Cowlitz County participates in the Federal Flood Insurance Study (FIS) program.

The federal government, through the Federal Emergency Management Agency (FEMA), oversees management of floodplains. Local governments have the authority to enforce the rules. FEMA conducts studies of rivers and streams throughout the United States or insurance and regulatory purposes.  The maps are called Federal Insurance Rates Maps (FIRMS) and are used by both the insurance industry and local governments to identify areas within floodplains. Cowlitz County has 41 FIRMS to cover all of its unincorporated areas. Each city within the County has its own set of FIRMS and its own responsibility for implementing floodplain rules.

FIRMS depict rivers and their adjacent areas that have a one percent chance of being flooded in any given year. However, this flood event, called the base flood, or, more commonly, the 100 year flood, has occurred in Cowlitz County twice in the last decade.

Development may be allowed in 100-year floodplains provided it can meet development standards identified within the Floodplain Management Chapter CCC 16.25 and the County's Building Code Chapter 16.05. An Elevation Certificate is required for all development within the floodplain. Elevation certificates must be completed by a land surveyor licensed in the State of Washington, and submitted to Cowlitz County during each appropriate phase of development. The elevation certificate shall record the elevation of:

     a. Lowest adjacent grade of the development site prior to development;
     b. The lowest floor, at under floor inspection; and
     c. Final as-built construction elevations.

CLICK here to view a flood video from winter 2009 (takes a few minutes to load).