Invasion: Major dredging operation to begin in Cape Town

Planned dredging of Lower Silvermine Wetlands (LSW) starts this week, to mitigate flood risk the City said. Picture:Supplied

Planned dredging of Lower Silvermine Wetlands (LSW) starts this week, to mitigate flood risk the City said. Picture:Supplied

Published Apr 2, 2023

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Cape Town - Planned dredging of about 79 000 square metres, starting from Main Road until the major wooden footbridge that runs between Hilton Road and Carlton Road in the Lower Silvermine Wetlands (LSW) commences this week, in efforts to reduce the risk of flooding for residents of the surrounding areas.

Dredging is the mechanical removal of accumulated sediments/silt deposits, including invasive water plants, litter and solid waste, using excavators.

The City said dredging work on the LSW would start during the first week of April.

“The dredge will remove the excess silt and sludge from any sewage spills, wildfire erosion and stormwater runoff. This will then reset the water capacity of the ponds back to their original levels,” the City said.

The City’s Catchment, Stormwater & River Management (CSRM) branch is investing approximately R7 million into the project.

The work being done is part of ongoing river maintenance and programmes to improve inland water quality.

“The LSW has been used as a reference location as to what urban waterways should look like – an interface between the environment, people and wellbeing,” said the City’s acting mayco member for water and sanitation, Siseko Mbandezi.

During the dredging process, excavators inside the river remove accumulated sediment and move the dredged material towards the river banks. The material is then lifted by means of a long boom excavator to stockpile it 10 m away from the banks and allow for dewatering for three weeks or more before the material can be carted away to the relevant disposal site.

Phase one of the project is expected to be completed by 30 June 2023.

Cape Times