Buildings that are located within a floodplain must be built to an elevation that is higher than the floodplain elevation. Elevation of the building must be documented on a Floodplain Elevation Certificate. Floodplain elevation certificates must be prepared by a licensed surveyor. Information about Floodplain Elevation Certificates can be found in Pierce County Code
Section 18E.70.A.2 of Title 18E - Development Regulations- Critical Areas.