§ 1105. Provisions for flood hazard reduction.

1105.1

General standards. In all areas of special flood hazard, the following provisions are required:

(a)

All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure;

(b)

Manufactured homes shall be anchored to prevent flotation, collapse, or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This standard shall be in addition to and consistent with applicable state requirements for resisting wind forces;

(c)

All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage;

(d)

All new construction or substantial improvements shall be constructed by methods and practices that minimize flood damage;

(e)

Electrical, heating, ventilation, plumbing, air conditioning equipment, and other service facilities shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding;

(f)

All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system;

(g)

New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters;

(h)

On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding; and

(i)

Any alteration, repair, reconstruction of improvements to a structure which is in compliance with the provisions of this ordinance, shall meet the requirements of "new construction" as contained in this ordinance.

1105.2

Specific standards. In all areas of special flood hazard where base flood elevation data has been provided, as set forth in Section 1103, Subsection 1103.2, or Section 1104, Subsection 1104.3(j), the following provisions are required:

(a)

Residential construction. New construction or substantial improvement of any residential structure shall have the lowest floor, including basement, elevated no lower than two (2) feet above the base flood elevation. Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate the unimpeded movements of flood waters shall be provided.

(b)

Non-residential construction. New construction or substantial improvement of any commercial, industrial, or non-residential structure shall have the lowest floor, including basement, elevated no lower than two (2) feet above the level of the base flood elevation. Structures located in A-zones may be flood-proofed in lieu of elevation provided that all areas of the structure below the required elevation are water-tight with walls substantially impermeable to the passage of water, using structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A registered professional engineer or architect shall certify that the standards of this subsection are satisfied. Such certification shall be provided to the official as set forth in Section 1104, Subsection 1104.2(e).

(c)

Elevated buildings. New construction or substantial improvements of elevated buildings that include fully enclosed areas formed by foundation and other exterior walls below the base flood elevation shall be designed to preclude finished living space and designed to allow for the entry and exit of flood waters to automatically equalize hydrostatic flood forces on exterior walls.

(1)

Designs for complying with this requirement must either be certified by a professional engineer or architect or meet the following minimum criteria:

(i)

Provide a minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding;

(ii)

The bottom of all openings shall be no higher than one (1) foot above grade; and

(iii)

Openings may be equipped with screens, louvers, valves, or other coverings or devices, provided they permit the automatic flow of flood waters in both directions.

(2)

Electrical, plumbing, and other utility connections are prohibited below the base flood elevation;

(3)

Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) or limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator); and

(4)

The interior portion of such enclosed area shall not be partitioned or finished into separate rooms.

(d)

Floodways. Located within areas of special flood hazard established in Section 1103, Subsection 1103.2, are areas designed as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles, and has erosion potential, the following provisions shall apply:

(1)

Prohibit encroachments, including fill, new construction, substantial improvements and other developments unless certification (with supporting technical data) by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in flood levels during occurrence of the base flood discharge;

(2)

If Section 1105, Subsection 1105.2(d)(1) is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of Section 1105.

(3)

Prohibit the placement of manufactured homes (mobile homes), except in an existing manufactured home (mobile home) park or subdivision. A replacement manufactured home may be placed on a lot in an existing manufactured home park or subdivision provided the anchoring standards of Section 1105, Subsection 1105.1(b) and the elevation standards of Section 1105, Subsection 1105.2(a) are met.

1105.3

Standards for streams without established base flood elevations and/or floodways. Located within the areas of special flood hazard established in Section 1103, Subsection 1103.2, where small streams exist but where no base flood data has been provided or where no floodways have been provided, the following provisions apply:

(a)

No encroachments, including fill material or structures, shall be located within a distance of the stream bank equal to five (5) times the width of the stream at the top of bank or twenty (20) feet each side from top of bank, whichever is greater, unless certification by a registered professional engineer is provided demonstrating that such encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.

(b)

New construction or substantial improvements of structures shall be elevated or flood-proofed in accordance with elevations established in accordance with Section 1104, Subsection 1104.3(k). When base flood elevation data is not available from a federal, state, or other source, the lowest floor, including basement, shall be elevated, at least two (2) feet above the highest adjacent grade.

1105.4

Standards for subdivision proposals.

(a)

All subdivision proposals shall be consistent with the need to minimize flood damage;

(b)

All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage;

(c)

All subdivision proposals shall have adequate drainage provided to reduce exposure to flood hazards; and

(d)

Base flood elevation data shall be provided for subdivision proposals and other proposed development (including manufactured home parks and subdivisions) which is greater than the lesser of fifty (50) lots or five (5) acres.

1105.5

Standards for Areas of Shallow Flooding (AO Zones). Located within the areas of special flood hazard established in Section 1103, Subsection 1103.2, are areas designated as shallow flooding. These areas have special flood hazards associated with base flood depths of one (1) to three (3) feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate; therefore, the following provisions apply:

(a)

All new construction and substantial improvements of residential structures shall have the lowest floor, including basement, elevated to the depth number specified on the Flood Insurance Rate Map, in feet, above the highest adjacent grade. If no depth number is specified, the lowest floor, including basement, shall be elevated, at least two (2) feet above the highest adjacent grade.

(b)

All new construction and substantial improvements of nonresidential structures shall:

(1)

have the lowest floor, including basement, elevated to the depth number specified on the Flood Insurance Rate Map, in feet, above the highest adjacent grade. If no depth number is specified, the lowest floor, including basement, shall be elevated at least two (2) feet above the highest adjacent grade, or;

(2)

together with attendant utility and sanitary facilities be completely flood-proofed to or above that level and, so that, any space below that level is water-tight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and efforts [effects] of buoyancy.