Johnson County, MO Water Table Trend
Johnson County, MO: what the water table is actually doing
Over 70 years of USGS readings, the well tracking Johnson County's aquifer is declining faster than most declining counties: 11.5 ft per decade.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
Johnson County's source well, in detail
Depth to water at the last reading was 184.2 ft below land surface. Readings span 1956-04-19 to 2026-04-08, 47 measurements from USGS well MO005-384545093331601 (Knob Noster), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
How Johnson County compares nationally
Johnson County sits at rank 1404th 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. Johnson County, Missouri is home to about 55,880 people. See the fastest-moving counties guide for how Johnson County stacks up against the most extreme cases nationally.
If you own a well in Johnson County
A dropping water table means a residential pump has to reach deeper and work harder, which shortens its life. In Johnson County, that trend is real, not assumed: 11.5 ft per decade over 70 years.
Depth and quality are separate questions
This page answers a depth question, not a quality one. A well in Johnson 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.