Emma Lanciault

The rapidly increasing number of eutrophics lakes in Southern Ontario is alarming. The shift to eutrophic environments has drastic impacts on water quality, biological activity, and recreational opportunities. Many of the lakes exhibiting eutrophication in Southern Ontario are shallow, man-made systems established over abandoned farmland, raising questions about the sources of excess nutrient inputs. Nutrients may originate from contemporary agriculture and land-use change in the watershed, or they could be from nutrient release within the lakes because of pre-flooding land-use practices. The goal of this research is to use a modeling framework for Dog Lake (located in Battersea Ontario) which was selected due to its origin being productive (Class 1) farmland, turned into a eutrophic lake. This study presents the opportunity to assess flows contributing to the watershed that have not previously been accounted for in hopes of mapping and assessing nutrient flows contributing to nutrient loading in the lakes. To address this problem, a modeling framework is needed to assess spatial and temporal controls over nutrient flows, and how factors such as land-use change has influenced those flows. To evaluate the different sources of phosphorus and nitrogen entering lake systems both a modeling framework and water quality monitoring will be utilized. Key research questions will assess the relative importance of different nutrient sources including the impact of land use change on nutrient budgets and water quality over time and how this can be applied to other watersheds experiencing poor water quality. The goal is to create a detailed framework to evaluate changes in watershed-scale nutrient budgets over time, and how this information can contribute to Source Water Protection programs being implemented in many of the Conservation Authorities in Ontario.