Sonderend Catchment Restoration

Conserving Freshwater fishes in the upper Riviersonderend Catchment

The Upper Riviersonderend catchment is a Freshwater Ecosystem Priority (FEPA) catchment, because of the good condition of the river, and presence of multiple threatened, endemic freshwater species, and the fact that the rivers draining the catchment feed into the City of Cape Town’s largest water supply dam – Theewaterskloof.

Thirsty invasive plants like pines and wattles are replacing the indigenous fynbos vegetation and reducing water flowing through the rivers and into Theewaterskloof – the City of Cape Town’s biggest water supply dam. In an effort to increase water security, and conserve biodiversity, the Nature Conservancy (through the Greater Cape Town Water Fund) is clearing invasive plants at an unprecedented scale.

The project represents South Africa’s biggest freshwater restoration project to date, and if successful could increase the amount of water flowing into the dam by up to 15%. But there may also be benefits for life beneath the surface of these rivers.

Since 2019, the Freshwater Research Centre has been monitoring freshwater biodiversity in the rivers where the clearing has been taking place, with a special focus on the Giant Redfin – a newly-discovered Endangered freshwater fish. Results thus far indicate that the removing the invasive plants will improve freshwater habitats and allow fish like the redfin to thrive.

In addition to the scientific monitoring, the FRC has also led a community conservation and citizen science programme aimed at involving local communities in freshwater conservation, and raising the profile of the areas hidden freshwater life. The project culminated in the building of a 5m-tall Giant Redfin sculpture celebrated a festival called the Rooivlerkiefees! The project is ongoing, in both the community science and ecological monitoring spheres. 





Project Leader
Jeremy Shelton

EFT Account Details

Account Name:               Freshwater Research Centre NPC 
Bank:                                 Nedbank Limited
Account No:                     102 680 5341    
Branch Code:                   104 309
Swift Code:                       NEDSZAJJ

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