One lawsuit involves the Mississippi River Gulf Outlet (MRGO) which connects the Gulf of Mexico with the Mississippi River. Some people believe the channel increased storm surge levels which led to the breached levee that ravaged New Orleans.

The judge also found that the court needed to review three major allegations made by the plaintiffs: (1) that the Corps did not consult with the U.S. Fish and Wildlife Service and the Louisiana Department of Wild Life and Fisheries regarding the MRGO's alignment; (2) that there were errors in constructing and maintaining the MRGO; and (3) whether there were decisions made that did not follow standard engineering practices.
A central question as to whether or not lawsuits against the Corps will be allowed involves the nature of the canals and levees. If the waterway in question was a flood control project, under the 1928 Flood Control Act, the Corps is free of liability. However, if it was a navigable waterway, the Corps could be found liable for the collapse of the walls. Therefore the courts must first determine whether or not a waterway is actually a flood control project before allowing a lawsuit to proceed.
The Army Corps of Engineers faces at least one lawsuit which claims that the organization knew before the hurricane that the flood walls of the 17th Street Canal levees were unstable. The suit, which is seeking class action status, alleges that the walls were weakened by dredging of the soil that supported the levees. If the lawsuit is granted class action status, thousands of residents could be included potentially costing the government billions of dollars.
Meanwhile, a group of New Orleans residents is asking Congress to set up an independent, bipartisan panel to investigate the failure of the levees during the Hurricane. So far investigators agree that part of the failure of the levees was due to weak soil and unstable designs. However it is not yet known how critical decisions in the design were made and whether or not the Corps ignored problems with the walls.