Washington ? Sen. Max Baucus, D-Mont., is holding up President Bush’s nominee to oversee the U.S. Army Corps of Engineers in a dispute about Missouri River management.

Baucus wants John Woodley to commit that the Corps of Engineers’ next “master manual” for the Missouri will call for more water to be held in Montana’s Fort Peck Lake and in other reservoirs on the river’s upper stretches.

Baucus believes the corps, which manages dams along the river, unfairly favors the needs of downstream interests such as barge shipping. He met with Woodley on Tuesday at Capitol Hill.

“I said, ‘I’m not going to let your nomination proceed until you come back to me with a concrete plan that assures me that you’re making fair changes that are fair to upstream states,”‘ Baucus said Wednesday.

“I take them at their word that they will come back, but we’ll see,” he added.

President Bush nominated Woodley in January to be the assistant Army secretary for civil works. The Senate Armed Services and Environment and Public Works committees have approved his nomination, but Baucus’ hold delays final confirmation indefinitely.

“The ball is in their court,” Baucus said. “If they come back … with a fair proposal that is action — it’s deeds, not words — then I certainly will lift the hold and he can proceed. But if they do not, this will drag on a lot longer.”

Defense Department spokesman Glenn Flood said the department would work to address any senator’s concern, but said he could not respond in detail to Baucus.

Debate has dragged on for more than a decade over how the corps should manage the river’s flow. The agency has said it would finish revising the master manual by next year.

Baucus and other senators from upstream states want the corps to keep enough water behind dams in the region for the boating, fishing and recreation industries.

Barge and farming interests downstream say the corps must provide enough water for shipping in that region. Others worry that plans to use the dams to mimic what would be the river’s natural flow — higher in spring and lower in summer — would cause flooding.

Those flows are the subject of a court dispute in which the corps has been ordered to lower the river level to protect birds and fish listed as threatened and endangered under the federal Endangered Species Act. The order has been suspended temporarily.