2023 LANDSLIDE RESPONSE EFFORTS OF THE VERMONT GEOLOGICAL SURVEY

On July 12, 2023 the Vermont Geological Survey (VGS) notified State leadership that heavy rainfall from an intense storm on July 9-11, 2023 may cause some slope areas to become unstable, and then prepared a press release on July 14, 2023 alerting the public of the same. During the ~two months that followed, the VGS and partners performed over 80 landslide evaluations along a north-south corridor on the eastern flank of the Green Mountains. The landslides and the hazards they presented varied significantly, and our timely response required effective coordination at all levels including leveraging existing partnerships and forging new ones to bring the proper expertise in service to Vermonters.

Timely and effective characterization and communication of hazards required close coordination between the VGS and academic, municipal, state, and federal partners. The VGS requested structural engineering support from the Urban Search and Rescue Team and geotechnical support from the Vermont Agency of Transportation, the Vermont Department of Public Safety, from academic partners, and from the Pennsylvania Department of Transportation through an Emergency Management Assistance Compact request. We additionally requested drone-based imagery and elevation data from the Spatial Analysis Lab at the University of Vermont. Requests for site visits were coordinated through the State Emergency Operation Center, and briefings were provided to State leadership including the Governor and the Senate Committee on Natural Resources and Energy.

Naturally, a number of questions arose during and after our active response. Affected landowners seek resources for mitigation or buy-outs; neighborhoods and towns are asking for more detailed assessment of hazards associated with their geomorphic positions; State leadership would like to understand the greater distribution of landslide susceptibility for both regional and state-wide hazard mitigation planning. With a greater frequency of intense storms projected for New England due to a changing climate, the VGS and our partners anticipate continued involvement with slope instability issues and seek to institutionalize the partnerships and procedures established this summer to be better positioned to answer questions such as these during future response efforts.