Waterpower Resources Near 

Petersburg and Juneau, 

Southeastern Alaska

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1529

Waterpower Resources Near 

Petersburg and Juneau, 

Southeastern Alaska

By F. A. JOHNSON

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1529

A discussion of potential development 

of power on 12 Alaska streams

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1962
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

Johnson, Frederick Ashby, 1903-

Waterpower resources near Petersburg and Juneau, southeastern Alaska. Washington, U.S. Govt. Print. Off., 1961.

v, 101 p. illus., maps, diagr., tables. 24 cm. (U.S. Geological 

Survey. Water-supply paper 1529)

Bibliography: p. 99.

1. Waterpower Alaska. 2. Stream measurements Alaska. 

3. Water-supply Alaska. I. Title. (Series)

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington 25, D.C.
CONTENTS

Page

Abstract .................................................................................................................... 1

Introduction ..................................._....._..___...................................................._.._.. 3

Purpose and scope - . .. ._ .. .._......... ... ...... - _ - 3

General discussion .......................................................^................................... 3

Previous investigations _-.._...__..______.._...____...._..___.___...___ 5

Acknowledgments - .......... . ..................._.. ._ _ . ..-- _._._. 7

Geography . .. .. . ......_ .... . .................. .._.._ . .. . .. _. . . 7

Location and extent of areas - _._.._ - _ .-...._.___...__ __ 7

Accessibility - _ - - - -._...____._______...___...._..__..._._..____ _________.______...... 7

Land use and potential value .-.- .-..-._..-._. -. . _ . ..-. . 9

Maps and photographs .___.......____.______...__.__..________ __________ ._..__..._..._._.__..._____. 10

Geology ............_.._...._...._.._....................._....................._...._ . . .-_..._____... 10

Climate _-.-_........................ ._......................................................_............._.... .._. 10

Precipitation __________________._______________ 11

Temperature _.. _.._... .......... -. ._-.-.- __________.............. 14

Glaciers and snow accumulation ..._........................ .... ............................. 15

Stream regulation ..........._......................................_..._........_. ............_.........._... 18

Developed powersites . ................ ............................ ........... .._......................... 21

Crystal Lake ._._ .._ . _................ .............-.........._ .-.-.-.........-..._ 21

Tease Lake .....__ ................_.................._....._ ............._....._....................... 22

Annex Creek -_.-.._...._ ........... .-- ..-_................_ .... __....... 22

Sheep Creek ................................._........._......................... _._........_..._......... 23

Gold Creek _____________________________________ 23

Salmon Creek ...... .-............................._.................._.._.__.-_................_._... 23

Nugget Creek .- -. . ........._-._.........................._._.._-............._.... 24

Treadwell Ditch ___-._._______-____-______-_-.________ 24

Undeveloped powersites - _-........___-_._._.-._.._...._._.______ ._.-...._..._._______._ 25

Factors that would affect the design and operation of powerplants______ 25

Methods for appraisal of power ......-.._....................._... .....................__ .. 26

Sites in Thomas Bay area _____.. ________............___________._ . .... ._________________... 26

Maps ..... ...........-..._........._..... _......................_....................._.............. 26

Local geography and topography . . ...._...... . ...._...... 27

Water supply . . .. _-......._ ...................--.-........_................ 30

Records of streamflow .................................................................... 30

Runoff at Ruth Lake outlet....._......................._........................_.. 31

Runoff at Swan Lake outlet .. __________._........., .___________._........ _ _ 31

Runoff at Scenery Lake outlet - _- __....._.___ _ ._......__...._ 32

Delta Creek powersite - _- _ - .......... ..-......._..... 32

Cascade Creek powersite .... ...... ... ......_.... . ..-..........._.... 35

Scenery Creek powersite . _..... . ... .. . 37

Potential power of sites in Thomas Bay Area .................................. 42

Locations at which power could be used ............ .................._.. ...... 43

III
IV CONTENTS

Page

Undeveloped ppwersites Continued

Sites at Gilbert Bay and Speel Arm of Port Snettisham area _ 45

Maps _ _ _ _______ 45

Local geography and topography ___________-________ 46

Water supply ._ .. . _. ._. . _ . ._. .._ _... _ ...... 48

Records of streamflow 48

Runoff at Upper and Lower Sweetheart Lake _ _ 49

Runoff at Tease Lake outlet ___________________ 51

Runoff at Long Lake outlet ___ 51

Runoff at Speel River damsite ____ 52

Runoff at Crater Lake outlet 53

Sweetheart Creek powersite ______________-______ 53

Tease Lake powersite 57

Long River powersite __.______________________._ 58

Speel River powersite 61

Crater Creek powersite 65

Long River, Speel River, and Crater Creek sites, coordinated

development _ ___ ___ __ _ - _ 68

Potential power of sites near Gilbert Bay and Speel Arm of

Port Snettisham 68

Locations at which power could be used __ 71

Sites in Taku Inlet and Gastineau Channel area 73

Maps 73

Local geography and topography 74

Water supply _ _ 77

Records of streamflow 77

Runoff at Lake Dorothy, Lieuy Lake, and Bart Lake ._ 78

Runoff at Turner Lake outlet _ _ . 80

Runoff at Carlson Creek damsite 81

Runoff at Sheep Creek damsite 81

Dorothy Creek powersite . __ __ __ ____ 83

Turner Creek powersite ________.__________-_____ 88

Carlson Creek powersite 91

Sheep Creek powersite 94

Potential power of sites in Taku Inlet and Gastineau Channel

area _______.__.__________________________ 96

Locations at which power could be used 97

References cited 99

Index 101

ILLUSTRATIONS

FIGURE 1. Map of southeastern Alaska showing location of powersite

areas --__---__-.-__________-__--___-_ 8

2. Storage requirements at Alaskan sites ___ ____ 20

3. Map of powersites in the Thomas Bay area 28

4. Aerial view across Ruth Lake 29

5. View toward upper end of Scenery Lake 29

6. View of Swan Lake outlet _ _ 35
CONTENTS V

Page

FIGURE 7. Aerial view of Scenery Lake outlet. 38

8. Map of powersites in the Port Snettisham area ________ 47

9. Aerial view of Lower Sweetheart Lake . 55

10. Aerial view of Long Lake _- _- __ _ 59

11. Aerial view of damsite at Crater Lake ________________________ 66

12. Aerial view of mountains between Port Snettisham and Taku

Inlet _________ ________________ _________________________________ _.._________ 74

13. Aerial view of Taku Inlet 75

14. Map of powersites in the Taku Inlet area 76

15. Aerial view of Lake Dorothy 83

16. Map of Lake Dorothy damsite . .__ 84

17. Map of Bart Lake damsite _________________________________________ 86

18. Aerial view of Turner Lake outlet 89

19. View of Carlson Creek reservoir site 91

20. Aerial view of Sheep Creek reservoir site _ ________________ 94

TABLES

TABLE 1. Monthly and annual precipitation, Juneau ______________ 12

2. Monthly and annual runoff, Cascade Creek near Petersburg ____ 30

3. Monthly and annual runoff, Sweetheart Creek near Juneau _ 49

4. Monthly and annual runoff, Long River near Juneau ....____ 50

5. Monthly and annual runoff, Crater Creek near Juneau __ _ .. 50

6. Monthly and annual runoff, Speel River near Juneau __ 53

7. Monthly and annual runoff, Dorothy Creek near Juneau __ _ 78

8. Monthly and annual runoff, Carlson Creek at damsite near

Juneau _ . __ ___ _ 78

9. Monthly and annual runoff, Sheep Creek at damsite near

Juneau _____________________.__________________ 79

WATERPOWER RESOURCES NEAR PETERSBURG 

AND JUNEAU, SOUTHEASTERN ALASKA

By F. A. JOHNSON

ABSTRACT

The bulk of the potential waterpower on the narrow strip of mainland in 

southeastern Alaska between Petersburg and Juneau is available at powersites on 12 mountain streams. The aggregate potential is 190,000 kw of 

primary power. Detailed surveys and geologic examinations of most of these 

sites were made by the U.S. Geological Survey between 1949 and 1958, and 

quadrangle maps compiled from aerial photographs of 1948 cover all but 3 

of the stream basins on a scale of 1 inch to 1 mile. Streamflow records were 

collected by the Geological Survey and the U.S. Forest Service on several 

of the streams at intervals between 1915 and 1946 and have been collected 

by the Geological Survey since 1946. The streamflow records, surveys, 

geologic examinations, and other data were used for appraisals of the powersites which are described in this report. Suggested methods of development 

generally follow plans described by the Federal Power Commission and 

Forest Service in 1947, modified to accord with information obtained after 

1947.

The geographic, climatic, and hydrologic conditions are described briefly 

and discussed in relation to their effect on power development. Very few 

places are suitable for industrial sites and towns, because of the mountainous 

terrain. Transmission of power to these places would be relatively difficult, 

and on some routes would require use of submarine cables for transmission 

across waterways. Heavy winter snowfall and relatively cloudy, cool summers account for the many glaciers and snow banks in the mountains. 

Perennial snow has an appreciable equalizing effect on the amount of annual 

runoff at some of the sites.

The 12 powersites are in 3 groups, 1 at the southern end of the mainland 

strip, within about 15 miles of Petersburg, and 2 near the northern end, 

within about 35 miles of Juneau. Storage for equalization of seasonal runoff 

is essential for generation of dependable power since 80 to 90 percent of the 

annual runoff occurs in a 6-month period. Eight of the sites have good 

storage possibilities in lake basins at relatively high altitude near tidewater. 

Sufficient storage could be developed at nearly all the sites for substantial 

equalization of the annual runoff.

Powersites on Delta Creek, Cascade Creek, and Scenery Creek, tributaries 

to Thomas Bay near Petersburg, have an aggregate potential of 44,500 kw 

of primary power of which about half is at the Cascade Creek site. Storage 

for regulation could be obtained at lakes on each of the streams by damming 

the outlets or tapping the lakes at depth with tunnels. The lakes are within 

2 or 3 miles of tidewater, and heads of more than a thousand feet could be 

developed. Petersburg on Mitkof Island is the nearest community at which
2 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

the power could be used. It is within a transmission range of about 20 miles, 

which includes several miles across Frederick Sound that would require transmission by submarine cable. Undeveloped areas on the mainland near Point 

Agassiz, about 8 miles southwest of Cascade Creek, are topographically 

suitable for industrial sites and supporting communities not far from the 

water supplies of Delta Creek.

The second group of powersites is about 35 miles southeast of Juneau near 

Port Snettisham, a fiord extending northeastward from Stephens Passage. 

One of the powersites is on Sweetheart Creek, a tributary to a southern arm 

of Port Snettisham called Gilbert Bay. The others, on Tease Lake, the Long 

River, the Speel River, and Crater Lake are located around the head of the 

Speel Arm of Port Snettisham about 10 miles north of Gilbert Bay. The 

estimated potential of the entire group aggregates 113,000 kw of primary 

power, of which 50,200 kw is at the Speel River site. This site appears to be 

the least favorable of the group. Storage at natural lakes could be developed 

at all of the sites except the Speel River, where sizable dams on the river and 

at a saddle would be required. A considerable amount of reserve capacity 

would be needed at this site for catchment of the heavy sediment load of the 

river. Power from all the sites could be transmitted some 50 miles to the 

Juneau area to serve new industrial development. The advantages of an 

existing community favor this possibility. An undeveloped area just south 

of Gilbert Bay is topographically suitable for location of factories and a 

community in the immediate vicinity of the Sweetheart Creek site and within 

transmission range of about 18 miles from the sites at the Speel Arm.

The third group includes Dorothy Creek, Turner Creek, and Carlson 

Creek, tributaries to Taku Inlet; and Sheep Creek, a tributary to Gastineau 

Channel. These sites have an aggregate potential of 31,800 kw of primary 

power, with Lake Dorothy on Dorothy Creek accounting for more than half 

of the power. Storage could be developed readily there by tapping the lake 

with a tunnel, at the sacrifice of only a small part of the 2,421 feet of head 

below the natural surface. Sufficient storage for control of Turner Creek 

could be provided by construction of a dam of moderate height at the outlet 

of Turner Lake, but not by drawdown since the lake is at a low altitude. 

Sizable dams would be required on Carlson Creek and Sheep Creek to develop 

the needed storage there. Power from the Dorothy Creek and Turner Creek 

sites could be transmitted about 20 miles to the Juneau area, and over shorter 

routes from the Carlson Creek and Sheep Creek sites. The transmission line 

from Dorothy Creek to Juneau, including 2 miles of submarine cable across 

Taku Inlet, could be designed to serve also for transmission of power from 

the Port Snettisham area along 15 miles of the route.

The development of a substantial portion of the power from any of the 

groups of sites of the Petersburg-Juneau area depends upon industrial development and the accompanying growth in population. In 1959 the electric 

energy being used in the service areas of Petersburg and Juneau was less 

than 2 percent of that available from the primary potential of 190,000 kw 

that could be developed at the waterpower sites.
WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA 3

INTRODUCTION

PURPOSE AND SCOPE

This report deals with three groups of waterpower sites on 

streams of the Alaska mainland from Thomas Bay near Petersburg northwestward to the vicinity of Juneau. It presents 

descriptions of the sites and estimates of the potential power 

based on surveys, examinations, and streamflow records of the 

Geological Survey between 1948 and 1958; and on the results of 

previous investigations. Schemes of development in accord with 

the topography and geology are outlined and used with the watersupply data available to 1956 for estimating the potential power.

The power possibilities are discussed only on the basis of 

regulated flows because natural flows are very low during winter 

periods; the demand for seasonal power is small, and the possibility of supplementing much of it from fuel-electric sources for 

production of firm power is unlikely.

Lands in most of the stream basins of this report have been 

withdrawn as potential powersites by classification of the Geological Survey or as a result of applications to the Federal Power 

Commission. Information presented in the report, and particularly the recent map data, make it possible to determine more 

closely whether retention of all the withdrawals is justified or 

whether some modifications should be made.

The present report consists largely of material from three openfile reports of the Geological Survey (Colbert, 1955; Johnson, 

1955, 1957), as revised and brought up to date, and it accordingly 

supersedes these reports.

GENERAL DISCUSSION

The conditions for waterpower development in southeastern 

Alaska were described by Hoyt (1910) and more recently by the 

Federal Power Commission and U.S. Forest Service (1947), and 

by the U.S. Army Corps of Engineers, (1952). Hoyt pointed out 

that development is favored by the existence of many precipitous 

streams discharging from lakes which offer excellent storage 

facilities near tidewater, but is greatly hampered by the difficulty 

of transmission. The routes from powersites to industrial sites 

or to existing communities generally are along very steep mountainsides which extend to tidewater, and on which avalanches 

are common. Furthermore, the mainland shore is indented in 

places by long inlets or fiords which would necessitate indirect 

transmission routes or crossings by means of submarine cables.
4 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

In some places large tidal glaciers would practically bar transmission along the mainland. The rugged terrain at the powersites generally would prevent location of sizable factories and 

supporting communities in their immediate vicinity.

The transmission costs from some of the more favorable sites 

in southeastern Alaska to load centers such as Petersburg and 

Juneau were estimated by the U.S. Army Corps of Engineers 

(1952). These are approximately 50 percent of the cost of generation, with transmission-line distances of about 50 miles. It was 

stated in the Army report that interconnection of load centers 

is impracticable because of the distance and the difficult terrain 

between them.

Most of the many sites in southeastern Alaska have a potential 

of only a few thousand kilowatts of primary power, and only 

a few have potentials greater than 20,000 kw. The potentials 

are low because most of the stream basins are relatively small, 

so that in spite of the heavy runoff per unit area, streamflows 

generally are not very great.

The powersites discussed in this report include some of the 

most favorable ones in southeastern Alaska from the standpoint 

of conditions at the sites, amount of potential power, and location 

with respect to possible service areas. They are described separately as 3 groups, within each of which power from several sites 

could be interconnected.

The first group comprises sites on Delta Creek, Cascade Creek, 

and Scenery Creek, all located at Thomas Bay near Petersburg 

(see fig. 3). An aggregate of 44,500 kw of primary power could 

be generated at these sites for transmission to the now underdeveloped areas at or near Thomas Bay. Alternatively, power 

could be transmitted to Petersburg on Mitkof Island by means 

of about 20 miles of line from Cascade Creek, including several 

miles of submarine cable. The Cascade Creek site has about 

half the potential power of the Thomas Bay group (21,900 kw) 

and is judged to be the best of the 3.

The second group includes sites on Sweetheart Creek at the 

head of Gilbert Bay of Port Snettisham; and sites on Tease Lake, 

the Long River, the Speel River, and Crater Creek, all near the 

head of the Speel Arm of Port Snettisham (see fig. 8). An 

aggregate of 113,000 kw of primary power could be generated 

at these 5 sites, but 50,200 kw would be from the Speel River site, 

which probably is the least favorable of the 5. Power could be 

transmitted for 20 miles from the 4 sites near Speel Arm to a 

flat area of several square miles just south of Gilbert Bay, and
INTRODUCTION 5

for 2 miles from Sweetheart Creek to this undeveloped area. 

Alternatively, the power could be transmitted for about 50 miles 

from Speel Arm to Juneau by overland lines and 2 miles of 

submarine cable crossing Taku Inlet.

The third group includes sites on Dorothy Creek, Turner Creek, 

Carlson Creek, and Sheep Creek in the vicinity of Taku Inlet 

near Juneau (see fig. 14). An aggregate of 31,800 kw of primary 

power could be generated at these sites, of which 17,800 kw 

would be from the Lake Dorothy unit of Dorothy Creek, probably 

the best of the 4 sites of this group. Power could be transmitted 

from the Dorothy Creek and Turner Lake sites to Juneau, some 

23 miles and 15 miles respectively, by means of overland lines 

and a submarine crossing of Taku Inlet, in part on the same 

route that might be used for transmission from the sites at Speel 

Arm to Juneau. Power could be transmitted to Juneau from 

Carlson Creek and Sheep Creek sites by shorter, overland lines.

The development of a substantial part of the potential power 

of any of the three groups of sites depends on industrial development and the accompanying growth in population. The use of 

power in southeastern Alaska has been very limited to date [1959]. 

As tabulated by the U.S. Army Corps of Engineers (1952), the 

installed capacity of existing developments in 1952 was about 

39,000 kw, of which only about 24,000 kw was for hydroelectric 

generation. The installed capacity was increased substantially 

by the construction of a pulpmill at Ketchikan in 1954. This mill 

is served by a steamplant fueled largely by waste products. The 

construction of pulpmills at other communities in southeastern 

Alaska was being considered in 1958 and may lead to some 

increased use of waterpower either directly or through an accompanying growth of population.

PREVIOUS INVESTIGATIONS

Investigation of some of the powersites was made before 1915, 

as shown by streamflow records for 1908 and 1909 for the outlet 

of Turner Lake, construction of a powerplant on Sheep Creek 

in 1910, and application to the Forest Service for powersites at 

Crater Lake and Long Lake in 1913 and on Carlson Creek in 

1914.

Dort (1924) discussed the Cascade Creek, Sweetheart Creek, 

Tease Lake, Long River, Crater Creek, Turner Creek, and Carlson 

Creek sites. His figures of potential storage capacities at the 

Cascade Creek and Sweetheart Creek sites were determined from 

topographic surveys made by him in 1921. The potential capac-
6 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

ities at the Long River and Crater Creek sites were determined 

from surveys made by the Speel River Project, Inc., a corporation 

which began investigation of the sites near Speel Arm as early 

as 1913. Dort was assigned to his study of the waterpower 

of southeastern Alaska by the Forest Service, and his report 

was to the Federal Power Commission.

Reconnaissance investigations of waterpower sites throughout southeastern Alaska were continued by the Forest Service 

in cooperation with the Federal Power Commission after the 

time of Dort's investigation. Data collected in these and earlier 

investigations were analyzed and used as a basis for discussion 

of the power possibilities of 200 sites scattered throughout southeastern Alaska. The report was published jointly by the Federal 

Power Commission and U.S. Forest Service (1947) and includes 

descriptions of the 12 sites discussed herein.

The U.S. Department of the Interior (1950) issued a reconnaissance report concerning the development of water and related 

resources in Alaska. It gives an appraisal of the outlook for 

the use of water in Alaska for power and other purposes in the 

light of economic conditions and trends at the time of the report.

The U.S. Army Corps of Engineers (1952), has reported on 

harbors and rivers of southeastern Alaska. The report contains 

estimates of the potential power of the eight largest sites between 

Thomas Bay and Juneau and estimates of the cost of generation 

and transmission. The physical conditions in southeastern Alaska, 

the economic development, and the outlook for future development 

are discussed in some detail.

An estimate of the potential power of Lake Dorothy was made 

and a plan of development described by the U.S. Bureau of 

Reclamation (1955). The bureau programmed field investigations 

and offices studies of the Crater Lake and Long Lake sites in 

sufficient detail for preparation of a report on the feasibility of 

the project.

Discharge records for most of the streams of this report have 

been collected by the Geological Survey and the Forest Service 

over periods since 1915. These records and some furnished by 

private companies are available through the 1956 water year 

(U.S. Geological Survey, 1957, 1958a, 1958b). (The 12-month 

period ending September 30 each year is called the water year, 

and the water year is designated by the calendar year in which 

it ends.)
INTRODUCTION 7 

ACKNOWLEDGMENTS

Acknowledgment is due the offices of the Forest Service in 

Juneau and Petersburg for the loan of equipment and facilities 

to the field parties. Radio communications with field camps near 

Juneau and Petersburg were handled by the Alaska Communications System.

GEOGRAPHY

LOCATION AND EXTENT OP AREAS

The principal part of southeastern Alaska extends northwestward between the Pacific Ocean and Canada about 400 miles 

from lat 55° N., near Ketchikan, almost to lat 60° N., near 

Skagway. It covers a rectangular area roughly 120 miles wide 

which includes a number of large islands and a narrow, irregular 

strip of mainland.

The powersites lie within the part of the mainland strip which 

extends from near Petersburg to near Juneau between lat 57° 00' 

N. and 58°20' N. The group of sites in the Thomas Bay area is 

near the southeastern end of this reach; the groups in the Port 

Snettisham and Taku Inlet area are near the northwestern end. 

(See fig. 1). It is judged from available information that the 

power possibilities along the mainland between these groups are 

small and relatively unfavorable. Only three sites in that area 

were considered by the Federal Power Commission and U.S. 

Forest Service (1947, map 5), and the aggregate potential of 

these was estimated as only 560 hp (about 420 kw) of primary 

power.

ACCESSIBILITY

Transport to Petersburg and Juneau or to available natural 

harbors or landing places is dependent on ships or airplanes. 

Boats or barges of light draft might be required for transport of 

equipment and materials from harbors to the vicinity of some 

of the powersites where there are tidal mudflats at low tide, as at 

the head of Speel Arm.

Except for the Sheep Creek basin, there are no roads in or 

near any of the sites. Construction of arterial roads or railroads 

would be impracticable in the foreseeable future because of the 

extremely rugged terrain, the existence of glaciers extending to 

tidewater in places, and the limited service areas.

A road from Juneau to the mouth of Sheep Creek could be 

extended to Carlson Creek, but transport of heavy equipment
8 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

133°

Taku Inlet and Gastineau 

/Channel area I

\

FIGURE 1. Map of southeastern Alaska showing location of powersite areas between Petersburg and Juneau.

or materials to the mouths of the other streams, as well as 

to Juneau, would be dependent on boats. Swan Lake on Cascade 

Creek, Scenery Lake, Lower Sweetheart Lake, Long Lake, Crater 

Lake, Lake Dorothy, and Turner Lake are accessible by float 

plane for transport of men, camp supplies, or light equipment.
GEOGRAPHY 9

Short access roads could be constructed part of the way from 

tidewater to some of the reservoir sites. Tramways could be 

constructed on the steeper part of the routes, and at some of the 

sites they probably would be the more practical means of transport over the entire route.

LAND USE AND POTENTIAL VALUE

Steep mountainsides extend down to tidewater along almost 

all of the mainland shore. Most of the area is within the Tongass 

National Forest and is generally timbered below an altitude 

of about 2,500 feet. The timber consists mainly of spruce and 

hemlock, which is of pulp grade below an altitude of about 1,500 

feet. Most of the commercial timber is within 3 miles of tidewater, readily accessible for logging and transport to mills.

The slopes above the timberline generally are featured by 

extensive exposures of glaciated rock. Glaciers are present at 

higher altitudes in all of the basins discussed herein, with very 

extensive ones in the upper part of the Speel River basin. The 

ridges surrounding the stream basins extend to altitudes of 

several thousand feet. Cirque glaciers are common above an 

altitude of 3,500 feet.

All the basins except that of Sheep Creek are uninhabited, 

primitive areas and probably are visited only occasionally, mainly 

for recreational and forest-management purposes. The mountains, glaciers, and lakes have great scenic beauty, but they are 

relatively inaccessible.

There are a number of mining claims and inactive mines in 

the Sheep Creek basin. Acquisition of some of these would be 

necessary for power development, but mining in this area appears 

to be a declining activity. Most of the basin is outside the forest 

reserve within the Juneau townsite.

Commercial fishing, mainly for salmon and halibut, is an 

important activity in the waterways along the mainland, but 

most of the tributary streams are so precipitous that they are 

inaccessible to migratory fish.

The few areas of moderate relief along the shore, and within 

feasible transmission range of the powersites, have potential 

value for industrial sites. The areas suggested in following 

sections concerning the powersites were selected only on the basis 

of reconnaissance examinations or map data, and detailed examinations would be essential for close appraisal of their suitability.

At present [1959], the most likely future use of the undeveloped 

lands in southeastern Alaska seems to be logging for the manu-
10 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

facture of wood pulp. The forest reserves are administered by 

the regional office of the Forest Service at Juneau, Alaska. Some 

information concerning the character, amount, and location of 

the timber in southeastern Alaska has been given by Heintzleman 

(1928).

It may be feasible to mine deposits of iron ore at Port Snettisham at some future time. The ore is magnetite with some 

titanium, and according to the U.S. Bureau of Reclamation (1955, 

p. 6, 21-22) smelting by electric furnace would be necessary for 

economic recovery. The estimated power requirement was stated 

to be at least 40,000 kw. The deposits are within transmission 

range of the powersites near Gilbert Bay and Speel Arm of 

Port Snettisham.

MAPS AND PHOTOGRAPHS

All the mainland area of Alaska between Petersburg and Juneau 

is shown on maps of the Geological Survey Reconnaissance Topographic Series covering the Petersburg, Sumdum, Taku River, 

and Juneau quadrangles on a scale of 1:250,000. Topographic 

maps on a larger scale are available for areas of the powersites 

and are listed herein in the sections relating to the three groups 

of sites.

Aerial photographs are available in files of the Geological 

Survey, Denver Federal Center, Denver, Colo.

GEOLOGY

The geologic conditions at the powersites near Thomas Bay 

and Port Snettisham, except Sweetheart Creek and Tease Lake, 

were described by Miller (1955, 1956), and those of the sites 

near Taku Inlet, except Dorothy Creek, by Plafker (1956). The 

geologic conditions at the Dorothy Creek powersites were described by the U.S. Bureau of Reclamation (1955, appendix 1). 

The Geology of southeastern Alaska was described by Buddington 

and Chapin (1929).

Brief mention of the geology of many sites is included herein 

in the descriptions of the sites.

CLIMATE

The climate at sea level is characterized by heavy precipitation, 

much cloudiness, and relatively mild weather for such northerly 

latitudes. The average annual precipitation is about 90 inches 

at Juneau and 106 inches at Petersburg. The average tempera-
CLIMATE 11

ture at both places is about 42° F. The temperatures at Juneau 

for the period November through February are about the same 

as at Spokane, Wash., but the summer temperatures are substantially lower. During a 20-year period the number of clear 

days recorded at Juneau averaged only 54 per year.

Cloudiness and fog, as well as precipitation and temperature, 

are influenced greatly by local topography, and the irregular configuration in southeastern Alaska results in considerable variability. For example, the average annual precipitation at Annex 

Creek on Taku Inlet, only 10 miles east of Juneau, is about 20 

percent greater than at Juneau, whereas the average number of 

clear days per year is 94 as compared with the 54 at Juneau.

The precipitation in the mountains near the waterways is 

much heavier than at sea level and the winter temperatures are 

much lower. As estimated from the runoff records, the average 

annual precipitation on the Carlson Creek basin, for example, 

is more than twice that at Juneau although the center of the 

basin is about 5 miles from Juneau. The bulk of the winter 

precipitation in the mountains is snowfall, as shown by the low 

winter runoff and the prevalence of glaciers.

The precipitation results from relatively warm, moist winds 

from the Pacific Ocean rising over the mountain barriers of the 

islands and mainland. These winds generally are from the south 

and are of moderate velocity. Exceptionally strong winds occur 

when there is a flow of cold air from inland, notably through 

waterways such as Taku Inlet or through mountain passes.

PRECIPITATION

Precipitation records have been maintained at Juneau since 

1881 but are incomplete or lacking for many of the years before 

1912. Furthermore, the amounts recorded in some of the early 

years, notably 1910 and 1911, appear to be abnormally small and 

probably are not representative of areal amounts. Figures of 

monthly and annual precipitation for Juneau are listed in table 

1 for the water years 1916-57, which include several series of 

wet and dry years and which probably are a representative 

sample of the long-term pattern.

Records for Petersburg near Thomas Bay, Speel River on Speel 

Arm, and Annex Creek on Taku Inlet have been collected for 

various periods. The records for the water years of complete 

record for these stations are summarized below for comparison 

with the mean values at Juneau for the water years 1916-57.
12 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

TABLE 1. Monthly and annual precipitation, in inches, Juneau, Alaska

[Data from records of the U.S. Weather Bureau. The published figures were rounded to the 

nearest tenth and added to obtain the annual totals]

Water year

1916............

1917............

1918............

1919............

1920. ...........

1921............

1922............

1923............

1924. ...........

1925............

1926............

1927............

1928. ..... .....

1929............

1930. ...........

1931 ............

1932..... .......

1933............

1934............

1935....... ....

1936............

1937............

1938. ...........

1939............

1940. ...........

1941 ............

1942............

1943............

1944............

1945............

1946............

1947............

1948............

1949............

1950............

1951 ............

1952............

1953............

1954............

1955............

1956............

1957............

Mean .....

Oct.

9 1

14.6

18.6

14.0

12.5

10 9

11.6

6.5

8.7

12.7

8.9

13.5

13.6

11.4

17.3

14.5

15.9

9.7

14.1

12.3

5.9

18.7

14.8

9 0

19.1

9 7

16.2

17.2

15.0

15.8

15.2

13.3

16.6

14.8

7.0

5.4

17.3

20.9

10.6

12.4

12.9

13.1

Nov.

8.6

8.0

16.8

15.0

9 9

5.6

6.0

11.4

11.7

9

K

11.7

3.2

3.6

9 0

17.6

13.2

7 ft

7.0

5.6

11.2

9>5 0

6.4

191

101

6.8

11.5

5.1

13.4

10.5

4.0

12.5

11 9

12.0

4.2

6.8

12.4

5.4

11.0

4.0

17.6

10.3

Dec.

S Q

7 9

6.4

1A 0

7.7

6.0

12.7

2.2

11 1

\ 1

10.1

14.4

7.5

10.4

4.6

12.9

5.6

5.4

.9

4.4

9.3

9 1

7.0

11.7

9 7

6.2

5.0

4.6

18.5

6.1

4.8

6.1

8.6

7.1

5.1

4.8

5.3

5.7

13.8

14.0

3.4

14.8

8.0

Jan.

fi Q

1A O

8.6

11.4

H O

4.1

11.6

5.2

6.8

5

0

11.6

3.8

13.5

q 1

Q

9.1

n

o

6.0

14 9

5.9

4.9

5.6

10.3

1f\ O

4.0

6.4

10.3

9.2

5 A

6.8

8.7

11.1

15.4

4.0

6.5

3.6

5.2

9 A

9 7

2.8

7.6

Feb.

6.7

5.9

5.8

1 1

10.1

8 9

^ ft

1^ d

7 2

3 7

5

0

4.3

5.3

7 9

8.6

8.3

9 3

6.7

7.6

7.5

2.4

3

Q

6.1

8.4

2

0

1.6

7.5

5.4

3.6

8

0

3.4

2.4

2 a

3

1

4.8

5

n

11.6

11.7

6.8

6.0

6.5

6.1

Mar.

3

D

A. 9

4.3

4.4

4.6

6.5

5.1

8.0

7 PL

6.5

8 7

8.6

6.7

10.1

3.4

2

O

3 0

4.6

3.2

7.7

6.1

5.7

9 1

5

0

6.2

7 9

2.9

8.4

Q 1

6.5

11.2

5

0

5.6

3.3

7.0

6.8

9.0

4.3

9 7

4.9

2.4

6.1

Apr.

4.8

1.7

5.9

6.5

4.6

4.0

10.9

5.4

8 0

6.2

7.6

4.0

4.7

3.3

4.0

7.4

2.8

7.1

6.6

5.0

7.2

5.8

5.7

4.8

3.3

5.0

4.6

8.2

4.1

5.2

7.8

7.3

.5

10.0

4.5

10.1

7.8

7.2

3.6

5.3

4.5

8.7

5.8

May

4.2

3.5

5.6

5.0

6.1

6.1

5.1

3.2

7.4

4.3

3.7

3.9

8.2

4.7

3 9

8.6

\ Q

4.6

2.8

7.6

5.6

5.8

8.2

5.6

6.4

3.8

1.7

3.6

6.1

2.5

3.6

5.7

5.1

5.1

6.2

3.8

10.5

4.2

4.2

10.0

9.0

3.8

5.3

June

6.0

5.3

3.8

1 7

4.9

1 9

2.7

1.4

1.0

4.9

2.6

1.9

.9

4.2

3.8

5.1

10.6

6 9

3.9

4.7

.5

4.8

8.9

4.6

6.1

5.2

6.0

3.5

3.7

5.6

1.4

4.2

4.0

7.4

1.6

6.1

3.6

4.3

2.0

3.3

2.9

2.7

4.1

July

5.0

10.5

2.3

6.4

1.4

7.1

3.2

4.1

8.2

7.6

4.0

1.4

4.6

4.8

6.3

5.7

5.8

3.7

3.4

7.2

6.5

8.2

7.3

8.4 4.5'

7.3

6.2

8.7

3.1

11.5

6.8

3.3

7.2

5.3

9.9

4.1

4.0

3.6

4.7

2.7

3.6

2.9

5.5

Aug.

6.5

11.1

11.5

5 9

Q 7

7 9

9.2

6.9

8.0

7.7

2.9

5.5

6.1

5.1

9.5

11.3

2.5

11.7

7.8

10.4

2.8

11.6

4.9

12.2

10.8

1.3

7.6

11.9

6.6

4.5

8.3

9.9

5.2

5.7

5.4

3.8

8.0

9.4

1.7

10.3

14.2

2.4

7.5

Sept.

12.2

12.3

12.4

11.4

8.2

8.6

10.3

16.5

18.8

8.7

3.3

10.4

8.4

5.5

9.8

9.4

11.8

4.6

5.2

11.9

12.3

9.9

13.2

14.1

9.3

5.6

8.4

16.8

5.0

12.1

8.1

17.8

17.6

10.3

10.9

5.5

14.1

10.8

8.8

8.3

7.3

9.3

10.4

Annual

76.2

95.3

102.0

97.1

94.0

77.6

92.2

84.2

107.3

81.9

80.9

74.9

83.1

80.9

96.4

108.9

91.6

77.3

85.0

85.7

76.3

115.3

98.5

111.1

93.7

65.1

93.2

98.2

96.7

97.3

77.7

103.4

90.0

111.3

78.0

65.2

84.7

99.1

86.3

101.0

74.9

86.8

89.9

Mean precipitation, in inches, at stations near sea level from Petersburg to

Juneau, Alaska

[Data from records of the U.S. Weather Bureau]

Month

October ..................

April .....................

May. ....................

July.....................

September. ...............

Petersburg

17.3

10.6

10.6

9.4

7.6

7.0

7.0

6.2

4.8

5.1

7.6

11.6

105.8

Speel River

21.0

18.4

14.2

11.1

10.8

11.2

7.4

6.3

4.2

7.9

11.6

18.0

142.2

Annex Creek

17.3

13.3

9.5

8.7

7.4

6.5

5.8

5.7

4.8

6.5

10.1

13.9

109.4

Juneau

13.1

10.3

8.0

7.6

6.1

6.1

5.8

5.3

4.1

5.5

7.5

10.4

89.9
CLIMATE 13

The station at Petersburg, at lat 56°49' N., long 132°57/ W., 

has been operated intermittently since 1924 and continuously since 

1937, with 23 years of complete record to 1957. The station at 

Speel River was on the east shore of Speel Arm, at lat 58°08' N., 

long 133 °34' W. It was operated between 1916 and 1930, with 

10 years of complete record.

The station at Annex Creek is on the west shore of Taku Inlet, 

at lat 58°19' N., long 134°06' W. It has been operated continuously 

between 1917 and 1951 and intermittently since 1951, with 34 

years of complete record.

The average monthly distribution of precipitation relative to 

the annual amount evidently is similar at the four stations and 

probably would be nearly the same if the periods of record 

were the same. The estimated average annual amounts for the 

42 water years 1916-57, computed by comparison with Juneau, 

are about 105 inches for Petersburg, 148 inches for Speel River, 

and 108 inches for Annex Creek. The Speel River station was 

at an altitude of 15 feet; the other 3 stations were at various 

altitudes within about 200 feet of sea level.

Several stations were operated at mining camps within a 

few miles of Juneau for brief intermittent periods, generally 

between 1916 and 1922. These stations were at altitudes of 750 

to 3,500 feet. Figures compiled by the Federal Power Commission and U.S. Forest Service (1947, p. 17) show that precipitation at these stations ranged from about 120 to 190 percent 

of that at Juneau.

The mean annual precipitation on stream basins for which 

streamflow records and reliable estimates are available for a 

substantial number of years can be approximately determined 

from the mean annual runoff. The estimates are given below 

for some of the streams discussed in this report.

Stream

Sweetheart Creek. .....

Long River ...........

Crater Creek ..........

Dorothy Creek. .......

Carlson Creek. ........

Mean annual 

runoff 

(inches) 1

144

126

188

220

128

176

149

Mean annual 

precipitation 

(inches)2

154

136

198

230

138

186

159

Normal, by comparison with 

Juneau. water years 

1916-57 (inches)

157

135

198

232

136

182

159

1 Different periods in each basin.

2 Runoff plus an estimated mean annual evapotranspiration of 10 inches.
14 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

In general the mean precipitation in the mountain stream 

basins is substantially greater than was recorded at stations near 

sea level. The amounts evidently depend not only on the altitude 

of the basins, but also on their aspect and location with respect 

to nearby topographic features. The mean altitude of the Dorothy Creek basin, for example, is roughly 2,500 feet and is somewhat higher than that of the adjacent Long River and Crater 

Creek basins, yet the precipitation is much less. The headwaters 

of the Dorothy Creek basin lie northwest, on the leeward side, 

of a high ridge; those of Long River and Crater Creek are southwest of this ridge.

Snowfall records for Juneau and Annex Creek are summarized below.

Station

Juneau. ..................

Do..................

Annex Creek. .............

Do........... ........

Altitude 

(feet)

72

72 - 204

24

24; 45

Period of record 

(calender years)

1937 - 43

1917-43

1937-43

1917-24, 1926-43

Mean annual 

snowfall (inches)

84

106

213

265

The data for both periods show that the snowfall at Annex 

Creek is about 2.5 times that at Juneau. If the average water 

equivalent of the snow was on the order of 0.1, as is possible, 

snowfall at Juneau accounted for about an eighth of the precipitation and that at Annex Creek for nearly a quarter of the precipitation during the period 1917-43.

TEMPERATURE

Mean monthly and annual temperatures, in degrees Fahrenheit, 

for Juneau, Petersburg, and Annex Creek were computed from 

the recorded figures and departures from long-term means as 

given by the Weather Bureau in the annual summary of climatological data for 1957, and are listed below.

The mean temperatures are approximately the same at Juneau 

and Petersburg but are appreciably lower at Annex Creek, 

especially in winter months. The difference probably is largely 

due to cold air flowing from inland through Taku Inlet.

Only a few temperature records have been collected at stations 

much higher than sea level in southeastern Alaska. Fragmentary 

records were collected at several mining camps near Juneau 

in 1917 and 1918. These camps were at altitudes of 750 to about
CLIMATE 15

2,800 feet. The mean monthly temperature generally ranged 

from about the same as at Annex Creek to several degrees lower.

Period

October ..................

November. ...............

January. .................

February .................

March ....................

April .....................

May. ....................

July..... .................

Annual. ............

Juneau

44.0

36.2

30.6

29.4

29.9

34.4

40.4

47.8

54.5

56.0

55.9

50.8

42.5

Petersburg

43.9

35.9

31.1

28.6

30.3

34.8

40.8

47.8

53.5

55.7

55.2

50.9

42.4

Annex Creek

41.8

32.6

25.4

23.4

25.9

32.7

39.8

47.4

53.2

54.9

53.7

49.0

40.0

The minimum temperature recorded at Annex Creek from 1917 

to 1957 was 18° F. (in February 1917), and there were minimums of 10° F. or lower in about a quarter of the years. As 

judged from the few monthly records for the mining camps near 

Juneau, minimum temperatures at least 14° lower than at Annex 

Creek may be expected at some mountain localities along the 

mainland between Petersburg and Juneau.

GLACIERS AND SNOW ACCUMULATION

The heavy snowfall in the mountains and the relatively cool, 

cloudy summers account for numerous glaciers which are prominent features in the mountains of southeastern Alaska. Cirque 

glaciers and glacierets are commonly located along the ridges 

between altitudes of about 3,000 feet to 4,000 feet in the stream 

basins discussed herein. There are some small valley glaciers 

in the Long River, Crater Creek, and Dorothy Creek basins, a 

few of which extend down to an altitude of about 1,500 feet. In 

the Speel River basin (exclusive of the Long River basin) larger 

and higher areas of snow accumulations account for several sizable 

valley glaciers, 2 of which extend down to an altitude of about 

500 feet.

Topographic maps of the Geological Survey show the extent of 

glaciers in the Port Snettisham and Taku Inlet areas (as interpreted from aerial photographs of 1948). Maps of the Thomas 

Bay area are not adequate for such determinations there. The 

glacier areas in 1948 are tabulated as follows for five basins in 

which glaciers cover more than a few percent of the total area.
16 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

Drainage

Speel River at damsite .............

Crater Lake outlet. ................

Total area 

(square miles)

36.3 

30.2 

226. 

11.4 

15.2

Glacier area

Square miles

3.0

8.2 

83.6 

3.3 

3.6

Percentage of 

total area

8 

27 

37

28 

24

Some perennial snow maintains the glaciers, but it is probable 

that in wet, cool years much of it is temporarily stored on and 

near the glaciers to appear subsequently as snowmelt in drier, 

warmer years. The equalizing effect of the snow and ice storage 

is shown qualitatively by the characteristics of annual runoff from 

several of the basins in relation to the characteristics of annual 

precipitation at Juneau and Petersburg. These are tabulated 

below.

Drainage

Cascade Creek near 

Petersburg .......

Cascade Creek near

Sweetheart Creek 

near Juneau .....

Long River near

Dorothy Creek

Carlson Creek at 

damsite. ........

Sheep Creek at 

damsite near

Water years

1927, i 1947-57 

1918-28, 1947-56 

1916-32, 1949-56

1916-24, 1928-32, 

1949-56

1930-41, 1943, 

1945-56

1917-20, 1947-57 

1917-20, 1947-57

Variability of 

annual runoff

Range 

(percent of 

mean)

+8 to - 14 

+28 to - 19 

+23 to - 19 

+20 to - 15 

+21 to -25

+25 to -27 

+21 to -20

Standard 

deviation 

(percent 

of mean)

6 

11 

11 

10 

13

14 

13

Variability of annual 

precipitation at Juneau

Range 

(percent of 

mean)

+26 to -26 

+22 to -28 

+25 to -27 

+26 to -26 

+27 to -28

+22 to -29 

+22 to -29

Standard 

deviation 

(percent 

of mean)

16 

18 

15 

13 

15

14 

14

1 Petersburg is much closer than Juneau to Cascade Creek. In this period the range of annual 

precipitation at Petersburg was + 19 percent to 27 percent, with a standard deviation of 

13 percent.
CLIMATE 17

If the annual runoff were not affected by natural storage, its 

variability in percentage of the mean would be approximately 

the same as that of the precipitation that caused the runoff, since 

evapotranspiration is small relative to the precipitation. The 

precipitation recorded at Juneau serves as an index to the areal 

precipitation and evidently is closely representative of the variability of precipitation on the nearby Carlson Creek basin, as shown 

by the close correspondence of the runoff and precipitation characteristics. Natural storage probably is small both in the Carlson 

Creek and Sheep Creek basins. Since the other basins are more 

distant from Juneau, the differences between the runoff characteristics in those basins and the precipitation characteristics at 

Juneau may be affected to a greater extent by random variations 

in the pattern of areal precipitation. The somewhat consistent 

nature of the differences, however, indicates that natural storage 

had an appreciable effect reducing the range of runoff and the 

standard deviation by at least several percent. In all except the 

Carlson Creek and Sheep Creek basins, ground-water storage 

probably is negligible in relation to snow and ice storage.

The effect of natural storage is very apparent in some years 

of extreme precipitation. Thus in water year 1949, precipitation 

was substantially above normal at Petersburg and Juneau, yet 

the runoff of Cascade Creek and Dorothy Creek was substantially 

below normal. The basin characteristics evidently are favorable 

for retention of part of the heavier snow packs through the 

summer. Furthermore, the summer of 1949 was exceptionally 

cool, a circumstance that apparently resulted in an abnormal 

carryover from the heavy snow pack of the previous winter. On 

the other hand, runoff in the Sheep Creek basin (and probably 

in the Carlson Creek basin) was the greatest of the periods of 

record in 1949, as was precipitation at Juneau for the same 

periods. The Sheep Creek basin and the adjacent Carlson Creek 

basin are at lower altitudes than the Cascade Creek and Dorothy 

Creek basins, and apparently even in wet years there is relatively 

little perennial snow. The correlation between the annual runoff 

from the Sheep Creek and Carlson Creek basins and the annual 

precipitation at Juneau is fairly close throughout the limited 

periods of record.

Although snow carryover tends to reduce the amount of artificial storage needed for a given degree of control by its equalizing 

effect on annual runoff, the seasonal distribution of runoff also is 

a determining factor. As shown in figure 2, for example, the 

storage requirements for control at Lake Dorothy are relatively
18 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

large in spite of the considerable amount of perennial snow in the 

basin. The bulk of the estimated seasonal runoff at Lake Dorothy 

is concentrated in a shorter period than at any of the other sites, 

and the range of monthly runoff above and below the average 

monthly runoff is greater.

In addition to changes in snow storage there may be annual 

as well as long-term changes in the volume of ice in the glaciers. 

Such changes, however, probably are equivalent to only a very 

small part of the annual runoff. Even rather large changes in 

the glaciers over a period of years probably would have little 

effect on the average annual runoff. The overall size of the Nisqually Glacier on Mount Rainier, Wash., for example, was about 

3 square miles in 1912, which is comparable to the area of the 

glaciers in the Long River basin. A comparison of maps of 1912 

and 1952 quoted in a report of the U.S. National Park Service 

(1954, p. 5) indicated that the net wastage of the Nisqually 

Glacier in that 40-year period averaged about 3.7 million cubic 

yards per year, which is approximately 2,300 acre-feet per year. 

Conditions are not similar in the Long River basin, but even if 

wastage or accumulation were 5 times that amount it would 

represent less than 4 percent of the average annual runoff.

The two large valley glaciers of the Speel River basin are shown 

on a map of the Alaska-Canada boundary prepared by the International Boundary Commission from surveys of 1906 to 1909, 

and also on the recent quadrangle maps compiled from aerial 

photographs of 1948. The termini of these glaciers are shown 

at about the same location on both maps, indicating that there 

probably was not a major difference in the volume of the glaciers 

in 1909 and 1948.

STREAM REGULATION

The runoff from the basins between Petersburg and Juneau 

is largely concentrated in the 6-month period May to October 

and originates from snowmelt and rainfall. On the average, 

about 91 percent of the runoff occurs from the drainage area 

above Lake Dorothy, which is above an altitude of 2,400 feet, and 

about 86 percent from the areas above Swan Lake on Cascade 

Creek, Long Lake on the Long River, and Crater Lake on Crater 

Creek, all of which are largely above an altitude of 1,000 feet. 

On Carlson Creek about 84 percent of the runoff occurs between 

May and October and on Sheep Creek and Sweetheart Creek 

about 79 percent. The runoff at the other sites probably has a 

seasonal distribution within the same range.
STREAM REGULATION 19

It would be possible to develop a considerable part of the 

potential power during this runoff period, either from natural flow 

alone or from natural flow equalized with relatively little storage. 

Such power, however, would have a very limited market unless 

used in connection with fuel-electric standby power. Four small 

hydroelectric plants near Juneau have been operated with natural 

flow and with supplemental power from steam-electric and dieselelectric units, although in 1959 only one was active. (See p. 21.) 

Generation of substantial amounts of power in this way probably 

would not be practicable in the foreseeable future since fuelelectric power is relatively costly in southeastern Alaska.

The power possibilities of the sites, therefore, were estimated 

only on the basis of regulated flow and with substantially complete control of the runoff where suitable reservoir sites are 

available.

The amount of storage capacity required for different degrees 

of control was determined from reservoir operation schedules 

for uniform monthly and annual releases. The amount required 

for control without any wastage over a period of many years is 

considerably affected by the infrequent occurrence of very wet 

years, and the extra storage capacity needed for complete capture 

of the runoff in such years is disproportionate to the gain in 

controlled flow. For example, a capacity of 125,000 acre-feet 

would have been required for complete control of the runoff of 

Dorothy Creek at Lake Dorothy during 25 water years of record, 

but a capacity of only 84,000 acre-feet would have provided 

for control of 98 percent of the runoff.

At some sites where reservoirs may be created by dams, the 

incremental cost of storage may not justify utilization of more 

than about 90 percent of the mean flow, as was pointed out by 

the Federal Power Commission and U.S. Forest Service (1947, 

p. 36). It was determined that in general the storage required 

for complete control of streams in southeastern Alaska is about 

twice that required to regulate 90 percent of the mean flow. At 

sites where relatively cheap storage can be developed by drawdown of natural lakes, it may be found desirable to provide for 

complete or nearly complete control of the runoff.

On the basis of streamflow records through 1956, the storage 

needed for complete control at the sites varies from about 80 to 

150 percent of the mean annual runoff, and that needed for 90 

percent utilization varies from 40 to 70 percent. At some sites 

the storage needed for complete control is roughly 3 times that 

needed for regulation to 90 percent of the mean flow. The
20 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

capacities are listed for 100-percent and 90-percent utilization 

for the sites where such degrees of development appear to be 

practicable. The variation of storage requirements for regulation 

from 80 percent to 100 percent of the mean flow is illustrated 

in figure 2 for a few of the sites. For a given full-reservoir level, 

regulation to somewhat less than the mean flow may correspond 

to the maximum development of potential power because of the 

reduction in drawdown and consequent increase in head. The 

optimum degree of development at each site would be determined 

by the intended use of the power and by cost studies.

The storage requirements in percentage of the mean annual 

runoff differ among the several sites partly because of differences 

in basin characteristics and to a considerable extent because of 

differences in the distribution of runoff during the varied periods 

of records and estimates which were used in the reservoir operation schedules. Future periods may include more critical years 

or series of years, so that the requirements may be somewhat 

underestimated especially for complete control. The estimates 

can be very inaccurate if based on relatively short or nonrepresentative streamflow records. (See discussion of the Sweetheart 

Creek site.)

Lakes formed by glacial action constitute favorable storage 

sites on eight of the listed streams between Petersburg and 

Juneau. Of these, all except Turner Lake are high enough so 

that storage could be developed by drawdown through tunnels

100

80

40 60 80 100 120 

STORAGE, IN PERCENT OF MEAN ANNUAL RUNOFF

140 160

FIGURE 2. Storage requirements at selected Alaskan sites for indicated degrees of regulation

during various periods.
STREAM REGULATION 21

tapping the lakes below their natural surfaces without sacrificing 

a large part of the power head. Turner Lake is at an altitude 

of only 73 feet, and impoundment of water by damming the outlet, 

with consequent gain in power head, would be the only practicable 

method of development. Dams could be constructed at or near 

the outlets of all the lakes, and, except at Turner Lake and at 

Lower Sweetheart Lake where the topography is unfavorable for 

drawdown, a combination of damming and drawdown might be 

considered. The distance for conveyance of water from the lakes 

to powerhouses at tidewater ranges from about !/% mile at the 

Turner Creek site to 3 miles at the Scenery Creek site.

On the Speel River and on Carlson and Sheep Creeks, storage 

would have to be developed by construction of dams at favorable 

places on the channels, supplemented at the Speel River site by 

an auxiliary dam at a saddle on the divide between the Speel 

River basin and the head of Speel Arm. The distance for conveyance of water from the reservoir sites to powerhouses at tidewater ranges from about Va mile at the Speel River site to 1^ 

miles at the Carlson Creek site.

DEVELOPED POWERSITES

The only waterpower sites that have been developed for significant amounts of power in or near the Petersburg-Juneau area 

are a group of 7 nea-r Juneau, 1 near Petersburg, and 1 on the 

Speel Arm of Port Snettisham, at which development has long 

been discontinued. The brief descriptions of these sites that follow 

are mainly from reports of the Federal Power Commission and 

U.S. Forest Service (1947) and the U.S. Army Corps of Engineers, (1952). In 1959, power was being developed at only four 

of the sites, but plants at other sites near Juneau could be put 

into service if needed.

CRYSTAL LAKE

The reservoir of the Crystal Lake plant is at the lake, about 

15 miles southeast of Petersburg. After enlargement of the plant 

in 1956 and 1957, storage capacity of 4,300 acre-feet was developed 

by means of a rockfill dam across the channel downstream from 

the natural outlet of the lake. This raises the surface 28 feet to 

an altitude of 1,296 feet at spillway level. Water is conveyed 

about 5,000 feet by pipe to a powerhouse near Blind Slough, an 

arm of Wrangell Narrows. There are 2 generators, each of 400 

kw capacity, and 1 generator of 1,600 kw capacity, all driven by
22 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

impulse wheels. A transmission line to Petersburg interconnects 

the hydroelectric plant with a diesel-electric unit having a power 

capacity of 1,250 kw.

The plant has been operated since 1925 by the Petersburg 

Municipal Light and Power Co. under a license issued to the 

town of Petersburg by the Federal Power Commission for Project 

No. 201.

TEASE LAKE

The Tease Lake plant was on the stream draining the lake, 

and its powerhouse was near the mouth of this stream on the 

east shore of Speel Arm. Water was conveyed to the powerhouse 

from a low timber dam below the outlet of Tease Lake by means 

of 2,600 feet of flume and 2,460 feet of penstock. The head of 

the penstock was at an altitude of about 990 feet. Power was 

developed by 2 impulse wheels of 1,000 and 350 horsepower which 

were directly connected to machinery of a pulpmill.

The plant was operated intermittently from 1921 to 1923 under 

a license issued by the Federal Power Commission to the Speel 

River Project, Inc., and the Alaska Pulp and Paper Co. for 

Project No. 4. The plant was abandoned in 1931 and the license 

was revoked in 1935.

ANNEX CREEK

The powerhouse of the Annex Creek plant is near the northwest 

shore of Taku Inlet, about 1 mile southwest of the upper Annex 

Lake and about 4,000 feet northeast of the mouth of Annex Creek. 

Storage is developed at the lake by means of a timber dam, first 

constructed in 1916 and replaced in 1936, and a tunnel tapping 

the lake about 135 feet below the natural surface. The present 

storage capacity is 23,360 acre-feet. Water is conveyed to the 

powerhouse through about 1,420 feet of tunnel and 7,100 feet of 

pipe. The mean net head is 755 feet. Power is developed by 2 

impulse wheels driving generators with a combined capacity of 

3,500 kva (kilovolt-ampere), listed as 2,800 kw in the report of 

the Corps of Engineers.

The plant is operated by the Alaska Juneau Gold Mining Co. 

under a joint permit of the Department of Agriculture and the 

Department of the Interior. The energy is transmitted 15 miles 

to Juneau where most of it was formerly used in mining and 

milling. Since 1944, when mining was stopped, the energy has 

been available for sale to the Alaska Electric Light and Power 

Co. for distribution in the Juneau area. The power system of
DEVELOPED POWERSITES 23

the Alaska Juneau Gold Mining Co. includes a steamplant of 

8,000-kw capacity at Juneau.

SHEEP CREEK

The present powerhouse of the Sheep Creek plant is located 

near the shore of Gastineau Channel, about 3 miles southeast of 

Juneau. According to Hoyt (1910, p. 157) a small amount of 

power was being developed on Sheep Creek as early as 1908. A 

plant was constructed by the Oxford Mining Co. in 1910 to utilize 

natural flow under a head of 270 feet. This was replaced by a 

larger development of the Alaska Treadwell Gold Mining Co. in 

1914, and the plant later was purchased by the Alaska Juneau Gold 

Mining Co., the present owner. Water was conveyed about a 

mile from a low diversion dam at an altitude of 620 feet to the 

powerhouse by way of a flume, a pipe, a short tunnel, and a 

penstock. Electric power was generated in 3 units driven by 

impulse wheels, 2 of 1,000-kw capacity each and 1 of 225-kw 

capacity. The energy was transmitted to the central fuel-electric 

station at Juneau. The plant was inactive for several years prior 

to 1959, and some of the facilities are in disrepair.

GOLD CREEK

The powerplant on Gold Creek is located at Juneau. Some 

of the natural flow of the creek is diverted at an altitude of 248 

feet and conveyed 5,100 feet by flume and penstock to a powerhouse near tidewater in Juneau. This houses 2 generators each 

of 500 kva capacity, and 1 generator of 1,000 kva capacity, all 

driven by impulse wheels. The aggregate capacity of the plant 

was listed as 1,600 kw by the Corps of Engineers (1952).

The plant is owned by the Alaska Electric Light and Power 

Co. and is connected with the system of the Alaska Juneau Gold 

Mining Co., and also with 2 diesel-electric units, each of 1,250-kw 

capacity, which are operated by the power company.

Power was being developed on Gold Creek as early as 1908, 

according to a compilation by Hoyt (1910, p. 157).

SALMON CREEK

The powerplant on Salmon Creek consists of 2 units operated 

in connection with a reservoir created by a 170-foot dam which 

was constructed in 1915. The storage capacity is 19,000 acre-feet, 

and the altitude of the full-reservoir surface is 1,188 feet. Water 

is conveyed about 4,480 feet from the reservoir by a steel conduit 

to a powerhouse on Salmon Creek at an altitude of about 450
24 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

feet. This houses 2 generators, each rated at 1,400 kw, driven 

by impulse wheels. Water is diverted from the tailrace of this 

powerhouse and conveyed by means of a flume and penstock 

11,500 feet to a powerhouse near the tidewater of Gastineau 

Channel, 2 miles northwest of Juneau. This houses two 1,400-kw 

generators, each driven by an impulse turbine.

The Salmon Creek plant is operated by the Alaska Juneau 

Gold Mining Co. under a joint permit of the Department of Agriculture and the Department of the Interior. Most of the power 

is sold to the Alaska Electric Light and Power Co.

NUGGET CREEK

Nugget Creek is a tributary of the Mendenhall River and is 

about 10 miles northwest of Juneau. The plant, now inactive, 

consists of a diversion dam at an altitude of about 550 feet on 

Nugget Creek near the east side of Mendenhall Glacier, and a 

conduit to convey the water about 1^4 miles to a powerhouse at 

an altitude of about 50 feet on the east side of the Mendenhall 

River valley. The power was generated in 2 units driven by 

impulse wheels, with capacities of 1,000 kw and 2,350 kva. The 

plant capacity was limited to about 2,350 kw because of inadequate penstock capacity.

The plant was constructed in 1914 and was operated by the 

Alaska Juneau Gold Mining Co. under a permit issued by the 

Forest Service. It is connected to the central station at Juneau 

by 15 miles of transmission line. The plant was in disrepair in 

1959.

TREADWELL DITCH

Tread well Ditch collected water from seven small creeks on 

Douglas Island near Juneau. Branches of the ditch conveyed 

water to the head of one penstock at an altitude of about 560 

feet and to another at an altitude of about 460 feet for power 

projects called No. 1 and No. 2, respectively. Development of 

power was started in 1882 and was continued until 1918 in 2 

powerhouses located near the town of Douglas, which is on 

Gastineau Channel only 2 miles from Juneau. The waterpower 

of both plants was used directly for driving the machinery of 

mines and mills of the Alaska Treadwell Gold Mining Co. and 

associated companies. Operation of powerhouse No. 2 was discontinued in 1918, and in 1922 a generator was installed in powerhouse No. 1 and the plant was connected by 5 miles of transmission line to the central station of the Alaska Juneau Gold Mining
UNDEVELOPED POWERSITES 25

Co. The installed capacity was listed as 1,044 kw by the U.S. 

Army Corps of Engineers, (1952). The plant was inactive and 

in disrepair in 1959.

UNDEVELOPED POWERSITES

FACTORS THAT WOULD AFFECT THE DESIGN AND OPERATION OF

POWERPLANTS

Snow avalanches are common, and rockslides have occurred 

in places in the mountains of southeastern Alaska. These are a 

potential source of danger to structures such as surface penstocks, 

powerhouses, and transmission-line towers located on or below 

steep mountainsides.

The occasional high winds at the mountain passes and along 

the inlets would have to be taken into account in the design and 

location of transmission lines. Icing of transmission lines at the 

higher altitudes also might be a troublesome factor. In the operation of the powerline from Annex Creek to Juneau it has been 

found desirable to heat the cables with periodic overloads to 

avoid accumulation of ice. This line crosses a ridge at an altitude 

of about 3,400 feet.

Ice would form on the surfaces of reservoirs during winter 

months, and at higher lake sites ice would persist as late as July 

and even early August in some years. The effect of ice on dams 

and outlet structures would have to be considered but probably 

would not present an unusual problem.

The streams at all of the storage sites carry some sediment 

at high stages, mainly from glacial debris. In several of the 

streams the suspended sediment is rock flour, which gives the 

water a milky appearance. Part of this is deposited in the lakes 

and part is carried through in suspension. It seems unlikely 

that the usual sediment loads at storage sites on these streams 

are great enough to cause rapid impairment of the storage capacity, or of gates, conduits, and turbines. An exception is the 

Speel River, which carries large quantities of heavy sediment, 

including sand and gravel, in suspension or as bed load. The 

possible effect of this sediment is discussed further under the 

section concerning the Speel River reservoir site.

Except for Turner Creek at Turner Lake outlet, fishways 

probably would not have to be considered at any of the dam 

sites, since the streams are generally too precipitous for fish 

migration. Turner Lake is at a low altitude, near tidewater, and 

salmon have been observed at its outlet. A fishway would have
26 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

to be provided if a dam should be constructed at the outlet, but 

since the lake level probably would not be raised more than about 

55 feet, this would not be a major problem.

In some waterpower developments, particularly where storage 

is limited, forecasts of seasonal runoff are useful in the establishment of operation schedules for the most effective use of the 

water. The forecasts commonly are based on snow surveys and 

the expected range of precipitation in the snow-runoff period. 

If the precipitation that occurs after the snow surveys has little 

effect on the runoff, the forecasts may be very reliable. In southeastern Alaska, however, precipitation that occurs during the 

period from June to September averages about 30 percent of the 

annual amount and may account for a substantial part of the 

runoff. Another relatively unpredictable factor is the natural 

storage as snow and ice, which tends to persist throughout wet, 

cool years and melt in dry, warm years.

METHODS FOR APPRAISAL OP POWER

The power possibilities of all of the sites except the Speel 

River are discussed only on the assumption that considerable 

storage would be provided for annual-use or holdover regulation. 

Storage capacity on the Speel River can be provided by damming 

the stream, but sedimentation of the reservoir may be rapid. 

The useful life of the project could be extended by design and 

operation in a coordinated system so that stabilization of the 

seasonal power would be provided by the Long River and Crater 

Creek plants. In that event much of the Speel River storage 

capacity could be reserved for sedimentation.

Potential power was computed on assumption that the flow 

could be utilized through the mean gross head for generation of 

electric power at an overall plant efficiency of 80 percent. In 

kilowatts this is given by the equation P = 0.068 Q H, where Q 

is the flow in cubic feet per second (cfs), and H is the mean gross 

head in feet. Unless otherwise specified the mean gross head was 

taken as the height from the tailrace (or nozzle elevation with 

impulse wheels) to the reservoir level corresponding to half of 

the usable contents.

SITES IN THOMAS BAY AREA 

MAPS

A plan and profile of Scenery Creek and Scenery Lake and a 

map of the damsite at the outlet of Scenery Lake were published 

by the Geological Survey in 1950. The creek and lake plan is
UNDEVELOPED POWERSITES 27

on a scale of 1:24,000 and the contour interval is 20 feet. The 

map of the damsite is on a scale of 1:4,800 and the contour interval 

is 10 feet.

A map entitled "Cascade Creek and vicinity, Alaska, Dam 

Sites" was compiled from aerial photographs and from planetable 

surveys of 1949 and 1950, and published by the Geological Survey 

in 1952. This is on a scale of 1:24,000 and has a contour interval 

of 40 feet. It shows the topography of a strip extending a few 

miles inland from Thomas Bay, in which the powersites on Delta 

Creek, Cascade Creek, and Scenery Creek are located. Maps of 

damsites at the outlets of Swan Lake and Scenery Lake are on 

scales of 1:2,400 and 1:4,800, respectively. The topography of 

Scenery Lake as shown on this map does not agree exactly with 

that shown on the map of 1950, which was based entirely on 

planetable surveys.

Maps of the Alaska Reconnaissance Topographic Series, Petersburg and Sumdum, Alaska-Canada, published by the Geological 

Survey in 1952, have a scale of 1:250,000 and contour intervals 

of 200, 250, and 1,000 feet. These show the basins of the powersites, the system of waterways, and the general topography of 

a large area in the vicinity.

A planimetric map of the Tongass National Forest published 

by the Forest Service in 1951 on a scale of 1 inch equals 12 

miles shows all of southeastern Alaska.

Soundings in Thomas Bay and Frederick Sound are shown on 

Chart 8210 of the U.S. Coast and Geodetic Survey. The scale 

is 1:40,000 and the soundings are in fathoms.

LOCAL, GEOGRAPHY AND TOPOGRAPHY

Delta Creek, Cascade Creek, and Scenery Creek are on the 

mainland east of Thomas Bay. The nearest town is Petersburg, 

about 15 miles southwest of Thomas Bay, on Mitkof Island. The 

population of Petersburg was 1,605 in the 1950 census, and the 

principal activity is fishing and related services. Mitkof Island 

is separated from the mainland by Frederick Sound, which at 

the narrowest is about 31/2 miles wide.

The headwaters of the 3 creeks are at altitudes above 4,000 

feet, and peaks near the eastern boundaries of the Scenery Creek 

and Cascade Creek basins are higher than 6,000 feet.

Drainage is from east to west, and along the course of each 

creek there are lakes which constitute good storage sites: Ruth 

Lake on Delta Creek, Swan Lake on Cascade Creek, and Scenery 

Lake on Scenery Creek. (See fig. 3.) In addition a pool called
28 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

Former U. S. Geological 

Drainage boundary Survey gaging station

345 MILES

FIGURE 3. Map of powersites in the Thomas Bay Area, Alaska.

Falls Lake extends half a mile along Cascade Creek, a mile downstream from Swan Lake. Photographs of Ruth Lake and Scenery 

Lake are shown in figures 4 and 5. Swan Lake is in similar 

rugged terrain.
UNDEVELOPED POWERSITES 29

FIGURE 4. Aerial view northward across Ruth Lake and divide between Delta and Cascade Creek 

basins. Thomas Bay in left background.

FIGURE 5. View eastward toward upper end of Scenery Lake.

Chart 8210 of the U.S. Coast and Geodetic Survey shows 

that Thomas Bay is as much as 600 feet deep and that large tugs 

or barges could reach the mouths of each of the three creeks. 

Transport of equipment and material from the shore to inland 

points for construction of powerplants might require tramways.
30 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

WATER SUPPLY

RECORDS OF STREAMFLOW

A gaging station designated "Cascade Creek near Petersburg," 

located near the mouth of the creek, was operated from October 

1917 to November 1928 and from October 1946 to date. The 

drainage area is 23.0 square miles. The average discharge for the 

21 water years of complete record was 244 cfs, corresponding to 

an average annual runoff of 177,000 acre-feet. Monthly and 

annual figures of runoff through September 1956 as rounded 

from records are listed in table 2

TABLE 2. Monthly and annual runoff, in thousands of acre-feet, Cascade 

Creek near Petersburg, Alaska

Water year

1919............

1920. ...........

1Q91

1Q99

1923............

1924............

1QOK

1926............

1927............

IQOQ

1947

1948. ...........

1950............

1951.... 

1952............

1953............

1954............

1955............ 

1956

Mean. ....

Oct.

36.2

23.1

20.5

9.7

34.8

15.5

23.7

22.0

12.9

23.9

18.4

11.6

11.6

13.3

23.1

8.6 

15.0

29.1

24.2

15.9 

13.2

19.3

Nov.

39.1

11. 0

6.1

7.6

7.4

15.1

14.2

12.1

10.9

9.6

5.0

13.5

9.5

8.7

22.2

5.1

6.7

9.1

7.9

13.3

8.2

11.5

Dec.

4.5

5.6

4.5

2.1

9.0

4.0

4.8

5.2

21.3

8.3

2.0

2.3

4.4

3.0

3.8

3.0 

4.1

3.9

4.7

9 2 

2^5

5.3

Jan.

4.0

9.9

4.8

2.0

3.1

1.7

2.2

1.1

24.9

3.3

8.7

2.6

5.3

2.8

1.5

2.6 

2.0

2.0

3.1

4.1 

1.4

4.4

Feb.

1.5

1.5

3.4

2.3

1.4

2.3

1.4

1.1

4.1

1.1

2.8

2.3

2.3

1.4

1.1

1.4 

1.9

1.7

11.0

2.5 

1.2

2.4

Mar.

1.2

1.7

2.0

2.5

1.2

3.4

2.8

1.5

8.6

1.9

4.1

11.5

1.6

2.1

1.4

1.8 

1.8

1.8

2.1

2.2 

1.0

2.8

Apr.

3.0

4.4

2.0

2.0

3.9

5.4

3.9

2.0

16.2

1.9

4.3

9.7

1.5

3.6

1.6

2.7

2.8

2.6

1.8

3.0 

2.1

3.8

May

12.0

9.5

6.1

12.3

11.1

15.2

18.0

20.5

17.7

10.1

22.4

20.1

21.4

17.8

10.1

17.9 

15.9

21.5

12.1

8.4 

22.1

15.3

June

28.7

19.2

26.2

30.3

18.4

30.4

35.3

29.0

24.4

32.8

34.0

30.3

29.5

26.5

30.8

34.7 

26.0

27.3

27.1

25.2 

25.2

28.2

July

32.7

29.3

33.8

26.6

29.1

27.7

32.5

38.3

25.3

29.6

36.2

23.9

24.8

30.4

31.0

29.9 

37.8

23.9

24.0

34.1 

33.3

30.2

Aug.

40.3

35.1

41.6

22.7

30.9

31.2

31.8

27.7

20.0

25.8

27.2

22.7

22.0

28.3

23.9

20.4 

28.6

25.3

17.3

33.7 

40.7

28.4

Sept.

23.8

29.0

19.8

24.0

23.5

33.0

40.7

18.7

13.7

31.5

25.2

31.3

28.8

27.1

25.5

17.0 

31.0

22.9

19.7

26.1 

17.9

25.2

Annual

227.0

179.3

170.8

144.1

173.8

184.9

211.3

179.2

200.0

179.8

190.3

181.8

162.7

165.0

176.0

145.1 

173.6

171.1

155.0

177.7 

168.8

177.0

A gaging station designated "Scenery Creek near Petersburg," 

near the mouth of the creek, was operated from September 1949 

to November 1952, when the station was destroyed by falling 

trees in a windstorm. The drainage area at the former station 

is 30.0 square miles. Monthly and annual figures of runoff in 

thousands of acre-feet, as rounded from the records for the 3 

water years of complete record are given below, 

water years of complete record, are given below.

Month

Oct....... ....

Nov ..........

Dec...........

Feb...........

Mar. .........

1950

28.8

28.2

4.9

2.2

1.4

1

Q

2.7

1951

12.6

6.7

3.7

3.4

1.8

9 Q

5.4

1952

19.3

8.3

4.4

2.6

2.8

3

C

6.6

Month

July.........

Aug...... ....

Sept. ........

Annual .....

1950

16.9

33.0

35.0

29.2

33.8

217.9

1951

21.6

37.6

33.8

22.9

22.3

174.0

1952

1Q 6

27.8

42.9

32.7

34.5

205.0
UNDEVELOPED POWERSITES 31

The monthly and annual records through September 1956, and 

daily discharge records for Cascade Creek from October 1946 to 

September 1956 and for Scenery Creek from September 1949 to 

September 1952 have been published by the U.S. Geological 

Survey (1957, 1958a, 1958b).

RUNOFF AT RUTH LAKE OUTLET

No streamflow records have been obtained for Delta Creek 

except for 10 discharge measurements at the mouth of the 

creek at times of relatively low flow between 1950 and 1956. 

Seven of these were made at times when the recorded flow of 

nearby Cascade was fairly steady and hence may give a rough 

indication of the relative amount of runoff from the two basins 

during periods of low flow. The average of the low-flow measurements is 35 percent of the corresponding flow of Cascade Creek 

whereas the drainage area is 45 percent that of Cascade Creek. 

This discrepancy may reflect a difference in seasonal distribution 

of runoff near the mouths of the creeks rather than a difference 

in annual runoff per unit area. The 2 lowest measurements on 

Delta Creek, 2.79 cfs (Feb. 3, 1955), and 6.51 cfs (Nov. 29, 1950) 

were only 18 percent of the comparable flows of Cascade Creek.

The storage site on Delta Creek at Ruth Lake has a drainage 

area of 7.9 square miles, or 42 percent of that at the outlet of 

Swan Lake on Cascade Creek. The Delta Creek and Cascade 

Creek basins are adjacent and have somewhat similar topography 

and aspect, although the headwaters of Delta Creek are not 

quite as high as those of Cascade Creek. It is probable that the 

runoff per unit area is roughly the same in the two basins. 

The water supply at the Ruth Lake outlet was estimated to be 

40 percent of that at the Swan Lake outlet, or slightly less than 

the drainage-area ratio. This corresponds to a mean discharge 

of 81 cfs. The seasonal and annual distribution of the runoff was 

assumed to be the same at the two lakes in the estimation of 

storage requirements at Ruth Lake, although the discharge measurements on Delta Creek show that the runoff at Ruth Lake 

probably is somewhat more concentrated than that at Swan Lake.

RUNOFF AT SWAN LAKE OUTLET

The storage site on Cascade Creek at Swan Lake has a drainage 

area of 18.9 square miles, or 82 percent of that at the gaging 

station. Since the area above the lake ranges between higher 

altitudes than the area below the lake, it undoubtedly receives 

proportionately more snowfall and less rainfall. The runoff there-
32 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

fore must be proportionately greater in summer months and less 

in winter months than at the gage. For the purpose of determining storage requirements, the following estimated distribution 

in percent of runoff at the gaging station, was used.

Oct.

Nov.

Dec..... .

.....90

85

..... 75

Feb

Mar. . . .

.... 50

en

.... 50

May ....

.... 50

.... 75

.... 85

Aug ......

Sept.

. ....90

.. . ..90

. ....90

Reservoir operation schedules were computed from the end 

of the high-water season, November 1917, through 250 months 

of record in the 21 water years of complete record, 1918 through 

1956. Although there is a gap from 1928 to 1946, the records 

were considered as being a consecutive series representative of 

a possible future series. The average estimated discharge is 

203 cfs at the outlet of Swan Lake, or 84 percent of the average 

discharge recorded at the gage for the months of the operation 

schedule.

RUNOFF AT SCENERY LAKE OUTLET

The period of streamflow record for Scenery Creek, water years 

1950-52, is too brief to give a measure of the reliable water 

supplies. During that period the runoff per unit area was 7 

percent less than from the area above the Cascade Creek gage, 

and was less in each of the 3 water years. It is assumed that the 

runoff per unit area above the two storage sites tends to have a 

similar difference over long periods of wet and dry years.

The storage site on Scenery Creek at Scenery Lake has a 

drainage area of 21.1 square miles, or about 11 percent more 

than the area above Swan Lake on Cascade Creek. Since the 

unit runoff probably is less, it was assumed that the total runoff 

at each of the 2 lakes is the same, corresponding to a mean 

discharge of 203 cfs. It was also assumed that the seasonal and 

annual distribution of the runoff is the same.

DELTA CREEK POWERSITE 

RESERVOIR SITE

A reservoir could be formed on Delta Creek by a dam near 

the outlet of Ruth Lake at its western end. This lake is 2 miles 

east of Thomas Bay, at an altitude of 1,353 feet. It is half a 

mile long and is bounded by steep mountainsides except at the 

upper end, where a delta has formed. The slope on the south side 

of Ruth Lake is heavily timbered, but that on the north side,
UNDEVELOPED POWERSITES 33

is extremely steep and supports very little timber. The lake has 

an area of only 55 acres and a volume of only about 2,500 acrefeet.

The sides of a V-shaped canyon downstream from the lake 

outlet are topographically suitable as abutments for a dam 

to a height of several hundred feet above the lake. At a point 

about 200 feet downstream from the outlet the right bank is 

practically vertical to a height of 60 feet above the stream. The 

creek channel is roughly 30 feet wide between the steep canyon 

sides. The damsite has not been mapped except as a part of 

the area shown on the Geological Survey topographic map "Cascade Creek and Vicinity." As nearly as can be determined from 

this map the canyon is about 380 feet wide 230 feet above the 

stream, and 500 feet wide 340 feet above the stream. The steep 

canyon sides extend upward for several hundred feet to knolls 

at an altitude of about 1,800 feet on both sides.

Since the subsurface capacity of Ruth Lake is small in relation 

to that needed for substantial control of the runoff, development 

by drawdown would not be practicable. Reservoir areas and 

capacities for a range above and below the lake surface are 

shown below.

Altitude 

(feet)

1,280... .................

1,300. ...................

1,320. ...................

1,340. ...................

1,353 i... ................

1 , 400 ....................

1,440. ...................

1,480. ...................

1 , 520 ....................

], 560 ....................

1 , 600 ....................

1 , 640 ....................

1,660. ...................

Area 

(acres)

15 

26 

35 

44 

55 

94 

113 

137 

165 

190 

222

Capacity 

(acre-feet)

Below lake surface

2,400 

2,000 

1,400 

600 

0

Above lake surface

0 

3,500 

7,600 

12,600 

18,600 

25,700 

33,900 

243,000 

2 48,000

1 Lake surface.

2 Estimated by extrapolation.

Rock is exposed on both sides of the canyon, and Miller 

(1955, p. 39) reported that it is satisfactory as a foundation for 

either a masonry or rock-fill dam.

On the assumption that the storage requirements are proportionately the same as at Swan Lake (see p. 35) 48,000 acre-feet
34 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

of capacity would have been needed for complete control of Delta 

Creek in the same 21 years of runoff recorded for Cascade Creek, 

This could be obtained by raising the lake surface 307 feet, with 

a dam about 340 feet above stream level at the damsite. Regulation for uniform release equal to 90 percent of the mean flow, 

or 73 cfs, might be more practicable. This would require a 

storage capacity of 24,000 acre-feet, which could be obtained by 

raising the lake surface only 197 feet with a dam about 230 

feet above the stream level at the damsite.

Since the terrain is very rugged, transport of materials from 

Thomas Bay would be relatively costly. The bulk of the material 

for a rock-fill dam could be quarried at the site, and this type 

therefore might be cheaper than a masonry dam.

If a side-channel spillway should be constructed, as might be 

appropriate for a rock-fill dam, the possibility of blockage or 

damage from slides should be considered. There were no signs 

of fresh slides at the time of the geologic examination in 1951, 

and since there are breaks in the slopes at the knolls directly 

above the site, the possibility may be remote.

PLANS OF DEVELOPMENT

Water could be conveyed from Ruth Lake to a powerhouse 

on Thomas Bay by means of a tunnel and penstock. There are 

at least 2 possible routes, each requiring about l 1/^ miles of 

tunnel and ^ mile of penstock. One is north of Delta Creek and 

bears southwestward from Ruth Lake to a powerhouse site at 

or near the mouth of Delta Creek. The other bears northwestward from the lake to a powerhouse site at or near the mouth of 

Cascade Creek.

The second route was suggested by the Federal Power Commission and U.S. Forest Service (1947, p. 64) because a strip 

along Thomas Bay extending a mile south of Cascade Creek 

was considered to be a satisfactory site for a mill and town.

If an investigation shows that industrial sites south of Thomas 

Bay are preferable, as seems likely, it might be advantageous to 

locate the Delta Creek powerhouse near the mouth of Delta Creek 

to minimize the distance for transmission of power and conveyance 

of water to the factory. It would be possible also to convey 

reservoir releases still farther south from Ruth Lake by means 

of about 2.1 miles of tunnel and penstock to a powerhouse at the 

Patterson River. This river is a glacial stream that has formed 

a wide delta at the southern end of Thomas Bay.
UNDEVELOPED POWERSITES 35

CASCADE CREEK POWERSITE 

RESERVOIR SITE

A reservoir could be created on Cascade Creek by construction 

of a dam near the outlet of Swan Lake at its western end, by a 

tunnel to provide for drawdown of the lake, or by a combination 

of the two methods. Swan Lake is 2.5 miles east of Thomas Bay 

at an altitude of 1,514 feet. It is 2 miles long and is bounded by 

steep mountainsides, except at the upper end. The slopes around 

the lake are timbered.

A narrow canyon downstream from the lake outlet constitutes 

a very good dam site. (See fig. 6). At the narrowest section of 

the canyon, 500 feet downstream from the lake outlet, the width 

at stream level is about 90 feet, and at 150 feet above stream 

level it is 390 feet.

Miller (1955, p. 31-32) reported that the bedrock is diorite 

and is a suitable foundation for either a masonry or rock-fill dam.

The topography also is favorable for development of storage 

capacity by tapping the lake with a tunnel outlet. Sufficient 

capacity for complete control of the runoff could be obtained 

either by drawdown alone or by damming alone. Reservoir areas 

and capacities tor a range above and below the lake surface 

are listed on page 36.

Schedules of reservoir operation were established for uniform 

monthly releases equal to 100 percent of the mean discharge, 

203 cfs, and 90 percent of the mean discharge, 183 cfs. These 

schedules would have required 121,000 and 60,000 acre-feet of 

usable capacity, respectively.

FIGURE 6. View of Swan Lake outlet and damsite area.
36 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

Altitude 

(feet)

1,250....

1,300. ...................

1,320. ...................

1,340............ ........

1,360. ...................

1,380.... ..........

1,400. ...................

1,420. ...................

1,440. ...................

1,460. ...................

1,480. ... .....

1 , 500 ....................

1,514 2 . ..................

1,520... .................

1,560. ...................

1,600.... .... .. 

1,640. ........... ......

1 , 680 ....................

1,720. ...................

Area 

(acres)

389 

410 

424 

441 

455 

469 

485 

498 

517 

532 

552 

570 

579 

730 

867 

946 

1,020 

1,130

Capacity 

(acre-feet)

Below lake surface

1 121,000 

101,700 

93,700 

85,400 

76,800 

67,800 

58,600 

49,100 

39,300 

29,100 

18,600 

7,800 

0

Above lake surface

0 

3,400 

29,600 

61,500 

97,800 

137,100 

180,100

1 Estimated by extrapolation.

2 Lake surface.

Since the terrain between the lake and Thomas Bay is very 

rugged, the transport of construction materials from Thomas 

Bay would be relatively costly. This circumstance might be a 

determining factor in the design of the dam or in the choice 

between damming and drawdown. The bulk of the materials 

for a rock-fill dam is adjacent to the site.

If a dam should be constructed it would be necessary to provide a spillway adequate to pass the maximum discharge that 

might occur. For a side-channel spillway, a type appropriate 

for a rock-fill dam, consideration should be given to the possibility of blockage or damage by slides. This hazard probably 

would be greatest during the spring or early summer when 

snowslides might bring down masses of brush, trees, and rocks. 

Miller reported that the right, north side of the canyon should 

be reasonably free from slides.

The maximum stream discharges probably are due to heavy 

rainfall combined with some snow and ice melt in the fall, which 

would be the period of maximum reservoir content. The maximum recorded discharge at the Cascade Creek gage was 3,280 

cfs in September 1947, possibly corresponding to about 2,800 cfs 

at the Swan Lake outlet.
UNDEVELOPED POWERSITES 37 

PLANS OF DEVELOPMENT

Water could be conveyed from Swan Lake in a westerly direction to a powerhouse a quarter of a mile northwest of the mouth 

of Cascade Creek. This would be about the shortest route for 

development of the head down to a suitable site at tidewater. 

The waterway would consist of 2.2 miles of tunnel and 0.6 mile 

of penstock. (The penstock length could be halved by location 

of the powerhouse farther to the northwest, but the terrain there 

may be unsuitable except for an underground installation since 

it is extremely steep.) It would be possible also to convey the 

water northwestward to the mouth of Scenery Creek, but this 

route is about 1 mile longer, requiring about 3i/*> miles of tunnel 

and §4 niile of penstock. The main advantage of this site is that 

a common powerhouse could be used for both the Cascade Creek 

and Scenery Creek units. The main disadvantage is that the 

point of power generation would be more distant from the area 

of probable use and powerlines would have to cross very rugged 

terrain between Scenery Creek and Cascade Creek.

In an alternative plan suggested by the Federal Power Commission and U.S. Forest Service (1947, p. 64) the head would 

be developed only from Falls Lake to Thomas Bay. A 50-foot 

dam would be constructed at the outlet of Falls Lake, raising its 

level to an altitude of 1,207 feet. Water could be conveyed from 

this fcrebay to the powerhouse site northwest of Cascade Creek 

through only about 1 mile of tunnel and 1X> mile of penstock 

for development of 1,190 feet of head. Storage could be developed at Swan Lake for complete regulation entirely by drawdown through half a mile of tunnel emptying into Cascade 

Creek above Falls Lake. The overall length of waterway would 

be roughly 70 percent of that required for conveyance directly 

from Swan Lake to Thomas Bay, and 86 percent of the mean 

head below the reservoir would be developed.

Miller (1955, p. 35) reported that a tunnel along the north 

side of the Cascade Creek valley to the site near the mouth 

of Cascade Creek would be in diorite throughout its length. His 

examination indicated that a tunnel along the route to Scenery 

Creek probably would be in diorite, but some calcareous gneiss 

might be included.

SCENERY CREEK POWERSITE 

RESERVOIR SITE

Storage capacity could be developed at Scenery Lake by construction of a dam near the lake outlet at its western end, by
38 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

drawdown, or by a combination of the two methods. The lake 

is at an altitude of 957 feet and is 3 miles east of Scenery Cove, 

an inlet of Thomas Bay. The lake extends about 2Va miles farther 

east between steep mountainsides. A smaller, unnamed lake is 

in the creek valley about a mile upstream. Timber grows on 

a flat area in the valley at the head of Scenery Lake and on 

the adjacent mountainsides in scattered stands broken by precipitous areas of bare rock. Evidence of snowslides is noticeable at several places around the lake.

Locations for a dam were considered at a point about 50 feet 

below the lake outlet and at about 350 feet downstream where 

a knoll constitutes a favorable abutment on the right, north 

bank (see fig. 7.) If the lake level were raised more than about 

70 feet, an auxiliary dam would be required across a saddle 

between the knoll and a hillside to the north. The distance 

across the saddle is 350 feet at a level 100 feet above the lake. 

The base of a dam at the center line of the downstream site 

probably would be somewhat lower than at the centerline of the 

upstream site, but the section for the main dam is narrower. 

Scenery Creek drops about 30 feet in a waterfall at the lake

FIGURE 7. Aerial view of Scenery Lake outlet. The damsite area is between the lake and the 

drain at the right edge of the picture.
UNDEVELOPED POWERSITES 39

outlet, which is a narrow V-shaped notch. The altitude of the 

stream at the centerline of the downstream site is 920 feet, 

or 37 feet below the lake surface.

Storage capacity of 60,000 acre-feet for regulation to 90 

percent of the mean flow could be developed by raising the lake 

surface 89 feet to an altitude of 1,046 feet. The width of the 

canyon at the centerline of the downstream site is only 275 

feet at this level, and the width of the saddle is 250 feet. The 

width at the upstream site at the same level is 900 feet. Storage 

capacity of 121,000 acre-feet for complete control could be created 

by raising the lake surface 157 feet to an altitude of 1,114 feet, 

but this would require a dam extending at least a thousand feet 

across the valley at either location.

Miller (1955, p. 21) reported that the bedrock at both damsites is satisfactory for foundation and abutments. He classified 

it as gneiss on the left side and across the channel, and as diorite 

farther to the north. The knoll at the lower dam axis separating 

the main and auxiliary dam sections was described as relatively 

impervious and suitable to serve as a natural dam.

The areas and capacities for a range above and below the 

lake surface are shown in the table below. Underwater contours on the map "Cascade Creek and Vicinity" were defined 

only above an altitude of 900 feet but soundings made at 5

Altitude 

(feet)

800. ...................

820. ...................

840. ...................

860. ...................

880. ...................

900. ...................

920 ....................

940 ....................

9572.. .................

960. ...................

980. ...................

1,000. ...................

1,020. ...................

1,040. ...................

1,060. ...................

1,080..... ...............

1,114. ...................

Area 

(acres)

473 

496 

518 

544 

570 

634 

685 

739 

781 

3814

Capacity 

(acre-feet)

Below lake surface

i 69,000 

1 62,000 

i 54,000 

1 46, 000 

138,000 

28,800 

19,100 

9,000 

0

Above lake surface

0 

1,600 

13 , 600 

26,800 

41,000 

56,200 

72,100 

i 89,000 

1 121,000

1 Estimated by extrapolation.

2 Lake surface.

3 Estimated in incomplete area of map "Cascade Creek and Vicinity."
40 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

sections across the lake showed that the underwater slopes are 

reasonably uniform down to an altitude of 800 feet, and the 

estimates for the range between 900 and 800 feet were made 

accordingly. The lake bottom flattens abruptly at altitudes between 800 and 750 feet so that drawdown much below the 800- 

foot level would tap relatively little storage. The lake bottom 

at a section a quarter of a mile east of the outlet is level at an 

altitude of 800 feet for much of its width. A usable capacity of 

60,000 acre-feet could be developed by drawdown to an altitude 

of 824 feet if the lake can be tapped by a tunnel at a level that 

is low enough to provide a water seal.

The storage requirements were assumed to be the same as at 

Swan Lake. These were computed as 121,000 acre-feet for a 

uniform monthly release of 203 cfs and 60,000 acre-feet for 

uniform release of 90 percent of this amount, or 183 cfs. The 

larger capacity could not be developed entirely by drawdown, 

and it probably would be relatively costly if developed entirely 

by damming.

Access to Scenery Lake for transport of heavy equipment and 

materials would be relatively difficult because of steep, rugged 

terrain extending about 0.6 mile west of the lake. Scenery Creek 

drops 560 feet through a crooked canyon in this area. An access 

road probably could be constructed without unusual difficulty 

from Scenery Cove about 2i/-> miles eastward to an altitude of 

about 400 feet in the Scenery Creek canyon. Tramways of some 

kind might be the most feasible means of transport from this 

point up to the lake outlet.

The right, north, side of the canyon at the damsite extends 

up only about 300 feet higher than the lake surface to a divide 

between Scenery Creek and a tributary, and thus should be 

relatively free from slides. This side would be a better location 

for a side-channel spillway than at the left abutment, which is 

below a steeper and higher slope (see fig. 7). Alternatively, it 

might be desirable to construct a concrete overflow structure in 

the saddle as a spillway for a nonoverflow dam in the channel 

section at the lower damsite. In connection with a main dam 

at that location, an excavated spillway through the saddle area 

could be used for reservoirs having a maximum pool level lower 

than an altitude of about 1,030 feet.

The peak discharge at the Scenery Creek gage ranged from 

about 150 percent to 200 percent of that at the Cascade Creek 

gage during 7 comparable rises from 1950 to 1952, although 

the drainage area is only 30 percent larger and the annual runoff
UNDEVELOPED POWERSITES 41

per unit area is less than that of Cascade Creek. The relatively 

large peak flows on Scenery Creek evidently are due to relatively 

large areas at medium and low altitude where precipitation may 

occur as rain rather than snow. For example, only 3 percent of 

the Cascade Creek basin is below an altitude of 1,200 feet, as 

compared with about 15 percent in the Scenery Creek basin. 

There is a somewhat similar difference in range of altitude above 

the storage sites on the two streams, so it is likely that peak 

discharges at Scenery Lake are greater than at Swan Lake.

FLANS OF DEVELOPMENT

Water could be conveyed from Scenery Lake in a westerly 

direction either to a powerhouse near the head of Scenery Cove 

or to one upstream in the Scenery Creek canyon for a lesser 

degree of development. Scenery Creek drops 680 feet, or 70 

percent of the total fall to tidewater, within about 1*4 miles of 

the lake. A waterway to Scenery Cove along the south side of 

the canyon would consist of about 3*4 miles of tunnel and about 

14 mile of penstock. A waterway to a powerhouse site 680 feet 

lower than the lake would consist of only about 1*4 miles of 

tunnel and a quarter of a mile of penstock.

The U.S. Army Corps of Engineers (1952, p. 120) considered 

the possibility of conveying water from Scenery Lake to a powerhouse site at the mouth of Cascade Creek. This would avoid 

the difficult problem of power transmission over the rugged 

terrain between Scenery Creek and Cascade Creek, but the 

distance for conveyance of water would be almost doubled, and 

it was concluded that a powerhouse site on Scenery Creek would 

be preferable.

The route to Scenery Cove crosses the South Fork of Scenery 

Creek, a precipitous stream draining the mountain slope just 

southeast of the mouth of Scenery Creek. It would be possible 

to capture natural flows of this creek by diversion into a shaft 

inlet at an altitude on the creek above the hydraulic gradient of 

the Scenery Lake tunnel. The drainage area that could be tapped 

in this way is 3.0 square miles or 14 percent of that above 

the outlet of Scenery Lake.

Miller (1955, p. 26) reported that a tunnel from Scenery Lake 

along the south side of the Scenery Creek valley would be in 

gneiss for a short distance west of the lake and in diorite for 

the remainder of the route to Scenery Cove.
42 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

POTENTIAL POWER OF SITES IN THOMAS BAY AREA

The potential power of each of the 3 sites was estimated on 

the assumption that the head would be developed from the reservoirs down to the nozzles of impulse wheels set 17 feet above 

mean sea level a few feet higher than the expected high-tide 

level. The power possibilities and related data are summarized 

as follows for 2 degrees of regulation.

Controlled flow . . . percent

Storage capacity. . . acreft......... .."..........

Operating range alt (ft) . . .

Delta Creek

100

48,000

/ 1,660 

\ 1,353

81 

1,533

8,440

90

24,000

1,550 

1,353

73 

1,459 

7,240

Cascade Creek

100

121,000

1,600 

1,396

203 

1,497 

20,700

90

60,000

1,562

1,458

183 

1,497 

18,600

Scenery Creek

100

121,000

1,046

824

203 

940 

13,000

90

60,000

1,004

898

183 

940 

11,700

The plan of storage development for Delta Creek illustrated 

in this tabulation is by a dam at the outlet of Ruth Lake 

(since drawdown is impracticable). The plan for Cascade Creek 

and Scenery Creek is by combined damming and drawdown, 

with storage capacity equally divided above and below the natural 

lake level, a division that is only one of many that might be 

considered. The potential power and some related data, with 

damming alone and drawdown alone, are summarized below for 

comparison.

Controlled flow . . . percent of mean flow

Operating range with drawdown .... alt

Continuous power with drawdown ....

(ft)., 

(ft) . . 

kw

kw

Cascade Creek

100

203

/ 1,664 

I 1,514

/ 1,514 

\ 1,250

21,900 

19,100

90

183

1,598 

1,514

1,514 

1,398

19,200 

17,900

Scenery Creek

100

203

1,114 

957

} m

14,200

(J )

90

183

1,046 

957

/957 

\824

12,300 

11,000

1 Storage available by drawdown is insufficient for this degree of regulation.
UNDEVELOPED POWERSITES 43

The estimates for Scenery Creek in the foregoing tabulations 

were made without allowance for the possible use of the natural 

flow of the South Fork of Scenery Creek. If the runoff per unit 

area of the South Fork basin is the same as that of the Scenery 

Lake basin, its mean flow at the possible point of capture is 

14 percent of the inflow to Scenery Lake. The continuous power 

could be increased somewhat accordingly by overall regulation 

from Scenery Lake, although this would require increased storage 

and waterway capacity.

The cost of storage at Swan Lake and Scenery Lake by damming or by combined damming and drawdown probably would be 

substantially more than by drawdown alone. The cost of drawdown above that for conveyance from dams or higher levels in the 

lakes would be due mainly to increases in length of the tunnels for 

tapping the lakes at depth. The increases would be relatively small 

because the underwater slopes are steep. Any saving in storage 

cost by drawdown, however, would have to be weighed against the 

reduction in power due to the reduction in available head.

LOCATIONS AT WHICH POWER COULD BE USED

An area of at least 10 square miles lies below an altitude 

of 200 feet between the shores of Frederick Sound near Point 

Agassiz and the Patterson River at the southern end of Thomas 

Bay. Much of it is topographically suitable for an industrial 

site. Point Agassiz is within a transmission range of about 6 

miles from Delta Creek, 8 miles from Cascade Creek, and 14 

miles from Scenery Creek.

A transmission line from Cascade Creek and Delta Creek 

could be located near the east shore of Thomas Bay to a crossing 

of the Patterson River, thence southwestward to Point Agassiz. 

A possible though unfavorable route between Scenery Creek 

and Cascade Creek is near the east shore of Thomas Bay along 

a very steep mountainside, which is subject to rock and snowslides as shown on some photographs of the area and on Chart 

8210 of the U.S. Coast and Geodetic Survey. The U.S. Army 

Corps of Engineers (1952, p. 120) judged that an alternative 

route along a ridge roughly a mile inland would be preferable. 

It is across very rugged terrain at an altitude of about 3,000 

feet, but the route would be free from slides. Transmission 

from Scenery Creek also would be possible by an underwater 

crossing of Thomas Bay to the land west of Scenery Cove,
44 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

thence southward to another underwater crossing to Ruth Island, 

and overland across Ruth Island and the peninsula south of it 

to point Agassiz. Although this 15-mile route bypasses most of 

the rugged terrain, it is separate from the Cascade Creek-Point 

Agassiz route and would require about 3 miles of submarine 

cable for transmission.

The suitability of an area for industrial purposes must be 

considered in relation to sources of pure water, particularly 

since many processes require fairly large quantities of water. 

For example, the requirements for a mill producing 400 tons of 

woodpulp per day, a somewhat typical size, may be on the order 

of 40 cfs. A dependable supply of about twice this amount would 

be available from regulated water of Delta Creek, and even 

more from Cascade Creek or Scenery Creek. Water could be 

piped from Delta Creek or Cascade Creek to the Point Agassiz 

area over a route similar to that for transmission of power, 

at the sacrifice of some of the power head. Alternatively, supplies 

possibly could be obtained from ground water in the valleys of 

the Patterson River and the Muddy River, both of which are 

glacial streams near Point Agassiz. (Investigation of the groundwater possibilities was suggested by C. D. Cederstrom, Geological 

Survey, after an aerial reconnaissance in 1952.)

A strip of land extending along the shore of Thomas Bay 

from Cascade Creek southward was mentioned by the Federal 

Power Commission and U.S. Forest Service (1947, p. 64) as a 

possible industrial site. It has an area of about 100 acres below 

an altitude of 200 feet. An apparent disadvantage of the site 

is its cramped nature and its location below a steep mountainside. 

A triangular area of moderate relief just south of the mouth of 

Delta Creek, about 2 miles south of Cascade Creek, lies between 

the Patterson River delta and a ridge separating the Delta 

Creek and Patterson River basins. It has an area of about 350 

acres between altitudes of 40 feet and 200 feet. Both areas are 

close to the Cascade Creek and Delta Creek powersites and to 

sources of water from one or the other creek. The area south of 

Delta Creek may be preferable because of its moderate relief 

and lesser slide hazard.

The U.S. Army Corps of Engineers, (1952, p. 121 and 132a) 

considered transmission of power from the Cascade Creek and 

Scenery Creek sites to the Point Agassiz area, or to load centers 

at Petersburg and Wrangell. The transmission distance to Petersburg is about 20 miles from Cascade Creek, including about 4 

miles of underwater crossing at Frederick Sound. The trans-
UNDEVELOPED POWERSITES 45

mission distance to Wrangell is about 60 miles, including about 

11/2 miles of underwater crossing at Eastern Passage near 

Wrangell. Much of the route would be over very rugged terrain 

on the mainland southeast of Thomas Bay. The cost of energy 

delivered at Petersburg and Wrangell was estimated to be about 

150 and 170 percent respectively of the cost at Cascade Creek, 

with all the power transmitted to one or other of those towns. 

The transmission cost evidently would be a serious handicap 

to development of the power for use very far from the Thomas 

Bay area.

SITES AT GILBERT BAY AND SPEEL ARM OP PORT SNETTISHAM

AREA

MAPS

Surveys of Upper Sweetheart Lake, Lower Sweetheart Lake, 

and Sweetheart Creek were made by the Geological Survey in 

1958 and published in 1960 ("Plan and Damsite, Lower and Upper 

Sweetheart Lakes, Alaska.") A flat area of several square miles 

southeast of the mouth of Sweetheart Creek which may be suitable for an industrial site is also included. The maps are on scale 

1:24,000 and have a contour interval of 20 feet. Maps of damsites 

below the outlets of the 2 lakes are on a scale of 1:2,400, with 

a contour interval of 10 feet.

A map of the damsite area at the outlet of Tease Lake has 

been prepared by the Forest Service from surveys of the Speel 

River Project, Inc., one of the licensees of the former waterpower 

development there which was operated as Federal Power Project 

No. 4. The map is on a scale of 1 inch equals 100 feet, with a 

contour interval of 10 feet. The topography is shown to about 

80 feet above the lake level. The damsite map is part of a map 

entitled "Crater, Long and Tease Lakes Projects near Juneau, 

Alaska." Photostat copies are available from the regional office 

of the Forest Service at Juneau.

A map entitled "Plan, Long Lake, Crater Lake and Vicinity 

near Juneau, Alaska, Dam Sites" was published by the Geological 

Survey in 1952. The scale of the map is 1:24,000 and the contour 

interval is 20 feet. Contours are shown to about 200 feet above 

and 200 feet below the lake surfaces. The damsite maps are on 

scales of 1:1,200; 1:2,400; and 1:4,800, with a contour interval 

of 10 feet on land and under water. These maps are of the sites 

at the outlets of Crater Lake and Long Lake, a site on the Speel 

River, and a saddle where an auxiliary dam would be required.

The powersites and their related drainage basins are shown 

on Geological Survey topographic maps of the quadrangles Sum-
46 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

dum D-5 and D-6 and Taku River A-5, A-6, B-5, and B-6,

Alaska; and on Sheet 7 of the map of the international boundary 

between the United States and Canada. The maps of the Sumdum 

and Taku River quadrangles were compiled by the Geological 

Survey in 1948 and 1951 on a scale of 1:63,360, with a contour 

interval of 100 feet. The international map was published by 

the International Boundary Commission in 1923 on a scale of 

1:250,000, with a contour interval of 250 feet.

Maps showing the waterways and terrain between Speel Arm 

and Juneau include those for the quadrangles Juneau (AlaskaCanada), Sitka, Sumdum, and Taku River, Alaska, all on a scale 

of 1:250,000, with contour intervals of 200 to 1,000 feet. Some 

of this region also is shown on the quadrangle maps Juneau (A-l) 

and (B-l), on a scale of 1:63,360, and Juneau (B-2), on a scale 

of 1:62,500; and on a special topographic map "Juneau and 

Vicinity," on a scale of 1:24,000.

Soundings in Taku Inlet, Gastineau Channel and a part of 

Stephens Passage are shown on Chart 8235 of the U.S. Coast 

and Geodetic Survey. Soundings in Gilbert Bay, Speel Arm, 

Port Snettisham, and Stephens Passage near Snettisham are 

shown on Chart 8227. Both charts are published on a scale 

of 1:40,000, and the soundings are in fathoms.

LOCAL, GEOGRAPHY AND TOPOGRAPHY

Port Snettisham is a fiord extending northeastward from 

Stephens Passage and terminating in a few miles of narrower 

section called Speel Arm. The Speel River flows into Speel Arm 

from the northeast through tidal flats of its delta. Stephens 

Passage joins Taku Inlet and Gastineau Channel 15 miles northwest of Port Snettisham.

Juneau, the nearest city, is on Gastineau Channel, about 25 

miles northwest of Port Snettisham. The population of Juneau 

was recorded as 5,956 in the 1950 census. The principal activities 

are operation of the territorial government, commercial fishing, 

and furnishing transportation and other services to outlying 

communities, and to tourists. The rugged mountains and large 

glaciers in the immediate vicinity of Juneau are outstanding 

attractions. Gold mining formerly was a very important industry 

but is has been inactive since 1944.

Four of the powersites Tease Lake, the Speel River, the Long 

River (a tributary of the Speel River), and Crater Creek are 

grouped close to the head of Speel Arm. The other one, Sweet-
UNDEVELOPED POWERSITES 47

heart Creek, is 14 miles south of this group at the end of a 

southern extension of Port Snettisham called Gilbert Bay. (See 

fig. 8.) It is about 35 miles from Juneau by water.

The drainage basins of the four powersites are in mountainous 

terrain, with divides above altitudes of several thousand feet. 

About an eighth of the Speel River basin lies in Canada, and

U. S. Geological Survey 

gaging station

Former U. S. Geological 

Survey gaging station

FIGURE 8. Map of powersites in the Port Snettisham area, Alaska.
48 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

that portion is largely covered with snowfields extending to 

altitudes above 6,000 feet. At present [1959] there are no settlements in the stream basins or nearby. .

There are several mine tunnels on the south side of Port 

Snettisham between its entrance and Gilbert Bay near the abandoned hamlet of Snettisham. A large deposit of magnetite ore is 

located nearby.

Deep water extends to near the heads of Speel Arm and Gilbert 

Bay. The Forest Service (written communication 1957) reported 

that conditions for anchorage and construction of port facilities 

in Gilbert Bay are favorable. The mountainsides adjacent to the 

delta of the Speel River and the head of Speel Arm are very 

steep, and special methods may be required for transport of 

materials from landing piers to the nearby powersites.

WATER SUPPLY

RECORDS OF STREAMFLOW

Gaging stations have been maintained on Sweetheart Creek, 

the Speel River, the Long River and Crater Creek as shown below.

Figures of monthly and annual runoff for Sweetheart Creek 

near Juneau, Long River near Juneau, and Crater Creek near

Gaging station

Tease Lake outlet at Port Snettisham 4 

Long Lake Outlet near Juneau. 

Long River near Juneau ...................

Drainage 

area (square 

miles)

336.3

10.9 

30.2 

32.5

226

11.4

Period of records 1

Aug. 1915 - Mar. 1917.

June 1918 - Sept. 1927. 

April - Oct. 1913. 

Feb. 1913 - Oct. 1915. 

Oct. 1915 - Sept. 1924.

Oct. - Dec. 1926. 

June 1927 - May 1933. 

Oct. 1951 - Sept. 1956.

July 1916 - Sept. 1918.

Feb. 1913 - Dec. 1920.

June - Aug. 1921. 

Oct. - Dec. 1922. 

June - Sept. 1923. 

June - Sept. 1924. 

June 1927 - Dec. 1932.

1 Through Sept. 1956. Except for the Tease Lake outlet the available monthly and annual 

records through Sept. 30, 1956, and daily discharge records for Long River near Juneau from 

Oct. 1951 to Sept. 1956 have been published by the U.S. Geological Survey (1957, 1958a, b).

2 Published as "Sweetheart Falls Creek near Juneau."

3 Revised.

4 The record is of questionable accuracy.
UNDEVELOPED POWERSITES 49

Juneau are listed in tables 3, 4, and 5, respectively. These were 

rounded from published records and include some estimates for 

years of missing record.

RUNOFF AT UPPER AND LOWER SWEETHEART LAKE

The average discharge of Sweetheart Creek for the 10 water 

years of complete record, 1916 and 1919-27, was 335 cfs. The 

record was extended by estimating the monthly runoff in the 

1917-18, 1928-32 and 1949-56 water years from records of the 

Long River near Juneau and relationships between the monthly 

runoff of Sweetheart Creek and the Long River in a period of 

overlapping records (see table 3). The average discharge for 

the 25 years of records and estimates is 345 cfs. The extended 

record provides a better estimate of the extremes of runoff to 

be expected, and thus provides a better basis than the 10-year 

record for estimating requirements for control of Sweetheart 

Creek.

Upper Sweetheart Lake, a potential storage site on a tributary stream, has a drainage area of 3.65 square miles at relatively 

high altitude. Its water supply was assumed to be about 10 

percent of that at the gaging station, or 35 cfs, in accordance 

with the drainage-area ratio. The monthly and annual distribution of runoff was assumed to be the same as at the gage.

TABLE 3. Monthly and annual runoff, in thousands of acre-feet, Sweetheart 

Creek near Juneau, Alaska i

Water year

1916............

1917............

1918..... ....... 

1919............

1920. ...........

1921............

1922...........

1923............

1924. ...........

1925... ........

1926. ...........

1927............

1928. ...........

1929............

1930..... ......

1931..... ......

1932............

1949............

1950. ...........

1951....... .....

1952. ...........

1953............ 

1954............

1955............

1956............

Mean. ....

Oct.

25.3

38.2

35.3 

23.1

30.1

21.5

36.8

21.3

30.4

28.2

18.7

30.1

18.7

28.4

58.4

29.6

37.3

28.6

30.3

17.2

16.8

61.0 

49.0

25.2

18.3

30.3

Nov.

10.0

11.5

38.5 

23.4

9.2

16.4

9.7

24.0

29.0

17.1

18.6

7.4

21.3

28.3

32.6

10.6

23.2

67.0

6.0

7.6

26.0 

8.3

27.4

12.3

20.3

Dec.

6.2

5.4

6.3 

no

8.4

3.3

18.0

7.1

12.5

10.0

30.2

13.7

3.3

20.7

9.6

21.8

5.6

8.1

7.8

2.9

6.1

8.0 

9.3

24.3

3.7

10.6

Jan.

2.4

3.5

6.3 

15.7

14.0

3.9

5.6

3.6

4.1

2.4

35.3

6.6

12.0

12.7

1.3

Q Q

3.6

6.4

2.5

3.6

2.4

3.8 

4.6

5.7

1 Q

7.0

Feb.

2.2

7.0

2.2 

s n

5.4

5.3

1.7

5.2

2.3

1.7

8.0

2.1

7.5

2.3

2.4

14.0

3.0

2.3

1.6

2.3

2.1

3.5 

15.2

2.8

1.6

4.3

Mar.

2.6

3.0

1.4

9 fi

2.4

3.9

1.5

8.2

4.6

2.8

4.8

6.5

5.7

3.3

2.8

3.3

3.0

1.8

2.6

2.6

2.6 

3.3

3.3

2.2

3.9

Apr.

9.3

4.4

4.6

8.8

3.0

6.8

6.8

13.7

6.8

5.0

OK 1

5.8

14.3

5.4

8.9

8.2

7.1

6.0

2.6

4.8

9.8

5.5 

3.3

4.4

4.6

7.4

May

22.6

22.7

20.2 

21.0

14.6

24.3

25.8

29.2

36.0

29.3

22.3

24.3

37.6

23.6

21.5

33.2

24.2

33.0

25.4

29.2

29.8

38.8 

22.0

19.4

33.2

26.5

June

46.8

39.2

44.8

37.0

37.5

40.3

37.2

49.3

41.2

26.8

45.6

46.0

46.8

40.1

54.4

42.6

43.0

43.5

54.5

41.5

53.2 

42.5

37.8

33.4

42.3

July

30.8

38.0

38.3 

37.7

34.9

29.5

35.3

29.7

47.6

39.2

21.2

29.6

41.1

33.8

34.4

36.4

31.3

33.6

35.7

40.0

40.0

35.6 

31.2

39.6

39.0

35.3

Aug.

35.8

42.0

41.0 

35.5

39.4

26.3

33.9

22.3

36.0

22.9

18.5

21.0

28.9

27.2

35.2

35.6

28.6

32.7

26.5

23.0

31.2

33.3 

20.6

37.4

44.2

31.2

Sept.

37.8

33.0

36.8 

35.9

24.9

25.3

31.2

42.2

48.9

25.2

14.2

35.2

29.6

26.9

29.3

29.3

34.8

32.3

35.2

26.4

39.6

31.4 

32.9

30.2

23.8

31.7

Annual

231.8

247.9

275.7 

250.4

223.3

204.0

246.6

243.7

307.5

225.0

257.5

237.4

252.9

254.8

272.7

307.8

232.0

252.2

279.9

212.5

229.5

302.7 

242.2

257.5

218.2

250.6

1 Data for April 1917-May 1918, October 1927-September 1932, and October 1948-September 

] 956 were estimated.
50 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

TABLE 4. Monthly and annual runoff, in thousands of acre-feet, Long River

near Juneau, Alaska

Water year

1916............

1917

1919............

IQOfi

1Q91

1923............

1924............

1928............

1QOQ

1931............

1QQ9

1949 1

10*01

1951 ^. ..........

1QCO

1953............

1954............

1QCC

1956............

Mean. ....

Oct.

32.4

37.2

40.1

31.0

32.3

23.4

42.3

29.3

34.6

21.3

32.3

66.4

33.7

42 .4

32.5

34.4

19.5

19.1

69.1

55.9

28.6

20.8

35.3

Nov.

8.1

8.6

39.3

20.4

11.4

15.6

12.4

31.1

31.0

7.5

21.7

28.9

33.3

10.8

23.7

68.5

6.1

7.7

26.5

8.5

28.0

12.6

21.0

Dec.

6.0

5.3

5.8

11.1

7.9

3.7

17.1

6.4

13.6

3.1

19.4

8.9

20.2

5.2

7.5

7.2

2.7

5.6

7.4

8.6

22.5

3.4

9.0

Jan.

3.1

5.4

6.0

12.9

11.1

4.2

5.6

3.8

4.8

11.4

12.1

1.2

9.4

3.4

6.1

2.4

3.4

2.3

3.6

4.4

5.4

1.8

5.6

Feb.

2.8

7.2

2.3

3.0

5.4

5.3

1.7

4.7

2.9

7.9

2.4

2.5

14.7

3.2

2.4

1.7

2.4

2.2

3.7

15.3

3.0

1.7

4.5

Mar.

3.1

3.2

1.6

3.1

2.8

4.2

1.5

7.2

5.5

7.4

6.5

3.7

3.2

3.7

3.4

2 0

3.0

3.0

3.0

3.7

3.7

2.5

3.7

Apr.

7.7

4.0

4.2

7.4

3.1

6.6

6.9

11.0

8.0

13.0

4.9

8.1

7.4

6.4

5.4

2.4

4.4

8.9

5.0

3.0

4.0

4.2

6.1

May

15.6

20.6

18.4

19.0

14.4

23.9

24.9

26.8

35.4

34.1

21.4

19.5

30.1

22.0

30.0

23.0

26.5

27.0

35.2

19.8

17.6

30.1

24.3

June

51.4

41.4

44.3

32.4

34.5

42.5

42.0

43.1

54.1

48.5

49.2

42.4

57.2

45.0

45.5

46.0

57.5

43.6

56.1

44.8

39.9

35.2

45.3

July

52.6

61.2

65.8

53.1

56.4

52.3

56.1

57.2

71.9

66.4

54.4

55.3

58.7

50.5

54.2

57.5

64.3

64.2

57.2

50.2

63.7

62.8

58.4

Aug.

65.8

79.3

75.0

64.6

73.8

52.7

64.6

59.8

54.5

51.4

66.4

67.0

53.9

61.5

50.0

43.1

58.9

62.6

38.8

70.4

83.2

61.9

Sept.

61.9

54.9

63.1

59.5

42.1

49.3

67.8

64.3

49.4

44.9

48.8

48.9

58.0

53.6

58.5

43 9

65.7

52.4

RA 1

50.3

39.7

53.1

Annual

310

328

366

318

291

324

348

391

324

321

352

384

304

326

354

277

SOS

382

on?

337

298

328

1 Data for the 1949-51 water years are estimated.

TABLE 5. Monthly and annual runoff, in thousands of acre-feet, Crater Creek

near Juneau, Alaska 1

Water year

1914

1915............

1916............

1917

1918............

1919

1Q9Q

1931............

1949

1950............

1951............

1952 ............

1QEO

1QPU

1955............

1956. ...........

Mean. ....

Oct.

16.0 

19.2 

11.4 

16.6 

15.4 

12.4 

12.9 

8.3 

11.9 

28.5 

13.8 

20.5 

13.5 

14.0 

8.0 

12.0 

27.0 

19.0 

11.0 

9.5

15.0

Nov.

6.4 

6.2 

2.7 

3.0 

14.9 

7.9 

4.0 

2.9 

6.7 

13.2 

15.2 

4.3 

8.0 

28.0 

1.1 

3.2 

13.0 

7.5 

9.0 

4.0

8.1

Dec.

2.4 

1.5 

2.0 

2.0 

2.2 

4.0 

2.8 

1.5 

5.0 

3.7 

9.0 

1.7 

.9 

1.3 

.9 

1.0 

2.4 

2.3 

5.5 

.5

2.6

Jan.

1.3 

2.2 

1.1 

2.2 

2.0 

4.2 

6.2 

5.4 

4.7 

.3 

4.2 

1.2 

1.4 

.3 

.4 

.3 

.3 

.7 

2.0 

.4

2.0

Feb.

2.5 

1.0 

1.0 

2.5 

.9 

.8 

2.0 

1.8 

1.1 

.5 

5.7 

1.2 

.3 

.4 

.5 

1.0 

1.3 

7.5 

1.0 

.3

1.7

Mar.

2.3 

2.7 

1.2 

1.4 

.8 

.7 

1.0 

2.5 

3.0 

.9 

1.4 

.9 

1.4 

.8 

.7 

1.0 

1.4 

1.5 

1.4 

.9

1.4

Apr.

3.1 

4.4 

2.6 

1.4 

1.2 

2.8 

1.2 

2.5 

1.7 

2.0 

2.7 

2.0 

1.2 

1.4 

1.1 

1.8 

1.9 

1.1 

1.5 

1.5

2.0

May

8.8 

14.4 

5.5 

8.7 

7.9 

7.3 

3.3 

11.9 

5.6 

6.4 

13.0 

6.5 

9.5 

6.0 

7.5 

6.8 

9.0 

5.5 

5.0 

9.0

7.9

June

16.2 

24.6 

22.0 

18.1 

20.6 

12.9 

10.5 

22.7 

22.7 

18.3 

23.9 

16.9 

17.0 

17.5 

22.0 

14.0 

19.0 

16.0 

13.0 

13.0

18.0

July

31.8 

30.6 

22.8 

27.1 

29.6 

25.6 

25.0 

32.5 

25.8 

25.8 

25.6 

22.3 

23.0 

24.0 

27.0 

25.0 

25.0 

20.0 

27.0 

25.0

26.0

Aug.

25.1 

28.8 

28.5 

33.1 

36.3 

31.4 

32.7 

23.2 

24.8 

29.8 

29.1 

22.5 

25.0 

21.0 

18.0 

24.0 

27.0 

17.0 

27.0 

36.0

27.0

Sept.

15.8 

23.1 

28.0 

21.5 

24.5 

25.0 

15.6 

20.4 

20.6 

21.4 

21.5 

25.5 

22.0 

24.0 

18.0 

27.0 

21.0 

19.0 

20.0 

19.0

21.6

Annual

131.7

158.7 

128.8 

137.6 

156.3 

135.0 

117.2 

135.6 

133.6 

150.8 

165.1 

125.5 

123.2 

138.7 

105.2 

117.1 

148.3 

117.1 

123.4 

119.1

133.4

i Data for the 1949-56 water years are estimated.

The actual amount of runoff probably is somewhat greater and 

more concentrated in months of snow melting.

Lower Sweetheart Lake, a potential storage site on Sweetheart Creek, has a drainage area of 35.2 square miles, or 97 

percent of that at the gage. Its water supply was estimated 

accordingly as 334 cfs.
UNDEVELOPED POWERSITES 51

RUNOFF AT TEASE LAKE OUTLET

The record of monthly discharge near the outlet of Tease 

Lake from April to October 1913 was listed by the Federal 

Power Commission and U.S. Forest Service (1947, p. 119). This 

presumably was furnished by an applicant to the Forest Service 

for a power permit, and is of questionable accuracy because of 

gaps in the record and crude methods of measurement. The runoff 

as listed for the period of record was 171,000 acre-feet (partly 

estimated). The period overlaps that of records for the Long 

Lake and Crater Lake outlets, the drainage basins of which are 

about 6 miles northwest and west of Tease Lake, across Speel 

Arm. The average runoff relations that existed for the period 

of overlap, and the longer records on Crater Creek and the Long 

River, were used to estimate the average discharge at Tease 

Lake as about 165 cfs. The same relation used with longer records 

and estimates through September 1956 leads to an estimate 

of about 155 cfs.

The average discharge at Tease Lake as estimated from the 

ratios of its drainage basin to those of Sweetheart Creek, the 

Long River, and Crater Creek, and the records and estimates for 

those streams, is respectively 104 cfs, 152 cfs, and 176 cfs. The 

Tease Lake area is centrally located between the Sweetheart 

Creek and Long River basins.

The mean annual precipitation at Speel River during the period 

of record was about 142 inches, which may correspond to a runoff 

of about 130 inches, or an average discharge of 105 cfs from an 

area equivalent to the Tease Lake drainage basin. The Speel 

River station was a mile northwest of Tease Lake near sea 

level. Although heavier precipitation would be expected in the 

mountains of the lake basin, which extend to altitudes above 

4,000 feet, there are only a few small glacierets. This lack shows 

that the precipitation may be substantially less than in the Long 

River basin where glaciers are prevalent at similar altitudes. It 

is estimated accordingly that the discharge per unit area in the 

Tease Lake area is intermediate to that in the Sweetheart Creek 

and Long River basins, and that the average discharge is about 

125 cfs.

RUNOFF AT LONG LAKE OUTLET

The period of record at the Long Lake outlet is too brief to 

provide a measure of reliable water supplies. The gaging station 

there was replaced in 1915 by one on the river 1 mile downstream from Long Lake because measuring conditions at the
52 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

lake are unsatisfactory. The record for this station, Long River 

near Juneau, covers 19 complete water years in the period from 

1916 to 1956. The mean discharge during the years of record, 

457 cfs, probably was not much different than during the 41 

years, 1916-56. However, the records do not cover 3 water years, 

1949-51, which were within a relatively dry period of exceptional 

length. Since this may be considered a critical period for storage 

regulation, estimates of monthly runoff were made for the 3 

years of missing record. These were based on the recorded 

monthly runoff of nearby Dorothy Creek, and monthly relationships for the period of overlapping records, 1952-56. The computed mean discharge for the 22 years is 454 cfs.

The water supply at the Long Lake outlet was assumed to be 

422 cfs, or 93 percent of that at the gage, in accordance with 

the drainage-area ratio.

RUNOFF AT SPEEL RIVER DAMSITE

The gaging station on the Speel River was in the immediate 

vicinity of the only practicable damsite, half a mile downstream 

from the mouth of the Long River. The record covered 2 complete water years, 1917-18, and is only of fair accuracy. As 

shown by the records for the Long River, runoff during those 

years probably was near or above average.

The monthly runoff of the Speel River exclusive of runoff of 

the Long River near Juneau was estimated for the dry period, 

1949-56, from the Long River record and the average relationship that existed during 27 months of overlapping records, 

1916-18. This provides an estimate of the runoff that would be 

available for control at the Speel River site after utilization 

of the Long River runoff, nearly all of which may be diverted 

from the basin for power generation.

The average-relation curve was based on scanty data; the 

relationship may vary seasonally and annually because of varied 

conditions for natural storage; and the Long River figures for 

the water years 1949 to 1951 are estimates themselves, so the 

simulated record for the Speel River can be only a crude representation of the historical runoff. It is intended to provide a 

basis for estimating the regulated streamflow that can be obtained 

with a given amount of storage capacity in a future dry period 

of roughly similar characteristics. The adjusted records and the 

estimates are shown in table 6. The computed mean discharge 

for the 10 water years 1917-18 and 1949-56 is 2,080 cfs.
UNDEVELOPED POWERSITES 53

TABLE 6. Monthly and annual runoff, in thousands of acre-feet, Speel River 

near Juneau, exclusive of Long River near Juneau, Alaska 1

Water year

1916............

1917. ...........

1918. ..... .....

1949............

1950. ...........

1951............

1952............

1953............

1954............

1955............

1956............

Oct.

141

220

120

130

63

80

350

270

130

88

Nov.

37

172

85

330

224

30

120

32

120

50

Dec.

20

25

28

28

10

18

24

32

98

12

Jan.

16

17

24

8

12

7

12

16

20

6

Feb.

21

8

8

5

9

13

66

10

6

Mar.

10

10

10

13

8

Apr.

16

17

22

8

18

11

18

10

14

15

May

84

78

150

100

120

160

84

73

140

June

171

1Q9

220

230

280

280

210

180

160

July

280

288

QO1

230

260

310

320

250

320

310

Aug.

367

444

380

280

210

160

290

300

180

370

450

Sept.

308

250

362

230

260

160

330

230

270

240

180

Annual

1,495

1,799

1,409

1,576

1,176

1,447

1,767

1,423

1,588

1,425

1 Data for the 1949-56 water years are estimated.

RUNOFF AT CRATER LAKE OUTLET

The record at Crater Lake outlet (published as "Crater Creek 

near Juneau") covers 12 complete water years between 1913 and 

1932. Estimates of monthly runoff were made for the 1949-1956 

water years from the records for nearby Dorothy Creek and 

relations between monthly figures for the period of overlapping 

records, 1930-33 (see table 5). In very cold months, as measured 

by temperature records at Juneau, the relations are abnormal, and 

the estimates were made accordingly. In such months the flow 

of Crater Creek has dropped to a low of 0.5 that of Dorothy 

Creek from an average of about 1.35.

SWEETHEART CREEK POWERSITE

RESERVOIR SITES

Upper Sweetheart Lake is about 8 miles east of Gilbert Bay 

and 0.8 mile east of the head of Lower Sweetheart Lake on an 

unnamed tributary. Sufficient storage capacity for substantial 

control of the runoff could be created by construction of a dam 

near the lake outlet, by drawdown, or by a combination of the 

two methods.

The lake is at an altitude of 1,865 feet and is 1,321 feet higher 

than Lower Sweetheart Lake. It extends southeast from its outlet 

for more than 1 mile between steep, barren mountainsides to a 

delta at the upper end. The steep slopes continue underwater to a 

depth of at least 150 feet. The surface area of the lake is 295 

acres.

Rock mantled with very little soil forms an irregular barrier 

across the valley at the lower end of the lake. The outlet creek 

flows in a passage through this barrier, which constitutes a good 

site for a dam of moderate height. The right abutment of the 

creek section is limited in height by a ridge northwest of the
54 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

creek, the top of which is at an altitude of about 1,920 feet at 

the dam site, or 60 feet above the creek. The left abutment is 

similarly limited by a knoll at about the same level, separated 

by a saddle from higher ground to the southeast. The saddle 

could be used as a natural spillway with crest level at an altitude 

of 1,913 feet. The width across the damsite at this level is 250 

feet, and the storage capacity above the natural lake surface 

is 16,500 acre-feet.

About the same capacity could be created entirely by drawdown 

of 65 feet to an altitude of 1,800 feet. This could be accomplished 

by tapping the lake with a tunnel at a point about 500 feet southeast of the outlet.

Reservoir areas and capacities for a range above and below 

the surface of Upper Sweetheart Lake are listed below.

Altitude 

(feet)

1,760. ...................

1 780

1,800. ...................

1,820. ...................

1,840. ...................

1,8651................ ...

1,880. ...................

1,900. ...................

1,920. ...................

1,940. ...................

1,960. ...................

1,980.. ..................

Area

(acres)

204 

216 

231 

244 

253 

295 

337 

368 

385 

413 

435 

468

Capacity 

(acre-feet)

Below lake surface

25,000 

20,800 

16,300 

11,600 

6,600 

0

Above lake surface

0 

4,700 

11,800 

19,300 

27,300 

35,800 

44,800

1 Lake level.

Storage capacity equal to the estimated average annual runoff 

of 25,000 acre-feet would provide for complete or nearly complete control on a schedule of uniform releases. This could be 

provided by a dam at the outlet raising the lake level to an 

altitude of 1,934 feet, but the topography is not favorable for a 

structure of that height. The capacity could be provided more 

readily by drawdown to an altitude of 1,760 feet.

A storage capacity of only about 12,000 acre-feet would provide 

for a uniform release equal to 90 percent of the average inflow. 

This could be created with a 36-foot dam at the outlet or by 

drawdown of 47 feet.

This site is farther from tidewater than any of the others 

considered in this report. If a reservoir is created at Lower
UNDEVELOPED POWERSITES 55

Sweetheart Lake, the best means of access probably would be 

by water from the lower to the upper end of the reservoir and 

thence by an access road or tramway to Upper Sweetheart Lake.

Lower Sweetheart Lake is at an altitude of 544 feet and its 

outlet is about 2 miles east of Gilbert Bay. The lake extends 

about 5 miles northeast from the outlet and lies in a narrow 

valley. There is a constriction about % mile from the outlet 

and another about 1 mile from the upper end where depths are 

only a few feet. (See fig. 9.) The lake is several hundred feet 

deep in its central part, but a tunnel extending nearly a mile 

beyond the outlet would be needed to tap this part at depth. 

Creation of storage by damming would be preferable not only 

because of the lesser requirement for waterway but also because it 

would result in a substantial increase instead of a reduction in 

the limited head.

FIGURE 9. Aerial view of Lower Sweetheart Lake. The outlet is just beyond the field of view 

in center of foreground. (U.S. Forest Service photograph; June 22, 1929.)
56 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

Sweetheart Creek flows westward from the lake in a V-shaped 

canyon featured by many cliffs along the sides. The narrowest 

section is about 300 feet downstream from the outlet, where 

the width at creek level at an altitude of 539 feet, is less than 

40 feet and at an altitude of 700 feet is only 350 feet.

So far as is known a geologic examination of the damsite has 

not been made. The rocks near the east side of Gilbert Bay 

are classified by Buddington and Chapin (1929) as mostly phyllite 

and, locally, slate. Dort (1924, p. 77) referred to the rock along 

a suggested tunnel route from the damsite to Gilbert Bay as 

slate, with nearly vertical cleavage planes crossing the eastwest route.

The reservoir areas and potential capacities for a range above 

the surface of Lower Sweetheart Lake are given below.

Altitude 

(feet)

544.....

560........ .

580. ........

600.........

620... ......

Area 

(acres)

1,250

1,380

1,450

1,550

1,630

Capacity 

(acre-feet)

0

21,200

49,400

70 400

111,000

Altitude 

(feet)

640. .......

660. .......

680. .......

700. .......

Area 

(acres)

1,680

1,720

1,770

1,850

Capacity 

(acre-feet)

144,000

178,000

213,000

249,000

Storage requirements for regulation to a uniform monthly 

and annual release were determined both for the 10 water years 

of complete record, considered as a consecutive series, and for 

25 years of records and estimates. These show that 146,000 

acre-feet would have been sufficient for complete control in the 

10-year period but that about 220,000 acre-feet would have been 

needed in the 25-year period. This could be provided with a 

dam about 140 feet high which would raise the reservoir level 

to an altitude of 684 feet. A capacity of 102,000 acre-feet would 

have been sufficient to provide for a uniform release equal to 

90 percent of the mean inflow. This could be provided by a 

dam about 71 feet high, which would raise the reservoir level 

to an altitude of 615 feet but would reduce the mean head 

available above sea level about 6 percent so that the uniform 

power generation would be only about 85 percent of that available 

with full control. At this site it seems likely that the value of 

the incremental power would outweigh the incremental plant 

cost for complete control, and it might even be advantageous to 

construct a dam higher than needed for the required storage in 

order to provide additional head. For example, the gain in mean
UNDEVELOPED POWERSITES 57

head and potential power by raising the full reservoir level 

from 685 feet to 750 feet would be 11 percent.

During the course of surveys in July and August, 1958, it was 

observed that the creek flowing into the upper end of the lake 

was clear except at times of heavy rain runoff, and that Sweetheart Creek below the lake was clear at all times. The lake 

constitutes a sediment catchment of ample volume, all of which 

would be available as dead storage in a reservoir created by a dam.

The topography at the damsite is favorable for an arch dam, 

but a rock-fill structure might be preferable if suitable rock 

could be quarried locally, as seems probable. Transport of heavy 

equipment and materials to the site would be relatively difficult 

because of the rugged terrain. Facilities for transport might 

consist of several miles of access road constructed from tidewater 

to the rim of the canyon above the damsite, and a tramway 

down the canyon side.

The maximum discharge of Sweetheart Creek during the period 

of record was 2,880 cfs, or about 80 cfs per square mile. Maximum 

discharges of 150 cfs per square mile or more have occurred in 

3 of 20 years on the Long River near Juneau from a drainage 

area comparable in size to that of Sweetheart Creek. The 

frequency of such discharges on Sweetheart Creek may be similar. 

A spillway of a special type, such as a side channel or side channel 

and tunnel, probably would be considered at this site and would 

be essential with a rock-fill dam.

FLANS OF DEVELOPMENT

Water could be conveyed westward from Upper Sweetheart 

Lake to a powerhouse located near the upper end of the reservoir 

site at Lower Sweetheart Lake. If Upper Sweetheart Lake were 

tapped at an altitude of about 1,750 feet for development of 

storage, the waterway would consist of about 1,000 feet of tunnel 

connecting with about 2,000 feet of penstock to the powerhouse.

Water could be conveyed from Lower Sweetheart Lake 2 miles 

to a powerhouse at Gilbert Bay. Dort (1924, p. 79) suggested 

an area 2,000 feet north of the mouth of Sweetheart Creek at 

the edge of Gilbert Bay for a powerhouse site and described the 

rock foundation as excellent. The waterway would consist of 

about 1% miles of tunnel and 14 mile °f penstock.

TEASE LAKE POWERSITE

RESERVOIR SITE

Tease Lake is 1 mile from the eastern shore of Speel Arm at 

an altitude of 1,006 feet. The Federal Power Commission and
58 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

U.S. Forest Service (1947, p. 66) estimated that construction 

of an 80-foot dam and drawdown of the lake surface 100 feet 

would provide a storage capacity of 22,000 acre-feet. An accurate 

topographic map was not available for this determination. As 

shown by the topographic map of the Taku River (A-5) quadrangle, the valley upstream from the lake ranges from about 

1/4, to y% mile wide for nearly 2 miles and is below an altitude 

of 1,100 feet. Low-level observations from an airplane in 1958 

showed that the valley floor is flat and that a considerable part 

of it is marshy. It is estimated accordingly that there is potential 

storage capacity of at least 25,000 acre-feet between the present 

lake surface and an altitude of 1,080 feet.

A photograph of the lake from its upper end shows that 

steep slopes on the sides extend to the shoreline on the south 

side and probably on the north side as well. Soundings have 

not been made, but the underwater volume must be relatively 

small since the surface area is only about 120 acres (as measured 

to the hillsides).

A dam could be constructed across the outlet channel about 

350 feet downstream from the lake. The width of the valley at 

an altitude of 1,080 feet is 540 feet.

The Federal Power Commission and U.S. Forest Service (1947, 

p. 66) reported that quartz diorite is exposed at several places 

across this section, and that there is loose rock in places that 

could be incorporated in a rock-fill dam without much stripping.

A storage capacity of 25,000 acre-feet is 28 percent of the 

estimated mean annual runoff of about 90,000 acre-feet. This 

probably would be sufficient to provide for a uniform release 

equal to about 80 percent of the mean discharge, or 100 cfs.

PLANS OF DEVELOPMENT

Water could be conveyed from the reservoir by means of about 

0.9 mile of tunnel and 0.3 mile of penstock to a powerhouse 

located on the shore of Speel Arm a few hundred feet south of 

the mouth of the creek discharging from Tease Lake. Alternatively, a surface conduit could be located near the 1,000-foot 

level for about two-thirds of a mile below the dam, connecting 

with about half a mile of penstock to the same powerhouse site.

LONG RIVER POWERSITE

RESERVOIR SITE

A large amount of storage capacity could be developed at Long 

Lake by construction of a dam at the lake outlet, by drawdown,
UNDEVELOPED POWERSITES 59

or by a combination of the two methods. The outlet, which is at 

the southeastern end of the lake, is at an altitude of 814 feet 

and is only 1^4 miles from the tidal flats at the mouth of the 

Speel River. The lake extends about 4 miles to the northwest 

between steep mountainsides. The Long River valley upstream 

from the lake is covered with glacial debris to an average width 

of about 2,000 feet for about 3 miles.

The Long River drains the lake in 2 channels around a rock 

island for 200 feet, and it falls 500 feet in a cascade extending 

1,500 feet southeast of the head of the island (see fig. 10). The 

river then flows eastward on a flatter gradient about 4 miles 

to the Speel River. About half of this reach is through a sizable 

body of water called Indian Lake, which is at an altitude of 

177 feet.

The hillsides at the outlet section are topographically suitable 

as abutments for a dam to an altitude of at least 900 feet, 

where the width of the valley is 700 feet. The width at stream 

level between the steep hillsides is 250 feet, including the rock 

island which extends generally about 10 feet above the stream 

and is 150 feet wide. The channel in a distance of 200 feet from

FIGURE 10. Aerial view of Long Lake and the cascade on the Long River below the island at the 

damsite. (U.S. Forest Service photograph ; June 22, 1929.)
60 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

the head of the island drops 70 feet, and in a distance of 450 

feet it drops 140 feet. The rock on the right bank slopes sharply 

downstream below a narrow ridge at the outlet section and the 

lake bottom drops sharply upstream so that the terrain is 

generally unfavorable as a base for a high gravity dam. It 

appears to be more suitable for an arch dam or a buttressed 

dam.

Miller (1956, p. 30) reported that the rock in the region of the 

lake outlet is quartz diorite, and that, because of fractures, 

considerable excavation and grouting might be required to prevent 

leakage. Alternatively it may be found that a higher dam 

farther downstream would be preferable, if the fractures at 

the outlet section extend to considerable depth, although the 

downstream topography is not as favorable for abutments.

The potential storage capacity at Long Lake and the corresponding surface areas for a range of altitudes above and 

below the lake surface are shown below.

Storage requirements for regulation were determined from 

operation schedules for the 22 years of recorded and estimated 

runoff at the Long River gaging station. These were converted 

to requirements at the lake outlet by application of the drainagearea ratio, 93 percent. It was found that 255,000 acre-feet of

Altitude 

(feet)

600........ ..............

620.. ....................

640 ......................

660. .....................

680. .....................

700. .....................

720. .....................

740. .....................

760.. ....................

780

800. .....................

8141........ .............

820. .....................

840... ...................

860 ......................

880......................

900.. ....................

920......................

940. .....................

960.. ....................

Area 

(acres)

844 

901 

940 

982 

1,020 

1,070 

1,110 

1,140 

1,190 

1,230 

1,280 

1,320 

1,440 

1,640 

1,830 

1,980 

2,090 

2,190 

2 2, 370 

2 2, 450

Capacity 

(acre-feet)

Below lake surface

231,000 

213,000 

195,000 

176,000 

156,000 

135,000 

113,000 

90,600 

67,200 

43,100 

18,100 

0

Above lake surface

0 

9,000 

39,800 

74,400 

112,000 

153,000 

196,000 

241,000 

290,000

1 Lake surface.

2 Estimated in incomplete area of map.
UNDEVELOPED POWERSITES 61

usable capacity would have been needed to provide a uniform 

monthly release equal to the mean discharge, 422 cfs; and that 

140,000 acre-feet woud have been needed for a uniform monthly 

release of 380 cfs or 90 percent of the mean discharge.

For access to the lake, a road might be constructed from the 

Speel River estuary about li/2 miles to a point near Long River 

at an altitude between 200 and 300 feet. Because of the steep 

slope it would be difficult to extend this up to the lake, and a 

short tramway might be preferable. Sand and gravel at the 

upstream end of the lake may be the best source of concrete 

aggregate, and, if so, transport by water probably would be 

considered since the construction of a road on the steep mountainsides would be extremely difficult.

If a dam were constructed at the Long Lake outlet, sufficient 

spillway capacity would be required for the maximum discharge 

that might occur. During the periods 1916-33 and 1952-56, the 

maximum recorded discharge at the gaging station 1 mile downstream from Long Lake was 6,000 cfs, in September 1927. This 

corresponds to the unit rate of 185 cfs per square mile.

PLANS OF DEVELOPMENT

Several alternative plans are possible, depending on whether 

the Long River site should be developed alone or in combination 

with the Speel River and Crater Creek sites.

Water could be conveyed from the Long Lake reservoir about 

9,700 feet southward by way of a tunnel and penstock to a 

powerhouse at the edge of the tidal flats of the Speel River 

estuary. The powerhouse site is about a quarter of a mile 

west of the mouth of Glacier Creek. It was pointed out in plans 

described by the Federal Power Commission and U.S. Forest 

Service (1947, p. 68) that the powerhouse could be used commonly 

for the Long Lake, Crater Lake and Speel River units. The 

waterway from Long Lake reservoir would require 8,000 feet 

of tunnel and 1,700 feet of penstock. The mountainsides above 

the powerhouse site extend up to an altitude of nearly 5,000 feet 

in a distance of 2 miles, and there is a glacier on the upper part 

of the slope. It seems possible that snow avalanches might constitute a hazard in this region, and if so the penstock and power 

house might have to be constructed underground.

SPEEL RIVER POWERSITE 

RESERVOIR SITE

The Speel River enters a narrow canyon half a mile downstream 

from the mouth of Long River, and about 8 miles upstream from
62 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

the head of Speel Arm. The canyon reach, which is about 

half a mile long, includes the only favorable damsite on the river. 

Both upstream and downstream from the canyon reach the stream 

flows on a wide deposit of glacial materials.

The canyon sides are favorable for the abutments of a dam 

at a section a few hundred feet downstream from the head of the 

gorge where the width is 700 feet at an altitude of 300 feet, 

and about 1,300 feet at an altitude of 450 feet. At medium-low 

stages the river at this section flows in a channel that is less than 

50 feet wide between steep rock sides and is at an altitude of 

160 feet. There is an overflow channel about 150 feet wide along 

the left side of the canyon, separated from the low-water channel 

by a narrow rock ridge.

A dam to an altitude of 245 feet would back water up the Speel 

River valley roughly 6 miles, and up the Long River basin roughly 

5 miles to a saddle between the basin and Speel Arm. At this 

place, called the Saddle damsite, an auxiliary dam would be 

required for flowage to a higher altitude. The saddle consists of 

a wide deposit of alluvium and glacial materials of unknown 

depth, under a cover of muskeg moss. The surface has somewhat 

uniform slopes on each side of the low point of the saddle up 

to an altitude of 300 feet, where the width is 1,200 feet. Rock is 

exposed in places on steeper slopes above this altitude. The width 

of the valley is 1,960 feet at an altitude of 450 feet. Just southwest of the saddle in the drainage area of Glacier Creek there is 

a sharp drop of 80 to 100 feet in a distance of 100 to 150 feet. 

On the other side there is a small body of water called First Lake, 

200 feet northeast of the saddle, at a surface altitude of 234 

feet. First Lake and Second Lake are in a short valley tributary 

to the Long River. The location and design of a dam might be 

determined somewhat by these topographic features on both 

sides of the saddle, particularly if bedrock is at considerable 

depth.

Miller (1956, p. 40) reported that the rock at Speel River 

damsite is of varying composition but apparently is suitable 

for the foundation of a masonry dam at least 160 feet in height. 

At the Saddle damsite it was not clear whether the abrupt 

slope southwest of the saddle represents a section of the valley 

fill or a rock formation covered with a layer of alluvium and 

glacial deposits. Miller classified the rock at the damsite as 

quartz diorite, overlain in the saddle section with alluvium 

or glacial fill to a depth that may be as much as 50 feet.
UNDEVELOPED POWERSITES 63

The potential capacity of a reservoir at the Speel River site 

can be determined only roughly from the available maps, which 

are on a scale of 1:63,360 and have a contour interval of 100 

feet. The capacities and corresponding surface areas thus determined are shown below.

Altitude 

(feet)

165.........

200.........

250.........

300.........

Area 

(acres)

0

2,375

13,284

4,192

Capacity 

(acre-feet)

0

42,000

183,000

370,000

Altitude 

(feet)

350........

400. .......

460........

Area

(acres)

14,993

5,794

Capacity 

(acre-feet)

600,000

869,000

2 1,240,000

1 Interpolated.

2 Estimated by extrapolation.

Water could be diverted from the reservoir at a point near 

the Saddle damsite, which is only 2,800 feet from the Speel 

River estuary. The outlet works could be located below the 

present surface of First Lake, and with a little excavation at the 

outlet of the lake the reservoir could be drawn down to an 

altitude of 235 feet, or about the present lake altitude. Alternatively, it would be possible to locate the outlet works at Second 

Lake, which is 3,900 feet from the Speel River estuary. The 

reservoir then could be drawn down to an altitude of about 200 

feet.

With a diversion near the Saddle dam the Long River arm 

of the reservoir would be effective as a settling basin between the 

Speel River valley and the outlet works. The potential capacity 

of this arm of the reservoir between the surface of Indian 

Lake, at an altitude of 177 feet, and a crest altitude of 300 

feet is about 88,000 acre-feet. Only 35,000 acre-feet would be 

usable capacity above an altitude of 235 feet, and 53,000 acre-feet 

would be dead storage above the altitude of Indian Lake. The 

underwater volume of Indian Lake, which has a surface area 

of 520 acres, probably is substantial, and this also would be 

effective as a catchment for sediment.

Operation schedules for the Speel River component of runoff 

show that a usable storage capacity of 1,100,000 acre-feet 

would have been required to provide for a uniform monthly 

release of 2,050 cfs from 1949 to 1956, or complete control of 

the estimated runoff exclusive of the Long River. This capacity 

would be available in a reservoir by drawdown from a maximum 

altitude of about 460 feet to 235 feet. A capacity of 730,000 

acre-feet would have been required to provide for a uniform
64 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

monthly release of 1,845 cfs or 90 percent of the mean flow 

from 1949 to 1956. It would be topographically feasible to construct dams of the required height at the Speel River and Saddle 

damsites, but they would be of considerable size.

It may be found that a much lesser degree of development 

would be preferable. For illustration of one possibility, a maximum flowage line was assumed at an altitude of 300 feet, approximately the same as in a plan for regulation proposed by the 

Federal Power Commission and U.S. Forest Service (1947, p. 67). 

A usable capacity of 234,000 acre-feet would be available by 

drawdown to an altitude of 235 feet, and this could have provided 

for a uniform monthly draft of 870 cfs from 1949 to 1956.

Any reservoir on the Speel River would tra^p relatively large 

amounts of sediment of glacial origin which is carried in suspension and as bedload. Miller (1956, p. 43) pointed out that 

sedimentation might seriously reduce the useful life of the 

reservoir. He observed that sand and gravel bars along the 

braided channel shift rapidly at times of high flow. Much of 

this material would be deposited in the upper end of a reservoir 

above the level of dead storage, causing a progressive reduction 

in the usable capacity from the outset.

Investigation may show that enough reserve capacity for sediment can be created so that the runoff could be substantially 

controlled over a long period. Alternatively it may be possible 

and desirable to operate a smaller Speel River unit essentially 

as a run-of-the-river plant, with only short-time regulation. Such 

a plan might be considered if enough storage can be economically 

provided in nearby reservoirs at Long Lake and Crater Lake 

for overall power regulation in a coordinated system of the 

three units.

A spillway would be required either at the Speel River or at 

the Saddle damsite with capacity sufficient to pass the maximum 

discharge that might occur. During the period of record, 1916 

to 1918, the maximum discharge was estimated as 35,600 cfs. 

A discharge of that amount would be difficult to control on the 

Va-mile slope between the Saddle damsite and the Speel River 

estuary since there is no natural channel of substantial size. 

Furthermore it would be undesirable to pass the excess water 

over the Saddle dam because this would favor the transport 

of sediments into the Long River arm of the reservoir at times 

of maximum sediment load. For these reasons it would seem 

preferable to locate the spillway at the main dam on the Speel 

River.
UNDEVELOPED POWERSITES (>5 

FLANS OF DEVELOPMENT

Water could be conveyed by way of a tunnel and penstock 

from the Speel River damsite for utilization through whatever 

head is concentrated in the reservoir and about 120 feet that is 

available in the i/^-mile reach of canyon downstream. This plan 

has two disadvantages: the Long River arm of the reservoir 

would not be effective for trapping sediment, and the powerhouse 

site is in a relatively isolated location.

A dam to a height of 75 feet or more at the Speel River 

site would back water up the Long River valley, covering 

First Lake near the Saddle damsite. Water could be conveyed 

southeastward from that point through about half a mile of tunnel 

and a short penstock for utilization down to the edge of the 

Speel River estuary. The shortest route is to a point about 

half a mile northeast of the mouth of Glacier Creek. Alternatively, water could be conveyed southwestward about 1 mile to 

the site west of the mouth of Glacier Creek which has been proposed for a common powerhouse of the Speel River, Long River, 

and Crater Creek units. Since relatively large waterways would 

be required for substantial utilization of Speel River water, 

the advantage of a common powerhouse might be largely offset 

by the increased distance for conveyance.

Miller (1956, pi. 3) reported that the rock is quartz diorite 

along each of the three possible tunnel routes.

CRATER CREEK POWERSITE 

RESERVOIR SITE

Crater Lake at its outlet is only % mile from the Speel River 

estuary and is at an altitude of 1,022 feet. A considerable 

amount of storage capacity could be developed there by construction of a dam at the outlet, by drawdown, or by a combination 

of the two methods. The lake extends about 2 miles southwest 

from its outlet between steep mountainsides. It is drained by 

Crater Creek, which flows eastward in a series of cascades 

about 1 mile to the Speel River estuary. (See fig. 11.)

The sides of the canyon just downstream from the outlet 

are topographically suitable as abutments for a dam to at least 

200 feet above the lake surface. The width of the canyon at 

that altitude is about 500 feet. The creek drops 50 feet in a 

distance of 200 feet from the lake outlet, and 30 feet of that 

drop is within the first 50 feet of distance. The rock on the north 

side of the creek also slopes sharply downstream from a narrow 

ridge at the outlet section. Because of these topographic features
66 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

FIGURE 11. Aerial view of damsite at the outlet of Crater Lake, showing Spesl Arm in background. The mouth of Crater Creek is left of and inshore from the wooded area at left center.

the site may be more suitable for an arch dam or buttressed dam 

than the gravity type.

Miller (1956, p. 23) found that the rock at the damsite is 

quartz diorite broken by vertical joints or fractures transverse 

to the direction of streamflow.

The potential storage capacities and corresponding surface 

areas for a range of altitudes above and below the lake surface 

at Crater Lake are shown below.

Storage requirements for regulation were determined from 

reservoir schedules for the 20 years of recorded and estimated 

runoff, considered as a consecutive series. These show that 142,000 

acre-feet of capacity would have been required to provide uniform 

monthly releases equal to the mean discharge, 184 cfs; and that 

71,000 acre-feet would have been required for a uniform monthly 

release of 165 cfs, or 90 percent of the mean discharge.

A capacity of 142,000 acre-feet could be developed entirely 

by damming. It could possibly be developed entirely by drawdown through an estimated range of some 400 feet, but the 

increased plant requirements and the large reduction in head 

make this plan seem impracticable. A capacity of 71,000 acrefeet could be developed entirely by damming or entirely by 

drawdown.

Construction of an access road from the Speel River estuary 

to Crater Lake would be very difficult, and investigation may
UNDEVELOPED POWERSITES 67

Altitude 

(feet)

800. ...................

820. ...................

840 ....................

860 ....................

880........ ............

900. ...................

920...... ..............

940. ...................

960......... ...........

980. ...................

1,000. ...................

1,022 i. ..................

1,040.. ..................

1,060. ...................

1,080. ...................

1,100. ...................

1,120. ...................

1,140. ...................

1,160. ...................

1,180... .................

1,200. ...................

Area 

(acres)

320 

338 

353 

363 

376 

392 

410 

423 

436 

447 

465 

503 

570 

633 

675 

723 

764 

792 

818 

847 

885

Capacity 

(acre-feet)

Below lake surface

89,100 

82,500 

75,600 

68,400 

61,000 

53,400 

45,300 

37,000 

28,400 

19,600 

10,500 

0

Above lake surface

0 

9,600 

21,700 

34,800 

48,800 

63,600 

79 , 200 

95,300 

112,000 

129,000

1 Lake surface.

show that a tramway would be needed for transport of construction equipment and materials. Sand and gravel suitable for concrete aggregate may be available in the creek valley at the upper 

end of the lake but, as at Long Lake, transport to the damsite 

would be impracticable except by water.

The required spillway capacity at the Crater Creek dam 

would be in excess of 3,100 cfs, a maximum which was recorded 

in September 1927. This corresponds to the relatively high unit 

rate of 260 cfs per square mile.

PLANS Or DEVELOPMENT

Water could be conveyed from Crater Lake 4,200 feet southeastward on the shortest route to a powerhouse site at tidewater. 

This is at a point 2,000 feet southwest of the mouth of Crater 

Creek and 2,000 feet northeast of a cove at the head of the 

Speel Arm. About equal lengths of tunnel and penstock would 

be required for drawdown to an altitude of about 850 feet.

Alternatively, water could be conveyed eastward to the site for 

a common powerhouse through about 1*4 miles of tunnel and 

14 niile of penstock. (Conveyance to this site from Long Lake, 

the Speel River reservoir, and Crater Lake would require an 

aggregate of more than 4 miles of waterway, whereas less than
68 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

2 miles would be required for conveyance to 3 individual powerhouses.)

Miller (1956, p. 26) reported that both tunnel routes would 

intersect joint systems in the quartz diorite.

LONG RIVER, SPEEL RIVER, AND CRATER CREEK SITES, 

COORDINATED DEVELOPMENT

The potential power available 100 percent of the time at the 

Long River, Speel River, and Crater Creek powersites is about 

86,000 kw with development by combined damming and drawdown at the lakes, and with substantially complete control of 

the runoff in periods like 1949 to 1956. The power available 

100 percent of the time with control of 90 percent of the runoff 

in such periods is about 72,000 kw. More than half of these totals 

are due to the Speel River site where two large dams would be 

required for either degree of regulation.

If provision for such regulation proves to be impracticable it 

still would be possible to utilize a considerable part of the Speel 

River flow in a system of the three plants designed for coordinated 

operation. For example, the Speel River reservoir might be constructed to a maximum altitude of 300 feet and operated only 

for short-time regulation with nearly all of the capacity reserved 

for sedimentation. With usable capacities of 250,000 acre-feet 

and 150,000 acre-feet at Long Lake and Crater Lake, respectively, 

the 3 plants could have been operated for a continuous generation of 58,000 kw. This was determined by an operation schedule 

through the dry 1952 water year, with the maximum draft on the 

Speel River reservoir limited to 3,000 cfs, and with all of the 

load carried by the Speel River powerhouse in months when 

the inflow equaled or exceeded that amount. A total plant capacity 

of 100,000 kw would have been required to carry an average 

load of 58,000 kw, but most of the excess capacity would have 

been available for daily peaking.

POTENTIAL POWER OF SITES NEAR GILBERT BAY AND SPEEL 

ARM OF PORT SNETTISHAM

The potential power of the upper unit of the Sweetheart Creek 

site and of the Tease Lake and Crater Creek sites was estimated 

on the assumption that the head below the mean reservoir levels 

would be developed down to the levels of impulse wheels. At the 

Sweetheart Creek site this was assumed to be at an altitude of 

700 feet, or a little above the assumed maximum flowage line of 

a reservoir that might be created at Lower Sweetheart Lake.
UNDEVELOPED POWERSITES 69

At the other sites the wheel level was assumed to be at an 

altitude of 17 feet, a few feet above the level of the highest 

expected tide.

The available heads at the lower unit of the Sweetheart Creek 

site and at the Long River and Speel River sites are less than a 

thousand feet, and thus development by means of reaction turbines and draft tubes would be appropriate. At these sites it 

was assumed that the head would be developed from the mean 

reservoir levels to the average level of tailwater. This was taken 

to be mean sea level at the Sweetheart Creek site and 8 feet above 

mean sea level at the other sites, where the tailwater level may 

be determined by the level of mudflats in the Speel River estuary.

In one of several possible schemes, the potential power of the 

Long River might be developed in two stages, with the tailwater 

of the first stage at the prospective Speel River reservoir. In 

that event the overall head would be reduced by drawdown in 

that reservoir. The potential power of the Long River site as 

listed in following tables corresponds only to full use of the 

available head without the reduction that would result from 

routing the water through the prospective Speel River reservoir.

If the storage for full control at Upper Sweetheart Lake were 

developed entirely by drawdown, the mean head would be 1,116 

feet, the operating range 1,865 feet to 1,760 feet, and the continuous power about 2,600 kw. Drawdown of Lower Sweetheart 

Lake and Tease Lake was not considered.

Controlled flow . . . percent

Storage capacity . . . acre-ft . . .

Operating range ... alt (ft) . . .

Upper Sweetheart 

Lake

100

35 

1,202 

25,000 

69

1,865- 

1,934

2,860

90

31 

1,184 

12,000 

36

1,865- 

1,901

2,500

Lower Sweetheart 

Lake

100

334 

619 

220,000 

140

544- 

684

14,100

90

301 

582 

102,000 

71

544- 

615

11,900

Tease 

Lake

80

100 

1 1,033 

128,000 

74

1,006- 

1,080

7,000

1 Estimated.

2 Above lake level.
70 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

Potential power and related data for the Long River, Speel 

River, and Crater Creek sites is shown below. The storage is 

provided by damming and drawdown except on the Speel River.

Controlled flow . . . percent of mean flow ....

Controlled flow . . . cfs . . .

Mean head. . .ft. .......

Storage capacity. . .

Height of dam. . .ft. ....

Operating range . . . 

alt (ft) ..............

Continous power . . . kw . .

Long River

100

422

isoe

255,000

274

/888 

\707

23,100

90

380 

1806

140,000 

244

858 

758

20,800

Speel River

100

2,050 

360

1,100,000 

3300

460 

235

50,200

90

1,845 

322

730,000 

3240

400 

235

40,400

Crater Creek

100

184 

U,005

142,000 

2108

1,130 

853

12,600

£0

165 

i 1,005

71,000 

260

1,082 

853

11,300

1 With the storage equally divided above and below the lake surface.

2 Above lake level.

3 Height of main dam above stream level.

The potential power and related data on the Long River and 

Crater Creek with storage developed by damming alone and by 

drawdown alone are summarized below for comparison.

Height of dam : ... ft .....................

Operating range with drawdown ... alt (ft) . . . 

Continuous power with dam . . . kw ..........

Continuous power with drawdown . . . kw ....

Long River

100

422 

133

/ 947 

\ 814

/ 814 

\ 575

25,300 

20,100

90

380 

80

894 

814

814 

695

22,000 

19,400

Crater Creek

100

184 

190

1,212 

1,022

} (2 ) 

14,000

(2)

90

165 

108

1,130 

1,022

/ 1,022

\ 853

12,000 

10,400

1 Above lake level.

2 Drawdown considered impracticable.
UNDEVELOPED POWERSITES 71 

LOCATIONS AT WHICH POWER COULD BE USED

A suitable industrial site for use of power from the Sweetheart Creek site and the sites near Speel Arm may be a flat 

area 1 mile from the mouth of Sweetheart Creek, extending 

about 3i/£ miles southeast between Gilbert Bay and Tracy Arm. 

At present [1959] this is entirely undeveloped. Power from the 

sites at Speel Arm could be transmitted to this area over a 

distance of about 18 miles including a %-mile span across the 

Speel Arm and a %-mile span across the Whiting River.

The neck of land is about % mile wide and slopes gradually 

from an altitude of 100 feet near Tracy Arm to the tidal flat 

of Gilbert Bay. About a third of it at the end near Gilbert 

Bay is marshy. The U.S. Forest Service (1957) made a field 

examination and found that much of the area appears suitable 

for location of a sizable industry, but recommended that geologic 

and other examinations be made before it is seriously considered 

for development.

Some water is available from natural flows of streams draining 

from the mountainsides on each side across the flat area, and 

some possibly could be obtained from ground water. A large 

supply of dependable water could be obtained if a reservoir 

is created at Lower Sweetheart Lake. Some storage there for a 

water supply probably would be essential to a sizable industrial 

development on Sweetheart Flats. Water could be diverted from 

Sweetheart Creek below the reservoir or from the waterway of a 

powerplant, sacrificing some of the potential power.

A plan of development for Long Lake and Crater Lake was 

suggested by Dort (1924, p. 81-88) in which a common powerhouse would be located a quarter of a mile west of the mouth 

of Glacier Creek. Land adjacent to this place was described 

as suitable for an industrial site. A tract of at least 50 acres 

within 2,000 feet of the mouth of Glacier Creek appears to be 

topographically suitable for location of structures. All of this 

area is below an altitude of 200 feet and most of it is below an 

altitude of 100 feet. Supplies of industrial water could be obtained 

by diversion from the penstocks above the powerhouse at sacrifice of some of the potential power.

Some disadvantages of the location are that the Speel River 

estuary is separated by mudflats from the deep water of Speel 

Arm, that terrain suitable for expansion of industries and settlements is very limited, and that there may be a possibility of 

slides from the nearby mountainsides.
72 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

In 1926 an applicant to the Federal Power Commission proposed transmission of power from Long Lake and Crater Lake 

to the vicinity of Juneau. The transmission system would have 

included a submarine cable across Taku Inlet and would have 

served in part for transmission of power from the Lake Dorothy 

site, the development of which also was proposed by the applicant. 

A location for crossing Taku Inlet, as suggested by the U.S. Army 

Corps of Engineers (1952, p. 133) and the U.S. Bureau of Reclamation (1955, p. 39), is near the mouth of Dorothy Creek 

where the width is less than 2 miles. If the transmission line 

were located near the waterways for the entire distance, the 

length of the route from the Long River site to Juneau would 

be about 51 miles. This could be reduced about 10 miles by a 

shortcut accross the mountainous peninsula between Port Snettisham and Slocum Inlet of Stephens Passage.

A powerplant at the Tease Lake site could be interconnected 

with plants at the Long River, Speel River, and Crater Creek 

sites by means of roughly 4 miles of transmission line including 

a 3/2-mile span across the Speel River. The lower unit of the 

Sweetheart Creek site could be interconnected with the Speel 

Arm plants by about 11 miles of transmission line joining the 

proposed Juneau line on the west side of Port Snettisham, 5 

miles southwest of Crater Creek. This would include %-mile 

spans across both the Whiting River and Port Snettisham, and 

the overall distance for transmission to Juneau would be about 

7 miles more than from the Long River site.

Juneau is located in part on steep slopes below a mountainside, 

but it has the considerable advantage of an existing community 

with harbor facilities and other utilities. Suitable terrain for 

expansion is available on the mainland a few miles northwest 

of the municipal area, or on nearby Douglas Island.

The domestic water supply of Juneau is obtained in part by 

diversion of some of the natural flow of Gold Creek. The average 

discharge of the stream is 104 cfs, but conditions are not favorable 

for development of storage for regulation. Nearby Salmon Creek 

has a drainage area and runoff that are about the same as that 

of Gold Creek. Part of the flow is controlled for power purposes 

at the reservoir of the Alaska Juneau Gold Mining Co. It 

would be possible to use regulated flow for an industrial water 

supply by diversion above the lower unit of the Salmon Creek 

powerplant.

Lemon Creek, which is about 2 miles northwest of Salmon 

Creek and about 4 miles northwest of Juneau, also might be
UNDEVELOPED POWERSITES 73

considered for water supplies in connection with power development. Two sites on this creek were described by the Federal 

Power Commission and U.S. Forest Service (1947, p. 74) at 

which storage could be created for partial control of the stream. 

Streamflow records collected from 1951 to 1956 and precipitation 

records at Juneau show that the long-term mean discharge 

may be about 140 cfs. An applicant to the Federal Power Commission in 1955 proposed development of both storage sites for 

power purposes, with the tailwater of the lower unit at an 

altitude of 30 feet. An area of several hundred acres lies between 

that level and the tidal mudflats of Gastineau Channel. The 

proposed use of the power was for operation of a prospective 

newsprint mill or pulp mill to be located on the northwestern 

end of Douglas Island where there is a good harbor.

Water supplies could be obtained on Douglas Island from 

runoff of creeks, but the winter flow would be small. Supplemental supplies would have to be obtained from ground water 

on the island if enough is available, or from regulated sources on 

the mainland, to provide a substantial and dependable supply of 

industrial water.

SITES IN TAKU INLET AND GASTINEAU CHANNEL AREA

MAPS

A map entitled "Plan and Profile, Sheep Creek and Carlson 

Creek near Juneau, Alaska, Miscellaneous Dam Sites" was published by the Geological Survey in 1953. The scale of the plan 

map is 1:24,000 and the contour intervals are 20 and 40 feet. 

Maps of damsites on Carlson, Sheep, and Turner Creeks, are on 

a larger scale with a contour interval of 10 feet.

The powersites and their related drainage areas are shown 

on the topographic maps of the Juneau A-l, B-l, and B-2 

quadrangles; Taku River A-6 and B-6 quadrangles; and the 

Taku River and Juneau quadrangles of the Reconnaissance Topographic Series. Except for the reconnaissance series, these maps 

were compiled by the Geological Survey from 1949 to 1952 on 

a scale of 1:63,360 and with contour interval of 100 feet. The 

reconnaissance maps were published by the Geological Survey 

in 1953 on a scale of 1:250,000 and with contour intervals of 

200, 250 and 500 feet. They show the system of waterways and 

topography of a large area in the general vicinity of Juneau. In 

addition to the maps of the regular topographic series there is a 

special topographic map entitled "Juneau and Vicinity" which 

includes the area at Juneau, the Sheep Creek basin, and a part
74 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

of the Carlson Creek basin. The scale is 1:24,000 and the contour 

interval is 40 feet.

A map of the Dorothy Creek basin prepared for the Bureau 

of Reclamation has been compiled on a scale of 1:7,200 and with 

a contour interval of 20 feet. Copies are available for examination 

in files of the Bureau of Reclamation or of the Geological Survey.

A map of a damsite on Carlson Creek at Mile 2.3 (distance 

from the mouth of the stream measured along mapped channel) 

was prepared by the Alaska Gastineau Mining Co. in 1920. The 

original scale was 1 inch equals 40 feet or 1:480, with a contour 

interval of 40 feet. Photostatic copies are available for examination in files of the Forest Service or of the Geological Survey.

Soundings in Taku Inlet, Gastineau Channel, and a part of 

Stephens Passage are shown on Chart 8235 of the U.S. Coast and 

Geodetic Survey. The chart is on a scale of 1:40,000, and the 

soundings are in fathoms.

LOCAL GEOGRAPHY AND TOPOGRAPHY

Taku Inlet extends northward from the northern end of 

Stephens Passage about 17 miles to the Taku River estuary. Most 

of the Taku River is in Canada, and there are no apparent power 

possibilities on the 20-mile reach of river channel in Alaska.

FIGURE 12. Aerial view of mountains between Port Snettisham and Taku Inlet along a possible 

transmission-line route. Gastineau Channel and Taku Inlet in background. (U.S. Forest 

Service photograph; June 22, 1929.)
UNDEVELOPED POWERSITES 75

FIGURE 13. Aerial view of Taku Inlet. The rock cliff at right center is just beyond the mouth 

of Dorothy Creek, and the Taku tidal glacier is visible beyond the cliff.

Steep mountainsides extends down to Taku Inlet except at 

the mouths of tributaries and at Norris Glacier and Taku 

Glacier, which flow from the northeast into the inlet near its 

upper end (see figs. 12, 13). Along the Taku River upstream 

there are strips of flat land below an altitude of 200 feet that 

aggregate more than 20 square miles. A land survey has been 

made of a part of this terrain, and there has been some recreational development and a few homestead entries. Access is 

dependent on boats or barges of shallow draft.

If there should ever be settlement or industrial activity along 

the Taku River justifying power development, power sites on 

Boundary Creek and Yehring Creek might be considered. Boundary Creek joins the Taku River from the north, just downstream 

from the international boundary, at a river altitude of about 

70 feet; and Yehring Creek joins the river from the south about 

6 miles farther downstream. The power possibilities have been 

discussed by the Federal Power Commission and U.S. Forest 

Service (1947, p. 70) on the basis of a reconnaissance of damsites on Boundary Creek and photographs and preliminary maps 

of Yehring Creek. The average potential was estimated to be 

9.000 hp (equivalent to 6,710 kw) on Boundary Creek and 14,500 

hp (equivalent to 10,800 kw) on Yehring Creek, but the possibilities for storage regulation are limited.
76 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

012345 MILES

FIGURE 14. Map of powersites in the Taku Inlet and Gastineau Channel area, Alaska.

Three of the four powersites discussed in this section are 

on streams tributary to Taku Inlet; Dorothy Creek and Turner 

Creek are on the east side and Carlson Creek on the west side. 

The other site is on Sheep Creek, which is tributary to Gastineau 

Channel about 3 miles southeast of Juneau and about 6 miles 

northwest of the mouth of Taku Inlet. (See fig. 14.)

All the stream basins are in mountainous terrain, with altitudes 

ranging up to 4,000 feet or more, but that of Dorothy Creek 

has a notable concentration of area at relatively high altitude. 

Lake Dorothy, at an altitude of 2,421 feet, could be developed 

for control of nearly 80 percent of the runoff of the entire basin.

There is a road from Juneau to the mouth of Sheep Creek 

along Gastineau Channel but because of the steep terrain, extension of this road to the mouth of Carlson Creek some 16 miles 

for access to the powersite would be costly. Construction of a 

road from Sheep Creek around the head of Taku Inlet would be 

entirely out of the question, not only because of the distance 

along steep mountainsides but also because the route crosses the 

two large glaciers and the wide estuary of the Taku Eiver. 

Dorothy Creek and Turner Creek are within about 25 miles 

of Juneau by water.

Except on Sheep Creek there has been no substantial development or settlement in the stream basins of the four powersites. 

A hydroelectric plant on Sheep Creek is described in the section 

"Developed Power." Existing structures in the upper part of
UNDEVELOPED POWERSITES 77

the Sheep Creek basin include mine buildings, aerial trams, and 

a transmission line.

The powerhouse of the Annex Creek hydroelectric plant described in the section "Developed Power" is about 2 miles northeast of Carlson Creek. Energy from this plant is transmitted 15 

miles to Juneau by a line that crosses part of the Carlson Creek 

and adjacent Sheep Creek basins.

WATER SUPPLY

RECORDS OF STREAMFLOW

Gaging stations have been maintained on Dorothy, Turner, 

Carlson, Sheep, and Gold Creeks as shown below. The records 

for Gold Creek were used for comparative purposes.

Gaging station

Dorothy Creel

Turner Creek 

Carlson Creek

Sheep Creek n 

Gold Creek at

c near Juneau ...............

ear Juneau. .................

Drainage 

area (square) 

miles)

15.2 

53.1

22.3 

24.3

4.30

9.76 

10.3 

9.76

Period of record l

Oct. 1929- 

Sept. 1942 - 

June 1944 -

May 1908 -

Jan. 1914- 

Oct. 1915- 

July 1916- 

July 1951 -

Jan. 1911- 

Aug. 1916- 

Oct. 1946-

Aug. 1916- 

Oct. 1946- 

Oct. 1949 -

Oct. 1941. 

Dec. 1943. 

Sept. 1956.

Mar. 1909.

Sept. 1914. 

Dec. 1915. 

Dec. 1920. 

Sept. 1956.

Dec. 1913. 

Dec. 1920. 

Sept. 1956.

Dec. 1920. 

Sept. 1948. 

Sept. 1956.

l To September 1956.

Except for those of Turner Creek, the monthly and annual 

records through September 1956, and daily discharge records 

for Dorothy Creek from October 1945 through September 1956, 

and for Sheep Creek from October 1946 through September 1956 

have been published by the Geological Survey (1957, 1958a, b). 

The monthly record for Turner Creek was published by the 

Federal Power Commission and U.S. Forest Service (1947, p. 125) 

as of unknown accuracy. The record was obtained by the Alaska 

Treadwell Mining Co. in its investigation of the powersite.

Recorded figures of monthly runoff from the brief Turner 

Lake record are listed herein under the section on the runoff
78 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

at Turner Lake outlet. Some monthly runoff figures for Dorothy 

Creek, as rounded from the records, and some estimates for the 

Sheep Creek and Carlson Creek damsites are given in tables 7-9.

TABLE 7. Monthly and annual runoff, in thousands of acre-feet, Dorothy 

Creek near Juneau, Alaska

Water year

1930............

1931............

1932............

1933............

1934............

1935............

1936............

1937............

1938............

1Q3Q

1940. ...........

1941............

1943............

1946. ...........

1947............

1948............

1949............

1950...........

1951............

1952............

1953............

1954. ...........

1955............

1956

Oct.

21.0

12.0

12.9

13.2

10.4

13.2

12.4

28.0

23.6

14.3

15.9

13.7

15.5

19.7

24.5

11.9

13.0

10.0

10.6

6.0

8.9

20.1

14.5

8.3

7.2

14.4

Nov.

9.0

11.5

3.8

2.5

9.4

4 Q

3.4

16.9

5.1

4.4

8.4

4.2

3.2

8.3

2.8

7.7

5.3

7.3

21.1

1.9

2.7

9.4

5.5

6.8

3.2

6.7

Dec.

4.0

6.2

1.0

1.4

2.0

3.3

5.1

7.0

3.0

3.4

4.6

2.0

1.9

5.2

1.2

1.6

3 Q

2.3

2.2

.9

1.4

2.0

1.9

4.4

1.3

2.9

Jan.

0.7

2.9

1.1

1.2

.6

1.0

1.1

1.5

2.6

2.0

1.6

1.1

2.3

1.2

.9

1.4

2.2

1.9

.8

1.1

1.1

1.2

1.6

1.7

.7

1.4

Feb.

0.7

3.9

.8

.9

.7

.6

.7

.8

2.1

1.3

1.9

1.3

1.1

.8

.8

1.0

1.1

.8

.6

.8

1.0

1.1

1.0

.6

1.2

Mar.

1.3

1.4

.8

.6

.9

1.2

1.4

4.2

1.0

1.4

2.5

1.5

1.1

5.3

1.0

1.1

.7

1.0

.9

1.3

1.6

1.2

.9

1.5

Apr.

2.9

2.0

1.6

1.3

1.2

1.1

2.1

1.6

1.3

1.4

2.2

3.2

3.7

1.6

1.1

2.8

.8

1.7

.8

1.4

1.3

1.4

1.0

1.2

1.2

1.7

May

4.6

7.2

4.3

5.3

3.7

3.3

6.7

4.1

7.7

4.5

7.1

5.8

5.8

7.2

8.6

7.3

8.2

7.1

4.5

5.6

5.0

7.2

4.0

3.8

6.8

5.8

June

11.7

19.6

14.9

8.9

14.9

Q 8

18.9

17.7

12.2

13 4

12.9

15.0

13.5

14.5

16.8

16.6

10 1

12.3

12.9

16.7

10.7

14.8

11.8

9.9

10.2

14.0

July

20.3

19.1

17.8

15.4

17.0

24.3

18.4

15.4

17.2

21.0

19.7

19.9

23 6

20.3

16.3

16.3

18.7

16.7

17.7

19.8

18.8

19.5

14.8

20.0

18.6

18.7

Aug.

22.9

22.2

17.3

16.5

25.0

18.8

16.7

18.4

15.1

26.8

24.8

13.3

20.8

16.1

20.4

14.9

16.8

18.9

15.4

13.3

17.8

20.5

12.2

20.9

27.1

18.9

Sept.

16.8

17.9

16.3

10.9

14.9

12.1

21.2

20.2

23.3

15.3

18.8

8.8

22.8

18.4

13.7

22.8

23.0

16.5

18.0

13.5

19.9

16.9

14.4

15.0

14.3

17.0

Annual

115.9

125.9

92.6

78.1

100.7

93.5

107.9

133.0

117.4

108.9

118.9

89.7

116.7

114.8

108.2

109.6

113.1

96.6

105.3

82.0

89.5

115.4

86.9

94.2

92.1

104.3

TABLE 8. Monthly and annual runoff, in thousands of acre-feet, Carlson 

Creek at damsite near Juneau, Alaska

[1917-20, from records for a drainage area of 22.3 square miles; 1947-51, estimated from records 

of adjacent basins (to June 1951); 1951-56, estimated for a drainage area of 22.3 square miles 

from records for 24.3 square miles]

Water year

1917............

1919............

1920............

1947. ...........

1948............

1949............

rn en

Ml............

1952............

1953............

1954............

i nee

1QKR

Mean. ....

Oct.

28.0

29.9

22.1

25.3

28.6

23.4

28.5

34.2

12.3

14.9

43.0

39.1

20.2

15.5

26.1

Nov.

7.3

28.9

16.1

7.7

33.2

22.6

29.0

32.8

5.3

6.4

19.2

20.2

8.7

17.4

Dec.

3.6

3

n

7.7

6.5

3.1

8.2

3.4

3.8

1.8

2.8

6.8

6.9

1.6

5.5

Jan.

3.1

4.1

8.4

6.8

3.1

6.8

q 0

1.5

1.5

1.0

2.1

2.4

4.2

1.2

3.5

Feb.

4.4

1.0

1.6

2.4

1.7

2.5

1.6

1.0

1.0

.8

1 ^

9.6

2.4

1.2

2.3

Mar.

2.5

.7

1.2

1.1

22.8

1.3

3.6

1.0

1.0

1.5

.7

1.8

1 Q

1.0

3.0

Apr.

3.6

2 7

5.7

1.5

15.0

1.5

6.9

1 3

4.0

5.1

5.6

1.6

2

K

3 n

4.3

May

23.0

n

o

20.1

14.8

28.8

36.8

26.0

17 9

30.2

20.8

18.2

1 K A

30.4

23.4

June

41 Q

46.4

34 fi

43.1

35.9

31.6

54.0

33.6

37 9

on o

36.0

35.6

9.0. f.

38.8

July

52.1

J.R Q

49 3

42.2

29.9

35.4

50.0

34 n

29.6

41.5

29.8

31.6

46.1

34.2

39.0

Aug.

51.5

45.4

38.1

45.1

28.1

19.1

48.5

20.6

17.2

32.0

15.9

4? 9

34.3

Sept.

35.8

07 7

36.7

24.6

45.0

38.4

28.5

OK 0

1^4

39.6

27.9

24.4

29.4

20.8

30.7

Annual

256.8

264.9

234.6

221.1

275.2

227.6

283.0

OAR 0

161.3

204.3

233.0

193.8

241.9

1Q1 9.

228.3

RUNOFF AT LAKE DOROTHY, LIEUY LAKE, AND BART LAKE

Dorothy Creek heads at an altitude of 2,421 feet in Lake 

Dorothy, which is the major storage site of the basin and could be 

used for complete control of the runoff at the lake. The drainage 

area is 11.0 square miles or approximately 72 percent of that at
UNDEVELOPED POWERSITES 79

TABLE 9. Monthly and annual runoff, in thousands of acre-feet, Sheep Creek 

at damsite near Juneau, Alaska

[1911-20, rounded from the gaging station records which for that period approximately represent 

the runoff at the damsite; after 1920, estimates of the runoff at the damsite based in records 

for upstream points]

Water year

1911............ 

1912............

1913............

1917............

1918............

1919............

1920............

1947. ...........

1948............

1949............

1950. ...........

1951............

1952............

1953. ..........

1954............

1955............

1956. ...........

Mean. ....

Oct.

'siso'

2.70

5.16

5.52

4.01

5.34

4.67

5.15

4.98

5.66

2.56

2.28

6.21

6.42

3.72

3.27

4.47

Nov.

'i!20'

1.21

1.92

6.37

3.74

1.68

4.81

4.99

5.92

5.49

1.39

1.81

4.23

1.74

3.61

1.75

3.24

Dec.

'2'i6'

1.80

.91

1.13

2.32

1.08

.79

1.66

.85

1.16

.59

1.08

1.52

1.62

3.16

.55

1.40

Jan.

0.60 

.59

.73

.35

.63

1.82

2.06

.77

1.30

.78

.49

.60

.50

.82

.91

1.13

.32

.85

Feb.

0.48 

1.15

1.01

1.09

.38

.44

.89

.47

.74

.44

.31

.28

.39

.67

1.15

.71

.27

.64

Mar.

0.42 

.73

.95

.57

.26

.30

.60

2.72

.40

.88

.30

.29

.42

.45

.52

.62

.27

.63

Apr.

0.30 

1.20

1.93

ni

.35

1.51

.46

2.80

.26

1.59

.42

1.18

1.02

1.51

.42

.62

.49

.98

May

2.70 

5.73

4.05

3.69

3.91

3.78

2.93

5.92

6.00

5.73

3.52

5.86

5.28

6.16

3.14

2.88

6.33

4.56

June

5.50 

4.30

4.05

5.37

6.13

5.16

6.90

5.67

5.37

8.05

4.46

7.41

6.96

5.70

4.96

5.77

4.56

5.67

July

5.70 

2.95

5.20

6.11

4.26

5.92

5.26

4.28

6.25

6.28

4.75

4.56

6.13

4.81

4.22

5.31

4.13

5.06

Aug.

4.60 

2.87

4.05

5.93

5.31

4.69

5.16

3.84

3.39

6.07

3.39

2.82

4.21

4.51

2.07

6.48

6.07

4.38

Sept.

2.40 

2.87

3.60

5.02

4.55

5.46

3.31

8.67

6.55

4.17

4.26

2.37

6.52

4.72

2.76

4.17

3.45

4.40

Annual

'ti'.w"

31.28

36.67

38.80

39.15

35.67

45.41

42.06

45.74

34.21

29.91

36.60

41.31

29.93

38.18

31.46

36.62

the gaging station. Because of the high altitude, the area above 

the lake undoubtedly has proportionately greater runoff than the 

average for the basin and proportionately more summer runoff 

and less winter runoff. The U.S. Bureau of Reclamation (1955, 

p. 28) estimated a monthly distribution which seems reasonable 

and is used herein. It is roughly consistent with three measurements of the Geological Survey made during the high-water season 

of 1954 at Lake Dorothy outlet, each of which showed more than 

90 percent of the corresponding flow at the gaging station. The 

estimated runoff at the Lake Dorothy outlet, in percent of runoff 

at the Dorothy Creek gaging station, is shown below.

Oct. . . . . .

DPP

..... 85

..... 75

.....50

Feb.....

A/Tar

....35

.... 35

....35

May

....35

....60

....80

Aug.

Sept .....

. .. ..85

.....85

..... 85

The mean discharge at the gaging station was 144 cfs during 

the 25 water years of record between 1929 and 1956. The mean 

discharge at Lake Dorothy outlet for runoff in accordance with 

the estimated monthly relationships was 112 cfs or about 78 

percent of that at the gage.

There are two small lakes along the course of Dorothy Creek 

downstream from Lake Dorothy; Lieuy Lake, formerly called 

Lake Veronica, and Bart Lake, formerly called Lake Mary. Their 

altitudes are 1,706 feet and 996 feet respectively, as determined 

for the special map of the Dorothy Creek basin. The Federal 

Power Commission and U.S. Forest Service (1947, p. 69) pointed
80 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

out that each of these lakes could be used as diversion points 

for utilization of intervening runoff below Lake Dorothy. The 

drainage area between Lake Dorothy and Lieuy Lake is 1.4 

square miles and that between Lake Dorothy and Bart Lake is 

3.7 square miles. These areas are about 13 percent and 34 percent respectively of the area tributary to Lake Dorothy, but 

since they are at lower altitudes the amounts of runoff are 

assumed to be only 10 percent and 25 percent of that at Lake 

Dorothy. The percentages correspond to increments of 11 cfs at 

Lieuy Lake and 28 cfs at Bart Lake, above the mean discharge 

at Lake Dorothy.

RUNOFF AT TURNER LAKE OUTLET

The former gaging station on Turner Creek was 600 feet downstream from the outlet of Turner Lake and 1/2 mile from the 

mouth of the creek at Taku Inlet. The figures of monthly runoff, 

rounded from those published by the Federal Power Commission 

and Forest Service are shown below.

Date

1908

July................

Runoff (thousands 

of acre-feet)

15.6

43.7

49.5

43.7

50.6

Date

1908 Con.

1909

January. ............

March. .............

Total ..........

Runoff (thousands 

of acre-feet)

40.0

17.6

15.1

8.9

5.0

6.5

296.2

The precipitation recorded during the winter of 1907-08 was 

substantially more than during the winter of 1908-09 at several 

stations in southern and southeastern Alaska. As nearly as can 

be judged from these early records the precipitation during the 

1907-08 water year was only slightly more than normal. Thus 

the mean annual runoff at Turner Lake outlet is at least 300,000 

acre-feet, corresponding to 106 inches on the drainage area of 

53.1 square miles, or to a mean discharge of about 410 cfs. The 

Dorothy Creek drainage basin of 15.3 square miles is just to the 

southwest of the Turner Creek basin. The mean discharge of 

144 cfs for the 25 years of record between 1929 and 1956 corresponds to 119 inches on that drainage area.
UNDEVELOPED POWERSITES 81 

RUNOFF AT CARLSON CREEK DAMSITE

A reservoir could be created along Carlson Creek and its tributary, Sheep Fork, by a dam at Mile 1.8 or alternatively at Mile 2.3. 

The gaging station on Carlson Creek prior to 1921 was at about 

Mile 2.0, where the drainage area is 22.3 square miles; and the 

present station started in July 1951 is at Mile 1.5, where the 

drainage area is 24.3 square miles. The runoff at the reservoir 

site is assumed to be the same as the recorded runoff from 1914 

to 1920, and the same as the recorded runoff times the drainagearea ratio, 0.92, from July 1951 to September 1956.

The records do not cover the 1950 and 1951 water years which 

are part of a period of generally subnormal precipitation and 

runoff extending through 1956. Figures of monthly runoff were 

estimated for the period from October 1946 to June 1951 and used 

with the records and adjusted records to provide a more representative sequence for the estimation of storage and power 

possibilities. Except for the 1949 water year, the estimates were 

based on the recorded runoff of Gold Creek at Juneau and the 

average relationship that existed between the adjusted monthly 

runoff of Carlson Creek and the monthly runoff of Gold Creek 

for the period of overlapping records, July 1951 to September 

1956. The Gold Creek basin is adjacent to the Carlson Creek 

basin, and the monthly distribution of runoff in the two basins 

is closely similar. The figures for the 1949 water year, were 

estimated from monthly runoff of Sheep Creek and the relationships that existed between Sheep Creek and Carlson Creek 

in periods of overlapping records.

RUNOFF AT SHEEP CREEK DAMSITE

The only reservoir site on Sheep Creek is a valley extending 

from a damsite at Mile 1.0 upstream to about Mile 3.0. The 

drainage area at the damsite is approximately 4.6 square miles, 

and that at the gaging station about at Mile 1.4 is 4.30 square 

miles. The intervening drainage area is 7 percent of that at 

the gage but probably is proportionately less productive than 

upper parts of the basin.

The records for the period 1916-20, and presumably from 1911 

to 1913, were based on measurements made 0.3 mile below the 

gage, near the damsite, and include some inflow that evidently is 

largely from water that passes the gage underground. As described by Plafker (1956, p. 15) the floor of the Sheep Creek 

valley is formed by moderately well sorted sand, granules, pebbles, and cobbles with subordinate amounts of talus. Four com-
82 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

parative sets of discharge measurements, as shown below, give 

an indication of the magnitude of the bypass flow during months 

of low flow.

Date

February 25, 1918. ...........................

March 20, 1919 ............................

April. ...15, 1920...... ......................

February 9, 1951 ............................

]

At gage

0

0

0

.5

Flow (cfs)

0 . 3 mile below gage

5.6

4.5

5.7

5.9

According to these measurements an average flow of about 

5.3 cfs returns to the channel between the gage and the damsite, 

and must originate largely from the drainage area above the 

gage, which is 93.5 percent of that at the damsite. A uniform 

flow of 5.3 cfs throughout the year would correspond to about 

12 percent of the mean annual runoff at the gage.

The records for the period 1946-49 were based on measurements made 0.1 mile below the gage, and after 1949 the records 

are of runoff at the gage. The minimum monthly discharge as 

recorded in several months at the gage is zero, as compared with 

a minimum of 4.2 cfs prior to October 1920 when measurements 

were made near the damsite.

The runoff at the damsite was approximately the same as 

the runoff recorded before 1921. During the 1947-49 water years, 

it was assumed that there was a uniform ground-water return 

between the measuring section and the damsite equivalent to 

8 percent of the recorded annual runoff, and a surface-water 

inflow equal to 4 percent of the recorded runoff during the 

months May to November. The surface-water inflow was estimated in the same way for the 1950-56 water years, but it was 

assumed that the ground-water inflow over the longer channel 

reach from the gaging station to the damsite was equivalent to 

12 percent of the annual runoff. The monthly runoff as recorded 

and estimated for the damsite is listed in table 9.

The runoff as estimated is about 16 percent more at the damsite 

than at the gage from 1950 to 1956. The ratio of this amount 

to that measured near the damsite during the 1917 to 1920 water 

years is 1.62. The ratio of recorded amounts of runoff on nearby 

Gold Creek in the same two periods was approximately the 

same, 1.63. This correspondence indicates that the Sheep Creek 

estimates probably are not greatly in error.
UNDEVELOPED POWERSITES 83

The mean discharge at the Sheep Creek damsite for 16 water 

years between 1911 and 1956 is estimated as 50.5 cfs.

DOROTHY CREEK POWERSITE 

RESERVOIR SITES

Lake Dorothy is 2.7 miles from the tidewater of Taku Inlet 

by the shortest route, which is from its northern end. The lake 

extends more than 3 miles southward between steep mountainsides, which are practically bare of vegetation, to a delta of 

glacial debris at the upper end. The terminus of a glacier is 

within a few hundred feet of the lake shore at this place. (See 

fig. 15.)

Dorothy Creek drains Lake Dorothy through an outlet on the 

west side, 0.4 mile from the north end. The topography of the 

lake outlet, as taken from the special map of the Dorothy Creek 

basin, is shown in figure 16. Both sides of the outlet section 

and the creek bed have been glaciated; consequently very little if 

any soil or gravel mantles the area.

FIGURE 15. Aerial view of Lake Dorothy showing glaciers at upper end of lake in lower center. 

Dorothy Creek flows from the lake down the canyon at left center. Taku tidal glacier in background. (U.S. Forest Service photograph, August 4, 1929.)
84 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

CONTOUR INTERVAL 20 FEET

DATUM IS MEAN SEA LEVEL 

FIGURE 16. Map of Lake Dorothy damsite.

It would be possible to develop sufficient storage capacity for 

control of the runoff at Lake Dorothy either entirely by damming 

or entirely by drawdown through a tunnel outlet. It is probable 

that all of the capacity would be developed by drawdown, as 

proposed by the U.S. Bureau of Reclamation (1955, p. 38), 

since only a relatively small part of the head would be lost, and
UNDEVELOPED POWERSITES 85

since access for construction of a dam at the outlet would be 

very difficult.

The potential capacities and surface areas for a range above 

and below the lake surface at the Lake Dorothy site are shown 

below. Areas and capacities below the lake surface were taken 

from curves determined by the Bureau of Reclamation; those 

at and above the lake surface from the map of the Dorothy 

Creek basin.

Altitude 

(feet)

2,240. ...................

2,260. ...................

2,280. ...................

2,300. ...................

2,320. ...................

2,340. ...................

2,360. ...................

2,380. ...................

2,400. ...................

2,421 i... ................

2,440. ...................

2,460. ...................

2,480. ...................

2,500....................

2,520. ...................

2,540. ...................

Area

(acres)

642 

670 

697 

727 

760 

793 

828 

864 

901 

968 

1,049 

1,114 

1,180 

1,239 

1,282 

1,319

Capacity 

(acre-feet)

Below lake surface

142,500 

129,500 

116,000 

101,500 

87,000 

71,000 

55,000 

38,500 

20,500 

0

Above lake surface

0 

19,200 

40,800 

63,700 

87,900 

113,100 

139,100

1 Lake surface.

Storage requirements for regulation were determined from 

reservoir schedules based on estimated inflows corresponding 

to the 25 water years of record between 1929 and 1956. These 

years were considered as a consecutive series. The schedules 

show that 125,000 acre-feet of usable capacity would have been 

required to provide for a uniform monthly release equal to the 

estimated mean inflow of 112 cfs. A capacity of only 50,000 acrefeet would have provided for a uniform monthly release of 101 

cfs, equal to 90 percent of the mean inflow. A capacity of 125,000 

acre-feet could be obtained by drawdown of 155 feet to an 

altitude of 2,266 feet; and a capacity of 50,000 acre-feet could 

be obtained by drawdown of 55 feet to an altitude of 2,366 feet.

Lieuy Lake is 0.6 mile downstream from Lake Dorothy, and 

about 1% miles from Taku Inlet, separated by extremely steep, 

rugged terrain. The surface area of the lake is 79 acres. Although 

it would be topographically feasible to develop several thousand
86 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

acre-feet of capacity by damming the lake outlet, the dam would 

be relatively costly because of the inaccessible location. The lake 

has not been sounded, but the mountainsides surrounding the 

lake are steep and some storage undoubtedly could be developed 

by drawdown. However, the possibility of any development 

seems very doubtful since the cost of a waterway to a powerhouse 

alone probably would be more than the value of the potential 

power that could be developed from the small inflow below Lake 

Dorothy.

Bart Lake is about ^ mile farther downstream and is about 

1*4 miles from the mouth of Dorothy Creek at Taku Inlet. The 

surface area of the lake is 229 acres. It is estimated that the 

runoff from the drainage area between Lake Dorothy and Bart 

Lake could be controlled for 90 percent utilization with storage

BART LAKE 

Elev 996 ft

600

CONTOUR INTERVAL 20 FEET

DATUM IS MEAN SEA LEVEL

1200 FEET 

_I

FIGURE 17. Map of Bart Lake damsite.
UNDEVELOPED POWERSITES 87

capacity of about 13,000 acre-feet. This could be obtained with 

a dam at the outlet, raising the lake surface 52 feet to an altitude 

of 1,048 feet. The outlet area is shown in figure 17 as traced 

from the special map of the Dorothy Creek basin. The reservoir 

areas and capacities for a range above the lake surface at the 

Bart Lake site are shown below.

Altitude 

(feet)

996.......

1,000.......

1,020. ......

1,040.......

Area 

(acres)

229

245

252

257

Capacity 

(acres-feet)

0

950

5,920

11,000

Altitude 

(feet)

1,060......

1,080......

1,100......

Area 

(acres)

261

266

273

Capacity 

(acres-feet)

16,200

21,500

26,800

Soundings have not been made but it seems likely that the 

required capacity also could be obtained by drawdown through 

a tunnel outlet.

Construction of roads to any of the reservoir sites would 

be extremely difficult because of the steep, rugged terrain. The 

U.S. Bureau of Reclamation (1955, p. 36) proposed construction 

of a cable railway from Taku Inlet to the downstream end of 

the tunnel route from Lake Dorothy, for construction and operating purposes.

The maximum discharge recorded at the Dorothy Creek gage 

was 1,780 cfs, November 3, 1949, which corresponds to 117 cfs 

per square mile. If dams were constructed at the outlets of the 

lakes, spillway capacities for more than twice this discharge 

probably would be considered, but if storage were developed 

entirely by drawdown the natural channels would serve as 

spillways.

FLANS OF DEVELOPMENT

Water could be conveyed from Lake Dorothy by way of a 

tunnel and penstock on one of several alternate routes to Taku 

Inlet. The shortest route, and the one favored by the U.S. Bureau 

of Reclamation (1955, p. 38), bears almost due west from the 

northern end of Lake Dorothy. The length of the tunnel would 

be about 1.6 miles and the length of a surface penstock about 1.2 

miles. It would be possible to locate the powerhouse 0.7 mile 

farther south near the mouth of Dorothy Creek, but the bureau 

reported that a penstock and powerhouse there would have to 

be located underground because of the steepness of the terrain.
88 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

According to geologic examination of the bureau, the entire 

tunnel route westward from the lake is in quartz diorite and 

crosses several fault zones; no unusual difficulty was envisioned, 

and it was suggested that an unlined tunnel (except through the 

fault zones) might be considered.

Water could be conveyed from Lieuy Lake to the proposed 

powerhouse of the Lake Dorothy unit on Taku Inlet for separate 

development of power from natural flows. This would require 

about 1^4 miles of tunnel and ^ mile of penstock. A waterway 

capacity of about 50 cfs would be sufficient for substantial 

capture of mean daily flows. The potential power corresponding 

to the estimated mean discharge of 11 cfs and a head of 1,689 

feet is 1,260 kw.

Water could be conveyed from Bart Lake northwestward 

through 1.6 miles of tunnel and 0.3 mile of penstock to the proposed powerhouse of the Lake Dorothy unit for separate development of power from natural or regulated flows. Alternatively, 

water could be conveyed westward from Bart Lake through about 

% mile of tunnel and 1/2 mile of penstock to a powerhouse site 

at the mouth of an unnamed creek on Taku Inlet about 1 mile 

south of Dorothy Creek. A waterway capacity of about 150 cfs 

would be sufficient for substantial capture of mean daily flows 

from all runoff below Lake Dorothy.

TURNER CREEK POWERSITE

RESERVOIR SITE

A considerable amount of storage capacity could be created 

in Turner Lake 1/2 mile upstream from the mouth of Turner 

Creek by construction of a relatively low dam. The lake extends 

about 6 miles eastward from its outlet near Taku Inlet, and there 

is an arm at the upper end extending about 2 miles to the south. 

Except at the short valley between the lake and Taku Inlet, 

and at small areas of glacial deposits from the larger tributaries, 

steep mountainsides extend down to the lake on all sides. The 

maximum depth of the lake shown in about 6 soundings of 1952 

was 682 feet. Since the lake surface is at an altitude of only 

73 feet, development of storage by drawdown would not be 

practicable. (See fig. 18.)

The distance between the mountainsides at the lake outlet 

is roughly 1,200 feet, but a rock knoll within this reach constitutes a favorable abutment for a dam of moderate height. It is 

estimated that a dam to an altitude of 160 feet would provide 

for substantially complete control of the runoff. This would
UNDEVELOPED POWERSITES 89

FIGURE 18. Aerial view of Turner Lake outlet and tidal mudflat at mouth of Turner Creek on 

Taku Inlet. Rockslide debris found at the damsite probably came from the area of the large 

scar on the slope left of the lake outlet.

extend about 1,000 feet across the main outlet section on a curved 

axis to the knoll, and 300 feet across a saddle west of the knoll. 

A dam to an altitude of 117 feet would provide sufficient capacity 

for control of 90 percent of the estimated runoff. This would 

extend 650 feet across the main section on a curved axis to the 

rock knoll. The saddle west of the knoll could be excavated for 

construction of a spillway with a crest at an altitude of 117 feet. 

The ground surface at the low point of the saddle is at an altitude 

of 136 feet, and there is a cover of talus estimated to be less 

than 15 feet thick.

Plafker (1956, p. 35) described the foundation at the main 

section as granodiorite bedrock concealed by landslide debris, 

including blocks of large size, except for a part extending about 

250 feet east of the knoll which has a cover of soil estimated to 

be less than 3 feet thick. He considered the foundation rock to 

be excellently suited for a concrete or rock-fill dam, with treatment perhaps limited to removal of landslide debris and other 

surficial material.

Plafker pointed out that the landslide debris at the outlet 

section and along the creek probably came from the mountain-
90 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

side north of the damsite, as evidenced by a large scar, and that 

a wall might have to be constructed on the north abutment to 

divert falling rock from the dam.

The approximate reservoir areas and capacities for a range 

of altitude above the surface of Turner Lake were determined 

from the map of the Taku River B-6 quadrangle and are shown 

below.

Altitude 

(feet)

73.........

100.........

Area 

(acres)

3,050

3,550

Capacity 

(acres-feet)

0

89,000

Altitude 

(feet)

200. ........

300. ........

Area 

(acres)

4,010

4,480

Capacity 

(acres-feet)

467,000

892,000

The runoff record at Turner Lake is too brief for a determination of the storage capacities needed for control. At many other 

storage sites in southeastern Alaska, capacity equal to the average 

annual runoff or less would provide for substantially complete 

utilization on a schedule of uniform monthly releases, and the 

capacity required for control of 90 percent of the runoff would 

be roughly half as much. The estimated mean discharge of 410 

cfs at Turner Lake corresponds to an average annual runoff of 

about 300,000 acre-feet. It is assumed accordingly that the storage 

capacities required for 100 percent utilization and 90 percent 

utilization are 300,000 acre-feet and 150,000 acre-feet respectively.

Materials and equipment could be transported by boat along 

Taku Inlet to the vicinity of Turner Creek, and from the shore 

to Turner Lake by a short construction road. Tidal flats extend 

outward from the shore about y% mile near the mouth of Turner 

Creek so that access there might be dependent on landing craft 

of shallow draft at times of high tide. The bulk of materials 

for a rock-fill dam is available near the damsite.

PLANS OF DEVELOPMENT

Water could be conveyed from the Turner Lake reservoir 

northwestward through a penstock to a powerhouse site on the 

left bank of Turner Creek about 600 feet from the lake outlet. 

This is at the foot of a rapids where the stream altitude is 16 

feet. Plafker described the exposed bedrock at the site as an 

excellent foundation for a powerhouse.

It might be practicable to lower the tailrace at this site by 

excavation in the creek channel downstream from the rapids. 

Alternatively, it would be possible to convey the water about
UNDEVELOPED POWERSITES 91

2,000 feet farther downstream to a powerhouse site near the 

mouth of Turner Creek at the edge of the tidal flats.

CARLSON CREEK POWERSITE

RESERVOIR SITE

The damsite at Mile 2.3, surveyed by the Alaska Gastineau 

Mining Co., is at the lower end of a valley where the altitude 

of Carlson Creek is 320 feet. A much narrower site is located 

in a gorge one-half mile downstream where the creek is at an 

altitude of 230 feet. A map of the lower site at Mile 1.8 is included 

with the "Plan and Profile of Sheep Creek and Carlson Creek," 

which was printed in 1953.

A reservoir with a pool level of 500 feet or higher would extend 

up the Carlson Creek valley to about Mile 3.2 and an arm from 

that point would extend up the valley of Sheep Fork more than 

1 mile. Plafker (1956, p. 23) interpreted the flat-floored valley 

upstream from the damsites to be a former glacial lake which 

was filled with aluvium. There is a very dense growth of alders 

over much of the valley floor. (See fig. 19.)

It seems unlikely that a reservoir with a pool level higher than

FIGURE 19. View of Carlson Creek reservoir site from point a quarter of a mile above upper 

damsite. The Sheep Fork flows from behind ridge at left center.
92 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

about 560 feet would be considered. This would require a dam 

to a height of 330 feet above stream level at Mile 1.8 or to a height 

of 220 feet at Mile 2.3. The width of the valley at that level 

is 800 feet at the lower site and 1,400 feet at the upper site.

Plafker (1956, p. 26) reported that the bedrock at the lower 

damsite, called injection gneiss, is suitable as a foundation for 

either a concrete or rock-fill dam. He called attention to closely 

spaced joints parallel to the creek which would have to be sealed 

with a grout curtain along the dam alinement.

The damsite at Mile 2.3 has not been examined in detail. An 

unpublished report of the Alaska Gastineau Mining Co., dated 

1913 and entitled "Power Possibilities of Carlson Creek," states 

that exposures of bedrock are rare on the sides of the site and 

that borings of considerable magnitude might be necessary to 

determine the depth of bedrock in the bottom. The feasibility 

of the site was described as uncertain.

The capacities and surface areas of potential reservoirs above 

both damsites at the Carlson Creek reservoir site are shown below.

Altitude 

(feet)

Area 

(acres)

Capacity 

(acres-feet)

Altitude 

(feet)

Area 

(acres)

Capacity 

(acre-feet)

With dam at lower site

230.... .....

260.........

280...... .. .

300. ........

320. .... .

340. ........

360. ........

380. ........

400........ .

0

1

8

23

33

41

160

220

286

0

10

100

410

970

1,710

3,740

7,600

12,700

420. .......

440. .......

460........

480. .......

500........

520. .......

540........

560........

327

365

398

428

463

502

546

595

18,800

25,800

33,400

41,600

50,600

60,200

70,700

82,100

With dam at upper site

320. ........

340

360. ........

380.........

400. ........

420.....

440.....

0

1

114

168

224

259

292

0

10

1,160

3,980

7,900

12,700

18,200

460. .......

480. .......

500. .......

520. .......

540. .......

560. .......

323

349

379

413

452

497

24,400

31,100

38,400

46,300

55,000

64,400

The storage requirements for complete control were determined 

from operation schedules for the 14 years of records and estimates, 

considered as a consecutive series. A usable capacity of 270,000 

acre-feet would have been needed for uniform monthly releases
UNDEVELOPED POWERSITES 93

equal to the mean discharge of 312 cfs. This could only be obtained 

by construction of very high dams at either site.

Operation schedules were computed for 2 assumed capacities, 

25,000 acre-feet and 50,000 acre-feet, that may be within the 

range of feasibility. The uniform monthly releases could have 

been maintained by yearly use of the storage, as shown below.

Release (cfs) for indicated capacity (acre-feet)

Water year

1917.. ......

1918.. .:..

1919.. ....

1920. .......

1947........

1948. .......

1949 ........

25,000

137 

124 

164 

141 

182 

150 

142

50,000

206 

206 

247 

210 

306 

232 

226

Release (cfs) for indicated capacity (acre-feet)

Water year

1950... ....

1951..... ..

1952. ......

1953..... ..

1954. ......

1955... ....

1956.......

25,000

111

109 

117 

138 

148 

149 

109

50,000

194 

178 

186 

221 

217 

253 

184

With a capacity of 25,000 acre-feet, the regulated flow available 

for 100, 90, and 50 percent of the time would have been about 

109 cfs, 111 cfs, and 141 cfs respectively. The corresponding 

flows with a capacity of 50,000 acre-feet would have been 178 

cfs, 186 cfs, and 217 cfs.

The only access to the reservoir site at present is by a trail 

which parallels Annex Creek to the Juneau transmission line. 

About 21/2 miles of the transmission line is located at the reservoir 

site above the lower damsite and would have to be relocated 

before construction of a dam.

Plafker (1956, p. 27) reported that the bedrock at the dam 

site area is satisfactory for crushed aggregate or dimension stone, 

and that suitable natural aggregate of varied size may be available in sufficient amounts along Carlson Creek at the reservoir 

site.

The maximum recorded discharge of Carlson Creek was 6,200 

cfs, on September 26, 1918. This corresponds to the fairly high 

rate of 278 cfs per square mile.

PLANS OF DEVELOPMENT

Water could be conveyed from a dam at either site by means 

of a tunnel and penstock to a powerhouse on Carlson Creek, i/£ 

mile upstream from the mouth. The altitude of the creek at 

this site is 20 feet. The length by way of a tunnel from the 

upper site would be 1.4 miles, and from the lower site, 0.9 mile. 

The length of the penstock would be 0.2 mile by either plan. 

Alternatively, it would be possible to extend the tunnel about i/£
94 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

mile and convey water to a powerhouse located at the tidewater 

of Taku Inlet. Conditions for a powerhouse foundation probably 

are better at the upstream site where the bedrock was described 

by Plafker as similar to that at the damsite. The tailwater level 

at this site could be lowered by excavating the channel of Carlson 

Creek down to tidewater. It was assumed that it would be practicable to lower the level to that of the higher high-water plane 

or an altitude of 8 feet, and the power possibilities were estimated 

accordingly.

Plafker (1956, p. 28) reported that the tunnel route from the 

lower damsite is in sound bedrock except for two fault zones. 

The gneiss bedrock was mapped along the sides of the valley 

upstream beyond the upper damsite.

SHEEP CREEK POWERSITE 

RESERVOIR SITE

The reservoir site on Sheep Creek extends from 1 mile to about 

3 miles above the mouth of the creek, and is in a broad, U-shaped 

valley. There is a scattered growth of trees on the alluvium of the 

valley floor and dense stands of brush and alders on talus slopes 

at the sides of the valley. (See fig. 20.) A narrow canyon at the

FIGURE 20. Aerial view of Sheep Creek reservoir site from above the divide between Sheep 

Creek and Carlson Creek basins. The towers of the Annex Creek-Juneau transmission line 

are visible in foreground, Gastineau Channel in background.
UNDEVELOPED POWERSITES 95

lower end of the valley constitutes a favorable damsite at a 

stream altitude of about 620 feet.

The sides of the canyon at the damsite extend up on steep 

slopes to altitudes above 1,000 feet. A dam probably would not 

be considered to an altitude higher than 890 feet. The canyon 

width at that level is about 650 feet.

Plafker (1956, p. 16, 19) reported that bedrock at the damsite 

is predominantly greenstone tuff, well suited as a foundation for 

either a concrete or rock-fill dam. The lower slopes at the site 

are mantled with talus debris estimated to be less than 25 feet 

thick.

The potential reservoir areas and capacities at the Sheep Creek 

reservoir site are listed below.

Altitude 

(feet)

617.........

640. ........

680. ........

720.........

760.........

Area 

(acres)

0

5

50

118

178

Capacity 

(acre-feet)

0

50

1,170

4,530

10,400

Altitude 

(feet)

800. .......

840. .......

880. .......

920........

Area 

(acres)

249

283

336

387

Capacity 

(acre-feet)

19,000

29,600

42,000

56,500

Schedules of reservoir operation were computed for uniform 

monthly releases equal to 100 percent of the mean discharge, 

50.5 cfs, and 90 percent of the mean discharge, 45.4 cfs. These 

would have required 42,000 acre-feet and 19,000 acre-feet of 

capacity respectively.

For flowage above an altitude of 720 feet it would be necessary 

to seal the Sheep Creek adit of the Alaska-Juneau gold mine, now 

inactive. Relocation of the Annex Creek-Juneau transmission 

line would be necessary for a distance of about l 1/^ miles.

An aerial tram possibly would be used for access to the reservoir 

site from the end of the road at the mouth of Sheep Creek. There 

is an existing tram from near the mouth of the creek to a point 

above the damsite, and another from a point in the reservoir site 

to mine tunnels on an upper slope of the Sheep Creek basin. There 

are many mining claims, millsites, and patented mineral land in 

the reservoir site, all inactive as of 1956.

The maximum discharge recorded at the Sheep Creek gage 

was 850 cfs, on September 8, 1948. This corresponds to 195 cfs 

per square mile, not an exceptionally high rate for such a small 

basin.
96 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

FLANS OF DEVELOPMENT

Water could be conveyed from the Sheep Creek reservoir southwestward to a powerhouse at Gastineau Channel by means of a 

tunnel or pipeline and penstock. The total length of waterway 

would be approximately 0.7 mile by the shortest route to a site 

near Thane, or about 0.9 mile to the site of the inactive powerhouse near the mouth of Sheep Creek. Plafker (1956, p. 20) 

described the slate bedrock at and near the mouth of Sheep 

Creek as excellent foundation material. He reported that the 

bedrock along any diversion route is the same as at the damsite, 

predominantly greenstone tuff.

POTENTIAL POWER OF SITES IN TAKTJ INLET AND THE GASTINEAU

CHANNEL AREA

The potential power at the Dorothy Creek site was estimated 

on assumption that the head would be developed from the reservoirs down to the nozzles of impulse wheels set 17 feet above 

mean sea level a few feet higher than the highest expected tide. 

At the other sites it was assumed that by means of reaction 

turbines and draft tubes the head would be developed down to 

mean tailwater levels 16 feet above mean sea level at the Turner 

Creek site, 8 feet above mean sea level at the Carlson Creek site, 

and mean sea level at the Sheep Creek site.

The power possibilities and related data for the Dorothy Creek 

and Turner Creek sites are summarized below.

Controlled fllow . . . perStorage capacity, .acre-ft. .

Operating range . . alt (ft) . . 

Continuous power .... kw . .

Dorothy Creek

Lake Dorothy

100

112 

2,333 

125,000

( 2,421 

\ 2,266

17,800

90

101 

2,378 

50,000

2,421 

2,366

16,300

Bart Lake

100

28 

1,031 

26,000 

100

1,096 

996

1,960

90

25 

1,005 

13,000 

52

1,048 

996

1,700

Turner Creek

100

410 

101 

300,000

87

160 

73

22,820

90

369 

79 

150,000

44

117 

73

1,980

1 Above lake level.

2 Continuous power of 3,060 kw could be generated with an operating range of 160 feet to 117 

feet, a suitable storage of 150,000 acre-feet, a controlled flow of 359 cfs, and a mean head of 122 

feet.
UNDEVELOPED POWERSITES 97

The power possibilities of Carlson Creek were estimated on 

assumption that it would not be feasible to develop enough storage 

capacity for more than partial control in any year. The controlled 

flows of each of the 14 years of the operation schedules constitute a basis for estimating the flows that would be available 100, 

90, and 50 percent of the time (Q100, Q90, and Q50 table below), 

and the corresponding power (P100, P90, and P50). The potential 

power and related data for the Carlson Creek site are tabulated 

below for 2 degrees of regulation and with a dam at either the 

lower or upper site.

Storage capacity 

(acre-feet)

25,000 i.... ..........

25, 000 2 .... ..........

50,000!.... ..........

50, 000 2 .... ..........

Mean flow (cfs)

Q100

109

109 

178 

178

Q90

111 

111

186 

186

Q50

141 

141 

217 

217

Mean 

head 

(feet)

440 

440 

470 

470

Power (kw)

P100

3,260 

3,480 

5,860 

6,200

P90

3,320 

3,550 

6,120 

6,490

P50

4,220 

4,510 

7,140 

7,550

1 Lower site.

2 Upper site.

The potential power and related data for the Sheep Creek site 

with two degrees of regulation are shown below.

Controlled flow. .cfs. . 

Mean head ....... ft ..

Storage capacity. . ,

Controlled flow 

(percent of mean flow)

100

50.5 

820 

42,000

90

45.4 

770 

19,000

Height of dam 1 . . . 

....... .......ft..

Operating range . . . 

......... alt (ft) . .

Continuous power . . .

Controlled flow 

(percent of mean flow)

100

273

/ 890 

\ 700

2,820

90

198

/ 815 

\ 700

2,380

1 From stream level to normal pool level.

LOCATIONS AT WHICH POWER COULD BE USED

Power that might be developed at the four sites tributary to 

Taku Inlet and Gastineau Channel probably would be used in 

the Juneau area. The length of a possible route for transmission 

of power to Juneau from the Dorothy Creek site is 15 miles and 

from the Turner Creek site is about 23 miles. These distances
98 WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA

are for overland routes near the shores of Taku Inlet and Gastineau Channel, and a submarine crossing of Taku Inlet near 

the mouth of Dorothy Creek where the width is about 1% miles. 

Power from the Carlson Creek site could be interconnected with 

that of the Dorothy Creek and Turner Creek sites by about 6 

miles of line along the west side of Taku Inlet, joining the Juneau 

line near the submarine crossing. Alternatively, it could be 

transmitted about 13 miles to Juneau along the general route 

now used for the Annex Creek-Juneau line. Power from the 

Sheep Creek site could be transmitted along the edge of Gastineau 

Channel a few miles to Juneau on the same route used from 

the existing powerhouse.

Locations that might be considered for industrial development 

in the Juneau area are discussed in the section on powersites in 

the Gilbert Bay and Speel Arm of Port Snettisham area.

Large areas adjacent to the Taku River are topographically 

suitable for industrial sites but are not accessible to deepwater 

vessels. The tract nearest Taku Inlet extends several miles along 

the east side of the Taku River estuary and has an area of 

about 4 square miles below an altitude of 100 feet. Supplies of 

fresh water there would be dependent on the runoff of several 

small creeks which flow across the tract from the adjacent 

mountainsides. The overall drainage area is roughly 12 square 

miles, but there are no apparent possibilities for control of the 

runoff. The tract is within a transmission range of about 10 

miles from the Turner Creek powersite.

An area of about 50 acres near the mouth of Turner Creek is 

topographically suitable for location of a factory and a small 

supporting community. It is in the immediate vicinity of sources 

of water and the Turner Creek powersite but the limited extent 

of suitable terrain and the lack of a harbor make the possibility 

of development seem very remote.
WATERPOWER RESOURCES, PETERSBURG AND JUNEAU, ALASKA 99

REFERENCES CITED

Buddington, A. F., and Chapin, Theodore, 1929, Geology and mineral deposits 

of southeastern Alaska: U.S. Geol. Survey Bull. 800, 398 p., 22 pis.

Colbert, J. L., 1955, Waterpower resources of Cascade Creek, Scenery Creek 

and Delta Creek near Petersburg, Alaska, U.S. Geol. Survey open-file 

rept.

Dort, J. C., 1924, Report to the Federal Power Commission on the waterpowers of southeastern Alaska: Washington, U.S. Govt. Printing Office, 

172 p.

Federal Power Commission and U.S. Forest Service, 1947, Water powers 

southeast Alaska: 168 p.

Heintzleman, B. F., 1928, Pulp-timber resources of southeastern Alaska: U.S. 

Dept. Agriculture Misc. Pub. 41.

Hoyt, J. C., 1910, A water-power reconnaissance in southeastern Alaska, U.S. 

Geol. Survey Bull. 442-C, p. 147-157, pi. 2.

Johnson, F. A., 1955, Waterpower possibilities of Crater Lake, Long Lake and 

Speel River near Juneau, Alaska, U.S. Geol. Survey open-file rept.

 1957, Waterpower possibilities of Sheep Creek, Carlson Creek, Lake

Dorothy and Turner Lake near Juneau, Alaska, Geol. Survey open-file

rept. 

Miller, J. C., 1955, Geology of water-power sites on Scenery Creek, Cascade

Creek, and Delta Creek near Petersburg, Alaska: U.S. Geol. Survey

open-file rept., 42 p. 1 fig., 5 pis.

 1956, Geology of water-power sites on Crater Lake, Long Lake, and 

Speel River near Juneau, Alaska: U.S. Geol. Survey open-file rept., 

46 p., 1 fig., 7 pis.

Plafker, George, 1956, Geologic investigations of proposed Sheep Creek, Carlson Creek, and Turner Lake power sites, Alaska: U.S. Geol. Survey 

open-file rept., 37 p., 4 figs., 3 pis.

U.S. Army Corps of Engineers, 1952, Interim report No. 1, on survey of 

harbors and rivers in Alaska, a comprehensive survey of southeastern 

Alaska: Portland, Oreg., 147 p., 25 pis.

U.S. Bureau of Reclamation, 1955, Status report on the Lake Dorothy project, 

Alaska, Alaska District, Juneau, 48 p., Appendix I, 3 p., Appendix II, 

4 p., 8 tables and 9 fig.

 1959, Feasibility report on the Crater-Long Lakes division of the 

Snettisham Project, Alaska, Alaska District, Juneau, 96 p., Appendix I, 

3 p., Appendix II, 6 photographs, 10 charts, 1 map.

U.S. Department of the Interior, 1950, A reconnaissance report on the potential development of water resources in the Territory of Alaska: 324 p., 

many illustrations. (A revision of a report, with the same title, that 

was published in 1948)

U.S. Geological Survey, 1957, Compilation of records of quantity and quality 

of surface waters of Alaska through September 1950: Water-Supply 

Paper 1372.

 1958a, Quantity and quality of surface waters of Alaska, October 

1950 to September 1953: Water-Supply Paper 1466.

1958b, Quantity and quality of surface waters of Alaska, October 1953

to September 1956: Water-Supply Paper 1486. 

U.S. National Park Service, 1954, Glacier studies, Mount Rainier National 

Park, 1953: Annual rept., Longmire, Wash.

INDEX

Acknowledgments ....__._. . ____________________._____. 7

Annex Creek, powerplant at............. 22-23, 77

Bart Lake, area of reservoir __. ___.____.____.____ 86

location and topography............ 79-80, 86

potential power ._.-__....__________.__._......... 96

runoff .... ..........._....-....__..._....____. 80

storage capacity ........._....................... 86-87

Bibliography ______.____.._____.....__..._.._._..__._._.._..___.. 99

Boundary Creek .... ................._................_.. 75

Carlson Creek, development plans ._..... 93-94

discharge ....... .... .... ........._.............. 92, 93

drainage area ....-.-.._._.._._-.._._.._....__..... 77, 81

location and topography ._. _ .......... 76

maps available ... .._............ . 73-74, 91-92

potential power ... . .... . ......... 97

precipitation --.._. _.-........_................... 13

reservoirs, area _.__.___ _._.___._ _.___.. .___ 92 

sites .._... ...._. . . . ._.__._ .._._ 91-93

storage capacity .......................... 92-93

runoff ..-.....-....--.._...._..... .._.......... 13, 78, 81

streamflow records .............._..... ._ . . 77

Cascade Creek, development plans .. . .. 37 

discharge .. . .. ._..... ._ ....... .. .._ 36

location and topography .................. 27, 28

maps available . ...................._._.......... 27

potential power ........._........... .......... 42, 43

precipitation ....................................... 13, 16

reservoir sites . _.._ -_-_ . _ _._________ 35-36

runoff .......--... ._.-...-._._.............._ 13, 16, 30

Crater Creek, development plans ....__ 67-68

discharge .... .. ..... ......................_.. 51, 67

drainage area . .... .. .........._...... ....... 48

location . ................_....... .. _. _ ... . 46

potential power ......_.......... _.. ........... 70

precipitation ........._... ........... ._.. ..._ 13

reservoir site -.-...-......._._.___._._.....___..___._ 65-67

runoff - .-.....__..____.______...._.__.____ 13, 50

Crater Lake, area of reservoir ........___._.. 67

location and topography ._........... _ 65-66

maps available _. .._....._.......... ... 45

runoff .. _.....-....-....--......................... ..... . 53

storage capacity ... .........._._ _...... 66-67

Crystal Lake, powerplant at _.._...__.......... 21-22

Delta Creek, development plans ......... .. 34

location and topography _____________________ 27

potential power ._....... . ..... ._..._.. _ 42

reservoir site ........ ._._......._._........ 32-34

runoff ............____.....____...__ 31

storage capacity ..........._........_.._.......... 33

Dorothy Creek, development plans ..._. 87-88 

location and topography ..... ......___ 76

maps available ... ._ _........_..._-_.. 74

precipitation ____....._.._..............___ 13, 16

reservoir sites _. ..._............_.._ 83-87

runoff ..............___._.__._ 13, 78-79, 87

streamflow records ...........___.___ 77

Falls Lake ........... ....... .................. .......... 37

First Lake .............._._.. -.-....... -.. . 62, 63

Fishways, for fish migration ..... ....... 25-26

Gastineau Channel area, location

and topography . ..._........ 74-77

maps available .. .... ..... . _ 74

powersites ... .--... ...........-........ ... .. 76-77

Gilbert Bay area, location and

topography ....._................_... 46-48

maps available ..........-_...--....... . - 45-46

powersites ....... ._.. .. . ...... _ 46-47

Glacier Creek ................ ... .........._. ._.. 62, 65

Glaciers, present extent ...._ ......... 16

Gold Creek, discharge ........__-..........__ - 72

drainage area . .......... ......_ . . .. 77

powerplant at . _....... . ............ ........ 23

streamflow records ._. ... _. .. 77 

Gross head, denned ...... .................. ...... 26

Ice, effect on construction ._.- ........ -. ..... 25

Icing, of transmission lines ......... 25

Indian Lake ................-.........._.......--....... 59, 63

Lake Dorothy, area of reservoir ................ 85

discharge _......-..............._...._._.__ 79

drainage area .. ....._... ..... ....._....... .. 78

location and topography __..___. ..._.. 76, 83 

potential power development __.... 96

runoff ........_......--...-.-.....-..-.....---- 78-79

storage capacity _ _............... .... 84-85

Lake Mary. See Bart Lake.

Lake Veronica. See Lieuy Lake.

Lemon Creek ._.._-._......._..._.-.........-.. 72

Liuey Lake ...................................... 79-80, 85-86

Long Lake, area of reservoir .................... 60

discharge . . 61

drainage area ._.......-........... . - _. 48

location and topography .......- 59-60

maps available _.._.__._.._.__.__.___._...-.._...... 45

runoff ......................................... 51-52, 61

storage capacity ._..__...... . 60-61

Long River, development plans .................. 61

discharge .................................. 51, 52, 57, 61

drainage area ..._.................... 48

location and topography .................. 46, 47

potential power .......................-_...- 70

precipitation ..._..._.. .............. . ... 13, 16

reservoir site ._._....... ..... _ .. 59 61

runoff ._.....................................--. 13, 16, 50

Mendenhall River. See Nugget Creek. 

Nugget Creek, powerplant at ....___ .._._ 24

Port Snettisham area. See Gilbert Bay area 

and Speel Arm.

Potential power, computation formula. 26 

See also names of undeveloped power

sites. 

Precipitation ...__..___......______. 11-14

101
102 INDEX

Rockslides __.____________.__.._ 25

Ruth Lake, area of reservoir __..___. 33 

drainage area ....._.___.._.______ 81

location and topography .._..27, 28, 32-33 

potential power _____.._____ 42 

runoff ______________._.__ 81 

storage capacity _............._.._.... 33-34

Saddle damsite ______________ 62, 63, 64, 65

Salmon Creek, powerplant at ____ 23, 72

Scenery Creek, development plans..____ 41

location and topography _______. 27

potential power _..___._._._.. 42, 43

reservoir site .____._._._..._ 37-41

runoff _______________.__ 30

Scenery Lake, area of reservoir _.._....... 39

drainage area _..______________.... 32

location and topography ._... 27, 28, 38 

maps available ..._ _.___.......___. 26-27

potential power .._.........__..___. 42-43

runoff ___ .____.__.......___... 32

storage capacity _____________ 39 

Second Lake _______________ 62, 63

Sediment, in streams feeding reservoirs_ 25

Sheep Creek, development plans ..._._ 96

discharge ________________ 83, 95

drainage area ..__________ 77, 81

location and topography _..._ 76, 94-95 

maps available ____._.______ 73-74 

potential power ._.___.. _.._.._..._ 97 

powerplant at _...____._.._.._.._.._. 23 

precipitation _......_.._.._......_... ._ 13

reservoir, area ._........_.__......._._ 95

site _ .. _- _.._._... ..... 94-95

storage capacity .._.._....._......._.... 95

runoff .._..._.__....___........... 79, 81-83

streamflow records ........_._..._..._..... 77

Snow avalanches ______________ 25 

Snowfall, annual .___._____........._._ 14

Speel Arm, location and topography__. 46-48 

maps available ........___._._._.___. 45-46

powersites _._..._.._._._......_......._._ 46

Speel River, area of reservoir ..._._.._.._ 63 

development plans .__.._._......_..._ 65

discharge ._.._.._____________________ 52, 64

drainage area .___.________.._._.___. 48 

location and topography _______ 46, 47-48

potential power ____.._____...____..___.. 70

precipitation _____________________._ 51

reservoir site ___._...__._.._.... 62 64

runoff ........._______.__..______. 52-53, 64

storage capacity ________________________ 63-64

Storage, effect on runoff ______________ 16-17

Streamflow records ____.___________. 30-31

Swan Lake, area of reservoir _____________ 36

discharge ______________________ 35, 36

drainage area ._____._.......__.__ 31

location and topography _______ 27, 28, 35

potential power ....__........._......... 43-44

runoff ______.______________________ 31-32

storage capacity _________............... 35-36

Sweetheart Creek, development plans..._. 57 

discharge ____...._____._.._. 49, 51, 57

drainage area ______________ 48 

location and topography _...____ 46-47 

maps available _______._______ 45 

precipitation .________________ 13, 16

reservoir sites _____________ 53 57 

runoff _______________...... 13, 16, 49, 57

Sweetheart Lake, Lower, area of

reservoir ____________ 56

Lower, drainage area __________ 50

location and topography _.._. 55, 57

maps available ___________ 45

potential power _______.__ 69

runoff _._-___._.________ 56

storage capacity _________ 56 

Upper, area of reservoir .______... 54

drainage area __ ___ ._ 49 

location and topography .......... 53-54

maps available ____....._._____. 45

potential power ________________ 69

runoff ________________ 54 

storage capacity .____________ 54

Taku Inlet area, location and

topography ......._..._........ 74-77

maps available __________________ 73-74

powersites _____._.___-_____. 75-76

Tease Lake, development plans....._...__ 58

discharge ___._-______________ 51, 58

drainage area _.______.__________ 48

location and topography __.___46, 47, 57-58 

maps available ..._______._____._. 45

potential power __________________ 69

powerplant at _____________._ _ __ 22

precipitation _ _._ 51

reservoir site _______________ 57 

runoff ___._ _ _____________ 51, 58

storage capacity _________...__.._ 58

Temperature ______________________ . 14-15

Thomas Bay area, maps -_._____..___ 26-27

powersites ______________________ 46-47

potential power of sites ____________ 42-43

Treadwell Ditch, powerplant at ______ 24

Turner Creek, development plans ______ 90-91

drainage area ______________________ 77

location and topography __________ 76, 88

maps available ____......_...... ._ 73

potential power ________________ _____ 96

reservoir site ________________. __ 88-90

streamflow records _._.__._______ 77

Turner Lake, area of reservoir ________ 90

discharge ___________________ _.__ 80, 90

drainage area .__.__.__.___ - 80 

location and topography _________ 88-89

runoff __.__...._---__-___------ 80, 90

storage capacity _______________ 90

Water year, defined _______________. . 6

Wind, effect on construction ...__ ._ 25 

Yehring Creek .___._._.___._____ 75

U. S. GOVERNMENT PRINTING OFFICE: 1962 6O2798