The project consists of modifications to the Madison Dam embankments, principal spillway, and outlet works; and all other related work as indicated and specified. Major components of the Work include: 3.1.1.1. Mobilizing to site. 3.1.1.2. Construction of temporary erosion control measures and access roads. 3.1.1.3. Decommissioning the existing low-level outlet, and construction of a filter/drainage system to capture concentrated seepage in the existing gate house and convey the flow to the relocated gate house farther downslope. 3.1.1.4. Construction of a new low-level outlet system consisting of 4 siphon pipes, an upper valve house, lower valve house, and energy dissipation system. 3.1.1.5. Rehabilitating both downstream dam embankments, consisting of installation of drainage systems, raising of the dam crest to EL 1218 Feet, and regrading of slopes with soil buttressing embankment fill. 3.1.1.6. Buttressing of the upstream slope of the right and left embankment with rockfill (rip rap). 3.1.1.7. Constructing a saddle dike at the right abutment to EL 1218 Feet. 3.1.1.8. Demolishing the existing principal spillway and replacing with a labyrinth spillway, chute, and stilling basin. 3.1.1.9. Restoring the project site and demobilizing from the project site.
