The power station lies on Lake Karapiro, a major rowing regatta venue.

Like all of the hydroelectric power stations on the Waikato River, Karāpiro is operated by electricity generator Mercury Energy.

Construction of the dam and power station began in 1940, but a materials and labour shortage due to World War II meant progress was slow.

The bridge was destroyed by the water running through the spillway in a significant flood event (Source: Mighty River Photo archives).

These were designed for the management of the lake level under normal river flow and the spillway gates were to be used in only extreme conditions.

The design of the siphon tubes was faulty: The flow of water was supposed to be stopped by a blast of air, but this never worked properly - resulting in the spillway gates to be used for lake level control.

[4] This line remains in service today as the main connection from Karāpiro to the rest of the national grid.