Brisbane accepts public tree inventory, adopts 23% citywide canopy goal

Brisbane City Council voted on May 21 to accept a new public tree inventory and three‑phase tree management plan, receive a staff demonstration of an interactive Tree Hub, and adopt a recommended citywide canopy goal of 23 percent by 2040.

"The good news is that Brisbane's tree population is largely healthy and diverse," Sustainability Manager Adrian Etherton said during the presentation. He told council the inventory and canopy assessment were produced with Planet Geo and a field inventory that recorded 4,720 city‑owned trees across roughly 180 species, with an average diameter of about 12 inches.

GIS Manager Bob Sage demonstrated a public Tree Hub site that displays individual tree records, health dashboards, and a volunteer vine‑management app that lets volunteers register, sign a liability waiver and update the inventory in real time. Sage described how the hub supports targeted volunteer efforts and helps Public Works coordinate maintenance.

Etherton summarized the city's canopy modeling: canopy rose from about 9% in 2010 to 13% in 2022, but gains and losses vary across neighborhoods. Staff and the Open Space and Ecology Committee recommended a citywide goal of 23% by 2040; Etherton said meeting that target would require planting an estimated 13,000 trees over 15 years (more than 8,000 in the Baylands and roughly 280 trees per year across public and private lands elsewhere).

The presentation included a management‑cost estimate. "The total estimated cost of about $510,000 does not actually include the replanting needs," Etherton said, explaining that the number covers prioritized maintenance phases focused on public safety and long‑term health, and that replanting and incentives will require additional funds.

Council members pressed staff about specific issues: whether the inventory included the Ridge and the Brisbane Acres (staff said the field inventory and canopy mapping use different datasets and that validation is needed), how utility conflicts would be handled (staff proposed a field verification project before forwarding a refined list to PG&E), and whether mortality and replacement cost estimates are realistic (Etherton said a default mortality value came from Planet Geo and will be refined over time).

Public comment came from Michelle Salmon, an Open Space and Ecology Committee subcommittee member, who described volunteer work on watering and vine removal, urged careful species selection for replacements, and asked the city to develop liability waivers and volunteer coordination to accelerate planting and maintenance.

The motion to accept the public tree inventory, management plan and hub site and to adopt the 23% canopy goal passed by voice vote with no recorded opposition.

Next steps spelled out by staff included integrating the Tree Hub with Public Works work‑order systems, validating proposed planting sites in the field, sending a refined list of utility conflicts to PG&E for action, working with community partners on volunteer programs and incentives, and reporting back annually on progress toward the canopy goal.