On 1 July 2025, NIWA merged with GNS Science to become Earth Sciences New Zealand.

Flows from Lake Wanaka between 1970 and 2002, representative of flows through the major South Island hydro-electric stations. The 1992 hydro drought had a peak RDI value at Lake Wanaka of 2, but the peak RDI for the longer drought that ended in 1978 was m