Sec. 78-60.2

The approximated floodplain district shall be that floodplain area for which no detailed flood profiles or elevations are provided, but where a 100-year floodplain boundary has been approximated.

Adequate drainage paths around structures on slopes shall be provided to guide floodwaters around and away from proposed structures.

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.

Existing structures in the floodplain area shall not be expanded or enlarged unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practices that the proposed expansion would not result in any increase in the base flood elevation.

The modification, alteration, repair, reconstruction, or improvement of any kind to a structure and/or use, regardless of its location in a floodplain area to an extent or amount of 50 percent or more of its market value shall be undertaken only in full compliance with this chapter and shall require the entire structure to conform to the VA USBC.

In the floodplain overlay district, the modification, alteration, repair, reconstruction or improvement that amounts to less than 50 percent of its market value shall conform to the VA USBC.

Under no circumstances shall any use, activity or development decrease the carrying capacity of, or increase the volume or velocity of inflow to, the channels of floodways of any watercourse, drainage ditch or any other drainage facility or system.

No new construction, or development shall be permitted within the floodplain overlay district unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, does not increase the elevation of the 100-year flood at any one point.

New construction and substantial improvements of nonresidential structures within zones A1—30, AE and AH zones on the flood insurance rate map shall have the lowest floor (including basement) elevated no lower than 18 inches above the base flood level or, together with attendant utility and sanitary facilities, be designed so that below the base flood level plus one foot the structure is watertight...

Recreational vehicles may be placed on sites for fewer than 180 consecutive days and must be fully licensed and ready for highway use.

New construction and substantial improvements of residential structures within zones A1—30, AE and AH zones on the flood insurance rate map shall have the lowest floor (including basement) elevated no lower than 18 inches above the base flood level.

If the structure in the floodplain overlay district is designed and used as a single-family detached dwelling that is a permitted use in the zoning district pursuant to Table 78-70.2. D: Table of Principal Permitted and Allowed Uses, it may be restored in its location prior to casualty so long as: ...

If no flood depth number is specified, the lowest floor, including basement, shall be elevated at least two feet above the highest adjacent grade; or completely flood-proofed to the specified 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.

Be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

Base flood elevation data shall be provided for subdivision proposals and other proposed development proposals (including manufactured home parks and subdivisions) that exceed 50 lots or five acres, whichever is the lesser.

All drainage facilities shall be designed to convey the flow of stormwater runoff in a safe and efficient manner.

Be constructed by methods and practices that minimize flood damages.

Be constructed with materials resistant to flood damage.

All new and replacement sanitary sewage systems, private package sewage treatment plants, and onsite wastewater treatment systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters.

Uses, activities, and development occurring within the FPO shall be undertaken only upon the issuance of approval of a site plan and special exception pursuant to this section, other than restoration or replacement of single-family detached dwellings after casualty damage.

Streets and sidewalks should be designed to minimize their potential for increasing and aggravating the levels of flood flow.

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

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

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

All utilities and facilities, such as sewer, gas, electrical, telecommunication, and water systems being placed in flood-prone areas should be located, elevated (where possible), and constructed to minimize or eliminate flood damages.

Be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and be located and constructed to minimize or eliminate flood damage and impairment.