Sec. 5-30

Floodplain

• Anchoring to prevent flotation

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

• Drainage plan required

  A detail erosion and sedimentation and/or storm water management plan shall be submitted to the town for review and approval.

• FEMA elevation certificate required

  All applications for zoning permits for structures in the floodplain as defined for purposes of this article shall include a standard FEMA elevation certificate completed by a licensed surveyor or engineer.

• Enclosed area use restriction

  Not be designed or used for human habitation, but shall be used only for parking of vehicles, building access, or limited storage of maintenance equipment used in connection with the premises.

• Expansion restriction in floodway

  Existing structures and uses located in the floodway district 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 or enlargement would not result in any increase in the base flood elevation.

• Methods to minimize flood damage

  New construction or substantial improvements shall be constructed by methods and practices that minimize flood damage.

• Flood-resistant materials required

  New construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

• Flood vent bottom heightMaximum heightThe tallest a building may be, given in feet, in storeys, or both — whichever binds first.1 ft

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

• Flood vent openings required1 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 shall be at least one square inch for each square foot of enclosed area subject to flooding.

• Encroachment prohibition in floodway

  Encroachments, including fill, new construction, substantial improvements, and other development, shall be prohibited unless certification such as hydrologic and hydraulic analyses (with supporting technical data) is provided demonstrating that the proposed encroachment shall not result in any increase in flood levels during occurrence of the base flood.

• Manufactured homesManufactured homeA dwelling built in a factory to a federal standard and transported to the site. prohibitedProhibitedNot allowed in the district at all, short of rezoning or a variance. in floodway

  The placement of manufactured homes or mobile homes shall be prohibited.

• Manufactured homeManufactured homeA dwelling built in a factory to a federal standard and transported to the site. permanent foundation

  All manufactured homes or mobile homes to be placed or substantially improved within the special floodplain area, as described in section 5-30(a)(2) of this appendix, shall be placed on a permanent foundation and anchored in accordance with the Virginia Uniform Statewide Building Code.

• Non-residential lowest floor elevation1 ft

  New construction or substantial improvements of any commercial, industrial, or non-residential building, or manufactured home, shall have the lowest floor, including basements, elevated to one foot above the determined base flood elevation.

• Zoning permit required in floodplainFloodplainLand expected to flood at a stated frequency, where building carries extra conditions.

  All uses, activities, and development occurring within any floodplain area shall be undertaken only upon the issuance of a zoning permit by the zoning administrator.

• FloodplainFloodplainLand expected to flood at a stated frequency, where building carries extra conditions. disclosure on sale

  Any owner or partial owner of real estate or his agent and any real estate broker or his agent who sells or contracts to sell real estate subject to a floodplain regulation without first notifying in writing the buyer or his agent that such real estate is subject to floodplain regulations shall be subject to the penalties set forth in section 5-13.

• Recreational vehicle 180-day rule180 days

  Be on the site fewer than 180 consecutive days, be fully licensed, and be ready for highway use (a recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions).

• Residential lowest floor elevation

  New construction or substantial improvement of any residential structures, including manufactured homes, shall have the lowest floor, including basement, elevated to or above the determined base flood elevation.

• Sanitary sewer flood design

  All new or replacement sanitary sewer facilities and private package sewage treatment plants, including all pumping stations and collector systems, shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharges from the systems into the floodwaters.

• Street and sidewalk flood design

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

• Base flood elevation data for large subdivisions5 acresacre43,560 square feet — about the size of an American football field without the end zones.

  It is required that all subdivision proposals and other proposed development proposals, including manufactured home parks and subdivisions, that exceed five acres or 50 lots, shall include base flood elevation data.

• Substantial improvement threshold50 pct

  For the purpose of this article, the modification, alteration, repair, reconstruction, or improvement of any kind to a structure or use located in a floodplain, to an extent or amount of 50 percent or more of its market value, shall be undertaken only in full compliance with the provisions of this article and shall require the entire structure to conform to the Virginia Uniform Statewide Building Code.

• Utility location in flood-prone areas

  All other utilities, such as gas lines and electrical, telephone, and cable television systems, being placed in flood-prone areas shall be located, elevated (where possible), and constructed to minimize the chance of impairment during a flood occurrence.

• Utility equipment flood protection

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

• Adjacent property owner list for varianceVariancePermission to depart from a specific dimensional rule, granted on a showing of hardship.300 ft

  A list of names, addresses, and official tax numbers of adjoining property owners and owners of property within 300 feet of the subject property.

• VarianceVariancePermission to depart from a specific dimensional rule, granted on a showing of hardship. application plan scale100 ft

  Plans in triplicate, drawn to scale not less than one inch to 100 feet horizontally, showing the location, dimensions, and contours (at two-foot intervals) of the lot, existing and proposed structures, fill, storage areas, water supply, sanitary facilities, and relationship of the floodway to the proposal.

• VarianceVariancePermission to depart from a specific dimensional rule, granted on a showing of hardship. notice to applicant10 business days

  The board of zoning appeals shall notify the applicant for a variance, in writing and signed by the zoning administrator, within ten business days of the public hearing, that the issuance of a variance to construct a structure below the 100-year flood elevation increases the risks to life and property and will result in increased premium rates for flood insurance.

• Waste disposal system flood protection

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

• Water facility flood design

  All new or replacement potable water facilities shall be designed to minimize or eliminate infiltration of floodwaters into the system and shall be located and constructed to minimize or eliminate flood damages.

• Water supply system flood protection

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

• Permit for watercourse alteration

  Prior to any proposed alteration or relocation of any channel within a regulatory floodplain within the town, a permit shall be obtained from the U. S. Corps of Engineers, the Virginia Department of Environmental Quality, and the Virginia Marine Resources Commission.