Roadside Guide to Clean Water: Urban and Suburban Trees
Urban and Suburban Trees at a Glance
Trees growing in communities, adjacent to residential and commercial properties, parks, along roads, and in parking lots provide a wealth of environmental, social and, economic benefits such temperature modification and energy conservation; air pollution removal, improved human health, stormwater reduction, and water quality improvements. Planting new trees or preserving existing large maturing canopy trees provides the most stormwater benefits. This is a simple, cost effective practice to improve water quality in urban and suburban landscapes.
How Urban and Suburban Trees Work
Trees reduce stormwater and associated pollutant loads, in several ways. Trees act as large umbrellas, intercepting rainfall in their canopies and often keeping that rain from ever reaching the ground. Deciduous trees can intercept 700 to 1,500 gallons per year, while an evergreen can intercept more than 4,000 gallons per year. Large trees that produce canopy cover over paved surfaces such as streets, sidewalks, and parking lots provide the most stormwater benefit. Trees develop extensive, deep roots that increase infiltration of stormwater. Actively growing trees are natural water pumps that return water back to the atmosphere through evapotranspiration. A mature tree can transpire 100 gallons per day. Trees actively remove nutrients and other pollutants, such as heavy metals and chemicals (gas, oil and pesticides) from polluted stormwater - a process called phytoremediation. Polluted stormwater can be treated, and flooding reduced, when it the water directed into areas planted with trees, instead of being piped directly to a stream.
Community Benefits of Urban and Suburban Trees
- Stormwater: Reduces stormwater runoff
- Pollution: Reduces pollution
- Flooding: Mitigates flooding
- Climate Change: Promotes climate change resiliency
- Habitat: Provides wildlife habitat
- Savings: Provides cost savings
- Landscape: Beautifies the landscape
You can expect to find urban and suburban tree plantings in urban and suburban settings.
How to Recognize Urban and Suburban Trees
Curbside Tree Planters that are designed to receive stormwater from the street or parking lot. In addition to treating the water, the trees themselves are watered and grow better. Photo by Vincent Cotrone
Trees planted in parking lots not only reduce stormwater and pollutants, but also shade and cool hot parking lots and the surrounding area, beautifying often unsightly seas of asphalt in our communities. Photo by Vincent Cotrone
Trees planted in a roadside swale that remove and filter polluted stormwater. Photo by Vincent Cotrone
Parking lot under construction before trees are planted to manage stormwater. Photo by Vincent Cotrone
Parking lot following construction with trees planted in a trench to receive and manage stormwater. Photo by Vincent Cotrone
