City curbs invasive water hyacinth at Zeekoevlei
28 January 2021
Pockets of water hyacinth were recently discovered by the City of Cape Town’s biodiversity management staff in the Groot Lotus River system. The hyacinth plants were found in the upstream portion of the river above the vlei, and posed a real threat of invading the Zeekoevlei waterbody. The False Bay Nature Reserve staff acted swiftly to curb the spread of this invasive species. Read more below:
The water hyacinth plants found in the upstream portion of the Groot Lotus River posed a massive threat to the river system. If left untreated, its population numbers would have soared and eventually choked the river system, with the risk of invasion of the 256ha open water recreational water body at Zeekoevlei which is part of the False Bay Nature Reserve.
Water hyacinth is an aggressive plant invader.
Water catchments that are connected to the rivers where the plant is present, as is the case at Zeekoevlei, are under constant threat as the water hyacinth has the potential to cover 100% of the water ways and water bodies.
Fortunately, the False Bay Nature Reserve staff discovered the presence of hyacinths plants at an early stage and treated the plants with a specific herbicide.
‘Our team at the reserve had to act fast. This was the quickest method to curb the reproduction of the plants and to minimise the threat of invasion. We are happy to report that this treatment was successful in killing off the water hyacinth in the river. Our teams will continue regular follow ups over the next two weeks, until no new plants are found,’ said the City’s Mayoral Committee Member for Spatial Planning and Environment, Alderman Marian Nieuwoudt.
The City is currently also doing a draw-down, which entails the lowering of the water level, at Rondevlei and have a contracted team dedicated to physically removing any water hyacinth they come across. This clearing is tricky as the staff have the added challenge of clearing water hyacinth in reed beds while on the lookout for the reserve’s hippos.
‘The City wants to thank the neighbouring residents as they have been true custodians of the water bodies in the area. The residents who live on the shoreline often alert us of water hyacinth pockets, or remove it themselves before it becomes established and causes a greater problem that would ultimately hinder activities on the vlei. This is what we call true active citizenship and for this we are grateful,’ said Alderman Nieuwoudt.
Prior to 2009 most of the Zeekoevlei catchment was infested. At the time the City succeeded in eradicating the plant from the system and we enjoyed eight years of a hyacinth free catchment. Unfortunately, water hyacinth was rediscovered in 2017.
Efforts to eradicate this very invasive species from our nutrient rich rivers and vleis remain a priority.
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Published by:
City of Cape Town, Media Office
