32.05.210 Flood openings.
All new construction and substantial improvements of structures with fully enclosed areas below the lowest floor (excluding basements) that are usable solely for parking of vehicles, building access or storage, and which are subject to flooding, shall be designed to automatically equalize hydrostatic and hydrodynamic flood forces on exterior walls by allowing for the automatic entry and exit of floodwater. Designs for meeting this requirement must meet or exceed the following minimum criteria:
A. For nonengineered openings:
1. Have a minimum of two openings on two different sides having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding; and
2. The bottom of all openings shall be no higher than one foot above grade; and
3. Openings may be equipped with screens, louvers, valves or other coverings or devices; provided, that they permit the automatic entry and exit of floodwater; and
4. Buildings with more than one enclosed area must have openings on exterior walls for each area to allow flood water to directly enter; or
B. Be certified by a registered civil engineer or architect. (Formerly 32.17.004)