Date of this Version
Prepared for the U.S. Army Corps of Engineers. April 2009.
The Missouri River has been developed for flood control, commercial navigation, irrigation, fish and wildlife conservation, municipal water supply, water quality control and hydropower production through a series of congressional acts. However, prior to development, the lower Missouri River was characterized by a highly sinuous to braided channel with abundant log jams, sand bars, secondary channels and cut-off channels. Construction of the Bank Stabilization and Navigation Project (BSNP) converted the lower Missouri River into a narrow, self scouring channel. The active channel downstream of Sioux City, Iowa was as wide as 1.8 km before river modification, but is now confined to a 91.4 m channel. Total river and floodplain habitat altered or destroyed by the BSNP is estimated at 211,246 hectares.
The Missouri River Fish and Wildlife Mitigation Project (Mitigation Project) was established to restore fish and wildlife habitat lost by the construction, operation and maintenance of the BSNP. The Water Resources Development Act of 1986 authorized the United States Army Corps of Engineers (COE) to acquire and develop habitat on 12,100 hectares of non public lands and the development of 7,365 hectares of habitat on existing public lands to mitigate habitat losses. The Water Resources Development Act of 1999 authorized an additional 48,016 hectares to the program. The Final Supplemental Environmental Impact Statement (FSEIS) for the expanded Mitigation Project was issued in March of 2003, and it included a preferred alternative proposing the creation of additional shallow water habitat (defined as areas less than 1.5 m deep with a current velocity of less than 0.76 m/s). The preferred action in the FSEIS for the expanded Mitigation Project included creation of 2,833 to 8,094 hectares of shallow water habitat (SWH).
In 2005, the Iowa Department of Natural Resources, Nebraska Game and Parks Commission (NGPC), Missouri Department of Conservation and U.S. Fish and Wildlife Service, Columbia Fisheries Resource Office (renamed to Columbia National Fish and Wildlife Conservation Office) were contracted by the COE to monitor and evaluate fish communities of select off-channel aquatic habitat sites that were constructed through the Mitigation Project. Additionally, the NGPC was contracted to collect physical habitat information from the secondary channels that were selected for biological monitoring in the upper channelized section above Kansas City. Sixteen sites selected for monitoring covered a range of aquatic habitats including backwaters and secondary channels with varying levels of engineering and development. Sites from upstream to downstream included Tieville-Decatur Bend (two backwaters), Louisville Bend (backwater), Tyson Island (backwater), California Bend (chute on the Nebraska bank and a chute with connected backwater on the Iowa bank), Tobacco Island (chute), Upper and Lower Hamburg Bends (one chute each), Kansas Bend (two small chutes, treated as one), Deroin Bend (chute), Lisbon Bottom (natural chute), North Overton Bottoms (chute), Tadpole Island (chute) and Tate Island (chute). The study was designed to include three field sampling seasons, but due to delays implementing contracts in 2005 another complete year of sampling was added. Thus, fish community monitoring and habitat assessment of offchannel mitigation sites began in April, 2006 and concluded in October, 2008. The objective of this project was to determine biological performance and functionality of chutes and backwaters and to compare chutes and backwaters in an effort to identify designs most beneficial to native Missouri River fish species. Additionally, this project was designed to help determine if additional modifications are needed at existing mitigation sites, if existing designs are providing a range of habitats, if these habitats are of value to the biological diversity of the Missouri River and if these habitats are of specific value to species of concern or importance, such as pallid sturgeon.