The Flood Hazard Overlay District (FH District) is intended
to minimize loss of life, property damage, health and safety hazards,
pollution, government expenditures, and disruption to the economic
and social well being of the community brought about by flooding.
The Flood Hazard Overlay District and its regulations are established
in compliance with the National Flood Insurance Program of the Federal
Emergency Management Agency in order to make federally subsidized
flood insurance more readily available within the Village.
The Flood Hazard Overlay District appears on the Zoning Map
as an overlay district imposed on top of other districts created by
this code and referred to in this article as "base districts." Development
of properties in the Flood Hazard Overlay District must comply both
with the regulations of the Flood Hazard Overlay District and with
the regulations of the base district in which they are located. When
there is any conflict between the Flood Hazard Overlay District and
the base district, the more restrictive provision shall control.
For purposes of this article, the following terms shall have
the meanings herein ascribed to them:
BASE FLOOD
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 flood." See §
260-804.
COMPENSATORY STORAGE
An artificially excavated volume of storage within the base
flood area used to balance the loss of natural flood storage capacity
when artificial fill or structures are placed within the floodplain.
FLOOD, FLOODED, or FLOODING
A general and temporary condition of inundation of normally
dry land areas from the overflow or unusual and rapid accumulation
or runoff of surface waters from any source.
FLOOD FRINGE
The portion of the SFHA located between the boundaries of
the floodway and the outside edge of the SFHA.
FLOODPROOFING
Structural and nonstructural additions, changes, or adjustments
to structures to eliminate or reduce flood damage to such structures
and to water and sanitary sewer facilities.
FLOOD TABLE LAND
Land adjacent to the SFHA with an elevation greater than
the BFE by three feet or less.
FLOODWAY
That portion of the SFHA required to store and convey the
base flood. The floodway for each of the SFHAs of the Village shall
be according to the best data available to the Illinois State Water
Survey Floodplain Information Repository.
RIVERINE SFHA
Any SFHA subject to flooding from a river, creek, intermittent
stream, ditch, or any other identified channel. This term does not
include areas subject to flooding from lakes (except public bodies
of water, ponding areas, areas of sheet flow, or other areas not subject
to overbank flooding).
SPECIAL FLOOD HAZARD AREA (SFHA)
Those lands within or adjacent to the jurisdiction of the
Village that are subject to inundation by the base flood. The SFHAs
of the Village are generally identified as such on the current Flood
Insurance Rate Map of the Village prepared by the Federal Emergency
Management Agency dated June 15, 1979, as annotated to show changes
made effective by a letter of map revision (LOMR) dated May 25, 1989.
The SFHAs of those parts of unincorporated areas that are within the
extraterritorial jurisdiction of the Village or that may be annexed
into the Village are generally identified as such on the current Flood
Insurance Rate Maps prepared for Lake County by the Federal Emergency
Management Agency dated November 3, 1982. To the extent that the Federal
Emergency Management Agency prepares and approves any updated Flood
Insurance Rate Map of the Village or of the unincorporated areas within
the extraterritorial jurisdiction of the Village (or portions thereof)
that delineates such SFHAs, such updated map shall establish the SFHAs
for purposes of this code.
STRUCTURE
For purposes of this article, the definition of "structure" (see §
260-1226) shall include any recreational vehicle stored on a site for more than 180 days during any year.
SUBSTANTIAL IMPROVEMENT
Any repair, reconstruction, or improvement of a structure
that increases the gross floor area by more than 20% or the cost of
which equals or exceeds 50% of the market value of the structure either
before the improvement or repair is started or, if the structure has
been damaged and is being restored, before the damage occurred. This
term, however, does not include:
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 a structure or site documented as deserving
preservation by the Illinois Historic Preservation Agency or listed
in the National Register of Historic Places.
WATERCOURSE
Any river, stream, creek, brook, branch, or other drainageway
in or into which stormwater runoff and floodwaters flow either regularly
or intermittently.
No use or development of any kind or nature whatsoever shall
be allowed in any floodway.
Subject to the issuance of a certificate of zoning compliance as required by §
260-805, the following uses and no others are permitted in the flood fringe and on flood table land, provided they would be permitted in the underlying zoning district, do not require structures, fill, or storage of materials or equipment, do not occupy any space below the BFE, and do not adversely affect the efficiency or unduly restrict the capacity of the floodway:
A. Private lawns, gardens, and play areas.
B. Public parks, playgrounds, forest preserves, wildlife and nature
preserves, hiking and horseback riding trails, and recreational areas.
C. Private and public tennis courts.
D. Accessory parking and loading areas.
Uses other than those specified in §
260-807 that are permitted in the underlying zoning district may be permitted in the flood fringe and on flood table land, subject to the issuance of a special use permit as provided in §
260-1162 of this code and subject to the following additional standards:
A. Standards for uses located in the flood fringe.
(1)
General design. All development proposals shall be designed
to minimize flood damage to the proposed development site as well
as to other properties.
(2)
Adequate drainage. All development proposals shall provide adequate
drainage pursuant to the Bannockburn storm and sanitary sewerage systems
and facilities regulations so as to reduce exposure to flood hazards.
(3)
Materials. Structures shall be constructed with materials and
utility equipment resistant to flood damage.
(4)
Method. Structures shall be constructed by methods and practices
that minimize flood damage to other properties.
(5)
Siting. Structures shall be constructed and placed on the building
site so as to offer the minimum obstruction to the flow of floodwater.
Whenever possible, structures shall be constructed with the longitudinal
axis parallel to the direction of the flood flow, and, so far as practicable,
structures shall be placed approximately on the same flood flow lines
as those of adjoining structures.
(6)
Anchoring. Structures shall be designed or modified and firmly
anchored with corrosion resistant materials to prevent flotation,
collapse, or lateral movement.
(7)
Residential structures. All residential structures shall be
constructed so that all habitable floor space, including any basement,
shall be located at least three feet above the BFE. All structural
components below the BFE shall be watertight and designed to resist
hydrostatic and hydrodynamic loads and the effects of buoyancy.
(8)
Nonresidential structures. All nonresidential structures shall either be elevated in the same manner hereinabove required for residential structures or shall be floodproofed in accordance with the provisions of §
260-811B. All structural components below the BFE shall be watertight and designed to resist hydrostatic and hydrodynamic loads and the effects of buoyancy.
(9)
Residential site elevation. The elevation of all land located
within five feet of the perimeter of any residential structure shall
be elevated at least one foot above the BFE.
(10)
Streets and roadways. Streets and roadways shall have a minimum
center line elevation of not less than the BFE.
(11)
Public utilities. All public utilities and facilities, such
as sewer, water, gas, and electrical systems, shall be located, elevated,
and constructed to eliminate flood damage and risk to human life and
safety from factors such as gas leaks, electric shock, and pollution
to the maximum extent feasible.
(12)
Water systems. All new and replacement water supply systems
shall be designed to eliminate infiltration of floodwaters into the
system to the maximum extent feasible.
(13)
Sanitary sewer systems. All new and replacement sanitary sewer
systems shall be designed to eliminate infiltration of floodwaters
into the system and discharges from the system into floodwaters to
the maximum extent feasible.
(14)
On-site waste disposal systems. All new and replacement on-site
waste disposal systems shall be located to avoid impairment to them
or contamination from them during flooding.
(15)
Fill. The use of fill shall be permitted, provided that a compensatory storage basin is constructed in the flood fringe in accordance with the requirements of Subsection
A(16) of this section and that any such fill shall be:
(a)
No greater in quantity than the amount required to comply with
the elevation requirements hereinabove set forth; and
(b)
Placed in layers no greater than one foot deep before compaction;
and
(c)
Protected against erosion and scour during flooding by year-round
vegetative cover installed on slopes no steeper than three horizontal
to one vertical, rip rap, or bulkheading; and
(d)
Placed so as not to adversely affect the flow of surface drainage
from or onto neighboring properties; and
(e)
Installed in compliance with all other provisions of this code
and other applicable ordinances and regulations of the Village of
Bannockburn.
(16)
Compensatory storage. Whenever any development in any portion
of an SFHA is authorized pursuant to this article, the volume of space
that is to be occupied by the authorized development below the BFE
shall be compensated for and balanced by at least an equal volume
of excavation taken from below the BFE. All compensatory storage basins
shall meet the following requirements:
(a)
The compensatory storage basin shall be of a size sufficient
to contain a volume of water equal to that which will be displaced
by fill.
(b)
The compensatory storage basin shall be located below the ground
and shall be no higher than the BFE and no deeper than three feet
above the depth of the bottom of the watercourse.
(c)
A drain shall be constructed from the bottom of the compensatory
storage basin to the watercourse. For the purpose of this subparagraph,
a drain may be a pipe, ditch, or swale which allows a basin to be
emptied by gravity.
(d)
The compensatory storage basin shall be constructed on the same
zoning lot as the use served; provided, however, that the Board of
Trustees may permit such compensatory storage basin to be located
in part on a different zoning lot or lots as the use served, subject
to the following conditions:
[1] At least 10% of the compensatory storage volume
shall be located on the same zoning lot as the use served;
[2] Any lot serving a portion of the compensatory storage
basin shall, in the opinion of the Board of Trustees, be in close
proximity to the zoning lot serving the development;
[3] The compensatory storage basin shall be designed
to permit a continuous and unobstructed flow of surface water throughout
the entire basin;
[4] The siting of a portion of the compensatory storage
basin on a zoning lot different from the lot serving the development
shall not, in the opinion of the Village Engineer, alter the drainage
or cause flooding upon any other zoning lot;
[5] Each lot upon which the compensatory storage basin
is located shall be in common ownership or under common control at
the time a development is approved;
[6] An easement in a form acceptable to the Village
shall be granted for the benefit of the zoning lot serving the development
which allows the maintenance of the compensatory storage basin on,
over, or across the zoning lot or lots serving such basin, which easement
cannot be terminated or otherwise modified without the express written
approval of the Board of Trustees; and
[7] Such other conditions that the Board of Trustees
may deem necessary or appropriate.
B. Standards for uses located on flood table land.
(1)
Residential structures. All residential structures shall be
constructed so that all habitable floor space, including the basement,
shall be located at least three feet above the BFE.
(2)
Nonresidential structures. All nonresidential structures shall either be elevated in the same manner hereinabove required for residential structures or shall be floodproofed in accordance with the provisions of §
260-811B.
(3)
Residential site elevation. The elevation of all land located
within five feet of the perimeter of any residential structure shall
be elevated at least one foot above the BFE.
(4)
Fill. The use of fill shall be permitted, provided that the
quantity of fill used shall be no greater than the amount required
to comply with the elevation requirements set forth hereinabove.
Before making a recommendation to the Board of Trustees with
respect to an application for a special use permit, the Plan Commission
shall evaluate the flood hazard on the site proposed to be developed
and shall determine what, if any, flood hazard could result from such
development. The Plan Commission shall determine and consider whether:
A. A proposed development, alone and in conjunction with existing or
proposed developments, will cause an increase in flood heights or
velocities which may endanger life or property.
B. The proposed water supply and sanitation systems are adequate to
prevent pollution and contamination.
C. A proposed development is susceptible to flood damage because of
its design, siting, use of materials, or location.
D. A proposed development is compatible with existing, proposed, and
anticipated development.
E. A proposed development will be readily accessible in times of flood.
F. The expected heights, velocity, duration, rate of rise, or sediment
transport of the flood waters expected at the site will endanger life
and property.
G. A proposed development alone or in conjunction with other proposed
development will have an adverse impact on the health, safety, and
welfare of Village residents by requiring large governmental expenditures
for flood control facilities to protect such development from damage
from flooding.
H. A proposed development complies with all other terms, conditions,
and standards of the Flood Hazard Overlay District and the underlying
zoning district.
An applicant for a special use permit under this article shall file with the Village Clerk, in addition to the items required by §§
260-805 and
260-1131, the following:
A. Four copies of plans drawn to a scale of one inch per 100 feet, showing
the nature, location, dimensions, and elevation of the lot; existing
or proposed structures, fill, and floodproofing measures; relationship
of the above to the location of the watercourse; elevations or contours
of the ground; pertinent structure or fill elevations; size, location,
and spatial arrangement of all proposed and existing structures on
the site; location and elevations of streets, parking areas, water
supply, and sanitary facilities; and base flood elevation data for
the site.
B. Elevations in relation to the benchmarks shown on the Flood Insurance
Rate Map of the Village, or, if no such benchmark exists, mean sea
level, of the lowest habitable floor, including the basement or cellar
floor, and in the case of floodproofed structures, the elevations
to which it will be floodproofed.
C. Plans for the construction of any required compensatory storage basin.
D. Plans for the construction of any required retention or detention
storage, showing the relationship to compensatory storage.
E. The application shall also contain such other information or certification
as reasonably may be required by the Building Commissioner, the Plan
Commission, or the Board of Trustees in order to determine eligibility
for permits or the flood hazards on the site and of the proposed development
or to enforce the terms of this code.
Upon the sale of property in the Village zoned in the Flood
Hazard Overlay District or known to be in a designated SFHA, a disclosure
statement shall be provided by the seller of such property to every
potential buyer of such property, stating that such property is all
or partially designated as being in an area subject to periodic flooding.
The degree of flood protection required by this article is considered
reasonable for regulatory purposes and is based on historical records
and engineering and scientific methods of study. Larger floods may
occur or flood heights may be increased by man-made or natural causes.
This article does not imply that areas outside the Flood Hazard Overlay
District or land uses permitted within the district will be free from
flooding or flood damage. This article shall not create liability
on the part of the Village or any officer, official, employee, agent,
attorney, representative, or consultant thereof for any flood damage
that may result from reliance on this code or on any administrative
decision, action taken, or inaction made hereunder. Nothing herein
shall be construed to prevent any property owner from taking such
additional, lawful measures (including nonuse of flood-prone property)
to protect against flood damage.