Components of an IHC floating suction dredger ordered by the city of Cape Town have arrived at Zeekoevlei in the False Bay Nature Reserve and the project team is now busy assembling it for launch at the end of this week for testing.
Two sections of Zeekoevlei will be dredged over a period of 26 months, namely Home Bay and Storm Bay.
The total volume of sediment to be dredged from Home Bay is 157,000m³ and is estimated to take about 14 months. The total volume for Storm Bay is 207,000m³ and is estimated to take about 12 months.
Hydrographic surveys of the dredged area will be conducted every two weeks to measure progress, and the dredged sediment will be pumped from Zeekoevlei via a 4.3-kilometre-long slurry pipeline to ponds for dewatering and storage.
"I am very pleased to say that all is on track for the dredging of Zeekoevlei to commence by mid-June 2025," said the city’s Deputy Mayor Eddie Andrews.
"The components arrived over the weekend, this in itself was quite an operation, and in coming days the dredger will be assembled and once ready, tested on the vlei.
"The last time the city dredged a vlei was 42 years ago, in 1983, when parts of Home Bay were dredged. Then, this will be the first time ever the city will be using a floating suction dredger to dredge organic rich sediment from the vlei bed.
"Normally, dredging is done by crane from the water’s edge, but given that the two sections to be dredged are located far from the edge, the city will be using a floating pontoon instead.
Zeekoevlei is located in the False Bay Nature Reserve, a Ramsar site of international importance for wetlands.
Over the past few decades, there has been a significant build-up of sediment and nutrient rich organics in the Zeekoevlei lakebed that has resulted in algal blooms, which has been impacting the overall health of the vlei and its water quality for recreational users.
"Improving the water quality at Zeekoevlei is a priority. The dredging will assist in removing pollutants and improving the overall health of this ecosystem. The intention is to dredge and remove as much of the nutrient rich sediment as possible over a period of 26 months," added Andrews.
