TOWN OF HASTINGS, FLORIDA

TOWN CODE

Chapter 7

Flood Control

Continued from Previous Page.

Sec. 7-7. Provisions for flood hazard reduction.

A. GENERAL STANDARDS. In all areas of special flood hazard the following provisions are required;

1) New construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure;

2) Manufactured homes shall be anchored to prevent flotation, collapse, or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This standard shall be in addition to and consistent with applicable state requirements for resisting wind forces.

3) New construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage;

4) New construction or substantial improvements shall be constructed by methods and practices that minimize flood damage;

5) Electrical, heating, ventilation, plumbing, air conditioning equipment, and other service facilities shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

6) New and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system;

7) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters;

8) On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding, and ;

9) Any alteration, repair, reconstruction or improvements to a structure which is in compliance with the provisions of this ordinance, shall meet the requirements of "new construction" as contained in this ordinance.

B. SPECIFIC STANDARDS. In all areas of special flood hazard where base food elevation data have been provided, as set forth in Article 3, Section B, or Article 4, Section C (11), the following provisions are required:

1) Residential Construction. New construction or substantial improvement of any residential structure shall have the lowest floor, including basement, elevated no lower than (_____ feet) above the base flood elevation. Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate the unimpeded movements of flood waters shall be provided in accordance with standards of Article 5, Section B (3).

2) Non-Residential Construction. New construction or substantial improvement of any commercial, industrial, or non-residential structure shall have the lowest floor, including basement, elevated no lower than ( ____ feet) above the level of the base flood elevation. Structures located in all A-zones may be flood-proofed in lieu of being elevated provide that all areas of the structure below the required elevation are water tight with walls substantially impermeable to the passage of water, and use structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A registered professional engineer or architect shall certify that the standards of this subsection are satisfied. Such certification shall be provided to the official as set forth in Article 4, Section B (3).

3) Elevated Building. New construction or substantial improvements of elevated buildings that include fully enclosed areas formed by foundation and other exterior walls below the base flood elevation shall be designed to preclude finished living space and designed to allow for the entry and exit of floodwaters to automatically equalize hydrostatic flood forces on exterior walls.

a Designs for complying with this requirement must either be certified by a professional engineer or architect or meet the following minimum criteria:

(i) Provide 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;

(ii) The bottom of all openings shall be no higher than one foot above grade; and,

(iii) Openings may be equipped with screens louvers, valves or other coverings or devices provided they permit the automatic flow of floodwaters in both directions.

b) Electrical, plumbing, and other utility connections are prohibited below the base flood elevation;

c) Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) or limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator); and,

d) The interior portion of such enclosed area shall not be partitioned or finished into separate rooms.

4) Floodways. Located within areas of special flood hazard established in Article 3, Section B, are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles and has erosion potential, the following provisions shall apply:

a. Prohibit encroachments, including fill, new construction, substantial improvements and other developments unless certification (with supporting technical data) by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in flood levels during occurrence of the base flood discharge;

b. If Section 7-7. B 4) a. hereof is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of Article 5.

c. Prohibit the placement of manufactured homes (mobile homes), except in an existing manufactured homes (mobile homes) park or subdivision. A replacement manufactured home may be placed on a lot in an existing manufactured home park or subdivision provided the anchoring standards of Article 5, Section A (2), and the elevation standards of Article 5, Section B (1) are met.

5) Coastal High Hazard Areas (V Zones). Coastal High Hazard Areas (V Zones) Coastal High Hazard Areas IV Zones are located within the municipal boundaries of the Town. These areas have special flood hazards associated with wave wash, therefore, the following provisions shall apply:

a. All buildings or structures shall be located ( _____ feet) landward of the reach of the mean high tide;

b. All buildings or structures shall be elevated so that the bottom of the lowest supporting horizontal member (excluding pilings or columns) is located no lower than ( _____ feet) above the base flood elevation level, with all space below the lowest supporting member open so as not to impede the flow of water. Open lattice work or decorative screening may be permitted for aesthetic purpose only and must be designed to wash away in the event of abnormal wave action and in accordance with Article 5, Section B (5) (h);

c. All buildings or structures shall be securely anchored on pilings or columns;

d. All pilings and columns and the attached structures shall be anchored to resist flotation, collapse, and lateral movement due to the effect of wind and water loads acting simultaneously on all building components. The anchoring and support system shall be designed with wind and water loading values which equal or exceed the 100 year mean recurrence interval (one percent annual chance flood).

e. A registered professional engineer or architect shall certify that the design, specifications and plans for construction are in compliance with the provisions contained in Article 5, Section B (5) (b), (c) and (d) of this ordinance.

f. There shall be no fill used as structural support. Non-compacted fill may be used around the perimeter of a building for landscaping/aesthetic purposes provided the fill will wash out from storm surge, (thereby rendering the building free of obstruction) prior to generating excessive loading forces, reamping effects, or wave deflection. The Building Inspector shall approve design plans for landscaping/aesthetic fill only after the applicant has provided an analysis by an engineer, architect, and/or soil scientist, which demonstrates that the following factors have been fully considered:

(i) Particle composition of fill material does not have a tendency for excessive natural compaction;

(ii) Volume and distribution of fill will not cause wave deflection to adjacent properties; and

(iii) Slope of fill will not cause wave run-up ramping.

g. There shall be no alteration of sand dunes or mangrove stands which would increase potential flood damage;

h. Lattice work or decorative screening shall be allowed below the base flood elevation provided they are not part of the structural support of the building and are designed so as to breakaway, under abnormally high tides or wave action, without damage to the structural integrity of the building on which they are to be used and provided the following design specifications are met:

(i) No solid walls shall be allowed, and;

(ii) Material shall consist of lattice or mesh screening only.

i. If aesthetic lattice work or screening is utilized, such enclosed space shall not be designed to be used for human habitation, but shall be designed to be used only for parking of vehicles, building access, or limited storage of maintenance equipment used in connection with the premises.

j. Prior to construction, plans for any structures that will have lattice work or decorative screening must be submitted to the Building Inspector for approval;

k. Any alteration, repair, reconstruction or improvement to a structure shall not enclose the space below the lowest floor except with lattice work or decorative screening, as provided for in Article 5, Section B(5) (h) and (i).

l. Prohibit the placement of manufactured homes (mobile homes), except in an existing manufactures homes (mobile homes) park or subdivision. A replacement manufactured home may be placed on a lot in an existing manufactured home park or subdivision provided the anchoring standards of Article 5, Section A (2), and the elevation standards of Article 5, Section B (1) are met.

C. STANDARDS FOR STREAMS WITHOUT ESTABLISHED BASE FLOOD ELEVATIONS AND/OR FLOODWAYS. Located within the areas of special flood hazard established in Article 3, Section B, where small streams exist but where no base flood data have been provided or where no floodways have been provided, the following provisions apply:

1) No encroachments, including fill material or structures shall be located within a distance of the stream bank equal to twenty feet each side from top of bank, whichever is greater, unless certification by a registered professional engineer is provided demonstrating that such encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.

2) New construction or substantial improvements of structures shall be elevated or flood-proofed to elevations established in accordance with Article 4, Section C (11).

D. STANDARDS FOR SUBDIVISION PROPOSALS.

1) All subdivision proposals shall be consistent with the need to minimize flood damage;

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

3) All subdivision proposals shall have adequate drainage provided to reduce exposure to flood hazards, and;

4) Base flood elevation data shall be provided for subdivision proposals and other proposed development (including manufactured home parks and subdivisions) which is greater than the lesser of fifty lots or five acres.

E. STANDARDS FOR AREAS OF SHALLOW FLOODING (AO ZONES). Located within the areas of special flood hazard established in Article 3, Section B, are areas designated as shallow flooding areas. These areas have special flood hazards associated with base flood depths of one to three feet (1'-3') where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate; therefore, the following provisions apply:

1) All new construction and substantial improvements of residential structures shall have the lowest floor, including basement, elevated to the depth number specified on the Flood Insurance Rate Map, in feet, above the highest adjacent grade. If no depth number is specified, the lowest floor, including basement, shall be elevated, at least two (2) feet above the highest adjacent grade.

2) All new construction and substantial improvements of non-residential structures shall:

a. Have the lowest floor, including basement, elevated to the depth number specified on the Flood Insurance Rate Map, in feet, above the highest adjacent grade. If no depth number is specified, the lowest floor, including basement shall be elevated at least two (2) feet above the highest adjacent grade, or;

b. Together with attendant utility and sanitary facilities be completely flood-proofed to or above that level so that any space below that level 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.