Flooding in Issaquah

Most locations along major City streams are classified as "Areas of Special Flood Hazard," which is another name for the 100-year floodplain. Development in these areas is allowed, but heavily regulated to meet floodplain standards to ensure structures are properly designed to withstand flooding, and development activities do not impact neighboring properties.

However, even with proper planning and building design, flooding is a natural hazard that creates risks to residents and businesses.


Learn how to be prepared for flood emergencies.

City Efforts

Examples of the City's projects to improve flood conditions include:

  • Purchasing open space along streams to prevent future development within high-risk areas (26 percent of the floodplain is in protected open space).
  • Acquiring properties and removing structures that have experienced repetitive losses.
  • Completing flood conveyance improvement projects, including 10 bridge replacements since 1995.
  • Providing assistance to homeowners to elevate their homes (using FEMA flood hazard mitigation grants).
  • Providing extensive outreach to floodplain residents and building owners, using the Community Emergency Response Team and Map Your Neighborhood programs, along with flood warning systems and response actions.
  • Participating in the National Flood Insurance Program.
  • To learn more, view the City's annual Floodplain Progress Report (PDF).