[7-21-2008(2)]
For the purposes of this Title, the following definitions are
adopted:
ACCESSORY STRUCTURE
A nonhabitable structure which is on the same parcel of property
as the principal structure to be insured and the use of which is incidental
to the use of the principal structure.
ACT
An act in relation to the regulation of the rivers, lakes
and streams of the State of Illinois," 615 ILCS 5/5 et seq.
APPLICANT
Any person, firm, corporation or agency which submits an
application.
APPROPRIATE USE
Only uses of the designated floodway that are permissible
and will be considered for permit issuance. The only uses that will
be allowed are as specified in § 13-1-7B.
BASE FLOOD
The flood having a 1% chance of being equaled or exceeded
in any given year. The base flood is also known as the one-hundred-year
frequency flood event. Application of the base flood elevation at
any location is as defined in § 13-1-5 of this Title.
BASEMENT
That portion of the building having its floor subgrade (below
ground level) on all sides.
BUILDING
A walled and roofed structure, including gas or liquid storage
tank, that is principally above ground, including manufactured homes,
prefabricated buildings, and gas or liquid storage tanks. The term
also includes recreational vehicles and travel trailers installed
on a site for more than 180 days per year.
CHANNEL
Any river, stream, creek, brook, branch, natural or artificial
depression, ponded area, flowage, slough, ditch, conduit, culvert,
gully, ravine, wash, or natural or man-made drainage way, which has
a definite bed and banks or shoreline, in or into which surface or
groundwater flows, either perennially or intermittently.
CHANNEL MODIFICATION
Alteration of a channel by changing the physical dimensions
or materials of its bed or banks. Channel modification includes damming,
rip-rapping (or other armoring), widening, deepening, straightening,
relocating, lining and significant removal of native vegetation from
the bottom or banks. Channel modification does not include the clearing
of dead or dying vegetation, debris, or trash from the channel. Canalization
is a severe form of channel modification involving a significant change
in the channel cross-section and typically involving relocation of
the existing channel (e.g. straightening).
COMPENSATORY STORAGE
An artificially excavated, hydraulically equivalent volume
of storage within the SFHA used to balance the loss of natural flood
storage capacity when artificial fill or structures are placed within
the floodplain. The uncompensated loss of natural floodplain storage
can increase off-site floodwater elevations and flows.
CONDITIONAL APPROVAL OF A DESIGNATED FLOODWAY MAP CHANGE
Preconstruction approval by IDNR/OWR and FEMA of a proposed
change to the floodway map. This preconstruction approval, pursuant
to this Title, gives assurances to the property owner that once an
Appropriate Use is constructed according to permitted plans, the floodway
map can be changed, as previously agreed, upon review and acceptance
of as-built plans.
CONDITIONAL LETTER OF MAP REVISION (CLOMR)
A letter which indicates that FEMA will revise base flood
elevations, flood insurance rate zones, flood boundaries or floodway
as shown on an effective Flood Hazard Boundary Map or Flood insurance
rate map, once the as-built plans are submitted and approved.
CONTROL STRUCTURE
A structure designed to control the rate of flow that passes
through the structure, given a specific upstream and downstream water
surface elevation.
CRITICAL FACILITY
Any facility which is critical to the health and welfare
of the population and, if flooded, would create an added dimension
to the disaster. Damage to these critical facilities can impact the
delivery of vital services, can cause greater damage to other sectors
of the community, or can put special populations at risk. Examples
of critical facilities where flood protection should be required include:
emergency services facilities (such as fire and police stations),
schools, hospitals, retirement homes and senior care facilities, major
roads and bridges, critical utility sites (telephone switching stations
or electrical transformers), and hazardous material storage facilities
(chemicals, petrochemicals, hazardous or toxic substances). Examples
of critical facilities where flood protection is recommended include:
sewage treatment plants, water treatment plants, and pumping stations.
DAM
All obstructions, wall embankments or barriers, together
with their abutments and appurtenant works, if any, constructed for
the purpose of storing or diverting water or creating a pool. Dams
may also include weirs, restrictive culverts or impoundment structures.
Underground water storage tanks are not included.
DESIGNATED FLOODWAY
The channel, including on-stream lakes, and that portion
of the floodplain adjacent to a stream or watercourse, generally depicted
on the FEMA FIRM map, which is needed to store and convey the existing
one-hundred-year frequency flood discharge with no more than a 0.1
foot increase in stage due to the loss of flood conveyance or storage,
and no more than a 10% increase in velocities.
A.
The floodways are designated for on the countywide Flood insurance
rate map of Cook County prepared by FEMA and dated August 19, 2008
When two floodway maps exist for a waterway, the more restrictive
floodway limit shall prevail.
B.
The floodways for those parts of unincorporated Cook County
that are within the extraterritorial jurisdiction of the Village that
may be annexed into the Village are designated for Thorn Creek on
the countywide Flood insurance rate map prepared by FEMA and dated
August 19, 2008.
C.
To locate the designated floodway boundary on any site, the
designated floodway boundary should be scaled off the designated floodway
map and located on a site plan, using reference marks common to both
maps. Where interpretation is needed to determine the exact location
of the designated floodway boundary, IDNR/OWR should be contacted
for the interpretation.
DEVELOPMENT
A.
Any man-made change to real estate, including:
1.
Construction, reconstruction, repair, or placement of a building
or any addition to a building.
2.
Installing a manufactured home on a site, preparing a site for
a manufactured home, or installing a travel trailer or recreational
vehicle on a site for more than 180 days. If the travel trailer or
recreational vehicle is on site for more than 180 days, it must be
fully licensed and ready for highway use.
3.
Drilling, mining, installing utilities, construction of roads,
bridges, or similar projects.
4.
Demolition of a structure or redevelopment of a site.
5.
Clearing of land as an adjunct of construction.
6.
Construction or erection of levees, walls, fences, dams, or
culverts; channel modification; filling, dredging, grading, excavating,
paving, or other non-agricultural alterations of the ground surface;
storage of materials; deposit of solid or liquid waste;
7.
Any other activity of man that might change the direction, height,
or velocity of flood or surface water, including extensive vegetation
removal;
8.
Substantial improvement of an existing building.
B.
Development does not include routine maintenance of existing
buildings and facilities such as re-roofing or re-surfacing of roads
when there is no increase in elevation, or gardening, plowing, and
similar agricultural practices that do not involve filling, grading,
or construction of levees.
ELEVATION CERTIFICATES
A form published by FEMA that is used to certify the elevation
to which a building has been elevated.
EROSION
The general process whereby soils are moved by flowing water
or wave action.
EXEMPT ORGANIZATIONS
Organizations which are exempt from this Title per Illinois
Compiled Statutes (ILCS) including state, federal or local units of
government.
EXISTING MANUFACTURED HOME PARK OR SUBDIVISION
A manufactured home park or subdivision for which the construction
of facilities for servicing the lots on which the manufactured homes
are to be affixed (including, at a minimum, the installation of utilities,
the construction of streets, and either final site grading or the
pouring of concrete pads) has been completed before April 1, 1990.
EXPANSION TO AN EXISTING MANUFACTURED HOME PARK OR SUBDIVISION
The preparation of additional sites by the construction of
facilities for servicing the lots on which the manufactured homes
are to be affixed (including the installation of utilities, the construction
of streets, and either final site grading or the pouring of concrete
pads).
FEMA
Federal Emergency Management Agency and its regulations at
44 CFR 59-79, as amended.
FLOOD
A general and temporary condition of partial or complete
inundation of normally dry land areas from overflow of inland or tidal
waves, or the unusual and rapid accumulation or runoff of surface
waters from any source.
FLOOD FREQUENCY
A period of years, based on a statistical analysis, during
which a flood of a stated magnitude may be expected to be equaled
or exceeded.
FLOOD FRINGE
That portion of the floodplain outside of the designated
floodway. See commentary on "designated floodway."
FLOOD INSURANCE RATE MAPS (FIRM)
A map prepared by FEMA that depicts the special flood hazard
area (SFHA) within a community. This map includes insurance rate zones
and floodplains and may or may not depict floodways.
FLOOD INSURANCE STUDY
An examination, evaluation and determination of flood hazards
and if appropriate, corresponding water surface elevations.
FLOOD PROTECTION ELEVATION (FPE)
The elevation of the base flood or one-hundred-year frequency
floods plus one foot of freeboard at any given location in the SFHA.
FLOODPLAIN
That land typically adjacent to a body of water with ground
surface elevations at or below the base flood or the one-hundred-year
frequency flood elevation. Floodplains may also include detached Special
Flood Hazard Areas, ponding areas, etc. The floodplain is also known
as the Special Flood Hazard Area (SFHA).
A.
The floodplains are those lands within the jurisdiction of the
Village that are subject to inundation by the base flood or one-hundred-year
frequency flood. The SFHAs of the Village are generally identified
as such on panel number(s) 0734J, 0742J, 0753J, and 0761J of the countywide
Flood insurance rate map of the Village prepared by the Federal Emergency
Management Agency and dated August 19, 2008.
B.
The SFHAs of those parts of unincorporated Cook County that
are within the extraterritorial jurisdiction of the Village or that
may be annexed into the Village are generally identified as such on
panel number(s) 0734J, 0742J, 0753J, and 0761J of the countywide Flood
insurance rate map prepared for Cook County by the Federal Emergency
Management Agency and dated August 19, 2008.
FLOODPROOFING
Any combination of structural and non-structural additions,
changes or adjustments to structures which reduce or eliminate flood
damage to real estate or improved real property, water and sanitary
facilities, structures and their contents.
FLOODPROOFING CERTIFICATE
A form published by FEMA that is used to certify that a building
has been designed and constructed to be structurally dry floodproofed
to the flood protection elevation.
HISTORIC STRUCTURE
Any structure that is:
A.
Listed individually in the National Register of Historic Places
or preliminary determined by the Secretary of the Interior as meeting
the requirements for individual listing on the National Register;
B.
Certified or preliminary determined by the Secretary of the
Interior as contributing to the historic district or a district preliminary
determined by the Secretary to qualify as a registered historic district;
C.
Individually listed on the State Inventory of Historic Places
by the Illinois Historic Preservation Agency.
D.
Individually listed on a local inventory of historic places
that has been certified by the Illinois Historic Preservation Agency.
IDNR/OWR
Illinois Department of Natural Resources, Office of Water
Resources.
LETTER OF MAP REVISION (LOMR)
Letter that revises base flood or one-hundred-year frequency
flood elevations, floodplains or floodways as shown on an effective
FIRM.
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 buildings 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 this Title.
MANUFACTURED HOME
A structure, transportable in one or more sections, which
is built on a permanent chassis and is designated for use with or
without a permanent foundation when attached to the required utilities.
The term "manufactured home" also includes park trailers, travel trailers
and other similar vehicles placed on site for more than 180 consecutive
days. The term "manufactured home" does not include a "recreational
vehicle."
MITIGATION
Mitigation includes those measures necessary to minimize
the negative effects which floodplain development activities might
have on the public health, safety and welfare. Examples of mitigation
include: excavation of compensatory storage, soil erosion and sedimentation
control, and channel restoration. Mitigation may also include those
activities taken to reduce a structure's susceptibility to flooding.
NATURAL
When used in reference to channels means those channels formed
by the existing surface topography of the earth prior to changes made
by man. A natural stream tends to follow a meandering path; its floodplain
is not constrained by levees; the area near the bank has not been
cleared, mowed or cultivated; the stream flows over soil and geologic
materials typical of the area with no substantial alteration of the
course or cross-section of the stream caused by filling or excavating.
A modified channel may regain some natural characteristics over time
as the channel meanders and vegetation is re-established. Similarly,
a modified channel may be restored to more natural conditions by man
through regarding and revegetation.
NEW CONSTRUCTION
New construction means structures for which the start of
construction commenced on or after the effective date of a floodplain
management regulation adopted by a community and includes any subsequent
improvements to such structures.
NEW MANUFACTURED HOME PARK OR SUBDIVISION
Manufactured home park or subdivision for which the construction
of facilities for servicing the lots on which the manufactured homes
are to be affixed (including at a minimum, the installation of utilities,
the construction of streets, and either final site grading or the
pouring of concrete pads) has been completed on or after April 1,
1990.
ORDINARY HIGH WATER MARK (OHWM)
The point on the bank or shore up to which the presence and
action of surface water is so continuous so as to leave a distinctive
mark such as by erosion, destruction or prevention of terrestrial
vegetation, predominance of aquatic vegetation or other easily recognized
characteristics.
PUBLIC BODIES OF WATERS
All open public streams and lakes capable of being navigated
by watercraft, in whole or in part, for commercial uses and purposes,
and all lakes, rivers, and streams which in their natural condition
were capable of being improved and made navigable, or that are connected
with or discharge their waters into navigable lakes or rivers within,
or upon the borders of the State of Illinois, together with all bayous,
sloughs, backwaters, and submerged lands that are open to the main
channel or body of water directly accessible thereto.
PUBLIC FLOOD CONTROL PROJECT
A flood control project which will be operated and maintained
by a public agency to reduce flood damages to existing buildings and
structures, including a hydrologic and hydraulic study of the existing
and proposed conditions of the watershed. Nothing in this definition
shall preclude the design, engineering, construction or financing,
in whole or in part, of a flood control project by persons or parties
who are not public agencies.
RECREATIONAL VEHICLE or TRAVEL TRAILER
A vehicle which is:
A.
Built on a single chassis;
B.
Four hundred square feet or less when measured at the largest
horizontal projection;
C.
Designed to be self-propelled or permanently towable by a light
duty truck; and
D.
Designed primarily not for use as a permanent dwelling but as
temporary living quarters for recreational, camping, travel, or seasonal
use.
REGIONAL PERMITS
Regional permits are offered for pre-approved projects which
are considered minor projects that are permissible per IDNR/OWR Part
3708 rules for Northeastern Illinois regulatory floodways. A complete
listing of the terms and conditions for specific project types can
be obtained from the IDNR/OWR website.
REGISTERED LAND SURVEYOR
A land surveyor registered in the State of Illinois, under
The Illinois Land Surveyors Act. (225 ILCS 330/1 et seq.)
REPAIR, REMODELING or MAINTENANCE
Development activities which do not result in any increases
in the outside dimensions of a building or any changes to the dimensions
of a structure.
REPETITIVE LOSS
Flood-related damages sustained by a structure on two separate
occasions during a ten-year period for which the cost of repairs at
the time of each such flood event, on the average, equals or exceeds
25% of the market value of the structure before the damaged occurred.
RETENTION/DETENTION FACILITY
A retention facility stores stormwater runoff without a gravity
release. A detention facility provides for storage of stormwater runoff
and controlled release of this runoff during and after a flood or
storm.
RIVERINE SFHA
Any SFHA subject to flooding from a river, creek, intermittent
stream, ditch, on-stream lake system or any other identified channel.
This term does not include areas subject to flooding from lakes, ponding
areas, areas of sheet flow, or other areas not subject to overbank
flooding.
RUNOFF
The water derived from melting snow or rain falling on the
land surface, flowing over the surface of the ground or collected
in channels or conduits.
SEDIMENTATION
The processes that deposit soils, debris, and other materials
either on other ground surfaces or in bodies of water or watercourses.
START OF CONSTRUCTION
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 placement of a manufactured home on a foundation.
STATEWIDE PERMITS
Statewide permits are offered for pre-approved projects that
are considered minor projects which are permissible per the IDNR/OWR
Part 3700 rules. A complete listing of the statewide permits and permit
requirements can be obtained from the IDNR/OWR website.
SUBSTANTIAL DAMAGE
Damage of any origin sustained by a structure whereby the
cumulative percentage of damage during the life of the building equals
or exceeds 50% of the market value of the structure before the damage
occurred regardless of actual repair work performed. Volunteer labor
and materials must be included in this determination. The term includes
Repetitive Loss Buildings See "Repetitive loss."
SUBSTANTIAL IMPROVEMENT
Any reconstruction, rehabilitation, addition, or improvement
of a structure taking place during the life of the building in which
the cumulative percentage of improvements equals or exceeds 50% of
the market value of the structure before the improvement or repair
is started.
A.
"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 building. This term includes structures
which have incurred repetitive loss or substantial damage, regardless
of the actual work done.
B.
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 "historic structure" listed on the National
Register of Historic Places or the Illinois Register of Historic Places,
provided that the alteration will not preclude the structure's
continued designation as a historic structure.
TRANSITION SECTION
Reaches of the stream or floodway where water flows from
a narrow cross-section to a wide cross-section or vice versa.
VILLAGE
The Village of Thornton, Cook County, Illinois, an Illinois
Municipal Corporation.
VIOLATION
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 is presumed
to be in violation until such time as that documentation is provided.
[7-21-2008(2)]
The provisions and sections of this Title shall be deemed separable
and the invalidity of any portion of this Title shall not affect the
validity of the remainder.