Thursday, April 18, 2024

Cabins at risk of coastal bluff erosion removed at Kalaloch in Olympic National Park

 

Some of the cabins at Kalaloch are (or were) quite close to the edge of the coastal bluff. Photo from 6 July 2023 

Eroding coastal bluffs are hard to manage, especially when valuable assets are perched on their edges. Coastal bluffs are by definition tall, and their erosion can be rapid and forced by a variety of processes, so engineering solutions aren't always easy to devise, and are invariably expensive and difficult to maintain. At Kalaloch in Olympic National Park, two factors recently converged to create particularly dangerous problems.  First, rates of erosion of coastal bluffs in a small area just south of Kalaloch Creek accelerated, and second, the locations where those erosion rates accelerated also happened to be developed. Buildings, in this case valuable rentable cabins at Kalaloch Lodge, were put at increased risk and, as a consequence, in March 2024, five cabins were deemed unsafe and removed.

A similar perspective as in the photo above, with cabins removed.  The former cabin sites are marked with the brown burlap.  Photo from 10 April 2024

I was part of efforts that looked for every opportunity to try to understand that erosion, in the hopes that some cause of erosion might be identified that could illuminate a potential solution. As is often the case, though, the best we can do is use our monitoring data to characterize rates of erosion, and how those rates vary along the shoreline, as I did in this recent recorded talk.


    To me, one of the most interesting things that we've done at Kalaloch is to install five Chronolog stations, which encourage visitors to submit photos from a fixed vantage point, which can then be complied into a time-lapse video. Those stations, and the people that have contributed to them, have created a rich visual record of bluff erosion and the removal of at-risk buildings, and other poorly understood coastal processes (like the loss and recruitment of large wood along the beach). 

A Chronolog station at Kalaloch.