§ 17.11.650. Other structures and development.

[Note: See NFIP Technical Bulletin #5, "Free-of-Obstruction Requirements."]

(A)

Decks and Patios.

In addition to the requirements of the Building Code or the Residential Code, decks and patios shall be located, designed, and constructed in compliance with the following:

(1)

A deck that is structurally attached to a building or structure shall have the bottom of the lowest horizontal structural member at or above the flood protection elevation and any supporting members that extend below the design flood elevation shall comply with the foundation requirements that apply to the building or structure, which shall be designed to accommodate any increased loads resulting from the attached deck.

(2)

A deck or patio that is located below the flood protection elevation shall be structurally independent from structures and their foundation systems, and shall be designed and constructed either to remain intact and in place during base flood conditions or to break apart into small pieces that will not cause structural damage to adjacent elevated structures.

(3)

A deck or patio that has a vertical thickness of more than twelve inches or that is constructed with more than the minimum amount of fill that is necessary for site drainage shall not be approved unless an analysis demonstrates no harmful diversion of floodwaters or wave runup and wave reflection that would increase damage to adjacent elevated structures.

(4)

A deck or patio that has a vertical thickness of twelve inches or less and that is at natural grade or on fill material that is similar to and compatible with local soils and is the minimum amount necessary for site drainage may be approved without requiring analysis of the impact on diversion of floodwaters or wave runup and wave reflection.

(B)

Other Development.

Other development activities shall be permitted only if located outside the footprint of, and not structurally attached to, structures, and only if an analysis demonstrates no harmful diversion of floodwaters or wave runup and wave reflection onto adjacent elevated structures. other development includes but is not limited to:

(1)

Bulkheads, seawalls, retaining walls, revetments, and similar erosion control structures;

(2)

Solid fences, privacy walls, and fences prone to trapping debris, unless designed and constructed to fail under base flood conditions; and

(3)

Mounded septic systems.

(Ord. No. O-24-12, § I, 7-23-2012)