A draft supplemental environmental assessment for a proposed modification at the Kansas and Nishnabotna Bends in Nemaha and Otoe counties, Neb. is currently available for public review.
The purpose of the supplemental action is to provide protection to Levee Unit R-562 by diverting overland flows from Kansas Bend away from the toe of the levee while allowing for continued operation of the mitigation project.
This draft supplemental EA is consistent with the National Environmental Policy Act of 1969, as amended, the Council on Environmental Quality’s regulations for implementing NEPA (40 CFR 1500-1508), the Corps’ regulations for implementing NEPA (33 CFR 325 and Engineering Regulation 200-2-2) and other applicable environmental laws and regulations.
BACKGROUND
Both the Kansas Bend chute (Missouri River miles 546.4 to 544.6) and Nishnabotna Bend chute (Missouri River miles 543.4 to 542.4) were constructed in 2004 as part of the Missouri River Bank Stabilization and Navigation Fish and Wildlife Mitigation Project. A portion of the excavated material from construction of the chutes was used to construct 13 earthen groins perpendicular to federal Levee Unit R-562 to help protect the levee from any overland flow that might occur from the normal operation of the chutes.
In 2011, high flows on the Missouri River widened an outside bend of the Kansas Bend chute and removed material from the high bank. This allowed water to escape the bend during non-flood flows, flow along the toe of Levee Unit R-562, and cause erosion to the levee. In 2012, a Supplemental EA assessed the environmental impacts of installing seven additional earthen groins perpendicular to the riverward levee toe and adjacent to the upstream end of the 13 groins installed in 2004.
During construction of the seven groins in August 2013, it was noted that the water escaping from Kansas Bend would still make its way to the toe of the levee during non-flood flows even after the seven groins are constructed. Therefore, the proposed project includes construction of 13 additional earthen groins perpendicular to Levee Unit R-562. Five new groins will be located just north of the seven groins currently being constructed, and eight new groins will be located just south of the original 13 groins constructed in 2004.
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Press Release, September 25, 2013