Cassia County, ID Water Table Trend
Cassia County's groundwater trend, from USGS's own readings
Cassia County's long-term well puts the trend at 7.1 ft per decade, declining faster than most declining counties, based on 188 measurements since 1949.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
Cassia County's source well, in detail
Depth to water at the last reading was 90.3 ft below land surface. Readings span 1949-08-10 to 2023-04-06, 188 measurements from USGS well USGS-421852113222601 (13s 26e 01ccc1), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
How Cassia County compares nationally
Cassia County sits at rank 1356th 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. Cassia County, Idaho is home to about 25,976 people. See the fastest-moving counties guide for how Cassia County stacks up against the most extreme cases nationally.
If you own a well in Cassia County
A dropping water table means a residential pump has to reach deeper and work harder, which shortens its life. In Cassia County, that trend is real, not assumed: 7.1 ft per decade over 74 years.
Depth and quality are separate questions
This page answers a depth question, not a quality one. A well in Cassia 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.