Fairfax County, VA Water Table Trend
Fairfax County's groundwater trend, from USGS's own readings
Fairfax County's long-term well puts the trend at 0.2 ft per decade, holding roughly steady, based on 1638 measurements since 1976.
One well stands in for Fairfax County's whole aquifer here, the honest simplification every page on this site carries.
What the well actually measured
The most recent reading put water 16.7 ft below land surface. Readings span 1976-10-28 to 2026-09-17, 1638 measurements from USGS well USGS-385638077220101 (52v 2d), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
Where Fairfax County ranks
Of the 1,449 US counties with a usable trend, Fairfax County ranks 840th from fastest-rising to fastest-declining, 1 is the fastest-rising water table measured, 1449 the fastest-declining. About 1,160,925 people live in Fairfax County, Virginia. See the fastest-moving counties guide for how Fairfax County stacks up against the most extreme cases nationally.
A dropping table says nothing about water quality
Whether Fairfax County's water table is rising or falling is independent of what's actually in the water. Depletion can concentrate naturally-occurring minerals, so it's worth checking directly with a water test rather than assuming a depth trend says anything about quality.