This Article 7 is enacted pursuant to the police powers granted
of the Village by 65 ILCS 5/1-2-1, 5/11-12-12, 5/11-30-2, 5/11-30-8,
and 5/11-31-2. The purpose of this Article 7 is to maintain the Village's
eligibility in the National Flood Insurance Program; to minimize potential
losses due to periodic flooding, including loss of life, loss of property,
health and safety hazards, disruption of commerce and governmental
services, extraordinary public expenditures for flood protection and
relief, and impairment of the tax base, all of which adversely affect
the public health, safety and general welfare; and to preserve and
enhance the quality of surface waters, conserve economic and natural
values and provide for the wise utilization of water and related land
resources. This Article 7 is adopted in order to accomplish the following
specific purposes:
(A)
To meet the requirements of Section 18g of the Rivers, Lakes and
Streams Act, 615 ILCS 5/18g;
(B)
To assure that new development does not increase the flood or drainage
hazards to others, or create unstable conditions susceptible to erosion;
(C)
To protect new buildings and major improvements to buildings from
flood damage;
(D)
To protect human life and health from the hazards of flooding;
(E)
To lessen the burden on the taxpayer for flood control projects,
repairs to flood damaged public facilities and utilities, and flood
rescue and relief operations;
(F)
To make federally subsidized flood insurance available for property
in the Village by fulfilling the requirements of the National Flood
Insurance Program;
(G)
To comply with the rules and regulations of the National Flood Insurance
Program codified as 44 CFR 59-79, as amended;
(H)
To protect, conserve, and promote the orderly development of land
and water resources; and
(I)
To preserve the natural characteristics and functions of watercourses
and floodplains in order to moderate flood and stormwater impacts,
improve water quality, reduce soil erosion, protect aquatic and riparian
habitat, provide recreational opportunities, provide aesthetic benefits
and enhance community and economic development.
The following definitions shall apply in the interpretation
and enforcement of this Article 7:
A uninhabitable 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.
The Illinois Rivers, Lakes and Streams Act, 615 ILCS 5/5
et seq.
Any person, firm, corporation or agency which submits an
application.
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 Section 12-7-7(B) of this Code.
The flood having a one-percent 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 Section 12-7-5 of this Code.
The elevation in relation to mean sea level of the crest
of the base flood.
That portion of the building having its floor subgrade (below
ground level) on all sides.
A walled and roofed structure, including gas or liquid storage
tank, that is principally aboveground, 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.
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 drainageway, which has
a definite bed and banks or shoreline, in or into which surface or
ground water flows, either perennially or intermittently.
Alteration of a channel by changing the physical dimensions
or materials of its bed or banks. Channel modification includes damming,
riprapping (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. Channelization
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).
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.
Preconstruction approval by IDNR/OWR and FEMA of a proposed
change to the Floodway Map. This preconstruction approval, pursuant
to this definition, 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.
A letter which indicates that FEMA will revise base flood
elevations, flood insurance rate zones, flood boundaries or floodways
as shown on an effective Flood Hazard Boundary Map or Flood Insurance
Rate Map, once the as-built plans are submitted and approved.
A structure designed to control the rate of flow that passes
through the structure, given a specific upstream and downstream water
surface elevation.
Any facility which is critical to the health and welfare
of the population and which, 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.
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.
The channel, including on-stream lakes, and that portion
of the floodplain adjacent to a stream or watercourse, generally depicted
on the FEMA Flood Insurance Rate 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 ten-percent increase in
velocities.
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The floodways are designated on the county-wide Flood Insurance
Rate Map of Cook County, Illinois, prepared by FEMA and dated August
19, 2008. When two floodway maps exist for a waterway, the more restrictive
floodway limit shall prevail.
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The floodways for those parts of unincorporated Cook County,
Illinois, that are within the extraterritorial jurisdiction of the
Village that may be annexed into the Village are designated on the
county-wide Flood Insurance Rate Map prepared by FEMA and dated August
19, 2008.
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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.
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Any man-made change to real estate, including:
Construction, reconstruction, repair, or placement of a building
or any addition to a building.
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 less than 180 days, it must be
fully licensed and ready for highway use.
Drilling, mining, installing utilities, construction of roads,
bridges, or similar projects.
Demolition of a structure or redevelopment of a site.
Clearing of land as an adjunct of construction.
Construction or erection of levees, walls, fences, dams, or
culverts; channel modification; filling, dredging, grading, excavating,
paving, or other nonagricultural alterations of the ground surface;
storage of materials; deposit of solid or liquid waste.
Any other activity of man that might change the direction, height,
or velocity of flood or surface water, including extensive vegetation
removal.
Substantial improvement of an existing building.
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Development does not include routine maintenance of existing
buildings and facilities such as reroofing or resurfacing 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.
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A form published by FEMA that is used to certify the elevation
to which a building has been elevated.
The general process whereby soils are moved by flowing water
or wave action.
Organizations which are exempt from this Article 7 pursuant
to state law, including state, federal and local units of government.
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.
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).
The Federal Emergency Management Agency and its regulations
at 44 CFR 59-79, as amended.
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.
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.
That portion of the floodplain outside of the designated
floodway.
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.
An examination, evaluation and determination of flood hazards
and if appropriate, corresponding water surface elevations.
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).
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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 Numbers 244, 265, 382, 401, 402 of the county-wide
Flood Insurance Rate Map of the Village prepared by the Federal Emergency
Management Agency and dated August 19, 2008.
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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 on the county-wide
Flood Insurance Rate Map prepared for Cook County by the Federal Emergency
Management Agency and dated August 19, 2008.
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Any combination of structural and nonstructural 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.
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.
The elevation of the base flood or one-hundred-year frequency
flood plus one foot of freeboard at any given location in the SFHA.
See definition of "designated floodway."
Any structure that is:
Listed individually in the National Register of Historic Places
or preliminarily determined by the Secretary of the Interior as meeting
the requirements for individual listing on the National Register;
Certified or preliminarily determined by the Secretary of the
interior as contributing to the historic district or a district preliminarily
determined by the Secretary to qualify as a registered historic district;
Individually listed on the State Inventory of Historic Places
by the Illinois Historic Preservation Agency;
Individually listed on a local inventory of historic places
that has been certified by the Illinois Historic Preservation Agency.
Engineering analyses which determine expected flood flows
and flood elevations based on land characteristics and rainfall events.
Illinois Department of Natural Resources, Office of Water
Resources.
Official determination by FEMA that a specific structure
is not in a one-hundred-year floodplain; amends the FIRM.
Letter that revises base flood or one-hundred-year frequency
flood elevations, floodplains or floodways as shown on an effective
FIRM.
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 Article
7.
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.
When used in reference to channels, 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 reestablished. Similarly,
a modified channel may be restored to more natural conditions by man
through regrading and revegetation.
National American Vertical Datum of 1988. NAVD 88 supersedes
the National Geodetic Vertical Datum of 1929 (NGVD).
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.
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.
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.
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.
Regional permits are offered for preapproved 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.
A land surveyor registered in the State of Illinois under
the Illinois Land Surveyors Act, 225 ILCS 330/1 et seq.
An engineer registered in the State of Illinois under the
Illinois Professional Engineering Practice Act, 225 ILCS 325/1 et
seq.
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.
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 damage occurred.
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.
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.
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.
The processes that deposit soils, debris, and other materials
either on other ground surfaces or in bodies of water or watercourses.
See definition of "floodplain."
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.
Offered for preapproved projects that are considered minor
projects which are permissible per the IDNR/OWR Part 3700 rules. A
complete listing of the state-wide permits and permit requirements
can be obtained from the IDNR/OWR website.
See definition of "building."
Damage of any origin sustained by a structure whereby the
cumulative percentage of damage subsequent to the adoption of this
Article 7 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 definition of "repetitive
loss.").
Any reconstruction, rehabilitation, addition, or improvement
of a structure taking place subsequent to the adoption of this Article
7 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.
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"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.
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The term does not, however, include either: (a) 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 (b) any alteration of an 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 an historic
structure.
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Reaches of the stream or floodway where water flows from
a narrow cross section to a wide cross section or vice versa.
The failure of a structure or other development to be fully
compliant with the Village'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.
(A)
The Community Development Director, or his or her designee, shall be responsible for fulfilling all of the duties listed in Section 12-7-4 of this Code.
(B)
To fulfill those duties, the Community Development Director, or his or her designee, should first use the criteria listed in Section 12-7-5 of this Code to determine whether the development site is located within a floodplain.
(C)
Once it has been determined that a site is located within a floodplain,
the Community Development Director, or his or her designee, must determine
whether the development site is within a flood fringe, a designated
floodway, or within an SFHA or floodplain for which no floodway has
been identified.
(D)
If the site is within a flood fringe, the Community Development Director, or his or her designee, shall require that the minimum requirements of Section 12-7-6 of this Code be met.
(E)
If the site is within a floodway, the Community Development Director, or his or her designee, shall require that the minimum requirements of Section 12-7-7 of this Code be met.
(F)
If the site is located within an SFHA or floodplain for which no detailed study has been completed and approved, the Community Development Director, or his or her designee, shall require that the minimum requirements of Section 12-7-8 of this Code be met.
(H)
The Community Development Director, or his or her designee, shall assure that all subdivision proposals shall meet the requirements of Section 12-7-10 of this Code.
(I)
If a variance is to be granted for a proposal, the Community Development Director, or his or her designee, shall review the requirements of Section 12-7-11 of this Code to make sure they are met. In addition, the Community Development Director or designee shall complete all notification requirements.
The duties of the Community Development Director shall be:
(A)
Floodplain designation: determining the floodplain designation.
(B)
New development sites.
(1)
Check all new development sites to determine whether they are
in a special flood hazard area (SFHA).
(2)
If they are in an SFHA, determine whether they are in a floodway,
flood fringe or in a floodplain for which a detailed study has not
been conducted and which drains more than one square mile.
(3)
Check whether the development is potentially within an extended
SFHA (with a drainage area less than one square mile), indicating
that the development would have adverse impacts regarding storage,
conveyance, or inundation which would be the basis for the applicant
being required to delineate the floodplain and floodway and be subject
to the remaining sections of this Article 7.
(C)
Professional engineer review.
(1)
If the development site is within a floodway or in a floodplain for which a detailed study has not been conducted and which drains more than one square mile, the permit shall be referred to a licensed professional engineer under the employ or contract of the Village for review to ensure that the development meets Section 12-7-7 or 12-7-8 of this Code.
(D)
Dam safety requirements.
(1)
Dams are classified as to their size and their hazard/damage
potential in the event of failure.
(2)
The construction or major modification of all Class I (high
hazard) and Class II (moderate hazard) dams requires an IDNR/OWR dam
safety permit.
(3)
Some Class III (low hazard) dams require an IDNR/OWR dam safety
permit, depending on the drainage area to the dam, the height of the
dam and the impounding capacity behind the dam. Most off-channel detention
basins that have an embankment are nonjurisdictional Class III dams.
(4)
A consulting engineer with dam safety knowledge can estimate
a hazard classification and determine if an IDNR/OWR dam safety permit
is required.
(5)
A permit application submittal must be made to IDNR/OWR for
the construction or major modification of jurisdictional dams.
(6)
Regulated dams may include weirs, restrictive culverts or impoundment
structures.
(E)
Other permit requirements: ensure any and all required federal, state
and local permits are received prior to the issuance of a floodplain
development permit.
(F)
Plan review and permit issuance.
(1)
Ensure that all development activities within the SFHAs of the
jurisdiction of the Village meet the requirements of this Article
7; and
(2)
Issue a floodplain development permit in accordance with the
provisions of this Article 7 and other regulations of this community
when the development meets the conditions of this Article 7.
(G)
Inspection review.
(H)
Damage determinations: make damage determinations of all damaged buildings in the SFHA after a flood to determine substantially damaged structures which must comply with Section 12-7-9(C) of this Code.
(I)
(J)
Records for public inspection. Maintain for public inspection and
furnish upon request base flood data, SFHA and designated floodway
maps, copies of federal or state permit documents, variance documentation,
conditional letter of map revision, letter of map revision, letter
of map amendment and as-built elevation and floodproofing and/or elevation
certificates for all buildings constructed subject to this Article
7.
(K)
State permits: ensure that construction authorization has been granted by IDNR/OWR for all development projects subject to Sections 12-7-7 and 12-7-8 of this Code, unless enforcement responsibility has been delegated to the Village. However, the following review approvals are not delegated to the Village and shall require review or permits from IDNR/OWR:
(1)
Organizations which are exempt from the provisions of this Article
7, pursuant to state law;
(2)
IDNR/OWR projects, dams or impoundment structures as defined in Section 12-7-2 of this Code and all other state, federal or local unit of government projects, including projects of the Village and county, except for those projects meeting the requirements of Section 12-7-7(B)(1) of this Code;
(3)
An engineer's determination that an existing bridge or culvert crossing is not a source of flood damage and the analysis indicating the proposed flood profile, per Section 12-7-7(B)(3)(e) of this Code;
(4)
An engineer's analysis of the flood profile due to Section 12-7-7(B)(3)(d) of this Code;
(5)
Alternative transition sections and hydraulically equivalent compensatory storage as indicated in Section 12-7-7(B)(3) of this Code;
(6)
Permit issuance of structures within, under, or over publicly
navigable rivers, lakes and streams;
(7)
Any changes in the mapped floodway or published flood profiles.
(L)
Cooperation with other agencies:
(1)
Cooperate with state and federal floodplain management agencies
to improve base flood or one-hundred-year frequency flood and floodway
data and to improve the administration of this Article 7;
(2)
Submit data to IDNR/OWR and FEMA for proposed revisions of a
regulatory map within six months whenever a modification of the floodplain
may change the base flood elevation or result in a change to the floodplain
map;
(3)
Submit reports as required for the National Flood Insurance
Program; and
(4)
Notify FEMA of any proposed amendments to this Article 7.
(M)
Promulgate regulations. Promulgate rules and regulations as necessary
to administer and enforce the provisions of this Article 7; subject,
however, to the review and approval of IDNR/OWR and FEMA for any ordinance
changes.
The protection standard set forth in this Article 7 is based
on the Flood Insurance Study for the county.
(A)
If a base flood elevation or one-hundred-year frequency flood elevation
is not available for a particular site, then the protection standard
shall be according to the best existing data available from federal,
state or other sources.
(B)
When a party disagrees with the best available data, they shall submit
a detailed engineering study needed to replace existing data with
better data and submit it to IDNR/OWR and FEMA for review and consideration
prior to any development of the site.
(C)
The base flood or one-hundred-year frequency flood elevation for
the SFHAs of the county shall be as delineated on the one-hundred-year
flood profiles in the Flood Insurance Study of Cook County prepared
by FEMA, dated August 19, 2008, and such amendments to such study
and maps as may be prepared from time to time.
(D)
The base flood or one-hundred-year frequency flood elevation for
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 shall be as delineated on the one-hundred-year flood
profiles in the Flood Insurance Study of Cook County prepared by FEMA
and dated August 19, 2008, and such amendments or revisions to such
study and maps as may be prepared from time to time.
(E)
The base flood or one-hundred-year frequency flood elevation for
each SFHA delineated as an "AH Zone" or "AO Zone" shall be that elevation
(or depth) delineated on the county-wide Flood Insurance Rate Map
of Cook County.
(F)
The base flood or one-hundred-year frequency flood elevation for
each of the remaining SFHAs delineated as an "A Zone" on the county-wide
Flood Insurance Rate Map of Cook County shall be according to the
best existing data available from federal, state or other sources.
Should no other data exist, an engineering study must be financed
by the applicant to determine base flood elevations.
(1)
When no base flood or one-hundred-year frequency flood elevation
exists, the base flood or one-hundred-year frequency flood elevation
for a riverine SFHA shall be determined from a backwater model, such
as HEC-II, HEC-RAS, or a dynamic model such as HIP.
(2)
The flood flows used in the hydraulic models shall be obtained
from a hydrologic model, such as HEC-HMS, HEC-1, TR-20, or HIP, or
by techniques presented in various publications prepared by the United
States Geological Survey for estimating peak flood discharges.
(a)
For a nonriverine SFHA, the base flood elevation shall be the
historic flood of record plus three feet, unless calculated by a detailed
engineering study.
(b)
For an unmapped extended SFHA (with a drainage area less than one square mile) which has been identified by the Community Development Director or designee pursuant to Section 12-7-4(B)(3) of this Code, the base flood elevation shall be determined by the applicant utilizing a method as approved in this Section 12-7-5(F).
Development in and/or filling of the flood fringe will be permitted if protection is provided against the base flood or one-hundred-year frequency flood by proper elevation, and compensatory storage, and other applicable provisions of this Article 7. No use will be permitted which adversely affects the capacity of drainage facilities or systems. Developments located within the flood fringe shall meet the requirements of this Section 12-7-6 and of Section 12-7-9 of this Code.
(A)
Development permit.
(1)
No person, firm, corporation, or governmental body not exempted
by law shall commence any development in the SFHA without first obtaining
a development permit from the Community Development Director or his
or her designee.
(2)
Application for a development permit shall be made on a form
provided by the Community Development Director or his or her designee.
(3)
The application shall be accompanied by drawings of the site,
drawn to scale, showing property line dimensions and legal description
for the property and sealed by a licensed engineer, architect or land
surveyor; existing grade elevations, using the North American Vertical
Datum of 1988, and all changes in grade resulting from excavation
or filling; the location and dimensions of all buildings and additions
to buildings.
(4)
For all proposed buildings, the elevation of the lowest floor (including basement) and lowest adjacent grade shall be shown on the submitted plans and the development will be subject to the requirements of Section 12-7-9 of this Code.
(5)
Upon receipt of a development permit application, the Community
Development Director or designee shall compare the elevation of the
site to the base flood or one-hundred-year frequency flood elevation.
(a)
Any development located on land that can be shown to be higher
than the base flood elevation of the current Flood Insurance Rate
Map and which has not been filled after the date of the site's first
Flood Insurance Rate Map without a permit as required by this Article
7 is not in the SFHA and, therefore, not subject to the requirements
of this Article 7. Conversely, any development located on land shown
to be below the base flood elevation and hydraulically connected,
but shown on the current Flood Insurance Rate Map is subject to the
provisions of this Article 7.
(b)
The Community Development Director or designee shall maintain
documentation of the existing ground elevation at the development
site and certification that this ground elevation existed prior to
the date of the site's first Flood Insurance Rate Map identification.
(6)
A soil erosion and sediment control plan for disturbed areas
shall be submitted. This plan shall include a description of the sequence
of grading activities and the temporary sediment and erosion control
measures to be implemented to mitigate their effects. This plan shall
also include a description of final stabilization and revegetation
measures, and the identification of a responsible party to ensure
post-construction maintenance.
(7)
The Community Development Director or designee shall be responsible
for obtaining from the applicant copies of all other federal, state,
and local permits, approvals or waivers that may be required for this
type of activity. The Community Development Director or designee shall
not issue a permit unless all other federal, state, and local permits
have been obtained.
(B)
Preventing increased damages. No development in the flood fringe
shall create a threat to public health and safety.
(1)
LOMR required. If fill is being used to elevate the site above
the base flood or one-hundred-year frequency flood elevation, the
applicant shall submit sufficient data and obtain a letter of map
revision (LOMR) from FEMA for the purpose of removing the site from
the floodplain.
(2)
Compensatory storage.
(a)
Whenever any portion of a floodplain is authorized for use,
the volume of space which will be occupied by the authorized fill
or structure below the base flood or one-hundred-year frequency flood
elevation shall be compensated for and balanced by an hydraulically
equivalent volume of excavation taken from below the base flood or
one-hundred-year frequency flood elevation.
(b)
The excavation volume shall be at least equal to 1.5 times the
volume of storage lost due to the fill or structure.
(c)
In the case of streams and watercourses, such excavation shall
be made opposite or adjacent to the areas so filled or occupied.
(d)
All floodplain storage lost below the existing ten-year flood
elevation shall be replaced below the proposed ten-year flood elevation.
All floodplain storage lost above the existing ten-year flood elevation
shall be replaced above the proposed ten-year flood elevation.
(e)
All such excavations shall be constructed to drain freely and
openly to the watercourse.
(C)
Construction of the lowest floor below the base flood elevation (BFE). A person who has obtained a letter of map revision based on fill that removes a site in the flood fringe from the floodplain due to the use of fill to elevate the site above the BFE may apply for a permit from the Village to construct the lowest floor of a residential building below the BFE in the flood fringe. The Village shall not issue such a permit unless the applicant has complied with all the criteria set forth in this Section 12-7-6(C).
(1)
Compensatory storage shall be provided per Section 12-7-6(B)(2) of this Code.
(2)
The elevation of the lowest opening in the basement wall (i.e.,
window wells, accessways) shall be at or above the flood protection
elevation (FPE).
(3)
The lowest adjacent grade to the foundation shall be at or above
the FPE, for a minimum distance of 10 feet beyond the outside face
of the structure. However, if site conditions are such that this requirement
cannot be met, the Community Development Director or designee may
waive the ten-foot minimum setback if an Illinois licensed professional
engineer certifies that an alternative method to protect the building
from damage due to hydrostatic pressures has been met. The certifications
shall be in the form of a detailed soils and structural design analysis,
which shall be submitted to the Community Development Director or
designee for review. The Community Development Director or designee
may require such additional documentation as necessary to prove that
the proposed shorter setback distance will keep the structure reasonably
safe. In no case shall the setback distance be less than four feet.
(4)
The grade around the perimeter of the structure, measured at
a distance of 20 feet from the structure, shall be above the BFE.
However, if site conditions are such that this requirement cannot
be obtained, the Community Development Director or designee may waive
the twenty-foot minimum setback distance if an Illinois licensed professional
engineer certifies that an alternative method to protect the building
from damages due to hydrostatic pressures have been met. A detailed
soils analysis and structural design proving that a shorter setback
distance will keep the structure reasonably safe from flooding shall
be submitted to the Village for review. In no case shall the setback
distance be less than four feet.
(5)
The ground around the building shall be compacted fill that meets all requirements of this Section 12-7-6(C) and is at least five feet thick under the basement floor slab. Nothing in this Section 12-7-6(C) shall be interpreted to require the removal or replacement of fill that was placed as part of an LOMR-F, if such fill consists of material, including soils of similar classification and degree permeability, such as those classified as CH, CL, SC or ML according to ASTM Standard D-2487, classification of soils for engineering purposes.
(6)
The fill material must be homogeneous and isotropic; that is,
the soil must be all of one material, and the engineering priorities
must be in the same direction.
(7)
All fill material and compaction shall be designed, certified
and inspected by an Illinois licensed professional engineer, as warranted
by the site conditions.
(8)
The basement floor shall be at an elevation that is no more
than five feet below the BFE.
(9)
There shall be a granular drainage layer beneath the floor slab,
and minimum of 1/4 horsepower sump pump with a backup power supply
shall be provided to remove seepage flow. The pump shall be rated
at four times the estimated seepage rate and shall discharge above
the BFE and away from the building in order to prevent flooding of
the basement or uplift of the floor under the effect of the seepage
pressure.
(10)
The drainage system shall be equipped with a positive means
of preventing backflow.
(11)
All foundation elements shall be designed to withstand hydrostatic
pressure in accordance with accepted engineering practices.
(12)
If the applicant is unable to meet all of the requirements set forth in this Section 12-7-6(C), the Community Development Director or designee may allow the construction of a basement below the BFE only if the applicant demonstrates that the proposed fill and structure meet the guidelines and requirements set forth in FEMA Technical Bulletin 10-01 and are reasonably safe from flooding. In order to demonstrate that the proposed structure is reasonably safe from flooding, the applicant shall submit a detailed engineering analysis of the proposed fill and foundation wall. The engineered basement study shall be completed in accordance with the latest edition of FEMA Technical Bulletin 10-01, with the analysis of the fill being prepared by an Illinois licensed professional engineer.
(13)
In order to provide the required compensatory storage on site,
in no case shall the depth of excavation in the front and side yards
of the lot exceed 18 inches, as measured from the previously existing
natural grade. The rear yard shall be permitted to have a greater
depth of excavation, if necessary. All such excavation shall be constructed
to drain freely and openly to the watercourse or storm sewer system.
The use of mechanical means to drain the compensatory storage area
will not be permitted.
This Section 12-7-7 applies to proposed development, redevelopment, site modification or building modification within a designated floodway. The designated floodway for North Shore Channel shall be as delineated on the county-wide Flood Insurance Rate Map of Cook County and referenced in Section 12-7-2 of this Code. Only those uses and structures will be permitted which meet the criteria in this Section 12-7-7. All floodway modifications shall be the minimum necessary to accomplish the purpose of the project. The development shall also meet the requirements of Section 12-7-9 of this Code.
(A)
Development permit. No person, firm, corporation or governmental
body not exempted by state law shall commence any development in a
floodway without first obtaining a development permit from the Community
Development Director or designee and IDNR/OWR.
(1)
Application for a development permit shall be made on a form
provided by the Community Development Director or designee. The application
shall include the following information:
(a)
Name and address of applicant;
(b)
Site location (including legal description) of the property,
drawn to scale, on the designated floodway map, indicating whether
it is proposed to be in an incorporated or unincorporated area;
(c)
Name of stream or body of water affected;
(d)
Description of proposed activity;
(e)
Statement of purpose of proposed activity;
(f)
Anticipated dates of initiation and completion of activity;
(g)
Name and mailing address of the owner of the subject property
if different from the applicant;
(h)
Signature of the applicant or the applicant's agent;
(i)
If the applicant is a corporation, the president or other authorized
officer shall sign the application form;
(j)
If the applicant is a partnership, each partner shall sign the
application form; and
(k)
If the applicant is a land trust, the trust officer shall sign
the name of the trustee by him or her as trust officer. A disclosure
affidavit shall be filed with the application, identifying each beneficiary
of the trust by name and address and defining the respective interests
therein.
(l)
Plans of the proposed activity shall be provided which include
as a minimum:
(i)
A vicinity map showing the site of the activity,
name of the waterway, boundary lines, names of roads in the vicinity
of the site, graphic or numerical scale, and North arrow;
(ii)
A plan view of the project and engineering study
reach showing existing and proposed conditions including principal
dimensions of the structure or work, elevations, using the North American
Vertical Datum of 1988, adjacent property lines and ownership, drainage
and flood control easements, location of any channels and any existing
or future access roads, distance between proposed activity and navigation
channel (when the proposed construction is near a commercially navigable
body of water), designated floodway limit, floodplain limit, specifications
and dimensions of any proposed channel modifications, location and
orientation of cross sections, North arrow, and a graphic or numerical
scale;
(iii)
Cross section views of the project and engineering
study reach showing existing and proposed conditions including principal
dimensions of the work as shown in plan view, existing and proposed
elevations, normal water elevation, ten-year frequency flood elevation,
one-hundred-year frequency flood elevation, and graphic or numerical
scales (horizontal and vertical);
(iv)
A soil erosion and sediment control plan for disturbed
areas. This plan shall include a description of the sequence of grading
activities and the temporary sediment and erosion control measures
to be implemented to mitigate their effects. This plan shall also
include a description of final stabilization and revegetation measures,
and the identification of a responsible party to ensure post-construction
maintenance;
(v)
A copy of the designated floodway map, marked to
reflect any proposed change in the designated floodway location.
(m)
Any and all other federal, state, and local permits or approval
letters that may be required for this type of development.
(n)
Engineering calculations and supporting data shall be submitted showing that the proposed work will meet the permit criteria of Section 12-7-7(B) of this Code.
(o)
If the designated floodway delineation, base flood or one-hundred-year
frequency flood elevation will change due to the proposed project,
the application will not be considered complete until IDNR/OWR has
indicated conditional approval of the designated floodway map change.
No structures may be built until a letter of map revision has been
approved by FEMA.
(p)
The application for a structure shall be accompanied by drawings of the site, drawn to scale, showing property line dimensions and existing ground elevations and all changes in grade resulting from any proposed excavation or filling, and floodplain and floodway limits; sealed by a licensed professional engineer, licensed architect or licensed land surveyor; the location and dimensions of all buildings and additions to buildings; and the elevation of the lowest floor (including basement) of all proposed buildings subject to the requirements of Section 12-7-9 of this Code.
(q)
If the proposed project involves a channel modification, the
applicant shall submit the following information:
(i)
A discussion of the purpose of and need for the
proposed work;
(ii)
A discussion of the feasibility of using alternative locations or methods [See Section 12-7-7(B)(3)(i) of this Code.] to accomplish the purpose of the proposed work;
(iii)
An analysis of the extent and permanence of the impacts each feasible alternative identified in Section 12-7-7(B)(3)(i) of this Code would have on the physical and biological conditions of the body of water affected; and
(iv)
An analysis of the impacts of the proposed project,
considering cumulative effects on the physical and biological conditions
of the body of water affected.
(2)
The Community Development Director or designee shall be responsible
for obtaining from the applicant copies of all other federal, state,
and local permits and approvals that may be required for this type
of activity.
(3)
The Community Development Director or designee shall not issue
the development permit unless all required federal and state permits
have been obtained.
(B)
Preventing increased damages and a list of appropriate uses.
(1)
Appropriate uses. The only developments in a floodway which
will be allowed are appropriate uses, which will not cause a rise
in the base flood elevation, and which will not create a damaging
or potentially damaging increase in flood heights or velocity or be
a threat to public health and safety and welfare or impair the natural
hydrologic and hydraulic functions of the floodway or channel, or
permanently impair existing water quality or aquatic habitat. Construction
impacts shall be minimized by appropriate mitigation methods as called
for in this Article 7. Only those appropriate uses listed in 17 Illinois
Administrative Code, Sec. 3708 will be allowed. The approved appropriate
uses are as follows:
(a)
Flood control structures, dikes, dams and other public works
or private improvements relating to the control of drainage, flooding,
erosion, or water quality or habitat for fish and wildlife.
(b)
Structures or facilities relating to the use of, or requiring
access to, the water or shoreline, such as pumping and treatment facilities,
and facilities and improvements related to recreational boating, commercial
shipping and other functionally water dependent uses.
(c)
Storm and sanitary sewer relief outfalls.
(d)
Underground and overhead utilities.
(e)
Recreational facilities, such as playing fields and trail systems,
including any related fencing (at least 50% open when viewed from
any one direction) built parallel to the direction of flood flows,
and including open air pavilions and toilet facilities (four-stall
maximum) that will not block flood flows nor reduce floodway storage.
(f)
Detached garages, storage sheds, or other uninhabitable accessory
structures that will not block flood flows nor reduce floodway storage.
(g)
Bridges, culverts, roadways, sidewalks, railways, runways and
taxiways and any modification thereto.
(h)
Parking lots built at or below existing grade where either:
(i)
The depth of flooding at the one-hundred-year frequency
flood event will not exceed one foot; or
(ii)
The applicant of a short-term recreational use
facility parking lot formally agrees to restrict access during overbank
flooding events and accepts liability for all damage caused by vehicular
access during all overbank flooding events.
(i)
Designated floodway regrading, without fill, to create a positive
nonerosive slope toward a watercourse.
(j)
Floodproofing activities to protect previously existing lawful
structures including the construction of watertight window wells,
elevating structures, or construction of floodwalls around residential,
commercial or industrial principal structures where the outside toe
of the floodwall shall be no more than 10 feet away from the exterior
wall of the existing structure, and which are not considered substantial
improvements to the structure.
(k)
The replacement, reconstruction, or repair of a damaged building,
provided that the outside dimensions are not increased, and if the
building was damaged to 50% or more of the market value before the
damage occurred, the building will be protected from flooding to the
flood protection elevation.
(l)
Modifications to an existing building that would not increase
the enclosed floor area of the building below the one-hundred-year
frequency flood elevation, and which will not block flood flows including,
but not limited to, fireplaces, bay windows, decks, patios, and second
story additions. If the building is improved to 50% or more of the
market value before the modification occurred (i.e., a substantial
improvement), the building will be protected from flooding to the
flood protection elevation.
(2)
Not included as appropriate uses. Appropriate uses do not include
the construction or placement of any new structures, fill, building
additions, buildings on stilts, excavation or channel modifications
done to accommodate otherwise inappropriate uses in the floodway,
fencing (including landscaping or planting designed to act as a fence)
and storage of materials except as specifically defined above as an
appropriate use.
(3)
Construction of appropriate uses; engineering and mitigation criteria. Within the designated floodway, the construction of an appropriate use will be considered permissible, provided, that the proposed project meets the following engineering and mitigation criteria and is so stated in writing with supporting plans, calculations and data by a licensed professional engineer and provided that any structure meets the protection requirements of Section 12-7-9 of this Code.
(a)
Preservation of flood conveyance, so as not to increase flood
stages upstream. For appropriate uses other than bridge or culvert
crossings, on-stream structures or dams, all effective designated
floodway conveyance lost due to the project will be replaced for all
flood events up to and including the one-hundred-year frequency flood.
In calculating effective designated floodway conveyance, the following
factors shall be taken into consideration:
(i)
Designated floodway conveyance, "K" = (1.486/n)(AR2/3) where "n" is Manning's roughness factor, "A" is
the effective flow area of the cross section, and "R" is the ratio
of the area to the wetted perimeter [See Ven Te Chow, Open Channel
Hydraulics, (McGraw-Hill, New York, 1959)].
(ii)
The same Manning's "n" value shall be used for
both existing and proposed conditions unless a recorded maintenance
agreement with a federal, state, or local unit of government can assure
the proposed conditions will be maintained or the land cover is changing
from a vegetative to a nonvegetative land cover.
(iii)
Transition sections shall be provided and used
in calculations of effective designated floodway conveyance. The following
expansion and contraction ratios shall be used unless an applicant's
engineer can prove to IDNR/OWR through engineering calculations or
model tests that more abrupt transitions may be used with the same
efficiency:
A.
When water is flowing from a narrow section to a
wider section, the water should be assumed to expand no faster than
at a rate of one-foot horizontal for every four feet of the flooded
stream's length.
B.
When water is flowing from a wide section to a narrow
section, the water should be assumed to contract no faster than at
a rate of one-foot horizontal for every one foot of the flooded stream's
length.
C.
When expanding or contracting flows in a vertical
direction, a minimum of one-foot vertical transition for every 10
feet of stream length shall be used.
D.
Transition sections shall be provided between cross
sections with rapid expansions and contractions and when meeting the
designated floodway delineation on adjacent properties.
E.
All cross sections used in the calculations shall
be located perpendicular to flood flows.
(b)
Preservation of floodway storage so as not to increase downstream
flooding.
(i)
Compensatory storage shall be provided for any
designated floodway storage lost due to the proposed work from the
volume of fill or structures placed and the impact of any related
flood control projects.
(ii)
Compensatory storage for fill or structures shall
be equal to at least 1.5 times the volume of floodplain storage lost.
(iii)
Artificially created storage lost due to a reduction
in head loss behind a bridge shall not be required to be replaced.
(iv)
The compensatory designated floodway storage shall
be placed between the proposed normal water elevation and the proposed
one-hundred-year flood elevation. All designated floodway storage
lost below the existing ten-year flood elevation shall be replaced
below the proposed ten-year flood elevation. All designated floodway
storage lost above the existing ten-year flood elevation shall be
replaced above the proposed ten-year flood elevation. All such excavations
shall be constructed to drain freely and openly to the watercourse.
(v)
If the compensatory storage will not be placed
at the location of the proposed construction, the applicant's engineer
shall demonstrate through a determination of flood discharges and
water surface elevations that the compensatory storage is hydraulically
equivalent.
(vi)
There shall be no reduction in floodway surface
area as a result of a floodway modification, unless such modification
is necessary to reduce flooding at an existing structure.
(c)
Preservation of floodway velocities so as not to increase stream
erosion or flood heights.
(i)
For all appropriate uses, except bridges or culverts
or on-stream structures, the proposed work will not result in an increase
in the average channel or designated floodway velocities or stage
for all flood events up to and including the one-hundred-year frequency
event.
(ii)
In the case of bridges or culverts or on-stream
structures built for the purpose of backing up water in the stream
during normal or flood flows, velocities may be increased at the structure
site if scour, erosion and sedimentation will be avoided by the use
of riprap or other design measures.
(d)
Construction of new bridges or culvert crossings and roadway
approaches.
(i)
The proposed structure shall not result in an increase
of upstream flood stages greater than 0.1 foot when compared to the
existing conditions for all flood events up to and including the one-hundred-year
frequency event; or the upstream flood stage increases will be contained
within the channel banks (or within existing vertical extensions of
the channel banks) such as within the design protection grade of existing
levees or flood walls or within recorded flood easements.
(ii)
If the proposed construction will increase upstream
flood stages greater than 0.1 foot, the developer must contact IDNR/OWR
to obtain a permit for a dam or waiver.
A.
The engineering analysis of upstream flood stages must be calculated using the flood study flows, and corresponding flood elevations for tailwater conditions for the flood study specified in Section 12-7-5 of this Code. Bridges and culverts must be analyzed using any commonly accepted FEMA approved hydraulic models.
B.
Lost floodway storage must be compensated for, pursuant to Section 12-7-7(B)(3)(b) of this Code.
C.
Velocity increases must be mitigated, pursuant to Section 12-7-7(B)(3)(c) of this Code.
D.
If the crossing is proposed over a public water
that is used for recreational or commercial navigation, an IDNR/OWR
permit must be received.
E.
The hydraulic analysis for the backwater caused by the bridge showing the existing condition and proposed regulatory profile must be submitted to IDNR/OWR for concurrence that a CLOMR is not required by this Section 12-7-7(B).
F.
All excavations for the construction of the crossing shall be designed per Section 12-7-7(B)(3)(h) of this Code.
(e)
Reconstruction or modification of existing bridges, culverts,
and approach roads:
(i)
The bridge or culvert and roadway approach reconstruction
or modification shall be constructed with no more than 0.1 foot increase
in backwater over the existing flood profile for all flood frequencies
up to and including the one-hundred-year event, if the existing structure
is not a source of flood damage.
(ii)
If the existing bridge or culvert and roadway
approach is a source of flood damage to buildings or structures in
the upstream floodplain, the applicant's engineer shall evaluate the
feasibility of redesigning the structure to reduce the existing backwater,
taking into consideration the effects of flood stages on upstream
and downstream properties.
(iii)
The determination as to whether or not the existing
crossing is a source of flood damage and should be redesigned must
be prepared in accordance with 17 Illinois Administrative Code, Sec.
3708 (floodway construction in northeastern Illinois) and submitted
to IDNR/OWR for review and concurrence before a permit is issued.
(f)
On-stream structures built for the purpose of backing up water.
(i)
Any increase in upstream flood stages greater than
0.0 foot when compared to the existing conditions, for all flood events
up to and including the one-hundred-year frequency event shall be
contained within the channel banks (or within existing vertical extensions
of the channel banks) such as within the design protection grade of
existing levees or floodwalls or within recorded flood easements.
(ii)
A permit or letter indicating a permit is not
required must be obtained from IDNR/OWR for any structure built for
the purpose of backing up water in the stream during normal or flood
flow.
(iii)
All dams and impoundment structures as defined in Section 12-7-2 of this Code shall meet the permitting requirements of 17 Illinois Administrative Code, Sec. 3702 (construction and maintenance of dams). If the proposed activity involves a modification of the channel or floodway to accommodate an impoundment, it shall be demonstrated that:
A.
The impoundment is determined to be in the public
interest by providing flood control, public recreation, or regional
stormwater detention;
B.
The impoundment will not prevent the migration of
indigenous fish species, which require access to upstream areas as
part of their life cycle, such as for spawning;
C.
The impoundment will not cause or contribute to
degraded water quality or habitat conditions. Impoundment design should
include gradual bank slopes, appropriate bank stabilization measures
and a presedimentation basin;
D.
A nonpoint source control plan has been implemented
in the upstream watershed to control the effects of sediment runoff
as well as minimize the input of nutrients, oil and grease, metals,
and other pollutants. If there is more than one Village in the upstream
watershed, the Village in which the impoundment is constructed should
coordinate with upstream municipalities to ensure comprehensive watershed
control; and
(g)
Floodproofing of existing habitable, residential and commercial
structures.
(i)
If construction is required beyond the outside
dimensions of the existing building, the outside perimeter of the
floodproofing construction shall be placed no farther than 10 feet
from the outside of the building.
(ii)
Compensation of lost storage and conveyance will
not be required for floodproofing activities.
(h)
Excavation in the floodway.
(i)
When excavation is proposed in the design of bridges
and culvert openings, including the modifications to and replacement
of existing bridge and culvert structures, or to compensate for lost
conveyance or other appropriate uses, transition sections shall be
provided for the excavation.
(ii)
The following expansion and contraction ratios
shall be used unless an applicant's engineer can prove to IDNR/OWR
through engineering calculations or model tests that more abrupt transitions
may be used with the same efficiency:
A.
When water is flowing from a narrow section to a
wider section, the water should be assumed to expand no faster than
at a rate of one-foot horizontal for every four feet of the flooded
stream's length; and
B.
When water is flowing from a wide section to a narrow
section, the water should be assumed to contract no faster than at
a rate of one foot horizontal for every one foot of the flooded stream's
length; and
C.
When expanding or contracting flows in a vertical
direction, a minimum of one foot vertical transition for every 10
feet of stream length shall be used; and
D.
Erosion/scour protection shall be provided inland
upstream and downstream of the transition sections.
(i)
Channel modifications. If the proposed activity involves a channel
modification, it shall be demonstrated that:
(i)
There are no practicable alternatives to the activity
which would accomplish its purpose with less impact to the natural
conditions of the body of water affected. Possible alternatives include
levees, bank stabilization, floodproofing of existing structures,
removal of structures from the floodplain, clearing the channel, high
flow channel, or the establishment of a stream side buffer strip or
green belt. Channel modification is acceptable if the purpose is to
restore natural conditions and improve water quality and fish and
wildlife habitat;
(ii)
Water quality, habitat, and other natural functions
would be significantly improved by the modification and no significant
habitat area may be destroyed, or the impacts are offset by the replacement
of an equivalent degree of natural resource values;
(iii)
The activity has been planned and designed and
will be constructed in a way which will minimize its adverse impacts
on the natural conditions of the body of water affected, consistent
with the following criteria:
A.
The physical characteristics of the modified channel
shall match as closely as possible those of the existing channel in
length, cross section, slope and sinuosity. If the existing channel
has been previously modified, restoration of more natural physical
conditions should be incorporated into channel modification design,
where practical;
B.
Hydraulically effective transitions shall be provided
at both the upstream and downstream ends of the project, designed
such that they will prevent erosion;
C.
One-sided construction of a channel shall be used
when feasible. Removal of streamside (riparian) vegetation should
be limited to one side of the channel, where possible, to preserve
the shading and stabilization effects of the vegetation;
D.
Clearing of stabilizing vegetation shall be limited
to that which is essential for construction of the channel;
E.
Channel banks shall be constructed with a side slope
no steeper than 3:1 horizontal to vertical, wherever practicable.
Native vegetation and gradual side slopes are the preferred methods
for bank stabilization. Where high velocities or sharp bends necessitate
the use of alternative stabilization measures, soil bioengineering
techniques, natural rock or riprap are preferred approaches. Artificial
materials such as concrete, gabions, or construction rubble should
be avoided unless there are no practicable alternatives;
F.
All disturbed areas associated with the modification
shall be seeded or otherwise stabilized as soon as possible upon completion
of construction. Erosion blanket or an equivalent material shall be
required to stabilize disturbed channel banks prior to establishment
of the vegetative cover;
G.
If the existing channel contains considerable bottom
diversity such as deep pools, riffles, and other similar features,
such features shall be provided in the new channel. Spawning and nesting
areas and flow characteristics compatible with fish habitat shall
also be established, where appropriate;
H.
A sediment basin shall be installed at the downstream
end of the modification to reduce sedimentation and degradation of
downstream water quality;
I.
New or relocated channels should be built in the
dry and all items of construction, including vegetation, should be
completed prior to diversion of water into the new channel;
J.
There shall be no increases in stage or velocity
as the channel enters or leaves the project site for any frequency
flood unless necessitated by a public flood control project or unless
such an increase is justified as part of a habitat improvement or
erosion control project;
K.
Unless the modification is for a public flood control
project, there shall be no reduction in the volume of floodwater storage
outside the floodway as a result of the modification; and
(j)
Seeding and stabilization plan. For all activities located in
a floodway, a seeding and stabilization plan shall be submitted by
the applicant.
(k)
Soil erosion and sedimentation measures. For all activities
in the floodway, including grading, filling, and excavation, in which
there is potential for erosion of exposed soil, soil erosion and sedimentation
control measures shall be employed consistent with the following criteria:
(i)
The construction area shall be minimized to preserve
the maximum vegetation possible. Construction shall be scheduled to
minimize the time soil is exposed and unprotected. In no case shall
the existing natural vegetation be destroyed, removed, or disturbed
more than 15 days prior to the initiation of improvements.
(ii)
Temporary and/or permanent soil stabilization
shall be applied to denuded areas as soon as possible. As a minimum,
soil stabilization shall be provided within 15 days after final grade
is reached on any portion of the site, and within 15 days to denuded
areas which may not be at final grade but will remain undisturbed
for longer than 60 days.
(iii)
Sedimentation control measures shall be installed
before any significant grading or filling is initiated on the site
to prevent the movement of eroded sediments off site or into the channel.
Potential sediment control devices include filter fences, straw bale
fences, check dams, diversion ditches, and sediment traps and basins.
(iv)
A vegetated buffer strip of at least 25 feet in width shall be preserved and/or reestablished, where possible, along existing channels [See Section 12-7-7(B)(3)(q) of this Code.]. Construction vehicle use of channels shall be minimized. Temporary stream crossings shall be constructed, where necessary, to minimize erosion. Necessary construction in or along channels shall be restabilized immediately.
(v)
Soil erosion and sedimentation control measures
shall be designed and implemented consistent with Procedures and Standards
For Urban Soil Erosion and Sedimentation Control In Illinois (1988)
also known as the "Green Book" and The Illinois Urban Manual (NRCS,
1995).
(l)
Public flood control projects. For public flood control projects, the permitting requirements of this Section 12-7-7 will be considered met if the applicant can demonstrate to IDNR/OWR through hydraulic and hydrologic calculations that the proposed project will not singularly or cumulatively result in increased flood heights outside the project right-of-way or easements for all flood events up to and including the one-hundred-year frequency event.
(m)
General criteria for analysis of flood elevations.
(i)
The flood profiles, flows and floodway data in the designated floodway study, referenced in Section 12-7-5 of this Code, must be used for analysis of the base conditions. If the study data appears to be in error or conditions have changed, IDNR/OWR shall be contacted for approval and concurrence on the appropriate base conditions data to use.
(ii)
If the one-hundred-year designated floodway elevation
at the site of the proposed construction is affected by backwater
from a downstream receiving stream with a larger drainage area, the
proposed construction shall be shown to meet:
(n)
Existing and future requirements for complying with bridge, culvert, or flood control projects. If the applicant learns from IDNR/OWR, local governments, or a private owner that a downstream restrictive bridge or culvert is scheduled to be removed, reconstructed, modified, or a regional flood control project is scheduled to be built, removed, constructed or modified within the next five years, the proposed construction shall be analyzed and shown to meet the requirements of this Section 12-7-7 for both the existing conditions and the expected flood profile conditions when the bridge, culvert or flood control project is built.
(o)
Conditional letter of map revision.
(i)
If the appropriate use would result in a change
in the designated floodway location or the one-hundred-year frequency
flood elevation, the applicant shall submit to IDNR/OWR and FEMA all
information, calculations and documents necessary to be issued a conditional
designated floodway map revision and receive from IDNR/OWR a conditional
concurrence of the designated floodway change before a permit is issued.
(ii)
The final designated floodway map will not be
changed by FEMA until as-built plans or record drawings of initial
filling, grading, dredging, or excavating activities are submitted
and accepted by FEMA and IDNR/OWR.
(iii)
In the case of nongovernment projects, the Village
in incorporated areas and the county in unincorporated areas shall
concur with the proposed conditional designated floodway map revision
before IDNR/OWR approval can be given.
(iv)
No filling, grading, dredging or excavating shall
take place until a conditional approval is issued.
(v)
After initial filling, grading, dredging or excavating,
no activities shall take place until a final letter of map revision
(LOMR) is issued by FEMA with concurrence from IDNR/OWR.
(p)
Professional engineer's supervision. All engineering analyses
shall be performed by or under the supervision of a licensed professional
engineer.
(q)
Activities in the floodway involving construction within 25
feet of the channel. For all activities in the floodway involving
construction within 25 feet of the channel, the following criteria
shall be met:
(i)
A natural vegetation buffer strip shall be preserved
within at least 25 feet of the ordinary high water mark of the channel.
(ii)
Where it is impossible to protect this buffer
strip during the construction of an appropriate use, a vegetated buffer
strip shall be established upon completion of construction.
(r)
Construction to proceed upon issuance of permit and CLOMR; map
revision. After receipt of conditional approval of the designated
floodway change and issuance of a permit and a conditional letter
of map revision, construction as necessary to change the floodway
designation may proceed, but no buildings or structures or other construction
that is not an appropriate use may be placed in that area until the
designated floodway map is changed and a final letter of map revision
is received. The designated floodway map will be revised upon acceptance
and concurrence by IDNR/OWR and FEMA of the as-built plans.
(4)
Development activities in delegated communities requiring state
review. For those projects listed below located in a designated floodway,
the following criteria shall be submitted to IDNR/OWR for their review
and concurrence and/or permit prior to the issuance of a building
permit by the Village or county-delegated state permitting authority
in the floodway:
(a)
An engineer's analysis of the flood profile due to a proposed bridge pursuant to Section 12-7-7(B)(3)(d) of this Code.
(b)
An engineer's determination that an existing bridge or culvert crossing is not a source of flood damage and the analysis indicating the proposed flood profile, pursuant to Section 12-7-7(B)(3)(e) of this Code.
(c)
Alternative transition sections and hydraulically equivalent storage pursuant to this Section 12-7-7(B).
(d)
The construction of any IDNR/OWR projects, dams (as defined in Section 12-7-2 of this Code) and all other federal, state, or local units of government projects, including projects of the Village or county.
(e)
An engineer's determination that a proposed bridge affected
by backwater from a downstream receiving stream may be built with
a smaller opening.
(f)
Projects which revise or establish the floodway and/or flood
profiles.
(g)
Projects in public bodies of water.
(5)
Other permits.
(a)
In addition to the other requirements of this Article 7, a building
permit for a site located in a floodway shall not be issued unless
the applicant first obtains a permit or written documentation that
a permit is not required from IDNR/OWR, issued pursuant to the Act.
(b)
No correspondence from IDNR/OWR shall be required if the project
meets the requirements of Regional Permit 3.
(c)
No permit from IDNR/OWR shall be required if IDNR/OWR has delegated
this responsibility to the Village.
(6)
Permits for dams.
(a)
Any work involving the construction, modification or removal
of a dam, as defined in 17 Illinois Administrative Code, Sec. 3702,
shall obtain an IDNR/OWR permit prior to the start of construction
of a dam.
(b)
If the Community Development Director finds a dam that does
not have an IDNR/OWR permit, the Community Development Director shall
immediately notify the IDNR/OWR Bartlett office.
(c)
If the Community Development Director finds a dam which is believed
to be in an unsafe condition, the Community Development Director shall
immediately notify the owner of the dam, the IDNR/OWR Bartlett office,
and the Illinois Emergency Management Agency (IEMA).
(7)
Activities that do not require a licensed professional engineer's
review. The following activities may be permitted without a licensed
professional engineer's review. Such activities shall still meet the
other requirements of this Article 7, including the mitigation requirements.
In SFHA or floodplains (including AE, AH, AO and unnumbered
A Zones), where no floodways have been identified and no base flood
or one-hundred-year frequency flood elevations have been established
by FEMA, and draining more than a square mile, no development shall
be permitted unless the cumulative effect of the proposals, when combined
with all other existing and anticipated uses and structures, shall
not significantly impede or increase the flow and passage of the floodwaters
nor significantly increase the base flood or one-hundred-year frequency
flood elevation.
(A)
Development permit.
(1)
No person, firm, corporation, or governmental body, not exempted
by state law, shall commence any development in an SFHA or floodplain
without first obtaining a building permit from the Community Development
Director or designee.
(2)
Application for a development permit shall be made on a form
provided by the Community Development Director or designee.
(3)
The application shall be accompanied by drawings of the site, drawn to scale showing property line dimensions; and existing grade elevations and all changes in grade resulting from excavation or filling, sealed by a licensed engineer, architect or surveyor; the location and dimensions of all buildings and additions to buildings; and the elevations of the lowest floor (including basement) of all proposed buildings subject to the requirements of Section 12-7-9 of this Code.
(4)
The application shall also include the following information:
(a)
A detailed description of the proposed activity, its purpose,
and intended use;
(b)
Site location (including legal description) of the property,
drawn to scale, on the designated floodway maps, indicating whether
it is proposed to be in an incorporated or unincorporated area;
(c)
Anticipated dates of initiation and completion of activity;
(d)
Plans of the proposed activity shall be provided which include
as a minimum:
(i)
A vicinity map showing the site of the activity,
name of the waterway, boundary lines, names of roads in the vicinity
of the site, graphic or numerical scale, and North arrow;
(ii)
A plan view of the project and engineering study
reach showing existing and proposed conditions, including principal
dimensions of the structure or work, elevations, using the North American
Vertical Datum of 1988, adjacent property lines and ownership, drainage
and flood control easements, distance between proposed activity and
navigation channel (when the proposed construction is in or near a
commercially navigable body of water), floodplain limit, location
and orientation of cross sections, North arrow, and a graphical or
numerical scale;
(iii)
Cross section views of the project perpendicular
to the flow of floodwater and engineering study reach showing existing
and proposed conditions, including principal dimensions of the work
as shown in plan view, existing and proposed elevations, normal water
elevation, ten-year frequency flood elevation, one-hundred-year frequency
flood elevation, and graphical or numerical scales (horizontal and
vertical); and
(iv)
A soil erosion and sedimentation control plan
for disturbed areas. This plan shall include a description of the
sequence of grading activities and the temporary sediment and erosion
control measures to be implemented to mitigate their effects. This
plan shall also include a description of final stabilization and revegetation
measures, and the identification of a responsible party to ensure
post-construction maintenance.
(e)
Engineering calculations and supporting data shall be submitted showing that the proposed work will meet the criteria of this Section 12-7-8(A).
(f)
Any and all other federal, state, and local permits or approvals
that may be required for this type of development.
(5)
Based on the best available existing data according to federal,
state or other sources, the Community Development Director or designee
shall compare the elevation of the site to the base flood or one-hundred-year
frequency flood elevation.
(a)
Should no elevation information exist for the site, the developer's engineer shall calculate the elevation according to Section 12-7-5(F) of this Code.
(b)
Any development located on land that can be shown to have been
higher than the base flood elevation of the current Flood Insurance
Rate Map identification is not in the SFHA and, therefore, not subject
to the requirements of this Article 7.
(c)
The Community Development Director or designee shall maintain
documentation of the existing ground elevation at the development
site and certification that this ground elevation existed prior to
the date of the site's first Flood Insurance Rate Map identification.
(d)
The Community Development Director or designee shall be responsible
for obtaining from the applicant copies of all other federal, state,
and local permits, approvals or waivers that may be required for this
type of activity. The Community Development Director or designee shall
not issue the development permit unless all required federal, state,
and local permits have been obtained.
(B)
Preventing increased damages.
(1)
Construction impacts to be minimized. No development in the
SFHA where a floodway has not been determined shall create a damaging
or potentially damaging increase in flood heights or velocity or threat
to public health, safety and welfare or impair the natural hydrologic
and hydraulic functions of the floodway or channel, or impair existing
water quality or aquatic habitat. Construction impacts shall be minimized
by appropriate mitigation methods as called for in this Article 7.
(2)
Standards applicable. Within all riverine SFHAs where the floodway
has not been determined, the following standards shall apply:
(a)
Licensed professional engineer approval. The developer shall have a licensed professional engineer state in writing and show through supporting plans, calculations, and data that the project meets the engineering requirements of Section 12-7-7(B)(3)(a) through (B)(3)(i) of this Code for the entire floodplain as calculated under the provisions of Section 12-7-5(F) of this Code.
(i)
As an alternative, the developer should have an
engineering study performed to determine a floodway and submit that
engineering study to IDNR/OWR and FEMA for acceptance as a designated
floodway.
(b)
IDNR/OWR permit. A building permit shall not be issued unless
the applicant first obtains an IDNR/OWR permit or a determination
has been made that an IDNR/OWR permit is not required.
(c)
Permits for dams.
(i)
Any work involving the construction, modification
or removal of a dam, as defined in 17 Illinois Administrative Code,
Sec. 3702, shall obtain an IDNR/OWR permit prior to the start of construction
of a dam.
(ii)
If the Community Development Director or designee
finds a dam that does not have an IDNR/OWR permit, the Community Development
Director or designee shall immediately notify the IDNR/OWR Bartlett
office.
(iii)
If the Community Development Director or designee
finds a dam which is believed to be in unsafe condition, the Community
Development Director or designee shall immediately notify the owner
of the dam, the IDNR/OWR Bartlett office, and the Illinois Emergency
Management Agency (IEMA).
(3)
Activities permitted without a licensed professional engineer's
review. The following activities may be permitted without a licensed
professional engineer's review or calculation of base flood elevation
and designated floodway. Such activities shall still meet the other
requirements of this Article 7.
(a)
Aerial utility crossings meeting conditions of IDNR/OWR State-wide
Permit 4;
(b)
Minor boat docks meeting conditions of IDNR/OWR State-wide Permit
5;
(c)
Minor, nonobstructive activities meeting conditions of IDNR/OWR
State-wide Permit 6 (activities not involving fill or positive change
in grade) are covered by this permit;
(d)
Outfall structures and drainage ditch outlets meeting conditions
of IDNR/OWR State-wide permit 7;
(e)
Underground pipeline and utility crossings meeting the conditions
of IDNR/OWR State-wide Permit 8;
(f)
Bank stabilization projects meeting the conditions of IDNR/OWR
State-wide Permit 9;
(g)
Accessory structures and additions to existing residential buildings
meeting the conditions of IDNR/OWR State-wide Permit 10;
(h)
Minor maintenance dredging activities meeting conditions of
IDNR/OWR State-wide Permit 11;
(i)
Bridge and culvert replacement structures and bridge widenings
meeting conditions of IDNR/OWR State-wide Permit 12;
(j)
Temporary construction activities meeting conditions of IDNR/OWR
State-wide Permit 13;
(k)
Special uses of public waters meeting conditions of IDNR/OWR
State-wide Permit 14; and
(l)
Any development determined by IDNR/OWR to be located entirely
within a flood fringe area shall be exempt from state floodway permit
requirements.
(4)
Flood-carrying capacity. The flood-carrying capacity of any
altered or relocated watercourse shall be maintained.
(5)
Compensatory storage.
(a)
Whenever any portion of a floodplain is authorized for use,
the volume of space which will be occupied by the authorized fill
or structure below the base flood or one-hundred-year frequency flood
elevation shall be compensated for and balanced by an hydraulically
equivalent volume of excavation taken from below the base flood or
one-hundred-year frequency flood elevation.
(b)
The excavation volume shall be at least equal to 1.5 times the
volume of storage lost due to the fill or structure.
(c)
In the case of streams and watercourses, such excavation shall
be made opposite or adjacent to the areas so filled or occupied.
(d)
All floodplain storage lost below the existing ten-year flood
elevation shall be replaced below the proposed ten-year flood elevation.
All floodplain storage lost above the existing ten-year flood elevation
shall be replaced above the proposed ten-year flood elevation. All
such excavations shall be constructed to drain freely and openly to
the watercourse.
In addition to the requirements found in Sections 12-7-6, 12-7-7 and 12-7-8 of this Code for development in flood fringes, designated floodways, and SFHAs or floodplains where no floodways have been identified, the following requirements shall be met:
(A)
Public health standards:
(1)
No developments in the SFHA shall include locating or storing chemicals, explosives, buoyant materials, animal wastes, fertilizers, flammable liquids, pollutants, or other hazardous or toxic materials below the flood protection elevation (FPE) unless such materials are stored in a floodproofed and anchored storage tank and certified by a professional engineer or floodproofed building constructed according to the requirements of Section 12-7-9(C) of this Code.
(2)
Public utilities and facilities such as sewer, gas and electric
shall be located and constructed to minimize or eliminate flood damage.
(3)
Public sanitary sewer systems and water supply systems shall
be located and constructed to minimize or eliminate infiltration of
floodwaters into the systems and discharges from the systems into
floodwaters.
(4)
New and replacement water supply systems, wells, sanitary sewer
lines and on-site waste disposal systems may be permitted, providing
all manholes or other aboveground openings located below the FPE are
watertight.
(5)
All other activities defined as development shall be designed
so as not to alter flood flows or increase potential flood damages.
(B)
Carrying capacity and notification.
(1)
For all projects involving channel modification, fill, or stream
maintenance (including levees), the flood-carrying capacity of the
watercourse shall be maintained.
(2)
In addition, the Village shall notify adjacent communities in
writing 30 days prior to the issuance of a permit for the alteration
or relocation of the watercourse.
(C)
Protecting buildings.
(1)
All buildings located within a one-hundred-year floodplain,
also known as an "SFHA," shall be protected from flood damage below
the flood protection elevation. This building protection criteria
applies to the following situations:
(a)
Construction or placement of a new building or alteration or
addition to an existing building valued at more than $1,000 or 70
square feet.
(b)
Substantial improvements or structural alterations made to an existing building that increase the floor area by more than 20% or equal or exceed the market value by 50%. Alteration shall be figured cumulatively subsequent to the adoption of this Article 7. If substantially improved, the existing structure and the addition must meet the flood protection standards of this Section 12-7-9.
(c)
Repairs made to a substantially damaged building. These repairs shall be figured cumulatively subsequent to the adoption of this Article 7. If substantially damaged, the entire structure must meet the flood protection standards of this Section 12-7-9.
(d)
Installing a manufactured home on a new site or a new manufactured
home on an existing site.
(e)
Installing a travel trailer or recreational vehicle on a site
for more than 180 days per year.
(2)
A residential or nonresidential building, when allowed, may
be constructed on permanent landfill in accordance with the following:
(a)
Lowest floor. The lowest floor (including basement) shall be
at or above the flood protection elevation; and
(b)
Fill requirements.
(i)
The fill shall be placed in layers no greater than
six inches deep before compaction and should extend at least 10 feet
beyond the foundation of the building before sloping below the flood
protection elevation; and
(ii)
The top of the fill shall be above the flood protection
elevation. However, the ten-foot minimum may be waived if a structural
engineer certifies an alternative method to protect the building from
damages due to hydrostatic pressures; and
(iii)
The fill shall be protected against erosion and
scour during flooding by vegetative cover, riprap or other structural
measure; and
(iv)
The fill shall be composed of rock or soil and
not incorporate debris or refuse materials; and
(v)
The fill shall not adversely affect the flow or
surface drainage from or onto neighboring properties, and when necessary,
stormwater management techniques such as swales or basins shall be
incorporated.
(3)
A residential or nonresidential building may be elevated in
accordance with the following:
(a)
The building or improvements shall be elevated on crawl space,
stilts, piles, walls, or other foundation that is permanently open
to floodwaters and not subject to damage by hydrostatic pressures
of the base flood or one-hundred-year frequency flood. Designs must
either be certified by a licensed professional engineer or architect
or the permanent openings, one on each wall, shall be no more than
one foot above existing grade, and consist of a minimum of two openings.
The openings must have a total net area of not less than one square
inch for every one square foot of enclosed area subject to flooding
below the base flood elevation; and
(b)
The foundation and supporting members shall be anchored and
aligned in relation to flood flows and adjoining structures so as
to minimize exposure to known hydrodynamic forces such as current,
waves, ice and floating debris; and
(c)
All areas below the flood protection elevation shall be constructed
of materials resistant to flood damage; and
(i)
The lowest floor (including basement) and all electrical,
heating, ventilating, plumbing, and air conditioning equipment and
utility meters shall be located at or above the flood protection elevation;
and
(ii)
Water and sewer pipes, electrical and telephone
lines, submersible pumps, and other waterproofed service facilities
may be located below the flood protection elevation, provided they
are waterproofed; and
(d)
The areas below the flood protection elevation may only be used
for the parking of vehicles, building access or storage in an area
other than a basement and not later modified or occupied as habitable
space; and
(e)
In lieu of the above criteria, the design methods to comply
with these requirements may be certified by a licensed professional
engineer or architect.
(4)
Manufactured homes and travel trailers to be installed on a
site for more than 180 days shall be elevated to or above the floor
protection elevation and shall be anchored to resist flotation, collapse,
or lateral movement by being tied down in accordance with the rules
and regulations for the Illinois Mobile Home Tiedown Act, 210 ILCS
120/1 et seq., issued pursuant to 77 Ill. Admin. Code 870.
(5)
Only a nonresidential building may be structurally dry floodproofed
(in lieu of elevation), provided that:
(a)
A licensed professional engineer or architect shall certify
that the building has been structurally dry floodproofed below the
flood protection elevation, the structure and attendant utility facilities
are watertight and capable of resisting the effects of the base flood
or one-hundred-year frequency flood.
(b)
The building design shall take into account flood velocities,
duration, rate of rise, hydrostatic and hydrodynamic forces, the effects
of buoyancy, and impacts from debris or ice.
(6)
A building may be constructed with a crawl space located below
the flood protection elevation, provided that the following conditions
are met:
(a)
The building must be designed and adequately anchored to resist
flotation, collapse, and lateral movement of the structure resulting
from hydrodynamic and hydrostatic loads, including the effects of
buoyancy; and
(b)
Any enclosed area below the flood protection elevation shall
have openings that equalize hydrostatic pressures by allowing for
the automatic entry and exit of floodwaters. A minimum of one opening
on each wall having a total net area of not less than one square inch
per one square foot of enclosed area. The openings shall be no more
than one foot above grade; and
(c)
The interior grade of the crawl space below the flood protection
elevation must not be more than two feet below the lowest adjacent
exterior grade; and
(d)
The interior height of the crawl space measured from the interior
grade of the crawl space to the top of the foundation wall must not
exceed four feet at any point; and
(e)
An adequate drainage system must be installed to remove floodwaters
from the interior area of the crawl space within a reasonable period
of time after a flood event; and
(f)
Portions of the building below the flood protection elevation
must be constructed with materials resistant to flood damage; and
(g)
Utility systems within the crawl space must be elevated above
the flood protection elevation.
(7)
Construction of new or substantially improved critical facilities
shall be located outside the limits of the floodplain. Construction
of new critical facilities shall be permissible within the floodplain
if no feasible alternative site is available. Critical facilities
constructed within the SFHA shall have the lowest floor (including
basement) elevated or structurally dry floodproofed to the five-hundred-year
flood frequency elevation or three feet above the level of the one-hundred-year
flood frequency elevation, whichever is greater. Floodproofing and
sealing measures must be taken to ensure that toxic substances will
not be displaced by or released into floodwaters. Access routes elevated
to or above the level of the base flood elevation shall be provided
to all critical facilities.
(8)
Toolsheds, detached garages, and other minor accessory structures
on an existing single-family platted lot may be constructed with the
lowest floor below the flood protection elevation in accordance with
the following:
(a)
The building is not used for human habitation; and
(b)
All areas below the base flood or one-hundred-year frequency flood elevation shall be constructed with waterproof material. Structures located in a designated floodway shall be constructed and placed on a building site so as not to block the flow of floodwaters and shall also meet the appropriate use criteria of Section 12-7-7 of this Code. In addition, all other requirements of Sections 12-7-6, 12-7-7 and 12-7-8 of this Code must be met; and
(c)
The structure shall be anchored to prevent flotation; and
(d)
Service facilities such as electrical and heating equipment
shall be elevated or floodproofed to the flood protection elevation;
and
(e)
The building shall be valued at less than $10,000 and be less
500 square feet in floor size; and
(f)
The building shall be used only for the storage of vehicles
or tools and may not contain other rooms, workshops, greenhouses or
similar uses and cannot be modified later into another use; and
(g)
The building shall meet the permanent opening criteria of Section 12-7-9(C)(3)(a) of this Code; and
(h)
All flammable or toxic materials (gasoline, paint, insecticides,
fertilizers, etc.) shall be stored above the flood protection elevation;
and
(i)
The lowest floor elevation should be documented and the owner
advised of the flood insurance implications.
(9)
Existing buildings located within a designated floodway shall also meet the more restrictive appropriate use standards included in Section 12-7-7 of this Code. Nonconforming structures located in a designated floodway may remain in use and may only be enlarged, replaced or structurally altered in accordance with Section 12-7-7(B) of this Code. A nonconforming structure damaged by flood, fire, wind or other natural or man-made disaster may be restored unless the damage exceeds 50% of its market value before it was damaged, in which case it shall conform to this Article 7.
The Village Board of Trustees shall take into account flood
hazards, to the extent that they are known, in all official actions
related to land management, use and development.
(A)
New subdivisions, manufactured home parks, annexation agreements, and planned unit developments within the SFHA shall be reviewed to assure that the proposed developments are consistent with Sections 12-7-6, 12-7-7, 12-7-8 and 12-7-9 of this Code and the need to minimize flood damage. Plats or plans for new subdivisions, mobile home parks and planned unit developments shall include a signed statement by a licensed professional engineer that the plat or plans account for changes in the drainage of surface waters in accordance with the Illinois Plat Act, 765 ILCS 205/1 et seq., as may be amended.
(B)
Proposals for new subdivisions, manufactured home parks, travel trailer
parks, planned unit developments and additions to manufactured home
parks and additions to subdivisions shall include base flood or one-hundred-year
frequency flood elevation data and floodway delineations.
(C)
Where this information is not available from an existing adopted study, the applicant's engineer shall be responsible for calculating the base flood or one-hundred-year frequency flood elevation per Section 12-7-5(F) of this Code and the "floodway" delineation per the definition set forth in Section 12-7-2 of this Code.
(D)
Streets, blocks, lots, parks and other public grounds shall be located
and laid out in such a manner as to preserve and utilize natural streams
and channels. Wherever possible, the floodplains shall be included
within parks or other public grounds.
(E)
The Village Board of Trustees shall not approve any planned unit
development or plat of subdivision located outside the corporate limits
unless such agreement or plat is in accordance with the provisions
of this Article 7.
(F)
All other activities defined as "development" shall be designed so
as not to alter flood flows or increase potential flood damages.
(A)
Whenever the standards of this Article 7 place undue hardship on a specific development proposal, the applicant may apply for a variance in accordance with this Section 12-7-11.
(1)
No variances shall be granted to any development located in a "designated floodway" as defined in Section 12-7-2 of this Code.
(2)
The Village Engineer shall review the applicant's request for
a variance and shall submit his or her recommendation to the Village
Board of Trustees. The Village Board of Trustees shall either grant
or deny the variance, and may attach such conditions to the granting
of a variance as it deems necessary to further the flood protection
intent of this Article 7.
(B)
No variance shall be granted unless the applicant demonstrates that
all of the following conditions are met:
(1)
The development activity cannot be located outside the SFHA;
and
(2)
An exceptional hardship would result if the variance were not
granted; and
(3)
The relief requested is the minimum necessary; and
(4)
There will be no additional threat to public health, safety,
beneficial stream uses and functions, especially aquatic habitat,
or creation of a nuisance; and
(5)
There will be no additional public expense for flood protection,
lost environmental stream uses and functions, rescue or relief operations,
policing, or repairs to streambeds and banks, roads, utilities, or
other public facilities; and
(7)
The activity is not in a designated floodway; and
(8)
The applicant's circumstances are unique and do not establish
a pattern inconsistent with the intent of the NFIP; and
(9)
The granting of the variance will not alter the essential character
of the area involved including existing stream uses; and
(10)
All other required state and federal permits or waivers have
been obtained.
(C)
The Community Development Director or designee shall notify an applicant in writing that a variance from the requirements of Section 12-7-9 of this Code that would lessen the degree of protection to a building will:
(1)
Result in increased premium rates for flood insurance up to
amounts as high as $25 per $100 of insurance coverage; and
(2)
Increase the risks to life and property; and
(3)
Require that the applicant proceed with knowledge of these risks
and that the applicant will acknowledge in writing the assumption
of the risk and liability.
(D)
Variances requested in connection with restoration of an historic site or historic structure as defined in Section 12-7-2 of this Code may be granted using criteria more permissive than the requirements of Sections 12-7-11(B) and (C) of this Code, subject to the conditions that:
(A)
The degree of flood protection required by this Article 7 is considered
reasonable for regulatory purposes and is based on available information
derived from engineering and scientific methods of study.
(B)
Larger floods may occur or flood heights may be increased by man-made
or natural causes.
(C)
This Article 7 does not imply that development, either inside or
outside of the SFHA, will be free from flooding or damage.
(D)
This Article 7 does not create liability on the part of the Village
or any officer or employee thereof for any flood damage that results
from reliance on this Article 7 or any administrative decision made
lawfully thereunder.
The penalty to be imposed for violations of the regulations
set forth in this Article 7 shall be a fine set forth in the Annual
Fee Schedule except where the conviction for which a penalty is being
imposed is the person's third or subsequent violation in the past
12 months of the regulations set forth in this Article 7, in which
case, the court may impose a fine as set forth in the Annual Fee Resolution.[1] Each day that a violation is permitted to exist shall
constitute a separate offense. No certificate of occupancy shall be
issued for any construction undertaken in conjunction with the provisions
of this Article 7 until such time that all penalties and fines have
been resolved to the satisfaction of the Community Development Director.
(A)
This Article 7 is not intended to repeal, abrogate or impair any
existing easements, covenants, or deed restrictions.
(B)
In the event of a conflict between a provision of this Article 7
and a provision of another ordinance, easements, covenants, or deed
restriction, the more stringent provision shall control.
(C)
This Article 7 is intended to repeal the original ordinance or resolution
which was adopted to meet the National Flood Insurance Program regulations,
but is not intended to repeal the resolution which the Village passed
in order to establish initial eligibility for the program.
