Bennett County, SD Water Table Trend
Bennett County's groundwater trend, from USGS's own readings
Bennett County's long-term well puts the trend at 0.4 ft per decade, holding roughly steady, based on 320 measurements since 1976.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
Bennett County's source well, in detail
Depth to water at the last reading was 22.1 ft below land surface. Readings span 1976-11-03 to 2025-06-17, 320 measurements from USGS well USGS-431136101200901 (37n34w09aaaa (Bt-76b)), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
How Bennett County compares nationally
Bennett County sits at rank 923rd 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. Bennett County, South Dakota is home to about 3,289 people. See the fastest-moving counties guide for how Bennett 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 Bennett 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.