[HISTORY: Adopted by the Township Board of the Township of Grosse Ile 8-11-1980 by Ord. No. 137 as Ch. 45 of the Grosse Ile Township Code; amended in its entirety 7-22-2002. Subsequent amendments noted where applicable.]
It is the purpose of this chapter to promote the public health, safety and general welfare and to minimize public and private losses due to flood conditions in specific areas by provisions designed to:
Restrict or prohibit uses which are dangerous to health, safety and property due to water or erosion or increase in flood heights or velocities.
Require that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction.
Control the alteration of natural floodplains, stream channels, and natural protective barriers which are involved in the accommodation of floodwaters.
Control filling, grading, dredging and other development which may increase erosion or flood damage.
Identify and provide a method of identification of the floodplains, floodways and watercourses located within the Township and to provide for the proper use of Township land and property located in areas within the Township subject to periodic flooding in order to attempt to protect and secure the safety of construction located in such areas from periodic flooding.
Reduce the financial burdens imposed upon the community by the improper occupancy and use of areas subject to periodic flooding within the Township.
Establish construction standards in areas within the Township subject to periodic flooding in order to attempt to prevent loss of life, property damage, and other losses and risk associated with flooding conditions.
Provide a procedure for obtaining building permits for construction within areas of the Township subject to periodic flooding.
As used in this chapter, the following terms shall have the meanings indicated:
- CONSTRUCTION BOARD OF APPEALS AND ADJUSTMENTS
- The Township of Grosse Ile Construction Board of Appeals.
- An overflow of water onto lands not normally covered by water where the inundation of land is temporary and the land is adjacent to and inundated by overflow from a watercourse, or lake, or other body of standing water.
- The relatively flat low lands which are contiguous areas paralleling major rivers or streams that constitute at their maximum edge the highest flood levels experienced in a period of 100 years; shall include wetland areas that are part of the river flow system; and shall include contiguous areas paralleling major rivers or streams that exhibit unstable soil conditions for development.
- The channel of any watercourse and those portions of the floodplain adjoining the channel which are reasonably required to carry and discharge floodwater.
- To construct, place, insert or excavate.
- Any organic or inorganic material or substance.
- ONE-HUNDRED-YEAR FLOOD
- A flood having an average of one in 100 probability of occurrence in any one year or a 1% chance of occurring in any given year.
- Any person who has dominion over, control of, or title to a parcel of land.
- Any individual, firm, partnership, association, corporation, company, organization or legal entity of any kind.
- Any assembly of materials above or below the surface of land or water, including but not limited to houses, buildings, bulkheads, piers, docks and waterway obstructions.
- SUBSTANTIAL IMPROVEMENT
- Any repair, reconstruction, or improvement of a structure, 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. For the purposes of this definition, "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 structures. The term does not, however, include either any project for improvement or 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 listed on the National Register of Historic Places or a State Inventory or Historic Places.
- A grant of relief to a person from the requirements of this chapter which permits construction in a manner otherwise prohibited by this chapter where specific enforcement would result in unnecessary hardship.
- Any waterway or other body of water having well-defined banks, including rivers, streams, creeks and brooks, whether continually or intermittently flowing.
The provisions of this chapter shall apply to all floodplains, floodway and watercourse areas located within the Township of Grosse Ile as the same are identified or determined by any of the following methods:
As such areas are identified on the Official Shoreland Protection and Management Ordinance Map of the Township of Grosse Ile.
As such areas are identified or determined on the basis of individual computation based on current standards and engineering techniques approved and employed by the Federal Emergency Management Agency.
As such areas are identified or determined by the Department of the Army Corps of Engineers.
The provisions of this chapter shall also apply to such areas within the Township as are identified or determined in accordance with the elevation standards set forth hereinafter.
The areas of special flood hazard identified by the Federal Insurance Administration in its Flood Hazard Boundary Map (FHBM) #26-0227, as amended, and any revisions thereto are adopted by reference and declared to be part of this chapter.
The Township Board of the Township of Grosse Ile hereby designates the Flood Insurance Rate Maps (FIRMs) of Grosse Ile Township, Wayne County, Michigan, panel numbers of 26163C0410E, 26163C0416E, 26163C0420E and 26163C0535E, dated February 2, 2012.
[Amended 1-9-2012 by Ord. No. 12-01]
The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by man-made or natural causes. This chapter does not imply that land outside the areas of special flood hazards or uses permitted within such areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the Township or by any officer or employee thereof for any flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder.
All applications for the construction of principal buildings and/or all accessory buildings in areas within the Township to which this chapter applies must include the following:
Name and address of applicant and of applicant's agent, if any, and whether applicant is owner, lessee, licensee, etc. If applicant is not owner, the written consent of the owner, duly acknowledged, must be attached.
Survey and topographical map of the property upon which the proposed construction is to take place, prepared in the manner provided for in this chapter.
A nonrefundable filing fee in an amount established by the Township Board.
The permit application shall be accompanied by a survey and topographical map drawn to a scale of no smaller than 1:40 prepared and certified substantially correct by a registered land surveyor or engineer, and shall include the following information:
Name and address of record of the affected property and of applicant, if other than owner; location and dimension of all boundary lines; scale; North arrow and date.
Existing contour data for the entire property with a vertical interval of no more than two feet and contour data at an interval of no more than one foot for all areas to be disturbed by the proposed construction, extending for a distance of at least 50 feet beyond the limits of such areas. Indicated elevations shall be based on USC and GS datum or NGV datum.
Areas within the Township of Grosse Ile subject to the provisions of this chapter shall depend upon the location of a particular parcel of land with respect to natural rivers, canals, streams and other watercourses within the Township.
The provisions of this chapter shall apply to those areas within the Township of Grosse Ile which are at and below the elevation determined by federal requirements and which are adjacent to sheltered streams, canals and watercourses and which are not affected by direct exposure to wind, wave action and wakes from the Detroit River or Lake Erie.
The provisions of this chapter shall also apply to those areas within the Township of Grosse Ile which are at an elevation of 580.0 USC and GS datum or NGV datum and below, and which are immediately adjacent to the Detroit River or have direct exposure to wind, wave action and wakes from passing ships.
As used in this chapter, the hereinbefore established elevation standards shall be defined as the "contour of the floodplain" or the "floodplain contour" within the Township of Grosse Ile.
In the event of a conflict between other ordinances of the Township of Grosse Ile and the elevation standards defining the floodplain contour or the contour of the floodplain within the Township of Grosse Ile, as set forth in this section, the provisions of this section shall supersede and control.
In all areas of special flood hazards, the following provisions are required:
All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure.
All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.
All new construction or substantial improvements shall be constructed by methods and practices that minimize flood damage.
All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.
New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharge from the systems into floodwaters.
On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
No structure which is located or is proposed to be located within the areas of the Township subject to the provisions of this chapter shall be constructed, extended, located, converted, or structurally altered except in conformance with the provisions of this chapter in accordance with the appropriate portions of State of Michigan Building Code. Such structures or proposed structures shall be required to also satisfy the following requirements:
Be located on a lot having a minimum building site of 6,000 square feet of its area at natural grade, or at a grade attained by depositing approved fill, above the elevation of the contour of the floodplain as defined in this chapter. All fill deposited to meet the foregoing grade requirement must be compacted to 95% Proctor, tested and verified by a certified testing laboratory. The required grade must extend a minimum of 15 feet beyond the limits of any building or structure; except side setback must meet minimum requirements;
Have lower floors, including basements, no lower than the elevation of the floodplain contour;
Be equipped with a positive means of preventing storm or sanitary sewer backup from drains serving the structure by installation of valves capable of being closed manually or automatically when sewers leave the building below elevation of 580.0, USC and GS datum;
Must be equipped with a sump pump to discharge floor drains and laundry tubs into the sanitary sewer;
Must have footing drains around basements or depressed portions of the structure (including crawl spaces) which are below the contour of the floodplain pumped into a separate discharge line which is taken directly to the adjacent watercourse;
Have all electrical equipment, circuits and electrical appliances located so as not to be subject to flooding, or shall be waterproofed against damage resulting from inundation by a one-hundred-year flood;
The location or storage of chemicals, explosives, buoyant and/or flammable liquids is prohibited below the contour of the one-hundred-year floodplain;
Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water;
Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
Be certified by a registered professional engineer or architect that the standards of this subsection are satisfied. Such certifications shall be provided to the Township.
When floodproofing is utilized for a particular structure, the applicant must provide to the Township a certification from a registered professional engineer or architect.
In the event a structure is adjacent to a floodplain and the basement is two feet below the flood elevation the basement must be floodproofed, all setback requirements must be met, and all utility restrictions of this chapter apply.
It shall be brought to the attention of both the owner of the property and the contractor performing the construction that, prior to issuance of a construction permit, both the owner and contractor must submit an affidavit as evidence that they have been advised of a potential danger of damage due to flooding conditions and/or sewer backup, that they will abide by the requirements of this chapter, and absolve the Township of any and all responsibility for liability for loss suffered by such an occurrence.
The Zoning Officer shall ensure that all necessary permits have been issued, including a floodplain permit, approval, or letter of no authority from the Michigan Department of Natural Resources under authority of Act 245, Public Acts of 1929, as amended by Act 167, Public Acts of 1968.
The Department of Community Development Manager and/or Zoning Officer shall maintain a record of new structures or substantial improvements erected in the flood hazard area indicating the actual elevation of the lowest structural member required to be elevated or as an alternative, in nonresidential structures, the elevation to which the structure has been floodproofed.
The Construction Board of Appeals of Grosse Ile Township shall hear and decide appeals and requests for variances from the requirements of this chapter.
The Construction Board of Appeals of Grosse Ile Township shall hear and decide appeals when it is alleged there is an error in any decision or determination made in the enforcement or administration of this chapter.
Variances shall only be issued upon all the following conditions being met. Personal hardship shall not be an acceptable condition for the granting of a variance.
A determination that failure to grant the variance would result in an exceptional hardship to the applicant.
A determination that the granting of a variance will not result in any threat to the public safety and would not result in any extraordinary public expense.
The variance within any designated regulatory floodway would not result in any increase in flood levels during the base flood discharge.
A showing of good and sufficient cause is made by the applicant.
A determination that the granting of a variance will not result in increased flood heights, additional threats to the public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public, or conflict with any other existing local laws or ordinances.
A determination that the variance is the minimum necessary considering the flood hazard to afford relief.
The structure or other development that is proposed will be protected by methods that minimize flood damages during the base flood and create no additional threats to public safety.
The Township shall notify the applicant in writing over the signature of a Township official that the issuance of a variance to construct a structure below the base of flood level will result in increased premium rates for flood insurance up to amounts as high as $25 for each $100 of insurance coverage and that such construction below the base flood level increases risk to life and property. Such notification shall be maintained with a record of all variance action. The Township shall maintain a record of all variance actions under this chapter, including justification for their issuance, and report such variances issued in its annual or biennial reports submitted to the Administrator for the Federal Emergency Management Agency or his designee.
The appeal or request for a variance shall be filed not later than 30 calendar days after the decision or action has been taken on an application form provided by the Township. The application shall specify the requirements from which a variance is sought and the nature and extent of such variance. The application shall be accompanied by a plan drawing. The application and plan drawing shall also be submitted to the Township Engineer for their review and recommendation to the Zoning Board of Appeals.