A leading economist is calling for the Government to start charging for water amid strong foreign interest in the resource.
Peter Fraser is battling what he calls the myth that New Zealand has an abundant supply of water. It's been one of the most enduring arguments from the current National Government.
Water belongs to the people - free, for anyone to enjoy. Now there's a call for that to change.
"As an economist, if no one owns anything, no one's got an incentive to look after it, so that's when you get overuse of it," Mr Fraser says.
He believes a charge is well overdue, calling it "absolutely necessary".
His comments come amid concern around foreign interest in the country's most pristine drinking water. Kiwis opposed to plans to harvest aquifers, rivers and lakes for overseas export have taken to the streets in protest.
On Saturday the Prime Minister hinted a water charge was possible.
"We have the opportunity over the next few years to change those rules if we want to," Bill English said.
Mr Fraser believes one of the main deterrents to charging has been Māori interest in water. He says the Government could be concerned any ownership would bring a Treaty dispute.
"They've been really recalcitrant to actually address those issues, and this whole point that nobody owns the water is a very useful way to defuse that question," he says.
To law professor Jacinta Ruru, the debate is long overdue, the Waitangi Tribunal making it clear years ago that Māori retain propriety interest in water.
"This is something that the Government cannot continue to shy away from and will need to look into and will need to seriously consider," she says.
Environment Minister Nick Smith was unavailable for comment on Sunday, but in the past has argued water bottling exports are too small to spark concern.
"If all the 100 percent of the water was pristine, potable water, then the Minister would actually have a very good point," Mr Fraser says.
"What we actually have, in many cases, is an abundant supply of water you can't actually drink."
One thing is for certain - the water debate is here to stay.