Bellevue commission hears water system plan update as city eyes capacity, storage and conservation

Bellevue’s Environmental Services Commission on May 1 received an informational briefing on the city’s water system plan update and discussed population-driven demand, storage capacity and policy choices that will guide utility decisions through mid-century.

Utilities Planning Manager Eric LaFrance told the commission the two-year update — the first comprehensive review since the 2014–17 cycle — is legally required and will re-evaluate system description, capacities and demand projections. "This effort improves our efficiency and minimizes costs and protects the community," LaFrance said.

Why it matters: staff reported the city’s service-area population has outpaced prior projections — a 2024 report exceeded older projections by about 10,000 people — and planners expect roughly 75,000 more people in the service area by 2044. LaFrance said that while population growth has been strong, per-capita retail water use has declined over decades, noting annual retail consumption fell from about 5.1 billion gallons to 4.8 billion gallons in recent years.

The presentation described the system’s physical footprint (roughly 36 square miles of service area, about 41 million gallons of storage spread across 24 reservoirs) and stressed trade-offs in reservoir siting and size. "Place it too high above the homes, and the pressure in the pipes can be damaging. Place it too low, and there's not enough pressure to fight fires," the presenter said, describing the "sweet spot" planners seek for elevation and capacity.

On fire protection, commissioners asked whether recent wildfire trends should prompt higher fire-suppression storage standards. The presenter answered that the current standard in the plan is one day of storage and that moving to two days would substantially increase storage needs and likely require many more reservoirs; staff said they will return this fall with policy recommendations.

Commissioners also questioned how the plan accounts for large single customers and commercial uses. Staff said standard demand factors are applied for projections but that large industrial or bottling operations are treated as special cases requiring direct coordination; staff cited the closure of a paper mill that had used millions of gallons a day as an example of a single large-customer change.

On treatment questions, staff clarified that fluoride is added at the regional treatment plant operated by Seattle Public Utilities and delivered to Bellevue via Cascade Water Alliance; Bellevue does not add fluoride at its own plants, staff said.

Public comment and other business: during oral communications, Alex Zimmerman spoke for several minutes expressing personal concerns about water contaminants and health risks; the chair reminded the speaker of rules limiting electioneering after the speaker referenced local elected figures. Director Lucy Liu and staff also recognized Chair Vanya Nezovic for eight years of service to the commission, highlighting her role on rate-setting and the emergency water supply master plan.

Next steps: staff said the heavy analysis for the water plan will occur this year, will include coordination with other agencies and lead to a draft plan for review in early 2026; final approval will follow city, county and state reviews. The commission did not take formal action on policy at the May 1 meeting.