Yucaipa Municipal Code Art. 4 Geologic Hazard (gh) Overlay District

§ 85.020401. Intent.

The Geologic Hazard (GH) Overlay District is created to provide greater public safety by establishing review procedures and setbacks for areas that are subject to potential geologic problems such as groundskeeping, earthquake faults, liquefaction, and subsidence.

§ 85.020405. Locational requirements.

(a) The Geologic Hazard Overlay District shall be designated in areas which are on or adjacent to active earthquake fault traces. This overlay district shall implement the requirements of the Alquist-Priolo Special Studies Zones Act of 1972.

(b) The Geologic Hazard Overlay District shall be designated in areas where landslides, mudslides, and subsidence are prevalent and in areas with volcanic activity.

(c) The Geologic Hazard Overlay District shall be designated in areas where liquefaction of the soil is associated with earthquake activity.

(d) The Geologic Hazard Overlay District shall be designated by the symbol (GH) on the city of Yucaipa Official Land Use Plan.

§ 85.020410. Geologic reports.

(a) A detailed geologic study prepared by a registered geologist shall be submitted with all land use applications and development permits proposed within the Geologic Hazard Overlay District that would lead to the construction of roads or structures or the subdivision of land. Said geologic report shall confirm the presence or absence of hazardous faults and, if applicable, the boundaries of existing or former marsh areas. Further, said report shall establish appropriate construction setbacks. Exemptions to the requirement for a geologic study include the following.

(1) One, single-family, wood frame dwelling not exceeding two stories.

(2) Single-family, wood frame dwellings located within a division of land for which an approved geologic report was prepared.

(3) A non-residential, accessory use.

(4) The alterations or additions to any structure where the value or area does not exceed 50% of the structure.

§ 85.020415. Development standards.

When a land use is proposed within a Geologic Hazard Overlay District, the following standards shall apply.

(a) Development of all structures used for human occupancy, other than single family, wood frame structures, shall take place 50 feet or further from any active earthquake fault traces. Active fault traces are those delineated on the Alquist-Priolo Special Studies Zones Maps or on maps contained within the City’s General Plan.

(b) Development of all structures used for critical facilities shall take place 150 feet or further from any active earthquake fault trace as indicated within the City’s General Plan. Critical facilities shall include dams, reservoirs, fuel storage facilities, power plants, nuclear reactors, police and fire stations, schools, hospitals, rest homes, nursing homes, and emergency communication facilities.

(c) Utility lines and streets shall not be placed within the construction setback area of a hazardous fault, except for crossing which can be made perpendicular to the fault trace or as recommended by the project geologist and approved by the reviewing authority.

(d) Development restricted areas are encouraged for use as recreation and common open spaces.

(e) The following conditions may apply to areas subject to periodic landslides, subsidence, and soil liquefaction.

(1) Siting. All facilities and streets should be sited so as to minimize the erosion potential.

(2) Vegetation. Natural vegetation shall be retained and protected where possible. Where inadequate vegetation exists, additional landscaping shall be provided. Any additional landscaping shall be compatible with the local environment and capable of surviving with a minimum of maintenance and supplemental water.

(3) Exposure of bare land. When land is exposed during development, only the smallest practicable land portion as an increment of a development project shall be exposed at any one time; the duration of time that the exposure remains unprotected shall be the shortest practical time period, and such exposure shall be protected with temporary vegetation or mulching where practical.

(4) Run-off. The development should be designed to minimize water run-off. Provisions should be made to effectively accommodate any increased run-off.

(5) Special measures. Measures shall be taken to offset the possible affects of landslides. A detailed geologic report identifying these measures shall be required prior to the issuance of building permits.

(6) All proposed facilities located within liquefication and landslide hazard areas shall be constructed in a manner to minimize or eliminate subsidence damage.