Labour says farmer and horticulturalists will only be charged about a cent per thousand litres of water under its water royalties policy.
The party announced its policy yesterday, which would apply to commercial users of water such as water bottling companies and the agricultural sector.
Both farmers and the horticulture industry have criticised the policy, saying the result would be increased costs to consumers for food and other products.
Labour's environmental spokesman David Parker said the cost to the economy would be less than $500 million.
“We’ve said that for the most pristine and therefore most valuable water that can be put in a bottle and sent off overseas without any treatment it’s in the region of cents per litre, not ten cents," he said.
For irrigation water, the charge would be even lower.
“We’re talking about a cent per thousand litres."
Most of the revenue would be given back to councils, he said.
“The likes of those horticulturalists - they can expect their regional council rates will go down. You can expect some of it will be spent on repairing our rivers.
"Some of those water consents are now very valuable and it’s fair that the public gets a share of that money."
A share of the royalties would also go to Māoridom, Mr Parker said.