Township of Park, MI Standards For Flood Hazard Reduction

[Ord. No. FP-1, 4-6-1978; Ord. of 2-5-1987]

In all areas of special flood hazard, the following general provisions shall apply and shall be required:

All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure.

(2)

All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

(3)

All new construction and substantial improvements shall be constructed by methods and practices that minimize flood damage.

(4)

All new construction and substantial improvements shall be constructed with electrical, heating, ventilation, plumbing, and air-conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the compartments during conditions of flooding.

(5)

For all new construction and substantial improvements, any fully enclosed areas below the lowest floor that are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or must meet or exceed the following minimum criteria:

A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.

The bottom of all openings shall be no higher than one foot above grade.

Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.

(6)

All new and replacement water-supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.

(7)

All new and replacement sanitary-sewer systems shall be designed to minimize or eliminate infiltration of floodwaters into the system and discharges from the system into floodwaters.

(8)

On-site waste-disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

[Ord. No. FP-1, 4-6-1978; Ord. of 2-5-1987]

In all areas of special flood hazards where base-flood elevation data has been provided as set forth in Section 10-52 or Section 10-89(9), the following specific provisions shall apply and shall be required:

(1)

Residential construction. New construction or substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above base-flood elevation.

(2)

Nonresidential construction. New construction or substantial improvement of any commercial, industrial, or other nonresidential structure shall either have the lowest floor, including basement, elevated to the level of the base-flood elevation or, together with attendant utility and sanitary facilities, be floodproofed so that below the base-flood level the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. A registered professional engineer or architect shall develop and/or review structural design, specifications, and plans for the construction, and shall certify that the design and methods of construction satisfy the standards of this subsection. A record of such certification, including the specific elevation in relation to mean sea level to which such structures are floodproofed, shall be provided to and maintained by the Township zoning inspector.

(3)

Manufactured homes. No manufactured home shall be placed in a floodway. All developers of manufactured home parks or subdivisions located within an area of special flood hazard shall file an evacuation plan indicating alternative access and escape routes with the Federal Emergency Management Agency (FEMA). All manufactured homes to be placed or substantially improved within such existing manufactured home parks or subdivisions shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is at or above the base-flood elevation and shall be securely anchored to an adequately anchored foundation system. All manufactured homes shall be anchored to resist flotation, collapse, or lateral movement by providing over-the-top or frame ties to ground anchors or by other anchoring techniques provided for in the FEMA manual entitled "Manufactured Home Installation in Flood Hazard Areas." Specific requirements shall be as follows:

If over-the-top ties are used, they shall be provided at each of the four corners of the manufactured home with two additional ties per side at intermediate locations. Manufactured homes less than 50 feet long require only one additional tie per side.

If frame ties are used, they shall be provided at each corner of the manufactured home, with five additional ties per side at intermediate locations. Manufactured homes less than 50 feet long require only four additional ties per side.

All components of the anchoring system shall be capable of carrying a force of 4,800 pounds.

Any additions to the manufactured home shall be anchored in the same manner and to the same extent as the principal manufactured home.

(4)

New manufactured home parks and subdivisions; expansions to existing manufactured home parks and subdivisions. With respect to new and existing manufactured home parks and subdivisions, with respect to existing manufactured home parks and subdivisions where the repair, reconstruction, expansion or improvement of the streets, utilities, and pads equals or exceeds 50% of the value of the streets, utilities, and pads before the repair, reconstruction, expansion or improvement has commenced, and with respect to manufactured homes not being placed in a manufactured home park or subdivision, specific requirements shall be as follows:

Stands or lots shall be elevated on compacted fill, on pilings or by other elevation techniques provided for in the FEMA manual entitled "Manufactured Home Installation in Flood Hazard Areas" so that the lowest floor of the manufactured home is at or above the base-flood level.

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

Where pilings are used for elevation purposes, lots shall be large enough to permit steps, piling foundations shall be placed in stable soil no more than 10 feet apart, and reinforcement must be provided for pilings more than six feet above the ground level. With respect to existing manufactured home parks and subdivisions which are being expanded or improved, these requirements shall apply only in the expanded or improved portion.

(5)

Subdivision proposals. All subdivision proposals, including proposals for new manufactured home parks and subdivisions, shall be consistent with the need to minimize flood damage and shall meet the following specific requirements:

All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage.

All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage.

Base-flood elevation data shall be provided for all subdivision proposals and other proposed development which contain at least 50 lots or five acres, whichever is less.

(6)

Designated floodways. Located within areas of special flood hazard established in Section 10-52 are areas designated as floodways. Since the floodway is an extremely hazardous area because of the velocity of floodwaters which carry debris, potential projectiles, and erosion potential, encroachments, including fill, new construction, substantial improvements, and other developments shall be prohibited unless certification by a registered professional engineer or architect is provided demonstrating that encroachment will not result in any increase in flood levels during occurrence of the base-flood discharge.

(7)

Undesignated floodways. Located within the areas of special flood hazard established in Section 10-52, are areas in which elevation has been designated but no floodway has been delineated. In such areas, no new construction, substantial improvements, or other development, including fill, shall be permitted, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing anticipated development, will not increase the water surface elevation of the base flood more than nine-tenths feet at any point within the community.