To 1941 Lake Taupo was a natural Lake.

In 1941 control gates were installed at the head of the Waikato River and only exit from Lake Taupo. The Waikato River was to become a river for Hydro Electric Power purposes. This was all done by the Governmenent through the New Zealand Electricty Department, NZED.

The Government created State Owned Enterprises, SOE’s and initially NZED became two SOE’s ECNZ Electricity Corporation New Zealand and Contact Energy. Contact Energy was sold by the Government to private enterprise.

ECNZ was then broken up to create 3 competiting companies; Meridian Energy, Genesis Energy, Mighty River Power, with a view that they all be sold to private enterprise.

The power stations on the Waikato River and the control of lake level of Lake Taupo are with Mighty River Power.

The Tongariro River along with the diversion waters through the Tokaanu Power Station remain the major flows into Lake Taupo.

The Advocates for the Tongariro River have a concern that a higher lake level means that the river is not able to carry its bedload into the lake resulting in sediments building up in the lower river.

The Advocates position is:

• that we accept that the lake be used for electricity storage
• that the lake level will fluctuate due to natural events
• that the lake level is held too high beyond what would be a natural term
• that the higher lake level causes problems in the lower Tongariro River