|»The Komati River Basin and Land Use|
The Komati River basin has a total catchment area of approximately 11 200 km2 from its headwaters to its confluence with the Crocodile River at Komatipoort. The natural mean annual runoff (before afforestation) of the catchment is estimated at 1 430 million cubic metres, of which the Lomati River contributes about 364 million cubic metres or 25%. The following table shows a comparison between the annual runoff of the ten largest rivers in South Africa.
The ten largest rivers in South Africa in order of volume of annual runoff
(km2 x 1 000)
|LENGTH OF RIVER (km)||ANNUAL RUNOFF|
|PERCENTAGE OF TOTAL RUNOFF IN SOUTH AFRICA|
|Orange and vaal||606,7||2340||12057||22,5|
|Olifants (Letaba included)||68,3||760||3103||5,8|
|Limpompo (main basin)||109,6||960||2290||4,3|
RSA OFFICIAL YEARBOOK 1993
In 1992, the projections for land use dependent on water from the portion of the Komati River Basin down to the meeting with the Crocodile River were:
- a population of 460 000 people;
- irrigation of 38 700ha including 9 500ha in the Mbuluzi River Basin in Swaziland;
- providing for 123 000ha of existing and additional afforestation;
- limited mining activity; and
- service industries (mostly small) except for water exported to the thermal power stations located in the highveld region in South Africa and the sugar mill at Mhlume in Swaziland.
With the exception of the thermal power stations, most of the consumers were dependent on unregulated flow of the Lomati and Komati Rivers before the Project. Existing storage reservoirs of significant size are the Noooitgedacht, Vygeboom, Barberton, Shiyalongubo dams in South Africa and the Sand River Dam in Swaziland.
The development of the water resources of the Komati River Basin upstream of the Mozambique border could ultimately result in the provision of a total water storage volume varying from 1 200 to 1 900 million cubic metres, depending on the final selection for implementation of possible development phases. These phases provide for the possible construction of seven new dams and one significant river diversion. The joint management of these resources allows for significant new developments in primary water use and irrigation in South Africa and Swaziland. It also ensures that water is available in the future for afforestation and industrial and mining water demands. Equally important is meeting the obligation to provide Mozambique with its equitable share of water from the basin.