Groundwater monitoring and research

Science Center Objects

Groundwater is an important water resource. The USGS collects information on the quality and quantity of groundwater and conducts advanced modeling of groundwater flow and groundwater/surface-water systems. The USGS also evaluates the effects of water-use, land-use, and climate change on groundwater, surface-water, and the ecosystems that rely on them.

Photo of the Frederick Springs sand boil

The continuously bubbling water at the Frederick Springs sand boil at Pheasant Branch Conservatory in Middleton, Wis., is created groundwater flowing up through cracks in the overlying rock and sand.

What is groundwater?

Groundwater is all the water below the land surface that fills the porous space in soil and rocks. The soil and rocks that store and transmit water are known as aquifers. The upper surface of the groundwater forms the water table. Groundwater is replenished (recharged) by rain and snowmelt that permeates through the soil and infiltrates downward to the aquifer. In Wisconsin, groundwater is the main source of drinking water for two-thirds of Wisconsin's residents, as well as for commercial, agricultural, and mining uses.

How is groundwater connected to surface water?

Nearly all surface-water features (streams, lakes, reservoirs, wetlands, and estuaries) interact with groundwater. These interactions take many forms. In Wisconsin, it is most typical that surface-water features gain water from ground-water systems. In certain circumstances however, a surface-water feature can act a source of ground-water recharge and can cause changes in ground-water quality. Because of the connection between surface and groundwater, withdrawal of water from streams can reduce the groundwater resource, or conversely, pumpage of groundwater can reduce the water that would typically flow to streams, lakes, or wetlands. Pollution of surface water can cause degradation of groundwater quality and conversely pollution of groundwater can degrade surface water. Effective land and water management requires a clear understanding of the linkages between groundwater and surface water as it applies to any given hydrologic setting.

Learn more about groundwater and groundwater-related issues.


USGS groundwater activities in Wisconsin

The USGS employs state-of-the-science techniques and expertise to advance the understanding of the relation of groundwater systems to other natural resources and humans. Some of our current work focuses on:

  • Operation and maintenance of the Wisconsin Observation Well Network, including data collection, processing, archiving, and presentation
  • Collection and analysis of water-use data
  • Simulation of groundwater/surface-water systems
  • Evaluating land use and climate change effects on groundwater, surface-water, and habitat
  • Simulation of groundwater/surface-water systems to ensure protection of water supply wells
  • Simulation of the effects of water diversion on shallow groundwater and lake systems
  • Relation between groundwater flow and water-quality, with particular expertise in pathogen detection and transport in groundwater
  • Hydrologic and biogeochemical budgets in temperate lakes and their watersheds
  • Groundwater water-quality assessments
  • Spatial and temporal shallow groundwater recharge rates
Example chart showing daily groundwater level measurements compared to historical mean

Example chart showing daily groundwater level measurements (blue line) compared to historical daily mean (green). At this site, daily values have been well below the historical mean for the past two years, but have recently started to rebound.


USGS groundwater data for Wisconsin

The USGS and its partners monitor groundwater levels in roughly a hundred of wells in Wisconsin. Groundwater-level data are collected and stored as either as continuous time-series data from automated recorders or discrete field water-level measurements. All Wisconsin data collected by the USGS and partners are stored and made available through the National Water Information System and Groundwater Watch. Additional partner data is available through the Wisconsin Active Water Level Network.


Hydrogeologic modeling

The TC Chamberlin Modeling Center provides advanced computing resources to modelers to implement powerful new computational and analytical techniques. The Modeling Center trains others in the skills needed for future modeling projects and develops, implements, and disseminates state-of-the-art techniques and tools so that models are more effectively applied to today’s decision-making.

Our modeling specialties include:

  • Groundwater-flow modeling
  • Coupled groundwater/surface-water modeling
  • Fate and transport modeling
  • Model calibration and evaluation of prediction uncertainty
  • Modeling in support of ecohydrology studies