Hydraulic performance of biofilter systems for stormwater management: Influences of design and operation

Abstract

In order to evaluate the long-term performance of stormwater biofilters, a study was undertaken to assess their hydraulic conductivity. Despite variability in conductivity (40% being below the recommended range of 50-200 mm/h, 43% within it, and 17% above), treatment performance is unlikely to be affected, as most systems are over-sized such that their detention storage volume compensates for reduced media conductivity. The study broadly reveals two types of systems: some with a high initial conductivity (>200 mm/h) and some with a low initial value (<20 mm/h). Significant reduction in conductivity is evident for biofilters in the former group, although most are shown to maintain an acceptab..