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Federal Water Pollution Control Administration
DEPARTMENT OF THE INTERIOR
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RECONNAISSANCE INVESTIGATION
WATER SUPPLY & WATER QUALITY CONTROL STUDY
BEAVER CREEK WATERSHED. OREGON
A reconnaissance survey has been made which discloses a need for
storage for municipal water supply. No need is foreseen in the basin
for water quality control storage. This conclusion is based on
economic, demographic, and engineering studies. A detailed study
will be conducted should specific storage sites be considered in the
future.
Prepared at the Request of the District Engineer
U. S. Army Engineer District, Portland
Corps of Engineers, Portland, Oregon
U. S. DEPARTMENT OF THE INTERIOR
Federal Water Pollution Control Administration
Portland, Oregon
JUNE 1966
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TABLE OF CONTENTS
Page Number
REQUEST AND AUTHORITY . 1
PURI’OSEANDSCOPE....... 1
STUDY AREA DESCRIPTION 1
SUMMARY OF FINDINGS AND CONCLUSIONS 2
WATER RESOURCES OF THE STUDY AREA . 2
THEECONONY 3
WATER REQUIREMENTS- -MUNICIPAL . . . 4
WATER QUALITY CONTROL
1. Domestic Wastes • • . • • 4
2. Water Temperature 4
MUNICIPAL WATER SUPPLY AND WATER
QUALITY CONTROL STORAGE NEEDS . 5
LIST OF FIGURES
LOCATIONMAP BackCover
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BEAVER CREEK WATERSHED, OREGON
REQUEST AND AUTHORITY
The request for this investigation was made by the District
Engineer, U. S. Army Corps of Engineers, Portland, Oregon, by letter
dated October 15, 1965. Authority for the investigation and report
is the “Federal Water Pollution Control Act,” as amended (33 U.S.C.
466 et seq.), and the “Memorandum of Agreement” dated November 4, 1958,
between the Departments of the Army and Health, Education, and Welfare,
relative to the Water Supply Act of 1958, as amended (43 U.S.C. 39Ob).
PURPOSE AND SCOPE
The Corps of Engineers requested data on present municipal and
industrial (M&I) water supply and water quality control needs in
Beaver Creek Watershed, Oregon, and on such future requirements as
could be estimated within the scope of a reconnaissance study. These
data are to be used to determine the advisability of initiating
detailed investigations of specific storage sites. A more detailed
study will be conducted at such time as the Corps of Engineers may
request information relating to a specific site(s). Initial projec-
tions are made to the year 2020 with an interim date of 1980.
STUDY AREA DESCRIPTION
The area under consideration is the Beaver Creek Watershed located
8 miles south of Newport, in Lincoln County, Oregon. The creek drains
about 33 square miles on the coastal slope of the Coast Range. Seal
Rock, situated on the coast about 1.5 miles south of Beaver Creek, is
the only community in the vicinity. (See Location Map, back cover.)
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SUMMARY OF FINDINGS AND _ CONCLUSIONS
The Seal Rock Water District now utilizes water sources outside the
Beaver Creek Watershed. When demand for water increases beyond the
capability of existing sources, the Water District plans to develop a
source on the North Fork Beaver Creek which would ultimately supply the
needs of several communities scattered along about 13 miles of the
Oregon Coast.
Although population is expected to increase in the lower Beaver
Creek Basin, no problems are expected to develop which would require
upstream storage for water quality control, assuming adequate treatment
of domestic wastes--at least 85 percent removal of biochemical oxygen
demand (BOD).
WATER RESOURCES OF THE STUDY AREA
The average annual yield of Beaver Creek near tidewater is
estimated to be about 40,000 acre-feet. Based on precipitation and
runoff: patterns over the past 25 years, the Oregon State Water
Resources Board has developed the following estimates of average
monthly stream discharges:
January 149 cfs July 9 cfs
February 164 cfs August 5 cfs
March 115 cfs September 6 cfs
April 71 cfs October 22 cfs
May 40 cfs November 82 cfs
June 17 cfs December 135 cfs
These limited data based on estimates indicate that a better
knowledge of streamfiow patterns will be needed to permit detailed
studies. Stream gages should be established near tidewater and at
other suitable locations.
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Adequate data on water quality are also lacking. Field surveys,
including stream sampling, will be necessary should a more detailed
study be requested. A brief reconnaissance of the area and data
gathered in nearby watersheds, however, indicate that water in the
upper reaches of North Fork Beaver Creek is relatively free of color
and turbidity, low in mineral content, and generally of adequate
quality for all anticipated uses.
THE ECONONY
The economy of the area is supported by forestry, recreation,
tourism, and a small amount of agriculture. Population in 1960 was
estimated at 500 persons, with most of the inhabitants located in the
vicinity of Seal Rock. Scenic attractions along the Oregon Coast,
plus recreational activities afforded by the streams, bays, and forests
have made tourism an increasingly important factor in the area’s
economy. Another factor is the present trend toward subdivision of
coastal lands for homesite development.
From these considerations, design populations shown below were
developed for Seal Rock and the study area.
Total
Year Seal Rock Study Area
1960 240 500
1980 350 750
2000 600 1,200
2020 900 2,000
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WATER REQUIREMENTS- - MUNICIPAL
Seal Rock obtains water from Dear and Hill Creeks, small streams
just north of town. Disinfection is the only treatment. Plant capacity
in 1960 was about 0.1 million gallons per day (mgd), serving an
estimated 250 people. The population served increased to about 500
by 1964. The community has a surface water right of 1.26 cubic feet
per second (cfs), or 0.8 mgd. Water needs in rural areas are supplied
by individual surface sources; geologic conditions are unfavorable for
the development of ground water.
WATER QUALITY CONTROL
1. Domestic Wastes
Wastes entering Beaver Creek are minimal and include
pollutants from domestic sources and land runoff. Domestic and com-
mercial wastes at Seal Rock and most of the study area are treated
by individual facilities such as septic tanks.
2. Water Temperature
Temperature is an important water quality parameter, particularly
as it affects the propagation of anadromous fish. Futhermore, tempera-
ture conditions in a stream substantially affect its capacity to
assimilate organic waste. However, because the migration pattern of
anadroinous fish is adapted to existing thermal conditions and because
waste discharges to the stream are expected to remain negligible in
the future, storage releases for temperature control appear unnecessary
in the Beaver Creek Watershed.
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MUNICIPAL WATER SUPPLY & WATER QUALI 1 CONTROL STORAGE NEEDS
The Seal Rock Water District serves a number of residential and
commercial users spread over a large area along the coast. The demand
for water is expected to triple in 10 years. Estimates of future water
requirements are based on projections of current population growth in
the area. To meet future needs, the Water District plans to pipe water
from a source on Henderson Creek, located about 7 miles north of Seal
Rock. Further demand would be met by storage on North Fork Beaver
Creek. Assuming that these existing and planned developments would
continue to serve the area through year 2020, an additional requirement
of 40 mg (120 acre-feet) is foreseen which could be provided by storage
or appropriated natural stream flow from the North Fork of Beaver Creek.
The Lincoln County Court has recently sponsored studies of water
supply needs in the developing areas of the County. The conclusions
drawn were that the most satisfactory and beneficial way to insure
sufficient water for the present and future populated areas, including
the Beaver Creek Watershed, would be to develop higher-elevation
potable sources of water, tie present systems together, make improvements
in pipe size and storage facilities, and eventually construct a contin-
uous supply line the full length of the coast. The North Fork Beaver
Creek was selected as the most suitable source of supply for Seal Rock
and adjacent communities along the coast.
The Beaver Creek Watershed is sparsely settled and wastes dis-
charged to the stream from domestic and agricultural sources are minimal.
Although population of the study area is forecast to quadruple, future
domestic and municipal wastes are not expected to overtax the assimila-
tive capacity of the stream, assuming that these wastes are given ade-
quate treatment (i.e., treatment which would result in an overall
removal of at least 85 percent of all oxidizable organic material
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discharged to the stream). No need is foreseen, therefore, for flow
regulation storage for water quality control.
The Oregon State Game Commission recommends a minimum perennial
streamfiow for fish life of 3 cfs from the North Fork and 1 cfs from
the South Fork. If this flow cannot be maintained by adjudication of
water rights for irrigation and other consumptive uses, then a need
for storage is indicated.
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Scale In Miles
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SCALE IN MILES
WATER SUPPLY & WATER QUALITY CONTROL STU DY
BEAVER CREEK WATERSHEDJOREGON
LOCATION MAP
UNITED STATES DEPARTMENT OF THE INTERIOR
Federal Water Pollution Control Administration
REGION IX (DATE: 3/66) PORTLAND,OREGON
NEWPORT
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