Regulatory Maps

The Alquist-Priolo Earthquake Fault Zoning Act (1972) and the Seismic Hazards Mapping Act (1990) direct the State Geologist to delineate regulatory "Zones of Required Investigation" to reduce the threat to public health and safety and to minimize the loss of life and property posed by earthquake-triggered ground failures. Cities and counties affected by the zones must regulate certain development "projects" within them. These Acts also require sellers of real property (and their agents) within a mapped hazard zone to disclose at the time of sale that the property lies within such a zone. Fault Evaluation Reports are available for those areas covered by a Regulatory Map however there are reports available for areas outside the Regulatory map boundary. For a complete set of maps available for purchase on CD please contact the CGS Library.