Suffolk County, NY Water Table Trend
Is the water table dropping in Suffolk County, NY?
Suffolk County's long-term well puts the trend at 0.1 ft per decade, holding roughly steady, based on 751 measurements since 1942.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
Suffolk County's source well, in detail
Depth to water at the last reading was 37.6 ft below land surface. Readings span 1942-04-14 to 2026-08-05, 751 measurements from USGS well USGS-404812073004101 (S 3521. 1), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
How Suffolk County compares nationally
Suffolk County sits at rank 724th of 1,449 ranked counties, ordered rising-to-declining, so a low number means a rising water table and a high one means fast decline. Suffolk County, New York is home to about 1,535,909 people. See the fastest-moving counties guide for how Suffolk County stacks up against the most extreme cases nationally.
Depth and quality are separate questions
This page answers a depth question, not a quality one. A well in Suffolk County can be stable in depth and still worth testing for quality, or declining and still test clean, the two are measured separately, and only a direct test settles the second one.