Loudoun County, VA Water Table Trend
Loudoun County, VA: what the water table is actually doing
Loudoun County's representative monitoring well shows depth to water holding roughly steady, a fitted trend of 0.3 ft per decade over 63 years of readings.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
Loudoun County's source well, in detail
Depth to water at the last reading was 60.3 ft below land surface. Readings span 1963-11-19 to 2026-09-14, 677 measurements from USGS well USGS-391542077423801 (49y 1 Sow 022), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
How Loudoun County compares nationally
Loudoun County sits at rank 865th 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. Loudoun County, Virginia is home to about 443,380 people. See the fastest-moving counties guide for how Loudoun 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 Loudoun 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.