Gifford Pinchot National Forest; Washington; Spirit Lake Outflow Safety Improvement Project

摘要

The USDA Forest Service is preparing an environmental impact statement for the Spirit Lake Outflow Safety Improvement Project (Project). Spirit Lake is within the Mount St. Helens National Volcanic Monument within the Gifford Pinchot National Forest, about 52 miles northeast of Portland, Oregon. The purpose of the Project is to provide for the safety of downstream communities by reducing the risk of flooding and mudflows from a failure of the Spirit Lake debris blockage. The Spirit Lake tunnel is at risk of failure due to its construction under emergency conditions and location in an area of volcanic, geologic, hydrologic, and seismic hazards. Downstream communities of nearly 50,000 people are at risk of catastrophic mudflow and flooding following a full lake breach. The Planning, Appeals, and Litigation System identification number for the Project is 66482.