Dam Safety Incident Report: Benson Creek Flood

On the evening of Thursday, August 21, 2014, the fire-swept Benson Creek watershed received from 0.4 to 0.9 inches of rain in a one-hour period. There were high runoff flows and numerous mudslides throughout the watershed. By the next day, State Highway 153 was closed 6 miles south of Twisp, and three of the five Wenner Lakes in Finley Canyon were empty. Fortunately, there were no fatalities, injuries or missing persons from this flooding.

On Friday, August 22nd and through the weekend, diligent efforts by dam owners, local contractors, and county, state and federal officials re-opened the spillways for the remaining two dams. The last of the runoff flows receded without further incident.

Photos and maps of the area are included at the end of this report.