By Aimee Robinette
Residents in the Delta who live or have property located up and down the Mississippi River continue to look for solutions to the biggest case of water woes in the country. The Mississippi River and backwater swirling causes immense flooding each year and those affected want these flooding problems to be addressed.
“Flooding on the Mississippi River occurs because of rainfall falling within the entire Mississippi River Basin—which is forty-one percent of the continental United States and includes all or parts of thirty-one states,” says Peter Nimrod, chief engineer of the Mississippi Levee Board based in Greenville. “When the Mississippi River gets high, the Steele Bayou Drainage Structure gates are closed to prevent the Mississippi River from backing up into the South Delta. Backwater flooding occurs when the gates are closed, and it rains in the Mississippi Delta. This is a 4,093 square mile drainage basin which starts north of Clarksdale and extends south 140 miles and is fifty miles wide.”
This year, the backwater crested at 97.2 feet on April 1 which inundated 512,000 acres in the Mississippi Delta including 208,000 acres of cropland.
“Every flood is different and affects a different number of people,” says Nimrod. “This year’s backwater flood is affecting thousands of people in the South Delta. We have had six major floods on the Mississippi River above fifty-four feet on the Greenville Gauge in the past twelve years including the past four years in a row. When the Mississippi River is predicted to rise above flood stage (forty-eight feet on the Greenville Gauge) we start getting organized. We work with the Corps of Engineers in getting Corps employees to inspect the levee and we activate our Levee Board crew to get ready to flood fight problem areas.”
Nimrod notes that inspectors look for sand boils and the Levee Board crew implements a temporary solution to stop a sand boil from moving any material under the levee. The crew installs barrels or builds sandbag rings around sand boils.
“Our goal is to permanently fix problem areas,” says Nimrod. “The Corps builds earthen land side seepage berms and installs relief wells. If the Corps cannot permanently fix the problem, the Levee Board installs flash board riser pipes and build earthen rings around problem areas, so they will be easy to activate in future high-water events.”
The Steele Bayou Drainage structure was closed on February 15 to prevent the Mississippi River from backing into the Delta. The gates remained closed for six weeks until they were opened on April 1. Nimrod says due to extensive April rainfall the backwaters have been extremely slow to drop.
Everyone acknowledges what the solution is to the backwater woes and how to achieve it.
“To prevent future backwater floods, the Yazoo Backwater Pumps need to be installed,” says Nimrod. “If the pumps were in place this year, instead of the Backwater cresting at 97.2 feet and flooding 512,000 acres, the pumps would have kept the crest down to 92.3 feet and flooded 347,000 acres. The pumps would have kept water out of homes and would have kept highways and major roads from being flooded in the South Mississippi Delta. Unfortunately, the pumps were vetoed by the Environmental Protection Agency (EPA) in 2008 even though the Yazoo Backwater Project would have resulted in significant gains in every environmental resource category. The 2019 Backwater Flood shows the need to build the pumps.”