The frenzied response to the BP oil well blowout in the Gulf of Mexico has featured any number of wing-and-a-prayer options from engineers and elected officials. But the debate over a sand-barrier plan that skeptical scientists are referring to as “The Great Wall of Louisiana” has been the most politically charged.

Republican Gov. Bobby Jindal, Sen. David Vitter (R-La.) and angry parish presidents have hammered the Obama administration in past weeks over what they characterize as a glacial federal approval process for the state’s plan to construct 128 miles of sand berms, dredging up 102 million cubic yards of seabed in the process, to bolster the state’s barrier islands and absorb oil before it reaches sensitive coastal marshes.

The Army Corps of Engineers gave final approval last week to a scaled-down version of the project after rejecting the state’s original proposal, which could have cost as much as $950 million and taken as long as nine months to build.

But as Jindal and other politicians celebrate the partial victory, coastal researchers warn that the project can’t be built in time to help — even if it had been approved when first proposed last month. And scientists warn that it may have unforeseen consequences.

The berm system could reroute the spill up the Mississippi Delta, and it would be unlikely to survive even a mild storm during the current hurricane season.

It also will absorb the short supplies of sand badly needed for projects to restore the state’s coastline, damaged by past hurricanes.

Heavy equipment, including barges and dredge lines, could interfere with nesting season, now at its peak, for protected bird species.

Even Coast Guard Adm. Thad Allen, who ultimately approved the project, was lukewarm in his endorsement.

“There are a lot of doubts whether this is a valid oil spill response technique, given the length of construction and so forth,” he said in announcing the first of six berm sites at Scofield Island, west of the Mississippi River. “We are not averse to attempting this as a prototype.”

BP, which was ordered by Allen to pick up the estimated $360 million cost of the revised 45-mile-long berm project, washed its hands of the outcome. “The company will not assume liability for unintended consequences,” said spokesman Mark Proegler. “We’re counting on the government to make the right decisions.”

Although the state signed contracts with a dredging firm, BP has yet to provide the funding.

“To date, BP has done a great job in sending us press releases and attorneys, but they haven’t sent us any money to dredge,” Jindal said Friday. “We are moving ahead without BP. We gave them two choices: They can either send us a check, get out of the way and let us start this work, or they can sign a contract and do it themselves. We are going ahead without them.”

The Army Corps of Engineers has located a dredger. “We could see sand by Monday,” Jindal said.

Jindal’s frenetic pace is part of the state’s gamble on the “worth-a-shot” approach to protecting its bays and bayous, 140 miles of which are coated in oil. So far, the state has built a “marsh fringe barrier,” made up of sand plugs and small berms, in four coastal parishes, and has filled sea-bottom depressions with sandbags. Workers have strung tall, four-sided Hesco basket barriers in bays and laid more than 750 miles of booms throughout the four-state gulf region.

The use of sand berms to collect oil has been around for some time but has never been employed on this scale. Jindal has been the plan’s most vociferous booster.

Louisiana has for decades been fighting a losing battle to reestablish its barrier islands, low-lying sand spits where natural shifting and erosion have been exacerbated by the channelization of the Mississippi and by recent catastrophic hurricanes. The Chandeleur Islands once extended almost to the Mississippi coast but lost 85% of their land mass in Hurricane Katrina in 2005.

The looming tropical storm season has some scientists questioning the expenditure of money and resources on an experimental project. Although the berms will be 300 feet wide at their base, tapering to 25 feet at the top, a sand wall is not considered a robust structure.

The berms “will not survive even a low-intensity tropical storm in the northern gulf,” said Jack Kindinger, director of the U.S. Geological Survey’s Coastal and Marine Science Center in St. Petersburg, Fla. “If we have one next week, the berms will be gone. We have to be careful not to do more harm than good.”

Kindinger said that the new barriers may increase tidal action in open water, which would boost the salinity in estuaries and alter the lives of marsh plants and wildlife.

In a similar manner, the project could inadvertently drive oil into the Mississippi sound, the Biloxi marshes and Lake Borgne, according to the Army Corps’ analysis.

Gregory Stone, director of the Coastal Studies Institute at Louisiana State University, warned that scooping sediment out of the sea bottom could accelerate wave action.

“It’s not advisable to go out into shallow water and dredge and not expect potential negative impacts,” Stone said. “That’s going to increase the energy of the waves.”

Such worries prompted the Interior Department to conclude: “We do not think the risks inherent in proceeding without more environmental study and knowledge are acceptable.”

Coastal scientists and oceanographers were brought in this week to present their views on the berm proposal to state and federal responders. Many said they were frustrated, wondering why their expertise was not brought to bear sooner.

“You cannot do this without some sort of reasonable quantification as to what will happen,” Stone said. " I understand we are in a jam right now, but, good Lord, we have sophisticated computer models that can do this in a matter of weeks.… It’s sort of unconscionable that we’ve gone well over a month without scientific input.”

Denise Reed, interim director of the Pontchartrain Institute for Environmental Science at the University of New Orleans, said that given the construction timelines, expectations that the berms will stop oil are unrealistic.

“There is a public sense that this is the solution that we need,” she said. “I found this proposal extremely difficult to evaluate because it’s so idealized and conceptual.… We are not going into it with our eyes wide open.”

julie.cart@latimes.com