Late last year Mountain View marked for removal 28 red oak trees planted in the 1970s on El Camino Real. The oaks were lifting and cracking sidewalks between Grant Road and Castro streets. The city was able to save all but three.
"We did everything we could to preserve those trees," said Bruce Hurlburt, Mountain View's parks and open space manager. The trees had to be cut during a sidewalk replacement project that finished in May.
The three trees that couldn't be saved had too much of their roots above sidewalk level. Only 15 percent of the root mass of each tree can be safely removed, Hurlburt said.
The trees that were saved usually had to have portions of their roots cut back before sidewalk cement could be poured, sometimes with iron bars reinforcing the concrete or a layer of steel plate sandwiched between the roots and the cement to prevent lifting and cracking.
The trees that were removed were replaced with a new, 24-inch box tree, which is required for every large tree removed on public or private property in Mountain View.
This winter a similar sidewalk replacement project is set for Shoreline Boulevard, between El Camino Real and Villa Street. Some of the magnolia trees there are lifting and cracking the sidewalk and may be tagged for removal.