Bioretention cell efficacy in cold climates: Part 1 — hydrologic performance

Abstract

Bioretention cells are an emerging low impact development technology that address urban stormwater runoff concerns. Field and column experiments were conducted to assess the efficacy of bioretention cells in cold conditions. Field experiments in a prairie environment demonstrated a significant decrease (91.5%) in effluent volumes compared to influent volumes. The majority (∼60%) of the runoff percolated to the surrounding soils or evapotranspirated. Cold condition performance significantly impacted high volume events and was characterized by significantly higher effluent volumes, significantly lower runoff storage, higher effluent peak flow rates, and longer peak delays. A partially frozen surface layer caused the changes in performance. Long-term simulation experiments on the columns indicated a significant decrease in saturated hydraulic conductivity over the first 4 equivalent years of operation, before levelling to a constant value.