St. Mary Parish, LA Water Table Trend
Is the water table dropping in St. Mary Parish, LA?
Over 62 years of USGS readings, the well tracking St. Mary Parish's aquifer is holding roughly steady: 0.2 ft per decade.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
St. Mary Parish's source well, in detail
Depth to water at the last reading was 8.8 ft below land surface. Readings span 1964-10-14 to 2026-09-02, 201 measurements from USGS well USGS-294749091402301 (Sm-57u), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
How St. Mary Parish compares nationally
St. Mary Parish sits at rank 825th 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. St. Mary Parish, Louisiana is home to about 46,799 people. See the fastest-moving counties guide for how St. Mary Parish 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 St. Mary Parish 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.