Mature trees, both as individual landscape features and as undisturbed areas of woodland cover, provide significant benefits in the interception of rainfall and the consequent reduction of stormwater runoff.  However, current design practices and regulatory programs for stormwater management in the Commonwealth of Massachusetts do not specifically recognize this ecological service provided by canopy trees.  Ironically, development practice often involves clearing large areas of woodland cover in order to provide space for installing stormwater management facilities to meet regulatory standards, with a permanent loss of the stormwater reduction function, not to mention other ecological benefits offered by mature tree canopy.

This study explores the potential stormwater reduction benefits of trees, as a foundation for a program to preserve, replace, and enhance mature tree canopy as an integrated component of stormwater management permitting, design, and implementation in Massachusetts.  The study characterizes the potential role of canopy trees in achieving significant reductions in stormwater runoff, offers model regulatory language for use at both the municipal and state level for fostering the employment of tree canopy as a Best Management Practice, and identifies guidelines for the use of trees for stormwater management in the urban landscape.