Commissioned in 1944, the Cobb Power Station lies 112 km Northwest of Nelson City in mountainous country at the junction of the Takaka and Cobb Rivers. Water for the station is taken from the Cobb River, which runs from the Tasman Mountains into the Cobb Valley, a typically glaciated U-shaped contour with a catchment area of 70.8 square kilometres.

There is a 13.7-metre range between the highest and lowest operational levels of the impounded water, which is 783-metres above sea level.  After passing through a tunnel system the water drops 4 km through two steel penstocks to the power station.

The power station itself houses six single-runner Pelton type turbines, four 3 MW on single jet, and two 10 MW on double jets.

A gross head of 595.9-metres, the greatest of any New Zealand power station, allows the generation of the full output of 32 MW from a water flow of only 7.25 cumecs.

The facility produces an average annual output of 192 GWh.

Consents were granted for a further 35 years during 2004.

The magnificent tussock lowlands and beech covered valley sides adjacent to and surrounding the lake are frequently used for recreational activities including tramping and fishing.