Washington Marine Shoreline Design Guidelines – Climate Change and Sea Level Rise Considerations

Prepared for the Washington State Aquatic Habitat Guidelines Program, the purpose of these guidelines is to promote responsible management of Puget Sound shores, preserve natural resources and coastal ecological processes, and increase resilience of the shoreline. These guidelines are intended to give the coastal designer an overview of all of the necessary elements to inform the development of project goals and the tools to design appropriate and environmentally responsible projects for marine shores in Puget Sound.

The guidelines provide a framework for assessing shoreline sites and coastal processes to inform project design, with an emphasis on utilizing coastal restoration alternatives to hard armoring.  The report contains background information on the geology of Puget Sound and the impacts of shoreline armoring; information on conducting site assessments, coastal processes assessments, and alternatives analysis; details on several shoreline design techniques; and guidelines for monitoring the effectiveness of the techniques utilized.

Design guidance was developed from the results of an in depth case study assessment in which design details, project performance, benefits and impacts, as well as site and local conditions were documented from 25 on-the-ground projects in the Puget Sound region. Appendix A provides the results of the case study assessment of the 25 existing erosion control projects. 

The coastal processes assessment helps determine the causes of erosion at the site, and is used together with the site assessment to perform the alternatives analysis and identify the most appropriate management technique that best matches natural conditions and results in the fewest impacts to the environment.

The coastal processes assessment includes a section to evaluate how the site will respond to sea level rise and other climate change impacts. The “Climate Change and Sea Level Rise” section describes different shore types and their anticipated responses to and impacts from sea level rise and climate change, such as increased erosion and storm damage to barrier beaches. It also describes the impacts of sea level rise and climate change on near-shore processes, such as more variable freshwater input. Additionally, the section details other variables that are relevant to maintaining resilience of shorelines to sea level rise, such as upland topography and geology and the presence of armoring and other modifications at nearby shorelines.

Sea level rise and climate change impacts are also considered in the sections of the guidelines detailing the alternative techniques available for shoreline design, including passive management, beach nourishment, bulkhead removal, and other techniques.

The Washington Aquatic Habitat Guidelines Program is a joint effort among state agencies including the departments of Fish and Wildlife, Ecology, Transportation, and Natural Resources, the Recreation and Conservation Office, and the Puget Sound Partnership. The program, which seeks to protect and restore marine, freshwater, and riparian ecosystems through responsible management, has developed other guidance documents including the 'Stream Habitat Restoration Guidelines' that were revised in 2012 (see separate resource entry in this Clearinghouse for more detail).

Publication Date: March 2014

Authors or Affiliated Users:

  • J. Johannessen
  • A. MacLennan
  • A. Blue
  • J. Waggoner
  • S. Williams
  • W. Gerstel
  • R. Barnard
  • R. Carman
  • H. Shipman

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Resource Types:

  • Best practice
  • Policy analysis/recommendations

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