ST. LOUIS (AP) — An environmental group’s federal lawsuit accuses the U.S. Army Corps of Engineers of ignoring requests that it publicly explain why it believes southwestern Illinois’ Mississippi River levees are deficient and in need of millions of dollars in upgrades.

The lawsuit, filed Thursday on the American Bottom Conservancy’s behalf, claims the Army Corps has failed to honor the group’s Freedom of Information Act requests over the past year for documents detailing supposed shortcomings in the 64 miles of levees protecting a swath of land known as American Bottoms, which stretches along the Illinois side of the Mississippi River near St. Louis from Alton to Columbia.