In the 21st century mankind has totally dominated the globe, and everything in it. Our endeavour to develop our natural resources for human growth and prosperity has affected every seen and unseen part of this small planet we all call home. Today all approximately eight billion people on earth are more connected than ever, we know almost instantly what is happening in some of the most remote parts of the world and get to participate in the who, what, why, when, and how of almost every discussion taking place around the world.
But our development of natural resources comes at a cost, a trade-off that we are not aware off, and generally not engaging in. Our resources are limited, we can use them up and we are most definitely overusing them. The consequences of our excessive use of our vulnerable water resources include social and ecological disasters.
On 11 September 2022, in a small mining community named Jagersfontein in the Free State province of South Africa, a more than 100-year-old, 65Ha, man-made tailings dam filled with processed waste from the nearby diamond mine burst its walls. The resulting spill claimed at least three human lives and damage to property estimated to cost more than R100 million. The social impact of the spill has been tremendous, affecting the livelihoods of many thousands of people and the whole community of Jagersfontein.
The ecological impacts of the spill, however, are still being played out. The estimated more than 6000m3 of tailings has spread over a massive area and reached the Kalkfontein Dam as well as the Riet River. From the Kalkfontein Dam the moderately utilised Riet River flows for about 200 km into the Vaal River just 35km upstream of the confluence between the Vaal and Orange Rivers.
The massive spill of tailings is now spread over such a vast area of more than 30km that a clean-up is virtually impossible. Which begs the question: What is going to happen next?
We are in a high rainfall hydrological period. This means that over most of the central and eastern parts of South Africa we expect above average rainfall. In recent years this has been evident from the floods in Durban and KwaZulu-Natal to the deluges experienced in Johannesburg and across the Free State. We expect similar rains over the 2022/2023 wet season.
Urgent attention required
The recent rains of the 2021/2022 season may already have contributed to a highly saturated landscape that after years of drought may have been one of many contributing elements to the Jagersfontein disaster. This year’s rains are now expected to mobilise the tailings and wash much of it into the upper Prosesspruit and the Kalkfontein Dam. Impacts of this event may be mobilised beyond the dam after the season’s first rains and possibly affect the Riet River along its length to the Vaal River and possibly the Orange River.
While the lower Vaal River is largely utilised and in an impaired ecological state, the Riet River has historically been a refuge area of aquatic biodiversity in the region and a favoured destination of specialist yellowfish anglers who frequent the Lilydale Rest Camp in the Mokala National Park to target regionally rare largemouth yellowfish. These fish are the living gold of South Africa.
The dedicated angling industry was worth more than R130 million in 2008 and has continued to grow. Yellowfish are also key indicator species and help us manage our river health. Today the Riet River below the Kalkfontein Dam is in a relatively better ecological condition than other tributaries of the lower Vaal River catchment and an important refuge area for aquatic biota and other biodiversity and key ecosystem processes.
The Riet River catchment also includes a nationally recognised Freshwater Ecosystem Priority Area: the Kromellenboogspruit fish sanctuary, a river that flows parallel to the Prosesspruit that has been affected by the Jagersfontein spill.
Should the tailings of the Jagersfontein Mine contaminate the Kalkfontein Dam and affect the 200km of the Riet River, this would be another regional disaster that may affect many more thousands of South Africans and threaten one of the few remaining refuge areas for aquatic biodiversity in South Africa. The worst impact of the Jagersfontein spill is yet to come.
Urgent action is required to ascertain the potential for the spill to spread across the landscape to contaminate the Kalkfontein Dam and the associated Riet River. In addition, the risk of multiple stressors associated with the spill to the vulnerable socio-ecological system of the Riet Catchment should urgently be determined. Only then a real understanding of the environmental impact of the spill will be understood and can mitigating measures be taken. Watch
The article is written by Dr Gordon O'Brien from the School of Biology and Environmental Sciences, Faculty of Agriculture and Natural Sciences at the University of Mpumalanga. Pictures supplied.