Pre-Sol Notice Hyrum Dam Spillway Replacement   5

Background
The United States Bureau of Reclamation, Upper Colorado Basin Region, is issuing a pre-solicitation notice for the Hyrum Dam Spillway Replacement Project. This project aims to replace the existing spillway to enhance safety and operational efficiency. The work will take place approximately 9 miles southwest of Logan, Utah, in Cache County.

Work Details
The project involves the construction of a new spillway and the removal of the existing spillway. Key tasks include:

- Removal and control of water;
- Construction of a new reinforced concrete spillway;
- Creation of a riprap outlet channel and inlet area;
- Installation of associated mechanical and electrical features;
- Development of drainage systems;
- Construction of foundation aggregate piers;
- Building a roadway bridge;
- Installation of gate hoist structures and equipment;
- Installation of radial gates;
- Construction of an embankment dike;
- Installation of new inverted siphons for irrigation canals;
- Development of an administrative access road and drainage;
- Roadway realignment;
- Excavation and removal of the existing spillway structure.

Principal components include:

- Constructing a new spillway,
- New gates and hoists,
- New hoist enclosure,
- New spillway chute and stilling basin,
- Embankment dike,
- Dewatering system,
- Rammed aggregate pier foundation treatment,
- Two new siphons,
- New precast concrete beam bridge,
- County road realignment construction,
- Re-grading reservoir rim between the spillway and dam,
- Rerouting two access roads,
- Mechanical and electrical equipment installation,
- Demolition of existing spillway, and
- Construction of cofferdams.

Period of Performance
The anticipated performance period is from March 2025 through January 2028.

Place of Performance
The construction projects will be performed approximately 9 miles southwest of Logan, Utah in Cache County.