Riverside County, CA Water Table Trend
Riverside County, CA: what the water table is actually doing
Riverside County's long-term well puts the trend at 10.8 ft per decade, declining faster than most declining counties, based on 534 measurements since 1921.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
Riverside County's source well, in detail
Depth to water at the last reading was 159 ft below land surface. Readings span 1921-04-14 to 2026-05-11, 534 measurements from USGS well USGS-335830117022201 (002s002w25b001s), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
How Riverside County compares nationally
Riverside County sits at rank 1400th 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. Riverside County, California is home to about 2,529,933 people. See the fastest-moving counties guide for how Riverside County stacks up against the most extreme cases nationally.
If you own a well in Riverside County
A dropping water table means a residential pump has to reach deeper and work harder, which shortens its life. In Riverside County, that trend is real, not assumed: 10.8 ft per decade over 105 years.
Depth and quality are separate questions
This page answers a depth question, not a quality one. A well in Riverside 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.