Key topics:Gauteng’s water load-shifting risks mixing sewage with drinking water.Expert warns system nearing collapse due to desperate water measures.Government blamed citizens, while infrastructure leaks remain critical..Sign up for your early morning brew of the BizNews Insider to keep you up to speed with the content that matters. The newsletter will land in your inbox at 5:30am weekdays. Register here.Support South Africa’s bastion of independent journalism, offering balanced insights on investments, business, and the political economy, by joining BizNews Premium. Register here.If you prefer WhatsApp for updates, sign up to the BizNews channel here..By Hanno Labuschagne.A renowned water infrastructure expert has warned that one of the measures municipalities in Gauteng are using to bring the province’s water crisis under control risks mixing sewage with drinking water.The deputy water and sanitation minister, David Mahlobo, recently announced that municipal water authorities in the province would implement water load-shifting.The announcement came amid days-long water outages in parts of Johannesburg, Ekurhuleni, and Tshwane.The mechanism is one of several “soft” water restrictions intended to stop a total collapse of the system in Gauteng.Load-shifting involves redirecting water away from reservoirs with sufficiently high water levels to those with critically low levels.The practice requires shutting off inlets and outlets from the healthier reservoirs for several hours or days, resulting in their areas of supply running out of water.In recent feedback to MyBroadband, Dr Anthony Turton described the limited “blunt” instruments of water throttling and load-shifting as desperate and undesirable.“In effect, it is robbing Peter to pay Paul, and at best, it is reducing the risk of rioting, but just by a fraction,” he said.Turton first warned of a looming water crisis in a paper titled “Three Strategic Water Quality Challenges that Decision-Makers Need to Know About and How the CSIR Should Respond,” published in 2008..Read more:.FT: Full reservoirs, empty taps – SA’s water crisis deepens.In the paper, Turton explained that South Africa was flying blind in terms of its water strategy and was losing experts to appropriately plan for and address its unique water infrastructure issues.Instead of heeding his warning, his employer at the time, the Council for Scientific and Industrial Research (CSIR), suspended him for insubordination and for bringing the agency into disrepute.Turton explained that water sub-system operators like Rand Water can implement water throttling, which can reduce flow to sub-sub-system operators.For Rand Water, these include 16 municipalities, 27 mines, and 952 other entities. Joburg Water is one example of a sub-sub-system operator.Mixing it up.While they can also implement water throttling, Turton said municipalities preferred to use load-shifting to ensure that water can be delivered to some of the sub-sub-systems some of the time.However, Turton said that frequent load-shifting could result in sewage water entering the potable water supply.“Sewage pipes are gravity-fed, but potable water pipes are pressurised,” he said. “If the pressure is reduced or lost, then a negative pressure is introduced into the system as water drains by gravity.”“This can collapse gaskets and O-rings used to seal joints, introducing sewage water into the drinking system.”It can also cause significant damage to pipes due to repressurisation, which expands pipes and compresses air.“This causes a water hammer that dislodges biofilm inside the pipes and destroys the structural integrity of the system,” he said. “Think of a system cannibalising itself.”“This is a last resort measure before rioting breaks out, but the price paid is an acceleration in the destruction of the system.”System failure is unavoidable.Turton said the fact that water shifting and throttling are needed was empirical proof that the systems are at the point of near-total collapse.“I am cautious of being a doomsayer, and for the last 18 years, I have tried my best to sound the alarm while not creating panic,” he said.“But my professional opinion is that systemic failure is now unavoidable,” he said. “Turton also criticised the government for shifting the blame for its own infrastructure failures to end-users.In many water shortages over the last few years, municipal authorities have accused their residents of excessive water consumption.While South Africa is a water-scarce country, Gauteng’s primary water source, the Vaal Dam, has been over 100% full throughout the summer season.Turton questioned a “failing state” for accusing the consumer of using too much water when the sole obligation of that state was to provide such services..Read more:.Water crisis threatens ANC in Gauteng elections.“If 50% of the water is lost to leaks and illegal connections, calculations that divide total consumption into the total population serviced will reflect that 50% leakage as a high consumption per capita,” he said.Turton said the state’s deflection was pushing South Africa to a point where few members of the public trust anything that the government says, and that was a tragedy..This article was first published by MyBroadband and is republished with permission.