Tree boxes are a green infrastructure stormwater control measure that are designed to collect the first flush of stormwater and treat it prior to discharge into the storm sewer system or to the subsoil. The structure is a pre-manufactured concrete box which is installed in-ground, filled with soil media and typically planted with native, non-invasive tree or shrub. The tree box functions as a compact bioretention system, which is a green infrastructure or low impact development stormwater control best management practice (BMP). In urban or built-out areas where space is limited, tree boxes can fit within a small existing footprint and as retrofit projects. The tree box chamber can be modified to accommodate for infiltration. If the tree box is modified to infiltrate runoff, the soil properties of karst soils or contaminated sites can create direct discharge of pollutants into groundwater and should be avoided.