Morganza Spillway emergency use to divert additional water from the Mississippi River into the Morganza floodway, which merges downstream with the Atchafalaya floodway before entering the Gulf. Diversion of water from the Mississippi's main channel has the effect of lowering water level in the Mississippi downstream of the spillway, helping to relieve stress on levees and other flood control structures both upstream and down. Besides controlling flooding in a given event, the system is also designed to prevent the Mississippi River from permanently altering course down the Atchafalaya River, bypassing Baton Rouge and New Orleans. Water that passes the Morganza Spillway first
Morganza to the Gulf benefits to the marshes and wetlands in the Terrebonne Basin. Safe Harbor: Fishermen will no longer have to leave the area in a storm event. A Reconnaissance Study for the Morganza, Louisiana to the Gulf of Mexico Hurricane Protection Project was authorized by Congress in 1992. Following completion of this report, the United States Congress authorized a Feasibility Study in the Energy and Water Development Appropriations Act of 1995 (Public Law 103-316). The Feasibility Study was completed in March 2002 and the Chief of Engineers letter was forwarded to the Secretary of the Army in August 2002 and supplemented in