Final report released on disputed delta tunnel
California's water agency released a final environmental report on the controversial plan to build a tunnel beneath the SacramentoSan Joaquin River Delta. The highly anticipated document is expected to lead to approval of the long-disputed water project.
State officials said the Delta Conveyance project will slow a long term decline in water supplies by capturing more water during intense storms. They estimate the project would yield about 500,000 acrefeet of water per year a significant amount but a fraction of California's annual water needs.
“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.”
The report is an updated final version of a draft Delta Conveyance environmental impact report released in July last year, including responses to hundreds of public comments. Its release concludes a lengthy review process under California's Environmental Quality Act and a major step toward finalizing the plan that would
fundamentally overhaul California's system of water management.
Gov. Gavin Newsom has prioritized the project as part of his water policy agenda, 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.”
Delta farmers, Native American tribes and environmental groups continue to vigorously oppose the plan. They say drawing freshwater from the historic region coupled with years of construction will endanger native fish, imperil farms and destroy vulnerable communities.
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.
They say the proposed tunnel is intended to slow that decline. It would capture water further upstream on the Sacramento River instead of letting it course through the Delta, bypassing the estuary and funneling supplies directly into the state aqueduct.
This final report is a response to comments based on a draft released last year.
In that report, state officials said the project could harm endangered and threatened species, including the Delta smelt, winter-run chinook salmon and steelhead trout. The draft also faced criticism for basing its estimates on historical water supply data, rather than models that factor in supply shortages due to climate change.
Carrie Buckman, environmental program manager for the project at DWR, said the project is meeting regulatory protections for fish and water quality. She also said the final report's appendices now include conditions where climate change has been factored in.
“We did analyze the potential for effects to fish,” Buckman said, “and we mitigated the effects that we found by avoiding or reducing them where we can.”
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.
In May, an advocacy group urged the Metropolitan Water District of Southern California to abandon the expensive project, saying it would not make water supplies much more reliable and would drive up costs for ratepayers.
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.