The Hawke's Bay land at the centre of legal battles since 2015 made it all the way to New Zealand's highest court yesterday.
The land in question is 22 hectares of the Ruahine Forest Park, needed for the Ruataniwha Water Storage Scheme to go ahead.
In October, the Court of Appeal upheld a Forest & Bird appeal that the proposal to exchange this land for 170ha of land the Hawke's Bay Regional Investment Company LTD (HBRIC) would potentially buy from Smedley Station, was unlawful.
This would have downgraded the protected conservation status of the Ruahine Forest land to allow it to be flooded as part of the water storage scheme.
Late last year HBRIC and the Minister for Conservation were granted leave to appeal this decision, and yesterday the two-day Supreme Court hearing began.
Lawyers on behalf of DoC spoke yesterday. The court heard from DoC lawyer Aaron Martin that the department had carefully considered the value of the 22 hectares before revoking its conservation park status to facilitate the exchange.
Although Forest & Bird's lawyers did not speak yesterday, chief executive Kevin Hague said today they would be arguing that "specially protected conservation land belongs to New Zealanders and to nature, and can't be traded away for commercial development".
Activities relating to the scheme are currently on hold as the Hawke's Bay Regional Council conducts a review on it - this does not extend to the Supreme Court case, but does prevent HBRIC acquiring the land through other means.
Yesterday HBRIC acting chief executive Blair O'Keeffe said the Supreme Court case was a key step in enabling the dam.
"The Ruataniwha Scheme represents a once in a generation opportunity to improve the biodiversity, environment and economy of the Hawke's Bay Region", he said.
When asked about the effect of the Supreme Court proceedings, Hawke's Bay Regional Council chairman Rex Graham said today was "just a hearing".
"What is relevant is that judgement, and we're going to have to wait for that," he said.
"[The judgement] will be very relevant to what we do next".
He said the judgment could affect the council's review into the scheme. However, he agreed there was a chance the judgement could be released after the review is completed - which is expected to be in May.
The hearing is expected to finish today.
THE STORY SO FAR:
March 2015: The Department of Conservation runs a review into the proposal to revoke conservation park status for the land. A number of parties challenge this during the consultation process, including Forest and Bird.
October 2015: DoC director general Lou Sanson approves the exchange.
November 2015: Forest & Bird files for High Court review of DoC's revocation and land swap decisions.
February 2016: The decision on December's High Court review is released, rejecting Forest & Bird's bid to overturn the swap.
March 2016: Forest & Bird files appeal High Court decision with the Court of Appeal.
October 2016: Following a hearing in May, the Court of Appeal upholds Forest & Bird's appeal that the land swap is unlawful.
September 2016: DoC and HBRIC seek leave to appeal this decision with the Supreme Court. HBRIC also begin exploring options for acquiring the land under the Public Works Act.
November 2016: A review of the scheme is announced. While HBRIC are instructed to not seek alternative means to acquire the land, they can continue with the court proceedings.
December 2016: DoC and HBRIC are granted leave to appeal the Court of Appeal decision with the Supreme Court.
February 2017: Supreme Court hearing begins.