Delta Conveyance Project
Zone 7's estimated share of the Delta Conveyance Project is $443 million, funded through water rates over the life of the project. I support hardening the conveyance against a major seismic event. I do not support operating rules that raise Delta salinity or trade Delta water quality for export volume. Each funding vote deserves its own public comparison of engineering, ecological, and cost accounting.
My position
I support hardening the conveyance so Tri-Valley imports survive a major seismic event. I do not support operating rules that raise trade Delta water quality for export volume. Each funding vote must show the ecological and cost accounting on the same page as the engineering case.
The project and the numbers
The Delta Conveyance Project is a proposed 45-mile, 36-foot-diameter tunnel beneath the Sacramento-San Joaquin Delta. Zone 7 is one of eighteen participating water agencies at a 2.2 percent participation level. Zone 7's share of the total cost is estimated at $443 million, based on DWR's 2023 cost estimate of approximately $20 billion for the full project, without escalation. That figure appears in Zone 7's own FY 2026-27 Ten-Year Water System CIP, adopted by the board in April 2026. Construction would start in 2029 if participating agencies proceed. The project would become operational in 2045. Zone 7's share is paid through water rates, not bonds.
The board has already voted up to $7.55 million in Delta Conveyance planning costs across actions in November 2020 and 2022. After a pause in funding, in June 2025 the agency executed an amendment to the funding agreement of up to $6.6 million for pre-construction work in calendar years 2026 and 2027. DWR anticipates an updated cost estimate and financing plan in advance of the participating contractors' decisions to invest further in the project in 2027. The next Zone 7 board will sit through that decision, and the funding votes that follow it.
This is the largest reliability commitment in front of the board, and it belongs in the same comparison as groundwater banking, local storage, and the rest of the reliability portfolio.
The seismic case
USGS estimates a 72 percent chance of a magnitude 6.7 or greater Bay Area earthquake by 2043. Many Delta islands sit 25 feet below sea level on subsided peat soils. A major quake could breach levees, flood the Delta with saltwater, and cut off Zone 7's Delta-sourced water for months. Today, that water travels through a single pumping plant, the Harvey O. Banks Pumping Plant near Tracy. One quake, one plant, one supply. That is the case Zone 7 has made for the tunnel, and on the seismic math alone, it is a serious case.
The questions that still need answers
A tunnel does not create new water. It redirects existing Sacramento River flows before they reach the Delta, which shifts the freshwater balance downstream and carries consequences for farming communities, drinking water, and the estuary ecosystem. The Delta Counties Coalition has argued the project delivers only a 23 percent volume improvement to the State Water Project if operated as described in the Final EIR. Zone 7 is about to commit ratepayer dollars across a multi-decade timeline, and those questions should be on the same ledger as the seismic risk the tunnel is meant to solve.
What I will do on the board
- Do the homework before every funding vote. Read the Final EIR, the project cost updates, and the opposition technical filings. Ask Zone 7 staff for a written explanation of how the seismic, cost, and environmental tradeoffs are being weighed against each other, in one document ratepayers can read.
- Ask for an independent comparison of what Zone 7's $443 million estimated share would fund if redirected to local alternatives: groundwater banking expansion, PFAS-cleared well capacity, and stormwater capture. I want the numbers in front of the board before any further funding increase is approved.
- Push for a Zone 7 Delta resilience plan that works whether the tunnel is built or not. Either way, the Tri-Valley should not be one earthquake and one pumping plant away from running dry.
- Insist that ecological impact stays on the ledger. The Sacramento-San Joaquin Delta is the largest estuary on the Pacific Coast and a critical flyway for migratory waterfowl and shorebirds. Any infrastructure decision of this scale must account for downstream freshwater flows, salinity, wetland habitat, and the health of the ecosystem that millions of Californians, and the state's wildlife, depend on. Responsible stewardship means weighing seismic resilience and ecological resilience on the same page.