Land & Resources Management

Toutle River System

Mount St. Helen’s 1980 eruption triggered an enormous debris avalanche that deposited more than 3 billion cubic yards of sediment into the Toutle River basin. In the ensuing three decades, only a small portion of the sediment has migrated downstream.

1980 eruption materials are highly erodible- cutting away the banks of the Toutle River.In 2017, the National Academies of Science, Engineering and Medicine (NASEM) issued a consensus study report on Spirit Lake and the Toutle River system. They determined a long term management solution was needed to better address current and future risks associated with the outflow. NASEM identified the need to include broader participation by communities and citizens whose safety, livelihood, and quality of life are affected by the decisions made at Spirit Lake and within the river system.

The report stated, “While the post-1980 eruption efforts addressed flood mitigation and related sediment control options, these individual solutions to system-wide problems were considered separately, and rarely in consideration of other issues. System wide thinking is needed in making decisions about management objectives, approaches, and alternatives.”

Gifford Pinchot National Forest managers engaged the William D. Ruckelshaus Center to assess interest in participation in a river system consortium. The Ruckelshaus Center conducted a situation assessment consisting of a series of interviews with a range of involved parties to understand interests, challenges, and opportunities.

The Forest Service continues to be committed to working with diverse stakeholders across the Toutle River Watershed to create collaborative solutions for long term management to benefit public safety, ecological health, economic vitality and scientific integrity of this unique region.