SFPUC outlines options and trade‑offs to reduce San Francisco flooding; supervisors press for targeted solutions

The Public Safety and Neighborhood Services Committee on April 12 heard an extended presentation from the San Francisco Public Utilities Commission (SFPUC) on short‑ and long‑term strategies to reduce storm flooding in low‑lying neighborhoods. General Manager Harlan Kelly Jr. and project manager Stephanie Harrison outlined the engineering constraints, potential projects and policy options, and fielded sustained questions from supervisors and residents about cost, equity and timing.

Harrison described San Francisco's combined sewer system and the design‑storm framework SFPUC uses to evaluate investments. She said the SFPUC's analysis shows it would cost roughly $2.3 billion in sewer system investments to meet a citywide 5‑year storm level of service and roughly $15 billion to reach protection against a 100‑year event; a 10‑year level was shown on study slides at about $3.7 billion. Harrison emphasized those figures are funded from sewer ratepayer dollars, not general tax revenues, and that projects targeted at particular corridors can still drive citywide costs because conveyance must be maintained to treatment plants.

Residents and neighborhood groups provided lengthy public comment describing repeated basement backups, mold and health impacts, damaged vehicles and property loss. Speakers from Cayuga, Mission Terrace, Sunnyside and other neighborhoods urged faster, focused action and criticized what several described as decades of underinvestment in the hardest‑hit areas.

Key policy and program points from the hearing:

- Short‑term operations and maintenance: SFPUC crews conduct sewer inspections and cleanings, deploy barriers and provide emergency response and sandbags (SFPUC reported delivering over 1,200 sandbags this season).

- Grants and property‑scale measures: SFPUC has a flood grant program that reimburses up to $30,000 per property for eligible measures such as backflow preventers and barriers; staff reported about $140,000 in grants paid and roughly $60,000 in applications under review.

- Neighborhood projects and costs: Harrison described local projects at Forrester & Mangels (sewer upsizing with construction expected before the next rainy season), Wawona & Fifteenth (larger project requiring more planning), and two alternatives under study for Seventeenth & Folsom with estimated construction costs in the range of $150–200 million to achieve 5‑year protection for that area. A concept for the Cayuga/Alemany corridor was estimated at roughly $350 million at the concept level and remains in planning.

- Policy options under evaluation: SFPUC is considering policy tools including targeted flood‑resistant building standards for redevelopment, disclosure at point‑of‑sale, larger grants to elevate or flood‑proof structures, and selective voluntary property acquisition programs.

Supervisors pressed SFPUC on whether it is possible to concentrate investment on the ~1% of the city that experiences severe flooding. Harrison and GM Kelly explained that, because the sewer network is a linear conveyance system, piecemeal upsizing can shift problems downstream unless downstream conveyance is also addressed; corridors that drive costs can make targeted investments nearly as expensive as broader upgrades. Kelly said staff are working to balance rate impacts and neighborhood benefits and asked for more time to return with a menu of options.

Residents raised a set of claims and demands in public comment: some alleged past budget reallocations (one public speaker said $400 million earmarked for Alemany/Cayuga was removed in 2012) and asked SFPUC to produce documents; SFPUC said it would check records and follow up. Residents also requested clearer timelines and stronger mitigation support for households still suffering mold and property damage.

Committee direction and next steps: Supervisors asked PUC staff to return with more concrete options and a timeline; SFPUC staff said they expected to present a more developed menu of options to their commission, the Board and the Mayor by July–August and commit to working with the Board. The committee moved to continue the item to the call of the chair and the motion passed without objection.

Quotes and illustrative remarks:

"To get the city up to our 5 year storm level of protection, we're already looking at spending $2,300,000,000," SFPUC project manager Stephanie Harrison said during the presentation. "If we want to have a higher level of flood protection up to the 100‑year storm, it would cost us something like $15,000,000,000."

Local resident testimony illustrated the human impact: "I've been through hell…My house still smells like mold. I have a grandson that has asthma," a Cayuga resident told the committee.

What remains unresolved: whether the highest‑priority corridors can be upgraded without disproportionately increasing rates, the precise funding mix for major projects, and documentation about past project programming that residents asked SFPUC to produce.

The committee will revisit the topic when SFPUC returns with the requested menu of targeted and citywide options; the chair committed to scheduling the hearing as soon as materials are available.