Alameda County, CA Water Table Trend
Alameda County, CA: what the water table is actually doing
Over 20 years of USGS readings, the well tracking Alameda County's aquifer is holding roughly steady: 0.5 ft per decade.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
Alameda County's source well, in detail
Depth to water at the last reading was 3.3 ft below land surface. Readings span 2006-12-05 to 2026-08-07, 128 measurements from USGS well USGS-374004122092106 (003s003w14k022m), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
How Alameda County compares nationally
Alameda County sits at rank 354th 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. Alameda County, California is home to about 1,649,060 people. See the fastest-moving counties guide for how Alameda 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 Alameda 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.