ST. LOUIS (AP) -- This year's severe flooding along the Mississippi River has prompted three federal agencies to discuss how they can work more effectively together.

A flood emergency excercise -- a sort of pre-flood dress rehearsal -- and exchanging key staffers are among the ideas under consideration.

The U.S. Army Corps of Engineers, National Weather Service and U.S. Geological Survey are holding their first-ever joint summit in St. Louis this week.

They're discussing what went well -- and poorly -- with forecasting rain and river stages during the floods, and how they can communicate forecasts more efficiently so that river communities, farmers and the barge industry can respond.

Corps Brig. Gen. Michael Walsh said the magnitude of this year's floods clarified how important it is for the three agencies to collaborate.

Walsh, who was Gen. David Petraeus' engineer in Iraq before leaving to head the corps' Mississippi Valley division in February, said veterans of his agency say they've never seen a year like this one: massive flooding that reached from the upper Midwest to Arkansas and Louisiana from punishing spring and summer rains and late-summer hurricanes.

He said the agencies must find ways to cope with what he called a "battle of uncertainty." He said they must dispatch information more efficiently to communities, farmers and businesses forced to make "life and death decisions."

Walsh said when the corps learns of a levee break, it should share the details of that with the National Weather Service to help in its forecast of river stages, "so that a mayor can decide whether to evacuate a town or organize a flood fight."

Brent Hoerr, president of the Marion County, Mo., Drainage District in Palmyra, said a levee break east of the Mississippi River in Illinois helped save the 4,000 farm acres and Burlington-Northern Railroad line that his district encompasses. "We were spared," he said, unlike in 1993, when floodwaters washed out the tracks.

Representatives of the barge industry emphasized that accurate river stage forecasting is critical to their making good business decisions. But they noted that forecasts from the Army Corps of Engineers tend to be more accurate than the National Weather Service's.

Walsh said the corps does its own river-stage forecasts to aid its operation of river locks and dams. He said the National Weather Service is the official forecast agency.

James Hoke, director of the National Weather Service's hydrometeorological prediction center, said the agency is working to improve its forecasts. He said the agency worked closely with state and county emergency officials to provide them with up-to-the-minute information during this year's floods.

(Copyright 2008 by The Associated Press. All Rights Reserved.)