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The Fish River Canyon is regarded as the second deepest canyon in the world after the
Grand Canyon in the USA.
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The canyon is located in Namibia near to the Orange River
mouth and is one of the most popular hiking trails for both local and overseas hikers in
Southern Africa.
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The Fish River has a total catchment area of approximately 76 000 km2 and an
annual runoff in the order of 400 million m3 at 1998 development levels.
More than 90% of the runoff occurs during the three months of January, February and
March. The river is ephemeral in that is is dry for most of the time and
the annual flow is often zero. It is, however, the largest contributor to the
Orange River downstream of the Orange/Vaal confluence and flash floods with flows
exceeding 2 000 m3/s do occur.
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Since there are no storage reservoirs downstream of the Orange/Fish confluence, any
inflows from the Fish River cannot be utilised efficiently although they can help to
supply the downstream irrigation and also the environmental demands. Unfortunately,
releases to meet these same downstream demands have already been made approximately 6
weeks earlier from Vanderkloof Dam. These reservoir releases cannot be prevented
from reaching the river mouth and considerable water is therefore wasted during times when
the Fish River is in flood.
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