Balancing Fisheries Management and Water Uses for Impounded River Systems

Operation of the Missouri River Reservoir System and Its Effect on Fisheries Management

Jack W. Erickson, Mark D. Rath, and Diane Best

doi: https://doi.org/10.47886/9781934874066.ch9

Abstract.—As authorized by the Flood Control Act of 1944, the Army Corps of Engineers operates six large earthen dams in Montana, North Dakota, South Dakota, and Nebraska on the main stem of the Missouri River. The six reservoirs make up the largest reservoir system in the United States and are used for flood control, navigation, irrigation, hydropower, water supply and water quality, recreation, and fish and wildlife.

Soon after the reservoirs were completed in the 1950s and 1960s, modification of the natural hydrograph, loss of riverine habitat, water quality changes, and introduction of nonnative fishes resulted in a drastic change in composition of the fish community. Recreational sport fisheries associated with the reservoir deepwater habitat developed into a major economic activity in Montana, North Dakota, and South Dakota. The changes in habitat also caused a corresponding decline in species historically found in shallow or riverine habitats.

Environmental legislation, litigation and a variety of river basin organizations have addressed conflicts between competing interests, and such efforts have directly affected the aquatic resources associated with the reservoirs and the remaining riverine portions of the Missouri River.