Tree box filters are typically filtration systems installed under a street or sidewalk which have trees planted in them. The systems collect stormwater runoff through methods such as permeable pavers or curb cuts. The runoff is then filtered by soil, microbes and vegetation before either being utilized by the tree or discharged into a storm drain system.
Benefits
Tree box filters have the potential to improve the quality and health of street trees by providing larger areas for roots to stabilize the tree and more availability of water and nutrients. Additionally, the filters can delay the peak flow and improve the water quality of water entering a storm drain system.
References
Tree box filter Wikipedia(Text) CC BY-SA