power at ordinary six months flow. The capacity at the
upper site is estimated at 2,450 horse-power at ordinary
minimum flow, or 3,600 horse-power at ordinary six months
flow.

Three sites on the lower Cameron River were investi-
gated in 1937, but the flow records subsequently obtained
indicate the power possibilities to be very small; only a
few hundred horse-power at each site.

Power Markets.—A potential power market exists in
the development of new mining properties in the Yellow-
knife mining area.

Beaulieu River

The Beaulieu River, draining some 2,500 square miles,
is adjacent to the Yellowknife drainage on the east and has
similar characteristics. The lower 45 miles of the river were
examined by an engineer of the Dominion Water and Power
Bureau in 1937. The fall in this reach is approximately
279 feet. Four locations were selected as being favourable
for the concentration of head by the construction of dams.
These are situated at approximately 1, 25, 37, and 44 miles

respectively from the mouth, offering heads of 55, 30, 50,
and 55 feet in the same order. Only a few miscellaneous
measurements of flow have been obtained, and it is necessary
to make assumptions in estimating power possibilities.
Based on such assumptions, the four sites combined should
yield about 2,900 horse-power under conditions of ordinary
minimum flow, or 5,300 horsepower ordinarily for six
months of the year. The sites are too small to warrant
transmitting power as far as the Yellowknife mining area,
and they would be of interest only if mines requiring small

amounts of power should be developed in reasonably close
proximity.

Lockhart River

The Lockhart River, draining an area of some 9,600
square miles to the north and east of Great Slave Lake, is the
outstanding river from a power standpoint in the Great
Slave Lake drainage. Rising in MacKay Lake at an elevation
of about 1,400 feet, the river runs generally east for about
seventy miles, its course being broken by Aylmer: and
Clinton-Colden Lakes. From Clinton-Colden Lake, it flows
nearly south into Artillery Lake and thence westerly by a
succession of falls and wild rapids into the east end of Great
Slave Lake at Fort Reliance. In this last course of about
25 miles, the river descends a total of some 668 feet.

Water Supply—Owing to the fact that lake areas
comprise a large part of the drainage, there is very sub-
stantial natural regulation of the flow of the Lockhart
River. Several of these lakes are of considerable area, such
as MacKay (400 sq. mi.), Aylmer (328 sq. mi.), Clinton-
Colden (282 sq. mi.), and Artillery (214 sq. mi.). Complete
regulation of the flow in the lower reach of the river should
be possible by utilizing Artillery Lake as a storage reservoir.
Scattered measurements of flow have been obtained since

3681—6

1944, ranging from a low of about 1,400 c.f.s. to a high of
8,900 c.f.s. For purposes of power estimates, it is believed
that an ordinary minimum flow of 1,680 c.f.s. and an ordinary
six months flow of 2,450 c.f.s. should be available.

Power Resources.—The fall of some 668 feet in the
twenty-five mile reach below Artillery Lake presents
opportunities for the development of a substantial amount
of power. Several abrupt drops, such as Anderson, Parry,
and Tyrrell Falls, are possibly the most favourable locations
for the concentration of head, but considerable field investi-
gations will be required to determine the most feasible and
economical scheme of development. Assuming that it may
be possible to utilize the total head for power, this reach of
the Lockhart is estimated to have a potential capacity of
100,000 horse-power under conditions of ordinary minimum

flow, or 150,000 horse-power ordinarily available for six
months of the year.

Power Markets.—A potential power market exists in
the development of new mining properties in the Yellow-
knife mining area, about 200 miles distant from the Lockhart
River. A substantial market would be needed, however,
to warrant transmitting power this far.

Taltson River

The Taltson River, draining an area of some 17,500
square miles south of Great Slave Lake and east of the Slave
River, is the largest tributary of Great Slave Lake apart from
the Slave itself. The drainage is almost wholly in the
Canadian Shield, only about 70 miles of the river’s lower
course being in the northerly extension of the Great Plains
region. The characteristics of the drainage are typical of
the Canadian Shield, with innumerable lakes both great
and small, and the course of the river is broken with many

rapids and falls. The principal tributary of the Taltson is
the Tazin River.

Water Supply.—Information regarding the flow of the
Taltson is meagre. Only two measurements have been
made, one in August, 1929, and the other in February, 1930.
For purposes of power estimates, run-off factors have been
assumed at 0-10 c.f.s. per square mile for ordinary minimum
flow and 0-15 c.f.s. per square mile for the flow ordinarily
available for six months of the year. Good opportunities

exist for artificial regulation of flow in the many large lake
areas in the watershed.

Power Resources.—Heads at various rapids and falls
are known, approximately, from explorations of the Taltson
River and its tributaries, but power investigations have
been confined to a reconnaissance of the lower 80 miles,
from Tsu Lake to the mouth, by private interests in 1929.
These investigations indicated a promising site at Pine
Lake Falls below Tsu Lake, where a head of 40 feet might
be concentrated by the construction ofa dam. The capacity
of the site is estimated at 6,350 horse-power at ordinary

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