Swift Creek Upper Reservoir Gate Failure

Posted: July 13, 2026

Afton, Wyoming — Lower Valley Energy personnel are responding to a failure involving the sluice gate at the Swift Creek Upper Reservoir. The failure is believed to have occurred during the early morning hours of Monday, July 13, 2026.

The damaged gate resulted in an uncontrolled release of water from the upper reservoir, substantially draining the reservoir. The rapid release also carried sediment, trees and other debris downstream. Sediment has accumulated in the reservoir over many years, including material deposited following the 2023 landslide upstream of the dam.

Lower Valley Energy personnel are on site assessing the condition of the dam and associated facilities. Crews are working to stabilize the situation and determine how emergency repairs can be safely completed on the damaged gate.

For their safety, members of the public should avoid the upper reservoir, Swift Creek and surrounding areas. Water flows, creek banks, accumulated debris and exposed reservoir areas may be unstable and hazardous. The public should not enter the reservoir bed or approach active work areas.
Lower Valley Energy is continuing to evaluate the incident and coordinate the response.

Additional information will be shared as it becomes available.