COSTS OF STREET TREE DAMAGE TO INFRASTRUCTURE

Abstract

Summary Street trees are an important component of the ‘green infrastructure’ in cities but damage caused by roots to sidewalks, kerbs and gutters and sewers is a multimillion dollar problem. To determine the magnitude of this problem, mxmicipal foresters were surveyed in 15 cities. Total annual concrete and sewer repair costs attributed to tree damage averaged $4.28 per street tree and ranged from $0.18 to $13.65 per tree. On average, repair costs are equivalent to 25 per cent of annual tree maintenance expenditures; sidewalk repair costs are the single largest expense in all cities, averaging $3.01 per tree. Annual kerb, gutter and sewer repair costs averaged $1.14 and $1.66 per tree respectively and damage is highly variable among cities tending to be most severe in older city areas with deteriorating infrastructure and large trees. Mitigation measures applied by tree managers are discussed.