Yankton County, SD Water Table Trend
Yankton County, SD: the closest actual trend
Cedar County, NE, 29 miles from Yankton County, is the closest county with a qualifying well, and its water table is holding roughly steady.
No well inside Yankton County clears this site's 15-year qualifying bar, so this is the closest real reading, not a measurement of Yankton County's own aquifer. Worth checking your own well's depth log against it rather than assuming it matches. See Cedar County, NE'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.
About Yankton County
Yankton County, South Dakota covers 521 square miles and is home to about 23,509 people. USGS's National Groundwater Monitoring Network covers 1,449 of 3,222 US counties (45%) today; Yankton County isn't one of them yet, see the methodology guide for the exact qualifying bar.