Anchorage, AK Environmental Rules: Flood Elevation Requirements (2026)

The lowest floor, including basement or crawl space, of residential structures shall be elevated to at least one foot above the base flood level. Within the structure, attendant utility and sanitary facilities shall be elevated to at least one foot above the base flood or completely floodproofed.

ii. The lowest floor, including basement, of nonresidential structures shall be elevated to at least one foot above the base flood level, unless the structure, with all utility and sanitary facilities, is designed so that below base flood level the structure is watertight with walls substantially impermeable to the passage of water and so that it is capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.

iii. All fully enclosed areas below the lowest floor that are usable solely for parking, building access, or storage in an area other than a basement or crawlspace shall have a minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area according to FEMA specifications. The bottom of all openings shall be no higher than one foot above grade. Openings may be equipped with screens, louvers or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.

iv. Where floodproofing is utilized a registered professional engineer or architect shall certify that the floodproofing methods are adequate.

v.