Johannesburg Water will start throttling water supply from between 21:00 and 04:00, as the city experiences increasingly frequent interruptions to daily water supply.

The new measure, set to start on November 14 and be implemented continuously until the system has fully recovered, will enable reservoir levels to recover overnight.

This in addition to the implementation, in September, of level 1 water restrictions, which prohibit the use of hosepipes to water gardens, wash cars, clean driveways and fill up swimming pools between 06:00 and 18:00. The restrictions remain in place until March 31, 2025.

This followed an urgent meeting over the weekend, convened by Water and Sanitation Minister Pemmy Majodina, which led to unanimous agreement on the causes of the water supply interruptions and what needs to be done to restore a stable water supply to the residents of Johannesburg.

Rand Water is already abstracting water at its set limits from the Integrated Vaal River System and is not able to supply any more water to municipalities in Gauteng than it is currently supplying, Majodina told media on Monday during a briefing post the Sunday meeting.

“The main underlying cause of the water supply disruptions in Johannesburg is that the peak demand for water is close to, and occasionally exceeds, the available supply from Rand Water. The demand-supply relationship for treated water in Johannesburg is very tight and the system is vulnerable to disturbances caused by electromechanical breakdowns or spikes in demand caused by heatwaves.”

Further, the Department of Water and Sanitation’s 2023 No Drop report found that water losses in Johannesburg were 35%, well above the global average of 15%, while the average consumption of water in Gauteng is 279 litres a person a day, 60% above the world average.

Even after the completion of the second phase of the Lesotho Highlands Water Project (LHWP), which will supply more water for Gauteng from 2028, the province’s long-term water consumption will need to be carefully managed, because there are limits to which further phases of the LHWP or other water transfer projects can continue to provide additional water to Gauteng at an affordable cost.

“We have to reduce the consumption of water at a faster pace. If we cannot do that, the system will not be in a position to carry us for longer. The restrictions that the City of Johannesburg has implemented will make a huge difference to deal with the water shortages. However, we need an overarching strategy to help us deal with water challenges,” said Gauteng Premier Panyaza Lesufi.

“Reducing water losses requires a multipronged approach by the city, including, besides others, improving billing and revenue collection to increase the funds available for maintenance and to provide better incentives for water to be used efficiently, improving pressure management, replacing ageing pipes, which burst frequently, and installing water meters or replacing dysfunctional bulk and customer water meters so that water flows can be measured accurately to determine the location of the losses,” Majodina added, pointing out that the City of Johannesburg also needed to reduce the leaks in its water distribution system and complete its current projects to construct more reservoirs and pumping stations.

In addition to the throttling of water supply, the City of Johannesburg and Johannesburg Water will embark on the cut-offs of illegal connections in key informal settlements and accelerate leak detection, an intervention that has provided an estimated water demand reduction of 9 457-million litres a year.

To date, 12 100 km of water pipelines have been surveyed and 2 396 burst pipes, 6 727 leaking meters, 442 leaking valves and 259 leaking hydrants were identified and repaired.

Alongside this, a panel of contractors will be procured for emergency repairs of large-diameter pipe water leaks and the number of teams on standby during the week will be increased to attend to leaks and burst pipes.

Johannesburg Water is also increasing the number of repair and maintenance teams on duty during the weekend with the aim of improving leak repair response times from 48 hours to 24 hours, as well as increasing the number of trucks available to its leak repair and maintenance teams.

Further, advanced pressure management systems will be installed, including 45 smart pressure controllers, or pressure reducing valves, in addition to the 15 already refurbished and retrofitted to date, to reduce water losses at night when demand is low.

Johannesburg Water will also work with National Treasury to establish a public-private partnership for the reduction of nonrevenue water to mobilise private-sector funding and expertise.

Majodina explained that the Sunday meeting noted and strongly supported the approval by the Johannesburg City Council of a turnaround strategy for Johannesburg Water, which includes ring-fencing of revenues from the sale of water for the water function, as well as creating single-point accountability for the water function in the city.

“The intention is to give Johannesburg Water control over all the functions related to managing water supply in the city, so that it can be held accountable.”