Recent rainfall has boosted the water levels of the Vaal dam significantly, with plans to fill the dam with water from Sterkfontein dam no longer necessary.

Over the past few months, as the Lesotho Highlands tunnel continues to be under maintenance and shut down until the end of March, the water levels of the Vaal dam had been dwindling, and preparations were under way to augment the water from the Sterkfontein dam as soon as the Vaal dam’s levels had reached 18%.

The Department of Water and Sanitation (DWS), closely monitoring the Vaal dam, said in a statement on Wednesday, that the water volumes drastically improved this week, from 24.3% to 46.2% by Tuesday.

Overnight, the levels have again significantly increased to 50.53%.

The Vaal dam is rapidly rising owing to the heavy rainfall experienced this week in Gauteng, and other provinces of North West, Free State, Limpopo, Mpumalanga and KwaZulu-Natal, explained DWS spokesperson Wisane Mavasa.

“We are now clear of the risk for the Vaal dam dropping below its minimum operating level of 18%.”

The dam had experienced continuous decline over the past few months owing to elevated temperatures, which have led to increased evaporation losses, and the low inflows into the dam owing to lack of rainfall in the Vaal catchment.

“The current dam level is now plotting above 50% and there is a good inflow because of recent rainfall in the catchment. There is therefore no more a need for water release from Sterkfontein dam to support Vaal dam,” said Mavasa.

The rise in the dam levels has also boosted the overall Integrated Vaal River System, which increased from 71.4% to 79.4% this week.

The recent heavy rainfall, while disruptive and resulting in localised flooding, has also significantly improved surface water storage levels across the country’s dams with 79.8% this week, an increase from last week’s 74.5%.

Water levels in Mpumalanga’s water storage systems surged from 82.9% to 93.1% this week, while KwaZulu-Natal’s water storage levels rose from 81% to 91.2%.

Likewise, increases have been recorded in Limpopo, which increased by 9.4% this week, rising from 73.2% to 82.6%, while the North West’s water storage levels increased from 64.7% last week to 72.5% this week and water storage levels in the Free State increased from 68.5% last week to 72.6% this week.

Rainfall in parts of the various provinces has exceeded 150 mm, while parts of Limpopo, Mpumalanga and KwaZulu-Natal received more than 200 mm.

“There is an expectation of isolated to scattered rainfall over central and eastern areas of the country, particularly in Free State, Limpopo, Mpumalanga and KwaZulu-Natal provinces this week, as a result, surface water storage in these areas is expected to improve further next week,” said Mavasa.

The storage capacity in major water supply systems (WSS) has also shown improvement, with Luvuvhu WSS in Limpopo, serving Thohoyandou, improving from 88.4% to 97.3% this week. The Polokwane WSS has also escalated from 82.2% to 98.6% this week.

Crocodile West WSS, which serves Tshwane, in Gauteng, and Rustenburg, in the North West, has improved from 86.4% to 92.5% this week, while the Crocodile East WSS serving Nelspruit, KaNyamazane, Matsulu, Malelane and Komatipoort, in Mpumalanga, increased from 60.1% to 73.8% this week.

In KwaZulu-Natal, the water supply systems have also increased, with Umgeni rising from 86.8% to 88.3%, and uMhlathuze from 91.5% 93.6%.

However, the Bloemfontein WSS, in the Free State, which serves Bloemfontein, Botshabelo and Thaba Nchu, has slightly dropped from 69.9% to 69.6% this week.

The Northern Cape has also reported a decrease in water storage from 72.9% to 67.8% this week, with the Orange WSS, which supplies the Northern and Eastern Cape, declining slightly from 74% to 73.8%.

The water levels in the Eastern Cape are stable, dropping slightly from 81.7% to 81.4%.

The Algoa WSS, which supplies Nelson Mandela Bay Metro, Sarah Baartman District, Kouga Local Municipality and Gamtroos Irrigation, has also dropped slightly from 81.2% to 80.2% this week, while the Butterworth WSS remained unchanged this week at 97.8%.

The Amathole WSS also remained stable at 98.5% this week. The system has a total of six dams which serve Bhisho, Buffalo City and East London. Klipplaat WSS which serves Chris Hani district municipality has also dropped from 90.4% to 89.1%.

Water levels in the Western Cape also declined from 83.0% to 80.9%, with the Cape Town WSS dropping from 88.0% to 85.9% this week.