Glen Canyon Park Wildfire Risk: What San Francisco Will and Won’t Do About Its Eucalyptus

San Francisco plans to thin brush and raise the lower branches of eucalyptus trees in Glen Canyon Park after a civil grand jury warned that the 66-acre canyon carries a wildfire risk. The Board of Supervisors this week agreed to act on the June 2026 report, the San Francisco Examiner reported on October 2. The city’s formal written response, signed in August by Mayor Daniel Lurie and four department heads, shows a narrower set of firm commitments than the headline suggests: a handful of items will happen, two will not, and most are listed as needing further analysis.

What the grand jury found

The 2025-2026 Civil Grand Jury’s report, titled “Red Flag Warning: Wildfire Risk in San Francisco’s Glen Canyon,” was released in June. According to ABC7’s report on June 25, the canyon is dominated by blue gum eucalyptus, an Australian species planted in the late 1800s. The report cites an evaluation that found 80% of 427 eucalyptus trees in poor condition as of 2012. It also notes that the canyon has two fire hydrants, and that a nearby 75,000-gallon cistern would run dry in about 50 minutes at typical pumping rates.

The jury did not call for clearing out the eucalyptus. Removing every tree on the steep slopes could cause landslides, so the report recommends clearing brush and fallen debris, removing diseased trees, and raising lower branches so a ground fire has a harder time reaching the canopy. “Taking out all the eucalyptus trees is not optimal,” Public Works spokesperson Rachel Gordon told the Examiner.

What the city has committed to

The city’s response, dated August 3, 2026 and posted as a PDF on sf.gov, was signed by the mayor and the heads of Recreation and Parks, the Fire Department, Public Works and the Public Utilities Commission. It partly disagrees with most of the jury’s findings. Among other points, it notes that CAL FIRE rates San Francisco’s wildfire risk as low and that coastal conditions slow how quickly vegetation ignites. It agrees with the finding that the Fire Department has already taken preparatory steps.

The firm commitments in the response are:

• Recreation and Parks will update its fire abatement best-practices web page by January 30, 2027.
• The Fire Department will write after-action summaries of its wildland-urban interface drills and share them with Public Works, the PUC and Recreation and Parks.
• Already in place: Recreation and Parks says replacing non-native trees with native species is its general practice in natural areas, and the Fire Department’s wildfire page already carries defensible-space guidance for residents.

The Examiner adds that Public Works crews will remove brush that could ignite quickly and raise the lower branches of some trees. The PUC, which manages part of the Islais Creek watershed that runs through the park, will hold its second annual restoration work party this winter.

What the city will not do, or has not decided

Two recommendations will not be carried out. The city declined to have Recreation and Parks sign a formal agreement with Public Works, the PUC and the school district for shared vegetation management, saying coordination continues informally and added resources are not justified. Items assigned to the Urban Forestry Council were also dropped, because the council ceased operating on June 30, 2026.

Most of the rest is marked “requires further analysis,” with target dates in 2027. That list includes a CAL FIRE training agreement for city crews, planting native understory after eucalyptus trimming, written wildfire mitigation plans for each department, putting Recreation and Parks’ tree inventory online, and expanding Fire Department wildland drills to Twin Peaks, Mount Davidson, Laguna Honda and McLaren Park.

Where it stands at City Hall

The Board of Supervisors’ Government Audit and Oversight Committee calendared a hearing on the report (File 260649) and the board’s formal response to the Superior Court (File 260650) for its September 17 meeting. That resolution urges the mayor to have department heads carry out the findings and recommendations the city accepted. The city’s own response sets out which ones those are.

If you use Glen Canyon Park

The response and the Examiner’s report do not announce any trail closures. Expect to see crews thinning brush and trimming trees as the work proceeds. If you live near the canyon or any of the city’s other wooded hillsides, the Fire Department’s wildfire page explains defensible space around homes. For the other half of the seasonal picture, our guide to getting ready for El Niño storms covers free sandbags and flood maps.

Photo: Calbookaddict, CC BY 3.0, via Wikimedia Commons.