WA0003-AG040727AGENDA REQUEST FORM
DATE: July 27, 2004
ITEM #: WS-3
WORK SESSION
B.
C.
D.
E.
F.
G.
2004 Water Master Plan Update Presentation.
l~liscussion regarding A*nerican Red Cross Representative.
Di~sion rega}~('~olice Patrols during summer season at Andy Brown East and Aquatic Center.
Discuss~'~e.~a~ng 20.05 Legislative Session and potential Special Session
Discussi~ding red-light cameras
Cou~hff'Ooals fo~ 2004.
.Diffcussion of Agenda Items.
Agenda Request Fonn- Revised 02/04 Document Name: %worksession
MEMORANDUM
FROM THE
DEPARTMENT OF ENGINEERING
To;
From:
Date:
RE:
Mayor and City Council
Kenneth M. Griffin, P.E., Director of Engineering/Public Works
July 27, 200~
2004 Water Master Plan update presentation /~c)
Work Session
For some time now the City has been working with the firm of Birkhoff, Hendricks and Conway,
LLP on an update to the city's water master plan. The current water plan is dated t994. Since
that time there has been substantial growth in the city and numerous modifications made to the
city's water infrastructure.
Based on the 1994 Water Master Plan, an additional elevated storage tank and ground storage
tank were constructed, additional pumping capabilities were installed at the city's Village
Parkway Pump Station and various water lines throughout the city were constructed and/or
upsized. Most notably a 30" and 24" water line was constructed from the Village Parkway Pump
Station down Sandy Lake Road to the new 2 million gallon elevated storage tank on the west side
of Coppell. All of these improvements, identified in the 1994 Master Plan, have significantly
increased the city's ability to provide water to the citizens of Coppell.
In reviewing the preliminary draft of the revised master plan by Birkhoff, Hendricks and
Conway, LLP, it is encouraging to note that very few recommendations are made to the city's
master plan.
The most notable recommendation is the need to begin negotiations to secure approximately 9
million gallons/per day for future usage. We currently purchase 17 million gallons/per day from
the City of Dallas and contractually we have the right to purchase 20 million gallons/per day
from the City of Dallas. The updated water master plan identified a maximum day demand of 29
million gallons; hence the need to secure an additional 9 million gallons. In the 1994 Master
Plan, the maximum day system demand was calculated at 30 million gallons.
As a general comparison between the two studies, Table 7 in the report compares the main points
of the 1994 Master Plan with the 2004 Master Plan.
With the recommendation in the 2004 Water Master Plan to secure an additional 9 million
gallons/per day, there is also the need to construct a pump station. Our current pump station is at
maximum design, so there is not an opportunity to enlarge it to receive the additional water.
Several years ago the City of Coppell traded a parcel of land with the developer of the St.
Joseph's Retirement Village to obtain a site for a future Starleaf Pump Station. The
"CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN"
recommendation in the 2004 Master Plan study is that the Starleaf Pump Station be designed in
such a way that it can delivery 14 million gallons/per day and have ground storage of 4 million
gallons.
The current master plan shows that we would receive water for the Starleaf Pump Station off of
our existing 60" water line from the City of Dallas. One item that I will be pursuing in the future
is the opportunity to trade water rights with the City of Irving so that the Starleaf Pump Station
could be fed from the City of Irving's 54" water line. This is discussed on page 6 of the report.
On the Water Distribution Master Plan all lines shown in red are areas where the water lines need
to be constructed and/or upsized. Currently, the City of Coppell is working on the construction
plans to upsize the existing 8" water line along Belt Line/Denton Tap (from Bethel Rd. to Airline
Dr.) to a proposed 16" water line and the construction plans for a new 12" water line from the
intersection of Coppell Road with SH 121 around the northwest comer of Coppell to the
intersection of Denton Tap with SH 121.
Also, included with this agenda item is a letter from the consultant concerning contact they had
with the Upper Trinity River Authority. Obtaining water from the Upper Trinity River Authority
could be a very expensive endeavor because of the need to construct approximately 5 miles of
water line to the City of Coppell. If that were accomplished, there would still need to be a site
obtained on the west side of Coppell to construct a pump station to accept this water. This option
does not appear to be viable.
In my opinion, the optimum solution to the water supply would be to negotiate with Irving to
obtain the additional capacity for the Starleaf Pump Station from the Irving 54" water line.
While the Irving 54" water line and the Dallas 60" water line generally follow the same path,
they are separate and distinct water supplies. Therefore, if one line was out of service, there
would still be water provided from the other water line. At this time, the City of Coppell will
continue to implement components of the master plan and begin the preliminary talks with both
Irving and Dallas concerning either additional future capacity from the City of Dallas or trading
capacity with the City of Irving.
Staff will be available to answer any questions at the council meeting.
"CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN"
WATER DISTRIBUTION SYSTEM
MASTER PLAN
Submitted To
T H ~: C. I T Y 0 F
COP?ELL
Submitted By
BIRKHOFF, HENDRICKS & CONW~4Y, L.L.P.
CONSULTING ENGINEERS
DALLAS, TEX~4S
June 2004
CITY OF COPPELL
WATER DISTRIBUTION SYSTEM
MASTER PLAN
TABLE OF CONTENTS
INSIDE FRONT COVER .............................. Figure No. I Water Distribution Overview Map
Page No.
INTRODUCTION
1
· General ..........................................................................................................................
1
· Purpose and Scope ........................................................................................................
2
· Planning Area ...............................................................................................................
· Planning Area Map, Figure No. 2 ................................................................................... 3
4
· Population .....................................................................................................................
4
· Definitions ....................................................................................................................
II.
5
WATER SUPPLY .............................................................................................................
III.
WATER DISTRIBUTION SYSTEM DEMANDS
7
· Residential Demands ....................................................................................................
· Non-Residential Demands ............................................................................................ 8
IV.
WATER DISTRIBUTION SYSTEM MASTER PLAN HYDRAULIC ANALYSIS
9
· Distribution System ......................................................................................................
9
· Pump Stations ...............................................................................................................
11
· Exhibit I ......................................................................................................................
11
· Exhibit II .....................................................................................................................
· Ground Storage Reservoirs ......................................................................................... 13
· Elevated Storage ......................................................................................................... 14
· Max Day Pressures ..................................................................................................... 15
· Max Day Pressure Areas, Figure No. 3 ...................................................................... 16
V. CONCLUSIONS AND RECOMMENDATIONS ......................................................... 18
VI. APPENDIX
VII. MASTER PLAN MAP
INSIDE BACK COVER .................................... Figure No. 4 Max Day Pressure Contour Map
Birkhoj~ Hendricks & Conway, L.L.P.
I. - INTRODUCTION
GENERAL
This analysis and report covers the water distribution system master plan for the City of Coppell.
Although the system is designed to accommodate the ultimate development of the City, it should be
examined at intervals and revised to conform to changing conditions that may arise as the City
continues to grow. Likewise, prior to undertaking a major capital improvement expenditure, an
examination should be made sufficient to verify that the design criteria used in developing the overall
plan is still valid.
PURPOSE AND SCOPE
The purpose of this report is to evaluate the existing water distribution system hydraulics, present a
comprehensive plan for the development of a water distribution system to serve the full growth and
development of the City of Coppell and make recommendations for necessary immediate
improvements.
The scope of this report includes the following:
· Review of the existing hydraulic map,
· Creation of a current water system layout in AutoCAD (release 2002),
· Preparation of a working hydraulic model in WaterCad (version 5.0),
· Inclusion of potential residential and commercial demands in the model scenarios,
· Inclusion of system pressure data gathered by BHC and City staff under separate task,
· Comparison of hydraulic system pressures simulated in the model with those gathered in the
field,
· Synthesis of existing and proposed land use and population expectations into model hypotheses,
· Inclusion of available water records as provided by the City of Coppell, and
· Development of pump station, ground storage and elevated storage options to maintain water
pressures to meet TCEQ guidelines.
Water Distribution System Master Plan Page l
Birkhoff, Hendricks & Conway, L.L,P.
The final products of this study and report are a water system master plan for build-out development
conditions, and a working hydraulic model for both the existing infrastructure and the build-out
distribution system. The build-out Master Plan recommendations are illustrated on the map included
as an attachment to this document.
PLANNING AREA
The planning area for this report is consistent with Coppell's anticipated ultimate city limits. The
total planning area for the water distribution system encompasses approximately 14.7 square miles.
The planning area is shown on Figure No. 2 as well as on the hydraulic model maps included with
this report.
Water Distribution System Master Plan Page 2
FIGURE NO. 2
Birkhoff, Hendrickx & Conway, L.L,?,
Water Distribution System Master Plan Page 3
Birkhoff, Hendricks & Conway, L.L.P.
POPULATION
Typically, the demand for water in a community is closely related to its residential population. Total
population of a fully developed area heavily contributes to the ultimate size of facilities required.
The rate of population growth is important because it determines when new facilities are required.
The water distribution system examined in this report is designed to serve a build-out residential
population of approximately 39,053 persons. The projected population is based on information
provided by the City's Planning Staff.
In addition to the estimated residential population, the City's land use plan also projects 4,030 acres
dedicated to non-residential use.
DEFINITIONS
Designing a water distribution system and establishing water supply requirements involves various
rates of water use, which are generally referred to as water demand. The three most significant
demand rates and a definition of each follows:
1. Maximum Daily Demand: This is the total amount of water used during the day of heaviest
consumption in any given year. This rate is the minimum rate that the high service pumps must
be capable of pumping and the minimum rate of treated water supply required.
2. Maximum Hour Demand: This is the rate in which water is drawn from the entire system during
the hour of maximum consumption on the day of maximum demand. The rate is generally of
short duration between the hours of 4:00 a.m. to 8:00 a.m. or in the evening between 5:00 p.m. to
7:00 p.m. It is most economically provided for by use of elevated storage in addition to water
being supplied to the system by pumpage. The distribution system, including elevated storage
and pumpage, must be capable of satisfying this demand.
Minimum Hourly Demand: This is the rate at which water is drawn from the distribution system
during the hour of minimum demand on the day of maximum demand. This demand rate is used
in the analysis of the water distribution system to determine the adequacy of the pump
capabilities to replenish or refill the elevated storage.
Water Distribution System Master Plan Page 4
II. - WATER SUPPLY
Birkhoff, Hendricks & Conway, L.L.P.
When the City of Coppell reaches its ultimate development, it will have an estimated population of
39,053 persons. Based on water demands developed for this study, this population will yield a total
maximum daily demand for treated water of approximately 29 million gallons per day (MGD).
Currently, the City of Coppell receives its treated water supply from Dallas Water Utilities (DWU) at
the Village Parkway Pump Station site and will take additional treated water at the future Star Leaf
Pump Station site. The water supplied to the City is transmitted through a 60-inch water line that
supplies the Village Parkway Pump Station.
Table No. 1 below shows the current and projected maximum day supply requirements at each of the
three pump stations.
TABLE NO. 1
20 15
0 14
TOTALS 20 29
Future treated water supply to the proposed Star Leaf Pump Station Ground Storage Reservoir(s) can
be accomplished through one of two treated water sources in the vicinity of the pump station:
1. The Existing 54" Dallas Water Utilities Water Supply Line
The upstream (60") portion of this line currently serves Coppell's Village Parkway Pump Station.
Coordination with Dallas Water Utilities and the City of Irving is necessary for connection to this
line and final determination of the capacity available. We understand the City of Coppell
currently has 20 MGD capacity through the existing DWU line to serve the Village Parkway
Pump Station. This is approximately 9 MGD less than the ultimate supply required for the City
at build-out. We recommend that the 29 MGD total supply be balanced between the existing
Village Parkway Pump Station and the future Star Leaf Pump Station.
By tapping the existing DWU Treated Water Supply Line, Coppell would retain DWU as their
sole source of wholesale treated drinking water and thereby simplify contract negotiations and
wholesale water rates.
Water Distribution System Master Plan Page 5
Birkhoff, Hendricks & Conway, L.L.P.
The new 54" City of Irving water supply line (parallel to the DWU supply line)
Although the treated water in this supply line has its source at the Dallas Water Utilities Elm Fork
Water Treatment Plant, it is owned by the City of Irving. Therefore, a tap on this supply line will
require contract negotiation with the City of Irving and Coppell would likely become customer of
the City of Irving. The water rights in the City of Irving Supply Line originate in Lake Chapman.
The City of Irving pumps raw water out of Lake Chapman into Lake Lewisville. Dallas Water
Utilities treats the City of Irving Raw Water at the Elm Fork Treatment Plant and delivers it to
Irving through the Elm Fork WTP high service pump station. Once the treated water leaves the
DWU City of Irving meter vault at the Elm Fork Plant, it is conveyed to the City of Irving via the
Irving Supply Line.
Additional capacity may be available in this line. For the purposes of enhancing the efficiency of
operation of the two supply lines to Irving, the City of Irving may be interested in trading water
capacity between the supply lines, with the City of Coppell supplementing its existing 20 MGD
with 9 MGD additional maximum day supply. The advantage to Coppell would be an alternate
delivery treated water line downstream of the Elm Fork Treatment Plant to serve the City and
therefore provide a measure of redundancy in the case of a catastrophic failure in one of the two
lines.
Water Distribution System Master Plan Page 6
Birkhoffj Hendricks & Conway. L.L.P.
III. - WATER DISTRIBUTION SYSTEM DEMANDS
RESIDENTIAL DEMANDS
Analysis and design of the proposed water distribution system is based on the anticipated maximum
water demand and the proposed future land use, including residential population and non-residential
acreage projections, in the City of Coppell. Daily consumption data for the summer of 2000 was
provided by the City. Based on the available information, a maximum daily residential demand of
525 gallons per capita per day (gpcd) has been utilized for this analysis. This information has been
used to determine a demand ratio for the Maximum Hour/Maximum Day.
Records from the summer of 2000 indicate that on August 1, 2000, the City of Coppell experienced
its peak hour demand for the year. Based on this data, the city's maximum hour to maximum day
ratio is 2.13. This is marginally higher than that observed in other Metroplex area cities and appears
to be related to the City's water conservation schedule.
Table No. 2 below shows the ratio for the maximum hourly demand rate versus the average demand
rate for the 24-hour period on the day of maximum use (Maximum Hour/Maximum Day).
TABLE NO. 2
WATER DEMAND RATIOS
Maximum Hour/Maximum Day .......................................... 2.13
RESIDENTIAL DEMANDS
Maximum Daily Demand ............................................ 525 gpcd
Maximum Hourly Demand ....................................... 1,217 gpcd
These unit demands and demand ratios are recommended as it is believed that they represent a severe
test of the water distribution system and accurately reflect the per capita demand currently
experienced by the City of Coppell.
Water Distribution System Master Plan Page 7
Birkhoff ttendricks & Conway, L.L.P.
NON-RESIDENTIAL DEMANDS
The analysis and design of the water distribution system is based largely on the total anticipated
water demand and the manner in which that demand is distributed throughout the City. For the
purpose of distributing the non-residential demands within the hydraulic model for this analysis, non-
residential areas, as dictated by the City and their Proposed Land Use Map, were measured. Based
on a review o£ water consumption rates for the City of Coppell and other North Texas communities,
per acre demands for the non-residential areas were established. The unit demands for each land use
and their corresponding ratios for Maximum Hour/Maximum Day are shown below in Table No. 3.
TABLE NO. 3
NON-RESIDENTIAL UNIT DEMANDS
Maximum Day
Retail ........................................................................................................ 3000 gpad
Office ....................................................................................................... 1500 gpad
Commercial .............................................................................................. 2000 gpad
Light Industrial ......................................................................................... 3000 gpad
Mixed Use ................................................................................................ 2000 gpad
Historic District ........................................................................................ 1500 gpad
Public ....................................................................................................... 1500 gpad
Park ............................................................................................................ 500 gpad
WATER DEMAND RATIOS
Maximum Hour / Maximum Day
Retail .................................................................................................................. 1.50
Office ................................................................................................................. 1.50
Commercial ........................................................................................................ 1.50
Light Industrial ................................................................................................... 1.50
Mixed Use .......................................................................................................... 1.50
Historic District .................................................................................................. 1.50
Park/Public ......................................................................................................... 1.50
Water Distribution System Master Plan Page 8
Birkhoff, Hendricks & Conway, L.L.P,
IV. - WATER DISTRIBUTION SYSTEM MASTER PLAN
HYDRAULIC ANALYSIS
The design of the proposed distribution system is based on two extreme conditions. The first
condition, which is used to size the water mains, is based on the water demand throughout the system
during the maximum hour demand period. The second condition, which is used to analyze the refill
rates of the elevated storage, is based on the minimum hourly demand on the day of maximum
demand. The minimum hourly demand rate on the day of the maximum demand is estimated to be
approximately 40% of the maximum daily demand for this analysis. The hydraulic results from both
of these conditions are included in the output data contained in the Appendix of the report.
DISTRIUBTION SYSTEM
The City of Coppell's Water Distribution System is very close to built-out. The Water Distribution
System Master Plan will require only a few infrastructure improvements and additions to
accommodate the proposed Star Leaf Pump Station and future residential and non-residential growth
in Coppell. The proposed pump station and ground storage tank facilities are shown on the Master
Plan map included with this report. The addition of the Star Leaf Pump Station is discussed in the
following section.
PUMP STATIONS
It is recommended that the City of Coppell plan for a total pump station capacity of approximately 47
million gallons per day. The City of Coppell is currently operating one pump station, the Village
Parkway Pump Station. The current firm capacity of the Village Parkway Pump Station, with the
largest pump out of service, is estimated to be in the range of 27 million gallons per day. The TCEQ
requires the firm capacity of the pump station be calculated with the largest pump out of service. The
Village Parkway Pump Station has no ability to be readily expanded. Therefore, it is recommended
for the City to consider construction of a new pump station located in the general vicinity of the
Dallas Water Utility (DWU) supply line adjacent to MacArthur Blvd. and Star Leaf Road. It is also
recommended that the station be sized for a finn capacity of no less than 20 MGD. The proposed site
is near the existing Dallas supply line and is located favorably to meet the hydraulic conditions of the
City's distribution system.
Water Distribution System Master Plan Page 9
Birkhoff~, Hendrick~ & Conway, L.L.P.
1. VILLAGE PARKWAY PUMP STATION
The Village Parkway Pump Station is located on the northeast comer of Mac Arthur Boulevard
and Sandy Lake Road. The existing pump facilities include two 250 horsepower pumps, three
400 horsepower pumps and one 600 horsepower pump. Using the actual pump curves provided
by the City, and construction record drawings showing the Village Parkway Pump Station layout,
the pump station piping, pumps and ground storage tanks were included in the model. The
hydraulic analysis of the existing system indicates the Village Parkway Pump Station can deliver
in the range of 27 MGD with the 600 horsepower pump and both 250 horsepower pumps out of
service. The Village Parkway Pump Station has no ability to be readily expanded. Therefore, the
Village Parkway Pump Station it considered to be at its ultimate capacity.
2. FUTURE STAR LEAF STATION
The future Star Leaf Pump Station is proposed to be located on proposed Star Leaf Road, just east
of MacArthur Boulevard between Sandy Lake Road and Belt Line Road. This site is near the
DWU supply line and is located favorably to meet the hydraulic conditions of the City's
distribution system. It is recommended that the future Star Leaf Pump Station be sized for a firm
capacity of no less than 20 MGD.
In the first phase construction of the Star Leaf Pump Station, a building, including slots for the
installation of six pumps, is recommended. Three pumps should be installed in the initial
construction scope. The pumps are expected to be vertical turbine pumps located inside the pump
building. The pump station building will also house the pump control valves, isolation valves,
discharge header, motor control center and a SCADA panel. To match the surrounding
development, it is envisioned that the pump station building be constructed of CMU block with a
decorative brick veneer. The building will likely be founded on a concrete foundation supported
on drilled concrete piers. An overhead monorail crane with a push trolley and hand hoist for
equipment manipulation inside the pump building have been included. One optional layout for
Coppell's future pump station is shown on the conceptual site plan, Exhibit I, and the elevation
view, Exhibit II.
Table No. 4, below, illustrates an overview of the pump and motor performance data for the
existing Village Parkway and future Star Leaf Pump Station.
Water Distribution System Master Plun Page 10
Star Leaf Pump Station Site Plan
Birkhoff, Hendricks & Conway, L.L.P.
Water Distribution System Master Plan Page I 1
Star Leaf Pump Station Elevation
Birkhoff, Hendricks & Conway, L.L.P.
Water Distribution System Master Plan Page 12
Birkhoff, Hendricks & Conway, L.L.P.
TABLE NO. 4
CITY OF COPPELL
PUMP STATION OVERVIEW
VILLAGE PARKWAY PUMP STATION
1 Worthington N/A 450 7000 GPM ~ 200' TDH
2 Worthington N/A 450 7000 GPM ~ 200' TDH
[.,~; 3 Worthington N/A 450 7000 GPM ~ 200' TDH
4 Ingersoll-Dresser N/A 600 9000 GPM ~ 210' TDH
5 Ingersoll-Dresser 17.2 250 3750 GPM ~ 200' TDH
6 Ingersoll-Dresser 17.2 250 3750 GPM ~ 200' TDH
FUTURE STAR LEAF PUMP STATION
" 1 N/A N/A 5500 GPM
~ 2 N/A N/A 5500 GPM
3 N/A N/A 3500 GPM
~ 4 N/A N/A 5500 GPM
~ 5 N/A N/A 5500 GPM
6 N/A N/A 3500 GPM
GROUND STORAGE RESERVOIRS
The Texas Commission on Environmental Quality (TCEQ) sets the minimum ground storage
requirements at 130 gallons per capita, resulting in 5.1 million gallons for the City of Coppell at
build-out. However, after careful evaluation, it is recommended that the City have no less than six
hours of total ground storage supply during the maximum day demand period. This volume provides
Water Distribution System Master Plan Page 13
Birkhoff, Hendricks & Conway L.L.P.
for a reasonable level of protection against interruptions in water supply from DWU during the
critical demand period. Using this approach, it is recommended that no less than 14 million gallons
of ground storage be available at build-out.
Presently there are 10.0-million gallons of ground storage in the City of Coppell, all located at the
Village Parkway Pump Station. When the Star Leaf Pump Station is constructed, it is recommended
that an additional 4.0 million gallons of ground storage be provided. The resulting build-out total
volume of ground storage will be approximately 14 million gallons (See Table No. 5, below).
TABLE NO. 5
CITY OF COPPELL
GROUND STORAGE RESERVOIR OVERVIEW
~ Village Parkway No. 1 Village Parkway Pump
Station 6.0
~q Village Parkway No. 2 Village Parkway Pump
m Station 4.0
Existing SUBTOTAL 10.0
~ Star Leaf No. 1 Star Leaf Pump Station 2.0
~ Star Leaf No. 2 Star Leaf Pump Station 2.0
Future SUBTOTAL 4.0
GROUND STORAGE RESERVOIR GRAND TOTAL 14.0
ELEVATED STORAGE
The City's existing elevated storage includes the 1.5 million gallon Southwestern Elevated Storage
Tank located on the north side of Southwestern Boulevard between Coppell Road and Freeport
Parkway, and the 2.0 million gallon Wagon Wheel Elevated Tank located off of Southpoint Drive,
west of Royal Lane. In addition to serving as a regulator for the systems water pressure and
providing emergency pressure during potential power outages at the pump stations, elevated storage
in a distribution system serves as a source of supply when the system demand exceeds the ability to
provide water by pumping alone. As previously stated, this normally occurs during the maximum
hour demand situation.
Water Distribution System Master Plan Page 14
j lclerical'~ogppell~2(lO l-I 06 master planlreporta lreport doc
Birkhoff, Hendricks & Conway, L.L.P.
In the City of Coppell system, the build-out maximum hourly demand has been estimated to be
61 MGD. The City has expressed the desire to expand their pumping capacity to meet the future
demand while maintaining their existing volume of elevated storage. Using an elevated storage
drawdown time of 6 hours, an additional 14 MGD can be contributed from the existing 3.5 million
gallons of elevated storage. Table No. 6, below, summarizes the existing capacities. The master plan
map shows the location of the existing elevated storage tanks.
TABLE NO. 6
CITY OF COPPELL
ELEVATED STORAGE TANK OVERVIEW
r~ Royal Lane and
~ Southwestern Tank 1.5
~ Northpoint Drive
;~ Southwestern Blvd.
m Wagon Wheel Tank 2.0
and Coppell Road
Existing SUBTOTAL 3.5
ELEVATED STORAGE TANK GRAND TOTAL 3.5
MAX DAY PRESSURES
As illustrated on Figure No. 3, Maximum Day Pressure Areas, there are essentially three areas of
pressure over 80 psi within the limits of Coppell's water system. These pressures are due mainly to
the geography and topography of the landscape as the elevation of the land descends towards the Elm
Fork of the Trinity River.
Although the nodes in the model, in this area, generally register pressures of 80 to 100 psi, the City
Staff has received relatively few complaints from residents who are experiencing associated negative
effects. Potential solutions include pressure reducing valves for the affected area or point-of-use
reducing valves at the affected service connections.
Water Distribution System Master Plan Page 15
Birkhoff, Hendricks & Conway, L.L.P.
Figure No. 3
Water Distribution System Master Plan Page 16
Birkhoff, Hendricks & Conway, L.L.P.
Pressure reducing valves installed on the system distribution lines are not recommended for this
application. In order to isolate the area of increased pressure, the City would have to purchase and
install at least three 8 to 12-inch pressure reducing valves and multiple blow off valves. This will be
a relatively expensive solution and may have a deleterious affect on water circulation and the ability
of the locally isolated system to handle pressure spikes. In essence, a new pressure plane would be
created for this zone, which is not advisable.
Point-of-use pressure reducing valves may be a more economical and homeowner responsive
solution. Although these units will require periodic maintenance, their installation on the City side of
water meters at affected customer service points is recommended. This will facilitate the
effectiveness of each unit in future years. Nevertheless, it is recommended that the City deal with
high-pressure issues on a case-by-case basis.
~Vater Distribution gystem Master Plan Page l 7
Birkhqff, Hendricks & Conway, L.L.P.
V. - CONCLUSIONS & RECOMMENDATIONS
The Water Distribution System Master Plan recommendations are generally identified on the
enclosed Water Distribution Master Plan Map. In addition to the sized water lines shown on the map,
other recommendations for improvements to the water distribution system need to be made to
accommodate build-out conditions. Included in these additional infrastructure improvements is the
construction of the Star Leaf Pump Station to its full build-out capacity, including pump capacity and
ground storage, within the next ten years. Appendix A documents the input information utilized to
develop and mn the model in WaterCad (Ver.5.0). For the two critical conditions, Maximum Hour
and Minimum Hour, the data in Appendix A identifies critical system characteristics, which effect
pressure and volume available to the end user.
Table No. 7, below, is a summary of the conclusions and recommendations made in this report, and
provides a comparison with the results presented in the previous water distribution system analysis
for the City of Coppell prepared in 1994 by Rady and Associates.
We recommend the City of Coppell make Dallas Water Utilities aware of the currently projected
maximum day demand of 29 MGD, and begin discussions as to planning efforts to secure the
additional 9 MGD requirement.
At this time the City of Coppell has an agreement to be supplied with water from the Elm Fork
Treatment Plant operated by Dallas Water Utilities through the DWU 60" (reducing to 54" south of
Sandy Lake Road) water line. Although there is an existing 54" water line owned and operated by
the City of Irving running parallel to the DWU line adjacent to the future Star Leaf Pump Station, the
City of Coppell does not have a contractual relationship with the City of Irving to receive water out
of this line. There may be good reasons for both Coppell to approach the City of Irving with the goal
of finding a way to trade water between the DWU line and the Irving line so that Coppell would
obtain a second soume of supply to the Star Leaf Pump Station from Irving. The cost of such an
arrangement may or may not make the opportunity attractive. It is recommended that the City of
Coppell approach the City of Irving in the near future to initiate discussions in this regard.
Water Distribution System Master Plan
Ill
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ROYAL
LN.
COPPE~.L RD.
HEARTZ
MOORE
TARRANT COUNTY
DALLAS COUNt'
BIRKHOFF, HENDRICKS & CONWAY, L.L.P.
CONSULTING ENGINEERS
7502 Greenville Ave., #220
JOHN w BIRKHOFF. P.E
RONALD V CONWAY, P.E
GARY C HENDPdCKS, PE
JOE R CARTER, PE.
PAUL A. CAP. LINE. P,E
MATT HICKEY, P.E
DOUGLAS K SHOWERS, PE.
Dallas, Texas 75231
Fax (214)361-0204
June 24, 2004
Phone (214) 361-7900
Mr. Kenneth M. Griffin, P.E.
Director of Engineering and Public Works
City of Coppelt
P.O. Box 478
Coppell, Texas 75019
Re: Water System Master Plan
Upper Trinity Regional Water District
Dear Mr. Griffin:
We have initiated contact with the Upper Trinity Regional Water District (UTRWD) regarding the
opportunity to be involved with it's water supply network in the Denton County / North Dallas County area.
We understand that the City of Coppell was given an opportunity to become a member city in or around
1990, however at that time the City made a decision to decline. Mr. Tom Tayler of the UTRWD was kind
enough to provide information regarding their system and the options available to the City of Coppell with
regards to obtaining Upper Trinity water.
There Were two options mentioned by Mr. Tayler in our conversation:
Approach the UTRWD to become a current member. If this status is granted, the district would
construct the infrastructure necessary to deliver water to the City of Coppell. Unfortunately, the
UTRWD has closed membership and it would take an act of the Board of Directors to allow Coppell
to join. It is likely that there would also be a significant price tag attached to becoming a member.
Water would then be purchased on a negotiated fee schedule (of which we had no conversation).
Approach the UTRWD to become a customer city. If this status is granted, the City of Coppell
would be responsible for construction of the infrastructure to bring water from the closest delivery
point to the City's existing distribution lines. Water would be purchased on a negotiated fee
schedule (of which we had no conversation). The closest delivery point is the Upper Trinity
Regional Water District Water Treatment Facility located adjacent to the comer of Kealy North and
Sewage Treatment Road in Lewisville. The shortest delivery line would likely travel south on
Kealy, along Hwy. 121 (Bus.), and continue down Denton Tap Rd. to a connection point
approximately 2000 feet north of Hwy. 121/Spur 553. The total length of this line is approximately
4.7 miles.