California’s final report on disputed Delta tunnel project shows fish and farms still at risk

California’s water agency released a final report Friday on the controversial plan to build a tunnel beneath the Sacramento-San Joaquin River Delta. The highly anticipated document is expected to lead to approval of the water project.

The environmental impact report said the tunnel’s construction and operations would significantly impact the Delta’s endangered and threatened fish species, tracts of important regional farmland and tribal cultural resources that include human remains.

State officials say some of those impacts will be mitigated, and that the Delta Conveyance project is needed to slow a long term decline in water supplies by capturing more during intense storms for southern California cities and farms.

“This is a project that generates a lot of controversy and intense feelings,” said Karla Nemeth, director of California’s Department of Water Resources. “But it’s just one part, a very critical part, of how we put together California’s water system to ensure that communities have a secure water supply into the future.”

This final, two-volume report outlines the proposed path of a 45-mile tunnel that would pipe water from the Sacramento River, bypassing the Delta, and funnel it into Bethany Reservoir, the “first stop” on a state aqueduct that carries water south.

It’s an updated version of a draft environmental impact report released last year, including responses to hundreds of public comments. The final report’s release concludes a lengthy process under the California Environmental Quality Act and a major step toward finalizing a plan to overhaul the state’s system of water management.

The report summary said the project and proposed alternatives would result in significant impacts to winter-run and spring-run Chinook salmon, Central Valley steelhead, and Delta and Longfin smelt.

To offset impacts to threatened or endangered fish, the agency has said it would restore up to 3,500 acres of wetland habitat by breaching or setting back levees.

The project will also convert significant amounts of farmland of statewide importance, the report concluded. Impacts to tribal cultural resources, including burial grounds, caused by construction were described as “significant and unavoidable.”

For decades, water has been pumped directly out of the Delta and shipped south to 30 million Californians and 6 million acres of farmland. But state agencies predict that climate impacts and environmental regulations will lead to a decreasing supply.

State officials say the proposed tunnel is intended to slow that decline by capturing water further upstream on the Sacramento River, bypassing the Delta estuary and funneling supplies directly into the State Water Project. They estimate the project would yield about 500,000 acre-feet per year — a significant amount but a fraction of California’s annual water needs.

Delta farmers, residents, regional Native American tribes and environmental groups vigorously oppose the plan.

Opponents say drawing freshwater from the historic region coupled with years of construction will endanger native fish, imperil farms and destroy vulnerable communities. Those communities, they added, were excluded from the development of Newsom’s water agenda.

This summer, the Environmental Protection Agency said it would investigate a civil rights complaint filed by a coalition of tribes and environmental justice organizations over alleged discriminatory mismanagement of water quality in the Delta.

“Governor Newsom’s proposed Delta tunnel, as outlined in this new EIR, is another failure of state water officials to imagine alternative approaches in a climate-impacted California,” said Barbara Barrigan-Parrilla, executive director of Restore the Delta.

“This is sadly just another zombie version of the Peripheral Canal idea that was rejected by California voters way back in 1982. And DWR seems to have learned nothing since California Governor Brown’s Twin Tunnel (WaterFix) died in 2019.”

Gov. Gavin Newsom has continued prioritized the Delta Conveyance project as a cornerstone of his water policy agenda despite that opposition, which also includes the Sites Reservoir and voluntary cutback agreements with major water users. He called the project an “essential update” needed to protect against a catastrophic earthquake and impacts of climate change.

“Doing nothing is not an option,” Newsom said in a written statement. “After the three driest years on record, we didn’t have the infrastructure to fully take advantage of an exceptionally wet year, which will become more and more critical as our weather whiplashes between extremes.”

The Delta, the central hub of California’s water system, is a giant network of waterways, sloughs, and islands at the confluence of the Sacramento and San Joaquin rivers. It’s home to hundreds of thousands of people and 415,000 acres of farmland, but its fragile ecosystem has been deteriorating for years as more water is exported or used upstream.

Plans to replumb the Delta have been decades in the making, changing shape over time from a canal to twin tunnels to, eventually, a single tunnel that Newsom promoted when he took office.

The last time California finalized an environmental impact report for it was in 2016. That project, which constituted a pair of tunnels, stumbled amid high costs and Newsom eventually withdrew support.

The price tag will be in the billions. In 2020, the estimated cost of one of the alternate paths was just under $16 billion. Bonds will be issued to fund design and the construction process, and beneficiary water agencies across the state will pay a significant portion.

Investment from agencies such as Metropolitan Water District of Southern California would be critical. In May, an advocacy group urged the to abandon the project, saying it would fail to make water supplies more reliable and drive up costs for ratepayers.

In a statement Friday, general manager of MWD Adel Hagekhalil said the tunnel project could be part of a “balanced, holistic solution” for capturing water during times of high flow.

“We look forward to reviewing the findings in the environmental documents released today, along with additional information that will be provided in the future, including a cost-benefit analysis,” he said. “All of this will inform Metropolitan’s Board of Directors in determining how best to invest our resources.”

If approved, the project would take decades more to complete. The permitting process itself, which includes a water rights hearing at the state Water Board, could last years. Construction is estimated to take another 12 to 13 years to complete.

In 10 days, DWR will determine whether to certify the final report and approve the proposed project. That will launch a months long permitting process on endangered species and water rights. An updated cost estimate is expected next year.