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ALIEN PLANT
ERADICATION BY
THE WORKING FOR
WATER PROGRAMME
IMPROVES
CONDITIONS FOR THE
ENDANGERED BERG
RIVER REDFIN
© WWF-SA / RIAAN VAN DER WALT
The Berg River dam is a vital water resource
for Cape Town and was completed around
2007. Prior to construction of the dam the
surrounding area was used for forestry. It was
infested with alien plants, including the banks
of the Berg River. The river above the dam at
this time had large numbers of rainbow trout
which had a significant negative impact on the
indigenous fish species present, including the
Endangered Berg River redfin.
During the planning phase for the Berg River
dam, it was realised that water generation
from the catchment would be optimised if
the invasive alien plants were removed. The
end result is a rehabilitated catchment of
mountain fynbos vegetation above the dam
that now yields high quality water to the
dam as part of a natural flow cycle. Clearing
of alien trees along the river has also had
another major benefit: recent river health
surveys show that it has resulted in warmer
river water, far less trout, and far more Berg
River redfin. Clearing of invasive alien plants
continues, because of the considerable seed
banks of alien plants that are still in the soil
and sprout every year.