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IWATER SUPPLY AND DISTRIBUTION STUDY
FOR
TIGARD WATER DISTRICT and CITY OF TIGARD, OREGON
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1 1971
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AN ENGINEERING REPORT
IBY
STEVENS, THOMPSON & RUNYAN, INC.
Engineers/Planners
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Portland—Seattle—Boise—Anchorage
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Stevens, Thompson 8z, Runyan, Inc.
MillIij Engineers / Planners
5505 S.E. MILWAUKIE AVE. • BOX 02201 • PORTLAND, ORE. 97202 • TELEPHONE (503) 234-0721
1920
M+ Portland
Seattle
Boise
Anchorage
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70-P-815.001 June 21, 1971
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LETTER OF TRANSMITTAL
.. Honorable Chairman and Water Commissioners
Tigard Water District
Honorable Mayor and Councilmen
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City of Tigard, Oregon
Gentlemen:
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Pursuant to our agreement of December, 1970, we have obtained field data, made
engineering studies, and have prepared preliminary plans and cost estimates of facilities
for water supply and of facilities necessary for the improvement and expansion of the
Tigard Water District. Our report on this project is presented herewith.
"" We appreciate this opportunity to be of service to you and the citizens of the area.
Respectfully submitted,
STEVENS, THOMPSON & RUNYAN, INC.
..Y
' 7h—e7-L-----
filbert R. Meigs
L Vice President
1., GRM:ss
;H,
TABLE OF CONTENTS
Page
,ik SUMMARY
General Statement I
Observations and Conclusions
Pr. Recommendations VI I
Addendum to Discussion of Water Supply VI I
INTRODUCTION 1
THE PROBLEM 2
Ito
EXISTING SUPPLY SYSTEMS 4
BASIS FOR DESIGN OF SUPPLY FACILITIES 6
tim
Growth of the Area 6
Future Water Requirements 9
Sources of Supply 11
General 11
Wells 11
Portland 13
Lake Oswego 14
Tualatin Basin Water Master Plan 14
Water Quality 15
Distribution Considerations 16
Proposed Supply Systems 16
Plan A 17
Plan B 19
Plan C 19
Tualatin Valley Master Water Plan 20
Construction Cost Estimates for Supply Systems 21
Annual Costs 24
PROPOSED DISTRIBUTION SYSTEMS 30
Existing System 30
Proposed Water Lines 31
tom Gravity System 31
Pumped Systems 33
Telemetering 34
Storage Considerations 34
Construction Cost Estimates and Priority Development 34
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TABLE OF CONTENTS
""' (Continued)
Page
DISTRIBUTION SYSTEM 36
Major Additions, First Priority 36
ism Distribution Replacements 36
Major Additions, Second Priority 38
Major Additions, Third Priority 38
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TABLE OF CONTENTS
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TABLES Page
No. I Tigard W.D. Water Sales 4
No. II Land Population Densities 8
No. III Water Quality Values 15
No. IV Volume of Water-100 Cubic Feet Per Year 24
No. V Amortization Requirements 25
No. VI Annual Cost Data
Plan A 26
Plan B 27
Plan C 28
PLATES
No. 1 Existing Sources 5
No. 2 Generalized Land Use 7
No. 3 Proposed Sources 18
No. 4 Distribution System 32
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FIGURES
No. 1 Population Projections 9
No. 2 Water Use Projections 11
No. 3 Static Levels of Tigard Water District Wells 12
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ACKNOWLEDGMENT
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The cooperation and assistance of Robert Santee, John Miller, and Elden Carter on
behalf of the Water District and of Stephen Telfer and Raymond Rangila of the City of
Tigard have been most helpful in the compilation of information on which this report
is based. Their efforts have been sincerely appreciated.
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SUMMARY
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IGeneral Statement
Continued growth of the Tigard area is dependent upon an adequate supply of water to
meet the demands of expanding population, business, and industry. At the present
II time the Tigard Water District is heavily dependent upon ground water, but it appears
that significant quantities of surface water will have to be imported because of the
I limited quantity of ground water available. In addition to the problems of furnishing
additional water to the area as its growth continues, there is also the problem within
the Tigard Water District of developing a distribution system that will meet not only
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current needs but also those of the future. Engineering studies covered in this report
have attempted to determine the most feasible and economical program to bring an
adequate supply of surface water to the area. The Tigard, Metzger, and parts of the
I Progress and Garden Home Water Districts as well as the City of Durham are included
in this water supply study, while only the Tigard Water District has been studied in
respect to the distribution of water. For the convenience of the reader, the
I observations, conclusions, and recommendations which have resulted have been
summarized at the beginning of this report.
IObservations and Conclusions
1. The Tigard area, as defined to include the City of Tigard, the Tigard Water
District, the Metzger Water District, the City of Durham, and portions of the
IProgress and Garden Home Water Districts, now contains approximately 23,500
persons spread over about 19.5 square miles. Both the population and the per
capita use of water are continually increasing.
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2. The Tigard Water District primarily uses well water but supplements this at
critical times with purchased water that originates at the City of Portland's
I system. All the other purveyors of water in the area purchase their water from
Portland either directly or through intervening water districts.
I3. The demand for water will continue to increase so that the supply systems
1111
provided by the districts will become inadequate within the next few years. An
additional problem to the water users is the cost of water purchased from the City
of Portland.
4. The Tigard Water District distribution system contains lines whose condition and
I size indicate the need for replacement. In addition there are problems within the
distribution system of transmitting water from point to point over relatively long
distances and the problem of providing new lines for current expansion that will
in addition be satisfactory for future needs.
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5. At the present time within the study area, there are approximately 23,500
persons with an average per capita demand of 102 gallons per day. Of these,
approximately 10,000 now reside within the Tigard Water District.
6. Supply facilities should be designed to serve the population anticipated in the
year 2000 and should be based on flow rates of twice the magnitude of average
daily demands. Pumping stations and storage facilities can be designed for shorter
time periods provided that it is possible to expand the size or capacity of these
facilities.
7. The population to be served in the year 2000 within the study area is estimated at
109,000, approximately four and one-half times the present population. This
projection of population is based on land use studies made by the City of Tigard
•W and population growth rates prepared by the Washington County Planning
Department.
8. The Tigard Water District could conceivably contain as many as 80,000 persons,
and the District within its present boundaries might contain as many as 36,500
persons.
9. Future water requirements are based on 130 gallons per capita per day present
usage including unaccounted for water together with a one gallon per capita per
day increase per year to the year 2000. Allowances have been made for
commercial and industrial requirements based on the acreage of land use.
The projected total water use for the study area in the year 2000 is 18.9 mgd
(million gallons per day). The expanded Tigard Water District is forecast for
13.5 mgd.
10. The present well water system supplying the Tigard Water District has a capacity
of 1.7 mgd. The Tigard Water District has facilities to purchase supplemental
water from Metzger Water District at the rate of 1 mgd and from the Capitol
Highway Water District at the rate of 5 mgd, provided that either district is able
to furnish these quantities of water without interfering with their own operations.
"" The Garden Home Water District has a connection into the Portland system that
should serve it adequately throughout the study period. The Metzger Water
District, which also provides water to Progress, has a connection which should be
satisfactory for several years until peak flows during summer require additional
transmission construction to serve the District's needs. Durham is provided
Portland water from the Lake Grove Water District and should be satisfactorily
r.. served so long as their needs do not interfere with those of the Lake Grove
District.
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11. In order to meet these demands for water, it will be necessary for the purveyors
to develop entirely new supply systems based on the use of imported surface
water.
' 12. While it may be possible for the Tigard Water District to continue the use of its
present wells at their present capacity, it is not possible to plan for additional
' water supplies based on additional wells to be constructed by the District.
13. The City of Portland has been able to serve the area according to its needs, but
' major additions to the Portland system will be necessary in order to meet the
projected future needs of the study area. The cost effect of Portland's future
construction to serve the needs of the study area cannot be determined at the
' present time. The present cost of water purchased directly from Portland is
essentially 25 cents per 100 cubic feet.
' 14. City of Lake Oswego has facilities in the Waluga area and sells excess water at the
rate of 14 cents per 100 cubic feet at the present time. Were the demands placed
on Waluga by outside customers in excess of the planned capacity, then it would
' be necessary for Lake Oswego to reinforce its capability and any customers
should expect to participate in the cost.
15. Washington County has proposed in the Tualatin Basin Water Master Plan a
esystem originating either at the Clackamas River or Willamette River and is
proposing further study of supplying the eastern county with a system using
water purchased from the City of Portland. The water master plan would provide
wholesale supplies to individual purveyors such as water districts or cities.
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16. The quality of water produced by the wells, the Portland system, and the Oswego
system is comparable in nearly all respects except that well water is classified as
moderately hard and Portland and Oswego waters are classified as soft. It is
anticipated that water taken from the Willamette River could be treated so that
its characteristics would compare with the Lake Oswego surface water supplies.
17. In the case of all systems except the Tigard Water District's, it is possible to bring
in supplemental sources of water to existing reservoir locations.
In the case of the T`gard Water District, it was found that a terminal storage
' reservoir located on Bull Mountain at elevation 450 would be required in order to
supply the distribution system without considerable reconstruction and
distribution line enlargement.
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18. Three plans for water supply through the area have been developed. Plan A is
based on serving the Tigard Water District with supplies purchased from the City
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of Lake Oswego and serving Metzger and Progress with water purchased from the
City of Portland. Plan B is based on the Tigard Water District purchasing water
from the City of Portland from a location on the westerly side of Mt. Sylvania
and Metzger and Progress purchasing water from the City of Portland with a
separate line as in Plan A. Plan C anticipates all the study area purchasing water
from the City of Portland through a single supply line beginning at the
northeasterly part of the study area and running to Bull Mountain in the Tigard
Water District.
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19. For the purposes of this study, it has been assumed that as an alternate to
1 Plans A, B, or C, the Tualatin Valley master plan would be constructed in
accordance with the general features proposed in 1969.
20. The construction costs for Plan A, B, and C are:
or
1 Construction Cost Summary
1975 1990
Plan "Owner" Construction Construction Total
A Tigard $1,280,000 $ 589,000 $1,869,000
I Metzger & Progress $ 291,000 $ 291,000
IM Combined Total $2,160,000
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B Tigard $1,336,000 $ 464,000 $1,800,000
Metzger & Progress $ 291,000 $ 291,000
Ili Combined Total $2,091,000
C Tigard, Metzger & Progress $1,870,000 $ 464,000 $2,334,000
"' 21. The average annual cost per 100 cubic feet for the several plans are summarized
below:
III PLAN A
Average for 25-year period:
.. Tigard $0.21/100 c.f.
Metzger & Progress $0.27/100 c.f.
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Consolidated &
Averaged $0.23/100 c.f.
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PLAN B
Average for 25-year period:
Tigard $0.31/100 c.f.
Metzger & Progress $0.27/100 c.f.
Consolidated &
Averaged $0.29/100 c.f.
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PLAN C
Average for 25-year period: $0.29/100 c.f.
TUALATIN BASIN MASTER PLAN
Average for 25-year period: $0.18/100 c.f.
22. Plan A, using water purchased from Lake Oswego and Portland takes advantage of
the lower purchase cost of water, although the purchase cost of water from
Oswego in the future could be considerably higher than it is now, and has the
further advantage of providing the area with two separate supply systems, a
feature that would tend to increase the dependability of the overall supply
system. Of the purchased water plans based on either Lake Oswego or Portland as
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the source, Plan A yields the least annual cost for the entire area.
23. Plan B has the desirable feature of two major supply sytems within the study area
but develops the highest unit cost of water. Plan B also has an advantage over
Plan A in that a larger bargaining group could conceivably result for purposes of
negotiating with the City of Portland.
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24. Plan C yields slightly lower costs for the Tigard portion of the study area and
slightly higher costs for the Metzger-Progress portion. It also requires the highest
first cost.
25. The Tualatin Basin Master Plan yields the lowest annual cost for the entire area
and has the potential of providing the customers a stronger voice in the
administration and operation of the system than would be provided by Plans A,
B, or C. The Tualatin Basin Master Plan is, however, only a plan and not an
operating system.
26. Only the water distribution system of the Tigard Water District has been studied
for this report. The system has evolved around wells located within the
distribution system. The present distribution system is designed on the basis of
supply from these several sources. Gravity service is provided to the majority of
the district with the summits of Little Bull Mountain and Bull Mountain both
being served by pumping stations.
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27. Analysis of the distribution system indicates that it is not feasible to use it as a
`' means of transmission of the quantities of water projected for the future. The
proposed alternative is a supply system running to Bull Mountain and feeding into
a terminal reservoir located above the existing reservoirs. Water from this reservoir
and from the transmission line would be fed into the distribution system, which
would keep its basic form as it expands.
r 28. Many of the original lines within the Water District which are now in aged
physical condition or of inadequate size need replacement. The District has an
ongoing program to correct this situation.
29. Preliminary plans have been prepared showing the location and diameter of
proposed water lines in both the gravity and pump distribution system. In
addition, the size and location of additional pumping stations and reservoirs have
been developed and cost estimates prepared. A priority schedule has been
recommended.
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30. First priority work for additions to the distribution system include a 12-inch line
across the northerly portion of the existing district to provide improved service
r from the Baylor tanks into this area. It also includes a new transmission system to
the summit of Bull Mountain, a line to the Tigard High School, and a telemetering
installation to provide supervisory control of the reservoirs and pumping stations.
amp
31. In addition to the proposed water mains, 17 mg of additional water storage are
proposed between now and the year 2000. Of this storage, 10 mg would be
provided in the proposed terminal reservoir with additions to be made at Station
No. 3 and new construction along S. W. 150th Avenue. A summary of the cost of
construction of the proposed improvements to the water distribution follows:
Major Additions, First Priority $ 794,000
Distribution Replacements 370,000
Major Additions, Second Priority
(to serve expansion to the north
and to the southeast) 383,000
Major Additions, Third Priority
(to serve expansion to the west) 1,956,000
TOTAL—All Distribution Projects $3,503,000
32. The works for improving the supply and for improving the distribution are eligible
for construction grant assistance from the Department of Housing and Urban
Development. This amount is 50% of the construction cost with an upper limit of
.,,, $500,000. If the water district were to apply for these funds, it appears to the
writers that it would be better to apply them to one program whether it be water
supply, water distribution, or a combination of supply and distribution, since the
likelihood of receiving grant aid on separate programs is not good.
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Recommendations
1. The districts should seriously consider supporting the Tualatin Basin Water Master
Plan on the basis that it would provide water on the least cost per unit and that
air they could have a constructive voice in the development, administration, and
operation of that proposal.
2. As an alternate to the Tualatin Basin Water Master Plan, the plan for purchasing
water from Lake Oswego for Tigard should be seriously considered and
negotiations should be undertaken with the City to see if a satisfactory
arrangement can be made.
3. The City of Portland should also be contacted to determine its plans for the
future and if it is not possible for mutual action to be taken by authorities within
the study area then the Tigard Water District should negotiate with Portland for
development of a major connection originating at the westerly side of
■, Mt. Sylvania.
4. The Tigard Water District should adopt the concept of the terminal reservoir for
purposes of expanding its water sytem. Steps should be taken to improve the
capability of serving the District and filling the reservoirs within it from the
Baylor tanks within the near future. The ongoing program of replacing water
mains should continue.
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5. The proposed plans for expansion of the distribution system should be adopted so
that reinforcement and duplication in the future may be minimized.
6. Financing the proposed work should include the possible use of Federal grant
funds.
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Addendum to Discussion of Water Supply
The Tigard Water District has been informed by the Metzger Water District that sales to
Tigard will be on the basis of 36 cents per 100 cubic feet and that sales from the
Capitol Highway Water District will be on the basis of 38 cents per 100 cubic feet. This
ir. information was received too late for inclusion in the text. It is interesting to note that
these rates exceed the per 100 cubic foot rates that have been developed for any of the
supply plans after the period beginning 1980.
VII
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IWATER SUPPLY AND DISTRIBUTION STUDY
FOR
1 TIGARD WATER DISTRICT and CITY OF TIGARD, OREGON
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INTRODUCTION
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An adequate supply of water to meet the present and future needs is essential to the
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continued growth of the Tigard area. At the present time, the Tigard Water District is
operated as a municipal corporation separate from the City of Tigard and obtains its
principal supply of water from the ground. Peaking supplies are obtained from other
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water districts furnished water by the City of Portland. Also included within the area
comprehended by this report are the Metzger Water District and parts of the Garden
Home and Progress Water Districts. These districts now obtain all needed water from
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the City of Portland, The City of Durham is also within the study area and obtains
water from Portland by way of two intervening water districts.
1 The purpose of the investigations covered by this report has been to determine
1. The facilities needed to import an adequate supply of water to the water districts
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in the Tigard area;
2. The facilities needed within the Tigard Water District to distribute and store
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municipal water supplies, and
3. The financial requirements to construct and operate the foregoing facilities.
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The work involved in this study has been preliminary in nature and is intended solely
as a guide for any more serious undertaking with reference to the increased utilization
of surface water by the area under consideration. The data and drawings included
Iherewith are for the purpose of general information and contain estimates essential to
the design of the proposed facilities. The cost estimates provided have been based on
current construction costs with a reasonable allowance for contingencies.
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THE PROBLEM
Expanding population and per capita increase in the use of water have resulted in
■+ substantial increases in the demand for water in the study area. The outline of the
study area is shown in Plate 1. The phenomenon of increased demand is normal and is
in line with the experience both locally and nationally.
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There seem to be no significant water supply problems in the area at the present time
for eight or nine months of the year. However, during late June, July, August, and
.. early September, the situation can become critical. This has been particularly true for
the Tigard Water District in recent years, but recent improvements made by the City of
Portland and by the Tigard Water District may help to alleviate the situation. Portland
has extended a 24-inch main from the Burlingame standpipes to the County line on
Multnomah Boulevard. The Garden Home Water District and the Metzger Water
District will be served from this line beginning in summer of 1971, and provided that
the Portland system is able to provide sufficient quantities of water to the Burlingame
standpipes these two districts should be well supplied for a number of years, although
Metzger's 10-inch supply line will need to be paralleled with a larger main in the near
future. Tigard has recently constructed a connection into the Capitol Highway District,
a customer of Portland, and provided that Capitol Highway is able to provide the
quantity of water needed by Tigard this measure should also bring relief to the area for
a number of years. However, in the case of Tigard, the point of connection into the
Water District is relatively remote from the major loads and points of storage within
the district, and reinforcement of the distribution system will be necessary to enable
Tigard to fully enjoy the benefits of potential from the connection to Capitol
i"' Highway.
Much of the area is at present residential and commercial, and there are many desirable
industrial sites. It is doubtful that there will be any industrial development within the
area which requires a significant quantity of water. Certainly, at the present time, the
location of such development within the area could not be considered.
Another important aspect of the problem is the cost of water to the users of the area.
The Portland water must be pumped over the West Hills in order to reach the Tigard
r. area. This results in rather high cost for this water, a situation which the customers are
anxious to improve if possible. There are other possibilities for water supply to the area
that are under consideration. One is the Tualatin Basin Master Water Plan proposed in
1969. Another is the possibility of purchasing water from the City of Lake Oswego.
Within the Tigard Water District, three kinds of problems with the distribution system
can be defined. The first is the matter of lines whose condition due to age or whose
size is such that the line requires replacement. The second is the previously mentioned
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Iproblem of transmitting water in large quantities through the distribution system over
long distances. The third problem is normal to any district experiencing the dramatic
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growth in number of customers, namely, the extension of water mains and
development of new storage sites on a basis which will provide for future needs
without imposing an unduly high cost on present customers.
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P' EXISTING SUPPLY SYSTEMS
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The location and size of the various water districts and cities involved are shown on
iii Plate 1. Pertinent data relative to the existing supply systems are shown thereon. At
the present time, it is estimated that there is a total of 23,500 persons living within the
I study area with an average per capita demand of 102 gpd (gallons per day).
Approximately 10,000 now reside within the Tigard Water District.
I It is estimated that the Tigard Water District has an average per capita daily demand of
96 gpcd (gallons per capita per day), the Metzger District of 109 gpcd, the Garden
Home Water District of 102 gpcd, and the Progress Water District of 106 gpcd. The low
L consumption for all and especially the Tigard Water District may be explained by the
semi-restricted availability of water during the critical summer months. The Tigard data
is based on sales, and system losses are not included.
IIn addition to this, there have been a considerable number of multiple-family dwellings
constructed in recent years and these installations have less irrigation demand than
I ordinary single-family dwellings. In some cases, shallow wells are also still being used
for irrigation. By comparison, the average for the City of Portland is 148 gpcd and
nationwide average has been estimated at 155 gpcd, including unaccounted water.
LMetered sales in the Tigard District and estimated population based on 3.3 persons per
connection are shown in Table I as an historical illustration of the increase in
population and demand for water that the study area must face.
TABLE I
ITIGARD W.D. WATER SALES
Fiscal Year Average Daily Sales Estimated Population Per Capita Use
L 1959-60 0.24 mgd 3,260 74 gpcd
1960-61 0.27 3,500 77
I 61-62 0.26 3,720 70
62-63 0.32 4,150 77
63-64 0.33 4,550 73
I 65 0.44 5,260 83
66 0.58 6,470 90
67 0.67 7,700 96
68 0.82 8,880 92
69 0.87 9,600 91
70 0.99 10,300 96
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,. \ ^ , `� EXISTING
WELLS AND RESERVOIRS BEAVERTON11 c `4'� � �"" ,. ,. o5Y�
'-'N--
Well Average Rate Reservoir Capacity Elevation rl, I .'-•, nw' OR 'L,1� ,__ .......-s.'-'..•4,21.;" SOURCES OF SUPPLY
(GPM) (M.G.) (Feet) 1 I �� PQ
TIGARD WATER DISTRICT r •^+ .t Q t ,
I GARDEN HOME LI _, l . ,< �9 ,.. ,I ..,r > �.
BAYLOR 2.0 416 1 i
HI TOR 0.2 690 .I - T• j 4 No 10 . ' i'r ,4" '.<. z
No.1 500 No. 1 2.0 410 \)'
No.2 315 No.2 0.28 413
go' T • z,E
No.3 285 Na.3 0.5 400 __ '� - �`��= LEGEND
No.4 175 No.4 1.0 417 o .."---n.• 4tr"� r
TOTAL 1275 5.98 — L._.I I• '
- - - - r r•-- Ii.7 STUDY AREA
OTHER DISTRICTS 1• i I • o )
CITY OF PORTLAND No.5 1.6 643 PROGRESS Nott > ti L.I t 1.
CAPITOL HIGHWAY No.6 1.5 685 •_No 12 «� I _.� � .......1 ,�• ;`° ., —•—--•— CITY LIMITS
CAPITOL HIGHWAY No.7 1.34 760 ,1 1 •
LAKE GROVE No.8 1.0 480 /1 �•�• U
— I WATER DISTRICT BOUNDARY
CITY OF LAKE OSWEGO No.9 0.1 323 ( -d
GARDEN HOME No. 10 1.0 427 / I_. re_._ / ,' I v'l..1
GARDEN
METZGER No. 11 1.2 500 — 1 i 12
PROGRESS No.12 0.2 380 -_._1r 0— — — - — — ' I -�' I WATER MAIN AND SIZE
CAPITOL HIGHWAY I i - " , I .
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a METZGER u RESERVOIR
��
, s c'—I • WELL
�� L._..�, _._.i!� ► LI •Ii i * PUMPING STATION
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j ) L._.
i _Ir._ L....1 L. -
I
8 L _ TIGARD i TIGARD � l j.Q j .Jjj\fl
- , �l ,1 l *451-6r1 _� L._._. .
l r n - -.J , 1 I I ._
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•
.. :',1j4.. J. // !_ i /./...j.,* .\./--•---'-
1. •/ 1
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OR —� rl_._� LAKE GROVE I
��� A I � e I /• LAKE OSWEGO
// P N O R T H
!I :- 10 I I . Nc 1 . I._.
< . I 1: ;a 4 •h I _ •— r No 9 - 000 — 0 2000 401 6000
00 Feer
•
F
•
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* — TIGARD OREGON
• / .1� fit.. /. /• _
HAh ! ' i •l !- 1 _._ _.J WATER SUPPLY AND DISTRIBUTION STUDY
`� ,iff Q R /'
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•1 fill I ''✓ I I Engineers/Planners
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• i -u __ i i _ i i i 11 HI i i i 11 u ■ PORTLAND • SEATTLE • BOISE • ANCHORAGE
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I Plate 1
her
ism BASIS FOR DESIGN OF SUPPLY FACILITIES
rag
In developing a basis for design of facilities which are to serve for some time in the
future, it is necessary to consider the probable life of the system and methods of
financing the construction. Unless such facilities which are long lived are planned and
financed for a distant date, the present users will be required to pay the cost of
benefits which will accrue to the future users. On the other hand, it is uneconomical to
design and build major improvements for only a short period. After consideration of
the various factors involved, it has been decided to base the design of facilities such as
major transmission pipelines to meet the predicted demands at the year 2000. The
expected useful life of such facilities would probably be at least double this period, but
it is not believed that the present users could or should be required to finance facilities
adequate to meet the demands beyond twenty-five years from the date of installation.
Pumping stations and distribution storage which can be readily enlarged should be
planned for shorter periods of ten to fifteen years.
The required capacity of the proposed facilities will depend on the population to be
served and the per capita consumption for domestic purposes plus commercial and
ir. industrial requirements.
rr Growth of the Area
It is believed that the Tigard area will continue to share in the impact of the population
„r pressures now being exerted on suburban communities. The sanitary sewerage
problems which have plagued the Fanno Creek basin and which have acted as an
impediment to growth are now being solved and the purveyors of water in the area must
be prepared for a rapid increase in the number of customers. The City of Tigard has
recently completed a "Preliminary Comprehensive Plan" on the area covered by this
report. Included is about 19.5 square miles with a current population with
approximately 23,500 persons, based on the 1970 census. Plate 2 indicates the land use
Nig
plan developed by that planning study. For purposes of this water supply and
distribution engineering study, the land use plan proposed by the City of Tigard has
governed the development of future population estimates, both in number and in
location. The density of population in the several land use categories is given below in
Table II.
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TIGARD9
OREGON
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WATER SUPPLY AND DISTRIBUTION STUDY
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PORTLAND • SEATTLE • BOISE • ANCHORAGE
•
Plate 2
I
ITABLE II
LAND POPULATION DENSITIES
, I Land Use Category Per Acre Density
I Suburban low 4.5 persons per gross acre
Urban low 12.0
Urban medium 21.6
cr, Residential-Commercial 28.6
iim
Growth rates are based on projections made by the County Planning Department. By
I the year 2000, it is projected that the total area will have a population of
approximately 109,000 persons. Within the area that the Tigard Water District could
possibly serve by that time, it is estimated that approximately 80,000 persons will be
residing by the turn of the century. This area is defined as being enclosed by the
lila Tualatin River on the south, Beef Bend Road on the west, Scholls Ferry Road from
Beef Bend to S. W. 122nd Avenue on the northwest, Manzanita Street, Tigard Street,
I and Tiedeman Avenue on the north, and the boundary between the Tigard and Metzger
Water Districts on the east to Durham Road where the eastern boundary continues as
the Spokane, Portland, and Seattle Railroad right-of-way to the Tualatin River.
aim The population forecasts used in this report are shown on Figure 1. A line indicating
the forecast for the Tigard Water District as it is presently constituted is also shown
I and indicates a year 2000 population of 36,500, slightly more than 3.5 times the
present population. If these population forecasts are borne out, then by the turn of the
century the area will be nearly "fully developed" and the population growth should
considerably decelerate. The shape of line indicating the expanded district is subject to
$r considerable influence by annexation policy and the availability of public works.
I
i
I
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I
-8-
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FIGURE 1
POPULATION PROJECTIONS
110 �
100 - -
- 90 - -
80 -
laN
z
N 70 -
0
I-- 60 - -
z
iw
Oz 50 - -
Q P��P
w O 40 - �y
a S
L\ \
30 - O\S��
20 AXP Pip pIIOC\
WATE
10 -
- I I I
1970 1975 1980 1990 2000
YEAR
Future Water Requirements
The use of water-consuming appliances in addition to the number of plumbing
installations per home is increasing every year. Some studies have indicated that an
average increase of about two per cent should be anticipated in per capita consumption
to provide for increased utilitzation of water-consuming home appliances. Experience
generally has shown that where an adequate supply is made available that per capita
use will increase therefrom. In order to be consistent with the Tualatin Basin Master
Water Plan, it has been decided to adopt the data used therein for purposes of this
study. That study concluded that the future use based on an average of 130 gpcd,
including unaccounted losses, at present with an increase of 1 gpcd per year would
result in a projection of water use which is consistent with general trends and which
will yield conservative planning data.
-9-
Jim
Insofar as commercial and industrial requirements are concerned, they have been
Or
projected on the basis of the general land use plan together with allowances of 750
gallons per acre per day for commercial and shopping centers, 900 gallons per acre per
day for commercial-industrial, and 1,270 gallons per acre per day for general industrial
uses. These estimating figures do not provide for the introduction of heavy water-using
industries.
The projected total water usage based both on population and allowances for
residential, commercial, and industrial uses are indicated on Figure 2, Water Use
Projections. Again, an effort has been made to not only indicate the total water usage
projected for the entire area but also for the area which the Tigard Water District could
serve in the future as well as a projection based on the total area within the present
District boundaries. For the year 2000, it is projected that the entire area will be using
his 18.9 mgd (million gallons per day), while the use of water within the expanded water
district could be as high as 13.5 mgd. The present District would be using 6.3 mgd.
Figure 2 also indicates that by 1975, the present District will be using well water at a
oft rate equal to present well capacity. Peaks will have to be supplied by existing
supplemental connections or a totally new supply system.
In addition to average daily demands, it is necessary also to estimate the maximum
daily demand in order to adequately size the required facilities. Little information is
available with regard to maximum daily demands. The data developed in the Tualatin
Basin Water Master Plan indicated that major water supply systems should be able to
ire
deliver at least twice the average daily demand and that even more severe peaks should
be satisfied from storage. The area under consideration is so large that there will be
diversity of peak demand and the ratio between average daily demand and peak day
demand will reduce as the number of customers increases.
ani
air
-10-
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FIGURE 2
WATER USE PROJECTIONS
err 20 I I
Oil
16 — —
0
-
0
z
Q 12 — —
r -
� J
Q
C5 8 — ��P —
P
Q
4 — 0 0 —
P�O DISTRICT
0 I I I
1970 1975 1980 1990 2000
YEAR
Sources of Supply
General. At the present time, ground water and water purchased from the City of
,r. Portland constitute the study area's sources.
Wells. Further planning based on the development of additional ground water supplies
of any considerable proportion is no longer possible. An investigation of the historical
performance of the Water District's wells has been made for this study. Owing to the
nature of the available data, it appears that the only reliable indicator of the condition
of the ground water lies in the static level of water within each of the four wells. Other
iiik
parameters such as capacity, specific capacity, draw-down, or water quality are either
limited, affected by reconstruction, or random. However, as indicated by Figure 3,
there has been a persistent downward trend of the static level of water within the wells.
This is interpreted by the writers as evidence of "mining" the ground water resource.
-11-
r.
Ir.
FIGURE 3
`' STATIC LEVELS—TIGARD WATER DISTRICT WELLS
aim
0 1 I I I I I 1 I I I 1 1
iii. 100
Imo WELL 2,
WELL 1,
381'D. 453'Deep Well 1 deepened to 612'
J 200 ••••
`r > WELL
—' 494'D ••••• ''
v • ••~•• •. •••. V•• ......
.r a ��•• /\ //,,,,,,...� WELL4�- •
��••• �•••• ♦// 725' i��.N••4.,.r'
300 1deepened ✓
v� to 925' + \`
r
I N
I
`.�•
400
OM _•`
NO
500 I I I I I I I I I I I I
1947 48 49 58 59 60 61 62 63 64 65 66 67 68 69 70 1971
ow
YEAR
MI
ON
The State Engineer is currently conducting an investigation of the ground water
situation in the Cooper Mountain-Bull Mountain area. His report is expected to be
iiii
published in late 1971. However, in "Ground-Water Levels, 1967-1968", the State
Engineer comments that this area has developed into a critical ground water area. He
Ow
further goes on to remark that the area must develop an outside source of water within
the next few years. Other information received informally from the State Engineer
iiis
-12-
MIS
indicates that the Bull Mountain area will most likely be declared a critical area, and
imp
that there will be future restrictions on the use of ground water and severe limitations
on the construction of additional wells.
For the purposes of this engineering study, it has been assumed that no further wells
will be drilled. It is understood that there is the possibility that the District might
purchase existing wells, but certainly there can be no mistaking that surface water
imported from relatively great distances will become the predominant feature of water
supply.
Portland. The City of Portland has an abundant source of supply on the Bull Run River
in eastern Multnomah County. Recently it has added to its pumping, storage, and
water main installations in southwestern Portland in order to enable it to better serve
' its outside customers. In order to continue this service, it will be necessary for Portland
to continue its improvement program and most likely this will include a new
transmission main from the headworks on the Bull Run River into the City of
+.. Portland, new lines across the Willamette River, new pumping stations and water mains
leading to eastern Washington County. This study has assumed that were the Tigard
area to commit itself to Bull Run water, the City of Portland would reciprocally
commit itself and continue on its present course of physical improvements.
Not all of the water originating at Bull Run is sold directly to the eventual district. In
the case of Garden Home and Metzger, these districts enjoy a direct connection into
Portland's piping and should be adequately served by their present connections for a
number of years, barring unforeseen developments and assuming Portland will meet
their needs for water. Tigard must, however, purchase from either the Metzger Water
District through a Metzger-owned line with a capacity of about 1 mgd or from the
Capitol Highway Water District through a Tigard Water District-owned line with a
capacity of approximately 5 mgd. For the time being, Metzger is probably in a better
position to provide water at the 1 mgd rate than Capitol Highway is at the 5 mgd rate,
for Metzger it is served directly from a large-capacity main beginning at Burlingame
while Capitol Highway must pump. It is understood that this pumping installation will,
'i" in 1971, have the capacity of approximately 5 mgd. Therefore, the amount of water
available to Tigard from Capitol Highway will be the difference between that District's
needs and the available pumping capacity, provided that Portland is able to supply
IWO 5 mgd. In order to improve the capacity of either the Metzger source or the Capitol
Highway source, it would be necessary to make major additions in those two system's
distribution systems, for they act as transmission facilities. In addition, the capacity of
the Metzger line into the Portland system is limited to 3.1 mgd, so planning should
begin for increasing this capacity.
aliti
-13-
rr
To the southeast, there is the Lake Grove Water District, a subsidiary customer of
Portland through the Palatine Hill Water District. The capacities of both of these
districts' systems is quite limited, although it might be possible to secure
approximately 1 mgd from Lake Grove at upper Boones Ferry Road west of Interstate
rt. Highway 5. It appears this capacity should best be "allocated" to Durham as at
present. Tualatin's shift to Lake Oswego water should ease the problem of supplying
Durham, since Tualatin has been one of Lake Grove's customers.
rr
Lake Oswego. At the present time, the City of Lake Oswego has an 18-inch main laid
to the Waluga Reservoir site. Future plans are for the addition of a 24-inch line in the
early 1980's, and a 3 mg reservoir at Waluga is in the planning stage.
These lines are served by the City's water treatment plant located in Robinwood at the
e• north end of West Linn near the Willamette River. The water treatment plant handles
water taken from the Clackamas River at Gladstone and has a design capacity of
10.7 mgd with a peaking capacity of about 15 mgd provided the raw water turbidity
rim is low. At the present time, Lake Oswego averages about 2 to 3 mgd consumption and
has had a peak of 5 mgd. It has been projected by Lake Oswego's consulting engineers
that the Robinwood plant will have to be expanded in the late 1970's.
Representatives of Lake Oswego have been contacted relative to the sale of water to
outside customers. The City evidently would be willing to sell such waters so long as
rr. they are surplus. It has been indicated by the City's representatives that the planning
involved with development of the Lake Oswego supply and distribution system did not
propose service east of Interstate Highway 5, although future expansion could make
this provision. Accordingly, it must be assumed that if water were to be purchased in
major quantities over long periods of time from Lake Oswego, that the same problems
as presented to the City of Portland in development of additional transmission and
rr
pumping works would be present.
Tualatin Basin Water Master Plan. This plan was prepared in 1969 for the Washington
County Board of Commissioners. Among the proposals for supply to eastern
INN Washington County were water treatment plants located either on the Willamette River
above West Linn and treating Willamette River or else in Robinwood and treating
Clackamas River water. Both plans of treatment and transmission yielded similar unit
costs of water. Since the plan was proposed, there has been a considerable study by
citizens and officials of the County, and it now appears that the County would prefer
to develop a program based on purchase of water from the City of Portland. If that can
+r• not be satisfactorily concluded, then a program based on construction of a water
treatment plant on the Willamette River in the Wilsonville area will be proposed.
Without going into the merits of either proposal for Washington County with regard to
.�, cost or source of water, it appears to the writers that cooperation with the County in
development of this master plan may be of interest to the area on the basis that the
master plan implementation could involve a local participation in basic decision making
that is not possible when water is to be purchased either from Portland or the City of
Lake Oswego.
r•
-14-
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Irr
Water Quality
IWO
The quality of water now being produced by the District's wells, from Portland, and
from the City of Lake Oswego is shown in Table III.
ow
TABLE III
a• WATER QUALITY VALUES
Parameter Source of Water
ow Portland Oswego
T.W.D. Wells System System
No. 1 No. 2 No. 3 No. 4
wr
pH 7.5 7.0 8.0 7.4 6.95 7.4
Total Solids mg/I 209 274 212 294 28 104
km Alkalinity (Total) mg/I 120 97 117 128
Carbonate 0.0 0.0
Bicarbonate 14.0 30.2
,fill, Hardness mg/I 100 85.6 102 109 11.6 33.4
Silica mg/I 74.5 54.6 55.0 68.6 10.8 17.7
Calcium mg/I 27.8 23.5 27.0 29.5 8.0 10.0
Magnesium mg/I 7.4 6.6 8.4 8.6 2.5 2.3
No
Iron mg/I 0.01 0.01 0.05 0.01 .26 0.05
Aluminum mg/I 0.07 0.08 0.08 0.09 .19 0.40
w
Manganese mg/I less less less less
than than than than
0.01 0.01 .01 0.01 .03 0.00
Sodium mg/I 7.6 5.8 13.4 10.8 1.1 4.0
""` Potassium mg/I 3.9 3.5 4.7 3.3 1.0 1.2
Arsenic mg/I less less less less
than than than than
"" 0.005 0.005 0.005 0.005 .001
Chloride mg/I 2.7 5.2 15.8 9.5 3.0 4.62
Sulfate mg/I 1.1 1.0 1.1 2.1 1.0 9.3
NU Nitrate mg/I 0.76 0.16 0.10 0.07 .012 0.01
Fluoride mg/I less
than
are 0.22 0.17 0.25 0.27 .05 0.12
Color Units 3 1 1 2 5
Turbidity JTU 15 2 1 .6
el. Feb. Feb. Feb. Feb. Sept. Aug.
Sample Date 1969 1969 1969 1969 1970 1969
INN
IN
-15-
fir
The water qualities of the various sources compare favorably. The Portland and Lake
Oswego waters have less alkalinity, hardness, turbidity, and solids than waters from the
Tigard Water District wells. Of these parameters, hardness is the most significant.
Hardness is an indicator of a water's ability to lather or foam when used with soap.
Hard water will not lather readily and leaves residues. The water supplies from Portland
and Lake Oswego are considered "soft," while that from the Tigard Water District
wells is "moderately hard."
Distribution Considerations
In developing improved supplies of surface water, consideration was given to the
location of existing storage reservoirs and the functioning of existing distribution
systems. Garden Home, Metzger, and Progress areas are served from one reservoir site
each, and the distribution systems are essentially independent of the supply systems. It
is assumed that reinforcement of the distribution systems in these areas as may be
So necessary would be carried out without relocation of the basic storage installation.
In the case of the Tigard Water District, considerable effort in network analysis was
made to develop a distribution system that would be capable of transmitting the
required volumes of water without the necessity of going to excessively large piping
networks. This was found to be impractical, especially considering the relative
locations and elevations of the existing distribution reservoirs and also the uncertainty
that probably will continue for some time with regard to the supplemental source of
water. In order to overcome these problems, it was determined that a centrally located
reservoir of large capacity, at an elevation of approximately 450 feet above sea level,
and independent of the direction of new supplies would be able to feed water into the
distribution system in a satisfactory manner that would only have secondary bearing
on the development of the distribution system. This reservoir is identified as "a
terminal reservoir" and would be located about 1,000 feet east of Station No. 2. The
use of ties into the major water mains in the Tigard District from the proposed
transmission system through pressure regulating valves is proposed in order to enable
the reduction in size of the transmission system.
Ito Proposed Supply Systems
Three proposed supply systems have been developed in addition to the system
.r• proposed in the Tualatin Basin Master Plan. The order of identification of these
systems is not intended to indicate any particular preference by the writers.
rr
rr
w
-16-
limb
�r.
In terms of services areas to be supplied, the land use and consumption data applied to
imi
land use are combined to develop the following average design flows for the year 2000:
Expanded Tigard W.D. 13.5 mgd
Metzger and Progress W.D.s 4.6 mgd
Southerly Garden Home W.D. 0.8 mgd
TOTAL 18.9 mgd
ins
Design flows for sizing pipelines are based on peak flow capacity of two-times average
design flow as forecast for year 2000. The requirements for peak flows indicate that
rrr the proposed systems be in operation in 1975. Plate 3 indicates the proposed systems.
Plan A. Plan A is based on the use of water purchased from Portland and Lake Oswego.
r,r A 30-inch water main would connect into the Waluga Reservoir currently planned for
3 mg (million gallons) and the easterly part of the main would be located in Bonita
Road as shown. The elevation of the Waluga Reservoir is such that it would be
necessary to pump and while the pumping station could be located anywhere between
the District boundaries and the Waluga site, it is proposed that the pump station be
located near S. W. 72nd Avenue so as to be convenient to operating personnel. The line
continues along Bonita Road to Highway 217 (Hall Boulevard). At this point, a tie
would be made into a proposed 12-inch water distribution main. From this point, the
line size reduces to 27-inches and the location follows Hall Boulevard to McDonald
where the line turns to the west and continues past 103rd to a point where a
connection would be made into an existing 12-inch water main. Beyond this point the
line continues westerly as a 24-inch main, crosses Highway 99, there connecting into an
existing 12- and proposed 16-inch line, and thence along Gaarde to S. W. 121st, with a
connection into the 12-inch line served by Reservoir No. 2 and then continues to the
proposed 5 mg terminal reservoir site. Baylor tanks would be filled by an additional
line from the distribution system. Initially, the pumping station would be sized for
1990 flows; in that year, the station would be expanded and a second 5 mg reservoir
would be installed.
A second feature of Plan A is a system proposed in northerly portion of the study area
to serve the Metzger-Progress area. This would consist of a 20-inch line connected to
the City of Portland's existing 24-inch line on Multnomah Boulevard. This line would
++�+ continue approximately along the County line to S. W. Taylors Ferry Road and tie into
the Metzger Water District system at that point. From that point, the line goes westerly
as an 18-inch line and terminates at Bradley Corner for connection into the Progress
system. This supply system for the northerly portion would not require pumping. It
also assumes that the supply storage needed could be provided by the City of Portland
and that any distribution storage in addition to that now existing would be developed
by the Metzger or Progress Water District. Garden Home Water District is not included
because its present supply system should remain adequate throughout the study
period.
r..
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-17-
, �, , .• r PROPOSED
�A �r.�r3X (7",:`,1'... .-"'••,7"."---A''''.7.-(--:,------,,,•""-- .7‘
� 4 � � � ';.�2,`_�-�- "1'` - SOURCES O F SUPPLY
-� /
(^ �= 2 fit. • Existing 24 by Portia 1,..-4• :,. Tt ` '
/ l` i_1s7,i `;'\ �, "( / ', t"er,i aect--,1,....::" i ice' vaw .
[ ".� r �t• -, ,7 ,:..A \ ^'. w c,� € ., a ; '•fir f{ �+ sDiEbt'-'2"'l1014. .- ..P
24 , -,.7 i£ r.T1 fq\''^ r.,,,-(4-./'---- ,,; .meq ./ c$,9a t
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LEGEND
00„,..,,I. w; �'< # 1 STUDY AREA
� • " 27 Min.�8y Portland re f `� ).--....,,,..........z,-)..„ 5• ,f`
r ..., r ,�� TUALATIN BASIN PLAN
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f rte ' • • x PLAN A
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PLAN B
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PLAN C
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.. / � ( ,�� �' ,lam \� WATER MAIN AND SIZE
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{ � � ;: s + � 3 t s i 7k PUMPING STATION
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t ) gr g 00 0 2000 d000 6000
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b PORTLAND SEATTLE BOISE ANCHORAGE
I
' Plate 3
as
Plan A has the advantage of enabling the Tigard Water District to develop a water
em
system that is independent of the needs of the other districts in the study area. It has
the disadvantage that eventually capital costs that have not been anticipated by Lake
Oswego would be necessary, and accordingly it is difficult at present to predict what
the eventual purchase cost of water might be.
Plan B. Plan B, like Plan A, consists of two supply systems. The northerly section of the
study area would be served by the same facilities proposed in Plan A.
For the Tigard Water District, Plan B proposes the construction of a major reservoir on
the westerly flanks of Mt. Sylvania at minimum elevation 580. A 30-inch line leaves
this reservoir and passes close to the Baylor tanks where a connection would be
provided. From this point, the line would come southerly along Interstate 5 to Varns
Street and then turn to the west and cross beneath the Tigard-Beaverton expressway.
At 72nd, the line would continue southerly to Bonita Road and then follow the same
route with the same general features as the line proposed in Plan A. Such ties as are
advantageous into major distribution lines would be made through pressure regulating
valves and the line would flow to the same terminal reservoirs as previously discussed.
Plan B assumes that eventually the City of Portland will annex the Capitol Highway
Water District and further it will construct a major reservoir at elevation 580. This plan
has the disadvantage of being founded on this assumption, and as in the case of
purchasing water from Lake Oswego, this plan requires major capital expenses on the
part of the City of Portland that make the predictability of future purchase costs
somewhat hazardous. No pumping would be required on behalf of any of the
customers served by Plan B, and this is an operating advantage over Plan A.
Plan C. Plan C ties all the study area together with one supply system using water
purchased from Portland. The initial phase of Plan C would include a 24-inch line
connected to Portland's line at Multnomah Boulevard. This line would follow the
County line to the Metzger reservoirs on Taylors Ferry Road. In the future, it would be
necessary for Portland to reinforce the supply system with a major line, perhaps larger
than 27-inches, and a major reservoir on Taylors Ferry Road at the County line. From
this point, the line consists of a transmission line that would flow by gravity
throughout the design period. Peak flow pumping at the County line and Taylors Ferry
Road would be required after year 2000. The route of the line is along Taylors Ferry
Road as a 42-inch to S. W. Cedarcrest Street and then westerly along Highway 217
(Hall Boulevard) to Bradley Corner. At this point, the Progress area would be served
and the line reduces to a 36-inch diameter. The line follows Greenburg Road,
Tiedeman Avenue, and Walnut Street to 121st Avenue. From Walnut and 121st, the
line continues southerly on 121st as a 36-inch main to the terminal reservoir identical
to Plan A or B. A connection would be made on Walnut into a proposed 12-inch
distribution main. The reservoirs serving the Tigard Water District would be filled by
ing
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the distribution system as tied into the transmission line, except that an additional line
from the distribution system to Baylor tanks will be needed to fill them. All ties would
have to be metered since backflow from the terminal reservoir should be permitted.
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Plan C has the advantage of being operable without pumping for many years.
Furthermore, it provides a large block of customers who by virtue of their numbers
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might be able to bargain as one with the City of Portland. In the writers' opinion, it has
the disadvantage of needing concurrent agreement among several agencies for the need
of a major scheme. It also requires Portland to make major additions which render the
I estimation of future purchase costs quite hazardous. It would be desirable for the
Districts to continue their present connections into their current sources of water in
case of difficulty with the single transmission line serving all of them. On the other
I hand, the route of the transmission line could enable the reinforcement of distribution
systems that otherwise might require considerable new construction.
I Tualatin Valley Master Water Plan. The Tualatin Valley Master Water Plan proposed a
transmission main going from south to north approximately through the center of the
study area. Its route is shown on Plate 3. A reservoir in the same vicinity as the
I terminal reservoir was proposed. In addition to the 42-inch transmission line which
entered the study area at S. W. 198th and Durham Road and continued westerly on
Durham to 109th and thence to Highway 99 before going west on Gaarde and thence
I north on 121st, the master plan also included mains on Scholls Ferry Road proceeding
northward to Raleigh and proceeding westerly to S. W. Davies Road before connecting
into the Beaverton area. The tie into the Beaverton area enabled connection into the
I Trask supply system that has been developed by the City of Hillsboro. A system of
pipelines would transmit this water as far west as S. W. North Dakota in its initial
phases. Although the Trask Dam has been completed to its first stage, the master plan
pipeline from Haines Falls intake is not an active project.
I
Were Washington County to develop the water master plan, it is understood that a
source if located on the Willamette River would require the same pipeline as proposed
I in 1969. On the other hand, if the source chosen for eastern Washington County is the
City of Portland, then Plan C could correspond to the planning requirements for use of
Bull Run water in the southeastern portions of Washington County. It might well be
I that the diameter requirements for serving the Tigard-Tualatin-Sherwood areas would
require main sizes six to twelve inches greater than shown, although no analysis has yet
been made. It should be noted that the master plan did not propose a system
I originating from Portland on the basis that the unit costs of water developed in the
master plan were somewhat less than the sales cost of Portland water at that time, and
it was considered that the additional costs of water required by construction of
I facilities to transmit Bull Run water would so much further increase the cost as to
render the plan economically undesirable. No particular effort was made to negotiate
with the City of Portland in connection with the development of the master plan.
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The Tualatin Valley Master Plan has the advantage, as earlier pointed out, that the
Jam
wholesale customers of whatever organization is set up might well have an effective
part in the control of the water supply system. In the writers' opinion, the
disadvantage of becoming continually more dependent on imported water could be
considerably ameliorated were the wholesale customers able to participate in the
organization and administration of the development of improved sources. Further-
more, it provides in the case of the Tigard planning area for two sources, an advantage
not to be overlooked. Although the financing plan is not known at this time, quite
possibly the capital requirements might not be imposed on water districts as such but
rather would be imposed on a "county service district" as a whole. If this, of course,
were to be followed, then the the bonding capacity of the districts might not be so
severely affected as would be the case if the districts were to undertake a major
development on their own.
Construction Cost Estimates for Supply Systems
ills
Cost estimates have been prepared based on present day general construction and are
based on quantities obtained from map studies, reconnaissance surveys, and
preliminary designs. A twenty-five per cent allowance for contingencies, legal services,
administration, and engineering has been allowed, but no attempt has been made to try
to adjust prices to some future date. At the time the work is to be undertaken, the cost
estimates may be adjusted to the cost index then prevailing. At time of preparation of
this report, the Engineering News Record Construction Cost Index was 1,540.
Certain of the proposed facilities such as main transmission lines should be built to the
required size initially. Other facilities such as pumping stations and storage may be
expanded as water requirements increase. Based on the future demands previously
developed, the following construction schedules and cost estimates have been
its
developed. These do not include the costs of facilities to be built by either the City of
Portland or Lake Oswego or by Washington County.
Nis
Plan A—Oswego and Portland Sources
1975 Construction
r.r
Pipelines to Lake Oswego
30" 10,500 lin. ft.
27" 6,000 lin. ft.
24" 5,700 lin. ft.
Ties to
distribution system 3 each
Pipeline Construction Cost $ 533,000
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Pumping Station
Bonita Road @
72nd Avenue 12 mgd $ 95,000
Terminal Reservoir at Elevation 450
5 mg (156'd x 35h') $ 396,000
Total Construction Cost
Contingencies, legal, and engineering (25%) 1:1,024,000
$ 25` 000
Oswego Source, Total Cost for 1975 $1,28,)0
Pipelines to Portland
20" 4,500 lin. ft.
• 18" 9,400 lin. ft.
Ties to
distribution system 2 each
Pipeline Construction Cost $ 233,000
Contingencies, legal, and engineering (25%) $ 58,000
Portland Source, Total Cost for 1975 $ 291,000
(no further costs for this system)
1990 Construction
Additions to System from Lake Oswego
Pumping Station
Bonita Road and
72nd Avenue—
expand to 27.0 mgd $ 100,000
Terminal Reservoir Storage
Increase by 5 mg
(156' dx35' h) $ 371,000
1Total Construction Cost $ 471,000
Contingencies, legal, and engineering (25%) $ 118,000
Total Cost for 1990 $ 589,000
Plan B—Two Portland Sources
1975 Construction
Pipelines from Mt. Sylvania
30" 15,700 lin. ft.
27" 6,000 lin. ft.
24" 5,700 lin. ft.
Ties to
distribution system 4 each $ 673,000
1
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Terminal Reservoir at Elevation 450
5 mg (156' d x 35' h) $ 396,000
Total Construction Cost $1,069,000
rr Contingencies, legal, and engineering (25%) $ 267,000
Total Cost for 1975 $1,336,000
Pipelines to Portland
See Plan A Total Cost for 1975 $ 291,000
(no further costs for this system)
1990 Construction
Terminal Reservoir Storage
Increase by 5 mg
(156' d x 35' h)
Total Construction Cost $ 371,000
Contingencies, legal, and engineering (25%) $ 93,000
Total Cost for 1990 $ 464,000
Plan C—Consolidated System from Portland
1975 Construction
Pipelines to Portland
24" 4,500 lin. ft.
42" 9,400 lin. ft.
,.„ 36" 17,800 lin. ft.
Ties to
distribution system 5 each
$1,100,000
Terminal Reservoir at Elevation 450
5 mg (156' d x 35' h) $ 396,000
Total Construction Cost $1,496,000
Contingencies, legal, and engineering (25%) $ 374,000
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Total Cost for 1975 $1,870,000
1990 Construction
Terminal Reservoir Storage
Increase by 5 mg (156' d x 35' h)
Total Construction Cost $ 371,000
"" Contingencies, legal, and engineering (25%) $ 93,000
Total Cost for 1990 $ 464,000
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Construction Cost Summary
1975 1990
Plan "Owner" Construction Construction Total
A Tigard $1,280,000 $589,000 $1,869,000
Metzger & Progress $ 291,000 $ 291,000
imi
Combined Total $2,160,000
B Tigard $1,336,000 $464,000 $1,800,000
Metzger & Progress $ 291,000 $ 291,000
Combined Total $2,091,000
°11 C Tigard, Metzger & Progress $1,870,000 $464,000 $2,334,000
Annual Costs
In addition to the payments necessary to meet the obligations incurred in construction
of facilities mentioned, there will be annual costs incidental to the purchase of water,
maintenance of pipelines, operation of pumping stations, and general administration.
Since the unit cost of providing water is dependent to a considerable extent on the
quantity used, it is necessary to determine the approximate volumes that will be
required over the period for which the facilities are planned. Table IV indicates the
average volumes per year which will be required at various future dates under the
different plans previously described.
TABLE IV
VOLUME OF WATER-100 CUBIC FEET PER YEAR
"Owner" 1975-1980 1980-1990 1990-2000
Tigard Water District* 1,050,000 2,195,000 4,807,000
Metzger & Progress
Water Districts 1,562,000 1,660,000 2,037,000
Consolidated Total 2,612,000 3,855,000 6,844,000
* Includes 830,000 from Tigard wells
It has been assumed that the construction of facilities will be financed by twenty-five
year bonds at six per cent interest. The annual payment necessary to retire the bonds
under the various plans is given in Table V, Amortization Requirements.
aim
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ITABLE V
AMORTIZATION REQUIREMENTS
Annual Payment Annual Payment
Plan "Owner" 1975-1990 1990-2000*
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A Tigard W.D. $100,960 $147,020
Metzger & Progress $ 22,760 $ 22,760
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B Tigard W.D. $104,480 $140,760
Metzger & Progress $ 22,760 $ 22,760
IC Tigard W.D., Metzger & Progress $146,230 $182,520
* Amortization of borrowings made in 1990 continue to 2015
tre
NW
The proposed plans presume that Portland water would be purchased at the present
cost which is that most recently established in 1971,25 cents per 100c.f. Likewise, the
proposed cost of purchase based on the current price of 14 cents per 100 c.f. for excess
water charged by the City of Lake Oswego. Pumping costs have been based on the
1 L pumping heads for various flow rates at the different stations, station efficiency of
seventy-five per cent, and power costs taken from Portland General Electric
Schedule 32. The costs of main line pumping by the City of Portland or the City of
ALake Oswego are assumed to be represented in their rate schedules.
Operation and maintenance costs include allowances for salaries, overhead, and
Imaintenance costs.
The annual costs for the several plans are tabulated in Table VI. The cost for water
purchased under the Tualatin Basin Master Plan is based on the unit costs of Willamette
River water developed in the 1969 report escalated by twenty-five per cent to
approximate the net effect of increases in construction cost and operating cost.
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TABLE VI
ANNUAL COST DATA
PLAN A
Annual
Water Operation Total
Purchase Debt Pumping and Annual Annual Cost
Period Cost Retirement Costs Maintenance Cost Per 100 C.F.
1975-1980
Tigard $ 30,800 $100,960 $ 2,620 $11,000 $145,380 $0.66
Metzger & Progress $390,500 $ 22,760 $ 4,000 $417,260 $0.27
1980-1990
rn Tigard $191,100 $100,960 $ 6,480 $11,000 $309,540 $0.23
Metzger & Progress $415,000 $ 22,760 $ 4,000 $441,760 $0.27
1990-2000
Tigard $556,780 $147,020 $33,090 $11,000 $747,890 $0.18
Metzger & Progress $509,250 $ 22,760 $ 4,000 $536,010 $0.26
Average for 25-year period:
Tigard $0.21/100 c.f.
Metzger & Progress $0.27/100 c.f.
Consolidated &
Averaged $0.23/100 c.f.
TABLE VI
ANNUAL COST DATA
PLAN B
Annual
Water Operation Total
Purchase Debt Pumping and Annual Annual Cost
Period Cost Retirement Costs Maintenance Cost Per 100 C.F.
1975-1980
Tigard $ 55,000 $104,480 $ 9,000 $ 168,480 $0.77
Metzger & Progress $390,500 $ 22,760 $ 4,000 $ 417,260 $0.27
1980-1990
Tigard $341,250 $104,480 $ 9,000 $ 454,730 $0.33
Metzger & Progress $415,000 $ 22,760 $ 4,000 $ 441,760 $0.27
1990-2000
Tigard $994,250 $140,760 $ 9,000 $1,144,010 $0.29
Metzger & Progress $509,250 $ 22,760 $ 4,000 $ 536,010 $0.26
Average for 25-year period:
Tigard $0.31/100 c.f
Metzger & Progress $0.27/100 c.f.
Consolidated &
Averaged $0.29/100 c.f.
I fit r r r t I r I III
TABLE VI
ANNUAL COST DATA
PLAN C
Annual
Water Operation Total
Purchase Debt Pumping and Annual Annual Cost
Period Costs Retirement Costs Maintenance Costs Per 100 C.F.
1975-1980
All $ 445,500 $146,320 $13,000 $ 604,820 $0.34
1980-1990
All $ 756,250 $146,320 $13,000 $ 915,570 $0.30
Co
1990-2000
All $1,503,500 $182,250 $13,000 $1,699,020 $0.28
Average for 25-year period $0.29/100 c.f.
TUALATIN BASIN MASTER PLAN
Average for 25-year period $0.18/100 c.f.
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IIt should be pointed out that the unit costs shown above do not include allowances for
depreciation. If twenty-five year bonds were sold prior to 1975, the major pipelines
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would be completely paid for by the year 2000 and should still have many years of
useful life, but at the same time it would be probably necessary to again add capacity
to some of the facilities to meet increasing demands.
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PROPOSED DISTRIBUTION SYSTEMS
Existing System
Imo
The existing water distribution system of the Tigard Water District has evolved over the
years on the basis of distributing water from sources within the distribution system.
This has enabled the District to proceed on an economical scale in as much as the
transmission from area to area has been relatively small. With the prospect of the well
supply becoming a relatively minor feature of the supply system, then the desirable
characteristics of the existing system become a potential obstacle.
The water distribution system was analyzed both in its existing form and expanded
form by use of the Hardy Cross method in connection with the digital computer. It
became evident in the course of analysis that it would not be feasible to use the
distribution system to any significant degree for purposes of transmitting water from
any major new source. This was particularly true in the case of the Baylor tank
connection into the distribution system. This problem results from the fact that while
the Baylor tanks have been constructed to the highest allowable elevation, they are
nevertheless but six feet higher than the nearest tank, No. 1, while being more than
two and one-half miles distant with no larger than 12-inch pipes interconnecting.
�.. Other difficulties with the distribution system are the result of the land development
pattern, the topography of the area, and the absence of dedicated public right-of-ways
through vacant land.
r�.
The summits of Little Bull Mountain and Bull Mountain itself are served by pump
systems. In the case of Little Bull Mountain, served from Tank No. 1, the water
system can take advantage of the street pattern and a conventional gridiron system is
all
being laid out. In the case of Bull Mountain, there is but one right-of-way through it
and until a street or streets paralleling Bull Mountain Road are developed, this area
must continue to be served from a major line with dead-end branches running north
and south. The economies of construction predominate and it is necessary to continue
to serve this area from a reservoir site at the summit. It is not feasible to divide the Bull
Mountain system into pressure zones at present. This means that many of the
customers served by gravity from the Hi Tor Reservoir will have excessive pressures
while others located nearer the reservoir could have somewhat deficient pressures.
+" In addition to the foregoing problems, there remains the matter of the older lines
within the system whose age or size indicate that they should be replaced. This
situation is acknowledged as evidenced by the District's continuing program of
replacing such lines out of the annual budget. The analysis of the existing system
-30-
MIN
mis
indicated that with the exception of the existing small mains that it is generally strong
enough to perform satisfactorily. Probably the most severe situation exists with respect
to supplying water in the area along Walnut Street from Tiedeman Road west to
S. W. 135th. This is an area of high growth rate with a limited distribution capability at
present. In as much as the future of ground water is so dim, it was deemed necessary to
supply this area from the Baylor tanks, and this will initially require construction of a
12-inch main from Hunziker Street across the northernmost part of the water district.
The route shown follows several existing lines that should be replaced. In addition,
another reservoir at Station No. 3 should be constructed in the near future.
Proposed Water Lines
Plate 4 shows both the existing and proposed water distribution system together with
additional pumping stations and reservoirs. A priority schedule has been developed and
is included in the cost estimates which follow this discussion of the water distribution
system.
Gravity System. The mains that are proposed for the District are predicated on the
;,. eventual development of the terminal reservoir located about 1,000 feet west of
Station No. 2. A pumping station is proposed on Hunziker Road near the Coe
Company for the purpose of improving the delivery rate from the Baylor tank. This
pump will go hand-in-hand with the 12-inch line to Walnut and 135th. It is assumed
that some time will pass before the District initiates a major water supply undertaking.
This pumping station would deliver 2 mgd and its installation would require the
increase of static pressure by 10 psi at the pump discharge. Higher pumping rates are
possible but would increase the water pressures in the lower parts of the area and could
result in difficulties with individual customer's plumbing systems.
When the terminal reservoir is installed, Supply Plan A or C requires that the Baylor
tanks be filled from the westerly direction instead of the easterly direction. In order to
accomplish this through the existing distribution system, a second line leading to the
Baylor tank will be necessary and is shown on Plate 4. The route of this line indicated
is proposed on the basis of minimum distance and the size is based on the District's
continued use of the existing 12-inch line on 67th Avenue and Hunziker Street to Coe
Company. It might be possible, if the time comes to consider this second line, to
arrange a transfer of the existing 12-inch line from Baylor to Hunziker Street over to
the Metzger Water District. If this were done, then the new line size should be
re-evaluated. Under this condition, the new line should be at least 18-inches and
possibly 24-inches in diameter depending on the length of the route.
IMO
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The other additions to the water distribution system are essentially the development of
a strong gridiron system that would be supplemented by distribution laterals on new
roads as they are developed. The line on Durham Road to 76th could be used to supply
the City of Durham.
A 2 mg reservoir is proposed in the vicinity of S. W. 150th Avenue at elevation 400 to
enable the reservoir to be filled from a line laid in Beef Bend Road. A one-million
gallon reservoir is proposed at the site of Well No. 3, and this reservoir could be
deferred until when the peak demand on the 12-inch line proposed indicates the need.
The reservoir proposed on S. W. 150th would not only serve the southwestern
expansion of the water district but could also be used in connection with a booster
pumping station discharging to a 2 mg reservoir at elevation 600 on the western end of
Bull Mountain. As the Bull Mountain area develops, the available storage capacity in
the Hi Tor area will become heavily burdened and yet more storage will be needed. The
proposed reservoir on 150th at elevation 600 would absorb the need for additional
storage and also make possible a saving of ninety feet of pumping lift. No lines are
shown on the proposed system leading from the 150th Avenue reservoir owing to the
total absence of any evident street system on Bull Mountain beyond what has already
been laid out.
■.
Pumped Systems. The area on Little Bull Mountain is now served by a pumping station
capable of 1.8 mgd at 50 psi. The current development of multiple dwellings together
las
with additional residential housing indicate that the pumping capacity is adequate. It
would be desirable to increase the larger pump's discharge pressure by 15 psi. In view
of the reconstruction program and additional lines being laid in the Little Bull
Mountain area, it appears that no reinforcement can be indicated at the present time.
Elevated storage on Little Bull Mountain would require a 115 foot high elevated tank
at the present well site to produce 50 psi, or a tank about 90 feet high could be used at
the very summit. Continued use of the present pumping scheme is recommended
instead, but auxiliary power should be available.
Bull Mountain itself is served by a 0.02 mg reservoir at Hi Tor, elevation 690. This tank
i"' is filled by an 8-inch line served by a pumping station on 132nd Avenue. Station
capacity is 0.65 mgd. Another pump located at Well No. 2 can also feed Hi Tor at the
rate of 0.11 mgd. The crest of Bull Mountain is served by a pump station adjacent the
Hi Tor reservoir, and within this system, the minimum normal pressure is 45 psi. At the
upper point where gravity service from the Hi Tor reservoir begins and pumped service
ends, pressures range from 15 to 20 psi.
The future average demand for the entire Bull Mountain area above elevation 300, a
level that allows 45 psi minimum pressures from existing reservoirs, is 1.7 mgd. Of this,
■. about 0.7 mgd will be needed east of 150th Avenue. The proposed system is based on
installing facilities to furnish 1.0 mgd average flow to Hi Tor, and, when the demand
exceeds this, installation of a line on 150th up to a reservoir at elevation 600 is needed
to satisfy the 1.7 mgd total demand.
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W. With the terminal reservoir concept, water to serve Bull Mountain will be available at
Reservoir No. 2. This will make more water available from Reservoir No. 3 to the
gravity system, and this is a primary need. A 2.0 mgd (total capacity) pumping station
�,. discharging into a proposed 12-inch main on Bull Mountain Road will supply the
Hi Tor site. In addition, 2 mg added storage is needed at Hi Tor with construction of
1 mg initially. The Hi Tor pumping station should be improved by addition of a fire
pump. As much of the existing line on Bull Mountain Road as possible should be
re-used to extend Hi Tor pumping pressure until minimums of 40 psi are achieved. The
existing supply system to Hi Tor should be preserved as a standby.
mis
Neither the Hi Tor nor the Little Bull Mountain systems are served by standby power,
and neither station has available space for it. Consideration should be given to purchase
of two mobile 25 KW generators.
imo
The booster station at Fern Street serves 12 customers and when a line down 135th
r■
from Hi Tor is possible, the station can be abandoned in favor of service from Hi Tor.
Telemetering. Control of the wells and booster pumps could be improved and labor
would be saved if reservoir level data and pump operating status were centrally
indicated. Probably, the office at Reservoir No. 1 is the most likely location for this
display. Transmitters at each reservoir and pump would send signals via leased
telephone lines to the office. Alarm circuits to remote locations such as the
superintendent's office, the fire station, or home of key personnel could be a part of
the system. In view of the increasing complexity of the system, a telemetering
installation of this nature is recommended.
Storage Considerations
Previous discussion has indicated locations of several proposed storage additions. These
have been sized in anticipation of distribution system loads at the year 2000. As a rule,
the State Board of Health encourages total storage to equal three days average demand.
Taking credit for availability of existing wells at 1.7 mgd and ties to Metzger and
Capitol Highway at 4.0 mgd total, out of 6 mgd potential capacity, it develops that
23 mg storage should be the goal. Of this, 6 mg are now in hand. The terminal reservoir
eventually stores 10 mg, Hi Tor stores an additional 2 mg, Station No. 3 stores an
additional 1 mg, and 4 mg are proposed for S. W. 150th Avenue.
Construction Cost Estimates and Priority Development
The estimates appear in three categories:
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' Major Additions, First Priority. This work that will be beneficial to the
District within its present general boundaries.
IDistribution Replacements. This work in the local distributors that is or will
be necessary due to age or insufficient size.
Major Additions, Second Priority. This work that will be generally beneficial
to the District as it expands to the north and the southeast. These areas
should develop prior to the western sectors due to earlier general availability
of sewers.
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Major Additions, Third Priority. This work that will be generally beneficial
to the District as it expands to the west.
The estimates are based on the preliminary plans and estimated costs for construction
by general contract. Allowances for pipeline work include valves, fittings, hydrants,
all special highway and railway crossing problems, and pavement replacement where
indicated as probable on a reconnaissance basis. An allowance of 25% has been added
to cover the cost of engineering, administration, legal, right-of-way, service taps, and
+N contingencies. No adjustment has been applied for reduction of cost to the District
where an assessment for 6-inch mains can be made.
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DISTRIBUTION SYSTEM
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Major Additions, First Priority
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Total
Item Estimated Cost
1. 12-inch line from Hunziker Street (near Coe Company)
to Scoffins Street, Tigard Street, Katherine Street,
+r• and Walnut Street at S. W. 135th Avenue $ 276,000
2. 12-inch line from Well No. 2 to S. W. Bull Mountain
®.. Road and to Hi Tor Reservoirs, including new pumping
station at Well No. 2 146,000
3. 12-inch line from Scoffins Street at Highway 217 to
Highway 217 and Durham Road to High School 178,000
rnn 4. Pumping station at Hunziker Street near Coe Company 26,000
5. One million gallon reservoir at Hi Tor and enlarged
Hi Tor pump capacity 132,000
6. Telemetering installation 36,000
I`" TOTAL COST $ 794,000
Distribution Replacements
Total
Item Estimated Cost
1. 8-inch line on Omara Street $ 25,800
2. 6-inch line on Edgewood Street to Omara 24,600
3. 10-inch line on Highway 99 from Gaarde Street
to Watkins 31,200
4. 8-inch line on south side of Highway 99 from
Watkins to Main 44,400
5. 6-inch crossing of Highway 99 at Johnson Street 6,000
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I6. 8-inch crossing of Highway 99 at Walnut Street 4,900
7. 8-inch line on north side of Highway 99 from
IWatkins Street to Walnut 32,400
8. 8-inch line on Watkins Street from Fairhaven
Street to Walnut 8,400
9. 6-inch line on Watkins Street from Park Street
1 to Walnut 16,900
10. 6-inch line on Grant Avenue 6,400
I11. 6-inch line on Cook Lane 4,600
I12. 6-inch line on 107th Avenue 5,000
13. 6-inch line on Park Street 18,200
I14. 6-inch line on Derry Dell Court 13,800
15. 6-inch crossing of railroads at Katherine Street
Iand 98th Avenue 7,900
16. 6-inch line on 95th Street 7,200
1 17. 6-inch line on Knoll Drive 5,500
1 18. 6-inch line on Errol Street 11,900
19. 6-inch line on James Street 11,400
I20. 6-inch line on 117th Avenue 6,400
I 21. 6-inch line on 146th Avenue, north of Bull Mountain
Road 10,200
I22. 6-inch line on Sunrise Lane 11,800
23. 6-inch line on 150th Avenue 10,100
I24. 6-inch line on Bull Mountain Road at 155th Avenue 3,600
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25. 6-inch line on 133rd Avenue 35,600
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26. 4-inch line west of 150th on Sunrise Lane 5,900
TOTAL COST (to nearest $1,000) $ 370,000
Major Additions, Second Priority
Total
Item Estimated Cost
1. 12-inch line on 135th from Walnut to Scholls Ferry
r. Road $ 84,800
2. 10-inch line from 135th near Scholls Ferry Road to
121st Avenue 53,500
3. One-million gallon reservoir at Well No. 3 112,000
4. 10-inch line on Sattler Road from Highway 217 to
98th Avenue 46,000
5. 12-inch line from Sattler and 98th Avenue to
Reservoir No. 1 49,000
6. 12-inch line from High School to 98th 38,000
TOTAL COST (to nearest $1,000) $ 383,000
Major Additions, Third Priority
Total
Item Estimated Cost
1. 12-inch line from Baylor Reservoirs to Hunziker Street $ 133,000
2. 6-inch line from Sattler Road at Highway 217 to Bonita
Road and 81st Avenue 26,500
3. 6-inch line on Dorburn Place and 81st Avenue north of
Durham Road 19,100
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,., 4. 8-inch line on 79th Avenue 31,500
5. 8-inch line on 76th Avenue 45,100
6. 12-inch line on Durham Road from 85th to 76th Avenue 39,800
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7. 10-inch line on 98th Avenue from Durham Road to
Sattler Road 29,000
8. 12-inch line on Durham Road from 98th Avenue to
Highway 99 81,000
9. 8-inch line on 109th Avenue and Naeve Street from
Durham Road to Highway 99 32,000
10. 12-inch and 16-inch lines on Highway 99 from Beef Bend
Road to Gaarde Street 48,400
11. 14-inch line, with 6-inch tie, on Beef Bend Road from
'r" line to Reservoir No. 4 to proposed reservoir on 150th
Avenue 194,000
• 12. Two-million gallon reservoir (el. 400) on 150th Avenue 238,000
13. 12-inch line on Fischer Road from Highway 99 to Beef
■, Bend Road at Meyers Lane 143,000
14. 12-inch line on Beef Bend Road from 150th to
Bull Mountain Road 178,000
15. 6-inch line on Bull Mountain Road, Beef Bend Road to
161st Avenue 22,900
16. 6-inch line on Roshak Road 25,100
17. 10-inch line on Beef Bend Road from Bull Mountain Road
to Scholls Ferry Road 38,500
18. 10-inch line on Scholls Ferry Road from Beef Bend Road
to Fern Street 91,200
19. 6-inch line on 150th Avenue above Scholls Ferry Road 14,600
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I20. 12-inch line on Fern Street 58,200
21. 10-inch line on Scholls Ferry Road from Fern to
I135th Avenue 72,500
22. 6-inch line on 135th from Fern to existing 8-inch
line to Hi Tor 18,200
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23. Pumping station on 150th Avenue 23,000
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24. Two-million gallon reservoir on 150th Avenue at
Elevation 600 238,000
25. One-million gallon reservoir at Hi Tor (total
addition, 2mg) 112,000
ITOTAL COST (to nearest $1,000) $1,956,000
TOTAL, ALL DISTRIBUTION PROJECTS $3,503,000
am
In addition to the foregoing costs, there may also be the cost of a surface water supply
Lsystem. This will amount to at least $1.8 million if the District goes ahead with a
system on its own. Federal assistance as a grant up to $500,000 is available from the
Department of Housing and Urban Development on a supply project of this sort. The
same aid in the amount of 50% of construction cost, up to the $500,000 grant limit, is
NO
also available for any major distribution program. We doubt that the District could
secure funds for more than one program and suggest that it might be better to apply
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for it on the supply system, unless the District decides that the Washington County
proposal will best serve it. The reason for this recommendation relative to supply
system funding is based on the high initial unit costs of water, which could be
considerably reduced by grant funding.
Respectfully submitted
/45,-;e4-.-e- 7'1-1-e-r-
Gilbert R. Meigs
Fir-
NM
NO
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