Volunteers help clean the polluted Jukskei River "prone" to flash floods

In South Africa's oldest township, volunteers in wetsuits jump into the thigh-deep water of the polluted Jukskei River to untangle a net that's designed to trap garbage but damaged by heavy rains.

Without the nets, the shacks in low-lying Alexandra, on the outskirts of Johannesburg, could face disastrous flooding.

They are a "big hazard," said Semadi Manganye, a resident and co-founder of the Alexandra Water Warriors.

He added that the Jukskei River is "prone" to flash floods, caused by "all the illegal dumping" of mixed debris, such as "big boulders", which he says has narrowed the river.

World leaders from the Group of 20 rich and developing nations will meet this weekend in Johannesburg for the bloc's first summit in Africa. Host South Africa wants to prioritize issues affecting poor countries, including responses to disasters made worse by climate change.

South Africa wants rich countries and international financial institutions to help more — a plea also being made at global climate talks in Brazil.

Alexandra, with over half a million residents, is within steps of South Africa's richest financial district, Sandton. But rising flooding often submerges bridges, leaving the township's children unable to reach school.

"We as the Water Warriors are trying our best without debris management, without urban greening activities, education and awareness activities, and the recycling, repurposing, and reusing of the waste that we find in the river and turning it into cash, like something that we can make something of," Manganye said.

The Alexandra Water Warriors have considered themselves the guardians of their environment since they formed in 2021, planting native trees to reduce urban heat and collecting and recycling trash from the river.

"We've halved the dirt and the pollution, especially in the river and on the riverbanks. If we didn't have the garbage trap in the water, or if we weren't working here collecting rubbish, I don't think you'd like the sight of this place. It would be polluted in such a way that you would be disgusted by what you see", said Themba Mofokeng, an Alexandra Water Warriors worker.

They face the kind of challenges seen in other townships and poor settlements across South Africa, which is the continent's most developed economy but also has some of the world's most dramatic inequality.