USGS Water-Year Summary 2024
404757073440401 N 9099. 1
Northern Atlantic Coastal Plain aquifer system
Glacial Aquifer, Upper
LOCATION - Lat 40°47'58.5", long 73°44'03.5" referenced to North American Datum of 1983, Nassau County, NY, Hydrologic Unit 02030201, at northwest corner of Middle Neck Road and Preston Road, Great Neck.
REVISIONS HISTORY - Groundwater levels for the period Aug. 1, 2019 to July 26, 2022, were periodically influenced by the well flooding during precipitation events. These erroneous precipitation spikes were deleted on Mar. 3, 2023.
GROUNDWATER RECORDS
WELL CHARACTERISTICS - Depth 71 ft. Upper casing diameter 4 in; top of first opening 66 ft, bottom of last opening 71 ft.
DATUM - Land-surface datum is 60 ft above National Geodetic Vertical Datum of 1929. Measuring point: Top of 4 inch blue insert holding Ecolog, 59.8 ft above land-surface datum, Feb. 18, 1976 to Oct. 12, 2023; Top of 4 inch blue insert holding Ecolog, 59.811 ft above land-surface datum, Oct. 12, 2023 to present; Top of 4-in steel casing, north edge, 59.763 ft above land-surface datum, Feb. 1, 2024 to present.
PERIOD OF RECORD - April 1976 to January 2000, March 2002 to current year.
GAGE - Water-level recorder installed July 2002; 15-minute recording interval. Periodic manual measurements made by USGS personnel.
EXTREMES FOR PERIOD OF RECORD - Highest water level recorded, 30.86 ft above NGVD of 1929, June 6, 2024; lowest measured, 14.90 ft above NGVD of 1929, Nov. 26, 1982.