What science tells us/What we know:
1. High bluffs are complex, unique nearshore systems
The feed rate of sediment from feeder bluffs is very complex. Feed volume, rate, and composition, varies by season and year.
2. These high bluff features are fundamentally erosional-this process is unstoppable.
3. Their management is also unique. Including:
What to do?
First and foremost: Undeveloped bluff properties should be conserved.
For properties that are developed:
New homes should be sited at least 200 feet back from the top of the bluff edge (providing approximately 100+ years of time until erosion becomes an issue). Erosion rates are too variable and development actions have too much interaction with bluff dynamics to develop closer with any certainty.
Native long lived vegetation provides important bluff edge stabilization that cleared edges and mowed lawns do not. Native vegetation should absolutely not be cleared from the bluff edge and face. Trees should not be topped, and yard waste should absolutely not be side cast onto/over bluff edges.
Careful consideration should be given to storm water and septic systems as additional water storage and runoff often exacerbates bluff erosion. If these cannot be managed to completely avoid increased interaction with the bluff system the site should not be developed.
While often offered as a popular engineering tool, armoring of high bluffs is expensive and the science is clear: armoring of high bluffs doesn’t stop erosion but instead increases it. Armoring just won’t solve the problem and leads to intractable and additional landowner costs as well as devastating effects to fish and wildlife. Look to the Elwha drift cell to understand that armoring is expensive, does not solve the problem and results in more armoring.
What can we do? Educate, and work together.
Link to average erosion rates by parcel along Dungeness and Elwha drift cell: http://www.arcgis.com/home/webmap/viewer.html?webmap=89f3c6777a554d01808d26b9b5856cc5&extent=-123.6961,47.9973,-123.0273,48.2599
The Last Beach; https://www.dukeupress.edu/The-Last-Beach/
Thanks to LightHawk for assistance with aerial imagery