Palo Alto is preparing to pass a law next week that would roughly triple the number of trees classified as "protected" and create new requirements for developers and residents looking to uproot these trees.
The City Council will consider on Monday a new tree ordinance to add four native species that are currently not protected: bigleaf maple, incense cedar, blue oak and California black oak. These trees will join a list that already includes the coast live oak, the valley oak and the coast redwood.
More significantly, the new ordinance would specify that all these trees except the redwood would be deemed "protected" when their diameter is 11.5 inches, a standard that today only applies to the coast live oak and the valley oak. For the redwood, the diameter would need to be larger — at least 18 inches — to ensure its protected status. For all other tree species, the diameter threshold would become 15 inches, well below the current standard of 36 inches.
With the new rules in place, the number of private trees in Palo Alto's urban forest that would now be protected would go from the current level of 82,000 to 224,000, according to an analysis by the Department of Public Works. The city's urban forest, which does not include open space preserves, includes about 600,000 trees.
If the council approves the new rules as expected, it would complete a process that began in 2018 and proceeded in fits and starts before accelerating again last fall with the council's blessing. Since early April, the ordinance has gone through numerous public hearings and earned the endorsement of both the city's Architectural Review Board and the Parks and Recreation Commission.
Proponents of the change have argued that the update is long overdue. Even though the city of Palo Alto is named after a redwood tree, it continues to lag behind neighboring jurisdictions when it comes to tree protection, many have noted in recent meetings. Catherine Martineau, executive director of the nonprofit organization Canopy, which worked with the city on the update, was among them.
The new ordinance, she said at a recent meeting, aligns more closely now with what the rest of the region is doing. She described the city's tree canopy as "our only nature-based solution to combat climate change and mitigate the urban heat island effect."
"Residents very often contact Canopy with their concerns because sometimes they're not just concerned, they are distressed about the number of trees that are removed on a regular basis," Martineau said at the April 6 community meeting on the new ordinance. "Those residents know that it's the mature trees that cool the air.
"There's no other solution to lower ambient temperatures outside. Each time we lose a tree we lose a natural and beautiful air conditioner that operates on clean energy."
Under the new rules, residents would not be allowed to remove protected trees unless they are dead, crowding out adjacent protected trees or are causing damage to the foundation or eaves of a residence. Trees deemed hazardous or classified as public nuisance are also eligible for removal.
While the city had initially proposed applying this only to primary residences, staff recently revised the ordinance to also include accessory-dwelling units and detached garages. In doing so, they addressed a concern from the public and from the Architectural Review Board that excluding accessory-dwelling units from protection could place the city in conflict with state law.
Developers who wish to remove protected trees for their projects would be required to demonstrate that there is no financially feasible alternative that would preserve the tree. If a project involves a subdivision, removal of protected trees would only be allowed to repair a geologic hazard, according to a report from Public Works.
"Overall, the combination of a significantly increased number of protected trees with more restrictive removal provisions during development is expected to preserve more trees but make development more challenging when trees are present," the report states.
Developers would also be required to hire an arborist from the city's list of designated arborists to complete tree-related reports associated with development applications, including tree disclosure statements and tree-preservation reports.
The new law also seeks to prevent situations in which someone removes a protected tree and then immediately tries to redevelop the property. A tree removal may now trigger a 36-month development moratorium, according to the ordinance, though the developer may propose mitigation measures to lift the moratorium early. A prior version of the proposed ordinance was more stringent on the topic of redevelopment and specified that the city "shall" impose such a moratorium.
Peter Gollinger, the city's urban forester, said the new law would also classify as protected any tree that is planted for carbon sequestration and storage purposes or to serve as a "replacement mitigation tree" as part of a condition for a development.
"So, if you're required to replace a removed protected tree with a new tree, those trees now become protected trees," Gollinger said at the April community meeting.
One key goal of the new ordinance, he said, is to better comply with new state laws pertaining to water conservation and wildfire prevention. Another goal is to bring the tree ordinance in alignment with Palo Alto's broad goals on sustainability and tree protection. Palo Alto's main land use bible, the Comprehensive Plan, calls for improving the overall distribution of citywide canopy cover, striving for getting 50% tree cover across the city, preserving trees and minimizing damage to trees due to construction-related activities.
Gollinger noted that the city's ordinance, which was initially passed in 1951, hasn't been updated since 2001.
"Our ordinance is old," he said. "It's been 21 years since we made any major changes to the ordinance."
Members of the city's Architectural Review Board and Parks and Recreation Commission all shared this sentiment. Peter Baltay, who serves on the architecture board, said that the city is overdue for a new ordinance.
"Palo Alto doesn't protect its trees properly," Baltay said at the board's April 21 review. "I've long felt that it's a shame that you can cut almost everything except a redwood and an oak with impunity, pretty much."
The Parks and Recreation Commission also strongly supported the effort, with commissioners Nellis Freeman and Jeff Greenfield both suggesting that the city treat the ordinance as a "living document" and revise it periodically.
"It may not be perfect from the outset, but it can be something that we can adopt and return to the commission to tweak as needed," Greenfield said at his commission's April 26 review. "Getting the changes adopted as soon as possible really is important for our trees.