After five years of almost unrelenting drought, farmers and meteorologists are cautiously optimistic that emerging La Niña weather conditions will bring SA's long dry season to a close - with above-normal rainfall predicted over the coming months.
This follows advisories from global climatology experts earlier this month suggesting a re-emergence of La Niña conditions, a complex weather pattern that occurs every few years as a result of variations in sea temperatures in the equatorial Pacific.
La Niñaevents have occurred regularly for hundreds of years and can significantly alter seasonal climate conditions such as temperature and rainfall patterns, often leading to intense rainstorms in some places and droughts elsewhere.
For Southern Africa, climate experts associate La Niña with wetter-than-normal conditions from December to February - but drier-than-normal conditions over equatorial East Africa.
The latest advisory by the US National Oceanic and Atmospheric Administration suggests that there is a greater than 70% chance of La Niña persisting from December to February, and a 50% chance of it continuing till April 2021.
The South African Weather Service (SAWS) also said that the likelihood of a La Niña phase in the coming summer months has "drastically improved in the last few months, and it will be continuously monitored as we move closer to the summer forecasts".
SAWS said its multi-model rainfall forecast for September to January indicated "increased chances of above-normal rainfall over most parts of the country with the main focus being on the summer rainfall areas in the northeast of South Africa".
"In general, most of the country is expected to experience above-normal temperatures during spring and late spring, with below-normal maximum temperatures pre-dicted for the northeastern parts of the country during early summer."
Janse Rabie, head of natural resources division of the Agri SA farmers' federation, said some parts of SA, notably the Northern Cape, had experienced drought since 2013 while dam levels in several provinces had still not recovered.
The Gauteng industrial area's main source of water supply, the Vaal Dam system, dropped to 36% last week while major feeder dams in neighbouring Lesotho have also dropped significantly.
While predictions of above-normal La Niña rainfalls spell good news for maize and other grain farmers, Rabie noted that it could take up to seven years for some citrus and macadamia farmers to restore full harvest levels after orchards were decimated by the drought.
Sections of the red meat industry, especially sheep farmers in the Northern Cape, would take several years to rebuild flocks and herds after several years of drought, he said.
Wine and tobacco farmers had also suffered a double blow from drought and the impact of Covid-19 sales bans.
Agri SA disaster risk manager Andrea Campher said good rains would bring welcome relief to drought-afflicted farmers in the Eastern, Northern and Western Cape, but there was a risk that too much rain could cause flood damage after one of the most severe droughts in a century.
Independent agricultural meteorologist Johan van den Berg also cautioned that droughts over the past 70 years were often followed by very wet conditions, including floods in the mid-1970s, late '80s and again in 2010/2011.
Van den Berg said La Niña events cause large-scale changes in weather systems that were generally positive for rainfall in mid- to late summer over most of the summer rainfall area of Southern Africa, including the western part of the country and Namibia.
"Although rain in the first part of 2020 helped to replenish some large storage dams, the situation is still very dire for the Eastern Cape, the Vaal Dam, Tzaneen Dam and smaller dams in the Western Cape. The levels of the Katse and Mohale dams in Lesotho are also very low.
"Stock farmers will probably benefit the most if sufficient rainfall occurs over the western grazing areas, and farmers who suffered losses to vineyards and trees can also start to rebuild."
However, Van den Berg said, it was time for a mind-shift for many farmers.
"Farmers should be calculating their water use from drought years rather than good or average years. Drought is now more the norm than wetter or favourable conditions. They must plan for the longer term, taking multiple dry years or unfavourable years into account and take the accumulation of risk into account."
Umgeni Water, which provides water to Durban and the KwaZulu-Natal interior, said above-average rainfall prediction data from the University of Miami/International Research Institute for Climate and Society was good news for a region that had experienced below-average falls last summer.
An analysis conducted by Umgeni Water showed that despite lower-than-normal rainfall over the past 10 months, most regional dams remained at acceptable levels - with the exception of the large Albert Falls Dam, which supplies Durban, which was only 35% full.
Echoing similar caution expressed recently by the department of water & sanitation and other water utilities across the country, Umgeni Water spokesman Shami Harichunder emphasised the need for all sectors to continue using water sparingly, as major spikes in demand could result in rapid reduction of the levels of smaller dams.
Agriculture accounts for roughly 60% of the country's available water use, followed by urban use (25%), mining and bulk industrial use (6%), rural use (4%) commercial forestry (4%) and power generation (about 2%).
Growing optimism around renewed La Niña conditions, however, has been tempered by the World Meteorological Organisation secretary-general, Petteri Taalas. "Even if a La Niña event does develop, its cooling signal will not be enough to counterbalance the impact of human-induced climate change," he said.
"The year 2020 remains on track to be one of the warmest years on record [globally], with much extreme weather, ranging from scorching temperatures and wildfires to devastating floods and marine heat waves. This is largely the result of greenhouse gases rather than naturally occurring climate drivers," said Taalas.
