Stormwater runoff from rainfall and snow melt harms waterways by picking up pollutants such as phosphorus, oil, and bacteria as it flows over roads, driveways, parking lots, and compacted soil and carrying them into rivers, streams, and lakes. Trees, especially those in an urban landscape, help to reduce stormwater runoff. They capture rainfall in their canopies and release it back to the atmosphere through evaporation. Tree roots slow down runoff, increase the infiltration of water into the soil, and take up nutrients and other pollutants. The USDA Forest Service estimates that just one newly planted tree can capture 76,000 gallons of rainfall and save about $500 in stormwater management costs over a 40-year life span.
