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Spring 2002 Vol. 2 No. 1

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Space radar image of Missouri River, Glascow, Mo.; courtesy NASA Bringing Back
the Big Muddy

Ecological Recovery Calls for a New Strategy

The Missouri River is still America's longest river, but it used to be even longer. The "Big Muddy" that once meandered in nearly circular loops in places has been dammed, straightened, and channelized to the point that it is now about 200 miles shorter than it was when Lewis and Clark explored it at the beginning of the 19th century.

But the taming of the Missouri has cost it more than just miles, says a new report from the National Research Council. The ecosystem of the river and its floodplain have been severely degraded by human activities and will continue to deteriorate unless its natural water flow is significantly restored.

"The science tells us that the river basin is in a serious state of decline," said the U.S. Geological Survey's Steven Gloss, who chaired the committee that wrote the report. "Now we need to use that science to guide restoration efforts."

Lewis and Clark were the first to document the vast biological richness of the Missouri, returning from their epic expedition with descriptions of several new species, some of which are now in serious trouble. Two species of birds and one of fish are listed as endangered by the federal government. Fifty-one more species of fish are considered rare, uncommon, or decreasing in numbers, and habitat and vegetation along the river continue to decline. The sediment flow that gave the river its nickname and is crucial to any river's ecological well-being has been reduced by more than 100 million tons a year in some places.

Restoring natural water flow has jump-started ecological recovery in some smaller rivers across the country, and should be tried here using a scientific approach known as adaptive management, the report says. The approach allows decisions to be based on the latest scientific evidence as well as changing social and economic situations. This is especially important in the case of the Missouri, since river managers have been hamstrung by conflicts among environmental and tourist-industry groups, who want greater natural water flow for ecological and recreational reasons, and farmers, who worry that more water will cause damaging floods.

Big Bend Dam on Missouri River, Fort Thompson, S.D.; courtesy U.S. Army Corps of Engineers The U.S. Army Corps of Engineers is at the center of this controversy because it operates the six large dams that are the centerpiece of the Missouri River water storage system. For the past 14 years, the Corps has been trying to rewrite the manual that guides its water-release schedule, but has been unable to finish given the competing demands of stakeholders. The report calls for a halt to further revision of this manual until the changes reflect an adaptive management strategy, which should be implemented by a group of directors representing all stakeholder groups.

For all of this to work, Congress will need to intervene. It should pass a Missouri River Protection and Recovery Act to keep river managers focused on improving the ecosystem, the report says.

Congress also should authorize the Corps to set different water-release schedules for different parts of the river. The Corps has always released water to maintain a proper channel for barges carrying crops to port. But barge traffic has been dropping steadily since 1977, so there may be parts of the river -- especially upstream -- where the navigation benefits are small.   -- Bill Kearney

The Missouri River Ecosystem: Exploring the Prospects for Recovery. Committee on Missouri River Ecosystem Science, Water Science and Technology Board, Division on Earth and Life Studies (2002, approx. 250 pp.; ISBN 0-309-08314-1; available from National Academy Press, tel. 1-800-624-6242; $37.00 plus $4.50 shipping for single copies).

The committee was chaired by Steven Gloss, program manager, Biological Resources, Grand Canyon Monitoring and Research Center, U.S. Geological Survey, Flagstaff, Ariz. The study was funded by the U.S. Army Corps of Engineers and U.S. Environmental Protection Agency.

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Copyright 2002 by the National Academy of Sciences