… California’s largest freshwater system, the State Water Project, is threatened both by catastrophic collapse from earthquakes in the Sacramento-San Joaquin Delta, as well as long-term decline from saltwater intrusion into existing pumps from rising sea levels. … The Delta Conveyance Project — which would connect existing aqueducts to a new, safer freshwater diversion point farther upstream from the Bay via an underground tunnel — has been studied for over 40 years at the expense of hundreds of millions of dollars and is simply the most cost-effective solution to this problem.
–Written by Jim Wunderman, president and CEO of the Bay Area Council.

Other Delta tunnel news:

• California Department of Water Resources: News release: Upgrading foundational water supply infrastructure makes economic sense​