Dimensional standards
Servicing
- Applies near
- Special Flood Hazard Area
- Geographic extent
- Special Flood Hazard Area (SFHA) as shown on FEMA Flood Insurance Rate Map (FIRM) for Loudoun County and Town of Hamilton
Extracted standards
12 individual requirements pulled out of this section’s prose, each with the sentence it came from.
Floodplain
- Minimum flood vent opening area per enclosed area1 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 (1) square inch for each square foot of enclosed area subject to flooding.
- No increase in base flood elevation in floodway0 ft
Within any floodway area, no new construction or development shall be permitted that would cause any increase in the base flood elevation.
The placement of manufactured homes (mobile homes) is prohibited, except in an existing manufactured home (mobile home) park or subdivision.
- Maximum accessoryAccessory useA secondary activity customarily incidental to the main use of the lot — a garage, a home office. structure size200 sqftsq ftSquare feet. An acre is 43,560 sq ft; a typical suburban lot is 7,000–10,000.
Accessory structures not to exceed 200 sq. ft.
- Maximum increase in base flood elevation outside floodway1 ft
No new construction or development shall be permitted within the floodplain district unless it is demonstrated through hydrologic and hydraulic analysis ... will not increase the elevation of the base flood more than one foot at any point.
- Maximum heightMaximum heightThe tallest a building may be, given in feet, in storeys, or both — whichever binds first. of flood vent bottom above adjacent grade1 ft
The bottom of all required openings shall be no higher than one (1) foot above the adjacent grade.
- Minimum lowest floor elevation above base flood elevation1 ft
New construction or substantial improvement of any residential structure (including manufactured homes) in Zones AE, AH and A with detailed base flood elevations shall have the lowest floor, including basement, elevated at least one foot above the base flood level.
- Minimum number of flood vent openings2 count
Provide a minimum of two openings on different sides of each enclosed area subject to flooding.
- Maximum days recreational vehicle on site without meeting manufactured homeManufactured homeA dwelling built in a factory to a federal standard and transported to the site. standards180 days
All recreational vehicles placed on sites must either: be on the site for fewer than 180 consecutive days, be fully licensed and ready for highway use ... or meet all the requirements for manufactured homes.
- Subdivision size requiring base flood elevation data50 lots
For subdivision proposals and other proposed development proposals (including manufactured home parks and subdivisions) that exceed fifty lots or exceeds five acres, base flood elevation data shall be obtained.
- Substantial improvement threshold50 pct
The modification, alteration, repair, reconstruction, or improvement of any kind to a structure and/or use ... to an extent or amount of fifty (50) percent or more of its market value shall be undertaken only in full compliance with the provisions of this ordinance.
Other
- Private package sewage treatment plants prohibitedProhibitedNot allowed in the district at all, short of rezoning or a variance.
Private package sewage treatment plants are prohibited under this Ordinance.
From the ordinance
The floodplain district is hereby established as an overlay district, meaning that it is a district overlaid upon other districts as shown on the Official Zoning Map, and as such, the provisions for the floodplain district shall serve as a supplement to the underlying district provisions.