Gareth Morgan says The Opportunities Party will give Māori rights to water and charge farmers for every litre they use.
The move has already sparked fresh debate on the contentious topic of water ownership and its use.
Currently, the crystal clear water flowing down the Rakaia River is pumped out for irrigation and there's no price on it. Dr Morgan thinks that's not on.
"We've just allowed business to rip sh** and bust through the water supply; you know, first come first served - that's nuts," he says.
He thinks commercial water users should pay for every litre they use, and that includes farmers.
"This resource belongs to New Zealanders; it does not belong to farmers."
His plan would see consents will be granted to priority users, with the market deciding the price per litre. Once the price is set, every commercial user pays, whether the water is for irrigation or bottling for export.
"The water should be at whatever the market price is," Dr Morgan says.
"So maybe water at the moment from the West Coast is nothing, but ripping water out of the middle of the Waikato, like I saw they were going to do last week, or out of here, man, that's expensive water because there's other competing users."
Support for charging royalties to water bottlers is high. The latest Newshub-Reid Research poll found 87 percent of New Zealanders are unhappy exporters are able to obtain the water for next to nothing then send it offshore for big profits.
But the Government thinks farmers are paying enough through infrastructure.
"If you talk to the farmers that are operating irrigating scheme, they can tell you how much they cost," Prime Minister Bill English says.
"There's a big cost in irrigation."
Dr Morgan says he doesn't care what farmers think about his proposed policy.
"I'm interested in policies that look after the wellbeing and the economic benefit of New Zealand."
So who gets the money? Partly it would be ring-fenced to look after our waterways, but Dr Morgan says there's also the question of ownership.
Mr English says "nobody owns the water" but Dr Morgan disagrees. He says under the Treaty, the rightful owners of water are Māori, so under his policy Māori would get a percentage of the profit.
"It would be a huge bonanza for Māori and also a huge bonanza for our waterways. We'll be able to fix our waterways; we'll be able to swim in them."
It's a controversial policy taking aim at our biggest industry and sparking what could be a huge election debate on water ownership.