War on water weeds: Rand Water is spraying a herbicide over the Vaal River in an effort to get rid of water lettuce and hyacinth. Picture: Facebook/RandWater
In an attempt to try and rid the Vaal River of its “bank-to-bank carpet” of water lettuce and hyacinth, Rand Water started spraying the sewage-loving weeds on Tuesday with the herbicide glyphosate.
On Monday, the water utility’s confirmation on social media of its intention to use the herbicide over the river was, however, met with widespread disapproval.
This despite Rand Water’s assurance that it was acting in accordance with the approved general authorisation from the Department of Water and Sanitation, as well as with technical guidance from the Department of Forestry, Fisheries and the Environment.
Dr Simone Dahms-Verster, lecturer at Wits University School of Geography, said she was shocked to hear that the herbicide solution was approved and will be implemented.
“Spraying glyphosate directly into a freshwater ecosystem is a terrible idea. The effects of glyphosate and its metabolites can cause reactive oxygen species and gene mutations in various aquatic species,” the lecturer said.
Her concerns were echoed by the Water Community Action Network (WaterCAN), a leading advocate for water conservation and safety initiated by the Organisation Undoing Tax Abuse (Outa).
“Spraying is a short-term solution and a long-term polluting disaster,” warned WaterCAN executive manager, Dr Ferrial Adam.
According to him, a multifaceted approach is needed to address the water lettuce and hyacinth infestation in the Vaal River.
“One of the critical components of this approach is tackling sewage pollution flowing into the river from Emfuleni and other surrounding municipalities. The nitrates present in sewage serve as fuel for the rapid growth of water lettuce,” he explained.
By addressing sewage pollution at its source, we can mitigate the nutrient influx that exacerbates the proliferation of invasive aquatic plants.
ALSO READ: Vaal River polluted ‘beyond acceptable standards’, says SAHRC
The Integrated Vaal River System serves as essential water source of 19 million people in Gauteng, the Free State, Northern Cape and North West provinces through 14 dams, which are purified by Rand Water.
The City of Johannesburg – which has been battling bouts of major water outages for the past two years – relies solely on the Vaal River for its water.
The water source has been polluted by tonnes of sewage which has been allowed to flow into the river for years because of the wastewater treatment plants in Emfuleni, according to News24.
Non-profit organisation Save the Vaal reported last year that the collapse of the treatment plants resulted in a shocking 170 million litres of raw or partially treated wastewater entering the Vaal River daily.
ALSO READ: Cholera updates: UN steps in, Vaal River tests positive
“The community living along the Vaal River has been manually taking the water lettuce out,” Adam said.
“Their efforts demonstrate the commitment to preserving the health of the river and its ecosystems. It’s imperative that their dedication is acknowledged and supported through sustainable, community-led initiatives.
“We urge stakeholders to prioritise sustainable solutions that address the root causes of the water lettuce and hyacinth infestation while upholding the integrity of the Vaal River ecosystem,” he added.
ALSO READ: Community removes 70 tonnes of water lettuce from Vaal River
Adam explained that integrated pest management strategies, mechanical removal, and biological control options offer environmentally friendly alternatives that minimise harm to ecosystems and safeguard public health.
Despite WaterCAN calling on Rand Water to reconsider its approach, the utility already started waging war on the water weeds on Tuesday, by spraying glyphosate over the river.
In an update posted on X and Facebook, the water utility said that it has embarked on an “integrated approach” to manage the situation.
“This involves physical removal, biocontrol, and chemical application. It has also been agreed by experts that this type of approach is most suitable at present,” the statement read.
According to Rand Water, the herbicides used as part of the project, are “set at a sub-lethal dose because we are implementing an integrated approach”.
It went on to explain that the sub-lethal dose actually increases the sugar and carbohydrate contents of the Pontederia crassipes plant, making it more palatable for the biocontrol agent.
Although biocontrol agents are already on the Vaal Barrage, Rand Water said additional biocontrol agents will be released on Thursday, 15 February, in the upper reaches of various stream inlets and elected areas between reed beds on the barrage.
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