California’s street tree population is a growing multi-billion-dollar public asset according to a 2015 US Forest Service study. Tree managers do not always fund the maintenance needed to keep this public benefit in good condition, which leads to hazardous trees and public liability. San Francisco’s Bureau of Urban Forestry recently found that inadequate funding raised concerns about the long-term health and future of the City’s trees.
Poor tree management results in death and disability every year. Two of the top ten personal-injury settlements in 2018 were on behalf of people catastrophically injured by hazardous trees. While arborists may say there is no such thing as a safe tree, owners manage risk and liability by making maintenance decisions based upon a hazard evaluation. The factors that go into this evaluation include the size of the part of the tree likely to fail, the likelihood of failure, and the likelihood that a failure will result in injury.
This article discusses evaluating liability for injuries caused by hazardous trees in the context of these factors and the likely legal claims and defenses.