Over the past few years Gauteng, the country’s most populous and economically active province, has suffered increasing water interruptions. More restrictions are expected. Water storage is stable in other parts of the country, but the government has urged people to save water.
Against this backdrop, we revisit two common claims that compare water use in South Africa to that in the rest of the world.
Africa Check last examined claims about the country’s water use in 2018. Then, average water consumption was roughly 235 litres per person a day. But a lack of data made it difficult to estimate a world average.
Has this changed? And what do the numbers now look like in Gauteng?
In October 2022, Rand Water, the public utility responsible for supplying water to Gauteng, blamed increased consumption for water restrictions.
“On average, water consumption in Gauteng per person per day is over 300 litres against a world's average of 173 litres per person per day,” it said in a statement.
Weeks later Mzi Khumalo, a member of the Gauteng government’s executive committee, made a similar claim. The province’s average daily water consumption was above the world average and should be reduced, he said during a parliamentary committee session.
South Africa has nine water management areas, or WMAs. These determine how water resources are used in specific regions.
Source: The Water Management Areas of South Africa, DWS
Rand Water supplies water to municipalities in the Vaal WMA, which covers the provinces of Gauteng, the Free State, North West and Mpumalanga.
Rand Water spokesperson Makenosi Maroo told Africa Check that since September 2022, its average daily supply of water to municipalities in these provinces had increased from 4.3-billion litres to 4.9-billion litres.
About 17-million people lived in the municipalities Rand Water served, she said.
These figures do work out to an average consumption of almost 300 litres per person a day. But this is for the entire Vaal WMA, not just Gauteng.
Kobus Du Plessis is a professor of hydrology and environmental engineering at Stellenbosch University in the Western Cape province. He told Africa Check that average water use cannot simply be calculated by dividing the water supply by the number of people in a municipality.
There are several reasons for this.
First, water isn’t only used in people’s homes. It’s also used by industry. Some municipalities have more industries than others, so water use will differ significantly. Municipalities with more industries would have distorted figures for water use per person, Du Plessis said.
Second, supply figures do not take into account the water lost as it leaks out during distribution. The water and sanitation department’s 2018 National Water and Sanitation Plan reports that 35% of municipal water is lost through leaks. This is the latest figure available.
Third, supply figures do not take unmetered water use, such as in parks and for firefighting, into account.
“It can easily get complicated,” Du Plessis said.
Consumption lower than 300 litres per person a day
In 2019, the Gauteng City-Region Observatory, a research partnership between universities and local and provincial governments in Gauteng, wrote the Water Security Perspective for the Gauteng City-Region plan.
It includes a water use figure of about 300 litres per person a day. The calculation was also based on Rand Water’s estimates of the total supply and the population served.
But the document adds that the figure includes all water supplied, including transmission and distribution losses as well as institutional, commercial, industrial and domestic use. Total individual consumption would therefore be lower than 300 litres per person per day.
The 2021 National State of Water Report by the water department shows that the average amount of water used by each person in areas served by the Vaal WMA has been decreasing. It projected that by June 2022, the water consumption would be 251 litres per person.
Source: Vaal WMA consumption trends, DWS report
Water consumption not the problem
Various experts have said consumers’ water consumption is not particularly high in Gauteng. The bigger challenge is the high volume of water that leaks from the distribution system of ailing water infrastructure, and so does not reach consumers.
How Gauteng’s water consumption compares to the rest of the world
Maroo told Africa Check that the figure for the world average came from a 2021 study, which looked at the efficiency of South Africa’s water utilities.
“South African water users consume 237 litres per capita per day and 64 litres more than the average global daily consumption,” the study says.
One of the study’s authors is Dr Victor Ngobeni, a lead programme management specialist at the Development Bank of Southern Africa. He told Africa Check that the water department’s 2019 Water and Sanitation Master Plan was the study’s source for the world water use figure.
In the 2019 report, the department says that the world average use of 173 litres per person per day “does not appear in any report but is based on expert opinion”.
Yet the number has been widely reported by the media.
No accurate figure for average global consumption
In 2018, we traced the 173 litre figure to a 2012 report for the Water Research Commission, an organisation that coordinates water research in South Africa. It used data from the International Benchmarking Network (IBNET) on water use in about 150 countries to estimate the world’s average daily use in litres.
But IBNET warned against using its country averages to estimate a world average, because local government data from several countries was unavailable.
Prof Heinz Jacobs is former head of the civil engineering department at Stellenbosch University.
We asked him what the world average might look like today. He said he “cannot imagine anybody at any institution anywhere in the world has an accurate figure for global per capita water use estimation”.
Some publications might estimate the number, he said, but it would not be of much use as “many millions of people in the world use water from all sorts of ad hoc sources, without it ever being metered”.
Varying climates, population sizes and housing systems, even within a country, also make it difficult to accurately determine a global water use average per person.
Water use per person in South Africa is “almost double the world average”, according to Sputnik Ratau, the department of water’s former spokesperson.
Africa Check reached out to Ratau, who sent us the department’s data on national water use. It shows that as of June 2021, the average national water consumption was 217 litres per person each day.
Ratau also referred us to the department’s 2021 National State of Water Report. This has water use data from the country’s nine water management authorities, but does not give a national average.
Khatutshelo Rasifudi, the manager of the department’s water studies division, sent us the same documents.
But neither Ratau nor Rasifudi responded to questions about how the water use figures were calculated and whether they had been independently verified. (Note: We will update this report if they do respond.)
So what do other data sources show?
IBNET has data on South Africa’s average water use up to 2017. In that year, total consumption was 194 litres per person per day. But this decreases to 114 litres for residential consumption. (Note: IBNET is set to update these figures on 27 January 2023. We will then update this report.)
IBNET calculates residential use with data from participating water utilities for that reporting period. But the organisation has warned that its data is based on “a subset of municipalities that may or may not represent the country average”.
Questions about South Africa’s average water use per day aside, the lack of an accurate global figure means Ratau’s comparison is unproven.
South Africa is water scarce
Given the difficulty estimating an accurate figure for global average water use, it’s unclear how South Africa’s consumption compares.
Dr Jeremiah Mutamba is a senior manager at the Trans-Caledon Tunnel Authority, a water department entity responsible for financing water infrastructure. He said what was “significant” was that there was “a high water use rate much above sustainable levels given our water availability” in South Africa.
South Africa is a water scarce country. According to UN Water, water scarcity is when demand for water exceeds supply. The water department’s 2021 report projects that South Africa will face a 17% deficit between water demand and supply by 2030.
This report was written by Africa Check., a non-partisan fact-checking organisation. View the original piece on their website.