President Donald Trump's proposed budget would deal a huge blow to Louisiana's program for protecting and restoring its disappearing coast.

The president's spending plan, which was released Monday, probably has little chance of passing Congress without major changes. But as proposed, it would end an arrangement under which the federal government shares the royalties it collects from offshore oil production in the Gulf with Alabama, Mississippi, Louisiana and Texas.

Louisiana expects to collect $420 million from those royalties over the next three years, which amounts to nearly 17 percent of the $2.5 billion the state plans to spend on coastal efforts over that period. 

Another $36 million from the arrangement was expected to flow directly to coastal parishes each year. 

Money from the state's settlement with BP over the company's 2010 Gulf oil spill is the only bigger source of revenue, but those dollars will stop flowing after 2033. And Louisiana's coastal master plan envisions 50 years' worth of expensive projects. 

The revenue sharing program, which stems from the Gulf of Mexico Energy Security Act, or GOMESA, is scheduled to last until at least 2055. The program was spearheaded by former Louisiana Sen. Mary Landrieu and signed into law in 2006. 

Not surprisingly, members of Louisiana's congressional delegation — even the president's fellow Republicans — were quick to denounce the move to kill the GOMESA funding. 

U.S. Rep. Garret Graves, who was chairman of Louisiana's Coastal Protection and Restoration Authority before he was elected to Congress, noted similar proposals were defeated when proposed by former President Barack Obama.

He said that if Trump is really as friendly toward the energy industry as he says, using royalties to protect the coast should be a priority. 

"If you care about offshore production, you need to do revenue sharing to help address some of the concerns that states have and some of the historic impacts" of the oil and gas industry, Graves said. 

Eliminating GOMESA revenue sharing, Graves said, is evidence of "a real policy inconsistency."

"We are going to be talking with the administration about how we view this as a conflict with becoming energy-independent," he said.

U.S. Sen. Bill Cassidy called the proposal to end revenue sharing a "deal breaker."

"Any cuts to coastal restoration efforts or GOMESA are short-sighted," he said. "I will not only oppose cuts to the revenue sharing program, but continue to work to expand it for the Gulf Coast."

The proposal also drew criticism from environmental and coastal advocacy groups.

It would "set back coastal restoration and protection efforts," said the Coalition to Restore the Mississippi Delta.

The loss of GOMESA funding would be "devastating," said a spokesman for America's Wetland Foundation. 

Gov. John Bel Edwards, in a statement, blasted several proposals in the Trump budget, including the plan to cut revenue for coastal restoration.

"This proposal would set us back decades," Edwards said. "The nation depends on the energy resources found off the coast of our state, but this budget doesn't reflect that."

Edwards' call for congressional opposition to the budget comes even as his administration is petitioning the Trump administration to help speed the permitting process for one of its key coastal projects: the Mid-Barataria Sediment Diversion, which would send sediment and water from the Mississippi River into the hard-hit Barataria Basin south of New Orleans. 

The U.S. Army Corps of Engineers has said that project is not likely to be permitted until 2022, a date that state officials have called "unacceptable."

Trump administration officials have asked the state to prepare a presentation outlining the federal hurdles that are impeding the project and why it's important to get it moving quickly.

Follow Faimon A. Roberts III on Twitter, @faimon.