NEW ORLEANS – Based on the reduced flows in the Mississippi River at Red River Landing, the U.S. Army Corps of Engineers, New Orleans District will close the final gate on Thursday, July 7, 2011. The Corps began closing gates at the Morganza Floodway on Tuesday, May 24, 2011.
Gates were left open to expedite drainage of the forebay so crews could inspect the structure and conduct damage assessments. Repair plans will be developed following the damage assessments.
The Morganza Floodway is designed to ensure that a maximum river flow of 1.5 million cubic feet per second (cfs) is passed through the Mississippi River and Tributaries system at Red River Landing. The Morganza Floodway was opened for the second time in history, (the first time for its intended purpose), on May 14, 2011. At peak operation, approximately 182,000 cubic feet per second of water was being diverted through the flood control structure.
Although water levels have receded allowing the closure of both the Morganza and Bonnet Carre’ flood control structures, the New Orleans District’s Emergency Operations Center staff will continue its flood fight inspections and environmental monitoring until further notice.
Morganza Floodway, located at river mile 280 in central Louisiana, begins at the Mississippi River, extends southward to the East Atchafalaya River levee, and eventually joins the Atchafalaya River Basin Floodway near Krotz Springs, Louisiana. It is a vital element of the multi-state Mississippi River and Tributaries (MR&T) system, which uses a variety of features to provide flood risk reduction to the alluvial Mississippi Valley from Cape Girardeau, MO to Head of Passes, Louisiana.
Intended to operate during emergency flooding, the purpose of the Morganza Floodway is to divert excess floodwater from the Mississippi River into the Atchafalaya Basin. The floodway consists of two structures both completed in 1954 – the 125 gate Morganza Control Structure and the Morganza Floodway – which are designed to pass up to 600,000 cubic feet per second (cfs) of water to the Gulf of Mexico, alleviating stress for mainline levees downstream along the Mississippi River.
The first time the Morganza Floodway was partially operated was during the 1973 high water event to relieve pressure on Old River’s Low Sill Structure. The 2011 opening marks the second time in history of the Morganza Floodway’s operation.