Report of Investigations--KGS


Sudden collapse of unconsolidated earth materials over soluble bedrock, known as cover collapse, damages buildings, roads, utility lines, and farm equipment in Kentucky. It has also killed livestock, including Thoroughbred horses, and injured people. The estimated annual cost of sinkhole cover collapse in Kentucky ranges from $20 million to $84 million and is sensitive to rare but expensive events such as the 2014 National Corvette Museum collapse. The Kentucky Geological Survey began developing a catalog of case histories of cover-collapse occurrences in 1997, and receives an average of 24 reports each year. Three hundred fifty-four occurrences of cover-collapse sinkholes throughout Kentucky are documented, and cover-collapse variables such as diameter, elongation, and depth as a function of bedrock type and time of year have been statistically analyzed. Statewide, cover-collapse sinkholes are on average 2.7 m long, 1.9 m wide, and 2.4 m deep. Some can be substantially larger and deeper. Data in the catalog show that new occurrences of cover collapse may initiate the formation of new sinkholes, but cover collapse generally does not occur in existing sinkholes. Historically, the number of collapses is smallest in February, steadily increases to peak in July, and then decreases through December and into January.

Publication Date



Series XIII

Report Number

Report of Investigations 3

Digital Object Identifier (DOI)


© 2018 University of Kentucky

Statement of Benefit to Kentucky

Much of Kentucky is underlain by bedrock susceptible to sinkhole development. Sinkholes formed by sudden and unpredictable collapse of overlying soil, called “cover-collapse sinkholes,” may result in as much as $80 million in damage annually. The information in this report was collected by the Kentucky Geological Survey over more than 20 years and improves our understanding of these potentially dangerous features.

Funding Information

This project was funded by the Kentucky Geological Survey.

Related Content

Statewide precipitation data for Kentucky (1895-2015) were provided by the University of Kentucky College of Agriculture, Food and Environment.

Included in

Hydrology Commons