New zealanders

NZ's rivers flows have changed much over decades, with warming climate one likely factor.

They’re also predicted to decrease on the east coast of the North and South Islands, and in Waikato and Northland, although these projections were less certain. Modelling has already suggested river flows are likely to increase on the west coast of the South Island and in rivers that drain the eastern side of the Southern Alps. “In the South Island, changes to the strength of the southern storm track have increased rainfall on the West Coast and that affects river flow in the region. In winter, meanwhile, average river flows had decreased in the upper North Island - but increased much on the West Coast of the South Island, and in Fiordland and Southland. “We’ve also seen increasing winter river flows in the snow-fed catchments in the South Island. A just-published study – and the first of its kind in New Zealand - found marked changes in average summer and winter flows in our rivers over the last 50 to 90 years.