State coastal officials are asking Louisiana's congressional delegation to help clarify why estimates of the revenue they can expect from the federal government's Gulf energy royalties have been cut so dramatically and whether anything can be done to offset the loss. 

Under a revenue-sharing program known as the Gulf of Mexico Energy and Security Act, or GOMESA, coastal states get a share of royalties from oil and gas drilling in federal waters in the Gulf. For the next three years, state officials had hoped that revenue would reach about $175 million per year.

Most of that money — $140 million — was earmarked for Coastal Protection and Restoration Authority projects designed to help restore Louisiana's coast and protect the state from catastrophic floods. The rest was to be funneled to coastal parishes. 

But on Wednesday, a state official said federal estimates of GOMESA revenue to Louisiana had dipped by about 50 percent. That will require the state to evaluate which coastal projects can be delayed or cut, said Chip Kline, an official in the governor's office.

On Friday, Johnny Bradberry, chairman of the CPRA board, sent a letter to Louisiana's congressional delegation asking the members to help clarify the estimates, when the state can expect to receive its money and whether any other funds could be found to help offset the shortfall.

"Due to the importance of this revenue stream and its potential magnitude, CPRA has sought transparency from the federal government regarding" how the funds would be administered, Bradberry wrote in a letter to Rep. Steve Scalise, the House majority whip.

Under the new estimates, the state would receive only about $78 million to $94 million a year, meaning CPRA would get $62 million to $75 million, he said.

Since many of CPRA's other funding sources are grants that require it to spend money first and then apply for reimbursement, Bradberry wrote, the GOMESA funds are especially important because they provide cash upfront. 

It's "one of the few true revenue streams we have that not only allows CPRA to implement projects, but also provides the cash needed to cover expenses under other grant-reimbursable funding streams," he said.

If the new estimates are correct, he added in the letter to Scalise, "we respectfully ask for your help to revisit and pursue other federal opportunities that could also provide assistance for coastal protection and restoration going forward." 

The new estimates are a sharp contrast to earlier this year, when CPRA presented a coastal master plan and an annual plan to the Legislature that included $140 million in GOMESA funds in each of the next three years. The annual plan called for spending only about $22 million in GOMESA money this fiscal year, however. The Legislature passed both plans overwhelmingly.

GOMESA funds were expected to be the second biggest source of revenue for the coastal master plan, just behind revenue sent to the state as part of the BP oil spill settlement. All told, CPRA projected $763,815,138 in revenue for fiscal year 2018. A loss of half the GOMESA funds would represent almost a 10 percent drop in that figure.

According to CPRA, it expects to have three projects in the planning phase, 42 in design and 30 under construction during fiscal year 2018.

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