Shoreline Armoring

A functioning, resilient Puget Sound ecosystem is defined to include dynamic shorelines maintained by coastal processes such as shoreline erosion and ecological exchange between terrestrial and aquatic systems. Shorelines are among the most valuable and fragile of our natural resources. More than 25 percent of the shoreline has been armored to protect public and private property, ports and marinas, roads and railways, and other uses. Shoreline armoring, the practice of constructing bulkheads (also known as seawalls) and rock revetments, disrupts the natural process of erosion, which supplies much of the sand and gravel that forms and maintains our beaches and creates habitat for many other species. This Vital Sign tells us how we are doing to protect intact shorelines, to reduce the total amount of shoreline armoring–particularly in those areas along feeder bluffs –and replace armoring with soft-shore techniques, and how much new armoring (whether hard or soft) in our effort to restore the natural processes and function of shorelines.


Key Messages

  •              Seahurst after restoration. H. Shipman
    Some progress has been made to reduce the impact of armor as the removal of armor appears to be increasing and the pace of permitting construction is slowing.
  • The length of armor along Puget Sound shores increased between 2011 and 2015, with a net addition of 1.3 miles (6864 feet). In 2014 and 2015, however, more was removed than added.
  • New armoring continues to be constructed at an average pace of 0.66 miles (3,483 feet) per year (mean of 2011 – 2015), but the pace has slowed since 2012.
  • In contrast, shoreline armoring is removed at an average rate of 0.4 miles (2,105 feet) per year, not enough to balance out new armoring.
  • Feeder bluffs and soft shorelines are getting significant attention, but quantifying their extent remains difficult. Current work is addressing limitations in location data, mapping criteria, and definitions.
  • An emerging Implementation Strategy for shoreline armoring has identified that the greatest near-term opportunities for armoring removal and natural shoreline protection are on residential shorelines, however initiating efforts now on non-residential shorelines is crucial for long-term gains. Public lands continue to provide opportunities to demonstrate successes with removing armor or using soft shore protection methods.

Strategies, Actions, and Effectiveness

Contributing Partners

PSEMP Nearshore Work Group (coordinator is Jason Toft)
Last Updated