Close to 30% of Puget Sound's shoreline is armored with seawalls and other structures meant to protect beaches against rising tides and erosion. But science increasingly shows that these structures are ineffective and cause significant harm to salmon and other creatures. State and federal agencies have been encouraging private property owners to remove armoring in a race to improve habitat, but why did so much of it start appearing in the first place?
The Elwha River has become famous as the site of the largest dam removal project in U.S. history. Several years ago, scientists began knocking down another barrier about a mile away from the river's delta. They removed a large seawall along the Salish Sea shoreline and discovered that sediment from the dam removal had huge benefits for their project.
Design innovations at the new seawall along Seattle's waterfront could inspire improvements for other shoreline structures around Puget Sound. They may even encourage broader regulatory changes that enhance habitat for migrating salmon and other species.
Climate change could cause sea levels to rise more than four feet in some parts of Puget Sound, leaving shoreline residents with some tough decisions. Experts say fighting the waves with conventional seawalls may not be the answer.
The average worldwide sea level has increased more over the past 150 years than during the previous 1,500 years, experts say, and the seas continue to rise at an ever-increasing pace.
Planning for rising seawater in Puget Sound has often focused on public property such as roads, buildings and utilities. Now local governments are looking more closely at private property despite regulations based on traditional flooding history.
Bulkhead removal is becoming an attractive option for many shoreline property owners as awareness spreads of their geological and ecological impacts, and as aging bulkheads come up for replacement. New state guidelines provide alternatives to hard armor.
For more than a hundred years, property owners have seen shoreline erosion as the enemy. But it turns out that in many cases erosion is actually a good thing — crucial, according to scientists — because it provides the sand and gravel needed for healthy beaches.
