Maps of Special Studies Zones (Active Fault Traces), California

Fault Hazard Zones Maps have been released by the California Department of
Conservation Division of Mines and Geology:

Official Maps of new and revised Special Studies Zones have
been issued pursuant to the Alquist-Priolo Special Studies Zones
(APSSZ) Act (Division 2, Chapter 7.5, California Public Resources
Code) and are effective on July 1, 1993. Revised maps supersede
earlier Official Maps.

Copies of the maps may be examined at the offices of affected
cities and counties, and at the offices of the Division of Mines
and Geology. Copies may be purchased from Blue Print Service
Company, 1147 Mission Street, San Francisco, California 94103,
phone [phone].

The APSSZ Act requires the State Geologist to identify active
faults and to issue maps of Special Studies Zones in order to
regulate development 'projects' near active faults. The purpose
of the Act is to reduce the hazard of surface faulting to
structures for human occupancy. Cities and counties affected by
the regulatory zones must regulate specified 'projects' within
the zones in order to locate structures for human occupancy away
from the traces of active faults.

Official Maps (* = Revised Official Maps) issued July 1, 1993
are:
Mark West Springs *
Mt. George *
Cordelia *
Fairfield South *
Vine Hill (formerly Port Chicago) *
Walnut Creek *
Clayton *
Landers *
Yucca Valley North *
Yucca Valley South *
Joshua Tree South

Cities and counties affected by new or revised Special Studies
Zones shown on Official Maps of July 1, 1993 are:

Cities:
Benecia
Concord
Fairfield
Walnut Creek
Yucca Valley

Counties:
Contra Costa
Riverside
San Bernardino
Solano
Sonoma

Two Official Maps of Special Studies Zones are withdrawn
effective July 1, 1993:

Antioch North
Antioch South

Special Studies Zones shown on these maps no longer affect the
City of Antioch and the County of Contra Costa.

The California Division of Mines and Geology also maintains an electronic
bulletin board. CDMG ONLINE is an MS-DOS BBS. Phone [phone]
CDMG ONLINE has Earthquake Information, Geology Programs, Echo Mail, and
much more. The Sysop is Ted Smith (see Technical Contact for contact
information).