Linking Groundwater and Climate to Understand Long-term Lake Level Fluctuations in Wisconsin

Water level changes in lakescan have substantial socio-economic and ecological consequences. Understanding long-term variations in water levels for seepage lakes (i.e., closed-basin systems that lack surface inflows or outflows) requires consideration of the role of groundwater, climate and other patterns in driving lake level dynamics. Natural resource management of stream ecosystems explicitly accounts forstreamflow variability, and similar frameworks will also advance groundwater and lake management. However, few Wisconsin lakes have long-term water level records, hindering informed management decisions. The objectives of this project were to first compile historical water level and climatic data into a publicly available database, then analyze the spatial and temporal coherence ofhistoric water levels. Next, we used the above information to model historic lake levels and characterize hydrologic regimes for all seepage lakes.