SIOUX FALLS, S.D. - A suggestion to tinker with the downstream navigation season as a means of saving water in the drought-affected Missouri River reservoirs was left high and dry Monday.

At a meeting of Missouri River states, Gov. Mike Rounds proposed changing how and when water is released for the downstream barge industry in order to keep more in the reservoirs and avoid a "navigational preclude" that's part of the Army Corps of Engineers' master manual for operating the dams and reservoirs.

When storage in the six reservoirs drops to 31 million acre-feet, the corps will be required to save water in the reservoirs. Discharges would be too small to float barges downriver.

The system now has a record low 35 million acre-feet of water, compared to 57 maf normally. Based on current snowpack conditions and projected runoff, the corps and others acknowledge the 31 maf trigger is almost a certainty in the summer of 2006 and likely in 2007.

Rounds argued that holding back some water this year might be enough to avoid the trigger next year.

With Missouri's representative voicing the most opposition to that, Rounds was able only to get agreement that the governors would work on a resolution encouraging the corps to conserve water whenever possible.

Much of the day's discussion revealed familiar themes - upstream states with the reservoirs want more water kept in the lakes for recreation and domestic water supplies, while downstream states want a steady flow for navigation, to cool power plants and for their municipal water systems.

The navigational preclude may be an advantage for upper basin states, said North Dakota Gov. John Hoeven, who backed Rounds' proposal.

Nebraska Gov. Dave Heinemann and Montana Gov. Brian Schweitzer also attended. The governors of Missouri, Kansas and Iowa sent representatives.

Ron Kucera, of the Missouri Department of Natural Resources, said changing the flow schedule now would interfere with contracts already signed to haul fertilizer, asphalt and other products by barge this spring and summer.

There were presentations throughout the day illustrating how low water levels in the reservoir and low flows below Sioux City, Iowa affect fish reproduction, recreation and intakes that carry water to drinking water systems or power plant cooling systems.