LOMA (Letter Of Map Amendment. A process whereby
FEMA will review the accuracy of a current effective panel to determine
if a structure(s) was (were) incorrectly placed within a SFHA. A LOMA
amends the current effective FEMA map and establishes that the property
is not in a SFHA.)
LOMR (A LOMR is an official revision to the current effective FEMA
map. It is used to change flood zones, floodplain and floodway
delineations, flood elevations, and planimetric features. A LOMR is
usually followed by a physical map revision.)
LOS (Loan Origination Software)
MHW (Mean High Water)
MHW(L) (Mean High Water (Level)
MLT (Mean Low Tide)
NFIA (National Flood Insurance Act)
NFIF (National Flood Insurance Fund)
NFIP (National Flood Insurance Program)
NFIRA (National Flood Insurance Reform Act)
NGVD National Geodetic Vertical Datum
NHWL Normal High Water Line
NN (A community which is NOT participating in the NFIP and has no
published flood hazard map panel.)
NSFHA (No Special Flood Hazard Areas)
NOAA (National Oceanic and Atmospheric Administration)
NPS (National Park Service)
NRC (National Research Council)
OHWL (Ordinary High Water Line)
OMB WG (Ofiice of Management & Budget Working Group on Shoreline
Protection)
OMHW (Ordinary Mean High Water)
SBA (Small Business Administration)
SDI (Spatial Data Institute)
SF (Single Family housing units)
SFHA (Special Flood Hazard Area)
SPA (Shoreline Protection Act)
UNCED (United Nations Conference of Environment and Development)
USACE (U.S. Army Corps of Engineers)
USEPA (U.S. Environmental Protection Agency)
USFWS (U.S. Fish and Wildlife Service)
USGS (U.S. Geological Survey)
WRDA Water Resources Development Act
Explanation of Terms
Accretion
- May be either natural or artificial. Natural accretion is the buildup
of land, solely by the
action of the forces of nature, on a beach by deposition of water or
airborne material. Artificial accretion is a similar buildup of land by
human accretions, such as accretion formed by a groin, breakwater, or
beach fill deposited by mechanical means.
A-zone
- Area subject to inundation by 100-year flooding where wave action
does not occur or where
waves are less than 3 feet high; designated Zone A, AE, A1-A30, A0, AH,
or AR on a Flood Insurance Rate Map.
Armor
- To protect slopes form erosion and scour by flood waters. Techniques
of armoring include the
use of riprap, gabions, or concrete.
Base flood
- Flood that has a 1-percent probability of being equal or exceeded in
any given year. Also
known as the 100-year flood.
Base Flood
Elevation (BFE) -
Elevation of the base flood in relation to a specified
datum, such as the National Geodetic Vertical Datum. The
Base Flood Elevation is the basis of the insurance and floodplain
management requirements of the National Flood Insurance Program.
Basic Report - A flood hazard determination
which is provided without Life of Loan monitoring. Commonly ordered for
short-term loans.
Beach
nourishment -
Replacement of beach sand removed by ocean waters. It may be brought
about naturally by alongshore transport or artificially by deposition of
dredged materials.
Breakaway
walls - Under the
National Flood Insurance Program, walls that are not part of
the structural support of the building and are designed and constructed
to break away or collapse under specified lateral loads imposed by flood
waters before transmitting damaging forces to the building and its
supporting foundation system. Breakaway walls are required by the
National Flood Insurance Program regulations for the portions of
buildings below the
Base Flood Elevation
in a Coastal High
Hazard Area, also referred to as V-zones, and are
recommended in areas where flood waters could flow at significant
velocities (usually greater than 4 feet per second) or could contain ice
or other debris.
Breakwater
- A structure protecting a shore area, harbor, anchorage, or basin
from waves.
Building code
- Regulations adopted
by local governments that establish standards for construction,
modification, and repair of buildings and other structures.
Bulkhead
- Wall or other structure, often of wood, steel, or concrete, designed
to retain or prevent
sliding or erosion of the land. Occasionally, bulkheads are used to
protect against wave action.
Coastal
barrier -
Depositional geologic feature such as a bay barrier, tombolo, barrier
spit, or barrier island that consists of unconsolidated sedimentary
materials; is subject to wave, tidal, and wind energies; and protects
landward aquatic habitats from direct wave attack.
Coastal
Barrier Resource Act of 1982 (CBRA)
- Act (Pub. L. 97-348) that
established the Coastal Barrier Resources System. The act prohibits the
provision of new flood insurance coverage on or after October 1, 1983,
for any new construction or substantial improvements of structures
located on any designated undeveloped coastal barrier within the Coastal
Barrier Resources System.
Coastal flood
hazard area - Area,
usually along an open coast, bay, or inlet, that is subject to
inundation by storm surge and, in some instances, wave action caused by
storms or seismic forces.
Coastal High
Hazard Area - Area of
special flood hazard, designated Zone V, VE, or V1-V30 on a Flood
Insurance Rate Map that extends from offshore to the inland
limit of a primary frontal dune along an open coast and any other area
subject to high-velocity breaking waves of 3 feet or more in height
caused by storms or seismic forces.
Coastline
- (1) Technically, the line that forms the boundary between the coast
and the shore. (2)
Commonly, the line that forms the boundary between the land and the
water.
Development- Under the National Flood Insurance Program, any
man-made change to
improved or unimproved real estate, including but not limited to
buildings or other structures, mining, dredging, filling, grading,
paving, excavation, or drilling operations or storage of equipment or
materials.
Downdrift
- The direction of predominant
movement of littoral materials.
E-zone
- An area along the coast where waves and other forces are anticipated
to cause significant
erosion within the next 60 years and may result in the damage or loss of
buildings and infrastructure.
Elevation Certificate - An elevation certificate is a
document provided by a certified Surveyor showing actual elevation
measurements taken on-site. This document is a requirement when applying
for a LOMA or LOMR.
Episodic
erosion -
Erosion induced by a single storm event. Episodic erosion
considers the vertical component of two factors: general beach profile
lowering and localized conical scour around foundation supports.
Episodic erosion is relevant to foundation embedment depth and potential
undermining.
Erosion
- Wearing away of the land surface by detachment and movement of
soil and rock fragments, during
a flood or storm or over a period of years, through the action of wind,
water, or other geologic processes.
Erosion Hazard
Area (EHA) – Area
anticipated to be lost to shoreline retreat over a given period of time.
The projected inland extent of the area is measured in years times the
average annual long-term recession rate.
Federal
Emergency Management Agency (FEMA)
- Independent agency created in
1978 to provide a single point of accountability for all Federal
activities related to disaster mitigation and emergency preparedness,
response and recovery. FEMA administers the National Flood
Insurance Program.
FEMA Standard Form - FEMA has mandated that all FZD
reports be provided on the standardized form since January of 1996.
Federal
Insurance Administration (FIA)
- The component of the
Federal
Emergency Management
Agency directly
responsible for administering the flood insurance aspects of the
National Flood Insurance Program.
Flood
- Under the National Flood Insurance Program, a general
and temporary condition
or partial or complete inundation of normally dry land areas from (1)
the overflow of inland or tidal waters, (2) the unusual and rapid
accumulation or runoff of surface waters from any source, or (3)
mudflows or the sudden collapse of shoreline land.
Flood depth -
Height of the flood
water surface above the ground surface.
Flood
elevation - Height of
the water surface above an established elevation datum, e.g.,
National Geodetic Vertical Datum, North American Vertical
Datum, Mean Sea Level.
Flood hazard
area - The greater of
the following: (1) the Special Flood Hazard
Area or (2) the area designated as a flood hazard area on a community's legal
flood hazard map, or otherwise legally designated.
Flood
Insurance
- Insurance coverage provided
under the National Flood
Insurance Program.
Flood
Insurance Rate Map (FIRM)
- Map of a community, prepared
by the Federal Emergency Management Agency, that shows
both the special hazard areas and the risk premium zones applicable to
the community. The latest FIRM issued for a community is referred to as
the "effective" FIRM.
Flood
Insurance Study (FIS)
- Examination, evaluation, and
determination of flood hazards and, if appropriate, corresponding water
surface elevations in a community or communities, or examination,
evaluation, and determination of mudslide (i.e., mudflow) and/or
flood-related erosion hazards in a community or communities.
Flood-related
erosion area or flood-related erosion prone area
- Land area adjoining the shore
of a lake or other body of water which, because of the composition of
the shoreline or bank and high water levels or wind-driven currents, is
likely to suffer damage from erosion caused by flood
forces.
Floodplain
- Any land area, including watercourse, susceptible to partial or
complete inundation by water from any source.
Floodplain
management -
Operation of an overall program of corrective and preventive measures
for reducing flood damage, including but not limited to emergency
preparedness plans, flood control works, and floodplain management
regulations.
Frontal dune
- Ridge or mound of
unconsolidated sandy soil, extending continuously alongshore landward of
the sand beach and defined by relatively steep slopes abutting markedly
flatter and lower regions on each side.
Groin
- A shore protection structure built (usually perpendicular to the
shoreline) to trap littoral drift or retard erosion of the shore.
Hand Mapping - A process used by SRG whereby a
research staff member physically references the appropriate FEMA flood
map panel and tax assessment plat map before making his/her
determination for SRG’s client.
High-velocity
wave action -
Condition in which wave heights are greater than or equal to 3.0 feet or
wave run up elevations reach 3.0 or more feet above grade.
Hurricane
- Tropical cyclone, formed in the atmosphere over warm ocean areas,
in which wind speeds
reach 74 miles per hour or more and blow in a large spiral around a
relatively calm center or "eye." Hurricane circulation is
counter-clockwise in the Northern Hemisphere and clockwise in the
Southern Hemisphere.
Jetty
- A structure extending into a body of water, designed to prevent
shoaling of a channel by
littoral materials and to direct and confine the stream or tidal flow.
Jetties are built at the mouths of rivers or tidal inlets to help deepen
and stabilize a channel.
Littoral
- Of or pertaining to the shore, especially of the sea.
Littoral Drift
- Movement of sand by
littoral (longshore) currents in a direction parallel to the beach along
the shore.
Littoral
Transport - The
movement of littoral drift in the littoral zone by waves and currents.
Includes movement parallel and perpendicular to the shore.
Lowest floor
- The lowest floor of
the lowest enclosed area (including basement) of a structure. An
unfinished or flood-resistant enclosure, usable solely for parking of
vehicles, building access, or storage in an area other than a
basement, is not considered a building's lowest floor.
Mean High
Water - The average
height of the high waters over a 19-year period.
Mean Sea Level
(MSL) - Average
height of the sea for all stages of the tide, usually determined from
hourly height observations over a 19-year period on an open coast or in
adjacent waters having free access to the sea. See National
Geodetic
Vertical Datum.
National Flood
Insurance Program (NFIP)
- Federal program created by
Congress in 1968 that makes flood insurance available in communities
that enact satisfactory floodplain management regulations.
National
Geodetic Vertical Datum (NGVD)
- Datum established in 1929 and
used as a basis for measuring flood, ground, and structural elevations,
previously referred to as Sea Level Datum or Mean Sea Level.
The Base Flood Elevations shown on most of the Flood
Insurance Rate Maps issued by the Federal
Emergency
Management Agency
are referenced to NGVD.
100-year flood
- See Base Flood.
Partial Determination - A determination which can not
be accurately completed until a Survey or Site plan is forwarded.
Post-FIRM
- For insurance purposes, post-FIRM construction in a given
community is construction or substantial improvement of a structure that
began after December 31, 1974, or on or after the effective date of the
first Flood
Insurance Rate Map
for the community, whichever is
later. For floodplain management purposes, post-FIRM construction in a
given community means structures for which the start of new or
substantial improvement construction began before the effective date of
the floodplain management regulation adopted by the community.
Primary
frontal dune -
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 the primary
frontal dune occurs at the point where there is a distinct change from a
relatively steep slope to a relatively mild slope.
Retrofit
- In flood proofing, any change made to a structure designed to reduce
or eliminate damage to that structure from flooding erosion.
Revetment
– A facing of stone, cement, sandbags, or other materials built to
protect a scarp, embankment, or short structure against erosion or scour
caused by flood waters or wave action.
Sand dunes
- Natural or artificial ridges or mounds of sand landward of the
beach.
Sand wave
- A large wavelike sediment feature composed of sand in very
shallow water. Wavelength may reach 100 meters; amplitude is about 0.5
meter.
Scarp
- An almost vertical slope along the beach caused by erosion by wave
action. It may vary in height from a few centimeters to a meter or so,
depending on wave action and the nature and composition of the beach.
Scour
– Removal of soil or fill material by the flow of flood waters. The term
is frequently used to
describe storm-induced, localized conical erosion around pilings and
other foundation supports where the obstruction of flow increases
turbulence. See erosion.
Seawall
- A structure separating land and water areas, primarily designed to
prevent erosion and other damage from wave actions.
Shear wall
- Load-bearing or non-load-bearing wall that transfers in-plane
lateral forces from lateral
loads acting on a structure to its foundation.
Shore
- The narrow strip of land in immediate contact with the sea, including
the zone between high and
low water lines. A shore of unconsolidated material usually is called a
beach.
Shoreline
- The intersection of a specified plane of water with the shore or
beach. The line delineating the shoreline on natural ocean service
nautical charts and survey approximates the mean high water line.
Shoreline
retreat - Progressive
movement of the shoreline in a landward direction caused by the
composite effect of all storms considered over decades and centuries
(expressed as an annual average erosion rate). Shoreline retreat
considers the horizontal component of erosion and is relevant to
long-term land use decisions and the siting of buildings.
Special Flood
Hazard Area (SFHA) –
An area within a floodplain having a 1 percent or greater chance of
flood occurrence in any given year (100-year floodplain); represented on
Flood Insurance Rate Maps by darkly shaded areas with zone
designations that include the letter A or V.
Storm surge
- Rise in the water
surface above normal water level on the open coast due to the action of
wind stress and atmospheric pressure on the water surface.
Structure
- Under the National Flood Insurance Program, a walled and
roofed building,
including a gas or liquid storage tank, that is principally above
ground, as well as a manufactured home; for insurance coverage purposes.
Substantial
damage - 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
percent of the market value of the structure before the damage.
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.
Surge
- See Storm surge.
Tsunami
- Great sea wave produced by submarine earth movement or volcanic
eruption.
Undermining
- Process whereby the
vertical component or erosion or scour exceeds the depth of the base of
a building foundation or the level below which the bearing strength of
at the foundation is compromised.
Updrift
- The direction opposite that of the predominant movement of littoral
materials.
V-zone
- also known as Coastal High Hazard Area. Flood hazard zone that
corresponds to the 100-year floodplain that is subject to high velocity
wave action from coastal storms or seismic sources; designated Zone VO,
V1-30, VE, or V on a Flood Insurance Rate Map.
Water surface
elevation - Height of
the water surface above an established elevation datum, e.g.,
National Geodetic Vertical Datum, North American
Vertical Datum,
Mean Sea Level, reached by floods of various magnitudes and
frequencies in the floodplains of coastal, lacustrine, and riverine
areas.
Wave height
- Vertical distance
between a wave crest and the preceding trough.
Wind tide
– The vertical rise in the stillwater level on the leeward side of a
body of water caused by
wind stresses on the surface of the water.
X-zone
– A flood hazard zone outside the 100-year floodplain, which have
moderate to minimal risk. Older
maps differentiate the X zone into Zones B and C, which represent
moderate and minimal flood risks, respectively.
Zone
– A geographical area shown on a Flood Insurance Rate Map (FIRM)
that reflects the severity or type of flooding in the area.
