USGS Columbia Environmental Research Center Project: Assessment of Side-Channel Chute Dynamics, Lower Missouri River


Statement of Problem: Regulation, bank stabilization, and navigation structures on the lower Missouri River have severely altered the hydrologic and physical characteristics of the channel and flood plain (that is, the river corridor). Reservoir regulation for navigation, flood control, power generation, and other purposes has changed the magnitude, frequency, timing, and duration of high- and low-flow periods. Navigation structures and bank revetments have narrowed and deepened the channel. Revetments and levees have confined the channel and disconnected it from the floodplain. As a result, the lower missouri river has changed from a dynamic, braided river to a swiftly flowing, single-thread meandering river. Declines of many riverine species have been attributed to these substantial habitat changes. However, little is known about the cause/effect relations linking management, habitat, and biotic responses. Efforts to rehabilitate the missouri river depend on developing quantitative understanding of these links: how can changes in release schedules and channel geometry affect availability of habitat? And if habitat is provided, do the native riverine biota respond?

Side-channel chute construction has become a popular approach to aquatic habitat restoration on the Lower Missouri and Mississippi rivers, with annual expenditures of several millions of dollars. Very little is known about the quality and quantity of habitat provided by these chutes, their geomorphic evolution and longevity, and their contributions to reproduction and survival of native aquatic species.

Objectives: 1) Quantify performance and contributions of side-channel chutes to habitat quantity and quality in the Missouri River. 2) Document rates of change and trends in habitat quantity and quality related to engineering designs and hydrologic variation.  
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