California’s Twin Tunnels Water Project Is Dead. What’s Next?

Environmental advocates are cautiously optimistic about plans to downscale the controversial WaterFix project.

This past February, Governor Gavin Newsom announced his decision to downscale California’s Delta tunnels project from two tunnels to one. In May, the Department of Water Resources withdrew the permit application it had previously submitted to the State Water Resources Control Board, officially killing the project, and gave notice that it would start planning for a single tunnel. The decisions were generally welcomed within the environmental community.  

photo of sacramento-san joaquin delta
The Sacramento-San Joaquin Delta has long been shaped by agriculture, channelization, and water diversions. California is wrestling with how to upgrade the aging water infrastructure in the Delta while minimizing harm to local habitat. Photo by IBM Research / Flickr.

The configuration of the Delta tunnels has long been controversial. First proposed more than a decade ago, former Governor Jerry Brown had initially considered building a single tunnel to divert water from the Sacramento-San Joaquin Delta to other thirsty parts of the state. Ultimately, however, he proposed a twin tunnel project, known as WaterFix, which centered upon the installment of two 40-foot wide and 35-mile long tunnels that would divert water from the Sacramento-San Joaquin Delta to an existing network of canals, and ultimately on to the San Francisco Bay Area, Central Valley, and Southern California.

The tunnel plan was meant to address a long-standing issue in California: most of the state’s water resources lie in the North, but more water is needed in urban areas in Southern California, as well as agricultural areas in the Central Valley. The Delta is already the hub of the state’s water system — some 4.5 million acre-feet of water are withdrawn on average every year. WaterFix was meant to stabilize the aging system, and moderately increase water diversions.

This plan, however, was unpopular in many quarters, particularly among local Delta farmers who have been struggling with salinization due to the long history of water diversion from the region, and among environmental groups concerned that a two-tunnel project would remove too much water from the Delta, negatively impacting the environment there.

Part of the concern has been around the capacity of the tunnels. Though the state insisted that it would only increase diversions to an average of 4.9 million acre-feet a year, the twin tunnels would have the capacity to remove much more water from the Delta system. Environmental advocates have insisted that preservation of the Delta ecosystem depends of extracting less water, not more.

In particular, environmentalists have pointed to the impact the project would likely have on native fish species like the endangered Delta Smelt and winter-run Chinook salmon, both of which are protected under the US Endangered Species Act . The fish are already stressed by local agricultural runoff as well as by the existing water pumps in the Delta, which at times result in reverse flows of local rivers and channels, pushing fish towards predators and even into the pumps themselves. The twin Delta tunnels, John McManus, executive director of The Golden Gate Salmon Association says, could increase the risk of overdrawing water from the Delta and therefore disrupt their existence further.

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At Big Break Regional Shoreline, nestled in Northern California’s San Joaquin-Sacramento Delta, Michael Moran, supervising naturalist for East Bay Regional Park District, leads about 30 people out along a path into the park.

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Because the tunnels would be funded in large part by water companies in Southern California, Delta advocates were particularly concerned that remote water demands would be prioritized over local needs and environmental interests.

Though the twin tunnel project is dead, WaterFix is not. Officials in Newsom’s administration have said that a single tunnel will help secure water resources in Delta region, provide water to other places that need it, and take less time to build than the former twin tunnel plan.

“I’d like to see a more modest proposal, but I’m not going to walk away,” Newsom said this winter. “Doing nothing is not an option…. The status quo is not helping salmon.”

Though Southern California water companies are not entirely happy about the shift, environmental groups are generally encouraged, and hope for a larger emphasis on environmental interests this time around. Doug Obegi, director of California River Restoration and Water Division with the Natural Resource Defense Council, hopes that the planning process is more inclusive of Delta farmers and environmental advocates this time around. “I want to see the administration engage with more local groups,” he says.

“If [Southern California water companies are] disappointed then it’s a sign that Governor Newsom would be moving towards the right direction,” adds McManus.

Still, McManus says, it’s too soon to celebrate the single-tunnel idea. Having a single tunnel is not a definitive indicator that less water will be transported South, or that the natural ecosystem will be less damaged than it would have been with two-tunnels. Until the Department of Water Resources conducts its environmental analysis of the new plan — which could take some time — the effects of implementing a single tunnel remain unknown. As McManus puts it, “The devil is in the details.”  

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