The project will consist of constructing a new setback levee 5,150 feet in length. The back slope of the levee will be 3 to 1, and will have a facing slope of 2 to 1. The alignment of the levee is shown in Figure 1.
The setback levee project will also include fortification of the existing levee downstream, across stream and upstream of the setback levee. This work will involve placing additional rock rip rap to the existing levee face and toe, and raising it up in some places. This work is needed to ensure that the existing levee will have adequate structural integrity and flood protection to withstand flood flows as a continuous structure to the setback.
The existing levee will be removed down to the water line. The material will be re-used to build the new setback levee. The removed material will be amended or blended with other material so that is meets specifications for structural embankment material.
Areas of habitat channels will also be dug to help induce river flows into the opened up floodplain area for lower river flow conditions. Large woody debris will also be placed along the setback levee alignment for more habitat features.
