Warren County, NJ Water Table Trend
Warren County's groundwater trend, from USGS's own readings
Warren County's long-term well puts the trend at 0.4 ft per decade, holding roughly steady, based on 10 measurements since 1991.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
Warren County's source well, in detail
Depth to water at the last reading was 6.5 ft below land surface. Readings span 1991-10-11 to 2026-10-07, 10 measurements from USGS well USGS-405003074495001 (410305-- Mw 85r), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
How Warren County compares nationally
Warren County sits at rank 416th 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. Warren County, New Jersey is home to about 112,031 people. See the fastest-moving counties guide for how Warren 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 Warren 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.