Hydrogeology of the Central Sands

The DNR worked with the Wisconsin Geological and Natural History Survey (WGNHS) to understand the interaction between groundwater and surface water of the three study lakes and to define the hydrostratigraphy of the groundwater system. Hydrostratigraphy divides the different sediments and rocks into distinct units based on their unique hydrologic properties and provides layers for the groundwater flow model.

The WGNHS reviewed existing literature and data relevant to the study. DNR staff helped refine locations for over 50,000 wells based on well construction reports and other sources. Staff from WGNHS and DNR conducted field work in the Central Sands to better characterize the geology and groundwater levels for areas in and around the three study lakes.

View the report and watch these presentations: Overview of Hydrostratigraphy and Central Sands Glacial Geology, Hydrostratigraphy and Lake-Groundwater Interactions, that detail the findings of the hydrogeologic study.

View the Hydrostratigraphy Report Appendices:

• Appendix A
• Appendix B
• Appendix C
• Appendix D
• Appendix E
• Appendix F
• Appendix G
• Appendix H
• Appendix I
• Appendix J

Key hydrogeological findings:

• The Central Sands Region is dominated by sand sediments but also has areas of fine-grained materials (as shown in the red areas in the schematic cross section below).
• Water levels in all three study lakes are closely linked to the surrounding groundwater levels - as precipitation and other variables cause the water table to rise and fall, the lake levels respond.