Big Bear Lake Municipal Code Art. III Provisions for Flood Hazard Reduction

In all areas of special flood hazards the following construction 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 Section 15.64.140 (A)(1).

B. Construction materials and methods. All new construction and substantial improvement shall be constructed as follows:

1. With flood resistant materials as specified in FEMA Technical Bulletin TB 2-93, 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. If within Zones AH or AO, with adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.

C. Elevation and flood proofing. (See Section 15.64.050 definitions for "basement," "lowest floor," "new construction," "substantial damage" and "substantial improvement"):

1. For residential construction, including either new or substantial improvement, the lowest floor, including basement, shall meet the following requirements:

a. In an A zone, the lowest floor shall be elevated to at least one foot above the base flood elevation; said base flood elevation shall be determined by one of the methods in Section 15.64.160 (B)(2) of this chapter;

b. In all other zones, the lowest floor shall be elevated to at least one (1) foot above the base flood elevation;

c. Upon 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 chief building official to be properly elevated. Such certification and verification shall be provided to the floodplain administrator.

2. For nonresidential construction, including either new or substantial improvement, the lowest floor, including basement, shall either be elevated to conform with Section 15.64.170 (C)(1) or together with attendant utility and sanitary facilities, shall meet the following requirements:

a. The lowest floor shall be flood proofed below the elevation recommended under Section 15.64.170 (C)(1) so that the structure is watertight with walls substantially impermeable to the passage of water;

b. The lowest floor shall have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and

c. Upon completion of the structure, the elevation of the lowest floor including basement, shall be certified by a registered professional engineer or architect that the standards of this Section 15.64.170 (C)(2) are satisfied. Such 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 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. A minimum of two (2) openings shall be provided 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 (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 floodwater; or

b. The structure shall be certified by a registered professional engineer or architect.

4. Manufactured homes shall also meet the standards in Section 15.64.200.

(Ord. 2002-324 § 1(part), 2002)

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.

(Ord. 2002-324 § 1(part), 2002)

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

B. All parcel map and subdivision map submittals shall include a composite development plan. For sites lying within an AE, AH, or AO zone the composite development plan shall show the base flood elevation. Proposed pad elevations shall be shown and shall be not less than one foot above the base flood elevation. If the site is filled above the base flood elevation, the pad elevations shall be certified by a registered professional engineer or surveyor and provided to the floodplain administrator at the time of map submittal.

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 designed, located, and constructed to minimize flood damage.

E. All subdivision plans shall provide for adequate drainage to reduce exposure to flood hazards.

(Ord. 2002-324 § 1(part), 2002)

A. The provisions of this section shall apply to manufactured homes that are placed or substantially improved within Zones A1-30, AH, and AE on the community's Flood Insurance Rate Map in the following locations:

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 on a site upon which a manufactured home has incurred "substantial damage" as the result of a flood.

B. All manufactured homes subject to Section 15.64.200 shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to at least one foot above the base flood elevation and shall be securely fastened to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

C. All manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within Zones A1-30, AH, and AE on the city's Flood Insurance Rate Map that are not subject to the provisions of Section 15.64.200 (A) shall be securely fastened to an adequately anchored foundation system to resist flotation, collapse, and lateral movement, and be elevated so that either of the following requirements are met:

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

2. The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than thirty-six (36) inches in height above grade.

D. 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 chief building official to be properly elevated. Such certification and verification shall be provided to the floodplain administrator.

(Ord. 2002-324 § 1(part), 2002)

All recreational vehicles placed on sites within Zones A1-30, AH, and AE on the community's Flood Insurance Rate Map shall be subject to the following requirements:

A. The recreational vehicle shall be on the site for fewer than one hundred and eighty (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; or

B. The recreational vehicle shall meet the permit requirements of Section 15.64.200 of this chapter and the elevation and anchoring requirements for manufactured homes in Section 15.64.200 (A).

(Ord. 2002-324 § 1(part), 2002)

Located within areas of special flood hazard established in Section 15.64.090 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters, which carry debris, potential projectiles, and erosion potential, the following provisions shall apply:

A. Any encroachments, including fill, new construction, substantial improvement, and other new development, shall be prohibited unless certification by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in the base flood elevation during the occurrence of the base flood discharge.

B. If Section 15.647.220 (A) is satisfied, all new construction, substantial improvement, and other proposed new development shall comply with all other applicable flood hazard reduction provisions of Section 15.64.200.

(Ord. 2002-324 § 1(part), 2002)

A. The floodplain administrator shall review permits for proposed construction of development to determine if it is proposed within a mudslide area.

B. Before issuing permits, development shall be reviewed to determine that the proposed site and improvement will be reasonably safe from mudslide hazards. Factors to be considered in making this determination include but are not limited to the following:

1. Type and quality of soils;

2. Evidence of ground water or surface water problems;

3. Depth and quality of any fill;

4. Overall slope of the site; and

5. Weight that any proposed development will impose on the slope.

C. Within areas that may have mudslide hazards, the floodplain administrator shall require that:

1. A site investigation and further review shall be made by persons qualified in geology and soils engineering;

2. The proposed grading, excavation, new construction, and substantial improvement shall be adequately designed and protected against mudslide damages;

3. The proposed grading, excavations, new construction, and substantial improvement shall not aggravate the existing hazard by creating either on-site or off-site disturbances; and

4. Drainage, planting, watering, and maintenance shall not endanger slope stability.

(Ord. 2002-324 § 1(part), 2002)

A. The floodplain administrator shall require permits for proposed construction and other development within all flood-related erosion-prone areas as known to the community.

B. Permit applications shall be reviewed 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, such improvement shall be relocated or adequate protective measures shall 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 lake, bay, stream 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. 2002-324 § 1(part), 2002)