Kankakee River at Davis, IN Mega Gage: Monitoring Groundwater/Surface-Water Interactions

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What is the groundwater contribution to nitrates in surface water? 

That's the question we are trying to answer by looking at surface-water and groundwater interaction and the role each play in the movement of nitrates. We have added additional monitoring equipment to the USGS super gage Kankakee River at Davis, IN, which will allow us to calculate the nitrate load in groundwater using flow direction, gradient, and nitrate values. We will compare the groundwater results to the surface-water data from the same time frame.

Kankakee River at Davis, IN during snow
Kankakee River at Davis, IN

We are looking at surface-water and groundwater interaction and the role each play in the movement of nitrates by adding monitoring equipment to the USGS super gage Kankakee River at Davis, IN. We will calculate the nitrate load in groundwater using flow direction, gradient, and nitrate values. We will compare the groundwater results to the surface-water data from the same time frame.

The physical interaction of groundwater and surface water has important implications for understanding the transfer of chemical constituents between the two domains. Most stream reaches in Indiana are anticipated to be gaining flow from groundwater; however, during periods of high streamflow the gradients can reverse and surface water can be forced to infiltrate into the aquifer. When this happens, surface-water chemistry can affect groundwater quality. The extent of surface-water intrusion into groundwater and the impact on groundwater quality is unknown. Understanding the range of possible groundwater/surface-water interactions in Indiana provides scientists, resource managers and regulators with boundaries for realistic expectations when interpreting how the interaction affects groundwater and surface-water quality.

In order to better understand groundwater/surface-water interactions in a northern Indiana outwash plain setting, we are installing additional equipment at the USGS super gage Kankakee River at Davis, IN (USGS site number 05515500). This site currently monitors continuous stream stage and water-quality properties (pH, specific conductance, dissolved oxygen, temperature, turbidity, and nitrate) and data are presented in real-time on the internet. This site is now considered a "Mega Gage" with the addition of four monitoring wells installed near the super gage; two wells will be installed on each side of the river.

  • Each pair of wells will be screened at different depths so that vertical hydraulic gradients can be measured, if they are present.
  • Continuous groundwater-level data and water temperature will be collected in the four monitoring wells for one year.
  • Tape downs will be made in all wells every 1-3 months to verify transducer water-level measurements.
  • Streambed temperature profiles will be continuously monitored at six locations between the two well nests.
  • Soil moisture will be continuously measured near one well nest at no less than six depths.
  • Water-quality properties will be continuously measured in one well for pH, specific conductance, dissolved oxygen, and nitrate. Groundwater levels, groundwater quality and soil moisture measurements will be transmitted in real time.