The Newsom Administration officially ended plans to build the Twin Tunnels, a river water bypass 40 miles around the Delta. However, it still wants to build one of the tunnels.

Department of Water Resources Director Karla Nemeth made the announcement on May 2.

Agencies, including Zone 7 Water Agency, had endorsed the Twin Tunnels approach, stating that they were necessary to provide enough water for the Valley long term. Zone 7 directors supported the tunnels on a 5-2 vote in 2017.

Even if alternatives were adopted, directors backing the tunnels said that Zone 7 would need Delta water to meet its future needs. The alternatives, such as potable reuse, more local water recycling, nearby local storage at Los Vaqueros Reservoir, and a possible desalination project from ocean or Bay water, would be insufficient.

They also said new alternatives would be much costlier than the tunnel approach.

Opposing directors said the Zone 7 endorsement of the Twin Tunnels was premature, because more details needed to be known about statewide financing. Water agencies, not state taxpayers, are expected to pay for the tunnels through their water rates. Zone 7, representing only 2% of the participants in the State Water Project, was the first water agency to endorse the Twin Tunnels.

Twin Tunnels backers said that two tunnels, instead of one, were advantageous. If one tunnel were knocked out of commission by an earthquake, the other could back it up, if it were to survive. Even without an earthquake, two tunnels would allow dropping one out of use for maintenance.

However, critics of Twin Tunnels throughout the state said that eliminating one tunnel would save at least billions of dollars in construction costs. The price tag for the Twin Tunnels was $17 billion, but critics claimed it would be much higher.

Those backing the whole Twin Tunnels project, called the WaterFix, make the underlying argument that water agencies will need the tunnels to shift water around the Delta, inserting it at the south Delta water pumps, so that fish and plant habitat are not disturbed at critical environmental times. The project would pipe the water directly to the pumping plants, without sucking spawning fish into the pumps.

Opponents say that the diversion around the Delta would still leave the Delta with a lower fresh water contribution for plant and fish life, bad for sensitive species. Choosing alternative methods to conserve on consumption and reuse water would be better to meet needs created by the future California population expansion.


One of the organizations favoring development of alternatives includes Restore the Delta (RTD), which is based in Stockton. It represents many Delta farmers, farmworkers, food canners and packers, sport fishers, commercial fishers, and species-protecting conservationists in the Central Valley. Sympathetic members in other parts of the state, including the Tri-Valley, have also joined the organization.

RTD Executive Director Barbara Barrigan-Parrilla said the organization likes DWR’s decision to withdraw its environmental application for the Twin Tunnels.

“We are relieved that our coalition’s critique of the California WaterFix to the State Water Resources Control Board was taken seriously,” said Barrigan-Parrilla. She promised to collaborate and participate in “as many processes as possible, and we will support other communities in California working on regional water solutions.”

RTD has indicated in the past that it does not approve of one tunnel either. Barrigan-Parrilla said, “Naturally, as Delta people, we don’t care for tunnels, but we look forward to engaging in an honest and transparent public process that helps move us towards the co-equal goals of the Delta Reform Act of 2009, including reducing reliance on the Delta.”