GEOLOGICAL SURVEY CIRCULAR 109 

WATER POWER RESOURCES OF 

HAM·MA HAMMA, DUCKABUSH AND 

DOSEW ALLIPS RIVERS 

WASHINGTON 

By Fred F. Lawrence 

PREPARED IN COOPERATION WITH THE 

DEPARTMENT OF CONSE:RVATION AND DEVELOPMENT 

OF THE STATE OF WASHINGTON 

UNITED STATES DEPARTMENT OF THE INTERIOR 

Oscar L. Chapman, Secretary 

GEOLOGICAL SURVEY 

W. E. Wrather, Director 

GEOLOGICAL SURVEY CIRCULAR 109 

WATER POWER RESOURCES 

OF HAMMA HAMMA, DUCKABUSH 

AND DOSEW ALLIPS RIVERS 

·WASHINGTON 

By Fred F. Lawrence 

Washington, D. C., 1962 

Free on application to the Geological Survey, Washington 25, D. C. 

GEOLOGICAL SURVEY CIRCULAR 109 PLATE 1 

OLYMPIC I 

=.. . . . . . . I OLYMPIC 

.· . . . . . . ~· . . 

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• • • :' · . age Basin sou • • • • • Qfa'~ •• , • , • 

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-r-'-=-··_._· . ..:....:_ . _ __/_~--- _____ J~FERS.9~r. :_ · COUNTY_ . .' MASON • COUNTY 

. . ... 

KITSAP SOUNT'f_ ___ _ 

---MASON COUNTY 

O'=='""";;;;;;;;i==i3""""'4i===::'==,;;6 Miles 

Scale one inch equals four miles 

Proposed developments shown in red overprint 

12PM9 shown in red indicates power site index number 

See text for explanation 

LOCATION MAP OF HAMMA HAMMA, DUCKABUSH, AND DOSEWALLIPS RIVERS 
WATER POWER RESOURCES OF HAMMA HAMMA, DUCKABUSH 

AND DOSEW ALLIPS lUVERS WASHINGTON 

CONTENTS 

Abstract •••••••••••••••••••.••••••••. ,. 1 

Introduction. • • • • • • • • • • • • • • • • • • • • • • • • • • 1 

Previous investigations and reports •• 2 

Maps................................. 2 

Future work.......................... 2 

Geology................................ 2 

Geography & History •••••••••••••••••••• 2 

Power site index numbers ••••••••••••••• 3 

Water supply. • • • • • • • • • • • • • • • • • • • • • • • • • • 3 

Precipitation •••••••••••••••••••. •.... 3 

Runoff •••••••••••••••••••••••• ,...... 5 

Hamma Hamma River •••••••••••••••••••• 8 

Duckabush River ••••••••••••• , •••••••• 10 

Dosewallips River •••••••••••• , • • • • • • • 12 

Page 

Water Utilization plan •••••••••••••••.• 13 

Hamma Hamma River ••••••••••••••.•••.. 14 

Duckabush River ••••••.•••••••.••••••• 14 

Dosewallips River ••••••••••••..••••.• 15 

Stream r~gulation ••••••••••••••••••••.. 15 

Hamma Hamma River •.••••••••.••.••••..• 16 

Duckabush River •••••••••••••••••••••• 16 

Dosewallips River •••••••••••••••••••• 18 

Water power ••••••• · ••••••••• • ••••••••••• 19 

Hamma Hamma River ••••••••••••.••••••• 19 

Duckabush River ••••••••••••••.••••••• 20 

Dosewallips River •••••••••••••••••••• 22 

ILLUSTRATIONS 

Plate 1. 

Figure 1. 

2. 

Page 

Map of the Hamma·Hamma, Duckabush, and Dosewallips Rivers ••• , •••••••••••• Frontispiece Annual precipitation, Seattle, Quilcene, and Cushman Dam ••••••••••••••••••••••••• 4 

Annual distribution of precipitation at Cushman Dam, Brinnon, and Quilcene, 

3. 

4. 

5. 

and Runoff of the Hamma Hamma, Duckabush, and Dosewallips Rivers ••••••••••••••• 7 

Monthly hydrographs for the Hamma Hamma, Duckabush, and Dosewallips Rivers ••••••• 9 

Daily flow duration curves for the Hamma Hamma, Duckabush, and Dosewallips Rivers 11 

Reservoir area and capacity curves for sites on the Hamma Hamma, Duckabush, 

and Dosewallips Rivers ••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 17 

ABSTRACT 

Th~ Hamma Hamma, Duckabush, and Dosewallips Rivers drain part of the east slope of the Olympic Mountains in northwestern 

Washington. The area is sparsely settled and 

for the most part is public domain lying in 

either the Olympic National Park or the 

Olympic National Forest. 

There are 500 feet of fall on the Hamma 

Hamma River, 1,100 feet on the Duckabush 

River, and 1,500 feet on the Dosewallips River available for power development. There are no reservoir sites in the upper portions of the basins so the proportion of firm power 

to total power is quite small. Each basin 

has one reservoir site near the mouth of the 

stream which can provide adequate regulation. 

It will not be possible to divert the entire 

streamflow for power because each of these 

streams is used as spawning ground for salmon. 

The amount of water necessary to maintain this 

spawning cycle will be a large proportion of 

the l9w flow of each stream, thus greatly 

reducing the power available 95.and 90 

percent of the time in a run-of-river plant. 

INTRODUCTION 

This report is one of a series prepared 

to assist in the classification of land within the public domain, with regard to its 

value in the production of hydro-electric 

power. 

The field work incidental to the prepara- tion of the report included plane-table 

surveys of each of the three. streams studied. 

These surveys were all made by Mr. W. C. 

Senkpiel in 1932 except Jefferson and Lena 

Creeks in the Hamma Hamma River basin, which were mapped by Mr. G. w. Crippen in 1936, and 

the Hamma Hamma River dam site mapped by Mr. Arthur Johnson in 1937. The 1936 and 

1937 surveys were made in cooperation with 

the Department. of Conservation and Development of the State of Washington. The author 

made two short reconnaissance trips into the 

three basins by automobile in 1949. 

l 
2 

-Previous Investigations and Reports 

Mr. E. E. Jones made reconnaissance 

surveys of the three streams in 1927 and 

prepared reports on the potential power available, These reports and maps were not 

released to the public, 

Geological Sur~-- River survey maps, all on a scale of 1:31,680 (! mile to 1 inch) 

with conto1:r intervals of 20 feet on land 

and either 5 or 10 feet on the water surface, 

have been published for all three streams, 

These maps are: Plan and profile of Hamma 

Hamma River and tributaries, Washington, with dam site (l plan sheet, l profile sheet); 

Plan and profile of Duckabush River, Washington, from mouth to mile 18 (1 sheet showing plan and profile); and Plan and ~ofile of 

Dosewallips River, Washington, from mouth 

to Deception Creek, and dam site (1 plan sheet, 1 profile sheet), · 

The dam sites on the Hamma Hamma and 

Dosewallips Rivers are on a scale of 

1:4,800 (400 feet to 1 inch) with contour 

intervals of 10 feet on land and 5 feet on the river surface, Mt. Constance quadrangle, 

scale 1:125,000, contour interval 100 feet, covers all of the Hamma Hamma River and 

those parts of the Duckabush and Dosewallips Rivers upstream from their respective gaging stations. 'The Brothers and Mt. Steele 

quadrangles, scale 1:62,500, contour interval 

100 feet, cover the south half of Mt. · Constance quadrangle and include the same parts of all three basins. 

Cor~s of Engineers, u. s. Army-- Pt. Misery 

qua rangle, scale 1:62,500, contour interval 

20 feet, covers the area to the east of 

The Brothers quadrangle and includes the area downstream from the gaging stations on the Duckabush and Dosewallips Rivers except for a small part of the Dosewallips River 

basin which appears on the Quilcene quad- rangle, scale 1:62,500, contour interval 50 

feet. 

U. S. Forest Service-- Two maps of the 

Olympic Peninsula; one on a scale of 2 miles 

to 1 inch shows contours where available. 

The other, on a scale of 4 miles to 1 inch, 

shows no contours but covers a slightly larger area on the north and south. 

The above Geological Survey and Corps of Engineers maps may be obtained from the 

Map Distribution Section, U. S. Geological Survey, nenver Federal Center, Denver, Colo. 

The price for quadrangle maps is 20 cents 

per sheet, and for river surveys 10 cents 

per sheet. The Forest Service maps are obtainable from offices of the Forest Service 

in Olympia, Wash,, or Portland, Oreg. 

In connection with the preparation of 

the maps of The Brothers and Mt. Steele 

quadrangles, a line of levels was run up each of the three river valleys and a series 

of bench marks set. Copies of the bench mark 

descriptions and elevations may be obtained 

from the Regional Engineer, U. S. Geological 

Survey, Sacramento, Calif. 

Future work 

Detailed topographic surveys are required 

at those dam sites not already mapped on a large scale, and the geology of all the dam 

sites should be investigated before any detailed planning is undertaken. 

GEOLOGY 

Very little geologic investigation has 

been made in the basins of the Hamma Hamma, 

Duckabush, and Dosewallips Rivers. So far as is known no reports have been published, 

The Geology Department of the College 

of Puget Sound in Tacoma, headed by Professor 

F. A. McMillin, has maintained a summer camp in the area for some years, studying the 

geology, No results have been published. 

GEOGRAPHY AND HISTORY 

The basins of the Hamma Hamma, Duckabush, and Dosewallips Rivers are on the 

eastern side of the Olympic Peninsula in the 

northwestern part of the State of Washington, about 30 airline miles west of Seattle. All 

three streams drain into Hood Canal which is an arm of Puget Sound. The adjacent drainage systems are as follows: on the south, 

the North Fork of the Skokomish River; on the west, the Quinault and Elwah Rivers; on the north, the Dungeness and Quilcene Rivers; 

and on the east, Hood Canal, Part of the 

Hamrna Hamma River basin is in Mason County and the rest of it and all of the Duckabush 

and Dosewallips River basins are in Jeffer- son County~ 

The central portions of the Duckabush 

and Dosewallips River basins and the re- mainder of the Hamrna Hamma River basin are in the Olympic National Forest, and the upper 

parts of the Duckabush and Dosewallips River 

basins are in the Olympic National Park. 

Moat of the land along the lower reaches of 

the three rivers is privately owned. The 

land 11•hich is under private ownership has, 

for the most part, been logged off and in 

many places a good stand of second-growth timber has come up. In spite of some rather 

heavy logging between 1920 and 1930, the 

National Forest .land has hardly been touched. 

No logging operations were under way at the 

time of this writing and the Forest Service 

has not planned any large timber sales for 

the next 5 years. Except for a fine stand 

along Washington and Jefferson Creeks in the 

Hamma Hamrna River basin the timber in the 

three basins is difficult to reach, and 

probably will not be sold until the more accessible Forest Service stands have been 

cut. The timber is predominantly an excellent 

grade of Douglas fir with small amounts of 

silver fir, cedar, and hemlock. 

The topography of all three basins is 

very rough except for the first few miles 

adjacent to Hood Canal. Altitudes vary from sea level at the mouth of each stream to 
7,772 feet on Mt. Deception at the headwaters 

of the Dosewallips River. The Brothers 

Mountain, which has an altitude of 6,866 feet 

and which lies between the Hamma Hamma and 

Duckabush Rivers, is the highest point in 

either basin. 

Basin 

Hamma Hamma 

Duckabush 

Dosewallips 

84.4 

76.3 

116.8 

83.6 

66.2 

93.6 

There·are no railroads o~ airports within the .three.'basins. u.s. Highway 101, a paved road, f~llows the shore of Hood Canal 

and crosses· the three rivers near their 

mouths. Gravelled roads go up the valley of 

each stream •. The Hamma Hamma River road 

extends 14 miles up the valley to a point about 1 mile above Whitehorse Creek. The 

Duckabush River road extends 6 miles up th~ 

valley to a point locally known as Big Hump. 

The Dosewallips River road extends 15 miles 

up the valley ending just inside the Olympic National Park. These roads are not passable 

at times during the winter months. 

The first settlements in this part of 

the State were at Shelton and Quilcene, on opposite sides of the three basins, in the 

1850's. By 1900 Hoodsport, Eldon, Duckabush, and Brinnon were thriving lumber towns, 

but as the timber was cut off'the more accessible hillsides, the population decreased 

considerably. Hoodsport, with a population in 1940 of 565, is the largest town in the 

general area although it is not within any of the three basins. The other three towns 

mentioned above each have a few inhabitants 

catering mainly to tourists, and marketing a limited amount of shell fish from Hood 

Canal. 

In each of the three valleys there are a few "stump ranches" on the privately owned 

land between the N~tional Forest boundary and Hood Canal. The U. s. Fish and Wildlife 

Service once operated a fish hatchery near the mouth of the Duckabush River but discontinued its operations some years ago. Game fish for the Olympic National Park were raised at the site but this work has now been 

transferred to the hatchery near Quilcene. 

The basins are now used primarily for 

growing.timber, for recreation, and for 

fishing and salmon spawning. 

POWER SITE INDEX NUMBERS 

For convenience in identifying power sites in the United States the country has 

been divided into 12 major drainage basins. 

Each of these basins has been subdivided, 

2910 

3360 

4060 

The table below summarizes some of the 

geographic data available for the basins. 

The median altitudes were determined from 

the topographic maps of Mt. Constance, 

Mt. Misery, and Quilcene quadrangles. 

2910 

3670 

4300 

.!/5 + - ~41.? Y300 ± 

' 

survey map. cesurvey map. 

and each subdivision has been divided. The 

major drainage basins are designated by numbers from 1 to 12, and the subdivisions 

and minor subdivisions are both designated by a system of lettering. Thus the area under 

discussion here is in major drainage 12, 

which includes the Columbia River basin and 

Pacific Ocean drainage nortn o.f the Kla~th 

River. The first subdivision is lettered 

"P" and includes Puget Sound drainage from 

Boundary Bay to Cape Flattery. The second 

subdivision is lettered "M" and includes 

Hood Canal and Puget'sound drainage from and 

including the Skokomish River to and including the Dungeness River. Thus the basins of the 

.Hamma Hamma, Duckabush, and Dosewallips Rivers are all within the area known as 12PM. 

Within the sub-subarea, which in most cases is a subdivision of a river basin, the power sites are numbered consecutively beginning 

at the headwaters and numbering downstream. 

Where several small independent basins fall 

within the smallest subdivision, as is the case here, numbering is begun with the first 

stream investigated and continued to the next 

without regard to the geographical position of the stream in the sub-subdivision. Thus 

power site 12PM9 is on the Hamma Hamma River, 

l2PM10, l2PM11, and 12PM12, are on the Dose~ 

wallips River, and 12PM13, l2PM14,. and 12PM15 are on the Duckabush River. 

WATER SUPPLY 

Precipitation 

Precipitation over the three basins is 

heavy and the major part falls in the seven months from October through April. (See 

fig. 2.) At Cushman Dam, altitude 790 feet, 

just outside the area on the south, 87 

percent of the annual precipitation falls in 

these seven months. At Brinnon, at the 

mouth of the Dosewallips River on Hood Canal, 

86 percent falls in the same period, and at 

Quilcene, just north of the area and also at 

tidewater, 83 percent of the precipitation occurs in these same seven months. Thus the 

percentage falling in the summer months is 

almost one-third greater at Quilcene than 

at Cushman Dam. 
+=-

80 

70 

60 ., 

cu "fi 50 

= 40 

30 

20 

60~------------------------------~--------------------~ 

., 50Ul------------------~----------~----~-------------.ll ~40 g 

·- 30 

20 

'-'i 

~ 

i i i ~ ~ 

2 ~ It) It) 10 C\1 

~ v 22 2! 2! 

QUILCENE, WASH. 

Mean tor. 29 years 43.24 inches 

It) 

·~ Q 

~ 

It) 

2! ~ 

SEATTLE, WASH. 

Mean for 71 years 33.30 inches 

120 

110 

100 ., 

~ 90 (,) 

.s 

80 

70 

60 

i1 

It) 

~ 

It) 

~ 

~ 

~ 2! 

:3 

.2! 

It) 

~ 

~ 

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2! 

It) 

v 

~ 

It) 

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2! 

CUSHMAN DAM,. WASH. · Mean for 25 years 93.67 inches.. 

Figure 1. - Annual precipitation, Seattle~ QUilcene, and ·Cushman Dam, 

g 

~ 

0 

It) 

~ 
The total annual precipitation shows a marked-decrease from south to north. (See 

fig. 1.) Cushman Dam has a mean precipita- tion of 93.7 inches, Brinnon 75.4 inches, 

and Quilcene 43.2 inches. Although the 

record at Brinnon covers only the period 

1899-1906 when, according to the 1879-1949 

record at Seattle, precipitation was some- what higher than during the periods 1921-49 

when records were obtained at Quilcene or 1925-49 when records were obtained at Cush- man Dam, the difference is not so great that 

it changes the over-all picture. The mean annual precipitation at Brinnon during the 

period 1921-49 was probably between 65 and 

70 inches. 

The variation in precipitation is due 

to the topography of the Olympic Mountains 

and to the direction of approach of the 

prevailing winds. These 1·•inds blow from 

the southwest and the air, while rising to 

clear the Olympic Mountains, loses a large 

part of its moisture. The mountains form a rectangle with its narrow .side east and 

west, and its southern extremity bounded 

by the Chehalis River. The ridge slope is 

fairly regular from near sea level on the 

Chehalis River to Mt. Olympus, altitude 

7,923 feet, which lies due west of the 

Dosewallips River. Thus the air passing over the Dosewallips River and Quilcene has traversed considerably higher ground than that 

which passes over the Hamma Hamma River and 

Cushman Dam, and consequently has lost a larger proportion of its moisture. This 

subject will be discussed further in the 

section on Runoff. 

A comparison of the long-time record at 

Seattle, 71 years, with the shorter records 

at Cushman Dam, 25 years, and at Quilcene, 

29 years, indicates that the latter two 

records cover periods of slightly below 

normal precipitation (the period 1879-1949 

is considered normal) but that the true mean will not differ ~reatly from the mean for 

these periods. {See fig. 1.) The record 

at Seattle shows that the 13-year period 1893-1905 was wetter than normal with no year falling below the 71-year median of 

32.80 inches. The period 1908-32 (25 years) was drier than normal with only 3 years above the median. The first 15 years of the 

period of record 1879-93 had 6 years below 

median, 1 at median and 8 years above, and 

the last 15 years, 1935-49, show 7 years above and 8 below median. Thus, although there have been rather extended dry periods and wet periods, no definite trend is 

apparent. 

Runoff 

Streamflow records for the three streams 

which have been used in this report cover the following periods: 

Hamma Hamma River ...•.. Oct. 1, 1926 through 

Sept. 30, 1930. 

Duckabush River ...••... Oct. 1, 1938 through 

Sept. 30, 1948. 

Dosewallips River .•...• oct. 1, 1930 through 

Sept. 30, 1948. 

Hydrographs of mean monthly flo,•rs for the 

three streams are shown on figure 3. 

Since these recOrds.are of varying length and cover different periods an 

5 

attempt was made to determine the relationship of the runoff th~oughout the period from the earliest to the latest record to a common base. To do this, the record for 

the North Fork of the Skokomish River below 

Staircase Rapids near Hoodsport, Wash., was used. This stream drains the area south 

and west of the Hamma Hamma River, an area of 60 square miles, and records are available for the period October 1, 1924 through September 30, 1947. For purposes of compari- son this 23-year period will be considered 

normal. 

This comparison shows that during the 

period 1927-30, when records were obtained on the Harnma Harnma River, the flow in the 

North Fork of the Skokomish River was 87 

percent of normal. The mean flow in the 

Hamma Hamma River, which was 5.50 second-feet 

per square mile for these 4 years, is 

probably close to 6.3 second-feet per square mile. The mean flow in the North Fork of 

the Skokomish River during the driest 2 

months, August and September, for these 4 

years, was 86 percent of normal, but the flow 

during the driest 2 months in the period, 

1927-30, August-September 1930, was 50 percent higher than the lowest 2 months (October 

and November, 1936) in the 23-year period, 1925-47. Extreme low flows of about 0.4 

second-feet per square mile can be expected for 2-month periods on the Hamma Hamma River. 

This 4-year period included the driest year of the 23-year 11 normal" period, 1930, and one rather wet year 1927, which was fifth 

wettest in the period. 

The mean flow for the Duckabush River 

for the 10-year period of record was 96 

percent of normal; the mean flow for August and September was 93 percent normal. The 

driest year for the 10-year period was 1944, 

which was the second driest in the 11 normal" 

23-year period. Mean flow for 1930 was 20 

percent less than for 1944. The driest 

2-month period in the 10 years of record 

occurred in September and October 1942 with mean monthly flows of 0.87 and 1.09 secondfeet per square mile. The fl.ow in the North 

Fork of the Skokomish River was about 180 

percent of the extreme low during these 2 

months. It is estimated that monthly mean flows of 0.7 and 0.6 second-feet per square mile occurred in October and November 1937, on the Duckabush River. 

Streamflow records for the Dosewallips River are available for 17 years and the mean flow for this period is 107 percent of 

the flow for the 23-year period. For the 

low-water months of August and September the flow was 106 and 109 percent 6f normal. 

The driest 2-month period occurred in October 

and November 1937 for both the Dosewallips and North Fork-of the Skokomish River. The 

flow of the Dosewallips River during these 

2 months was 1.14 and 0.84 second-feet per 

square mile. 
6 

The hydrology or the area covered by these three basins is considerably more com- plex than would be expected or an area or only 244 square miles, The following tabla 

River 

Hamma Hamma River 

Duckabush River 

Dosewallips River 

84 

66 

94 

brinss out some or the apparent inconsistencies. In this table the streams are listed from south to north, 

1,1 

1,5 

1.9 

2 

or por on o as n ups on. g( Month of minimum flow. 2/ Estimated by comparison with the· 23-year record on the North Fork of 

the Skokomish River. 

It will be noted that the runoff per square mile varies considerably, varying inversely with altitude for the annual figure but 

directly with altitude for the month of 

September, which is the montl:l of lowest 

streamflow, and that the unit runoff decreases as latitude increases, This seeming inconsistency is due primarily to the effect 

of the·Olympic rain shadow in which some of 

the most remarkable variations of precipitation in the United States occur, For example, the runoff of streams on the west slope of 

Mt. Olympus indicates that the precipitation 

at high elevations exceeds 200 inches per 

year yet the mean annual precipitation at 

Sequim, only 35 miles northeast of Mt. Olympus, is· 15 inches. The prevailing winds during t.he precipitation period, November through March, are from the southwest and drop most 

of their· moisture on the west and south sides 

of the Olympic Mountains • The Hamma Hamma 

River, draining the southern part of these 

mountains, is only partially in the rain 

shadow while the Dosewallips River to the 

north is much more affected. The effect is even more pronounced further north where the 

Dungeness River, which flows north and drains 

the area north of the Dosewallips River, has a mean flow or only 1.6 second-feet per square mile for 16 years of record, It should be 

noted that during the low-water season the 

precipitation is ordinarily so low that it 

affects the streamflow only slightly and 

streamflow is primarily from ground-water 

return. Basins with the higher median altitudes produce the greater flow, For Dosewallips River the summer flow is also increased by small glacial areas at its headwaters. Although obscured by the rain shadow 

for annual figures, the effect of altitude on runoff because of snow storage and melt is 

quite apparent when the annual distribution 

of runoff is examined. (See fig. 2.) The 

Hamma Hamma River with the lowest median 

altitude has its high-water season from 

November through January with a somewhat 

lower peak in the spring. The Dosewallips River with the highest median altitude has 

its highest peak in the spring with a smaller· one in December and January. The Duckabush 

River with a median altitude lower than the 

Dosewallips River but higher than the Hamma 

Hamma River has two peaks very nearly the .same height, December showing the greatest runoff with May a close second. For all 

thr.ee streams flow falls orr rapidly from 

May to October with September showing the 

lowest flow, The set of flow duration curves shown in figure 4 also shows that the 

unit runoff is considerably higher in the 

low-water period on the streams with the 

higher median altitude, The low flows for 

the .year are or particular inte:rest. on these 

streams because or the bearing they will 

have on the amount or water to be left in the 

stream to protedt fish life, This water will 

not, or course, be available tor generat_ing 

power, 

Because of the many variables and the 

lack or recorda or streamflow in the higher portions or the three basins, estimates of 

streamflow at points remote from the gaging stations involve considerable error, Since 

.data 1prereq,uisite to a more precise analysis are rlot available, for the purpose or these 

pre,liminary estimates the streamflow at each 

site upstream from the gaging stations has 

been computed on the basis of a direct re- lation between drainage-area and discharge, The flows at all sites except l2PM12 on the 

Dosewallips River have been computed in this 

manner, For site l2PM12 the streamflow has 

been assumed to be 110 percent of the flow 

at the gage. More detailed analyses, if 

made, should be based on actual gaging or streamflow at the prospective sites, 

Since a power plant constructed on any of these three streams will, in all prob- ability, be interconnected with the Northwest 

Power Pool, and since the heaviest load for 

the pool comes in December and Janliary when 

the power from Columbia River is at its lowest point, some thought should be given to 

developing power on these streams utilizing the heavy winter runoff. Although the power available during the low-water period of 

August through October may be negligible, it seems possible that an economical project could be built to produce power primarily 

during the winter months, In the following discussion of each of'· the three streams, 

special emphasis has been placed on the 

streamflow during these months, 
-...J 

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8~~~;f~~i~~ CUSHMAN DAM, WASH. 

Elevation 790 feet 

26 years~ 1924 through 1949 

~ ~ c,; c: ~ ..: ~ ~ ! :>. o a 8 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 

HAMMA HAMMA RIVER NEAR HOODSPORT 

October I, 1924 to September 30. 1947 

Estimated by comparison of the record for Hamma Hammo River, 

1927-1930, with thot of North Fork Skokomish River, 1925-1947 

• :.o c,; c:..o..: s_:>.! :>.o 8 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 

BRINNON, WASH. 

Elevation 80 feet 

8 years,l899 through L906. 

• ~ c,; c:~..: 115._:>.~ >-oa 8 ~ ~ ~ ~ ~ ~ ~ , ~ ~ ~ 

OUCKABUSH RIVER NEAR BRINNON 

July I, 1938 to September 30, 1948 

~ ~ u c:·~ ~ ~ ~! ~ o a 

0 z ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 

QUILCENE, WASH. 

Elevation 30 feet 

29 years,l921 through 1949 

~ > u c: ~ ..: ~ :>. ! ~ ~ a 8~~~~:i~:i~~c¥t! 

OOSEWALLIPS RIVER NEAR BRINNON 

October I, 1931 to September 30, 1948 

Figure ~.-Annual distribution of precipitation at Cushman Dam, Brinnon, and Quilcene, 

and Runoff of the Hamma Hamma, Duckabush, and Dosew~llips Rivers. 
8 

A detailed discussion of the water 

supply in each of the three basins follows. 

Hamma Hamma River 

The Hamma Hamma River is the southernmost river, has the lowest median altitude 

(2,900 feet), is least affected by the 

Olympic rain shadow, has the highest mean 

unit flow, and has the lowest unit flow during low-water of the three streams under discussion. An examination of figure 2 will 

show that although there are two peaks in the 

monthly hydrograph the peak in December is 

considerably higher. The streamflow record 

covers only 4 years, 1927-30, a period which 

was considerably drier than normal and ver~ 

much drier for the month of December. The 

mean monthly runoff at the gage for this 

montp for the 4 years was 8.65 second-feet 

per square mile. Using the North Fork of 

the Skokomish River as a base and comparing the December flow for the period 1927-30 

with the same flow for the period 1924-47, 

it is apparent that the 1927-30 flow in · December was only about 64 percent of normal 

and that the mean flow on the Hamma Hamma 

River in December is very likely near 13.5 

second-feet per square mile. 

The period of record covers one of the 

two periods of lowest flow in the last 25 

years. The two years 1929 and 1930 were 

both very dry. The lowest flow recorded in 

23 years of record for the North Fork of 

the Skokomish River below Staircase Rapids occurred in September 1930, when the flow 

at the gage dropped to 16 second-feet, or 

0.27 second-feet per square mile. During the 

same month the low flow on the Hamma Hamma 

River was 37 second-feet, or 0,44 secondfeet per square mile. However, in September 1929 the reverse relationship prevailed when 

the North Fork of the Skokomish River had a 

low of 47 second-feet or 0.78 second-feet per 

square mile and the Hamma Hamma River had 23 

second-feet or 0.27 second-feet per square mile. The mean of the five annual minimum . flows recorded for the Hamma Hamma River is 

42 second-feet, or exactly one-half seoond-foot 

per square mile, Based on. the 23-year record 

of the North Fork of the Skokomish River, the 

mean low annual flow of the Hamma Hamma River 

is probably about 54 second-feet, or 0.64 

second-feet per square mile while the median 

for 23 year~ is 50 second-feet, or 0.60 

second-feet per square mile. This latter· 

amount is probably close to the flow which 

will be· required for fish life. 

Daily flow duration curves for the 4 

years of record are shown on figure 4, The 

following data on streamflow were taken 

from these curves. 

Flow duration on the Hamma Hamma River 

(Flow in sec.-ft. per sq. mi.) 

Oct. 1, 1926 -

0 ----------- . 0 

or the above 4'years, 1927 was a wet· 

year and 1930 was a very dry year but none 

of the four could be classed as an average 

year which would fall somewhere between 

1927 and 1928. 

The table below shows the estimated 

flows at power site l2PM9, where the 

drainage area is 76 square miles, for dry, 

average, and wet years. Since the period of 

record did not include what could be called 

an average year a synthetic average year has 

been assumed when the streamflow was less 

than in 1927 but more than in 1928. 

Dry 

Average 

Wet 

The Hamma Hamma River has its highwater period during the winter season and 

December is the month.of greatest runoff. 

Since this is the time of year when the 

demand for power is greatest and when the 

flow of the Columbia River is low, some consideration should be given to the possibility of developing power in the winter even though the power available in August and September is negligible. 

The following table shows the mean 

monthly flo"'s for the winter periods from 

1927 to 1930 and the corresponding winter 

flows from 1925 to 1947 estimated on the 

basis of the record for the North Fork of 

the Skokomish River. 

Flow on the Hamma Hamma River 

during the winter months 1927-30 

(In sec.-ft. per sq. mi.} 

Mean monthly Probable ·Minimum 

1927-30 long time monthly mean Minimum daily flow 

Month Flow mean y Month Flow J.Ja.te 

Nov. 9.01 9.7 Nov. 1929 0.35 Nov. 19-23, 1929 

Dec. 8.65 13.5 Dec. 1927 5.47 Dec. 1-3, 1929 

Jan. 7.69 9.7 Jan. 1930 2.13 Jan. 25, 1930 

Feb. 7.90 9.4 Feb. 1929 1.04 Feb. 20, 1929 

Mar. 5.38 5.9 Mar. 1930 4.14 Mar. 1-4, 1929 

1/ Based on comparison with flo'~~>r of the North Fork of the 

Skokomish River below Staircase Rapids. 

.tt'.lOW 

0.31 

.32 

.65 

.88 

1.29 
\0 

.. 

~ •5· .• I 

I! 

a !O 

i 

10 

Mean discharge 4 full ,..... 5.50 ...... teet per ..... mie 

Drainage area at gaging slalian 84 ..... •ilea 

20 20 

.!! 

·: 15 I I I I I I I I I I I I 115 

i; 

:I 

ll 

&10 I I • I • I • I I I • I II • I I I • I .1 I. • ItO 

! 

] 

0 

DUCKAEIJSH RIVER NEAR ~~..art . Mean discharge 10 fuH ,_. !:.58 .._.. feet per ..... Illite 

Drainage area at gaging slalian 66 squan1 miles 

5 

0 

,!!15 fi 

·e 

!? 

i-10 I I I I • I I Ill I I I I • I I I I I I I I I I • I I ;;I 110 

& 

Mean disc:hargl 18 full ,..... 4.74 -=--1 ... per ..... llllile 

Dn*lage area at gaging slalla 94 squan1 .._ 

Figure 3.- Monthly hydrogra.phs :for the Hamma. Hamma.. Duckabush. and Dosewal11ps R1 vera. 

5 
10 

. Since this 4-year period included a period O"f very low streamflow (1929-:50), a record for the period or comparison (1925-47) 

would show extreme low flows very nearly the same as for the shorter period. Slightly 

lower flows might have existed in 1936-37. 

Duckabush River 

The hydrograph or mean monthly runoff 

shows that~ similar to the Hamma Hamma River 1 

the Duckabush River has two periods of high runoff and one of very low runoff, (See fig. 2~ 

However, because of the higher median altitude of the drainage basin, the winter peak is lower and the spring peak higher than for 

the Harnma Hamma River. The two peaks ·for 

the Duckabush River are of nearly equal height. It should also be noted that although the mean annual unit runoff is lower on the 

Duckabush River than on the Hamma Hamma River, 

5.5 against 6.3 second-feet per square mile, 

the unit runoff in September, which is the 

lowest month~ is higher on the ·nuckabush River~ 1.5 against l.l·second-feet per square mile. These figures for the Hamma Hamma 

River are somewhat higher than the mean for 

the 4 years of record 1 but are based on the 

comparison of these 4 years with the 23-year . record on the North Fork of the Skokomish 

River. 

• Flow duration curves for a dry, average, and wet year are shown on figure 4. The 

following data on streamflow were taken from 

that figure. 

Flow duration on the Duckabush River 

(Flow in sec.,ft. per sq. mi.) 

mean 

3.89 

5.82 

6.78 

The above figures aPe fairly representa- tive of the flows to be expected on the 

stream except that it is probable that for a dry year Q 95 and Q 90 are somewhat high. Comparison of the record with that of the 

North Fork of the Skokomish River indicates 

that Q 95 and Q 90 were 0.6 and 0.7 secondfeet per square mile-respectively in 1936-37. 

For the period of record, the mean of the 

seasonal ·low flows is 0.89 and the median 

0.77 second-feet per square mile. 

The table below has been developed from the flow duration table by applying 

the appropriate drainage-basin area. 

Streamflow on the Duckabush River 

In sec.-ft. 

l1:ower site N). See plate 1 Year Q 95 Q 90 

12PMl3 {1944 40 

Drainage area,. 1945 44 

47 sq. mi. 1946 48 

12PM14 r944 46 

Drainage· area, 1945 51 

54 sq. mi. 1946 56 

l2PM15 f944 56 

Drainage area, 1945 62 

66 sq. mi. 1946 68 

Mean monthly flow and minimum monthly and minimum daily flow for the winter period 

47 

63 

78 

55 

72 

go 

67 

88 

110 

Mean flow Reserve 

Q 50 Q mean 10 years for fish 

137 183 

203 274 260 36 

249 319 

157 210 

233 314 299 42 

286 366 

192 257 

284 384 365 51 

349 447 

are shown in the table below. 
IT 

HAMMA HAMMA RIVER It DRAINAGE AREA AT GAGE 

84 SQUARE MILES 

Ill EACH FULL YEAR OF RECORD 

14 SECOND FEET PER SQUARE MILE 

\ YEAR Ote Oeo Oao QM£AN 

13 1927 1.37 1.90 5.41 7.98 

\1 \ 1928 0.56 0.75 4.0S 5.58 

1929 0.47 0.75 3.16 4.48 12 

\\\ \ 1930 0.32 0.36 1.88 3.95 

1927-1930 5.50 II 

~ 1929~ \ \ i: \ \ \ 0: 

le 

t- 8 

~\ ~ 

\\ \ 1&1 

1&1 "" 1&. I 7 \ '\_ \ "' K'27 '-.... 6 

~"" ""'"" ~ 

5 ...... "' \ "' ~'\ ~ 

4 ~ 

~ \ ~ " 3 ~ 

~ "" "-.._ \ ""' 2 

~ ""' ""'- I 

.....___ ' 

~ ~ ---'---- -~ 0 

0 10 20 30 40 so 60 70 80 90 10C 

PERCENT OF TIME 

14 14 DOSEWALLPS RIVER _\ \ DUCKABUSH RIVER I DRAINAGE AREA AT GAGE DRAINAGE AREA AT GAGE 13 

\ 66 SQUARE MILES 13 94 SQUARE MILES 

DRY, AVERAGE, AND WET YEARS \ DRY, AVERAGE, AND WET YEARS 

12 \\ 12 

SECOND FEET PER SQUARE MILE SECOND FEET PER SQUARE MILE 

II YEAR Q" Q90 QIIO QMEAN \ YEAR Qtlll Q90 QIIO a_ 

\ 1944 0.85 1.01 2.91 3.89 II 1944 1.26 1.40 2.45 3.10 

1\ 1\ 1945 0.94 1.33 4.31 5.82 \ 1932 1.36 1.54 4.20 5-03 

10 1946 1.03 1.67 5.29 6.78 10 1935 1.70 2.30 5.20 6.23 \ \ \ 1939-1948 5.58 1931-1948 4.78 

9 9 

~ \ 1\ 1&1 

~ .J i 1\ i 

~8 1&1 8 \ \ \ I \ \ ""' ~ [\ ~ 7 \ ~ 7 

1&1 

Q 

t-

~ 6 1\ 1\ t-

~6 ~ ~ 

\ ~ \ v Q \ I r-.... s5 I~ ~ " '(""'"1935 5 

"\ e4~ 1\\ "" <'e44 ~ ~ ........._ 4 

19~ ~ 4 

""' ""' ...... 

"" ~~ "" 3 3 "'-.. 

~ " ..... 

~ .......... ..__ '-... ~ ~ ~~ 2 

---- ~ ~ 

~ 2 

I ~ ~ I --~ ~ 

00 10 20 30 40 50 60 70 80 90 100 00 10 20 30 40 so 60 70 80 90 

PERCENT OF TIME PERCENT OF TIME 

Figure 4.-- Daily flow duration curves for the Hamma Hamma, Duckabush, and Dosewallips Rivers. 

11 

IOC 
12 

Daily flow duration curves were drawn 

for the 90-day period from December 1 through February 28 for dry, average, and wet years 

and the following table was prepared showing the mean flow and the flow available 95, 90, 

and 50 percent of tbe time. 

Winter daily flow duration on the Duckabush River 

December 1 through Februar 28 (90 days) 

In sec.-ft • 

. Power sit~ No. 

12PM13 

Drainage area 47 sq. mi. 

12PM14 

Drainage area 54 sq. mi. 

Examination of the hydrograph of mean monthly runoff for the Dosewallips River shows that~ as for the other two streams, there are two p~riods of high runoff, but on this 

stream the spring peak is the highest. Be- cause of the higher median altitude for the 

basin more winter precipitation falls as snow. This higher altitude together with some small areas of glaciers, probably accounts 

for the somewhat higher unit flows in the 

low-water season. This basin is affected more than either the Harnma Hamma or Duckabush 

Rivers by the Olympic rain shadow and its 

annual unit runoff is consequently the least 

of the three. 

Flow duration curves for a dry, a wet, 

and an average year are shown on figure 4 

from which the following data on streamflow were taken. 

The mean low annual flow at the gage ~or 

the 18·-year period is 97 second-feet and the 

median 98 second-feet or 1.04 and 1.05 secondfeet per square mile respectively. These 

annual low flows varied from 65 second-feet 

(or 0.70 second-feet per square mile) in 1937 

to 121 second-feet (or 1.30 second-feet per 

square mile) in 1938. It has been assumed 

for this report that 100 second-feet will be 

released.at all times at storage site 12PM12 

and that 75 and 80 second-feet respectively will be released over the dam or through the 

fishways at sites 12PM10 and 12PM11 when 

available. 

The following table for streamflow at 

the three power sites has been developed from the flow-duration table by applying the 

drainage-basin area for sites 12PM10 and 

12PM11. Since site 12PM12 is downstream from 

the gaging station the unit runoff is estimated to be less than at the gage, and 

streamflow has been estimated to be 110 

percent of the flow there although the drainage area is 119 percent of the area above 

the gaging station or 111 sq~re miles. 

Streamflow on the Dosewallips River 

(In sec.-ft.) 

rower site N)• Mean flow Reserve 

See plate 1 Year Q 95 Q 90 Q '50 Q. mean 18 years for fish 

12PM10 1944 88 98 172 217 

Drainage area, 1932 95 108 294 352 335 75 

70 sq. mi. 1935 119 161 364 -436 

' 12PM11· f944 1~ T07 f87 237 

Drainage area, l~932 118 321 385 366 80 

76.5 sq. mi. 1935 130 176 398 477 

12PM12 r~~ 130 144 252 2113 

Drainage area, 932 140 158 431 516 491 100 

111 sq. mi. 935 175 236 534 639 

Gaging Sta. 

r~ 1U:S 1~1 229 

Drainage area, 932 127 144 392 ~:- 446 --- 93.3 sq. mi. 935 159 215 485 581 
Winter flows are not proportionately as high on the Dosewallips River as on Hamma Hamma and Duckabush Rivers, but the spring 

peak is somewhat higher. Nevertheless the 

amount pf power available at this time of 

November 

December 

January 

FeQruary 

March 

4.27 Nov. 1936 

5.78 Dec. 1930 

5.28 Jan. 1937 

4.30 Feb. 1937 

3. 78 Mar. 1942 

The 1945-46 water year had an average winter flow. The mean monthly and minimum 

daily flows at the gaging station and at the 

combined high demand and low Columbia River 

flow is worth considering. The mean monthly, minimum monthly, and minimum daily flows for 

the five winter months are tabulated below. 

0.84 

1.81 

1.13 

1.18 

1.97 

ow 

three power sites are shown in the following table. 

Flow on the Dosewallips River 

during winter months 1945-46 

In second-feet 

Flow duration during the 3-month period from December 1 to February 28 is .shown on the table below for a dry year (1944), an average year (1946), and a wet year {1945). The flows at the three sites have been computed from the flow at the gage on a straight line drainage-basin-area ratio for sites 

12fM10 and 12PM11. For site 12PM12 the flow 

has been computed as 110 percent of the flow 

at the gage. 

Winter daily flow duration on the Dosewall1ps River 

December 1 through February 28 (90 days) In second-feet 

WATER UTILIZATION PLAN 

Except for a few small farms near Hood 

Canal, all three basins are now used only for recreational purposes. No water resources development has taken place on any of the 

three streams except for a fish hatchery,now abandoned, which was once operated on the 

Duckabush River by the u. s. Fish and Wildli·fe Service. 

Salmon spawn in all three streams and 

game fish are comparatively plentiful in the 

three main streams and their tributaries. 

There is little land to be reclaimed or benefited by irrigation or flood control 

projects, and any future development of the 

water resources of any of the three streams 

will probably involve hydro-electric power generation. 
14 

Any development which would obstruct the 

channel ot any ot the•streams will have to 

include adequate facilities tor passinl fish 

lite over or around the obstruction, It is 

probable that permission to develop power on any ot these streams will include a stipula- tion that a minimum amount ot water must be 

permitted to flow in the natural channel at 

all times, In the power estimatee included 

in this report this min~ amount"hae been 

asiumed to be the median ot the ·seasonal low 

flows tor the period ot streamflow record, 

Since all the power sites discussed involve 

diversion through artificial conduits, this 

amount ot water must be deducted from the 

total flow to give the flow available for 

power, The proposed developments on each 

stream are discussed in detail as follows, 

Hamma Hamma River 

Power site 12PM9 

Location.--At mile 3.5, in sec. 16, T. 24 N., 

R. 3 W. 

Drainage area.--76 square miles. 

~.--Storage dam with tunnel to power house at tidewater. 

Altitude and head.--The altitude of the 

water surface at the dam site is approximately 400 feet. A dam 140 feet high will give a maximum flow line at altitude 540 feet, ·and 

when regulated a mean water-surface altitude 

of 515 f.eet. Loss of head in the tunnel is 

estimated at 10 feet· leaving a mean gross head 

from top of penstock to tailrace of plant of 

505 feet when regulated, and 530 feet with 

the reservoir full. 

Storage or ponda~e.--18,000 acre-feet of 

usable storage wit a dam 140 feet high. (See figure 5 and capacity table in section 

entitled Stream regulation.) . 

Duckabush River 

Power site 12PM13 

Location.--Point of dive~sion at mile 10.5, · lt miles upstream from Cliff Creek and one- half mile downstream from the east boundary of the Olympic National Park. The site is in 

the Olympic National Forest. 

Drainage area.--47 square miles. 

~.--Diversion and conduit (probably tunnel). A low dam for diversion purposes only, combined with a tunnel 1.5 miles long to a power house located at the forebay of power site 12PM14 (see below). 

Altitude and head.--The forebay at the 

point of diversion would be at approximate altitude 1,125 feet and the tailrace (fore- bay of site 12PM14) would be at approximate altitude 720, giving an over-al1 difference 

in altitude of 405 feet. Loss of head in 

the tunnel is estimated at 5 feet leaving a ~ross head of 400 fee~. 

Storage or pondage.--None. 

Power site 12PM14 

·Looation.·-Point ot divertion at mile 8,9, 

just downstream trom Clift Creek. The s~te 

is in the Olrmpic National Forest, 

Drainage area.--54 square miles, 

~.-·Diversion.and conduit (probably tuMi"I). A low diversion dam combined with a tunnel disoha~ging into a power houee at 

the upper end ot the reservoir created by a dam at site l2PM15, This latter site 

offers two alternative d4m sites and, of 

course, many possible heishts of dam. Two 

possible schemes of development will be dis· 

cussed here with maximum pool altitudes of 

340 and 500 feet. The former would require a 2.4-mile tunnel at site 12PM14, and the 

latter would require. one only 1.5 miles 'long. 

Altitude and head.--The forebay of this 

site wouid be at approximate altitude 720 

feet (the tailrace altitude of site 12PM13}, and the tailrace of the power plant would be 

either at. altitude 500 feet or 340 feet, 

giving differences in altitude of 220 or 380 feet. Loss of head in the tunnel is. es- timated at 5 feet for the 1.5-mile tunnel 

and 10 feet for the 2.4-mile tunnel leaving a gross head o.f 215 or 370 feet. 

Storage or pondage.--None. 

Remarks.--If site l2PM15 should be built 

to a reservoir elevation of 500 feet, it is 

possible· that the most economical plan would 

combine sites 12PM13 and 12PM14· into one unit with a tunnel 3.0 miles long and a gross head of 615 feet. Such a plan wc>uld lose the 

power from the water entering the stream between mile 8.9 and 10.5 but would require only one power house. 

Power site 12PM15 

Location.--Two alternative dam sites. If a- low dam is built to provide usable storage of 14,000 acre-feet or less, the site at 

mile 4.3 (12PM15B) in sec. 12, T. 25 N., R. 3 W. 

would probably be more desirable. If a high- er dam is required providing usable storage 

up to 60,000 acre-feet, then the dam site at 

mile 4.8 (12PMl5A) in sec. 1, T. 25 N., 

R. 3 W., would probably be more satisfactory. A tunnel 4.2 miles long for 12PM15A and 3.7 

miles long for 12PM15B would connect the dam 

with the power house located at sea level in sec. 16 or 21, T. 25 N., R. 2 w. 

Drainage area.--66 square miles. 

~.--Storage dam with tunnel and power house at tidewater. 

Altitude and head.--The river surface at 

the dam site of l2PM15A is at altitude 253 

feet and at 12PM15B, 207 feet. With a dam 

247 feet high and usable storage of 60,000 

acre-feet, the mean water-surface altitude 

in the reservoir for site 12PM15A would be 

440 feet. With a dam 133 feet high and 

usable storage of 14,000 acre-feet, the mean water-surface altitude of the reservoir for 

site 12PM15B would be 320 feet. The loss of 

head in either tunnel is estimated to be 20 

feet leaving a mean gross head of 420 feet 

for 12PM15A and 300 feet for 12PM15B. 
Storage or pondage.--l2PM15A: 60,000 acre- feet of usable storage with a dam 247 feet 

high. l2PM15B: 14,000 acre-feet of usable 

storage with a dam 133 feet high. (See 

figure 5, and capacity table in section 

entitled Stream regulation.) 

Dosewallips River 

Power site l2PM10 

Location.--Point of diversion at mile 15 

at upstream side of Upper Jumpoff and 1 mile 

inside the Olympic National Park. 

Drainage area.--70 square miles. 

~.--Diversion dam and tunnel 2.4 miles 

long to power house at forebay of site 

12PM11. . 

Altitude and head.--Foreba¥ elevation 

1,526, tailrace elevation, 780. Over-all 

head, forebay at dam t9 tailrace, 740 feet. 

The loss of head in the tunnel is estimated 

to be 15 feet leaving a gross head estimated 

to be 725 feet. 

Stora~e or pondage.--None. 

Remarks.--Since this site is within the 

Olympic National Park and would divert water 

around a scenic falls, its development will 

be opposed. Approval might be obtained with 

the stipulation that water would be diverted 

only in the winter time. 

Power site l2PMll 

Location.--Point of diversion at mile 12.6, l~ miles east of the Olympic National Park 

boundary and in the Olympic National Forest. 

Drainage area.-.. 76 square miles. 

~~.--Diversion dam and tunnel 4.1 miles 

long-to a power house at mile 8.5, at upper end of reservoir s~te l2PM12. 

Altitude and head.--Forebay elevation 780 

feet, tailrace elevation 400 feet. Overall head, forebay of dam to t•i1race, 380 

feet. The loss of head in the tunnel is 

estimated at 20 feet leaving a gross head of 

360 feet. 

Storage or pondage.--None. 

Remarks.--If site l2PM10 is not developed, the point of diversion for this site could 

very·well be moved upstream to the east 

boundary of the Olympic National P~rk where 

the water-surface altitude is l,o4o feet. 

Power site 12PM12 

Location.--Dam site at mile 3.1, in sec. 28, 

T. 26 N., R. 2 W. Power house in sec. 35, 

T. 26 N., R. 2 w., on the shore of ·Hood 

Canal. 

Drainage area.--111 square miles. 

Type.--Storage dam at Rocky Brook dam site 

ana-pressure tunnel 2.1 miles long to power house at sea level. 

15 

Altitude and head.--The altitude of the 

river surface at the dam site is 98 feet. A 

dam 300 feet high will provide 100,000 acre- feet of usable storage with a mean altitude 

of the pool surface of 340 feet. The estimated loss in the 2.1-mile tunnel is 10 feet, 

leaving an average gross head of 330 feet~ 

Storage.--100,000 acre-feet of usable 

storage with 300-foot dam. (See figure 5 

and capacity table in section entitled 

Stream regulation). 

The foregoing scheme of development is 

by no means the only way to develop the 

water-power resources of the three streams 

but it is illustrative of the magnitude of 

these resources. 

It will be noted on the location map (pl. 1) that the Dosewallips and Duckabush 

Rivers come quite close to each other nea~ 

the west boundary of the Olympic National 

Park. The water-surface altitude of the 

Duckabush River at the park boundary is 

1,140 feet, while on the Dosewallips River 

at the park boundary, it is 1,050 feet. A 

tunnel 2.5 miles long could divert the 

Duckabush River at power site 12PM13, where 

the drainage area is 47 square miles, into 

the Dosewallips River. The Dosewallips River 

could be diverted into the Duckabush River in 

the same·general area by a slightly longer 

tunnel or tunnel and conduit. The power of 

both streams could therefore be developed 

through one. set of power houses. 

Diversion could also be made at power 

site 12PM15A (mile 4.8) on the Duckabush 

River through a tunnel 2.7 miles long to a point in the reservoir site for power site 

l2PM12 on the Dosewallips River. Stream 

altitude at power site l2PM15A on the Duckabush River is 253 feet.· The reservoir on the Dosewallips River can be raised to 400 

feet. If this reservoir is developed to its 

full height, diversion on the Duckabush River 

would have to be made near mile 7. Such a development would involve only one reservoir on the two streams thus reducing the area·. of 

salmon spawning grounds which would be flooded. Diversion between the Hamma Hamma and 

Duckabush Rivers, although possible, does 

not appear particularly attractive. 

STREAM REGULATION 

The flow of all three streams drops 

to a very low stage during August and 

September, as indicated by figure 2. If.any appreciable amount of firm power is to be 

developed, it will be necessary to provide reservoirs to impound the high-water flow and 

:release it during the low-water period. There is such a reservoir site on each stream 

but in each case it is near the mouth. On 

the Hamma Hamma River the only power site is near the mouth of the stream. All the 

available power can be firmed to some extent on each, but on the other two streams there are power sites upstream from the reservoir 

sites which must be operated as run-of-river 

plants with little or no power available 

during the low-water period. A detailed 

discussion of regulation in each of the three 

basins follows. 
16 

Hamma Hamma River 

The flow of the Hamma Hamma River·oan 

be partially regulated by a dam'at. power site l2PM9, the capacity table tor which is 

shown below. 

Capacity table at power site l2PM9 on the Hamma Hamma River 

(Dam site at mile 3.5 in sec. 16, 

T. 24 N ._,_ R. _2 W. ) 

Attit~~e Area . Capacity feet (acres) (acre-feet) 

400 0 0 

420 6.4 64 

440 25.7 385 

460 69.0 1,330 

480 119 3,210 

500 184 6,240 

520 324 11,320 

540 439_ 18,950 

B¥ regulating between altitudes 45~and 

540, 18,000 acre-feet of usable storage can be made available. This storage could have 

been used to increase low-water flows so that 

for the period of record, 1927-30, the mini- mum flow would have been 120 second-feet in 

the fall of 1929. In an average year the 

minimum flow would have been 120 second-feet 

in the fall of 1929. In an average year the 

minimum flow would be about 200 to 250 secondfeet. The availabiiity of 18,000 acre-feet 

of storage during the 4-year period of re_cord, 

1927-30, would have resulted in the following flows: 

Q 95-----140 sec.-ft. I Q 50-----400 sec.-ft. 

Q 90-----167 sec.-ft. Q mean---420 sec.-ft. 

Because of the importance of winter 

power, a daily differential mass curve was plotted for the period November 1, 1926, 

through February 28, 1927. This period approximates a normal winter. By utilizing 18,000 acre-feet of storage, a flow of 614 

second-feet would have been available during ~he period under consideration with some additional water being lost over spillway on December 3, 4, and January 12-16. Under this 

assumed operation the reservoir was empty November 11 and full on December 3 and 4 

and from January 12 through January 16. On 

February 28, 4,500 acre-feet of water re- mained in the reservoir. 

Duckabush River 

There are two possible storage sites on the Duck~bush River. These are alternate 

sites and development at one would preclude development of the other. The first designa- ted as power site 12PM15A, is at mile 4.8 

in sec. 1, T. 25 N., R. 3 w. The capacity table for the reservoir created by a dam at . 

this point is shown below, 

Capaci~y table at power site l2PMl5A on the Duckabush~iver 

(Dam site at mile 4.8 in sec. l, 

T • 25 N • • R • 3 W; ) 

Altit~e Area Capacity 

(feet (acres) (acre-feet1 

253 0 0 

260 4 14 

280 35 414 

300 109 1,850 

320 168 4,610 

340 237 8,650 

360 285 13,870 

380 336 20,070 

40Q 379 27,230 

420 416 35,190 

440 437 43,730 

460 462 52,730 

480 499 62,330 

500 539 72,710 

By regulating between elevations 360 

and 500, approximately 60,000 acre-feet of 

storage is available, enough to give almost 

complete regulation on a yearly·basis •. A 

differential mass curve of monthly flows was prepared for the period October 1938 through September 1948 when the mean flow for the 

10-year period was 365 second-feet. The_ 

period of lowest flow occurred in the 28 

months from July 1942 through October 1944. 

A regulated flow of 305 second-feet could 

have been maintained for the first 13 months 

and 290 second-feet for the last 15 months. 

In an average year a regulated flow of 365 

second-feet could be maintained 100 percent ·of the time, and in a wet year 420 secondfeet would be obtainable. 

The other site, designated as power site 

12PM15B, is known as 'the Interrorem dam site 

and is located at mile 4 .• 3, in sec. 12, 

T •· 25 N., R. 3 W. The capacity table for 

the reservoir created by a dam at this site 

i's shown below. 

Capacity table at power site l2PM15B, 

Interrorem dam site, on the Duckabush River 

(Dam site at mile 4.3, in sec. 12, 

T. 25 N., R. 3 W.) 

Altitude Area Capacity 

_{_feet1 (acres) J.acre-ft.1 

210 0 0 

220 2 10 

240 6 90 

260 26 410 

280 74 1,410 

300 181 3,960 

320 262 8,390 

340 339 14,400 
..... 

-..:J 

Area in acres 

540 400 350 300 250 200 150 100 50 0 540 Area in acres -.............. 

~ ~ ~ 400 1000 800 600 400 200 0400 

520 ............. -~ --~ ~---~ - ..- 520 ~'-... > < 350 ~ . 350 

C> l.--" v ~ 

500 ...... 500 :::,. 

~h / ~ 

~ 300 !'-... 300 i v 

:;48o ~ 480 ~ IC".lmft ~ / ~ Area r 

/ " CD ~y ~ :;250 250 CD 

~ v 

""' 't:J 

~460 / v I " 460 

!2oo r-.... 200 I .......... <i HAMMA HAMMA RIVER ~ ~ DOSEWALUPS RIVER 

440 440 ROCKY BROOK RESERVOIR SITE ~ .... I 

420 

400Q 2 4 

340 

320 

310 

.e ~280 CD 

~260 

<i 

240 

220 

2000 2 

Dam site at mile 3.5 \ 150 

In sec. IS, t 24 N.,R. 3 W. Dam site at mile 3.1 

Power site index number 12PM9 420 ln·se,c. 28, T.26 N., R. 2.W. 

' 100 Power site index number 12PM12 

6 8 10 12 14 16 181~ 500 20 40 60 80 

Capacity in thousands of acre-feet Capacity in thousands of acre-feet 

Area in acres Area in ocres 600 400 300 

250 200 150 ~ 500 

320 450 

310 

~ 

J!40Q 

280 .e 

~ DUCKABUSH RIVER 

260 ~350 

INTERROREM RESERVOIR SITE 

Dam site at mile 4.3 DUCKABUSH RIVER 

In sec. 12. T. 25 N., R. 3 W. 300 Dam site at mile 4.8 

Power site index number 12PMI5B In sec. I, T. 25 N., R. 3 W. 

Power site index number 12 PM 15A 

4 6 8· 10 12 14 i€00 2500 

Capacity in thousands of acre-feet 10 

Figure 5.- Reservoir area and capacity curves for sites on the Hamma Hamma, Duckabush, 

and Dosewallips Rivers. 

\ 150 

100 

100 12050 

200 ~ 

450 

350 

300 

70 
18 

By regulating between elevations 260 and 

'40, 14,.000 acre-feet of storage is available, 

This is not suffioi&nt to control the stream 

but does increase the low-water flows. Computations on the differential mass curve indicate that this storage would have been drawn 

upon for 15 periods between October 1, 19'8 

and September ,o, 1948. These periods varied 

from 2 to 5 months and totaled 56 months .or 47 percent of the time. Low flow for the 

period was during a 3-month period in the summer and fall of 1942 when only 153 secondfeet could have been maintained. The flow 

would have been less than 200 second-feet 

for 17 months, and the mean flow during the 

56 months of regulation would have been 252 

second-feet. A very considerable part of the 

flow of the stream would have been lost over the spillway with only 14,000 acre-feet of 

storage. The flow duration for regulated flow.would have been as follows. 

Q 95 Q 90 Q 50 Q mean 

12PM15A 290 290 365 372 

12PM15B 158 195 339 365 

Because of the special importance of 

winter flows, a differential mass curve of 

daily flows was prepared for the period November 1, 1945, through February 28, 1946. 

This period is fairly representative of an average winter, and 14,000 acre-feet of 

storage was found to be sufficient to regu- late the flow during this period. The 

reservoir did not start to fill until 

November 13, but from then until January 5 a flow of 586 second-feet could have been 

maintained with the reservoir full on the 

latter date. From January 6 through February 22, a flow of 431 second-feet was available 

with the reservoir empty on .the latter date. 

For the rest of February, flows in excess of 500 second-feet could have been maintained 

with the reservoir filling. 

Dosewallips River 

As with both the Hamma Hamma and the 

Duckabush Rivers no storage sites exist in 

the headwaters of the Dosewallips River and no regulation is possible at power sites 

12PM10 and 12PM11. Plants at these sites 

will operate as run-of-river plants and will 

develop ·little if any power during the low~ 

water season in August and September. Tne 

small glacial areas at the headwaters act as natural storage reservoirs but do not re- lease enough water in the low-water periods 

to be of any practical value since all this 

flow will probably be required for fish 

preservation. 

Site 12PM12 includes a reservoir site 

which will regulate the flow through the 

lowest 400 feet of head on the stream. A 

capacity table for this· site follows. 

Capacity table at power site 12PM12, 

Rooky Brook reservoir site, on the Dosewallips River 

(Dam site at mile 3.1 in sec. 28, 

T. 26 N,, R. 2 W.) 

Altitu1e Area: Capacity 

feet {acres) {acre-feet) 

98 0 0 

120 8 88 

140 34 508 

l60 93 1,780 

180 150 4,210 

200 250 8,210 

220 314 13,850 

240 368 20,670 

260 406 28,410 

280 458 37,050 

300 525 46,880 

320 603 58,160 

340 675 70,940 

360 752 85,210 

380 838 101,110 

400 950 118,990 

By regulating the top 160 feet of the 

reservoir 100,000 acre-feet of usable 

storage is available with a mean watersurface elevation of 340 feet. 

The differential mass curve for the 

period October 1930 to September 1948 shows 

that with 100,000 acre-feet of usable storage, a regulated flow of 400 second-feet could 

have been maintained 100 percent of the 

time. The minimum flow would have occurred 

from August 1936 through April 1944. The 

flows available under these conditions would 

have varied from 400 second-feet to 645 

second-feet, with a flow in an average year about the same as the mean flow for the 

period, 491 second-feet. In a wet year such as 1935, the average flow would have bee'n 

590 second-feet. The available flow for 

power generation would be reduced 100 secondfeet for fish preservation, leaving 300 

second-feet in a minimum year, 391 secondfeet in an average year, and 490 second-feet 

in a wet year. 

A dam 142 feet high with a flow line at 

altitude 240 feet would provide 15,000 acre- feet of storage between altitudes 188 feet 

and 240 feet. The mean wate~surface 

altitude, while regulated through thi& range, would be 218 feet. This amount of storage will not completely regulate the flow of the 

stream and considerable water will be lost over the spillway during high water. It 

will increase the low flow considerably, however, and is sufficient to completely regulate the flow during the winter months of an average year such as 1946. 
Storage of 15,000 acre-feet at Rocky Brook dam site would 'increase the low-water 

flow to about 200 second-feet in a dry year and to 320 second-feet in an average year. 

A differential mass curve.of daily 

flows was plotted for the period November 1, 

1945 through February 28, 1946, which period approximates a normal winter. By utilizing 15,000 acre-feet of storage the following flows could have been maintained during this 

period. The reservoir would have started to 

fill on November 13 and from then until the 

end of February a flow of 485 second-feet 

could have been maintained. With 100 secondfeet reserved for fish preservation, 385 

second-feet would have been available con- tinuously for power development. 

The flow duration for regulated flow 

would have been as follows. 

WATER POWER 

Any power plants constructed on these 

streams will very likely be interconnected 

with the Northwest Power Pool. The largest source of power in this pool is the Columbia 

River where the available storage is only a small fraction of that needed to completely regulate the flow and,where both minimum 

flow and minimum power production come in 

January or February. Since peak demand in 

the Pacific Northwest comes in December or January, any generating capacity on the 

smaller western washington streams which is 

firm for the 90-da¥ period from December 1 

through February 28, can be used to firm up the Columbia River capacity. For this reason power estimates in the following pages have been shown in two ways, 

The first is the conventional basis 

which gives power estimates based on the mean flow and the flow available 95, 90, and 50 

percent of the time. The ·second shows the 

power available during the 90-day period December-February based on the above-mentioned flow conditions. 

19 

In the. following pages all water-power estimates have been computed from the 

formula: P • 0.068 Q H 

where P • power in kilowatts at low 

side of power house transformer. 

Q • flow of water through the 

turbine in second-feet. 

H • gross head, the difference in 

altitude between the top of 

the penstock and the tail- race of the plant, in feet. 

This formula assumes an over-all efficiency of 80 percent. 

Hamma Hamma River 

At power site 12PM9 (mile 3.5) a dam 

140 feet high would have a maximum flow 

line at altitude 540 feet and while regu- lated the mean altitude would be 515 feet. 

A tunnel 2.0 miles long would connect the 

dam with a penstock to the power house at sea level on Hood Canal. The mean gross head on such a plant is estimated at 505 

feet. If a plant were operated on a run- of-river basis with the reservoir elevation 

always at 540 feet the gross head would be 

530 feet. 

In the following estimates of power it 

has been assumed that 50 second-feet have 

been spilled at the dam continuously to 

provide for fish life. This amount of 

water has been subtracted from the available 

flows. 

The following table shows_ the power available on an all-year basis for the 

period 1927-30. This period was one of 

subnormal flow and these estimates are believed to be conservative, 

The power available during an average winter period has also been shown in this 

table, 
20 

Power estimates in kilowatts at pow~ site 12PM9, 

mile 3,5 on the Hamma Hamma River 

Year rose Flow 1n eecona-reet .t'OWer l.n Kl.J.OWa1JlJ6 or head, Dercent of time Qercent 'Of time 

Period feet I 95 90 50 mean I 95 90 _,o J mean 

With natural flow.V 

Dry year 1930 530 0 0 93 250 0 0 ,,,50 9,000 Average year 530 4 20 300 429 144 3.~§8 :g,8oo 16,4go Wet :vear 1927 33o 54 94 361 556 1_,_950 1 .ooo 2 .o 0 

With regulated flowY 

1927-30 505 90 117 350 370 3,090 4,020 12,020 12,700 

.11 Winter power.2/ 

Nov, 11, 1926. 505 - - - 564 - - - 19,370 

to 

Feb, 28, 1927 

(Average·) .winter • 

1/ Flow available after bypassing 50 second-feet for fish preservation. g( Flow available with 18,000 acre-feet of storage and bypassing 50 

second-feet for fish preservation, 2/ Flow available continuously with 18,000 acre-feet of storage and 

bypassing 50 second-feet for fish preservation. 

Duckabush River 

Estimates of flow available 95, 90, and 

50 percent of the time and mean annual flow 

for dry, average, and wet years at the three 

power sites have been listed in the table 

entitled Streamflow on Duckabush River. 

Since some water will have to be left in the 

stream for the protection of fish life, the 

water available for power generation will be 

the amount shown in this table less the amount 

required for fish. This amount has been 

assumed to be the median low annual flow or 51 second-feet at the gaging station, On a straight drainage-basin~area ratio the flow 

would be 36, 42, and 51 second-feet at power sites 12PM13 1 12PM14, and 12PM15 respectively. 

Power ·from regulated flow.--A dam built 

at site 12PM15A to provide 6o,ooo acre-feet 

of usable storage will regulate the flow at 

this site. Estimates of the power available 

with the stream so regulated, allowing 51 

second-feet for fish preservation, for the 

10-year period from October 1938 through September 1948 are as follow, The minimumflow period came from July 1942 through October 1944. For the first 13 months of 

this period, 7,250 kilowatts and for the 

second part of the period, 15 months, 6,830 

kilowatts could have been generated continuously. In an average year, such as 1945, 

8,970 kilowatts, and in a wet year, such as 1946, 10,540 kilowatts could have been 

generated 100 percent of the time. 

If a low dam were constructed at site 

12PM15l3, 14,000 acre-feet of usable storage, would be provided. This amount of storage, 

while insufficient to permit utilization of 

all the runoff from the basin, will materially increase the low-water flow, The lowest flow came in a 3-month period in the summer and 

fall of 1942 when 2,080 kilowatts of power could have been generated. Storage would 

have been drawn upon for 56 months or 47 

percent of the 10-year period of record, 

The regulated flows provided during these 

low-water periods would have generated power varying from 2,080 to 7,900 kilowatts with a mean of 4,100 kilowatts. During theremaining 53 percent of the time more than 

7,900 kilowatts could have been generated, 

Because of the importance of winter 

power when the Columbia River flow is low and 

power demand is at its maximum, the power available during an average winter period such as November 1, 1945 to February 28, 1946 was determined, For such a period the 

14,000 acre-feet of storage provided adequate control. In the above period the reservoir 

would have started to fill on November 13. 

From that date until January 5, 10,900 kilowatts and from January 5 until February 28, 

7,750 kilowatts could have been generated. 

Power for various years and periods is 

shown in the following table. The years 1944, 1945, and 1946 shown for natural flow are considered representative of dry, average, and wet years. For winter power with natural 

flow the representative dry, average, and 

wet years were 1944, 1946, and 1945 respectively. 
Power estimates, in kilowatts, on the Duckabush River 

Gross Year Flow in second-feet .!:'ower l.n kllowaffs 

Power site Head or percent of time percent of time 

number feet period 95 90 50 mean 9:> 90 I 50 mean 

With natural flow Y 

{ 1944 4 11 101 147 109 299 2,750 4,000 

12PM13 400 1945 8 27 167 238 218 734 4,540 6,470 

1946 12 42 213 283 326 1,140 5,790 7,700 

I{ 1944 4 13 115 168 58 190 1,680 2,460 

12PM14A 215 1945 9 30 191 272 ~32 439 2,790 3,980 

1946 14 48 244 324 205 702 3,570 4,740 I{ 1944 4 13 115 168 100 327 2,890 4,230 

l2PM14B 370 1945 9 30 191 272 226 755 4,800 6,840 

1946 14 48 244 324 352 1,210 6,140 8,150 

12PM15A_s/ I{ 1944 5 16 141 206 163 522 4,600 6·, 720 

480 1945 11 37 233 333 359 1,210 7,600 10,870 

1946 17 59 298 396 555 1,930 9.730 12,920 

12PM15~ I{ 1944 5 16 141 206 109 348 3,070 . 4,480 

320 1945 11 37 233 333 239 805 5,070 7,250 

1946 17 59 298 396 370 1,280 6,480 8,620 

With regulated flow 

12PM15A2./ { 19,8 420 to 239 239 314 321 6,830 6,830 8,970 9,170 

1948 

12PM15:i!/ I{ 1938 300 to 107 144 288 314 2,180 2,940 5,880 6,410 

1948 

Winter power with natural flow2/ §/ 

I{ 1944 54 69 133 219 1,470 1,880 3,620 5,960 12PM13 400 1946 76 85 190 314 2,070 2,310 5,170 8,540 

1945 91 98 203 322 2,480 2,670 5.520 8,760 

I{ 1944 62 79 152 251 906 1,150 2,220 3,670 12PM14A 215 1946 87 97 217 360 1,270 1,420 3,170 5,260 

1945 104 112 233 36__2_ 1,520 1,640 3,410 5,390 I{ 1944 62 79 152 251 1,560 1,990 3,820 6,320 12PM14B 370 1946 87 97 217 360 2,190 2,440 5,460 9,060 

1945 104 112 233 369 2,620 2,820 5.860 9,280 

Winter power with regulated flow 2/ 

12PM15A 420 1946 380 380 441 535 10,850 10,850 12,590 15,280 

12PM15B 30() 1946 _380 380 441 535 7.750 7.750 9,000 10,900 l/ Flow available after appropriate deduction for ish purposes from values 

shown in table on page 10. 

g/ With reservoir full and operating as a run-of-river plant. :!/ Flow available utilizing 60,000 acre-feet _of storage and bypassing 51 sec.-ft. for fish preservation. ~Flow available utilizing 14,000 acre-feet of storage and bypassing 51 sec.-ft. for fish preservation. 5/ Three-month period ending February 28 of year indicated. 2/ Flow availsbleafter appropriate deduction for fish purposes from values 

shown in table on page 12. 

21 
2?. 

Dosewallips River 

Estimates of flow available g5, go, and 50 peroent of the time and mean annual 

flow for dry, average, and wet years have. 

been listed in the table entitled Streamflow on the Dosewallips River. These 

estimates are for the entire flow past the 

three power sites. Sinoe some water will 

have to be left in the stream for the pro- tection of fish life, the water available 

for power generation will be the amount 

shown in this table less the amount required for fish. The amount has been assumed to 

be the median of the lowest flows recorded 

each year for the period of record, or g8 

sec.-ft. at the gaging station. The com- parable flows, computed on a straight drainage-basin-area ratio, would be 75 secondfeet for site 12PM10, and 80 second-feet for 

site 12PM11. A value of 100 second-feet 

has been assumed for site 12PM12 as the 

tributary area between it and the gaging station contributes very little runoff during the low-water period. 

Power. sites l2PMlO and 12PMll· have no storage possibilities and will be operated as run-of-river plants. Power site 12PM12 

is located at the Rocky Brook dam site where 

regulation is possible. Regulated streamflow from behind dams 142·and 302 feet high have been discussed under Stream regulation, and flows available g5, go, and 50 percent 

of the time and mean flow have been listed on page 1g. The flow available for power generation will be reduced 100 second-feet 

because of the requirements for fish preserva- tion. 

Available winter power is not as great, proportionately, on the Dosewallips River as on the H~mma Hamma or Duckabush Rivers. It 

is however, considerably greater than that 

available in July and August. Complete regulation of the winter flow at site 12PM12 

is possible with only 15,000 acre-feet of 

storage in an average winter such a~ lg46. The power available on the Dosewallips River 

under the conditions outlined above is shown 

in the table on the next page. 
Power estimates~in kilowatts~· 

on the Doeewallipe .River 

Gross Year Flow in second-t'eet !'ower l.n Kl.lowatts 

Power site Head or percent of time percent of time 

number feet period 95 90 50 mean 95 90 50 mean 

With natural flow !/ 

I{ 1944 13 23 97 142 641 1,130 4,780 7,000 

l2PM10 725 1932 20 33 219 277 986 1,630 . 10,800 13,660 

1935 44 86 289 361 2,170 4,240 14,250 17,800 

{1944 16 27 107 157 392 661 2,620 3,840 

12PM11 360 1932 24 38 241 305 588 930 5,900 7,470 

1935 50 96 318 397 1,220 2,350 7,780 9,720 

.12PM12 y r944 30 44 152 218 796 1,170 4,030 5,780 

390 1932 40 58 331 416 1,060 1,540 8,780 11,030 

1935 75 136 434 539 1,990 3,610 11,510 14,290 

With regulated flow 

12PMl2 ~ 330 1930 300 300 389 391 6,730 6,730 8,730 8,770 

12PM12 208 1948 150 180 335 391 2,120 2,540 4,740 5,530 

Winter power with natura·! flow .2/ §/ 

tg44 45 51 107 173 2,220 2,510 5,280 8,530 

12PM10 725 1946 65 7"4 184 250 3,200 3,650 9,070 12,320 

1945 89 104 195 302 4,390 5,130 9,610 14,890 

.e44 51 58 119 191 1,250 1,420 2,910 4,680 12PM11 360 1946 73 82 203 -275 1,790 2,010 4,970 6,730 

1945 99 116 215 332. . 2,420 2,840 5,260 8,130 

12PM12 y fg44 76 85 167 263 2,020 2,250 4,430 6,970 

390 1946 106 118 280 376 2,810 3,130 7,430 9,970 

1945 140 163 296 452 13,710 4_,320 7,850 11,990 

Winter power with regulated flow§/ 

12PM12 330 1946 ~ 385 ~,640 208 1946 385 5,450 

!/ Flow available after appropriate deduction for fish purposes from 

values shown in table on page 12. 

E/ With reservoir full and operating as run-of-river plant. 2/ Flow available utilizing 100,000 acre-feet of storage and bypassing 100 second-feet for fish preservation. 1/ Flow available utilizing 15,000 acre-feet of storage and bypassins 100 second-feet for fish preservation. 2/ Flow available after appropriate deduction for fish purposes from 

values shown in table on page 13. · §/ Three-month period ending February 28 of year indicated. 

7/ Flow and power available 100 percent of time for 90 days utilizing 15,000 acre-feet of storage, dam built to an altitude of 400 feet, 100 

second-feet bypassed for fish preservation • .§/ Flow and power available 100 percent of time for 90 days utilizing 15,000 acre-feet of storage, dam built to an altitude of 240 feet, 100 

second-feet bypassed for fish preservation. 

23 
24 

The power on the three streams under 

consideration has been summarized in the 

following table. This table ·has two sections, one showing power with natural flow at all 

sites and one showing power with the regulat- ed flow at the one storage site on each 

stream combined with the run-of-river sites. 

In the former case the dams at the potential 

storage sites have been considered as develop- ing head only and no use made of the storage, 

operating always at a full reservoir. Details relating to the sites are shown in the 

footnotes to the table. Power values at the 

sites using natural flow are based on streamflow values for what was considered an average year whereas power values at the sites 

with regulated flow are based on a mean value 

for the period of available streamflow record. 

The values in the following table clearly indicate the advantage to be gained by using regulated flow at the sites where it can be developed. 

Summary of estimated power, in kilowatts 

.Percent or time 

Location Type of flow ~~ ~u ~u mean 

Hamma Hamma River {natural Y 144 720 10,800 15,460 

Site 12PM9 regulated 3,090 . 4,020 12,020 12,700 

Duckabush River { natura1 Y 710 . 2,380 14,930 21,320 

Sites 12PM13, regulated Y 7,180 8,000 16,300 19,600 

12PM14A, and 

12PM15A 

Dosewallips River {natural2/ 2,630 4,100 25,480 32,160 

Sites 12PM10, regulated 2./ 8,300 9,290 25,430 29,900 

12PM11, and 

12PM12 

Total {natural 3,480 ·7,200 51,210 68,940 

regulated 18,570 21,310 53,750 62,200 

1/ All sites operated as run-of-river plants. 2/ Natural flow at sites 12PM13 and 12PM14A; regulated f~ow 

at sTte 12PM15A. 2./ Natural flow at sites 12PM10 and 12PM11; regulated flow at 

site 12PM12. 

An analysis of the effect on the power picture of operating several of the run-ofriver plants jointly with one or more of the 

storage plants has not been attempted. Such an analysis would undoubtedly show a greater 

amount of firm power than the sum generated by the individual plants, but since the 

plants will be operated in connection with 

the Northwest Power Pool the value of the 

·data so obtained would be small. Such interconnection will be a very simple and inexpensive operation because Bonneville Power 

·Admininistration has recently c.onstructed a transmission line along the west side of 

Hood eanal a few miles back from tidewater 

which cuts across ail three basins. 

In addition, the city of Tacoma operates a transmission line from Hoodsport to Tacoma, 

where ties exist with the Bonneville Power 

Administration, the city of Seattle, and the 

Puget Sound Power and Light Company systems. 

The illustrative plans of development suggested in this ·report may not.be the ones followed in actual development. However, 

these schemes along with the basic data do 

indicate the magnitude of the potential 

power available and the methods by which it can be most lo.gically developed. 

INT.-DUP. SEc., WASH., D.C.l9622