USGS Water-Year Summary 2024
370504116404901 ER-OV-01
Southern Nevada volcanic-rock aquifers
Volcanic Rocks
LOCATION - Lat 37°05'03.69", long 116°40'52.38" referenced to North American Datum of 1983, in NE 1/4 SE 1/4 NE 1/4 sec.11, T.10 S., R.47 E., Nye County, NV, Hydrologic Unit 18090202,
REVISIONS HISTORY - Revisions: Groundwater levels above NGVD 1929 and NAVD 1988 from August 7, 2023, at 17:00 UTC to October 31, 2023, at 18:50 UTC were revised on November 28, 2023, because land-surface datum was resurveyed. The previous land-surface datum of 4,007.32 ft above NGVD 1929 was used from October 27, 1997, to July 25, 2023. The current/updated land-surface datum of 4,010.45 ft above NAVD 1988 is applied from July 26, 2023, to the present.
GROUNDWATER RECORDS
WELL CHARACTERISTICS - Depth 180 ft. Upper casing diameter 2.5 in; top of first opening 142 ft, bottom of last opening 180 ft.
DATUM - Land-surface datum is 4,010.45 ft above North American Vertical Datum of 1988. Measuring point: Red mark on top of pvc casing, 2.5 ft above land-surface datum, Oct. 2, 1997 to present. The NAVD of 1988
datum was determined by a level 2 GNSS survey (Reference Frame
NAD_83 (2011) (EPOCH:2010.0000), GEOID18) by USGS on July 26, 2023, and tied to the land-surface reference mark on the well casing. Prior to July 26, 2023, the land-surface datum was 4,007.32 ft above NGVD of 1929 as determined via level survey by
USGS on August 27, 1997.
COOPERATION - U.S. Department of Energy as part of the Nevada Environmental Management Operations Activity.