Floodplains
Many floodplains in Puget Sound have been lost through a combination of shoreline armoring, levees and residential, commercial, industrial and agricultural development.
Indicator Lead: Jennifer Burke, Nathalie Hamel, and Alex Mitchell, Puget Sound Partnership
Data last updated on June 27, 2017
Photo Credit: Joe Kunzler

Importance to Puget Sound recovery

Floodplains work like giant sponges. As rains increase with fall storms and snowpack melts in the mountains in spring and early summer, waters in the rivers around Puget Sound rise and flood low-lying land along the rivers and streams. In addition to absorbing this overflow, floodplains provide functions and services like refuge, food, and fresh water for a variety of species, good agricultural land through soil and habitat formation, and flat land that supports a variety of human uses.

Unfortunately, the functions and services in large areas of floodplains in Puget Sound have been lost through a combination of shoreline armoring and levees, as well as residential, commercial, industrial, and agricultural development. Improving riverside and floodplain habitat is a key part of virtually all recovery plans for endangered salmon. Restoration and better management of floodplains are essential for both recovering salmon and Puget Sound.

What you can do

  1. Keep people and property out of flood-prone areas.
  2. Protect floodplain areas that can still provide functions like flood storage and salmon habitat.
  3. Avoid building in a flood-prone area unless you plan to elevate and reinforce your home and its utilities (such as the furnace and electric panel).
  4. Find out how your insurance rates are affected by your risk of flood loss and how these rates can be reduced with good flood management planning.
  5. If you live in a floodplain area, learn about your local floodplain management plan and how to minimize your effect on the floodplain by visiting your city or county website.
  6. If you do not live in floodplain area, follow guidance on what you can do in your back yard by planting and maintaining native vegetation, and increasing water infiltration, in order to reduce water runoff. For more information on native plants, visit the Department of Ecology's website or the Washington Native Plant Society.
  7. If you have concerns about your property, consult the Federal Emergency Management Agency (FEMA), who can help fund qualified activities such as home elevations, relocations, and the acquisition and removal of structures in high-risk areas.

What our partners are doing

View Near Term Actions helping to advance this Vital Sign

Links for more information

USGS Geospatial assessment of ecological functions and flood-related risks on floodplains along major rivers in the Puget Sound basin

USGS floodplain area and function assessment products

Managing Floods and Floodplains in Puget Sound: A Synthesis of Flood Manager and Decision‐maker Interviews and Research

Floodplain Management: A Synthesis of Issues Affecting Recovery of Puget Sound

Coastal Resiliency, the Nature Conservancy