USGS Water-Year Summary 2023
383031090384101 Eureka
Ozark Plateaus aquifer system
Gasconade Dolomite
LOCATION - Lat 38°30'33.1", long 90°38'39.8" referenced to North American Datum of 1983, in NE 1/4 SE 1/4 sec.35, T.44 N., R.3 E., St. Louis County, MO, Hydrologic Unit 07140102,
REVISIONS HISTORY - Revisions: Land-surface datum was updated to 614.89 ft NAVD88 on May 22, 2023, as determined by a GNSS survey by Missouri DNR. Land-surface datum was previously published as 615 ft NAVD88 from topographic map. Discrete water-level measurements prior to May 22, 2023, are referenced to the original datum.
GROUNDWATER RECORDS
DATUM - Land-surface datum is 614.89 ft above North American Vertical Datum of 1988. Measuring point: unknown, 1.8 ft above land-surface datum, Jan. 1, 1966 to present.
PERIOD OF RECORD - October 14, 2000 to present.
GAGE - Prior to 05/11/2005, the water level measuring device was a float driven encoder. A vented, submersible pressure transducer setting in metal box on top of casing was installed on 05/11/2005. On 02/23/2012, the vented submersible pressure transducer was replaced with a float driven encoder. On 04/05/2012, the float driven encoder was replaced with a vented submersible pressure transducer. The water level recording device is a DCP with telemetry capability.
COOPERATION - Data furnished by Missouri Department of Natural Resources (MDNR). Record furnished by MDNR and the USGS.