Grant: Collaborative Research and Development Grants

In urban areas the presence of impervious surfaces results in greatly increased volumes and rates of surface runoff. Stormwater management lakes, or stormwater ponds, are used primarily to control the excess water by temporarily storing surface runoff and then releasing it at a decreased rate. Stormwater ponds are designed not only to reduce flooding but also to improve water quality by removing pollutants. Ponds are often located in urban subdivisions and their close proximity to residential dwellings creates two problems. First, poor water quality caused by algae blooms and excessive aquatic plant growth lead to frequent complaints from nearby residents about odours and the presence of unsightly pond scum. Second, residents find frozen stormwater ponds attractive for winter recreational activities such as skating, hockey and broomball but unpredictable ice cover behaviour makes these activities dangerous. Concerns about the safety of ice covers and the ongoing problems with nuisance algae blooms in Edmonton's stormwater ponds are the motivation for this research proposal. The objectives of the proposed research are to: (i.) Identify the causes of poor water quality in stormwater management ponds. (ii.) Evaluate methods to reduce algae growth in stormwater management ponds. (iii.) Identify the causes of ice cover variability in stormwater management ponds.We propose to achieve these objectives by conducting a two year field measurement program and by applying state-of-the-art numerical models to four Edmonton stormwater ponds. The field measurements will be used to determine the factors that control ice cover formation and algae growth. A coupled hydrodynamic-biogeochemical numerical model will be used to determine the causes of excess algae growth and to evaluate remediation methods to improve water quality. A hydrodynamic numerical model that includes a new ice cover algorithm will be used to predict ice cover formation and to determine the factors that cause pond ice covers to be unsafe.