Chapter 16-60 FLOODPLAIN OVERLAY DISTRICT

The purpose of this legislation is to diminish threats to public health and safety caused by floodwater, reduce economic losses to individuals and the community at large; enhance broader social and economic objectives; protect, conserve and promote the orderly development of land and water resources; prevent victimization and fraud; and to comply with the guidelines for the National Flood Insurance Program as published by the U.S. Department of Housing and Urban Development. The provisions of this chapter further regulate, guide and control:

1. The use, subdivision, layout and improvement of lands located in floodplains;

2. The excavating, filling and grading of lots and other land parcels or areas located in floodplains and the storing of certain materials thereon;

3. The location, construction and elevation of buildings and other structures or parts and appurtenances thereof, and of sanitary and storm sewers and appurtenances such as manholes, located in floodplains. (Ord. 2286 § 19.0 (part), 1982)

16-60-030 Chapter provisions as additional requirements.

The provision of this chapter shall be as additional requirements to minimum standards required by other ordinances of the city. In case of conflicting requirements, the most restrictive shall apply. (Ord. 2286 § 19.1, 1982)

16-60-040 Other regulations.

Before starting any of the work regulated by this chapter, an applicant shall comply with the requirement set forth in other applicable ordinances with respect to the submission and approval of preliminary and final subdivision plats, improvement plans, building and zoning permits, inspections, appeals and similar matters, along with those set forth in this section and as may be required by federal or state laws and the regulations of any department of the state of Illinois. Where provisions of this chapter are more restrictive than other requirements, this chapter shall apply. (Ord. 2286 § 19.2, 1982)

Article II. General Conditions

16-60-050 Floodways.

In floodways which have been identified in Sec-ion 16-60-130 as elements of floodplains associated with the flood having a one-hundred-year recurrence interval, fill, encroachments, and new construction and substantial improvements of existing structures, which would result in any increase in flood heights, or velocity shall be prohibited. The location of any portion of a new mobile home park, of any expansion to an existing mobile home park, and of any mobile home not in a mobile home park shall be prohibited in the floodway. (Ord. 2286 § 19.3(1), 1982)

16-60-060 Flood fringes.

In flood fringes which have been identified in section 16-60-130 as elements of the floodplains associated with floods having one-hundred-year recurrence interval, construction, filling or use of hose low lying lands may be permitted under the conditions specified in the following sections of this chapter. (Ord. 2286 § 19.3(2), 1982)

16-60-070 Watercourse alteration.

In riverine situations, the plan commission shall notify adjacent communities, the Illinois Division of Water Resources and Federal Insurance Administration prior to any alteration or relocation of a watercourse within the municipality’s jurisdiction by any person or agencies. The plan commission shall assure that the flood-carrying capacity within the altered or relocated portion of any watercourse be maintained. (Ord. 2286 § 19.3(3), 1982)

16-60-080 Freeboard.

All structures located in base flood areas shall be required to be so sited on fill or be otherwise designed and constructed so as to include a freeboard of at least one foot between the lowest floor and the base flood elevation, except, as provided for in Section 16-60-240. (Ord. 2286 § 19.3(4), 1982)

16-60-090 Base flood.

Wherever the areas expected to be inundated by the base flood have been specifically identified, it is the intention of this chapter to provide protection in those areas against the high waters of the flood. (Ord. 2286 § 19.3(5), 1982)

16-60-100 Historical flood of record.

In the absence of specific information pertaining to the base flood, it is the intention of this chapter to provide protection in the low lying areas of this community against the high waters of the historical flood of record. (Ord. 2286 § 19.3(6), 1982)

16-60-110 Land use controls.

This floodplain chapter is not intended to reduce or eliminate existing flooding, nor is it intended to impose a complete prohibition of construction in base flood areas. On the contrary, these regulations are designed to guide and control development in such a manner as to lessen the damaging effects of floods on developments proposed for the low lying areas of this community. (Ord. 2286 § 19.3(7), 1982)

16-60-120 Base flood elevation.

The city council shall base its review on the high water elevations and limits of the one-hundred-year flood as established by the most recent and best available data. If the one-hundred-year flood information is not available, the review will be based on the flood of record data. The data which will be used by the city is listed below in descending order of overall accuracy, completeness, and correctness. When data of higher order becomes available, data of lower order will not be used.

A. HUD flood insurance studies (FIS), if certified by Illinois Department of Transportation, Division of Water Resources (IDOT-DWR);

B. IDOT-DWR Regulatory floodplain maps and profiles;

C. Soil Conservation Service-Metropolitan Sanitary District of Greater Chicago, (SCS-MSDGC) floodwater management plans, using the “without project” data shown therein;

D. Other detailed one-hundred-year flood studies, if certified by IDOT-DWR;

E. HUD flood hazard boundary maps (FHBM) and approximate FIS data;

F. USCS maps of flood-prone areas;

G. USGS-NIPC hydrologic investigation atlases (floods of records). (Ord. 2286 § 19.4, 1982)

16-60-130 Floodways identified.

In base floods where the floodways have been identified, the following provisions shall prevail:

A. Occupation and Use of Floodways: In floodways which have been identified in Section 16-60-130 as elements of the flood plains of the base flood, only those uses and structures will be permitted which will not impede or increase the flow and passage of floodwaters. All such uses and structures shall meet applicable zoning requirements for the area.

B. Occupation and Use of Nonfloodway Areas. Development in and use or filling of nonfloodway areas including flood fringes will be permitted if protection is provided against the base flood by proper elevation, and other provisions of this ordinance. No use will be permitted which will adversely affect the capacity of channels, the floodway, or drainage facilities or systems. All uses and structures shall meet applicable zoning requirements for the area. (Ord. 2286 § 19.5, 1982)

16-60-140 Open storage of floatable materials.

Logs, wastes, lumber, lumber products and other floatable materials, or containers shall not be placed, displayed or stored in the floodway and may be stored in flood fringes only upon the issuance of special use permits. (Ord. 2286 § 19.6, 1982)

16-60-150 Open storage of other materials.

The open storage or display on a flood fringe of inoperable motor vehicles and similar nonmovable machinery and other nonfloatable materials and products, where permitted by the regulations of the zoning district applicable to such land, shall be considered the same as the placement of fill on the floodplain and shall be subject to the regulations of this chapter relating to compensatory storage. (Ord. 2286 § 19.7, 1982)

16-60-160 Open storage of hazardous materials.

The open storage of materials anywhere in the base flood area which are flammable, explosive, toxic or which could be otherwise injurious to human, animal, or plant life is prohibited. (Ord. 2286 § 19.8, 1982)

Article III. Subdivision, Development and Improvement Regulations

16-60-170 Required information.

Accompanying the preliminary plans of each proposed subdivision which involves any portion of a base flood areas as described by the official maps of the city, there shall be furnished the following information and data:

A. Contour Map. A topographic map with two-foot interval contours of the land to be subdivided and such adjoining land whose topography may affect the layout or drainage of the subdivision. On such a map, there shall be shown the following:

1. The location of streams and other floodwater runoff channels, their normal channels, the extent of their floodplains at the established high-water elevations, and the limits of the floodway, all properly identified;

2. The normal shoreline of lakes, ponds, swamps, and detention basins, their floodplains and lines of inflow and outflow, if any;

3. The location of farm drains and their inlets and outlets;

4. Storm, sanitary, and combined sewers and any sewer outfalls;

5. Seeps, springs, and flowing and other wells;

6. Septic tank systems and outlets, if any;

7. Location of existing structures that will remain;

8. One-hundred-year flood elevation and limits, including floodway, data for that portion of a subdivision development which is in the base flood area.

B. Channel Profiles. Profile drawings of each stream channel, pond, and basin showing elevations of the following:

1. The streambed;

2. Channel banks, if any;

3. Waterway openings of existing culverts and bridges within and near the tract;

4. Size and elevation of sewer and drain outlets into the stream channel or basin;

5. The base flood elevations established by this title. (Ord. 2286 § 19.9, 1982)

16-60-180 Subdivision design.

The following rules shall govern the design of land improvements with respect to floods:

A. General. All proposed subdivision and other developments within the base flood area shall be reviewed to assure that the proposed developments ire consistent with the need to minimize flood damage, that all public utilities and facilities, (such as sewer, gas, electrical and water systems) are located and constructed to minimize or eliminate flood damage and that adequate drainage is provided.

B. Design. Streets, blocks, depths of lots, parks and other public grounds shall be located and laid out in such a manner as to preserve and utilize natural streams, channels and detention basins. Wherever possible, the larger streams and floodplains shall be included within parks or other public grounds.

C. Channel Straightening. Sharply meandering streams or channels may be partially straightened and minor changes made in other channels, subject to the approval of the plan commission, provided;

1. The hydraulic capacity of the floodway is maintained,

2. The volume of floodwater storage outside the floodway is not reduced,

3. Provision is made to stabilize the banks of the modified channel to control erosion, and

4. Any additional permits for this work that are required by the Illinois Department of Transportation and the Corps of Engineers are obtained.

D. Lots in Base Flood Area. Land lying wholly or partially in the base flood area may be laid out and platted as building lots or parcels, provided a building site not lower than the base flood elevation plus one foot exists on the high part of the lot or parcel, or the parcel will be built up during execution of the subdivision improvement plan through general excavation or filling.

E. Streets and Roads. When failure or interruption of service of streets or roads would endanger public health or safety, streets and roads shall be protected to a level of plane foot above the base flood elevation protection shall be provided to the extent practical.

F. Drainageways. Whenever the plans call for the passage and/or storage of surface runoff or excess stormwater on lots, the grading of all such lots shall be prescribed and established as part of the passage and/or storage of surface run-off or excess stormwater on lots shall be recorded on the plat of record and shall be covered by an easement.

G. Manholes. All sanitary sewer manholes constructed in a floodplain must have a rim elevation of a minimum of one foot above the base flood elevation or be provided with a locking, watertight manhole cover. (Ord. 2286 § 19.10, 1982)

16-60-190 Water supply and sanitary sewer systems.

The design of water supply and sanitary sewer systems to be located in the floodplain shall minimize or eliminate the discharge from the system into the floodwaters and the infiltration of floodwaters into the system. On-site waste disposal system shall be located so as to avoid impairment of them or contamination from them during or subsequent to flooding. (Ord. 2286 § 19.11, 1982)

16-60-200 Building regulations.

Building permits are required for all proposed construction, substantial improvements, or other development, including the placement of mobile homes, within floodplain areas having special flood hazards. Such permits shall assure that all other necessary permits have been received from those governmental agencies from which approval is required by federal or state law. The building permit applications will be reviewed to assure that any proposed development is:

A. Designed and anchored to prevent flotation, collapse or lateral movement of the structure;

B. Constructed with materials and utility equipment resistant to flood damage; and

C. Constructed by methods and practices that minimize flood damage.

D. At the time of issuing a building permit, the following information will be noted and recorded by the city:

1. Elevation of the lowest flood including basement,

2. Where the elevation of the lowest floor is below grade on one or more sides, the elevation of the floor immediately above,

3. Where a structure has been floodproofed the elevation to which the structure was floodproofed. (Ord. 2286 § 19.12, 1982)

16-60-210 Building site.

Each main building or structure that is built on fill shall have or shall be provided with a site, area or yard that is not lower than the established base flood elevation plus one foot, and which shall extend beyond the outside walls for a distance of at least five feet. The finished grade or surface of this area beyond the aforesaid five-foot distance shall be graded or surfaced so as to drain away from the walls over a distance of not less than five additional feet. (Ord. 2286 § 19.13, 1982)

16-60-220 Design criteria.

The following general design criteria shall apply to all new construction and substantial improvements which may be authorized in flood plains:

A. Residential Structures. The lowest floor, including the basement, of residential structures must be at an elevation not less than that of the base flood elevation plus one foot, unless they are adequately floodproofed and the city has been granted an extension from the Federal Insurance Administration for placing the lowest floor of the structures at a lower elevation. Within any AO Zone, all new construction and substantial improvements of residential structures shall have the lowest floor, including basement, elevated above the crown of the nearest street to or above the depth number specified on the community’s FIRM map.

B. Nonresidential Structures. The lowest floor, including the basement, of nonresidential structures must be elevated or floodproofed to an elevation not less than that of the base flood elevation plus one foot. Within any AO Zone, all new construction and substantial improvements of nonresidential structures shall have the lowest floor, including basement, elevated above the crown of the nearest street to or above the depth number specified on the FIRM, or together with attendant utility and sanitary facilities shall be completely floodproofed to or above that level to Federal Insurance Administration (FIA) standards.

C. Walls. The walls, foundation, and other features which may be authorized for construction or installation at an elevation below that of the base flood elevation plus one foot must be designed to resist appropriate hydrostatic pressures.

D. Anchoring. All authorized structures, including underground and above ground tanks, shall be firmly anchored to prevent flotation. Anchoring materials should be rust resistent.

E. Service Facilities. To the maximum extent feasible, all service facilities, such as electrical and heating equipment, shall be installed, constructed, or otherwise protected so as to remain operational should floodwaters reach the base flood elevation plus one foot. Water supply and wastewater collection and treatment systems shall be designed and constructed so as to prevent the entrance of floodwaters.

F. Floodproofing. Where the lowest floor elevation, including basement, is below the base flood elevation plus one foot, the structure, with the attendant utility and sanitary facilities, shall be floodproofed to a level of one foot above the base flood elevation. Where floodproofing is required, a registered professional engineer or structural engineer shall certify that the floodproofing methods employed are adequate to withstand the flood depths, pressures, velocities, impact and uplift forces and other factors associated with the base flood and a record of such certificates indicating the specific elevation to which such structures are floodproofed shall be maintained by the city. (Ord. 2286 § 19.14, 1982)

16-60-230 Existing, new and reconstructed mobile homes.

Within areas of special flood hazard for new mobile homes, new mobile home parks and mobile home subdivisions and for existing mobile home parks where the repair, reconstruction or improvement has commenced, the following provisions are required:

A. Ground Anchors. Mobile homes to be placed within areas of special flood hazard shall be anchored to resist flotation, collapse or lateral movement by providing over-the-top and frame ties to ground anchors. Specific requirements shall be that

1. Over-the-top ties be provided at each of the four corners of the mobile home, with two additional ties per side at intermediate locations and mobile homes less than fifty (50) feet long requiring one additional tie per side;

2. Frame ties be provided at each corner of the home with five additional ties per side at intermediate points and mobile homes less than fifty (50) feet long requiring four additional ties per side;

3. All components of the anchoring system be capable of carrying a force of four thousand eight hundred (4,800) pounds;

4. Any additions to the mobile home be similarly anchored.

B. Floor Elevation. Stands or lots shall be elevated on compacted fill or on piers so that the lowest floor of the home will be at an elevation not less than that of the base flood elevation plus one foot.

C. Drainage. Adequate surface drainage and easy access for a hauler shall be provided.

D. Piers. Where piers are used, steps to the home shall be able to be provided and piers shall be placed on stable soil no more than ten feet apart. Steel reinforcement shall be provided for piers more than six feet high. (Ord. 2286 § 19.15, 1982)

16-60-240 Nonconforming structures and uses.

A. Nonconforming Structures. Nonconforming structures may remain in use subject to the following regulations:

1. Alterations. A nonconforming structure shall not be enlarged, replaced or structurally altered. A nonconforming structure accidentally damaged may be restored unless the damage exceeds fifty (50) percent of its replacement value in which case it must thereafter conform to this title. The planning director shall determine the amount of the damage.

2. Building Permit Issued Prior to Adoption or Amendment of the Zoning Ordinance. Proposed structures for which building permits have been issued prior to their designation as nonconforming by adoption or amendment of the zoning ordinance may be completed and used as originally intended subject to the nonconforming provisions of this section.

B. Nonconforming Uses. Nonconforming uses may be continued subject to the following regulations:

1. Extensions. A nonconforming use shall not be expanded or moved to occupy any portion of the premises, either land, or structure, which was not originally occupied by the nonconforming use.

2. Discontinuance. Whenever a nonconforming use of any premises has been discontinued for a period of twelve (12) months, it may not be reestablished.

3. Changes. A nonconforming use shall not be changed to another or different nonconforming use. (Ord. 2286 § 19.16, 1982)

Article IV. Variances

16-60-250 Variances.¹

The director of planning of the city may grant variances from the regulatory standards of this title for residential garages and other similar structures. All other variances from the regulatory standards of this chapter shall be granted by the planning and zoning commission of the city. Variances granted by the director of planning or the planning and zoning commission shall be in accordance with the following requirements:

A. All Variance Requests. No variance shall be granted unless the applicant for the variance can demonstrate that:

1. A showing of good and sufficient cause,

2. An exceptional economic hardship would result to the applicant without the variance,

3. The relief granted is the minimum necessary,

4. There will be no additional threat to public safety or creation of a nuisance or conflict with existing local laws or ordinance,

5. No additional public expense will result.

B. Variances to Lower Protection Levels. In addition to the requirements of subsection A of this section, a variance from the requirements of Section 16-60-240 that would result in a structure not being protected to the elevation of the base flood shall also meet the following requirements:

1. The structure is to be located on a lot on one-half (0.5) acre or less in size, contiguous to and surrounded by lots with existing structures constructed below the base flood level;

2. The planning and zoning commission or the director of planning notifies the applicant in writing that the variance will result in increased premium rates for flood insurance up to amounts as high as twenty-five dollars ($25.00) for one hundred dollars ($100.00) of insurance coverage; and

3. The planning and zoning commission or the director of planning notifies the applicant in writing that such construction below the base flood level will increase the risks to life and property and that the applicant proceeds with knowledge of these risks;

4. The planning and zoning commission or the director of planning notifies the applicant if the variance is issued, it is contingent upon the applicant obtaining approval from agencies, having jurisdiction, when the variance violates the requirements of such agencies.

C. Variance to Increase Flood Heights. In addition to the requirements of subsection A of this section, a variance from the requirements of Sections 16-60-130 or 16-60-140 that would significantly impede or increase the flow and passage of floodwaters, shall also meet the following requirements, except that no variance will be granted that would result in an increased flood height greater than one-tenth (0.1) foot within the designated regulatory floodway:

1. The resulting increase in the base flood elevation will not affect any existing structures or utilities;

2. The owners of the properties affected by the increased base flood elevations are compensated for the resulting effect on property values and give their written agreement to granting the variance;

3. The resulting increased flood elevations will not affect any flood protection structures.

D. Historical Structures. Variances requested in connection with the reconstruction, rehabilitation, or restoration of structure listed on the National Register of Historic Places are documented as worthy of presentation by the Illinois Department of Conservation may be granted using criteria more permissive than the requirements of subsection A or B of this section.

E. Appeal Procedure. A decision of the director of the department of planning or the planning and zoning commission may be appealed to the city council of the city for a final determination of the matter, by filing with the city clerk within thirty (30) days of the decision a written notice of intent to appeal and the stating therein of the basis of the appeal. (Ord. 3462 § 17, 2022; Ord. 2286 § 19.17, 1982)

16-60-260 Appeals of administrative decisions.

All decisions and findings of the zoning board of appeals on appeals or upon applications for a variation, after a hearing, shall in all instances be final administrative decisions and shall be subject to judicial review as by law may be provided. (Ord. 2286 § 19.18, 1982)

Code reviser’s note: Ord. 3462 included amendments to an incomplete version of Section 16-60-250. Material that was omitted from this ordinance has been editorially restored for completeness.