In terms of the Rand Water Board Supplementary Water Supply (Private) Act 1914, the Board decided to construct a barrage at the Lindeque’s site, 25 miles down stream from Vereeniging where the Vaal River had a width of 620 feet. This barrage was designed to provide an additional 10 million gallons a day, but the outbreak of the 1914 – 18 world war delayed construction until 1918. Work commenced on the 1,400 -ft wide barrage, as well as river intakes and the main plant in Vereeniging which included pumping plant, sedimentary tanks, filters and clear water reservoir.
Despite every effort at reduction, water consumption had reached 13.448 million gallons per day in 1920. On July 2nd 1922,
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 -Hartzscheme. 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.
With the rapid expansion of in dustry and the development of the O.F.S. Goldfields the wall was raised some 6 meters in 1952, which included 60 sluice gates. In 1958 the wall was strengthened and raised a further 3 meters odd and the outlet and tunnel were built to feed Suikerbosrand purification plant. The water previously obtained from the Barrage had become so infested with bacteria that it was becoming difficult to purify.
The dam 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.
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. It is interesting to hear that the next phase to increase the capacity of the Highland Scheme has been cancelled due to the expected minimal increase in population due to aids. In 1987 the dam dropped to some 13% and the island was connected to the main land. Hawaii, the ‘underwater island’ became a peninsula and Beacon Island came to view where a mass of seagulls nested. The weather here is varied and unpredictable as it is situated at the edge of the cyclonic belt, which brings the thunderstorms to the Witwatersrand. Besides the few tornadoes, winds of over 60 knots have been recorded. The general westerly winds are punctuated by strong easterlies which generate two meter waves that pound the Deneysville shores.
Besides otters and snakes and the occasional hippo the dam is populated by yellow tail, carp and barbel, which grow up to three meters in length.
The Vaal Dam monster?
Divers at the wall are real scared of them. Fresh water prawns have also been seen. The dam was commonly called Lake Deneys, but the name was ignored and still remains the Vaaldam.
Technical Advances -1930 From a review published by the Star newspaper.
On February 22, 1934, The Star announced a bold Government plan to harness the waters of the fickle Vaal River, which only five months before had run dry. The summer of 1934 witnessed billions of litres of floodwater going to waste simply because the Vaal had no storage capacity.
The £3.5 million cost would not only give the country the biggest irrigation scheme down to Vaalhartz, but supply the Rand, with it’s expansion, with all the water needed for the next 50 years. (The time span was spot on: 50 years later, to the year, the Rand was in the grip of one of it’s worst ever droughts.
The lake to be formed was unofficially called Lake Deneys. The Star wrote of how this vast stretch of water would be a recreational boon to the Rand. In fact it was to remain a mostly bare, featureless scene.