Auckland will have to look at new options to secure its water supply as climate change makes extreme weather like the present drought more frequent, Mayor Phil Goff says.
The city council has asked Hamilton to consider stepping in and help it with its drought, by transfering some of its unused water allocation to Watercare, on a short-term basis.
Hamilton mayor Paula Southgate has said any help would come with conditions to protect the Waikato River and the city's long-term interests. The council will make a formal decision in late June.
Goff told Morning Report Auckland would be looking to co-operate on Waikato River water quality improvement, particularly in relation to its longer term resource consent application to draw off more water.
He said Auckland had the second lowest per capita water consumption of any city in the country, had significant storage capacity and was planning for growth.
But extreme weather conditions would become more frequent with climate change, so Auckland needed to investigate other options for the future such as recycling waste water, desalination plants, though that may be too expensive, or using rain water run-off better.
"We've got to build a whole lot more resilience."
Low rainfall has left Watercare's storage lakes at Hūnua and Waitakere desperately low and forecasts mean the outlook for the coming summer are dire.
Auckland's reservoirs are at just over 43 percent capacity.