The Global Water Crisis: Our Inevitable Fate?

Global Water Use
Domestic Water Use
Industrial Water Use
Agricutural Water Use

How has global water use changed over the last 100 years?

Over the past decade global water use has been climbing steadily because of increased population growth. However, while the global population increased by about four times between 1900 and 2000, the global water usage saw a sixfold increase. Water is used in myriad of ways around the globe, but the three main sectors that all those uses fall into are the Agricultural, Industrial, and Domestic sectors.
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To understand how water use in developing countries differs from that in industrialized countries, it is important to look at each sector individually.
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How is Water Used in the Domestic Sector ?

Domestic water use is defined as the amount of water that is available to the populations that are residing in cities and towns. From the map one the left, we see that domestic water use is a very small percentage of global water use. Most countries, regardless of developmental status, are currently using only 0-30% of the freshwater supply for domestic purposes.
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However, the graph is somewhat misleading because it fails to take into account the total amount of available water for each country. For example, although the United States and Egypt both use <15% of their freshwater for domestic purposes. The US has a large water supple that Egypt, meaning that in reality the US actually uses more freshwater in the domestic sector than Egypt does.

In fact, the average person in an industrialized country uses 500-800 litres of water per day (300 cubic m per year), which is ten times more than the average person in a developing country, who only uses 60-150 litres per day (20 cubic m per year)¹. Furthermore, since the monetary price of water in developing and industrialized countries is very similar, water takes up a greater part of the incomes of people in developing countries because of the large disparity in income.

For more on domestic water use, please see: Residential Water Waste

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How is water used in the Industrial Sector?

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The Industrial sector is the second largest comsumer of water, making up about 20% of the global freshwater usage.¹ It is clear, from the above graph, that industrial water usage is primarily concentrated in industrialized countries. Most of the developing world, and even parts of the industrialized world use <16% of their freshwater for industry. The majority of this water is stored in dams and resevoirs in order to be later utilized for electrical power generation and irrigation.

57-69% of Industrial Sector water is used for power generation (hydro or nuclear power), 30-40% is used for industrial processes, and the remainder is used for the generation of thermal power.¹ However, just as irrigation is a big point of agricultural water loss because of evaporation, the storage of industrial water in resevoirs can also lead to excessive evaporative water loss. It has been determined that since the 1970s, more water is being lost due to resevoir evaporation than is acutally being consumed by both the industrial and domestic sectors combined. Therefore if we able to reduce water loss by implementing the use of covered resevoirs we would bee able to significantly improve the efficiency of industrial water usage.


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How is Water Used in the Agricultural Sector ?

The agricultural sector is the most dominant user of water, accounting for up to 70% of the world’s freshwater usage. Agricultural water use is especially heavy in the developing world, with some countries in Asia, Africa, and South America using more than 79% of their total freshwater supply for agricultural purposes. In fact, 85-90% of all the freshwater that is used in Africa and Asia is for agriculture.¹                                [click picture to enlarge]
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One extremely important conclusion arises from this finding. As the global water shortage worsens and global water resources are reduced, for developing countries, less water will mean less food. This will lead not only to people dying of water-borne diseases, but also to people dying from starvation and malnutrition.

Irrigation is by far the biggest user of agricultural water all over the globe. Even in the United States, 80% of agricultural water is used for irrigation, maximizing irrigation effieciency may be an easy way to extend the global freshwater supply.¹

Farmers in developing countries use upto twice as much water than their counter parts in industrialized countries, and often obtain crop yields that are three times less. Therefore, if farmers implemented simple solutions to increase their agricultural water use efficiency it has been estimate that global water use could be reduced by between 20-30%.² This aim can be obtained by through the implementation of some of the following changes^2,3:

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•Technology - Implement the use of more water efficient irrigation systems like sprinklers or drip irrigation, like the one pictured above.
•Mechanization - Mechanize the release of water in order to increase efficiency of use.
•Integration - Use both ground water and surface water in order to maximize the use of the freshwater supply.
•Scheduled Irrigation - Irrigate early in the morning and at night when evaporation is at its minimum.
•Land Preperation - Prepare the land so that it is able to take up the maximum amount of water
•Crop Choices - Produce less water intensive crops, or crops that are more tolerant to salt water. Reduce the amount of virtual water.

For more on agricultural water use, please see: Agricultural Water Waste.
To learn more about water use and water use efficiency see: Water Use Efficiency
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