HomeMy WebLinkAboutTract Map 33584 Parcel 3-7 Prelim Drainage ReportPRELIMINARY DRAINAGE REPORT
BUTTERFIELD RANCH SHOPPING CENTER
PARCEL MAP NO. 16918
TEMECULA, CALIFORNIA
PREPARED FOR:
MARK P. ESBENSEN INC.
41625 MARGARITA ROAD SUITE #100
TEMECULA, CA 92591
PREPARED BY:
AEI
IF
AE
ENGINEERING
12396 WORLD TRADE DRIVE, SUITE 306
SAN DIEGO, CA 92128
(858) 674-2888 • FAX (858) 674-2890
S =ISv t
DECEMBER 992004
FEB 3 - 2005 J
PRELIMINARY DRAINAGE STUDY
BUTTERFIELD RANCH SHOPPING CENTER
PARCEL MAP 16918
PROJECT DESCRIPTION
The Butterfield Ranch Shopping Center is a proposed retail development located within the City
of Temecula. The 19.2 acre site is bounded by Butterfield Stage Road to the west, State
Highway 79 to the north, Tract 29031 to the east and Temecula Creek to the South. The project
proposes to develop approximately 6.5 acres of the site for commercial use. An additional 4.7
acres of commercial use is ultimately planned, but is not proposed at this particular time. The
remaining 8.0 acres will be used for slope protection or stay undeveloped as part of Temecula
Creek.
DRAINAGE AREA OVERVIEW
The entire site is currently undeveloped. Except for the portion that lies within the boundaries of
Temecula Creek, the site gradually drains westerly to Butterfield Stage Road. These flows are
directed into a double 120" storm drain system running in Butterfield Stage Road that discharges
into the creek.
The site proposes to convey surface flows within the private streets and parking facilities using
longitudinal gutter and curb and gutter. Until the future commercial area is developed, the
project will create interim desilting basins to mitigate runoff and reduce sediment infiltration into
the storm drain system. Storm drain facilities then intercept the runoff and discharge it into
Temecula creek. No offsite flows enter the project site. Prior to discharging flows to Temecula
Creek, the project proposes to filter pollutants and sediment. The type of filtration device will be
determined during the final engineering phase of this project.
All proposed improvements will be outside of the existing banks of Temecula Creek and several
feet above the flood plain's 100 -year water surface elevation. Appendix "A" of this report
contains excerpts from the approved flood plain analysis for Temecula Creek.
RESULTS AND RECOMMENDTIONS.
The following table represents the results of the preliminary drainage analysis:
Condition
Receiving Water
Tributary Area
tYield
100 -Yr Flow
Ac
CFS/Ac
Rate (CFS)
Existing
Butterfield Storm
12.1
2.2
26.6
Drain/Temecula Creek
Proposed
Temecula Creek
12.5
3.5
43.8
T Yield is an approximate factor based on available hydrological information and land
use.
During the final engineering the following is recommended:
A hydrology analyses shall be prepared to determine the offsite and onsite flow rates
generated by the project.
Prel imDrainageStudy.doc
PRELIMINARY DRAINAGE STUDY
BUTTERFIELD RANCH SHOPPING CENTER
PARCEL MAP 16918
2. The final report shall prepare street capacity hydraulic calculations, using Manning's
Equation, for the streets to determine the total depth of water within the streets and parking
facilities based upon the 10 -year and 100 -year storm events.
PrelimDrainageStudy.doc
APPENDIX "A"
�xr✓ERP'� FRP/V� �Zf..F�- Ai'PRoVEO �E-'P�'�2�
Run Date: IMAY92 Run Time: 16:52:31 HMVerSion: 6.20 Data Fife: MECUD.HEC Page 28
SECNO DEPTH CVSEL CRIWS WSELK EG HV HL GLOSS L -BANK ELEV
0 OLDS OCH OROB ALOB ACH ARDS VOL TWA R -BANK ELEV
TIME VLOB VCH VROB XNL %NCH XNR WTN ELMIN SSTA
SLOPE XLOBL XLCH XLOBR ITRIAL IDC ICONT CORAR TOPWID ENDST
-SECNO 22655.000
o 33D1 HV CHANGED MORE THAN HVINS
i3470 ENCROACHMENT STATIONS= 4650.0 5350.0 TYPE= 1 TARGET= 700.000
3495 OVERBANK AREA ASSUMED NON -EFFECTIVE, ELLER= 1108.00 ELREA= 100000.00
•1 22655.000 9.09 1108.09 .00 .00 1108.97 .88 .63 .26 1108.00
36000.0 .0 36000.0 .0 .0 4792.2 .D 1069.0 117-2 100000.00
.36 .00 7.51 .00 .000 .040 .000 .000 1099.00 4650.00
.003196 160. 160. 160. 3 0 0 .00 700.00 5350.00
CCHV= .100 CEHV= .300
'SECNO 22955.000
3301 HV CHANGED MORE THAN HVINS
3302 WARNING: CONVEYANCE CHANGE OUTSIDE OF ACCEPTABLE RANGE, KRAT10 = .67
.. i OVERSANK
AREA ASSUMED NON -EFFECTIVE,
ELLER=
1120.00
ELREA=
1116.30
1.63
5.00
00 22955.000
8.06
11 9.06 .00
.DO
1110.51
1.45
1.37
.17
:•.1120.00
36000.0
.0
36000.0 .0
.0
3730:1
.0
1098.3
122-0
`'1116.30
.37
.00
9.65 .0D
.000
.040
.000
.000
1101.OD4700.89
2
.007D47
300.
300. 300.
2
0
0
.00
684.22
5385.11
'SECNO 23705.000
P 23705.000
B.84
1113.94
.00
.00
1115.56
1.63
5.00
.05
1110.80
36000.0
252.7
33525.5
2221.8
77.6
3190.7
409.0
1162.3
133.3
1109.30
.39
3-26
1D.54
5.43
.053
.04D
.053
.000
1105.10
4778.18
.006296
700.
750.
B00.
2
0
0
.00
630.49
5408.67
'SECNO 24395.000
e
3301 HV CHANGED MORE THAN HVINS