Mississippi, Claiming Louisiana Dam Causes Flooding, Sues Federal Government

The state of Mississippi this week sued the federal government, claiming a dam complex in Louisiana that keeps the Mississippi River from changing course is harming state land.

The suit seeks at least $25 million in damages and touches on one of the most sensitive engineering questions in the nation – the U.S. Army Corps of Engineers’ decades-long effort to keep the Mississippi in its current channel flowing past Baton Rouge and New Orleans.

Without what’s known as the Old River Control Structure, the Mississippi River would likely shift course to Atchafalaya River in Louisiana, which offers a shorter, steeper route to the Gulf of Mexico. Such a shift would cut off the current source of fresh water for drinking in New Orleans and for industrial use at dozens of chemical plants in south Louisiana. It would also create major obstacles along a key shipping route.

Mississippi Secretary of State Delbert Hosemann said his state isn’t challenging the decision to try to lock the river’s current flow in place. But he said Mississippi landowners should get paid for increased flooding caused by siltation. The river carries sediment that is dropping out of the current and piling up on the riverbed, constricting its flow and causing water upstream to rise higher, especially during a flood.

The U.S. Justice Department declined to comment on the lawsuit.

Mississippi officials say nearly 8,000 acres (3,237 hectares) in public land is being degraded by increased flooding. That land, set aside for the benefit of public schools, is normally used to grow timber. Hosemann, though, said trees are being damaged and that once this generation of trees is cut, commercially valuable species probably won’t regrow. That means less money for the Wilkinson County, Natchez-Adams, and Claiborne County school districts. The lawsuit asserts the federal government is taking the land without compensation and should pay for it.

“This 8,000 acres that is owned by the state of Mississippi, we believe it is being turned into a permanent reservoir,” Hosemann told reporters Monday.

He said only 75 days of flooding were recorded in the area from 1950 to 1972, while more than 1,000 were recorded from 1973 to 2016.

The Republican, who is running for lieutenant governor this year, said he appealed to the Mississippi River Commission 2016 for relief. The commission oversees the levees and dams that are meant to prevent flooding and enhance navigation along the river.

Private property owners in southwest Mississippi have also complained about increased flooding in recent years, and Hosemann acknowledged that if the state’s lawsuit is successful, private landowners would likely follow suit.

Despite the assertions in the lawsuit, Hosemann said the state has not yet conducted studies of the river’s water flow meant to scientifically prove that siltation from Old River is to blame for increased flooding. Hosemann said such studies would be conducted over the next two years at a cost of $50,000.

There could be other factors driving flooding as well. Some experts say increased upstream development is sending more water downstream. And in two of the last three years, the lower Mississippi has seen unusual wintertime floods sparked by heavy rains upstream that could be related to climate change. Historically, the Mississippi’s peak flood has been in the spring