Introduction to Desalination. Louis Theodore
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Even in what is considered a highly advanced country like the United States, which receives 3,069 km3 a year of renewable fresh water and has historically invested in water infrastructure as well as the management of its water resources, it is estimated that as of 2014, 1.6 million people (0.5% of its population) were without a toilet, a tub or shower, or running water (UNC Environmental Finance Center 2017). Despite availability of renewable fresh water resources, equitable and affordable supply and access to these resources remain a significant challenge, particularly to minority and low-income communities, even in the most developed countries in the world.
Figure 1.1 summarizes the total per capita water consumption (consumption of surface or groundwater for domestic, commercial and industrial purposes; water for crop production; and water required for the assimilation of pollutants produced from domestic, commercial, and industrial activities) for the select countries in the world whose daily consumption is above and below the global average (Mekonnen and Hoekstra 2011). The global average for total per capita daily water usage is roughly 1,000 gal/capita/d (Grace Communication Foundation 2019). This is water that is used for domestic purposes such as laundry, cooking, drinking, washing, etc., as well as water used for food production, and the production of consumer goods, like cars, plastic bags, clothing, etc. At the top of this list with 2,270 gal/capita/day is the United Arab Emirates, 76% of which is associated with products or ingredients of consumer goods imported annually into the UAE (virtual water). In the United States, of the 2,200 gal/capita/day of total water use, only 20% is associated with imported external water consumption. The significant differences seen in the daily internal versus external per capita total water consumption are directly attributed to the consumption habits of each country’s citizenry.
Figure 1.1 Total daily per capita water consumption by selected country. Data from Grace Communication Foundation (2019).
1.4 Global Water Resource Issues
The root of all major issues pertaining to global water resources today stems from a lack of water accessibility. It is estimated that over 1 billion people live without access to safe water (WHO 2017). This number more than doubles to over 2.3 billion people when basic sanitation services are considered. It is this lack of access to safe drinking water and adequately treated wastewater that drives other major water-related issues in the world today. As indicated earlier, this access issue stems directly from the lack of necessary water infrastructure as well as the poor maintenance and management of the limited infrastructure that currently exists.
Improved water resource management and water storage capacity makes an economy more resilient to external shocks, such as rainfall variability, and thus provides a stable and sustainable base for increased food and industrial productivity and production to maintain economic growth and development. Consider a heavily water-dependent country like Kenya where frequent floods and droughts take a heavy toll on the economy (SIWI 2005). These floods and droughts translate to a direct long-term fiscal liability and decline in economic growth of about 2.4% of Kenya’s annual GDP (SIWI 2005). Much of this loss in economic output comes from lack of adequate water storage capacity, a deficit of more than $10 billion in 2004 (SIWI 2005). If Kenya, as for many other African countries, had invested in storage facilities for water, they would be able to store the excess water received in heavy flood years for use in heavy drought years, thus, avoiding flood liabilities and water scarcity cost, allowing the country to avoid the drops in economic growth that have occurred in the past.
The SIWI (2005) indicated that national economies are more resilient to rainfall variability, and economic growth is increased when water storage capacity is improved. Investing in adequate water resource management in developing countries would be expected to produce significant economic gains of between two to four times the infrastructure investment. The SIWI (2005) concluded that an even greater return on investment of $8.00–$200 would be saved in water treatment costs for every $1.00 invested in watershed protection. Investments in improved water and sanitation infrastructure in developing countries also has significant economic benefits when considering increased productivity from the improved health of workers in households and the commercial and industrial sectors, ranging from hundreds of millions to billions of dollars annually (SIWI 2005).
In today’s world, the term hydro-politics is becoming more and more known. Hydro-politics can be defined as debate or conflict