Katse Dam in Lesotho is the biggest of the Lesotho Highlands Water Mission reservoirs, with a storage capability of almost 2-billion cubic metres.. (Walter Dhladlhla/Getty Photos)
At midnight on 30 September, massive gates had been closed at two factors alongside the Lesotho Highlands Water Mission (LHWP), marking the start of a six-month upkeep shutdown, the longest in its 20-year historical past.
The stoppage comes amidst ongoing water provision points in South Africa’s city highveld, which pulls water from the LHWP through the Vaal Dam. Johannesburg’s water provision issues have been linked to poor administration of water infrastructure by municipalities, however prematurely of the LHWP shut down, some analysts warned that the stoppage might exacerbate these issues.
However water administration specialist Carin Bosman disagrees.
“An rising variety of folks, together with some who ought to know higher, seem to imagine that the deliberate shutdown of the LHWP will contribute to the water provide issues skilled in Johannesburg, however these elements are in truth unrelated,” says Bosman.
The truth that the extent of the Vaal Dam stood at 41% p.c of capability final week in comparison with 80% this time final yr, “isn’t serving to to dispel notions that we face water shortages,” says Bosman, who labored for the division of water earlier than and after the appearance of democracy.
She says, “It isn’t uncommon for the extent of the Vaal Dam to be round 40% on the finish of the dry season. There’s a distinction between a meteorological drought, which is the results of rain not falling within the wet season, and an institutional drought, which is the consequence of water administration failures. Johannesburg is affected by the latter.”
Division of Water and Sanitation (DWS) spokesperson Mandla Mathebula mentioned the Sterkfontein Dam, on the sting of the Drakensberg escarpment, capabilities as a reserve dam for the Vaal Dam. Sterkfontein Dam has an analogous storage capability to that of the Vaal Dam, however in accordance with Mathebula, “it’s a deeper dam, and the surroundings is cooler, so it doesn’t lose as a lot water by evaporation”.
“The usual working rule is that Sterkfontein Dam releases water to the Vaal Dam when the Vaal Dam reaches a stage under 18%. The Sterkfontein Dam is presently full [98%] and can be used to high up the Vaal Dam ought to the necessity come up,” mentioned Mathebula.
Richard Holden, a water and sanitation skilled, put it extra starkly: “Sterkfontein has a capability of over 2,600-million cubic metres, which by itself is sufficient to meet the calls for of Johannesburg and surrounding areas for nearly two years,” he mentioned.
However Johannesburg is utilizing extra water than is smart. Rand Water, which provides bulk water to Gauteng Province, has exceeded the amount of water it’s licensed to supply to Gauteng’s municipalities yearly for the previous six years. The utility is licensed to produce the province with 1,600-million cubic metres a yr, however exceeded this by 193 million cubic metres in 2023/2024.
In a June speech to the Strategic Water Companions Community, DWS director normal Sean Phillips warned, “It could be irresponsible to permit [Rand Water] to summary extra. If we had a drought, this might imply a day zero scenario in Gauteng.”
The time period Day Zero – referring to the day on which municipal water could be largely shut off because of provide shortages – was utilized by Western Cape authorities in the course of the water disaster of 2015-2020 to galvanise folks to make use of water sparingly. There isn’t any official Day Zero marketing campaign for Johannesburg however the time period has been seized on by some.
“Some unscrupulous scaremongers are utilizing it to promote water storage tanks, and it’s more and more current in media headlines, which is unlucky as a result of Johannesburg shouldn’t be dealing with Day Zero,” mentioned Bosman.
“It is crucial that folks turn into extra water smart and the division faces a fragile balancing act of placing stress on residents and native water authorities to vary their methods, on the one hand, and on the opposite to keep away from creating the impression that there isn’t sufficient water round to fulfill wants.”
After which there may be the massive drawback that just about half of Johannesburg’s water is misplaced to leaks. We can be writing extra about this in a future article.
How Johannesburg will get its water
Mathebula defined that Johannesburg receives water from the Built-in Vaal River System (IVRS), a community of fourteen dams which can be linked to one another by a system of rivers, canals, tunnels, pipelines and pump stations, and which collectively retailer over 9,300-million m3 of water.
“The Vaal Dam is an important impoundment in that system as a result of it’s from right here that Rand Water abstracts water for remedy, however it’s only one a part of the very massive system that the DWS manages, wherein water may be transferred from one a part of the system to a different, as and when required,” he mentioned.
Based on Johan Tempelhoff, Professor of Historical past at North West College, the complexity of the IVRS is a consequence of the truth that Johannesburg was constructed on a watershed.
“A number of streams come off the watershed and there are some good springs within the space, however their capability to fulfill the quickly rising metropolis’s wants had been exceeded as early because the drought of 1895,” he mentioned.
To unravel the issue, the federal government appeared to the waters of the distant Vaal river, finishing an impoundment referred to as the Vaal Barrage in 1923, and the a lot bigger Vaal dam in 1938. At the moment, all of Johannesburg’s handled water comes from the Vaal dam.
“It wasn’t lengthy earlier than the water that naturally enters the Vaal dam was not adequate to fulfill the calls for of the industrialising highveld. It was for that reason that two main “inter-basin” water switch schemes had been developed, able to feeding water into the Vaal’s most important feeder rivers from catchments a whole lot of kilometres to the south,” Tempelhoff mentioned.
The primary of the inter-basin schemes to be accomplished, in 1974, was the Thukela-Vaal Switch Scheme, which is fed from Mont-Aux-Sources atop the Drakensberg escarpment.
Based on Holden, “Water from the Thukela River enters Woodstock Dam, and a few of that is in the end pumped over the Drakensberg into Driekloof Dam to be used within the Drakensberg Pumped Storage Scheme. When Driekloof is full, the surplus water enters Sterkfontein Dam, and it’s saved right here till it’s wanted within the Vaal River System,” he mentioned. The DWS doesn’t launch water from Sterkfontein till it’s completely vital.
“The truth that it’s pumped water implies that it’s costly water, so it’s saved up there for emergency use solely,” he mentioned.
The opposite scheme is the LHWP, which impounds the water from a number of catchments in Lesotho in two massive reservoirs referred to as Mohale and Katse.
Water launched from these reservoirs is gravitated by means of a collection of pipes and tunnels into South Africa’s Ash River, which flows into Liebenbergsvlei, which joins the Wilge River, that discharges into the Vaal dam.
Holden chuckled when requested if the LHWP was the most important provider of water to the Vaal dam.
“We don’t function the system that manner,” he mentioned. “Some components of that system will all the time be compensating for different components. That’s simply the character of the water cycle.”
He gave the instance of 2015, a yr wherein, throughout a drought in Lesotho, “the move of water from Lesotho was considerably decreased with out impacting on the reassurance of provide”.
Holden mentioned that LHWP is, nevertheless, essentially the most constant supplier of water to the Vaal Dam.
“There’s a hydroelectric energy station on the Lesotho aspect, and water must run constantly by means of that plant to maintain the generators shifting, so it runs constantly down into South Africa and the Vaal Dam, regardless of how excessive or low the extent of the Vaal Dam occurs to be,” he mentioned.
Mathebula mentioned that the governments of South Africa and Lesotho yearly agree on the quantity of water to be transferred.
“This yr the settlement was for 780-million cubic metres to be delivered whereas producing 72 megawatts of hydropower by means of Lesotho’s Muela Energy Station,” he mentioned.
The stoppage of the LHWP has meant that there’s a shortfall of 80-million cubic metres, which Mathebula mentioned can be made up when the LHWP resumes in April 2025.
Section II of the LHWP, now scheduled for completion in 2028, will impound the waters of the Senqu and Khubelu rivers in a dam referred to as Polihali, including roughly 2,325-million cubic metres in storage capability to the LHWP. Based on Holden, the LHWP will then be the most important contributor of water to the Vaal River system.
“It is because of this that the upkeep stoppage is so necessary. If it isn’t accomplished it might lead to an extended stoppage sooner or later, and if this occurs in a drought yr it might spell bother. If folks might concentrate on that, as an alternative of this misinformed notion that Johannesburg doesn’t have sufficient water, we’d all be higher off,” mentioned Holden.
This text was first printed on GroundUp