California’s Bay Delta: In Search of a Permanent Solution
 The Sacramento-San Joaquin Delta and our rapidly changing water future is an important subject that will require a lot of thought and planning. The Delta is fast becoming a prominent topic of discussion - one that you will hear a great deal more about in the near future. The information on this Web page will brief you on how the future of the Delta will affect our future here and the challenges that we face ahead.

Metropolitan Water District of Southern California
 Metropolitan is a wholesaler of water for Southern California. It buys and imports water from Northern California and the Colorado River and then sells it and distributes it to its 26 member agencies in six counties, from Ventura to San Diego. Metropolitan serves about 18 million people, and its region is adding about 220,000 people each year.

Regional Storage Investments
Most people haven’t worried too much about water in recent years because since the last prolonged drought of the early 1990s, Metropolitan has been very busy adding storage capacity to our system. This way, Metropolitan can store water in wet years and have it available in dry years.

Colorado River into Lake Powell
The ample rain after the drought in the early 1990s helped, but changes since then have affected our water supply from both the Delta and the Colorado River.

California Water Today
For the first time in our history, we are facing water challenges that affect all of our major sources.

•  The Los Angeles supply from its Owens Valley system is the lowest on record.
•  The Colorado River system is in a prolonged drought that has wiped out surplus supplies that used to be available to Southern California.
• In Southern California, we’re facing record low rainfall, which means we aren’t naturally replenishing our groundwater basins.
• In the Delta, environmental problems are causing new challenges. A federal court recently cut supplies for 2008 by as much as 30 percent, and some level of cuts is likely for years to come unless we figure out some ways to heal this estuary.

The Delta: Hub of California’s Water System
The Delta is an expansive inland river delta and estuary situated in northern California where the major rivers from the Sierra Nevada all converge before heading to San Francisco Bay. Water from the Delta is moved to millions of acres of farmlands and to 25 million people via the Central Valley Projects and State Water Projects.

Importance of the Bay Delta
The Delta is just as important to wildlife - a variety of birds and fish species - as it is to humans. It is the most important estuary in the state of California.

Land Subsidence – Islands or holes?
Farming is taking place on many of the islands in the Delta, and this is now becoming a challenge.
Before 1880 the islands were marshlands just above sea level. As soil was exposed to grow crops, the peat soils began to oxidize. Over time, approximately 1,600 miles of levees were built.  Now, the levees are the only thing keeping many of the islands above sea level.  Levee failure would cause the islands to become a submerged landscape in the Delta.

Our Water Supply pathway
To move water from north to south, water must flow through the Delta around the islands to get to the pumping plants. So long as we depend on moving water through the Delta, we are dependent on these levees holding back water.

6.5 Magnitude Earthquake
The Delta is in earthquake country. We are fortunate to have avoided a major seismic event in this area since the construction of the water projects. But experts say there is a greater than 60 percent chance of an event occurring within the coming few decades. If that happens, levees could collapse, the islands would submerge and salt water from the Bay would rush in. We could lose this water supply for several years if we aren’t prepared.

Climate Change
Climate change could have a major impact on the Delta.  Salinity will increase as the sea level rises. The pumps that are used to move water through the Delta are already located in one of the more saline reaches of the Delta.

Delta Fisheries 2006
The salmon that migrate through the Delta are relatively stable and in some cases improving. It is the fish that live year-round in the Delta that are struggling. Although pumping water is one reason, there are others. Certain pesticides have increased in recent years. An invasive species of clam is now consuming much of the food supply for Delta fish. The effects to the Delta smelt, a two-inch fish that is vulnerable to pumping effects and has a typical lifespan of one year, is a main cause of the current cutback in water supplies.

Long-term Vision: Water moves through Delta; new barriers
There is considerable agreement on many fronts that we need to restore more Delta land into habitat to create food for fish like the smelt. But there is not yet agreement on how and where to pump water supplies from the estuary. One approach that government agencies are looking at is to maintain the existing system while adding some temporary barriers along some specific waterways in the southern Delta. The barriers would prevent any small smelt from drifting toward the pumps. But this system would still be vulnerable to failure during an earthquake and to rising salinity from climate change.

Long-term Vision: Water moves through and around Delta
A second approach is to build a new water intake plant just north of the Delta and to move supplies to the existing pumps via a new canal.  This is quite different from the Peripheral Canal debate of 1982.  The canals that are being studied now are significantly smaller. Continuing to pump at certain times of the year would pose the smallest conflicts with the migrating fish. Smaller canals would likely withstand an earthquake better and as sea levels rise due to climate change, the northern Delta would remain a source of fresh, high-quality water supply.

Metropolitan Service Area Supplies
Metropolitan is not expecting to get more water from the Delta. Its long-term strategy is to find the water for growth from conservation and local programs such as replenishing groundwater basins with wet year water.
This chart shows Metropolitan’s plan for the future. Water from the Delta is represented by the blue area titled “SWP” - State Water Project. It represents a relatively modest portion of the entire water supply.

2025 Dry-Year Resource Targets
During a future drought we will rely more on local solutions. But we will continue to need the Delta as a source of high-quality water and as a wet-year supply to help fill our storage systems.

California’s Bay Delta: In Search of a Permanent Solution
Metropolitan plans to continue to work on conservation, and to maximize our own resources in Southern California.  In the Delta, we need to create a smarter water delivery system, which may include a new Delta canal. We need a comprehensive solution that works for the ecosystem, provides high quality water and addresses the risks from seismic events and climate change.  As long as we recognize that change is necessary for both the sake of our economy and the Delta environment, we have a very good chance at an outcome we can all be proud of.
It’s an exciting time to be in the water world.  Metropolitan continues to encourage people to communicate with us, with their local water district and with their state legislators to help work towards bipartisan, comprehensive solutions in meeting our water needs and living in harmony with our environment.