HomeMy WebLinkAbout12-1975
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f REPORT ON
LONG • RANGE WATER' SUP
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CITY OF
DENTON, TEXAS
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PRELIM MARY
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FREESE AND N ICHOLS
CONSULTING ENGINEERS
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TABLE OF CONTENTS
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INTRODUCTION
2. POPULATION AND WATER REQUIREI4ENTS 2,1
2.1
2.1 Populntion 2.4
~ 2.2 Historical Water Requirements 2,7
( 2,3 Projected Water Requirements
I 3,' EXISTING WATER SUPPLY AND PROPOSED AUBREY RESERVOIR 3.1
3.1
3.1 Existing Water Supply 3.3
3,2 Proposed Aubrey Reservoir
f r 3.3 Estimated Costs of the Aubrey t'ra}ect 3,5
4.1
G 4, POTENTIAL WATER SUPPLY SOURCES
4
4.1 General .1
4.3
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4.2 Proposed Water Sou"ces 4.3
4,2,1 Sulphur Bluff Reservoir 4.6
4.2,2 Cooper Reservoir 4,7
4.2 .3 Bois d'Arc Creek Reservoir 4.8
4,2,4 Tri-Lakes System 4,10
4.3 Summary of Alternatives 1
5. LONG RA14GE WATER SUPPLY DEVELOPMENT 5'1 1
5,1 General 5,1
6.2 Transfer of 30 MGD to Lewisville Lake 612
6,2,1 Plan I 5,6
6.2.2 Plan 11 5,6
5,2.3 Plan 111 6110
! 6.3 Delivery to Denton Water Treatment Plant
5, SUMMARY AND RECOMMENDATIONS 6'1
6,1 Summary of Existing and Proposed Water 5,1
Supply Sources 6,3
6,2 Recommendations
A,f'PENDIX A LIST OF REFERENCES
APPENDIX B DETAILED COST ES71FUtTCS
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LIST OF TABLES
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Table
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2.1 Population Projections: Denton and
Service Area 2.4
2.2
Historical Finished Water Requirements 2,6
E2.3 Projected Raw Water Requirements
2,9
3.1 Preliminary estimate of Denton's Costs 3,7
! for the Aubrey Project
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j f 6.1 Estimated Annual Cost of Plan 1:
3 ~ 5,3
' f Transporting 30 MGD of Raw Water from
i Sulphur Sluff to Lewisville Reservoir
by Pipeline
-5.2 Estimated Annual Cost of Plan II
{ 5,7
Transporting 3
0 MGD of Raw Water from .
Sulphur Bluff to Lewisville Reservoir
} Utilizing Combined Canal and Pipeline
I Systems
5.3 Estimated Annual Cost of Plan III;
Transporting 30 MGD of Raw Water from 5'~
Bois d'Arc Reservoir to Lewisville
Reservoir by Pipeline
' i 5.4
4 Denton Long-Range Water Supply; 5.11
Transfer of 30 MGD to Lewisville Lake
5.5
Estimated Annual Cost of Transporting 5.14
^55 MGD from Lewisville Lake to the
Denton Water Treatment Plant
5.6 Estimated Unit Cost for Transporting 5,15
55 MGD from Lewisville Lake to the
Denton Water Treatment Plant
6.1 Estimated Cost for Transfer of
30 MGD to Lewisville Lake 6.3 {
6.2 Estimated Costs for D,enton's Long-Range 6.5
Water Supply
6.3 Schedule of Construction for Denton's
Long-Range Water Supply Development 6.6
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Fi ure After Page
2.1 Denton and Vicinity 2.2
2.2 Projected Average Annual Population 2.2
2.3 Projected Sumner Population 2.2
2.4 Historical Per Capita Consumption 2:5
2.5 Historical Finished Water Requirements 2.5
1 I 2.6 Projected Raw Water Requirements 2.7
3.1 Denton Water Supply System Development 3.5 I
to Year 1997
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4.1 Area Existing and Proposed Reservoirs 4.1
5.1 Denton Water Supply System Development 6.1
I to Year 2020
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6.2 Plan I Development 512
r 5.3 Plan II Development 5.5
5.4 Plan III Development 6,7
6.5 Raw Water Pump Station and Supply Line 5.11
Development
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INTRODUCTION
The City of Denton now derives its water supply primarily from
Lewisville Reservoir of the U.S. Army Corps of Engineers. On days of
heaviest demand in summer months, some of the requirements are also ,
obtained from municipal welts. With these existing surface water and
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N ground water resources, the City has sufficient. supply to satisfy anti-
cipated demands until about 1980.
In order to provide for increasing needs beyond 1980, Denton is
participating as a local sponsor of the proposed Corps of Engineers f
Aubrey Reservoir, for which construction is expected to begin to the
fE near future. The added dependable yield from the Aubrey project should
' give Denton enough total supply until the late 1990's, at which time
another new source probably will be needed,
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The purpose of this report is to evaluate existing sources and
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potential additional sources of water, with the goal of showing how
Denton can best meet projected water requirements through the year 2020,
The range of•investigation covers present and proposed sources which
Denton might utilize in the Trinity River Basin and also other feasible
lE sources in neighboring basins, The following specific elements are
i treated in this study;
(a) Historical population growth and anticipated future
growth based on existing trends,
(b) Past municipal and industrial water production and
estimated future water requirements,
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(c) The.quantities of water available to Denton under
existing appropriations in Lewisville Reservoir and
from the City's wells.
(d) The potential quantity of water available to Denton
from the proposed Aubrey Reservoir,
(e) potential sources of supply which maybe available
to Denton elsewhere in the future,
(f) Quality of the various water sources being investigated.
' (g) Estimated capital and annual costs for development of
r f the various sources of supply and delivery of the water
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to the City's filter plant.
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POPULATION AND WATER RE UIREMENTS ~
2,1 Population
The general prospect for the City of Denton and the surrounding
area in the foreseeable future is one of continued growth. Several
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presently observable characteristics and trends in the area bear out
this fact. Between 1960 and 1970, the number of employed persons in
manufacturing in Denton County almost doubled, and 60% of the Denton
County population reside in the City of Denton. The total number of
J employed persons in Denton County also nearly doubled between 1960 and
1970, pointing up the high level of over-a11 commercial activity in
Denton County and in the City of Denton, Between 1960 and 1970, the
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population in the City of Denton increased by 49%. This percentage
carries even more significance when it is realized that the increase in
f the state population was 17% during the same time period.)
Commercial growth for Denton-has been influenced positively by
its location relative to other business centers and its location on a
major transportation route, Interstate 35, The interstate system makes
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Denton accessible to large cities from the'north and from the south)
Denton is also relatively close to the new Dallas-Fort Worth Airport,
I Another factor tending to bring growth to Denton is its proximity
to Lewisville Lake. The nearby smaller communities of Corinth, Shady
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1 Numbers correspond to references listed in Appendix A.
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Shores, Hickory Creek, and Lake Dallas (known collectively as the Four
f~ Cities) have all exhibited growth in the past primarily as a result of
the recreational attraction of Lewisville Lake. Relative locations of
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Denton, Lewisville Lake, and the Four C1 ties are shown in Figure 2.1,
When the Aubrey Reservoir is completed, Denton's economic and population
r growth should be further accelerated by similar development to the north.
Of considerable local impact on the Denton socioeconomic structure
j is the presence of North Texas State University and Texas Woman's
University, Although the Denton State School Is not actually within the
city limits of Denton, its students are also counted as local residents.
In 1970, about one-third of the Denton population consisted of students
from these three institutions, which naturally affect the economy and
i water use of the area.
Represented in Figures 2,2 and 2,3 are the projected average annual
water use population and the summer water use population, respectively,
1 of Denton and customer cities. Because Denton probably will supply water
( to the Four Cities area in the future, the population trends in these
figures include Corinth, Shady Shores, Hickory Creek, and Lake Dallas,
Also included in the total population figures are the resident student
populations of North Texas State University, Texas Woman's University,
and Denton State School,
The Denton end-of-year population projection is also shown in
II Figures 2,2 and 2.3. This is the official published projection for the
City of Denton and reflects ';he predicted total without deductions for
loss of student population during the summer. Since the Denton city
E projection dons not represent the actual water use population, it was
2.2
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DENTON AND VICINITY
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PROJECTED AVERAGE
ANNUAL POPULATION
250
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200
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150
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I ~VEAAOE SIUOEN PtlPUTAY ON ~ r
POUR CIYIfS 1~A A
1970 1080 1990 2000 2010 2020
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YEAR
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FIGURE 2.2
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_.PROJECTED SUMMER POPULATION
250 - -
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100
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Oti~1ES ~AEN
f0U UMM A S1Up[Nt OP VION j
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1970 1894 logo 2000 2010 2020
YEAR
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FIGURE 2,8
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modified to produce the annual average and summer population projections
shown.
Representation of the population in this manner is necessary because
the City's peak-day water requirements are dependent on the summertime
population while the over-all yearly needs are related to the average
' annual population. The water treatment plant and the supply lines from
Lewisville Reservoir must be designed on a peak-day basis in order to
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' satisfy the summer condition. In contrast, the annual average population
j should be used'in measuring the total adequacy of the basic sources of
supply.
Future facilities to transfer additional supply from more distant
sources to Lewisville Reservoir, en route to Denton, will not be required
€ to meet the peak-day flow condition but will need to be capable of
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f1' transferring water at rates somewhat higher than the annual average rate,
+ for purposes of this study, such facilities will be planned on the basis
of maximum operation at 1,50 times the annual average rate,
As shown i,i Figure 2.2, the Denton annual average water use popu-
lation is predicted to continue trending upward as in the past from a
E present population of about 50,000 to a 2020 estimate near 250,000,
The summer water use population will also trend upward but is predicted
to lag behind the annual average by about 6,000 persons in 1980 and
about 11,000 in the year 2020. Shown in Table 2.1 is a summary of the
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population projections for the City of Denton and for the total water
use population under summer conditions and on an annual average basis.
2,3
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Table 2.1
Population Projections
j Denton and Service Area
Year Denton ' Denton Denton Average Summer
End of Annual Summer Water Water
Year Average Population Use Use
Population Population _ Population Population
1970 39,874 39,547 33,574 4211200 36,227
1980 55,000 53,80n 489 600 59,300 54,000
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1990 810600 79.500` 73,500 89,500 83$00
f 2000 1141,800 113700 1050100 131,300 122,700
2010 154,600 163,000 143,300 183,000 173,300
2020 199,700 1979800 186,800 246,800 235,800
2.2 Historical .Water Requirements
Water requirements may be classified in one of two broad categories; j
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residential or industrial. While residential use is self-explanatory,
the term industrial here denotes application of water in any of u j
wide variety of commercial'aO manufacturing enterprises, including the ,
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production of electrical. power. Until 1972, the Denton power station
used raw water for cooliriu,water, At that time, facilities were con- 1
strutted at the wasteriaf;o- froatment plant to utilize the reclaimed
water for power plant coalfilglpurposes. At present, reclaimed water is
! being used exclusively for, power plant operation.
Historically, annual residenN,ta1 water use has been about equal to
annual commercial use•in UenI"n'.' Additionally, water requirements for
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all uses have been increasing at a rate slightly greater than the
population growth rate. Whereas total water requirements for both
residential use and commercial use have each increased by 25% since
19700 the numbers of customers in both categories have increased by
l about M., During the same period, per-customer use has increased by
about 7% in both classifications. Figure 2.4 illustrates the increases
both in per capita peak-day consumption and average-day per capita con-
sumption since 1950. Figure 2.5 shows the upward trend in average-day
and peak-day finished water use during the same time period. These +
figures are summarized and described numerically in Table 2.2. Popu-
lations used in deriving average-day'per capita consumption and peak-day
j per capita consumption were the historical average water use population
and the summer water use population, respectively.
The ratio of peak-day to average-day use observable in Figures 2.4
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and 2.6 and noted in Table 2,2 comes as a result of seasonal fluctuation
in water demand. This is caused by a marked increase in water use
during the summer due to lawn watering and other seasonal factors, The
ratio o peak to average flow will, however, tend to he less in Denton
than in other cities due to the lower level of university enrollment
and subsequently lower Denton population during the summer session, As
may be determined in Table 2.20 the average and peak-,day water use rates
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inm eased about 2.4 times between 1960 and 1974, and the average and
perk-day per capita consumption increased about 1.4 times during the
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Sam period,
Figures '2,4 and 2.5 indicate by dashed lines the potential peak-day
,4se ana`patemtial peak-day per capita consumption for the City of Denton.
2.5
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o,sHISTORICAL PER CAPITA CONSUMPTION
00
1-41
PO ENT AL EAK DAY
/ '
400 PER CAP TA ON5 MPT ON' 'll
ell
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i PEAK DAY PER
oll
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tVER tGE~-. API A C NSU PTI N
0
60 62 64 66 68 70 72 74
YEARS
FIGURE 2,4
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HISTORICAL FINISHED WATER
REQUIREMENTS
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TEIt IAL
PE -DA USE
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W AVE AOE DAY SE
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j 1960 92 84 66 68 0
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FIGURE 2.8
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Table 2.2
Historical Finished Water-Requirements
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Year' Average- Average- Peak-Day Peak-Day 1
Day Day Per Use Per Capita
Use Capita Consumption
Consumption
MGD GPCD MGD (GPCD ~I
'1960 2.96 108 6.53 260
1961 3.01 102 6.50 260
1962 3.18 109 7.24 275
1963 4.38 136 9.23 324
1964 3.86 119 8.97 309
1965 4.16 121 8.67 290
EE 1966 4.16 120 8.55 280
f ( 1967 4.88 137 11.26 ;65
1968 4.63- 126 9.92 315
1969 6.57 145 13.60 410
1970 6.49 161 13.73 395
1971 6.81 162 15.05 411
E 1972 7.18 163 15.12 392
1973 6.70 148 12.70 -310
1974 6.80 146 - 16.74 382
Note; Ratio of peak day to average day use is approximately
2.34 in an average rainfall year and approximately 2.16
in an extremely wet. or dry year.
In 1963, a particularly dry year was experienced over this area and
other parts of;7exas, and the water consumption was inordinately high.
The potential values, about 15% greater than the peak-day values, describe
the possible peak condition which could occur in any year with extreme
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conditions such as those experienced in 1963. While the average-day'
historical per capita water Use figures will be applied to calculate
average annual water use requirements for Denton, and vicinity, the
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potential peak-day water use figures will be used to determine design
criter'a for sizing future Denton water treatment plant facilities.
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2.6
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2.3 Pro ected Water Requirements
Shown In Figure 2.6 are curves describing projected potential
peak-day demand and average-day demand for the City of Denton to the
year 2020. Determination of these water requirements was achieved
through a combined evaluation of Denton's past water use experience
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~ and judgment of probable future developments which may alter observed
use trends.
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The projections were developed in conformity with the water use and
population patterns discussed earlier in this section and with the water
€ use projections published previously in "North Central Texas Regional
Study" and "Denton, a Twenty Year Comprehensive Plan.11213
Water Supply
j ; The full range of average-day demand values which appear in Figure 2,6
corresponds to the future water use projections detailed in the "North
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4 Central Texas Regional Water Supply Study." The curve represents the
suin of the predicted water use r@tes in the City of Denton and in the
Four Cities area. Excluded from the average-day demand projection is
Denton's industrial water requirement inherent in operation of the
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electrical power generating station. As presented earlier, Denton
currently uses reclaimed water for this purpose. It is anticipated that
in the future the return flows, calculated at about 60% of total water
consumption, will fully satisfy the power station requirement, thereby
freeing raw water for other municipal uses.
The potential peak-day demand curve in Figure 2,6 was derived from
projections of future water requirements contained in the Uenton Compre-
hensive Plan. In order to define future water treatment plant needs,
the Denton Conriunity Development Department developed and published in 1
2.7
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PROJECTED RAW WATER REQUIREMENTS
175
150
125
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75
25
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1870 1980 1,090 2000 2010 2020
YEAR
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FIGURE 2,6
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the Comprehensive Plan the potential peak-day water requirements through
1994. The peak-day demand projection illustrated in Figure 2.6 was
obtained by extrapolating the curve contained in the Comprehensive Plan
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from 7994 to the year 2020. The projected water requirements described
by the curves in Figure 2.6 are listed in Table 2,3.
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EXISTING WATER SUPPLY AND PROPOSED AUBREY RESERVOIR
3.1 Existing Water Supply
Denton presently obtains its water supply from two sources - the
city.well system and Lewisville Reservoir, The reservoir, which lies
to the east and southeast of Denton, is a Corps of Engineers multiple-
j purpose project for flood control, water conservation and recreation.
The dam was completed in 1956 and controls a drainage area of 1,660 square
miles on the watershed of the Elm Fork of the Trinity River. The name of
j j the lake was originally Garza - Little Elm, but was changed to Lewisville
in 1972.
Both Denton and Dallas are participating as local sponsors in the
Lewlsville project, with Denton paying 4.8% of the local interests' costs j
and the remaining 95.2% being paid by Dallas. Denton holds water rights 1
in Lewisville Reservoir under Permit No. 1706, which was issued by the
Texas Board of Water Engineers (predecessor agency to the present Texas
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Water Rights Commission) in 1954. The permit allows Denton to utilize
21,000 acre-feet of conservation storage space in the lake and to divert
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a maximum of 11,000 acre-feet per annuin for municipal water supply pur-
poses, Under terms of a contra with the Federal government, dated
December 10, 1953, Denton is entitled to use the 21,000 acre-feet of
conservation storage in return for payment of 4.8% of the costs allocated
to local sponsors;
In November of 1962s Denton and Dallas entered into an agreement
which recognized the need-for eventual full development of the Elm Fur(
.1 watershed by construction of an additional storage reservoir at the
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Aubrey site, upstream from Lake Lewisville, It was agreed that the two
cities would work together toward construction of Aubrey Reservoir and
that they would share in the'costs and benefits on the basis of 26% for
Denton and 74% for Dallas. Thus, Denton would be responsible for 26% of
the cost and would receive 26% of the incremental yield made available
by the Aubrey project.
Thv 1962 contract also recognized that, although Denton holds water
rights covering diversion of 11,000 acre-feet per year from the existing
Lewisville (then Garza - Little Elm) Reservoir, 4,8% of the hydrologic
I
j safe yield would be significantly less than that amount. It was agreed
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j that (a) Dallas would sell Denton as much as 13,0 MGb of water'out of
the Dallas share of the Lewisville supply and (b) Denton would pay Dalla!;
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for any Lewisville Reservoir,water used by Denton in excess of 4.8%
of the estimated safe yield. Denton's share of the safe yield was j
evaluated as an annual average diversion of 4.5 MD as of 1976 I ~ . and sub.
Sequent years, i
At that time, it was contemplated that the Aubrey project would be
; completed and placed in service prior to 1980, and the 1962 contract sat
j a cutoff date of 1980 for the sale of surplus water to Denton by Dallas.
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It is now apparent that Aubrey probably cannot be-completed by 1980.
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Dallas and Denton are Iii the process of finalizing sponsorship agreements
with the Corps of Engineers, and applications for water rights have been
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filed with the Texas Water Rights Commission, In recent discussions,
Dallas representatives have indicated that the period of availability
of supplemental water for Denton from the existing Lewisville supply
could be extended for a reasonable time until Aubrey Reservoir is
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operational, but that the price of the water would need to be re-
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negotiated.
Denton's wells are able to provide approximately 4.0 MGD on a
short-term basis for days of high demand in the summer months, but are
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not suitable for prolonged operation and should not be counted on to
furnish any significant amount of water on a year-round basis. For
practical purposes, the annual supply obtained from the wells should be
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I considered as negligible, Thus, Denton presently has access to 17.5 MGD
j ' of average annital water supply, all from Lake Lewisville, of which
13.0 MGD is supplemental supply that can be purchased on an interim basis
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from Dallas. Assuming that the Aubrey project proceeds to completion in
a timely manner, Denton can presumably count on this 17.5 MGD until
water can be obtained from Aubrey Reservoir. Based on the projections
of future Denton requirements (see'Figure 2.6), this should be suffi-
cient to meet the City's needs until about 1988.
3,2 Proposed Aubrey Reservoir
The Aubrey Dam.site is at river mile 60.0 on the Elm Fork, in
Denton County,.30 river miles upstream from Lewisville Dam. The drainage
area above the Aubrey site is 692 square miles, or about 42% of the
total watershed above Lake Lewisville. Aubrey is basically intended as
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a water supply project, with significant recreational facilities also
included. The top of the conservation storage pool will be at elevation
632.5. At that elevation, the total storage volume will be 799,600
acre-feet, of which it is estimated by the Corps of Engineers that
60,400 acre *,et will be filled by sedimentation during the first 100
years of reservoir operation. The project plan also contemplates a partial
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transfer of flood control storage from Lewisville Reservoir to Aubrey
Reservoir and enlargement of the conservation pool at Lewisville. Aubrey
Reservoir is to be designed with 265,000 acre-feet of flood control
volume between elevation 632,5 and elevation 640,5. This wil; allow
the lower.portion of the present flood control pool at Lewisville to he
converted to conservation storage. The Lewisville conservation level
is to be raised 7 feet,from the present elevation 515.0 to elevation
522.0. which will add 1779,600 acre-feet of conservation storage and
I increase the total conservation volume of Lewisville Reservoir to an
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estimated 618,400 acre-feet as of about 1985.
It The Corps of Engineers has estimated the incremental yield made
k available by the proposed Aubrey project to be 81.4 MGD, of which
f Denton's 26% would be 21,2 MGD, independent computations by Freese and
Nichols confirm the validity of the Corps estimate with respect to the
{ gain in yield attributable to Aubrey. It is also apparent that the water
supply benefit of Aubrey stems almost entirely from having a greater
volume of water in storage at the beginning of a critical drouth. The
~...J existing Lewisville Reservoir would be able to impound and use virtually
all runoff from the Elm Fork watershed during the drouth period, leaving
very little remaining runoff to be controlled by additional storage.
Thus, the increase in yield gained by building Aubrey is nearly all due
to having a greater total volume of conservation storage to be filled
during more plentiful years prior to a drouth and available for with.-
drawal and use over the dry period.'
The total Denton supply after completion of Aubrey will consist of
4,5 MGD derived from 4,8% participation in the local sponsorship of the
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original Lewisville Reservoir, plus 21.2 MGD due to 26% participation as
i local sponsor of the Aubrey project, for a total of 25.7 MGD. This is
enough to handle the estimated needs of Denton until approximately the
year 1997.
Figure 3.1 is a graphic indication of the comparisons between
Denton's anticipated water supply availability and requirements before
- and after the Aubrey project goes into service. Although the exact date
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{ of first supply from Aubrey is not certain at this point, 1985 seems a
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realistic prediction and has been used for purposes of this report.
3,3 Estimated Costs of the Aubrey Project
Preliminary analysis of the estimated costs of the Aubrey project,
based on material furnished by the Corps of Engineer's, indicates that
( about 30% of the first cost of the project will be borne by the Federal
government and that the local sponsors will be responsible for the re-
maining 70%. Including interest'during construction, the.present (1975)
estimate of the allocable first cost to build the Aubrey project is
$156,374,000. Of this, the local sponsors' share allocated to water
LJ
supply will be $97,875,000, In addition, the local interests are re-
quired to reimburse 59% of the capital cost of certain recreation
facilities. The total local responsibility for repayment of recreation
costs is estimated at $10,922,500, plus $355,000 for interest during
construction! Denton's portion of these obligations (26%) would be
$251447,500 for water supply and $2,932,145 for recreation facilities,
or a total of $28,379,645, As presently estimated by the Corps of
Engineers, Denton could defer for ten years the payments of principal
and interest on half of the.water supply cost of Aubrey Reservoir itself,
3.5
$<113rp;
i
i
.`I. DENTON WATER SUPPLY SYSTEM
DEVELOPMENT TO YEAR 1997
` so
,y.
R1,
~ Ju
r 1!•r a N
AUQREY SUPPLY
J 20 - 112 M0 b
E !
b~
10
i
DENTON YIEL fAOM THE
i
Cs W o EIIISTINO LEWIS ILLE AESFRYOIA
1970 1980 1980 2000 2010 2020
}k+` YEAR
FIGURE 3,1
r
t
i
h r~
Part of the recreation improvements would not be constructed immediately,
but would be planned for future construction and therefore not involved
in the first years' repayment obligations.
The local sponsors will also be obligated to repay part of the cost
of reservoir maintenance and operation and to maintai, and operate the
recreational facilities at their own expense. Denton's portion of the
` lake maintenance and operation costs is estimated at $24,364 per year
I
Initially and $34,996 per year after the first 10 years. The Carps
studies indicate cost of maintenance, operation and replacement of the
i
full program of proposed recreation facilities at $1,011,651 per year,
of which 26% would be $263,000.
These estimates are tentative only, and are subject to revision
i
based on the actual costs experienced when the project is built and
I placed in operation. The exact method of repayment 'to the government is
also subj6ct to varying approaches. To obtain a general concept of the
scope of financial obligation associated with Denton's 26% of the Aubrey
project, the Corps figures.have been interpreted and summarized in Table
3.1. The table assumes that Denton would repay its capital cost obli-
gations in fifty equal annual amounts covering the non-deferrable water
supply costs and the initial recreational development costs at the
current Federal interest rate of 4,371%. It further assumes that the
deferred water supply repayments and the future recreational development
€ charges waule be added at a later date on the same basis, The estimated
annual charges for maintenance and operation have been taken from pro
G i
jections prepared by the Corps of Engineers. Where annual maintenance
and operation costs for recreation were not separated as to immnediate
i
3.6
10
.t1Y3
`^die 1.iV. yvn;
1
4 ,
i
Table 3.1 jj
r Preliminary Estimate of Denton's Costs for the Aubrey Pro•ect r°
Capitai Cost Debt Service Maint. & Op. Total Annual '
. Initial Costs ~ , iG7 97t
1
Water supply $13,143,800 $ 623,931 $ 24,364 $ 648,295
Recreation I,825,460 86 654 G2y,822 716;47fr tsn, i8f
! Total 14,969,260 ,710,585 $ -_654;•l86 364•,771
j id'F'~9y r-fr6f,yl
Additional Deferred and Future Costs 99Tbs
E ~
~r E Water supply $12,303,700 $ 584,052 $ 10,634 $ 594,686
Recreation 1 106,685 52 534 381,829 -434--369• -70Pf
Total 3,410,385 636,586 .392; 63 •1;029:f W
Over-All Costs, Immediate and Future 7°2 y~9 ~YG, vf1
• 2G3, ono
{ Water supply $259447,500 $ 1,207,983 $ 34,998 $ 1,242,981 {
Recreation 2,932,145 139 188 •1,01.1,651 1;150••839- ydzi0010
Total $28,379,645 1,34 71 1;046;649 $
93;820
applicability versus future applicability in the government estimates, ~E
they have been divided in proportion.to the amounts of capital cost
attributed to initial and future development
Table 3.1 indicates that the initial y payments for the Aubrey {
project, covering debt service, maintenance and operation, would be ap- ~
ley%ooo per le4e.
proximately,,$a,~66-wri-44-en. Assuming an annual average water use of j
15 MGD, which is the rate predicted for Denton in about 1985, this cost
a,naec wiaerr/y /l:•
would represent an increase of~-ea y-2-6* per thousand gallons if applied
uniformly to the City's total water consumption at that time. Similarly,
if it is assumed that the payments will rise to the indicated total
amount of some,+2-r394 million per year about ten years thereafter, in
1995, when the water use rate is expected to be around 23 MGD, the across-
the-board incremental cost for water as of that time due to the Aubrey
I { i
{
3.7
10 7
Y. Ta 14
fProject costs will be approximately ZGl
j O per thousand gallons,
,
It may be .convenient to also view the Aubrey supply unit costs in '
to s of full utitiza
! tion
of the 21.2
B9AGd'y MGD yield, Taking the annual cast I
of~`~};~64,} for the initial investment on Aubrey and dividing by the
1 total yield. of 21,2 MGD, the unit cost amounts t 14-,•6¢ per 1,000 gallons.I
Similarly, for 21,2 MGD at /'7y6v r
the annual d cost of -$`1-r02-g.;.ggg^ oo the deferred
investment, ?-e
the unit cost would beA13:-3i~ per 1,000 gallons. The combined
i annual cost at ~ 2i ; G~
, ,IA A for 21.2 MGD, would be a&A
j IThis foil utilization a roar A per 1,000 gallons.
pp h to estimation of unit costs will appear
in Chapter 6 as a means of comparison with unit costs for the long-range '
supply.
It should be emphasized that these costs are not final, The capital
costs are subject to change based on the actual cost of project con-
struction. Maintenance and operation charges will be incurred based on
the actual costs from year to year, The City will be entitled to
derive
some revenues from the recreational facilities and can tnas offset the ,
i
! increased water charges to the extent of such recreati ;
( anal revenues,
Nevertheless,, the foregoing figures are at least reasonable guidelines
i
to the probable cost of the Aubrey supply and are considered to be as
j
!!definite as is possible at this stage, '
i
}
•t
.Y~
1
POTENTIAL W8TER SUPPLY SOURCES
4,1 General
Once the combined Lewis vi•l1e-Aubrey system is fully utilized, Denton
will. then be required to turn to an additional source of supply. Figure
4.1 illustrates that this supply will in all likelihood come from a source
- more distant from Denton, since the construction of Aubrey Reservoir
f ! will essentially complete water supply devel~,pment in the upper Trinity
River Basin. Individual examination of the existing reservoirs and lakes
in this region points lap the fact that water in these developed supplies '
.is already committed to other cities and water districts. The West Fork
drainage basin, which contains Lake Bridgopor't, Lake Amon G. Carter,
Eagle Mountain Lake, and Lake Worth, is fully committed to Fort Worth
and other cities in the surrounding area. The East Fork yield, developed
by Lavon Reservoir and L
~ ake Ray Hubbard, has prier claim by the City of
Dallas and the North Texas Municipal Water District. Grapevine Reservoir
}
on Denton Creek does not provide a possible source of water for Denton
E since it is owned jointly by the City of Dallas, the City of Grapevine,
and by the Park Cities Municipal Utility District.
The only other major water supply project now proposed in the upper
Trinity Basin is the Corps of Engineers Lakeview Reservoir on Mountain
i
Creek,, in southwest Dallas County and southeast Tarrant County. This
is an unlikely source for Denton, which will need more water than the
Lakeview Reservoir can provide and has other, more economical options to
choose from. Lakeview is estimated to yield 12.1 MGD of new supply,2
part of which is already being spoken for by commnunities nearer to the
4,1
11 I
`IKCi[~i':1
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i ~ r.' rr 1" . ~ Y ~1\ ter:✓~...._..
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r ~ r {j• IN 1 1 I µ..I1 ~ iC , ~rc. ! ,r I
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lake site than Denton is. Present estimates2 indicate that the water will
cost about 50~ per thousand gallons, which is appreciably more than other €
possibilities that will be discussed later in this section.
In the past, a reservoir has also been considered by the Corps of
j
Engineers for the Roanoke site on Denton Creek, upstream from Lake
~ i .
Grapevine. The Roanoke protect, as presented in former studies,4 would
have no conservation storage itself, but would provide new flood control
storage which would allow an increase in the conservation storage capacity.
1 and yield of Grapevine Reservoir. No funds have been appropriated to
date for advanced planning of the Roanoke project. As with the Lakeview
Reservoir, preliminary indications are that the additional yield would
E ! be relatively small and the cost of the water relatively high. This
j source is not considered in further detail in this study because there
c are apparently several more promising alternatives open to Denton.
E t
s Recognizing the restricted availability of added water supply in
the upper Trinity River Dasin, Denton should look to neighboring basins
for a long-range source, to be developed by the late 1990's. There are
i
problems of water quality and limited amounts of undeveloped yield in
i ,
the Brazos River Basin. The chemical quality of the water of the main
i
stem of the Red River is not satisfactory for municipal use. It is clear.
that the best prospects for consideration by Denton are (a) the upper
Sulphur River Basin, (b) tributary streams of the Red River below Lake
Texoma, and (c) the upper Sabine River Basinf
Focusing attention on the lowen tributaries of the Red River and
basins to the east, it is seen that the proposed Sulphur Bluff and Cooper
j
Reservoirs in the Sulphur River Basin, the proposed Bois d'Arc Reservoir
4.2
y'"d._i PJ• SS.
!i f~L
1~ 1
in the Red River Basin, and the proposed Tri-Lakes System in the Sabine
River Basin provide the most likely solution to Denton's future water
needs in terms of distance to potential sources of supply. These are
discussed in detail in the following pages.
4.2. Pro osed Water Sources
i
r 4.2.1 Sulphur Bluff Reservoir
The Sulphur Bluff Dam site is about 90 miles northeast of Dallas
I and extends across the two tributary forks of the Sulphur River, crossing
the South Sulphur at river mile 3.6 and the North Sulphur at river mile
5.5. The dam site is about 15'miles east of Cooper, Texas, and about two
miles north of the town of Sulphur Bluff. The total drainage area
upstream from t, site amounts to about 1,026 square miles, of which
645 are in the South Sulphur River basin and 381 are in the North Sulphur
River basin. Of the total drainage area, Cooper Dam will intercept run-
off from
476 square miles on the South Sulphur,
i
Sulphur Bluff Reservoir is proposed to be built in two stages.
1 The principal structures of Stage 1 would include an earthen dam across
1
the South Sulphur River and a spillway controlled by six 401x28' tainter
gates. The second stage, or ultimate development, would include an
earthen dam across the North Sulphur River and a channel excavated
through the divide to conne^t the two arms and equalize the water level.
It would be possible also for the total Sulphur Bluff project to be
constructed at one time should it be desired.
The total project, constructed with the proposed top of water
supply pool at elevation 401.0, will yield 227.4 MGD. This assumes
4.3
,a
t,
Cooper Reservoir to be operative upstream at an annual demand equal to
its yield. The 107.4 MGD yield from Stage I of Sulphur Bluff is tenta-
tively scheduled for development in about 1990. Sulphur Bluff 11 will
be constructed at a later and yet undetermined date. Water rights at
Sulphur Bluff have not yet been applied for, although the North Texas
Municipal Water District and the City of Dallas have botH included
the project as a tentative source of supply in their to
j ~ ng-range planning.
4 I The estimated cost of the Stage I dam and reservoir is $13,897,000
including interest during construction. An additional $23419,000 would
be required to construct the Stage 11 portion of the project. These
costs are based on estimates
given in Reference
2, ~ d updated In accordance
with.1975 price indices5 (see Appendix B). The annual cost of water in
i the reservoir for Stage I, using 30-year bonds at 7% interest and an
annual operation and maintenance cost of $1179200 would be computed as
follows.
i
Local Sponsors` Annual Annual
' G:tpital Total ~
Cost Debt Service Operating Annual
Cost Cust Cost
$73o897,000 r
$6,955,400 $117,200 $610729600
Annual cost for the incremental yield of Stage II would be as follows,
Local Sponsors' Annual Annual
Capital Debt Service Operating Total
! Cost Annual ,
f Cost Co~tr Cost
$23,819,000 $1,9190600 $15,700
$1,935,300
,
( In the event Denton utilizes a portion of the Sulphur Bluff suppI
Yt
it will probably develop water transmission facilities jointly with other
entities. The facilities at Sulphur Bluff would include a pump station
I
E
4.4
10
s71
`l
rt
+i
at the Sulphur Bluff I project and a pipeline from that,pump station to
Cooper Reservoir. Transport of water from Cooper Reservoir to the
Trinity River Basin could be accomplished either by pipeline or by canal.
The point of input in the Trinity River Basin would be a tributary stream
to Lavon Lake. Water would then be transferred directly from Lavon Lake
to Lewisville Lake for consumption by Denton. One attractive feature
of this project is that the topography would allow water transport in I
-i ! part by canal. Yransmission by canal should be considerably less ex
r. pensive than by pipeline.
4.2.2 Cooper Reservoir
i
Cooper Reservoir is an authorized Federal multiple-purpose project
f under the jurisdiction of the Corps cf Engineers, New Orleans District.
The dam site is located at river mile 23.2 on the South Sulphur River in
II Delta and Hopkins Counties, Texas, about 78 miles northeast of Dallas.
I The proposed reservoir will have flood control storage of 131,400 acre-
. I
feet and active water supply storage of 273,000 acre-feet, which will
I yield 107.1 MGD. Water rights are divided among the Sulphur River
Municipal Water District, the City of Irving, Texas, and the North Texas
Municipal Water District. Of the total yield of 107.1 MGD, the Sulphur
River Municipal Water District is permitted to withdraw 28.1 MGD, and the
City of Irving and the North Texas Municipal Water District are each
permitted to withdraw 39.5 MG0.2
The estimated cost of the Cooper project is $68,955,700 including
interest during construction. This As based on the July 1972 cost esti-
mate furnif'ned by the Corps of.Engineers, escalated on the basis of
Enjineeri~nc News Record construction cost indices to April 1975 price
4.5
0 '
levels, The local sponsors' share of the project is estimated to be
$28,182,500, and the estimated annual cost, based on 50-year financing
at 4.371% interest, would be as follows:
Local Sponsors' Annual Annual Total
Capital Debt Service Operating Annual
Cost Cost Cost Cost
$28,182,500
Ei,395,900 $80,100 E1,476,000
i
As stated, the water rights to the proposed Cooper Reservoir are
i already spoken for by the City of Irving, the North Texas Municipal Water
District, and the Sulphur River Municipal Water District. However, of
i
its 28.1 MGD, the Sulphur River Municipal Water District has allocated
a total of 25 MGD to the Cities of Sulphur Springs and Cooper, which,
~ j
due to the delayed completion date of Cooper Reservoir, may be required
f
to seek other supplies instead, Sulphur
Springs has recently P
I comleted
Ia new reservoir on White.Oak Creek. If the Cities of Sulphur Springs and
A
I Cooper do not make use of the Cooper Reservoir supply, as much as 25 MGb i
might then become available for use by others, Thus, although Cooper
Reservoir is not at present an apparent option for Denton, it should be
kept in view as a potentially viable alternative if a significant part of
the yield should later be found surplus to the probable needs of the
Sulphur River Municipal Water District.
If Cooper were developed as a supply, it would naturally be
operated much as the Sulphur Bluff system, Transport of water from Cooper
would be achieved through pipeline or canal from Cooper to Lavon. Water
would then be transferred from Lavon to Lewisville through pipeline. The
inherent similarity of the Cooper transmission system to the Sulphur Bluff
i
4.6
"1 ;!1
1
transmission system would allow realitively simple substitution of Cooper
Reservoir into the overall plan of transporting Sulphur River Basin water
to Denton. Therefore, this study will incorporate Sulphur Bluff as a
water supply alternative for preliminary design and costing considerations,
with the implication that Cooper could later be included or substituted
in the plan on a firm basis if acquisition of that water becomes feasible.
4.2.3 Bois d'Arc Creek Reservoir
- The Bois d'Arc Creek Reservoir is located about 15 miles to the
I
northeast of Bonham, at the confluence of Bois d'Arc Creek and Honey
j Grove Cr,,k. (This should not be confused with a smaller reservoir once
? 3 investigated by the Corps of Engineers at a location farther upstream on
Bois d'Are Creek.6) Bois d'Arc Creek flows into the Red River near the
Fannin-Lamar County line. The proposed lake should have a normal water
surface level not higher than elevation 530.01 in order to avoid backing
water up on the face of.Lake Bonham Dam, At that elevation, the storage
capacity would be 329,238 acre-feet. Assuming a net usable conservation
capacity of 300,000 acre-feet, after allowance for sediment and dead
storage, the yield would be 94,500 acre-feet per year, or 84.3 MGD, if
the entire conservation pool were utilized and 75,000 acre-feet per year,
or 66.9 MGD, if a safety factor reserve equal to one year's use were left
in storage at the end of the critical drouth of record.6
At 1975 price levels, the capital cost of the Bois d'Arc Creek
Reservoir (see Appendix B) is estimated to be $27,7630600, including
interest during construction, Assuming equal yearly payments on 30-year,
•7% bonds, the annual cost of debt service would be $2,237,500, On the
additional assumption that the cost of maintenance and operation would
4.7
k~
!Y
r. .1
t
r
k
be 0.3% of the initial investment, the overall costs would be as follows:
r1,
Total Annual Annual Total
Capital Debt Service Operating Annual
Cost Cost Cost Cost
$27,763,600 $2,237,500 $83,300
$2,320,800
It would be anticipated that development of the Bois d'Arc Creek
project would be a joint effort, with Denton being a co-sponsor. Since
Denton will need only 30 MGD for its long-range needs to the year 2020,
i
I, a significant portion of the yield could be sponsored by others, thus
making the project easier economically, The Cities of Sherman and Denison
would be logical choices in seeking other sponsors for the project,?
Assuming Sherman-Denison participation, the plan to take water from the
Bois d'Arc Creek Reservoir would involve constructing transmission
1 { facilities from Bois d'Arc Reservoir west to the-Trinity River Basin,
with a take-off near Sherman to fulfill the needs of that area. The
pump station at Bois d'Arc Reservoir would be supplemented by a booster
station near Sherman to transport water. from the Red River Basin to the '
Trinity River Basin. The point of input in the Trinity River Basin would
be Range Creek, a tributary of the Elm Fork above the proposed Aubrey
Reservoir,
4.2.4 Tri-Lakes System
The proposed Tri-Lakes project is in the Sabine River Basin east
of Dallas and consists of the proposed Mineola, lake Fork and Big Sandy
Reservoir projects. The Mineola site, which was recently re-designated
as Carl L. Estes Lake, is on the Sabine River immediately downstream from
Lake Tawakoni and will back water against the Iron Bridge Dam, Lake Fork
4.8
1~ J
f~
and Big Sandy Reservoirs are on creeks of the same names which are tri-
butaries of the Sabine River, Mineola Dam is about 93 miles from
Denton, Lake Fork Dam about 103 miles, and Big Sandy Dam about 120 miles.
Lake Fork Reservoir, which will be owned by the Sabine River
Authority, is currently in the early construction stages. Water rights
have been obtained for the use of 120,000 acre-feet per year for in-
dustrial purposes (to be used for generation of power) and 44,940 acre-
feet per year for municipal and domestic purposes. Completion of the
'I dam is planned for the latter part of 1978. The permitted withdrawal A
i
rate from the Reservoir is 147.2 MGD, and the total cost is estimated at
I
$60,000,000.2
The Mineola and Big Sandy projects are multi-purpose reservoirs for
flood control, water supply, recreation, and fish and wildlife enhance-
ment. The projects are planned for construction by the Corps of Engi-
neers, with the Sabine River Authority as the local sponsoring agent.
The yield from water supply storage of the project is estimated to be
91.3 MGD from Mineola Reservoir and 64.9 MGD from Big Sandy. The esti-
mated costs of the reservoirs, including interest during construction,
are $141,876,000 for Mineola and $62,284,000 for Big Sandy. If Denton
were to develop a supply from the Tri-Lakes system, the most likely j
source would be the Lake Fork project. To transport water from this
project to Denton would require a pipeline extending from the lake to
the northwest, around the upper terminus of Lake Tawakoni, and then west
to Lavon Lake. Water would then be pumped directly from Lavon Lake to
Lewisville Lake as in the Sulphur Bluff plan, However, Lake Fork and
the other reservoirs of the Tri-Lakos system would obviously be more
4.9
'Van
F;
+i
, it
if II
f
r.
expensive than the other alternative solutions. With roughly the same
basic water cost as Sulphur Bluff and Bois d'Arc, the Lake Fork water
would require transmission over a distance 20 miles longer than that for
the Sulphur Bluff system and about 40 miles longer than the transmission
system from the Bois d'Arc Reservoir. Additionally, the terrain from
/ j Lake Fork to Lavon would not be conducive•to canal construction, thereby
{ further tending,to eliminate Lake Fork as a competitive alternate to
Sulphur Bluff. Thus, for the purposes of this plan, Lake Fork does not
seem•to be competitive with either Bois d'Arc Creek or Sulphur Bluff as
a practical solution to Denton's long-range water supply needs, and
j primary attention will, therefore, be focused on those two alternatives.
4.3 Summary of Alternatives
This chapter has presented an overview of water availability in the
r
North.Texas river basins, with the general conclusions (a) that con-
struction of Aubrey Reservoir will more or less complete the water
► development in the upper Trinity River Basin and (b) that long-range
water requirements for Denton must be met from a source in one of the
surrounding basins, Additionally, from water quality and general engi-
neering considerations it was concluded that the probable best source of
j water could be further narrowed to the Bois d'Arc Creek tributary of the
Red River and the North and South Forks of the Sulphur River. Actual
water supply facilities would take the form of either a reservoir on the
lower portion of Bois d'Arc Creek in the Red River Basin or a two-stage
reservoir on the North and South Forks of the Sulphur River. It would
be anticipated that joint development would occur, with Denton taking
only part of the yield, in either case.
J
4,10
3
F ~f
2e ICI
Upon initial examination, these sources appear to be quite favorable
for development. From the standpoint of quality, both sources indicate
a relatively high grade of water, The range of total dissolved solids
will vary from about 100 mg11 to 400 mg/l for both supplies, with the
average around 250 mg/i for Bois d'Arc and about'100 mg11 for Sulphur
Bluff. The concentration of chlorides will vary from 10 mg/1 to SO mg/1
1 for both supplies, with the average at about 35 mg/l. Sulphates in both
streams will range between 20 mg/l and 70 mg/l, with the average at
r about 35 mg/1. Biological quality in both watersheds is also quite
i
good. No significant domestic or industrial wastes are discharged into
j
these watersheds. With the enactment of recent Federal water pollution
control legislation the water should continue to demonstrate a high
degree of chemical and biological quality.
Having isolated two alternate sources of supply and having determined
i the two as being feasible from the water quality aspect, the decision as
f to the specific selection will hinge on timing and estimated cost. As
to the time schedule, Denton is expected to exceed the Lewisville-Aubrey
J capability by about 1997 and will need to look toward an additional {
supply at that--time. Since use of the Bois d'Arc supply would lead to 1
Denton accepting a major share of the financial responsibility for that
project, the reservoir and facilities could presumably be constructed
at a date convenient to Denton. It appears, at present, that,the Sulphur
Bluff protect may be developed in about 1992 to meet the needs of other
Ih potential participants,2 and that date would also be generally compatible
-with Denton's requirements.
1
4.11
r
4
WtiYd4 7
¢D04iU - N:fVlilEFY
u
.;'1 tNLt
The water quality and probable schedules of development for
E Bois d'Arc Reservoir and Sulphur Bluff Stage I are acceptable for Denton's
purposes, so cost remains the primary criterion for °lection of a pre-
ferred long-range water supply. Details of the system designs and
estimated development and operation costs are covered in the next section.
i
i
i
}
1
i
L '
i
i
i
1
4,12
yJ
Y
nl j
J
I
LONG RANGE WATER SUPPLY DEVELOPMENT i
•
5.1 General
i
pre-
Figure 5.1, which is an extension of Figure 3.1, indicates the pre-
viously developed conclusion that the Lewisville supply and the proposed
Aubrey supply will be sufficient to provide Denton's water needs through
about 1997. At that time, Denton's total available supply will be 25.7
I G
f + MGD. Placing the 2020 water requirement at 54.9 MGD, the long-range
I water development will need to supplement the Aubrey-Lewisville supply
by about 30 MGD. Figure 5.1 illustrates a total water supply development {
of 65.7 MGD, or slightly more than enough to meet the 2020 requirements.
Three alternatives have been developed for transferring the necessary
i
30 MGD to Denton. Two alternatives involve the proposed Sulphur Bluff
system and the other involves Bois d'Arc Reservoir. For all alter-
natives, 30 MGD would be developed in cooperation with other entities,
i
J from either the Bois d'Arc supply or the .sulphur Bluff project. Either
~ j
project would be constructed between 1990 and 1995 to ensure availability
by 1997.
i
5,2 Transfer of 30 MGD to Lewisville Lake
The various alternatives for transporting 30 MGD to Lewisville Lake
for eventual transfer to the Denton water treatment plant will be pre
p
rented in the form of three proposals, designated Plan I, Plan Ii'
and Plan III. Plans I and II entail' the cooperative construction of
the Sulphur Bluff I project and the joint development of transportation
facilities originating at Sulphur Bluff I and extending through Cooper
6.1
`TA°iSti. I
a
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OENTON WATER SUPPLY SYSTEM
OEVEL9PMENT TO YEAR 2020
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ONG NGE SUPPLY- 0 M 0 D
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IE AUBREY SUVPIV
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DENION VIECO FROM V E
XISVNO l£WISYICL£ RES RVOIR
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11070 1990 1990 2000 2010 2020
YEAR
FIGURE S.I
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Reservoir and Lavon Lake, terminating at Lewisville Lake, Plan 11 would
differ from Plan I in that Plan II would call for canal delivery from
Cooper Reservoir to Lavon Lake instead of conveyance by pipeline. Plan
III would provide for pipeline transmission of Bois d'Arc water for
release into an upper tributary of the Elm Fork above the proposed
Aubrey Reservoir. 1
In the ensuing pages, a detailed description of each proposed
system Is presented, with specifics given on system designs and cost
estimates. Associated with each plan is a figure outlining significant
•aspects of the system design concept,
1 6.2.1 Plan I
( Plan I, illustrated in Figure 5.2, consists of constructing a
pipeline from Sulphur Bluff Stage I Reservoir to Cooper Reservoir, a
pipeline from Cooper Reservoir to Lavon Lake, and a pipeline from Lavon
Lake to Lewisville Lake. Since the supply would be developed jointly
1
with others, the pipelines from Sulphur Bluff to Cooper and from trooper ;
to Lavon would be constructed with capacities much greater than the 30
MGD Denton requirement. The pipelines would, therefore, be constructed
with Denton 'owning a share proportional to the fraction•of the pipeline
capacity needed by Denton. The pipeline from Lavon to Lewisville would
The estimated annual
be built solely by Denton at a capacity of 30 MGD.
f costs to Denton for Plan Fare summarized in Table 5.1. Included in j,
this table are the costs for the basic supply, the pipeline from Sulphur
Bluff I to Cooper, the pipeline from Cooper to Lavon and the pipeline
E i
from Lavon to Lewisville, Principal and interest payments are based on
30 year bonds at a 7% rate, The Denton share of the Sulphur Bluff i
5,2 '
HAIL
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FIGURE 5.2
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PLAN i DEVELOPMENT
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Table 5.1
Estimated Annual Cost of Plan I.
Transporting 30 NO of Raw Water From
Sulphur TI-Of I to Lewisville Reservoir b Pipeline*
Sulphur Bluff Water Supply
Principal & Interest on 20,639,400 $1,6630300
Operation and Maintenance Cost 32,700
1,696,000
Raw Water Pipeline from Sulphur Bluff I
keservoir to Cooper Reservoir
Principal & Interest on 2,334,900 $ 1880200
t I Power @ 2.0t per KWH for delivery of 30 MGD 177,100
Labor 7,500
Pump Station Maintenance 69300
Pipeline Maintenance 800
379,900
Raw Water Pipeline from Cool,.r Reservoir
to Lavon Lae
Print pal 9 --Interest on $5,964,300 $ 4809700
Power @ 2.0¢ per KWH for delivery of 30 MGD 411,900
I' Labor 10,I00
Pump Station Maintenance 100600
Pipeline Maintenancc 2 300
915,600
Raw Water Pipeline from Lavon Lake to
-Lew`isvTfle Lake
Pr n clpaf & Interest on $10,923,200 $ 880,300
Power @ 2.Ot per KWH for delivery of 30 MGD 3590500
Labor 28,400
Pump Station Maintenance 18,300
Pipeline Maintenance 5 000
$1,291,500
ESTIMATED ANNUAL COST - PLAN I $4,2839000
*All costs represent Denton's share,of respective items
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water cost would be $20,639,400, calculated on the basis of Denton re- r
ceiving 30 MGD of the 107.4 MGD yield, or a ratio of 30/107.4 of the
Sulphur Bluff I
cost of' $73 84
7,000. Including its share of the operation
and maintenance ecss
Denton would Pay $7,696,000 annually for the
Sulphur Bluff I supply.
The p1poiine from,Sulphur Bluff I to Cooper would be 66 inches in
f diameter, would be about 9 miles in length, and would have a capacity of
Flo
107.4 MGD. The total capital cost for this pipeline would be $8,359,800,
of which Denton would have a $20334,900 share based on Denton `s 30 MGD
portion of a total capacity of 107.4 MGD. Using this capital cost as a
3 basis for calculating a principal and interest cost of $188,900 and
i
. adding power cost, labor; and maintenance, the total annual payment would
` amount to $379,900 for the raw water line from I ~ Sulphur Bluff I to Cooper
Reservoir.
f The raw water pipeline from Cooper to Lavon would have a diameter of
96 inches, a total length of about 33 miles, and would have a capacity
of 272 MGD. The 212 MGD includes water developed from both Cooper and {
Sulphur Bluff I. The total annual cost to Denton for the pipeline
installation and operation would be $915,500, including the annual
princt.pal and interest payment of $480,700 calculated from Denton's
$5464000 share of the total $42,150,800 pipeline 'cost.
f
J The raw water line from Lavon Lake to Lewisville Lake would be
wholly purchased and operated by Denton. The pipeline would have a
diameter of 42 inches to carry a flow of 30 MGD, and a length of 23.9
miles. The total capital cost.of this line would be $10,923,200, on
which the principal and interest payment would
be
$880,300, In
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power, labor, and maintenance costs, the total annual payment for this
section would be $1,291,500.
Combining the annual Sulphur Bluff water supply cost of $1,696,000,
'i
the Sulphur Bluff to Cooper pipeline cost of $379,900, the Cooper
Reservoir to Lavon take pipeline cost of $915,600, and the pipel'ne cost
j from Lavon Lake to Lewisville Lake of $1,291,500, the total annual cost
for Plan I.would be $4,283,000. Supporting data for all costs tabulated
t in Table 5:1 are located in Appendix B. I
I 5.2.2 Plan II
i
Plan II is illustrated in Figure 5.3, As in Plan I, Plan II
involves bringing 30 MGD from Sulphur Bluff I through Cooper Reservoir
j and Lavon Lake to Lewisville Lake, The distingui0ing feature between
Plan I and Plan 11 is the transfer of water from Cooper Reservoir to
I
Lavon Lake. Plan II utilizes the same system design as does Plan I
except that a canal would replace the pipeline between Cooper and Lavon,
4
f Given a topography conducive to canal construction and operation, a
u canal can be designed to carry a large flow at a lower capital cost than
a pipeline of comparable capacity, Additionally, since gravity is the
prime mover over much of the total distance, power costs for canal
operation are reduced greatly over power costs for pipeline operation.
The terrain between Cooper Reservoir and Lavon Lake does prove to
be suitable for canal constw.,^tion. The canal would originate on the
south shore of Cooper Reservoir near the dam, would then continue west R
roughly to the Sulphur-Sabine Basin boundary, and proceed northeasterly
to Arnold Creek, a tributary to the Fast Fork of the Trinity River above
Lavon Lake. The total length would be about 39 miles and would be
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' FIGURE 5.3
ii PLAN II DEVELOPMENT
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built to carry 307 PQGo, the combined yield of Cooper, Sui hur
and Sulphur Bluff II p Bluff I
excluding the quantity of water to remain in the
Sulphur River Basin. Although the total supply t
Sulphur River Basin up to 2020 will Include on Coop ad in the
.
Bluff I yields, the canal should be constructed to handleetherE combined
r
yield from Cooper, Sulphur Bluff I and Sulphur Bluff II.'
Costs associated with Plan l '
j I are shown in Table 5.2. 'Canal costs
i are estimated on the basis of Denton's 30 MGD s
r bare of 2
to be transported west from Cooper and Sulphur )2 MGD, the supply
Bluff I. The capital
cost of the canal attributable to Denton would be $43565,700 o
the principal and.interest,payment n which
would be
$361
labor, and maintenance, the total annual cost to'Denton lforutra sppor n
f 30 MGD from Cooper Reservoir to Lavon Lake would be $680,500. T ting
the other costs, including the bas- 1- suppl aking
y, the raw water line
from Sulphur Bluff to Coopers and the raw water line from Lavon Lake to
Lewisville Lake, the total annual cost would be $49047,900. In
Individual
costs are further amplified in Appendix B.
5:2.3 Plan III
Plan IIi, Illustrated in Figure 5.4, involves transfer of 30 MG
from the proposed Bois d'Arc Reservoir to the proposed Aubre
y Res D
An 84,3 MGD yield for Bois d'Arc Reservoir is assumed in Plaervoir.
Ill
the premise that the full capability of the reservoir would be utilized
with no reserve storage remaining after the critical period, The safe '
Yield during a severe drought would be 66,9 MGD, assuming a reserve
sufficient to supply one year's use would remain after the criti )
peFor equitable comparison with the Sulphur Bluff I pro Oct
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Table 5.2
1
Estimated Annual Cost of Plan II
Transporting 30 MGD of Raw Water from Sul hur Bluff to
Lewisv3TTe Reservoir Uti yzinn Comb ne Cana an P iel ne7ystems* i
I
Sulphur Bluff Water Su I J
Principal C -Interest on 2006390400 $1,663,300
Operation and Maintenance Cost 32 700
,696,000
Raw Water Pipeline from Sulphur Bluff I
i
Reservoir to Cocper Reservoir
Principal & Interest on ,334,900 $ 188,200
Power @ 2.Ot per KWH for delivery of 30 MGD 177,100
Labor 7.500
Pump Station Maintenance 6,300
Pipeline Maintenance, 800
379,900
Canal System from Cooper Reservoir to Lavon Lake
Principal Interest on $4,565,700 $ 3679900
Power @ 2.Ot per KWH for delivery of 30 MG0 239,90C
Maintenance @ 1.5% of Capital Cost 68,500
I Labor 4,200
8 , 500
i
Raw Water Pipeline from Lavon Lake to +
Lewisville Lake
Principal & Interest on $10,923,200 $ 880,300
Power @ 2.0¢ per KUH for delivery of 30 MGD 359,500
Laobr 28,400
Pump Station Maintenance 18,300
Pipeline Maintenance 5 000
1;29~150()
ESTIMATED ANNUAL COST - PLAN II $4,047,900
*All costs represent Denton's share of respective items
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~ PLAN III DEVELOPMENT
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yield of which is estimated on the basis of no reserve,. the 84.3 MGD
yield will be utilized for calculating Bois d'Arc water costs.
The pipeline for this project would run from Bois d'Arc Reservoir
to a point south of Sherman and would continue from that point to the
upper potion of Range Creek, which is a tributary of the Elm Fork of
Jay \ the Trinity River upstream from the Aubrey site. The portion of pipe-
line from Bois d'Arc to Sherman, running a total distance of 34 miles,
i i
would be 60 inches in diameter to accommodate the full yield of
{
' Bois d'Arc Reservoir, 84.3 MGD. At Sherman, 25 MGD would be taken off
E to supply the Sherman-Denison area. The remaining 59.3 MGD would be
pumped about 9 miles to Range Creek through a pipeline 54 inches in
diameter. It will be assumed that 29.3 MGD would be sold to other cities
and water districts in the region. Although the 30 MGD to Denton is
assumed to be a reasonable estimate of the City's long-range needs, the
25 MGD to the Sherman-Denison area is more variable and may, depending
i
on area needs, be supplemented by or may in fact be a supplement to the
29.3 MGD which will go to Lewisville Lake.
Estimated costs for this plan are presented in Table 5.3. All
costs are calculated using a fraction representing Denton's proportional
share of the water supply or water supply facilities. Denton's 30 MGD
share of the Bois d'Arc supply would cost $9,797,800, from which would
i
result a principal and interest payment of $789,600. Including operation
and maintenance, the annual cost for the basic water supply would be
$819,000. The capital cost to Denton of the pipeline system would be
$10,928,700, which would create a principal and interest payment of
$880,600. Including all principal and interest payments and power,
5.6
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Table 5.3
Estimated Annual Cost of Plan III
Transportino 30 MGD of Raw Water from
,Bois d'Arc Reservoir to Lewisville Reservoir b Pi eline
Bois d'Arc Reservoir Water Su 1 * '
Principal & Interest on 9,797,800 $ 7899600
Operation and Maintenance Cost @ .3% of
1 Capital Cost 29 400
619,000
Raw Water Pipeline - Bois d'A_rc Reservoir
to --man Takeoff*
I Principal & interest on $80110,000 $ 653,600
Power @ 2.U per KWH for delivery of 30 MGD 473,800
Labor 19,100
Pump Station Maintenance 15,900
Pipeline Maintenance 4,600 3
7,000
r
Raw Water Pipeline from Sherman Takeoff I
to~~_y**
Principal & Interest on $2,818,700 $ 2271200
€ Power @ 2.0t per KWH for delivery of 30 MGD 243,400
l Labor 12,000
Pump Station Maintenance 7,900
Pipeline Maintenance 1,300
(491,800
ESTI14ATED ANNUAL COST - PLAN III $2,477,800
*Costs from Bois d'Arc to Sherman Takeoff based on Denton's 30 MGD
pro rata share of the 85 MGD Bois d'Arc supply
**Cost from Sherman Takeoff to Range Creek based on Denton's 30 MGD
pro rata share of the 60 MGD flow
i
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labor, and maintenance costs, the Bois d'Arc supply would carry an
annual cost of $2,477,800. Specific details on costs of the system
components are contained in Appendix B.
Presented below is a tabulation of the annual costs for transporting
30 MGD of water by the three proposed plans to Lewisville Lake for
ll
eventual transfer to Denton;
Plan Source Annual
Cost to Denton
of 30 MGD
1. Sulphur Bluff I $4,283,000
II Sulphur Bluff I $4,047,900
III Bois d'Arc $20477,800
Table 5.4 presents a summary of the schedules of development for, and
f ~
l(~ pertinent data on the three alternative systems proposed for delivering
l the Denton tong-range water requirements to Lewisville Lake.
5.3 Delivery, to Denton Water Treatment Plant '
Shown in Figure 5.5 is the schedule of development for the con-
veyance system„from Lewisville Lake to the Denton Water Treatment Plant.
With the existing pumping capacity and the newly installed 30-inch '
pipeline, the maximum delivery rate is 25.2 MGD, At the projected rate
of growth, the potential neak-day demand will exceed this capacity by
1975. As was reconinended previously in "Report on Water Supply System,"
1974, the City should increase the pumping capacity in the very near
~
future in order to accommodate the potential peak-day demand.8 By
replacing raw water pumps No, 2 and No, 3 with pumps of 8.0 MGD capacity
and by installing 10,000,000 gallons of terminal storage with a 4.0 MGD
5.10
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! 41
RAW WATER PUMP STATION
AND SUPPLY LINE DEVELOPMENT
r 115
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150
125 ' i
SUPPLY NE AND j
p PUMP SPA ION DEYELOPMEN !
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25
j 1910 1980 1990 2000 2010 2020
YEAR
FIGURE 5.3
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low-lift; pump station, it is estimated that the raw water transmission
facilities would be capable of pumping at a rate of 32.6 MGD. With
this arrangement, the pumring station would be sufficient to meet the
peak demand through about 1979,
In 1979, a second intake structure and pumping station will be
required. As determined by the trend projected in Figure 5.5, Denton
will require 125 MGD of additional capacity to meet the 2020 demand.
Future studies will have to determine the final configuration of the
~ proposed firtake structure and pumping station, but it will. be assumed
for costing purposes that an intake structure with the full 125 MGD
f
capacity will be built and pumping units will be added in two increments,
one of 60 MGD in 1979 and another of 75 MGD in the year 2000.
PipO ine construction will also follow the schedule indicated in
Figure 6.6. In 1979) a pipeline should be built to parallel the existing
27" and 30" pipelines, In the year 2000s a 48" pipeline would be laid
parallel to the pipelines existing at that time. The 42" and 48" pipe-
-lines would have a combined capacity of 125 MGD.
' Table 5.5 is a summary of costs associated with the transfer of
55 MGD from Lewisville Lake to the Denton Water Treatment Plant, The 1979
development would have a capital cost of $4,063,200, on which the princi.
pal and interest would be $327,600. Including operation and maintehanco
costs and assuming an annual average flow of 28 MGD, the annual cost of
this system would be $545,200, 'rho year 2000 dovelopment would cost
11 $3,4016900 for an additional 75 MGD~of pumping capability, Principal and
I
interest on this amount would be $274,200. Assuming an average delivery
t rate of 27 MGD for this portion of the plant, the total of principal and
rill
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Interest and operation and maintenance would place the annual cost at
$467,900. The combined 1979 and 2000 development, which would have total
capability of 125 MGD, would cost $1,003,100 per year assuming an annual
average flow of 55 MGD,
The costs listed in Table 5.5 include only those facilities which
are proposed for construction in and after 1979, It is assumed that the
} entire average demand of 55 MGD will be transported through the new
system, and the old system w11 be used for standby. Elemental costs
i
comprising the total capital cost are detailed in Appendix B. Annual
costs and unit costs for the system are described in Table 5,6,
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Table 5.5
Estimated Annual cost of
ransporting 55 GD from
Lewisville Lake -o the Denton Water Treatment Plant*
1979 Development Stage I
Construct 125 MOD pump station (50 MOD capacity installed.) and
42" pipeline
Principal & Interest on $4,063,200 $ 327,540
Power @ 2,0t per KWH for delivery of 28 MOD 182,200
Labor 22,000
Pump Station Maintenance 11,700
r Pipeline Maintenance 1,800
Subtotal $ 545,200
2000 Develq ment - Stage 11
Install additional 76 MGD capacity in existing,125 MOD pump station and
j Construct 48" pipeline
E Principal & interest on $3,407,900 $ 274,200
Power 0 2.Od per KWH for delivery of 27 MOD 161,700
Labor 26,500
Pump Station Maintenance 30500
Pipeline Maintenance 20000
Subtotal $ 457,900
Total $1,003,100
*Assume now 125 MOD plant will take full 56 MOD average load;
old plant will be on standby.
5.14
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Table 5 6
from Le Estimated Unit Costs for Trans ortin 55 MGD
`w'is`v~1~e a-e_~ DentontOr reatment'p1
ant
Phase Average Annual
Flow Cost Unit Costs
MGD Cost Per Cost Per
Acre LFoot 1 X000 Gal '
Stage I 28 1979 Development $ 546,200 $17,30 6,3
Stage 11
27 {
2000 Development $ 457,900 $16,14 4,60
' Combined System
66 $1,003,100 $16,42$
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' , 5,15
` Y
SUMMARY AND RECOMMENDATIONS
6.1 Summary of Existing and Proposed Water Supply Sources
The City of Denton currently utilizes the Lewisville Reservoir as
its primary source of supply. Denton's share of the Lewisville supply
is 4,6 MGD, based on an agreement made'with the City of Dallas in 1962.
In addition to this amount, Dallas has agreed to, sell Denton up to
' . I
13 MGD of its share of the Lewisville yield until 1980, so that by right
and through purchase Denton presently has access to a total of 11,5 MGD
from Lewisville Reservoir, Denton also owns a well system which will
produce about 4.0 MGD for a short pumping duration, but it will not
sustain this yield on a year-round basis, The well system should not be
4
considered as part of Denton's firm water supply.
j ~
Denton'now has a total supply of 17,6 MGD, which should satisfy
demand until about 1988. The ori'ginai arrangement by which Dallas
j -agreed to sell part of its Lewisville yi(ald to Denton was predicated on
the assumption that the proposed Aubrey Reservoir would be in operation
L11
by 1980 and that after 1980 Denton would not require supplementary
supply on a purchase'basis. Since it is evident now that Aubrey Reser-
voir will not be completed by 19809 Dallas representatives have Indi-
cated that they would keep the 13 MGD supply available for purchase
after 1980 at a re-nogotiated price, On that basis, Denton will have
the 17.5 MGD supply at its disposal until Aubrey Reservoir hoes into
t service, at which time the 13 MGD purchase arrangement will no longer be
effective,
6.1
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It is anticipated that the Aubrey project will be :In operation
prior to 19880 thereby providing Denton afirm supply at that time in
addition to the existing Lewisville yield, The Corps of Engineers has
estimated that the Elm Fork yield will be increased by 81,4 MGD upon
i
construction of Aubrey Reservoir. Denton will receive 26% of the in-
creased yield, amounting to 21.2 MGD, in return for Denton's proportional
participation in the project. Taking the 4,5 MGD as the original Denton
E share of the Lewisville yield, and adding the 21.2 MGD increase from
Aubrey, Denton will have available a total of 25.7 MGD, This supply
should meet Denton'
needs until approximately 1997, at which time
another supply will have to be acquired,
Through examination of existing and proposed reservoirs in the
North Texas region, it is apparent that Denton should look to neighboring
basins for a source of water after 1997. Through considerations of
+ prior water rights, distance to source, and water quality, it has been
l concluded that the proposed Bois d'Arc Reservoir fn the Red River Basin
t
and the Sulphur Bluff Reservoir in the Sulphur River Basin would be the
best prospects for future water development by Denton.
In order to satisfy demand in the year 20200 Denton will be ro-
! quired to supplement the 25,7 MGD sufficiently to accumulate a total
supply of 54.9 MD. Thus, the long-range requirement for additional
E water threrigh 2020 would amount to about 30 MGD. Since the yield of the
Bois d'Arc Reservoir would be 84.3 M% and the yield of :sulphur Bluff
would be 107,4 MGD, the 30 MGD could be more than satisfied at either
site, It is anticipated that with either alternative, Denton would
cooperate with other cities In construction of the reservoir and
1 N~
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Pipeline farilities development and would share the costs in proportion
W to its 30 MGD requirement.
It is concluded that development of the long-range resources should
be based on one of three plans. Plan I would involve transporting water
entirely by pipeline from Sulphur Bluff I Reservoir to Cooper Reservoir,
from Cooper Reservoir to Lavon Lake, from Lavon Lake to Lewisville Lake,
and finally from Lewisville Lake to the Denton water treatment plant,
l Plan II would transport water from Sulphur Bluff I as in Plan 1, but
would substitute a canal from Cooper to Lavon for the pipeline in Plan
I, Plan III would call for construction of Bois d'Arc Reservoir on the
lower end of the Boos d'Arc Creek and construction of a pipeline from j
r 1
E there to Range Creek, a tributary to the Elm Pork of the Trinity River.
Presented in Table 6.1 are the annual costs, calculated in Chapter 6 i
. ,
] for transporting water to Lewisville Lake by the three plans,
f
Table '6.1
Estimated Costs for
Transfer '6T 36`~IG6'to Leiu`r ilie Lake
Plan Source Annual
Cost to Denton
- of 30_ MGD
I Sulphur Bluff 1 $4,293,000
l1 Sulphur Bluff 1 $4,0475500
III Bois d'Arc $2,477,800
6.2 ecQnm~endatIons '
As indicated in Table 6.1, the Bois d'Arc plan is the least costly
alternative for developing'Denton's long-range water supply system
i
6.3
L
1
beyond Aubrey Reservoir. This plan would cost about 60% less than the
least expensive method of diverting Sulphur Bluff I water. The
Bois d'Arc alternative provides savings over the other two plans both
by virtue of the shorter transmission distance and the cheaper basic
water supply cost.
1 view of the cost consideration, it is recommended'that Denton
I pursue the Bois d'Arc supply as the solution to its long-range water
supply needs. It is believed that Denton should seek to negotiato with
r" other cities in the vicinity of the Bois d'Arc site, to create an agree-
ment on Joint development of the Bois d'Arc supply. Tho next likely ~
alternative would be Sulphu.p Bluff Reservoir with the canal from trooper
i
Reservoir.
i, Installation of conveyance facilities from Lewisville Lake to the
- Denton Water Treatment plant will complete Denton's long-range raw,water
requirements to the year 2020. It is recommended that, after developing
1 the full capability of the existing raw water delivery system from
Lewisville Lake, Denton should construct another pumping facility and
I
system of supply lines to accommodate the future supply, Based on the
potential peak-day water roquirement of 168 MGD in the year 2020 and
based on the maximum capability of 32,6 MGD of the existing plant with
modifications, about 125 )f new delivery capacity will be required
to meet peals water requirements in the year 2020. It is proposed that a
pumping station and intake structure be built in 1979 to accommodate the
full 126 MGD demand. Pumps• should ttien be installed as required by
demand. 'For estimating purposes it is assumed here that o.ie set of
pumps rated at 50 MGD would be installed upon construction of the plant,
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and another 75 MGO would be added in'the year 2000.
Table 6,2 gives a summarization of annual and unit costs for the
t.
Aubrey supply, the Bois d'Arc supply, and the water delivery system from
Lewisville Lake to the Denton water treatment plant. Unit costs are
calculated on the basis of the 21.2 MGD Aubrey yield for the Aubrey
supply costs, the 30 MGD long-range water requirement for the Bois d'Arc
costs, and the average 66 MGD pumpage rate for the Lewisville Lake to
' Denton water treatment plant supply system costs. The recommended
schedule of construction for Denton's long-range water supply and water
transmission facilities is detailed in Table 6,3, Also included in
Table 6,3 are the previously recommended modifications to the existing
raw water pump station.
Table 6.2
Estimated Costs for
Denton'
Phase Average Annual Unit Cost
Supply Cost Cost per Cost per
Acre-Foot 1000 Gail
Aubrey Supply i
~ Pay r~r
Initial
Deferred $,1-r02.9;049
Total 21.2 11GD lKr,~sf G~z y1 3
42a9aT820--• $ "11.• •30,90l-
Bois d'Arc 30,0 MOD $2,499,900 $ 74,10 22,8¢
Supply and
Supply System
Lewisville 6510 MGD $f,0ll)31100 $ 16.28 610¢
to Denton
Supply System
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Table 6.3
Schedule of Construction for
Denton'sTong-Range aater~up_ply Develo ment
1976-1977
Replace Number 2 and Number 3 raw water pumps with 8,0 MOD pumps-$102,200
Install 10 million gallon tank and low lift pump station-$317,800
1979-1980
i Construct 125 MOD pump station (50 MOD capacity installed) and 42"
j i pipeline to Denton Water Treatment Plant - $4,063,200
j 1980-1981
s
Construct Aubrey Reservoir - $28,379,645 (Denton's cost for 26% share;
21.2 MGD).*
1990-1995
Construct Bois d'Arc Reservoir - $27,7630600
A
Construct 85 MOD Bois d'Arc pump station, 85 MOD booster station, and
60" pipeline from Bois d'Arc to Sherman - $8,110,000 (Denton share for
30 MGD supply)
Construct 60 MOD booster station, 54" pipeline from Sherman Takeoff to
Range Creek - $2,81,8,700 (Denton share for 30 MGD supply).
1995-2000
~I
Install additional 76 MOD capacity in existing pump station and construct
'48" pipeline to Denton Water Treatment Plant - $3,4010900,
*Initial Capital'Cost is $14,9691260 and the deferred cost is $13,4101385,
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i APPENDIX A
1
REFERENCES
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REFERENCES
1. Texas Water Development Board: "Projections of Economic Activity
for Denton County, Texas," December 1972.
2, Freese and Nichols, Consulting Engineers, and URS/Forrest and
Cotton, Inc,, Consulting Engineers: "North Central Texas
j Regional Water Supply Study," November 1974.
3. Community Development Department, City of Denton, Texas: "Denton,
A Twenty Year Comprehensive Plan," 1974,
4., U. S. Army Corps of Engineers, Fort Worth and Galveston Districts:
"Comprehensive Survey Report on Trinity,River and Tributaries,
Texas," June 1962.
j
6,. MaGraw-Hill, Inc,: En~inee" ring News-Record MagazHe, quarterly
construction price index summary, June 9, 1975,
6. U. S. Army Corps of Engineers, Tulsa District: "Comprehensive
Basin Study, Red River Below Denison Dam," Tulsa, Oklahoma,
June 1068 (unpublished),
7. Freese and Nichols, Consulting Engineers: "'iexoma Region Areawide
Water Plan," March 19i2.
8. Freese and Nichols,'Consulting Engineers: "Report on Water Supply
System," July 1974.
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I APPENDIX B
DETAILED COST ESTIMATES
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TABLE OF CONTENTS
' P_a9e
Costing Criteria
Annual Salary Cost for Pumping Stations
B-2
Annual Cost for Sulphur Bluff Water Supply
B-3
T ,
able B-1 Estimated Cost of Bois d'Arc
Creek Reservoir
B-4
Table B-2 Pertinent Data and Estimated Capital
Cost for Raw Water Delivery system from
Sulphur Bluff I to Cooper Reservoir
B-5 I
Table B-3 Pertinent Data and Estimated Capital
Cost for Raw Water Delivery System from
Cooper Reservoir to Lavon Lake
8-6 it
Table B-4 Pertinent Data and Estimated Capital
Cost for Raw Water Canal System from
Cooper Reservoir to'Lavon Lake 84
Table B-5 Pertinent Data and Estimated Capital
Cost for 30 MGD Delivery System from
Lavon Lake to Lewi'svi7le Lake B-g
Table B-b Pertinent Data and Estimated Capital
Cost for Raw Water Delivery System from
Bois d'Arc Site to Aubrey Reservoir 8-70
Table 8-7 ,Pertinent Data and Estimated Capital
Cost for Raw Water Delivery.System iron,
Lewisville Lake to Denton Water Treatment
Plant
B-12
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f-~ COSTING CRITERIA
Cost estimates on pipelines were developed using the following guidelines:
j Pipelines Texas Water Development Board, Report 42:
"Cost of Transporting Water By Pipeline,"
March 1967. Add 71% for inflation to
1975 prices.
Right-of-Way $3,000 per mile
Right-of-Way
Contingencies 20% of ROW cost
1 ,
Pumping station estimates were prepared according to the following
schedule:
Pumping stations Texas Water Development Board, Report: 42:
"Cost of Transporting Water By Pipeline,"
€ March 1957. Add 84% for inflation to
1975 prices.
i
Excavation $2.00 per cubic yard
Annual costs are calculated as follows:
Amortization Calculated on a 30 year basis with an,
;
interest rate of 7%.
{
Power Cost $.02 per kilowatt-hour
Pipeline maintenance $5.00 per inch of diameter, per mile
Pump station
maintenance 1,5% of station capital cost
Pump station labor As shown in Figure B-1
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ANNUAL SALARY COST
FOR PU14PING STATIONS
f .
60
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f
40
30 f
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F
E
l0,00p
20000 30,000
40, 000
HORSEPOWER
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Annual Cost for
r1 Sulphur Bluff ater Supply
j January 1974 Costs
From "North Central Texas Regional Water Supply Study,"
URS/Forrest and Cotton, Inc., Freese and Nichols,
November 1974.
Sulphur Bluff I
1 Capital Cost $56,170,000
Interest During Construction 5,617,000
x,787.000
O&M Cost $ 104,500
Sulphur Bluff 11
i i
Capital Cost $18,526,000
Interest During Construction 1 389000
GAM Cost
$ 1a,DOO I
January 1975 Costs I
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Cappital costs include 19,.6% inflation
' 0&►4 cot includes 12,2% cost of living increasz
Sulphur Bluff 1
Capital Cast $679179,000
Interest During Construction 6,718,000
73,897,000
O&M Cost $ 1170200
Sulphur, Bluff 11
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t Upit;al Cast $220167,000
Interest During Construction 1,662,000
$•r U 9,000'
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ON Cost $ 15,700
01
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Table B-1 ;
r Estimated Cost of Bois d' Arc Creek Reservoir
Item Unit Unit Cost Quantity Amount _
Preparation of site L.S. $ - - 3 1000000
Core trench excavation C.Y. 1.00 244,530 244,500
1lettod and rolled embankment C.Y. 1.20 3,4116530 49093,800 '
Riprap blanket C.Y. 18.00 33,908 610,300
RipraP C.Y. 20.00 81,707 1,634,100
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Service spillway and outlet L.S. 470,000
Mulching Ac. 1200.00 48 570600
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Irrigation system L.S. - - 27,600
}
Land clearing Ac. 160.00 41461 6690200
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Relocate FM 1396 L.S. 219520200
i Relocate 138 KV power
f transmission line L.S. - - 413,200 ;
I
i Wrap and weight 10-inch natural
gas line L.S. - 7$0800
Riprap protection on downstream - -
slope of Laku Bonham dam L.S. 179,200
Engineering and contingencies
® 26ii .2,882,640.
Subtotal - Reservoir $140413,100
Land purchase in fee Ac. 600,00 19,670, 9,8350000
,
Flood easement Ac. 100.00 49680 468,000
Land acquisition' ` 523,600
Total $26,23q,600
{ Interest during construction 21524000
1 Total 1,763`,666
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Table B-2
Pertinent Data and Estimated Capital Cost for
Raw Water Deliver System from Sulphur Bluff I
to Cooper Reservoir
Pertinent Data
Average annual pumpage 107.4 MGD
/ Design delivery capacity 125 MGD
Pipeline length 8.7 Miles
I Pipeline diameter 66 Inches
Number of pumping units (including standby) 6
Name plate capacity per unit 26 MGD
Total dynamic head 233 Feet
Horsepower per unit 1,100 HP
Total installed horsepower 6,600 HP
Estimated Cost
I
! Pump station $1,602,600
11 Intake structure 766,000
I 4.46 miles )f 66 inch, 100 class pipe 10929,200
I 4.26 miles of 66 inch, 160 class pipe 2,045>900 ;
Contingencies 0 15% 936,600
Engineering & administration 0 7-)/2Z 638,500 f
Right-of-way 8,7 miles 0 $3,000/mile 26,000 E
Conflicts 616 000
Estimated Total Cost g, 0
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Denton pro rata share for 30 MGD supply (30/107,4); $2,334,900
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Table B-3
Pertinent Data and Estimated Capital Post for
Raw Water Delivery ~rstem from Cooper Reservoir
Lo Lavon Lake
Pertinent Data Lake Station Booster Station
1 Average annual pumpa,ge 212 MOD 212 MOO
Design delivery capacity 240 MOD 240 MOD
f Pipeline length 16.7 Miles 15.9 Miles
Pipeline diameter 96 Inches 96 Inches
r, Number of pumping units
(including standby) 5 5
L Name plate capacity per unit 60 MOD 60 MOD
Total dynamic head 280 feet 243 Feet ;
Horsepower per unit 31700 HP 3,200 HP
Total installed horsepower 14,750 HP 12,800 H?
j
Estimated Cost
Lake pump station $ 2►603,800
j Tiooster station 2,368,200
Lake intake structure 924,400
2 - 5 Mt, ground storage tanks 441,100
30.8 miles of class 100 pipeline 23,557000
1.8 miles of class 150 pipeline 1,575,400
+ Contingencies @ 15% 41720,500
Engineering & administration @ 7.1/2% 2,714,300
Right.-of-way 32.6 miles @ $3,000/mile 97,800
Conflicts 31481000
Estimated Total Cost TO 0M80U
Denton pro rate share for 30 MOD supply (30/212), $5,964000
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Table B-4
Pertinent Data and Estimated'Capital Cost for
Raw Water Cana System from Cooper Reserio r to
Lavon Lake
+
3 '
Pertinent Data
j Average annual flow* 307 MGD
Maximum flow 340 MGD
Canal length 38,8 Miles
Total lift 279 Feet
I
€ Estimated Cost
f
1 1 Pump stationrj $ 6,894,500 {
Intake structure 9079000
Intake channel dredging 392,600
E Control station 11000,000
Earthwork 1,233,000
fff Cana, lining
10999,000
Inverted siphons 414,200 !
Site preparation and clearing 67,900
Gate structures
'
Overflow spillways 420800 I 1
Local drainage 21218,000
Access roads and fences 1,270,800
i Bridges 4,833,600
Pipeline crossings 39,000
Transmission line crossings 90,000
Arnold Creek clearing and lining 194,000
~ Subtotal
$22,761,200
Contingencies 0 25% _ 50690 300
Subtotal
$28,451,500
Engineering @ 5.5%
1,564,800 }
Supervision @ 4.5% 1,280,300.
Total Cost of Design and Construction $31,296,600
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Table B44 (Continued)
Land and improvements S 729,000 i
Land'contingencies @ 25% 1829300
Land administrative costs @ 7% 510000
Relocation assistance @ l% 7,300
Total Cost of Land and Relocations _ $ 969,60Estimated Capital Cost M3266,200-
Denton pro rata share for 30 MGD supply, $4,565,7009 computed o
the basis of 30/212 where 212 MGD I!) the supply to be transported
to Lavon assuming transmission of Cooper water and Sulphur Bluff I
water.
*It is assumed that a canal would be built to eventually transport
the combined yield of Cooper, Sulphur Bluff I, and Sulphur Bluff Il,
or 307 MGD.
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` Table S-5
Pertinent Data and Estimated Capital Cost for
30 fIGD Deliver System from Lavon Lake to
Lew sv 1 e Lake
k Pertinent Data Lake Station Booster Station
Average annual pumpage 30 MGD 30 MGD
` Design delivery capacity 33.5 MGD 33.6 MGD
- Pipe length 7,8 Miles 16.1 Miles
Pipeline diameter 42 Inches 42 Inches
Number of pumping units
(including stand-by) 4 4
Name plate capacity per unit 10 MGD 10 MGD
Total dynamic head 222 Feet 237 Feet
Horsepower per unit 600 HP 600 HP
I Total installed horsepower 1800 HP 1400 HP
~ I
Estimated Cost
30 MGD lake pump station $ 6000200
30 MGD,booster station 621,600
Lake intake structure 5429300
1.6 MG gground storage tank 1100300
20,9 miles of 42" class 100 pipe, 4,111,400
3.0 miles of 42" class 160 pipe 668,600
Contingencies @ 15% 998,200
' Engineering and Administration @ 7-1/2% 573,900
Right-ofLWay 23,9 miles @ $3000/mile 71,700
Conflicts 2,626,000
t
Estimated Total Cost $100231200
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Treble B-6 ~
Pertilt Data and Estimated Capital Cost for
Rw-C'ater Delive`r~ stem from
8o s d rc Site to Aubre Rese yr air '
{ Pertinent Data
lake Station
Average annual pumpage Booster station No. 1 85 MGD
Design delivery capacity 95 MGD 85 MGO
Pipeline length 95 MGD
Pipeline diameter 18 Miles 16'Miles
Number of pumping units 60 Inches
(including standby) 60 Inches
Total dynamic head 5
L Horsepower per unit 366 filet 5
11600 HEM 252 Feet
Total installed horsepower 70500 HP 1,100 HP
Pertinent Data 5$50A HP
Booster Station No, 2
1 I Average annual pumpage
Desiggn delivery capacity 60 MGD
Pipeline length 67.5 MGD
I _^1 Pipeline diameter 8.6 Miles
Number of pumping units 54 Inches
(including standby) Y
Name plate capacity per unit 4
Total dynamic head 20 MOD
Horsepower per unit 301 Feet
Total installed horsepower 1025 HP
Esti__ maw cost 4,500 HP
Bois d'Arc Reservoir to Sherman Takeoff
lake pump station
Booster Station No. 1 $ 1,6899700
Bois d'Arc intake structure 1014,900
24.6 miles of 60 inch, 100 class pipeline 520,900
9,4 miles of 60 inch, 150 class pipeline 90056'000
1 5 MG ground storage tank 30801,200
Contingencies @ 15% 264,400
Engineering & administration @ 7-1j2~ 2~497,10o
Right-of-way 34 miles @ $31000/1111le 1'435,800
.Conflicts 102,000
Estimated Total cost 2299)000
M2
,9(31, 00
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Table B-6 (Continued)
' Sherman Takeoff to Range Creek
1 Booster Station No. 2
1 05
6.6 miles of 54 inch, 100 class pipeline 5,400
2.0 miles of 54 inch, 150 class 2,052,200
'1 - 6 MG round storage tank pipeline 687,600
{ Contingencies @ 15% 264,400
608,900 ;
Engineering & Administration @ 7-1/2% 350,100
Right-of-way 8.6 miles .@ $3,000/mile 259800
Conflicts 593,000
j Estimated Total Cost
5,631.,440
Denton share of Bois d'Arc Reservoir to Sherman Takeoff Pipeline
(30/85); $8,1100000
' l Denton share of Sherman Takeoff to Range Creek Pipeline (30/60);
$2,818,700
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Table B_7
Pertinent Data and Estimated Capital
1 Cost for Raw Water Delivery System From
Lewisville Lake to Denton Water Treatment Plant
1976 Development
Replace number 2 and number 3 raw water pumps with 8.0 MGD pumps.
Install 10 million gallon tank and low lift pump station
Total cost - $420,000
4
1979 Development - Stage T
Construct 125 MGD pump station (215 capacity) and 42" pipeline to
Denton Water Treatment Plant.
Pertinent Data
Average annual pumpage* 28 MGD
j Desicn delivery capacity 50 MGD
1 PipX ne length 8.5 Miles
Pipeline diameter 42 Inches
Number of pumping units 2
i Name plate capacity per unit 25 MGD
f Total dynamic head 348 Feet
Horsepower per unit 20000 HP
Total horsepower 49000 HP
Estimated Cost
Lake pump station (50 MGD installed capacity) $ 7830100
Intake structure (125 MGD capacity 482,800
5.0 Miles of 42" Class 100 pipeline 9919400
3.5 Miles of 42" Class 150 pipeline 779,800
'Contingencies @ 15% 455,600
Engineering and Administration @ 7-112% 261,900
Right-of-Way: 8,5 Miles @ $3,000/mile 250500
Conflicts 283,100
Total Cost - Stage I $4,063,200
*Assume new pump station will carry-full load; use old station for
peaking.
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Table B-7 (Continued)
f 2000 Development - Stage II
Install additional 75 MGD capacity in existing pump station and construct
48" pipeline to Denton Water Treatment Plant,
f
S
Pertinent Data
j *Average annual pumpage 27 MGD
Design delivery capacity 75 MGD
Pipeline length 8,5 Miles
Pipeline diameter 48 Inches
Number of pumping units 3
Name Plate capacity per unit 25 MGD
Total dynamic head 367 Feet
! Horsepower per unit 2000 HP
Total Horsepower 6000 HP
is !
} I Estimated Cost
l j f 76 MGD pump installation $ 2300900
5.0,M1 es of 48° Class 100 pipe T,279,700
j ! 33 Miles of 48" Class 150 pipe 991,6'10
< Contingencies @ in 375„f00
Engineering and Administration (d 7-112% 215,800
i Right-of-Way; 8,5 miles @ $4000/mile 25,600
Conflicts 283, T00
! Total Cost Stage II $3,401,900
Overall Cost $7,466,100
* In addition to Stage I average capacity total - 54 MGb1
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