West Coast iwi Ngāti Waewae is calling on the government to revoke its decision to block a hydroelectric power scheme on the Waitaha River.
The scheme would have powered up to 12,000 homes, but it was vetoed last week by the Environment Minister David Parker, who said it would be inappropriate to build a dam structure in a wilderness area.
Last week Mr Parker said the scheme would have been "a not insignificant contribution to West Coast power".
However, he added: "The area is valued for its natural beauty and wilderness qualities for recreation. The proposal would have significantly undermined the area's intrinsic values which people experience when they tramp and kayak there."
Ngāti Waewae chair Francois Tumahai said that decision was shortsighted and went against the wishes of most people in the community.
"If you come down here and speak to people on the ground, there's overwhelming support on the coast for it, from everyone," he said.
"From the Tai Poutini Conservation Board, DOC supported it in principle, both iwi support it, the three councils, 90 percent of the population on the coast support this.
"[The minister] has made the decision from some office in Wellington, which actually has a huge impact on us on the coast, it's just crazy. Absolute madness."
Mr Tumahai said the development would have provided essential power to the region, and created much-needed jobs.
"There's a $100 million worth of investment going into the region. We don't have any electrical resilience here and this will help that.
"This is just over 20 megahertz of electricity, the coast only uses 30, so instantly there's going to be some power-savings and it'll affect people in their pocket. This, in line with the resilience, in line with the fact that it's an environmentally-friendly, green-renewable energy project, no dams, small environmental footprint, and the bulk of the infrastructure is underground, the positives outweigh the negatives two-fold.
"There's a handful of people that are bloody against this thing. They just happen to be Forest and Bird, Federated Mountain Club and some kayaking people, that only half a dozen do this Goddamn thing every year, at the expense of everyone on the coast. It's just ridiculous."
He urged the minister to visit the people on the coast, and explain his decision.
"Something needs to be done. The minister needs to get down here and explain why he made such an outrageous decision."
South Island power company Westpower has also voiced its opposition to the government's decision.