Lake-Groundwater Interactions of Plainfield, Long, and Pleasant Lakes in the Central Sands of Wisconsin
Image credit Wisconsin AWRAAbstract
The Wisconsin Department of Natural Resources (WDNR) is conducting a groundwater and lake level evaluation for Pleasant, Long, and Plainfield Lakes in Waushara County, referred to as the Central Sands Lakes Study (CSLS). An important component includes fieldwork designed to track water levels of the three study lakes and an accompanying network of lake-proximate monitoring wells. This hydrologic dataset provides a means to test hypotheses about lake-groundwater flow regimes and improve our understanding of localized groundwater-surface water interactions. Additional lines of evidence for the importance of groundwater to dynamics of these study lakes include seepage meter measurements, lake water budgets derived from stable isotope measurements, and lake water budgets derived from a groundwater flow model (MODFLOW). Results indicate that lake-groundwater fluctuations and gradients are largely consistent with physical (seepage meter), chemical (stable isotope), and modeled (MODFLOW) lake water budget investigations. These findings confirm the hypothesis that groundwater is a key component of the water balance at each of these dynamic lake systems and will ultimately inform the DNR’s decision-making process in regards to lake-level impacts.
