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

075(c) sets Salem's one-foot freeboard above the FEMA base flood elevation for riverine Zones A1-A30, AH, and AE. 075(a): a minimum of two openings sized at one square inch of net open area per square foot of enclosed space, with the bottom of each opening no higher than one foot above grade. Non-residential structures may instead be floodproofed to one foot above the base flood elevation, watertight and engineered to resist hydrostatic and hydrodynamic loads, certified by a registered engineer or architect; floodproofed buildings are warned their flood insurance will be rated as if built to the base flood level, one foot lower than the floodproofed elevation actually reached.

Attached garages need only the floor slab one foot above the base flood elevation, while detached garages must meet either the appurtenant-structure or non-residential standard depending on size. Manufactured dwellings must sit with the bottom of the chassis frame beam at least one foot above the base flood elevation, with electrical crossover connections at least 12 inches above it. Where a formal base flood elevation has not been established, the Floodplain Administrator obtains and applies the best available federal, state, or other data, and unnumbered A-zone development must still be reasonably safe from flooding or risk higher insurance rates for failing to reach two feet above grade.