The City of Cape Town council has approved a contract with the Department of Water and Sanitation (DWS) that proposes boosting water supply to the metro by 40-million litres of drinking water a day from 2024/25.
This investment, which is estimated to cost more than R2.3-billion over 20 financial years once the contract is in effect, puts in action what the city says is its “commitment to prioritising water security for its residents in the face of future droughts”.
The city says it is “making every effort” to ensure that its new water programme, as outlined in the city’s water strategy, which is currently being executed, remains on track to produce about 300-million litres more water a day by 2030.
The metro believes that the Berg River to Voëlvlei Augmentation Scheme (BRVAS) is an important component of this strategy to help ensure long-term water security to navigate future climate shocks and droughts.
The Western Cape Reconciliation Strategy Study, developed by the DWS, identified the need to augment the Western Cape water supply system.
A detailed feasibility study found that the BRVAS would be the most cost-effective solution, producing an additional roughly 63-million litres of water a day and increasing the yield by about 4.5% once completed.
The city’s allocation from the scheme will be 40-million litres of water a day.
In order to secure an allocation of water from the scheme, the city had to conclude a 20-year water supply agreement with the DWS.
“This long-awaited water scheme will hopefully now proceed to the implementation phase as soon as practically possible,” says the city council.
This scheme will involve the pumped abstraction of water in the winter rainfall months from the Berg river to increase the yield of the Western Cape water supply system by around 23-million kilolitres a year; a low-level weir and pump station located at the Lorelei site on the Berg river; and a 6.3-km-long pipeline to deliver the water from the Berg river into the Voëlvlei dam.
The pipeline will be designed for reverse operation during summer, so that releases can be made from the Voëlvlei dam to downstream municipal and agricultural users.
The scheme will also ensure the implementation of the ecological water requirements for the estuary.
“The city’s climate change modelling indicates that, over the next 30 years, the Western Cape water supply system’s yield will decrease by 25%,” says acting Water and Sanitation MMC Siseko Mbandezi.
“For this reason, the city is very excited to be entering into this agreement with DWS because BRVAS is an important component of the city’s water strategy.”
Mbandezi adds that Cape Town is in a water-scarce region and that the city has to investigate diverse water sources such as desalination, reuse and groundwater.
“Diversifying our water sources will reduce the city’s current dependence on rain-fed dams as the main source of water.”