A sidewalk-installation project along Oregon Expressway has damaged several large trees to the point to the point city officials have deemed them dangerous. Some Midtown residents are upset over the mistakes.

"There are numerous instances along the trail where they just crashed into trees and used them as bumper cars," Palo Alto City Arborist Dave Dockter said.

The $768,000 Oregon Expressway Pavement Improvement Project links up several stretches of formerly bare ground with existing stretches of sidewalk on the south side of the expressway. Pedestrians had no easy way to walk along the area, which is covered by dense brush that serves as a traffic screen for nearby homes.

But the project, which was welcomed by many as an important link for residents, turned sour when workers hired by the Santa Clara County Roads and Airports Department struck several oaks, a 50-year-old avocado tree and other trees with backhoes and other equipment.

The roots of some trees were also severed as workers installed the sidewalks and irrigation systems between Waverley and Cowper streets and between Middlefield and Ross roads.

The incidents have raised fears among residents already concerned with tree removal that could occur with the upcoming, broader Oregon Expressway Improvement Plan, which will modify the configuration of intersections to improve traffic flow.

Residents and Dockter said they are concerned that mature trees could be damaged if safeguards and communication between the city and county are not in place.

"The planning group is stellar," Midtown resident Pam Radin said, surveying the damaged trees last Friday. But based on what has been demonstrated during the pavement project, the execution -- how the work will be carried out when they do the road-improvement project -- is concerning, she said.

Workers knocked bark off some trees at points near the soil that will cause bacteria and fungi to infect the trees, Dockter said.

The city has an ordinance against damaging oaks and redwoods, which are deemed of important value economically and environmentally, he said.

Steam rollers so badly damaged one of the oaks that had it been a resident rather than the county a fine or penalty would have been involved, he said.

"They would have been fined $100 an inch for the damage to the bark. There was a 12-inch wound on one of the oaks -- a $1,200 damage penalty," he said.

But Oregon Expressway is county property, so the city has little say-so, he said.

City protocol would be to assess the conditions of trees first and then build accordingly around them, he said.

"The City Planning Department subscribes to Hippocrates' creed: First, do no harm. In this case, it's questionable if that was done at all by the county.

"What's unfortunate is that two different agencies didn't really connect. The normal course of development is to review responsibly and build accordingly with the trees in mind. But the county has its own protocol and the city wasn't really in the loop on any of the project," he said.

Dockter surveyed the damaged trees and deemed them to be hazardous, he said. Major holding roots were cut through on some trees, and 8-inch-diameter roots were severed on the avocado.

"That tree's dead and doesn't know it yet," he said. "It provided so much interesting character to Oregon."

A venerable oak had its life expectancy cut short when workers tore off bark at the soil line. It probably reduced its life expectancy to 50 years instead of 150. "That tree is one that will never live a productive life," he said.

City and county officials had differences of opinion about the dangers posed by the trees, Dockter said. A large acacia tree near Cowper Street with overarching branches has a huge "widow maker" directly over the pavement, he said.

"We had our difficulties in seeing eye-to-eye to agree even when there was something that was clearly unsafe," he said.

The county had the contractor hire an arborist to evaluate the trees. That report confirmed the city's assertion that the trees should be removed, Craig Petersen, the county project engineer, told the Weekly. The county and the contractor will share the cost for tree removal, but he did not yet have an estimate of costs, he said.

The report lists nine trees that are damaged beyond repair and won't survive. The county will remove eight, he said.

He defended the workers' damages as in many instances being unavoidable.

"The area has been so neglected for so many years. ... Really, it was a rat's nest. ... Almost all are volunteer trees. They were growing at weird angles and were unhealthy," he said.

"From an engineering perspective, there were dense bushes. It was so hard," he said. The county considers any tree under 12 inches in diameter a sapling, so most of the damaged trees qualify, he said.

"We don't require a permit to remove trees like that. One of two was diseased and falling down and then we damaged it and the other was in the way," he said.

A copy of the arborist's report, by TruGreen LandCare, obtained by the Weekly, showed that six out of 11 trees evaluated were more than 12 inches in diameter, with circumferences of 16, 17, 18, 20 and 21 inches. Two of the trees were not recommended for removal, however.

There is no plan to replace the trees currently, but the county could discuss that possibility with the city, he said.

Dockter said he hoped better communication between the two agencies would help to resolve future issues. Technically speaking, the county has no requirement to listen to the city, he said.

But he hoped the more extensive expressway-improvements project would work out differently, he said. Work in the median could wipe out old trees if not properly executed, he said.

"The most important thing both of these agencies can do is set expectations together with all of the stakeholders and not leave a lot up in the air," he said.

Petersen said he had two walk-throughs with the city prior to the project's commencement and the city had wanted irrigation to be added as part of the project. That caused most of the problems, he said.