§ 22.14.070. Geologic Study Area (GSA).

A.

Purpose. The Geologic Study Area (GSA) combining designation is applied to areas where geologic and soil conditions could present new developments and their users with potential hazards to life and property. These standards are applied where the following conditions exist:

1.

Seismic hazard. Areas of seismic (earthquake) hazard are identified through application of an Earthquake Fault Zone. Earthquake Fault Zones are established by the state geologist as required by Sections 2621 et seq. of the Public Resources Code (the Alquist-Priolo Earthquake Fault Zones Act), and are identified in the Land Use Element (Part II);

2.

Landslide hazard. Areas within urban and village reserve lines, identified by the Seismic Safety Element as being subject to moderately high to high landslide risk, and rural areas subject to high landslide risk;

3.

Liquefaction hazard. Areas within urban and village reserve lines, identified by the Seismic Safety Element as being subject to moderate to high soil liquefaction.

B.

Applicability of GSA standards. The standards of this Section apply to all land uses for which a permit is required, except:

1.

One single-family residence, not exceeding two stories, when not constructed in conjunction with two or more residences by a single contractor or owner on a single parcel or abutting parcels, unless the site is located in an area subject to liquefaction or landslide.

2.

Any agricultural use not involving a building, and any agricultural accessory structure.

3.

Alterations or additions to any structure, the value of which does not exceed 50 percent of the assessed value of the structure in any 12-month period.

C.

Application content - Geology and Soils Report required. All land use permit applications for projects located within a GSA (except those exempted by Subsection B.) shall be accompanied by a report prepared by a certified engineering geologist and/or registered civil engineer (as to soils engineering), as appropriate. The report shall identify, describe and illustrate, where applicable, potential hazard of surface fault rupture, seismic shaking, liquefaction or landslide, as provided by this Section. Provided, however, that no report is required for an application located in an area for which the County Engineer determines that sufficient information exists because of previous geology or soils reports. Where required, a geology report shall include:

1.

A review of the local and regional seismic and other geological conditions that may significantly affect the proposed use.

2.

An assessment of conditions on or near the site that would contribute to the potential for the damage of a proposed use from a seismic or other geological event, or the potential for a new use to create adverse effects upon existing uses because of identified geologic hazards. The conditions assessed shall include, where applicable, rainfall, soils, slopes, water table, bedrock geology, and any other substrate conditions that may affect seismic response, landslide risk or liquefaction potential.

3.

Conclusions and recommendations regarding the potential for, where applicable:

a.

Surface rupture or other secondary ground effects of seismic activity at the site;

b.

Active landsliding or slope failure;

c.

Adverse groundwater conditions;

d.

Liquefaction hazards.

4.

Recommended building techniques, site preparation measures, or setbacks necessary to reduce risks to life and property from seismic damage, landslide, groundwater and liquefaction to insignificant levels.

D.

Review of geology report. As required by California Code of Regulations, Title 14, Section 3603, the geology and soils report required by Subsection C. shall be evaluated by a geologist retained by the county who is registered in the State of California. Within 30 days of the acceptance of such report, the Director shall file one copy with the State Geologist.

[Added 1992, Ord. 2553]

E.

Geologic Study Area special standards. All uses within a GSA shall be established and maintained in accordance with the following, as applicable:

1.

Grading. Any grading not otherwise exempted from the permit requirements of Chapter 22.52 (Grading) shall be performed as engineered grading under the provisions of those sections.

2.

Seismic hazard areas. As required by California Public Resources Code Section 2621 et seq. and California Administrative Code Title 14, Sections 3600 et seq., no structure intended for human occupancy shall be located within 50 feet of an active fault trace within an Earthquake Fault Zone.

[Amended 1986, Ord. 2250; 1992, Ord. 2553; 1995, Ord. 2741] [22.07.080 to 086]