St. Tammany Parish, LA Water Table Trend
St. Tammany Parish's groundwater trend, from USGS's own readings
Over 77 years of USGS readings, the well tracking St. Tammany Parish's aquifer is holding roughly steady: 0.3 ft per decade.
This is one representative well, not a county-wide survey, the same grain limit every page here discloses.
St. Tammany Parish's source well, in detail
Water in this well currently sits 10 ft above land surface (flowing/artesian), a flowing or artesian well rather than one pumped from below. Readings span 1949-10-19 to 2026-08-06, 121 measurements from USGS well USGS-302052090010201 (St-532), 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. Tammany Parish compares nationally
St. Tammany Parish sits at rank 853rd 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. Tammany Parish, Louisiana is home to about 277,615 people. See the fastest-moving counties guide for how St. Tammany 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. Tammany 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.