PUC seeks up to $4 million to repair Stern Grove after pipeline valve failure; supervisors add reporting requirement

The Public Utilities Commission asked the Budget & Finance Committee to approve a declaration of emergency and associated emergency contracts to repair damage at Stern Grove caused by a failed air valve on a city transmission pipeline.

PUC construction manager John Scarpulla said crews responding to the Aug. 23 failure found extensive erosion, silted culverts and structural damage to backstage buildings and pathways. He estimated the failure released about 700,000 gallons of water, damaged roughly 60–63 trees and required removal of debris from the concert meadow. PUC said it is working with Hernandez Engineering and Anvil Builders and presented an estimated emergency repair budget not to exceed $4,000,000. Scarpulla broke the estimate into roughly $1,000,000 for soil and tree removal, $2,500,000 for slope stabilization and tree replanting, and $500,000 for meadow and concert infrastructure restoration.

PUC staff described steps already taken — fencing and site security, removal of approximately 1,500 cubic yards of soil, interior building remediation, storm‑drain cleaning and temporary slope stabilization — and said geotechnical surveys and slope design work are underway. The department projected work would be completed in time for the 2022 Stern Grove concert season (spring 2022).

Supervisors asked about whether similar maintenance work might pose risks elsewhere on the San Andreas pipeline system; Katie Miller, director of water capital programs, said the affected air valve was old (part of San Andreas pipeline no.2, installed in 1928) and that PUC will conduct lessons learned including consideration of depressurizing before certain maintenance tasks. PUC and contract managers also told supervisors both chosen contractors use union labor and that standard contract clauses will be included in the emergency contracts where appropriate.

Budget and Legislative Analyst staff recommended approval of the emergency authorization but noted the main contract was not final for review. Multiple supervisors urged adding a requirement that PUC and Recreation & Park provide a documented completion report that includes photos and lessons learned; the committee adopted that amendment and then forwarded the emergency declaration to the full board with a positive recommendation (3 ayes).

What’s next: The committee approved the emergency declaration with an added reporting requirement and forwarded the item to the full Board of Supervisors.