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Although some natural features remain, sulphur mining has damaged extensive areas of altered ground on the Rotokawa Geothermal System, which have since been rehabilitated. Rotokawa’s acid lake is home to a unique leech.

Natural features

Lake Rotokawa

  • Sulphur mining between 1960 – 1980s has modified many natural features.
  • An acid lake, sulphur deposits, sinter deposits, mud pools, steaming ground and hot springs remain.
  • The lake is home to a unique leech which lives in very acidic water (pH 2.2).
  • Springs along the Waikato River are affected by river level fluctuations for hydro-electric generation.


Rotokawa is classified as a Development Geothermal System by Waikato Regional Council.

The sulphur mining has damaged Rotokawa’s natural features. The mining operation stripped large areas of hot ground, destroying natural contours and geothermal vegetation in the vicinity. The geothermal vegetation is now regenerating on the hot ground.

The Maori land owners and the Department of Conservation are caring for the natural vegetation around the geothermal lake, the geothermal Parariki Stream, and the hot springs by the Waikato River.

A joint venture by the Maori landowners and Mighty River Power produces 35 megawatts of geothermal electricity from a power station built in 1998 and expanded in 2001. In 2010 the Nga Awa Purua geothermal powerstation commenced generating 140 MW of electrical power.