A team of plaintiffs’ attorneys has spent roughly $16 million to sue the Army Corps of Engineers over levee breaches that flooded most of New Orleans after Hurricane Katrina. Joseph Bruno, one of those lawyers, estimates that they ultimately will recoup a mere $3.5 million of their investment.

There won’t be any windfalls for their clients, either. A string of court rulings has insulated the federal government from liability for billions of dollars in flood damage that many residents and business owners have blamed on the corps’ shoddy design, construction and maintenance of the region’s system of levees and floodwalls.

The courts have been a dead end for many other plaintiffs seeking compensation for Katrina-related losses. Rulings have consistently affirmed the insurance industry’s position that its homeowner policies don’t cover damage from a hurricane’s rising water, a blow for many Katrina victims in Louisiana and Mississippi whose homes were wrecked by Katrina’s storm surge.

Only a handful of Katrina legal battles continue to linger. A notable example is a jury trial scheduled to start this month for flood damage claims against Jefferson Parish and its disgraced former parish president, Aaron Broussard, over a decision to evacuate drainage pump operators just before the storm’s landfall.

But the bulk of the civil litigation spawned by the 2005 hurricane already has been resolved, usually to the plaintiffs’ detriment.

“In my mind, Katrina is done,” Bruno said.

Two weeks ago, U.S. District Judge Stanwood Duval Jr. in New Orleans dismissed tens of thousands of levee-related claims against the federal government. Duval has presided over a batch of consolidated claims that has generated more than 21,000 docket entries over the years. And his work on the litigation is largely done.

Duval’s recent order essentially was a formality. The fate of those cases was sealed more than a year ago, when a federal appeals court reversed itself and overturned Duval’s landmark ruling that the federal government wasn’t immune from lawsuits blaming flood damage on the corps’ operation and maintenance of a New Orleans shipping channel. In June, the U.S. Supreme Court declined to hear the case.

Dr. Martin Schoenberger, an ophthalmologist whose St. Bernard Parish office was wrecked by flood waters, was among the plaintiffs whose claims against the corps were dismissed by Duval on Dec. 20. He reopened his practice within several months, but lost many of his old patients and hasn’t made up the difference in a parish that struggled to rebound.

Disappointed but hardly surprised by the dismissal of his claims, Schoenberger said the outcome doesn’t change his view that the corps’ construction and maintenance of the Mississippi River-Gulf Outlet navigation channel was responsible for his losses.

“Everybody knew it was dangerous. People had been complaining about the MRGO for decades,” he said.

Plaintiffs’ lawyers have used class-action settlements to secure some modest relief for Gulf Coast residents.

In September 2012, a federal judge in New Orleans approved a $42.6 million settlement resolving claims against the manufacturers and installers of government-issued trailers that allegedly exposed occupants to hazardous fumes after Katrina and Hurricane Rita struck the same year. But the same judge also dismissed related claims against the federal government.

Bruno, meanwhile, helped broker a $20.2 million settlement with three levee districts in the New Orleans area over flood damage after Katrina. He said hundreds of thousands of claimants will be eligible for payments that could start going out early this year.

Even in hindsight, Bruno insists he doesn’t regret his gamble on taking the corps to court.

“It had to be done by somebody,” he said. “There are fewer and fewer lawyers willing to take these kinds of risks.”

Other attorneys who have spent years on Katrina flooding litigation are still waiting for a final ruling or a jury’s verdict.

A judge sitting on the U.S. Court of Federal Claims in Washington heard testimony in November for class-action claims against the federal government by St. Bernard Parish and property owners who blame flood damage on the Mississippi River-Gulf Outlet, which was completed in 1965.

“We’re eagerly awaiting the judge’s ruling,” plaintiffs’ attorney Charles Cooper said. “All of the evidence is now before the judge.”

On Jan. 13, jury selection is scheduled to begin for a trial in state court against Jefferson Parish and Broussard in a class-action case over Katrina flood damage. In October, Judge John Peytavin refused to dismiss the case before trial.

Thousands of homes in the suburban New Orleans parish flooded after its pump operators were evacuated under a “Doomsday Plan.” Broussard, who is serving a prison sentence for his role in an unrelated bribery case, has testified that he didn’t know about the plan’s existence before the parish carried it out in advance of Katrina.

Plaintiffs’ attorney Darleen Jacobs said the rulings that shielded the corps from liability have no bearing on the case against Jefferson Parish and Broussard.

“It’s an entirely different lawsuit and an entirely different set of facts,” she said.

Gerald Meunier, a plaintiffs’ lawyer who worked on the settlements with the levee districts and the trailer manufacturers, said he felt a civic obligation to take on the cases. He doesn’t regret the decision, either, even though the outcomes haven’t met his early expectations.

“The litigation chapter of Katrina is not a happy one for plaintiffs,” he said. “We all went into it eyes wide open about the risks.”