Trinity County Municipal Code Art. III Provisions for Flood Hazard Reduction

In all areas of special flood hazards the following standards are required:

A. Anchoring.

1. 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 and certified per paragraph (3) of this subsection;

2. All manufactured homes shall meet the anchoring standards of Section 15.16.190;

3. All standards in this subsection and Section 15.16.190(B) shall be certified by a registered professional architect or engineer.

B. Construction Materials and Methods.

1. All new construction and substantial improvements shall be constructed with materials 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. 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.

C. Elevation and Floodproofing.

1. New construction and substantial improvement of any structure shall have the lowest floor, including basement, elevated not less than one foot above the base flood elevation. Nonresidential structures may meet the standards in paragraph (C)(3) of this section. Upon the completion of the structure, the elevation of the lowest floor, including basement, shall be certified by a registered professional engineer or surveyor to be properly elevated. Such certification, or verification, shall be provided to the floodplain administrator;

2. Nonresidential construction shall be elevated in conformance with paragraph (1) of this section, or together with attendant utility and sanitary facilities:

a. Be floodproofed so that below the base flood level 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 are satisfied. Such certification shall be provided to the floodplain administrator;

3. Require, for all new construction and substantial improvements, 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 floodwater. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or meet or exceed the following minimum criteria:

a. Either 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; or

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

4. Manufactured homes shall also meet the standards in Section 15.16.190.

(Ord. 1176 §5.1, 1993)

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

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

(Ord. 1176 §5.2, 1993)

A. All preliminary subdivision proposals 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 to the floodplain administrator.

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

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

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

(Ord. 1176 §5.3, 1993)

All new and replacement manufactured homes and additions to manufactured homes shall:

A. Be elevated and certified by a registered professional engineer or surveyor so that the lowest floor is at or above the base flood elevation; and

B. Be securely anchored to a foundation system or mobile home support designed to resist flotation, collapse or lateral movement and certified per Section 15.16.160 (A)(1) and (A)(3).

(Ord. 1176 §5.4, 1993)

A. All recreational vehicles placed on sites within Zones A1-30, AH, and AE on the county's Flood Insurance Rate Map will either;

1. Be fully licensed and ready for highway use. A recreational vehicle is ready for highway use 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

2. Meet the permit requirements of Section 15.16.120 and the elevation and anchoring requirements for manufactured homes in Section 15.16.190.

(Ord. 1176 §5.5., 1993)