Lake Restoration

Lake restoration is a complex activity. Many modifications may have unintended results if not all variables are taken into account. Lack of careful evaluation of these variables may not result in the esthetic or fisheries benefits that were intended. Most lake rehabilitation projects are required because of excessive sedimentation and / or nutrient loading. Sedimentation and nutrient loading either cause esthetic problems or reduced fishing opportunities. The best way to improve a lake is to improve the watershed or water supply by implementing best management practices (BMP's). When the lake environment has already been degraded, implementing BMP's do not produce the desired results, sedimentation and nutrient loading still exceeds acceptable levels, and water clarity and chemistry are limiting factors, then rehabilitation of the lake itself is required. The use of sediment traps, sediment bypassing, and hypolimnetic siphoning or discharge need to be explored in these cases. This paper presents an overview of all of the above factors in lake rehabilitation with an emphasis on sediment traps, sediment bypassing, and hypolimnetic discharge and how each method affects water quality. Applications and limits of applicability for these methods will be discussed.