Eye On Earth: Tree trenches will help cool Watertown
WATERTOWN - Watertown is a community going green by adding more green. A $240,000 federal grant will go directly to install 15 tree trenches across the city.
"This straightforward investment will deliver a sustainability hat trick. Absorbing climate-warming pollutants out of the air, filtering water pollutants out of the ground and the Charles River and reducing extreme summer temperatures for everyone," Congresswoman Katherine Clark stated.
"In urban environment, it's hard to find places to grow your urban forestry and try to develop the urban canopy that we are trying to build here. Anywhere we can install trees here in Watertown we are trying to increase our canopy to deal with the heat island effect and climate change," said Greg St. Louis, Superintendent of Public Works in Watertown.
An urban heat island is a bubble of warmth that develops from all the dark-colored buildings and rooftops and pavement that retain heat during the day. The city releases that heat very slowly, especially at night. So much so, that the city can be 15 degrees warmer than the outlining area. So by lowering the temperatures during the day by providing much needed shade is just one benefit of trees and filtering pollutants is another.
"We clean our storm drains every year and we remove tons of sediment from the water system. Each year there are varying levels of pollution or sedimentation on the roadway that we are trying to capture," St. Louis explained.
Now these tree trenches, some that will include rain gardens, will help with that.
"There are numerous layers to the tree trench, and we want to collect the physical debris at the top, we clean that by hand, and then the nutrients will filter down into the soil and be up taken by the tree," St. Louis told WBZ.
Otherwise, debris and nutrients would go right into the storm drain and pollute waterways.
"This is just one way we can address climate change with our local infrastructure. One tool in the toolbox," St. Louis said.