Improving the Groundwater Flow Model of the Mahomet Aquifer Including Geological Mapping and Geophysical Exploration in Champaign County
The Mahomet aquifer and overlying upper Banner and Glasford aquifers are a vital source of water to communities, industries, and rural residents of east-central Illinois. These aquifers, for example, have been estimated to provide more than 80 million gallons of water per day (mgd) to nearly 200 community supplies spread across 15 counties. A primary goal of recent ISWS efforts has been to construct a three-dimensional, digital groundwater flow model that unifies geologic and hydrologic interpretations of the aquifer system. Unfortunately, the eastern portion of the ISWS Mahomet aquifer flow model is not well -calibrated. This is due, in part, to the complex geometry of the Mahomet aquifer and permeable deposits within the overlying Glasford formation and Mason Group underlying Champaign County and counties to the north and east.
The ISGS is collecting new geologic data through the drilling of observation wells and geophysical surveys. Geologists are using the new data along with existing data to create new geologic maps for the Champaign area. ISWS hydrogeologists are collecting water level data from wells and streams to better define groundwater flow patterns in the aquifer systems. All data are being used to create a well-calibrated groundwater flow model that can greatly aid in interpreting the effects of different groundwater management schemes. The results of this study will provide a common source of geologic and hydrologic data and information that will serve as a basis for resolving potential conflicts over specific groundwater developments and for creating future development strategies. The diverse local needs and interests in the region can then be considered in developing locally-based resource management strategies.