A new report from the National Research Council says that more organized and systematic procedures for gathering and evaluating data on Missouri River sediment are required to improve decisions and better manage the river’s ecosystem, including protecting endangered species and developing water quality standards. In addition, the report finds that the U.S. Army Corps of Engineers’ projects to restore habitats along the Missouri River are not significantly changing the size of the oxygen-depleted “dead zone” in the Gulf of Mexico, nor will options for reintroducing sediment to the system be able to substantially re-establish historic volumes of sediment that were transported downstream to the Louisiana delta. During the 20th century, a network of dams and riverbank stabilization structures was built to control and manage the flow of water in the Missouri River for a variety of purposes, including flood control, water supply, and navigation. In addition to these many benefits, the projects also significantly reduced the amount of sediment traveling down the river to the Mississippi River and ultimately out to the Gulf of Mexico. These engineering projects and the resulting changes in the river’s natural habitat contributed to declines of one fish species, the pallid sturgeon, and two bird species, the least tern and piping plover, which are all listed as threatened or endangered. Currently, most river management authority lies with the Corps, essentially delegating it as the “water master” and hence sediment manager of the Missouri River.
Understanding Missouri River’s sediment dynamics key to protecting endangered species
September 29, 2010