[JURIST] The US Court of Appeals for the Fifth Circuit [official website] has ruled [opinion, PDF] that several contractors responsible for dredging the Mississippi River, which some claim exacerbated damage from Hurricane Katrina [JURIST news archive], cannot be held liable since the contractors were acting under Congress' express authorization. The plaintiffs' suit claimed that dredging in the Mississippi River Gulf Outlet (MRGO) [USACE backgrounder] compromised the effectiveness of levees and increased Katrina's storm surge. Relying primarily upon the US Supreme Court's decision in Yearsley v. W.A. Ross Construction [opinion text], the court held last Wednesday that government-contractor immunity protected the contractors because the plaintiffs did not allege that the companies acted outside of the authority given them by the federal government or that the government granted that authority improperly. The appeals court also affirmed a lower court's refusal to grant the plaintiffs' request for discovery to see if the contractors acted outside of their contracts with the government. The plaintiffs will not be allowed to amend their complaint, as the court ruled any claim based on the facts would be futile.

Earlier this month, a judge in the US District Court for the Eastern District of Louisiana [official website] found the US Army Core of Engineers (USACE) [official website] negligent [opinion, PDF; JURIST report] in its construction and operation of the MRGO. The USACE had sought dismissal of the suit on several occasions. In March, a judge found [JURIST report] that material questions of fact existed as to a potential violation of the USACE's mandate that, if proven, would preclude it from protection under the discretionary function exception of the Federal Tort Claims Act. The court previously allowed the lawsuit to proceed in May 2008, when he ruled [JURIST report] that the outlet was a shipping channel and not a flood control outlet in connection with which the USACE would have been properly immune in tort, and rejected the USACE's argument that the MRGO was nonetheless part of a larger flood control system in the New Orleans area. The court made a similar ruling [JURIST report] in February 2007 in the context of an earlier motion to dismiss. Three months before Hurricane Katrina struck New Orleans, an expert at the LSU Hurricane Center [official website] predicted that the MRGO could amplify storm surges by 20-40 percent. After Katrina, the center determined through computer modeling that the presence of the MRGO also increased the speed of the surge, causing an even greater detrimental effect [Washington Post report].