California would not exist as it does today were it not for the
extensive system of levees, weirs and flood bypasses that have
been built through the years, particularly in the Sacramento-San
Sea levels in San Francisco Bay have risen nearly 8 inches in
the last 100 years and continue to rise. The sea level in this
area could rise as much as 3 feet over the next 50 years, and
this project will help protect future generations. In December
2021, Valley Water and its partners broke ground on the first
portion of the South San Francisco Bay Shoreline Phase 1
Project. … Once completed, this project will help reduce
coastal flood risk for about 5,500 residents, commuters and
businesses within the vicinity of Alviso and North San José.
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.
The Yolo Bypass is one of two large flood bypasses in
California’s Central Valley that are examples of multi-benefit
floodplain projects (Figure 1; Serra-Llobet et al.,
2022). Originally constructed in the early 20th century
for flood control, up to 75% of the Sacramento River’s flood
flow can be diverted through a system of weirs into the Yolo
Bypass and away from nearby communities (Figure 2; Salcido,
2012; Sommer et al., 2001). During the dry season, floodplain
soils in the bypass support farming of seasonal crops (mostly
rice). Today, the bypass is also widely recognized for its
Rivers in California’s Central Valley like to go their own way:
they expand, contract, meander and regenerate soil in the
process. The historic movement of rivers is what made Central
Valley soil so fertile. Naturally flowing rivers recharge and
save water for people and nature, providing habitat for many
species including four distinct runs of chinook salmon.
Before the early 20th century, the Sacramento River had one of
the biggest salmon runs in North America …
A colorful, widely visible, but graffiti-marred mural on a
flood-control dam near Corona that celebrated the nation’s
bicentennial no longer enjoys the protection of a court order.
But officials say a plan is in the works to replace the
patriotic image on Prado Dam, which was originally created with
toxic lead paint. The fate of the mural near the 91 and 71
freeways has been uncertain since the U.S. Army Corps of
Engineers, which controls the dam, announced plans to begin
removing the gigantic painting in spring 2015.
Climate change is worsening the already significant threat of
flooding in California’s farm country, and state officials said
Thursday that as much as $30 billion may be needed over three
decades to protect the region, an increase from five years ago.
Every five years, flood protection plans are updated for the
Central Valley, where about 1.3 million people live at risk in
floodplains. State officials released a draft of the latest
update that calls for investing in levees, maintenance and
multi-benefit projects that recharge aquifers and support
wildlife while enhancing flood protection.
Napa County has joined an effort to raise an early alarm about
flood control agencies potentially losing out on millions of
dollars if the state doesn’t take action to extend a
deadline. Specifically, a loss of access to reimbursement
funds would happen if the funding from Proposition 1E — a $4.09
billion bond measure for flood control projects passed by
California voters in 2006 — is allowed to expire by its current
deadline of July 1, 2023. The funds come by way of a state
program, managed by the California Department of Water
Resources, that pays back agencies their costs for
federally-required flood control projects.
Between vast almond orchards and dairy pastures in the heart of
California’s farm country sits a property being redesigned to
look like it did 150 years ago, before levees restricted the
flow of rivers that weave across the landscape. The 2,100 acres
(1,100 hectares) at the confluence of the Tuolumne and San
Joaquin rivers in the state’s Central Valley are being reverted
to a floodplain.
Hundreds of millions of new federal dollars are headed to the
region to help fund the massive Natomas levee project.
President Joe Biden has signed legislation that includes $157
million for an existing project in the Natomas Basin, as well
as $17.9 million to begin construction in West Sacramento. In
addition, Biden’s budget proposal for fiscal 2023, the 12 month
period that begins Oct. 1, includes another $172 million for
the levee project and $79.7 million to help the West Sacramento
Land and waterway managers labored
hard over the course of a century to control California’s unruly
rivers by building dams and levees to slow and contain their
water. Now, farmers, environmentalists and agencies are undoing
some of that work as part of an accelerating campaign to restore
the state’s major floodplains.
This tour guided participants on a virtual journey deep into California’s most crucial water and ecological resource – the Sacramento-San Joaquin Delta. The 720,000-acre network of islands and canals support the state’s two major water systems – the State Water Project and the Central Valley Project. The Delta and the connecting San Francisco Bay form the largest freshwater tidal estuary of its kind on the West coast.
Many of California’s watersheds are
notoriously flashy – swerving from below-average flows to jarring
flood conditions in quick order. The state needs all the water it
can get from storms, but current flood management guidelines are
strict and unyielding, requiring reservoirs to dump water each
winter to make space for flood flows that may not come.
However, new tools and operating methods are emerging that could
lead the way to a redefined system that improves both water
supply and flood protection capabilities.
Farmers in the Central Valley are broiling about California’s plan to increase flows in the Sacramento and San Joaquin river systems to help struggling salmon runs avoid extinction. But in one corner of the fertile breadbasket, River Garden Farms is taking part in some extraordinary efforts to provide the embattled fish with refuge from predators and enough food to eat.
And while there is no direct benefit to one farm’s voluntary actions, the belief is what’s good for the fish is good for the farmers.
Along the banks of the
Sacramento-San Joaquin Delta in Oakley, about 50 miles southwest
of Sacramento, is a park that harkens back to the days when the
Delta lured Native Americans, Spanish explorers, French fur
trappers, and later farmers to its abundant wildlife and rich
That historical Delta was an enormous marsh linked to the two
freshwater rivers entering from the north and south, and tidal
flows coming from the San Francisco Bay. After the Gold Rush,
settlers began building levees and farms, changing the landscape
and altering the habitat.
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.
A new look for our most popular product! And it’s the perfect
gift for the water wonk in your life.
Our 24×36 inch California Water Map is widely known for being the
definitive poster that shows the integral role water plays in the
state. On this updated version, it is easier to see California’s
natural waterways and man-made reservoirs and aqueducts
– including federally, state and locally funded
projects – the wild and scenic rivers system, and
natural lakes. The map features beautiful photos of
California’s natural environment, rivers, water projects,
wildlife, and urban and agricultural uses and the
text focuses on key issues: water supply, water use, water
projects, the Delta, wild and scenic rivers and the Colorado
With the dual threats of obsolete levees and anticipated rising sea levels,
areas adjacent to waterways that flood during wet years—are
increasingly at the forefront of many public policy and water
issues in California.
Adding to the challenges, many floodplains have been heavily
developed and are home to major cities such as Sacramento. Large
parts of California’s valleys are historic floodplains as well.
Roughly 1,115 miles of levees protect farms, cities, schools and
people in and around the Sacramento-San Joaquin
Delta, a crucial conduit for California’s overall water
supply. But the Delta’s levees are vulnerable to failure due to
floods, earthquakes and rising sea levels brought about by
climate change. A widespread failure could imperil the state’s
California would not exist as it does today were it not for the
extensive system of levees, weirs and flood bypasses that have
been built through the years, particularly in the Sacramento-San Joaquin
These levees have been in place dating back to 1850, when
California first joined the union.
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.
This printed issue of Western Water examines the issues
associated with the State Water Board’s proposed revision of the
water quality Bay-Delta Plan, most notably the question of
whether additional flows are needed for the system, and how they
might be provided.
This printed issue of Western Water discusses several
flood-related issues, including the proposed Central Valley Flood
Protection Plan, the FEMA remapping process and the dispute
between the state and the Corps regarding the levee vegetation
Levees are one of those pieces of engineering that are never
really appreciated until they fail. California would not exist as
it does today were it not for the extensive system of levees,
weirs and flood bypasses that have been built through the years.
This printed copy of Western Water examines the Delta through the
many ongoing activities focusing on it, most notably the Delta
Vision process. Many hours of testimony, research, legal
proceedings, public hearings and discussion have occurred and
will continue as the state seeks the ultimate solution to the
problems tied to the Delta.
This printed copy of Western Water examines climate change –
what’s known about it, the remaining uncertainty and what steps
water agencies are talking to prepare for its impact. Much of the
information comes from the October 2007 California Climate Change
and Water Adaptation Summit sponsored by the Water Education
Foundation and DWR and the November 2007 California Water Policy
Conference sponsored by Public Officials for Water and
This issue of Western Water examines the extent to
which California faces a disaster equal to or greater than the
New Orleans floods and the steps being taken to recognize and
address the shortcomings of the flood control system in the
Central Valley and the Delta, which is of critical importance
because of its role in providing water to 22 million people.
Complicating matters are the state’s skyrocketing pace of growth
coupled with an inherently difficult process of obtaining secure,
long-term funds for levee repairs and continued maintenance.
This issue of Western Water analyzes northern California’s
extensive flood control system – it’ history, current concerns,
the Paterno decision and how experts are re-thinking the concept
of flood management.