One of the smaller southern glacial lakes, Lake Monowai is 12 miles long, 520 ft deep, 643 ft above sea level, up to 1 mile wide, and covers an area of 11 sq. miles. In plan the lake is shaped like a boomerang and has but one inlet on the northern shore. The only river flowing into Lake Monowai is Electric River; the small Monowai River draining the lake (495-cusec discharge) is used to generate hydro-electric power. The absence of a river at the head of the lake is due to the fact that the glacier ice, which carved the lake, spilled over a divide from a neighbouring glacier system and did not form a long trunk glacier. Lake Monowai can be reached by road from Tuatapere, but the road ends at the lake outlet and there are no walking tracks around the lake beyond that. The lake abounds in fish, and the surrounding forested mountains carry large numbers of deer and other game. The area is part of the Fiordland National Park.
The surveyor-explorer James McKerrow wrote the name of the lake as “Monowai”. This is probably a corruption of an earlier form, one meaning of which is “channel full of water”.
by Bryce Leslie Wood, M.SC., New Zealand Geological Survey, Dunedin.