3-D GEOLOGIC MAPPING FOR GROUNDWATER APPLICATIONS IN KANE COUNTY, IL

As urban sprawl brings more people westward from the vast Chicago metropolitan area, Kane County, IL is confronting issues of rapid population growth. Future water resource needs will likely be met by utilizing the Fox River and aquifers in the glacial drift and shallow bedrock. A thorough understanding of the nature and extent of these potential resources is necessary for effective water resource management and development. The Illinois State Geological Survey (ISGS) and Illinois State Water Survey (ISWS) are in the third year of a five-year study to assess groundwater resources for Kane County.

ISGS efforts are centered around a three-dimensional approach to geologic mapping. The resulting 3-D geologic model is being incorporated into a groundwater flow model being developed by the ISWS. At the center of the 3-D geologic mapping effort is a relational database that allows researchers to examine a large amount of data relative to other data in a spatial environment at scales appropriate to different modeling approaches. This permits an increased focus on aquifer properties based on lithology, independent of stratigraphy. A 3-D view offers a better conceptual picture of the aquifer system and points out areas where more detailed investigation is needed to make sense of the geologic environment. As expected, preliminary results from Kane County indicate the thickest successions of aquifer materials tend to be found in association with the bedrock valleys. These valleys can potentially be too narrow to be accurately represented on a regional scale model, however, by examining these feature in 3-D, data gaps were identified and investigations were structured to more accurately map these areas.