Assessing Performance of Bioretention Boxes in Hot and Semiarid Regions

bioretention, its applicability to a hot and semiarid region has rarely been evaluated. Existing manuals are developed primarily by studies from temperate-climate regions and focus on residential–commercial uses (3–5). Therefore, bioretention research that addresses hotclimate areas and large-scale highway conditions is needed. To apply bioretention on highway roadsides, design specifications such as vegetation types, soil media, and maintenance schemes must be developed to meet local environmental conditions. The research presented in this paper assessed the performance of bioretention in the Hydraulics, Sedimentation, and Erosion Control Laboratory (HSECL) on the Texas A&M Riverside campus in Bryan, Texas, which is considered a hot, semiarid region. Pilot-scale bioretention boxes, each with a specific type of vegetation, were constructed to evaluate pollutant-removal performance. This research is part of an ongoing project intended to develop a bioretention design manual for the Texas Department of Transportation. Field demonstration is being implemented for further evaluation of the performance of bioretention in hot, semiarid climate regions.