The California Delta Stewardship Council voted six to one last week to advance Gov. Gavin Newsom’s Delta Conveyance Project, a half-century infrastructure plan to build a 45-mile tunnel around the Sacramento-San Joaquin Delta. The council’s vote conditions the project’s advancement on the Department of Water Resources (DWR) resolving outstanding environmental conflicts and land-use disputes before construction can begin.
While Governor Newsom hailed the vote as proof that the state is “closer than ever to seeing this important piece of infrastructure completed,” water policy experts and Delta residents say the tunnel still faces financial, legal, and political hurdles of a different magnitude. The project remains mired in a statewide water war over cost allocation, unresolved water rights, and whether the next administration will maintain the current push.
The Delta Stewardship Council, whose seven members include four Newsom appointees, was tasked with weighing opponents’ many challenges to the project. The board ultimately required DWR to address just two issues. Among the most significant is a siting conflict with Harvest Water, a major agricultural recycled water initiative that has received more than $400 million in state funding. DWR plans to place a nearly 600-acre construction complex and a permanent 214-acre mound of excavated tunnel materials on land adjacent to the Harvest Water project footprint.
Carrie Buckman, the DWR environmental program manager for the tunnel, disputed staff assessments of the conflict in a letter to the council but said the department would “work promptly” to address the council’s directives. Legal representatives for tunnel opponents celebrated the mixed victory, with attorney Kelley Taber calling the siting conflict the project’s “most obvious fatal flaw.”
The financial pathway for the tunnel remains legally uncertain. State water managers originally intended to issue revenue bonds repaid by water agencies receiving tunnel water and their customers. A trial court ruled that the water code did not grant DWR “carte blanche to do as it wishes,” finding the financing plan exceeded its delegated authority. The Third District Court of Appeal agreed, and in April, the California Supreme Court declined to review the case.
Buckman said the department still plans to issue bonds and is determining its next steps. No water agency has committed to paying for the project, and legal representatives for tunnel opponents argue agencies will not commit until DWR resolves the financing authority. The federal government and major irrigation districts have already opted out of the tunnel, shifting the financial burden to urban water suppliers. The Metropolitan Water District, which supplies half the state’s population, is already funding nearly half of the tunnel’s planning costs but is expected to vote on shoulder construction costs in 2027.
DWR estimates the 45-mile tunnel will cost $20.1 billion, though an economic assessment commissioned by opponents places the total impact between $60 billion and $100 billion. Delta communities characterize the plan as a water grab that would devastate one of the nation’s largest estuaries. Residents fear that diverting freshwater will push the fragile Delta ecosystem past a tipping point, exacerbating algal blooms, degraded water quality, and fish species declining toward extinction.
Duane Martin Jr., a third-generation cattleman in the Delta, expressed frustration over the prospect of heavy truck traffic, concrete batch plants, and the permanent muck pile planned for grazing lands. “Nobody seems to care about the people out here on the ground,” Martin said. He expects the state to use eminent domain to acquire the necessary land. “They’re gonna have to take it,” Martin said. “I ain’t about to quit. I’m a fighter, and I’m going to stay here and fight for it to the death.”
With Newsom in his final year as governor, the project’s political trajectory remains unclear. Jeffrey Mount, a senior fellow at the Public Policy Institute of California, called the remaining obstacles “existential,” though he noted that construction is likely inevitable across generations.
“If you don’t build it in this generation, you’ll build it in the next,” Mount said. “Build a tunnel, or start a very painful process of really cutting back on water supplies from the Delta.”
Whether the next governor maintains Newsom’s aggressive timeline will depend on upcoming leadership appointments. “Whoever they appoint, that is really where it happens,” Mount said. “It’s hard for me to imagine that if Brown and/or Newsom weren’t all in on this, it would have gotten this far.” State regulators are holding hearings through the summer to decide whether to grant DWR the water rights necessary to divert Sacramento River water into the proposed tunnel intakes.