Lake Tekapo, in Canterbury, is 65 miles by road from Timaru. It is 12 miles long from north to south, up to 4 miles wide, and has an area of about 32 square miles. The inflow from its 550 square miles of catchment, which ranges from 800 to 14,600 cusecs and averages 3,000 cusecs, is mainly from the Godley River, which is fed by the Godley, Classen, Grey, Maud, and numerous other glaciers; and from the Macaulay River. The lake water is not clear as it has much fine sediment in suspension, and is cold (46°F). The lake occupies the lower end of a glaciated valley, and is confined by a moraine 16,000–18,000 years old.
The outflow from the lake, and hence the amount of water stored in it, is controlled by a dam – the level of the lake can be varied between 2,310 and 2,330 ft above sea level – enabling more effective use to be made of the water, not only in the 25-megawatt hydro-electric station near the outlet, but also in the 105-megawatt Lake Waitaki station further downstream. The water will also be used in other stations either under construction or planned in the Waitaki catchment.
The correct Maori name is said to be Takapo. The components of the word – “taka” and “po” mean, respectively, “sleeping mat” and “night”. According to legend, an exploring party, disturbed here at night, took fright, hastily rolled up their sleeping mats, and fled.
by Leslie Eric Oborn, A.O.S.M., New Zealand Geological Survey, Christchurch.