The intent and purpose of the FP, Floodplain District is found in § 156.084(J).
(A) All uses. Refer to § 156.092 for a listing of permitted and special uses in the Floodplain District. Those uses which are listed as permitted do not significantly obstruct flood flows and shall be permitted in the FP District to the extent that they are not prohibited by any other ordinance, or any other section of this chapter, and provided that they do not adversely affect the capacity of the channel or floodway of any stream, drainage ditch, or tributary thereof, or any other drainage facility or system.
(1) Development standards and requirements for all uses. The first floor or basement floor of any building or structure, including residences, to be erected, constructed, reconstructed, altered, or moved on the floodplain shall be constructed on fill with the finished surface of these floors at or above a point two feet above the regional flood elevation or flood profile shown on the interim flood plain as designated by the official zoning map. The landfill itself shall be at or above a point one foot above the regional flood elevation for this area and the fill shall extend at such elevation at least ten feet beyond the limits of any building or structure erected thereon. However, no use or fill shall be constructed which will adversely affect the capacity of any channel or floodway of any stream, drainage ditch, or tributary thereof, or any other drainage facility or system.
(2) Accessory uses. Accessory uses to both permitted and special uses shall be subject to the regulations in division (A)(1) above.
(3) The regional flood can be most accurately predicted by a detailed engineering study. When such a study has not yet occurred or been completed, this chapter's protection standard will be the regional flood according to the best data available to the State Water Survey's Floodplain Information Repository. Whenever a party disagrees with the best available data he may finance the detailed engineering study needed to replace existing data with better data and submit it to the state water survey.
(4) For development proposals located in the designated interim floodplain where the floodway has not yet been identified, the following rule shall apply, the Building Inspector shall review the development plans to determine whether a new obstruction to flood flows would be created. If an obstruction may be created, the applicant shall be required to obtain a permit from the State Department of Transportation, Division of Water Resources, issued pursuant to ILCS Ch. 615, Act 5 § 23. The Building Inspector shall not issue a development permit unless the applicant has obtained either a Section 70 permit or a "waiver of permit required" from the Division of Water Resources.
(Ord. 80-0-24, passed 1-12-81) Penalty, see § 156.999
(B) Special uses. Refer to § 156.092 for a listing of special uses in the Floodplain District. These uses may be permitted only on application to the Plan Commission and approval by the City Council of a special use permit, as provided by §§ 156.035 through 156.042. These uses are subject to the standards and requirements as provided in the following divisions.
(1) All special uses in the Floodplain District.
(a) No structure (temporary or permanent), fill, including fill for roads and levees, deposit, obstruction, storage of materials or equipment, or other uses, may be allowed as a special use which, acting alone or in combination with existing or future uses, unduly affects the capability of the floodway or unduly increases flood heights. Consideration of the effects of a proposed use shall be based on a reasonable assumption that there will be an equal degree of encroachment extending for a significant reach on both sides of the stream or ditch. In addition, where a use is listed as both a special use in the Floodplain District and a special use in the underlying T, D, B, or I District, the provisions set forth in §§ 156.115 through 156.119 shall also apply. A table which clarifies the relation between the Floodplain District regulations and regulations in the underlying districts is provided in § 156.117(A). Furthermore, the uses, buildings, and structures listed in divisions (2) through (9) of this division shall comply with the standards and requirements contained herein.
(b) The following floodproofing measures shall apply to all special uses in the Floodplain District, to the extent that they are applicable to each particular case of a special use. These floodproofing measures shall be designed at or above a point two feet above the regional flood elevation for the particular area, flood velocities, durations, rate of rise, hydrostatic and hydrodynamic forces, and other factors associated with the regional flood. The Plan Commission shall require that the applicant submit a plan or document to the Building Inspector, certified by a registered professional engineer that the floodproofing measures are at a point two feet above the regional flood elevation and associated flood factors for the particular area. Required floodproofing measures may include:
l. Anchorage to resist flotation and lateral movement or addition of mass or weight to structures to resist flotation.
2. Installation of watertight doors, bulkheads, and shutters, or similar methods of construction.
3. Reinforcement of walls to resist water pressure.
4. Use of paints, membranes, or mortars to reduce seepage of water through walls.
5. Installation of pumps to lower water levels in buildings and structures.
6. Construction of water and waste treatment systems so as to prevent the entrance of flood waters.
7. Pumping facilities or comparable practices for subsurface drainage systems, for buildings to relieve external foundation wall and basement 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 to be closed to prevent backup of sewage and storm waters into the buildings or structures. Gravity draining of basements may be eliminated by mechanical devices.
10. Location of all electrical equipment, circuits, and installed electrical appliances so as to be protected from inundation by the regional flood.
11. Location of any structural storage facilities for chemicals, explosives, bouyant materials, flammable liquids, or other toxic materials which could be hazardous to public health, safety, and welfare, at a point above the regional flood elevation, or their floodproofing, so as to prevent flotation of storage containers, or damage to same, which could result in the escape of toxic or dangerous materials into flood waters or the environment.
(c) Where existing conditions make compliance with the regulations in division (A) of this subsection (those regulations covering all uses) impractical, or in other special circumstances, the Building Inspector may specify other floodproofing or building elevation measures such as those listed above in lieu of fill, provided that the first floor of the building is at or above a point two feet above the regional flood level for this area, and provided that no special use permit under this section shall be issued where the ground adjoining a building or structure designed for human habitation is more than two feet below the regional flood elevation.
(2) Fill, dumping of materials or waste.
(a) Any fill, dumping, or similar use proposed in the Floodplain District must be shown to have some beneficial purpose with regard to the intent of the Floodplain District, and the amount thereof not greater than is necessary to achieve that purpose, as demonstrated by a plan submitted by the Building Inspector by the owner showing the uses to which the filled land will be put and the final dimensions of the proposed fill.
(b) Such fill shall be protected against erosion during flooding by rip-rap, vegetative cover, or bulkheading.
(3) Buildings and structures.
(a) Buildings and structures shall be constructed so as to have a low flood damage potential.
(b) Buildings and structures shall be placed on the site so as to offer the minimum obstruction to the flow of flood waters:
l. Wherever possible, buildings and structures shall be constructed with the longitudinal axis parallel to the direction of the flood flow.
2. Wherever practicable, buildings and structures shall be placed approximately on the same flood flow lines as those of adjoining structures.
(c) Buildings and structures shall be firmly anchored to prevent flotation which may result in damage to other buildings, structures, property, or people.
(d) Service facilities such as electrical and heating equipment shall be constructed at or above a point two feet above the regional flood elevation for this area or floodproofed to the same level in accordance with division (B)(1)(b) hereof.
(4) Storage and processing of materials and equipment.
(a) The storage or processing of materials that are, in time of flooding, buoyant, flammable, explosive, or could be injurious to human, animal, or plant life is prohibited unless storage and processing of materials are at or above a point two feet above the regional flood elevation for this area, or floodproofed to the same level in compliance with division (B)(1)(b).
(b) Storage of other material or equipment may be allowed if not subject to major damage by floods and if firmly anchored to prevent flotation, or if readily removable from the area within the time available after flood warning.
(5) Garbage and solid waste disposal.
(a) No special use permits shall be issued for garbage and waste disposal sites in the Floodplain District.
(b) There shall be no further encroachment on the floodplain at existing garbage or waste disposal sites.
(6) Commercial, manufacturing, and industrial uses. Commercial, manufacturing, and industrial buildings, structures, and additional works shall be constructed on fill with no first floor or basement floor below a point two feet above the regional flood elevation, or shall be floodproofed in accordance with division (B)(1)(b) hereof to two feet above the regional flood elevation. Measures shall be taken to minimize interference with normal plant operations.
(7) Utilities, railroad tracks, streets, and bridges. New public utility facilities, railroad tracks, and bridges within the Floodplain District shall be designed to minimize increases in flood elevations. Protection to the regional flood elevations shall be provided where failure or interruption of these facilities would result in danger to the public health or safety, or where such facilities are essential to the orderly functioning of the area. Where failure of interruption of service would not endanger life or health, a lesser degree of protection may be provided for minor or auxiliary roads, railroads, or utilities.
(8) Water and waste treatment plants or systems.
(a) New construction of, or additions and modifications to existing treatment plants shall be floodproofed in accordance with the provisions of division (B)(1)(b) hereof to a point two feet above the regional flood elevation.
(b) Water or sewer systems shall be installed at elevations in accordance with the first floor and basement floor elevations required in division (A) hereof.
(9) Flood control works. Flood control works shall require a special use permit and shall comply with applicable state statutes.
(C) Rules for interpretation.
(1) Removal of lands from the Floodplain District. Compliance with the provisions of this chapter shall not be grounds for the removal of lands from the Floodplain District unless such lands are filled to a height of at least two feet above the elevation of the regional flood for this area and are contiguous for a significant distance to other lands outside of the Floodplain District and unless such filled lands lie at a significant distance from the channel or floodway of a stream or ditch. Removal of lands from the Floodplain District is a zoning map change and must be done in accordance with the procedure set forth in §§ 156.065 through 156.071.
(2) Warning and disclaimer of liability. The degree of flood protection required by this chapter is considered reasonable for regulatory purposes. Larger floods may occur on rare occasions, or the flood height may be increased by man-made or natural causes. This chapter does not imply that areas outside the Floodplain District will be free from flooding or flood damages. This chapter shall not create liability on the part of the city or any officer or employee thereof for any flood damages that result from reliance on this chapter, or any administrative decision lawfully made thereunder.
(Ord. 80-0-24, passed 1l-12-81) Penalty, see § 156.999