A water main break at Stern Grove has closed the area "until further notice," and the ensuing water damage has led to the cancellation of the final Sunday concert of the Stern Grove season this weekend. Tower of Power fans, we feel you.

A video posted to Twitter Monday showed an erupting geyser of water at least 30 feet tall, and this apparently flooded Stern Grove to the point of closure to the public. Reportedly, more than 700,000 gallons of water spilled into the Stern Grove park, sending rivers of mud into the stage, seating, and backstage areas of the annual festival (see photos below).

The Rec & Parks Department tweeted Tuesday that both Stern Grove and Pine Lake are closed until further notice due to the ruptured water main.

As the Chronicle reports, crews from the Public Works department and Public Utilities Commission (PUC) have been working on the problem, and the PUC tweeted on Monday about an "air valve" that was in poor condition and needed repair — but nothing about the water main.

It's not entirely clear whether the work at the site caused the geyser, or if this was just a symptom of another problem they discovered while working.

When asked by an SF resident if this was responsible for low water pressure elsewhere in the city, the PUC seemed to confirm that it was, advising anyone who sees brown in their tap water to just let the tap run for a bit — drought be damned.

Oakland's legendary Tower of Power was slated to perform on Sunday along with legendary Oakland rapper Too $hort, and as of Wednesday afternoon, the Stern Grove Festival announced that there will be no final Sunday concert.

In a release, a rep for the festival explained that this weekend's Big Picnic fundraiser and grand finale to the 84th Stern Grove concert season had to be canceled because "the public park has recently experienced such extensive damage that the Festival grounds are now unsafe and unusable for any events in the immediate future."

"We are devastated to announce the sudden cancellation of our season finale and annual fundraiser with Tower of Power and Too $hort," said festival Executive Director Bob Fiedler in a statement. "This was definitely one of our most highly anticipated concerts of an incredible season, but the damage is too severe to move forward safely at this time. We are grateful that no one was hurt, and we are proud to have overcome so many challenges this year to have presented nine exceptional concerts for more than 50,000 people. We look forward to restoring the Grove and being able to welcome the community back next year.”

Photos below show some of the mud and damage.

Photo courtesy of Stern Grove Festival
The backstage area. Photo courtesy of Stern Grove Festival

Fans of the festival are being told to look out for two upcoming one-hour specials on KPIX/CBS SF with highlights from this concert season, which are set to be announced in the coming days.

If you want to help by donating to the non-profit festival, you can do so here, or by texting "sterngrove" to 56512.