Floodplain management

Start of Construction

(for other than new construction or substantial improvements under the Coastal Barrier Resources Act) includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition placement, or other improvement was within 180 days of the permit date the actual start means either 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 on a foundation permanent construction does NOT include land preparation (clearing, grading and filling) the instillation of streets and/or walkways, excavation for a basement/footings/piers/foundations, the erection of temporary forms, the installation on the property of accessory buildings (garages or sheds not occupied as dwelling units or not part of the main structure) for a substantial improvement, the actual start 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

Mudslide or mudflow

a condition where there is a river, flow or inundation of liquid mud down a hillside usually as a result of a dual condition of loss of brush cover, and the subsequent accumulation of water on the ground preceded by a period of unusually heavy or sustained rain. may occur as a distinct phenomenon while a landslide is in progress, and will be recognized as such by the Administrator only if it, and not the landslide, is the proximate cause of damage that occurs

Primary frontal dune

a continuous or nearly continuous mound or ridge of sand with relatively steep seaward and landward slopes immediately landward and adjacent to the beach and subject to erosion and overtopping from high tides and waves during major coastal storms. the inland limit of this occurs at the point where there is a distinct change from a relatively steep slope to a relatively mild slope.

Area of shallow flooding

a designated AO, AH, AR/AO, AR/AH, or VO zone on a community's Flood Insurance Rate Map (FIRM) with a 1 percent or greater annual chance of flooding to an average depth of 1 to 3 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.

30-year setback

a distance equal to 30 times the average annual long term recession rate at a site, measured from the reference feature

60-year setback

a distance equal to 60 times the average annual long term recession rate at a site, measured from the reference feature

Independent scientific body

a non-Federal technical or scientific organization involved in the study of land use planning, flood plain management, hydrology, geology, geography, or any other related field of study concerned with flooding

storm cellar

a space below grade used to accommodate occupants of the structure and emergency supplies as a means of temporary shelter against severe tornado or similar wind storm activity

Breakaway wall

a wall 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.

Second layer coverage

an additional limit of coverage equal to the amounts made available under the Emergency Program and the Regular Program

Developed Area

an area of a community that is: (a) a primarily urbanized, built-up area that is a minimum of 20 contiguous acres, has basic urban infrastructure, including roads, utilities, communications, and public facilities, to sustain industrial, residential, and commercial activities, and (1)within which 75% or more of the parcels, tracts, or lots contain commercial, industrial, or residential structure or uses (2)is a single parcel, tract, or lot in which 75% of the area contains existing commercial or industrial structures or uses (3)is a subdivision developed at a density of at least 2 residential structures per acre within which 75% or more of the lots contain existing residential structures at the time the designation is adopted (b)Undeveloped parcels, tracts, or lots, the combination of which is less than 20 acres and contiguous on at least 3 sides to areas meeting the criteria of paragraph (a) at the time the designation is adopted (c)a subdivision that is a minimum of 20 contiguous acres that has obtained all necessary government approvals, provided that the actual "start of construction" of structures has occurred on at least 10% of the lots or remaining lots of a subdivision or 10% of the maximum building coverage or remaining building coverage allowed for a single lot subdivision at the time the designation is adopted and construction of structures is underway. Residential subdivisions must meet the density criteria in paragraph (a)(3)

Coastal high hazard area

an area of special flood hazard extending from offshore to the inland limit of a primary frontal dune along an open coast and any other area subject to high velocity wave action from storms or seismic sources

Zone of imminent collapse

an area subject to erosion adjacent to the shoreline of an ocean, bay, or lake and within a distance equal to 10 feet plus 5 times the average annual long-term erosion rate for the site, measured from the reference feature

Flood Hazard Boundary Map

an official map of a community, issued by the Federal Insurance Administrator, where the boundaries of the flood, mudslide (i.e., mudflow) related erosion areas having special having special hazards have been designated as Zones A, M, and/or E.

Development

any man-made change to improved or unimproved real estate, including buildings or other structures, mining, dredging, filling, grading, paving, excavation, or drilling operations or storage of equipment or materials

Historic Structure

any structure that is: (a) Listed individually in the National Register of Historic Places (a listing maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register (b) certified or preliminarily determined by the secretary of the interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the secretary to qualify as a registered historic district (c) individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of the interior (d)individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either (1) By an approved state program as determined by the secretary of the interior (2) Directly by the Secretary of the Interior in states without approved programs

Principally above ground

at least 51% of the actual cash value of the structure, less land value, is above ground

structure

for floodplain management purposes: a walled/roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home for insurance purposes: (1)a building with two or more outside rigid walls and a fully secured roof, that is affixed to a permanent site (2)a manufactured home (mobile home, built on a permanent chassis, transported to its site in one or more sections, and affixed to a permanent foundation) (3)a travel trailer without wheels, built on a chassis and affixed to a permanent foundation, that is regulated under the community's floodplain management and building ordinances or laws For the latter purpose, 'structure' does not mean a recreational vehicle or a park trailer or other similar vehicle, except as described in paragraph (3) of this definition, or a gas or liquid storage tank

Emergency Flood Insurance Program or Emergency Program

the Program as implemented on an emergency basis in accordance with section 1336 of the Act. It is intended as a program to provide a first layer amount of insurance on all insurable structures before the effective date of the initial FIRM

Flood-related erosion

the collapse or subsidence of land along the shore of a lake or other body of water as a result of undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as a flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding.

Standard Flood Insurance Policy

the flood insurance policy issued by the Federal Insurance Administrator or an insurer pursuant to an arrangement with the Federal Insurance Administrator pursuant to Federal statutes and regulations

Highest adjacent grade

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

Area of future-conditions flood hazard

the land area that would be inundated by the 1-percent-annual-chance (100 year) flood based on future-conditions hydrology

Area of special flood-related erosion hazard

the land within a community which is most likely to be subject to severe flood-related erosion losses. The area may be designated as Zone E on the Flood Hazard Boundary Map (FHBM). After the detailed evaluation of the special food-related erosion hazard area in preparation for publication of the FIRM, Zone E may be further refined.

Lowest Floor

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 non-elevation design requirements of 60.3

First-layer coverage

the maximum amount of structural and contents insurance coverage available under the Emergency Program

Regular program

the program authorized by the Act under which risk premium rates are required for the first half of available coverage (also known as 'first layer' coverage) for all new construction and substantial improvements started on or after the effective date of the FIRM, or after December 31, 1974, for FIRM's effective on or before that date. All building, the construction of which started before the effective date of the FIRM , or before January 1, 1975, for FIRMs effective before that date, are eligible for first layer coverage at either subsidized rates or risk premium rates, whichever are lower. Regardless of date of construction, risk premium rates are always required for the second layer coverage and such coverage is offered only after the Administrator has completed a risk study for the community.

Chargeable rates

the rates established by the Federal Insurance Administrator pursuant to section 1308 of the Act for first layer limits of flood insurance on existing structures.

Reference feature

the receding edge of a bluff or eroding frontal dune, or if such a feature is not present, the normal high-water line or the seaward line of permanent vegetation if a high-water line cannot be identified

Risk premium rates

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 section 1307 of the Act and the accepted actuarial principles. these rates include provisions for operating costs and allowances