NEW ORLEANS (AP) — Louisiana on Thursday canceled a $3 billion repair of disappearing Gulf coastline, funded by the 2010 Deepwater Horizon oil spill settlement, scrapping what conservationists called an urgent response to climate change but Gov. Jeff Landry viewed as a threat to the state’s way of life.

Despite years of studies and reviews, the project at the center of Louisiana’s coastal protection plans grew increasingly imperiled after Landry, a Republican, took office last year. Its collapse means that the state could lose out on more than $1.5 billion in unspent funds and may even have to repay the $618 million it already used to begin building.

The Louisiana Trustee Implementation Group, a mix of federal agencies overseeing the settlement funds, said that “unused project funds will be available for future Deepwater Horizon restoration activities” but would require review and approval.

The Mid-Barataria Sediment Diversion Project aimed to rebuild upward of 20 square miles (32 kilometers) of land in southeast Louisiana to combat sea level rise and erosion on the Gulf Coast. When construction stalled last year because of lawsuits, trustees warned that the state would have to return the hundreds of millions of dollars it had already spent if the project did not move forward.

Former Louisiana Rep. Garret Graves, a Republican who led the state’s coastal restoration agency between 2008 and 2014, said the move to end the project was “baffling.”

“It is going to result in one of the largest setbacks for our coast and the protection of our communities in decades,” Graves said. “It’s just a boneheaded decision.”

Project supporters stressed that it was a science-based approach to mitigating the worst effects of a vanishing coastline in a state where a football field of land is lost every 100 minutes. The project, which broke ground in 2023, would have diverted sediment-laden water from the Mississippi River to restore wetlands disappearing due to a range of factors including climate-change induced sea level rise and a vast river levee system that choked off natural land regeneration.

“The science has not changed, nor has the need for urgent action,” said Kim Reyher, executive director of the Coalition to Restore Coastal Louisiana. “What has changed is the political landscape.”

The Louisiana Trustee Implementation Group last year had noted that “no other single restoration project has been planned and studied as extensively over the past decades.”

While the project had largely received bipartisan support and was championed by Democratic Gov. John Bel Edwards, his successor has been a vocal opponent. Landry recoiled at the rising price tag and amplified concerns that the massive influx of freshwater would devastate local fisheries.

Landry has said the project would “break” Louisiana’s culture of shrimp and oyster harvesting and compared it to government efforts a century ago to punish schoolchildren for speaking Cajun French.

“We fought this battle a long time, but Gov. Landry is the reason we won this battle,” said Mitch Jurisich, who chairs the Louisiana Oyster Task Force and sued the state over the project’s environmental impacts. “He really turned the tide.”

Landry said in a statement that the project is “no longer financially or practically viable,” noting that the cost has doubled since 2016.

“This level of spending is unsustainable,” Landry said. The project also “threatens Louisiana’s seafood industry, our coastal culture, and the livelihoods of our fishermen — people who have sustained our state for generations.”

Louisiana’s Coastal Protection and Restoration Authority, the lead agency overseeing the project, said in a statement that the project was “no longer viable at this time based on a totality of the circumstances.” It plans to push forward with a smaller scale diversion project nearby that would “deliver similar benefits to rebuild and sustain our coast,” the agency said.

Chairman Gordon “Gordy” Dove said that “our commitment to coastal restoration has not wavered.”

But conservation groups bristled at the change in plans. The project’s termination marked “a complete abandonment of science-driven decision-making and public transparency,” Restore the Mississippi River Delta, a coalition of environmental groups, said in a statement, adding that the state was “throwing away” money intended to protect its coastal residents and economy.

The coalition said alternative measures proposed by the state, such as rebuilding land by dredging or by the proposed smaller-scale diversion, were insufficient and did not undergo the same level of scientific vetting as the original project.

“A stopgap project with no data is not a solution,” the coalition said. “We need diversion designs backed by science — not politics.”