South Africa’s rivers are dying

A quarter of South Africa’s major rivers are ‘critically endangered’, according to a WWF SA report last year.

According to the authoritative Atlas of Freshwater Ecosystem Priority Areas in South Africa, when a Cape clawless otter is found with necrotic feet in the Hout Bay River in Cape Town, it's a sign that the river is in dire straits.

Unabated pollution and excessive water extraction is typical of the assaults on major rivers across South Africa, more than half of which are in bad condition, the Atlas adds.

The Hout Bay River meanders across the beach in its quest to reach the sea.

Professor Justin O'Riain, director of the University of Cape Town Institute for Communities and Wildlife and a Hout Bay resident, found a dead otter with severe plastic contamination and a second otter with missing hind toes, a symptom of a dying river.

Rivers feed dams and 29 of 100 major dams have a ‘red’ health risk from either high nutrient levels or algae-like organisms called blue-greens, some of which produce toxins dangerous to humans.

Pullquote: “Our rivers have a double whammy: they are losing flow to extraction and they are getting too much nutrient-rich water from sewage.”
Dr Liz Day of Freshwater Consulting

The water supply is put at risk by taking too much water out of rivers during a drought, aggravating pollution, as there is insufficient rain for the natural dilution to take place, said Sputnik Ratau, spokesman for the Department of Water and Sanitation

He said rivers were a serious concern in the Western and Eastern Cape, where the drought has not yet broken, while other provinces face major problems from mining pollution, acid mine drainage and industrial pollution.

The department identified several rivers severely affected by pollution:

In Gauteng: the Jukskei (sewage, industrial and urban runoff), the Apies, Hennops and Rietspruit;

In Northern Cape: the lower reaches of the Vaal and the Harts (sewage, irrigation runoff, untreated abattoir waste, illegal alluvial diamond and sand mining); and

In Mpumalanga: the upper reaches of the Olifants and its tributaries (coalmining and acid mine drainage).

One in 10 residents rely directly on rivers and springs for water, said Christine Colvin, WWF SA's senior manager for freshwater programmes.

Founder of CyanoLakes which monitors dams, Dr Mark Matthews, said: “Dams are a good indicator of river health and many systems have been affected by nutrient pollution. This indicates effluent and other contaminants which lead to waterborne diseases.”

Sewage continues to be a pollution scourge says Dr Liz Day of Freshwater Consulting, “Our rivers have a double whammy: they are losing flow to extraction and they are getting too much nutrient-rich water from sewage.”

every drop

Water scientist Dr Anthony Turton said systematic failures to police municipalities for badly run sewerage systems were major drivers of the contamination of rivers.

The greatest threat to the Hout Bay River is wealthy residents taking too much water out and poor residents lacking adequate infrastructure for sewage and wastewater, which in turn, flows into drains, Professor O'Riain pointed out.

houtbay river
The Hout Bay River enters the weir in Hout Bay next to Orange Kloof, bound for the wetlands and the sea.

The lagoon at the beach, where children swim, had E. coli levels above a million cells per 100m, whereas the safe limit for this bacterium from faeces is considered less than a thousand, he adds.

O’Riain says there are no fish left in the river, “For the first time I’ve found sewage worms in the river. This little red worm is the only thing that can survive when the oxygen is so low.”

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