Aerial of the Hyrum Dam spillway replacement project site June, 2025
HYRUM, Utah – Just weeks into construction, the landscape around Hyrum Dam is rapidly changing as a major construction project gets underway to replace the dam’s aging spillway. The $115.9 million effort will improve safety, boost resilience, and ensure reliable water deliveries for years to come.
Located about nine miles southwest of Logan, Utah, Hyrum Dam and Reservoir were built in the 1930s and play a critical role in storing and delivering irrigation water for the surrounding agricultural region. The reservoir fills and spills each year, controlling runoff from a 212-square-mile drainage area.
The new spillway is designed to safely pass high flows and withstand seismic activity—upgrading an original structure that no longer meets modern engineering standards. While construction is underway, the recently enlarged outlet works bypass will help manage runoff.
“This project will help ensure the long-term safety and reliability of Hyrum Dam,” said Reclamation’s Provo Area Office Manager Rick Baxter. “It’s a big step forward in securing the water supply for this region’s future.”
Construction began in May 2025, and is expected to take four years. As part of the work, the road atop Hyrum Dam (W 300 South) is closed and will remain closed until the project is complete. Detours are clearly marked, and Hyrum State Park remains open to visitors.
The project, funded by the South Cache Water Users Association and the federal government, includes:
- 330,000 cubic yards of excavation
- 15,500 cubic yards of concrete
- 5.4 million pounds of reinforcing steel
The South Cache Water Users Association is responsible for operating and maintaining the dam. This construction contract is a result of many years of hard work by Reclamation and project partners.
For more information and updates, visit: https://www.usbr.gov/uc/progact/hyrum/index.html
For photos and video of the project, visit: https://www.flickr.com/photos/usbr/albums/72177720326968518/
