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
earthquake hits.
* 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
dams.
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
large-scale fires.
* 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
unavailable.
A key priority of the Newsom Administration – the Delta
Conveyance Project – has officially entered its next chapter.
On July 22, the Department of Water Resources (DWR) released
its draft environmental impact report (Draft EIR) for the Delta
Conveyance Project. The Delta Conveyance Project is DWR’s and
Governor Newsom’s plan to build an underground tunnel to bring
water from the Sacramento-San Joaquin Delta to the State Water
Project pumps near Tracy in order to reduce the risk from
earthquakes and climate change to the State’s water supplies.
A recent earthquake in the Oroville area has many wondering how
stable the Oroville Dam is. The Department of Water Resources
told Action News Now the Dam is in good condition and was not
damaged by the 4.2 earthquakes. Many people in Oroville
said they’ve experienced several earthquakes but are always on
alert when a fire or earthquake happens, especially after the
Oroville Spillway Crisis in 2017. The crisis pushed nearly
190,0000 people to evacuate but the DWR said the Dam can
withstand a lot and is constantly being evaluated in case an
emergency breaks out.
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.
