Mud Mountain Dam Steel Liner Repair   5

Background
The U.S. Army Corps of Engineers (USACE), Northwestern Division (NWD), Seattle District (NWS) is undertaking a project to repair the Steel Liner at Mud Mountain Dam, which was authorized as part of the Flood Control Act of 1936 and constructed in the 1940s.

The dam is located on the White River in Enumclaw, Washington, and plays a critical role in flood control for the densely populated Tacoma metropolitan area. The existing steel lining of the 9-Foot Tunnel has suffered significant erosion over the past decade due to bed load damage, necessitating this repair to ensure continued operational stability and safety of the dam.

Work Details
The contractor will be responsible for repairing the steel liner of the 9-Foot Tunnel at Mud Mountain Dam. Key tasks include:
- Restoration of the steel liner from the bellmouth to the steel transition ramp.
- Addressing erosion damage that has led to holes and thinning in the existing steel liner plates.
- Implementing environmental protection measures during construction, including sediment removal (minimum of 25 cubic yards), dust control, and spill prevention protocols.
- Conducting a preconstruction survey to document existing conditions and protect environmental features.
- Compliance with federal, state, and local environmental regulations throughout construction activities.

Place of Performance
Mud Mountain Dam, Enumclaw, Washington.