HomeMy WebLinkAboutUtility Availability Analysis7607 Eastmark Drive, Ste. 250-F <77840>
P.O. Box 9253, College Station, TX 77842
Off/Fax: (979) 764-0704
email: civil@rmengineer.com
December 13, 2010
Josh Norton, P.E.
Assistant City Engineer
City of College Station
Planning & Development Services
1101 Texas Avenue South
College, Station, 77840
RE: Randall's University Park, Replat of Lot 311-2 - College Station, TX
Utility Availability Analysis
RME No. 220-0419
Josh Norton:
There is sufficient capacity in the existing water distribution system and sanitary sewer
collection system to support the above referenced development and the associated proposed
improvements. The existing and proposed improvements and projected demands, for both water
and sanitary sewer, are summarized below and are in accordance with the B/CS Unified Design
Guidelines Manual (UDGM):
WATER SYSTEM IMPROVEMENTS:
❖ The subject property has accessibility to existing public water for both domestic and fire
use at the following locations:
o An existing 8" PVC public water line that traverses along the south right-of-way
line of Chimney Hill Drive. This water line is located within the right-of-way of
the street;
o A flow test was obtained from one existing hydrant. Existing fire hydrant B-009,
located near the project's southwest property corner, yields a flow of 1,300 gpm,
from the 2.5" nozzle, with a residual pressure of 82 psi and a static pressure of 85
psi. The static pressure was obtain from existing fire hydrant B-062(see attached
CoCS Flow Test Report);
o Fire flow will be accommodated from the existing hydrant B-009 located at the
cul-de-sac bulb of Chimney Hill Drive. The existing 8" PVC water line will be
tapped, along with a proposed 4" PVC water line, for residential domestic
services (see attached sheet U-01 - Water Line "WI " Plan/Profile & Sanitary
Sewer Service Plan);
❖ Projected daily water demands are as follows:
o The residential development is anticipated to have an average water demand of
7.5 gpm_ This average water demand is as determined by B/CS UDGM for
average demand calculations with average daily water consumption of 1.5 gpm
per connection or dwelling unit at normal conditions. At domestic use conditions,
whether residential or commercial, a minimum 35 psi pressure rating will be
CD1-220-0419-L04.docx Pagel of3
Randall's University Park - College Station, TX
Utility Analysis Letter
tr ary s December 13, 2010
maintained and during fire flow use conditions a minimum 20 psi pressure rating
will be maintained.
o At average demand, for domestic uses, the proposed 4" domestic water service
line would experience an approximate velocity of 0.19 fps with a pressure loss of
approximately 1 psi. This pressure loss will allow the distribution system to
remain above the minimum TCEQ domestic pressure requirement of 35 psi (see
attached Domestic Hydraulic Analysis). Pressure losses reported are at worse-
case scenario with the maximum line length calculated;
o The fire flow demand, for residential developments, will require that each
residence can be protected by a minimum 1,000 gpm. At fire flow conditions the
existing 8" PVC water line would experience an approximate velocity of 6.39 fps
(see attached Fire Flow Hydraulic Analysis).
SEWER COLLECTION SYSTEM IMPROVEMENTS:
❖ The subject property has accessibility to public sanitary sewer at the following locations-
o An existing 12" PVC public sanitary sewer line, flows in a northeastern direction
along Chimney Hill Drive. This sanitary sewer line is located within the right-of-
way of Chimney Hill Drive;
❖ Projected daily sanitary sewer demands, for this development, are as follows (peaking
factor of 4.0). The sanitary sewer requirements, for the proposed development, were
derived by Method 2 - "Land Use Determination" of the UTSDS. Land use coverage
was assigned to the subdivision based on the Replat. Resulting average sanitary sewer
flow values were calculated and are summarized in Table #1 - "Sanitary Sewer Flows"
shown below. As calculated, the proposed Average Daily Flow (ADF) for this
subdivision is 1,335 gpd and a 2-Hour Peak Flow (PF) at 0.01 cfs.
TA
BLE 41 - SANITARY SEWER FLOWS
Average
Average
2-Hour
Daily Flow Dwelling
Daily Flow
Peak Flow Peak Flow
Section/Phase
(gpd/cap) Units
(gpd)
(gph) (cfs)
N/A
100 5
1,335
223 0.01
IV IAIL EXI'.UIED VLUwa= 1,335 223 0.01
Flow Determination Notes:
1) Residential density is at 2.67 capita/Dwelling Unit;
2) Commercial uses were estimated at 30 capita/acre;
3) Average Daily flows, for each use, were assigned per Table III-"Average
Wastewater Generations" per the UTSDS;
4) Peaking factor of 4.0 was applied to the Average Daily Flows to determine the
Peak Flow which is used for line sizing;
The proposed development and correlating water and sanitary sewer improvements are designed
and analyzed in accordance with the criteria outlined in the B/CS UDGM of the City of College
Station (CoCS).
CD1-220-0419-L04.docx Page 2 of 3
Csartsa~r
Randall's University Park - College Station, TX
Utility Analysis Letter
December 13, 2010
Please call should you have any questions or require assistance.
Sincerely,
~1, 0
ICE
Rabon A. Metcalf, P.E. No. 88583
Texas Firm Registration No. F-4695
rabonCrmengineer.com
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CD1-220-0419-L04.docx Page 3 of 3
College Station Utilities
Reliable, Affordable, Community Owned
Date Thursday November.18 2010
Time 13:00
Test
completed by Wyatt Jefferson
Witness Justin Tamplin
Location 607 University Dr. E
Nozzle size 2.5
Flow hydrant B-009
Pitot reading 60
G.P.M. 1300
Static hydrant 8-062
Static PSI 85
Residual PSI 82
Comments Requested Flow
RANDALL'S UNIVERSITY PARK
DOMESITC FLOW HYDRAULIC ANALYSIS
PROPOSED 4" WATER LINE
HEAD
FRICTION
STATIC
FLOW
FLOW
DIST. ID C LOSS
LOSS
VELOCITY
HEAD
TDH
(gpm)
(cfs)
(ft) (in) VALUE (ft/100)
(ft)
(fps)
(ft)
(ft)
7.5
0.02
105 4 140 0.01
0.01
0.19
2.00
2.01
1
7.5
0.02
105 4 100 0.01
0.01
0.19
2.00
2.01
1
Domestic-Fire Water-Hydraulic Analysis.xlsx
RANDALL'S UNIVERSITY PARK
FIRE FLOW HYDRAULIC ANALYSIS
EXISTING 8" WATER LINE
HEAD FRICTION STATIC
FLOW FLOW DIST. ID C LOSS LOSS VELOCITY HEAD TDH
(gpm) WS) (ft) (in) VALUE (ft/100) (ft) (fps) (ft) (ft)
1000.0 2.23 500 8 140 1.61 8.06 6.39 2.00 10.06
Domestic-Fire Water-Hydraulic Analysis.xlsx