Whitley County had an estimated population of 34,898 in 1999 with 60 percent on public water. The estimated 2008 population was 38,668 with 99 percent served by a water utility.
The Water Resource Development Commission has prepared a report on water supply infrastructure in the county.
It is estimated that there are over 200,000 water wells in Kentucky. The Kentucky Ground-Water Data Repository, maintained by the Kentucky Geological Survey, has information on over 50,000 of these wells. The locations of wells and springs in the county for which data is available is shown on the map of wells and springs in the county. A map of certified well drillers in Kentucky has been prepared by the Kentucky Division of Water.