McHenry County Hydrologic Information: McHenry County, Illinois has current and long-term issues with water resources in providing drinking water, responsible handling of stormwater, and balancing these needs while preserving the rich and diverse ecological systems. In the effort to supply and present timely data to assist in determining the hydrologic conditions of the area, the U.S. Geological Survey (USGS) Illinois Water Science Center presents a near real-time data network of groundwater wells, streamgages and rain gages, in addition to other relevant information such as water-quality data for many of these sites.

The groundwater wells are all in glacial deposits and have well depths ranging from 20 to 345 feet. These wells have multiple owners, including those owned by the McHenry County, the Illinois State Geological Survey (ISGS) and the USGS. Data are collected at 15 minute intervals and transmitted on an hourly basis for the real-time sites. The Illinois State Water Survey (ISWS) is developing a groundwater-flow model of the shallow glacial deposits to assist the county with future groundwater resource management decisions. Periodic measurements of groundwater levels are obtained at varying intervals for the non-real-time wells.

The USGS has several real-time streamgages on the Fox River and Nippersink Creek, with new gages on the Kishwaukee River at Marengo and Franklinville Creek at Franklinville. Data is collected at other surface-water sites on occasional intervals for discharge or other types of data. Real-time data is collected at 15 minute intervals with the data transmitted on an hourly basis.

The USGS and McHenry County rain gage data are collected on 5 or 15 minute intervals, with real-time transmissions on an hourly basis.

All available groundwater, surface-water, and rain gage data described above are available through this web site.

If you have questions or suggestions, please feel free to contact the USGS via email at: dc_il@usgs.gov or at our phone number 217-328-8747 (USGS). For issues with the website, please contact cataylor@usgs.gov.