The Vaaldam is the third largest in the Republic and boasts the longest shoreline of any dam as a result of the very flat area, which includes the confluence of the Vaal and Wilge rivers. Construction commenced in 1934 after the promulgation of the Vaal River Development Act. No. 38 of the same year, and the wall was completed in 1938. As Minister of Agriculture, Deneys Reitz visited the site in 1935. He had also helped initiate the Vaal-Hartz scheme. As Minister of Land he had some years previously visited the alluvial diamond diggings along the Vaal nearby. The quarry, now part of the Deneysville Aquatic Club was the one used to build the original wall.
The dam is navigable up to the low-level bridge at Oranjeville and to Villiers and beyond up the Vaal River. The huge surface area at the Jim Fouche Resort area is very shallow and rapidly turns back to but a river when the level drops during dry seasons. Water is now also received from the Highlands Scheme and Sterkfontein Dam.