There are a ton of benefits that trees provide for our cities, neighborhoods, and homes that we can take for granted. Last week we mentioned that a large percentage of the monetary value provided by trees is by mitigating stormwater.
In the Gulf coast, the damage from both the drought and flooding are disrupting city and rural life as Ivan (now a Tropical Storm) passes. Although here in Washington State we don’t encounter hurricanes, all urban folk rely on cities to take care of water flowing through our soil and over our roads. Cities provided the infrastructure to collect, distribute, and treat stormwater and sewage at once, meaning that the pipes and tunnels can get overwhelmed when storms occur.
Here in King County, the Wastewater Treatment Division (WTD) is concerned about overflows that can occur when the system’s capacity is overwhelmed by stormwater. This causes environmental and health problems when overflows contain more than just stormwater, but also some sewage. The WTD’s project for Bioretention is one way the county takes advantage of the natural absorptive power of vegetation.
Trees are great at managing stormwater runoff from the leaves disrupting rainfall, to the roots system’s
storage of rainwater. According to the Alliance for Community Trees, mature trees can hold 50 to 100 gallons of water during large storms. Strategic tree planting can relieve pressure off of more traditional infrastructure – Detroit reduced overflow in 2010 by 10-20% in volume, saving about 159 million dollars a year. Trees are an effective, environmentally-friendly solution to an expensive problem.