South Africans must embrace drinking treated sewage water or risk severe shortages
The lack of attention to maintenance and upgrades in the water sector, coupled with demographic shifts, has led to water insecurity in South Africa’s most populous province of Gauteng.
The long-term prognosis is not good, unless society can be mobilised towards fully reusing water and embracing the reuse of fully-treated sewage, according to water expert Craig Sheridan, writing in the latest issue of the South African Journal of Science, which is focused on discussions on service delivery.
South Africans are familiar with electricity load-shedding, which has been a part of life since 2007.
“Unfortunately, ‘shedding’ has moved beyond electric power and firmly into the domain of water supply. Gauteng, and particularly the Johannesburg metro, has started to be subjected to significant occurrences of ‘water shedding’ or intermittent water supply,” Sheridan wrote.
South Africa has engineered effective systems to reduce and prevent water insecurity. Systems of dams and inter-basin transfer schemes have been built across Southern Africa to continue supplying water to primarily Johannesburg and Gauteng.
Sheridan, who is the Claude Leon Foundation chair in water research and the director of the Centre in Water Research and Development at the University of the Witwatersrand, noted that this strategy was highly effective at ensuring security until very recently.
The regular occurrence of intermittent water supply in Johannesburg is a new phenomenon. As a strategy for managing water supply, it has serious negative consequences, including increasing residential capital outlay for water storage through the need for additional capacity, such as water tanks and booster pumps, causing damage to the distribution network and compromising the quality of the water, particularly with regard to its microbiological profile.
Water scarcity is defined as an excess of water demand over available supply, Sheridan said. The department of water and sanitation (DWS) ensures the country’s security, allocating water based on the population of a region and its availability in storage systems such as dams.
This allocation is sold by the department to the bulk water utility — Rand Water for Gauteng, including Johannesburg — which treats it to obtain a potable quality. It sells this fresh potable water to a number of metropolitan municipalities including Johannesburg Water as the metro entity, which then sells it onwards to consumers.
“There is currently, however, a mismatch between what the department sells and what is needed, as the DWS is responsible for supplying both current and future needs,” Sheridan said.
South Africa, and particularly Johannesburg, is not water-scarce. This could change quite rapidly if “we were to experience a day-zero type drought” — but the city is “currently very water insecure”.
Located on the African continental divide at an altitude of above 1 600m above mean sea level, Johannesburg has no large rivers or natural water sources and all its water is imported. To maintain water security, additional dams are being built in Lesotho as part of the Lesotho Highlands Transfer Scheme.
“Unfortunately, the construction of these dams has been delayed by eight years. This delay coincides exactly with a period in which Gauteng grew from 12 million to 15 million people. This means that in 2023, the province had the same water storage for a population which had grown by 25%,” Sheridan wrote.
Over the past three to four years, the City of Johannesburg has increasingly supplied water intermittently to its customers. “In the summer of 2023-2024, water outages became a regular occurrence, especially for those living at higher elevations or in older suburbs in the city.”
These characteristics fit all the criteria for water insecurity, such as an excess of demand over supply. “In the older suburbs, the initial cause of these outages was primarily due to leaking water supply pipes, which were patched … During the patching process, water to the entire suburb would be shut off.”
This temporary nature of intermittent supply has “now totally changed”, which is indicative of a larger system which is not being properly maintained.
“When some minimal maintenance is conducted, the job is not properly completed. As a result, the roads are left with large, open excavation works, sometimes for months on end following a water repair, and the water repair often still leaks,” said Sheridan.
“This is happening across all suburbs now. While this was (and is) happening in Johannesburg, in Hammanskraal in Pretoria there was an outbreak of cholera in 2023 which claimed over 30 lives.”
At the same time, the blue and green drop audits and reports were re-established and published. Both reports indicated that the freshwater treatment works supplying the country’s drinking water, and the wastewater treatment works treating its sewage, are increasingly dysfunctional. This is a trend seen across the entire country.
Similarly, a no-drop report revealed the amount of water which is stolen or lost through leaking pipes. For Joburg, this amount is close to 50%. “This means that the allocation of water for Gauteng, which is distributed to Johannesburg, Pretoria and other cities, is reduced by 50% (in the case of Johannesburg), because of theft and/or leakages.”
The department will not increase the quota for Gauteng because they are the stewards or the custodians of the resource at a national level. “They are concerned with meeting both current and future needs for the entire country, not just the immediate needs of Gauteng, or Joburg. These statistics indicate that we have 50% less water for 25% more people. This extra usage and loss overloads the system entirely. The rate of drawdown on our potable water reservoirs is greater than the maximum rate of recharge.”
This discrepancy has resulted in reservoirs running empty and the City of Joburg throttling back supply during periods of high demand for reservoirs to recover, leaving many residents without water, not just for nightly periods but in some instances for weeks. For those in the highest-lying areas, the impact is the greatest.
Then, the occurrence of load-shedding and power supply challenges means that pumping stations are often also not working. “This is the current state of water systems, especially in Johannesburg,” Sheridan wrote, noting that the blame for this poor state must be firmly placed with the administration of the city.
He said that although it is possible to live for weeks without electricity, without water, the options rapidly diminish in terms of how long people can be resilient.
“The cost of purchasing bottled/container water is prohibitive, and yet, under these circumstances, it becomes the only available option. For those who grow food in their gardens (as happens in many poorer settlements), the cost increases exponentially because the allotment-type gardens, which contribute towards food security, are dry and barren from lack of water,” he said, noting that the poorest have to purchase not only water but additional food too.
There is very little space left in South Africa to construct new large dams, Sheridan said. This means that water security will decline after 2028, especially if the country proceeds with current social, cultural, political and engineering practices.
The “confounding” effect of the climate crisis also drives up water demand because temperatures are higher; it increases evaporative losses on the dams and there is an increased number of flood events from bigger storms, which “pose the very real risk of destroying infrastructure such as dams, water treatment plants and wastewater treatment plants”.
Johannesburg, in particular, notwithstanding the high rates of water lost from broken infrastructure, still uses too much water per capita —more than any other province. Changes need to be made to ensure long-term sustainability and to improve water security, he said.
Real shifts in the economics and pricing of water must occur, Sheridan said. “Much steeper tariffs can be applied to users of water that exceed their fair share … and this will undoubtedly drive consumption downwards.”
The administrations of the country’s cities, particularly Joburg, need to urgently ring fence funding for maintenance and infrastructural improvement.
“As a global society, we need to reconsider how we value water. Our future requires some truly creative problem-solving. We might need to consider how to bring water from the African tropics such as transfers from the Congo belt or the Zambezi.”
Once the energy crisis is solved, the opportunity for desalination of sea or mine water for augmentation of potable supply might become a viable possibility.
“The future, however, must include direct reclamation (sewage to potable water) as the global population moves towards 10 billion people.”
There is still a critical need to conduct additional research to understand how pathogenic organisms (including emerging pathogens and viruses) and emerging contaminants (such as pharmaceuticals and pesticides) behave in wastewater treatment plants.
“This is such that when we return the treated sewage, especially to the potable water reticulation systems, we do not harm our societies with increased exposure to these compounds at potentially harmful levels,” Sheridan said, noting that these will build up, possibly to toxic levels, if they are not removed at wastewater treatment plants.
Significant civic education needs to take place to remove the “yuck” factor of drinking treated sewage, despite South Africans already drinking water sourced from rivers that are highly contaminated by sewage and wastewater treatment plant outfall. This is “made all the worse by our failing wastewater treatment works”.