If City residents are interested to know whether their property is located in a floodplain the City's Community Development Department as well as Lewis County maintains copies of the Flood Insurance Rate Maps (FIRM). FIRMs of Centralia are maps of floodplains and are used to determine whether properties located in the floodplains will be required to carry flood insurance.
FIRMs are used to apply the City's land-use regulations that apply to floodplains. The FIRMs were mapped about 20 years ago using the data that was available at the time. The Federal Emergency Management Agency (FEMA) provides FIRM maps on their website: