Marshall County, IA Water Table Trend
Marshall County, IA: what the water table is actually doing
Over 28 years of USGS readings, the well tracking Marshall County's aquifer is declining, slower than most declining counties: 1.1 ft per decade.
One well stands in for Marshall 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 8.9 ft below land surface. Readings span 1997-07-09 to 2025-06-10, 22 measurements from USGS well USGS-420117092505601 (083n17w05dcdd 1997nawqa Marshall Co Iadrn-5), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
Where Marshall County ranks
Of the 1,449 US counties with a usable trend, Marshall County ranks 1102nd from fastest-rising to fastest-declining, 1 is the fastest-rising water table measured, 1449 the fastest-declining. About 40,392 people live in Marshall County, Iowa. See the fastest-moving counties guide for how Marshall County stacks up against the most extreme cases nationally.
What a declining table means for a well pump
Because Marshall 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 Marshall 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.