A flotilla of hundreds of boats sailed effortlessly on the Vaal River at the weekend, without being hindered by invasive water lettuce and water hyacinth
A flotilla of hundreds of boats sailed effortlessly on the Vaal River at the weekend, without being hindered by invasive water lettuce and water hyacinth that had blanketed its surface earlier this year.
They formed part of the “Celebrating the Vaal River” event, which marked the opening of the spring and summer boating season and the celebration of the removal of the invasive aquatic weeds that had infested the sewage-polluted Vaal River Barrage Reservoir.
“We couldn’t navigate this river literally,” said Rosemary Anderson, the managing director of Stonehaven on Vaal. “We had 400 hectares — that’s the size of a farm — of water lettuce and now it’s all gone.”
That the coverage is down to less than a hectare on the barrage made Saturday an “exceptionally happy day” for Anderson.
Anderson, the national chairperson of the Federated Hospitality Association of Southern Africa (Fedhasa), praised the community-government collaboration for the removal of the free-floating invasive species that forms dense mats on the surface, which had seen a R10 million investment by the Vaal River community.
“We worked together with Rand Water and the DWS [department of water and sanitation], the department of forestry, fisheries and the environment and Julie Coetzee [the deputy director of the Centre for Biological Control (CBC) at Rhodes University].”
Other partners include agrichemicals and explosives group Omnia, Save the Vaal Environment, Fedhasa and AfriForum.
“Today is a day to celebrate and I’m hoping that this template of biocontrol, physical removal, herbicide and curtaining can be used in other water bodies that have got a similar problem [with invasive aquatic weeds],” she added.
The weed invasion caused losses for many businesses along the barrage.
“It was really bad for aquatic life too. We have very rich water birdlife on the Vaal River that were totally decimated because they couldn’t access the areas that they had before and we had land birds that were on top of the water lettuce,” Anderson said.
The department of water and sanitation has appointed Rand Water as the official implementing agent to ensure that the barrage “never experiences what it went through earlier this year”. It has allocated R42 million over the next three years, together with a comprehensive preventative programme.
The infestation of water lettuce and water hyacinth is fuelled by high levels of polluted water in the catchment of the Vaal River. Efforts by the department to reverse this include monitoring hotspots, assisting and intervening with municipalities and taking legal action when required.
This will further be supported by an anti-pollution forum that will meet next month under the leadership of the deputy water and sanitation minister, Isaac Seitlholo, said Leslie Hoy, the project manager at Rand Water.
“This is part of an integrated plan to revert the river and its tributaries back to a more healthy state, allow for biodiversity to be restored, for communities to enjoy and experience a cleaner environment and for business to flourish,” he said.
“For the invasive alien species in the Vaal River Barrage, we’ve come up with a strategy to say what plants are here because there might be others,” said Anet Muir, the chief director of water use compliance and enforcement at the department. The strategy is to identify invasive aquatic species and find appropriate sustainable controls.
Her job is to sort out the water quality for industry, mines and wastewater. And it’s not only the troubled Emfuleni local municipality that can be blamed for the sewage loads in the Vaal River.
“It’s Mpumalanga, it’s Johannesurg, it’s Sasolburg, it’s Vanderbijlpark, it’s everywhere and that’s just the municipalities. That’s not even the industries; the mines, and agriculture and urban runoff.
“That’s just the formalised wastewater coming in. Everything else that’s not point source [pollution] must also be sorted out,” she said.
The Centre for Biological Controls’ Coetzee said: “Today is a celebration of open water as a result of a community getting together to sort out a huge problem. I think the community did a huge amount through their removal and what-have-you, but maybe weren’t aware of all the behind-the-scenes things going on with the government and Rand Water to facilitate the process.”
Ferrial Adam, the executive manager of WaterCAN, added: “This is beautiful and we can’t help but celebrate people coming together to solve a problem.”
But she can’t help but feel a “division” in South Africa, highlighting the recent drowning of an 18-month-old in the Klip River, where initial efforts to locate the toddler’s body were stalled because the water was so polluted.
“How do we make our rivers a place of celebration across the country? I literally have to switch off my WhatsApp at night because you get picture after picture of acid mine drainage and sewage. How do we garner this kind of money and the influence that money brings but I applaud the [Vaal] community for actually getting together and doing stuff,” Adam said.
She remains worried about the use of Kilo Max 700, a glyphosate sodium salt herbicide, to clear the invasive aquatic weeds on the Vaal. “We don’t test our water for glyphosate. Glyphosate is in our water, it’s in our food,” she said, citing research that had found traces of glyphosate in a local brand of tomato sauce.
“Glyphosate is poisonous to our human bodies, to animal bodies, to the environment, so we have to be realistic about this. People wanted a quick fix, they wanted this thing gone from their river and they had the means to do so. On the one hand, you have to say well done to them, but we have to be mindful of the long-term effects on the environment.”
Hoy said that although Kilo Max contains glyphosate, its formulation “is such that it is not carcinogenic and we’ve got documents in writing [from the supply company UPL] to tell us that”.
He said spraying the herbicide would continue next year for as long as needed to control the invasive species.
Coetzee said the quality of the water upstream needs to be remediated. “We’ve put a Band-Aid on a compound fracture. We’ve treated this explosive growth of an invasive plant but we haven’t solved the source of the problem. It’s all about water quality.”
She said the Vaal community cleared the barrage so that boats could be sailed and people “can have a nice braai and go to a resort, but “we have to look at the ecosystem. You can’t have a non-functional aquatic system because then you lose all those benefits of this function.”
Rand Water has a preventative programme to ensure the barrage reservoir “never experiences the level of invasive aquatic weed coverage as experienced earlier this year”, Hoy said.
It is issuing requests for quotations to reduce regrowth and limit the invasive species’ spread through physical removal, chemical control and biocontrol.
Through the support of the CBC, three community stations and one station at Rand Water have been set up to rear biological control agents such as weevils and hoppers that have been approved as host-specific feeders. Biological control will be used as a long-term, natural control mechanism that will need to be supplemented annually.
“I am just hoping that when the plants come back, we can work on the biocontrol solution as a sustainable solution rather than spraying herbicides,” said Coetzee.
Water lettuce and water hyacinth are likely to be a long-term problem for the barrage, Hoy said. His theory is that the more plants that are removed in the early stages, the “less chance we have of a problem late in summer”.
For her part, Anderson vowed: “We already are so ahead of the game. The moment we see it we’re going to be on it like a wet blanket.”