The U.S. Army Corps of Engineers opened parts of the Bonnet Carre Spillway (2/27/2019) due to the rising Mississippi river. Workers pulled out the “needles” to open 30 bays Wednesday morning out of 350. The corps say they could open up to 200 bays. Experts predict the river levels could reach 17 feet by March. 17 feet is the flood stage. Excessive rainfall and snow melt across the Ohio and Mississippi Valleys in recent weeks have caused the river to rise that high. This has been the wettest Winter in that area in 124 years, according to experts. The spillway is expected to stay open for at least one month. This marks the first time in its-88 year history, that the spillway has been opened in two consecutive years. The Bonnet Carre has been operated 13 times since 1937. It was build was built in response to the Great Mississippi Flood of 1927.
How Does It Work?
Opening the spillway will help the river flow through the area so it doesn’t get backed up. The Bonnet Carre consists of a control structure and a floodway. The control structure is a concrete weir that parallels the river for a mile and a half. It has 350 gated bays, each holding 20 timber “needles,” for a total of 7,000 needles. When needles are removed, river water flows into the floodway and is conveyed nearly six miles between guide levees to lake Pontchartrain. The spillway opening sends fresh water into the normally salty and brackish waters of Lake Pontchartrain.