Y--Herbert Hoover Dike Rehabilitation Structure Replacements, S-271 (C10-A) Reconstruction, Palm Beach County, Florida

The work includes demolition and removal of the existing Herbert Hoover Dike Culvert 10A and the construction of a new outlet works S-271 at the same location of the existing Culvert 10A. The demolition and reconstruction efforts will be performed in the dry requiring the installation of an earthen cofferdam within Lake Okeechobee and a steel sheet pile (SSP) cofferdam on the landside at the L-8 canal in order to dewater the construction site. To maintain flows between Lake Okeechobee and the L-8 canal, a steel sheet pile canal will be constructed to divert flow from the L-8 canal to a three barrel bypass culvert. The bypass culvert will be constructed with 10-foot diameter HDPE pipe and will be operated during the construction of the new outlet works. The bypass culvert with have a sheet pile headwall on the landside and steel pile supported gates on the lakeside. The new outlet works structure will include cast-in-place reinforced concrete headwalls (lakeside and landside), conduit and endwalls. Combination flap/slide gates will be installed in each bay of the lakeside headwall. The outlet works will consist of four (4) barrels that vary in geometry from 10-foot square at the headwalls to 7-foot high by 13.5-foot wide rectangles through the embankment. The reconstructed embankment will feature a cutoff wall, an impervious core, a vertical chimney drain, and a horizontal drain and filter. The reconstructed embankment will match the existing crest elevation of the dike at the site. Riprap will be installed along the lakeside embankment face for erosion protection. A steel sheet pile groin structure will be installed on the lakeside to reduce sedimentation in the entrance canal. A control building will be installed on the landside work platform. Work also includes the demolition and removal of two existing residential structures at the project site and clearing an electrical corridor.