Tag Archives: Marine conservation

Seawalls along Sensitive Coasts: What is Shoreline Armoring?

Earlier this summer, three conservation groups in Washington State joined together to launch a legal battle in an attempt to change how a federal agency regulates the construction of seawalls, bulkheads and other coastal barriers. Having spent about ten years living in Seattle, I wanted to learn more about the impact that such seawalls could have on the environment, and the legal reasoning behind this recent campaign.

Environmental Issue:  “Shoreline armoring” is the practice of modifying marine shorelines with rocks or other materials. By building these armoring structures to hold back the sea and prevent the loss of sediment, coastal land is stabilised and both residential and commercial infrastructures are protected. While this practice can help to prevent erosion, conservation groups claim that it’s destroying Puget Sound habitat.

coastal armoring, marine, conservation, Whidbey Island, Washington, Beach

An example of coastal armoring on Whidbey Island, WA.

Rock and concrete walls have already been erected along about one-quarter of Puget Sound’s 2,500 miles of shorelines, with more than 1 mile of armor being added each year. By altering the geologic processes that build and maintain beaches, bulkheads and other types of sea walls impact erosion patterns and hydrology, and reduce the availability of large wood. Over time, these barriers diminish the availability and condition of key shoreline habitats, turning sandy beaches into rocky areas that aren’t welcoming to forage fish and other species.

Legal Argument:   The Clean Water Act provides federal protection for marine environments up to the true high tide line. It also mandates that a permit be obtained from The U.S. Army Corps of Engineers (CoE) for any construction in, over or under  regulated waters.

However, most of the sea barriers in Puget Sound have been constructed without CoE permits – because the CoE asserts that its jurisdiction only goes to the “mean” high water line. As such, these projects are never reviewed by federal fisheries biologists to determine whether they harm species – such as orca whales and Chinook salmon – which are protected by the Endangered Species Act.

Across many shorelines, the difference between the tides – as illustrated above – can be several feet of tidal elevation. On a gently sloping beach, this could mean that there are huge areas of intertidal habitat which should be regulated and protected under the law, but are not.

This discrepancy has prompted Sound Action, Friends of the San Juans, and Washington Environmental Council – with legal representation by EarthJustice – to petition the CoE to revise its jurisdiction. Hopefully, doing so will result in better environmental and wildlife protection for the Puget Sound.

Further Reading