Article 2, Division 5, Sec. 19.2-27; Section 19.2-83.C.1

Floodplain

• Maximum increase in base flood elevation1 ft

  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, unless it is demonstrated that the cumulative effect of the proposed development... will not increase the water surface elevation of the base flood more than one foot.

• Maximum heightMaximum heightThe tallest a building may be, given in feet, in storeys, or both — whichever binds first. of flood vent bottom above grade1 ft

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

• Maximum consecutive days for recreational vehicles180 days

  All recreational vehicles placed on sites must either be on the site for fewer than 180 consecutive days

• Threshold for full compliance50 pct

  The modification, alteration, repair, reconstruction, or improvement of any kind to a structure and/or use located in any Special Flood Hazard Area district, to an extent or amount of 50% or more of its value... shall be undertaken only in full compliance with the floodplain management ordinance

• Access driveway elevation requirement

  All new construction and substantial improvements to existing structures shall have the access driveways elevated to at least the base flood elevation.

• Minimum elevation for critical electrical installations1 ft

  All electric water heaters, electric furnaces and other critical electrical installations shall be permitted only at elevations at least one foot above the base flood elevation.

• Minimum number of flood vent openings2 count

  Provide a minimum of two openings on different sides of each enclosed area subject to flooding.

• Minimum flood vent opening area ratio1 sqin/sqftsq ftSquare feet. An acre is 43,560 sq ft; a typical suburban lot is 7,000–10,000.

  The total net area of all openings must be at least one square inch for each square foot of enclosed area subject to flooding.

• Minimum floor level for existing parcels1 ft

  One residential dwelling is permitted on each parcel that was recorded as of March 16, 1983, that is at least 95% inundated by the base flood... provided it shall have a minimum floor level, including basement, of one foot above the base flood

• Minimum lowest floor elevation above base flood1 ft

  New construction or substantial improvement of any residential structure (including manufactured homes) in Zones AE and A with detailed base flood elevations shall have the lowest floor, including basement, elevated to a minimum of one foot above the base flood level.

• Minimum lowest floor elevation above base flood1 ft

  New construction or substantial improvement of any commercial, industrial, or non-residential building (or manufactured home) shall have the lowest floor, including basement, elevated to a minimum of one foot above the base flood level.

• Minimum anchoring force for manufactured homesManufactured homeA dwelling built in a factory to a federal standard and transported to the site.4,800 lbs

  all components of the anchoring system shall be capable of carrying a force of 4,800 pounds

• Minimum elevation above grade for manufactured homesManufactured homeA dwelling built in a factory to a federal standard and transported to the site.3 ft

  All such manufactured homes shall be located no less than three feet above grade

• Minimum lowest floor elevation for manufactured homesManufactured homeA dwelling built in a factory to a federal standard and transported to the site.1 ft

  stands or lots be elevated on compacted fill or on pilings so that the lowest floor of the home will be at least one foot above the base flood elevation of the nearest A zone

• Minimum setbackSetbackThe distance a building must be held back from a lot line. from base flood boundary25 ft

  All new construction and substantial improvements of residential dwellings adjacent to the base flood area/backwater shall be set back at least 25 feet horizontal distance from the outermost boundary of the base flood area/backwater

• Minimum setbackSetbackThe distance a building must be held back from a lot line. from 100-year floodplainFloodplainLand expected to flood at a stated frequency, where building carries extra conditions. boundary35 ft

  In the Upper Swift Creek Watershed, all new construction of and substantial improvements to residential dwellings shall be setback at least 35 feet horizontal distance from the outermost boundary of the 100-year floodplain where the contributing drainage area exceeds 100 acres.

• Minimum setbackSetbackThe distance a building must be held back from a lot line. from base flood boundary25 ft

  Within the Upper Swift Creek Watershed all new construction and substantial improvements of nonresidential structures and accessory buildings shall be located outside the floodway fringe and shall be set back at least 25 feet horizontal distance from the outermost boundary of the base flood area, wetlands, Resource Protection Areas and 100-year floodplains where the contributing drainage area exceeds 100 acres

• Minimum setbackSetbackThe distance a building must be held back from a lot line. from base flood boundary (with LID)5 ft

  provided however, that when LID practices, as determined by the Director of Environmental Engineering, are used adjacent to wetlands, floodplains and Resource Protection Areas, the setback may be reduced to five feet.

• Minimum setbackSetbackThe distance a building must be held back from a lot line. for manufactured homesManufactured homeA dwelling built in a factory to a federal standard and transported to the site.25 ft

  and be set back at least 25 feet horizontal distance from the outermost boundary of the base flood

• ProhibitedProhibitedNot allowed in the district at all, short of rezoning or a variance. uses in floodway

  The following shall be prohibited in the floodway district: structures, substantial improvements, manufactured homes, fill or other development.

• ProhibitedProhibitedNot allowed in the district at all, short of rezoning or a variance. uses in Upper Swift Creek Watershed

  The following shall be prohibited within the Upper Swift Creek Watershed 100-year floodplains when the contributing drainage area exceeds 100 acres in size: Clear cutting; Removal of tree stumps; Clearing of vegetation; Filling; Grading; Placement of fences or other appurtenant structures.

• ProhibitedProhibitedNot allowed in the district at all, short of rezoning or a variance. placement of new manufactured homesManufactured homeA dwelling built in a factory to a federal standard and transported to the site.

  The placement of new manufactured homes on individual lots or parcels, the construction of new manufactured home parks and manufactured home subdivisions, and the expansion or substantial improvements to existing manufactured home parks and manufactured home subdivisions shall be prohibited within the base flood area.

• ProhibitedProhibitedNot allowed in the district at all, short of rezoning or a variance. filling of floodplainFloodplainLand expected to flood at a stated frequency, where building carries extra conditions.

  Filling in the base flood area shall be prohibited to make a building lot for the purpose of constructing a residential dwelling unless permitted by a variance