The Board of Mississippi Levee Commissioners has filed an appeal of a March federal court decision that threw yet another monkeywrench in a 70-year battle over a giant pumping station that would alleviate flooding in the lower Mississippi Delta near Vicksburg.

The board filed the action with the Fifth U.S. Circuit Court of Appeals.

The Yazoo Backwater Project pumping station, which engineers say would lower a 100-year flood by 4 feet, was first authorized by Congress in 1941, but seven decades later the project remains embroiled in legal battles.

The proposed pumping station would be one of the largest in the world, with cost estimates of $220 million or more.

When the Mississippi River floods, the natural gravitational flow of other smaller rivers in the area is impeded, causing them to overflow and inundate the Yazoo backwater area. The station would lift water out of the area and pump it back into the Mississippi River.

The final reformulation report for the project was released Nov. 16, 2007, but the Environmental Protection Agency, in a rare use of its veto power under the Clean Water Act, turned thumbs down on the project Aug. 31, 2008.

“In 2008, the backwater got to 92.2 feet, which flooded 344,000 acres, including 121,000 acres of farmland,” Peter Nimrod, the board’s chief engineer, told a hearing of the Mississippi River Commission at Greenville last month.

“In 2009, the backwater got up to 93.7 feet, which flooded nearly 400,000 acres, including 152,000 acres of farmland. Trees and wildlife were decimated by this flooding.”

The board’s position, Nimrod says, is that the EPA veto was illegal, and in August 2009, with assistance from the Pacific Legal Foundation, it sued the agency in the U.S. District Court of Northern Mississippi, contending that the proposed station fell under an exemption in Section 404 of the Clean Water Act.

The Pacific Legal Foundation is a donor-supported legal watchdog organization that litigates for balance and common sense in environmental regulations.