Springfield, OR Environmental Rules: Flood Elevation Requirements (2026)

Springfield Development Code Section 3.3.430(B)(3), part of the Floodplain Overlay District, sets the elevation and floodproofing standards that apply once a special flood hazard area carries Base Flood Elevation (BFE) data from the Flood Insurance Study, the Flood Insurance Rate Map, or data the Floodplain Administrator gathers under SDC 3.3.430(A)(8). New construction, a conversion, or a substantial improvement of a residential structure must have its lowest floor, including any basement, elevated to 1 foot above the BFE, and enclosed areas below that lowest floor must meet the flood-opening standards of SDC 3.3.430(B)(1), which require at least 1 square inch of non-engineered opening per square foot of enclosed area with the lowest opening no higher than 1 foot above grade.

A nonresidential structure gets an alternative: elevate the lowest floor 1 foot above BFE, or floodproof the structure and its utilities 1 foot above BFE so it is watertight, with the design certified by a registered engineer or architect and reported to the Floodplain Administrator; the code also warns applicants that a floodproofed nonresidential building's flood insurance premium is rated as if it sits 1 foot lower than its floodproofed level. Manufactured dwellings must have the bottom of the chassis frame beam at or above BFE, with electrical crossover connections at least 12 inches above BFE.

In AO zones with shallow flooding, residential structures must be raised to the FIRM's depth number or a minimum of 2 feet above the highest adjacent grade if no depth number is shown. The Floodplain Administrator, the Development and Public Works Director, records the actual as-built elevation of every regulated lowest floor from a licensed surveyor's or engineer's certification before final inspection under SDC 3.3.425(C).