A water reduction from 9pm until 5am in areas with high consumption and reducing pressure are some of Johannesburg Water’s interventions to conserve water.
The utility’s operations general manager, Mzakhe Mtshweni, said some of these interventions had already been implemented by October.
He was responding to questions during a media briefing about the state of the city’s water supply after a problem this week at Rand Water’s Palmiet system, which halted pumping of water into reservoirs.
He said the Palmiet pump station had been affected by a power interruption. “The system is now constrained; we are sitting with 40% of our reserves in terms of daily demand and, preferably, you’d want to have reserves that would cover you for, at least, the whole day,” he said.
According to Johannesburg Water, there was a power trip on Monday for about three hours but that had not disrupted the water supply. But on Wednesday, there was another power trip at Rand Water’s Palmiet booster pumping station for about four hours which had disrupted the water supply in some areas and severely affected the Midrand system.
“Linksfield reservoir was also affected. We had the South Hills tower which, when this incident happened, had water supply challenges already going for a week. When these incidents happen, it worsens the situation,” Mtshweni said.
He added that the system started recovering on Thursday, with the Linksfield reservoir supplying normally. They then recovered the Midrand system, where they configured and made some changes to prioritise critical reservoirs.
Mtshweni said they wanted to bring back the system in phases to avert collapsing the whole bulk supply. “The Diepsloot reservoir is still affected. We now have technical teams from Johannesburg Water and Rand Water doing some investigations. There is a suspicion of an airlock.”
He said the South Hills tower was still experiencing no water supply through normal reticulation, and this was due to the bulk supply reservoir that was still low and unable to pump water into the tower.
Mtshweni said they were aggressively implementing interventions as they needed to build up the storage reserves and reduce the water losses across the city. The water reduction would be done on a scheduled basis that would be published and sent to customers.
This was expected to assist Johannesburg Water reduce the losses “as we know we have high system losses, [and] our non-revenue water is quite high”.
He said these were short to medium-term interventions as the infrastructure has to be replaced and rehabilitated, and the projects take a year or longer depending on the scale of those projects.
Mtshweni added that they would be intensifying an intervention to manage the pressure as they believe it would help them to speed up the process of reducing losses. “These interventions started in October already, where we’re doing repair and rehabilitation of key reservoirs within the network.
“The other one is bylaw enforcement. We know we have illegal connections, we have some of the illegal connections on our bulk supply pipes, which are pipes supposed to be supplying the reservoirs. Because there’s an illegal connection on those pipes, we’re now unable to keep the reservoirs at acceptable levels.”
Mtshweni said they were reducing pressure in the Randburg and Roodepoort areas as certain areas have very high pressure. “We started the project there because that is where the biggest problem is. So it could be that [the reason for residents experiencing low water pressure].”
The other problem in those areas could be attributed to a line from Honeydew that supplies water to Muldersdrift, where they have a technical problem which is affecting certain Randburg/Roodepoort areas, he said. “We also do our maintenance in terms of attending to bursts and leaks and some of these low to no water [problems] might be as a result of that.
“Overall the system is at 40%. The reservoirs will be at different levels. We need to take note that within the city of Joburg, we have a combined more than 100 water reservoirs and towers,” he added.
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