Tree pits to help mitigate runoff in dense urban areas

Abstract

Tree pits are attractive stormwater control measures (SCMs) for implementation in dense urban areas because of their small footprint, their potentially low cost and the co-benefits they may bring through improved street tree growth. While they provide street trees with passive irrigation, it remains to be determined if tree pits may achieve meaningful reductions in stormwater runoff. We undertook a streetscape experiment to quantify runoff retention of tree pits in a heavy clay soil with low-rates of exfiltration. We calibrated and validated a water balance model using the field experiment data to identify tree pit characteristics driving runoff retention performance. We then applied the mod..