Red Bluff Municipal Code Art. V 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 adequately anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

(2) All manufactured homes shall meet the anchoring standards of § 26.5-5.

(B) Construction materials and methods. All new construction and substantial improvement shall be constructed:

(1) With flood-resistant materials as specified in FEMA Technical Bulletin 2-93, Flood Resistant Materials, and utility equipment resistant to flood damage;

(2) 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 zones AH and AO, adequate drainage paths around structures on slopes are required to guide floodwaters around and away from proposed structures.

(C) Elevation and floodproofing.

(1) Residential construction, new or substantial improvement, shall have the lowest floor, including basement:

(a) In an A zone, elevated at least one foot above the base flood elevation, the base elevation shall be determined by one of the methods in § 26.4-3(B).

(b) In all other zones, elevated at least one foot above the base flood elevation, as determined by the city.

(c) 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 the city Building Inspector to be properly elevated. The certification and verification shall be provided to the Floodplain Administrator. Verification means that the engineer or surveyor has properly completed the flood elevation certificate.

(2) Nonresidential construction, new or substantial improvements, shall either be elevated to conform with § 26.5-1(C)(1) or together with attendant utility and sanitary facilities:

(a) Be floodproofed below the elevation recommended under division (C)(1) above 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 section are satisfied. The certification shall be provided to 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, underfloor access (crawlspaces) 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 1-93, Openings in Foundation Walls, and 7-93, Wet Floodproofing, 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.)

(b) Be certified by a registered professional engineer or architect that the standards of this section are satisfied; (The certification shall be provided to the Floodplain Administrator.)

(4) Manufactured homes shall also meet the standards in § 26.5-5.

(`61 Code, § 26.5-1) (Ord. 913, passed 4-18-2000)

(A) The storage or processing of materials in the flood hazard area that are, in times of flooding, bouyant, flammable, explosive or could be injurious to humans, animals or plant life, is prohibited.

(B) Storage of other material or equipment in a flood hazard area may be allowed if not subject to damage by floods and if firmly anchored to prevent flotation.

(C) The floodplain administrator may require certification by a registered professional engineer that the site conditions comply with this section.

(`61 Code, § 26.5-2) (Ord. 913, passed 4-18-2000)

(A) All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate:

(1) Infiltration of flood waters into the systems; and

(2) Discharge from the systems into floodwaters.

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

(`61 Code, § 26.5-3) (Ord. 913, passed 4-18-2000)

(A) All applications to subdivide, rezone, change land use classification, move property lines or annex land within a flood hazard area or on lands 50 feet or less, measured horizontally, from a flood hazard area shall identify:

(1) The flood hazard area (boundary), the elevation of the base flood, the floodway boundary and existing lowest floor elevations;

(2) The 50-foot setback from the floodway boundary;

(3) The elevation of pads and lowest floor elevation of proposed residential structure(s); and (If the site is filled above the base flood elevation, the lowest floor and pad elevations shall be certified by a registered professional engineer or surveyor and provided to the Floodplain Administrator.)

(4) The elevation or means of floodproofing nonresidential structures. If the site is filled above the base flood elevation, the lowest floor and pad elevations shall be certified by a registered professional engineer or surveyor and provided to the Floodplain Administrator.

(B) All applications listed in division (A) above shall be consistent with the need to minimize flood damage.

(C) All applications listed in division (A) above shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage.

(D) All applications listed in division (A) above shall provide adequate drainage to reduce exposure to flood hazards.

(`61 Code, § 26.5-4) (Ord. 913, passed 4-18-2000)

(A) (1) All manufactured homes that are placed or substantially improved, within zones A1-30, AE, AH and AO on the city’s flood insurance rate map, on sites located:

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

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

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

(d) In an existing manufactured home park or subdivision on a site upon which a manufactured home has incurred “substantial damage” as the result of a flood shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated at least one foot above the base flood elevation and be connected to an adequately anchored foundation system to resist flotation collapse and lateral movement.

(2) Certification, by a registered professional engineer, that the standards of this section are satisfied is required. The certification shall be provided to the Floodplain Administrator.

(B) (1) All manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within zones A1-30, AE, AH, and AO on the city’s flood insurance rate map that are not subject to the provisions of § 26.5-5(A) will be elevated so that either the:

(a) Lowest floor of the manufactured home is elevated at least one foot above the base flood elevation; or

(b) The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade and are securely fastened to an adequately anchored foundation system to resist flotation, collapse and lateral movement.

(2) The manufactured home may be installed to comply with the least restrictive of the two elevation options listed in division (B)(1)(a) and (b).

(3) Certification, by a registered professional engineer or architect, that the standards of this section are satisfied is required. The certification shall be provided to the Floodplain Administrator.

(C) No manufactured home shall be placed in a floodway.

(`61 Code, § 26.5-5) (Ord. 913, passed 4-18-2000)

All recreational vehicles placed on sites within zones A1-30, AE, AH and AO on the community’s flood insurance rate map will either:

(A) Be on the site for fewer than 180 consecutive days, and 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.)

(B) Meet the permit and certification requirements of Article IV hereof and the elevation and anchoring requirements for manufactured homes in § 26.5-5(A); and

(C) Certification, by a registered professional engineer, that the standards of this section are satisfied is required. The certification shall be provided to the Floodplain Administrator.

(`61 Code, § 26.5-6) (Ord. 913, passed 4-18-2000)

(A) All fill supporting structures within the flood hazard area must be designed by an engineer.

(B) All new foundations within the flood hazard area must be designed by an engineer.

(C) Essential facilities shall not be allowed within the 500-year flood plain, except with a use permit.

(D) No fill or other development with a surface elevation above existing undisturbed grade shall be placed within 30 feet of a floodway.

(E) New or substantially improved structures are prohibited within 30 feet of a floodway.

(F) All measurements set forth in divisions (D) and (E) above are measured horizontally from the edge of the floodway.

(G) No development on private property shall be permitted unless:

(1) The lot or is contiguous to an improved public street;

(2) A use permit or planned development use permit is issued; or

(3) The Technical Advisory Committee makes written finding that adequate access for emergency services and equipment exists to serve the site.

(`61 Code, § 26.5-7) (Ord. 913, passed 4-18-2000; Am. Ord. 919, passed 9-19-2000; Am. Ord. 940, passed 5-20-2003)

(A) Located within areas of special flood hazard established in § 26.3-2 are areas designated as floodways.

(B) Since the floodway is an extremely hazardous area due to the velocity of flood waters, which carry debris, projectiles and cause erosion, the following provisions apply.

(1) Encroachments within a floodway are prohibited, including fill, new construction, substantial improvements and other new development unless:

(a) Certification by a registered professional engineer is provided demonstrating that encroachments shall not result in any increases in the base flood elevation during the occurrence of the base flood discharge; (This criterion is also known as “no rise.”)

(b) A design by a registered professional engineer is submitted to the floodplain administrator demonstrating that all structures and development within the floodway will withstand the forces caused by flood waters;

(c) New construction, substantial improvement and other proposed new development complies with all other applicable flood hazard reduction provisions of this chapter; and

(d) Certification, by a registered professional engineer, is submitted certifying that the standards of this section are satisfied. The certification shall be provided to the Floodplain Administrator.

(2) If a floodway is not identified in maps or documents adopted by the city then no encroachment is allowed within the flood hazard area without either approval of the Technical Advisory Committee or submittal of documents, including a scaled map, from a registered professional engineer defining the boundaries of the floodway. The purpose of this section is to prohibit development within the 100-year floodplain until a qualified professional defines the location of the floodway.

(C) The criteria herein do not apply to temporary fare, police and other public agency facilities providing immediately needed emergency services including but not limited to rescue, temporarily enhancing flood-control facilities and making temporary repairs to other public facilities.

(`61 Code, § 26.5-8) (Ord. 913, passed 4-18-2000)