On June 27, the Supreme Court issued its judgment in a case called Paki v Attorney General. Its decision opens up the potential for iwi to claim ownership rights to riverbeds.
It may also strengthen Maori claims to the water above the riverbeds, as well as their management and allocation rights under various river claims.
This week the Waitangi Tribunal will urgently hear the New Zealand Maori Council's challenge to the Crown's introduction of the mixed-ownership model for state-owned electricity companies, and why this breaches Treaty of Waitangi obligations, given claimed Maori rights to water.
The decision comes at a time when the Government has just passed legislation introducing mixed-ownership models over the state-owned electricity companies - which are dependent on rivers for power generation. The three dams that Mighty River Power own may be on riverbeds affected by this decision, and it will be the first SOE to sell some of its shares.
This is not the first time the courts have touched on Maori ownership rights to the land underneath water. In 2003, the Court of Appeal issued a decision that let the Ngati Apa iwi commence proceedings in the Maori Land Court to find out if their customary title to the seabed and foreshore in the Marlborough region had been extinguished.
That process was circumvented when the then Prime Minister, Helen Clark, announced that Maori could not own the foreshore and seabed and that her Government would legislate against any such claim immediately. As a result, the Foreshore and Seabed Act 2004 was passed.
This was repealed by the current Government and replaced by the Marine and Coastal Areas (Takutai Moana) Act 2011, which gave Maori a statutory mechanism for recognising their interests in the foreshore and seabed.
The claimants in the Paki case represented the descendants of the owners of five blocks of land along the Waikato River at Pouakani. This land was transferred from Maori ownership to Crown ownership between 1887 and 1899. The descendants claimed the Crown acquisition of the riverbed was not explained to the Maori owners and occurred without their consent, which was in breach of the Crown's duties.
The claimants sought a declaration from the High Court that Crown ownership of the riverbed, to the middle of the river, was vested in a constructive trust that favoured the Pouakani Maori owners.
The Crown argued that the appellant's claim could not succeed because the river is "navigable" and the bed of the river is therefore the property of the Crown according to section 14 of the Coal Mines Amendment Act, which states that the beds of navigable rivers "shall remain, and shall be deemed to have always been, vested in the Crown".
The claimants disagreed and argued the river adjoining the land at Pouakani was not navigable and so the act did not apply. The Supreme Court, by a majority of four to one, agreed.
Although there are limitations to a claim of ownership in riverbed rights that will have to be carefully considered by the courts, the Paki case means that hapu and iwi claimant groups can now seek declarations in the High Court that the rivers in their region are non-navigable and iwi could investigate the impact declarations can have on the status of legal and beneficial ownership of riverbeds.
Where a stretch of river is not navigable, an enforceable interest to the riverbed might potentially remain in the hands of the Maori customary owners.
How the Government responds to the Paki decision will be interesting. The sensitive state of settlement negotiations regarding freshwater will be at the front of the Government's mind, as will be the announcement that shares in Mighty Rover Power are expected to be floated by September.
The Marine and Coastal Area (Takutai Moana) Act 2011 was passed as a consequence of the National Party's confidence and supply arrangement with the Maori Party in 2008. The Maori Party is supporting the Government again this term and Tariana Turia has said of the Paki decision: "I know that whanau, hapu and iwi will be really interested to see where this debate now goes.
"The Attorney General's reported comments that the Supreme Court decision, as with any claim, could set a precedent for other parts of the country will no doubt lead to many iwi looking closely into the relevance of the Pouakani decision for their own situation," said Mrs Turia.
"The statements by Tuwharetoa that they need to revisit the operation of energy schemes upon their lakes and rivers [in the context of the debate around the mixed-ownership model] will inevitably revive discussions of water ownership, management and allocation rights."
The philosopher Heraclitus said that you cannot step into the same river twice. Change is constant. It remains to be seen whether the Government finds the Supreme Court's decision in Paki "navigable".
Mai Chen is a partner in the firm Chen Palmer and author of Public Law Toolbox.