HomeMy WebLinkAbout1974
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1974
REPORT ON
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WATER SUPPLY Sy'&TEM
r
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CITY OF
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0 E'NT 0 "N TEXAS
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r Freese
Mchols
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P: i + t~o-:li 7L k 77
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JAM[/ 11. W..40LS
0100rnT L. XHOLS
FRC5E A1'p N[C110L3
►~~,T. 61AlCN ,
C 0 k 5 U L T I N a E N G I N E E R S JO' PAUL JONILS
JOL 8, MArtb
NC CAA A' TMOMryON w
W. dIN[!f CLEMLNV
Alb[ T H. ULLIUCH
' July 24, 1914
' Mr Jim W. White
City Manager
City of Denton
Municipal Building
Denton, texas 76201
Dear Mr. White:
' We are pleased`to submit our 1974 report on Water ~D
of Den to Texas. The water system has been aria yze•j 0r_1 roeectedil 80
anal con t ons, Specific recommendations for impro±!ements to the
water supply system for the period 1974-1980 are presented, and long-
range recoarendati6ns for Improvements during the period 1981-1994 are
included. The total estimated cap~,tal cost for the 1974-1980 improve-
ments is $12,623,300.
We appreciate this opportunity to be of service to, the City of Denton.
p We also wish to acknowledge the very effective help given by the City's
personnel; in the colldction of the data on the historical water use and
on the field testing of selected lines in the water distribution pipeline
network.
Yours very truly,
8 FREESE AND NICHOIS
J. a
' T. Anthony Reid, P.E.
TAR:bg
' TALIPMONt 017 318.7141 811 LAMAR STRAAT FORT WORTN, T1I(A8 fe10A
TABLE OF CONZENTS
1
INi RODUCTION Pai
POPULATION AND WATER REQUIREMENTS 1.1
POPulation
Historical Water Requirements 2.1
Projected Water Requirements 2.3
THE WATER SUPPLY SYSTEM 2.7
Sources Of Supply
Raw Water System 301
Water Treatment P16ht
THE WATER DISTRIBUTION SYSI,CM 3.6
Existing Water Distribution System
Pressure Planes 41
High Service Pumping Fac!ities 4.1
Ground Storage 4.4
E1eVated Storage ?4.6
Distribution Network 4.9
Analyses of 1980 Conditions 4.10
Analyses of 1994 Conditions '4,14
PROPOSED PROGRAM OF IMPROVEMENTS THROUGH 1980 4.19
CONCLUSIONS AND RECONjEhUATIONS b,i
6.1
APPENDICES
APPENDIX A LIST OF REFERENCES
APPENDIX 6 INVENTORY OF PUMPING FACILITIES
APPENDIX C PIPELINE CONVEYANCE CAPABILITY
1
r
►19969 AND NICHOLI
7 7N3 T c
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r LIST OF TABL~►~5
Table
P,ae
2.1 Denton's U. S. Census Popuiatio~~s
r 2.2
2.2 Historical Finished Mater Requirements
2.4
2.3 Historical Raw Water Requirements
25
2.4 Protected Potential Avetage-Day Water Requirements 2.8
2.5 Protected Patential'Pea1;-VSO Water Requirements 2,9
4.1 High Service Pumpi,n Nio 1itios
4.C Ground''Stor,ige` rac'11 61?3s
4,7
' 4.3 Recommended Ground Storage Capacities
4.8
4.4 Elevated Storage Tank Characteristics
4.9
4.5 Recommended Elevated Storage Capacities
4.10
4.6 1980 Maximum-Hour Sourcon of Supply
' 4.18
I 4.7 1994 Maximum-Hour Sources of Supply
4.20
5.1 Proposed Schedule of Construction: 1974-1980
• 5.3
5.2 Estimated AVerage Unit Costs for Distribution
System Pipeline Construction
`5.10
5.3 Summary of Estimated Constriction Costs: 1974-1980 ' 5.10
1
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r - ►e[,1tt AND NIONOU
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,7771 dj ^k#~, ~ 7f1R,,rr.~
LIST OF FIGURES
F1 ure
2.1 Denton and Vicinity After Page
2.2 Projected Populations 2.1
2.2
2.3 Typical Seasonal Pattern of Water Use
2.6
2.4 Historical Per Capita Consumption 2,6
2.6 Hourly Pattern of Water,Usage
2.7
2,6 Proirected Potential Finished Water Reipi1'enwents
3.1 Surface Water Supply and Raw Water'§y3tem
;.2 Raw Water Pumps 3.l
~'.3 Pr 3.3 ,
o,Jected Potential Water Treatment Plant
Req,lirements
,,6
4.1
Principal Elements of Existing Water Distributlon
System a 4.1
4.2 EloVated Storags - Preferable Spacing of Pl
anes ,I.t.
4.3 WaTreatment Plant High Service Pump d 6
r i~ ~'otf
4.4 Criterla for Spacing of Smaller Mains
4,12
4.5 It aol 1994 Proposed Water Distribution -Systems 4,14
1
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1 NT Rl10UCT I ON
The City of Denton authorized frease and Nichols to update anti
revise where necessary the findings of the 1965 water distribution system
report (1), and to prepare a report on specific recommended improvements
for 1974-1980, and on long-range improvements' for the development.of the
distribution system throuih 1994. The following items were included In
the assignment:
(a) An analysis of the historical wuter use ek;ords t¢ d4termine 5;
seasonr.l and daily patterns of water usago and 06 'geographic
r~
distribution of the loads within the system.
(D) An analysis of the raw water system to determine Ox m6st
effective method of furnishing future raw water ,,iquirmirts.
(c)'`An analysis of the 'water treatment plant and the high service
pumps to determine the requirements for, future exptnsloils,
(d) A'retest of the conveyance capability, oUtwo or.#hre4..E1is-
tributlon lines to verify the age-conveyance captibili,tir
chara(,teristics established in the 1966 study.
(e) A corputer analysis of the system's perfoiwnc%i under potential
maximum-hour demand conditions for 1980 and 199x.
' (f) A computer analysis of the system's perfottnanut under tank
f'1°'ng and fire fighting conditions.
1
1.1
/R{Clt AND HICHOL/ -
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Fy f , r r♦ r 4 t` k,
•'A { pia i'rk I" . " tr ~~~h~~' nji by ~ r ,yr•.
" Sir`-,-`""~..~i~.~-.,~..~
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MOP ULATI4N`AhD ti~/ITCR itE JIaEMEtiTS
2.1
Fowlrti,~
Ienton's historical mater,use po•5u16tlon has been a cmbination of
two groups, local residents ani the $Jniverslty students. The Denton
State School students, even though it i•, outside the city Emits, are ,
considered to ba local residents,' In the future, the D
' enton water( '
~ use..
population may also Nclude, in addition to these two groups, a Ketion k 4rg~~ •^I
tr
or; alb, of thei` Pour'-C'stles' Area' (Cori;Sth, Shad SF~or
Y sr, Hickory;Creek, and '
Lake Ila)16s) ~'fyure 2, Denton has contracted to furnish CorintF, with
water, The 6lr-Cities Area should develop` steadily during the 1970's
and,, hwe an e4h rriore^apid growth during the 19FA's. If this potential
net atrvito•oreir is served, it will have an impact on the Denton water
supply systefti.
the'univer0ty students have historically` represented a sfgnificant
percentage of De~ton's population.. The U.• Si census pupuiatlons (Table
2.1) 9nwlude thosirl students that live in thl`Ncirth Texas State Univtr,ity
and Texas Woman's'Jniversity dormitbrl
es am
thq,O studeents that live in
nff,•campus housiil1. In 1970[ approximately one third of Denton's popu-
lation were students at the universities. This fact and the associated
decline in the•enrollment during the summer have a profound effect, on.
Da
_n i
taly s water re,luis ements.
Monthly estimates of the historical waiter-use population for I
the
1 period 1960 through 1972 were derived for use in the computations d the
2.1
lMtt1R AND NICHOU
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b t
i
DENTON AND VICINITY
O
PENTON
' E!r tr ~ l
L, 4t,
01
f! `fit Y'
SffAJ)Y Sri E'S
ILO" fN ' .
.in
s 1,' TH C1s t.Ge~~
11
D AS
ARGYLE :e EEK Res.
I Mlles Yo
,d~ 7 ai M11.
t0>,
i *e ~
bte 2 !
r~
n nr
e
s U-..S.:-.1-ensus P~taulatlons
I Yrar Njuldtion
1 E100 87
I lE)10 4 `132
1920 7 625
1930. 9,587 A
M 5 f
1 a ' L v to Y (137
P6 ,844 1;?7L1 L9' 874
a
histor'fcat`her 4dpifz;` cQnsumFl;lliins, TIx~ anr'riial charges in tl;e total
popufa tI6n were estl4lwd frond thli
number of water connectionsr North',
es ity dr;v T)Xas Woman's University provided tie,
histolAkal enrollments vnd`statlstlical ¢at on the number of reside+.nt,' ,
I and commuter students (2) nd 3 z s `4~ r.
a (f 1H' decieases l+i`the water-use
population during the sumh2rs due 'to the smaller ehr'oilment's,~n.the '
universities have Dokrn 0 to definite. 'the canbiiiation ot``local resf-
I
dents and resident-students represents Denton's principal historfcal
I a
water users. The commuter student does not materially affect thr~ water
reguirenints because he does not perform his principal water-consowption
d.ttvities while in Denton. The commuter-student water use can be
I incorporated in the resident-student water requirements. ~
The futuro water-use populations have been projected for the period
1974 through 1994 (Figure 2.2). The local-resident population will
2.2
I _
lit
{ ° I1(~7~^_x''tti~~`~....9L a tC7 ~""~'y"~•~}~~~«'i.'~•'~~t.-..~.t ~~.~.~.-L'^..t.~:3' ► ~Y~~ ~ t k .~i,~l
li ~ ~ I 1 ~ .S t r ~
a■I,Yd - ~ ~ us~~~~~, a .fir ~
~.y l7 r.yM'IYT Try ....l,
I20
40
AVERMo ANNUAI, WAt,ER WE ?OIV ATI
r
SrtVV ~ i 4.. r 111 q~
,4~a y~ l +I ii
80
hP1
Z
r R 1 i :~r ae
70
try --wYY1 ...ry Y'--' r_. ♦•it a~-w- 1~.yy alYMw
50
ell
1 40 a:rr... r..r-..i: 1..r. ..r.» y i '
v
FALI RESIDENT-5TUUE~lis
va h
20 - SUMMER RESIDPNY-5 UDENTS -
10 r tip. ~a r
(FOUR-CITIES
AREA
0 J..ML_s._.l- L"L..~_.L' I i
1 74 76 78 80 11 84 11 80 90 92
YEARS
►llll{t AHD klcHCU
wOIGURE 2.2
1-71
'f35~~~~~. 44'V 1 l'p ,f •'f :g~
' continue to increase at a steady rate, It will incr i
ease from an estt-
i' mated 28,800 liersons at the beginning of 1974 to an estimated 760400.
persons at the end of 1994. The resident-student population will con.
.
tinu
etoi
ncretse during the period, but will become a smaller percentage
of the total population. T,Se fall resident-student population is pro-
jetted to increase from an estimated 13,00 students in 1973
to approxi-
' mately 19,100 students in 1994. The sui;m r resident-student popu'iation
` will increase frog approximately 7,500 students to 10,400 students during
the 1974 to 1994 period, The four-Cities Arpa population is projected
f to increase from its present Estimated 3,400 perskins to approximately
12,600 persons in 1994.
The projected Denton average annual and summer water-use popultltions
I. are shown on Figure A.2. These projected water-use population "
~ s include
tha local residents, 'resident-students, Four-Cities Area citizens and the
1,700 students at the.Denton State School.
One of the obJect-ves of this `study is.to design water distribution
systems for the projectild 1980 and 1994 conditions. The projected annual
av+3rage water-use population for 1980 is 59,300, while the projected
{ summer water-use population is 54,000. For 1994, the projected annual
average water-use population is 1060600, and the projected summer water-
use population is 99,20, " All of ,tnese projected populations are based
' on complete service to the Four-Cities Area,
2.2 Historical Water Iteouirtments
Denton's historical finished water requirements are summarized in
1 Table 2.2. The finished water includes both the water produced at the
1
AND WCMOL, 4~ 1
P ~ OY~t i
Tcbte 2~? 1
Histoi,ical Finished Water Requirements
Year Average- Peak-Day Patio of
Day Usage Peak-Day to
Usaile Average-Day
MG11) t GO' Usage
M 1960 2:96 6.53 2.91
1961 3.01 6.60 2.19
1962 3.18 7.24 2.28
19G3 4.313 9.23 2.11
1964 3.86 8.97 3.32
1965 4.1E 8.67 2.05
i 1967. 4.16 1.26 2.06
e„ 11.25 2.~1
1968 4.63 9.92 2.14
1969 5.57 13.50 2c42
1970 6.49 13.73 2.12
1971 6.81 15.05 2.36
1972 7.18 15.12 2.11
Note: Ratio of peak-day to average-day usage is approximately
2.30 in an average rainfall year and approximately 2.15
in an extremely wet or dry year.
water treatment plant an'Pthe ground water that was used during the
higher use periods of the year. Both the average-day and peak-day usages
1 have increased during the period. This has resulted from an increase in
' both the population and the per capita use rate. The ratio of the peak-
day to average-day usage fluctuates from year to year. The ratio has
e bec: found to be generally relt.ted to the amount of precipitation. The
ratio of the peak-dey to average-day usage is approximately 2.30 in an
average rainfall year and approximately 2.15 in an extremely wet or dry
i year.
Denton's historical raw water requirements are summarized in Table
2.3. In the past, raw water has been required for both the water
2.4
FW56 AHD WCHO"
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e
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I Tabl e_ 2._3
r Hi--deal Raw Water
errgn is
Year Water Treatment Plant
Power Plant
ea ;may v' . Peak $a Total
1964 ~MGD MGD L MGQ MGO _y MGD. AeMGDDay
4.44 .52 .40
1965 4
1966 4.51 .44 4.84 10:98
1067 5.31 5l 4A6 10,49
1968 5.06 .54 _ 6.02 10.31
1909 5.99 .49 5.85 12.43
1970 6.79 13.73 .64 1.64 6.55 .1143
1971 7.22 13.73 .76 1,.64 6.63 15.37
1972 14.21 .83 7.55 15.41
' 7.62 14.93 .24* 2.02. 8.05 16:23
` 7.86 14.93*
*Wastewater ti•entment plant effluent was used for part of power
cooling water requirements during the year. Plant
' treatment plant production and for ,
' Power plant cooling Water. During
19120 facilities were instilled to utilize the wastewater treatment' effluent as the coolie wal~~
: Plant
9 r for the Power plant. "he average-day raw
water requirements for the water treatment plant during the period T
through 1972 averaged approximately "8% greater `han the ay 964
erage-day
treated water that was delivered to the sy,;tem. This additional water
was used in the maintenance and operation of the water treatment plant.
During the same period, the plant's Peak-day raw water requirements
approximately 7% greater were
than the finished water requirements, llimi.
t nation of the power plant raw water requirements and the use
the
wastewater recovery facilities presently under construction atfthe water
treatment plant should bring future
raw water requirements close to the
' actual system needs.
2.5
Ah0 NIp MO~~
Sk^
N741
17it iv
i Ft f g 7~ W :f K IIK:rYqi e. ,
rr~
rte,
c rL
T A'demands fir water aro not{constant throughout tha year. Figure
s
2:3'shows'"a t, P1,ra,'°seasonat itWern of water use for Oe period 1967
through 1972. `ihe figure shot4s a definite increase in the water require-
' meats during the summer months who additional water is required for lawn
watering. Denton's typical sessonal pattern of trattir use has less
' fluctuation than other citie of comparable size that have been eva`lu
at6d recently. This is a r0flect.ion of the decrease in the water-use
population "that occurs when the universities enter their summer sessions.
Potential water requ, :tents are those that can be expected to occur
under the most severe demand conditions. M s Ori'(M water use records
' for extended dry periods can be used to esiaYttate ¢~ature potential
water requirements. However, water use rates that are greater than the
projecief,'potential water requirements may occur in the future if we are
' Onfronted with hydrologic events that are more severe than those that
have been recorded. The historical average-day and pei Way per capita
r consumptions for the period 1960 through 1972 are shown iraphically In
Figure 2.4. The average-day per capita consumption increased from 94 GPO
in .?46'0 to 165 GPD in 1972, The average peak-day per capita consumption
increased from 243 GPD in 1960 to 427 GPD in 1972. The potential average-.
day per capita consumption is shown by a dashed line, and the potential
' peak-day per capita consumption is indicated with a dotted line in Figure
2.4. Extended dry periods occurred during 1963 and 1969, and it can be
seen that in general their
per capita use rates lie near or slightly
below the potential lines. The potential average-day per capita use is
22% greater than the average-day per capita use, and the potential peak-
day per capita use is 12% greater than average peak-day per capita use.
2.6
1 Mild AND NitHM l
f~
~ u
T 77777%
r
I TYPICAL SEASONAL PATTERN 4OF
WATER _ USf
11 2.0
i . 8 _
~I
1.6
_ 1967 1972
a 1.4 `
1.2
W
0
1.0
t Q
0
J
0.8
l,loll Z
O
O 0.6
0
cc 0.4
~ 0.2
0
F M A M J J A 5
O N D
'
MONTHS
L
IOItlL ANO NICNpt1 F _M"__i•-`_ _
FIGURE 2.3
s b
N.ISTORICAL PER CAPITA°,CUNSi'r~1PT101 ~s.
s00 z
77
POTENTIAL PEAK- DAY PER
CAPITA CONSUMPTION
400 -
CL., A ER WE PEAk- UA; PI R
CAP('EA `CONs-um,o)'ION
Z i
,air
0
w
i
O
200
CL. kI TENTIAL AVERAGE-DAY PER
6PITA CONSUM10TfON
i
i
L
100
AVERAGE DAY PER CAPITA CONSUMPTION
0
60 62 64 66 68 70 72
YEARS
reuse ANO WCMOU _
FICURE 2.4
77777,
~l ita usC to the potential
The' ratio tSf the Patent peal •dey per Cap
average-day per capita u~sc is' Vr 37.
The rate of riater use is not constant throughout the day. The
ratios of the hout^ly use rates to the average drily use rate for the
1972 peak day and the second highest peak day are shcn+rn graphically in
Figure 2.5. The ratios range front a lotir,of approximately 0.45 in the
early morning hours to a peak of 1,58 between 7.00 and 8;04 P.M. This
pe4!+ ratio is somewhat lower tfiOn'is normally rxpectPdt but it is not un-
reasonably low. The maximum-ho jr`use-rate he measure against which
3 ! to
the adequacy Of tho pipe Oetworr~r,high~service putnps and elevated storage
tanks must be tested, and for Witi`f a~di Tonal; improvemenis to these
items must be diisigneJ.
y' i1 r
dl
2.3' Projected Uiater RegUrew-._....w
The projected potential aJ~j-aye-day water requirements are suxinar-
ized in Table 2.4, and'theFpeoJected poten(ihl peak-use water requirements
are surmarize+f in Table 2.5. `!he prbected potential average-dy treated
water requirements are the products of the projected annual average
water-use populations and the potential avoage-day per capita consump
' tions. The projected potential peak-day treated water requirements are
the products of the potential peak-day per capita consumptions and the
projected summer populations. The potential maximum-hour treated water
requirements ire 1.60 times the potential peak-day treated water
requirements.
Anticipated changes in the maintenance and operational procedures
at the water treatment plant will reduce the amount of raw water
2.1
S pUttt A!4O NICNOU -
NUNN"
~r a nR r .r~'Y b µ r~ R.. 4 L " 7i'
.M :.f Y X11 ~~d ~ Yr~ 1, ~k~,c ~~d, "f~: a it 'y~ 7~•
HOURLY PATTERN 'OP' 1NA F.R U AG
1
' 2.0 ••T~ 1"7' 'T'1"?"T`~""1"
1.8
_J .1.
1912 )91"21 AK ()J
1.4
w
d 71
1.2 _ ..j
O
1.0
~n
w
nc
1972 2nd PEAK DAY
u 0.6
1 O O r-~-
0.4
1
0.2
0.0
{ M 3 6 9 N 3 6 9 M
TIME IN HOURS
r
_..Y~ r-- fMf~t ANG NiGw OL• -
FIGURE 2.5
r a q x v ~ 1 ~
♦:i i,.,'..' C r 1Ytl
.
1 .r! , 4
Table 2.4
Pro ected Potential Average`U~ Water Requirements:
nnual Potential Projected___Pot(nd al "rWater Re v lrements
` Year AAVnnual Overage-Day Treated aw Aeter
water-Use Per Capita Water
population consumption _LMGD LYrI
- 215 9.72 10.21 11,400 .
1974 45,200
10.12 x'1.6 1201; 'y
222
1916 48,300
228 11.54 12,0~
1976 50,600
€ 233" 12.30 1,.92 14,500
1977 52,800
1978 13.04 13..•6'1 15,300
54,800 238
242 13.79 14.48 16,200
1919 57,000
246 14.59 15.32 17,200
1980 59,300
255 18.56 19.49 21,800
1985 72,800
1,990 89,500 260 23.27 24.43 279400
264 27.88 29.27 3200
1994 105,600
N
41 wr,ttif l 1 f
SrF
LIF7 7777 All
t a 9` .p~ ION On
ow
I
fable 2.5
P?Vfcteq_.~otential peak+U e.Water Re trements
Year `
Summer potent91 }
Water-Use ~'ro~jeted Potential Water Re ulrements r
Population Peak Day"
Treated
F'er Capt tt, e1T~ Raul
Consumpl;ibii 1rlaxTrtu`m VeErK
C L Oa [lour Dai
1F74 41,900 _ 510
R1, 37 34.14 22.44
5 43,604 192
k 526 , L.93 w
1975 36:69 24.08
45,700 540 24.68
1977 34.49 25.91
479800 552 26.39
42.22 27.
1978 49,800 564 211.09 41-94 h 71 '
1979 51,800 514 ,.9.49
29.13 47.57 31.22 x
1980 54,000 563
31.48 50.37 33.05
1985 51,300 604
40.65 65.04 42,68
1990 832500 616
1994 51.04 82.30 54.01
526
99,200 62.10 1f
99.36 65.21
N
zo
771
J
}
;4
1r 1 i. y {ye r.
IlpR a
t rErquit d for th a faski to,a
n Ostimated 6.0% of ti►4 treated !ra
xter re
4~1i►`emi~nts. Titre W6jectdd j;OtEn't1af raw water requirements in Tables es 2.4
r
artd 2,5 are th( priducts of the ratio 1,05 and the projected potential
treated water Nquirerraents.' The wastewater treatment plant effluent will
be used pis :a ►:ooling water For the power plant iri the future, and this
retiuired amounts are lot included in the protected raw water requirements.
For 11080, the projected potential treated water requirements are
for average,'day 14.59 MGD, for peak day -
31.05 MGD► and for maximum
hour - 50 3? MGD. The pro vcted potential 1980 raw water requirements
s
are'lE~,~ l%la; or 17,200 tare-feet per, year for average day and 3345
`~MGD,faa, pda~''.' y. Between°1980 and 1994► there wi~T 64-approximately'increascr in the water demands. The projected 1994 potential
fi`iiished waver requirements sire average day - 27.88 MGD, peak day -
62.10 MGD, and M'ximum hour -
99.36 MGD. The projected potential raw
water requirementt% for 1994 aft average day 29.'27 WD, or 32.600 acre-
feet per year and.heak day - 65.21 MGD. The protected potential finished
weti requirements are shown graphically in Figure 2.6.
II
1
i
1
1
1
2.10
1 _ /At[it ANU NICNOLO
,i
4~.a
UED POTENTIAL
1 ;
loo -r
{
1 90
E
80
70
,G
60
Z
1 ~ 56
w
I ~ aPy
40
Q~P
30 000
1 20 Not
10
1
70 72 74 76 78 60 82 84 86 88 90 92 94 96
reltsti .NYF„ AI
FIGURZ 2.6
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t i.`.,~ ~7 a W JeY
K
f V it I VVr a °7 r, t 1 V 77
S 1
THE WATER SUPPLY SYSTEM
3.1 Sources of Supply
Dentan's principal source of supply is Garza-Little Elm heserv;ir
wheTv i't has a permit to store 21,004 acre-feet of water and to'divert
11,000 Acre-feet annu'Ally. Garze-Lit W Elm Reservoir dam is located
approximately 12 m1les southeast of the center of Denton (Figure s.l).
Hydrologic studlgs"have shoiin that the sc.fe yield of benton't"portion of
1
Gari -Little 'El'4 Rese)'yoir ot'ter' 1975 will be 4.6 MGIi
~ 4 which is 'less
tharr Oenton's current annual average use rate. To 'supplement -this
'
supply; the pity has entered Into a contractual agreemenC that is in
effect lentil ;1980 to"purchase a p6Ption of the City of Dallas surplus
supply. The contract entitles the City to withdraw an annual alliount
equal to an average annual rate of 13.0 MGb. Denton is also maintaining
sever, of its wells in usable condition. Historical pumping` records
indicate that the dependable yield from th0e wells over an extended
period of time is approximately 4.0 MGD.
The projected potential average-,day raw water requirements can be
met with water that is available from Garza-Little Elm Reservoir through
its contractual agreement with the City of Dallas until 1980. After that
date, Denton will need to obtain a source of supply to supplement its
yield from Garza-Little Elm Reservoir. This source of supply could be
another contract with the City of Dallas for surplus water or a new source
of supply. Denton and Dallas have agreed to jointly develop the
3.1
$119901 ANO NICHOLS
y
f _
SURFACE WATER SUPPLY AND
RAW WATER SYSTEM t'
I '
1 ~ 1
Is t
AUBREY RESERVOIR (Proposed;
' NORTH
' .t I
r ti
0 4
Scot* In Miles
DENTON
'WATER THE TMENT NANT
~ I
271, RAW WATER LINE
J(
GARZA- LITTLE ELM
RESERVOIR
Vw
RAW WATER j
PUMP STATION
FIGURE 3.1
i S
conservation storage in the propised Aubrey Reservoir (Figure 3.1) as a
e future source of supply. As now planned, the construction would be com-
pleted sometime between 1980 and 1981 (5). Under the terms of the
agreement between Denton and Dallas, Denton has the right to a maximum
of 26% of the increase in the safe yi'old of the Aubrey-Garza-Little Elm
combination. If the Aubrey Reservoir is developed, Denton's available
safe yield will be sufficient to meet the projected water requirements
through 1994. Until an additional source of surface water is available,
it is veconmended that the wells be maintained in a functioning con-
dition. After the additional source of surface water is obtained, the
wells can be mainiained as a standby supply.
To assure the adequacy of the distribution network, the assumption
has been made that all of the requirements would be met with a'surface
' water supply for both the 1980 and 1994 conditions. This would be the
most demanding arrangement for the distribution system network.
3.2 Raw Water_System
Denton's rjw water intake structure and pump station are located
on the Hickory Creek Arm of Garza-Little Elm Reservoir (Figure 3.1).
i The intake 15 a 20-foot in diameter, 65-foot high concrete structure.
Two 36-inch popes extend out from the intake structure into the reservoir.
Tr.e upper pipe is at elevation 505.0 feet and is approximately 83 feet
long, The lower pipe's centerline elevation is 480.0 feet, and it has
a length of approximately 135.0 feet. The intake structure has a
capacity of approximately 60.0 MG0 when the lake level is at elevation
1 488.0 feet. The lowest recorded lake level is 507.0 feet.
3.2
L Pflt4bt APO HM"01-S
~777777 77N ri
7 fJ~ d S ir. d i R
II The porp curves for the four existing raw water
pumps are shown on
Figure 3.2. The system curve for the existing 27-inch (44,8oo feet in
length) raw water line when Garza-tittle Elm Reservoir is at the top of
O its conservation storage (elevat`::a 515.0) is also shcwn on the figure.
I
the capacity of the existing raw water system with all the existing pumps
►e operating is approximately 15.2 MOD. The firm capacity when one of the
larger pumps is out of service is approximately 13.4 MGD. The projected
potential peak-day raw water requirements are indicated along the dis-
charge axis of the graph. The existing raw water system is riot capable
of furnishing Cie' °;,ture'po,ent W peak-day demands.
A structural evaluation of the existing intake structure indicated
that the maximum pump capacity that can be instailed without extensive
modifit:ation is approximately four pumps the same size as the'-largest f
' existing raw water pumps. The existing 27-inch raw water line was de- I
signed for a maximum head of 345 feet and a capacity of 16 MGD. This
head is indicated by a dashed horizontal line on Figure 3.2. If raw
water pumps No. 2 and No. 3 were replaced with pumps that are similar to
raw water pumps No. 1 and No. 4, the station discharge at the maximum
design head would be approximately 32.6 MGD and the firm capacity would
be 24.2 MGD,
e Denton's most important raw water system need is an additional raw
water supply line. A series of system curies for various sizes of
parallel raw water lines is presented in Figure 3.2. Using the projected
water requirements, the existing 21'-inch pipeline should be paralled with
a 33-inch pipeline to obtdin approximately ten years of service before a
third raw water pipeline it, required. Approximately eighteen years of
3.3
IRAW AND NKNOLA
1 `~1 •J 1.4.Y 1 t 467
rv
' 777
11 RAW WATER PUMPS
EXISTING 27-INCH AND 27-INCH
400 EXISTING 27-INCH AND 30-INCH
_ ~ EXISTING 27-I1,4CH AND 33-INCH
13
I;, 3w ISTING 27-INCH AN 36-iNC4
cUu~..,
4 _ r EXISTING 27-INCH AND 9ANCfTh
O _ EkISYING 27-iNC'r1 AND d2•INCH
s _ 200
EXISTING 27-INCH D 48-INCH
4-8-OMC;D@345 FEET OF HEAD PUMP -
O
r- 100 /Z 3-8.0 MGD9345 FEE OF HEAD PUMPS
a a a a P " P
POTENTIAL PEAK-DAY -
WATER REQUIREMENTS _
0
10 20
A 30 50 60
70
DISCHARGE-MGD
N
i
-7777771
service can be obtained if a 42-inch pipeline is used and over twenty
years of service can be obtained from a 48-inch pipeline.
The use of a raw water terminal storage structure will often permit
the reduction of the size of the raw water line. The stored water is
used to supply the small amount of additional water that is required
during the highest use days of the summer, and also serves as an emergency
supply of raw water. Associated with the terminal storage structure
would be a low-lift pump station that would only operate when the stored
■ water was required. Using the pattern of usage in a thirtyday high use
e period 4,n the summer 1972 as a guide, it wrs 'found jhdt the use of
terminal storage would `permit 'a reduction in the size of Vz raw water
line. A parallel 30-inch raw water line and 109000,000 gallons of raw
water in a terminal storage structure, with a, 4.0-MG1,4 low-lift, pump
station, would furnish the 1982 potential demands ss ming that tuffli-
cient pumping capability is available %twthe raw water intake. Also,
a 42-inch raw water line and 10,000,000 ga4lons of terminal storage,
with a 4.0-MGD low-lift pump station aN capable of meeting the 1994
dovands when the raw water pumps are operating a± the maximum desirable
head. The terminal storage would not be required initially and could
be constructed at a later date. An economic analysis indicated that
M the more economical approach is a smaller diameter raw vat6r line and the
® terminal storage structure because of a lower initial coot for the pipe-
line and the ability to delay A.;:a constru.tion of the terminal storage.
After Denton's raw water requirements exceed the modified rah water
pump station's firm capacity, a second intake structure and pump station
3.4
/41181 AND WOJOLI
Will be required, 8assd on thq projected potential raw water require-
if , these facilities wi'li be required in 1977 if the existing raw
water line is paralleled with the 30-inch line and the 10,000,000-gallon
terminal storage is constructed, or in 1980 if it is paralleled with the
42-inch line and the 10,000,0GO-gallon terminal storage is constructed.
proposed
Since the current estimate of the completion de of the Aubrey Reservoir (1980-81) essentially coincides with the estimate of
the required completion date of the second intake structure and pump
' station, the City of Denton may have the Option of locating these
facilities at the proposed Aubrey Reserlrolr. At this time, the current
projection of the directions of growth of the City makes
to construct additional intake capabilities at it more desirable
Garza-Little Elm Reservoir.
However, if more growth in the northern portion of the City is stimulated
by the construction of the proposed Aubrey Reservoir than is now pro-
Jected, and if it becomes desirable to furnish treated water to some of
' the small communities to the north of Denton, then an Intake at the pro-
posed Aubrey Reservoir and a separate water treatment plant on the north
side of Denton might be feasible at a later date.
It is recommended that Denton parallel their existing 27-inch raw
water supply pipeline with a 30-inch lint and replace the existing raw
Ldn ps No. 2 and No. 3 with two pumps that have characteris
similar to the two largest existing pumps as soon as possible.
le speed pump could be used to permit more efficient operation
wer demand periods. The construction of a 10,000,00o-gallon
terminal storage structure and 4.0-HGO low-lift pump station
planned for 1976-1971', The second intake str ucture and
pump
3
IIUC1C ,Imo NICMOL{ .5
1
station should be in service prior
to the summer of 1979. These
' facilities well be adequate to meet the Projected potential demands until
approximately 1982.
3.3 Water Treatment Plant
The water treatment plant will have a capacity of 16.0 MGD and an
overload capacity of 24.0 MGD when the current expansion is completed.
The water treatment plant should be capable of supplying enough finished
water to meet the potential peak-day demands. A curve showing the
potential peak-day demands for the period 1974 through 1994 is presented
in Figure 33. The water treatment plant overload capacity of 24.0 MGD
and the 4.0 MGD of well capacity are sufficient to provide the projected
potential peak-day demands through 1978. The next expansion of the water
treatment plant should be in service by the peak-use period of 1979. An
8.0-MGD expansion will increase the overload capacity of the
water treat-
ment plant to 36.0 MGD.
The scheduling of the construction of the expansions to the water
r treatment plant after 1479 is based on th6 assumption that the wells
will be con- :zrted to a standby status after about 1980. An 8,0-MGD
expansion in 1982-1983 will provide all the treated water requirements
until approximately 1989 when another 8.0-MGD expansion should he
completed.
1
3.6
roue aNO Niuwu ~
PROJECTED POTENTIAL
WATER TREATMENT PLANT REQUIREMENTS
70
WATER TREATn1ENT PLANT
PEAK CAPACITY
i
60
50 L °
0
~C
Z~
.a
D F
30
4-
WELL CAPACITY
4.0 FAGD
20 i
' - WATER TREAT TENT PLANT
RA1ECI CAP~4CITY
10 -
0
73 75 77 79 81 83 85 81 89 91 93 93
YEARS
/RL[[[ ANb NIC NOIf i _
FIGURE 3.3
1 THE WATER DISTRIBUTION SYSTEM
the principal elements of a water distribution system are the high
service pumping facilities, ground storage tanks, elevated storage tanks,
and the distribution system network of pipes. The operation of a water
' distribution system involves the inter-reaction of each of these elements.
The primary purpose of a water distribution system design is to provide
economical and compatible facilities that are zapable of furnishing suf
ficient water of suitable pressures to satisfy the consumer's needs.
4.1 Existing water Distribution System
' The principal elements of Denton's existing water distribution
system are shown in Figure 4.1, The water treatment plant is located in
' tha southeast part of town. Two Plovated storage tanks are located on
t the north side of town, and one elevated storage tank is located on the
west side of town. Ground water wells, storage tanks and booster pump
stations are located throughout the City. The major water distribution
^ystem transmission lines spread out from the water treatment plant to
' the north and to the west.
4.2 Pressure Planes
The operating pressures in the distribution network will vary con-
siderably throughout the day. The pressure at a given point is a
function of its location in relation to the sources of supply, of how
much water is being consumed, and of the ground topography. In the
1
' 4.1
PRIM AND NICHOLS
7711,711
I
! 4 i e t ~ k
r .
1 s 1, ,
, , R\~ X11 1 t!'_P~kV , _ , 1. 1 1
I
` ~ ` ' ' Y S f . I ♦ Y ~ 1 1. - '
i
~
l I `
6 6 f 71/w,
oz, li
~ I t, w•nsi.~• ~ t E ~ ~ n
Iwo
• l
r W
6 0% La
JA J
Y. W
R
;
r
FIG'•IR4 4,1
- - il~Cl•~ ..r.
design of a water distribution system, minimum and maximum desirable
pressures for various types of consumption are established. The most
desirable pressures are approximately 50 psi in residential areas and
somewhat more in industrial areas. Pressures of 40 psi are normally
considered satisfactory during peak-use hours, but values as low as
30 psi in the primary network are not normally considered as acceptable.
Pressures of 20 psi are ac:eptable during temporary emergencies such as
a fire. Normallys the maximum desirable` pressure in a distribution sys-
tem is 100 ksi, while the maximum pressure` should not exceed 125 psi.
In the design of modifications and expansions to are existing distriW'd on
system, it ig desirable not to exceed the historical maximum pressures
11 ,
in the existing portion of the system. This would be approximately
75 psi for most of the Denton system.
Denton "is ^eoerally located on a ridge between Hickory Creek on the
south arod Clear Creek on the north. The City is drained by Pecan Creek
and Cooper Creek, within the present systems the ground elevations
ranile from approximately $70.0 feet on the east to approximately
745.'0 feet on the north, or a difference of 175.0 feet, The terrain of
' a city often dictates that more than one pressure plane be established.
The preferable spacing of pressure planes is shown in Figure 4.2. For
thi conditions a single pressure plane has a difference in ground
■ elevation of 110 feet. If the elevated storage tanks have an overflow
elevation that is 120 feet higher than the maximuri ground elevations
the static pressure will range from approximately 52 psi to 100 psi.
The overflow elevation of the McKenna Park and the Nigh School
elevated tanks is 827.0 feet, while the Bell Avenue elevated tank
I~
4.2 II
_ FW14 AND NICHOLI
1 ,1 77
r f
ELEVATED STORAGE PREFERABLE SPACING OF PLANES
R 3111
i cv + .
HR
n
C
A
N
1 a • I
i
-
a I overflow elevation is 817.1 feet. If the preferable spacing is applied
to the existing tanks, they should serve that portion of the City that
lies between elevdtions 597.0 and elevation 707.0. Any area outside of
these limits probably Mould be served by a separate pressure plane.
The lowest elevaticn that is served by the present system and the
lowest elevation in the projected growth areas are only slightly lower
than the computed limit of the preferable spacing of prtitssure planes `
based on the existing Plevated tanks. The highest elevttion that is
served by the existing system exceeds the upper limit of the computed
preferable pressure plane spacing. The highest elevation in the poten-
tial growth'arnas could ba as great as 780`X feet. This higher area in
the northwestern portion of the City should be served ty a separate
pressure plane. The overflow elevation In the upper pressure plane
should be set at 120 feet above the highest elevation to be served
(elevation 780,0), but not greater than 230.0 feet above the lowest
elevation to be served (elevation 707.0). ThE overflow O evation of
the upper' pressure plane should be established cat an elevation of
910.0 feet.
The maximum ground elevation in the proposed upper pressure plane
is not ',10 feet above the maximum ground elevation in the lower pressure
plane (783.0 - 707.0 = 73.0 feet). Some portions of the City can be
served from either pressure plane. This condition has a distinct
advantage in that it permits m,)re flexibility in the location of the
' boundary between the two pressure planes.
4.3
F h
v
1 4.3 Nigh Service PumpinFacilities
' H th? daily water use cycle, the duration of the period of the
highest de+rand is relatively short. It is normally not pr..ctical to
provide all of the highest demand with the high service purping units.
Experience has shown that in thv design of a water distribution system,
not less than 6010' of thr maximum-hour requirements should be supplied
' by pumping capacity. Denton's peak-day hourly distribution of water use
indicates that the most desirable high service pumping rate is approxi-
mately 75% of the maximum-hour use rate.
The rated capacities of the existing high service puraps and the
proposed capacities for 'the high `service pumy►s are summarized in Table
4.1. The indicated rated capacities are those that are or shield be
1vailable with the largest pump out of service. Additional data on the
existing high service pumps is presented in Appendix D. The 1974 total
dynaraic head was taken from the existing pump curves. The total dynamic
head; for 1980 and 1994 are based on the results of the computer analyses
of the distribution systems proposed for the respective years. The
percent of the potential maximum-hour demand that the existing pumps are
capable of delivering is less than the percent that is nonnally con-
sidered satisfactory in design. The sum of the percentages for both
1980 and 1994 exceeds 75%. In the proposed two pressure plane system
operation, water would be pumped through the lower pressure plane to the
upper pressure plane ground storage tank at maximum rate equal to 1.05
times the potential pea4;-day use rate for the upper plane. The as-
sumption has also been made that all of the Four-Cities Area's demand
mould be supplied by pumping. These procedures increase the lower plane
4.4
1 - /IlttS[ AND NICHOL$
y r;
. ' T mss' Y 4 t
WPM >~h:o- I~~fsb`C. ~Wh ~ ar py 'y 4~°e a k ~l.o Y~~
~
NAT
4 ,g
Tabte 4,1
High Service Runj,,Facilitins
' Year
Location Rated Total Percent of
Opacity W1,311ic Potential
MGD)_ Head Maximum-Hour,
03mand
1974 Water Treatment 19,8 250 I~
Plant 57.4 }
' 1980 Water Treatment
39.03 240 71.5 f
Plant i '
Upper Plane 2;15
Booster Station 2.4
1934 1¢~ajtei' Treatment 5
77.Od' 23
Plant
Upper Plane 5.96 235 6.0
Booster Station
' pumping requirements to a level that is greater than the amocn
t that
' would be required to satisfy the lower plane's demands,
The pump curves for the existing pumps and a Sel'iE5 Of system CUI'YES
are shown in Figure 4.3. The pump curves are the results of the manu••
I facturer's tests. The estimated 1974 system curve is based on recorded
high service pump flows and pressures, while 1950 and 1994 potential
maximum-hour system curves are based on the results of the computer
analyses.
I~ The 1974, 1980 and 1994 potential maximum-hour demands that would
be required from the water treatment plant pump station are indicated
along the total flow axis of the graph. The figure indicates that the
existing pumps operating with the existing system would not be capable
4.5
►Rtt{t ANO HICHOt.t
MIN
y +v ~0 4
T
WATER TREATMENT PLANT H',J'H SERVICE PUMPS
340
390
04
:00 - - _ -
12'13'15 - - - - - -
~ 280
- * BALI PUMPS---
260
r I l
y ti 240.
~ '~1p~~;MT` Mpx1~~alM
1' 13 1 1996 pO
200
v WATER TREATMENT KANT
180
15 HIGH SERVICE PUMP STATION ~
POTENTIAL MAXIMUM-HOUR
160 REQUIREMENTS
140 - ~r_
0 L0 20 30 40 50 60 70 80 90
TOTAL. PLOW-MGD
n
A ~
T
P
A
v 4 C ^ k i4 d L of V'rnlshing the tpi ential,1914 rt,axirnum
hiur df nd if it should orcur.
The telationship of the combined curves for the existing pul.tis and the
1:74 4stem curve iit;ilcates that additional
Po~ping capacity ot the
crater treatment plait alone wovld rot materially increase the pu;>tp
station's delivery capability because of d•istr Coition system limitations.
For the high service pump station t) be M'pat
it )e with the existing
water treatment plant and ground s,t0ra9a oinks it sho,rld have a i'irYn
capacity of 2$^g MGp, This could be accorrplished by replacing the two
1v smaller pumps with two larger pumps (one should be a variable speed
that are [omparablo in sage to the two exiting larger pumps. ,
4.4 `Ground Storaii4
fhe s.ritem, currently vs a total of f' "
storage cad;city.' Of this am,~'unts 5opad o`b0~Ob0 gallons of ground
,Idlp gallons are located at the
water treatment plant in the form of clearriells. Another 1,000,000
gallons are contained in the lower portion, of tho McKenna Park tank, and
the remainder is contained in ground storl~ie tanks that are adjacent to i
A
walls. The ground storage tank capacfties are summarized in Table 4.2.
For the purpose of this study, the assumption has been made that all of
the demand wil;` bt, supeiled from the water
treatment plant. For this
condition, the 7ri,und storage tanks associated` with the wells cannot be
considered as ar,i4fective part of the distribution system. The McKenna
Park tank is con:ridered to be an elevated storage tank and the lower
~I portion cannot be used as a ground storage tank.
Ground storage tanks in the form of clearwells at the water treat-
ment plant permit ,:he water to be produced at a more nearly constant rate
throughout the day. Ground storage tanks 7kiy also be required within
4 , b
PRIME ANO NiCHOLN
77, 77, V ~"l r Table 4.2
ti
Ground Stora a Facili
ties
Location
Gipacity
RalionsI
Water Treatment Plant
1,000,000
A 2 0
oc0, 00f1
McKenna Park Tank (Lower ,Half)
1,000,000
a Well No. 2
Well No. 5 95,000
ii 50,000
l~ Well No. 7
95,000
Well No. 8
,000
Well Ho. 9 95
95,000
Wei i No. 10
Well No. 12 955000
95,000
Total 6,620,000
A the distribution system to provide stored water that can be boosted to
meet special conditions. This type of ground storage 1071 be rettuired
when the upper pressure plane is established.
The required clearwell capacity is a function of,Ml high service
pumping rates that exceed the capacity of the plant. 'For the Ctiy of
A Denton, this involves approximately 14 hours of pumpirg if the water
treatment plant capacity is equal to the pe4-day use rate (Figure 2.5).
Sufficient storage should be aval j1ble in the cTcarw~i'!!s to provide the
difference between the high service pumping rates and the water treatment
' plant production rate. It is also desirable to incluie additional storage
4.7
r K i .y.. ~p
l^ 5 C f n M~y'r 1
MIRN a r~,,
t r3 ~1 +1~e Iy4i R1,
capacity (approximately one Laird of the total required ground storage,,
capacity) as a margin of safety for use 6 ring an eivr9eri.y. the capacity
of the proposed upper plane ground storage tank is a Function of the
difference between the inflow to the tank from the lower pressure plane
!1
and the high service pumping rates. {
The Stato Board of Insurance recce-mends 130 gallons per capita of
ground storage. For the 1374 water-use p%°pulation, the existin<3 ef-
fective grourd storage is approximately 85% of the amount recommended
by the State Board of Insurance. The recommended 1980 and 1994 ground
storage caps a ties for both the Stag Board of Insurance requirements
and for system operation are stmmarized in'Table U. Of the amount
reconlr nded'for system operatics in 1980, 500,000 gallons would be for
a ground strsrage tank for the u~~per pressure plane, and the remaining
7,000,000 glllons would be clearrrells at the water treatment plant. For
the 1994 conditions, the recomvended caFncity for the upper plane remains
at 500,000 gallons, while the recommended capacity at th,, water treatment
plant increases 13,000,000 gallons for a total of 131500,000. The
recommended capacities for system operation are essentially equal to
those recorrnended ►%y the State Board of Insurance.
Table 4.3
Recommended Ground Storage Capacitiei
' Year Water Use State Board Recommended for System
Population of Insurance _ _1 Operation
Standard Ga,'ons % of~
Gallons Peak Day
' 1980 599300 7,7G9,000 7,500,000 23.8
1994 105,600 131728,000 139500,000 21.7
4.8
0 _ AND NIGXOLS _
9 IVY
F~4 f C x'f~~~~f ll' d ]11r y'i ,Y
i 4.5 i levated Store
to charactei^istics of 'ttie existinj elevated storage ulnks are 111
listed -In Table 4.4. The McKenna Park tank has it capacity of 29000,000
j
gallons, but only the upper hale` can be co,nted as elevated storage
because of it,., 1,w elevation. The overflow elevation of the Bell Avenue
tank is 10 feet loner than the other tanks. 9ec:ause this tank is located
near majcr transmfss!en lines, it will probably remain full during lower
demand periods, but will be drawn down quickly d,iring hither demand
periods due to its central location. T1,e system taeration studies ind-r'-
cated that a special piGing arrangement will be required near this tank
if"At is to perform within its ca0bilities.
Table 44
Elevated Storage Tank Characteristics
Tank Capacity Head Overflowd Height to
_ Range Elevation Overflow
_ M& f t. Ftj__ ~Ft. )
Bell Avenue 0.36 52.6 817.1 104.9
McKenna Park 1.00 34.35 827.0 68.7
(Upper Half)
High Schoc'l 2.00 34.75 827.0 119.5
Sanger r'oad)
There mu:It be a sufficient volume of water a-aailable in elevated
storage to supply the demand during the periods that exceed the capacity
of the high service pumping units. Elevated storage also serves as an
' emergency supply foi- temporary heavy demands such as fire fighting or
loss of pumping capacity. The recommended elevated storage capacities
4.9
F0191119 A40 NICHOLS
7'
7111
s. ,1,4E q .r
i are summarized' in Tab
le 4.5. TDe systeh operation requires '3,860;000
gallons of elevated storage in 1980. Of this arwunt, 3,360,000 gallons
1 would be located in thn proposed larier Denton pressure plane. An
I
additional 500,000-gallon elevated tank would he located in the upper
pressure plane. For 1994 conditions, an additional 1,000,000 gallons of
alevated storage would be added to Denton's lower pressure plane. The
State Board of Insurance recommended amounts of elevated storage for
City of Denton populations, using 54.17 gallons of elevated storage per
capita, are also listed in Table 4.5, The amount of elevated storage
i'-equired for system operation in 1980 exceeds the amount recG^niertded by
I~
a the. §tet~ Board of Insurance and thy, amount ►ec
' ommended for 1994 is
only slightly less than Board's Mquirements.
~ f
1 Table 4.5
Reced Elevated Storage Canacitles
Year City of Denton State Board
Pro,lected of Insurance ReCO"m pera for System
Population Standard Operation
- Gallons a tons
1980 Peak bay
53,950 2,9220500 308600000
1994 i 12.26
93,301, 500549100 4,8609000
' 7.83
f 4.6 Distribution Network
' The principal lines In the distribution system network tire shown in
Figure M. The high servict? pumps at the water treatment plant discharge
0 into a 27-inch transmission lins
A 20-inch transmission line along
Woodrow lane from Shady Oak Drive serves the northern portion of the City.
This transmission line reduces to an 18-inch and then to a 16-inch before
1
4.70
AND NtCHOI,
Another
it reaches the High School tank on the north side of the system.
transmission line consisting of 20-inch, 18-inclr, and 16-inch pipes
passes through the southern portion cf t►!s system to the McKenna Park
tank. There are a few other 16-inch lines, il~.cluding arie in Avenue A,
another in East McKinney, and a third in the northern part of the system
that ties the two larger elevated tanks together. All of the existing l
system is served from a single pressure plane.
The analysis of a water distribution system the size o` Dent.on's is
normally limited to the primary network. lheie principal linos distribute`
the water th►'oughout the system where it is delivered to the coi~sumtr
through 0h,. smaller lines. It is assumed in this type of enalysi~ that
of
if the primary network is capable delivering an adequate supply of
water at a suitable pressure to all sections of the City, the.smaller,
lines, if adequately designed, can deliver the water to the consumer.
' The larger lie's that are considered in a distribution system
analysis are normally ten inches in diameter or larger and are located ~I
at intervals of 112 to 1 mile. They should be connected to the system in
"loops"'; this is, they should connect to the network at both ends, so
that water can reach any given point from at least two directions. Some-
times it is necessary to include smaller diameter lines in a distribution
system analysis to complete loops.
If the system is to function properly, it is important to establish
■ certain standards in the design and construction of the smaller lines.
Observation of the following rules should provide satisfactory service.
f') The minimum size line for a house service should be 3/4-inch
copper pipe.
4.11
,N,LC6 AND NICNOL/
EL v p^ i r1 t ~ L 4 4. 'a
. us . 7x, q 1 j ✓ fit t;. 4'b
r
4~~ e~j1~S~',rd. ~ ~'t S t~,a'r a 7 F r s`' y~;-~' ~ g 1~et t'.~ '~'k~ ,
1'. (2) The ofni. 04 size_ 'distribution 5ysten line that could be
installed, if the line d, less tha+i one quarter mi'e long,
is a 6-ir;ch line. If two or rmre fire hydrants art ,required,
the minimum size should be an P-inch line. At intervals of
about one half mile, the S-inch line should cross and be
connected to lives at least 8 inches in diameter (Figure 4.4).
(3) In a cul-de-sac, a 4-inch line can be used if a fire hydrant I~
is not required and if not more than six customers are to be
served. ihp,; minimum line size that should be used in a cul-
de-sac where a fire hydrant is required 1s a 6-inch. If the
distance` from the connectihni treet to the `center of the`
cul-de-sac is 300 feet or lety, the fire hydrant should W. located at the intersection with'the connecting street.
1 (4) All lines beside those in c6-de-sacs should be connected to
other distribution system IMes at both ends, Where it is not I
practical to connect a line to the system at both ends, such
de,id-end lines should be at least 6 inches in diameter and
should be 8 inches in diameter if they are more than 300 feet
long, or if there are two or more fire hydrants.
(5) If the length if a distribution system line is greater than
ono quarter mile between connections, the rA nimum size should
' be an 8-inch. In parallel street systems where the streets
are consistently longer than one quarter mile between looping
t connections, 6-inch lines may be alternated with 3-inch lines
(i.e. 6-inch, 8-inch, 6-inch, 8-inch, etc.).
4.12
' ,R,[ft AND NICHOLS -
' 7u
a P
wl~
I
CRITERIA FOR SPACING 'OF
f SMALLER MAINS
MAXIMUM SPACING APPROXIMATELY 1/2 MILE
MILE MAX
1/4 _ MUM
8" OR LARGEil"
6" '6p
I► 6" 610
E" 611
fu 6 ~i
611 d
o
Z _ 6 _ 6ro
u co
4 rO
y6r~ _
61' 6"
rr~ r~wr~
OR LARGER
)'Rtgfg AFL, WCHoLf
FIGURE 4.4
1.
t
' Some Portions of the existing system do riot conform to the design
c MW ria\ listed above. These lines may not be capable of carrying the
projected future demands. They should be supplemented or replaced with
lines that will meet the design standards as the opportunities arise.
The retest of the conveyance capability of two of the transmission
lines in the exis-'ng water distribution nek~iork (Appendix C) indicated
that it had droppi:d to a low level in many of the principal transmission
lines. The rate of decline of the conveyance capability of the trans-
mission lines in the Denton system has been fairly rapid when compared
with other systems. It is important that the conveyance capability of
the major transmission lines 'oe maintained at a high level to assure the
effective and economical operation of tha' distribution system.
The loss in carrying capacity of the water mains can be caused by
a decrease in the area of the pipe due to accumulation of deposits on
the interior of the pipe, by an increase in the roughness of the pipe,
even when the deposits are very thin and cause no significant decrease
' in the area, or by both conditions. The physical, chemical and biologi-
cal characteristics of the water, and the choice of pipe materials are
among the factors that influence the nature and degree of deposition
in pipelines.
' Several chemical and physical techniques now exist for cleaning
pipelines and undoubtedly better techniques will be developed in the
future. It is recormnded that the City consider initiating a program
of cleaning all major transmission lines after they have been in service
from 10 to 15 years and each 5 to 10 years thereafter, All unlined pipes
should be lined after cleaning becau:•: experience has shown a rapid
IIIL[IS ANO NICHOLS
Yk..y
deterioration of
the conveyance capability if this is not done. The
need to clean a line can be determined from field tests. This type of
cleaning and lining program should maintain the majority of the major
transmission lines with a "C" Factor of 100 or higher. All transmission
lines installed in the future can include in the construction some of
the facilities necessary for cleaning lines.
In the analyses of the 1980 and 1994 water distribution network,
the assumption was made that the major transmission lines had not been
cleaned, and the results, therefore, indicate the most severe conditions.
If a cleaning and lining program were initiated, some of the projected
maximum-hour prassures might`be improved.
4.7 Analyses of 1980 Conditions
To assure iIat all of the critical conditions are satisfied, the
proposed 1980 distribution network wrs evaluated for maximum-hour, tank-
filling and fire-flow conditions. The results discus4ttd`in the following
pages are in most instances the culmination of a number of intermediate
computer analyses. To assure that lines Installed during the next six
years will be adequate to meet long-range needs into the reasonable
future, the 1994 analyses were performed first, and the 1980 improvements
' were based on these results. The work sheets of the final and ell•inter-
mediate computer analyses are aVailable if additional information is
required at a later date.
The proposed 1980 water distribution system network is shown in
Figure 4.6. The system has been divided i,1tto two separate pressure
1 planes, and the proposed division line is indicated by a heavy red dot-
4.14
P09109 AND NICHOL$
t „ v ,W)17 . 7 ~TTT
~n
.i G ~ t t Y'w, c~. Tt -
.
l
r :
y
f
~L,, 1-w .R I M1 !i 1
s ~ .
■
I,',, , I ~ } • it 'Y19M• _ ~\h
,
.r
I
1 ` 4 r yr, +i~ n~~' r s ~ i ~`4 ( , -JI
:
~ J Y
E
r J j c
It
ca eg
E
C4 W
)Mae Jw
} 5 M
~r
•arx4 0"" OO
t _
r
p1 - .
FIGURE 4.i
v y~ 19 ` ' ' n s ti•~ A F r . 'r K, , !'a}t ,fit(ab! • 'A b '"~.,i 'n~ : t M .
tea3 - f
dash line on the figure. Pipt,lines bill connect tM two planes, but Il
0 valves in these lines will be cios, cl. Tip cross-connections can
limited ae~rvice to the u Provide
pper plane fron: the lower daring pan E.+nergency.'
This boudarYiocation was seloctsd so thit,as much of
the older portion
of the s;istem as possible could be Glaintaned at prECSures that are more
riY nearly ill the range to Mhich they have been scab,iected
Th4 upper pressure plane i's supplied'irom a 1.2•F"GD booster pump
station located on University Drive near Bennie Brae. A 500,000-gailoii
ground storage tank will be located adj acen-t to the booster pump statiof,;
and ft will be supplied at a steady rate throughout the day with flow
• , ~ ..from ''the .lower pressure., lane a
p , nd the stared water will be used to
supply the abovo-average usage. In the upper
pressure plane, a 5000000.
gallon elevated storage tank with, an overflow` elevation of 910.0 'feet
is proposed near Payne Drive between Bonnie Brae and Fladger Drive.
The terms of the contract for the sale of water from the Denton
system to'the Four-Cities Area for 1980 are not known at this
time. The
most demanding terms from the aspect of physical requirements Ir, the
Denton system would be to serve them as if they were a part of the lower
' pressure plane. This condition has been assumed in the analyses of the
1980 and 1994 distribution networks. The exact high service pumping re-
i quirements and line sizes in the southeastern portion of the system can
be confirmed when the terms of the contracts are available.
Thp Denton lower pressure plane and the four-Cities Area are serv,d
from the high service pump station at the water treatment plant. ho new
elevated storago tanks will be required in the Denton lower pressure
' plane until after 1980. The principal line construction requirements
c-V 4 15
ORCM ANS WCHrL, - _
:E !l '4 ♦ ! r . ~Q..~ e. A
14, ck
? ( 'f.
include a 42-inch line'f
ran the IWa ter 'treatment plaht to spAncer Roac# j
a 30•inch and 24-inch through the c3Rrt,~sl portion of the s f
36-inch, 30-inch 20-i►h and 16_ Y~tem, C:: {
Q 1 inph`1f06 through .
of the southern portt:~ri6
the system, a 30-inch, 20-inch and i8a nch line throu Y
gh till? eastO' i
portion of the system, and a 24-inch and 20-inch line from the Hi
elevated tank to the northeast portinn of the High S:i+oul
ly
other proposed lines are sm31ler in diameter andcare designed n net primarily
to complete law s i
P In the system and to serve developing areas,
i To achieve satisfactory elevated storage tan, verations, it 11 necessary to assume that some valves' was
were ba
. Near the Ee11 Ayenue
eleva sed.
ted tank, valves that would sepa"rote the tank from the 16-1nch
transmission line that is located to the`nOrth of thp!fit,~
to be closed. _ wei'e'assiimed
The constructi•nn of the' rtepbled 12-i
Avenuq should include ties to the etevated P" 12-inch Tine in Qelj
tank discharge line and tc~'en
existing 8-inch line in Peach Street.
The Pressures for the proposed 1980 water distribution system under
the projected maximum-hour demand conditions are shown on Figure '4.5
For the proposed 11,90 water distribution system under the protected
maximum-hour demand conditions, the pressures in the higher pressure
plane range from less than 80 psi near the elevated tank to over 100 'iii
on the;r4st side of the j
pressure plane. The higher pressure plane is a
relatively new part of the 'system and should be c!pable of using these
higher pressures without any undue problems. Pressures in the lowa r
pressure plane range from less than 40 psi near the McKenna park elevated
tank, to over 102 ps,i on the east side of the system. The pressures av
most of the system are in the range of from a0 psi t er
to 90 psi. The re4~ion
' r. - 4.16
tAlt
f1 AND N!CHOLA
A y,_
of higher'prassur^ on the east side of the system is considered to be!'
acceptable. It is a newer portion of th& system and should be capable
of utilizing these higher pressures. The region of lower pressure iii
' the vicinity of the McKenna Park tank is also considered acceptable
because it is confined prlwi rily to the park area.
the sources of sapply for the upper and lower pressure plitnes under
the maximum-h-ur demand conditions are summarized in Table 4.6. In both
pressure planes, 75% of the demand is supplied from the high service
pumps, while the remaining 25`" of the demand is supplied from the ele-
vated storage tanks, in addition to the projected 32,36 f1u0 that water
treatme,lt plant l lgh service pupips must be cap0fe of dclivering to the ,
Benton lov,-Pr pressure plane, they must pump an estimated '1.04 h%O through
the iower pressure plana,to tip ground storage tank for the upper pressure
plane and 5.63 MG0 to the four-Cities Area. This is a total of 39.03 Mt,0.
In the analysis of the tank-filling conditions, it was assumed that
' the Bell Avenue elevated tank would fill quickly because of its closeness
1 to major transmission lines and its size. the analysis of the filling
of the McKenna Park and the High School tank indicated that the Mcl'.enna
Park tank would fill more rapidly during the six-hour period of low
demand. The operation of altitude valves on the McKenna Park tank after
it has filled would divert all of the flow to'the High School tank and
' complete the filling operation within the available time.
Additional analyses were made to evaluate the system's a')ility to
i~ provide adequate fire protection. Appropriate fire flows were added to
11 the potential maximum-hour demand conditions at selected critical loca-
tions. The residual pressures at all tested locations were above the
a.lr
1 - - - 111411[ ANA NiCN061
~ d11S =1177T7777, dt ~s
. A!F
Table 4.6
1980 Maximuet-Hour '
Source
Amount
II - ,4G0
!I Payne Road 65-MG Elevated Storage Tank
(Proposed) .40
University Drive 1.2-MG0 Booster High Service
' Pump Station (Proposed) 1.19
UPPer Pressure Plane Total
Bell Avenue 0.3C-MG t'ievated Storage Tank
(Existing) l.94,
McKenna Park 1.0-PIC Elevated Storage Tank
(Existing) 1.81 s' 1
Hi h School 2.0-MG Elevated Storage Tank
Existing) 1:48
Water Treatment Plant 39.03-MGD High Set-vice
Pump Station (Expanded) 32.36
Lower Pressure Plane Total
43.15
a four-Cities Area supply from Ot.ntcWl'Cower
Pressure Plane 5.63
System Total
50.31
acceptable minimum of 20 psi during temporary emergencies. The fire
protection capability of the 8-inch line along the west side of Inter-
state 35 north of west Oak is marginal, and if development occurs in
this area, this lire should be loope. to the system with a 12-inch or
larjer lire.
4.18
y
j)NAW
7 A71,
4.8 An at ses of 1994 Conditions
The proposed 151§4 distribution network 'was .iU6 evaluated fi,r the
projected maximum-hout'% tank-filling and fire flow conditions. The
distribution
network improvements proposed for the 1989 and 1994 period
are shown an Figure 4,5. The principal improvements in tho 1994 system {
[ Include the development of the network to the west of I-35 and to the
south of Lhe City, and the construction of a 11000,000-gallon elevated
stortre tank on, the west side of the City. The proposed elevated storage
tank was assumed to be located adjacent to the existing 1k Kenna Park tank.
Tha tank was located at this site to reduce the construction cost. If a
Wrt desirable site is available on the west side oil. thit 'Ci ty, it could
be used without materially affecting the hydraulic operation of the
f distribution network,';`
In 1994, the distribution network will continue to operate as a
two pressure plane system. The upper pressure plane will continue to be
served from the booster pump station located on University Drive near
Bonnie Brae, but its capacity will be increased to 6.0 MGD. No addi-
tional elevated or ground storage will be required in the upper pressure
plane. The lower pressure plane and the Four-Cities Area were assua4d
to be served from expanded high service pumping facilities at the loca-
tion of tha existing water treatment plant. The sources of supply for
the water distribution network under the projected maximum-hour demand
conditions are summarized in Table 4.1. In each pressure plane, 76% of
the demand is supplied from the high service pump and 25% is obtained
fro+n the elevated storage. i
4.19
Rl1111 AND Nickocs
r, 774
11 ii`jk'~ i a vi I }1 ^ p
S. ~L [ ♦,'rr 4 ti Q f S T..~ 4
i The pressures in the distribution network under the 1994 maximum-
hour demind conditions were essentially the same e's those obtained for
the 1980 conditlonsi Tle 1994 distribution network was tlso analyied
for tank-filling snd fire-flow condition ,,and was found to be adequate.
~I I Tahte 4.7
i
19,14 Maximain-Hour _Sources of Supper
Source mount
Payne Road 0.6-HG E1evbted Storage Tank 1,98 I
(Proposed)
University Drive 6.0-MG0 Moster Hlgh Service 5.96
Pump Station (Proposed)
Upper Pressure Plane Total -w,
y.94
Bell Avenue 0.36-MG Elevated Storage Tank 1,68
(Existing)
McKenna Park 1.0-MG Elevated Storage Tank 9,32
r (Existing) and 1.00-MG Elevated Storage
Tank (Proposed)
' Hi h'School 2.0-MG Elevated Storage Tank 8,70
Existing)
Water Treatment Plant 77.00-MGD High Service 58.)•9
Pump Station (Expanded)
Lov.-er Pressure Plane Total 78.38
Four-Cities, Area Scpply from Den ton's Lower 13.04
Pressure Plane
System Total 99.36
4.20
IAtt$9 AND MI[HOL/
PROPGSEO PROGRAM OF
WATER SYSTEM IMPROVEMENTS TeAk'J _l9$O
The proposed program of water system improvements for the period i
1974 through 1980 is outlined in Table 5.1. Pse improvements are divided
into years and should be in service prior to tie summer of the last in-
dicated year. The proposed locations for most of the network lines,
elevated storage tanks ground storage tank, and booster pump station can
be nbdified slightly without materially affkting'!~je hydraulic operation
of the distribution system. Only those improvements tbot were cor+.idereu
i necessary for satisfactory operation of the system have been incl'Wed.
Some of the pipelines and the elevated tank have been oversized to'allow
for anticipated future growth in the area. This study has only con-
sidered the principal transmission lines in the distribution network.
In new service areas, additional smaller lines will also be required.
The overall estimated average unit costs for pipeline construction
e arc 'summarized in Table 5.2. These amounts are intended to reflect the
complete cost of placing a line in service, including engineering and
contingencies. These are based on recent experiences for in-town
construction with some allowance for inflation during the period. The
cost of individual projects can be expected to vary above anO below the
' indicated cost, depending on the complexity.
Table 5.3 summarizes by years the estimated capital cost for the
' major distribution system improvements through the spring of 7984. The
' 5.1
FR[[,[ ANO NICHOLR - -
total estimated capital cost duthe
period is $1,2,623,300.
largest Yearly 'ring
Y expenditure is 4US0 The
struction of in 1918-1970, ~rheii the Con-
required. expansion of the water tre~itment plant wil
required, Che initiation of the construction of will be
intake strut;ture and pump station is also the pro;rosed raw water The estimated construction costs fo required during this period.
much as r the other years were equalized as
they range from $1,527,800 in 1916-1917 to
$1,8199200 1n 1979. 1980,
The major finprove
ments will
p robabl lndi-
cated, but the Proposed Y be required In the year Qate of
1 inns m.,..
construction of some of the smaller
,r require adjustment if in zrea to be
rapidly or more slowl served develops more
y than is now erected.
j
1
1
1
1
t 1
L
NfCMOU
y.~ d 5 .}!.9,• gip,. ~ ; ..i~i~~ ~ ~ Table 5.1
Proposed Schedule of Construction: 1974-1980
1914-1975 Estimated Cost
a. 44,800 feet of 20-inch, raw water supply line from Garza-Little Elcr X1,436,500
intake and pump station to water treatment plant
b. Pglace existing raw water pumps No. 2 and No. 3 with two 8.0-MGD 0 85,200
34S feet of head pumps „
C* `,Re;04ce existing high 5oYfce pus)ps No. 2 and No. 3 with two 10,0-MGU 0 74 600
250 feet of head pumps '
d. 19300 feet of 42-inch, Across country front water treatment plant to E~G,B00
Spencer Read
N
e. 3,400 feet of 30-inch, Spencer Road from'Sha'dy,Oaks Drive to intersection 129 200
with proposed 42-inch from water treatment plant }
S1,8i2,300
1975-1976
a. 5,300 feat of 36-inch, from Spencer Poad to intersection of I-35E and
Loop 288 $ 2699060
on intersection of
to 30-incho from
and SWainwright Orive and 324,500 1
b. 8,546feet e Lane of
I
w
Proposed C2 4-198Continued
1975-1976. Continued I
Estimated Cost
c. 4,600 feet of 24-inch, from the intersection of t,ycamore and
Wainwright to intersection of Mulberry and Avenue A
4 13T,i00
d. 4,400 feet if 24-inch, from High School elevated rank to
N. Locust
125,400
e. 3,300 feet of 20-inch, Loop 288 from M.K.aT. RR to Spencer Road
76,40Q
f. 1040 feet'of 20-inch, Robson Lane from Pennsyl%,ania to end of
existing 16-inch.
31,800
g. 2,500 feet of 16-inch, Spencer Road from Loop 20 to Mayh Ol Road
p 49,400
h• 3,300 feet of 16-inch, University Drive East from Ruddell to Bell b5,200
1, 3,300 feet isf 12-Inch, Pennsylvania from Ridgecrest to Hobson Lane
54,506
J. 5,780 feet of 1'i-inch, Audra from Loop 288 to Ltttimore
95,400
k. 14,200 feet of 12-inch, Mayhill Road from U. S. 380 to Spencer Road
234,300
1. 2,300 feet of 12-inch, U. S. 380 from loop 288 to Riyhill koad
38,000
Ma 1,601 feet of 12-inch, Loop 288 From University Drive East to Audra
29,7G0
n. 1,900 feet of 12-inch, Bell from University Drive to Peach
31,400
o. 5,900 feet of 12-inch. Carmel extended from Hobson Lane to Ryan Road
97,400
$1,655,500
s
♦ ~~.4 il ~dE r w1'c ~•Y, rJ,r.,'~'k G
7 - va W W
Prsosed Schedule o_f Construction: 1974-1980, Continued
Estimated Cast
19;6_-1977
a.` 10.0-MG terminal raw water storage facility and low lift pump $ 265,000
station at existing water Treatment plant
b. 4,350 feet of 30-inch, from intersection of 1-35E and Loop 288 165,300
to intersection of Hobson ',ane and FM 2181
c. 1,009 feet of 20-inch, Hobson Lann rnd James from Santa Monica 166,300
to Roselawn
d. 5,800 feat"of 20-inch, r x 2181'from Hobson Lane to cyan Road } 31>Qr}f)
e. 5400 feet of 20-inch, from intersection of Sherman Drive and }30,600
Windsor to 10500 feet north of Windsor on Locust
~
F. 3,304 feet of 16-inch, Ryan Road from F.M. 2181 to Carmel extended 65,200
g, 9,000 feet of 16-inch, from intersection of James and Roselawn to 171,800
intersection of Collins and Avenue A
g},300
h, 20500 feet of 12-inch, Old North Road from University Drive East
to Audra
S, 5,280 feet of 12-inch, from intersection of Old North Road and 87.100
Audra to intersection of McKinney and Bellaire
J. 81200 feet of 12-inch, from intersection of Hobson Lane and 135,300
F.Mo 2'181 to intersection of State School Road and Brighton drive
u+
y.
w
~ril r'. p 'r
. r
Proposed Schedule of Construction: 1974-1480, Continued
1976-1977, Continued Estimated Cost
k. 6,160 feet of 12-inch, from intersection of Fort Vorth Drive and
E. Daniels to intersection of Teasly Land and extension of Mission $ 301,600
1. 2,000 feet of 12-inch, Windsor from Kings Row to Heather 33,000
M. 1,300 feet of 12-inch, Nottingham from Victoria to Kings Row r 21,500
$1,527,800
1917-197$
a. 500400-gallon elevated storage tank, near Payne Drive between
Bonnie Brae and Fladger Drive $ 300,000
b. 600,000-yallon ground storage tank, near the intersection of
University Drive and Bonnie Brae 1500000
c. 1.2-MGD booster pump station, "near the intersection of Universi•"t
Drive and Bonnie Brae 120,000
d. 7,200 feet of 16-inch, Ryan Road from F.M. 1830 to extension
Carmel 142,200
e. 11,900 feet of 12-inch, from intersection of Ryan Road an? F.M. 2181
to intersection of 1-35E and city limits 196,400
f, 5,300 feet of 12-inch, F.M. 1830 from Hobson Lane to Ryan Road 87,500
cn
Pro osed Schedule of Construction: 1474"1960 Continued
Estimated Cost
1977-1978 Continued 5 99,000
9, 6,000 feet of 12-inch, Willowood from Bonnie Brae to Bernard of 1 h BonniefBrae and2AirportBRoadetorl~OGOafeettsouthtofn of 16'500
Airport Road BMW
i, 5,100 feet of 12-inch, Precision from Airport load to 1-35 99,000
J. 61000 f rt Of 12-inch, Hercules from Locust to Sh&.nan Drive
59 ►400
k, 3,600 feet of 12-inch, Bonnie Brae from University Drive to
Payne Drive
29,700
t. Linda Lfeet of ane to CountyhRoad 5. 380 from 1,200 feet west of
C Y
m. 5,300 feet of 1G-inch, from intersection of Bonnie Brae and 76'900
Payne Drive to the intersection of the extensions of Mesa
and Hampton UrIvP
42,100
n, 2 900 feet of 10-inch, County Road from U. S. 380 to
Hampton Drive 38,400
p, 2,900 feet of 8-inch, Hampton Drive from Cindy Lane to Mesa
r_ VI
P. 1,300 feet of 8-inch, Mesa from Barcelona to extension of
Hampton Drive 51,556,500
w
V
u '
4
kty~ tY y h 1.~. < .r" k' ,.A✓' sl ;E \ r~~" r` a. r
i `
Y E1
4 Y l•
i
FF
F Proposed Schedule of Constructoar 1914-ta80 L Conti no.oed
1978-1979 Estimated Cost
a. 8.0-MGD exponsion of existing water treatment plant $29750,b00
b. Raw water intake structure and 35.0-MGD pump station at
Garza-Little Elm Reservoir (Approximately one half of pump
station design capacity installed) 11500,000
$4,250,000
1919-1980
a. 169650 feat of 30-inch, from intersection of Loop 288 and
Spencer Road to intersection of S. 380 and Old North Road $ 632,700
b. 5,600 feet of [0-inch, Old North Road from U. S. 380 to
Silver Ok* "Road 133,000
c. 6,500 feet of 18-inch, from intersection of Silver Dome Road
and Old North Road to intersection of Sherman Drive and
Yorkshire 1419400
d. 130100 feet of 16-inch, from intersection of Spencer Road and
Mayhill Road to intersection of 1-35E and city limits 258,700
e. 2,400 feet of 12-inch, N Locust from Hercules to city limits ;00
f, 9,450 feet of 12-inch,, across country from 2,400 feet north of
Hercules on N. Locust to i~itersection of F.M. 428 and Stuart Road 1559900
M
fi n 1 iw
,~4 Tilt
,~"s
4r. ~ tail at
45,.. , 9 y:L1
e r
Proposed Schedule of Construction:' 1974-1980, Continued
1979-19801 Continued Estimated_Cost
9. 3,200 feet of 12-inch, from intersection of F.M. 422 And
Hercules to 3,200 feet north $ 52,800
h. 10450 feet of 12-inch, from FM, 428 (3,200 feet north of
Hercules) to intersection of Silver Dade Road and Old North
Road
174,100
i. 3,500 feet of 12-inch, Bonnie Brae from Payne Drive to
3,500 feet north 1i57,600
J.4 6,000 feet of 10-inch, from the intersection of University Drive
East and TV M.K.&T. RR to 1,260 feet north of Emerson on Old
North Roa' 870000
k. 1,800 feet of 0-inch, Stuart Road from Hercules to Juna and from
f Selene to city limits 23,900
1. 4,700 feet of 8-inch, from 3,500 feet north of Payne Drive on
Bonnie Brae to 41700 feet west 62,300
$1,819,200
v,
,
:t x n ,x - . . IN
w Table G_2
Estimated Average Unit Costs for Distribution System
Pipeline Construction
' Cement Mortar Lined Cast Iron Pipe
8-inch 513.26/foot
10-inch 14.60/foot
12-inch 16.50/foot
Pretensioned Steel Cylinder Concrete Pipe
16-inch $19,76/foot
18-inch 21.75/foot
20.1nch 23.76/foot
24-inch 28.50/foot
27-inch 33 00/foot
30-inch 38.00/fgQo~~~f
33-inch 44.00/foot
36 inch 60:75/foot
42-inch 66.75/foot
' Table 5.3
r Summary of Estimated Construction Costs; 1974.1980
Year Estimated Construction Cost
1974-1975 $ 118129300
1976.1976 19655,500
1976-1977 1,521,800
1977-1978 19558,500
1978-1979 4,2509000
1979-1980 1,8141200
' $120623,300
5.10
' - ,119149 ANO BKMOLO
t
fy-."- 77T,' r+'_.y T.r--~-. r•{
ti.. ri.yw ,O nM14 _y 1A' '~z
I
w CONCLUSIONS AND RECOMMENDATIONS
The current growth trends indicate that Denton should reach an
annual average water-use population of approximrtely 69,300 by 1980.
This includes service to the entire Four-Cities Area. For 1980, the
projected potential average-day finished water requirement is 14.59 MGD,
and the projected potential maximum-hour finished water requirement is
50.37 MGD. By 1994, the average annual water-use population is expected
' to reach IOS,600, and the projected potential average-day finished water
requirement is 27.88 MGD, and the projected potential maximum-hour
finished water requirement is 99.36 MGD, the future raw water require-
ments should average approximately 6% more thain the finished water
■ requirements. The power plant cooling water will be obtained from the
' wastewater treatment plant effluent.
The existing raw water system is not capable of furnishing the
future potential peals-day demands. It is recommended that the existing
27-inch raw water supply line be parallel with a 30-inch line, and that
the two smaller raw water pumps be replaced with two larger pumps
approximately the same size as the two existing larger pumps. One of j
the new pumps should be a variable speed pump so that the lower demands
can be more efficiently handled. By the summer of 1977, a 10,000,000-
gallon terminal storage structure and 4.0-MGD low lift pump station
' that can be used to supplement the row water supply line should be
' completed adjacent to the water treatment plant.
6.1
FPPMR AND NICNOu
a lip H' K'~ ~l i ~ a4~ j• 4 ~,i .;e
When the current expansion f f the water treatment plant is com-
' pletedt its overload capacity, plus the 4.0 MGD of well capacity, will
be sufficient to provide tht projected peak-day demands through 1978.
The next 8.0-MGU expansion of the water treatme~it plant should be in
service by the summer of 1979.
' The topography of the City of Denton dictates that the distribution
system network be divided into two pressure planes. This separation
should be completed by the peak-use period of 1978.
' The existing high service pumps' firm capacity is not adequate to
meet the future potential demands. The high service pumps that are
associated with the existing'portion of the water treatment plant Should
have a firm capacity of 28.8 MGD. It is recommended that the two
s.r
existing smaller high service pumps be replaced with two larger,
approximately the same size as the two existing larger pumps.. Ono of the
new pumps should be a variable speed pump so th t the lower dew- .can
be more efficiently handled, The next 8.0-MGD expansion of th1 :6r
treatment plant should include approximately 10.2 MGD of high service
' pumping capacity. When the distribution system network is divided into
two pressure planes, a 1.2-MGD booster pump station will be required
near the intersection of University Drive and Bonnie Brae.
For satisfactory system operation in 19801 7,500,000 gallons of
ground storage are reconr*nded. The system currently has 5,000,000
gallons of effective ground storage capacity. An additional 2[000,000-
gallon tank should be included in the 1979 expansion of the water
treatment plant, and a 500,000-gallon ground storage tank is required
for the upper pressure plane operation.
6.2
rMtIt I ANO NICMOt,
r
r e a, rr _
7-7777.7
y L e demands of the 1980 water-
Fgallons tisf use population, 3,860 1000
elevated sto rage capacity are recommended for the system's
operation. The system currently has,,3,3601000 gallons of elevated
storage. A 500,000-gallon elevated storage tank is recommended for
'.he Denton upper pressure plane.
Several transmission lines and distribution lines are required to
provide a distribution network that can deliver the 1980 demands. It
is recommended that the City of Denton implement the proposed schedule
of distribution network improvements for the period of 1974 U. ough
1980 as outlined in Table 5.1.
r The estimated total capita' cost for the construction of all the
recommended items is $12,623,300. These improvements will provide an
effective and economical system to supply the projected potential 1980
t water demands. This cost does not include that required for the con-
struction of smaller lines in new service areas.
' It is also recommended that a program to clean the major trans-
mission 11
i ~ nes In the system be initiated, The conveyance capability of
many of the principal tronsmissiar, lines has been reduced to a low
level. It is important that the conveyance capability of the major
transmission lines be maintained at, a high level to assure the effective
and economical operation of the distributioa':ystprr;,
e
6.3
►Rtttt AN* NiCNOL•
(fit :n K r7 77 Y1 Y3". l1'rri''1
1
M
1
1
1
1 ~
I
APPENDIX A
1 '
1
1
1
1
/hint AND NICHOLS
wool" 1~ IV
A
'LIST OF REFERENCES
' (1) Freese, Nichols and Endress, Consulting Engineors, "Denton - Water
System Study 1965s" Fort Worth, Texas, December 1965.
' (2) North Texas State University: UnpuUlished enrollment statistics
furnished by letter dated January 23, 1973s Denton, Texas,
(3) Texas Woman's University: Unpublished enrollment statistic'
furnished by letter dated February 1, 1973, Denton, Texas.
(4) Agreement between the City of Denton and City of Dallas for the
' development of the Aubrey-Garza-Little Elm System, November 1962.
(5) Corps of Engineers# U. S. Army Engineer District Fort, Worth:
"Aubrey Like Deflgn Memorandum No, 2 - General ,'tPreliminary
Subject To Revision)," Fort Worth, Texas, October 1973.
1
1
TF
i#
e
APPENDIX B
■
1
r
I _ PPI AK A%*
Y {
F I) k . ^'tE' L.,r,. .l sh y" a r ~~'r.sl s Yr
I
Inventory of Pumping Facilities
Station and Manufacturer Model No. Serial No. Type Rated Characteristics
Unit No. eet
GPM Head RPM
Raw Water 1 Layne 6 Bowler 70ORW16FS D16313 VT 5,500 345 10780
2 Layne 8 Bowler 14 MSL 22805 VT 3,000 175 19770
3 Layne 6 Bowler 18FXHMMrIM 22806 VT 4,200 190 1,770
4 Peerless 18 HH 198910 VT 50500 345 1,800
High Service 1 Allis-Chalmers C 69400 250 1,200
2 Wheeler-Economy 10 x 8 M A8-21263 C 2,150 250 19760
3 Wheeler-Economy 12 x 10 MAA A10-21264 C 40167 250 1,760
4 Fairbanks-Morse 10-5825 K2M 1036567 C 6,500 250 11185
o~
i
i
it .
1
i
1 APPENDIX C
1
1
1 .
1
i
' fllff ff XrN6 NKNOL~
7117
PIPELINE CONVEYANCE CAPABILITY
r
The conveyance capability of an installed pipeline can be deter-
r mined by computing the head loss between two selected points that are a
known distance apart and at known elevations. The head loss is based
on field measurements of the flow rate and the pressure at the two
r points. The conveyance capability is commonly expressed in terms of
the Hazen-Williams "C" Factor.
An extensive program of testing the conveyance capabilities of key
pipelines in the Denton water distribution system network was under-
taken in the summer of 1965. The results of those tests were used as
' guidelines for the pipe conveyance characteristics in the detailed
analyses of the distribution system network in 1965.
r To confirm; that the pipe conveyance capability versus age of pipe
relationship established in the previous study was still valid, two
r pipelines were retested. With the aid of employees of the Denton Water
Department, tests were performed on the 20-inch line that lies between
the intersection of Teasley Drive and Dallas Drive and the intersection
r of South Locust and Myrtle, and on the 8-inch iina in Ector between
University Drive and Sena. The tests were made with Simplex Type PFA
pitot rods, U-tube manometer with carbon tetrachloride and pressure
gages. During the tests, all connecting distribution network lines and
individual services were valved-off, and fire hydrants were opened at
r the downstream end to increase the flow through the lines.
The conveyance capability tests were performed in January during
r
C-1
reLt►f ANn WC"OLO
1
d K P M ~I
' the lower usage portion of the year. Tests of this type are normally
scheduled during the summer months. Because of the lower flow rates,
the tests were rot as satisfactory as is normally desired. The results
did indicate that rate of decline of the conveyance capability with time
that was established in the previous study was too great, and it was
reduced for this study. This relationship is shown graphically in
' Figure C-1. The 1973 "C" Factors versus age of pipe are simmarized in
Table C-1.
Table C-1
' Hazen-Williams "C" Factors
versus ego Pipe
Denton Dist-e-Mu-tion System Network 1973
Date Age of Hazen Date Age of Hazen
of Pipe in Williams of Pipe in Williams
' Installation Years "C" Installation Years "C"
1973 0 135 1955 18 86
' 1972 1 133 1954 19 85
1971 2 130 1953 20 83
1970 3 127 1952 21 82
1969 4 124 1951 22 81
1968 5 121 1950 23 80
1967 6 117 1949 24 79
' 1966 7 112 1948 25 77
1965 8 108 1947 26 76
1964 9 104 1946 27 76
1963 10 101 1945 28 75
' 1962 11 98 1944 29 74
1961 12 96 . 1943 30 73
1960 13 94 1942 31 73
1959 14 92 1941 32 72
1958 15 90 1940 33 71
1957 16 89 1930's 34-43 65
1956 17 87 1920's 44-53 60
C.2
Pitt It AND NICNQIt
r
s;
ar od sYs ~,d+y~Y `r t ~dFfd''+;~.
11"00--r-7-7 7
HAZEN •WILLAMS "C FACTORS
DENTON DISTRIBUTION SYSTEM
1 150
1 140
130:
120
u li0
' 100
V
90
~ ao
' w
70
r
6C
' 50
40
30 0 10 2C 30 40
AGE OF PIPE IN YEARS
1
fittest ANo « cHoLs
FIGURE C- 1