USGS Water-Year Summary 2024
422308088231002 8-GRN-D
Sand and gravel aquifers (glaciated regions)
Quaternary System
LOCATION - Lat 42°23'08", long 88°23'10" referenced to North American Datum of 1983, in SE 1/4 SE 1/4 SW 1/4 sec.11, T.45 N., R.7 E., McHenry County, IL, Hydrologic Unit 07120006, 80 feet north of Wondermere Road on McHenry County property, 0.3 mi. east of Greenwood Road, 0.2 mi. south of Nippersink Creek and 1.4 mi. west of Wonder Lake, and 0.5 mi. southeast of the City of Greenwood. Owner: McHenry County.
REVISIONS HISTORY - Revisions: Land-surface datum was updated to ft 856.06 NAVD88 on May 30, 2023, as determined by a GNSS Level II survey. Land-surface datum was previously published as 855.97 ft NAVD88 (furnished). Discrete water-level measurements prior to May 30, 2023, are referenced to the original datum.
GROUNDWATER RECORDS
WELL CHARACTERISTICS - Depth 153.1 ft. Upper casing diameter undefined; top of first opening 148.1 ft, bottom of last opening 152.6 ft. Well-casing includes 2-inch schedule 40 PVC pipe, 6 in. diameter borehole with bentonite seal, observation well.
DATUM - Land-surface datum is 856.06 ft above North American Vertical Datum of 1988. Measuring point: Top of PVC casing; High point marked, 2.42 ft above land-surface datum, Sep. 23, 2008 to present.
PERIOD OF RECORD -
GROUND-WATER LEVELS: February 2009 to current.
GROUND-WATER QUALITY:
CHEMICAL: Water year 2011.
GAGE - Water level recorder and satellite telemeter.
EXTREMES FOR PERIOD OF RECORD - Highest water level, 12.83 ft below land-surface datum, May 23, 2020; lowest, 22.89 ft below land-surface datum, July 8, 2012.