Two Presentations: 1) The Central Sands Lakes Study: Findings and Recommendations to Guide Groundwater Management 2) Evolution of Groundwater Quantity Management in Wisconsin
Presentation #1: The Central Sands Lakes Study: Findings and Recommendations to Guide Groundwater Management
2017 Wisconsin Act 10 required the DNR to implement a study of groundwater withdrawals on three Central Sands Lakes. This interdisciplinary study, involving over 30 scientists across multiple agencies and institutions, was completed in 2021 and the study’s findings and recommendations were sent to the Legislature for consideration. The study confirmed that the study lakes and other surface water resources in the Central Sands Region are well-connected to groundwater. Modeling showed that current groundwater withdrawals from irrigated agricultural reduce lake levels across the full range of levels. Those reductions cause significant impacts to human uses (e.g., boating), fish, plants, and chemistry on Long Lake and human uses and plants on Plainfield Lake. Reductions at Pleasant Lake are less severe but may impact lake stratification and dock usage.
A key finding is that the impacts to the lakes are not caused by any one well, but rather by the collective impacts from hundreds of wells within about 5 miles. With lag times of months to years, management based on trigger levels would not be effective. Also, natural variability of the lakes is ecologically important and makes managing to a single lake level undesirable. Due to the large numbers of high-capacity wells and water resources in the Central Sands, DNR recommended a regional approach: the creation of a water use district composed of landowners and other stakeholders to work with the DNR to find workable solutions.
Presenter: Jeff Helmuth
Presentation #2: Evolution of Groundwater Quantity Management in Wisconsin
Wisconsin has abundant water resources, with 1,000 miles of Great Lakes shoreline, 84,000 miles of streams, 1 million acres of inland lakes, 5 million wetland acres, and 1.2 quadrillion gallons of groundwater. Although water rich, access to productive aquifers varies regionally, and Wisconsin experiences water level fluctuations resulting from natural climate variability, climate change, and a continued demand for groundwater. Wisconsin has grappled with how to sustainably manage water resources while meeting the needs of communities and the economy. In 2021, the completion of the Central Sands Lakes Study and a decision from the Wisconsin Supreme Court further clarified the science of groundwater withdrawals and the legal responsibility to evaluate them. The findings from both the Study and the Court were another step towards a groundwater management framework that began nearly 20 years ago with 2003 Wisconsin Act 310. Since the passage of 2003 Wisconsin Act 10 there has been a 50% increase in the number of high capacity wells (over 4,000 wells). Ongoing litigation and legislation have resulted in an ever-changing approach towards groundwater quantity management. This talk focuses on the current groundwater management framework and the technical complexities that surround its implementation.
Presenter: Adam Freihoefer