Dam Synchronisation and Flood Releases - agriwaterpedia.info

DAM SYNCHRONISATION AND FLOOD RELEASES IN THE ZAMBEZI RIVER BASIN: ANNEX 4 OF FINAL REPORT
Executive Summary
The Zambezi and its tributaries are important to the economies of the southern African states
through the provision of hydropower, irrigation water, fisheries, water transport and many other
uses. Different investments are being planned to improve one or more of these uses. These
investments may impact on the flows or may change the impact of floods.
The document is presented as ―Recommendations for Investments‖ which seek to achieve the
following:
Identify investment options which support the flood management and flow regulation that
is the overall topic of this study; and
Identify investment options that are counterproductive in this respect.
A full evaluation of different investment options would have very limited value within the scope
of this study, as (i) almost all the possible investments have other main objectives (ii) the
investments impact on different areas of the Zambezi River Basin and are different in their
nature and (iii) criteria for investing by possible investors differ and may use national priorities.
To be able to compare the various investment options and weigh their suitability, a set of criteria
was used. Each criterion is explained by a question:
Technical and legal feasibility;
Contribution to flood protection;
Impact on ecosystems;
Cost effectiveness;
Impact on human use;
Biophysical impact;
Likelihood of realization; and
Impact on more than one country.
The investment options which have been analyzed are grouped in the following eight topics:
1. Regulation of Shire River and Lake Malawi;
2. Investments in Multipurpose Dams on the Zambezi and Kafue;
3. New Multipurpose Dams on the Tributaries;
4. Investments in Cahora Bassa reservoir;
5. Flood risk zoning;
6. Structural flood protection and diversion of floods;
7. Sediment Management; and
8. Diversification of the Electric Power Pool.
The challenges of effective and efficient investments in the Shire River flow regulation
infrastructure lies in maximizing the conservation of Lake Malawi water resources, maintenance
of vital ecosystems and minimizing the likelihood of flooding around the Lake and Shire Valley
as well as minimizing too low flows for hydropower production and environmental management.
The upgrading of Kamuzu Barrage is almost certain and will contribute to the operating
possibilities of the barrage. The barrage is not, and has never been intended for flood control.
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