Lake Benmore

The Lake Benmore (Maori: Te Ao Marama ) is a reservoir in the south of the Canterbury region on the South Island of New Zealand. The lake level is at 361 meters above sea level in the Mackenzie, Waimate and Waitaki District. The place Benmore is due to its drain.

The lake was created in the 1960s by the construction of the dam used for hydroelectric power recovery Benmore Dam.

The lake is about 75 km across and up to 120 m deep. It is 361 m above the sea level. Its shoreline is 116 miles and it contains 12.5 million cubic meters of water and thus 1.5 times the volume of Wellington Harbour. Important tributaries are the Ohau, Pukaki and Tekapo River. Downstream of the dam starts the Lake Aviemore and Waitaki River, follow to the other eight reservoirs.

The lake is for swimming, water-skiing, boating and used for fishing for trout. On the northern part of the lake is a campsite

In the lake there is, as in other lakes of New Zealand to the strong expansion of entrained Waterweed ( Lagarosiphon ), which is controlled by herbicides. In addition, the diatom species " Didymo " widespread in the lake, whose existence one tries to reduce at once by releasing large amounts of water.

Benmore Dam

The resulting 1958-1965 dam is 823 m crest length and 110 m in height New Zealand's largest earth dam and part of the Waitaki hydroelectric project. With 540 megawatts he's after the power plant Manapouri hydroelectric power plant with the second highest performance in New Zealand.

Its core consists of impermeable mudstone, which is laterally supported by a mound of Flußschotter.

The overflow of the dam is designed for a discharge of 3400 m³ / s, which is about ten times the average inflow into the reservoir of 340 m³ / s

With a capacity of 540 MW and an annual output of 2,200 GWh of the Benmore Power Station is the second largest hydroelectric power plant in New Zealand.

The construction of the dam and power plant began in 1958 and cost 62 million NZ $. The dam was made ​​on 15 May 1965 by Prime Minister Keith Holyoake officially in service.

Originally built for the New Zealand Electricity Department, it is since 1999 owned by the present operator Meridian Energy.

From 2008 to 2010, six of the turbines for $ 67 million have been revised. This allows to produce at the same water flow rate 5 % more energy, which corresponds to an annual output of 70 GWh.