ISSN 0258-2244 January/February 2007 Volume 6 No 1
Building starts at Braamhoek Water Institute of Southern Africa Membrane Technology Division (MTD) http://www.wisa.org.za/Divisions/membrane/mtd_index.htm
7th WISA-MTD Symposium and Workshop 18 – 20 March 2007
Mabalingwe Nature Reserve Limpopo Province, South Africa
Limited to 150 delegates Register early (before 15 February 2007)
INVITATION
Membranes are an important technology employed in a variety of processes. They play important roles in water treatment, chemical separation and environmental management. The continued development and application of membrane processes are taking place at an ever-increasing rate. The Committee of the WISA Membrane Technology Division is pleased to invite those with an interest in membranes to the 7th Biennial Symposium and Workshop, to take place from 18 - 20 March 2007.
PROGRAM OF EVENTS REGISTRATION FORM – WISA MTD 2007
Sunday 18 March 2007 Surname ...... 16:30 – 18:00 Early Registration Title...... Name...... 18:00 – 19:30 Icebreaker Snacks and Cocktails Company ...... 19:30 Meet & Greet Dinner Department ...... Address ...... Monday 19 March 2007 7:30 Registration ...... 8:30 Welcome and Opening Address Postal Code ...... Country ...... 8:45 – 9:30 Plenary Lecture: International Speaker Vat Reg No...... 9:40 – 10:40: Session 1 Telephone ...... 10:40 – 11:00 Short break Fax ...... 11:00 – 12:00 Session 2 Mobile ...... 12:00 – 13:00 LUNCH E-mail ...... 13:00 – 15:00 Workshop1 15:00 – 15:30 AGM/Tea Break Registration (please tick) 15:30 – 16:30 Poster Presentations Non-WISA Member R1450 WISA Member R1250 16:30 – 18:30 Game Drive Student R300 Spouse R850 18:30 Symposium Dinner and Entertainment Late Registration add R200 (after 15 Feb )
Tuesday 20 March 2007 Payment to be made directly to WISA 5:00 – 7:00 Game Drive 8:30 – 8:45 Start of day’s proceedings Banking Details for conference registration: 8:45 – 9:30 Plenary Lecture: International Speaker Acc Name: Main WISA 9:40 – 10:40: Session 3 Bank: FNB 10:40 – 11:00 Tea Break Branch: BOULDERS BRANCH 11:00 – 13:00 Session4 Branch Code: 250 856 13:00 – 14:00 LUNCH Acc No: 620 4455 2710 14:00 – 16:00 Session 5 Ref No: Invoice no. (will be sent later)
MORE INFORMATION Special Dietary Requirements ...... Marshall Sheldon: [email protected] Tel: +27 21 460-3160 Signature ...... Date ...... Stephanie Marais: sdm.marais@eskom.co.za. Tel: +27 11 800-4307 Please fax to Marshall Sheldon: +27 21 460-3854 Table of contents 3
LETTERS 4
UPFRONT 6
HYDRO-ELECTRICITY 14 Balancing power and water at Braamhoek
FRESHWATER CONSERVATION 19 Helping rivers fight for their lives
TRANSBOUNDARY AQUIFERS 23 Managing Southern Africa’s shared aquifers
CLIMATE PREDICTION 27 Locally-developed climate model verified
MINE-WATER POLLUTION 30 Solutions sought for SA AMD ‘hot spots’
WATSAVE AWARD 33 Cover: Engineers face tremendous SA irrigation innovation scoops international award environmental challenges at the construction of Eskom’s Braam- ESTUARIES 34 hoek Pumped Storage Scheme. KwaZulu-Natal’s catchment keepers See page 14.
WATER KIDZ 36 The power of water
THE LAST WORD 38 Excellent research rewarded
THE WATER WHEEL is a two-monthly magazine on water and water research published by the South African Water Research Commission (WRC), a statutory organisation established in 1971 by Act of Parliament. Subscription is free. Material in this publication does not necessarily reflect the considered opinions of the members of the WRC, and may be copied with acknowledgement of source.
Editorial offices: Water Research Commission, Private Bag X03, Gezina, 0031, Republic of South Africa. Tel (012) 330-9031. Fax (012) 331-2565. WRC Internet address: http://www.wrc.org.za Editor: Lani van Vuuren, E-mail: [email protected]; Editorial Secretary: Rina Human, E-mail: [email protected]; Layout: Drinie van Rensburg, E-mail: [email protected]
The Water Wheel January/February 2007 4 Letters
LETTERS TO THE EDITOR
Editor’s Letter Bottled vs. tap debate rages on
he Water Wheel received both praise and off by a discussion paper titled Bottled Water: advertised as a positive selling point for tour- Tcriticism for its article on bottled water in Understanding a Social Phenomenon by ist destinations, even WWF’s Eco-Safaris. the September/October 2006 issue. Catherine Ferrier of the University of Geneva A third reason is that bottled water is a One specific reader (who did not want (www.panda.org/livingwaters/pubs/bot- healthy alternative to other beverages such her letter published) went so far as accusing tled_waterpdf). From this reasonable, as sodas, drinks with high sugar levels and the magazine and its publisher, the Water balanced article a number of points made by beverages containing artificial sweeteners or Research Commission of the “uncritical Ferrier have been taken and expanded upon colouring. It is a calorie-free thirst quencher promotion of a commercial product, one to become various website and newspaper and now freely available in South Africa. which is hardly environmentally-friendly”. articles. Of these, the most prominent one did Indeed, the huge rise in bottled water con- The reader specifically mentioned the issues the e-mail rounds a year back (www.earth- sumption over the last 20 years is closely around the environmental impact of the sector. policy.org/Updates/2006/Updates51.htm). linked to the way consumers face their nutri- While the debate over the merits and The latter article picked out and expanded tion, i.e. the current trends for healthier eating. disadvantages of bottled water rages on on just the two negative aspects of bottled Lastly, it is the convenience factor. Cruis- internationally, the sector keeps on expand- water from the Ferrier article, namely that ing down the highway, or lying on the beach, ing in almost every country, even in South bottled water is up to 10 000 times more having a bottle of water at hand is far more Africa, which has always been thought to expensive than tap water, and the energy cost convenient than having to look for a tap. A have some of the highest-quality tap water. associated with making the containers and sign of modern times is the bottle of water on Even the country’s largest tap water supplier, transporting the finished product. The rest of the desk next to the computer. Our estimate is Rand Water, is now entering the bottled water the Ferrier article was ignored. that more than half of those bottles will be tap market in a bid to tap into new markets and There are various reasons why people water re-fills: Our view – great, so long as it diversify its income streams. consume bottled water, as noted in Ferrier’s is water and not sugary cooldrink. The Water Wheel asked John Weaver, article. Taste is high on the list. Tap water Bottled water versus tap water: we have Chair of the South African Bottled Water Asso- with high chlorine levels, while being safe no argument with the tap water industry. ciation) to respond to some of the criticisms (bacteriologically) to drink, is not nearly as These are two very different water markets, against bottled water. He writes: pleasant as bottled water. with a small overlap. It would be a wonderful “The original ‘highly controversial issue’ In a bottled water tasting organised world if the tap water industry could provide around the bottled water industry was sparked by Men’s Health magazine 16 waters were safe water to all, but the overwhelming presented to three tasters, including myself. reality is that the combination of inadequate These were presented blind and one stood personal primary health training, human out as having an off smell and taste, and we behaviour and social customs will continue correctly identified it as tap water. to result in human deaths, despite the best The next reason is for personal safety. efforts of water engineers, social workers Bad quality water has given rise to many and water people. The bottled water industry quaint phrases in the English language, such does not pretend to be able to solve these as ‘Delhi belly’ and ‘Gyppo guts’. The travel- enormous problems. In emergencies, bottled ler who has paid lots of money for air tickets water can be called upon, e.g. the Crypto- and accommodation should never drink tap sporidium outbreak in Sydney, Australia, but water, even in supposedly safe countries. it is not a long-term solution to the provision Risking a few days being sick in order to save of safe drinking water. the price of a bottle of water is a silly choice. An aspect of bottled water that was One of my brothers was in West Africa, highlighted is the energy cost associated and being confronted by a US$10 cost for with making the containers and transporting bottled water in a five-star hotel, opted for tap the finished product. Packaging is one of the water. The result: ten days down with ‘rumble unfortunate aspects of modern life, and is in the jungle’. In fact, bottled water is often not something for which the bottled water
The Water Wheel January/February 2007 Letters 5
industry should shoulder all the blame, and I found your Water Wheel to be the most and progressively, allowing reservoir exper- also cannot solve by itself. Yes, in South interesting and educative, and well managed. tise to degenerate to the extinction level. Africa we really do need plastic recycling It is relevant in water technology and environ- Perhaps these questions will always remain policy and legislation that will apply to all mental aspects and very informative. It is also largely unanswered, as the decision-making plastic used in our daily lives, not just bottled keeping up to date with the modern world and players of the day have passed on, and the water containers. with the future vision of water co-ordination of topic does not merit a national commission The energy cost of transportation also both rural and urban centres, highlighting and of enquiry. I could offer a lengthy personal adds to our energy cost. The Ferrier articles creating awareness on waterborne diseases. analysis which would cover themes such as notes that 75% of bottled water is consumed Since I started receiving the journals I am politics, economics, institutional reorganisa- locally, and advocates that this should be meeting with points tip with stakeholder tions, culture, personalities, the rise of the increased. We have no argument with this. meeting with our small town in Kenya called river scientists – all of which contributed. Indeed the sight of Italian bottled water on the Nanyuki. Keep up the good work. I would like This however is another subject. shelves of some of our supermarket chains at to continue receiving your journal and It was predicted many years ago that the prices lower than local water can be bottled conference invitations. focussed romance with river science would for, is startling and a reflection of the crazi- John Sikote, Water Technologist, eventually play out, and at some stage South ness of export subsidies. Kenya Africa would resuscitate its reservoir science An important item in the Water Wheel base. Hopefully, the University of KwaZulu- article is that South Africa now has legisla- Bring back reservoir Natal, my alma mater where I received my tion governing bottled water. This legislation limnology early training, has produced a report that which has been approved by the Minister of I have read with great interest the September leads to a revitalization of this science. Health will come into operation in July. The 2006 issue of Water Wheel which contains However, it will take more than a report to legislation covers both quality standards, an article on South African reservoirs and the reconstruct the pool of expertise that has the and also the wording on the label so that the message of expectation that an extinct necessary intellectual capacity to serve South origin, and treatment applied, and mineral science might be “revived through a report”. Africa’s reservoir science requirements. It will content must be clearly stated. This legisla- For someone who was trained in South require the development of a similar type of tion is in line with the international standards African reservoir limnology, and who expe- stakeholder-based reservoir science program of the Codex Alimentarius Commission. rienced the indignities of the “extinction” of that was initiated more than 30 years ago. The My final image I present is one of an reservoir science, it would be remiss to not support and leadership of the WRC is criti- obese junk-foodie driving a fuel-guzzling pass comment on this article and the impli- cal on this, as it should have been when the suburban SUV sucking a can of sweet cations it conveys to the leaders of South science was becoming extinct. cooldrink, versus a gym-fit person driving a Africa’s water resource institutions. One final word of caution – beware of let- fuel-litre car with a bottle of water in the pop- The pool of South African reservoir ting the pool of river science expertise follow out tray. It is all about choices.” expertise in the 1970s and 1980s was indeed the same extinction process – in what seems internationally renowned, as were the institu- to be an eternal global cycle of casualties Ancient knowledge tions that housed the teams of scientists. in expertise – as managers and institutions forgotten Today, those scientists have moved on, either chase the next “flavour of the month”. The twelfth century king of Sri Lanka, through a process of retirement, to other Danny Walmsley (Former Coordinator Parakramabahu I, officially decreed that not one topics, or to greener pastures elsewhere in of the CSIR Inland Water Ecosystems drop of water should reach the sea without first the world. It took more than two decades to Program 1985-1990) Dartmouth, Nova serving humanity. And his regulations of how attract and build up those teams, a process Scotia, Canada water should serve humanity (and humanity that was achieved through a network of stake- serve water) were far ahead of his time. holder-based cooperative scientific programs Bottled water article Many of his wewas have since been with high-level governmental and institutional ‘fascinating’ rendered inoperable by encroaching jungle. support. The decline began in the mid 1980s This is an appreciative note to congratulate Why have we, in Southern Africa, who have and was largely associated with the demise you on your outstanding editorship of the followed western and scientific approaches to of eutrophication as a Department of Water Water Wheel and your significant personal water usage have to deal with an encroaching Affairs priority issue, coupled to the quest contribution to its wide-ranging water-related jungle instead? for assessing ecological water requirements articles. Ben Dekker, Port St Johns (Ecological Reserve). You have raised the content and range of With an arid landscape, reservoirs will the reporting to a new plateau of excellence. Praise for the Water Wheel always be the backbone of the country’s Your article on bottled water in the issue of It is high time to say a word of hallo to you water supply and therefore we need to ask the November/December 2006 is both timely and all. I have been a subscriber of the Water questions of how, and why, the leadership of fascinating. Rand Water has recently joined Wheel for many years since you enrolled me our water resource and research institutions the band wagon. in your Water Wheel. committed the cardinal sin of collectively, AH Charnaud, Howick
The Water Wheel January/February 2007 6 Upfront
Choose loos Lifestyle carefully, says costing expert made easy unicipalities should carefully weigh with new Mall the options before selecting a software sanitation technology. So said David Still of Partners in Development at the Water Institute of Southern Africa’s Appropriate Technolo- ngineers and designers of bulk water functionality of the AQUA Hydraulic Utilities gies conference, held in Umhlanga towards pipelines now have a tool available to program. E the end of last year. Still, who has been them to determine the most economical The program requires the user to enter investigating the cost of sanitation in a solution for the complete design life of their the demands, design life, pipeline profile, project funded by the Water Research system. pipeline characteristics, laying details, rates The software, named AQUA Hydraulic and costs of the proposed pipeline. It will Commission, reported that many local Utilities, is described in a new report avail- then determine the initial capital require- municipalities were still set on implement- able from the Water Research Commission, ments, the annual maintenance and opera- ing full waterborne sanitation, even though entitled Lifecycle Costing Analyses for tional costs and, in the case of a pumping at times neither the authority nor the users Pipeline Design and Supporting Software. system, the energy costs. The program also could afford it. The report, authored by Prof Fanie van provides a graphical representation of these Compared to ventilated improved pit Vuuren and Marco van Dijk, both from the costs, as well as the hydraulic capacity of the toilets or urine diversion toilets, which cost University of Pretoria’s Department of Civil ageing system. about R4 000 per unit, waterborne toilets and Biosystems, is a guide to lifecycle cost- could cost about up to R30 000 per unit ing analysis, limited to the design/analyses • The AQUA Hydraulic Utilities program can to install, including bulk sewer and waste- of bulk pipelines. be downloaded from www.wrc.org.za or water treatment costs. “This is only con- The guide introduces different lifecycle www.sinotechcc.co.za. struction costs, but what about long-term cost elements to the design engineer, and • To order the report, WRC Report No operation and maintenance?”, Still asked. indicates how these cost elements will 278/06, contact Publications at Tel: (012) The costs of on-site sanitation systems affect the final decision. It also explains the 330-0340 or E-mail: [email protected] fall well within local government finance allocations, such as the Municipal Infra- structure Grant and the Equitable Share. More bulk infrastructure planned for SA Moreover, these systems often did not require much operation and maintenance evelopment of bulk infrastruc- of proposed developments. This compared to waterborne sanitation. Dture remains top of mind for the includes the feasibility reports for the “When waterborne sanitation does not Department of Water Affairs & Forestry Mooi-Mngeni Transfer Scheme Phase function properly, it cannot be considered (DWAF), at least in the short term. II, which proposes the construction an improvement in service. Unmaintained While this may be good news for of the Spring Grove Dam on the Mooi systems can be extremely hazardous to the the construction industry it could con- River as well as the De Hoop Dam on health of communities, and have far- cern ecologists and conservationists, the Steelpoort River. reaching environmental consequences,” especially since the department’s Investigations into the construc- noted Still. He advised local authorities latest annual report reveals that only tion of a dam on the Lower Orange not to even consider waterborne sanitation 28,2% of the rivers surveyed under river close to the border between if they did not have the necessary skills or the River Health Programme to date South Africa and Namibia are also financial capacity to operate and maintain remain in natural or good condition. going ahead. such a system. Already 29% of the rivers surveyed In addition, pre-feasibility study In addition, the cost to the household are in poor condition. reports were completed for the had to be borne in mind. “A household Construction of bulk infrastruc- use of low-level storage at Vander- with waterborne sanitation will use about ture projects such as the Berg River kloof Dam and viability of irrigation 10 kℓ more water per month than a family Dam and the Vaal River Eastern Sub- schemes for resource-poor farmers without,” noted Still. “This means having System Project are continuing at full in the Eastern Cape. The refurbish- a flush toilet could cost that family about steam. Pre-feasibility and feasibility ment of 20 dams has also been R100 more per month in water bills.” studies were completed for a number initiated across the country.
The Water Wheel January/February 2007 Upfront 7
Give private sector a chance
outh Africa needs the private sector Snow more than ever to assist in rapid services delivery. So said Laila Horton, senior project advisor in the National Treasury’s Public- Private Partnership (PPP) Unit. She was speaking at the Africa Water Congress, held in Gauteng, in November. The cumbersome legislative frame- work, opposition from labour and the persistent preference of public sector provision have led to a decline in PPPs in the South African water sector since the 1990s. Other constraints include the Maguga Wins limited capacity within the public sector as Rob Fraser of Ninham Shand won this year’s photographic award presented well as the historically poor bankability of by the South African Institution of Civil Engineering for his photograph of the these projects. Maguga Dam, situated in the Komati River in Swaziland. According to Horton, current efforts to meet the 2008 target for basic water services and 2010 target for sanitation Water Diary services would have to quadruple. “Private sector investment can go a long way in WATER & SANITATION Germany. Topics include decentralised waste- assisting municipalities to meet these FEBRUARY 12-24 water systems, non-conventional wastewater deadlines for delivery.” International company Bushproof is offering treatment systems, economics, social aspects At the time of writing, National Treasury an introductory course on water and sanita- and case studies, among others. Enquiries: was in consultation with the Department tion technologies for development situations Peter Lambertz; Tel: 0049-(0)241-8026821; of Provincial and Local Government to and emergencies in Fort Dauphin, Madagas- E-mail: [email protected] find ways of simplifying and streamlining car. Enquiries: Eric Fewster; Tel: +44 (7814) present PPP legislation. 788 846; E-mail: ericfewster@bushproof. TECHNOLOGY The PPP Unit is also offering local com; Visit: www.bushproof.com MARCH 14-16 LabAfrica 2007, a showcase for suppli- authorities financial assistance for Section NUTRIENT REMOVAL ers of laboratory equipment and analytical 78 assessment and feasibility studies into MARCH 4-7 instrumentation will be held at the Coca-Cola possible involvement of private compa- The Water Environment Federation, in coop- Dome, in Johannesburg. Enquiries: Tel: (011) nies in water projects through its Project eration with the IWA Nutrient Removal and 460-0247; Visit: www.labafricaonline.co.za Development Facility. “Many a time, local Recovery Group, US EPA and the Chesapeake authorities only consider public delivery Water Environment Federation will be host- DESALINATION options, without even considering the ing a Speciality Conference covering the MARCH 18-20 potential of a PPP,” noted Horton. latest research and experience in the design The Seventh WISA Membrane Technology Possible suitable projects for PPP and operation of nutrient removal systems at Division Workshop will be held at Mabalingwe involvement include those in areas with municipal and industrial wastewater treatment Nature Reserve, in Limpopo. Enquiries: Mar- high-income users (for example, min- plants. The conference will be held in Mary- shall Sheldon, Tel: (021) 460-3160; Fax: (021) ing companies and resort towns); as well land, US. Enquiries: Tel: +1 708-684-2400 460-3282; E-mail: [email protected] as projects in water scarce areas which ext 7010 or E-mail: [email protected] require sophisticated technologies such WATER IN PROTECTED AREAS as the establishment of desalination plants SANITATION APRIL 25-27 along the West Coast. Horton said cost MARCH 12-13 The IWA & UNESCO are hosting a the Second saving endeavours (leakage reduction, The International Water Association and International Conference on Water in Protected improved billing and collection) also the Institute of Environmental Engineering Areas in Dubrovnik, Croatia. offered significant potential for private of RWTH Aachen University are hosting an E-mail: [email protected] or Visit: sector investment. Advanced Sanitation conference in Aachen, www.hdzv.hr
The Water Wheel January/February 2007 8 Upfront
Sanitation falls short of the grade
outh Africa’s public sanitation assets Sonly managed an overall E grade in the first Infrastructure Report Card for South Africa, published by the South African Institution of Civil Engineering (SAICE). The report, a reflection of the present state of the country’s built environment, including water, sanitation, solid waste, roads, rail, ports, airport, electricity, hospitals and clinics, is based on the expert perception of eminent professionals in the civil engineering field, backed by existing research. “While the South African government has made significant strides in addressing backlogs of the past, and continues to invest at a rapid pace in infra- structure to the previously disadvantaged, significant challenges remain which are threatening our nation’s support systems,” SAICE President Sam Amod at the launch of the Infrastructure Report Card. noted SAICE President Sam Amod. Two key themes emerged from the capacity. Another survey of 51 micro, small to do this and at the same time also main- report. The first is the extreme shortage of and medium-sized wastewater treatment plants tain both old and new infrastructure, as well skills and the terrible impact this is hav- undertaken in 2005/6 found that “immediate as upgrade or replace infrastructure that is ing on planning, procurement, design, intervention” was required at about 30% of overloaded or has become obsolete.” construction and care of infrastructure. The the works to avoid crisis situations such as an Commenting on the findings of the second is the lack of adequate funding for outbreak of waterborne diseases. report, Fred van Zyl, DWAF Director: the maintenance of the existing asset base Bulk water infrastructure scored a D+. Planning & Infrastructure, said it came as and the new assets that come on stream The report noted with concern that some 150 no surprise, as most of the findings were each day. “It is imperative that we do not of the Department of Water Affairs & Forest- based on surveys carried out by the national continue to build only to permit decay. ry’s (DWAF’s) 350 dams have significant department itself. “Government faces Neither can we continue the culture of dam safety shortcomings. On a positive note, massive infrastructure challenges, not the ‘patch and pray’ that typifies too many of a dam refurbishment programme is starting least being meeting the water and sanita- our maintenance activities,” Amod said. during the 2006/7 financial year. tion targets of 2008 and 2010 respectively. The challenges of skills and main- A further assessment of water sup- It is estimated that a 350% increase in the tenance are most acute in the sanitation ply infrastructure owned by water services present rate of delivery is required to meet sector, which scored the lowest ranking of authorities (mostly municipalities) and water the water target. We also need to increase the public infrastructure graded. The report boards showed that while some water serv- present sanitation delivery from the esti- pointed out that, while South Africa has ices institutions have exemplary practices in mated 100 000 units a year to some very adequate sanitation infrastruc- place with respect to many of the aspects of 900 000 units a year.” ture and service delivery, it has an increas- infrastructure management, gross shortfalls Investigations also showed that in ing proportion of deteriorating infrastructure in management policies and practices exist in many local authorities, present infrastruc- together with poor and often unacceptable many others. Most non-metro water services ture was not able to meet the increased quality services. authorities are failing in their compliance with demand. According to Van Zyl, a series of A nationwide sanitation sustainability the compulsory national standards for the intervention strategies have been launched audit in 2004/5 to ascertain the functionality quality of potable water. by the national department to aid munici- of sanitation projects completed since 1994 “Government should not change its palities in improving the management of revealed that 28% of households’ sanitation focus from providing the new infrastructure new and existing infrastructure. facilities have failed or are in the process to address backlogs from the past,” said Dr of failing, and only 53% of municipalities Kevin Wall, past President of SAICE, and the • The report is available from SAICE’s have adequate operations and maintenance main author of the report. “The challenge is website: www.civils.org.za
The Water Wheel January/February 2007 Global water science news 9
Sewage threatens With regards to water resources, the report shows that freshwater species have world’s oceans declined by 28%. The main drivers are habitat destruction, over fishing, invasive species, pollution and the disruption of river systems for water supplies. It is reported that the alteration and damming of river systems for industrial and domestic use, irrigation and hydroelectric power have fragmented more than half of the world’s large river systems. Water withdrawals worldwide amount to about World population 4 000 km3 per year, equivalent to about 10% running out of of global freshwater runoff. Fragmentation and alteration of natural early 90% of sewage entering coastal resources river flows affect the productivity of wetlands, zones in many developing countries are N umans are consuming natural resources flood plains, and deltas, disrupt the migration estimated to be raw and untreated, according faster than they can be replaced, accord- and dispersal of fish, and cause decline in to a new study by the United Nations Environ- H ing to the 2006 Living Planet Report by world freshwater species. Some 83% of rivers’ total ment Programme (UNEP). conservation organisation WWF. annual flow is affected – 52% moderately, This rising tide of sewage is threatening The report notes that on current 31% severely – with Europe’s river flow being the world’s seas and oceans, endangering projections humanity will be using two the most regulated and Australasia’s the least. human health, wildlife and livelihoods, the planets’ worth of natural resources by Worldwide, the amount of water stored in State of the Marine Environment report warns. 2050 – if those resources have not run reservoirs behind dams is three to six times It is estimated that an additional US$56- out by then. It also confirms the trend of the quantity contained in rivers. billion a year is required to address the global biodiversity loss seen in previous Living According to the report, worldwide sewage problem. Planet reports, produced biennially. “We Mediterranean woodlands, deserts and xeric With regards to South Africa the report are in serious ecological overshoot, con- shrublands, temperate broadleaved forests, notes that untreated sewage does enter the suming resources faster than the Earth and temperate, flooded and montane grass- marine environment via informal settlements, can replace them,” said WWF DG James land biomes all have more than 70% (by and is cause for concern in larger coastal Leape. “The consequences of this are catchment area) of their large river systems cities such as Cape Town, Port Elizabeth and predictable and dire.” severely disrupted, primarily for irrigation. Durban. Contaminated stormwater runoff is considered the major cause of any non- compliance to bathing quality standards. Other areas in need of attention are the School girls filling water declining flows in many of the world’s rivers bottles at a water tap in as a result of dams, over-abstraction and Nairobi, Kenya. Water is global warming; new streams of chemicals; a threatened resource the state of coastal and freshwater wetlands and with population and sea-level rise linked with climate change. growth and expanding Meanwhile, around 700 delegates from 15 urbanisation the pressure countries attended an international confer- can only increase. ence in Beijing, China, to combat sewage, pesticides and other forms of pollution com-
ing from the land into the seas and oceans. WWF-Canon/Martin Harvey Credit:
Killer spinach found in US . coli tainted spinach caused the deaths of bacteria at a cattle ranch in California’s The produce company that processed Eat least three people and sickened nearly Salinas Valley within a mile of spinach and packaged the spinach at the centre of 200 others in the US. fields, but were unsure how the bacteria the outbreak investigation has repeatedly It was the twentieth such outbreak in made its way on to the spinach. Agricultural asserted its factories are blameless, and lettuce or spinach since 1995, reports runoff, irrigation water and the hygiene of pointed to the fields where the greens are Associated Press. At the time of writing, farm workers as potential sources were grown as the potential source of the investigators had found the same strain of being investigated. problem.
The Water Wheel January/February 2007 10 Global water science news
Most Polluted Places Named New report on world water
he World’s Water 2006-2007, published Tby the Pacific Institute, is now available. Produced biennially, the report identifies and explains pertinent trends, and offers some of the best data available on a variety of water-related topics. Present worldwide water issues covered include water and terrorism, preserving and restoring instream water allo- cations, desalination, growing risks of floods and droughts, environment justice of water, water risks facing industry, and bottled water. According to Editor Peter Gleick, there have been some positive changes in the world regarding water. There seems to The encapsulated Chernobyl reactor.
Courtesy of Wikipedia be a growing public interest in water, and increased involvement of communities. In he world’s ten most polluted places have In Dzershinsk, Russia, a significant addition, there are new efforts at ecosystems Tbeen named by independent environmen- centre of the Russian chemical manufactur- restoration. tal action group, the Blacksmith Institute. ing industry, the average life expectancy is The World’s Water describes more than Sites in eight countries affecting a total 42 years for men and 47 for women. Until 50 incidents of water-related terrorism, start- of more than ten million people were identi- the end of the Cold War, the city was among ing in the 1700s. Other interesting numbers fied as the areas where environmental degra- Russia’s principal production sites of chemi- include the fact that there are more than dation presents the worst long-term health cal weapons. It is reported that from 1930 to 10 000 desalination plants worldwide. threats and, at the same time, an opportunity 1998, almost 300 000 t of chemicals waste The bottled water sector is expanding to reverse the problems. “A key criterion in were improperly disposed of. The city draws fast, and is now a US$400-500 billion a year the selection process was the nature of the its drinking water from the same aquifers into business. Despite its tremendous growth pollutant,” said Richard Fuller, Director of the which these old wastes and unused products worldwide, it remains 1 000 times more Blacksmith Institute. “The biggest culprits are were pumped. expensive than high-quality tap water. Inter- heavy metals – such as lead, chromium and The effects of tannery waste, contain- estingly, the publication also notes that there mercury – and long-lasting chemicals, such ing hexavalent chromium and azodyes, have been more than 100 official ‘recalls’ of as persistent organic pollutants.” potentially affects 3,4 million people in bottled water in recent years. Living in a town with serious pollution is Ranipet, India. The contamination of the soil The report underlines the fact that like living under a death sentence, according and groundwater with wastewater, as well science is crucial to water policy. “The to the report. “If the damage does not come as runoff from solid wastes has affected the integrity of science is key. We live in an from immediate poisoning, then cancers, health, resources and livelihood of thousands increasingly polarised, critical, cynical world: lung infections and mental retardation are of people. efforts to diminish respect for media, govern- likely outcomes.” The selected polluted There are 23 tailings dumps and 13 ment, academics and science will diminish places listed bear testimony to the severe waste rock dumps scattered throughout the chances of solving the remaining water impact man has on his environment. Mailuu-Suu, Kyrgyzstan, home to a former problems,” noted Gleick. While it has been 20 years since the Soviet uranium plant. An estimated 1,96 world’s worst nuclear disaster, Chernobyl, in million m3 of radioactive mining waste To purchase the report go to www.world- the Ukraine, remains arguably the most pol- threatens the Ferghana valley, one of the most water.org or www.pacinst.org luted place on earth. The 19-mile exclusion fertile and densely populated areas in Central zone around the plant remains uninhabitable Asia. Due to the high rates of seismic activity to this day. The reactor was enclosed in a in the area, million of people are potentially at concrete casing after the accident to con- risk from a failure of the waste containment. tain radioactivity within the plant. There are In April last year, about 300 000 m3 of mate- concerns, however, that leaks in the structure rial fell into the Mailuu-Suu River. have caused rainwater and fuel dust to form a toxic liquid that may be contaminating the To access the report go to www.blacksmith- groundwater. institute.org/top10/10worst1.pdf
The Water Wheel January/February 2007 Global water science news 11
The world in brief More plants, Water by Numbers more rain • Trees that live in an odd forest in Oman, • 8,3 km – The length of the new pipeline in the Middle East, have found an statistical study of satellite images has being constructed from the Crocodile unusual way to water themselves by ex- indicated that more plants make for more River in Nelspruit to White River, via tracting moisture from low-lying clouds. A rain. Rocky Drift. The pipeline is expected to According to researchers from the Mas- The study, published in Geophysical be completed by mid-2007. sachusetts Institute of Technology the Research Letters, concludes that vegetation • R112-million – The Water Research trees have preserved an ecological niche effects account for about 30% of annual Commission’s planned research funding despite being surrounded by desert by rainfall variation in Africa’s Sahel region. for 2006/07. exploiting a wispy-thin source of water This should assist scientists in understand- • R154-million – The profit posted by that only occurs seasonally. ing rainfall patterns in the area, which is Umgeni Water for the 2005/6 financial threatened with increasing desertification and year. The previous year’s profit was The US government has partnered with • periods of drought. “It gives us an additional R40-million. two large non-profit organisations, the element of predictability: a bit of an edge in • 59% – The estimated proportion of Case Foundation and the MCJ Founda- knowing where it might rain,” reports study people in the world that have access to tion, to help bring clean drinking water co-author Peter Cox, Director of the Climate basic sanitation. Only 37% of people in to millions of people in sub-Saharan and Land Surface Interactions Centre. sub-Saharan Africa have access, Africa. The so-called Playpump Alliance according to the UN. hopes to install 4 000 pumps in schools • R2,5-billion– The money to be spent by and communities over the next few Rand Water over the next five years on years. upgrading and refurbishing its distribu- tion infrastructure. The company report- • Members of the G-77 backed plans for edly spent R607-million on refurbishing the establishment of the Consortium on and upgrading its infrastructure in the Science, Technology & Innovation for 2006 fiscal year. the South (COSTIS). COSTIS will focus • 25 million – The estimated number of on organising South-South forums on ‘environmental refugees’ – people forced developing appropriate and affordable to leave their homes due to increased technologies in sectors such as energy water insecurity – according to inter- and water. national NGO Tearfund. For example, in Nigeria, thousands of square kilometres • Ghana has finalised a US$600-million of land are converted to desert each year, deal with a Chinese corporation to build forcing farmers and herdsmen to move to a 400 MW hydro-electric dam in the US scientists the cities. north of the country. • 3 600 – The estimated number of score big by international treaties signed since the last • Australia’s worst drought in known water war between two Sumerian city- history has sparked an increase in the thinking small states 4 500 years ago. number of water bandits who use crow- • US$81,8-million – The funds loaned esearchers at the University of California, bars to crack open water tanks and steal to Tanzania by the African Development in the US, have designed nanoparticles to the contents. Farmers have been advised R Bank for water and sanitation projects in create a membrane that does not clog easily, to lock their water stores. rural areas. The funds will be channelled allowing water to be pumped through using through the Tanzania Rural Water & less energy. • US scientists have identified a ‘new Sanitation Programme. Sci-Dev.Net reports that in the new mem- generation’ of byproducts of the disin- • R27-million – The value of the tender brane, used in reverse osmosis, nanoparticles fection processes used to purify drink- issued by the Limpopo government for are designed to attract water, soaking it up like ing water at municipal water treatment the repair of sewerage systems in the a sponge, while repelling nearly all contami- plants. They reportedly identified 28 Elias Motswaledi District Municipality. nants that might ordinarily stick to the surface. previously unreported so-called dis- • 93% – The percentage of the South This creates a water purification process that is infection by-products (DBPs), however African population who have access to as effective as present methods, but may use toxicity studies are still to be conducted basic water supply, according to the half the energy, reducing the total cost of water to determine the health implications of Department of Water Affairs & Forestry. desalination by 25%. these DBPs.
The Water Wheel January/February 2007 12 Company news
and 11 ℓ of water. The mechanism keeps the cistern dry until needed. When it is flushed, a pilot-operated diaphragm valve opens and lets water flow into the cistern quickly. When the water reaches the level of the height-adjustable float, the flush valve is automatically operated and the cistern flushes. On flushing, the inlet valve is closed so that, once the water empties the cistern remains empty until the next time it is needed. According to Mitchley, conventional toi- lets can easily be retrofitted with the leak-free cistern. Local plumbers can also be trained to fit the cisterns, creating valuable employ- ment. More than 1 000 of these cisterns have Two successes for turnkey firm already been fitted in the Mangaung munici- pal area, in the Free State, with positive WS Envig has completed two large a final stage where the water is polished results. Vprojects involving the construction with a mixed bed to meet the required For more information, contact Ray Mitch- of water recycling plants for SAPREF and specifications. The company supplies all ley at Tel: (031) 701-3185 or e-mail: ImproChem at the Chevron Refinery. the chemical requirements to the automated [email protected] The SAPREF reverse osmosis (RO) plant, and has a service contract to maintain plant was designed, built and commis- a smooth operation. sioned by VWS Envig. Water from the In turn, the Chevron/Improchem project CSIR part of EU Durban Water Recycling Plant is directed to in Milnerton involved the design, construc- solar project the RO plant where it undergoes carbon fil- tion and commissioning of an ultrafiltration/ tration to remove impurities such as odours RO plant. Domestic and industrial effluent SIR is representing South Africa in an and organic compounds. The water then from a nearby wastewater treatment plant is Cinternational, multi-partner programme goes through two stages of RO followed by directed to the water recycling plant. aimed at demonstrating the solar disinfection (SODIS) of drinking water as an appropriate intervention against waterborne diseases. Software helps demands for each node proportionally to the The programme, which has been lengths of the adjoining pipes. awarded a €1,9-million research grant from water demand In certain cases, certain parts of the the European Union, is being undertaken planning network can have different per area demands. under the auspices of the EU Sixth Framework This is the case with low-income suburbs Programme. SODIS is reportedly a low-tech, ivil Designer’s Water Module allows located next to a high-income area. In affordable method of improving water qual- Cusers to establish water demands accu- these instances, total demands should be ity. It involves placing contaminated water in rately and efficiently. established individually for each part of the transparent bottles, then placing it in direct In residential areas, demands can be network and the appropriate pipes and nodes sunlight for six hours. The method has been established according to stand areas, while should be selected. approved by the World Health Organisation. reticulation pipelines are fairly evenly dis- For more information, contact Knowledge The three-year SODISWATER programme tributed along the area. When demands are Base at Tel: (021) 701-1850 will be carried out by nine research groups in distributed in the Water Module, it is only Ireland, Spain, UK, Switzerland, South Africa, necessary to establish total demand in the Leak-free toilet Zimbabwe and Kenya. The multidisciplinary network using a number of people and per team will investigate the health benefits of capita demand, or measured consumption saves water using solar-disinfected drinking water in for existing networks using the menu option developing countries, the factors which ‘Adjust Demands’ in the Data menu. oilet leaks, which often go undetected, influence communities to adopt or reject Choose the option ‘Demand to Distribute Tcan waste large volumes of potable water. SODIS, whether the basic technique can be (ℓ/s)’ and enter the appropriate amount. The Akuvuzi leak-free cistern, supplied improved or whether there are any major The program will now automatically assign by Ray Mitchley, is one solution to frequent waterborne diseases that are not susceptible toilet leaks. The Akuvuzi can hold between 6 ℓ to the technique.
The Water Wheel January/February 2007 Company news 13
New nozzles for New magflow meter introduced
CT plant he new Safmag Beta Meter is the latest The meter delivers accuracy of about Tedition in the Safmag range. The meter 0,5% using the non-intrusive principle of he City of Cape Town has purchased is reportedly cost-effective, easy to use, and electro-magnetic induction, has no moving T55 000 nozzles and 10 000 sockets to install, while providing accurate and reliable parts and introduces zero head loss. replace the nozzles in the rapid gravity sand flow measurement. According to supplier, Readings are independent of density. filters at the Wemmershoek Water Treatment Flowmetrix SA, the product is available with Plant. wetted parts to suit all potable water and For more information, contact Flowmetrix The filtration plant was commissioned in effluent applications. SA E-mail: [email protected] or the late 1960s, and has a design capacity of Visit: www.flowmetrix.co.za 318 Mℓ/day. The original nozzles were report- edly supplied by Jeffrey Manufacturing and had a 1’’ BSP thread. The new polypropylene nozzles were manufactured locally by Isekeni Trading. To match the thread and the municipality’s design requirements, which included a detachable head with 0,45 mm, new tooling was required.
In brief
• Rand Water has reportedly estab- lished a bottled water unit to explore ways of entering this lucrative market. • Dr Shadrack Ralekeno Moephuli has been appointed the new President and CEO of the Agricultural Water on the Web Research Council (ARC). He joined the ARC from the Department of http://www.fao.org/landandwater/iptrid/ promoting an increased awareness of the Agriculture where he was the Chief index.html importance of disaster reduction as an Director responsible for Agricultural This is the official website of the International integral component of sustainable develop- Production. Programme for Technology and Research in ment. • Johannesburg Water is working Irrigation and Drainage (IPTRID), an inde- with the City of Johannesburg to pendent multi-donor trust-fund programme www.worldwatercouncil.org/index. provide 20 households in informal hosted by the United Nations Food and Agri- php?id=705 settlements with ventilated improved culture Organisation. This website contains This is the website of the World Water pit toilets and improved water sup- information about IPTRID’s strategy, projects, Council to promote international reflection plies through communal standpipes publications, database and news. to enhance the effectiveness of the right to through Project Thonifho. water. A project has been initiated to analyse • International company Coca Cola www.personal.leeds.ac.uk/~cen6ddm/ how several countries are dealing with the has signed an agreement with This is the personal website of Prof Duncan right to water. This site provides information UNESCO-IHE for a four-year co- Mara from the School of Civil Engineering, on the project, among others. operation aimed at improving the University of Leeds, UK. It contains free-to- water and environmental sectors. It use video and audio PowerPoint mini-lectures www.blacksmithinstitute.org includes training programmes for and supporting material on sanitation and This is the website of the US-based Black- Coca Cola staff members, with the water supply topics. smith Institute whose objectives are aimed at first group of 40 receiving training on developing and implementing solutions for advanced water treatment technolo- www.unisdr.org pollution-related problems in the develop- gies, groundwater treatment and risk This is the website for the International ing world. The NGO is most well known for management in Johannesburg earlier Strategy for Disaster Reduction, which aims its Polluted Places Initiative to address most this year. to build disaster resilient communities by severely polluted sites around the world.
The Water Wheel January/February 2007 14 Hydro-electricity Balancing Power and Water at Braamhoek
It might be situated in the Little Drakensberg Escarpment, but the R8,9-billion Eskom Braamhoek Pumped Storage Scheme is certainly not a small project. In addition to economic and social considerations, the project faces tremendous environmental challenges. Lani van Vuuren visited to site to see how the needs of power generation and water are being balanced.
t has been almost 20 years since in KwaZulu-Natal, and Bedford farm, regards to implementing the latest the construction of South Africa’s located some 23 km east-north-east pumped-storage technology. Ilast pumped storage scheme, of Van Reenen, in the Free State. The Palmiet, near Grabouw in the Western pumped storage station itself will be BCJV Resident Engineer Michael Cape. Braamhoek will not only be the located in KwaZulu-Natal. Neumann explains that the scheme most modern pumped storage facility basically comprises two reservoirs in South Africa but, with a capacity of MAIN FEATURES situated about 6 km apart, with 1 332 MW, also certainly the largest. an elevation difference of 470 m Pumped storage schemes are said Development of the Braamhoek between them. Unlike the Drakens- to be desirable, as they reportedly do Pumped Storage Scheme started berg Pumped Storage Scheme, not require much water, as the water in earnest following the Record of Braamhoek is designed solely for is being continuously recycled. The Decision in 2002. Main consultants, the purpose of generating peak-time main water losses stem from evapo- Braamhoek Consultants Joint Venture electricity, and will not be used for the ration from the reservoirs. (BCJV), comprising Knight Piésold, inter-basin transfer of water. There- Stewart Scott International and Arcus fore, the dams will be relatively small, The site straddles the Klein Drakens- Gibb, started basic design in 2004. with an active capacity of approxi- berg escarpment and spans over the Various other local and international mately 22 million cubic metres each. farms Braamhoek and Zaaifontein, specialist sub-consultants are assist- Water will only be drawn from the some 40 km north-west of Ladysmith ing in the project, especially with rivers to top up the reservoirs.
The Water Wheel January/February 2007 Hydro-electricity 15
The reservoirs will be connected by (NGO) first opposed the pumped “Without focused attention brought underground waterway tunnels, an storage scheme, but later withdrew about through the Braamhoek underground powerhouse complex, its objection. “As a conservation project, the area would never have and access tunnels. Access roads organisation we could see that inter- received the attention it requires,” the and a new substation also form part vention was required to prevent it NGO states on its website. of the project. from degrading even further.” Three years ago, the Braamhoek RESPECT FOR THE The Middelpunt Wetland Trust, which Partnership was established between ENVIRONMENT was created a few years ago with Eskom, Birdlife South Africa and the the sole aim of protecting the white- Middelpunt Wetland Trust. This is Conservation organisations initially winged flufftail, confirms this. reportedly the first time in the power opposed the construction of Eskom’s latest pumped storage scheme at Braamhoek. Sparsely populated, the 8 500 ha site features mainly grass- lands with wooded gulleys along the mountain streams. Yellowwood forest predominate in the ravines of the escarpment (none of which will be affected by this project). This is reported to be the third-largest com- plex of this forest type in KwaZulu- Natal.
However, closer inspection revealed that while the area offers huge con- servation potential, overgrazing and historically poor land management have resulted in severe erosion and a loss of biodiversity in the surround- ing veld. Invading alien plants, most notably black wattle, are widespread All water from the tunnel is pumped to a holding dam before being treated and in the area. released back into the river system. Solid waste is also strictly controlled.
The biggest bone of contention was the 240 ha peat wetland situated in the Bedford catchment. This wetland is home to a number of bird species that are either critically endangered, near endangered or at risk, includ- ing the elusive white-winged flufftail. About 5% of the total wetland area will be covered by the upper reservoir.
Following negotiations, leading to an amended Record of Decision, Eskom and various conservation organisa- tions are now working together to improve biodiversity in the area. As BirdLife SA Executive Director Prof Gerhard Verdoorn points out, much of the land in the area of the marsh was degraded and in poor condi- An aerial view of the present construction site. The entrance to the exploration tion prior to the start of the project. tunnel is on the left. Unlike the Drakensberg Pumped Storage Scheme, no The non-governmental organisation permanent construction village is planned for the site.
The Water Wheel January/February 2007 16 Hydro-electricity
generator’s history that conservation excellent condition. Nelson explains discharges at all impounded water NGOs have been brought on board the importance of finding a balance levels to meet the strict release long before construction of a power between power generation and water. requirements to accommodate the plant is due to start. “Eskom realises the importance of conditions set out in the Record infrastructure development that is of Decision. The outlet works will Eskom is compelled by the Record of sustainable, from an economic, social comprise a tower in the reservoir Decision to turn the entire site into a and environmental point of view. South with radial gate and maintenance conservation area. This will increase Africa needs more power but, at the stoplogs. The tower will be accessed the present extent of ‘conserved same time, we are a water-scarce by a bridge from the dam. This high- grasslands’ by about 81%. Eskom country, thus we must protect the water flow bottom outlet system will have a has committed itself to, among oth- resources that we have. We cannot maximum discharge capacity of ers, rehabilitating eroded areas, and ignore the fact that this project is being 70 m3/s at fully supply level, and halting alien plant encroachment. constructed in the headwaters of two 52 m3/s at minimum operating level. All areas affected by construction, strategically important river systems.” including all quarries, will be fully A flow distributing weir will also be rehabilitated. UPPER RESERVOIR constructed downstream of the dam to distribute reservoir outflows Peter Nelson was appointed Reserve Situated in the top catchment, the across the wetland. This is crucial, Environmental Manager a few months Bedford Dam will be located in the as a disregard for the instream flow ago, and he will inherit any develop- headwater tributary of the Wilge requirements would have a significant ment that takes place on site. “There River, which flows into the Vaal River impact on the wetlands downstream is no reason why this project cannot system. The concrete-faced rockfill of the dam. be a world-class example of respon- dam will have a length of 810 m and sible infrastructure development. Cru- a height of 40,9 m, with a 100 m-long It is interesting to note that the pres- cial to this, however, is a respect for emergency spillway. The dam crest ence of an isolated population of the land on which the development elevation will be 1 740,6 m while the an unidentified Barbus species has is taking place, a respect that has to crest width will be 8 m. All the rockfill been found in a stream draining the be instilled in every single employee material will be sourced on site, and eastern section of the Bedford catch- from the lowest worker to the project the main quarry will be located within ment. To prevent hybridisation of fish manager.” the reservoir basin. species in the different river systems, fish barriers will be constructed at the Rivers and streams in the area have It is reported that the outlets works headrace and tailrace tunnels. been found to be in a good to will be capable of a range of Important plant species that will be inundated by the two reservoirs, such as the Red Data Kniphofia flammula, will be identified and relocated. A nursery will be established to house endemic and rare plants.
LOWER RESERVOIR
In turn, 38,6 m-high roller-compacted concrete Braamhoek Dam will be located in a very distinct poort in the headwater of the Klip River (Braam- hoek Spruit), which flows south-east- wards into the Thukela River.
Design selection is based mainly on the presence of underlying dolerite. The spillway will be a stepped chute Many of the soils found in the area are highly leached and strongly acidic. The on the downstream face of the dam, presence of light textured, silty subsoils underlain by slaking mudrock renders with a 40 m-long crest featuring a many of these soils susceptible to erosion. stilling basin with baffles. The
The Water Wheel January/February 2007 Hydro-electricity 17
Entrance to the 5 m x 5 m exploration tunnel. The 6 m3 dump trucks used at present will later make way for articu- lated dump trucks once construction of the main machine hall starts. Pass- ing bays are being excavated every 100 m along the tunnel to permit empty trucks give way to fully laden trucks hauling uphill.
Braamhoek Dam will have a length of 331 m and a crest width of 5 m.
The dam will have a high-flow outlet with a maximum discharge capac- ity of 74 m3/s and a low-flow outlet capacity of about 2,3 m3/s. Neumann The waterways will include an intake The main access tunnel will be notes that the dam wall height has structure for twin 6,6 m-diameter 9 m x 9 m with a gradient of 1:10 and been selected to provide a 0,5 m concrete-lined headrace tunnels, a length of 1 250 m. Tenders for this freeboard to accommodate flood each with a length of 1 030 m, to tunnel closed in November. Con- inflows, such that a 1:200-year flood the surge shafts (the main headrace struction on the tunnel is scheduled will not cause the dam to spill. surge shaft will have a diameter to start in March, with completion of 15 m). Twin inclined steel-lined expected by December 2009. Nonetheless, flood inflows will nor- pressure shafts of 5,1 m-diameter mally be released downstream through will lead into steel-lined penstocks Spoil and waste rock material result- the outlet works to mimic the natural of varying diameter. In turn, these ing from the tunnelling process is flow of the stream. The dam therefore bifurcate to two smaller penstocks being stockpiled temporarily for use attenuates the effects of natural floods. leading to the inlet valves and the as fill to the access roads, to create machine hall. They will have an over- temporary terraced working platforms POWER GENERATION all length of just over 1 200 m to the for the power station contractor, and main inlet valves, which are housed for rehabilitation of erosion features Similar to the Drakensberg Pumped in the machine hall. within the project boundaries. All Storage Scheme, power generation excess waste rock will be disposed of will be conducted entirely under- In addition, there will be four below the minimum operating levels ground. The machine hall, housing 4,7 m-diameter draft tube tunnels of the two reservoirs. four 333 MW single-stage reversible with a length of 135 m each, to reach Francis pump-turbine units, will have the twin 20 m-diameter tailrace surge EXPLORATION TUNNEL a length of 172 m, a height of 40 m, chambers. Two short 6,6-m diameter and an average width of 23 m. The tailrace tunnels will lead to a single The first construction contract was adjoining transformer hall will be of 9,4 m-diameter tailrace tunnel, in turn, awarded to Concor-Ukhozi Joint similar length or longer (depending leading to an outlet structure. This will Venture in August 2005 for the on the equipment needed), with a be situated 2 530 m downstream of construction of the 873 m-long span of 18 m and a height of 17 m. the surge chambers. exploration tunnel. The 5 m x 5 m
The Water Wheel January/February 2007 18 Hydro-electricity
date. The projected completion of the generator does not want to merely tunnel is June. move these communities, but wants to equip them with sustainable land The geology of the area has proven management practices for the long quite challenging. The area is under- term. lain by sedimentary rocks (mostly sandstone and mudrock) of the Ecca ENVIRONMENTAL and Beaufort Groups of the Karoo RESEARCH AND Supergroup, intruded by dolerite DEVELOPMENT dykes and sills, with some faulting occurring. Approximately 137 bore- Prof Verdoorn is happy to report that holes have been drilled around the Eskom is diligently following the stip- site to explore the underlying rock ulations of the Record of Decision. formations in the dam foundations, BirdLife South Africa has performed along the various tunnel alignments, extensive surveys on birds and plants potential quarry sites and cuttings of on the Braamhoek site, and a moni- the access roads. toring programme on habitats and The Braamhoek Spruit will be birds has been established. dammed by a roller-compacted con- “By studying this core material, we crete wall. Compensation flows will, believe we have gained important In addition, the NGO participates however, ensure uninterruoted flow to insight into what lies where,” BCJV actively in monitoring the construc- downstream users. geologist John Reid tells the Water tion work, advising on environmental Wheel. This knowledge is crucial as management and mitigating impacts. horseshoe-shaped tunnel has a the dolerite will require less support Field officer David Maphisa was gradient of 1:8 and leads to the than mudrock, which typically of appointed to conduct all the bio- underground powrhouse complex. many Karoo mudrocks, experience logical work. A formal conservation As the name implies, the explora- rapid disintegration when exposed. project on the southern bald ibis, tory tunnel was initially planned for For this reason, Neumann empha- which has been found nesting in the investigating different types of sup- sises the importance the immedi- area, has also been launched. port materials, exploratory drilling and ate installation of support following for the installation and monitoring of blasting, comprising roof bolting and Middelpunt Wetland Trust has estab- instrumentation (incorporating con- shotcrete. lished links with the Ethiopian Natural vergence stations, extensometers, History Society (Ethiopia being the instrumented rockbolts, and rock The present minimal water ingress into only other country where the white- anchors) to provide geotechnical the tunnel is being pumped out to a winged flufftail has been recorded). data for design purposes. holding dam outside the portal. While With funding from Eskom, the NGO the water was mainly used for dust established an education centre at Since construction of the machine suppression in winter, it is now being the main breeding site of Berga, in hall will start prior to the comple- treated at a 44 m3/day water treatment Ethiopia. tion of the main access tunnel, the plant on site before being released exploration tunnel will initially form the back into the river system. Water Eskom is also a trustee of the Ekan- only access for the excavation of the samples are tested weekly by an inde- gala Grassland Trust, which is driving underground works. It will later house pendent laboratory in Winterton. a pilot study to conserve high-altitude the 400 kV transmission cables lead- grassland in South Africa at present. ing to the surface switchyard, and SOCIAL ASPECTS provide a second means of egress A number of neighbouring farms from the underground power station. About 30 families remain in the upper have expressed interest in joining the In addition, it will be used as a venti- and lower catchments of the Braam- conservation area, and it is hoped lation tunnel. hoek Pumped Storage Scheme. It is that more will follow as the project understood that all the homesteads progresses. “This is going to be the Construction of the exploration tunnel in the area will be relocated, and best example of how industry and is taking place in three shifts working alternate tracts of land has been NGOs can collaborate to improve 24 hours, six days a week. Neumann purchased for this process. environmental conditions for a reports that more than 600 m of natural area” concludes Prof tunnelling has been completed to Nelson reports that the power Verdoorn.
The Water Wheel January/February 2007 Freshwater conservation 19
Buckling under the pressures of Helping Rivers growing water demand and Fight for pollution, the world’s fresh- water biodiversity their Lives and habitats are being lost at an unprecedented rate. International freshwater experts from as far afield as the US and Australia gathered at Skukuza, in the Kruger National Park, to iden- tify solutions for freshwater conservation. Lani van Vuuren reports.
With large infrastructure developments threatening the flow of the Olifants River, the Sabie River is the last remaining perennial river in the Kruger National Park.
lthough freshwater ecosystems Most governments afford low priority the needs of both terrestrial and fresh- occupy less than 1% of the to improved freshwater ecosystem water ecosystems.” Aworld’s surface, they make management, with decision makers some of the largest contributions to and communities often being unaware SAVING WATER FOR human welfare. Historically, the world of the threats and opportunities to con- SOCIETY has taken a utilitarian view of rivers serve freshwater ecosystems. “Con- (if water is left flowing into the sea it is serving river ecosystems depend on “Conservation of freshwater ecosys- being wasted). Everyday, more rivers, whole catchment management, where tems is crucial for providing reliable wetlands, estuaries and groundwater land and water is managed in an and clean water supplies needed to resources are threatened by over- integrated manner aimed at achieving sustain people and nature,” noted abstraction, damming, urbanisation, ecological and socio-economic sus- Jamie Pittock, Director of WWF’s industrial and agricultural pollution. tainability,” noted Jeanne Nel of CSIR’s Global Freshwater Programme. An In fact, global trends indicate that Natural Resources & the Environment example of the extent of the prob- freshwater biodiversity is declining Unit. “This requires the development of lem is the fact that two thirds of the faster than that of terrestrial and integrative assessment and planning world’s large rivers (longer than marine biomes. approaches that proactively consider 1 000 km) have already been diverted
The Water Wheel January/February 2007 20 Freshwater conservation
for human use. In Africa, there are 23 Assessment in 2004/05 emphasised of alien aquatic animals. All of South rivers longer than 1 000 km of which how hard most of the country’s rivers Africa’s main rivers are inhabited by 35% remains free-flowing. are working to meet its economic and alien fish species. social development needs. Many of the last remaining free-flow- At least 33 species of introduced ing rivers have been earmarked for The country’s main rivers are heavily alien aquatic animals and 25 species future development. WWF estimates utilised and regulated to improve water of translocated indigenous species that of the world’s remaining 64 large security for socio-economic use, and have been recorded free-flowing rivers, at least 17 are in there are widespread water transfer in natural water danger of being dammed by 2020, schemes across the country to cater bodies in most of these in developing countries. for areas where water requirements South exceed the natural water availability. Africa. Global pressures to reduce poverty About 84% of the ecosystems of main It is are conflicting with demands to sus- rivers are threatened, 44% of them repor- tain biodiversity. “The United Nations critical. ted Millennium Development Goals call that for countries to halve the number of In addition, the analysis of the data intro- those without access to basic water collected on South Africa’s River duced and sanitation, increase food produc- Health Programme, which measures freshwater fish tion and use alternative sources of rivers’ ecological conditions, shows such as trout and energy (including hydropower) on the that only 1,6% of the 13 river systems bass threaten rare one hand, and to protect biodiver- that have thus far been studied are indigenous fish, sity on the other hand,” Pittock told in a natural condition, 26,6% are in delegates. “International donor aid a good condition, 42,8% are in a fair for water is shrinking, and remains condition and largely focused on development 29% are in a of infrastructure. “The environment poor state. always ends up at the bottom of the to-do list.” By threate- ning fresh- TOO LITTLE, NOT TOO water habi- LATE tats we also threaten the In South Africa, such as elsewhere in species reliant the world, the focus has historically on them. About fallen on the protection of terrestrial 30% of South ecosystems, with river ecosystems Africa’s indigenous fish species are such as redfin minnows in the West- being in a much poorer state overall. considered threatened, of which ern Cape, and have led to the near A study undertaken of South seven are critically endangered, six extinction of Treur River barbs. Africa’s 112 main rivers as part of are endangered and nine are vulnera- the National Spatial Biodiversity ble. A major threat is the introduction The introduction of trout in neighbour- ing streams in Lesotho 70 years ago have also nearly eradicated the Maloti minnow, the country’s only known endemic fish species, explained Dr All over the world, Ernst Swartz, an aquatic biologist at freshwater bio- the Institute of Aquatic Biodiversity. diversity is dis- The fish has already become extinct appearing faster in South Africa. than terrestrial and marine biomes. Furthermore, the Mohale reservoir, constructed as part of the first phase of the Lesotho Highlands Water Project (LHWP), flooded 77% and Courtesy of SA Tourism 99% of the existing habitat of the
The Water Wheel January/February 2007 Freshwater conservation 21
population in the Jordane and one catchment area to another. While of these areas, leaving them effec- Bokoaneng rivers respectively. Fish in alien plant control programmes are tively unprotected. these rivers were translocated to four well spread within South Africa, there sanctuary streams in an effort to save are no known national or even catch- While it is recognised that conserving the Maloti minnow from extinction. ment-level control programmes to whole river systems in protected While reports from LHWP developer eradicate alien fish yet. However, the areas is seldom a practical manage- TCTA indicate that the translocated Cape Action for People and Environ- ment option, changing the way in minnows are thriving, conservation- ment is leading a project to clear which future protected areas are ists remain concerned as some priority rivers in the Cape Flo- designated or expanded could help ristic Region of invasive alien species. improve the representation of fresh- water ecosystems within protected SAVING WHAT IS LEFT area systems. For example, by delineating protected areas to coin- There is no doubt that cide with catchment boundaries, as efforts to reverse opposed to using rivers themselves declining trends to mark protected areas. need to increase. But how to effect “Integrated protected areas need not that positive stop at a river’s mouth. For instance, change is far a combined terrestrial-freshwater- from obvious. marine protected area might be One possible built around meeting the linked solution debated goals of maintaining water quality in by Skukuza symposium freshwater and marine systems by delegates was the improved protecting both critical management establishment and management of zones and catchment management protected areas. zones on the terrestrial landscape,” reported Dr Robin Abell of WWF-US. no barriers While large areas of freshwater have been constructed habitats are incorporated into pro- Freshwater ecosystems that do fall to date to keep predator alien tected areas already, for example, within protected areas are often fish out of the sanctuary streams. Ramsar sites (such as St Lucia viewed and managed as a necessary Lake), these have been found not resource for conserving terrestrial According to Dr Swartz, translocated to be properly representative of the biodiversity rather than for their intrin- species, indigenous fish that have diversity of habitats. Most existing sic biodiversity value. Due to the linear been translocated either intentionally protected areas have neither been characteristic of rivers, freshwater eco- or unintentionally into catchments designated nor managed for fresh- systems inside protected areas are in which they were not naturally dis- water conservation. In South Africa, especially vulnerable to exogenous tributed, can be just as threatening 90% of the country’s main rivers fall threats. For example, the Olifants if not more so than alien fish. “This outside protected areas, while an River flowing through the Kruger often leads to hybridisation (genetic additional 5% serve as boundaries National Park stopped flowing for the mixing) between species of which the outcome is unpredictable. Differ- ent species have their own genetic The analysis of the makeup that has been influenced by data collected on its adaptation to specific habitats. South Africa’s River Resultant hybrids can be sterile or Health Programme could be viable causing one species shows that only to dominate the other.” 1,6% of the 13 river systems that have Great engineering feats, such as thus far been stud- the Orange-Fish tunnel, have been ied are in a natural considered an environmental disaster condition. as they became enormous conduits for fish species to translocate from Courtesy of SA Tourism
The Water Wheel January/February 2007 22 Freshwater conservation
Symposium participants commit- ted themselves to several actions, including preparing and distribut- ing guidelines and case studies on management guidelines for optimal conservation of freshwater biodiversity in protected areas; and supporting governments to implement national protected area systems to conserve freshwater biodiversity.
KEEPING FLOWING RIVERS FREE
Another concept that received much attention at the symposium was that of free-flowing rivers. These are rivers, or distinct sections of rivers, that flow undisturbed without We hold the future of our aquatic ecosystems in our hands. encountering any dams, weirs or barrages. A free-flowing river should have sufficient flows to sustain the full range of freshwater ecological attributes. Also known as ‘wild’ or ‘heritage’ rivers, the concept has taken off in countries such as Canada, the US and parts of Australia where these free-flowing rivers are important new conser- vation icons and tourist attractions.
South Africa has very few free- flowing rivers left. Most of these rivers are situated in the Eastern Cape and KwaZulu-Natal, and have already been earmarked for future infrastruc- ture development. The largest of these is reported to be the Mzimvubu
Courtesy of SA Tourism River, which only has a few small farm Freshwater ecosystems that fall within protected areas are often viewed and dams on its tributaries. managed as a necessary resource for conserving terrestrial biodiversity rather than for their intrinsic biodiversity value. From the symposium it is hoped to develop criteria, guidelines and case first time on record for 78 days in 2005 services, it is important for managers studies and to develop a place where due to drought and growing demands to take cognisance of the influences rivers that are protected as free- on its water. Planned upstream infra- of upstream activities on freshwater flowing rivers can be registered and structure developments, such as the within their protected area. “Conser- celebrated. De Hoop Dam, on the Steelpoort River ving freshwater ecosystems within the and the rehabilitation of the Massingir fence often means spending more Freshwater protection is for many Dam in Mozambique, further threaten time outside the park taking part in countries still a novel concept. How- the park’s freshwater. catchment management decisions.” ever, it is hoped that by working Integrated catchment management as together across boundaries and dis- According to Dr Harry Biggs of the well as the provision of adequate water ciplines, that a sustainable solution Kruger National Parks’ scientific flows are critical, delegates concurred. might be found before it is too late.
The Water Wheel January/February 2007 Transboundary aquifers 23
Managing Southern Africa’s Shared Aquifers
During the last 50 years, more than 200 international trea- ties for transboundary watercourses have been signed across the globe. Unfortunately, the same cannot be
Even aquifers that do not necessarily said for transbound- straddle the political boundaries of coun- ary groundwater tries could at times be considered ‘trans- boundary’ as they may contribute to river resources. Lani van base flows. Vuuren reports.
he world’s aquifers have been worldwide in the joint management of Two, in almost all cases, groundwater described as ‘secretive’, ‘hid- these resources, even though some systems are, by their very nature, Tden’, and ‘mysterious’. All indi- of them contain huge quantities of transboundary.” cations are that we just do not know water. enough about them. Transboundary Even aquifers that do not neces- aquifers, i.e. those underground Today’s best practice in sustainable sarily straddle the political bounda- resources which cross the border water management – Integrated ries of countries could at times be between two or more countries; are Water Resources Management considered ‘transboundary’ as they an estimated three times greater in (IWRM) – focuses on river basins as may contribute to river base flows. volume than internationally shared the unit of management, explains Dr Groundwater use in such aquifers surface waters. However, they are Anthony Turton, Head of the African therefore may have an impact down- generally not well understood by Water Issues Research Unit at the stream across international bounda- decision makers and policy develop- University of Pretoria. “However, this ries. Aquifers may also receive most ers, in some cases being blatantly overlooks two fundamental realities; of their recharge in one country, but ignored. one, that groundwater aquifer sys- discharge in another. tems, while being an integral part of There is still no comprehensive the overall water resource, seldom Internationally, there is a trend to worldwide inventory of transboundary correspond with the surface water increasingly address groundwater aquifers, and very little experience management unit, i.e. the river basin. in international agreements,
The Water Wheel January/February 2007 24 Transboundary aquifers
non-binding instruments and interstate flow should be taken into account groundwater will undoubtedly play compacts, from a resource manage- when determining how to apply an increasing role in socio-economic ment as well as an environmental per- international law principles to ground- development in the future. spective. Unfortunately, many of these water,” notes Yamada. agreements only contain a passing As it is elsewhere in the world, there reference to the subject. The complex characteristics of are more transboundary aquifers in groundwater place increased pres- the region than there are transbound- “Aquifer characteristics need to sure on the scientific community ary river basins, with South Africa and be adequately considered when to provide the necessary data and Botswana both having the greatest formulating groundwater law and information for the formulation of number of known shared ground- policy,” maintains Chusei Yamada, adequate policies and laws concern- water systems. The UNESCO-led Special Rapporteur on shared natu- ing transboundary aquifers. This ISARM (Internationally Shared Aquifer ral resources to the United Nations includes the quantification of aquifer Resources Management) Initiative International Law Commission. For potential, recharge calculations, has identified 19 transboundary example, groundwater flows though defining compartment boundaries, aquifers in southern Africa to date. small pores in rock material and can determining recharge ‘episodes’, While the extent of these transbound- thus move at a snail’s pace of around and defining recharge zones. Most ary aquifers is relatively known, the a few millimetres a day. This slow groundwater investigations under- resources have not been properly movement of groundwater does not taken by individual countries still tend quantified to take the transboundary allow for much mixing of its constitu- to stop at the border. conditions into account. Moreover, ents. Therefore, pollutants are con- there are no formal structures (if any) centrated and move slowly. On the TRANSBOUNDARY to govern these shared resources. other hand, surface water can flow at AQUIFERS IN SOUTHERN a rate of several metres per second. AFRICA Fundamental tools for transbound- The turbulent flow of the water allows ary groundwater management, such pollutants to mix and distribute more Within the Southern African Develop- as hydrogeological maps and maps evenly throughout the water system.” ment Community (SADC) it is esti- of groundwater vulnerability and mated that 37% of the population rely water scarcity, are not available in “An understanding of basic hydro- on formal or improved groundwater the SADC region, with existing infor- geology, including the proper use of supplies, while another 40% rely on mation mostly limited to the country scientific terminology, is thus neces- unimproved resources (both surface concerned. The most arid countries sary for law and science to agree and groundwater resources). With such as Botswana, South Africa and on groundwater issues. Factors that about a third of the regional popula- Namibia have devoted understanda- determine groundwater quantity and tion living in drought-prone areas, bly the most attention to groundwater resources exploration, assessment, developing and monitoring.
There seems to be little regional consensus on the measurement and management of transboundary groundwater resources, resulting in the lack of regional monitoring net- works, for example. The international arena offers little guidance in this respect, notes Dr Turton.
The responsibility for management of groundwater resources is often fragmented between different authori- ties and at different scales. This issue has been exacerbated in recent years with the move towards decentralisa- tion of management responsibility. Irrigated agriculture is a large user of groundwater, especially in countries such Typically, local government, water as South Africa. departments, planning departments
The Water Wheel January/February 2007 Transboundary aquifers 25
and environmental departments are responsible for different aspects of groundwater management, with both central and regional offices of the departments further diffusing respon- sibility.
Dr Turton reports that there is only one known international agreement involving management of ground- water systems in SADC, focused on the waters shared by Botswana and Namibia in the Chobe-Linyanti area of Courtesy ISARM the Caprivi Strip.
Investigations by organisations such as CSIR indicate that various trans- boundary aquifer systems are not yet A transboundary aquifer. on record. This tends to make these aquifers more vulnerable to overab- While South Africa’s water legislation pollution, is not being managed as a straction and pollution as countries and policies have received worldwide transboundary aquifer.” sharing the same resource might acclaim, there is a significant gap as have different policies regarding far as management of transboundary Another example is the Pomfret- groundwater use and protection. aquifers are concerned, DWAF Dep- Vergelegen Aquifer, a high-yielding uty Director: Groundwater Resource karstic aquifer in the North West of One possible reason why trans- Assessment & Monitoring, Eddie van South Africa, straddling the border boundary aquifers have remained Wyk tells the Water Wheel. “This can with Botswana. Water abstraction for largely in the shadows could be be seen with groundwater resources irrigated agriculture from this aquifer the lack of political interest, former such as the Zeerust-Gaborone Aqui- has been increasing on the South Department of Water Affairs & For- fer, straddling South Africa and Bot- African side, causing a dewatering of estry (DWAF) Deputy Director: Geo- swana, which, despite being prone to the overlying unconfined upper hydrological Information, Jan Girman, points out. “International transbound- TABLE 1 ary groundwater resources, such as Transboundary aquifers in SADC as identified by ISARM the Nubian Sandstone Aquifer Sys- Aquifer Name Countries tem, shared between Libya, Egypt, Rift Aquifers Kenya, Tanzania, Uganda Chad and Sudan, have been highly Kagera Aquifer Tanzania, Uganda politicised. The same cannot be said Kilimanjaro Aquifer Tanzania, Kenya for southern African aquifers.” Coastal Sedimentary Basin I Kenya, Tanzania Coastal Sedimentary Basin II Mozambique, Tanzania As of yet there does not seem to Limpopo Basin Mozambique, Swaziland be the same intense competition Coastal Sedimentary Basin III Angola, DRC for transboundary groundwater Coastal Sedimentary Basin IV Angola, Namibia resources between countries as there Coastal Sedimentary Basin V Namibia, South Africa are for shared surface resources. Congo Intra-cratonic Basin Angola, DRC Generally, where large-scale abstrac- Karoo Sandstone Basin Mozambique, Tanzania tion takes place on one side of Shire Valley Alluvial Aquifer Malawi, Mozambique the border, little or no abstraction Northern Kalahari/Karoo Basin Angola, Botswana, Namibia, Zambia takes place on the other side. Of SE Kalahari/Karoo Basin Botswana, Namibia, South Africa course, this could change signifi- Ramotswa Dolomite Basin Botswana, South Africa cantly in future as more groundwater Nata Karoo Sub-basin Botswana, Namibia, Zimbabwe resources are earmarked for social Tuli Karoo Sub-basin Botswana, South Africa, Zimbabwe and economic development, reports Medium Zambezi Aquifer Botswana, Mozambique, South Africa, Zimbabwe Girman. Karoo Sedimentary Aquifer Lesotho, South Africa Source: ISARM
The Water Wheel January/February 2007 26 Transboundary aquifers
the hydrological cycle,” says Girman. “Much has needed to be done since then to quantify the country’s ground- water resources, build a strong sci- entific understanding of the aquifers present and, more recently, to evalu- ate and award groundwater licenses. All of this has stretched the limited available skills base. At this stage, transboundary aquifers are just not at the top of the to-do list.”
SADC GROUNDWATER INITIATIVE
Despite the challenges in implement- ing sound transboundary aquifer Groundwater is playing an increasingly important role in water supply, especially management, the region does have a in rural areas. good starting point, namely the SADC Protocol on Shared Watercourses, deposit below the Limpopo River for Kalahari Aquifer, a CSIR report which came into force in 2003. A use in the kimberlite treatment process reveals. This also has the potential to regional strategic plan for IWRM was at De Beers’ Venetia Mine and by irri- unknowingly impact upon groundwa- developed in 1998 which includes 31 gation farmers at Weipe and Pontdrift, ter users in Botswana, because of the priority projects, one being regional explains Willem du Toit, Deputy Direc- inherent transmissivity of the system. groundwater management. tor: Water Resources Information: Limpopo. Differing legislation in the two coun- To assist with the latter, the interna- tries and the differing approach tional donor community is funding a to groundwater management and “Lack of institutional project investigating ways to enhance water resource protection can cause capacity at all levels regional cooperative management of South African farmers to migrate to transboundary aquifers. This forms Botswana to exploit the groundwater seriously hampers trans- part of a larger drought management there from the same aquifer. boundary groundwater initiative. Funded jointly by the World Bank, the Global Environment Facil- Where international surface water management.” ity and the Swedish Development treaties are in place, the lack of Agency, the US$7,5-million SADC understanding of groundwater “Potential recharge reduction as Drought Management Project has the resources can cause it to be largely a result of the dam could not only establishment of a regional Ground- ignored when it comes to develop- impact these water users, but also water Management Institute of ments in transboundary basins. The the already endangered riparian Southern Africa (GISA) as one of its government of Botswana is report- forest remaining along the Limpopo objectives. This institute will continue edly going ahead with construction River and the emergent Limpopo- long-term monitoring of transbound- of the Lower Shashe Dam to be built Shashe Transfrontier Park.” All indi- ary groundwater resources. about 50 km east of Francistown. cations are that users of the alluvial The dam, which is expected to be aquifer were not informed of plans to It is hoped that the tools developed completed by 2010, will be the construct the dam prior to approval through this project will assist in largest in the country at an estimated by the Botswana government. building some consensus regarding 4,9 million cubic metres fill volume. the management of transboundary Lack of institutional capacity at all lev- groundwater resources. There is also The Shashe River is one of the main els seriously hampers transboundary a hydrogeological mapping compo- tributaries of the Limpopo River, shared groundwater management. “In South nent to this project, which is being between South Africa, Zimbabwe, Africa, for example, groundwater funded by the French and German Mozambique and Botswana. On the issues were largely ignored until 1998 governments. Once established, South African side, huge volumes of when the National Water Act officially GISA will be the custodian of these water are abstracted from the alluvial recognised groundwater as part of outputs.
The Water Wheel January/February 2007 Climate prediction 27
Locally-Developed Climate Model Verified A South African-based climate prediction model which can be applied for multi-year regional and river-flow analyses and predictions has now been tested and verified, writes developer Will Alexander, Professor Emeritus at the Department of Civil and Biosystems Engineering at the University of Pretoria.
n particular, it is believed that the wetter and greener than at any time plants, and large areas of southern model can be used with greater in human memory. Floods occurred Africa becoming a desert within the Iassurance than current methods in many rivers from Angola in the next 50 years. for multi-year simulations required north through to the coastal rivers of for water resource development the southern Cape. Dams filled over VERIFICATION OF THE and management. In November most of the region. The loss of life MODEL 2005, during the then present was minimal thanks to the emergency drought, the first of four flood alerts services in the areas. The prediction model is based on the were issued based on the model. statistically significant (and therefore Details of action for local authori- The threatened succulent (Quiver predictable) 21-year periodicity in ties to limit the potential loss of tree) and fynbos species are now in South African hydrometeorological life in informal settlements were a healthy condition throughout the data. Two figures generated by Alwyn included. region. This is in contrast to claims van der Merwe illustrates the applica- that global warming would result in tion of the model following the first Three months later large regions of threats to the region’s water supplies, complete hydrological year after its the African subcontinent were the destruction of these valuable publication.
The Water Wheel January/February 2007 28 Climate prediction
Figure 1: Annual rainfall for the Highveld region. Figure 2: Annual river flow in the Orange River.
Figure 1 shows the annual rainfall for This negates the fundamental view the Highveld region where the interest The next ten years will of national and international climate is in the availability of water for cool- change scientists that solar activity is ing at the coal-fired power stations. be critical for water not the cause of climatic variations. Figure 2 shows the annual river flow resource development From this it was erroneously main- in the Orange River where the interest tained that all multi-year changes are is in hydropower generation at the and operation. This has the result of the discharge of unde- Gariep and Van der Kloof dams. nothing to do with global sirable greenhouse gases into the atmosphere from industrial and other The figures show box and whisker warming. activities. probability plots derived directly from recorded data within the regions of Note the increase in rainfall relative to interest. The outer thin lines show the While not the purpose of the analy- the mean values during the four years observed maximum and minimum ses, besides confirming the validity in Figure 1. This is contrary to publi- values. The upper values are off the of the model, they highlight the seri- cations of climate change scientists sheet in the Gariep Dam figure. Cur- ous shortcomings in present climate in which it was maintained that global rent simulation models used for water change science. The model is based warming would result in a decrease in resource analyses assume that all the on the observed 21-year periodicity in rainfall within this region. boxes are in the same vertical posi- the data. Although not included in the tion, i.e. there is no year-to-year vari- model, the synchronous linkage with Also note that the observed annual ability in the probability distributions. sunspot activity is beyond all doubt. rainfall and river flow during the past years were nowhere near the historical maxima and minima. This is contrary to claims in the climate change literature that global warm- ing will result in an intensification of the hydrological cycle with increases in the magnitude of floods and droughts.
Most importantly, refer to Figure 2 and note that, with the sole excep- tion of year 13 (2007/08), the mean values of the predictions for the next ten years are all less than the long- term mean annual runoff (MAR). The predictions for the present hydrolo- The stabilised fossil sand dunes in the Kgalagadi National Park. They show no gical year in both regions are below signs of being rejuvenated as a result of global warming. average rainfall and river flow.
The Water Wheel January/February 2007 Climate prediction 29
The next climate reversal from drought to flood conditions based on the analysis of historical data is only expected to occur in 2016. This confirms the linkage with the double sunspot cycle. The next ten years will be critical for water resource development and operation. This has nothing to do with global warming.
WATER RESOURCE DEVELOPMENT IN THE DECADE AHEAD
It is extremely important that all those involved with water resource stud- ies should appreciate that there are fundamental flaws in present global climate models used for climate change applications. These models fail to accommodate the statistically significant, multi-year periodicity in the
rainfall and river flow data observed Ebrecht Courtesy of Lutz and reported by South African scien- Rejuvenation of the vegetation in the Namib Desert after the widespread rains of tists and engineers for the past 100 January-February 2006. years. They also failed to predict the recent climate reversal based on the Alexander climate prediction model. The provision of water and con- long way towards meeting this servation of the water environment requirement. Those who have expressed con- are non-commensurate objectives cerns regarding the environmental in that one cannot be met without Further reading: consequences associated with water sacrificing the other. Reasoned • www.wrc.org.za/downloads/ resource development should appre- compromises will have to be watersa/2005/Apr-05/1788.pdf ciate that the provision of water to made. This can only happen if all • Climate Change and Its Conse- meet rising demands is essential for parties have a sound knowledge of quences – An African Perspective, the prosperity of any nation. South the multiyear properties of rainfall available from Prof WJR Africa does not have the luxury of and river flow. The Alexander Alexander, Tel: (012) 991-3151; abundant water supplies. climate prediction model goes a E-mail: [email protected]
The Kalahari dessert countryside completely grass covered with a prolific scattering of seed along the desert roads.
The Water Wheel January/February 2007 30 Mine-water pollution Solutions sought for SA AMD ‘hot spots’
The pollution of South Africa’s scarce water resources through mining is arguably one of the greatest challenges facing the country. While South Africa is considered a global leader in mine-water treatment technology the magnitude of the problem threatens to engulf progress made to date. Lani van Vuuren attended the Water Institute of Southern Africa’s recent Mine-water Conference where present challenges and possible solutions were discussed.
cid mine drainage (AMD) is More than 120 years of formal mining mine rehabilitation. Thousands of not unique to South Africa. In has left its mark on the South African mining operations have been left Afact, it is a truly international landscape. The country is reported unrehabilitated and ownerless as problem faced by all the major min- to have an estimated 10 000 km2 of dwindling resources and changing ing countries, with some arguing hydraulically interlinked coal mines in markets forced their closure. that it is perhaps the industry’s most Mpumalanga alone, with about significant environmental legacy. The 300 km of interlinked gold mines on The Department of Minerals & Ener- problem with South Africa is that the the Witwatersrand. Many of these gy’s abandoned mines database has country does not have much water to mines were operated at a time when recorded more than 4 770 derelict begin with, thus any pollution could legislation was not cognisant of and ownerless mines across the have serious future consequences. environmental management and country. This excludes abandoned
The Water Wheel January/February 2007 Mine-water pollution 31
sand quarries and other small opera- technologies for the management Investigations of the hydrochemistry tions, which brings the number to and treatment of polluted mine-water. of the surface water of the Tweelopies about 8 000. These mines have now Several areas were highlighted at the through the Krugersdorp Nature become the legacy of the State, and mine-water conference. Reserve has confirmed that the water will take years, even decades, to fully quality has deteriorated to such an rehabilitate. Meanwhile, all of these “The country is reported extent that it is unfit for human and mines threaten the air, soil and water, animal consumption. In fact, the river and thus the health of the communi- to have an estimated is now considered a Class V river with ties, around them. 10 000 km2 of hydrau- a “very high acute hazard.”
WINDS OF CHANGE lically interlinked coal Downstream communities have little mines in Mpumalanga to no access to piped water, and are Recent international trends have thus very vulnerable. These include started to bring about change. As alone.” the Sterkfontein informal settlement Dave Salmon of Anglo American’s and Krugersdorp Brickworks hostel Civil & Environmental Engineering Delegates heard how radioactive dwellers. The Tweelopies further Department pointed out: “There is and acid mine-water is threatening flows through a camp site used by increasing recognition globally, and the health and well-being of com- church and youth groups. It has been at all levels of society, that manage- munities and wildlife in the Western reported that groundwater quality in ment of water resources is essential Witwatersrand Basin. Mine-water the area is also deteriorating. to everything in life, such as food, decanting from the 44 926 778 km3 energy, transportation, nature, leisure, mined-out void has flowed into the Of concern is the fact that the culture, enhancing living standards headwaters of the Tweelopiespruit, Tweelopiesspruit flows through the and ecosystems health. Mining can- which flows through the Krugersdorp Cradle of Humankind. Contaminated not afford to ignore this trend. ” Game Reserve. While some of the water, especially water with a low water is treated by Randfontein pH, could affect the natural water There has been some international Estates, on whose property the resource base of several sections collaboration in efforts to stem the decant is taking place, suggestions of this World Heritage Site, which problem of AMD through, for exam- are that contaminated water is still includes the Sterkfontein Caves. A ple, the International Network on entering the river. working group has been established Acid Prevention (INAP). This is an organisation of international mining companies dedicated to reducing the liabilities associated with sul- phide mine minerals. Member companies have agreed to freely share information on issues of common concern. The network is supplemented with a Global Alli- ance of key research organisations (including South Africa’s Water Research Commission), which are actively developing management and treatment options for AMD. Present INAP initiatives include the development of a global guide to the management of AMD.
AMD ‘HOT SPOTS’
Meanwhile there are several AMD ‘hot spots’ in South Africa which require Courtesy: SA Tourism urgent intervention to prevent total ecological disaster. These hot spots The future of the Sterkfontein Caves, a World Heritage Site, could be in the have largely driven research into new balance if decanting mine-water on the West Rand is not brought under control.
The Water Wheel January/February 2007 32 Mine-water pollution
probable future scenario would be the establishment of a soften- ing/membrane desalination plant to treat the Margaret shaft water before blending it with Midvaal water for distribution to municipal, industrial and mining water users.
An independent Section 21 (not-for- gain) company will most likely be established to manage the water from Margaret Shaft. The new com- pany will be responsible for the operation of the shaft and the opera- tion of all pumping equipment at the shaft to transfer all fissure water to surface on a daily basis. Each of the mining companies have agreed Pollution due to mining remains one of the greatest threats to South Africa’s to provide one-third of the start-up water resources. capital required on loan account to the new water company. It is to investigate possible solutions. It writing, Chemwes Limited, which is expected that the proposed water comprises Harmony Gold (which reworking some of the old Stilfontein company will operate for the next owns Randfontein Estates); Depart- tailings dams, was using 18 Mℓ/day 18 years or so while the existing ment of Water Affairs & Forestry; from Margaret Shaft; while another mines remain in operation. Department of Minerals & Energy; substantial amount was being con- Department of Agriculture; Council veyed to Buffelsfontein Gold Mine for for Geoscience; independent consult- general potable and process use. A SOUTH AFRICAN FIRST ants, Mogale City and the Gauteng small fraction of the water is stored In Mpumalanga, excess water from Department of Agriculture, Conserva- and chlorinated before distribution to more than a century of coal-mining tion and Environment. a number of farmlands in the area. has led to the first initiative in South COLLECTIVE ACTION Africa where treated mine-water will “Downstream communities be sold to a local municipality. A In the Klerksdorp-Orkney-Stilfontein- have little to no access to R300-million joint initiative between Anglo Coal and Ingwe Collieries will Hartbeestfontein (KOSH) area, piped water, and are thus Simmer and Jack, Harmony Gold and see the neustralisation and treat- AngloGold together with the Midvaal very vulnerable.” ment of 20 Mℓ/day of AMD from three Water Company are collaborating collieries using mainly membrane to formulate a long-term water strat- The remainder of the water is technology for sale to the Emalahleni egy to deal with AMD in the area. released into the Koekemoer Spruit, Local Municipality (Witbank) – for The underground mine systems of a tributary of the Middle Vaal River. It more details about the process, see these gold-mining companies are all has been reported that the deteriorat- the May/June 2006 issue of the Water interconnected, and they all rely on ing water quality from the Koekemoer Wheel. responsible and collective mine-water Spruit is impacting on the treatability management to sustain their indivi- of the water from the Midvaal. According to Anglo Coal senior dual operations. project manager Peter Günther, the A study was undertaken last year to treatment plant was fast nearing Most water is pumped out at Mar- assess a number of different mine- completion, with commissioning garet Shaft, located on Stilfontein water scenarios, and to establish expected by March. Meanwhile, a Gold Mine. While the mine itself is the amount of available water for similar project has been initiated in no longer in use, about 37 Mℓ/day is reclamation and reuse from Margaret the Steve Tshwete municipal district pumped to the surface to allow sur- Shaft. Dr Ralph Heath from Golder (Middelburg), and initial studies into rounding mines to continue to oper- Associates, the firm responsible for the best process to treat mine-water ate deep underground. At the time of the study, indicated that the most from those coal mines have begun.
The Water Wheel January/February 2007 WATSAVE Award 33
SA Irrigation Innovation Scoops International Award
he developer of a uniquely “This water management system is a is almost 28% of the irrigated area South African water admin- prime example of taking the innova- of South Africa serviced by water Tistration system, which has tion process through the full cycle user associations (formerly govern- increased the productivity of water – from research to practical applica- ment water schemes and irrigation use in irrigation agriculture, has won tion to exploitation of its commercial boards). This includes about 9 500 a sought-after international accolade. potential,” comments Dr Gerhard abstraction points. In some schemes, Backeberg, Director: Water Utilisation WAS has been operational for the last Dr Nico Benadé was awarded the in Agriculture at the WRC, and Chair of 15 years, with great effect. International Commission on Irriga- SANCID, who nominated Dr Benadé tion and Drainage’s (ICID’s) Innova- for the award. “The gratification Field measurements have shown that tive Water Management Award for the associated with the ICID Award is the losses at these schemes have been Water Administration System (WAS) international recognition of an innova- reduced by 10% to 20% through at a ceremony held in Kuala Lumpur, tion which is truly South African.” improved water releases in canals in Malaysia in September 2006. This and rivers. With an average water is the first time a professional repre- The system can be implemented allocation of 8 147 m3 per hectare sented by the South African National at various levels from a small water and estimated losses of 20%, this Committee on Irrigation and Drainage office that manages a few abstrac- translates to an average water (SANCID) has scooped the award in tions and measuring stations up saving of between 23 to 46 million m3 this category. to a catchment management level of water per year. with thousands of abstraction points To provide irrigation schemes with and measuring stations. Among its Training is offered to all end-users of decision support for efficient water capabilities, WAS calculates water the program, and Benadé has set up management, the WAS was developed releases from rivers and canal net- a private company to provide ser- with funding from the Water Research works, taking lag times and various vices support. “Feedback from WAS Commission (WRC). WAS is a deci- water losses into account. users at training courses indicates sion-support program for use by water that after converting, it is considered user associations on irrigation schemes Largely as a result of Dr Benadé’s impossible to manage irrigation in managing their water accounts and efforts, the WAS is now being imple- schemes without the use of the WAS their water supply to clients through mented on irrigation schemes with program,” he concludes. rivers, canal networks and pipelines. a total area of 142 843 ha, which
TABLE 1: Irrigation schemes where the WAS program is used Irrigation scheme Area Quota Full quota Abstraction Years (ha) allocation (m3) points in (m3/ha) use Impala WUA 17 012 10 000 170 120 000 423 10 Gamtoos Irrigation Board 7 408 6 000 44 448 000 808 3 Groenland Irrigation Board 5 864 6 000 35 184 000 146 6 Hartbeespoort Irrigation Board 13 915 6 200 86 273 000 1 721 9 Hereford Irrigation Board 3 425 7 700 26 372 500 53 3 Korentte Vetterivier Irrigation Board 852 7 000 5 964 000 121 4 Lower Olifants River WUA 9 212 12 200 112 386 400 1 415 10 Loskop Irrigation Board 16 135 7 700 124 239 500 794 15 Groot Marico Government Water Scheme 2 523 5 300 13 371 900 309 5 Mooirivier Government Water Scheme 4 954 7 700 38 145 800 603 12 Orange/Riet WUA 15 941 11 000 175 351 000 679 6 WatSave Award winner Dr Nico Benadé and Sandvet Government Water Scheme 10 542 1 080 11 385 360 616 10 WRC Director: Water Utilisation in Agriculture Vaalhartz WUA 35 060 9 140 320 448 400 1 873 12 Dr Gerhard Backeberg.
The Water Wheel January/February 2007 34 Estuaries Courtesy of SA Tourism
KwaZulu-Natal Wildlife has embarked on a catchment-wide conservation approach to safeguard biodiversity from source to sea. Lani van Vuuren reports.
waZulu-Natal’s conservation Specific challenges threatening As Dr Peter Goodman, Coordinator approach starts with its estua- the health of the province’s estuar- of Biodiversity Research at KwaZulu- Kries, many of which are of ies include siltation due mainly to Natal Wildlife, points out, there is national and even international impor- inappropriate agricultural practices probably not a single estuary in the tance. By far the greatest amount in the catchments and flow reduction province that has not been affected of estuarine habitat is found along as a result of increased upstream by upstream activities in some way. the northern coast of the country, water demand. Urban encroachment, Even the well protected St Lucia has where the largest number of estuary- particularly developments around experienced a reduction in freshwater dependent species in South Africa is estuary mouths, industrial pollution inputs compromising its function as to be found. The nursery areas along and uncontrolled exploitation of living a nursery habitat. These challenges this part of the coast support inshore resources also threaten the biodiver- confirm that managing the estuaries marine biodiversity and fisheries, sity of KwaZulu-Natal’s estuaries. in isolation is not an option. including crustacean fisheries such as those of the Thukela banks. According to an assessment of South LOOKING UPSTREAM African estuaries undertaken under Just over half of the country’s estua- the leadership of the South African Beneficial to this catchment-wide rine area is made up by the St Lucia National Biodiversity Institute estua- approach is the fact that due to Kwa- estuary alone (over 38 000 ha). A ries along the intensely developed Zulu-Natal’s boundaries, almost all of Ramsar World Heritage Site, St Lucia areas of KwaZulu-Natal’s coastline the catchments fall entirely within the forms a critical habitat for a great are most threatened. Estuaries fed provincial boundary. This reduces the number of species, including the by larger catchments tend to be in need for cross-boundary collaboration, largest, southern-most population of poorer health than the estuaries in and allows for more specific focus on hippos, and at least 1 000 crocodiles. adjacent smaller catchments. the biodiversity needs of the province.
The Water Wheel January/February 2007 Estuaries 35
Of course, this does not mean that These freshwater systems can either feeding Lake St Lucia, for example, KZN Wildlife works in isolation. As be located in primary catchments or is one such a potential heritage river. trainee aquatic ecologist Mncedi smaller subcatchments that feed the Keeping this river free from future Nkosi points out: “In this planning strategic estuaries. Of course, protec- impoundments could go a long way process you deal with many stake- tion does not imply exclusion, and in protecting the estuary.” Another holders, from other government limited human activities which do not potential heritage river is the 160 km- institutions such as the department affect the ecological state of the river long Mtamvuna River which forms the of Water Affairs & Forestry and Agri- or wetland, such as regulated fishing, KwaZulu-Natal/Eastern Cape border. culture, to municipality and tribal and small-scale agriculture will still be community representatives.” allowed. Linked to aquatic biodiversity targets are terrestrial or vegetation targets. Conserving biodiversity starts with the Investigations into the state of Kwa- “Freshwater and land systems can- estuaries. Of the more than 70 estua- Zulu-Natal rivers’ ecological health not be separated, and thus within ries in KwaZulu-Natal, 25 have been continue. KZN Wildlife contract our already identified primary or identified to date as being of strategic aquatic ecologist Nick Rivers-Moore sub-catchments we will also identify importance. The estuaries are selected reports that the task is made difficult where we can achieve most of our mainly on their biodiversity attributes. by the lack of historical data. “We do terrestrial biodiversity targets,” notes This includes the number of aquatic not know what constituted a pristine Dr Goodman. species to be found in the estuary, river a hundred years ago. A river the number of rare species, the actual we may regard as being in a natural The fourth component looks at the estuary type as well as goods and state might not actually be so.” Data province’s primary water produc- services provided by the estuary. on invertebrate biodiversity also tion areas, these are the headwater remain sketchy. catchments which deliver the most “In the end we aim to conserve a rep- freshwater during the high rainfall resentative sample of all our different Dr Goodman and his team are also months (November to March). It types of estuaries,” explains exploring the concept of preserving is crucial that the integrity of these Dr Goodman. There is no point in the last remaining natural free-flowing water production areas, such as the safeguarding all the estuaries along rivers in the province as ‘heritage Drakensberg escarpment, be con- the North Coast, but none at the rivers’. This is a relatively new con- served, not only for the ecosystems South Coast, for example. The objec- cept taking off internationally aimed lower in the catchment, but also for tive is to protect the biodiversity of at protecting rivers that have signifi- other uses (agriculture, industrial, and these estuaries against potential cant recreation, nature conservation domestic consumption). pollution, streamflow reduction scenic or cultural heritage attributes activities, and overutilisation. from future impoundment. “The By incorporating all of these elements Mkhuze River, the largest river the strategically important catch- Apart from St Lucia, other priority ments for the protection of biodiver- estuaries include Kosi Bay (also a sity (both terrestrial and aquatic) can Ramsar site); Mhlatuze (one of South be identified. This provides for a more Africa’s largest mangrove estuarine focused approach to conservation. habitats); Mgobezeleni (situated at Sodwana Bay it is the only estuary THE TIME IS NOW between St Lucia and Kosi Bay); Mtamvuna; and Mzimkulu. Dr Goodman notes that there is no better time for the implementation RIVERS, WETLANDS AND of such a conservation plan than LANDSCAPES now. “With the extent of degrada- tion of the province’s terrestrial and The second step in this process looks freshwater ecosystems we might at rivers and wetlands which are already struggle to find enough crucial to the functioning of the priority areas to protect in order to meet our estuaries and need to be preserved. biodiversity targets. Tomorrow might The idea is to identify rivers and be too late.” wetlands which still have a healthy Courtesy of SA Tourism ecology and to include these in the More than a 1 000 crocodiles call The final conservation plan is overall biodiversity conservation plan. St Lucia home. expected to be completed by March.
The Water Wheel January/February 2007 The Power of Water
Ever switch on power it has, this is usually depend- a light and ent on the size of the dam); and THE BASIC wonder the amount of water falling (more COMPONENTS OF where the water falling through the turbine will A CONVENTIONAL electricity produce more power, the amount HYDROPOWER UNIT came of water available depends on the from? amount of water flowing in the river). Dam: Most hydropower plants rely It might on a dam that holds back water, have While hydropower stations are con- creating a large reservoir. just been sidered more environment-friendly Intake: Gates on the dam open generated than coal-fired stations, there is some and gravity pulls the water through by the power debate whether they should really the penstock, a pipeline that leads of water. be actively pursued. This is because to the turbine. Water builds up pres- most hydropower stations involve the sure as it flows through this pipe. Water can be used construction of a dam, which can be Turbine: The water strikes and in two ways to disruptive to the surrounding environ- turns the large blades of a turbine, generate electricity. ment and to communities who might which is attached to a generator Conventional hydro- be displaced. above it by way of a shaft. electric stations Generators: As the turbine blades capture the energy of Because of its limited water turn, so do a series of magnets falling water to gener- resources and erratic rainfall, South inside the generator. Giant magnets ate electricity. A turbine Africa does not have much poten- rotate past copper coils, producing converts the kinetic tial for large hydropower stations. alternating current (AC) by moving energy of falling water Whereas, worldwide, about 20% electrons. (usually from a dam) of all electricity is generated by Transformer: The transformer into mechanical energy. hydropower, in South Africa it varies inside the powerhouse takes the Then a generator converts between 2% and 4%. The country’s AC and converts it to higher-voltage the mechanical energy from the largest power producer, Eskom, current. turbine into electrical energy. The operates six hydropower schemes at Outflow: Used water is carried electricity generated is fed on to the present. through pipelines, called tailraces, transmission lines that link up with the and re-enters the river downstream. national electricity grid. Once the water There are two hydropower stations has run through the turbines it is dis- on the Orange River. The Gariep Source: www.howstuffworks.com charged back into the river below the power station to continue its course.
On the other hand, pumped storage schemes reuse water to generate power. The schemes use off-peak energy to pump water into an elevated dam from a lower dam from which it can be released to generate electric- ity when required. When the energy is needed, the water is released from the top dam to flow through the power station to the bottom dam.
The amount of electricity a hydro- power plant produces depends mainly on how far the water falls (i.e. The Steenbras Dam forms part of the Palmiet Pumped Storage Scheme, the further the water falls, the more in the Western Cape.
The Water Wheel January/February 2007 (formerly known as Hendrik Verwoerd) hydropower station started feeding into Eskom’s transmission system in 1971. Vanderkloof, a similar hydro- power station, was commissioned in 1977.
Eskom also operates four smaller hydropower stations, namely Colley Wobbles (Mbashe River), First Falls and Second Falls (Umtata River), and Ncora (Ncora River). The Eastern Cape (particularly the area of the former Transkei) and parts of KwaZulu-Natal have been identified as having the most potential for the The Gariep Dam is also used for hydropower. future development of hydropower in South Africa. There are also a number of independ- HYDROELECTRIC FIRSTS ently-operated hydropower stations in IN SOUTH AFRICA In addition, there are two pumped South Africa, for example, the 2,5 MW storage schemes at present. The Friedenheim mini-hydropower plant • The first hydropower plant on the Drakensberg Pumped Storage situated on the Crocodile River, near Orange River was constructed Scheme not only supplies the country Nelspruit, Mpumalanga. This plant near Kakamas, in the Northern with 1 000 MW of electricity during has been operational since 1998 to Cape. peak periods, it also assists in sup- provide power for the Friedenheim • The Sabie River Gorge power plementing the Vaal Dam with water Irrigation Board while excess power is station was the first hydropower transferred from the Tugela River in sold to Mbombela Municipality. station to be erected by Eskom. KwaZulu-Natal. Completed in 1988, It started commercial operations the 400 MW Palmiet Pumped Storage The Bethlehem Hydropower Project in 1927, and was built mainly to Scheme is situated about 50 km from is currently under construction. The support mines in the area. The Cape Town. This scheme is also used project comprises two generation plant closed in 1964. to pump water from the Palmiet River facilities: a 2,2 MW run-of-river site • The hydroelectric power station catchment into the Steenbras Dam located on the As River, midway at the Vanderkloof Dam was the to supplement Cape Town’s water between Bethlehem and Clarens; first power station in South Africa supply. At present, Eskom is also and a 1,7 MW facility at the exist- situated entirely underground. developing a third pumped storage ing concrete wall of the Saulspoort • The Friedenheim Hydro Power scheme at Braamhoek, in the Klein Dam, in Bethlehem. The first elec- plant is recognised as the first Drakensberg (for more details, see tricity is expected to be delivered independent power producer in the article elsewhere in this issue). later this year. South Africa. HYDRO-ELECTRIC WEBSITES TABLE 1 Eskom’s hydropower & pumped storage schemes • http://www.dme.gov.za/energy/ Hydroelectric Stations Area Total Capacity renew_hydro.stm Colley Wobbles Mbashe River 42 MW • http://assets.panda.org/down- First Falls Umtata River 6 MW loads/africahydropowerre- Gariep Orange River 360 MW port2006.pdf Ncora Ncora River 2 MW • www.eskom.co.za Second Falls Umtata 11 MW • http://mp2mas26.eskom.co.za/ Vanderkloof Orange River 240 MW heritage/main.htm Pumped Storage • http://people.howstuffworks. Drakensberg Bergville, KZN 1 000 MW com/hydropower-plant.htm Palmiet Grabouw, Western Cape 400 MW Source: Eskom
The Water Wheel January/February 2007 38 The last word
Excellent Research Rewarded
he Excellence in Research Awards are held biennially in Honour of Dr Gerrie Stander, the first Executive Direc- tor of the Water Research Commission (WRC), who was recognised internationally for his contributions to water Tresearch. Hosted by the Water Institute of Southern Africa (WISA), the evening allows three young researchers to share the stage with an experienced water sector professional. This year, the memorial lecture was presented by Prof Peter Rose, Director of the Environmental Biotechnology Research Unit at Rhodes University on South Africa’s contribu- tion to the remediation and treatment of polluted mine-water. Also presenting their research were Dr Jonathan Taylor of North West University, Jennifer Molwantwa of Golder Associates and Scott Sinclair of the University of KwaZulu-Natal.
Deon Nel of Biwater SA, WISA CEO Above: Dr Jonathan Wallace Mayne and Koetoe Botha, Taylor, Prof Peter husband of WISA president
Rose, Jennifer Dr Marlene van der Merwe-Botha. Molwantwa, Scott Sinclair and Master of Ceremonies, Prof Left: Dr Renias Dube, Jay Bhagwan, Fred Otieno. Dr Shafick Adams and Dr Kevin Pietersen, all of the WRC.
Jennifer Molwantwa, Tebogo Sehlabelo of Golder Liezl and Dr Marius Claassen of CSIR, and Dr Ralph Associates, Laetitia Coetser of SRK Consulting, Tracy Heath of Golder Associates. Heath, wife of Dr Ralph Heath of Golder Associates, and Siyanda Ngebulana of Biwater SA.
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