The dam is at the outflow of what was the upper and lower Arrow Lakes; today the two lakes are joined forming one long reservoir extending 232 km (144 mi) north to Revelstoke Dam, and contains 8.76 km3 (7.1 MAF) of reservoir volume.

[4] Immediately downstream of the dam a 185 megawatt (MW) hydroelectric powerhouse, the Arrow Lakes Generating Station, began construction in 1999 and was completed in 2002.

Lower Arrow Lake was raised 12 metres (40 feet) above the natural levels, resulting in several towns being dismantled and relocated before their sites were flooded, including Burton.

[6][7] The dam was named after Hugh Llewellyn Keenleyside, the Canadian ambassador to Mexico, 1944–1947.

The Arrow Lakes reservoir is described by BC Hydro as a "great waterway for boating", despite the effect that the 20 m (66 ft) difference between high and low water has on docks and ramps.