lies astride the fall line, a geological transition point that is marked by a change in elevation, resulting in rapids where the Chattahoochee River crosses. Historically, the fall line was a point of portage for river travelers, and a location associated with the building of dams and mills which harvested the power of the falling water. The Chattahoochee River was an essential resource in deciding to locate the new city of Columbus in 1828. The city saw the construction of three dams. As Columbus grew, the North Highlands Dam was built to capture power specifically for the Bibb City Mill, which at the turn of the 20th century had more spindles turning than any other mill in the United States. Later, power from the dam was also used to grind corn and wheat and saw lumber for the growing community. The dam was nearly destroyed by a flood in 1901, and was rebuilt and reconfigured two years later. Two separate power houses were built, one generating 5,000kw of electricy for general use, and the other which delivered power, by way of a rope drive, to the Bibb City Mill. The rope drive system was maintained until 1954. The dam underwent an extensive upgrade in 1963, when the old powerhouses were replaced with a four unit power generator house capable of producing 29,600kw. The North Highland Dam impounds Bibb Pond, which has 131 acres of surface water, with three miles of shoreline, at a crest elevation of 269 feet above mean sea level. The dam, which is controlled remotely from Bartletts Ferry and is completely automated, is currently owned by Georgia Power.
Discharge
Discharge from the dam averaged 6,286 cubic feet per second, over the 31 year period of observation 1929-1960. Discharge rates, over the course of a given year, vary considerably with seasonal changes in rainfall, within the 4,670 square miledrainage area of Chattahoochee river system supplying water to the dam. In 1960, maximum discharge was measured at 59,100cfs and a minimum of 1,220cfs. Recorded extremes, during the period 1929-1960, are a maximum discharge rate of 104,000cfs, and a minimum discharge rate of 294cfs. The highest recorded discharge took place on March 16, 1929 at the rate of 198,000cfs.