The City of Cape Town started removing sludge from the Rondevlei weir to improve the health of the wetland.
The organic sludge is a very fine sediment that consists mainly of old organic matter such as dead reeds, algae, and pondweed, but heavy metals and plastic waste are washed in by stormwater run-off and trapped in the dead organic matter.
The City explained that high nutrients have a negative impact on wetlands because all of the special indigenous organisms in local wetland systems are adapted to low nutrient conditions. By removing the organic sludge the overall health, biodiversity, and water quality of the wetland is improved.
The City of Cape Town started earlier this month and once complete, the sluice gates at Rondevlei will be opened and allowed to drain. The drawdown will take about four months.
