Appendix 3707. Provisions for flood hazard reduction.

(a)

Standards for construction. In all special flood hazard areas the following standards are required:

(1)

Anchoring.

a.

All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

b.

All manufactured homes shall meet the anchoring standards of section 3707(d).

(2)

Construction materials and methods.

a.

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

b.

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

c.

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 components during conditions of flooding.

(3)

Elevation and floodproofing.

a.

New construction and substantial improvement of any structure shall have the lowest floor elevated to or above the base flood elevation. Upon the completion of the structure, the elevation of the lowest floor shall be certified by a registered professional engineer or surveyor, or verified by the community building inspector to be properly elevated. Such certification or verification shall be provided to the floodplain administrator.

b.

Nonresidential construction shall either be elevated in conformance with section 3707(a)(3)a. or, including attendant utility and sanitary facilities, must meet the following standards:

(i)

Be floodproofed so that below the base flood level, the structure is watertight with walls substantially impermeable to the passage of water;

(ii)

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

(iii)

Provide certification from a registered professional engineer or architect that the standards of this subsection are satisfied. Such certification shall be provided to the floodplain administrator.

c.

For all new construction and substantial improvements, it is required that 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 meet or exceed the following minimum criteria:

(i)

Provide a minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding. The bottom of all openings shall be no higher than one (1) 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; or

(ii)

Be certified to comply with a local floodproofing standard approved by the Federal Insurance Administration.

d.

Manufactured homes shall also meet the standards in section 3707(d).

(4)

Construction below lowest floor. The space below the lowest floor of a structure located in an SFHA may be used only for parking, temporary storage, or access.

(b)

Standards for utilities.

(1)

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

(2)

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

(c)

Standards for subdivisions.

(1)

All preliminary subdivision proposals shall identify the flood hazard area and the elevation of the base flood.

(2)

All final subdivision plans shall 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.

(3)

All subdivision proposals shall be consistent with the need to minimize flood damage.

(4)

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

(5)

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

(d)

Standards for manufactured homes. All new and replacement manufactured homes and additions to manufactured homes shall:

(1)

Be elevated so that the lowest floor is at or above the base flood elevation; and

(2)

Be securely anchored to a permanent foundation system to resist flotation, collapse or lateral movement.

(e)

Standards for floodways. The following standards shall apply to floodways:

(1)

Encroachments, including fill, new construction, substantial improvements, and other development are prohibited 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. If no floodway sources are designated, the registered professional engineer or architect shall demonstrate that the cumulative effect of all encroachment in the floodplain does not increase the base flood elevation (BFE) by more than one (1) foot.

(2)

If section 3707(e)(1) is satisfied, all new construction and substantial improvements shall comply with all other applicable flood hazard reduction provisions of section 3707.

(Ord. No. 140, § 1, 2-24-88; Ord. No. 01-307, §§ 2, 3, 5-23-2001; Ord. No. 17-430, § 2, 8-23-2017)