Hyrum Dam and Reservoir are located on the Little Bear River just south of Hyrum City, Utah.
HYRUM, Utah - The road atop Hyrum Dam, W 300 South, will be closed starting June 2, 2025, while crews construct a new spillway before demolishing the existing one. The road will remain closed to all traffic until construction is completed, which is anticipated to take 3 to 4 years. Road detours will be clearly marked. Hyrum State Park will remain open and can be accessed from S 400 West in Hyrum.
“We appreciate the public’s patience and understanding during this project that is needed to keep the reservoir and spillway in good working order and to ensure reliable water deliveries,” said Rick Baxter, Provo Area Office Manager for the U.S. Bureau of Reclamation.
It is not anticipated that reservoir levels will be negatively impacted by this work. The spillway at Hyrum Dam is nearly 90 years old and is used every year to release excess water downstream. Though the spillway has been regularly maintained, it is in need of replacement. When spillway releases reached high volumes in recent years, Reclamation performed around-the-clock monitoring to assess risks of spillway failure and staged heavy equipment and riprap material nearby in case immediate action was needed.
In March, Reclamation announced the $115.9 million contract award to AMES Federal Contracting Group for the construction of the new spillway.
Hyrum Dam was built on the Little Bear River in northern Utah in 1935 and impounds Hyrum Reservoir, which provides water storage for irrigation and municipal use. Hyrum Dam is owned by Reclamation and is operated and maintained by the South Cache Water Users Association.
For more information about the road closure or project construction, please contact ucbpao@usbr.gov.
