From Creamer Media in Johannesburg, this is the Real Economy Report.

Sashnee Moodley:

Rand Water has embarked on a three-pronged integrated programme to clear the invasive water lettuce currently overwhelming the Vaal River, one part of which is the release of hundreds of weevils as biological agents across several sites across the Barrage area. Natasha Odendaal has the story.

Natasha Odendaal:

The water utility, after being approach by communities, had been working with Rhodes University and various technical experts to develop options to mitigate the increasing challenge of invasive plants in the Vaal Barrage.

The result is a programme that entails an integrated approach that combines physical removal, chemical control and longer-term biological agent control.

Rand Water environmental services manager Dr Lesley Hoy…

Natasha Odendaal:

While biological agents, such as the weevils and hoppers, can control the majority of these invasive floating species over the long term, there is a need to get rid of a large majority of these plants as quickly as possible, which is where the manual removal or the chemical treatment play a significant role, to prevent further spread.

Centre for Biological Control deputy director Dr Julie Coetzee…

Natasha Odendaal:

Released onto the aquatic plants, the biological agents eat on and damage the plants, which eventually kills them off, and while it does take time and requires patience, their long-term use on the invasive plants are said to be safe, environment-friendly and sustainable, reducing the need for chemical control.

The programme will be ongoing with the release of biological agents every few weeks, with the insects being reared in Grahamstown and at the newly established hot house within Rand Water’s nursery in Alberton, for future releases.

Rand Water environmental services manager Dr Lesley Hoy…

Rhodes University has also developed a monitoring application for the project, which provides satellite imagery that gets uploaded and updated once a week, enabling Rand Water and other interested stakeholders to monitor the extent of the growth of the water lettuce, the extent of the problem and to see where it has had impact.

Rand Water environmental services manager Dr Lesley Hoy…

Sashnee Moodley:

That’s Creamer Media’s Real Economy Report. Join us again next week for more news and insight into South Africa’s real economy. Don’t forget to listen to the audio version of our Engineering News daily email newsletter.