The Ertjieskloof Dam, situated near Stellenbosch University’s (SU) Coetzenberg sports grounds, started being refilled from June 2024 after being drained for repair work since 2021. This is according to Petro Mostert, communications specialist at SU.
“The dam is primarily a storage facility for irrigation water used for our sporting fields and landscape,” said Mostert.
Stellenbosch University’s Ertjieskloof Dam is located at the foot of Stellenbosch Mountain. The dam has undergone repairs recently, following a leak caused by a geological fault line, according to Petro Mostert, communications specialist at Stellenbosch University. The subsequent projects were initiated to increase its full water capacity, and improve its extraction and pumping capabilities, said Mostert. PHOTO: Nkululeko Ndlovu
The initial problem: a leaky dam
“On 31 March 2021, [SU] finished a project to repair and upgrade the Ertjieskloof Dam […] this reconstruction of the dam increased the capacity of the dam to 79 000m3,”said Mostert.
The reason for the repair work being required is because the dam is situated along a geological fault, which caused the leak. This is according to a Maintenance Management Plan (MMP) obtained from Mari de Villiers, an environmental consultant acting on behalf of Cornerstone Environmental Consultants, the environmental control officers involved in the project.
“A fault line – is a geological feature, in the ground, where rock masses have slipped past each other, mostly millions or hundreds of millions of years ago, here in the Cape,” said Professor Alexander Kisters, professor of geology at SU .
“Fault lines are commonly relatively weak zones, because the original rock has been broken up and crushed by the fault action that makes many faults prone to a potential ‘reactivation’, meaning, if, at a much later stage, this part of the region is being stressed/loaded (buildings, etc.) the fault is likely the first feature to ‘fail’ (slip again) in the otherwise intact, strong rock,” according to Kisters.
A drainage system located at the bottom Ertjieskloof Dam used to drain and fill the dam. This is according to a maintenance management plan prepared by Mari de Villiers, the representative environmental control officer of Cornerstone Environmental Consultants. The intake is located beneath water-surface level due to concerns that this intake might be damaged by the public accessing the dam, according to de Villiers. PHOTO: Nkululeko Ndlovu
Although there was a leak in the dam which caused it to operate at below full capacity, “there was no [water] lost as we [SU] filled the dam below the point of leak”, said John de Wet, environmental sustainability manager at SU.
“The dam was originally designed for 79 000m3. Due to a leak the dam safety level was reduced,” said De Villiers.
According to Mostert, the cost of the construction work done to repair the leak in Ertjieskloof dam and increase its full water capacity was R11,1 million.
More projects more water extraction:
“We have also commenced on a new project to install a dual pipe system from the dam to the river. In the past, we only had one pipe which we can either pump or extract water from the Eerste River,” said Mostert. “With this dual pipe system, we will be able to pump water and irrigate our sporting fields simultaneously.”
A new dual-pipe system implemented at Stellenbosch University’s (SU) Ertjieskloof Dam will allow them to pump water and irrigate the university’s sports facilities. This is according to Eugene Van Vuuren, a civil engineer at All Fence Construction. This is part of a new dual-pipe system which will allow Stellenbosch University to simultaneously pump water and its sports facilities. This is according to Petro Mostert, communications specialist at SU. This pipe system is located beneath the dam’s surface. PHOTO: Nkululeko Ndlovu
According to Mostert, this project follows the tail-end of repairs at the dam. Mostert said that the current project is along the Eerste River, where weather storms have caused damage to extraction systems serving water into Ertjieskloof dam.
“The recent storms in February damaged the extraction point that serves the dam. The current construction work that is ongoing next to the Eerste River forms part of this project (at a cost of R2,7 million) to repair this system,” said Mostert.
“The total extraction is 98 390m3. We are storing 79 000m3 and the balance we pump directly to sport fields and landscape,” said De Wet.
The final project of installing a dual-pipe system is at an additional total cost of R10,2 million.