The Bonnet Carré Spillway delivered a plume of thick sediment to Louisiana’s Lake Pontchartrain in mid-May 2011. Taken on May 17, 2011, this astronaut photo shows a muddy plume in the lake, as well as the sediment-clogged Mississippi River meandering through the city of New Orleans. Water flowing through the spillway into Lake Pontchartrain is also muddy brown.
The Bonnet Carré Spillway, Morganza Floodway, and breached levee near Cairo, Illinois, all diverted some of the flood waters from the Mississippi River in the spring of 2011. The diversion measures aimed to lessen the damage caused by an unusually severe spring flood season.
The Advanced Hydrological Prediction Service (AHPS) of the U.S. National Weather Service reported that the Mississippi River at New Orleans reached 17.05 feet (5.20 meters) at 9:00 a.m. CDT on May 20, 2011. This was just above the flood stage for this location, of 17.0 feet (5.18 meters), and well below the record flood level of 21.3 feet (6.5 meters), set in 1922. The Mississippi River at Baton Rouge, meanwhile reached 44.71 feet (13.63 meters) at 9:00 a.m. CDT on May 20, the AHPS reported. This qualified as major flooding for the Mississippi at that location, but it was below the record flood level of 47.3 feet (14.4 meters) set in 1927. Mississippi River water levels were projected to remain fairly steady at both locations through May 25, 2011.
- National Weather Service. Advanced Hydrologic Prediction Service. Accessed May 20, 2011.
- U.S. Army Corps of Engineers. Bonnet Carré Spillway. Accessed May 20, 2011.