Northeastern Illinois Shallow Bedrock Aquifer Interactive Map
Prior to glaciation episodes in Illinois, the predominately carbonate bedrock exposed at the land surface in northeastern Illinois was subjected to weathering and dissolution. This resulted in the development of significant secondary porosity, particularly within the upper 125 feet of bedrock, creating a productive aquifer. We refer to this aquifer as the shallow bedrock carbonate aquifer. This aquifer is an important source of groundwater for municipalities, industry, and private homeowners throughout northeastern Illinois.
The potentiometric surface for the shallow bedrock carbonate aquifer represents groundwater elevation (head) in feet above mean sea level (AMSL) and is available to download. It is a composite of 1,461 water level measurements in wells taken between 1990 and 2006 as part of various Illinois State Water Survey (ISWS) studies, and an additional 231 surface water elevations along rivers and creeks where there is a hydraulic connection with the shallow bedrock aquifer.
Additional information about the data and methods used to construct the potentiometric surface can be found in Abrams et al., 2014. The bedrock geologic maps and glacial moraine maps depicted were developed by the Illinois State Geological Survey and are also available to download.
Last Updated: 10/19/2016