Ingula is located in the Little Drakensberg range and straddles the border of the Free State and KwaZulu-Natal provinces.
A 2km long headrace tunnel connects the upper reservoir to the underground power station.
of water. The dams, 4.6km apart, are connected by underground waterways passing through a subterranean powerhouse with four 333MW generators.
Peak demand
The plant uses water from the upper reservoir to generate electricity when there is peak demand during the day. At night, excess power on the grid,
18 Water Sewage & Effluent January / February 2017