Floods
Of all natural hazards that affect Thurston County, floods are the most common and, on an annual average basis, the costliest. They can occur at any time of the year, and at any time of day or night, especially during the winter months. Most injuries and deaths occur when people are swept away by flood currents, and most property damage results from inundation by sediment-filled water.
Flooding can be caused by several days of prolonged rainfall, a rapidly melting snowpack, dam or levee failure, or a combination of these conditions. Four principal sources of flooding impact Thurston County: river and stream, groundwater, tidal and urban flooding. Each source of flooding can happen independently or simultaneously with each other during a single weather event.
In Thurston County, the five river systems most susceptible to significant flooding are the Nisqually, Chehalis, Deschutes, Skookumchuck, and Black rivers. Many of our county’s lakes and other drainages are also susceptible to flooding as well.
Thurston County Flood Bulletin
River Flood Monitoring
Prepare your property for flooding with sandbags
The use of sandbags is a centuries old, tried, and true method for mitigating flood impacts. For more information and procedures on submitting requests for sandbags, visit our sandbagging information page.
Do you live in a Flood Hazard Zone? Learn more about the National Flood Insurance Program (NFIP) and Flood Insurance Rate Maps (FIRM)
The National Flood Insurance Program (NFIP) is a program managed by FEMA that provides flood insurance to property owners, renters and businesses located within designated Flood Hazard Zones. FEMA routinely partners with local officials to conduct flood risk map studies to develop and maintain Flood Insurance Rate Maps (FIRM) to assist communities with flood hazard preparedness.
You can visit FEMA’s Flood Map Service Center for access to public flood hazard information produced in support of the National Flood Insurance Program. You can also visit FEMA’s Flood Insurance website for more information on the NFIP and resources on obtaining flood insurance.
Questions about land use and development regulations in flood hazard zones? Visit our experts at Community Planning and Economic Development
Thurston County’s Community Planning and Economic Development manages the implementation of development standards and restrictions on building in flood hazard areas. For more innovation on land use, permitting and elevations of homes within the flood hazard zone, visit their page on Development Regulations in Flood Areas.