The sudden change in SA’s water situation has all the hallmarks of science fiction with a touch of divine intervention, writes Themba Khumalo.
The sudden rise of water levels at the Vaal and Bloemhof dams this week is a miracle that has left water scientists and hydrologists scratching their heads for answers. Some called it a “four-day miracle” that changed the country’s water scenario.
The sudden change in South Africa’s water situation from gloom to ecstasy has all the hallmarks of science fiction with a touch of divine intervention.
Otherwise, how does one explain the fact that a mere three months ago there seemed to be no hope that South Africa’s dams would be filled to capacity during the current hydrological season that ends in May?
The saga started two weeks ago with the arrival of Cyclone Dineo that swept through the coastal regions of Inhambane, Xai Xai and Beira provinces in Mozambique, where it displaced 160000 people and caused structural damage to buildings.
By the time the storm crossed into South Africa it had lost its steam and caused minimal damage in Mpumalanga and Limpopo.
After Dineo left our shores, in came the tropical front that ensconced itself in Gauteng, the Free State, Northern Cape, KwaZulu-Natal and North West.
A tropical front lacks the ferocity of a cyclone and normally comes with soft, tenacious rains that fall for several days.
Water scientists and meteorologists are agreed, however, that the tropical front is much more qualitative and desirable for its hydrological impact.
Because of its tenacity, it fills up rivers and dams very quickly. Fast forward to February 21, when the dams were barely half full and the water level at the Vaal Dam was 65%.
With the heavy downpours that were engendered by Cyclone Dineo, there were sudden improvements in the country’s water situation as rivers picked up their flow and dam levels rose steadily.
At a meeting of the National Disaster Management Committee, the chief forecaster at the SA Weather Service, Kevin Rae, warned of a tropical front that would come after Dineo.
“The front will bring along soft, persistent rains that may result in flash floods in affected provinces,” Rae warned.
What Rae didn’t prepare us for was a complete change of the water scenario that would happen in a matter of days. It took exactly four days to change the entire water picture in the country.
Amid the soft rains that followed, a few days later the hydrologists in the Department of Water and Sanitation swung into action as the rivers swelled and dam levels rose alarmingly. Subsequently, communities who live in Douglas, downstream of Bloemhof Dam in North West, were asked to relocate as they were in danger of being swept away by potential flash floods.
The department planned to open eight sluice gates to prevent Bloemhof from overflowing.
The Vaal Dam was in a similar situation as its water level rose daily after the Vaal River System increased its flow as a result of persistent rains.
Minister Nomvula Mokonyane visited the dam last Sunday where she addressed the media before opening two sluice gates to symbolise and acknowledge the full capacity of the Vaal for the first time in six years.
Hordes of people from around Gauteng went to witness the opening of the gates. It was a huge celebration for everyone.
People took photos and videos and social media was abuzz with the news.
In a matter of hours, the department’s social media desk recorded a whopping 500 000 people talking about the issue.
At the media briefing, Mokonyane announced the department’s decision to lift the year-old water restrictions in Gauteng.
The process of lifting the restrictions was done in collaboration with affected municipalities after her decision was gazetted the following day.
“As at February 25, the Vaal Dam increased to 94.86%; Grootdraai was at 103.1% and Bloemhof was at 81.7%,” Mokonyane said.
“The current status of the Integrated Vaal River System necessitates a consideration around the lifting of the water restrictions in Gauteng with immediate effect, while the system review planned for May will still happen to consider the outcomes for the 2017/18 hydrological year.
“We have also begun releasing water from the Bloemhof Dam, 250 cubic metres per second on Friday; this rose by another 250 to 500 cubic metres per second on Saturday,” she said.
Flood warning protocols were activated to ensure that the department mitigated any damage to property and avoided any loss of life.
A buoyant Mokonyane said that the last two to three years had been difficult for the country, based on the drought that had devastated large parts of the countries comprising the Southern African Development Community. The drought had truly not been just a South African experience, but was felt across the region.
“Looking at where we came from a few months ago, when the country’s dams averaged a lowly 54.8% on April18, 2016, and 49.1% on December19, 2016, we averaged 60.5% on February 20 this year.
“This rose to 67.1% as of February24, a great deal different from the 54% at the same time last year,” she told journalists.
The provincial averages at the moment are as follows (with the previous year’s average in brackets):
Eastern Cape: 63.4% (73.1%)
Free State: 74.9% (53.7%)
Gauteng: 90.2% (83.2%)
KwaZulu-Natal: 52.8% (52.4%)
Limpopo: 72.4% (59.3%)
Mpumalanga: 72% (59.7)
Northern Cape: 104.7% (56%)
North West: 86.7% (44.4%)
Western Cape: 32.8% (49.1%)
However, according to hydrologists in the department, the decision to release water from the dam was informed by several hydrological factors. Chief among these is the fact that once the dam has reached its capacity, it has to be analysed for any social or environmental impact.
“Secondly, there must be a safe river or a resource that has the capacity to contain large volumes of water at a time.
“At the moment we are under no pressure whatsoever to open the sluice gates at the Vaal.
“It is worth noting that Vaal Dam has an additional capacity of 26% to store surplus water,” said a hydrologist.
However, the water situation in the Western Cape remains dire as some dams have reached dangerously low levels. Consequently, the City of Cape Town is urging caution as it battles to supply water for basic needs such as drinking, cooking and washing.
The Department is monitoring the situation and is working with the provincial government to avert a potential disaster.
* Khumalo is a content developer in the Department of Water and Sanitation.
** The views expressed here are not necessarily those of Independent Media.