Sec. 86-567

Until a regulatory floodway is designated, no new construction, substantial improvements, or other development (including fill) shall be permitted within the areas of special flood hazard, designated as zone AE on the FIRM, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within King William County.

Development activities which increase the water surface elevation of the base flood may be allowed, provided that the applicant first applies, with King William County's endorsement, for a CLOMR, and receives the approval of the FEMA.

The provisions of this article relating to the repair, reconstruction, or improvement of existing structures shall not apply to any structure identified as a historic structure, provided that the repair, reconstruction, or improvement does not preclude the structure's continued designation as a historic structure.

When such base flood elevation data is utilized, the lowest floor shall be elevated to at least 18 inches above the base flood level.

If no flood depth number is specified, the lowest floor, including basement, shall be elevated no less than two feet above the highest adjacent grade.

Accessory structures, as defined in section 86-557, shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of floodwaters and shall be designed to equalize hydrostatic flood forces on exterior walls.

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

All uses, activities, and development occurring within any floodplain district, including placement of manufactured homes, shall be undertaken only upon the issuance of a zoning permit.

All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage and by methods and practices that minimize flood damage.

All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from systems into flood waters.

Within any floodway area, no encroachments, including fill, new construction, substantial improvements, or other development shall be permitted unless it has been demonstrated through hydrologic and hydraulic analysis performed in accordance with standard engineering practice that the proposed encroachment will not result in any increase in flood levels within the community during the occurrence of the base flood discharge.

Flood protection elevation means an elevation that is one foot or more above the base flood elevation.

The flood-carrying capacity within an altered or relocated portion of any watercourse shall be maintained.

All manufactured homes shall be anchored to prevent flotation, collapse, or lateral movement, and shall be installed using methods and practices that minimize flood damage.

New manufactured homes and replacement manufactured homes shall be elevated so that the lowest floor is at or above the flood protection elevation and shall be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

Manufactured homes placed or substantially improved in an existing manufactured home park or subdivision shall be elevated so that either: (1) The lowest floor is at or above the flood protection elevation; or (2) The chassis is supported by reinforced piers or other foundation elements of no less than 36 inches in height above grade and is securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

The placement of manufactured homes (mobile homes) is prohibited, except in an existing manufactured home (mobile home) park or subdivision.

Accessory structures are not to exceed 600 square feet.

The bottom of all openings shall be no higher than one foot above grade.

A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.

New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated to the flood protection elevation; or, together with attendant utility and sanitary facilities, shall be floodproofed so that below the flood protection elevation the structure is watertight with walls substantially impermeable to the passage of water.

Recreational vehicles placed on sites within special flood hazard areas shall either: a. Be on the site for fewer than 180 consecutive days; or b. Be fully licensed and ready for highway use, on wheels or jacking system, attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions.

New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to the flood protection elevation.

All subdivision proposals shall be consistent with the need to minimize flood damage; shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize or eliminate flood damage; shall have adequate drainage provided to reduce exposure to flood damage; and where base flood elevation data has not been provided, it shall be generated for subdivision proposals which contain at least 50 lots or five acres, whichever is less.

Variances shall only be issued when: (1) There is a showing of good and sufficient cause; (2) The variance is the minimum necessary, considering the flood hazard, to afford relief; and (3) There is a showing that the granting of the variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public, or conflict with existing local laws or ordinances.