San Francisco’s Stern Grove Balloon Repair Costs $20 Million, 5 Times Original Estimates

The cost to repair flood-damaged Stern Grove in San Francisco has soared to $20 million, according to a recent report by the San Francisco Public Utilities Commission, five times the $4 million originally estimated by the authorities. city ​​officials.

The concert hall hill was washed away after an air relief valve failed during maintenance on a 54-inch-diameter water main last August.

About 700,000 gallons of fresh drinking water poured down Sloat Boulevard and into the bowl just before the last concert of the season. The escaping water washed away the tennis courts before continuing down the hill at the southern end of the grove, washing away 63 eucalyptus trees and a footbridge before leaving a layer of mud up to 4 feet deep in the concert meadow.

The elevated stage was mostly unscathed, but the backstage buildings also suffered water damage. The final show, featuring funk band Tower of Power, was cancelled. The 2023 season will open as scheduled on June 12, but signs of the flood and its ongoing repair will be visible to spectators descending the hill from the 19th Avenue entrance to Sloat.

“I was worried it would be a disastrous event for the venue, and it turned out to be the case,” said Bob Fiedler, executive director of the Stern Grove Festival. “There will be parts that will be changed forever. In our lifetime, it will never be as beautiful as before.

A representative for SFPUC, which oversees the city’s water system, did not immediately respond to a request for comment. According to a report the agency submitted to the board of supervisors last month, the initial estimate of $4 million for repairs was made within 48 hours of the flooding and before the damage could be fully assessed.

Since then, a major sewer line has been identified within the right-of-way of the existing embankment. Although it was not damaged by the flood, the sewer will need to be reinforced and protected, according to the SFPUC report. Then the hillside and the retaining wall will have to be completely rebuilt to protect against future erosion.

While the original tree clean-up and removal project was worth just under $3 million, on March 30 the repair contractor submitted an additional estimate of $17 million. Restoration of the slope alone will cost $4.5 million, and shoring of the sewer line is estimated at $3 million.

Located on a steep slope at the northwest corner of 19th Avenue and Sloat Boulevard, Stern Grove is a 60-acre urban park that was donated to San Francisco by Rosalie Meyer Stern in memory of her late husband Sigmund, heir of the wealth of Levi Strauss. . It’s run by the Department of Recreation and Parks, but the non-profit Stern Grove Festival puts on the 10-concert summer season.

In 2005, the Festival invested $15 million in an upgrade that included a new stage, backstage facilities and landscaping designed by famed Lawrence Halprin.

The schedule submitted to the Supervisory Board provides for the tennis courts to be restored by the end of the year and for the hillside to be restored and replanted next year. The entire project is expected to be completed by summer 2023.

The lineup for the 2022 Stern Grove Festival was due to be announced on Tuesday.

Sam Whiting is a writer for the San Francisco Chronicle. Email: swhiting@sfchronicle.com