NorthWestern Energy will release water from Hebgen Dam to flush fine sediments from Madison River gravel to maintain the quality of spawning gravels that support the healthy wild trout fishery.
The Madison River Flushing Flow Program was designed during U.S. Federal Energy Regulatory Commission licensing to augment natural flows with surplus water in good snowpack years. The 2020 flushing release from Hebgen Dam is a cooperative effort planned by NorthWestern Energy, Montana Fish, Wildlife & Parks, and the U.S. Forest Service.
Hebgen Dam outflows will be gradually increased to maximize releases for a minimum of three days coinciding with peak runoff in the West Fork Madison River and other tributary streams. To protect the outlet of Quake Lake from erosion, the Madison River flows will be maintained at about 3,500 cubic feet per second at the Kirby Ranch stream gage.
The flow releases should increase in early June with the exact timing based upon weather and snowmelt runoff.