the longest in the TVA system. The dam has a generating capacity of 223,100 kilowatts, and its 24-bay spillway has a total discharge of . Kentucky Lake's of shoreline, of water surface, and of flood storage are the most of any lake in the TVA system. Kentucky Dam is served by a navigation lock, soon to be supplemented by a larger lock which will be better able to accommodate the long barge tows that navigate the river in the 21st century. A large industrial complex of chemical plants has developed below the dam near Calvert City due to the convenient barge transportation and inexpensive TVA electricity. The locks' lift raises and lowers vessels up to between Kentucky Lake and the lower part of the river. Background and construction Throughout the 19th century, Congress passed a series of initiatives to improve navigation on the Tennessee River between the river's mouth and Florence, Alabama. By the 1890s, a continuous channel had been secured, but was still deemed insufficient for major river traffic. The U.S. Army Corps of Engineers conducted an extensive survey of the lower river in the early 1900s, and recommended constructing a dam at Aurora Landing (roughly above the present site), but the project was never funded. In the 1930s, the Tennessee Valley Authority sought to create a continuous minimum channel along the entirety of the river from Paducah to Knoxville. The Authority also sought to help control flooding on the lower Mississippi River, especially in the aftermath of the destructive Ohio River flood of 1937. Research had shown that 4% of the water in the lower Mississippi originates in the Tennessee River watershed. TVA surveyed the lower part of the river and considered the Aurora Landing site, but eventually settled on the present site at river mile 22.4. The Kentucky Dam project was authorized by Congress on May 23, 1938, and construction began July 1, 1938. The construction of Kentucky Dam and its reservoir required the purchase of land, of which had to be cleared. 2,609 families, 3,390 graves, and of roads had to be relocated. 65 new bridges were built, 7 were rebuilt, and 3 were razed. The Illinois Central Railroad— which crossed a bridge just downstream from the dam— was rerouted to cross the top of the dam. The communities of Johnsonville and Springville in Tennessee, and Birmingham in Kentucky were completely inundated by the project. A