The Northland Regional Council is uneasy at plans to give Māori more authority over freshwater.
The government is consulting on plans to amend the Resource Management Act to allow iwi and councils to work together on bylaws, consents and other statutory responsibilities.
Northland council chair Bill Shepherd said his councillors were not averse to Māori involvement but they were adamant decision-making was the job of elected councillors.
He said the council had created a Māori Advisory Committee, and took advice from it as a part of the community.
But there were many other members of the community and the ultimate authority must remain with elected members, he said.
Mr Shepherd said the government's use of the word 'iwi' in consultation documents was also problematic for Northland, where the landowners were primarily hapū - and there were 190 of them.