Lesotho keen to get LHWP phase 2 going

"The treaty authorising the second phase was already signed in 2011 and we are expecting an official launch by the end of this year‚" she says.

"The second phase‚ like the first phase‚ will be of immense benefit to both countries‚ so we are keen to get going as soon as possible. We are hoping that the two-year slippage since the treaty was signed will not delay the first delivery of water from this phase beyond 2020."

Water-stressed SA has for decades sought ways to supplement the natural water of Gauteng‚ the industrial heartland. Feasibility studies undertaken in the 1950s showed the water supplied by gravity feed from Lesotho was more economically viable than trying to pump water from the lower-lying Orange River to high-altitude Gauteng.

Droughts in 1983 and 1985 brought home how dire the need was‚ with water having to be pumped from the Vaal River to Mpumalanga's coal-fired power stations‚ and a treaty between Lesotho and SA was signed in 1986.

The original treaty envisaged several phases but so far only phase 1A (the Katse Dam and water transfer tunnel to SA) and phase 1B (the Mohale Dam and water transfer tunnel to Katse) have been completed.

At peak construction‚ phase 1A provided 22‚000 jobs and phase 1B 15‚400. Total spending on the project so far is near R17bn.

The Orange River rises in the highlands of Lesotho‚ where it is known as the Senqu‚ and flows in a westerly direction nearly 2‚000km to the Atlantic Ocean. SA has built several dams on the Orange River to provide water for irrigation and for hydroelectric generation.

Although the Lesotho Highlands constitute only 5% of the river's total catchment‚ it provides about 50% of the total catchment run-off. The water originating in the mountains is characterised by its purity and low sediment content.

Lesotho lies within the summer rainfall area of Southern Africa and more than 85% of the annual rainfall occurs in the seven months from October to April‚ but this year‚ the last major rains took place in April and the summer rains are the latest they have been since 2003.

Lesotho's water resources far exceed its requirements‚ even allowing for possible future irrigation projects and for general development and improvement of living standards. The average total available water in Lesotho is about 150 cubic meters per second and current national consumption is not more than two cubic meters per second. Lesotho does not draw from the Highlands project for its own water needs.

Phase 1 provides SA with an average of 23 cubic meters per second with summer transfer at 18 cubic meters per second‚ as Gauteng then receives its rainfall‚ while in winter the transfer rate rises to 30 cubic meters per second‚ as that is when the coal-fired power stations operate at maximum output.

Phase 2 is likely to double the transfer rate although the detailed feasibility studies have yet to be undertaken. The existing water transfer tunnel to SA would be able to cope with this doubling in volume‚ but further phases would require a parallel transfer tunnel to be built.