Floodplain Ordinance Definitions

Base Flood Elevation: The Federal Emergency Management Agency designated one hundred (100)-year water surface elevation. The water surface elevation of the base flood in relation to the datum specified on the community Flood Insurance Rate Map. For the purposes of this ordinance the one hundred (100)-year flood or 1% annual chance flood.

Critical Infrastructure: Critical Infrastructure falls within the following categories:

• Governmental Facilities: Essential for the delivery of critical services and crisis management including data and communication centers, key government complexes and similar facilities as determined by the Floodplain Administrator.
• Essential Facilities: Those that are vital to health and welfare of entire populations including hospitals and other medical facilities retirement homes, police and fire facilities, emergency operations centers, prisons, evacuation shelters and schools, and similar facilities as determined by the Floodplain Administrator
• Transportation Systems: Those systems and the supporting infrastructure necessary for transport of people and resources including airports highways railways and waterways during major disasters including flood events up to the 500-year flood.
• Lifeline Utility Systems: Those vital to public health and safety including potable water, wastewater, oil, natural gas, electric power communication systems and similar facilities as determined by the Floodplain Administrator.
• High Potential Loss Facilities: Failure or disruption of operations may have significant physical, social, environmental, and/or economic impact to neighboring communities including nuclear power plants, high-hazard dams, urban levees and military installations.
• Hazardous Material Facilities: Involved in the production, storage and/or transport of corrosives, explosives, flammable materials, radioactive materials, toxins and similar facilities as determined by the Floodplain Administrator.

Flood Zone: Areas identified as an AE Zone on the Flood Insurance Rate Maps for Chesapeake for which the one hundred (100)-year flood elevations have been provided.

Substantial Improvement: Any reconstruction rehabilitation addition or other improvement of a structure the cost of which equals or exceeds 50 percent of the market value of the structure before the start of construction of the improvement. This term includes structures which have incurred substantial damage regardless of the actual repair work performed. The term does not however include either:

• Any project for improvement of a structure to correct existing violations of state or local health sanitary or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions, or
• Any alteration of a historic structure provided that the alteration will not preclude the structure continued designation as a historic structure.
• Historic structures undergoing repair or rehabilitation that would constitute a substantial improvement as defined above must comply with all ordinance requirements that do not preclude the structure continued designation as a historic structure. Documentation that a specific ordinance requirement will cause removal of the structure from the National Register of Historic Places or the State Inventory of Historic places must be obtained from the Secretary of the Interior or the State Historic Preservation Officer. Any exemption from ordinance requirements will be the minimum necessary to preserve the historic character and design of the structure.