This commentary was published in CALmatters on February 21, 2019.

The Sacramento–San Joaquin Delta is a major source of water for cities and farms across the state, and a major source of water conflict.

In a Sacramento Bee editorial two years ago, we and our colleague Brian Gray promoted a grand compromise for the Delta. We suggested that the three broad interests fighting about its future—water users, environmental groups, and Delta residents—give up something in order to reduce conflict and make progress. During his first state of the state address, Gov. Gavin Newsom opened the door to just such a compromise.

Three interrelated issues in the Delta are in tension and need resolution:

• First, the reliability and quality of its water are in decline. More than 25 million Californians and 3 million acres of farmland rely on the Delta for a portion of their water supply.
• Second, ecosystems in its watershed are changing, harming fisheries and threatening extinction of some native species.
• Finally, many of the 1,100 miles of fragile levees that protect people’s farms and homes are in need of costly upgrades.

Climate change and rising sea levels are making all of these problems worse.

Gov. Jerry Brown’s WaterFix program aimed to solve the supply problem by building two large tunnels underneath the Delta to route Sacramento River water to Bay Area and Southern California cities and San Joaquin Valley farms.

The project’s size, and its potential for ecological harm if mismanaged, made it untenable to most Delta residents and environmental groups. It also was very costly, with uncertain financing prospects. A stalemate developed in which none of these interrelated issues—water supply, ecosystems, levees—could be adequately addressed.

Gov. Newsom has changed that equation by proposing to build one tunnel, not two.

A single tunnel would perform almost as well as two tunnels, particularly when operated in tandem with the existing pumps in the south Delta. It would cost substantially less. And it would give assurances to environmental groups and Delta residents that the project would not create the large impacts many fear.

Environmental groups should take this opportunity to sign on to a new approach for managing the Delta.

This would involve focusing less on the volume of flows dedicated to protecting endangered species and more on how flows and habitat—managed together—can improve ecosystem conditions.

Doing this well will require major commitments to habitat restoration from the state and water users. It will also require new approaches to managing environmental water.

We recommend establishing ecosystem water budgets that can be stored, traded, and flexibly allocated. This makes the environment a partner in water management rather than merely a constraint. Reliable funding, good governance, and robust scientific support will be essential components of this package.

There’s an opportunity for the new governor to move forward on the ecosystem issue as well. The State Water Board is revising its Water Quality Control Plan for the Delta.

Governors Brown and Newsom have stated their desire that water users and environmental groups develop negotiated agreements as an alternative to new environmental flow regulations from the board.

Done well, such agreements have the potential to create flexible allocations of water for the Delta ecosystem. The clock is ticking. Getting these negotiations completed is critical to resolving the Delta’s problems.

The administration also must address the future of the Delta’s fragile levees. Some are essential for managing water quality, and all are under threat from climate change, sinking land, and earthquakes. There is an opportunity to build upon the recently completed Central Valley Flood Plan and the Delta Stewardship Council’s efforts to prioritize investments in levees. A comprehensive, reliably funded plan that accounts for the multiple threats to levees is sorely needed.

In California’s complicated water wars, some may consider “compromise” synonymous with surrender. But those who insist on fighting will only be rewarded with more fights. Progress happens when parties give up something to get what they really need. By proposing to build one tunnel instead of two, Governor Newsom has opened the door for a grand compromise in the Delta. The Delta’s many interests should seize this opportunity.