Union County, IL Water Table Trend
Union County, IL: the closest actual trend
The closest qualifying well to Union County is 22 miles away in Alexander County, IL, where the trend runs rising, getting shallower over time.
Union County itself has no monitoring well with enough history to call its own trend, so treat this as a regional estimate, not Union County's own number. If you own a well here, comparing your own depth log against this regional figure is worth doing before assuming either way. See Alexander County, IL's full page. See the no-data guide for why a county this close to a qualifying well still doesn't get its own number.
Union County, Illinois in brief
About 16,886 people live across Union County's 413 square miles, in Illinois. USGS's National Groundwater Monitoring Network covers 1,449 of 3,222 US counties (45%) today; Union County isn't one of them yet, see the methodology guide for the exact qualifying bar.