Sonoma Water wins board approval for 2025–26 sewer rate increases; capacity charge hike deferred

The Sonoma County Board of Supervisors on Tuesday approved a package of sewer service charge increases for eight sanitation districts and zones managed by Sonoma Water and authorized a $600,000 Sanitation Rate Relief Program, but decided not to adopt proposed increases to capacity charges and instead maintain current charges while staff completes further study.

The action affects Airport, Larkfield‑Wikiup, Geyserville, Penngrove, Sea Ranch and the county sanitation districts for Occidental, Russian River, South Park and Sonoma Valley. Sonoma Water staff told the board the yearly sewer service increases range roughly from 3.5% to 8.9% across the districts and zones, translating to monthly rate increases of about $4 to $16 for district customers and about $9 to $14 for zone customers. The board also approved continuing the Sanitation Rate Relief Program for qualifying households using up to $600,000 from Sonoma Water’s general fund.

Why it matters: Sonoma Water said increased costs reflect inflation, supply‑chain pressures, rising regulatory demands, water‑quality work and aging infrastructure — some facilities are 40 to 70 years old. Board members and affordable‑housing advocates warned that steep, uneven capacity charges could stall housing production and small business activity, and asked staff for a fairer, more targeted approach before imposing higher connection fees.

Sonoma Water’s presentation and staff comments: Lynn Roselli, Sonoma Water financial services division manager, told the board that grants and Sonoma Water general‑fund support have significantly reduced rate impact: over the past five years Sonoma Water contributed about $18 million from its general fund and secured roughly $13 million in grants for the districts and zones — roughly $31 million in outside support, Roselli said. She said capacity charge increases were proposed after a Bartle Wells Associates study that showed existing charges had not kept pace with replacement‑cost values.

Kent Gilphy, Sonoma Water director of engineering, described the capacity charge study’s methodology. The consultant presented two standard options: Option A, a buy‑in based on reasonable replacement cost of system assets; and Option B, replacement cost reduced by depreciation. Staff recommended Option B as the industry standard because it places a fair share of the value of existing facilities on new connections while reducing the immediate burden on new development compared with Option A. The proposed effective date for new capacity charges was July 1, 2025.

Board discussion and decision: Supervisors expressed broad support for the sewer service increases and the relief program but many voiced concerns about the capacity charge proposals. Chair Hopkins said, “I can't support the capacity charges as proposed because I do think that it will cause an undue burden on businesses and homeowners at this point in time,” and asked staff to return with additional options and outreach. Supervisor Gore said she favored maintaining the status quo on capacity charges while the county conducts a more detailed proportionality study.

Public comment: Generation Housing representatives and local housing advocates urged the board to postpone capacity charge increases, saying higher connection fees would undercut the board’s recent impact‑fee reforms intended to spur affordable housing. Protest returns under Proposition 218 were small overall; Sonoma Water reported 241 signed protests received across all districts and zones (out of roughly 18,800 mailed notices), with Occidental registering the highest protest percentage at 11.1% (no district reached the 50%+1 threshold required to block the charges).

Formal actions taken: The board adopted the resolutions and ordinances to set sewer service charges for the eight districts and zones and authorized Sonoma Water to continue the Sanitation Rate Relief Program using up to $600,000 from Sonoma Water’s general fund. The board also voted to maintain current fiscal‑year 2024–25 capacity charges (do not implement the consultant’s proposed increases) and directed staff to return with a more detailed nexus/proportionality study and outreach plan before considering capacity charge changes.

What’s next: Staff said a more comprehensive rate and ESD (equivalent single‑family dwelling) study is planned for later this year; supervisors requested that Sonoma Water accelerate work on master plans and regionalization options, and prioritize strategies to protect housing affordability and small businesses while addressing deferred maintenance and resilience of sanitation infrastructure.