§ 34-57. Standards for streams without established base flood elevations or floodways (A zones).

Located within the areas of special flood hazard established in section 34-5, where streams exist, but no base flood data has been provided (A zones), or where a floodway has not been delineated, the following shall apply:

(1)

When base flood elevation data or floodway data have not been provided in accordance with sections 34-4—34-11, then the engineering department shall obtain, review and reasonably utilize any scientific or historic base flood elevation and floodway data available from federal, state or other source, in order to administer the provisions of this article. Only if data is not available from these sources, then the following provisions (subsections (2) and (3)) shall apply.

(2)

No encroachments, including structures or fill material, shall be located within a distance of the stream-bank equal to five times the width of the stream at the top of the bank or twenty feet on each side from top of bank, whichever is the greater, unless certification by registered professional engineer is provided demonstrating that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the waters surface elevation of the 100-year and 500-year flood at any point within the community. The engineering certification should be supported by technical data that conforms to standard hydraulic engineering principles.

(3)

In special flood hazard areas without base flood elevation data, new construction or substantial improvements of existing shall have the lowest floor of the lowest enclosed area (including basement) elevated no less than three feet above the highest adjacent grade at the building site. Openings sufficient to facilitate the unimpeded movements of floodwaters shall be provided in accordance with standards of section 34-52, and "elevated buildings."

(Ord. No. O-07-2-102, § 1(Exh. A), 4-16-07)