Ngati Kahungunu is accusing the Hawke's Bay Regional Council of steaming ahead with its proposed Ruataniwha dam, despite the tribe's opposition.
The Government has appointed a board of inquiry, which took feedback on the plan until last Friday.
The council had wanted the independent board because it considered the proposal a matter of national significance.
The Ngati Kahungunu Iwi Incorporation says it has filed its submission against the Ruataniwha Water Storage scheme.
A council report found that if the 83 metre-high dam wall collapsed it would send 90 million cubic metres of water through Waipawa, causing catastrophic damage.
Ngati Kahungunu chair Ngahiwi Tomoana said the tribe had met the council three times, and also asked for a submission extension, which was declined.
The process had proceeded and there had been no room for further negotiations, Mr Tomoana said.
Therefore, the tribe had had to carry on, and put in a submission opposing the scheme.
