In its decision the board granted the 17 resource consent applications relating to the dam and water storage scheme, subject to conditions.
It allowed the plan change based on a detailed set of conditions including limits on nitrogen and phosphorus levels in the Tukituki catchment.
The regional council had argued during the hearing that only phosphorus levels needed to be controlled but environmental groups pushed for the inclusion of restrictions on nitrogen as well.
The board, which is headed by retired High Court Judge Lester Chisholm, will consider submissions on its draft decision before issuing a final determination which is due by May 28.
Hawke's Bay Regional Council's corporate and strategic committee will tomorrow consider a proposal to spend $80,000 on a public consultation process ahead of a vote by councillors in late June on whether to invest up to $80 million of ratepayers' money into the Ruataniwha project.
The council's commercial arm, Hawke's Bay Regional Investment Company Ltd, is currently in the process of trying to firm up other forms of funding - from private investors and the Government - in order for the project to go ahead.