In celebration of World Wetlands Day, which is observed on 2 February, the City of Tshwane is happy to announce that it has taken the first steps in rehabilitating the Centurion Lake and Hennops River.
On 5 February 2020, the City will remove the remaining two sluice gates of the Centurion Lake Weir at the Hendrik Verwoerd Bridge, which will increase the free flow of water through the lake, and get the drainage and desilting process of the lake underway.
While this signals the end of an era of a major Centurion landmark, the lake was not constructed in such a way that it could deal with the extent of pollution and accumulated sediment from upstream municipalities. Over the past decade, more than 50 000 m3 of sediment has accumulated in the lake and opening the weirs will relieve the pressure on the existing storm water systems flowing into the lake. It will also reduce leakages from the sewage system on the southern side of the lake, and reduce odours from stagnant water.
Once the weirs have been opened, the City will start removing silt from the northern and southern stretches of the lake, as well as the silted area in front of the Centurion Hotel. This will create channels on either side of the lake, improve the water flow and speed through the lake, and eventually improve storm water drainage.
The City is constantly interacting with the National Department of Water Affairs and Sanitation to ensure that all processes are in accordance with the City’s water use licence. The rehabilitation process will have a minimal downstream impact, however, residents downstream will notice a darkening of the water colour for the first few weeks. As the water levels in the lake drop, exposed sediment may release unpleasant odours, which will improve as the sediment dries out.
As part of the lake rehabilitation process, much consideration has been given to preventive upstream measures, such as minor excavations of silt at the ARC Weir. The City is also planning to construct a sediment and litter trap at the weir. This will significantly reduce the amount of silt and litter being flushed downstream. The entire project will require the cooperation of our neighbouring municipalities as well as the National Department of Water Affairs and Sanitation.
The City will continue to work with all spheres of government and the non-governmental organisation sector to find sustainable solutions for a cleaner, safer Hennops River.
Cllr Dana Wannenburg
MMC for Environment and Agriculture Management
082 442 3400