USGS Hydrologic Conditions Maps for Long Island, NY, 2006

Two user-friendly Map Viewers from U.S. Geological Survey:

2. USGS online mapper for water-table altitude, and potentiometric surface of the Magothy, Jameco, Lloyd, and North Shore aquifers on Long Island, NY

Description: The U.S. Geological Survey (USGS), in cooperation with State and local agencies, systematically collects ground-water data at varying measurement frequencies to monitor the hydrologic situation on Long Island, New York.  Each year during March and April, the USGS conducts a synoptic survey of hydrologic conditions to define the spatial distribution of the water table and potentiometric surfaces within the three main water-bearing units underlying Long Island—the upper glacial, Magothy, and Lloyd aquifers.

Water-level measurements made in 502 wells across Long Island during March-April 2006, were made by the wetted-tape method to the nearest hundredth of a foot.  Water-table and potentiometric-surface altitudes in these aquifers were contoured using these measurements.

The water-table contours were interpreted using water-level data collected from 341 wells screened in the upper glacial aquifer and (or) shallow Magothy aquifer; the Magothy aquifer’s potentiometric-surface contours were interpreted from measurements at 102 wells screened in the middle to deep Magothy aquifer and (or) contiguous and hydraulically connected Jameco aquifer; and the Lloyd aquifer’s potentiometric-surface contours were interpreted from measurements at 59 wells screened in the Lloyd aquifer or contiguous and hydraulically connected North Shore aquifer.

In these datasets, all water-level altitudes are referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29).

Three feature classes depict the potentiometric-surface altitudes in the upper glacial, Magothy, and Lloyd aquifers. A raster dataset depicts the estimated depth to water table beneath Long Island.

Download the Data and Metadata (20.0mb Zip file):

Supporting USGS Report:

USGS Scientific Investigations Map 3066 (abstract & data dwnld instr., four PDF map sheets; scale 1:125,000; 72x34 in.; 45mb each): Long Island 2006 Hydrologic Condition Maps

Summary Handout for report USGS SIM 3066:
8.5x11 PDF , 11x17 PDF