Sinkhole Size

This paper discusses the average size of a sinkhole as determined from Southwest Florida Water Management District data for sinkholes that have occurred in west-central Florida. From review of this information an average sinkhole size of about 3.4 meters (11.2 feet) has been found. The information is valuable in planning sinkhole investigations because it provides an approximate measure of the size of the zone that can be affected by a sinkhole. Based on the average sinkhole size, the minimum depth of a subsurface investigation should be to approximately 22 meters (72.2 feet) based on estimates of critical beam thickness. Because of the relatively small size of a sinkhole, the probability of finding the feature in a sinkhole investigation using borings alone is very low.