Water Scarcity

updated February 2017

Water scarcity is a favourite topic for the headlines of doom, in company with overpopulation, climate chaos and nuclear war. The threat of a destabilising water crisis invariably wins attention in the annual Global Risks Reports published by the World Economic Forum.

In reality, our water woes reflect international political dysfunction as much as scarcity. If governments were more willing to collaborate in safeguarding the water cycle on which we all depend, and to share its beneficence fairly, they would discover that there is more than sufficient water to meet our needs.

Definitions

The current global per capita availability of freshwater from rivers, lakes, aquifers and rainfall averages a potentially healthy 6,000 cubic metres per annum. Only 9% of this resource is actually withdrawn, evidence of the worldwide abundance of freshwater.

However, freshwater is very unevenly distributed and scarcity is more realistically assessed within regions, countries or individual river basins. Seasonal variation can also be very significant. Amongst several approaches to a definition of water scarcity, there are two broad methods, each verifying that the reality experienced by millions of households is inconsistent with the statistics of global abundance.

The first approach considers the per capita availability of freshwater within a country or region, regardless of actual withdrawal. Availability of 1,000 cubic metres per annum is regarded as the minimum necessary to meet the needs of households, agriculture, and industry – and to sustain local ecosystems.

A state of water scarcity exists below that threshold. Below 1,700 cubic metres, the less severe description of “water stress” applies. By way of illustration, renewable per capita freshwater availability in the US is over 7,700 cubic metres; in Jordan and Israel availability is less than 500 cubic metres; in Yemen the figure is now below 200. Water scarcity is most acute in the Middle East region.

The second approach to a definition of water scarcity focuses on withdrawals as a proportion of available freshwater. Indicators approved for monitoring the Sustainable Development Goal for water adopt this method. A country that withdraws less than 25% of its availability enjoys at least a degree of water security. Above that threshold, it experiences water stress; consumption of over 60% is classed as water scarcity.

There are 10 countries, nearly all in the Middle East, which consume more than 100% of their renewable water resources. Their aquifer levels are falling and they must seek alternative sources such as desalinisation.

The concept of “water security”, the inverse of scarcity, also lacks a consensual definition. It implies consistent and affordable access to unpolluted freshwater for households, agriculture and industry.

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The Forgotten Cycle, an animation by Sahana Singh,
reminding us how the water cycle has been abused by human intervention.


Botswana’s water scarcity – Botswana depends on South Africa for much of its water supply. Prolonged drought may put the relationship under pressure
from CCTV Africa

more Water Scarcity briefings
Water Cycle
Water Energy Food Nexus
Causes of Water Scarcity
Climate Change and Water Scarcity
Solutions to Water Scarcity
Sustainable Development Goal for Water
Access to Drinking Water
Water Wars
Source material and useful links

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