Lake Wanaka lies in a glacial lake basin oriented approximately north and south and situated 20 miles east of the main divide at Mount Aspiring and 20 miles south-south-west of Haast Pass. The township of Wanaka at its southern end is 35 miles north by road from Cromwell and 54 miles south by road from Haast Pass. The name Wanaka is a corruption of Oanaka, which means “place of Anaka”, Anaka being the name of an early Maori chief of this district. The lake is 27 miles long and though its northern part is walled in by ranges up to 6,000 ft high, the southern end spreads out into more subdued country, where the shore line is deeply indented by bays, the most prominent being Glendhu Bay on the west and Stevensons Arm on the east. The lake stands 928 ft above sea level and is probably more than 1,000 ft deep.
Both Lake Wanaka and its close neighbour, Hawea, occupy basins excavated by successive advances of great glacial systems that rose on the main divide between Mount Aspiring and the head of the Hunter River. The ice occupying the two lake basins was connected over a low pass now called the Neck, and the lake basins had a similar glacial history. Ice extended over the Wanaka area south-east down the Clutha River, at least as far as the Lindis River Junction, in later Pleistocene time. Ice submerged Mount Barker and Mount Iron, sculpturing Mount Iron into a typical “roche moutonnée” shape. A prominent loop of terminal moraine encircles the lower end of the lake, encloses Wanaka township, and marks the limits of the last of the great Pleistocene ice advances. The early Lake Wanaka was formed during the retreat of the ice terminal northwards from this loop about 10,000 years ago. It stood at first at a much higher level than at present. The outlet became entrenched in the glacial silts forming part of this moraine, and water level sunk in post-glacial time to its present 928 ft above sea level.
The first European to reach the lake was Nathaniel Chalmers, who in 1853, accompanied by two Maoris, walked from Tuturau in Southland to Wanaka via the Kawarau River and returned by raft down the Clutha River. The Otago Provincial Surveyor, J. T. Thomson, sighted Lake Wanaka in 1857 from the summit at Mount Grandview, which he reached on foot from the Mackenzie basin. The environs were mapped by surveyors Jollie and Young, who visited Lake Wanaka in 1859. They went up the Matukituki Valley to the west branch, explored the Motatapu Valley, and climbed Mount Motatapu. The head of the lake was first explored by H. S. Thompson and G. M. Hassing at about the same time, and they discovered a ruined Maori village in the Makarora Valley remaining from a Maori raid of 1836. By 1861 there were several newly established sheep stations on the south end of the lake, when James McKerrow first arrived to carry out survey work. In 1862 McKerrow surveyed the lake in a whaleboat.
A number of large sheep stations lie around the lake shores, including Glendhu Bay, West Wanaka, Minarets, Mount Albert, and Makarora Stations. Access to Minarets Station is mainly by boat. Mount Albert Station can be reached only by fording the Makarora River; access to other stations is by road. The only parts of the lake shores that can be reached easily from public roads are at the south end of the lake and on the north-east end from the Neck to the head of the lake.
For many years the southern end of the lake has been a popular tourist and holiday area, and its importance has now increased by the recent opening of the Haast Pass Road and because of improved hotel facilities at Wanaka township. The lake forms one of the most important sources of water for the Roxburgh Hydro-electric Station but, unlike Lakes Hawea and Wakatipu, its level is not artificially controlled.
by lan Charles McKellar, M.SC., Geologist, New Zealand Geological Survey, Dunedin.