Running dry: Residents protest at South Hills reservoir. (Delwyn Verasamy/M&G)
The frequency of water supply interruptions in Johannesburg is creating “very hostile and unhappy communities”, according to a senior Johannesburg Water official.
Logan Munsamy, the utility’s senior networks manager, was speaking at a virtual media briefing on the current water outages and shortages in the city on Tuesday. It has now undertaken to hold bi-weekly briefings on its system.
Detailing the implications of the bulk water supply interruptions since August that have left large parts of the city struggling with severe water cuts. Munsamy said this has led to a prolonged recovery period of both the Rand Water and Johannesburg Water supply systems.
There is also the prolonged period of no water supply in high-lying zones and an increased cost of providing alternative water supply.
“Our intention is never to draw out any process,” Munsamy said. “Joburg water is committed together with Rand Water to finding the shortest possible solution to this problem. And going forward, to developing something that is sustainable,” he added.
“Until such time as their system [Rand Water] increases or improves in capacity, then the ripple effect is that our systems will start to increase. Once our systems are stable and we have consistent supply, then we have more or less uninterrupted supply to customers. But in the absence of that happening … we basically face these challenges,” he said.
As part of its mitigation plans, he said Johannesburg Water will intensify water tankers if needed, but at the same time, “we will continue to curb demand at our system — we will operate valves, restrict flows at night to try and build up flows as well”.
Not in danger of collapse
Johannesburg Water’s system is not in danger of collapse, Munsamy said, as it consists of multiple reservoirs. “We’ve got 86 reservoirs alone and 35 water towers. There’s just certain parts of the Johannesburg system that are affected as we speak,” he said.
“One of them is the South Hills pump station, which is having primarily the problem because the incoming supplies are poor and we’re unable to pump sufficiently.”
The other system where “there is a little bit of a challenge” is the Crown Gardens system, with its reservoir battling to recover, too, because of poor incoming supplies. The third system is the Commando system, which is Brixton, Hursthill and Crosby.
While these three systems are currently under “tremendous strain”, they are three systems in relation to 86 reservoirs systems in the city, he said.
“While it is not a good experience to go without water, it’s safe to say that it’s not the entire Joburg Water system that is impacted by these issues. We are managing the other systems so that they don’t go down the same path but at the same time we’re working with Rand Water to see how we can improve supply to these three systems.”
Water shifting
Last month, water and sanitation minister Senzo Mchunu announced that water shifting would be implemented in some areas of Gauteng to deal with water shortages.
Munsamy explained that it involves moving a volume of water from an area that has excess water to an area that does not have water or that needs water. There is some degree of water shifting underway between the Palmiet and Eikenhof systems.
“But at the same time, Rand Water has alluded us to high consumption patterns on our side. So, as much as they might be shifting water and pumping, we must understand that the demand on the system, not just because of the high weather conditions, but the demand on the system as a whole [from Johannesburg, Ekurhuleni and Tshwane] and all other users is collectively too high for their systems to cope with,” he said.
He added that the reservoirs don’t have ample time to recover because the draw on the system is just too high at this stage. He also said that coupled with that are the operational challenges but there are contingencies to bring down consumption as a whole.
Supply interruptions
Rand Water experienced bulk water supply interruptions between 24 August and 24 September, which have had “a ripple effect in that it actually depleted or had a negative impact on our reservoir network so people went without water or poor pressures for periods of time”.
On 24 August, Rand Water’s Zuikerbosch purification plant as well as the Lethabo pumping station supplying the Vereeniging purification plant had a power dip that affected their total pumping capacity. This caused the depletion of the Zwartkopjes, Eikenhof and Palmiet systems. The incident lasted for about four hours with pumping restored later on the same afternoon.
“One might think that four hours is a short period of time but in the water industry, when you lose four hours pumping time, it’s a question of whether reservoirs will go dry or empty and the recovery period is also equally longer.
“Every hour , every minute you lose in a strained water network, has a major ripple effect in that the downstream reservoirs, specifically Johannesburg, can go empty or reach critical low levels and it takes a very long time to recover if you don’t have consistent supply.”
This incident had a major impact as “we could not pump water into our South Hills tower and feed the residents of greater Tulisa Park, South Hills, Linmeyer, Risana and so on, because the incoming supply from Rand Water was so low that our pumps were unable to run.”
The incident also affected supply to the Alexander Park reservoir as well as the Linksfield reservoir. The Rand Water system downstream of the Palmiet pump station experienced the impact of the power dip resulting in a drop in reservoir levels.
On 14 September, Rand Water noticed increasing consumption on the Eikenhof system meters.
“This increase placed severe strain on the system, and because of the high demand, although Rand Water might be pumping fully on their side at times, the issue is that their reservoirs and our reservoirs are unable to recover sufficiently.”
All Rand Water primary and secondary pump stations and infrastructure operated at their maximum capacity as guided by the raw water abstraction licence. Reservoir levels, however, were at their lowest, resulting in supply pressures being low and high-lying areas having low to no water supply.
“The ripple effect of the Rand Water supply interruptions has an impact on our reservoirs and water network in that customers do not have water or [have] poor pressures at times.”
Munsamy said that high potable water consumption could result in a collapse of the Rand Water bulk supply system, which will result in intermittent to no water supply, but “we are trying to avoid that at all costs”.
Severe thunderstorm
On 19 September, the Zuikerbosch purification plant power lines were affected by a severe thunderstorm around midnight, which subsequently tripped the plant.
Attempts to restart the plant revealed faults along the overhead power lines supplying the auxiliary plant. The power failure resulted in the loss of 2 000 million litres per day. Consequently, the load reduction affected all municipalities supplied by Zuikerbosch, including Johannesburg, Tshwane and Ekurhuleni.
The Palmiet system supplies the Linksfield, Alexander Park and South Hills towers, as well all of the Sandton and Midrand reservoirs and all were severely affected. As a result some of the systems ran dry, “and people had no water for prolonged periods”.
The Eikenhof system was also affected resulting in low water pressure or no water, especially to the high lying areas, for days after the incident.
Another power failure
On 21 September, Rand Water’s Zuikerbosch purification plant engine room four experienced a power failure. This incident further affected the water supply to the Palmiet system resulting in further strain on an already constrained Johannesburg water system especially the Midrand Sandton, South Hills, Alexander Park and Linksfield Reservoir systems.
“The systems have not been given sufficient time to recover, whenever there’s an operational challenge, if we don’t get consistent supply after that, any subsequent failures has a ripple effect and the systems don’t recover fully and we have these spiralling effects.”
Burst pipe
At 2pm on 24 September, Rand Water had a major burst that occurred at the Zuikerbosch purification plant on a transfer line that supplies the Palmiet pump station. The pipe was successfully repaired at 9pm.
Munsame said that for repairs to be conducted and for the Palmiet system not to lose capacity, pumping had to be reduced by 600 million litres for seven hours. He said that seven hours is a long time for Johannesburg Water’s reservoirs which were affected and lost capacity.
“Whatever gains we had been trying over a period of time because we have been not having consistent supply, it obviously has a ripple effect in that our reservoirs now become more strained, they do not recover to full capacity, they are always hovering around critical low to empty levels, resulting in poor pressures to no water conditions to customers.”