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DRY the beloved country

Written by  Schalk van der Merwe
| in Landbou
| July 7, 2015

Sensitised by Eskom, many South Africans are realising that basic resources are indeed finite, at least as far as supply is concerned.

Our energy crisis has also made us realise the importance of long-term supply planning, including the timeous development of new sources and infrastructure to keep pace with growth of the population and economy. And it has given us a bounty of candlelit hours in which to contemplate matters.  

With the poor rainfall season last summer in large parts of the country, drought in parts of Limpopo and KwaZulu-Natal, the late onset of winter rains and dam levels 37% lower than last year this June in the Western Cape, many have started to wonder about water. Could chronic water shortages and semi-predictable rationing be next in store for the country?

Energy is one thing, but fresh water is arguably an even more fundamental resource. Water is the basis of all life on the planet, and access to fresh water a key prerequisite to maintaining human health and dignity, sustaining and growing our economy, and feeding our population. Not to mention that much of the rest of the living world – our habitat - also requires its share of fresh water to survive.

“Energy is one thing, but fresh water is arguably an even more fundamental resource.”

While a simple energy-water comparison is incongruous for a number of reasons, the basic question whether we are sufficiently prepared to meet the future fresh water needs of our growing population, increasing urbanisation and desired economic growth in coming years, is extremely valid. For unlike energy, fresh water is for all practical purposes finite, and without substitute. Energy sustains culture, but water sustains life. Without water, a healthy human adult can survive up to an agonising one week. All our land-based food production systems require water in some form or another. Our economies run as much on water as oil. Our cities stand or fall by water.

Not surprisingly, water is identified as a key driver and game changer in many provincial and national-level development planning frameworks. These include the National Development Plan (NDP), which provides our overall national economic development framework up to 2030. A number of key NDP strategies aimed at meeting socio-economic developmental goals hinge on access to more water. These include extending the 1.6 million ha under irrigation by 33%, and generating 40 gigawatt (GW) more energy, mainly from water use-intensive thermal plants. In addition, the NDP sets the target of universal access to clean running water for all South Africans by 2030.

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Whether the weather

At the same time, government planning frameworks acknowledge the wild card of climate change – and that, as generally hotter, drier conditions are predicted for much of the country, the prognosis for our water future is not good. 98% of currently available surface water sources have already been allocated. We are already trapping more than two thirds of our rainfall in dams, and many of our river systems are in trouble. Of our 223 river ecosystems, 60% are currently classified as threatened, 25% of which critically endangered. Our 792 wetland ecosystems are in an even worse state. The media has reported extensively on the threats of acid mine drainage into the Vaal/Orange and other systems. Groundwater is the key rallying point for those hot under the collar about fracking in the Karoo.

It seems that just hanging on to the supplies we have may become a challenge, not to mention meeting future developmental needs. Does government have a plan to see us into the future? Is it being implemented, and is it feasible?

The short answer is yes, we do have a plan, the National Water Resource Strategy (NWRS). The NWRS is currently in its second iteration (NWRS2), and is up for revision in 2018. The NWRS2 covers the planning period up to 2035, and identifies measures and targets to align future supply with demand.

Unlike energy, our water supply is decentralised, mainly organised by grouped river catchment areas, associated dams, and a few inter-catchment transfer schemes. We currently have nine Water Management Areas, each entrusted with the task of implementing water reconciliation strategies for its area, including the phased development of new sources. Water from Lesotho plays a major part in meeting Gauteng’s water needs, and Phase 2 of the Lesotho Highlands project is currently underway. The Clanwilliam dam’s wall is in the process of being raised, and an extension of the Voëlvlei dam is to increase Cape Town’s water supply by storing surplus winter water from the Berg River dam.

However, the key findings of a recent re-
port by the Institute of Security Studies (ISS) indicate that the country may already be operating at more than a km3 water deficit, and that, unless more stringent policies are implemented than those provided for in the NWRS2, this may increase to 3.23 km3 by 2035. Specifically, the ISS study indicates that more stringent water demand management and water use efficiency measures would be needed to see us into the future.

Dry, the beloved country

As a country, we have the 30th lowest average rainfall among the world’s 192 nations. Our average annual rainfall of 495mm per annum is less than half of the world average by country (1 033 mm/a). Much of this is unevenly distributed, with much of the western part of the country classifying as arid (<250 mm/a) or hyper-arid (<100 mm/a). To make matters worse, we have very high evaporation rates – up to three times higher than our rainfall. Of the 49 km3 rainfall we receive on average, only 10.24 km3 is actually reliably available for use. We have an estimated 5.5 km3 ground water, but much of it is locked deep away and expensive to tap. Currently we withdraw around
2 km3/a.

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Yet we are some of the most spendthrift nations when it comes to fresh water. The average South African uses 235 litres of water per day – well above the world average of 177 l/d. We are also very inefficient users of water - as much as 35-40% of our agricultural irrigation water and up to 37% of municipal water is lost, mainly from leaking infrastructure. While this is on par with global averages, it compares poorly with performance rates achieved by other water-stressed countries such as Australia (10%).

According to ISS modelling, annual national supply is currently at 14.6 km3, 79% of which from surface sources such as rivers and dams, 14% from groundwater and 7% from reuse. Approximately 2.1 km3 treated waste water is produced each year, some of which has direct re-use applications. Desalination makes a locally valuable, but nationally very minor contribution (0.025 km3).
 
At the same time, ISS modelling indicates that South Africa is currently already at a system deficit, withdrawing 15.6 km3/a. In terms of use by sector, agriculture is the largest user at 57%, or 8.9 km3, followed by municipal use at 35%, and industrial use at 8% - approximately 2% of which is devoted to energy generation. The brunt of over-extraction is borne by our river systems. Groundwater reserves are locally over-exploited in some places.

While this deficit has been masked by an extended period of above average rainfall, a return to average or below average conditions is likely to make this deficit very manifest. We know that South Africa’s rainfall patterns are significantly influenced by medium-term global climatic events like the still somewhat unpredictable El Niño/La Niña Pacific oscillation cycles. After more than a decade of relatively good rainfall, we are likely approaching a dry phase.

Supplies, surprise

The NWRS2 includes a number of strategies to increase our water supply to 2035. New surface dams, mainly Phase 2 of the Lesotho Highlands project currently in progress, are envisaged to generate an additional 1 km3/a. Hard treatment and recovery targets set for municipalities and industry are envisaged to add an additional 0.25 km3 of reusable water. An additional feasible 0.177 km3 of groundwater withdrawal is envisaged. Desalination is envisaged to make a small strategic contribution of 0.15 km3 in at least three Water Management Areas (WMAs). In total, the plan provides for increasing our supplies to 16.37 km3.

However, according to ISS modelling, likely growth and our socio-economic development goals are likely to result in a significant gap between supply and demand, as much as 3.5 km3 by 2030, and only slightly decreasing to 3.2 km3 by 2035.

The ISS study predicts that, taking into account the effects of increasing population growth and urbanisation, as well as the implications of the NDP, water demand is likely to increase to 19.9 km3/a by 2035. Municipal water demand is forecast to increase from 5.5 km3 in 2014 to 7.2 km3 by 2035, mainly as a result of increased urbanisation. Industrial water demand is set to increase from 1.2 km3 to over 3 km3 in 2030 and then to decrease to 2.8 km3 by 2035 as non-thermal energy plants start to make a difference.

To enable additional irrigation targets, agricultural demand is likely to increase from 8.9 km3 to 9.7 km3 – this despite the fact that the NWRS2 does not make provision for any increase in the current allocation of 8.9 km3 for the sector, and sets an even more ambitious target of a 50% increase in area under irrigation than the NDP’s 33%.

As the ISS report points out, its predicted total demand of 19.9 km3/a tallies well with the Water Resources Group’s estimate of 17.7 km3/a for 2030, as well as the 20 km3/a estimated by the Department of Water and Sanitation (DWS) for the same date.

How are we going to meet this supply challenge? Should we build more dams?

No dam solution

I have seen many an engineer and farmer bemoan the ‘senseless waste of water to the sea’. There are excellent reasons why some water should simply flow into the sea. Estuaries are the spawning grounds of the fish we eat. The wetland systems associated with healthy rivers provide crucial habitat to vast numbers of birds, and also serve to attenuate the effects of localised flooding and to filter the water for downstream users. Fresh water keeps the fabric of our habitat together. For these reasons, and in line with international best practice, our National Water Act makes provision for an environmental reserve for all rivers. There are also other practical considerations.

Besides the fact that we have very few remaining suitable dam building sites and untapped catchments, surface dams are also not the most efficient way of storing water, at any rate not with our evaporation rates. Sil-
tation in many of our dams further means that the surface-to-volume ratio is even greater, leading to even less efficient storage. Looking ahead, the ISS predicts that a paradigm shift away from surface systems towards natural and artificial aquifer storage may become inevitable in the long term.

With 97% of the planet’s water in its oceans, desalination may seem to hold the key to a virtually unlimited fresh water supply. The reality is that desalination is a very energy intensive and thus costly process, and at the volumes required, only feasible for oil-rich areas like the Middle East, or some isolated towns. The process also produces concentrated brine waste, which may pose a risk to marine and land environments. Even if ways are found to increase energy efficiency, the distances from coastal to inland areas would require very expensive pipeline infrastructure. In South Africa, settlements like Sedgefield and Bitterfontein (brackish water) largely run on desalination. Durban is looking at a plant to supplement its potable supplies. However, the ISS estimates that, realistically speaking, the contribution provided by desalination could be grown by no more than 70% over that envisaged in the NWRS2.

Increasing supply from ground water sources holds more potential. However, the resource is poorly understood, variable in occurrence, and in many cases too deep to merit economic withdrawal. The ISS envisages that only an additional 1.43 km3 from groundwater sources could be feasibly developed by 2035.

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Altogether, the ISS predicts that by introducing more aggressive supply development policies, total supply could be extended by 1.43 km3 over and above provided for in the NWRS2, namely to 17.82 km3 by 2035. That would however still leave a shortfall of more than 2 km3 against the predicted 2035 demand of 19.9 km3/a.
Minding the gap

According to the ISS report, we have only two realistic options for addressing this critical shortfall. We need to be much more efficient with the use of the resource, and manage our demand. While the NWRS2 identifies strategies and sets targets aimed at increasing efficiency and lowering demand, the ISS study indicates that more aggressive policies and targets are required. According to the ISS, demand could feasibly be lowered to 17.74 km3 by 2035, thus ‘closing the gap’.

As indicated, we currently have huge system losses in our largest water use sectors, agriculture and municipalities, mainly as a result of leaking infrastructure. Ineffective metering and billing systems in many municipalities currently lead to huge wastage, as consumers place no value on this artificially ‘free’ water. Compared to many water-stressed countries, our water is also cheap.

Leaking irrigation canals in our irrigation schemes are a major problem, but would be extremely costly to solve. Municipal infrastructure holds greater potential. Thus, the City of Cape Town has managed to cut its demand significantly by an aggressive policy of fixing leaks and reducing system losses.

But ultimately much boils down to you and me, the consumer. As indicated, as a nation we are prolific users of water. Just reducing our average water use to global levels would already reduce the ‘gap’ by half. While more efficient billing and metering would go a long way in changing consumer behaviour, a more fundamental shift is required.

The vagaries of Eskom supply and ongoing energy cost hikes have sensitised us to the finite nature and value of the energy resource. Many are contemplating off-grid solutions. We need to rethink water in the same way, now while there is still time. Water wise gardening, fixing leaks at home, using gray water, harvesting rainwater, reconsidering having a pool – it is really ultimately up to us whether we will make it or not. The supply side of the equation is pretty finite. 


SOURCES

Department of Water and Sanitation (2015). About 88% of South Africans have access to water and 78% have access to sanitation-Minister Mokonyane. DWS media statement, 25 May 2015.

Department of Water and Sanitation (2015). UN warns of 2050 deadline for dwind-ling water supplies. DWS Internet article. 16 April 2015.

Department of Water and Sanitation (2015). There is no substitute for Water. DWS Internet article, 10 March 2015.

Department of Water and Sanitation (2015). Minister Mokonyane to engage West Coast Community on Raising of Clanwilliam Dam Water Project. DWS Press Release, 12 February 2015.

Department of Water and Sanitation (2015). Government Plans are in Place towards water security. DWS Internet article, 27 January 2015.

Department of Water Affairs (2013). National Water Resource Strategy 2.

FAO (2015). Towards a Water and Food Secure Future. Critical Perspectives for Policy-makers. FAO, Rome, and World Water Council, Marseilles.
 
Institute for Security Studies; Fredrick S Pardee Centre for International Futures, University of Denver, Colorado (2014). Parched Prospects – The emerging water crisis in South Africa. African Future Papers 11, September 2014.

UNESCO (2015). Water for a Sustainable World. The United Nations World Water Development Report 2015. UNESCO, Paris.

Western Cape Department of Environmental Affairs and Development Planning (2012). Western Cape Sustainable Water Use Plan 2012.

Western Cape Department of the Premier (2014). Western Cape Provincial Strategic Plan 2014-2019.

https://www.dwa.gov.za/Projects/RS_WC_WSS/ (Reconciliation strategy for the Western Cape Water Supply System).

https://www.dwa.gov.za/Hydrology/Weekly/Province.aspx (State of Dams)

www.weathersa.co.za/learning/climate-questions/36-what-kind-of-droughts-does-south-africa-experience?recache=1 (SA Weather Service - Drought statistics 1960-2004).