Contact Info
Missouri River Institute
The University of
South Dakota
414 E. Clark Street
Science Center
Vermillion, SD 57069

Financial support for website development provided by the
Living River Group
of the
Sierra Club




Site Description:

The original town of Niobrara was situated about a mile downstream of the Niobrara-Missouri River confluence. Built in 1857, Niobrara was one of many towns built along the Missouri River for its easy access to steamboat traffic. Twenty-four years after the town of Niobrara was established, the town experienced its first major flood in the spring of 1881. The flood destroyed the town and Niobrara's nearly 850 residents decided to relocate about a mile and a half to the southwest onto higher ground. More recently, the town of Niobrara was threatened by rising ground water as a result of the closure of Gavins Point Dam and formation of Lewis & Clark Lake. The town chose to relocate a second time during the 1970s roughly a half-mile to the southwest onto higher ground. The effects of sedimentation at the Niobrara-Missouri River confluence go beyond the relocation of the town of Niobrara. Closure of Gavins Point Dam in 1955 and the formation of Lewis and Clark Lake has drastically slowed the river's current and reduced the river's ability to carry sediment downstream. Increasing ground water levels have resulted in more frequent flooding, and have made access difficult to some recreation areas. In the future, accumulating sediment may lead to water quality and supply problems for municipal water intakes. Less sediment downstream of Gavins Point Dam has resulted in decreasing wetland and backwater habitat as the Missouri River continues to cut deeper into its main channel. At this time, several solutions to the sediment problem are being tested and sediment-reduction actions are being implemented, which may reduce the amount of sediment entering the river.

Web Link