Water security still a worry – experts
This is in spite of recent downpours around the country and Imvuselelo initiatives, reports Desalination on the back-burner
THANKS to La Niña which has brought greater- than- normal rainfall, the country may have experienced copious rains recently, but water security remains worrisome.
That’s the word from a management commentator and KwaZulu-Natal’s largest potable water supplier.
The situation has been so dire that all manner of interventions have been made.
Minister of Water and Sanitation, Nomvula Mokonyane, has started the Imvuselelo initiative to pray for rain.
No sooner had she organised the prayers than flash floods hit Gauteng.
KwaZulu-Natal also experienced downpours, with a hail storm in the past week.
Because most parts of the country remain in the throes of a three-year drought, the inadequate infrastructure and bad management, things are not about to change for the better suddenly.
Umgeni Water corporate stakeholder manager Shami Harichunder said: “The uMngeni system, the largest in the Umgeni Water operational area, is in a storage deficit of 107 million cubic metres.
“Much of the torrential rains in the past two weeks occurred outside catchment areas. This does not assist dams as rain has to fall in the dams’ catchments to impact positively on dam levels.”
President of the SA Institution of Civil Engineering, Chris Herold, said: “There has not been any change to the water situation in the country.
“The combined storage has not improved markedly. Vaal Dam’s storage has increased a bit, but not nearly enough.
“Moreover, the Vaal Dam’s full storage capacity is only 23 percent of the total Vaal River system’s full storage capacity of 11 cubic kilometres.
“Part of the increase in Vaal Dam’s storage is also attributable to water releases from Sterkfontein Dam.
“Water leakage, because of ageing pipes and lack of maintenance, is another issue that has brought forward water restrictions by a year.
“This has cost us 10 percent of the full storage capacity of the entire Vaal River system (about 43 percent of the capacity of Vaal Dam).
“This is already a big enough purely man-made disaster.
“Furthermore, the inability of the Department of Water and Sanitations’ pumps to transfer water at the required rate of 20 cubic metres per second from the Tugela River to Sterkfontein Dam has lost another 4 percent of the total Vaal River system storage.
“This, together with other glaring failures speaks of an alarming breakdown in maintenance of some of the most strategic water transfer schemes in South Africa.
“Hence before the end of September, 14 percent had already been wasted and cannot be replaced until the drought is broken – nearly one year’s supply by Rand Water,” Herold said.
“Worse still, if the drought were to extend to become a full blown eight- to nine-year long design drought sequence, continued failure of the municipalities to meet the longplanned 15 percent reduction in water demand due to leak reduction would cost us a further 13 percent loss of water from the Vaal River system during the next six years.
“To add to our woes, the paltry pumping rate of only 7.1m3/s achieved for the first year after water was released from Sterkfontein Dam during the 2015/16 rainy season is only expected to ramp back up to 20m3/s in two years’ time.
“All in all, by the end of a critical design drought, we would be short of about two years’ worth of Rand Water’s entire demand. Since this loss could not be replaced, it would mean ever-increasing draconian levels of water restriction as storage levels drop. But the picture is a little more positive for eThekwini Municipality’s northern parts.
Herold said: “eThekwini Municipality seems to have made progress in meeting the demanding supply targets.”
On the positive side from the recent rainfall, Harichunder said: “The level of Midmar Dam as at November 14 was 50 percent. This is an increase of 2 percent over the past week – an increase that is attributed to run-off into the dam, weekend rainfall in the catchment of about 30mm and transfer of water into it from Spring Grove Dam.
“The current level of Hazelmere Dam is 70 percent – reached as a result of about 300mm rainfall since July.
“A year ago, Hazelmere Dam was at 26 percent, caused by a severe drought that had taken a firm grip.”
Herold bemoaned the exodus of suitably qualified and experienced engineers. “In South Africa, there is an underlying lack of technical expertise within the government (public) sector.
“Coupled with that, there is a tendency to leave things until too late.
“The five-year delay in the expected commissioning date of Polihale Dam in Lesotho is a case in point. It is a no-brainer that the water sector suffers as a result.”
Long-suffering residents of northern Durban will be pleased about the rain. As a result of the scarcity and water-saving measures, they have had to endure restrictions.
Harichunder said: “All water restrictions have been lifted in the supply areas of Hazelmere Water Treatment Plant following a significant increase in the level of Hazelmere Dam.
“Umgeni Water had to implement a R33 million emergency scheme to transfer water from uThongathi River into Hazelmere Dam to augment resources. The emergency scheme has since been decommissioned after restrictions were lifted.
“The areas where restrictions no longer apply are Verulam, Waterloo, Ballito, Sea Tides, La Mercy, Umhlali, parts of Ndwedwe and Desainager.”
On what was being done to mitigate water shortages in the short and long-term, Harichunder said: “Umgeni Water, however, is currently implementing numerous major projects that will serve as a mitigation against future droughts and also eradicate water backlogs in rural areas.
“Some of these projects are the Lower Thukela Bulk Water Supply Scheme (BWSS), the Greater Mpofana BWSS and the Mshwathi BWSS. The Lower Thukela BWSS will begin supplying 25Ml/d from end of December 2016.”
The Lower Thukela scheme will mean more water will become available at Hazelmere for supply to the north of eThekwini Municipality.
“Under consideration are Lower uMkhomazi BWSS or a desalination plant and uMkhomazi Water Project.
“According to the Council for Scientific and Industrial Research, if good rains materialise, possibly above average, they are likely to be at the end of the year or the first quarter of next. Therefore, water in main dams, that is the Midmar, Albert Falls and Inanda, must last until the next rains. If rains do not materialise and water use is without restrictions, Midmar and Albert Falls are likely to dry up.
“Water restrictions of 15 percent have been imple- mented to prevent possible dam failure.”
SA Weather Service’s prediction research scientist, Cobus Olivier, said the country was likely to have wet conditions from this month to midMarch.
“The forecasting system shows enhanced chances for above-normal rainfall conditions for the coming seasons. The likelihood for extreme wet conditions is also highly favoured at least for the beginning of the summer season.”
Whether the drought ends, the rains continue to fall, the sector retains and attracts skilled human resources and gets modern, top-notch infrastructure, one thing is certain: all role players must change their behaviour.
“Water conservation, sparing use of water and change in consumer behaviour are required to collectively and successfully deal with the situation,” Harichunder concluded. DESALINATION has long been touted as a sustainable means of ensuring water security, but a water expert and KwaZulu-Natal’s largest potable water supplier agree that it is unlikely to be harnessed in the near future.
Desalination refers to the removal of salts and minerals from a target substance, such as salt water, to produce water that is suitable for human consumption or irrigation.
Umgeni Water spokesman Shami Harichunder said the potable water supplier had considered desalination, but it was now on the back-burner because of recent developments. These included the construction of the Lower Thukela Bulk Water Supply Scheme.
“Umgeni Water investigated the feasibility of two desalination plants: one in the south of eThekwini at Illovo and the other in the north of eThekwini at Desainagar,” he said.
“These schemes would have been able to produce a combined total of 150Ml/d. The proposed desalination plant in the north of eThekwini is unlikely to be constructed due to the Lower Thukela Bulk Water Supply Scheme having been built.
“The cost of the proposed desalination scheme in the south of eThekwini is being examined against the cost of a conventional water project. The conventional scheme that is being considered is the Lower uMkhomazi Bulk Water Supply Scheme.”
On the progress of the uMkhomazi water scheme project, Harichunder said it was still awaiting approval from the national Department of Water and Sanitation.
The president of the South African Institution of Civil Engineering, Chris Herold, said: “This option (desalination) is viable along the seaside only in areas that have run out of cheaper fresh water resources. Since eThekwini still has other options, this expensive solution is unlikely to be required for some time.” – Langa Khanyile