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- Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
- For water years 2014 onward, choose a water year and parameter and an on-demand Water-Year Summary report will be generated.
- For water years 2006 through 2013, choose a water year and an Annual Water Data Report will be provided.
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USGS Water-Year Summary 2025
381427075081102 WO Dg 21
Northern Atlantic Coastal Plain aquifer system
Manokin Aquifer
Manokin Aquifer
LOCATION - Lat 38°14'28.3", long 75°08'10.8" referenced to North American Datum of 1983, Worcester County, MD, Hydrologic Unit 02040303, at Assateague Island State Park.
GROUNDWATER RECORDS
WELL CHARACTERISTICS - Depth 310 ft. Upper casing diameter 4 in; top of first opening 300 ft, bottom of last opening 310 ft. Drilled, observation, artesian well.
DATUM - Land-surface datum is 4.94 ft above North American Vertical Datum of 1988. Measuring point: Undefined, distance above land-surface datum not defined, UNDEFINED BEGIN DATE to present; Top of well cap, 3.36 ft above land-surface datum, Sep. 30, 2014, to present.
PERIOD OF RECORD - October 1975 to current year.
GAGE - For 2015 Water Year, records good. Water-level measurements by U.S. Geological Survey personnel. Equipped with non vented pressure sensor with 6 minute recording interval, October 2014 to September 2015.Previously equipped with digital water-level recorder--60-minute recording interval from April 1985 to October 1990.
REMARKS - Ocean City Groundwater Monitoring Network observation well. Also part of the Assateague sea level rise study. Water levels are affected by local groundwater withdrawal. Water-quality records for some prior periods have been collected at this location.
EXTREMES FOR PERIOD OF RECORD - Highest water level measured, 1.37 ft above land surface, April 22, 1991; lowest measured, 7.65 ft below land surface, August 23, 2007.
