If U.S. Sen. David Vitter is elected governor this fall, operation of some of the most expensive and complex projects in the New Orleans-area flood protection system would be dropped into the lap of the U.S. Army Corps of Engineers, whether or not the agency gets the money it says it needs to run them, Vitter said Friday.

That could raise the stakes in a long-running argument among the Corps, the state’s Coastal Protection and Restoration Authority, and the Southeast Louisiana Flood Protection authorities over which of them is responsible for operating three key pieces of the system of levees, floodwalls and pumps in the New Orleans area and who is on the hook for those costs.

The structures — the West Closure Complex, the Lake Borgne Surge Barrier and the Harvey Canal Sector Gate — are being run and paid for by the local agencies, despite the passage of a law Vitter championed last year that put that responsibility — and most of its costs — on the Corps.

Vitter said that wouldn’t remain the case should he make it to the Governor’s Mansion in January.

“We’ll drop off the keys to these three structures to the Corps office, literally drop off the keys, and we’ll send you a monthly check for 35 percent,” Vitter said. “So you all have between now and January to figure it out.”

That ultimatum came as Vitter grilled Col. Richard Hansen, commander of the Corps’ New Orleans District, in front of a crowd at Lakefront Airport as part of a one-man field hearing for the Senate’s Transportation and Infrastructure Subcommittee, which he chairs.

The event was one of several similar events that Vitter, in his role as senator, has held in Louisiana in recent months that also have provided him with opportunities to stump on various issues as he seeks votes in the governor’s race.

Vitter is facing two fellow Republicans, Public Service Commissioner Scott Angelle and Lt. Gov. Jay Dardenne, and Democrat state Rep. John Bel Edwards in the fall gubernatorial election.

Local levee agencies and the Coastal Protection and Restoration Authority have long pushed for the Corps to take responsibility for the three projects, arguing that because the projects include elements that are part of the area’s navigation system, they fall under the federal agency’s responsibilities.

The projects include the two most expensive elements — costing $1 billion each — of the $14.5 billion flood protection system constructed after Hurricane Katrina for Orleans, Jefferson and St. Bernard parishes: the surge barrier across Lake Borgne and the West Closure Complex, the largest pump station of its kind in the world, which sits in the Gulf Intracoastal Waterway.

Legally, that argument was settled last year when President Barack Obama signed the Water Resources Reform and Development Act, which Vitter sponsored in the Senate, into law. That law requires the Corps to run the three projects, though it did not provide additional funding for their operations. In exchange, local governments were required to kick in 35 percent of the costs.

Hansen said the Corps “plans to comply” with the law but that because Congress didn’t provide funds for the operations, there is little the district could do. The projects are now being run by the local agencies.

“Your answer is, ‘We’re not doing it even though it’s clearly our responsibility because we don’t have the funding to do it?’ ” Vitter asked.

And while Vitter pointed to a $1 billion appropriation given to the Corps last year as a possible funding source, Hansen said that money was used to fix a backlog of about $140 billion in deferred maintenance on projects around the country.

Running the three local projects “was one of the needs that was not able to be funded,” he said.

Follow Jeff Adelson on Twitter, @jadelson.