Local Government Minister Nanaia Mahuta is promising "more cost effective and efficient" changes to New Zealand's water infrastructure, despite concerns expressed by councils.
The bill for fixing the country's water infrastructure is expected to cost up to $185 billion.
The Three Waters reform includes drinking water, wastewater and stormwater.
The reforms would see the current 67 water authorities across the country, which are owned and managed by councils, condensed into just four, which would essentially be controlled by central government.
However, issues of cost, efficiency and privatisation have been raised.
This morning on Breakfast, Mahuta defended the reforms, though, saying "the current system isn't working", citing burst pipes, unswimmable beaches and sewerage leaking into lakes and streams.
"Yes, it will be more cost effective and efficient for ratepayers and we want to ensure that every ratepayer across the whole country benefits because these are New Zealand wide changes that can improve our water infrastructure system," she said.
"No council is immune from the fact that they have under-invested over a long period of time into their infrastructure system, they're continually making trade offs between the broader community expectations and waters infrastructure and it's just not financially sustainable.
"These water changes are set to ensure that every council will benefit, more importantly every ratepayer will pay less over the next 30 years with this type of change happening."
Last week on Breakfast, Taupō District Mayor David Trewavas expressed concerns about the cost and quality of service to his community.
However, Mahuta said Taupō would save around $6000 "and that's got to be good for ratepayers".
She also assured the new four entities would still deliver prompt service when incidents happen like broken water pipes.
"We are going to ensure that in terms of serviceability, the sole role and function of the new entities will be exactly about ensuring that their consumers and ratepayers are provided with reliable drinking water and better freshwater outcomes."
However, also on Breakfast last week, Dunedin city councillor Jim O'Malley was concerned about the risk of privatisation.
But Mahuta said New Zealand had learned its lessons of the past.
"To an extent we've learned from the electricity reforms, you dare not repeat the mistakes of the past," she said.
"Certainly in the water space I've been really clear over this four-year conversation that the public ownership of these assets will remain key to the changes that we introducing."
Labour and Greens have made that commitment, but O'Malley raised the point that governments change.
However, Mahuta said there was legislation they could bake into the changes to make it "very difficult" for privatisation to occur.
"You can set the threshold at 75 per cent, you can ensure that there is a public referendum, you can make the design of the entities such that there's no shareholding interest and no dividend to be taken off these entities," she said.
"All the benefits of this reform is to ensure that we can have a financially sustainable model to continually invest in asset management and our waters infrastructure."