.700(Ft.)
Bottom (of initial area) elevation = 1114.100(Ft.)
Difference in elevation = 7.600(Ft.)
Slope = 0.01044 s(percent)= 1.04
TC = k(0.370)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 12.862 min.
Rainfall intensity = 3.033(In/Hr) for a 100.0 year storm
CONDOMINIUM subarea type
Runoff Coefficient = 0.860
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 2) = 75.00
Pervious area fraction = 0.350; Impervious fraction = 0.650
Initial subarea runoff = 5.345(CFS)
Total initial stream area = 2.050(Ac.)
Pervious area fraction = 0.350
2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 102.000 to Point/Station 103.000
**** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION ****
______________________________________________________________________
Top of street segment elevation = 1114.100(Ft.)
End of street segment elevation = 1109.100(Ft.)
Length of street segment = 413.000(Ft.)
Height of curb above gutter flowline = 6.0(In.)
Width of half street (curb to crown) = 22.000(Ft.)
Distance from crown to crossfall grade break = 18.000(Ft.)
Slope from gutter to grade break (v/hz) = 0.083
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 10.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 2.000(In.)
Manning's N in gutter = 0.0150
Manning's N from gutter to grade break = 0.0150
Manning's N from grade break to crown = 0.0150
Estimated mean flow rate at midpoint of street = 8.604(CFS)
Depth of flow = 0.548(Ft.), Average velocity = 3.146(Ft/s)
Warning: depth of flow exceeds top of curb
Distance that curb overflow reaches into property = 2.38(Ft.)
Streetflow hydraulics at midpoint of street travel:
Halfstreet flow width = 14.743(Ft.)
Flow velocity = 3.15(Ft/s)
Travel time = 2.19 min. TC = 15.05 min.
Adding area flow to street
CONDOMINIUM subarea type
Runoff Coefficient = 0.857
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 2) = 75.00
Pervious area fraction = 0.350; Impervious fraction = 0.650
Rainfall intensity = 2.782(In/Hr) for a 100.0 year storm
Subarea runoff = 5.957(CFS) for 2.500(Ac.)
Total runoff = 11.301(CFS) Total area = 4.550(Ac.)
Street flow at end of street = 11.301(CFS)
Half street flow at end of street = 11.301(CFS)
Depth of flow = 0.587(Ft.), Average velocity = 3.235(Ft/s)
Warning: depth of flow exceeds top of curb
Distance that curb overflow reaches into property = 4.36(Ft.)
Flow width (from curb towards crown)= 16.729(Ft.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 103.000 to Point/Station 106.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
______________________________________________________________________
Upstream point/station elevation = 1104.000(Ft.)
Downstream point/station elevation = 1103.200(Ft.)
Pipe length = 31.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 11.301(CFS)
Nearest computed pipe diameter = 18.00(In.)
3
Calculated individual pipe flow = 11.301(CFS)
Normal flow depth in pipe = 10.78(In.)
Flow top width inside pipe = 17.64(In.)
Critical Depth = 15.40(In.)
Pipe flow velocity = 10.23(Ft/s)
Travel time through pipe = 0.05 min.
Time of concentration (TC) = 15.10 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 103.000 to Point/Station 106.000
**** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area = 4.550(Ac.)
Runoff from this stream = 11.301(CFS)
Time of concentration = 15.10 min.
Rainfall intensity = 2.776(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 104.000 to Point/Station 105.000
**** INITIAL AREA EVALUATION ****
______________________________________________________________________
Initial area flow distance = 774.000(Ft.)
Top (of initial area) elevation = 1119.300(Ft.)
Bottom (of initial area) elevation = 1009.600(Ft.)
Difference in elevation = 109.700(Ft.)
Slope = 0.14173 s(percent)= 14.17
TC = k(0.370)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 7.824 min.
Rainfall intensity = 3.986(In/Hr) for a 100.0 year storm
CONDOMINIUM subarea type
Runoff Coefficient = 0.868
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 2) = 75.00
Pervious area fraction = 0.350; Impervious fraction = 0.650
Initial subarea runoff = 5.469(CFS)
Total initial stream area = 1.580(Ac.)
Pervious area fraction = 0.350
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 105.000 to Point/Station 106.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
______________________________________________________________________
Upstream point/station elevation = 1103.700(Ft.)
Downstream point/station elevation = 1103.200(Ft.)
Pipe length = 134.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 5.469(CFS)
Nearest computed pipe diameter = 18.00(In.)
Calculated individual pipe flow = 5.469(CFS)
Normal flow depth in pipe = 12.77(In.)
Flow top width inside pipe = 16.34(In.)