Lyman County, SD Water Table Trend
Lyman County, SD: the closest actual trend
The closest qualifying well to Lyman County is 38 miles away in Tripp County, SD, where the trend runs rising, getting shallower over time.
Lyman County itself has no monitoring well with enough history to call its own trend, so treat this as a regional estimate, not Lyman 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 Tripp County, SD'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.
Lyman County, South Dakota in brief
About 3,721 people live across Lyman County's 1,642 square miles, in South Dakota. USGS's National Groundwater Monitoring Network covers 1,449 of 3,222 US counties (45%) today; Lyman County isn't one of them yet, see the methodology guide for the exact qualifying bar.