For the purposes of these regulations, a structure on the same lot with, and of a nature customarily incidental and subordinate to, the principal structure.

A designated Zone AO on a community's Flood Insurance Rate Map with a one-percent annual chance or greater of flooding to an average depth of one to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.

The flood having a one-percent chance of being equaled or exceeded in any given year; the base flood also is referred to as the "one-hundred-year flood" (or the "one-percent-annual-chance flood").

The volume of water resulting from a base flood as it passes a given location within a given time, usually expressed in cubic feet per second (cfs).

The elevation of the base flood, including wave height, relative to the National Geodetic Vertical Datum (NGVD), North American Vertical Datum (NAVD) or other datum specified on the community's Flood Insurance Rate Map.

Any area of the building having its floor subgrade (below ground level) on all sides.

A wall that is designed and certified by a registered design professional that is not part of the structural support of the building and is intended, through its design and construction, to collapse under specific lateral loading forces, without causing damage to the elevated portion of the building or supporting foundation system.

The family of Building Codes specifically adopted by the City of Lewes in Chapter 70, Building Code. The code that applies to one- and two-family dwellings is referred to as the "Residential Code."[3]

Area within the flood hazard area that is subject to high-velocity wave action, and shown on a Flood Insurance Rate Map (FIRM) or other flood hazard map as Zone V, VO, VE or V1-30.

Hospitals, nursing homes, police stations, fire stations, and emergency operation centers that are needed for flood response activities before, during, or after a flood; public and private utility facilities that are vital to maintaining or restoring normal services to flooded areas before, during, and after a flood; and structures or facilities that produce, use, or store highly volatile, flammable, explosive, toxic and/or water-reactive materials. The term includes facilities that are assigned Risk Category III and Risk Category IV, assigned pursuant to the Building Code, or Flood Design Class 3 and Flood Design Class 4 assigned pursuant to ASCE 24, if applicable.

Any man-made change to improved or unimproved real estate, including but not limited to buildings or other structures, placement of manufactured homes, mining, dredging, filling, grading, paving, excavation or drilling operations or storage of equipment or materials.

A combination of measures which results in a structure, including attendant utilities and equipment, being watertight with all elements substantially impermeable and with structural components having the capacity to resist flood loads.

The National Flood Insurance Program, Elevation Certificate (FEMA Form 086-0-33), used to document building elevations and other information about buildings. When required to be certified, the form shall be completed by a licensed professional land surveyor.

The federal agency with the overall responsibility for administering the National Flood Insurance Program.

A series of guidance documents published by FEMA to provide guidance concerning building performance standards of the National Flood Insurance Program. See sections where specific TBs are identified.

Any construction material capable of withstanding direct and prolonged contact with floodwaters without sustaining any damage that requires more than cosmetic repair. See FEMA Technical Bulletin No. 2, Flood Damage-Resistant Materials Requirements, and FEMA Technical Bulletin No. 8, Corrosion Protection for Metal Connectors in Coastal Areas.

An Official Map on which the Federal Emergency Management Agency (FEMA) has delineated both the special flood hazard areas and the risk premium zones applicable to the community.

The official report provided by the Federal Emergency Management Agency (FEMA) containing the Flood Insurance Rate Map (FIRM), the Flood Boundary and Floodway Map (FBFM), the water surface elevations of the base flood and supporting technical data.

A general and temporary condition of partial or complete inundation of normally dry land areas from:

Any land area susceptible to being inundated by water from any source. (See "flood or flooding.")

The National Flood Insurance Program, Floodproofing Certificate for Nonresidential Structures (FEMA Form 86-0-34), used by registered professional engineers and architects to certify dry floodproofing designs.

The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to pass the base flood discharge such that the cumulative increase in the water surface elevation of the base flood discharge is no more than a designated height.

A margin of safety added to the base flood elevation to account for waves, debris, miscalculations, or lack of data.

A use which cannot perform its intended purpose unless it is located or carried out in close proximity to water; the term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, but does not include long-term storage or related manufacturing facilities.

The highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.

Any structure that is:

An analysis performed by a professional engineer, licensed in the State of Delaware, in accordance with standard engineering practices as accepted by FEMA, used to determine the base flood, other frequency floods, flood elevations, floodway information and boundaries, and flood profiles.

An official FEMA determination, by letter, to amend or revise an effective Flood Insurance Rate Map, Flood Boundary and Floodway Map, and Flood Insurance Study. "Letters of Map Change" include:

The lowest floor of the lowest enclosed area, including basement, but excluding any unfinished or flood-resistant enclosure, usable solely for vehicle parking, building access or limited storage, provided that such enclosure is not built so as to render the structure in violation of the nonelevation requirements specified in the Building Code for enclosures below the lowest floor.

A structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when connected to the required utilities. The term "manufactured home" does not include a "recreational vehicle."

Buildings and structures for which the "start of construction" commenced on or after March 15, 1977, including any subsequent improvements to such structures.

An individual or group of individuals, corporation, partnership, association, or any other entity, including state and local governments and agencies.

A vehicle which is built on a single chassis, 400 square feet or less when measured at the largest horizontal projection, designed to be self-propelled or permanently towable by a light-duty truck, and designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.

The land in the floodplain subject to flood hazards and shown on a Flood Insurance Rate Map as Zones A, AE, AO, and VE. The term includes areas shown on other flood hazard maps that are specifically listed or otherwise described in § 197-73A(4).

The date of issuance of permits for new construction and substantial improvements to existing structures, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within 180 days after the date of issuance. The "actual start" means the first placement of permanent construction of a building (including a manufactured home) on a site, such as the pouring of a slab or footings, installation of pilings, or construction of columns. Permanent construction does not include land preparation (such as clearing, grading and filling), the installation of streets or walkways, excavation for a basement, footings, piers, or foundations, the erection of temporary forms or the installation of accessory buildings such as garages or sheds not occupied as dwelling units or not part of the main building. For a substantial improvement, the actual "start of construction" means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building.

That which is built or constructed.

Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed 50% of the market value of the structure before the damage occurred.

Any combination of repair, alteration, reconstruction, rehabilitation, addition, or other improvement of a structure, the cumulative cost of which equals or exceeds 50% of the market value of the structure before improvement or repair is started. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The term does not, however, include any project for improvement of a building required to correct existing health, sanitary, or safety code violations identified by the Building Official and that are the minimum necessary to assure safe living conditions.

The failure of a structure or other development to be fully compliant with the community's floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in these regulations is presumed to be in violation until such time that documentation is provided.

An individual who has experience in wetland identification and delineation. This individual has a current certification as a "Professional Wetland Scientist" from the Society of Wetland Scientists.

Areas inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions and that are not defined as tidal wetlands in the City Code. These include, but are not limited to, isolated, seasonal, and ephemeral* wetlands.

The mean high-water line of a tidal water body, tidal stream, or tidal marsh. The average height of all the high-tide water recorded over a nineteen-year period as defined by the National Oceanic and Atmospheric Administration tidal datum.

Areas under jurisdiction of Title 7, Chapter 66, of the Delaware Code, as regulated and mapped by DNREC.

An area located upland and landward of the delineated wetlands line, at the time of accepted delineation, that is established or will be established with vegetation to protect the wetlands and terrestrial environment from human disturbance, even if the area was previously disturbed by human activity.

Activities carried out to compensate for freshwater wetlands or state open water loss or disturbance caused by regulated activities.

A single containment vessel greater than 250 gallons as defined in the Delaware Regulations Governing Aboveground Storage Tanks, dated February 11, 2005. ASTs with a storage capacity greater than 12,499 gallons containing petroleum or hazardous substances, and ASTs with a storage capacity greater than 39,999 gallons containing diesel, heating fuel or kerosene, are subject to the design, construction, operation, and maintenance requirements of the Delaware AST regulations.

See Article XVI.

A geological formation, group of formations or part of a formation composed of rock, sand, or gravel capable of storing and yielding groundwater to wells.

Those substances specifically designated as hazardous under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA),[1] otherwise known as the "Superfund Law," or those substances identified under other laws. In all, the Superfund Law includes references to four other laws to designate more than 800 substances as hazardous and identify many more as potentially hazardous due to their characteristics and the circumstances of their release.

Any physical, chemical, biological, or radiological substance that enters the hydrological cycle through human action and may cause a deleterious effect on groundwater resources; it shall include, but is not limited to, hazardous waste, limiting nutrients, and sanitary sewage.

The process by which surface water (usually from rainfall) moves across the land surface. See "stormwater management."

The delineated areas that currently contribute or are proposed to contribute runoff to a specific location or point.

See Article XVI.

Those areas with high percentages of sand and gravel that have "excellent" potential for recharge as determined through a stack unit mapping analysis delineated by the Delaware Geological Survey and presented in the Report of Investigations No. 66, Groundwater Recharge Potential Mapping in Kent and Sussex Counties, Delaware, Geological Survey, 2004.

See Article XVI.

A portion of the subsurface water that occurs beneath the water table in soils and geologic formations that are fully saturated.

An underground storage tank system that contains a hazardous substance defined by § 101(4) of CERCLA[2] (but not including any substance regulated as a hazardous waste under RCRA[3] Subtitle C), or any mixture of such substances and petroleum, and which is not a petroleum UST system.

A solid waste, or combination of solid wastes, which, because of its quantity, concentration, or physical, chemical, or infectious characteristics, may cause or significantly contribute to an increase in mortality or an increase in serious irreversible or incapacitating irreversible illness, or pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, or disposed of, or otherwise managed. Without limitation, included within this definition are those hazardous wastes described in the Delaware Regulations Governing Hazardous Wastes, §§ 261.31 to 261.33.

A well from which the water is used to serve a community water system by § 22.146 (Public Water Systems) in the Delaware Regulations Governing Public Drinking Water Systems.

Any proposed expansion, addition, major facade change or rebuilding to an existing building, structure or parking facility.

That portion of precipitation or snowmelt that has not evaporated or infiltrated into the soil but flows on land surface.

Refers to any aquifer from which water is drawn either periodically or continuously by the City's water system or any community water system which provides piped water for human consumption.

Wellhead protection areas and excellent groundwater recharge potential areas.

The runoff of water from the surface of the land resulting from precipitation or snow or ice melts.

Surfaces providing negligible infiltration such as pavement, buildings, recreation facilities (by example, but not by limitation, tennis courts, swimming pools) and covered driveways.

One or a combination of tanks including underground pipes, the volume of which is 10% or more below ground, as defined in the Delaware Regulations Governing Underground Storage Tank Systems, dated March 12, 1995. The following USTs are not subject to the design, construction, operation, and maintenance requirements of the Delaware UST regulations: residential heating fuel, agricultural, and residential motor fuel USTs less than 1,100 gallons and any UST less than 110 gallons.

The upper terminal of a well, including adapters, ports, seals, valves, and other attachments.

The surface area extending to a minimum one-hundred-fifty-foot radius around the wellhead.

The remaining surface area of the delineated WHPA outside Zone 1.

Surface and subsurface areas surrounding public water supply wells or well fields where the quantity or quality of groundwater moving toward the wells or well fields may be adversely affected by land use activity.