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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.
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:
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.
Activities on Metropolitan's Delta island properties have focused on land use and habitat opportunities, subsidence reversal efforts and resilience against climate change.
Floating Wetlands Research
This pilot project on Bouldin Island, a partnership between Metropolitan, DWR, the UC Davis Center for Watershed Sciences and other entities, is studying floating peat wetlands, which historically existed in the Delta. If these floating wetlands can be re-established, it could improve the ecosystem and reduce the risk of levee failures.
Bacon Island Levee Improvements
The $14.5 million Bacon Island Rehabilitation Project strengthened 4.7 miles of the island’s west-side levee. It enhances the water conveyance pathway in the central Delta corridor and reduces the risk of a levee failure that would potentially impact water quality in the Delta and for the State Water Project and Central Valley Project. This project was completed with a grant from DWR and through the collaboration of urban water agencies: Alameda County Water District, Contra Costa Water District, East Bay Municipal Utility District, San Francisco Public Utilities Commission, Santa Clara Valley Water District, Zone 7 Water Agency and Metropolitan.
The existing approach to levee maintenance looks at needs over a five-year cycle. This pilot project on Bouldin Island evaluates the levees with a broad suite of technologies on a real-time basis to identify levee locations with critical needs, some of which may not be visible.
The program will allow for advanced planning to address levee maintenance and repair needs and could be applied at other Metropolitan islands and DWR-sponsored levee programs.
Were Delta levees to fail due to an earthquake or other natural event, an “emergency freshwater pathway” would have to be constructed for fresh water supplies to move north-to-south through the Delta to the existing SWP and CVP pumping facilities.
DWR has stockpiled several hundred thousand tons of materials and equipment that can be quickly deployed in an emergency situation in the Delta.
Webb and Holland tracts are two of the eight priority islands identified by the state for special protection because of their location in the western Delta and potential to counteract saltwater intrusion. Metropolitan works with DWR, U.S. Army Corps of Engineers, and local reclamation districts on emergency preparation exercises and seismic analyses.
This project was completed with a grant from DWR and through the collaboration of urban water agencies: Alameda County Water District, Contra Costa Water District, East Bay Municipal Utility District, San Francisco Public Utilities Commission, Santa Clara Valley Water District, Zone 7 Water Agency, Metropolitan, and local entities Reclamation District #2028 and PG&E.
Metropolitan also leases land on its Delta islands for farming. These leases allow us the opportunity to evaluate alternative farming practices and alternative land uses.
Delta Island Adaptations Project
The Delta Island Adaptations Project seeks to improve the resilience and sustainability Metropolitan-owned islands in the Sacramento-San Joaquin Delta. The project supports the state’s co-equal goals of ecosystem restoration and water supply reliability for California, while valuing the Delta as an evolving place.
The project calls for Metropolitan to undertake a comprehensive analysis of opportunities for island-wide improvements. These enhancements include a mosaic of multiple land uses for stopping or reversing subsidence and promoting sustainable agricultural practices, carbon sequestration, greenhouse gas reductions, water quality improvements and habitat restoration.
Funded under the Prop. 1 Watershed Restoration Grant, this collaborative planning process has two phases. The first will select one of the four islands owned by Metropolitan (Bouldin Island, Bacon Island, Holland Tract, and Webb Tract) that offers the best opportunity for island-wide, landscape-scale scenario planning. The second co-design phase will focus on landscape-scale scenario planning for the chosen island, which includes developing and evaluating conceptual-level, multi-use scenarios for the selected island. In addition, Metropolitan will develop future partnerships to support this restoration effort.