Grant: Alliance Grants

Stormwater retention ponds are features of many Canadian neighbourhoods that play a crucial role in managing urban stormwater. They collect runoff to prevent flooding, both in the locality in which they are located and downstream. These ponds are additionally important for safeguarding river water quality, as they retain sediments and contaminants bound to them that could harm aquatic life. A goal in pond design is to retain a significant amount of sediment carried by the water entering them. However, sediment accumulations within ponds affect their flow conditions and storage capacities, requiring municipalities to remove the deposits through regular dredging. This maintenance activity can be expensive, reaching up to $2.5 million per pond. As the ponds perform better at removing deposits and toxins, the need for dredging occurs more frequently. Given the large number of ponds used in Canada (e.g., 31 in Saskatoon and about 1000 in the Toronto area), managing sediment in these ponds poses a costly challenge for municipalities. This research project aims to develop improved methods for managing sediment in stormwater retention ponds, with the goal of reducing overall costs. The study will focus on enhancing pond design to effectively retain sediment, determining the optimal timing for dredging interventions based on sediment accumulation levels, exploring alternative approaches for handling sediment to lower expenses, and testing a technology to minimize sediment contamination within the ponds. The outcomes of this research will provide Canadian communities with recommendations and tools for designing ponds and suggestions for standards that can help reduce the lifecycle costs associated with managing pond sediments.