How do you refill a sinkhole?

Answer 1

The How is pretty simple in theory, you simply must provide as much fill as it takes to fill the cavity that caused the sinkhole in the first place. There is the rub, sometimes the cavity is a fairly small underground open air cavern that over time has had its roof weakened by rainwater and a few thousand tons of fill will replace the cavity and other times the sink hole could be caused by the wearing away of the ceiling / ground by a moving underground river in which case it would take "quite a bit" more fill. I live in Florida and am a dive instructor. We see lots of sink holes the quickly fill with fresh (moving) water because there are openings to underwater caves somewhere in the sink either open to the surface of filtered through the rubble. Other times they just fill with runoff and there is no connection. As you can see there is no simple answer to this one. Another technique tried in Florida where a sinkhole drained a lake was to toss old automobiles to the bottom in hopes of stopping up the drainage, and then allowing the lake to refill. It did work for a while.