Monday, October 15, 2012

Dune restoration: changing the world plant by plant

I had the opportunity to work on a dune restoration project on the Olympic Peninsula in Washington last week. We were working out of Sequim (pronounced ‘Squim’), which is known affectionately as “the blue hole,” because it gets only about half the rainfall of other towns on the peninsula (and approximately the same as L.A., for any Angelenos looking to relocate northwards). The goal of the project was to build/restore a natural bluff along a beach where houses had suffered considerable storm damage in 2006. The houses are built between a long beach and a large wetland, and are thus a classic case of buildings that are not “supposed” to be there. However, given that they are, we were working on helping implement the best option for mitigating winter storms that are continually eroding the beach and causing flooding up over the houses’ decks.

Initially, when the landowners approached Dave (of Shreffler Environmental, the company working on the project), they proposed building a large rock seawall to fend off storms. This is an interesting, and common, case of misguided decision-making in the continual battle between coastal houses and the ever-present, ever-hungry ocean. Namely, the feeling that big (non-porous) walls will protect us better than what nature had there in the first place (i.e. a bluff or wetland). Luckily, the landowners were both amenable to hearing alternatives to the seawall, and also clearly possessed impressive collaborative skills – it’s not often you get 13 landowners to all agree on a land-use plan, and then cooperatively implement it! The idea behind the bluff restoration is that by providing a natural vegetative barrier, the plants will absorb a lot of the water. Imagine a hillside of grass versus a hillside of pavement –water will run off a non-porous surface like pavement much more quickly. The difference is similar with the bluff of dune grass versus a seawall; incidentally, this is one of the many reasons that channelizing rivers is also undesirable (i.e. increased flash flooding potential).

The bluff had already been engineered and built back in 2006, by carting in large amounts of sand and gravel, and pouring it over a bunch of large logs and driftwood anchored together with chain to form a solid base. This formed an ~8ft bluff, on which they planted dune grass. Our goal was to replant dune grass where there was localized erosion. Overall, the dune has held up remarkably well since 2006, with only minor erosion, and no breaches or flooding of the houses.

Canada hiding behind the clouds
Bluff on left, stretching down the beach
The beach we worked on was out on a beautiful spit of land, with views of the Olympic mountains behind us, and the Canadian mountains (and snow-capped Mount Baker) across the bay. We spent three peaceful days on our hands and knees, scooping up sand and plopping the small plants into the holes, stopping occasionally to watch a heron, bald eagle, Northern Harrier, flock of migrating Canada geese, or lone fisherman towing a gill net. We had hopes of talking one of them out of a Coho, but unfortunately they always drifted by before they had caught any. As Dave said, “it’s hard to talk a guy out of a fish when he doesn’t have any.” The Coho are almost all hatchery spawned, from the nearby Dungeness river. And I can confirm that they are indeed delicious.

In the end, we planted around 1000 plants. It was inspiring to participate in a hands-on project with such direct restoration application. Since I’ve recently spent most days staring at fish data on my computer, with the goal of contributing to river restoration practice through more indirect routes, it was nice to actually get out there and dig in the dirt, restoring the beach plant by plant.  

Freshly planted dune grass!
American Gothic (nouveau version)

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