State Breaches Dam to Prevent Creek Contamination

By Beacon Staff

BUTTE – The state breached a section of the Silver Bow Creek dam west of Butte to reduce the possibility of a blowout that could spread mine waste down a section of the creek already cleaned up through the Superfund Program.

The Montana Department of Environmental Quality approved Tuesday’s work as the creek’s water flows neared 800 cubic feet per second, more than double recent years’ peak flows of 300 cfs.

The Montana Standard reports Jordan Contracting of Butte used an excavator to breach a 150-foot wide section of the rock dam to relieve pressure, prevent a washout and keep the trapped sediments in place. The work was estimated to cost $10,000.

The dam and the contaminants it traps will be removed in the coming years as part of the creek cleanup.