Rough River Lake was designed and built by the Louisville District of the U. S. Army Corps of Engineers. The lake serves as a unit of the comprehensive plan for the Ohio River Basin to effect reduction in flood stages downstream from the dam. The lake provides water supply and serves to augment low-flow conditions downstream in the interest of water quality control. In addition, the lake provides general and fish and wildlife recreation. The lake was authorized by the Flood Control Act of 1938. Construction was initiated in November 1955 and the project became operational in June 1961. Rough River Lake lies within the "Clifty" area of the Pennyroyal Region of Kentucky. The term "Pennyroyal" or "Pennyrile," used interchangeably, denotes an area exceeding 11,000 square miles. The name derives from a plant of the mint family which grows profusely throughout the area. The Clifty area comprises the western edge of the Pennyroyal region and was carved by streams through alternating layers of sandstone, shale and limestone, formed in shallow seas of the remote geologic past. These rock layers have been assigned by geologists to the Chester Series of Late Mississippian Geologic Age, a period estimated to have existed about 300,000,000 years ago.

Dam Information:

Area History

Rough River Lake lies within the “Clifty” area of Pennyroyal Region of Kentucky. The term “Pennyroyal” or “Pennyrile,” used interchangeably, denoted an area exceeding 11,000 square miles. The name derived from a plant of the mint family which grows profusely throughout the area.

The Clifty area comprises the western edge of the Pennyroyal layers have been assigned by geologist to the Chester Series of Late Mississippian Geologic Age, a period estimated to have existed about 300 million years ago.

An abundance of water in the area, both surface and underground, has caused solutioning in the limestone and as a result, created a myriad of sinks and caverns. The most important cavern in the area is Mammoth Cave, the longest cave system in the world with more than 240 miles of mapped passageways. The Pennyroyal plain, extending from northern Tennessee through Kentucky to central Indiana, is an outstanding example of “Karst” (sinkhole) topography and is the most widespread topographic feature of this type in the United States.