Hartbeespoort Dam is an arch type dam situated in the North West Province of South Africa. It lies in a valley to the south of the Magaliesberg mountain range and north of the Witwatersberg mountain range, about 35 kilometres north west of Johannesburg and 20 kilometres west of Pretoria
The dam wall is 149.5 metres (163.5 yd) long and 59.4 metres (195 ft) high, built across a gorge cutting through the Magaliesberg. The reservoir is fed by the waters of the Crocodile River and Magalies River and covers approximately 18.83 square kilometres (7.27 sq mi), with a mean depth of 9.6 metres (31 ft) and maximum depth of 45.1 metres (148 ft). It has a surface area of 20 square kilometres (7.7 sq mi), and its normal range of annual water level fluctuation is 0.8 metres (2.6 ft). The mixing type of the reservoir is monomictic.
A single-laned, tarmac road skirts the water’s edge on the north side; along its route it passes through a 56.6 m long tunnel and also crosses the dam wall.