Kansas City, Mo. ? A controversial move to save an endangered fish by artificially raising water levels on the Missouri River will go forward despite a lawsuit to halt it, the Army Corps of Engineers announced Monday.

Atty. Gen. Jay Nixon filed suit Friday to stop the release of water from reservoirs along the upper Missouri River because of concerns it would flood farmland.

The Corps of Engineers said it would go forth with its plan anyway, though it is unclear precisely when.

Paul Johnston, an Omaha, Neb.-based spokesman for the corps, said the release depended on water temperature, current and forecasted river flows and rain. It will happen sometime before May 19.

The plan is the result of a 2003 Fish and Wildlife Service opinion calling on the corps to protect the endangered pallid sturgeon by attempting to replicate the way melting mountain snow made the river rise each spring before dams were built.

The corps’ plan had called for two spring rises this year, but the first was canceled because water levels in reservoirs feeding the river were too low. The corps said the reservoirs now have more than enough water.

Artificially increasing the river level has sparked dissent. Along the river’s northern reaches, concerns abound that it will drain reservoirs too much to sustain boating and fishing interests. Along its lower banks, there are worries crops could be flooded and barging could be sidetracked.

However, most environmental groups see the plan as a good way to protect the river’s wildlife.

Brig. Gen. Gregg Martin, the corp’s northwestern division commander, said all those concerns were considered.