A Waitangi Tribunal report on freshwater makes sweeping recommendations about water management, allocation and ownership.
It says it is time for the courts to decide whether Maori retain native title in water and a group, including Auckland mayoral contender John Tamihere, has just instructed lawyers to lodge such a case.
The 565-page report and non-binding recommendations released today, also says the Crown should devise a new regime in partnership with Maori to allocate water, involving a national co-governance body.
It says the Crown should arrange for an allocation of water to iwi and hapu on a percentage basis, according to a regional, catchment-based scheme to be devised by the national co-governance body.
"All allocation to iwi and hapu should be perpetually renewable and inalienable other than by lease or some other form of temporary transfer," the report says.
It says if any local authority reports that catchment circumstances do not allow the allocation to be made, the national co-management body should hold an inquiry and consider alternatives – including the possibility of compensation.
It recommends that the Crown arrange for an allocation of water for the development of Maori land where such allocation is sustainable.
It also says the national co-governance body should investigate setting royalties for water.
"The national co-governance body should investigate other possible mechanisms for 'proprietary redress' including royalties, as there is insufficient evidence for the tribunal to make a recommendation to the Crown.
"We think this should include leading a wider conversation within Maoridom on proprietary rights and how these might be recognised."
The report virtually invites a court case to be lodged in order to definitively test issues of ownership.
"It may now be necessary for a test case to be brought before the courts on whether native title in fresh water (as a component of an indivisible freshwater taonga) exists as a matter of New Zealand common law and has not been extinguished.
"We have given our view but our jurisdiction is recommendatory only, and the question has not been decided definitively by the courts."
New Zealand First's Coalition agreement with the Labour Party specifically rules out any "resource rentals for water in this term of Parliament" but also promises to "introduce a royalty on exports of bottled water."
The report is officially called stage two of the National Freshwater and Geothermal Resources inquiry and was filed by the New Zealand Maori Council in 2012.
The Government's plan to privatise part of state-owned Mighty River Power sparked the original claim to the tribunal and then the Supreme Court.
The court found that the sale would not impair the Crown's ability to remedy any breach of the Treaty of Waitangi in regards to Maori interests in the Waikato River.
The Government argued at the time that Maori had rights and interests in water and geothermal resources which could be addressed on an iwi by iwi basis.
The prevailing legal view was that no one owned the water - and under common law that water could be owned only once it was contained.
Tamihere and one of the original claimants, Maanu Paul, have issued a statement saying they were "exultant" with the tribunal's stage two report.
Paul said he had split from the original Maori Council claimants because he was "firmly of the view that Maori always owned the water and still do own their water.
"We feel absolutely vindicated," Mr Paul said.
"Our claimant group had a very strong sense that Maori have always owned and controlled the water and no legislation had ever appropriated our rights of ownership.
"The tribunal has now agreed with us."
He pointed to the challenge in the Waitangi Tribunal report for a court case to be lodged to test native title in water.
"We have now instructed our lawyers and a QC to proceed with such a test case."
Speaking to the Herald, Environment Minister David Parker said it was a "long, complex and challenging report."
"Obviously we haven't formed a view on it yet."
But he agreed with the report's findings that the Resource Management Act had not been effective in preventing the decline of water standards.
"It calls for a great use of Maori values and input into achieving better water quality outcomes and water quality issues we have been working with Maori in the past year through Kahui Wai Maori, which is one of our reference groups for our water work."
He had announcements on Thursday next week on water quality.
"We have already acknowledged that water allocation issues need to be addressed both in terms of rights to take and use water but also rights to discharge pollutants to water."
Parker said those issues needed to be addressed in order for Maori to be able to properly develop their under-developed land.
Some of the issues could also be addressed through the review of the Resource Management Act which he announced earlier this month.
• An earlier version of this story incorrectly said Janet Mason was one of the original claimants. She is the lawyer acting on behalf of Maanu Paul and the claimant group.