It's the hub of South Africa’s economy, but the Gauteng-City region is fast “reaching the limits of existing water supply solutions”.
And urbanisation and climate change will only amplify existing water security challenges.
This is the focus of an upcoming report from the Gauteng-City Region Observatory (GCRO) on water security, which outlines the key risks the region faces to its supply.
“Our infrastructure is designed to say ‘don’t worry, we’ve got this’, but as we get more water-stressed, as we don’t manage our catchments properly and droughts kick in, that resilience of the engineering system becomes more pressurised,” said Gillian Maree, a senior researcher at the observatory.
The observatory, a partnership between the universities of Wits and Johannesburg and the Gauteng provincial government, points out that the large-scale water supply infrastructure in Gauteng - the dams, water treatment plants and pipes - that brings water in has created a buffer for residents.
“Urban residents don’t immediately feel the impact of a drought and we often only notice it a year or two into the drought when dam levels are low.
“However, when we experience extended periods of drought in the future, water shortages will become more likely and difficult choices need to be made around how much water can be used and what is an equitable allocation of limited water supplies.
“Our challenge is that because of the population growth in the province, we are likely to have water security challenges in the future, even without a drought or climate impacts.”
There are three key risks to water security in the region: distributional challenges, resource quality challenges and challenges facing the “business of water”.
“It costs a lot to move water from Lesotho to Gauteng and to maintain it, and water tariffs need to cover the cost of supplying potable water.
“There’s also a significant challenge to changing consumer behaviour and reducing wasteful water use.”
Chris Curtis, professor of environmental change at Wits University, said for a large city located on a major watershed divide with no large surface waterbodies, it’s remarkable that Joburg enjoys the level of water security that it has done in recent years.
“But this is clearly under increasing threat. Gauteng residents need to accept that the Cape Town situation could arrive in Gauteng in the near future and start planning and acting immediately.
“Don’t wait for the crisis change your behaviour now and use water as sparingly, wisely and sustainably as possible.”
Urbanisation, rural-urban migration and an increasing population are pushing demand while damaging the local resource.
This includes pollution from acid mine drainage, failing wastewater treatment works and informal settlements with no sanitation infrastructure.
“At the same time, urbanisation concretes over our water catchments, including wetlands and that means rainfall, instead of being stored in soils and groundwater and released slowly, is transported ever more rapidly into our degraded urban streams - increasing downstream risk of flooding and extreme hazard to communities located alongside our rivers.”
Bob Scholes, a professor of systems ecology at Wits University, believed the water crisis along the coast would unfold in Gauteng.
“We’re not unprepared in terms of infrastructure and legislation, but we are almost never as well prepared as we should have been; humans have a short memory.
“We need to take a more holistic view of the water system than we do. We treat the ‘grey’ (engineered) infrastructure as separate from the ‘green’ (natural) infrastructure.”
Behaviour change, he says, takes a perception of clear and immediate danger, and strong pricing signals.
Water expert Anthony Turton hopes that the impending approach of Day Zero in cities such as Cape Town and Port Elizabeth will “bring a new awareness” of the value of water to Gauteng.
Nico de Jager, the MMC for Environment and Infrastructure in the City of Joburg, points out how there has been a reduction in the amount of water used per person per day in Joburg.
“It was 347 litres per person per day and it’s now about 287 litres per person. This reduction has been systematic over a three-year period because of demand tariffs, pressure control and faster response times (to water bursts, for example).
“What we’ve learnt from Cape Town is that they’ve invested in the refurbishment of their infrastructure.
“In Joburg five years ago, we had on average 35000 bursts a year - five years later, we have 45000 a year we need to keep on communicating about changing behaviour and reducing consumption.
“The city is growing in leaps and bounds and all those people need water. Unless we conserve water, we’re going to end up with massive problems.”