Iroquois County, IL Water Table Trend
Iroquois County's groundwater trend, from USGS's own readings
Iroquois County's long-term well puts the trend at 3.1 ft per decade, rising, getting shallower over time, based on 22 measurements since 1999.
One well stands in for Iroquois 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 12.3 ft below land surface. Readings span 1999-07-09 to 2026-06-02, 22 measurements from USGS well USGS-405458087484601 (28n13w-15.2g), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
Where Iroquois County ranks
Of the 1,449 US counties with a usable trend, Iroquois County ranks 91st from fastest-rising to fastest-declining, 1 is the fastest-rising water table measured, 1449 the fastest-declining. About 26,067 people live in Iroquois County, Illinois. See the fastest-moving counties guide for how Iroquois County stacks up against the most extreme cases nationally.
A dropping table says nothing about water quality
Whether Iroquois 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.