Delta Islands And Habitat Restoration

Delta Islands

Investing in our Future

Providing water supplies for 19 million consumers and our economy cannot be at the expense of the environment. We make major investments to protect our natural resources. Our acquisition of islands in the Sacramento-San Joaquin Delta allows us the extraordinary opportunity to help secure and guard the Delta’s future. We are using the strategically located islands to explore ways to help improve the Delta’s declining ecosystem and promote water reliability for those we serve.  

While the Delta is important to Southern California’s water supply, it’s a place everyone should care about. It’s the heart of California’s water delivery system and is vital to our economy, a diverse ecosystem, and quality of life for millions of Californians.  

We contribute to science and research and identifying potential projects on the islands that support water system reliability, restore habitat and promote sustainable agricultural practices. We are partnering with state and federal agencies, technical experts, academia and environmental organizations as we develop these studies and projects.

Delta Islands

Restoring Habitat

The Delta was once home to about 80 percent of California’s fishery species and the West Coast’s largest estuary. It is also part of the Pacific Flyway for migratory water birds. But the original habitat that supported native species has been modified and looks significantly different than its natural state, due to a number of factors, such as agricultural reclamation, non-native species introduction, water diversions, and land subsidence. The healthy habitat and food web that support native species are part of the delicate Delta ecosystem, and many fish populations are declining.

We are expanding scientific studies and research that can benefit ecosystem health in the Delta. Some areas of the islands offer opportunities to:

  • Develop food production (zooplankton) for fish
  • Restore native tule vegetation to rebuild peat soils to increase land elevation and reduce carbon emissions, while protecting the quality of drinking water sources
  • Convert some lands to non-tidal wetlands, or preserve cultivated land with food for birds to improve waterfowl habitat and help protect threatened and endangered species
  • Restore tidal wetlands, as is being done on Chipps Island, which Metropolitan recently sold to the state Department of Water Resources for this purpose

Managing Risks, Promoting Reliability 

California’s water system through the Delta relies on about 1,100 miles of levees that protect farms, cities, and people. For the Delta islands, the levees surround subsided land that is below sea-level. These levees are vulnerable to earthquakes, floods and rising sea levels under climate change. When levees fail, water rushes in, pulling in saltwater from the bay and impacting water quality before it can be delivered to Southern California, the San Francisco Bay Area, the Central Coast and the Central Valley. 

We are working with our project partners to strengthen levees along the freshwater pathway, as well as ensure comprehensive emergency response to protect this vital water supply in the event of an earthquake or other disaster.  

We’re also studying climate change risks, managing peat soils to reduce carbon emissions, and strengthening levees to improve water quality and supply reliability. The Delta faces many challenges. We are committed to managing those risks for the benefit of those we serve.