Water set to be on everyone’s lips in a hot 2024
Experts say climate change will reduce availability and increase demand, writes Claire Keeton
Water consumption — and scarcity — are likely to increase next year with the hotter and drier conditions expected over much of the country. “South Africa is already using 98% of its available water,” says Caroline Gelderblom, manager of water source partnerships at WWF South Africa.
Water shortages, flooding and droughts are being exacerbated by the climate crisis, which is changing rainfall patterns.
Climate change is causing some frontal systems to be displaced, reducing the frequency with which they bring rain to the southwest Cape.
The systems are moving about 200km to the south, tripling the risk of the Cape running out of water, says climatology professor Francois Engelbrecht, head of the Global Change Institute at Wits University.
Cape Town narrowly avoided running out of water in 2018 after the cold fronts it depends on for rain diminished, leading to lower rainfall for three years in a row. Cape Town gets 97% of its water from high rainfall catchments in the Boland, says Gelderblom.
Engelbrecht says: “The entire Cape Garden Route depends to some extent on frontal rain and is very vulnerable to drought.”
WWF South Africa environmental scientist Nokwethaba Makhanya, who researched the risk of droughts over the major river basins in Southern Africa, says projections for the Western Cape show it has an “alarmingly high drought risk”.
Gauteng almost ran out of water in 2016 when climate change made a long-lasting drought much worse, says Engelbrecht.
“Few people realise how close we came to our own Day Zero in September 2016 when the level of the Vaal Dam dropped to 25%; the dam has never been below 20%.” Below 20%, the water cannot be treated for quality or pumped uphill.
“But October 2016 saw the start of La Niña [the cycle with cooler than normal sea surface temperatures], which saved us,” says Engelbrecht.
Now that the El Niño counter-cycle is back, summer rainfall is predicted to drop.
THREATS TO CROPS AND CATTLE
Applied climatologist Dr Peter Johnston of the University of Cape Town says that in general El Niño increases the probability of drought in the summer rainfall region, pushing up the chance of drought by 60% and making January and February drier than normal.
“This could have a knock-on effect. If there are shortages of maize, they would affect the food chain,” says Johnston, who does research with farmers.
Farmers with fruit trees or vineyards in the Western Cape are concerned about the heat, he says. Wine estates are changing cultivars, for example growing shiraz grapes, which are hardier in the heat, rather than merlot grapes.
The climate crisis is determining what farmers plant, Johnston says. In the Western Cape, they are diversifying from wheat into higher-value and more resilient crops such as rooibos tea and olives.
Engelbrecht warns that cattle cannot cope with the biophysical stress of “more intense and lasting heatwaves”, which could cause the collapse of the industry in years to come. “There is a physical threshold beyond which any animal, including humans, will die if exposed.”
Botswana lost 20% of its cattle in 2015 and another 20% in 2016 with the drought. “In KwaZulu-Natal, North West and Limpopo, thousands of cattle also perished,” Engelbrecht says.
“Herd management will be critical,” Johnston adds, suggesting farmers may need to sell surplus cattle to ensure they have enough pasture and feed during a drought.
All South Africans need to bolster water security, Gelderblom says. “It is important to maintain infrastructure, as we currently lose 35% of our water to leaks. We also need to keep the catchments of our strategic water source areas healthy by clearing thirsty invasive alien trees, which can use over 60% of the dry season flows.
“Individuals can take part in volunteer hacks and companies can sponsor professional clearing teams. We must all also make sure that we use water carefully and avoid polluting this precious resource.”