Any new construction within the fault precaution zones, dam failure inundation areas, and liquefaction susceptibility zones, shall comply with the following requirements.
A. Separation from Active Faults.
1. No new structure (including foundation systems and basements) designed for human occupancy shall be permitted within 50 feet of an active fault, except that alterations and additions to any structure may be allowed if the alteration or addition does not increase floor area by more than 50 percent of the floor area of the existing structure, or 10,000 square feet, whichever is less. This shall not apply, in Fault Precaution Zone 1, to single-family homes of two stories or less; or to developments consisting of no more than four detached single-family homes of two stories or less; or to developments of up to eight units wherein each unit has living space on the first floor with a minimum of two first-floor exits with direct access to a public right-of-way; or to any property in an R1 or R2 zoning district; and shall not apply to any structure in Fault Precaution Zone 2.
2. In Fault Precaution Zone 2, no new structure designed for human occupancy shall be permitted unless the requirements of either (a) or (b) below are met:
a. A fault rupture investigation conducted in compliance with the State Mining and Geology Board Guidelines determines that the structure (including foundation systems and basements) is not within 50 feet of an active fault. Data for the fault rupture investigation may be collected from on-site and at accessible off-site locations to determine specific fault locations and recency of fault movement. Fault rupture investigations shall be performed by a California Certified Engineering Geologist with experience conducting these types of investigations. The geologist shall submit a work plan for the proposed investigation to the city for review and approval before preceding with the fault rupture investigation. The completed fault rupture investigation report shall be submitted to the city for review and approval.
b. Prior to the issuance of building permits, soils and geology studies (although not including a fault rupture investigation) must be submitted for the review and approval of the Building
Official. Design of the building must comply with the West Hollywood Business Code, using Seismic Source Type A.
B. Liquefaction Susceptibility Zones. Within liquefaction susceptibility zones:
1. A soils report by a registered civil engineer shall be submitted to the satisfaction of the Building Official before the issuance of building permits, for all new structures, and any alteration or addition that increases floor area by more than 50 percent of the existing floor area or 2,000 square feet, whichever is less, or adds one or more stories to any portion of a structure. This requirement shall not apply to single-family dwellings of no more than two stories which are in projects of no more than four units; and this requirement may be waived by the Building Official on the basis of a previous soils study on nearby property.
2. The soils report shall include liquefaction potential studies, and where liquefaction potential is identified, mitigating siting and design features shall be required. The review of the report shall include concern for blockage of road access and the interruption of essential utility service as a result of liquefaction in the area.
3. All appropriate recommendations in the soils report shall be incorporated into the building design.
C. Emergency Response Plans. All critical, high occupancy, and sensitive facilities shall develop and maintain emergency plans for efficient shut-down of operations and evacuation of the facility in the event of damage to area dams, to the satisfaction of the Public Safety Manager.
(Ord. 01-594 § 2, 2001; Ord. 02-619 § 1, 2002)