High or low flood risks can determine where wetland restoration might occur on the lower Missouri River, according to a new study by the U.S. Geological Survey Columbia Environmental Research Center and the Nature Conservancy’s Missouri River Program.
The U.S. Army Corps of Engineers has projected record flooding through mid-August for the lower Missouri River downstream of Gavins Point Dam, Yankton, S.D.
Areas along the lower Missouri River that have a greater risk of high floods tend to have a larger potential for wetlands restoration whereas those areas with a low potential for wetland restoration have a lower flood risk, the study’s authors noted. Consequently, restoring wetlands in the high-risk areas could lower flood costs and increase the ecological benefits of the river. The study is published in the journal Wetlands Ecology and Management and is available online.
"This study can be used by agencies, such as the Army Corps of Engineers, to help balance protecting the public from flood hazards and restoring wetland ecosystems," said USGS scientist and senior author of the study, Robert Jacobson, Ph.D. "Land managers can also use studies like this to assist them in making informed decisions about their property, farms and livelihood."
The study revealed that wetland restoration potential is not uniform along the river For example, areas just downstream of Gavins Point Dam have a lack of sediment, which has caused the river channel to deepen, leaving the floodplain in that area high and usually dry. These eroded areas have low potential for restoring wetlands and a relatively low flood hazard.
The amount of channel erosion begins to decrease about 60 miles downstream of the dam, resulting in more opportunity to get water to potential floodplain wetlands, and more flood risk. The stretch of the river with the highest wetland restoration potential is between Omaha, Neb. and St. Joseph, Mo. This area is also more susceptible to flooding than the remainder of the lower Missouri River.
More information about the USGS Columbia Environmental Research Center is available online.
To learn more about the Nature Conservancy's Missouri River Program, visit their website.