Water Supply Plan for Bull Mountain Area 9/1986 ..., WATER SUPPLY PLAN
for
BULL MOUNTAIN AREA
TIGARD WATER DISTRICT
liNi
Imo
#�`` 'p,qs4' $ t A^:. . 3 f' x dj.�`d.d'?"T T�,29 _.,'. Ip .,,d„fg'a
,.”"P to r�a.,�i� y i's '. ,,,--/,,- 4241,144a «. :� r F d a - e ,,',z-:,, :4 b p � � a ,� s
-.-. yo-of g„„ �T tl?. is 't,, ,,.- i 'F: ' 'r �
7
t r ' any dam' oda e ,�'}a..ak ," ?i t-" s: f. .7"4;,,,,,,,,,,:
�, e r,... 8:', "d:..w,41,a ra: `s ,. _s .. '^J ..:.s aS �, e a Ta,."ti C
+ a .,` .:' S aa. 1,'4 . : y r a'Via,' %
- ' -. ,a",' a 'z�;� e '"c:: a,u ° >
,
° :+ „tea sem, -
I
t ,, � �- � ': •+ r.*
lik
� R"' r .-
- s.: 'tip" 9'r ' .. ', „ 2 ....,
ii.
�" A e,. "tea
Q. liv
o- ate ' 414. t ., ,r �:.
w imt, 4 ,,` {40,14 o a
.�
°
tit
a 6
W
q
y
/ � LF
':. ��° �`':9 x .,e v,p 410.««,,., .•>.
II
SEPTEMBER 1986
GILBERT R. MEIGS — CONSULTING ENGINEER
I
110110 Gilbert R. Meigs, Consulting Engineer
Consultation for Waterworks
and Hydraulic Engineering Projects
2 Plaza Southwest
6900 S.W. Haines Road
Tigard, Oregon 97223
(503) 620-8080
is*
Iwo
September 24, 1986
a
Honorable Chairman and Commissioners
Tigard Water District
8841 S.W. Commercial Street
Tigard, Oregon 97223
Gentlemen:
Pursuant to our agreement of June 1986, I have made engineering
studies and have prepared preliminary plans and cost estimates of
facilities for water supply to the Bull Mountain area of your
district. My report on this project is presented herewith.
I appreciate this opportunity to be of service to you and the
district's customers.
Respectfully submitted,
A./a...4/7e
ti.
Gilbert R. Meigs
GRM/dh
Enclosure
PR
le
\� ,v.tN-es�/O�
444a
OREGON . / 1
G' qV 2, \ CD
POW
WATER SUPPLY PLAN
FOR
BULL MOUNTAIN AREA
TIGARD WATER DISTRICT, OREGON
SEPTEMBER 1986
AN ENGINEERING REPORT
BY
GILBERT MEIGS, CONSULTING ENGINEER
Tigard, Oregon
Cover Photo: Bull Mountain viewed from above Pacific
Highway at Bull Mountain Road looking west.
ACKNOWLEDGEMENT
The cooperation of Robert E. Santee, P.E., administrator
00 and engineer for the District; Terry Chamberlain, project engineer
Ifor the Unified Sewerage Agency; Larry Svart, associate planner
for Washington County Department of Planning; Randy Clarno,
ICity of Tigard Engineering Division; Deborah Stuart, City of
Tigard Planning Division; and Gene Birchill of the Tualatin Rural
Fire Protection District have been most helpful in the compilation
r of information on which this report is based, and their cooperation
ills
is sincerely appreciated.
wo.
r
I
I
I
I
I
a
TABLE OF CONTENTS
SUMMARY
General Statement 1
Observations 1
Recommendations 7
INTRODUCTION 8
THE PROBLEM 10
bee
EXISTING SYSTEMS 13
BASIS FOR PLANNING NEW INSTALLATIONS 15
Growth of the Area 16
Water Use 19
PROPOSED SYSTEMS 21
Plan A 24
Plan B 27
L
Schedule 30
Construction Costs 32
Annual Costs 36
L
TABLE OF CONTENTS
(continued)
FIGURES
No. 1 Aerial View of Bull Mountain (April 1986) 9
No. 2 Study Area and Land Use 11
No. 3 Existing Facilities 14
No. 4 Water Supply Plan A 25
4.4 No. 5 Water Supply Plan B 29
TABLES
No. I Land Use Within Study Area 16
No. II Population at Full Development Within
Urban Growth Boundary 17
No. III Population Forecasts, Year 2005 18
No. IV Water Demands at Full Development 20
No. V Construction Cost Summary 36
No. VI Annual Cost Data 37
I
1
Ogg
SUMMARY
General Statement
More than 325 acres of the Bull Mountain area have recently been
provided with sanitary sewers and plans are being considered for sewer service
to much of the remaining land. Thus, land development on an urban scale is
imminent. The Tigard Water District now serves about 1,600 persons in the
area, and there is capacity for a total of more than 20,000 persons within the
Urban Growth Boundary. A long-range plan to supply domestic water to support
this growth is needed now so that an integrated, cost-effective supply system
will be the outcome of supply to individual expansions of the distribution
systems on the mountain.
Observations and Conclusions
1. The Bull Mountain area as defined for this study includes 2,780 acres. Of
this acreage, about 2,140 are within the Urban Growth Boundary. The 640
acre balance lies on the west and southwest sides of the mountain and
could be served from facilities installed to serve the 2,140 acres.
2. As of July 1, 1986, preliminary plans for 420 single family residential lots
on Bull Mountain had come to the District's attention. These will be in
ih addition to 609 customers now being served by the mountain's pumped
!to
supply to the High Tor Reservoirs at elevation 713. On a peak-day basis,
the supply system will then deliver about two-thirds of its capacity.
I
e
i
3. The base of the mountain, defined as land below elevation 300, is served
from stations No. 1, 2, 3 and 4 at nominal elevation 410. It is estimated
that about 50 customers are on this supply system within the study area.
The 10 mg (millions of gallons) reservoir at S.W. 125th and Bull Mountain
Road is used to supply these stations on a peak basis.
4. The summit and all land above the base are served from reservoirs on High
Tor Drive. The installed storage totals 1.3 mg. These reservoirs are filled
by a 1.3 mgd pump at Station No. 2 and a 0.57 mgd pump station on S.W.
132nd Avenue south of Walnut. The lines from these pumps to the
reservoirs also serve as distribution mains to land within intervening
elevations 300 to 600, also known as the Bull Mountain gravity zone. The
district plans to install standby power at Station No. 2.
5. Land above elevation 600 is served by pumps fed by the High Tor
reservoirs. A network of pipes serves the Bull Mountain high zone. A
standby power system is installed to service the pumps during an electrical
outage. No improvements other than distribution main extensions are
N
envisioned for the high zone.
6. There is very little looping in the gravity zone. Most of the distribution
lines are dead-ended. This is a consequence of the sparseness of side
streets and causes a serious lack of redundancy for fire protection and for
continuing normal service in case of a planned or unplanned line closure.
7. Preliminary plans for supply to the area are based on land use districts
shown on the Bull Mountain Community Plan adopted by Washington County
in 1984. Land use is entirely residential.
- 2 -
I
8. Density of past and proposed development and estimates of household size
within the Urban Growth Boundary lead to the conclusion that, when full
development has occurred, about 20,700 persons will be served by supply
systems to this 2,140 acre portion of the study area.
9. The 640 acres beyond the Urban Growth Boundary are now in rural use; the
next planned rezoning is expected in year 2000. For this study it is
assumed that the area has a capacity for 6,500 persons.
10. The specific sites for most of the population increase are not known, so
plans for expansion of the supply system must be formulated to enable
response to specific needs and opportunities, as they arise.
11. Water use for the total 2,140 acres during a peak-use day is forecast at 6.4
mgd at full development. Pumped supply is 4.5 mgd, and 1.9 mgd will come
directly from reservoirs at Stations 1, 2, 3 and 4. It will be necessary to
add additional pumping facilities, supply mains, and reservoirs throughout
the area.
tof two alternate supply 12. Plan A is the first w pp y methods considered. It assumes
that all supply to land above the base will, in effect, be pumped to the
summit. Land below the base will be served from Stations 1, 2, 3 and 4.
Plan A is thus an enlarged version of the present supply system, although
the distribution plan includes reservoirs placed between the summit and base.
13. Plan B assumes that land above elevation 450 south of Bull Mountain Road
A. and that the R-9 zoning district south of Scholls Ferry Road will be served
by pumping from mains fed by Stations 1, 2, 3 and 4. The remainder of
land above the base will be served from the summit. Service to land below
- 3 -
0
wr
)
the base will continue from Stations 1, 2, 3, and 4, as in Plan A. Thus,
Plan B reduces the total pumping energy requirements and adds diversity to
the supply system.
14. Construction scheduling is proposed on these general concepts:
{ (a) Phase One
Individual projects all of which will be parts of both Plan A and Plan B,
and which will be scheduled for construction within the next 10 years.
Projects are:
(1) Increase capacity of Station No. 2 to deliver 2.0 mgd to High Tor
Drive;
(2) Install auxiliary power supply at Station No. 2;
(3) Initiate land acquisition for four new reservoirs;
(4) Install a 16-inch main along the Murray Road-Gaarde Street
extension and increase the capacity of the 132nd Avenue pump
station to deliver 0.86 mgd to High Tor Drive; and
(5) Construct a 1.0 mg reservoir at High Tor.
(b) Phase Two
Individual projects, some of which will be common to Plan A and Plan B
and some of which will be exclusive to Plan A or to Plan B. These
rr projects may not be needed within the next decade.
(1) Main extensions within the 410 level to a new reservoir on S.W.
150th for either Plan A or B;
(2) A 2.5 mg reservoir on S.W. 150th at water surface elevation 410
for either Plan A or B;
(3) Main extensions within the 410 level from S.W. Fern Street to a
1
new reservoir south of Scholls Ferry Road for either Plan A or B;
- 4 -
(4) A 2.5 mg reservoir south of Scholls Ferry Road at water surface
elevation 410 for either Plan A or B;
(5) A 2.5 mg reservoir between Bull Mountain Road and Beef Bend
Road at water surface elevation 550 for either Plan A or B;
(6) Main extensions to fill the reservoir at elevation 550 from the High
Tor reservoirs for Plan A;
(7) Alternatively, a pumping station and pipeline to fill the reservoir at
elevation 550 from the main extensions named in (1) above for
Plan B;
(8) A 1.0 mg reservoir south of Scholls Ferry Road at water surface
470 for either Plan A or B;
(9) Main extensions of a minor nature to fill the reservoir at elevation
470 from the High Tor reservoirs for Plan A;
(10) Alternatively, a pumping station and pipeline to fill the reservoir at
elevation 470 from the main extensions named in (3) above for
Plan B;
(11) A pump station at the 10 mg reservoir on S.W. 125th and Bull
I1'
4Mountain Road to supply the reservoirs at High Tor for Plan A; and
(12) A transmission line from the 10 mg reservoir to High Tor for
Plan A.
(c) Phase Three
Individual projects to complete service to the study area, especially to
the 640 acres beyond the present Urban Growth Boundary. These
projects may not be needed until after the year 2000 scheduled review
of the Boundary.
(1) Main extensions within the 410 level to encircle the western area
- 5 -
I11'
above Beef Bend and Scholls Ferry Roads for either Plan A or
Plan B;
(2) A pipeline from 125th Avenue and Bull Mountain Road to Reservoir
No. 4 for either Plan A or Plan B;
(3) A pump station at the 10 mg reservoir to serve the pipeline of (2)
above when warranted by the need for supplemental supply to
Reservoir No. 4 for either Plan A or B; and
(4) A main extension on S.W. 150th from Bull Mountain Road to
Hawkridge Road for Plan A.
15. Construction costs are estimated to total:
Phase Plan A Plan B
First $1,047,000 $1,047,000
Second 4,787,000 4,484,000
Third 1,104,000 1,001,000
Total $6,938,000 $6,532,000
16. Assuming that the district finances pump stations, reservoirs, pressure
reducing valves, the Murray-Gaarde pipeline, and new pipelines connecting
pumping stations to reservoirs, the total capital and annual costs of the
first two phases are:
Plan Debt Service Power Total Annual Cost
A 4490,200 $36,100 $526,300
B 460,500 24,100 484,600
17. When the new pump stations and associated new pipelines of either Plan A
or Plan B must be designed, their financial feasibility should be reviewed in
terms of the district's installed system at that time.
Recommendations
1. The district shold plan to implement the first phase of construction as soon
as funds are raised.
2. The second and third phases should be implemented in response to more
distant future needs and opportunities for construction.
3. Preference should be given to Plan B because it diversifies the supply,
reduces exposure to high pressures, and is eventually less costly to
construct and operate than Plan A.
- 7 -
WATER SUPPLY PLAN FOR BULL MOUNTAIN AREA
Introduction
Now that sanitary sewers are in place on the southern flank of Bull
Mountain east of 150th Avenue and sewer extensions are soon possible on the
northern and eastern flanks, land development on an urban scale may be
imminent throughout the Bull Mountain area. An adequate supply of water to
the area must be provided by Tigard Water District to support this density of
land use, as private wells will not suffice and fire protection will be needed.
The District now supplies the summit and developing land along the ridge
traversed by Bull Mountain Road as well as land at the base of the mountain
along Fern Street and above King City. Between the higher and lower land,
there are now comparatively few customers or district facilities. Figure 1 is an
aerial photo covering much of the Bull Mountain area.
The purposes of the investigations covered by this report are to
determine:
1. The supply facilities needed to provide water distribution systems
I throughout the study area,
2. A schedule for construction, and
3. The costs to construct and operate these facilities.
The work involved in this study is preliminary in nature and is intended
solely as a guide for any more serious undertakings with reference to water
- 8 -
1 e
1 Fw
, -,`toklf$4,4*4:, -• :
.e` i ,>(40 ,.•-• '''i'll"
,IPMIV le.
tib '
t 4,,..„.,.. ,.... , 4,4- .' 440,41r ..`,,. • „ .Ni
^e W • .'''',::-.,4„'Y'',
i ; 4 iy :-
� '
A, '1 - °y4 ::;.:;:4'.‘,.-1::-.111.,/
�,z ' f „ 16 4 rY� . 'R. �. . { "d 0( Y * mk'i '- y�P r',:-
ll ' :1
f ryas L� ¢ r v _ r .
w .^ t,. mac '":,.n.,,-,:i
s ALL' � �:� . z- +� .. .�R' .'7.w ..,ii 1
��ik ..--•-,1.,,;
• '7,,,;-,
f-.) Y .'q!(o- f'.'g..-
�qIPit
fY f.' h, Yp ^..g°r Yp.
t.
R� k� }' '• '';�&.,pt `--:,f',1,-'..),
M ' S '' j TT )(L< y p i',. pt '.
'!-Y "- " '
'7.:
,1y�" "4„;,!'' ".,. : '. t. ''0.00‘,A,. .rW ,*vi �t�T RiA Wyk fira;: ryP Y +� f'.'
�`,�s..- „,,,-,'.1;.::.';‘`,1-:- r �.„i 4,4-1,i',%''� �„. ., � t r .�t�, .. .,•*",� '
' •w *r;rte.'” "^xpaf A&.E .. q+',7r 3 ;,!. • , 4,
;7.-:! , <;,.•,,,,,
'A .:�.:`" ,:' �' „ . ' ,..,.,,,,,,..t..,..:...-.....!..;,,
' w
•
Y t-p h .x l `'*•,!. ... „,:A.,!7.,:',-;‘,L
yyaq�r ,,,,,,,,,,,,,,,...-„,„,.:,. . .,,,,...",i..,
w
f ' .:"s, A c.kx {'* a 0 a ->}� !b. a ,n • x ....
. eyr "'f'
. 1. ,f yS k, e-' 4 °"`s x' •` 'v "gf A f
" " ..' 4. •' .1 °1.1` k;, ''` y...01;0.,,,j...,..,,,,, !►rear° .01 ;
401 ° ',ft,'''Y .-!,,,.,°'',4!' Iti-"'Y 7- t,-..-:.'"4.,*Y ', 1-7't'''' 7''
i L.,...,: --. ,, -.
... .. ...
ad. to
T
.,,,..- . ,
.' ,,,,....,-. ..,,,..„.„,....„ -:„, ,._
c �[ a �'= i y moi, w a " ` -,444."-' ; , �.
*a a+Sm''• '�` �,.` ^e` 17 j !,-/#4‘...,,..,„:,:::,.
fir,+ c Yn , °":
P ,,,,j•-••::
c,g & • , _ .+,fit .,. i�'r'!� t,' ,' y �,t•,: '^ �,
..Ir.:'.'''''.';..." .- .; ' 'OF .'''''.'•....'°.,
....„. :::-; ,'7,..,81111.*, .' • . t7,...4',LN.,•..... .41.i .„.•,t.,,i,....„.,:.
411,4*
4.
v.*
;1•!'
•!' s - ..', a«» ..: a rt^f. .u,„lR `«tT y .1......4.- :1 « ;
f
..
..
4
''''''''''''''A
- i:':''''..
ar ,� ora x� ,� of, �;,..:.: ,,,, - , 'ar4e.`%''''''. ;!- *- ';'''''''' ,.'..4. c .:_� . s �' >w �'� � .,-41.N.111:.. ...„:140? a �,
` -- i. �. mow- . .€ '� '11;;,,;,' '' '� rr �+ 'i
= 0 .. '., - --7,7;?- , 1"!,,,,,,,,,
X
.;. f � � 'r. «'�.-° «t' +«ef' c� '�+tea � "� � �,. ..r9.
�� ''&.:,p' «+ Ar . w:. +uCF Jt . ffi.... `L4lpgd «
NF
q y
y �
r t
st
11-1 � fig, «fig .+{e �" ? 4. ":� ;�..a
.1167"
.. ei-::44%; - .-:...."..'e'-i: ;;.a.;0': '; ,-....:' :'-:-;.7.7.';','„kf'•': 4*- -,X-,,t',..:' ' ' , - . .,,„;',V,4,::,:.1i-•-•;.• -. ,r-:4-'.,-,,-..:• ;.,. „ ..,:;„,.. :,
ti
i At
'tette �' ��
•rt —.6.
FIGURE 1
,
, ......: , ,...„. TIGARD WATER DISTRICT BULL MOUNTAIN AREA
. ` � APRIL 1986
supply to the Bull Mountain area. The data and drawings included are for the
purpose of general information and contain physical estimates essential to the
design of the proposed facilities. Cost estimates are based on current
construction and power costs with a reasonable allowance for contingencies.
The Problem
The Bull Mountain area of the Tigard Water District includes 2,780 acres
of residential and agricultural land lying between elevations 200 to 700. Of this,
about 2,140 acres are zoned for residential use and the balance of 640 acres
lies beyond the Urban Growth Boundary but within the district's planning area.
Figure 2 shows the Bull Mountain area, land use, and topography.
Water service is now provided to most of the Bull Mountain area from
reservoirs at the summit in the HIGH TOR Subdivision. A small part is served
from reservoirs near the base of the mountain.
Recent installation of sanitary sewers has, up until July 1, 1986, led to
proposals for 420 new single-family connections between Bull Mountain Road
and Beef Bend Road, east of 150th Avenue. The Unified Sewerage Agency of
Washington County (USA) very recently installed trunk sewers for this and
adjacent areas totalling about 335 acres. USA also proposes eventually to
extend the Weir Trunk along Scholls Ferry Road to Old Scholls Ferry Road. In
the northeastern sector, the City of Tigard is annexing land, extending roads
and sewers, and this encourages urbanization.
The regional transportation plan shows a potential bypass road from
Aloha to Sherwood along the north-south leg of Beef Bend Road. Were this road
to be constructed, it is reasonable to assume that efforts will be made to shift
the Urban Growth Boundary westward to it and that the district would provide
service out to the new boundary.
- 10 -
�`� 'f r r pt I 1 ,r 7,- [ E - LEGEND
-'' ` 7/ i "
,„,„„ ...
e ; y .. l jrn
/ ,.t fi �r (' � l �� i STUDY AREA BOUNDARY
r
ft
11
w
'« • .! �i #,` t J { URBAN GROWTH AREA BOUNDARY
C-7---} � �� ✓' if,. .„.-1 rla ND U Y AREA B UNDARY
�' S
-1"'HI:
� �• � ;` e CITY OF TIGARD WITHIN STUDY AREA
} III ..,- 1 � `=, m,..,.,.,:" ,: ��,..,....,*.Y.,',,..--,,,,,--,� "ti. ,, pr' _.,, �,"- s � r"" t f r. ^M t F'"a` � d ,r
«_ I's '' �a. • tt � ,. R-6 LAND USr DISTRICT '.
33,3333 3b
li
,.''d17111V-11,4-'--",4-42:11 .61,,. _...-...-. a.._..,... .r ,„,,.. �..... sr'�a, d'J.r�.._„ 'y F ',r... ,"/-%,,v' lik � `.t,�
a\ : _,,,/' r ...__. t .l4'
4 '' ( 8 '✓f�;°' ' `„-^" ,,\ i , i _. ° ...✓ bw^ .? !f 'r,� r °s ,.^'r ✓1 aY w� a f ii,
111111, .,' �?�?Y �r i � ax?Et7,. . ,- 1,. .. .71 ,,',:-,--___77
rf a w # a, ^�« • d A
—Ls
.....__._.__ ,u-...._�.w,,...,....,,. a ?; s �.. - 4 �. r.. r' l a � �,+. iia...-« ..�� �„ 3..` :,.
".._.._w. -`"'.,- d^ � t t ."r^-.-.» ate- _'-- � _ 'w-qx� , s'n ." , .,. '-ae � a a�ILL** � ��� �,
i..._ .,,.-ate.._ 451„-- .�..a .�, . .:. „x»._�: =,.r 4r , . '""... �`d ,''°'�„ st',l ` ^f i t,i €` .ee „�.,�
400'
• . m,,,,, ( ''''C, '-' ,'t'r 1 { [..;r §` ':�.,. .� .. .'^Y-^" :' 5� l;t ---0 d ,t# td ��.-;, n,q.-_ : ,^§'' �...
-""/ I € • - ' ., , ,(. t x i i ''; .,.? a € .@ r „.,. „„.w-` . _ "a 1 :c E --
m......., I� } "� .t ---- .A.'"--- --,-1"'":\' '''''
i1j '` P l 30 It .«, i _x".-„«. - ..--'
;( he ,,,..°". _-. �.....�.'" r a I ..:t ,` ,` cr , . ',y � } 1, .r „ tt °trf, _. -�„ al,€ a r,1,1:1114:11
�.-.^� f
i :.r .«..,.., � __.-_..... "�" \.. �...»•"� t , i� ,-�_• t k,:tl,; '.:d-,ti.. .'.7��;. � a, rr _ �r • `�"a,`",..�.._._ � � - r` �=
�... ---_—_-2---------,:--
-.,_ " r ',fa !. 1 - Ire ;r, �-
ms � a ; r •�
"" f .,...„,„-.55---,„_ ,d_.. -. x PrE, -.., .. ,,-,�.a ZZ i ��� �.‘.**4/
�s �,>��.
"..-.: ,,.»,. ,� ,�«, ..._..._;^�_. -., i3 f= --s.,.., err I �.. _i. t m rek ,€m
,_,_____,/,,,./3„/,7- /-
,� .,�". �.�. �.. ... .. ..�. jr,.. ----,- ,-,tea„ .,,,.} #, , _-s.:.�- i, J 7 8: ,a-°` E'er
/ ,,.moi_; .,,. "_ � ' . ,t.m: "-,P; « ti � • v` ^ i' � ,#
r . 1 I ._.-._... a?:; ..t,./.7. 4,-,,, ,,44,.. ,,,,,x,a .:...`:: E:.. ,....,�V , .„4„o, I J `:,4 .., - b \
._..---__-' � x d Li ...a; a-r.` } .. - ^ ( Er d I '` .t _. t3. f `��:. �
ems'
•
,
, r� t €� , :;€",-. . '^,.�,.�}. ,. � � � .�-..:-, L:I , � i \1 :�`��,a� �}• �....�r..-,. € ' e; . � �.:to
-;17---,-- ::: : .✓J,r .�'" r f t `> ``{ \Z Edt,€. . .,,. r;:.. Slrl .---, i `r #t• .,."./'.. #'it # 1 at t° ...., i y y^,^'"., , , a
.w,.-^ I ,C. „,: { r E.,e, r qty .,r, ,, .-4 ( l < '7 >&
,,,,.'. °., &.�P s '1,/:; , nt.l, # „"�._ �.hi!.#,_ _"`,., a - : .", } � �r, ,tr..--. .. �s� ,t„- „r77-,4440,,t . r` �'�: ( ..
1 ,- �Nr 1 ! :'r,,."�"^" ”„ .,� ; 1 ff ,. . ', -, ,,..,..�'"...: }. . . E,:,.. -„ ..x :'dha' ``, «-.... , t r a a :•:„..--‹..,----*',
.. ,r.;'-r a, ” __ m Itt
/�°`�°' *",3-3-33*-
� ^ ., .---�, [,tq sirI: § !",«�.. 0:.,.� :,:- �,._.- ....(.. .�;.- x .,�',. » ,� r^ ,'. r� . •.s..• s••.•.•tea � �'' f ppy f
:a "_._. .,'✓" .� ✓ "� , ,.."-. tl {,,: jt # :r � J ...-„u,. � s. .:ia �w- , .,., i �> � PI '' � 'p `� '`~°a"^..... �• �2,,.-0,-1,, 1 ^`E�' �>�
' r . : * III# t ' t rd 1a 'f t :</---",.
,.-._ j x t Ir "<a.
, ,'! � ®„ ^ � , � 9t�#-�:":.=" A a, :l'.-, i:.� r.°`_,. ,�� 'e:= �, `�.� ;ig ' A�^),/?///:/./././//1-66
, }` `, 1 ;` �. E�aa•i
... � {�: - ,x} - _, ,,`\. �,f td #.�.>Ir°<s. ,> '} � , 4t�i.; a d.. � `::� ^:;. ,{ >r'� eve; ; ,
II '#' ,t # { ; t �«. . ti. ,. .... ,, t :, , rr~~`. � [E ,-. : ,.., ,� _, s, r. ;, it n = '7',",,k tlt�", r � �` t ii
.�T� :� t
{t s , ,._33- �f,1 i:, , -,v-,1 € �. ^ .:4" ,.} '`""Z , = f:'r'',F ^�- I :' p.,,, ,,...-41., €m.a , €
t } - /,',Y;1„,\--_--:':
,
- '''';‘,.,***1
}b. ;' ..-'�\2,.,. y( ` , '1`I r l ^ '. 'a�,"", f E
� i i � I � t�.f r �„�".. � { Via, . ,, ,^ � .��;., ,.,..�.- 73:\\../ E 1 m . �: r f t � ,f f�,W.� ;"&{ €#s Fl f t`� f :`v✓ �al
p ,--.'. -v...- ,"„ \',''',\,\‘'.,‘:,
i4t �y i # }. �„ .,�„ ".,.� � # r a � ,;,,.�''.:', t�'.j:.,.««n <,y ' tr ,p1 :'rte,—. :A-4 Jild
.-" ..� . . ...�� . a."' t 1 4 >...,s, "..... � ,�r�.tt� ' Xl� �-�.....__. ,t.r 1. ,. i g$ �' f rt, +'r `' ;`/•/f��`, �,�i r I - ..�,
1 p .m: 7-'-'°°''''-;-
dr T F \1 i I 'f jq{{ .t._ l33.;td R _W-1_ 1M„✓.w` d t "bbR� F 'F °fid, ,
{ s 1 EE \, ,. /c .. , tet 1 '`.. / 4' J
Fp,t ,,.« -,l- ",� ,3I' .t , b:x l1: .. , . la -,.... i- ',g.r I ac{ 8t ��a W^,..'.. g l ®,� ,. «-_..,_.�.. ,,�.. 4.; '1� ' ;.E �i'^.." /y^�� (#t:i«.._,,.. .-,., \ n. . .s« r'<'" ( �i'p.._` �s� • ,T,"'� �["„'': g ,4p, , // „- -w:,---'w. ,, ,a I, r, / �` z. .-,.,.._✓,.. i dj',, 1? { "(. ..+. 4 yg , I6 a,; r.- „ 1 ._./ f.._" ,._...._^,,.,:. '^.1'F,4-.. .:;^^-x,I t' I 1,t Z., 1 t ,.W.:' '\ / mi - _t�eqa },' jp
,r` �`,�""' f' ija .,( "tet r r w,,. , o. i`; # I,., ., i \` �. { ./ '-.. 'a ,,..1- 'ii # i '}} _ f
I. 44
I E ; I 1 - '..,._._ ''" ! i a. . t -----
' ,J)14i - :4.'s/ .s.»-" _ /F'"'"' - /bit
t
) i / ,3,
7 } r
I
^" ` E r A/571
! it \ t�: , ;'' t I I I §° iii 1.ijg m I I l ,,i _� ', •t f`r^=',„- ,. If ,:,E,m'" : Fra ; \ Pr 1ir✓ �` fr-' \ i , , t x �1; "'a\ *.., • `, (
,J }F .:- _"., a .d _ ;.P i l t i �`1 } a 'E�,,._ f d• } r € ; , ------,,---ti P "t ;P --1-1
s'' r • _
I
rtit =, "sla � E� ,k?
a E _,� '}. a -_. ,r1,;(.1 - "-„� d- ,� ,f rP ,Sar pFe"` » • i �
,,no
j t f i.
/, f' r .`i l � . #`a ` }} ' ( f ,`a a. • 1 ,P 'IadI �, s,1t3 l
tf
/J i`' z„' E' (E, t I 7 a\, 1 ,...... .....t-... ...,.,,...--`{�4 I t: -- ----A ,� if_ 1 2 :'1'k1,4,:'`.� .-„'c,
" \ #
�m
(„.
� "°�� d { �3 \ ` wl".. .%'>: .,.r ;w. - €. & #!� v , j f f,�. ' C • f f +aPd gI
4 q /J/
._`"'�., �-.^- / !€ �,J a I e4 S : 1,,. " �. 1 i ... a".. \. 7 € ( 1 ., we`. Cf r.,i_ .«"r {{ (f! '.: ....
'^w.._ ( �`e f!�l� y„ . „ ...,y ' ✓" j ` 4 "f':`.. a 3:. t e ,r 5mm E )- g d� f I P t f
� aj,----,„:• "2,_-____,
, _"--i _ ��,r / ,.,' �� +°A....✓i t,. `... : >,� a �,r�-s,i: �{'° ' '� 'S`\ d !. t 70,/,'
,'Js r�;��i /� s ' q"j, f 1...,-
d t'» "". tt ,.?,5 : 1 m E 1j :is
i ..,�„` ' .✓" �..i `'„"-" `" ;
There appears to be no deficiency with the present water supply to
existing developments. Many facilities are relatively new and all are
well-maintained. As of June 1986, 609 meters were supplied by the Bull
Mountain system and used an average amount of 0.25 mgd (millions of gallons
per day). Of these, 208, or about one-third, received water that had passed
through district-owned pressure reducing valves. These are needed because of
the elevation differences between the reservoirs at the summit and the location
of these 208 services below it.
The area to be served from reservoirs above the base of the mountain
has, however, the ultimate capacity for more than 15,000 persons and an
average demand of about 2.0 mgd, an eight-fold increase of usage. To continue
the present supply by pumping all system demand to the summit would lead to
energy inefficiencies if large areas are to be served subsequently through
pressure reducers. Further, the space available for more storage at the summit
is limited.
On the other hand, a different scheme of supplying the areas between
the base and the summit would have different capital and operating costs and
will be more complex to operate because reservoirs at mid-elevation would
require new pumping stations even though pumping energy requirements would
be lessened.
Thus, it is now appropriate to estimate the future needs and prepare a
long-range plan for supply so that water system construction that could soon
begin within subdivisions can be coordinated into a plan that will eventually
provide cost-effective water service throughout the area and so that sites for
new reservoirs and pumping stations may be acquired while the land is yet raw.
- 12 -
I
Existing Systems
The major pipelines and all reservoirs, pumping stations and pressure
reducing valves that are involved with the Bull Mountain area are shown on
Figure 3.
Areas generally below elevation 300 are served from distribution
reservoirs at Stations No. 1, 2, 3 and 4 at reservoir hydraulic level of 410 feet,
and these provide pressures on the order of 45 to 50 psi.
These reservoirs are primarily filled by water pumped from the
Clackamas River via the City of Lake Oswego. The balance (4% of the total
volume) comes from a City of Portland (Bull Run) pipeline at Bradley Corner.
This study has assumed that the district supply will be sufficient to fill these
reservoirs.
At Bull Mountain Road and 125th Avenue, the district maintains a 10 mg
(million gallon) reservoir at elevation 470, approximately 60 feet above the
lower reservoirs. This facility serves as a terminal reservoir for the district's
supply system and can backfeed the lower reservoirs through the distribution
and supply pipelines. At present , the 10 mg reservoir is filled by a 3.0 mgd
pump at Station No. 2; eventually it will be filled via a 36-inch line at Gaarde
and 121st Avenue by pumping from the City of Lake Oswego and/or by gravity
from the City of Portland.
Adjacent to High Tor Drive on the summit of Bull Mountain, elevation
713, are two reservoirs storing 1.3 mg. They are filled by a 1.3 mgd pump at
Station No. 2 and/or a 0.57 mgd pump station on 132nd Avenue, south of
Walnut Street; neither is provided with standby power. There is space on
district property on High Tor Drive for an additional 1.0 mg tank; otherwise the
summit is completely occupied by single family residences. The area
- 13 -
1
LEGEND 16" 12„ asa> "-24' TO PORTLAND
WATER MAIN A WELL )1
`* T 8„
AND SIZEv. V i, ° a 'v '
O VALVE �f tI 5. ! ;;
PUMP STATION 12" t2'� 12" „., 24/°
----600-\CONTOUR 12� ` F2'
• RESERVOIR / \
r 12
aw. a tRI12'
/-3 l 24”
/24"
12"
112'
/ 12 l 132nd Ave
- -� • 2020 INP STA.
0 ----- --/---
r
4)0 0.8 MG c' J 200 GPM EA.
RESERVOIR& 8" PR VALVE
3 ,
/ 2.5 MG RESERVOIR
9 WELL No.3 8„^ ELEV.412' /00 (/�/ o
12'I 1/
12°
��2 1g 12
�"�/
//-\._____
0.21 -G RESERVOIR 12"' I 12" 12...Th
12.'16" TO
I "T usrKK<< ELEV. 713' 8 ' IG" /LAKEOSWEGO
__...... et 8"J 0.28 MG RESERVOIR 88" 36"
HIGH TOR PUMPING STA, a WELL No.2 A 12„ ( V 8
8,,; PR VALVE 1 8 300
/ 3-25 HP 800 GPM EA ELEV. 413 12
I T - j 6" I.I MG RESERVOIR , IZ,, 12 12"
',71
ELE V.713 12� '5' \ 12" ff12" PUMPING STA.No. 2 ' I 12" 12„
6„ 12 I-IOGHP 2000 GPM TO 10 MG 12'
Vit,
8" 8„ I12" 12" 12" 1-100 HP 900 GPM TO HIGHTOR ✓
._ I I. . 10' 12„ 12"
8 8" PR VALVE ' 12'"
12
00.
10° , - 2-I MG
300 00l) 7:1 - / 7 12" 12°' RESERVOIRS
co 0 10 MG RESERVOIR ELEV•410' 12"
/ ELEV. 470' / WELL No.1 a
PUMPING STA. „
111 / \
��: N N - :� � ",,,s,-',,,..,,,:‘`,."--....%
. 600 0 • 2-5OHP 12
M
-)\
1 MG RESERVOIR. 12„ 1000 GPM EA. ___//-
1 ELEV.417' 8 d
/; WELL No. 4 12, 00
��
7 j
�_� 8c) 12"I - L
12
*olt
! t. ! Ill--. .
0 5„
O
---,.----..„,/ ,
' /6)c)o
3 f 12., 12"
111
d0 / X%
O } 12' 12" IZ„
J
��/ TIGARD WATER DISTRICT_____ - , „,,,,,,_„.--1/4„, -
'
h
12BULL MOUNTAIN AREA
11 , ,4, h,
e
_ _ FIGURE 3
I;, �,_ swr1 EXISTING FACILITIES
) . -,
,21 ", 0 500 1 000 2000
12"
GRAPHIC SCALE - FEET
2 r----- ''Vs, j
W° w44 : swIZ'�lM 12 , GILBERT R. MEIGS - CONSULTING ENGINEER
� W__._:.w 12 ��� SEPTEMBER 1986
11II
A
2 II
GOLDIE
surrounding the summit is served from a pumping station at the High Tor
property, and this system currently serves 127 meters. The station is connected
to a standby generator.
The lines from the Station No. 2 and the 132nd Avenue pumping stations
also serve as distribution lines and generally serve the side streets below
elevation 600. There are 482 meters served from these sites, 208 of which are
served via pressure reducing valves.
There is very little looping of the distribution pipe. It is found primarily
in the High Tor system and in the Colony Park area, which actually is served
from a single main on Bull Mountain Road. The remainder of the lines are
dead-end lines off the mains in Bull Mountain Road or on the eastern end of
Beef Bend Road and Fern Street.
There are no lower cross-streets to allow tying the branch lines together.
This is a problem that requires concerned attention if only to provide
redundancy for fire protection and for distribution system continuity in event of
main closure.
Basis for Planning New Installations
Two general plans have been prepared for supply to the area. In both
cases it has been assumed that new distribution mains will be 8-inch or larger
in diameter whenever there is no reasonable expectation of looping. Each plan
is premised on phased construction timed as opportunities arise or as needs
develop. Because the growth rate within the area and the location of
development cannot be accurately specified, the plans include facilities that
can be added gradually in an orderly manner.
The required capacities of the proposed facilities will depend on the
growth of the area and the per capita consumption for domestic purposes.
- 15 -
r
Growth of the Area
The study area is composed of land now zoned as follows by the Bull
Mountain Community Plan, which was prepared by Washington County in 1984:
TABLE I
Land Use Within Study Area
Zoning Estimated Acreage
R-5 30 acres
R-6 1,890
R-9 80
R-15 140
Rural 640 (beyond Urban Growth Bndry.)
Total 2,780 acres
I
Although these zonings may allow from 5 to 14 dwellings per acre, it
appears that less-dense usage will be the pattern. The preliminary plans for 420
units that have been proposed this year involve densities from 2.9 to 3.1
dwellings per gross acre in the R-6 zone. The High Tor density is about 1.8 lots
per gross acre. The Unified Sewerage Agency used 5 to 6 dwellings per acre, a
higher figure which is expectable with respect to the essentially fixed capacity
of gravity sewer systems.
Further, the nature of the land to be developed on the north side of Bull
Mountain will lead to a low usage per gross acre between elevation 300 and 600
due to several deep ravines emanating from the summit.
As for household size, the City of Tigard now estimates 2.6 persons per
dwelling and expects that to continue until year 2000. USA uses 3.2 persons per
dwelling for sewer capacity planning.
- 16 -
P
Some neighborhoods within the study area are well established, and there
is no reason to expect a change in development pattern. There are about 260
acres at the summit above the 600-foot contour that are used or appear will be
eventually used on the basis of two dwellings per acre. The Hawkridge area on
' 150th Avenue in the R-5 zone consists of about 30 acres but is developed for
about one dwelling per acre.
From the foregoing, the following estimates of population at full
development have been prepared on the basis of present zoning, existing and
known planned developments, and realistic projections of land use:
1
TABLE II
Population at Full Development Within U.G.B.
Zone Acreage Dwellings/Acre Household Size Population
R-2 * 260 2 3 1,560 persons
6.
R-5 30 1 4 120
R-6 (S)** 770 3.2 3.2 7,880
R-6 (N)** 860 1.5 3.2 4,130
R-9 80 9 2.5 1,800
R-15 140 15 2.5 5,250
Total 2,140 acres 20,740 persons
Ito
* Land above elevation 600
** (S) indicates land south of Bull Mountain Road
(N) indicates land north of Bull Mountain Road
The 640 acres beyond the Urban Growth Boundary are not to be zoned
for other than rural use until after the year 2000. For this study, an R-6 zone
- 17 -
has been assumed with 10.2 persons/acre density and, therefore, a potential
population of 6,500 persons.
Thus, the planning area population estimate is 27,240 persons at full
development sometime after the year 2000. The USA master plan is based on
85% development within the Urban Growth Boundary by year 2005. If that were
to prove correct then the study area will hold 17,600 persons at that time.
There are now 609 meters in the area served from Bull Mountain plus an
estimated 50 served from the low zone, or a population equivalent of about
2,000 persons. The City of Tigard growth rate expectation is 5.07% per year,
straight line. If that figure will apply to the study area, then about 4,000
persons would dwell within it in 2005. This is clearly too low when one recalls
the fact that 420 proposed dwelling units or about 1,300 persons may be added
to the Bull Mountain area within two years.
The city population is now 22,000 and the Planning Department projects
a population of 33,400 in year 2000. This includes the Bull Mountain area within
the Urban Growth Boundary. If the 33,400 figure increases by 5.07% per year,
then in 2005 the city-wide population forecast is 41,900, or about 20,000
persons more than today's population.
Table III summarizes these forecasts or planning populations for the year
2005.
TABLE III
Population Forecasts, Year 2005
Basis Area Population
USA Study Area Only 17,600
City of Tigard Study Area, zero 19,000
growth elsewhere
- 18 -
17-
Sewerage planning such as the USA's must be conservative because of
the inflexibility of installed systems; clearly it is absurd to assume that all city
growth will occur within the study area. For purposes of this study, it has been
assumed that the land above elevation 300 will be occupied by 10,000 persons
10 years hence.
The scope of this report does not permit further studies of population
growth rates, and the writer doubts their value for this report's purpose
because location is as important as magnitude of the need for water within a
distribution system. The water supply planning for the study area should be
based on total population; implementation of it should follow a long-range plan
but be accomplished as needs develop and opportunities arise. It is expected
that the needs will develop gradually and should be accomodated by normal
rates of waterworks construction. Land and right-of-way acquisition for all
L facilities ought to be thought-out ahead of the immediate need for
construction.
Water Use
For the district as a whole, during the last 10 years, the average per
meter usage was 412 gallons per day within a range from 381 to 462 gallons per
day average. For this study, utilizing an average of 3.17 persons per meter, it
is estimated that the residential use is thus 130 gpcd (gallons per capita per
day) except in the area above elevation 600. A comparable figure used by the
Wolf Creek Highway Water District is 124 gpcd.
In the present Bull Mountain system, water usage totaled 429 gallons per
day per meter in 1984-85. For the pumped system at the summit, usage is
estimated at 140 gpcd.
- 19 -
At present, the Bull Mountain system has an average monthly total
demand of 0.25 mgd and a peak two-month average demand of 0.41 mgd.
Service meters are read bi-monthly; no pump discharge metering is installed.
ismIn terms of the district's monthly demand as a percentage of its annual
average demand, the peak month is 84% greater than the annual average (1.84
times the average).
No peak day data are available for Tigard, but the Wolf Creek district
bxo
has used a factor of 2.25 times average month for the peak day. The City of
Portland's peak supply day demand is about twice the average daily demand.
For this study a peaking factor of 2.25 has been used for pipeline and pump
station sizing.
By combining the foregoing estimate of population, per capita usage,
peak factors and then distributing them over the topography of Bull Mountain
according to present zones of distribution, this study estimates the full
development demand flows as shown below:
TABLE IV
Water Demands at Full Development
Present Future Future
Average Average Peak
Zone Demand Demand Demand
Bull Mtn. High Zone 0.22 mgd 0.50 mgd
(from High Tor P.S.)
Bull Mtn. Gravity Zone 1.79 4.03
(from reservoirs at El. 713)
Subtotal 0.25 mgd 2.01 4.53
I ,
Low Zone 0.84 1.90
(from reservoirs at El. 410)
Total 2.85 mgd 6.43 mgd
- 20 -
1
Thus, the future average water demand at full development to be served
from the Bull Mountain pumped system is 2 mgd with a peak demand of
hip
4.5 mgd.
The present pumping system can deliver about 1.9 mgd to the reservoirs
on the summit. In order to continue the present method of service to the area,
it will be necessary to install new pumping facilities and supply mains to the
summit.
The present high zone is served by three 1.1 mgd pumps. This capacity
exceeds projected demands but is necessary for fire protection and redundancy
to allow for maintenance.
Proposed Systems
Two plans with many common facilities have been prepared for the Bull
Mountain area. Any plan for this mountainous area must include the capability
to supply sufficient water to the the summit and thus will necessitate pumping
because the district's total supply only feeds lower reservoirs. With large
differentials in elevation, pressure control becomes an essential concern for
safety. Pressure control also wastes energy and, thus, money. Means of
managing pressures and energy are thus the significant differences between the
two plans.
Common Features
Both plans propose that two new intermediate distribution zones be
established and that accompanying reservoirs be constructed, one on the south
side at elevation 550 and one on the north side at elevation 470. Further, both
plans call for two new reservoirs at the district's primary hydraulic elevation of
- 21 -
I
410 feet. Both plans include provisions to install a major intertie between the
1 intersection of 121st and Gaarde Street and the 132nd Street pump station, in
addition to increased capacity of pumps located at 132nd Street and at Station
INo. 2, which will improve flows to High Tor reservoirs. Also, a pipeline and
Itransfer pump station should be installed at the 10 mg reservoir to supplement
water supply to No. 4 reservoir.
I
Pipeline sizes and pumping heads were determined by computer network
analyses which also determined reservoir operating levels. Portions of the
Iexisting low level system were included in these analyses to simulate their
effectiveness as a part of the supply system for the Bull Mountain area. The
analyses included all existing pump stations, reservoirs (except the 2 mg's
1 storage located at Haines overpass on I-5 freeway), and mains 8-inch and larger
that might serve the study area.
IThese analyses showed that the proposed 12-inch line on the east side of
Pacific highway from Canterbury Lane to Beef Bend Road as shown on the
1 District's Master Water Plan of July 1985 will not be needed to supply the
I
area. This is due to the adequacy of existing 12-inch lines through the
SUMMERFIELD Subdivision and on Durham Road. The final connecting link, a
1 12-inch main on Durham Road, between 108th and 113th, should be constructed.
These analyses also showed that the proposed 12-inch line on Bull Mountain
Road paralleling the existing 10-inch line from 130th to 136th is not essential.
The planned 1.0 mg reservoir at the summit of Bull Mountain must be
built in any case.
Station No. 2 should be fitted with a standby generator capable of
4.
serving the well (56 KW) and the pump for High Tor (112 KW). Dual utilization
r makes this location more favorable than S.W. 132nd Avenue.
r
iiii - 22 -
1
Or No improvements or additions to specifically supply the high zone are
required. A distribution network analysis confirmed that 6-inch distribution
mains west of 144th Avenue and north of Bull Mountain Road will be adequate.
If 139th Avenue north of Bull Mountain Road is improved, an 8-inch distribution
line should be installed. All new dead-end lines should, as a rule, be 8-inch.
For the south side of the mountain, the main running the full length of
the MOUNTAIN GATE Subdivision should be 12-inch so that it can be connected
to other proposed subdivisions at lower elevations, such as BARRINGTON PARK
and FOXGLOVE.
It is assumed that certain 12-inch and 16-inch lines in the low zone on
Beef Bend Road, Scholls Ferry Road, Durham Road, 131st Avenue west of King
City, and a 36-inch line from Duchilly Court to Gaarde Street will eventually
i
be constructed. These lines are component parts of the District's Master Water
rw
Plan of July 1985.
The first alternate plan assumes that the present method of service will
continue. That is, all land above elevation 300 will receive water that has been
pumped to the summit and distributed from the reservoirs at elevation 713 on
High Tor Drive. All new pressure zones between the base and summit will be
iksupplied from the summit. Land below elevation 300 will continue to be
supplied from Stations 1, 2, 3 and 4 at elevation 410.
I fwi The second alternate plan assumes that the same new distribution zones
and reservoirs will be established but that much of the supply will be pumped
only as high as necessary. Service from the summit may therefore be reduced.
One zone will cover land between elevation 300 and 450 north of Beef Bend
Road. The other will cover land between elevations 300 to 370 south of Scholls
Ferry Road and immediately east of the Urban Growth Boundary. Land below
elevation 300 will be served by the same facilities as in the first plan.
- 23 -
I
Plan A
Plan A proposes to expand the present method of supply and is
illustrated in Figure 4. It is based on the assumption that all new distribution
lines will generally be unlooped 8-inch pipes which will require pressure
reducing valves between elevation 480 and 500 with water supplied from the
summit.
Referring to Figure 4, studies showed that the Bull Mountain gravity
zone can be served by the expanded facilities at Station 2, a new pump station
drawing from the 10 mg reservoir, a 16-inch and 12-inch supply main from the
10 mg reservoir to High Tor Drive, a 1.0 mg reservoir on the district property
adjacent to the existing 1.1 mg reservoir off High Tor Drive, and larger pumps
in the station on 132nd Avenue.
The new supply line along Bull Mountain Road should be 16-inch to the
first side street with an existing 8-inch main and should be interconnected to
the existing 12-inch main at all intersections that now serve side streets. The
Y station on 132nd Avenue would be remodeled to provide 0.86 mgd after the
Murray Road-Gaarde Street pipeline is in service. The pumping station at the
10 mg reservoir should be rated at 1.14 mgd for the urban-zone area and would
be expanded to 2.0 mgd if the area above elevation 300 that is beyond the
raw
Urban Growth Boundary were to be served from the summit.
I The area beyond the Urban Growth Boundary and above elevation 300
west of 150th Avenue will require service from a 12-inch line on 150th from
Bull Mountain Road to Hawkridge Road.
For full development, the ideal total storage at elevation 713 is three
days of average demand, or about 6.0 mg. It is believed that the practical
maximum addition is 1.0 mg due to land occupancy. Thus Plan A can provide
- 24 -
I
r
12"
, ,,,,,____7„,,- .,,,*..„...f .\\\.....„__„,„,,_.,/„.-/A i i\N„,,,,,_—_—*,?,'1 7,,,,,,,„,„,,,,,,,,,;;,,,,.....1„,„„.4!„,!. 4„,,,,',4'1 ,1:-. ',\ --,... ::::., ' ' '' ) 82;- (:',7,41-'4.'1*3.'"----""-,,- ....--- --'.\6_,J11, ' *1 0 1
r _,,,,_ ,\,-----,/,--- ,\,, „ ,../...„-: ),/-\ ,-„:::::_,,,,/,../..,,,,„\\,.„,\„_,,,;:z_.. „-„,- -
12"
<
v..) t,. < 1. - ,, ,„�.�.,-x , '.�- :,�°` s.ad - ` w� ° < /1,,,,,,,I ;7.,,,,,.;,,';;;-"'2',,',1:-
/'r - Y m '�" ° `„g�.,.'".^`"_-._ � -m. .✓"" I„ ,�,,, ,,.,. ;`.. ',.,�'t1 , �, x ,'a," ° rt �) al .„,.t.",_,', "'..);",$:::.;
„ x e s� .�'
ar
,, ,
3 ra;
/''�\, IE .I / .` ` x +? s f t? F' , i :::: Ym ' Yj :,..;,..„7”.
!�'` tce 7a'' f'-:'---
. Op ,,l
fp -�. t ',, r' ez P _ . / '�� x600 CONTOUR
i ;',' „---` / ;�':w< "__. ..... :1 t •�F;3 �.j,,9`.,...�\� �<<..z - "., �j},(��y t r ✓ < -'6' �3{a-.,�"` � �1a? t= s- :i—�� �«,r, a�, ,�i'' r--" - _. ft i 3 � * F , s T••r.. I:! •:tx .,,.r-. _.},�Y<•' "t. '',,-- 33F .. w�r
r ',:',_,',.\ .,'a.«•-""'-,-_...'' .,r'' ✓'... _..-. f t A. ':! 1Th j !_ ;; �,, --1,,.., ,,3 = 3 tr {-- - - .,i .. A ry.m . p.0 's, ., .rs 9w ` . w ,,rz,,,% / �' - 'ri I ''t `, t � , , , 'y,.. '..--, ' � _«tet `4 ./ «,t. l
.v � e
✓" r �. ,�,.• - s 1 "t max ., f, �' {;o' '1 Y IX /1
f/6/4;:://f'''::'*
\---...-.,„-------.._._.mr-r '«� ,,.. , ' I �,�"J ;�,,,.,.`...,. r, 7 S\ ) = ..w.^mom . «_ _ ._� -,®:, «�"-'" '"` - ,t,„„,_____.,
x'. Ir
,, .: t H .«. �`�� i � t 4',�q:�.-:-..'i .'• <r .•�*:tm ;.,'4 r -.v � e w w.wsl ,...(r.,/,',,:.,
jjf d �a jjj�` -'—� -_y\^,..,... .^' / / .,.7 f e,r�... J i d; '�� ,,x 4 1 ,, j «,` '". M 1t. ;E6 \._- it'-r. w#
r-`" ``�,. / / .' / j ,A. "`.'.zz s ..',;�°' ,x'T ®.., x i � � • '.1'
-. '-:-, r"` j sw `tl w
s '
,✓ <t' '' '`,. , / Q ((//'; 18 fx .e « ff . '.«Yx F xs
't 4Z f' _ t'
,.�..,... 1 ^ 1 *1*
„. 4” w ,-;‘L."
- ,-, p" d 1 .= .x,,s� *ww siN, axe '` xwe
f ( 7, t f 0 MG RESERVOIR FIt LED FROM N.40-7-',115
W 15 5th AVE p , . # , «P,: ,-«a '11'1)1 14 t ;; ffi,'' &-:
.. /i6.,„......,°®,
' '' '''' ''')I\
= ' �- W.S. 470', SERVES R-9 ZONING ABOVE Ei_ ;370`- Z__;" s � • � x+ `<
? f0
• 2 MG RESERVOIR A _ i Y • « YY +
5
2 �; WS. 410' :./1 l (', exe •
# «
iff
o
<
f i rr 9 Q Na RESERVOIR ° Gtr �« - __"--.- #1,;,,,
ffi
L.
aF . �, 11 3_ c
`600xIV 36" pUMPiNG SrA. No. L 00-'
/« 4'.1\
' � � '- =!w Ir r fr•� w IN
ti� /'1400 GPM TO hiGhi (UR
,
,:,,,,,
' /
w .. r a. 1 11'1.1 ,w4 ,.,,, ;;-";.‘‘"\,-,',.'. f`$ 4''.o.,—,"'""--, m,:=r f(17:11
I�: 1 :r, ,. \ T", -;4:t.' - - --';
-"". ..' -;
It '; _ - „� '.."\ ; x - - t .� �: � ;�, t! Y ; - ',; 800 - 1400 PM 1�r.,, _ \ g•.:, ".,�..
« I ( ..« NIGH SERVICE c\ _, IR « Y
.-e t j $f I :e 1 .�"'j, �E I t......„,,,,,,..._ __-„,..., ,.....lz,..... .._'�'Y' '_-f_„" d"'.'.. f"' �-.�
• , a r v._ r+- "{ f / 3 as , e. , , --4-Y-..,-4-------'
...a-_...._�:.._. .13 i '-, -:. I . r'�'-1 , '''.-+' t} — Y 9 t W
E
s ' i_ , < a ,i I I, ![ t [ �1 1 a �a :, �a_.........._ p, _=-- e E �� .�� "''�° •,�...�� " '�':�� 1,!::-, _=,,,Y� J.
) f a ,e,'/ � -# 'ai ,e{ jffi € R �.t �� � "re'" .o'
ld,u J .�*M � `_ � -; —'—a--=.\\ ,,, G ,1
G -I'-'4- --,,-)---`).
-J F l ,.$' �.,II..3 b<P .,f, 3.. ,e - e i, ,t. KV„,, I a it « '11 a ------,„ 'a f:J q'.e`",',:.. € ✓"�:. +t I "\ ..a \� ---- , gy
; __ . 4 _ I . -- \ .' . lJ h1 o RESERVOIR `..,
w
,' — __a..._, s, r i r I � tiflgr�, i �9�'. �: « � �,__.FI t1 1 � 'i`� a "q'':-� r« f<�i ,� /. -� _"�, '� q,7; «'f .
I
31.-:'\:":7:;t:::: , , r I 1I i -,„ \ \ # . , ` `;i....,.'r >,,. i d`,fid` .. w • ' y - -°• `�� � ;� �. Y6" fir,
C0_slt:t" .., })tc,1 / l II ' ` :r,,. . .. _ 1 I F; , ',,, f w �` „,1..,...., t h 00 FrM .1 - % .s,.. i„,t,,,,ttt,71 t it i itT i.7, f <:\,\I .__ r.y �, T> A.N ER PU~M`P STA ,f1.,:2://:/:,1--',1
t «x
t } ;31 • Yt
s _ fie, 12' iiV P�� Di)
a 3 1
- , mouNTAIN G„,, ,yy Ai �S1':,b1C7 RE5! PR
a
< << . I/7/,,,,_,
\ q
_. ., t- �.,;• - t, E, « ;,. r :� ., ;d , T;,„ ' ,E� ' EDI'v1 1 a' _ _"� d,'tk';>L
E _0-,s �1 1,f 011
w
tf. -.- . `., it ' Y'°t � i, S
< < � S GN � � �Oi
t'ai -, .y\,': _ ',.,:// �t _ - ��_w,,, �v ... rv•�` _.. PSV 4 AT�'
.
„ , Jot, � -_-_ ;,v .✓,, - \ RESERVOIR N0.4 -.0.14-,. �'
.1,,,,k,,,,,,‘,.:,' ._ i BEYON PRESEN 1 - - - ., R �'� p
E.. \ �' yr
5 MGERVO s
I t
' `} � i� I 1)D C L_____45jO A S: 550, SERVES��
} ... - - .
[ ' _ ..�� v4 11f.. . €L ,300 TO 450 N(;R?H '-✓ Y
�„ ..,'\ �>,.� � , •r;. _._. >' 1 .jj 11/ p' _-- , ,., ��_ 0F8EEF SEND ROaD ; -,�, � • �,�
12
7:1:'”
g\\., ft - /t i i
fIt 1 � �� � ,: ,d. /,;;<,///1„,„,,-\._r', `�,.8,i PR 4' �_ N� 01 � ...E �i� ✓' �� �....0„,,,4).,.
g $,tea � � ��
p .. I
�,s � \_,,'�«"'°�,.. ,> / 'I .`_ .� I EL 450 ... -= n� ;�.�w���«��- �... �` . �« �' ..� � � „�-
F'r � ' , 1;�t,� ,'. : ° /1v� c.5 MG RESERVOIRl `/ UIURE12° C STRlBUT10N.o `,. ' ''� �'� Yf r}� �,[(.. f rtr- ,,.. � � --.�.� K,�� �„ �(��e � ,� ..._ <.� �:(}� , __ —' I 1 ru` ' t. 5 C LINE RE .'E,`JcS 15QthA'�te w % � x gx„,.,
«�;t�..i i, i 1 ' .. '' i( `\e.. /try, <... `�' ,{ . .d. ,,�”"��� w �`� '' _::111://:ii.:1:1:ifiz,---,.
,• '' ".,. ._- «' «€ /'"`.,'"'] e1> ,v a., i I`� ,�,i` l ! ! r [rtw • =`.:;: ,?,. a. '7 YY`" s
„,,
t ii t . „,,,,„..„,„.,,,,,,(.„/„..„,„,,,,,.....„,.......t
�? 12 fN P SEG ..
�V r„_ f r B A R r?t N{r, tAGLC\ E 14 �_> --.
., <E ,, , , „/"„�,,, ,--------.P PR V "b ,,,,,,,„7-
.'"." «,. . � . j” t h« .. �..� `�`-�;`r-�-"'�.'7"�W t'-e'��--- a.�'��
16" z IGS �,��:«` lik ;" «, �� _. •� ,% �;.. �\
\ .., _________
,,„.\.,,t, \ .. .
` t,• Wim. ELvQO' i ii ;
7_,\‘‘..,,,,,,,,
__ .,
,v : «. �Tls°~, ,,, �� E '..--LA ; TiGARD WATER DISTR I C T
—....\„,._-_-..- %,,„, "^-`.`..'`11< `",I '. `-`" < x P S 3; `"v.._-..1� _! i t 7 t° :i:'-/;;ITI:.,,...:-.:;,1,,,,,,,,7:::::,,L.:; :,
K
ig
��, _ � . I - �. NTAIN AREA
:, �_�_ ' �\ II ``r�, .. � _.. „ ��� � I �� � _ — � ��,� �, BULLMOU>. �^, II 1 II ' (� y,,. ,_.,_ - `a__.......w- ^...--wn" fly . i E�9 ...., �� '�� , "I �•.. 11 ....._, §1° +S II ".....�»_- ,,t ... s !, .,.. « x13g° )' ... ,....» ---- ;,.� � � mx j'^� r s! . -� #-v r- tl roII .:+' __���`'�• __ �� _ - _ <� � '. I �� 'w §�;"-' affi lam, t td s�'"�_--�'ir� ` ` « _ 1 � r ,.� FIGURE 4
�-_ « '' WATER SUPPLYPLAN �A•
.� „,w.._. -'� r.-/' .. �c �°` if r'.F f �-_.., t.v..._117--
..,-I 1 �^' enc ."_'"- e . '
f riiiiii
V//////A ///////////////l
0 500 1000 2000
LL
GRAPHIC SCALE - FEET
GILBERT R1
. MEIGS CONSULTING ENGINEER
SEPTEMBER 1986 1
'a},.. GOLDIE
2.3 mg storage, about 1.2 days average demand at full development. This is the
most disadvantageous non-cost feature of Plan A. New distribution reservoirs at
lower elevations will solve the volumetric part of the deficiency. These are
shown at elevation 550 south of Bull Mountain Road and 470 south of Scholls
Ferry Road. Both will be filled by distribution mains through pressure
regulators.
When the Murray Road-Gaarde Street arterial is constructed, a 16-inch
line should be installed between the intersection of 132nd and Walnut and 121st
and Gaarde and be connected to the 10 mg reservoir through the proposed
36-inch line. The 16-inch line will provide 0.86 mgd to the 132nd Avenue pump
station as well as a needed supply to Reservoir No. 3 through an 8-inch
pressure reducing valve connected to a 12-inch line in 132nd Avenue. The
16-inch line should serve as a distribution main up to elevation 360.
The proposed loop of 16-inch pipe on Scholls Ferry Road and Beef Bend
Road will serve land below elevation 300. Two new reservoirs having overflows
wi
at elevation 410 and side water depths of at least 30 feet should be connected
to this loop. One 2.5 mg reservoir will be south of Scholls Ferry Road and the
other 2.5 mg reservoir will be located on 150th Avenue north of Beef Bend
Road. The latter is shown on the current Master Plan but as a 5.0 mg tank; the
16-inch loop is also shown on the Plan. The 150th Avenue reservoir in Plan A
and B is sized to serve all the study area south and west of it.
A new pressure zone would be created on the southern flank of the
mountain by means of a 2.5 mg reservoir having its overflow at elevation 550
and at least a 30-foot side water depth. It would be filled through several
8-inch mains along 139th, 141st and 144th Avenues, south of Bull Mountain
Road and the 12-inch main in MOUNTAIN GATE.
- 26 -
A smaller new pressure zone would be created above Scholls Ferry Road
essentially to serve the R-9 area above the R-15 area shown on the Community
Plan. Facilities required include a 1.0 mg reservoir having its overflow at
elevation 470. It would be filled through 8-inch mains on 150th Avenue and
Sunrise Lane.
The final element is a connection from the 10 mg reservoir to Reservoir
No. 4, which cannot be adequately filled from Beef Bend Road. This may be
accomplished in several ways. A pressurized pipeline between the two reservoirs
would be extremely difficult to install by normal methods because of
intervening high ground. Gravity flow can be developed by a tunnel 45 feet
beneath the intersection of 125th and Bull Mountain Road, but this appears to
be a prohibitively expensive method. Gravity flow could also be developed by a
4,000 to 5,000 foot pipeline that would lay below the 430 foot contour on a
route from the booster station at Reservoir No. 2 to Reservoir No. 4. This,
also, is impracticable, especially across the land south of Bull Mountain Road.
A true siphon by direct connection is physically possible but should be ruled out
as a potentially unsanitary facility.
When additional supply to Reservoir No. 4 is needed, it is proposed that
a 12-inch line be installed off the new supply line going to High Tor Drive. This
line would bleed-off the higher pressure through a combination pressure-sustaining
altitude valve. A meter could be installed to determine when a separate 1.1 mgd
pumping station is economically desirable for transferring water over the ridge
between the two reservoirs.
Plan B
Plan B proposes to supply all land south of Bull Mountain Road above
elevation 450 and most of the land north of the road above elevation 300 from
- 27 -
the reservoir on the summit. Land below elevation 300 would be supplied from
Reservoirs 1, 2, 3 and 4. Intervening land would be in new pressure zones
pumped from lines below. It is based on the same distribution line assumptions
as in Plan A. Please see Figure 5.
Referring to Figure 5, studies showed that the high-head pump at Station
No. 2 should be replaced with a 2.0 mgd unit and that the existing supply line
along Bull Mountain Road is adequate. The 132nd Avenue pump station should
be remodeled to pump 0.86 mgd, as in Plan A. A new large line on 150th
Avenue to serve the rural land west of 150th and above elevation 450 does not
appear necessary because much of this land can be served by a new pressure
zone supplied from the 410 level.
Additional storage at elevation 713 is needed, and ideally it should total
about 3.5 mg. Again, as in Plan A, only 2.3 mg can be provided when 1.0 mg is
added. Thus Plan B can provide about two days' average demand, at full
development of the high zones and again this is the greatest non-cost
disadvantage of the alternate.
A new pressure zone would be created on the southern flank of the
mountain by means of a 2.5 mg reservoir having its overflow at elevation 550
and at least a 30-foot side water depth. It would be filled through a 12-inch
line by a 1.1 mgd pumping station supplied from the main in Beef Bend Road.
The 12-inch line could be a part of the initial distribution system to serve the
BARRINGTON and FOXGLOVE developments recently proposed north of Beef
Bend Road, west of 137th Avenue.
Early developments north of Beef Bend Road could be initially served
from the summit and later transferred to this new zone. This new zone would
require rights-of-way between adjacent tracts either in the form of streets or
- 28 -
r t( 12° _
LEGEND
{ // "j�\ �_f,,//j 4 "+ 9"'° .'`.� '; _ a{a' »a a a i. ea '- mill• rl}— •# i e•. .( __ a 1.4
r a
_.,,!`Y `f0 ` `wiy,,,r✓✓..,,... �: '^��„�.i-w""' - iY� �- _,- i�� • .. r ..%. ii, r t � ' .r+^ f –�}1 ra • i (j �p� Y•,N = r rt'( 2��
• a ,
I l *°`t L? f , "-`- . • '* tta„ a WATER MAIN 9 SIZE
ji .. ✓ �` • '-- } °` I (2�� 'r
. .a_ e (j " • •�.' • jl -- aea** Si* } tl {t : A • RESERVOIR �l
r 333""
�� 16 ' ,Q 1 a i , 8" PR ° 'E ) J` ",. .. • PUMPING STATION
1a � /. 'rs 4•t E L. 5i
N
t..- ` 3 OP T 132 nd Ave PUMP _ VALVE
,r t ,"✓/".. r /. /.• s:f...* ♦ ��, .w a A r r t Y l � „,,.:_/. .„!
w .,- e O r? ?f st'.""3 ,. STA. 600 GPM ✓ r '. P r600 CONTOUR
f_. -✓ ; j 1 .1 \ JtJ' TO HIGH TOR „ w1 �- .✓--,.-
_,� :\
{
. ' t..a."..--""”. r" n V .`�... �.�. `''s.. t f I 'J \ '.all _ _ - p• iib”; I ,,.,. `,, s {.y�• M' a "' ,"�+,
I. .----._..-J �..✓',M'" ., '',. :t > i "i, r: 4 f': ' '�`^... 1"'"*. a� ,,a ,+; r • ,j a_• " 1 r;r �G
r ..,...
\ n4 ��,., ...3..✓ .l �' , } ' ` ab�m a a ' �� ,.' ..L `I.
1/
.,-- ri / . 2 +w A s ;, -' <e I r.j,-... _ 1 // l(1< "/ - 1:;C:i'll':143'.1.::11,:'-::',1*'-'4,
,ri { „s'-1 as a.• wVim.. J /�/ �y /, ..r '''''' '''-'71‘":':,-':� ., t`i_ �� -`•• , 1 �,. tYi \ ;y. 3 Q a ,JjJ 's `� X° •:Lrral,'yr Ate l _ - �: rte'. ,t.tl-r j/•„r.,-"�- , ' A” ."l Q � 4, A:. +p, m • -.1 I( f "� ` / ,,; 111A; ..�,�t'((( ! 'I- ,� �t t`"rf. � :'t�, .��.1��-. } iF-- a` _ i. �x ss•' �$ i.ww'�t/ 1 .' 'f 1 b - i r 1, k {' err}j ? f -':ca,t.. . ,' , __ (s s •
( � +r lr f 9/'lrr`! ' #l. i. e f 7r a• •: a a, ` y-'1 wsas,.� ( t. � r a :rj r ♦./mss(5. ` 375 GPM PUMP ) 13 ` "' 1 - • ' �•''',j�..c, ! i 1 I�; ��.0am" :=� u r ",,. .4 `,,°"'• �i(s a �' •. ,�" ' w..
1 p'� 1 " STATION n : �,�,,, ,--- -- .\ a - G , i ,;� .,..1 t �( r '-_ kj 1.0 MG RESERVOIR a �� Clte O a « �I : , v, ... Iva a ,A _{ / . ,mf , ; .., `f} j. ; 8„ W.S. 470 , ERVES N.%/FF, • :�»as i . . ,**.
�.' ) f R-9 ZONING ABOVE-,7----\,....:_::„.„,„_\,..,"-- ',, \11 1 ;:� ( �.'. ( • • ..
,,,-.,<:'=„� 3 -' L. 370 1 2._.
' �j ` jf crier • 1,�� + j .
" I Jr i !� 2.5 M G �__,,T
•• ��1 .
L s
I i -t t •�. % • .RESERVOIR a f--'3�t� I.0s. MG RESERVOIR rr�-///f 1 °i j�` "J .~�} � r► au1;�
3a.` .1 F , T Lt +�° l mar...,
r $11k 7416'r16 ✓/ ;,�..w t.. �a� t.
, Jr � 'Jr. ���_,a f3 al 3- • ,_ � + _ �'`'�i STA. A T 10 M G i-^.:-4,--*.'_ `-._
• 1• .. 11 \ 11 ` \' , , 6,,,,,,I\\ . ' j1 RESERVOIR r —9.3,:.°9;,-/. ,• .
i
tip .. *---.1-----0 \ �. :I / ; ,, ( ,w x �-.:41-..,01.14° .--Ha -- %-- 9 t 9 C
} tjjf Jf ,}J / /may' p
i' ::,, --"a._....-''' �' �.. i# � ,..\,-,c 'r Q �� � ,. .s .�� i f' " A�� d f T ��µ /�'...,c- MrYf.
a �
IIIIIF
L. �„ `.",... ''' t( 1 1 I ; ../ (o� I ,./-',17 �• 1 w 1 r ' �� 'fi °/,✓`.� t -, .. w 1,___...1 :i,-..
+r f t a
y� ag f�t� _ t _�
„II
L. __,_. (,,,(2 • 1 \:--------,N:--ii"
• far.." d
as
___
-., . .
.,,,, :.0.:,,, t 600 )10. __till' O I, ..
. f,
"
1I,...„,:„/„.,3,
,,
� , l _''� .�� ._\‘ .
\--,,,,_-.
` ti 1 1 ,,,.._//f,/ll�' \A,'...._...`.., a ,-- 8 u P.S.V. -A.V. -7.'-.-4,-.1f-ii,'
;a"' " --
r 1 •�// �1 ' - 4 , _..,/eNi 10/41/,', fie,..✓'' ° . A T RESERVOIR s,•� O
41._ i 6trIt rl
L' \_ O e.,. �I ,' 450 `"5 r '.�, 7„;>,...-7,-;"::---..' N 4 ,� . 1 '
_w. _ wt ,;._- 2. 5 ING+RESERVOtR � ''.114t,
� ^� `
C , \\ i - i� A» ..,`r , W.S. 550, SERVES
^''''''.. .)
., EL 300 TO 4 50 � �� • ' r
NORTH OF BEEF ¢ • . �/ $ s' ` 1# x ,..�- 4 ••-� •,.
f • �•
`� / \' 12�� BE 0 ROAD t - `x .......-
,6" e ✓ ., ,
f •
x
✓ •3
`5O
A �\. 2.5 MG RESERVOIR .3 " `,
` .,...,,,,, \ _. ,;,i &.-ry W. S. 410 t2" IN PROPOSED i®c. �e r ®.✓ � +r !& ark * a.
f
/ 1 `` �/� .y ami * yl'''
w a a
() �,> j ,, ...� BARRINGTON A - d �1 .. �.�•a �. `'f' '• � �.
,:, i ) ,,r^•--'..' ..,,�: \k7:27, I p P , -"-- ..„...............././
/ -� «,a,- or y"' a r _ �'f '..:','',/,.1,/211.,....,, ,,,,,_„</::, _ •, .., +t r
m_..._
G •
/ ili.
,. °� �'', ,7 J F0XGL0VE SUB s _,
✓ f ,,,•,••- J` ,,i‘,,,,,...,,,,,,,..„ r c r . .m• a . ,'-r 3 m yt.
u DIVIS ONS a asp s a s--`,---/ ' ,....,,,,,,I.,..-::,:,
. 'ma r ,, a
O
1 _✓� I6 I -- M ., g5 bta +Y i.......... .y ¢ h f lxf
'. STA. TO SERVE �!• , t1k. ,,.;,,,41471„„ ..
da
_ 1� 750 GPM PUMP �' ,� -~tom 1•r
O •
{
i 1 •91 „„.7.,z
RESERVOIR AT
,...........i..6.1.............-----------*- ° r iIr *~ I?: a t`,_.
:-,...,, -----,,,,,,, ...2...,\:. 7�,...../-�'-^,-..II
✓ V. 50
\'''
r .-- 12” of wa a $'. / ,..57 7
iI it -- -- f-' _... 1 6 u 'a `�---..._ ..,.. fir., _....,/ .�• r i t . w .
.w IGAR WATER DISTRICT
`� — r( ` ,..� ll / �, - /� BULL MOUNTAINS AREA
�""'^".- ft \ a t}l} ?'d ---^^-' "r-N: y,....._.,..- k'�”' a _.✓`�......&..-A.4Fa"`-w _ _ .J r-• TS'
✓gy m+re r: ice`
II -.-........,..„--,-,/,,'l\„ _ f .., • rr f mow` FIGURE 5
., - �y.✓ e.,, _,.-�-�^� l `�#".."a. a ry a ■�M „y/-4
.,. a.a a �;..:!-, aur �v,s� , to t t..�'. �.. --....:::\
•
f Y �.. _ w,., ..i7 7 r ,_�'
--�-� �"� WATER SUPPLY PLAN B
0 500 1000 2000
GRAPHIC SCALE - FEET
GILBERT R MEIGS - CONSULTING ENGINEER
{ SEPTEMBER 1986
GOL DIE
I
1r' utility easements. It would not be completely effective during the time that a
patchwork development pattern is possible.
r.
A smaller new pressure zone would be created above Scholls Ferry Road
essentially to serve the R-9 area above the R-15 area shown on the Community
Plan. Facilities required include a 0.54 mgd pumping station and a 1.0 mg
reservoir having its overflow at elevation 470.
The Murray Road-Gaarde Street connection, the Beef Bend-Scholls Ferry
Road loop, and the reservoirs at elevation 410 are the same as in Plan B. The
connection from the 10 mg reservoir to Reservoir No. 4 is essentially the same
as for Plan A except that the future transfer pump would move 2.3 mgd.
Schedule
In either alternate for supply, a time table can only be created on the
basis of one's expectations of specific future events and the district's growth
policies. Today, the Bull Mountain system has the capability to serve about
1,500 to 1,600 residential meters and it now serves 609, with 420 known
proposed additions. In the near future, one may expect that the supply system
ii.
will be at about two-thirds of its capacity on a peak basis.
Common to each Plan is a new 1.0 mg reservoir at the summit and
increased capacity at Station No. 2 and at the 132nd Avenue pump station.
These could be constructed initially and would "buy some time" before a major
supply installation has to be chosen. The least cost for the work at the 132nd
Avenue pump station can be realized if it is remodeled after the Murray
Road-Gaarde Street extension because the pumps' motor size may be minimized
ap
due to reduced total pumping head.
- 30 -
Together, these additions would permit a total of 2,500 to 2,600 meters
serving a population of about 9,000 persons. On a meter basis this is about 4.2
times the present loading and 2.5 times the near-future loading of 1029 meters.
The Murray-Gaarde pipeline should be installed concurrently with the
roadway regardless of the Bull Mountain supply need. It is an element of both
alternate plans. Construction time would be dependent on the road contract,
which the City of Tigard presently expects to be let in mid-1988. When this
pipeline is completed, the 132nd Avenue pump station should be remodeled.
In summary, the first capital improvement phase recommended by this
report includes the following:
(1) Increase capacity of high head pump at Station No. 2 to 1400 gpm (2.0
mgd).
(2) Provide auxiliary power (156 running KW) at Station No. 2.
(3) Begin reconnaissance and study on the purchase of land sites for four new
reservoirs.
Subsequent phases of capital improvements would include:
(4) 1988-90: Installation of 16-inch main along Murray Road - Gaarde Street
extension and increase capacity of the 132nd Avenue pump station to 600
gpm (0.86 mgd).
(5) 1990-95: Construct 1.0 mg reservoir at High Tor.
The remainder of the work can be scheduled on the basis for increased
water demand. None of the projects will require long duration construction
periods and no very sudden needs for major volumes of additional supply will
probably occur. For purposes of this study it is assumed that new reservoirs,
pumping stations and lines to serve them will be constructed in the late 1990s
to serve an added population of 10,000 persons in the first decade of the next
century.
- 31 -
r
Construction Costs
The estimates are based on the preliminary plans and estimated costs by
general contract. Allowances for pipeline work include valves, fittings, hydrants
and pavement replacement where indicated as probable by reconnaisance of
existing conditions. Reservoirs are assumed to be post-tensioned concrete in
bedrock-free ground. Pumping stations are assumed to be factory-assembled and
mounted on concrete slab footings. An allowance of 25% has been added to
cover the costs of engineering, legal, and administrative work and for
contingencies. Costs are current at time of preparation.
It is assumed that the district will incur all costs to construct reservoirs,
111
pump stations, and pressure-reducing valves. Developers and home owners will
incur the cost of most pipeline extensions, although the district will probably
pay for oversizing some, the exact amount of which cannot be determined at
this time. This does not apply to main extensions which benefit a large portion
of the district such as: Murray Road - Gaarde Street extension; 12-inch main
between 10 mg reservoir and No. 4 reservoir, and paralleling existing mains on
Bull Mountain Road and 150th Avenue. It is assumed that all of these costs will
be borne by the water district.
Major Additions, First Priority, Plan A or B
(* - indicates a district expense)
Total
Item Estimated Cost
1. Remodel No. 2 Pump Station 19,000 *
2. Install auxiliary power at No. 2 Pump Stations 56,000 *
3. 16-inch Murray Road-Gaarde Avenue connection 362,000 *
and 36-inch Gaarde Avenue Duchilly Court
connection
- 32 -
Major Additions, First Priority, Plan A or B
(* - indicates a district expense)
(continued)
Total
Item Estimated Cost
4. Remodel 132nd Avenue Pump Station 20,000 *
5. 1.0 mg reservoir on High Tor Drive 590,000 *
Total Cost $1,047,000 *
Major Additions, Second Priority, Plan A
(* - indicates a district expense)
Total
Item Estimated Cost
1. 12-inch line on Beef Bend Road $37,000
from 128th to 131st
2. 16-inch line on Beef Bend Road from 414,000
131st to 2.5 mg reservoir on 150th
3. 2.5 mg reservoir on 150th 970,000 *
4. 2.5 mg reservoir at elevation 550 and 1,011,000 *
12-inch line from Barrington subdivision
5. 12-inch line from west end of Fern Street 50,000
to Scholls Ferry Rd.
6. 16-inch line on Scholls Ferry Road to 336,000
2.5 mg reservoir south of Scholls Ferry Road
7. 2.5 mg reservoir south of Scholls Ferry Road 970,000 *
8. 1.0 mg reservoir at elevation 470, south of 590,000 *
Scholls Ferry Road
9. Pump station at 10 mg reservoir for service 64,000 *
to 1.0 mg reservoir at High Tor Drive
10. 16-inch and 12-inch line from 10 mg reservoir 345,000 *
pumps to reservoir on High Tor Drive
Total Cost $4,787,000
Total by District $3,950,000
- 33 -
Major Additions, Third Priority, Plan A
(* - indicates a district expense)
+. Total
Item Estimated Cost
1. 16-inch line on Scholls Ferry Road from $156,000
branch to 2.5 mg reservoir to
Urban Growth Boundary
2. 16-inch line on Beef Bend Road from Scholls 390,000
Ferry Road at Urban Growth Boundary to
Bull Mountain Road
3. 16-inch line on Beef Bend Road from 324,000
Bull Mountain Road to 150th
4. 12-inch line on 150th from Bull Mountain 103,000 *
Road to Hawkridge
5. 12-inch line from 125th and Bull Mountain 80,000 *
road to Reservoir No. 4
6. Pump station at 10 mg reservoir for 51,000 *
service to Reservoir No. 4
Total Cost $1,104,000
Total by District $234,000
Major Additions, Second Priority, Plan B
(* - indicates a district expense)
Total
Item Estimated Cost
1. 12-inch line on Beef Bend Road $37,000
.,: from 128th to 131st
2. 16-inch line on Beef Bend Road from 162,000
131st to Barrington Subdivision
— 3. 2.5 mg reservoir at elevation 550 and 1,011,000 *
12-inch line from Barrington Subdivision
4. Pump station to serve reservoir at 51,000 *
elevation 550
- 34 -
1
Major Additions, Second Priority, Plan B
(* - indicates a district expense)
kw (continued)
Total
Item Estimated Cost
5. 16-inch line on Beef Bend Road from 252,000
Barrington Subdivision to 2.5 mg
reservoir on 150th
6. 2.5 mg reservoir on 150th 970,000 *
7. 12-inch line from west end of Fern Street 50,000
to Scholls Ferry Rd.
8. 16-inch line on Scholls Ferry Road 336,000
from Fern Street to 2.5 mg reservoir
south of Scholls Ferry Road
9. 2.5 mg reservoir south of Scholls Ferry Road 970,000 *
10. Pump station and 8-inch line to serve 55,000 *
1.0 mg reservoir at elevation 470
r
11. 1.0 mg reservoir at elevation 470 590,000 *
south of Scholls Ferry Road
service to Reservoir No. 4
Total Cost $4,484,000
Total by District $3,647,000 *
ing
tr.
Major Additions, Third Priority, Plan B
(* - indicates a district expense)
Total
Item Estimated Cost
1 1. 16-inch line on Scholls Ferry Road from $156,000
branch to 2.5 mg reservoir to
Urban Growth Boundary
2. 16-inch line on Beef Bend Road from 390,000
Scholls Ferry Road at Urban Growth Boundary
to Bull Mountain Road
- 35 -
lir Major Additions, Third Priority, Plan B
(* - indicates a district expense)
(continued)
r Total
Item Estimated Cost
III 3. 16-inch line on Beef Bend Road from Bull 324,000
Mountain Road to 150th
4. 12-inch line from 125th and Bull Mountain 80,000 *
1 Road to Reservoir 4
5. Pump station at 10 mg reservoir for service 51,000 *
to Reservoir No. 4
Total Cost $1,001,000
I Total by District $131,000
Table V summarizes the construction cost estimates and facilitates
comparison:
TABLE V
Construction Cost Summary
Phase Plan A Plan B Timing
First $1,047,000 $1,047,000 Near Future
Second 4,787,000 4,484,000 Within 20 years
Third 1,104,000 1,001,000 After 2000 A.D.
ai
Total $6,938,000 $6,532,000
Annual Costs
The annual cost of debt retirment is based on 20-year bonds bearing an
effective interest rate of 7-1/2 percent, uniformly retired. Recurring costs for
N, power are based on an average charge of 5.5 cents per kilowatt hour to cover
- 36 -
1
energy and demand. Power costs are applied to pumps supplying water to 10,000
persons, or about 3,100 customers.
Debt retirement of district expenses is calculated for pump stations,
reservoirs, pressure reducing valves, the Murray Road-Gaarde pipeline, and new
pipelines connecting pumping stations to reservoirs. The third phase of priority
are so distant in time that their annual costs are irrelevent today.
Table VI summarizes the annual costs of Plan A and Plan B on the
foregoing bases.
TABLE VI
Annual Cost Data
..r Plan Water District Capital Costs Debt Power Total
First Phase Second Phase Total Service Annual Cost
A $1,047,000 $3,950,000 $4,997,000 $490,200 $36,100 $526,300
B 1,047,000 3,647,000 4,694,000 460,500 24,100 484,600
Plan B will have lower capital and annual costs. In either case, Plan A or
B, the management and policy issue would seem to be in the timing of
improvements to match actual needs in response to specific land developments
taken in the context of growth within the total Bull Mountain area. For
I �
example, although Plan B is more economical than A, its financial feasibility
will depend on the amount of pipelines installed around the base of the
mountain when a decision must be made to construct the pump stations and
associated pipelines of either Plan A or B.
Plan B will always have lower power costs than Plan A simply because
less water is pumped to the summit.
- 37 -