We need to up the ante on eradicating alien trees in order to capitalise on new research which shows that it is the best way to free up extra water.
Highlighting the urgent need for change in the alien clearing regime, at current rate of progress in the Kouga River catchment – which supplies the Kouga Dam and which presently sits at 7.2% of capacity – it will take us at least 700 years to finish the job.
Senior NMU botanist Prof Richard Cowling, who was one of a small team of experts behind the launch of the Working for Water programme in the mid-1990s, said on Friday the water supply regime in the southwest region of the Eastern Cape was in crisis.
“We’ve known since the 1940s how much water these alien trees suck up and it’s exasperating that the clearing work has not been mainstreamed by municipalities to protect their water supplies.
“At the same time the inefficiencies of the Working for Water programme are well documented, and we need to rectify those problems.
Alongside the large groups of badly managed and unskilled temporary workers, we need to put in crack teams of highly skilled workers to clear aliens trees from the difficult terrain of the Kouga catchment.
“Government is trying to win political gains at the expense of ensuring reliable and sustainable supply of water from our catchments.”
Yet, the programme was presently benefiting neither the environment nor true empowerment, he said. “No water will mean no jobs at all.
“The new look teams would consist of permanent employees who would benefit from high level training and who would be paid well for their skills and the back-breaking work that this job entails.”
Cowling, who has been honoured four times with a National Research Foundation A-rating, and who ranks among the 250-most cited ecological researchers globally, said the clearing of alien trees was vital in times of drought.
“During these times, we have to rely on ‘base flow’, that little bit of water that trickles down the streams after a shower.
But because most streams are clogged with wattles and pines, most of this flow is sucked out before it gets to the rivers.The small showers that we have had recently have contributed virtually nothing to the Kouga Dam.
The highly regarded Gamtoos Irrigation Board has been the implementing agent for the Working for Water programme in the Kromme and Kouga for 23 years.
While progress in the Kromme catchment, which is easily accessible, has been relatively good, progress in the mountainous Kouga catchment has been slow.
A 2012 research paper on the cost-effectiveness of alien plant clearing by a team of scientists headed by Matthew McConnachie of NMU found that “at current rates of clearing it will take 54 and 695 years to clear the Kromme and Kouga catchments respectively and... invasions are likely to continue spreading”.
In the same paper, Prof Brian van Wilgen of the Centre for Invasion Biology at Stellenbosch University, noted that “despite substantial spending on control operations [R3.2-billion] the extent of invaded areas in South Africa has grown since the inception of Working for Water in 1995”.
The issue was brought to the fore earlier this month by a report from the Environmental Policy Research Unit at the University of Cape Town’s School of Economics which said clearing aliens in feeder catchments was the most cost effective way to address the city’s water supply crunch.
With more dams not an option in the area, the Cape Town municipality is pursuing a solution geared around desalination.
But lead author Dr Jane Turpie and her team found clearing and maintaining the catchments would generate annually an extra 50.8 million cubic metres of water – the approximate equivalent of Wemmershoek, one of Cape Town’s main feeder dams – and this was a far better option.
“Clearing alien plants from within the key water catchments will bring a better return on investment than building desalination plants.”
The UCT report said that while alien clearing was underway “it needs to be scaled up dramatically” and consistent follow-ups needed to be integrated to prevent regrowth.
Botanist Dr Tineke Kraaij from NMU’s George campus, another leading voice in South Africa’s invasive aliens debate, said the Turpie report made sense.
Besides the as yet insoluble problem of eradicating black wattle seed beds, clearing could be made much more efficient, she said.“We need a completely new system that is about productivity.
At the moment Working for Water is about job generation. But even those jobs are temporary so it’s not truly uplifting people.”
Gamtoos Irrigation Board CEO Pierre Joubert said while he agreed with many of the findings in the Turpie report funding would still be needed and the present labour intensive component of Working for Water was a key attraction for government.
Nelson Mandela Bay Municipality spokesman Mthubanzi Mniki said although the metro got a large part of its water supply from the Kromme’s Churchill and Mpofu dams and the Kouga’s Kouga Dam, the catchments fell under Kouga Municipality’s jurisdiction.
Questions were sent to Kouga Municipality but no comment was available by the time of going to print.