Trees owned by the city of Oakland line about 1,200 miles of the municipality's streets, and many cause crack in sidewalks.

The City Council is now determining their future.

Council members participating in the Life Enrichment Committee decided Tuesday to postpone their vote on a proposal that aims to limit the number of city-owned trees that Public Works staff can remove.

The office of City Councilwoman Jane Brunner (District 1-North Oakland) drafted this proposal as an amendment to the municipal code. But committee members are now asking Brunner for more specific details and a cost analysis of the proposal.

Once approved by the committee, the City Council will then consider the amendment.

The proposed amendment is part of a citywide debate on how to manage city-owned trees. The Departments of Public Works and Parks and Recreation released a report in February that called for more latitude in cutting down city-planted trees.

While many residents have said they want city-planted trees to stay in front of their homes, many trees have sprouted roots and mangled sidewalks -- creating a liability issue for Oakland. Public Works staff estimates repairs will cost $17 million, but has $700,000 budgeted for the fixes.

Oakland paid about $600,000 last year in trip-and-fall lawsuits allegedly caused by deformed sidewalks.

Part of Brunner's proposal calls for changes that Oakland could implement immediately at little cost, she said. For instance, the city would assess all the trees on one block before repairing sidewalks; and it would fill tree wells with dirt, rather than cement. This should beautify a street and save Oakland money, Brunner said.

The more costly part of the proposal calls for Oakland to embrace a variety of practices. City staff could, for instance, be asked to document that removing a tree remains their only option, or Oakland could limit the number of city-owned trees removed to 10 percent per block -- a figure, Brunner said, that came from residents' suggestions.

"We absolutely know we can't implement this without the money," she said.

In all cases, Oakland could cut down trees that present "emergencies" or "imminent hazards," the proposal states.

The proposed changes to local tree maintenance comes when Public Works staff is preparing to integrate the Parks and Recreation Department's 167 maintenance employees -- a $13.2 million budget transfer taking place in July. Public Works officials said it's unclear if the unification will make tree maintenance more efficient in Oakland.

Brunner thinks it will. "This will make them have to have sidewalk-people and tree-people coordinate," she said.

While Brunner's amendment calls for protecting "street" trees, City Councilwoman Jean Quan (Montclair-Laurel) said the city should focus on removing trees now adjacent to sidewalks. Many city-owned trees in the hills grow in parks or along streets without sidewalks.

Also, the city needs the flexibility to remove some trees in the hills, like Eucalyptus, that are fire hazards, she added.

A 10 percent limit on tree removals per block would prevent the city from addressing issues on a case-by-case basis, said councilman Danny Wan (Lake Merritt-Chinatown). He added that he wants as many trees as possible to shade the streets but said it's unclear how the proposal might strengthen the city's existing ordinance.

"I don't see a wholesale cutting down of trees," he said.

Trees eventually crack the sidewalks adjacent to where they grow, said Jaime Heredia, a Public Works supervising civil engineer.

Maintenance crews fix sidewalks and return to check on them five years later, he said. If crews fix a sidewalk without removing trees they consider a problem, these trees often cause more damage, Heredia said.

"This (proposed) ordinance could limit our ability to repair," he said, though Brunner disagreed.

About a dozen supporters spoke in favor of the councilwoman's proposal at Tuesday's committee meeting.

Walter Miles, a Rockridge resident, said he helped plant several hundred city-owned trees in his neighborhood about 30 years ago.

"It changed the character of the neighborhood," he said. "See the kids going down the street: There's a difference in the effect they have on children."

Committee members are set to consider modifications to the tree ordinance at 6 p.m. Tuesday, July 13. For information on the proposed tree ordinance, call the office of councilwoman Jane Brunner at 510-238-7001 or Public Works at 510-238-3961.

Reach Bruce Gerstman at 510-748-1681 or by e-mail at bgerstman@cctimes.com.