Dam Synchronisation and Flood Releases - agriwaterpedia.info

DAM SYNCHRONISATION AND FLOOD RELEASES IN THE ZAMBEZI RIVER BASIN: ANNEX 4 OF FINAL REPORT
Table 3.1: Identified potential dam sites on the main Zambezi, their contributions to flood protection and hydropower production and their technical and environmental
feasibility.
Project, location & Contribution to flood Planned power Technical Feasibility Environmental Other considerations
proposed usage control
production
considerations
and overall conclusion
Middle Zambezi Basin
Batoka Gorge Between
Victoria Falls and Kariba,
54 km downstream of
Victoria Falls, 160 m
high. For hydropower
production.
Kariba Extension
Kafue Basin
Itezhi-Tezhi
Hydroelectric Project
at Itezhi-Tezhi dam on
the Kafue river
Contribution to flood
control by this project is
very limited due to small
size of the reservoir.
(1680 Mm 3 )
Contribution to flood
control by this project is
very limited due to its
location as an extension
in hydropower of the
current plants at lake
Kariba. The extra
turbines create extra
capacity to release flows,
adding to dam safety.
Will utilise existing
regulatory storage at
Itezhi-Tezhi reservoir for
hydropower production.
Firm energy at both
Itezhi-Tezhi and Kafue
Gorge increases as the
regulatory storage
1,600 MW
maximum. In
average years the
spillway is
assumed
operational several
months a year,
meaning that
maximum power
production is quite
reliable.
600 MW; the extra
turbines make it
possible to create
extra energy when
dams are emptied
in advance of
forecasted floods
and during floods.
This is considered to be a
high dam, built in a
narrow gorge. The
feasibility study of 1993
has shown that this
project is technically a
viable scheme.
120 MW There is no new dam
proposed on this site.
Raising of the existing
dam is being considered,
but foundation suitability
may pose a problem.
Conjunctive operation of
Batoka and Kariba dams
is being proposed to
maximise hydropower
generation and minimise
environmental impacts. A
lower level outlet will be
incorporated on the dam
to enable environmental
releases.
The impacts of extra flow
to meet peak demand are
likely to be more severe
than with present
operation, due to
downstream fluctuations
that destabilize banks and
economic activity.
If the operation will not
change and the
hydropower plant will
make use of the releases
currently being made for
the Kafue Gorge, the
A second EIA done in
1998 was apparently more
positive than the 1993
EIA, but was not sourced
in time for this study.
Tourist activity of white
water rafting will be
affected as the rapids will
disappear.
North Bank currently
being executed. South
Bank more difficult.
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