Flood Insurance Rate Maps and Flood Insurance Studies

Floodplain maps (see supporting documents) are the basis for implementing floodplain regulations and for delineating flood insurance purchase requirements. A flood insurance rate map (FIRM) is the official map produced by the Federal Emergency Management Agency (FEMA), which delineates special flood hazard areas or floodplains where National Flood Insurance Program regulations apply. The maps are also used by insurance agents and mortgage lenders to determine if flood insurance is required and what insurance rates should apply.

The City of Scappoose uses the FIRM to advise prospective homeowners of flood hazards; to locate zoning boundaries that separate developable land from open space; to make decisions for new development in floodplains; and to administer the terms of the NFIP during the issuance of building permits. The City received new digitized FIRM maps from FEMA in 2010.

For mapped floodplain areas, the flood hazard data included in the flood insurance study (FIS) allow quantitative calculation of the frequency and severity of flooding for any property within the floodplain. Such calculations are very important for mitigation planning because they allow the level of flood risk for any structure to be evaluated quantitatively.

Standard hydrologic and hydraulic study methods were used to determine the flood hazard data contained in the FIS. Flood events of a magnitude expected to occur once on average every 10-, 50-, 100-, and 500-year period were studied for each of Scappoose's rivers and creeks.

Flood Insurance Study 
Information on FEMA's flood insurance study for Columbia County can be found here: https://www.scappoose.gov/sites/default/files/fileattachments/planning/page/7541/columbia_co_flood_insurance_study.pdf

Floodplain Mapping 
The current effective floodplain maps for the City of Scappoose can be found here: https://www.fema.gov/flood-maps