Vaal Dam

The Vaal Dam in South Africa was constructed in 1938 and lies 77 km south of OR Tambo International Airport, Johannesburg. The lake behind the dam wall has a surface area of about 320 square kilometres (120 sq mi) and is 47 meters deep. The Vaal Dam lies on the Vaal River, which is one of South Africa's strongest-flowing rivers. Other rivers flowing into the dam are the Wilge River, Molspruit and Grootspruit. It has over 800 kilometres (500 mi) of shoreline and is South Africa's second biggest dam by area and the fourth largest by volume.

Dam data from Wikidata (CC0) plus curated additions. Summary from Wikipedia (CC BY-SA).