Water wars: managing urbanization, agriculture and climate change

Water wars: managing urbanization, agriculture and climate change

March 09, 2018

Water wars: managing urbanization, agriculture and climate change

With massive urbanization and intensive agriculture, we witness greater and greater pressure on the supply of water, a precious resource that is threatened by climate change.

Cape Town, in South Africa, has been enduring restrictions in its water consumption (limited to 16 gallons per person per day, circa 50 liters to do everything: cooking, washing, cleaning, and flushing the toilet). This in spite of the fact that several measures to reduce water consumption have been introduced since 2012, resulting in a 25% reduction in water consumption. But that is not all: while the residents of one of the most modern and progressive towns in Africa buy special toilets that can 'dry process' waste, the authorities wonder about the risks to health and the environment resulting from a rationing that risks becoming a permanent feature. Next April 22 has been dubbed Day Zero: on that day, the region's water basin capacity will fall below the no return threshold of 13.5 per cent, and the town will be forced to close the taps completely. It is not accidental that the second of the 17 United Nations' Sustainable Development Goals aims to "Ensure access to water and sanitation for all”. 

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However, guaranteeing water security to the entire world population is a complex challenge, also because of  urbanization and climate change. According to UN reports, today over 2 billion people live in countries with a high level of water stress, which is defined as a ratio between water withdrawn and total renewable water resources below 25%. In North Africa and Western Asia the situation is even worse, with water stress reaching 60% and threatening severe water scarcity in the future. 

Everyone towards the city

Nearly 54% of the world population - 3.9 billion people - today lives in urban areas, and this percentage is expected to grow to levels ranging between 60% and 92% by the end of this century. 

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With the growth of urban population, the demand for water will also grow to satisfy the needs of city residents. "Domestic water use almost quadrupled over the last 60 years due to increasing population, wealth and access to drinking-water infrastructure", states an article from the Nature Sustainability magazine, which also reports that domestic water use is even higher in urban contexts, and that water demand will increase by 80% by 2050. Climate change will make this bad situation even worse, with 3.5-4.4 billion people estimated to live with water scarcity issues by 2050, because of climate change and increased water demand for human activities. 

New agriculture

Agriculture is undoubtedly one of the human activities that has the greatest impact on water consumption, as it accounts for nearly 70% of global water usage.

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As the Food Sustainability Index co-produced by BCFN and The Economist Intelligence Unit illustrates, in some countries local water consumption is much higher than its availability (in Egypt it reaches 114.9%, while in Saudi Arabia it reaches 867.9%, meaning that this country imports or produces, via techniques like sea water desalinization, nearly eight times the amount of water it has). This brings about a real conflict  between the water needs of urban areas and those of farming areas, which is particularly acute in Southern Asia. On the one hand, crop irrigation is a necessary condition to guarantee food security to a growing world population, and, on the other hand, many water security programs require a reduction of the share of water reserved to the farming sector. How can we deal with this trade off? "We need to aim for a more efficient use of water in agriculture" says the article quoted above, and there are several ways to achieve this: shifting from inefficient spray irrigation to drip irrigation, reducing water loss by improving water carrying infrastructure, changing crops and getting better information on when and how to irrigate. "Our research shows that a 10% improvement in irrigation efficiency translates into water savings that could help avoid future problems for 78% of cities that are vulnerable to water scarcity", the authors wrote.

A global issue

It would be wrong to think that water scarcity and water stress are a problem only for the poorest countries, where there is no infrastructure or ad hoc financing. Beside the emergency in Cape Town, this is also shown by the data of the 100 resilience cities project, promoted by the Rockefeller Foundation, which lists 26 cities where water security is already one of the significant issues. Among them, some definitely surprising cities, like Calgary and Montreal in Canada, and Bristol in rainy England. Certainly, climate change is a factor when it comes to water availability and water and food security, but on its own, it cannot explain this complex phenomenon. Efficient use of resources, sustainability in water use in agriculture and urban areas, or the impact of agriculture on water, are all relevant factors. These are also variables included in the Food Sustainability Index where the top country, France, shows virtuous behavior when it comes to water management. 


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