The lake covers 12sq km and is also a popular camping and recreational area used for water-skiing, picnicking and duck shooting. Each year around 20,000 people stay at the campground on the lake's edge, which is particularly popular over summer.

The catchment also includes large areas of plantation forests and farming, as well as scenic reserves such at the Ngaawapurua Rapids and Orakei Korako geothermal fields. A large tributary, the Waiotapu Stream, drains an area east of the river.

History

At Ohakuri, the river passes through a deep ravine, well-suited for dam construction. However, initial enthusiasm for the site around 1939 was tempered by its distance from main population centres and the limitations of construction techniques at the time.

Ten years later, engineers advised that an earth dam would overcome the construction challenges. The project was approved in November 1955 and work began on the seventh dam in the Waikato system in 1956.

Before work started, the river was diverted past the site through a concrete-lined tunnel in the right bank. When the dam was filled several years later, this tunnel was closed by a hydraulically operated sluice gate. This gate is maintained as part of the dam's emergency management strategy so that water can be diverted if required. The riverbed was excavated 6m to solid rock to provide a firm foundation on which to build the dam's core.

At the peak of construction, 600 workers were employed on the site. Most were housed at Mangakino, the operational centre for the various hydro projects on the upper Waikato River. It was the home of many of the people who built the dams and stations at Maraetai, Whakamaru, Waipapa, Ohakuri and Atiamuri.

Three generators had been planned and in 1958 a fourth was approved. In January 1961, two months ahead of schedule, the diversion tunnel was closed, the lake was filled and the first electricity came on line.

How Ohakuri got it's name

Oha' means keepsake or relic and 'kuri' means dog. This name may refer to a prized dogskin cloak.