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 Valley Water News

Blog: A groundbreaking effort to protect the San Francisco Bay from sea-level rise

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.

Aquafornia news The New Yorker

The biggest potential water disaster in the United States

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.

Aquafornia news California WaterBlog

Blog: Five “f”unctions of the Central Valley floodplain

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 ecological benefits.

Aquafornia news The Nature Conservancy

Blog: Hamilton City

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 …

Related article: 

Aquafornia news San Bernardino Sun

Prado Dam patriotic mural near Corona loses legal protection, but could be repainted

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.

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Aquafornia news Associated Press

California hikes costs for flood protections in farm country

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.

Related article: 

Aquafornia news Napa Valley Register

Napa’s flood control district could lose out on millions in state reimbursement funding for Napa River projects

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.

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Aquafornia news Associated Press

California gives rivers more room to flow to stem flood risk

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. 

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Aquafornia news The Fresno Bee

Natomas CA levee project gets millions, could get more money

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 project.

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.

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. 

Publication

Layperson’s Guide to the Delta
Updated 2020

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.

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.

Aquapedia background

Floodplains in California

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

Aquapedia background

Sacramento-San Joaquin Delta Levees

Sacramento-San Joaquin Delta Levees

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 water supply.

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.