Oglala Lakota County, SD Water Table Trend
Oglala Lakota County, SD: what the water table is actually doing
Oglala Lakota County's long-term well puts the trend at 0.6 ft per decade, rising, getting shallower over time, based on 263 measurements since 1980.
One well stands in for Oglala Lakota 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 28.5 ft below land surface. Readings span 1980-05-08 to 2025-06-17, 263 measurements from USGS well USGS-430200102130001 (35n42w01cdcb (Sn-79c)), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
Where Oglala Lakota County ranks
Of the 1,449 US counties with a usable trend, Oglala Lakota County ranks 320th from fastest-rising to fastest-declining, 1 is the fastest-rising water table measured, 1449 the fastest-declining. About 13,360 people live in Oglala Lakota County, South Dakota. See the fastest-moving counties guide for how Oglala Lakota County stacks up against the most extreme cases nationally.
A dropping table says nothing about water quality
Whether Oglala Lakota 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.