Article IV — PROVISIONS FOR FLOOD HAZARD REDUCTION

SEC. 18-35. STANDARDS OF CONSTRUCTION.

In all areas of special flood hazards, the following standards apply:

(A) Anchoring -

(1) All new construction and substantial improvements shall be adequately anchored to prevent flotation, collapse or lateral movement of the structure resulting

from hydrodynamic or hydrostatic loads, including the effects of buoyancy.

(2) All manufactured homes shall meet the anchoring standards of this chapter.

(B) Construction materials and methods -

(1) All new construction and substantial improvements shall be constructed with flood resistant materials as specified in FEMA Technical Bulletin TB 2-93 and utility

equipment resistant to flood damage.

(2) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.

(3) 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 components during conditions of flooding; and

(4) Within Zone AH or AO, so that there are adequate drainage paths around structures on slopes to guide flood waters around and away from proposed

structures.

(C) Elevation and flood proofing. (See section 18-2 definitions for "basement," "lowest floor," "new construction," "substantial damage," and "substantial improvement.")

(1) The lowest floor, including basement, of a residential construction, new or substantial improvement, shall:

(a) In a Zone AO, be elevated above the highest adjacent grade to a height equal to or exceeding the depth number specified in feet on the FIRM, or elevated at

least two feet above the highest adjacent grade if no depth number is specified. In Zone AO without velocity, the lowest floor shall be elevated above the highest adjacent grade to a height exceeding the depth number specified in feet on the FIRM by at least two feet, or elevated at least four feet above the highest adjacent grade if no depth number is specified.

(b) In a Zone A, be elevated at least two feet above the base flood elevation. Said base flood elevation shall be determined by one of the methods in section18-

21(B).

(c) In all other zones, be elevated at least two feet above the base flood elevation. Upon the completion of the structure, the elevation of the lowest floor including

basement shall be certified by a registered professional engineer or surveyor, and verified by a city building inspector to be properly elevated. Such certification and verification shall be filed with the floodplain administrator.

(2) Nonresidential construction, new or substantial improvement, shall either be elevated to conform with subsection 18-35(C)(1) or, together with attendant utility

and sanitary facilities:

(a) Be flood proofed below the elevation recommended under section 18-35(C)(1) so that the structure is watertight with walls substantially impermeable to the

passage of water;

(b) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and

(c) Be certified by a registered professional engineer or architect that the standards of this subsection 18-35(C)(2) are satisfied. Such certification shall be filed

with the floodplain administrator.

(3) All new construction and substantial improvement with fully enclosed areas below the lowest floor (excluding basements) that are usable solely for parking of

vehicles, building access or storage, and which are subject to flooding, shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwater. Designs for meeting this requirement shall follow the guidelines in FEMA Technical Bulletins TB 1-93 and TB 7-93, and must exceed the following minimum criteria:

(a) Have 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. 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 floodwater; or

(b) Be certified by a registered professional engineer or architect.

(4) Manufactured homes shall also meet the standards in this section.

(`64 Code, Sec. 35-21) (Ord. No. 2426, 2640)

SEC. 18-36. STANDARDS FOR UTILITIES.

(A) All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system and discharge from systems into flood waters.

(B) All final subdivision plans will provide the elevation of proposed structure(s) and pads. If the site is filled above the base flood, the final pad elevation shall be certified by a registered professional engineer or surveyor and provided to the floodplain administrator.

(C) On-site waste disposal systems shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage.

(D) All subdivisions shall locate and construct public utilities and facilities such as sewer, gas, electrical, and water systems to minimize flood damage.

(E) All subdivision proposals shall provide adequate drainage to reduce exposure to flood hazards.

(`64 Code, Sec. 35-22) (Ord. No. 2426, 2640)

SEC. 18-37. STANDARDS FOR SUBDIVISIONS.

(A) All preliminary subdivision proposals, including proposals for manufactured home parks and subdivisions, greater than 50 lots or five acres, whichever is the lesser, shall identify the flood hazard area and the elevation of the base flood.

(B) All final subdivision plans will provide the elevation of proposed structure(s) and pads. If the site is filled above the base flood, the final pad elevation shall be certified by a registered professional engineer or surveyor and provided as part of an application for a Letter of Map Revision based on Fill (LOMR-F) to the floodplain administrator.

(C) All subdivisions shall be designed to minimize flood damage.

(D) All subdivisions shall locate and construct public utilities and facilities such as sewer, gas, electrical and water systems to minimize flood damage.

(E) All subdivisions shall provide adequate drainage to reduce exposure to flood hazards.

(`64 Code, Sec. 35-23) (Ord. No. 2426, 2640, 2989)

SEC. 18-37.1. STANDARDS FOR MANUFACTURED HOMES.

(A) All manufactured homes that are placed or substantially improved, on sites located:

(1) Outside of a manufactured home park or subdivision;

(2) In a new manufactured home park or subdivision;

(3) In an expansion to an existing manufactured home park or subdivision; or

(4) In an existing manufactured home park or subdivision upon which a manufactured home has incurred “substantial damage” as a result of a flood shall:

(a) Within Zones A1-30, AH and AE on the community’s Flood Insurance Rate Map, be elevated on a permanent foundation such that the lowest floor of the

manufactured home is elevated to or above the base flood elevation and be securely fastened to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

(b) Within Zones V1-30, V and VE on the community’s Flood Insurance Rate Map, meet the requirements of Section18-39.

(B) All manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within Zones A1-30, AH, AE, V1-30, V and VE on the community’s Flood Insurance Rate Map that are not subject to the provisions of section 18-37.1(A) will be securely fastened to an adequately anchored foundation system to resist flotation, collapse, and lateral movement, and be elevated so that either the:

(1) Lowest floor of the manufactured home is at or above the base flood elevation; or

(2) Manufactured home chassis is supported by reinforced pies or other foundation elements of at least equivalent strength that are not less than 36 inches in

height above ground.

(C) Upon the completion of the structure, the elevation of the lowest floor including basement shall be certified by a registered civil engineer or licensed land surveyor, and verified by the community building inspector to be properly elevated. Such certification and verification shall be provided to the floodplain administrator.

(Ord. No. 2783)

SEC. 18-37.2. STANDARDS FOR RECREATIONAL VEHICLES.

(A) All recreational vehicles placed in Zones A1-30, AH, AE, V1-30 and VE will either:

(1) Be on the site for fewer than 180 consecutive days; or

(2) Be fully licensed and ready for highway use. A recreational vehicle is ready for highway uses if it is on its wheels or jacking system, is attached to the site only by

quick disconnect type utilities and security devices, and has no permanently attached additions; or

(3) Meet the permit requirements of section 18-25 of this section and the elevation and anchoring requirements for manufactured homes in section18-37.1.

(B) Recreational vehicles placed on sites within Zones V1-30, V and VE on the community’s Flood Insurance Rate Map will meet the requirements of section18- 37.2(A) and section 18-39.

(Ord. No. 2783)

SEC. 18-38. FLOODWAYS.

(A) Located within areas of special flood hazard are areas designated as floodways.

(B) Until a regulatory floodway is adopted, no new construction, substantial development, or other development (including fill) shall be permitted within Zones A1-30 and AE, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other development, will not increase the water surface elevation of the base flood more than one foot at any point within the city.

(C) Because the floodway is an extremely hazardous area due to the velocity of flood waters that carry debris, potential projectiles, and erosion potential, the floodplain administrator shall:

(1) Prohibit encroachments, including fill, new construction, substantial improvements, and other development unless certification by a registered professional

engineer or architect is provided demonstrating that encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.

(2) If the requirements of subsection (1) above are satisfied, ensure that all new construction and substantial improvements shall comply with all other applicable

flood hazard reduction provisions.

(`64 Code, Sec. 35-25) (Ord. No. 2426, 2640, 2989)

SEC. 18-39. COASTAL HIGH HAZARD AREAS.

Within coastal high hazard areas designated on the effective FIRM, the following standards shall apply:

(A) All new construction and substantial improvements/damage shall be elevated on adequately anchored pilings or columns and securely anchored to such pilings or columns so that the lowest horizontal portion of the structural members of the lowest floor (excluding the pilings or columns) is elevated above the base flood level. The pile or column foundation and structure attached thereto shall be anchored to resist floating, collapse, and lateral movement due to the effects of wind and water loads acting simultaneously on all building components. Water loading values used shall be those associated with the base flood. Wind loading values used shall be those required by applicable State or local building standards.

(B) All new construction shall be located on the landward side of the reach of mean high tide.

(C) All new construction and substantial improvements shall have the space below the lowest floor free of obstructions or constructed with breakaway walls. Such temporarily enclosed space shall not be used for human habitation and may be usable solely for parking of vehicles, building access, or storage.

(D) Fill shall not be used for structural support of buildings.

(E) Manmade alteration of sand dunes that would increase potential flood damage is prohibited.

(F) The floodplain administrator shall obtain and maintain the following records:

(1) Certification by a registered engineer or architect that a proposed structure complies with this section; and

(2) The elevation (in relation to mean sea level) of the bottom of the lowest horizontal structural member of the lowest floor (excluding pilings or columns) of all new and substantially improved structures, and whether such structures contain a basement.

(`64 Code, Sec. 35-26) (Ord. No. 2426, 2640, 2989)

SEC. 18-40. FLOOD-RELATED EROSION-PRONE AREA.

(A) The floodplain administrator shall require permits for proposed construction and other development within all flood-related erosion-prone areas.

(B) The floodplain administrator shall review permit applications to determine whether the proposed site alterations and improvements will be reasonably safe from flood-related erosion and will not cause flood-related erosion hazards or otherwise aggravate the existing hazard.

(C) If a proposed improvement is found to be in the path of flood-related erosion or would increase the erosion hazard, the floodplain administrator shall require that such improvement be relocated or adequate protective measures be taken to avoid aggravating the existing erosion hazard.

(D) Within Zone E on the Flood Insurance Rate Map, a setback is required for all new development from the ocean, lake, bay, riverfront or other body of water to create a safety buffer consisting of a natural vegetative or contour strip. This buffer shall be designated according to the flood-related erosion hazard and erosion rate, in relation to the anticipated "useful life" of structures, and depending upon the geologic, hydrologic, topographic and climatic characteristics of the land. The buffer may be used for suitable open space purposes, such as for agricultural, forestry, outdoor recreation and wildlife habitat areas, and for other activities using temporary and portable structures only.

(Ord. No. 2640)

CHAPTER 19: PUBLIC WORKS