Lake aeration is largely a misunderstood process. For four decades, Sweeney Lake homeowners have operated an aeration system year-round, intending to oxygenate the water, improve conditions for native fish, and reduce the buildup of phosphorus and harmful algal growth in the impaired deep lake. While a total maximum daily load (TMDL) study established a path toward better water quality, there was still a question about whether the lake’s aeration system was part of the problem or the solution.
Another approach to limiting in-lake cycling of nutrients was reducing common carp access and spawning in waters upstream of Sweeney Lake. Schaper Pond, located immediately upstream of the lake, was evaluated as a likely spawning and nursery area for carp. Barr monitored water-quality treatment effectiveness in Schaper Pond, conducted carp and bathymetric surveys, and confirmed that carp were compromising treatment efficiency of the pond and that fish passage control was likely needed.
Monitoring and modeling results were used to differentiate sediment phosphorus release and the effects of rough fish from watershed nutrient sources. Barr developed animated lake-water-quality modeling results to improve understanding of the aeration system's contribution to the water quality problem and to convince users that recommended management actions will meet the goals. We worked with the commission and City of Golden Valley to develop factsheets and conduct stakeholder participation opportunities for further discussion of the issues and solutions to be considered.
Vice President Senior Water Resources Engineer
Senior Water Resources Scientist
Senior Water Resources Engineer
Water Resources Engineer