Karst Features of the Upper Floridan and Biscayne aquifers

Sinkholes from subsidence event, Florida, February 1998. Over 700 sinkholes formed over a 20-acre area in response to well drilling. A well had been drilled about 20 feet into a cavity, when air-lift well-development methods began being used. Immediately after, small sinkholes started appearing in the surrounding area. Subsidence continued for several hours, with sinkholes closest to the well expanding to become the largest in the area. (Photo by Ann Tihansky)

Sinkhole-formed lakes near Winter Haven, FL. These sinkholes, which often are filled with permeable surficial sands, provide more direct avenues for water from the surficial aquifer system to recharge the underlying Upper Floridan aquifer. (from Spechler and Kroening, 2006)