As dam levels drop and water becomes even more scarce, Cape Town is racing against time to deal with the worst drought in the city’s history.
Over the past few weeks, Capetonians have been hurtling towards Day Zero, when the City of Cape Town has warned that water to households will be cut off. If people continue using water at the current rate, it says there will not be enough water in the system to maintain normal services and the taps will run dry. With alternative water sources not yet ready, and with little chance of rain, the only solution is to go all out to save water.
Day Zero is a shifting target, but has edged closer over the past few weeks. On January 23, it was forecast to happen on April 12, as dam levels had slipped by 1.4% in the previous week. Day Zero is calculated based on the level of water in the six big dams that feed Cape Town and the Western Cape water supply system, evaporation, as well as the amount of water being used by the city’s residents and agriculture.
The city is working on establishing small-scale desalination plants at the V&A Waterfront, Strandfontein and Monwabisi, but in an about-turn recently, it is aquifer extraction that will make up the largest component of the city’s water augmentation programme going forward.
A recent groundwater survey has confirmed that aquifers around Cape Town could deliver 150-million litres of water a day. Prime locations have been identified to abstract more water from three aquifers, and drill rigs are on site.
“In the longer term, the Table Mountain Group (TMB) aquifer has much more potential to deliver, but drilling the deep boreholes to access that store of water will take much longer than the Atlantis and Cape Flats aquifers,” Christine Colvin, senior manager for freshwater programmes at World Wide Fund for Nature – South Africa (WWF-SA), told Engineering News.
“The Atlantis and Cape Flats aquifers are the most accessible from the perspective of shallower drilling depths and potential links to the existing water infrastructure system, so they will come on line first.”
But this will take time.
“The city is aiming to have the infrastructure for aquifer abstraction completed in July 2018, but this is a best-case scenario,” the Mayoral Committee Member for Informal Settlements, Water and Waste Services in the City of Cape Town, Xanthea Limberg, told Engineering News.
She said the process of drilling boreholes had started, while construction of the related infrastructure to transport the water to the supply system would be done while drilling is under way.
Despite the urgency, Colvin says groundwater development, much like mining exploration, has to happen in a phased manner.
Colvin explained that hydrogeologists normally carry out exploration using geophysics to define the aquifer parameters and limits and then do pilot drilling to get an estimate of the actual subsurface conditions, water quality and yield. Before starting full-scale production, the wellfield needs to be pump-tested and monitored to test the medium-term sustainable yield. Filtration and disinfection treatment also have to be done before water is added into the bulk system.
The new wellfields are being sited as close as possible to city infrastructure and on city-owned land in many cases.
“To build resilience going forward, we are working on finding a sustainable balance between storage on the surface (dams) and what we have in underground storage. The data from the geophysical surveys will help us to manage the storage and abstraction of groundwater sustainably in the years to come,” said Limberg.
In the meantime, there should be some progress on temporary desalination projects.
Limberg estimates that desalination plants at Strandfontein and Monwabisi, on the outskirts of Cape Town, will start delivering water into the system by February, and will be running at full capacity, producing seven-million litres a day each, by April.
“It is estimated that the plant at the V&A Waterfront will produce two-million litres per day by March,” said Limberg.
The city’s statistics show that most new sources of water – groundwater, desalination and reclaimed water from wastewater treatment plants – are about 50% complete, while some are behind schedule.
As dam levels drop, the city has tightened its water threshold. People will be allowed to use only 50 ℓ each per day for 150 days from February 1.
While many worry about the prospect of queuing for their 25 ℓ of water each at one of the 200 planned water distribution points across the city, those who can afford it have been racing to drill boreholes. With pool companies and many nurseries left high and dry, there has been a bonanza in the borehole business, with many companies pushing up their prices.
Colvin has also warned of a “real danger” of the overabstraction of groundwater as a result of the cumulative impact of many unregulated and unmanaged users.
“It’s essential that private homeowners and businesses monitor their groundwater use and understand that groundwater is not ‘private’, nor is it a second-rate source to be used on gardens or for high-volume, low-value uses. It could end up being our most strategic store of water inside the city,” said Colvin.
National government, as well as the city, is looking at amending by-laws and regulations to institute better control of groundwater use in future.
The attitude of Cape Town’s residents towards the water crisis has been mixed. Many have taken on the water-saving challenge with a missionary zeal, using grey water to flush toilets and for others uses, foregoing showers, installing rainwater harvesting tanks and spreading the word about water conservation. Some have planned to build temporary pit latrines. But others have been worryingly nonchalant.
The city has accused many people of not taking the water crisis seriously. Well over half of the city’s four-million residents have not reduced their water consumption, despite calls and pleas.
The City of Cape Town says it is taking more steps to reduce the amount of water being used by individuals and businesses. “The city is making an enormous effort to delay Day Zero by rolling out aggressive pressure management operations, installing thousands of water management devices on the properties of high users. Our main focus must be on what we can do now to prevent our taps running dry by April,” executive deputy mayor Ian Neilson said. Council employees are also trying to respond more quickly to reports of leaks and bursts.
Some hard lessons have been learnt for the future, but that may be cold comfort for residents and businesses, who face pending water cuts. The situation has been exacerbated by political infighting.
The drought in Cape Town has pitted politicians and officials against one another, as water wars have played out in the political arena. The City of Cape Town and the Western Cape government have been blamed for not waking up to warnings of looming water shortages over the past few years, while the cash-strapped National Department of Water Affairs and Sanitation has been criticised for not investing in infrastructure earlier.
Many Capetonians have not taken kindly to the prospect of a form of surcharge on water users to compensate for the city’s loss in revenue from water saving and lower sales, saying it is not their fault that the city was unprepared for the drought.
“You cannot punish customers for using less of what the city cannot supply anyway. The water problem is the result of poor council planning and it is the council that must pay, not the victims,” said the Cape Chamber of Commerce and Industry.
With a flood of objections from residents, the city has backed off a drought charge and opted for a punitive tariff.
Water experts have warned that, in the long run, Capetonians are going to be paying more for their water if the city has to increasingly rely on aquifers, desalination and recycled wastewater to supplement its freshwater resources.
Water strategist, Anthony Turton, has also criticised the city for saying groundwater is a much cheaper option than desalination, which was widely touted last year.
Turton says desalination has proved to work in many water-scarce countries around the world, but it is far cheaper when done on a large scale. Small desalination plants at a high unit cost may not be sustainable in the long run, but, with climate change and population growth, he sees large desalination projects as essential for South Africa’s coastal cities in future.
“All our coastal cities of significance – Cape Town, Port Elizabeth, Durban, East London and Richards Bay . . . have no future without desalination,” he told Engineering News.
Whichever methods are used, the way people view water may soon change forever. South Africa has been called out for behaving as if it is a water-abundant country when it is actually a water-scarce country. Per capita, South Africa uses far more water on a daily basis than the global average, yet South Africa is one of the 30 driest countries in the world.
“What this crisis is going to do is to radically change the way we think about water,” said Turton.