Many Sources, One Bill: What Zone 7's $874 Million Plan Means for Tri-Valley Water Customers

On April 15, 2026, the Zone 7 Water Agency board adopted a ten-year Capital Improvement Plan totaling $874.7 million across 50 projects. Whether you are a customer of Dublin San Ramon Services District, California Water Service, the City of Pleasanton, or the City of Livermore, that plan will reach your water bill. How fast, how visibly, and how large the impact depends on who your retailer is and on a wholesale rate forecast Zone 7 has not yet published.

Many sources is the strategy

Zone 7 draws water from several sources: the State Water Project imported through the South Bay Aqueduct (roughly 70 percent of supply in a typical year), the Livermore Valley groundwater basin, local surface capture and storage in the Chain of Lakes quarry system, approximately 198,000 acre-feet banked in Kern County, and recycled water managed through retail partners.

The new Capital Improvement Plan adds one new source: Zone 7's share of the Sites Reservoir, a North-of-Delta project that does not depend on Delta conveyance to deliver water to the Tri-Valley. Three other major projects expand or restore existing sources rather than adding new ones:

• Chain of Lakes Conveyance System ($356.5 million) unlocks roughly 36,400 acre-feet of existing local storage capacity.
• Mocho PFAS Treatment Plant ($54.4 million) restores groundwater capacity that would otherwise be lost to contamination.
• South Bay Aqueduct Enlargement ($74.29 million) expands import capacity on the existing State Water Project corridor.

Six sources after the plan is executed. Diversification, not concentration, is the point.

What Zone 7 has committed to, and what it has not

Two years before the Capital Improvement Plan was adopted, Zone 7's board locked in a 5.5 percent annual wholesale revenue adjustment for calendar years 2023 through 2026 (Zone 7 news release). That path was set based on the debt service and operating commitments known in November 2022. It does not account for the decisions adopted on April 15, 2026.

Inside the new plan, $209 million moved from developer-funded accounts to ratepayer-funded accounts compared to the previous plan. That is a structural choice. A larger share of infrastructure cost now lands on existing residents and businesses rather than on new development.

The wholesale rate path for calendar year 2027 and after has not been adopted. Zone 7 has committed the capital. It has not yet published the rate math that will pay for it.

How the plan reaches your bill depends on your retailer

Zone 7 does not send customer bills. Four retailers do, and each handles the pass-through differently.

Dublin San Ramon Services District (DSRSD) serves Dublin and most of San Ramon. Zone 7's wholesale cost appears on every DSRSD bill as an explicit "Zone 7 Cost of Water" line item (DSRSD Rates and Fees). Rates auto-adjust each January 1 by the San Francisco-Oakland-Hayward CPI. Past actions include a July 2019 restructuring that flattened residential tiers to $1.30 per unit (Patch, July 2019) and a November 2021 drought consumption increase of 25.8 percent (CBS News Bay Area). DSRSD customers see Zone 7 decisions with the shortest delay of any Tri-Valley retailer.

California Water Service Company (Cal Water) serves much of Livermore as an investor-owned utility regulated by the California Public Utilities Commission. Rates are decided by the CPUC through General Rate Cases every three years. In the 2021 General Rate Case, Cal Water requested a cumulative 17.6 percent bill increase over 2023 through 2025 for a typical residential customer (CPUC fact sheet, Livermore). The 2024 General Rate Case, now underway, seeks Livermore revenue increases through 2028 and proposes consolidating Livermore with the Dixon district into a new "Diablo Ranch Region" (Cal Water rate case page; Results of Operations filing). A 3 percent interim increase took effect January 1, 2026. Cal Water customers see Zone 7 decisions on a twelve to thirty-six month lag, whenever the next CPUC proceeding reaches a decision.

City of Pleasanton is the most exposed retailer. After PFAS contamination forced the shutdown of Pleasanton's three groundwater wells, the city imports essentially 100 percent of its supply from Zone 7. Following twelve years of inflation-only rates (Pleasanton Weekly deep dive, January 2024), the City Council adopted a two-year catch-up in November 2023 totaling approximately 42 percent cumulative over 2024 and 2025 (Pleasanton Weekly, November 2023), and a four-year package in October 2025 that now recovers 100 percent of Zone 7's fixed costs as a fixed pass-through charge on every bill (Pleasanton Weekly, October 2025; City of Pleasanton press release; current Pleasanton rates). By 2029, some residents see bills up $80 or more versus current. Pleasanton customers see Zone 7 decisions faster and more visibly than any other retailer.

City of Livermore Water Resources (LMW) serves the eastern portion of Livermore. The 2012 and 2013 rate cycle explicitly included a 7 percent Zone 7 pass-through (Livermore Patch, 2013). The 2017 Cost of Service Study governed rates through 2021. The 2022 Cost of Service Study was adopted through Prop 218 and subsequently challenged in court by a local taxpayers' group (Livermore Independent). Current rates are posted on the city's Utility Billing page. LMW's current methodology for passing through Zone 7's 5.5 percent annual adjustments is not clearly documented in publicly indexed sources. LMW customers who want the full picture should request the 2017 and 2022 Cost of Service Studies directly from the city.

A June 2025 Pleasanton Weekly editorial captures how differently two of the four retailers approach Zone 7 billing disputes. That same variance applies to how each retailer will pass through the $874 million plan.

What this means for 2027 and after

Pleasanton customers should expect pass-through pressure on every Zone 7 rate adjustment adopted for 2027 and after, with the size depending on the wholesale rate path the board adopts and the debt service on Capital Improvement Plan bonds. DSRSD customers will see the same pressure arrive through the Zone 7 Cost of Water line item and the annual CPI adjustment. Cal Water customers will see it through the next CPUC proceeding on a lag. LMW customers will see it on a schedule the city has not documented publicly.

Many Water Sources. Solid Planning.

Zone 7's diversification strategy is the right one. Six sources after the plan is executed is better than four or five, and the State Water Project, which delivers only 54 percent of Zone 7's entitled allocation under current conditions, is precisely why diversification matters.

Solid planning means publishing the wholesale rate path for 2027 through 2031 before Zone 7 issues the next round of debt to fund the Capital Improvement Plan. Each retailer will pass that math through to customers on its own timeline and in its own format. None of them can translate a forecast Zone 7 has not yet published. That is the discipline I want to bring to the board.