A chain of sand berms built by the State of Louisiana to block and capture oil from BP’s runaway well in the Gulf of Mexico stopped a “minuscule” amount of oil and was largely a waste of money, the staff of the presidential commission investigating the spill said in a report issued on Thursday.

The report, a draft, found that a decision by Thad W. Allen, the retired Coast Guard admiral who led the spill response, to approve construction of the berms was made under “intense political pressure” from federal, state and local politicians and against the advice of an expert panel advising on the spill response.

“The decision to green-light the underwhelmingly effective, overwhelmingly expensive Louisiana berms project was flawed,” the commission staff wrote.

The berms were first proposed by a Dutch engineering firm and became a top priority for Gov. Bobby Jindal of Louisiana, who exhorted President Obama and federal agencies to authorize the project. The state drew up plans for 101 miles of berms and requested a permit from the Army Corps of Engineers.