SFPUC outlines long‑term water supply strategy, stresses storage and risk planning

Assistant General Manager for Water Steve Ritchie told the San Francisco Public Utilities Commission that the agency plans for the long term and that storage is central to ensuring reliability.

"We have to provide service in perpetuity," Ritchie said, describing a system that supplies about 2,700,000 people and that relies roughly 85 percent on the Tuolumne River and 15 percent on local reservoirs. He said SFPUC planning is guided by a "water‑first" policy, institutional experience from the 1970s–1990s droughts and formal risk management that assumes "there will always be a worse drought someday." Ritchie said the commission uses an 8.5‑year drought scenario derived from the water supply improvement program environmental review as a planning tool to test system responses and options.

The briefing explained the legal and contractual constraints that shape operations. Ritchie said San Francisco's water rights on the Tuolumne River are junior to irrigation districts and noted the city operates under a…