Lake Tekapo is one of the southern hydro lakes that act as a reservoir for power stations along the Waitaki River. In the winter of 2002 lake levels dropped to almost two-thirds of their permitted level. The government, concerned that the national electricity grid would not be able to meet winter demand, ran a campaign asking consumers for a 10% saving in electricity use until the lakes had regained their storage capacity.

Because nearly 60% of New Zealand’s electricity supply comes from water, there is widespread public interest in the state of storage lakes during dry periods, and it is often reported in the news media.