Last month, landslide hazard geologists from the DNR Division of Geology and Earth Resources (DGER) attended a landslide conference hosted by the U.S. Geologic Survey (USGS) and Indonesian Center for Volcanic and Geologic Hazard Mapping at the Cascades Volcano Observatory in Vancouver, Washington. To promote greater cooperation among state and federal agencies, and reduce potential landslide losses, the USGS also invited landslide geologists from the Oregon Department of Geology and Mineral Resources and our program.
After two days of workshops discussing programs and projects, we went on two field trips; the first day we traveled to the Bonneville landslide in the Columbia River Gorge and the Eliot debris flow off of Mount Hood. The next day those of us at the conference from DGER led attendees on a field trip to the Aldercrest-Banyon landslide. Aldercrest-Banyon (a neighborhood in Kelso, Washington) experienced a large, slow-moving landslide in 1998 that eventually damaged or destroyed 138 homes.
We had the honor of meeting Don Matheson, a former planner for the city of Kelso, who lost his home to the landslide. Mr. Matheson showed us around the now-abandoned neighborhood to view the slide’s headscarp and damage firsthand. He stressed the importance of clear communication between planners and geologists so that the planners have a full understanding of the methods and protocols geologists use to map hazards.
We also met with Dr. Scott Burns, a Portland State University geology professor with an extensive background in landslides, who participated in the investigation of the Aldercrest-Banyon landslide. Dr. Burns shared his photos and maps of the site, and showed us some of the features of the massive slide.
The Aldercrest-Banyon landslide affected many people, and forever changed the community of Kelso. Many in the neighborhood saw their homes become worthless because insurance plans did not cover landslides. While several homes still stand adjacent to the landslide, the many lots where homes were removed have been transformed by the remaining neighbors into a park-like setting.
Our goal as landslide hazard geologists is to help towns and cities make better planning decisions so that similar events do not happen again. Meeting regularly with other organizations that perform similar research helps ensure that we can all stay at the top of the current technology, understanding, and methodologies used to help others make critical land-use decisions.
More information about the Aldercrest-Banyon landslide can be found in the DGER 2004 field trip guide:
Wegmann, Karl W., compiler, 2004, Geologic field trip to the Aldercrest-Banyon landslide and Mount St. Helens, Washington, Part 1–Stevenson to Castle Rock: Washington Division of Geology and Earth Resources, 24 p.