Topic: Levees

Overview

Levees

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 Delta.

Aquafornia news Spectrum News

Ventura County voters decide on a water bond this election

Besides local races, state races and propositions, some Ventura County voters are voting on whether or not to approve a $350 million water bond this election.  Known as Measure D, the United Water Conservation District is asking county voters within its service area to approve the bond to help fund three capital improvements projects it says are required. The bond, if passed, would cost property owners in the district’s service area approximately $24 per $100,000 of assessed value annually. United Water says the bond would run 30 years, from 2028 through 2057. It would help fund improvements to the Santa Felicia Dam, Freeman Diversion, and Extraction Barrier and Brackish Water Treatment. … [T]he dam is classified as an extremely high hazard dam by the state due to the high population amount below the dam.

Other infrastructure news:

Aquafornia news SFGate

A deteriorating levee is the weak link as king tides roll into Marin County

A Marin County neighborhood with a deteriorating coastal barrier is already feeling the impacts of king tides and coastal flooding sweeping into the Bay Area this week. … The North Bay started to feel the effects earlier this week when flooded roadways stranded a driver in Mill Valley, and now officials are focusing on a deteriorating 2-mile levee protecting 700 homes in an unincorporated community of San Rafael. … Bordering Gallinas Creek near where it empties into San Francisco Bay, the neighborhood was originally built as a luxury canal development modeled after Venice, Italy. … In September, the Marin County Flood Control District submitted an additional environmental review for the proposed Santa Venetia floodwall — a massive upgrade to replace the current levee system. It has also asked property owners to consider donating an easement so it can use their property to “construct, inspect, maintain, repair or replace flood protection infrastructure.”

Other levee news:

Aquafornia news CalMatters (Sacramento, Calif.)

State watchdog flags poor upkeep of Central Valley levees

With California bracing for a wet winter, the state auditor warns that nearly a third of local agencies maintaining vital flood control levees in parts of the Central Valley have been performing “unacceptable routine maintenance” — some of them, for years. The audit says the state’s Department of Water Resources “has not followed state law requiring it to take over the maintenance of levees” when local agencies fail to do so — and urged it to start. But state water managers at the department pushed back, saying the audit “portrays a fundamental lack of understanding of the complexities of flood management” and draws too direct a link between routine maintenance and flood risk. Taking over maintenance can cost tens of millions of dollars up front “that must be weighed against other investments that may yield greater risk-reduction benefits,” the department said in a letter responding to the audit. 

Publication Sacramento-San Joaquin Delta Map

Layperson’s Guide to the Delta
Updated 2025

Image shows the cover of the Layperson's Guide to the Sacramento-San Joaquin Delta.

The 24-page Layperson’s Guide to the Delta explores the competing uses and demands on California’s Sacramento-San Joaquin Delta. The 11th edition examines this critical water hub and its myriad challenges. The 2025 version includes the latest information on the tunnel project, habitat restoration efforts, climate change impacts and an updated section on the legal and political facets of the Delta.

California Spent Decades Trying to Keep Central Valley Floods at Bay. Now It Looks to Welcome Them Back
WESTERN WATER IN-DEPTH: Floodplain restoration gets a policy and funding boost as interest grows in projects that bring multiple benefits to respond to climate change impacts

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.

Tour Nick Gray Jenn Bowles Layperson's Guide to the Delta

Bay-Delta Tour 2021
A Virtual Journey - September 9

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.

Western Water California Water Map Gary Pitzer

Can a New Approach to Managing California Reservoirs Save Water and Still Protect Against Floods?
WESTERN WATER NOTEBOOK: Pilot Projects Testing Viability of Using Improved Forecasting to Guide Reservoir Operations

Bullards Bar Dam spills water during 2017 atmospheric river storms.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.

Western Water California Water Map Gary Pitzer

When Water Worries Often Pit Farms vs. Fish, a Sacramento Valley Farm Is Trying To Address The Needs Of Both
WESTERN WATER SPOTLIGHT: River Garden Farms is piloting projects that could add habitat and food to aid Sacramento River salmon

Roger Cornwell, general manager of River Garden Farms, with an example of a refuge like the ones that were lowered into the Sacramento River at Redding to shelter juvenile salmon.  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.

Western Water Layperson's Guide to the Delta

ON THE ROAD: Park Near Historic Levee Rupture Offers Glimpse of Old Sacramento-San Joaquin Delta
Big Break Regional Shoreline will be a stop on Bay-Delta Tour May 16-18

Visitors explore a large, three-dimensional map of the Sacramento-San Joaquin Delta at Big Break Regional Shoreline in Oakley. 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 soil.

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.

Video

Delta Warning

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.

Publication

Layperson’s Guide to the State Water Project
Updated 2013

The 24-page Layperson’s Guide to the State Water Project provides an overview of the California-funded and constructed State Water Project.

The State Water Project is best known for the 444-mile-long aqueduct that provides water from the Delta to San Joaquin Valley agriculture and southern California cities. The guide contains information about the project’s history and facilities.

Publication

Layperson’s Guide to Flood Management
Updated 2009

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. 

Maps & Posters California Water Bundle

California Water Map
Updated December 2016

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 River.

Floodplains in California

Restored floodplain at Dos Rios Ranch Preserve near Modesto

With the dual threats of aging levees and anticipated rising sea levels, floodplains — low areas along 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.

Aquapedia background

Levees

Levees

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 Delta.

These levees have been in place dating back to 1850, when California first joined the union.

Western Water Magazine

Meeting the Co-equal Goals? The Bay Delta Conservation Plan
May/June 2013

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.

Western Water Magazine

How Much Water Does the Delta Need?
July/August 2012

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.

Western Water Magazine

Levees and Flood Protection: A Shared Responsibility
May/June 2012

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 policy.

Western Water Excerpt Gary PitzerRita Schmidt Sudman

Levees and Flood Protections: A Shared Responsibility
May/June 2012

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.

Western Water Magazine

Finding a Vision for the Delta
March/April 2008

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.

Western Water Magazine

A Significant Challenge: Adapting Water Management to Climate Change
January/February 2008

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 Environmental Reform.

Western Water Magazine

It Can Happen Here: Assessing California’s Flood Risk
November/December 2005

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.

Western Water Magazine

Flood Management 2004: A System in Peril
September/October 2004

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.