The Board of Inquiry into the controversial Ruataniwha Dam project has finished six weeks of public hearings and will now begin work on a draft report.
Hawke's Bay regional council, which is proposing the dam, told the hearings the dam and an associated plan change will improve the health of the Tukituki River and increase river flows in the summer.
But groups such as Fish and Game say the project is highly risky and based on imprecise science.
Local iwi Ngati Kahungunu told the hearing that consultation with Maori has been non-existent.
The board will release a draft report in the next month which will be open to submissions.
A final determination must then be given to the Ministers of Conservation and Environment by early April.