St. Charles County, MO Water Table Trend
St. Charles County's groundwater trend, from USGS's own readings
Over 75 years of USGS readings, the well tracking St. Charles County's aquifer is declining faster than most declining counties: 13.8 ft per decade.
One well stands in for St. Charles 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 242.2 ft below land surface. Readings span 1951-10-01 to 2026-05-06, 78 measurements from USGS well MO005-384846090510301 (Wentzville), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
Where St. Charles County ranks
Of the 1,449 US counties with a usable trend, St. Charles County ranks 1419th from fastest-rising to fastest-declining, 1 is the fastest-rising water table measured, 1449 the fastest-declining. About 423,726 people live in St. Charles County, Missouri. See the fastest-moving counties guide for how St. Charles County stacks up against the most extreme cases nationally.
What a declining table means for a well pump
Because St. Charles County's water table is actually declining, not just a general worry, a well owner here should consider comparing home-warranty plans that cover well-pump failure before one happens.
A dropping table says nothing about water quality
Whether St. Charles 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.