Sinkholes are common in areas underlain by limestone. Central Florida is such an area, and in one small area of about 25 km2, over 1000 sinkholes have formed by collapse in recent years.
Sinkholes may form as a result of lowering the water table by excessive pumping for human use of the water. This appears to be responsible for sinkhole formation in Florida. Caverns that were forming just below the water table were filled with water. The water table was lowered over the years resulting in the level of groundwater in the caverns to become lower. While the water table was high, the water in the cavern helped to support the roof of the cavern. This support is removed when the water table is lowered, and thus the unsupported roof eventually becomes unstable and collapses to form a sinkhole
.Sinkholes may also form by slow enlargement of caverns by continued dissolution of the limestone. This may no matter what the level of the water table.
When sinkholes collapse to expose the water table at the surface, the sinkhole will be filled with water forming small circular lakes.