Sec. 27-242.  Definitions - Flood Plain Overlay District.


(1)  Unless specifically defined below, words or phrases used in this division shall be interpreted so as to give them the same meaning as they have in common usage and so as to give this division its most reasonable application.


Actuarial rates or “risk premium rates” shall mean those rates established by the Federal Insurance Administrator pursuant to individual community studies and investigations which are undertaken to provide flood insurance in accordance with 42 U.S.C. 4014 and the accepted actuarial principles.  Actuarial rates include provisions for operating costs and allowances.


Appeal shall mean a request for a review of the zoning official's (local administrator) interpretation of any provision of this chapter or a request for a variance.


Appurtenant Structure shall mean a structure, of a size 864 square feet or less, on the same parcel of property as the principal structure, the use of which is incidental to the use of the principal structure.


Area of shallow flooding shall mean a designated AO or AH zone on a community's Flood Insurance Rate Map (FIRM) with a one percent or greater annual chance of flooding to an average depth of one to three feet where a clearly defined channel is unpredictable and where velocity flow may be evident.  Such flooding is characterized by ponding or sheet flow.


Area of special flood hazard shall mean the land in the flood plain within a community subject to one percent or greater chance of flooding in any given year.


Base flood elevation shall mean elevation indicated in the official flood plain study as the elevation of the 100-year flood.


Base flood protection elevation shall mean an elevation one foot higher than the water surface elevation of the base flood.


Channel shall mean a natural or artificial watercourse of perceptible extent, with a definite bed and banks to confine and conduct continuously or periodically flowing water.  Channel flow, thus, is that water which is flowing within the limits of a defined channel.


Community shall mean any state or area or political subdivision thereof which has authority to adopt and enforce flood plain management regulations for the areas within its jurisdiction.


Existing construction (for the purposes of determining rates) shall mean structures for which the “start of construction” commenced before the effective date of the FIRM or before January 1, 1975, for FIRM's effective before that date.  “Existing construction” may also be referred to as “existing structures”.


Flood or Flooding shall mean a general and temporary condition of partial or complete inundation of normally dry land areas from the overflow of inland or tidal waters, or the unusual and rapid accumulation of runoff of surface waters from any source.


Flood elevation - ten year shall mean the flood elevation which has a probability of being equaled or exceeded once in ten years.


Flood Insurance Rate Map (FIRM) shall mean an official map of a community, on which the flood insurance study has delineated the flood hazard boundaries and the zones establishing insurance rates applicable to the community.


Flood insurance study shall mean the official report provided by the Federal Emergency Management Agency.  The report contains flood profiles, as well as the Flood Boundary Floodway Map and the water surface elevation of the base flood.


Flood plain management shall mean the operation of an overall program of corrective and preventive measures for reducing flood damage, including but not limited to emergency preparedness plan, flood control works and flood plain management regulations.


Floodproofing shall mean any combination of structural and nonstructural additions, changes or adjustments to structures, including utility and sanitary facilities, which would preclude the entry of water.  Structural components shall have the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy.


Flood protection system shall mean those physical structural works constructed specifically to modify flooding in order to reduce the extent of the area within a community subject to a “special flood hazard”.  Such a system typically includes levees or dikes.  These specialized modifying works are those constructed in conformance with sound federal and state engineering standards.


Floodway (FW) shall mean the channel of a river or other watercourse and the adjacent portion of the flood plain that must be reserved in order to discharge the 100-year flood without cumulatively increasing the water surface elevation more than one foot at any point assuming equal conveyance reduction outside the channel from the two sides of the flood plain.


Floodway fringe (FF) shall mean that area of the flood plain, outside of the floodway, that on the average is likely to be flooded once every 100 years (i.e.:  that has a one percent chance of flood occurrence in any one year).


Freeboard shall mean a factor of safety usually expressed in feet above a flood level for purposes of flood plain management.  “Freeboard” tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as wave action, clogged bridge openings, and the hydrological effect of urbanization of the watershed.


Highest adjacent grade shall mean the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.


Lowest floor shall mean the lowest floor of the lowest enclosed area (including basement).  An unfinished or flood resistant enclosure, usable solely for parking of vehicles, building access or storage, in an area other than a basement area, is not considered a building's lowest floor, provided that such enclosure is not built so as to render the structure in violation of the applicable nonelevation design requirements of this division.


Mobile home (flood plain overlay) shall mean 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.  For flood plain management purposes, the term “mobile home (flood plain overlay)” includes a manufactured home dwelling which is not set on a permanent foundation and also includes park trailers, travel trailers, and other similar vehicles placed on a site for greater than 180 consecutive days.  For insurance purposes, the term “mobile home (flood plain overlay)” does not include park trailers, travel trailers, and other similar vehicles.


Mobile home park or subdivision (flood plain overlay) shall mean a parcel (or contiguous parcels) of land divided into two or more mobile home spaces or lots for rent or sale.


New construction shall mean structures for which the “start of construction” or substantial improvement is commenced on or after the effective date of the FIRM.


Start of construction (for other than new construction or substantial improvements under the Coastal Barrier Resources Act (Pub. L. 97-348) includes substantial improvement) shall mean the date the building permit was issued, provided the actual start of construction, repair, reconstruction, placement, or other improvement was within 180 days of the permit date.  The actual start means the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation or the placement of a manufactured home dwelling on a foundation.  Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure.


Structure (flood plain overlay) shall mean a walled and roofed building that is principally above ground, as well as a manufactured home dwelling, and a gas or liquid storage tank that is principally above ground.


Substantial improvement shall mean any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure either, (1) before the improvement or repair is started, or (2) if the structure has been damaged and is being restored, before the damage occurred.  For the purpose of this definition, “substantial improvement” is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure.  The term does not, however, include either (1) any project for improvement of a structure to comply with existing, state or local health, sanitary, or safety code specifications which are solely necessary to assure safe living conditions, or (2) any alteration of a structure listed on the National Register of Historic Places or a State Inventory of Historic Places.


Variance (flood plain overlay) shall mean a grant of relief to a person from the requirements of this division which permits construction in a manner otherwise prohibited by this division where specific enforcement would result in unnecessary hardship.


100-year flood shall mean the base flood having a one percent chance of actual occurrence. 


Source:  Ord. No. 4603, § 1, 9-16-02; Ord. No. 5434, § 2, 10-3-16; Ord. No. 5563, § 61, 8-20-18