We had to move to a larger room, so many attended this groundwater talk at VSU (about 90). Plus a guest appearance by SAVE.

Here are Dr. Donald M. Thieme‘s slides in PDF, with his longer title:

Coastal Plain Surficial Deposits, Groundwater Resources, and Recent Subsidence in south Georgia

While we are lucky to have abundant groundwater, both from the Upper Floridan Aquifer 100 feet below us trapped in Eocene limestones and from shallow groundwater with its karst features, nonetheless overpumping has caused falls in the level of the aquifer (about 0.6 feet a year at Valdosta), resulting in rapid loss of shallow groundwater, plus surface water that enters and often contaminates the aquifer through those karst features.

Sometimes those karst features subside and manifest as sinkholes like the one that ate Snake Nation Road in Lowndes County and others that can develop slow (many years) or fast (weeks or minutes).

There were also many questions, starting with what water do personal wells reach? Also including a brief history of Valdosta well drilling from artesian to hundreds of feet down, and a sinkhole in a garage in Lowndes County, should local governments require sinkhole insurance (including mention of Moody AFB subsidence and Florida citrus growers pumping so much water it causes sinkholes). I also introduced the WWALS board members present: Gretchen Quarterman (Treasurer and videoing), Bret Wagenhorst (Outings), Heather Brasell (Secretary), Dave Hetzel (President), April Huntley (Director), me (Vice President), and Chris Graham (Member); plus a brief summary of WWALS events and outings. Here’s a video playlist: