Water-table elevation contours, Columbia County, Wisconsin (2012, 1:100,000)

These data represent work performed by the Wisconsin Geological and Natural History Survey and are released to the open files in the interest of making the information readily available. The data have not been extensively reviewed for conformity with the Wisconsin Geological and Natural History Survey standards and nomenclature. 

The Columbia County Groundwater Project is a joint project of the Columbia County Land and Water Conservation Department; the United States Geological Survey; and the Wisconsin Geological and Natural History Survey (WGNHS), a unit of the University of Wisconsin-Extension.

Water-table elevation contours were interpolated from the elevations of surface water features such as streams, lakes, and wetlands; and inferred from ground surface topography. The accuracy of the map varies throughout the study area, increasing where surface-water bodies are more prevalent. Water-table elevation contours are less accurate in areas of steeper topographic relief, such as in the Baraboo Hills and south of Lake Wisconsin.

Contours were drafted on paper using USGS 24K DRGs as a base. To aid interpretation and generalization, the DRGS were overprinted with supplemental information such as surface-water elevations and 100K hydrography [to be used for the final map]. Scanned images of the paper compilations were registered and vectorized in ArcMap. On-screen edits were made to edge-match and smooth the scan-vectorized contours. The county boundary was imported from the WDNR 100K DLG file (ctyppoly). The contours were compared to digital elevation model (DEM) values to identify any that might exceed ground surface. In addition, mapped water-table elevations were verified at several locations throughout the county using monitoring well data obtained from the Wisconsin Department of Natural Resources online database of closed remediation sites.