This chapter establishes seismic safety standards that are designed
to protect development proposed for hazardous areas within the dam
failure inundation areas, fault precaution zones, and liquefaction
susceptibility zones established by the General Plan.
(Ord. 01-594 § 2, 2001)
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)
A. Restricted Areas. New critical facilities shall not be allowed
within a dam failure inundation area or fault precaution zone. Limited
expansion of critical facilities within a dam failure inundation area
shall be allowed. The approval of a proposed expansion shall require
that the review authority first find that:
1. The
proposal will ensure the continued functioning of essential facilities
following a disaster, prevent loss of life from the failure of critical
facilities in an earthquake, and help prevent major problems for post-disaster
response (e.g., difficult or hazardous evacuations or rescue, large
numbers of injuries, and major clean-up or decontamination of hazardous
materials);
2. Critical
facilities shall be protected from damage, loss of function, or inaccessibility
in the event of damage directly or indirectly related to local dams
or fault rupture;
3. Effective
response shall be provided to a disaster, and serious damage and injuries
shall be prevented through effective hazard mitigation; and
4. The
siting of the critical facility observes a 100-foot minimum setback
from an identified, active earthquake fault plane. This setback may
be increased if, based on the earthquake fault rupture study, a greater
setback is necessary to protect the public health, safety, and welfare,
if deemed necessary by the Community Development Director.
B. Special Studies. The following studies shall be submitted
for review and approval by the Building Official before the issuance
of building permits:
1. A liquefaction potential study in compliance with Section
19.32.020(B), above;
2. Detailed
site studies for ground shaking characteristics and fault rupture
potential; and
3. Where
the studies indicate, compensating siting and design features shall
be required.
(Ord. 01-594 § 2, 2001; Ord. 02-619 § 4, 2002; Ord. 19-1058 § 99, 2019; Ord. 24-16, 6/24/2024)
A. Required Findings. New sensitive facilities shall not be
allowed within a fault precaution zone unless the review authority
first makes all of the following findings.
1. A
fault rupture investigation conducted in compliance with the State
Mining and Geology Board Guidelines determines there is no hazard
from fault rupture at the site. 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.
2. The
proposed sensitive facility shall be sited outside 100-foot setback
planes drawn parallel to any active faults. A greater setback from
any active fault may be required if, based on the fault rupture determination
study, the Community Development Director determines that the additional
setback is necessary to protect the public health, safety, and welfare.
B. Special Studies. Before issuance of building permits, the
applicant shall submit site-specific engineering geology and geotechnical
engineering reports prepared to the satisfaction of the Building Official.
1. The
engineering geology report shall be prepared and signed by a California
Certified Engineering Geologist, and the geotechnical engineering
report shall be prepared and signed by a California Registered Civil
Engineer experienced in the area of geotechnical engineering.
2. These
reports shall include detailed site-specific studies and analyses
for all potential geologic and geotechnical hazards (e.g., ground
shaking, slope stability, liquefaction).
3. These
reports may be prepared separately or together, but shall incorporate
the findings and recommendations of the fault rupture investigation.
4. Where
the studies indicate, compensating siting and design features shall
be required.
(Ord. 01-594 § 2, 2001; Ord. 19-1058 § 100, 2019; Ord. 24-16, 6/24/2024)
A. Required Findings. No new high-occupancy structures (including
foundation systems and basements) shall be permitted within 50 feet
of an active fault. Construction of new high occupancy facilities
shall not be allowed within a fault precaution zone unless the review
authority first makes all of the following findings:
1. A
fault rupture investigation determines that there is not hazard from
fault rupture at the subject site. The fault rupture investigation
must comply with the following criteria:
a. Was conducted in compliance with the State Mining and Geology Board
Guidelines;
b. Was performed by a California Certified Engineering Geologist with
experience conducting these types of investigations;
c. Was subject to a work plan approved by the city before initiation
of the investigation;
d. Utilized data collected from on-site and at accessible off-site locations
to determine specific fault locations and recency of fault movement;
and
e. Was reviewed and approved by the city.
2. All
proposed high occupancy facilities (including their foundation systems
and basements) shall be sited outside 50-foot setback planes drawn
parallel to any active faults. A greater setback from any active fault
planes may be required if, based on the fault rupture investigation,
the Community Development Director determines that the additional
setback is necessary to protect the public health, safety, and welfare.
C. Special Studies. Before issuance of building permits, the
applicant shall submit site-specific engineering geology and geotechnical
engineering reports prepared to the satisfaction of the Building Official.
1. The
engineering geology report shall be prepared and signed by a California
Certified Engineering Geologist, and the geotechnical engineering
report shall be prepared and signed by a California Registered Civil
Engineer experienced in the area of geotechnical engineering.
2. These
reports shall include detailed site-specific studies and analyses
for all potential geologic and/or geotechnical hazards (e.g., ground
shaking, slope stability, liquefaction).
3. These
reports may be prepared separately or together, but shall incorporate
the findings and recommendations of the fault rupture investigation.
4. Where
the studies indicate, compensating siting and design features shall
be required.
(Ord. 01-594 § 2, 2001; Ord. 04-685 § 4, 2004; Ord. 19-1058 § 101, 2019; Ord. 24-16, 6/24/2024)