Public can comment volcano monitoring system expansion

The public can comment on a proposal to expand the volcano monitoring system in Mount Rainier National Park.

The U.S. Geological Survey, Cascades Volcano Observatory has requested a permit to expand the existing volcano monitoring system inside Mount Rainier National Park. The proposal included 17 new site locations in the park as part of a broader effort to implement a Lahar Detection System for Mount Rainier and to expand the existing volcano monitoring system.

The goal of the USGS Lahar Detection System proposal is to mitigate human risk by reducing the amount of time it takes for an alert to be sent out to potentially affected populations and communities after a lahar has been generated, according to the National Park Service. The proposal would also increase the number of total drainage areas covered by the alert system to include the Tahoma Creek and the Nisqually River drainages, which along with the Puyallup River valley, are vulnerable to future landslide-caused lahars from Mount Rainier.                                          

The expanded monitoring system would also improve detection capabilities for smaller debris flow events, particularly along Tahoma Creek, which has experienced multiple debris flows since the late 1980s. Five of the proposed monitoring sites were approved and installed in 2020 within developed areas of the park, bringing the total number of existing sites within the park to 15.

Of the 12 remaining proposed monitoring sites, several are within the designated boundaries of the Mount Rainier Wilderness. These lands are managed pursuant to the 1964 Wilderness Act, which normally prohibits permanent installations. Sites proposed also include areas within or adjacent to the Mount Rainier National Historic Landmark District (NHLD).

The Lahar Detection and Volcano Monitoring System Expansion Environmental Assessment was prepared to analyze the USGS proposed action and alternatives, and to facilitate public review and comment.

The EA evaluates four alternatives:
Alternative 1: The USGS Proposed Action, would add twelve new monitoring stations within Mount Rainier National Park.
Alternative 2: No Action, would not authorize new stations with the park, although existing stations would be maintained within the park.
Alternative 3: Would modify the USGS proposed action to avoid most adverse effects to historic structures within the Mount Rainier National Historic Landmark District (NHLD) by relocating five of the proposed monitoring stations from the NHLD to currently undeveloped areas within the Mount Rainier Wilderness.
Alternative 4: (NPS Preferred Alternative) would modify the USGS proposed action to reduce the number of new installations within designated wilderness and reduce adverse effects on historic structures in the NHLD. This alternative would approve nine of the proposed 12 monitoring sites.
The public is invited to offer comments through 11:59 p.m. June 25 at https://parkplanning.nps.gov/commentForm.cfm?documentID=112776.