Some conservation groups and scientists assert that the project has not only been ineffective but could also threaten wildlife. They warn that the intensive dredging associated with the berms has already killed at least a half-dozen endangered sea turtles and could kill many more.

They have also repeatedly raised concern that further dredging may squander limited sand resources needed for future coastal restoration projects.

“As the summer went on, we became increasingly convinced that the amount of money that was being put into these projects was not worth the benefits,” said Karla Raettig, the national campaign director for coastal Louisiana restoration at the National Wildlife Federation. “It was BP’s money, but perhaps that money could have been better invested elsewhere.”

Some scientists and federal officials suggest that the remaining money allocated for the berms might be better spent on other coastal restoration projects, a move that BP says it would support. The money could be spent, they say, on barrier island restoration, for example, in which dredged sand is used to bolster existing islands, mimicking natural processes.

But state officials are unswayed. “I don’t see a downside to continuing to do this,” Mr. Graves said. “Maybe we’re being too protective of our coast. O.K., accuse me. I don’t have a problem with that.”

The berm project has been a boon to Louisiana industry: although many of the dredging companies working on the project have out-of-state headquarters, all have a major presence in Louisiana. The Shaw Group, the lead contractor on the project, is based in Baton Rouge and has been one of Mr. Jindal’s leading campaign contributors over the years.

Several of the project’s other contractors are also along the Louisiana coast. CF Bean, an engineering firm, is based in Plaquemines Parish, and one of the four dredging companies involved, Great Lakes Dredge and Dock, has offices there, for example.