Throughout the state, there are more than 100 active faults that
have produced earthquakes resulting in widespread damage and
deaths. In Southern California alone, since 1933, there have been
23 significant quakes of magnitude 5.9 or greater. The San
Andreas Fault, the major fault line running through California,
is expected to be the source for a major earthquake. It was the
source for the earthquake that leveled San Francisco in 1906.
Water infrastructure is vulnerable to earthquakes:
* In the Sacramento-San Joaquin Delta, man-made levees
dating back to 1850 are identified as at risk when a major
* The U.S. Geological Survey (USGS) estimates a magnitude
7.8 temblor on the southern portion of the San Andreas Fault will
cause major damage to infrastructure, including water lines and
A panel of experts in Southern California also has identified the
following risks as a result of a major earthquake:
* Likely major damage to the main aqueducts bringing water
to Southern California from Northern California and the Colorado
River. Repairs may be hampered due to damaged roads and
* In the following days after a major quake, there may be
no water available due to infrastructure breaks and loss of
power. After that, repairs will bring supplies online slowly.
Water districts and agencies have prepared earthquake
preparedness and emergency plans to address the emergency.
Also, groundwater basins will be used as emergency reservoirs to
make up the water shortages when imported supplies are
Old environmental arguments over the consequences of nuclear
power had seemed almost resolved in California. Antinuclear
sentiment was intensified by the 33-year succession of
accidents, from Three Mile Island in 1978 to Chernobyl in 1986
to Fukushima in 2011, severely diminished their appeal.
California was getting ready to wave goodbye to its last
nuclear plant. Up Close We explore the issues, personalities,
and trends that people are talking about around the West. The
political realities of 2022 and the need to reduce carbon
emissions might change things.
The Delta is crucial because, if it ever failed as a hub, the
resulting water crisis in California would increase existing
tensions with the Colorado’s other parched dependents. … The
Delta’s problems are as dire, but they receive far less public
attention. The main threat to the Delta is saltwater
intrusion. If an earthquake caused a major levee failure, the
sunken islands would flood, drawing salt water from the Pacific
into waterways that are now kept fresh by the pressure of
inflows from the Sacramento.
Constructed four generations ago, the massive rock and clay dam
at El Capitan Reservoir is capable of storing over 36 billion
gallons of water, enough to supply every resident in San Diego
for most of a year. Today, it’s three-quarters empty,
intentionally kept low because of concerns it could fail under
the strain of too much water. … Seismic instability and
a spillway in need of “significant repair” led El Capitan
to be added to a growing list of dams rated in poor condition
or worse that would likely cause deaths downstream if they
15-minute DVD that graphically portrays the potential disaster
should a major earthquake hit the Sacramento-San Joaquin Delta.
“Delta Warning” depicts what would happen in the event of an
earthquake registering 6.5 on the Richter scale: 30 levee breaks,
16 flooded islands and a 300 billion gallon intrusion of salt
water from the Bay – the “big gulp” – which would shut down the
State Water Project and Central Valley Project pumping plants.
The 24-page Layperson’s Guide to
Flood Management explains the physical flood control system,
including levees; discusses previous flood events (including the
1997 flooding); explores issues of floodplain management and
development; provides an overview of flood forecasting; and
outlines ongoing flood control projects.
The 24-page Layperson’s Guide to the Delta explores the competing
uses and demands on California’s Sacramento-San Joaquin Delta.
Included in the guide are sections on the history of the Delta,
its role in the state’s water system, and its many complex issues
with sections on water quality, levees, salinity and agricultural
drainage, fish and wildlife, and water distribution.
This issue of Western Water looks at the BDCP and the
Coalition to Support Delta Projects, issues that are aimed at
improving the health and safety of the Delta while solidifying
California’s long-term water supply reliability.