USGS Water-Year Summary 2023
391825091285101 Vandalia
Cambrian-Ordovician aquifer system
Champlainian Series
LOCATION - Lat 39°18'25", long 91°28'50" referenced to North American Datum of 1983, in SE 1/4 SE 1/4 SE 1/4 sec.05, T.52 N., R.5 W., Audrain County, MO, Hydrologic Unit 07110007,
REVISIONS HISTORY -
Revisions: Land-surface datum was updated to 761.58 ft NAVD88 on May 22, 2023, as determined by a GNSS survey by Missouri DNR. Land-surface datum was previously published as 764 ft NAVD88 from topographic map. Discrete water-level measurements prior to May 22, 2023, are referenced to the original datum.
The record from 12/26/2007 to 11/16/2009 was modified after it was previously set to 'Approved' status. A -2.0 ft measuring point height correction was applied to this period of record to reference water levels to land surface instead of the measuring point which is referenced in the field.
GROUNDWATER RECORDS
DATUM - Land-surface datum is 761.58 ft above North American Vertical Datum of 1988. Measuring point: unknown, 2.0 ft above land-surface datum, Jan. 1, 1939 to present.
PERIOD OF RECORD - December 26, 2007 to present. Gage was installed on December 20, 2007.
GAGE - December 26, 2007 to present; DCP with float, encoder, with telemetry capability were installed as the water level measuring and recording devices. Unit values begin December 26, 2007
COOPERATION - Data from December 20, 2007 to present, furnished by Missouri Department of Natural Resources (MDNR). Data processed by USGS and MDNR.