The national farming lobby group is weighing up legal options following an appeal being filed that challenges the Hawke's Bay's Ruataniwha dam getting the go-ahead.
Fish and Game and Forest and Bird have appealed at the High Court after the Board of Inquiry approving the proposed 25,000-hectare irrigation scheme. They feel the board has failed to adequately protect the environment.
Federated Farmers says it could fight against the appeal.
Hawke's Bay provincial president Will Foley said the federation needs more detail on the nature of the appeals, but could team up with other organisations and challenge it in court.
"Obviously, I guess head to court and perhaps contest whatever Fish and Game perhaps are coming up with," he said.
"Until we know what grounds they are appealing against, it's a bit unsure - but certainly look to sit alongside other indsutry groups that were reasonably happy with the report in its final form and I guess try to keep it that way."