Evaluation of the influence of rainfall on phosphorus loading in Lake Simcoe

Abstract

Lake Simcoe is a major source of fresh water supply and serves as a favorite hub for recreational activities in southern Ontario. The cold water aquatic life of this Lake is facing serious threats due to depleted levels of oxygen caused by excessive growth of algal plants. The major reason for this growth is the entrance of high phosphorus loads through heavy stream discharges in the months of January until April. The results of analysis of phosphorus concentration and flows conducted in this project shows a direct dependence of phosphorus load on flow. Although the relation of rainfall and phosphorus load could not be supported by strong statistical evidence, the flow variations have been shown to be the major cause of variations in phosphorus load. The control strategies should be focused on reducing the generation of phosphorus at source level and preventing the direct entry of heavy flushes in the lake though Best Management Practices (BMPs), including detention facilities.