USGS Water-Year Summary 2023
393544093075601 Mendon
Sand and gravel aquifers (glaciated regions)
Drift
LOCATION - Lat 39°35'44.0", long 93°07'56.0" referenced to North American Datum of 1983, in SE 1/4 SE 1/4 NW 1/4 sec.10, T.55 N., R.20 W., Chariton County, MO, Hydrologic Unit 10280103,
REVISIONS HISTORY - Revisions: Land-surface datum was updated to 687.25 ft NAVD88 on May 22, 2023, as determined by a GNSS survey by Missouri DNR. Land-surface datum was previously published as 690 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 687.25 ft above North American Vertical Datum of 1988. Measuring point: unknown, 1.4 ft above land-surface datum, Sep. 15, 2009 to present.
PERIOD OF RECORD - September 15, 2009 to present.
Periods of Missing Record: 09/26/2009 to 09/27/2009; 10/24/2009 to 11/03/2009; 12/31/2009 to 01/02/2010; 02/16/2010 to 02/17/2010; 04/11/2010 to 04/12/2010; 07/02/2011 to 07/03/2011; 10/23/2011 to 11/01/2011; 03/24/2012 to 04/04/2012; 03/20/2013 to 04/08/2013; 04/12/2013 to 04/23/2013; 09/13/2013 to 09/25/2013; 06/08/2015 to 06/23/2015; 07/20/2015 to 07/28/2015; 08/17/2015 to 08/18/2015; 12/14/2015 to 12/29/2015; 09/10/2016 to 09/20/2016; 12/16/2016 to 12/17/2016; 12/17/2016 to 12/19/2016; 03/29/2017 to 04/13/2017; 04/14/2017 to 04/18/2017; 07/19/2017 to 07/22/2017; 01/05/2018 to 01/06/2018.
GAGE - From 09/15/2009 to present, water level recording device is a DCP with telemetry capability setting in metal box on top of casing. Water level measuring device is a float driven encoder.
COOPERATION - From 09/15/2009 to present, data furnished by the Missouri Department of Natural Resources (MDNR). From 09/15/2009 to present, data processed by the USGS and MDNR.