The Louisville-Metro Levee System is federally authorized and constructed under the Flood Control Act approved 28 June 1938, and non-federally operated and maintained. It is located in Jefferson and Bullitt Counties, Kentucky, along the left bank of the Ohio River; extending from river mile 602.0 to 628.6. The Louisville-Metro Levee provides flood risk reduction to the City of Louisville and portions of Jefferson and Bullitt Counties. As of the 2010 census, the total population of Jefferson County was 741,096. The levee system has a total length of near 26 miles and consists of approximately 21.0 miles of earthen embankment, 4.20 miles of concrete wall, 15 pump stations (housing 73 pumps), 152 gates, 77 closures, and other necessary appurtenances. The leveed area is estimated at approximately 49,000 acres and reduces risk against Ohio River floods equal to the maximum of record, elevation 460.15 feet (NAVD88) in January 1937, with a freeboard of three feet (providing risk reduction to an estimated 8,000 year return event). Construction on the Louisville Reach began in March 1947 and was completed in 1956. It was transferred to local interests for operation and maintenance in two parts, with the first portion transferred in January 1953 and the second portion transferred in July 1954. Design top of levee elevations along this reach vary from 458.3 to 463.7 feet (NAVD88). The Southwestern Jefferson Reach (which extends into a portion of Bullitt County) was authorized by the Flood Control Act of August 1968. Construction of the Southwest Jefferson Reach began in October 1973 and was completed in 1989. Design top of levee elevations vary from 457.2 to 459.0 feet (NAVD88). Upon completion of the Southwest Jefferson Reach, approximately 4.7 miles of levee embankment and a pump station located along the Mill Creek Cutoff were abandoned (Section E, Louisville). This portion of levee is obsolete and is no longer required to be maintained.