HomeMy WebLinkAboutCUP 2017-0002; LA COSTA TOWN SQUARE BUILDING 5; PRIVATE WATER SYSTEM ANALYSIS; 2013-11-14•
LA COSTA TOWN SQUARE
COMMERCIAL CENTER
PRIVATE WATER SYSTEM ANALYSIS
November 14, 2013
Prepared by:
Dexter Wilson Engineering, Inc.
2234 Faraday Avenue
Carlsbad, CA 92008
(760) 438-4422
Job No. 534-016
RECEIVE
APR O 5 2017
CITY Of-c:" ',L:,;, l
LANNING DiV1cc
DEXTER WILSON ENGINEERING, INC . . ,;;;,;;;;;,,;:,;.;;:;,;,,,,,;,;;;:;;:.,:..;,,;;;;,,;,;.,;;,;;;;;;;;,;,;;,;;;;;,;,,,;;,,;,;;,;,===========
November 14, 2013
O'Day Consultants
2710 Loker Avenue West, Suite 100
Carlsbad, CA 92010
Attention: Tim Carroll, Project Engineer
Subject: La Costa Town Square Commercial Center
DEXTER S. WILSON, P.E.
ANDREW M. OVEN, P.E.
STEPHEN M. NIELSEN, P.E.
DIANE H. SHAUGHNESSY, P.E.
NATALIE J. FRASCHETTI, P.E.
534-016
This letter-report provides a water system analysis for the commercial center portion of the La
Costa Town Square project. The project water system will serve 22 commercial buildings and
will be supplied by the Olivenhain Municipal Water District. The project is located at the
intersection of La Costa Avenue and Rancho Santa Fe Road. There are existing 12-inch and
18-inch 582 Zone water lines in La Costa Avenue and Rancho Santa Fe Road, respectively that
will provide a water supply to the project.
Background
A water system analysis was prepared for the La Costa Town Square project in January 2009 by
AECOM on behalf of the District, This analysis provided recommendations for the commercial
center, residential area, and future "office" area of the project. At the time of the study, it was
envisioned that the District would serve the project by installing public lines through the
commercial center with looped connections in La Costa Avenue and Rancho Santa Fe Road.
Due to some operational changes that occurred in the District since the time of the January
2009 study, the District requested a re-evaluation of how to supply water to the project.
2234 FARADAY AVENUE • CARLSBAD, CA 92008 • {760) 438·4422 • FAX (760) 438-0173
Tim Carroll
November 14, 2013
A revised approach to serving the commercial center portion of the project was presented to the
District in March 2012 and was approved in concept. This revised approach includes making
the onsite water system private with separate domestic and fire protection pipelines. The
purpose of this current study is to provide the recommended sizing and layout of the private
water system that will serve the commercial center portion of the project.
Domestic Water Demands
The two demands used to design the system are domestic demands from the buildings and fire
flow demands. Although the plumbing plans for the buildings have not yet been prepared,
Table I summarizes the maximum projected fixture units for each building based on
information provided by the building mechanical engineer. Using this information and Chart A
2 from the California Plumbing Code, the total projected fixture unit count of approximately
2,440 at each connection was determined to have an estimated peak water demand of 370 gprn
through each connection. In addition to these demands, there are two proposed water features
on the project that could each have a peak demand of up to 30 gpm for make-up water.
Table 2 summarizes the maximum number of Water Fixture Units that can be served by a given
pipe diameter based on a maximum pipeline velocity of 8.0 feet per second. This table was used
to size the piping within the project by determining the total number of fixture units that any
line will serve.
DEXTER WILSON ENGINEERING. INC. PAGE 2
Tim Carroll
November 14, 2013
TABLE 1
LA COSTA TOWN SQUARE -COMMERCIAL CENTER
MAXIMUM WATER FIXTURE UNIT SUMMARY
Building Type Mas.imum Water Proposed Building
Fixture Units Service Size
1 Restaurant 270 2 ½"
2 Restaurant 270 2 ½"
3 Financial 128 2 ½"
4 Financial 128 2"
5 Pharmacy 128 2"
6 Retail Shops 270 2 )".)"
7 Retail Shops 270 2 ½"
8 Retail Shops 270 2 ½"
9 Retail Shops 270 2 ½"
10 Financial 128 2"
11 Financial 128 2"
12 Gas Station 270 2 ½"
13 Retail Shops 270 2 ½"
14 Grocery 220 3"
15 Major Retail 128 2"
16 Retail Shops 270 2 ½"
17 Retail Shops 270 2 ½"
18 Major Retail 128 2"
19 Open Space ... . ..
20 Major Retail 128 2"
21 Retail Shop 128 2"
22 Restaurant 270 2 ½"
:cm Retail Shops 270 2 ½"
24 Common Space -·· ...
25 Fitness Facility 270 3"
TOTAL 4,882
TOTAL PER 2,441
DEXTER WILSON ENGINEERING, INC. PAGE 3
Tim Carroll
November 14, 2013
TABLE2
SIZE OF PRIVATE DOMESTIC SYSTEM PIPING
BASED ON NUMBER OF
WATER FIXTURE UNITS SERVED
Number of Fixture Units Minimum System Pipe
Slze1
0 -14 3/4-inch
15 -29 1-inch
30 -53 l¼-inch
54 -105 1½-inch
106 -270 2-inch
271 -500 2½-inch
501 -780 3-inch
781 -1,920 4-inch
1,921 -3,575 -inch
3,576-6,175 6-inch
1Based on a maximum pipe flow velocity of 8 fps.
Required Fire Flow
Information on the required fire flow for the project has not changed since the January 2009
Water System Analysis was prepared. Based on this analysis, the required fire flow for the
commercial center portion of the project is 4,000 gpm.
Proposed Domestic Water System
Figure 1 shows the recommended water facilities for the project. To provide domestic service to
the project, we recommend two 6-iuch connections to the existing system with 4-inch master
meters and back.flow preventers at each connection. A 4-inch master meter has a rated capacity
of at least 600 gpm, whereas the estimated peak domestic demand for the project is
approximately 400 gpm at each connection, including water fountain make-up water. Appendix
A provides the Uniform Plumbing Code tables that were used to estimate peak project demand.
DEXTER WILSON ENGINEERING, INC. PAGE 4
Tim Carroll
November 14, 2013
Private onsite domestic service piping is recommended as 3-inch through 6-inch backbone lines
as shown on Figure 1, with building services as indicated in Table L
The available maximum static water pressures to this site based on pad elevations ranging from
315 feet to 350 feet will range from 100 psi to 116 psi. Even with losses through the proposed
master meters and backflow preventers, this system will provide adequate domestic service
pressures to the project.
Private Fire Protection System
The private fire protection system was sized based on the required fire flow for the project and
taking into consideration the proposed piping configuration. The only significant change to the
proposed fire system piping from the January 2009 study is that it will now be private. This
will require backflow preventers at the connections to the existing system, but the available
pressure to the site is adequate even with the projected losses through these devices. Figure 1
shows the proposed fire system for the project. Appendix B provides the hydraulic analysis
results for the proposed private fire system.
If you have any questions or require additional information, please let us know.
Dexter Wilson Engineering, Inc.
~ M. ~
Stephen M. Nielsen
~~~
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EXP. 9130115
SMN:pjs
Attachments
DEXTER WILSON ENGINEERING, INC. PAGE 5
◄
5
LEGEND
EXISTING 854 ZONE
EXISTING 672 ZONE
EXISTING 582 ZONE
PRIVATE FIRE LINE (582)
PRIVATE DOMESTIC LINE (582)
EXISTING PR STATION
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BUILDING NUMBER
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\----NOTE: PRIVATE FIRE LINES ARE / /
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COSTA TOWN
UARE BOUN
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UNLESS• OTHERWISE NOTED. /
\ 1 o• CONNECTION TO
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14 15 "'"·
1 o• CONNECTION TO ----~
EXISTING WATER LINE FUTURE ·omcE" AREA
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\\PAOFlC\DWG\534016\flGURE 1.DWG 04-05-12 08:08:32 LAYOUT: LAYOUT
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SCALE: 1" • 300'
FIGURE 1
WAlER SYSTEM
LA COSTA TOWN SQUARE
APPENDIX A
CALIFORNIA PLUMBING CODE DATA
RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYSTEM
500
400 l
300
=rl-
-
200 I·
·+ -1
100
. +; I 1 . ~ t f ,~ I
0
CHARTA·2
ESTIMATE CURVES FOR DEMAND LOAD
m
-t-.
. --~
---
-
1 l .
-• ~· . -~-. ; -• -
. .. . -. . ~-. . --..
-.. -~"' ~ -. .. ,,.. -·r ~.:..t .. I J,1"~1 -t . i -i !r··
"' .. whH I + d ~ LL i{ t l. I ll
~,.~ No. I for syst..:m predominantly for tluslwmcu.a valves •
2
• N~. 2~for ?stem pr~or immlly '~l1¥.ll~1'111 '.""kts -'~ :
~ 1 I . r~ •
3000 500 1000 1500
FIXTURE UNITS
CHART A·2 {Metric)
2000
ESTIMATE CURVES FOR DEMAND LOAD
2500
31.5 _]....,.........,._...,..,......,.: _ _..... .... ___ .............. _ ............... J .................... i .................. -.........................
I I . .. -~ -~
i 25 •• i-;.....4-44~-14+.l,-l.-l-_ +~14--..... _.µ....i.-1-1-!_ -l-4-i_l-!,· . .;.l l-l r_M"--l-4-!-+-!!-14-1-!:~ ..--µ.~4--1-4-1--~"-l-~14l~-6lo!c.-+-i-1-1--1
0 -.. • If -"~" --i 18.9 ~-l-l-!-l-l-i-44+!!-14-4+-l-4-,14_ -14-44+...;,.-1,~~~~"+-~---~4"-l,+,l-...4-,;~!-l,~l-l~-!-l--!-+4--1-'1.
1 · · · ---~ <~~ rt
o --,l -I ~ 12.6 1-1+1-+H_ ~~--1~+ l ~tM=~-r ~+~t ~ ··t~·~r r-flr -+fw ·_ -IT -1 t ,-t No. I l"or system prcdo m111ontly for llu~hcnn.:tcr valves ,l 2 N•:r"rr1r~,-·rr r .. ,1 f1 l t
6.3
2000 2500 3000
0 500
2010 CALIFORNIA PLUMBING CODE
1000 1500
FIXTURE UNITS
321
APPENDIXB
PRIVATE FIRE PROTECTION SYSTEM ANALYSIS
la Costa Town Square Private Fire System Analysis 04-04-12
FLOWRATE IS EXPRESSED IN GPM AND PRESSURE IN PSIG
A SUMMARY OF THE ORIGINAL DATA FOLLOWS
PIPE: NO. NODE NOS. LENGTH DIAMETER ROUGHNESS MINOR LOSS K FIXED GRADE
(FEET) (INCHES)
1 0 2 200.0 10.0 130.0 28.00 570.00
3 2 4 460.0 8.0 130.0 .00
5 4 6 370.0 8.0 130.0 .00
7 6 8 200.0 8.0 130. 0 .oo
9 0 8 300.0 10.0 130.0 28.00 570. 00
11 8 10 270.0 8.0 130.0 .00
13 10 12 640.0 8.0 130.0 .00
15 12 14 420.0 8.0 130.0 .00
17 14 16 250.0 8.0 130.0 .00
19 16 20 550.0 8.0 130.0 .00
21 2 18 600.0 8.0 130.0 .oo
23 18 20 525,0 8.0 130.0 .oo
25 20 22 250. 0 8.0 130.0 .00
27 6 16 920.0 8.0 130.0 .00
JUNCTION NUMBE:R DEMAND ELEVATION CONNECTING PIPES
2 .00 321.00 1 3 21
4 .00 319.00 3 5
6 .00 323.00 5 7 27
8 . 00 305.00 7 9 11
10 .00 308.00 11 13
12 .00 335.00 13 15
14 .00 337.00 15 17
16 .oo 340.00 17 19 27
18 .00 337.00 21 23
20 2000.00 346.00 19 23 25
22 2000.00 364.00 25
OUTPUT SELECTION: ALL RESULTS ARE OUTPUT EACH PERIOD
THIS SYSTEM HAS 14 PIPES WITH 11 JUNCTIONS , 2 LOOPS AND 2 FGNS
THE RESULTS ARE:. OBTAINED AFTER 3 TRIALS WITH AN ACCURACY= .00049
La Costa Town Square Private Fire System Analysls 04-04-12
LA COSTA TOWN SQUARE PRIVATE FIRE SYSTEM 534016A
4000 GPM FIRE FLOW SPLIT :BETWEEN NODES 20 AND 22
PIPE NO. NODE NOS. FLOWRA'l'E HEAD LOSS PUMP HEAD MINOR LOSS VELOCITY HL/1000
1 0 2 2071.19 4.75 .00 31.12 8.46
3 2 4 210. 25 • " .OD .00 1. 34
5 4 6 210.25 .38 .00 .00 1. 34
7 6 8 -974.29 -3.48 .00 .00 -6.22
9 0 8 1928. 81 6.24 .oo 26.99 7.88
11 8 10 954.52 4. 53 .oo .00 6.09
13 10 12 954.52 10.73 .00 .00 6.09
15 12 14 954.57. 7.04 .00 .00 6.09
17 14 16 954.52 4. 19 .DO .DO 6.09
l 9 16 20 2139. 06 41. 08 .00 .00 13. 65
21 2 18 1860.94 34.63 .00 .DO 11.88
23 18 20 1860.94 30.30 .00 .OD 11.88
25 20 22 2000.00 16. 49 .00 .DO 12.76
27 6 16 1184.54 23.00 .DO .00 7.56
JUNCTION NUMBER DE:t-1.AND GRADE LINE ELEVATION PRESSURE
2 .00 534.14 321.00 92 .36
4 .OD 533.67 319.00 93.02
6 .DO 533.29 323.00 91.13
8 .00 536.77 305.00 100,44
10 .oo 532.25 308.00 9'/. 1 7
12 .OD 521.52 335.00 80.83
14 .OD 514.48 337.00 76.91
16 .00 510.29 340.00 73.79
18 .OU 499.51 337.00 70.-42
20 2000.00 469.22 346.00 53.39
?. ?. 2000.00 452. 7 3 364.00 38.45
THE NET SYSTEM DEMAND 4000.00
SUMMARY OF INFLOWS{+) AND OUTFLOWS (-) FROM FIX.ED GRADE NO::JES
PIPE NUMBER FLOWRATE
1 2071.19
9 1928.81
THE NET FLOW INTO THE SYSTEM FROM FIXED GRADE NODES=
THE NET FLOW OUT OF THE SYSTEM INTO FIXF,D GRADE NODES
4000.00
.OD
23.73
1.02
1.02
-17.41
20.80
16.76
16.76
16.76
16.76
74. 69
57.71
57. 71
65.95
25.00
-LEGEND
m
EXISTING WATER LINE
PROPOSED WATER LINE
FIRE HYDRANT
COMPUTER MODEL
PIPE NUMBER
/
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~ COMPUTER MODEL .._'o / .,,,.
\-::,_./ NOOE NUMBER / I .,,,.
\ /
\ 10• CONNECTION TO / ~ ,;
\ \ EXISTING WATER LINE /;/"> /
\ ..../ 0
'\ /
' Q
/~,
/ '~ / X >' -x .?•~
10• CONNECTION TO
EXISTING WATER LINE
✓
NOTE: PRIVATE FIRE LINES ARE RECOMMENDED
AS 8-INCH UNLESS OTHERWISE NOTED.
\\PAClflC\DWG\5J4016\EXHIBIT A.DWG 04-05-12 11:27:01 LAYOUT: LAYOUT
/
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LA COSTA TOWN SQUARE
BOUNDARY
RANCJJO jf!'TA PE,,..!!.OAJ?-----
~
PROPOSED Io• BACKFlOW PREVENTER,
TYP. OF 2
[ill
----,,,.
,,,,,.
FUTURE RESIDENTIAL
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--~
SCALE: 1" = 200'
EXH IBIT A
PRIVATE FIRE SYSTEM
NODE AND PIPE DIAGRAM