Australia is not the only country in the world whose economy and environment are threatened by water shortages, as currently experienced in the Murray–Darling Basin.
It is very likely that current water shortages are the result of climate change and give us a window into the future, when water scarcity and resulting food insecurity will be the norm for many countries unless we act now to overcome them.
This year, the world – in particular developing countries and the poor – has been hit by both food and energy crises. As a consequence, prices for many staple foods have risen by up to 100 per cent. When we examine the causes of the food crisis, a growing population, changes in trade patterns, urbanisation, dietary changes, biofuel production, and climate change and regional droughts are all responsible. Thus we have a classic increase in prices due to high demand and low supply.
However, few commentators specifically mention the declining availability of water that is needed to grow irrigated and rainfed crops. According to some, the often-mooted solution to the food crisis lies in plant breeding that produces the ultimate high-yielding, low-water-consuming crops. While this solution is important, it will fail unless attention is paid to where the water for all food, fibre and energy crops is going to come from.
A few years ago, the International Water Management Institute (IWMI) demonstrated that many countries face severe water scarcity, either as a result of a lack of available fresh water, or due to a lack of investment in water infrastructure, such as dams and reservoirs. What makes matters worse is that this scarcity predominantly affects developing countries where the majority of the world’s under-nourished people – approximately 840 million – live.
The causes of water scarcity are essentially identical to those of the food crisis. There are serious and extremely worrying factors that indicate water supplies are steadily being used up. Essentially every calorie of food requires a litre of water to produce it; thus, those of us on Western diets use about 2500 to 3000 litres a day. A further 2.5 billion people by 2030 will mean that we have to find more than 2000 additional cubic kilometres a year of fresh water to feed them. This is not any easy task given that current water usage for food production is 7500km3 and supplies are scarce.
According to Water for Food, Water for Life – a recent study carried out by the Comprehensive Assessment of Water Management in Agriculture that drew on the work of 700 scientists – unless we change the way we use water and increase ‘water productivity’ (more crop per drop) we will not have enough water to feed the world’s growing population. This population is estimated to increase from six billion now to about 8.5 billion in 25 years.
Compared with the lengthy agenda to combat climate change, this is a very short time indeed and yet the impacts of water scarcity will be profound. However, very little is being done about it in most countries.
Since the formulation of the UN Millennium Goals in 2002, much of the water agenda has been focused around the provision of drinking water and sanitation. This water comes from the same sources as agricultural water and as we urbanise and improve living standards there will be increasing competition for drinking water from domestic and other urban users, putting agriculture under further pressure. While improving drinking water and sanitation is vital with respect to health and living standards, we cannot afford to neglect the provision and improved productivity of water for agriculture.
There are potential solutions.
Better water storage has to be considered. Ethiopia, which is typical of many sub-Saharan African countries, has a water storage capacity of 38 cubic metres per person. Australia has almost 5000m3 per person, an amount that in the face of current climate change impacts may be inadequate.
While there will be a need for new large and medium-sized dams to deal with this critical lack of storage in Africa, other simpler solutions are also part of the equation. These include the construction of small reservoirs, sustainable use of groundwater systems, including artificial groundwater recharge, and rainwater harvesting for smallholder vegetable gardens. Improved year-round access to water will help farmers maintain their own food security using simple supplementary irrigation techniques.
The redesign of both the physical and institutional arrangements of some large and often dysfunctional irrigation schemes will also bring the required productivity increases. Safe, risk-free re-use of wastewater from growing cities will also be needed. Of course these actions need to be paralleled by development of drought-tolerant crops, and the provision of infrastructure and facilities to get fresh food to markets.
While Australia does not have all the solutions to water scarcity, many innovative approaches already adopted in Australian rural and urban areas provide examples of what may become best practice for other nations. Australia has already invested in considerable water-storage capacity to cope with drought. Further key examples are the current focus on improving water productivity in the Murray–Darling Basin and innovative new policies set to overcome past over-allocation of water via the recent moves to manage the basin’s water under one authority.
Additionally, successful urban water demand management practices, the development of water grids, safe re-use of wastewater and artificial recharge of groundwater are all at the international cutting edge.
Current estimates indicate that we will not have enough water to feed ourselves in 25 years’ time, by when the current food crisis may turn into a perpetual crisis.
Just as in other areas of agricultural research and development, investment in the provision and better management of water resources has declined steadily since the Green Revolution.
Along with my water science colleagues, I am raising a warning flag that significant investment in both R&D and water infrastructure development are needed, if dire consequences are to be avoided.
Dr Colin Chartres has 30 years’ experience in driving research and policy reform across the area of natural resource management, with a focus on water and soils both in Australia and overseas. He is Director General of the Sri Lanka-based International Water Management Institute (IWMI) and spent a considerable part of his career working on international development issues with organisations such as CSIRO and AusAid, the Australian Geological Survey Organisation and the Bureau of Rural Sciences. Prior to his IWMI appointment, he was Chief Science Adviser to Australia’s National Water Commission.
Editor's Note: Article originally posted on Australian Academy of Technological Sciences and Engineering here. The book Water for Food, Water for Life: A Comprehensive Assessment of Water Management is available in PDF form here.