Trees and grasses planted outside Lindsley Hall on the Richard H. Fulton Campus.
General Services’ landscapes include many trees of a variety of ages and species. Many of these trees are located on highly urban sites and are therefore especially important for the protection of water quality and stormwater management. Trees reduce stormwater runoff by intercepting rainfall, through evapotranspiration, and by filtering and storing water. In fact, one mature deciduous tree can intercept 500-700 gallons of water per year.
Mature trees provide shade to visitors and employees at the Fulton Campus office complex.
Green infrastructure also serves to manage stormwater and protect water quality. Examples of green infrastructure practices on General Services’ sites include permeable pavement and bioretention areas.
Permeable pavers at Fire Station 19.
General Services manages eight sites with permeable pavement. Permeable pavements allow stormwater runoff to filter through voids in the pavement surface and into an underlying stone reservoir, where it is temporarily stored and/or infiltrated into the ground. Permeable pavements reduce runoff and provide water quality treatment.
Pervious pavement at a Metro facility.
Bioretention area at Fire Station 19.
A total of 13 General Services sites boast bioretention areas. Bioretention areas are vegetated depressions to which runoff is directed. Captured runoff is treated by filtration through an engineered soil, and is then either infiltrated into the subsoil or is released through an underdrain. Bioretention areas reduce runoff and pollutant loading and can provide aesthetic benefit to a site.
Bioretention area at Fire Station 19 provides rainwater catchment, filtration, and helps counter the urban heat island effect.
For more information, see Trees are Good www.treesaregood.com and Low Impact Development https://www.nashville.gov/Water-Services/Developers/Low-Impact-Development.aspx.
Blog author, Mr. Treff Alexander, is the Landscape and Green Infrastructure Manager for Metro’s Department of General Services.