2 minute read
Building Habitat with High Flows
Our Madison River Flushing Flow Program helps improve spawning habitat for fish.
At the end of May, flows on the Madison River were higher than normal.
This was due to NorthWestern Energy increasing the volume of water released from Hebgen Dam. When snowpack allows, NorthWestern Energy implements our Madison River Flushing Flow Program. The program is designed to augment natural river flows with surplus water.
The goal of sending the extra water down the river is to flush fine sediments from Madison River gravel to enhance the quality of spawning gravels that support the healthy wild trout fishery.
High spring runoff flows, which the flushing mimic, are a natural occurrence in undammed rivers. These high flows help create spawning habitat for fish by clearing out fine particles from the river bottom where fish spawn. It also helps distribute food for fish and improves the quality of the river’s insect community.
While the water was at its peak, NorthWestern Energy conducted a drone flight to capture aerial footage of the river at high water. This allowed us to see how wide the river channel expanded. When a river channel reaches its floodplain, it has the opportunity to deposit fine sediment onto gravel bars and streambanks, which helps provide fresh soil for new cottonwood and willow seedlings to grow.
The 2023 flushing release from Hebgen Dam is a cooperative effort planned by NorthWestern Energy; Montana Fish, Wildlife & Parks; Montana Department of Environmental Quality; the U.S. Bureau of Land Management; the U.S. Fish and Wildlife Service; and the U.S. Forest Service.
