Groundwater-Level Monitoring Network

WGNHS and the U.S. Geological Survey (USGS) Upper Midwest Water Science Center have collaborated for decades to operate, maintain, and manage the Wisconsin Groundwater-Level Monitoring Network (WGLMN). This network consists of roughly 100 long-term monitoring wells, plus dozens of project-funded wells that are monitored for specific groundwater studies. Wisconsin’s long-term network wells are also part of the USGS’ National Groundwater Monitoring Network (NGWMN) and therefore bolster groundwater-level monitoring efforts across the country.

About the Network

The WGLMN dates back to 1946, when the Wisconsin State Legislature requested that WGNHS and the USGS Upper Midwest Water Science Center formally establish a groundwater-monitoring network. In recent decades, the Wisconsin Department of Natural Resources (WDNR) has become more involved and today serves as a critical partner in supporting the ongoing operation, maintenance, and management of the network.

Since 2015, multiple grants from the NGWMN program injected over $750,000 in new funding to repair and evaluate old wells, replace failing wells, and drill new wells in areas of the state lacking monitoring coverage. These investments have resulted in repairs and evaluations of over 40 monitoring wells and the drilling of over 20 new wells across almost half of Wisconsin’s 72 counties.

The WGLMN’s long-term network provides a consistent, high-quality record of water-level fluctuations in both shallow and deep aquifers systems across the state. Water levels collected from the WGLMN help scientists and managers evaluate the effects of well pumping, the response of groundwater levels to drought or increased precipitation, and the effects of land-use change as well as climate change on groundwater resources. These data are also routinely used in the development of regional groundwater flow models because long-term water-level measurements serve as reliable calibration targets.

Monitoring a well

Following the installation of a new well, a detailed well-construction report is generated and a representative set of drill cuttings is transported to WGNHS’s Core Repository in Mount Horeb, Wisconsin. WGNHS then uses borehole video imaging and geophysical methods to record data about the well’s geologic characteristics while the USGS establishes an elevation datum and deploys water-level monitoring equipment—making the well fully operational for generations to come.

The photos below were taken at a monitoring well installation at Havenwoods State Forest in Milwaukee County. (Photos by Sara Stathas for the University of Wisconsin Water Resources Institute, used here with permission.)

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