LINKING CHLORIDE DYNAMICS IN LAKE WINGRA WITH CLIMATE VARIABILITY

Abstract

Salt pollution has become prominent over the past 80 years in freshwater ecosystems across the Midwest United States. This study focuses on chloride dynamics in Lake Wingra, a eutrophic, urban, small, and shallow lake in Dane County, Wisconsin. Due to Lake Wingra’s size, it responds rapidly to changes in chloride loading. Since the 1940’s, chloride concentrations have risen 30-fold. Climate drivers such as precipitation play a role in chloride transport. It is crucial to investigate and distinguish human impacts from natural variability in chloride concentrations. Using a dynamic model, this study integrates historical data on precipitation, road salt application, and chloride concentrations with projected future scenarios of reduced road salt application. This model additionally simulates chloride accumulation in Lake Wingra from 1962 to 2024 and analyzes trends under different climate and road salt application scenarios. Results from this model provide insights into the long-term consequences of road salt use, as well as the potential for sustainable management practices to preserve water quality in freshwater systems outside of Lake Wingra. Understanding the interplay of climate and human decision making will allow us to assess the impacts of the strategies implemented and guide future advocacy efforts to protect, maintain, and further emphasize the importance of healthy freshwater ecosystems.