Bannockburn City Zoning Code
ARTICLE VIII
Flood Hazard Overlay District
§ 260-801 Purpose.
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.
§ 260-802 Overlay district.
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.
§ 260-803 Definitions.
For purposes of this article, the following terms shall have the meanings herein ascribed to them:
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.
The highest water surface elevation of the base flood. See § 260-804.
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.
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.
The portion of the SFHA located between the boundaries of the floodway and the outside edge of the SFHA.
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.
Land adjacent to the SFHA with an elevation greater than the BFE by three feet or less.
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.
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).
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.
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.
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:
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
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.
Any river, stream, creek, brook, branch, or other drainageway in or into which stormwater runoff and floodwaters flow either regularly or intermittently.
§ 260-804 Flood hazard area maps; base flood elevations.
A.
Maps designated and incorporated.
(1)
The mapping of the Flood Hazard Overlay District and the requirements applicable to properties within the Flood Hazard Overlay District are based on, and the SFHAs and BFEs are shown on, the following maps and studies, which maps and studies are by this reference incorporated herein and made a part hereof:
(a)
The BFE for the SFHAs of watercourses within the Village shall be as delineated on the one-hundred-year flood profiles in the current Flood Insurance Study of the Village prepared by the Federal Emergency Management Agency.
(b)
The BFE for each SFHA delineated on the Flood Insurance Rate Map of the Village shall be that elevation (or depth) delineated on said Flood Insurance Rate Map. When no base flood elevation exists, the base formulas presented in Depth and Frequency of Floods in Illinois published by the U.S. Geological Survey, 1976, shall be applied.
(c)
The BFE for 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 shall be as delineated on the Flood Insurance Rate Maps for relevant unincorporated areas of Lake County.
(2)
The SFHAs and BFEs shown on aforesaid maps and studies shall, except as provided in the following subsections, be the data upon which the administration of the Flood Hazard Overlay District is based.
B.
Conflicts in data; incomplete data.
(1)
In the event of any conflict in the data shown in the aforesaid maps, the flood profiles shall control in the absence of clear evidence that they are in error.
(2)
The BFE applicable to a specific parcel of land, if not otherwise depicted by the official maps and profiles incorporated in Subsection A of this section, shall be that elevation established for the adjoining watercourse measured at right angles to the general direction of the flow in that watercourse. When a bend in a watercourse exists and more than one line can be placed at right angles to the parcel of land, the highest BFE resulting shall prevail.
C.
Owner's right to submit more accurate data. The maps and profiles incorporated in Subsection A of this section shall be used in the administration of this article whenever they provide the most accurate data available; however, the applicability of this article to any specific parcel, whenever possible, shall be based on an accurate survey of the ground elevation of the specific parcel in question compared to the BFE. Any owner of land included in the Flood Hazard Overlay District shall be permitted to present data to the Building Commissioner to show that the property is not properly included within the Flood Hazard Overlay District or that it is not subject to any specific regulation of this article that depends upon its specific elevation. The determination of the Building Commissioner based on such data shall in all instances control over the maps incorporated in Subsection A of this section and over the exact location of the Flood Hazard Overlay District as shown on the Zoning Map. Any such data relied upon by the Building Commissioner shall be submitted to the Illinois State Water Survey and the Federal Emergency Management Agency.
§ 260-805 Certificate of zoning compliance required.
A.
Certificate required. No use, development, or substantial improvement of any land within the Flood Hazard Overlay District, except as approved in connection with the issuance of a special use permit pursuant to § 260-808, shall be permitted unless a certificate of zoning compliance evidencing compliance of such use, development, or substantial improvement with the provisions of this article shall have first been issued in accordance with § 260-1141 of this code.
B.
Additional application requirements. In addition to the data and information required pursuant to § 260-1131 of this code, every application for a certificate of zoning compliance for any use, development, or substantial improvement within the Flood Hazard Overlay District shall provide, unless waived by the Building Commissioner in accordance with the procedures set out in § 260-1131G of this code, the following information:
(1)
A map or plan showing:
(a)
The location and cross-section of streams and other floodwater runoff channels on and adjacent to the subject property, their normal channels, the extent of the flood fringe and flood table land at the established BFE, and the limits of the floodway, all properly identified; and
(b)
The normal shoreline location and elevation of lakes, ponds, swamps, and detention basins on and adjacent to the subject property, including the flood fringe and flood table land and lines of inflow and outflow, if any; and
(c)
The location of any of the following structures on and adjacent to the subject property:
(2)
Profile scale engineering drawings of each stream, channel, pond, and basin showing:
(a)
The elevation, slope, cross-sectional area, and type of streambed and channel banks, if any; and
(b)
The size and elevation of waterway openings of existing culverts and bridges on and adjacent to the subject property; and
(c)
The size and elevation of sewer and drain outlets in the stream, channel, or basin.
(3)
Plans showing the nature, location, dimensions, and elevation of the lot, existing structures, streets and parking lots, and proposed improvements and landscape treatments.
(4)
The BFEs (USGS datum) for the subject property.
(5)
A topographic survey of the subject property showing the spot elevation and contours at one-foot intervals, both before and after the proposed development.
(6)
Information on the soil type and vegetation of the site.
(7)
All permits from those governmental agencies from which approval is required.
§ 260-806 Prohibited uses.
No use or development of any kind or nature whatsoever shall be allowed in any floodway.
§ 260-807 Permitted uses.
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:
§ 260-808 Special uses.
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.[1]
(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.
§ 260-809 General development standards.
A.
Site design. Streets, blocks, lots, parks, and public grounds shall be located and laid out in such a manner as to preserve and utilize natural watercourses and detention basins. Wherever possible, watercourses and the entire base flood area shall be included within parks or other public grounds.
B.
Lots in SFHA. Land lying wholly or partially in the SFHA may be laid out and platted as lots, provided that a building site not lower than the BFE of sufficient area at such elevation for the proposed building:
C.
Drainageways. Whenever plans call for the passage or storage of surface runoff or stormwater on lots, the grading of all such lots shall be prescribed and established as part of the subdivision plat. The areas so designated for the passage or storage of such waters shall not be obstructed. The limits of the high water levels resulting from the passage or storage of such waters on such lots shall be included on the plat of record and shall be protected by a recorded easement acceptable to the Village.
D.
Storage of specified materials prohibited. Storage of floatable materials or flammable, explosive, hazardous, toxic, or other pollutants that could be injurious to animal or plant life shall not be permitted in the Flood Hazard Overlay District.
E.
Anchoring of recreational vehicles. Recreational vehicles to be stored in the SFHA for more than 180 days in any one year shall be tied down in accordance with the rules and regulations for the Illinois Mobile Home Tiedown Act (210 ILCS 120/1 et seq.).
F.
Watercourse standards. Notwithstanding any other provision of this article, no watercourse shall be relocated or altered so as to reduce its flood-carrying capacity. Prior to any proposed alteration or relocation of any watercourse, the Building Commissioner shall notify adjacent communities and the Illinois Department of Transportation, Division of Water Resources, and the Federal Emergency Management Agency of the proposed alteration or relocation of a watercourse.
§ 260-810 Determination of flood hazard.
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.
§ 260-811 Conditions attached to special use permits.
A.
Conditions. Upon consideration of the flood hazards of a proposed development and its site, the Plan Commission may recommend and the Board of Trustees may impose conditions upon the granting of a special use permit to further the purposes of this article. Such conditions may include, without limitation:
(1)
Requirements for waste collection and disposal facilities.
(2)
Requirements for water supply facilities.
(3)
Requirements for constructions of dikes, levees, or other protective measures.
(4)
Floodproofing measures required for flood protection, taking into consideration the elevation of a site compared to the BFE and the elevation of adjacent sites, and the flood velocities, duration, rate of rise, hydrostatic and hydrodynamic forces, and any other relevant flood conditions on the site.
B.
Floodproofing. The floodproofing measures which may be required may include, without limitation:
(1)
Installation of watertight doors, bulkheads, shutters, or similar methods of construction.
(2)
Reinforcement of walls to resist water pressures.
(3)
Use of paints, membranes, or mortars to reduce seepage of water through walls.
(4)
Addition of mass or weight to structures to resist flotation.
(5)
Installation of pumps to lower water levels in structures.
(6)
Construction of water supply and waste treatment systems so as to prevent the entrance of floodwaters.
(7)
Installation of pumping facilities or comparable practices for subsurface drainage systems for structures to relieve external foundation wall and basement floor pressures.
(8)
Construction to resist rupture or collapse caused by water pressure or floating debris.
(9)
Installation of valves or controls on sanitary and storm drains which will permit the drains to be closed to prevent backup of sewage and stormwaters into structures.
(10)
Location of all electrical equipment, circuits, and installed electrical appliances in a manner which will assure they are not subject to flooding.
C.
Other submittals. As a condition to the granting of a special use permit hereunder, an applicant shall:
(1)
Acknowledge, in writing, that flood protection in excess of that required by this article may be required to fully protect property subject to flooding and that neither the Village nor any officer or employee thereof shall be liable for any flood damages that may occur on property located in the Flood Hazard Overlay District.
(2)
If floodproofing is required as a condition to the grant of a special use permit as hereinabove provided, submit the written certification of a registered professional engineer or architect that the floodproofing required is adequate for the structure to withstand the flood depths, pressures, velocities, impact and uplift forces, and other flood hazards associated with the base flood.
§ 260-812 Application for special use permits.
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.
§ 260-813 Reports and records.
A.
Annual report. To the extent required by federal, State, or local regulations other than this code, the Building Commissioner shall provide the Board of Trustees, the Illinois Department of Transportation, Division of Water Resources, and the Federal Insurance Administration with an annual report on forms provided to the Village by the Federal Insurance Administration.
B.
Records. The Building Commissioner shall maintain records of the following information concerning every structure hereafter constructed in the SFHA:
(1)
Lowest floor elevation: the elevation, as built, of the lowest opening and floor (including the basement or cellar floor).
(2)
Floodproofed elevation: where a structure has been floodproofed, the elevation, as built, to which the structure was floodproofed and the engineer's certificate as to the adequacy of such floodproofing.
§ 260-814 Disclosure statement.
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.
§ 260-815 Disclaimer of liability.
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.