The City of Cape Town is planning to redevelop and upgrade weirs at Zeekoevlei and Rondevlei, that are located within the False Bay Nature Reserve.
The purpose of the project, is to of construct a new weir with sluice gates at Rondevlei, to improve the management of Rondevlei’s water levels downstream.
The False Bay Nature Reserve is a Ramsar site, declared an internationally significant wetland for conservation.
Residents are invited to an information session today, Wednesday, 3 July 2024, to elaborate on the project proposed, to supplement other medium-term interventions, including the dredging of Zeekoevlei, to improve the overall water quality of the system.
In a statement, the City said, both Zeekoevlei and Rondevlei are managed by a system of penstock sluice gates, to allow for the water level to be dropped to a minimum depth, which is known as the annual ‘drawdown’, usually at the end of the summer sailing season.
The intention of the drawdown is to remove nutrient-rich water and sediment from the system, and to increase the capacity of the vlei prior to the winter rainfall season, to reduce the risk of flooding of surrounding areas.
The current manually operated weirs limit the depth of water which can be drawn down. The weir walls, built in the 1950s, prevent the movement of marine and estuarine fish into and from the vlei.
Alderman Eddie Andrews, the City’s Deputy Mayor and Mayoral Committee Member for Spatial Planning and Environment, said about the planned project, ‘our intention is to lower the weirs at both Zeekoevlei and Rondevlei and to install mechanically operated sluice gates, as opposed to the current systems where we remove the penstocks manually for the drawdown.
Many residents and interest groups from the False Bay Nature Reserve join us for the annual drawdown and are well aware of what this task entails. With mechanically operated sluice gates we will be able to do drawdowns quicker, and the lower weirs will allow for a lower level drawdown of the vlei water.”
He said the intention is to keep the existing penstocks, but to modify the Zeekoevlei weir, with a new sluice channel.
“The installation of fish swim ways will assist with the reintroduction of natural estuarine fish into the vlei, restore fish diversity and abundance, restore the nursery function of the two estuaries, and enhance the conservation status of estuarine dependent marine fish species. We are extremely excited about the prospect of having our indigenous fish back in the two vleis” he said.
The City has appointed an independent Environmental Practitioner to undertake the necessary Environmental Impact Assessment related to the proposed redevelopment of the weir complex located within the False Bay Nature Reserve.
Interested parties are encouraged to register and comment on the draft basic assessment
The relevant documents can be accessed at www.infinityenv.co.za/Zeekoevlei weir
Comments can be submitted electronically by sending an email to comments@infinityenv.co.za, remember to provide your name, contact details, and the interest you may have in this application.
Picture: Otto Schmidt via Cape Bird Club