Fall River County, SD Water Table Trend
Fall River County's groundwater trend, from USGS's own readings
Fall River County's representative monitoring well shows depth to water rising, getting shallower over time, a fitted trend of 6.6 ft per decade over 26 years of readings.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
Fall River County's source well, in detail
Depth to water at the last reading was 517.4 ft below land surface. Readings span 1992-09-16 to 2018-09-26, 175 measurements from USGS well USGS-432548103414801 (007s04e19bccb Fr92a), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
How Fall River County compares nationally
Fall River County sits at rank 41st 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. Fall River County, South Dakota is home to about 7,359 people. See the fastest-moving counties guide for how Fall River County stacks up against the most extreme cases nationally.
Depth and quality are separate questions
This page answers a depth question, not a quality one. A well in Fall River 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.