Since 1993, the United Nations has designated March 22nd of each year as World Water Day, a day dedicated to celebrating water. This year’s theme is “Water and Sustainable Development.” As the world continues to grow and the demand for water rises, the management of water and water systems is becoming ever more critical. This Sunday, take the opportunity to learn more about water’s place in the world and how we as engineers and thoughtful citizens make an impact.
Water by the numbers:
- 748 million people do not have access to an improved source of drinking water. 2.5 billion do not use an improved sanitation facility. It would cost an estimated US$ 107 billion a year over a five-year period to cover every person worldwide with safe water and sanitation. However, the return on investment of attaining universal access to improved sanitation has been estimated at 5.5 to 1, and for universal access of improved drinking-water sources the ratio is estimated to be 2 to 1.
- 93% of urbanization, currently occurring globally at a rate of one million people per week, occurs in poor or developing countries, and nearly 40% of the world's urban expansion is growing slums. Wastewater infrastructure is non-existent, inadequate or outdated in many fast growing cities.
- Global water demand for manufacturing is expected to increase by 400% from 2000 to 2050, - much larger than many other sectors. Water efficiency and conservation are becoming a top priority.
- More than 80% of power generation is by thermal electricity which requires water to be heated to create steam to drive electrical generators. Billions of gallons of water are also needed for cooling. Worldwide hydropower accounts for 16% of global electricity production - an expected 3700 major dams may more than double the total electricity capacity of hydropower within the next two decades. Using alternative water sources, such as sea or wastewater, offers a great potential for reducing the pressures on freshwater resources.
- One litre of water is needed to irrigate one calorie food. Inefficient water use can mean 100 litres are used to produce one calorie. Irrigation takes up to 90% of water withdrawn in some developing countries. Globally, agriculture is the largest user of water, accounting for 70% of total withdrawal. By 2050, agriculture will need to produce 60% more food globally. Inefficient use of water for crop production depletes aquifers, reduces river flows, degrades wildlife habitats, and has caused salinization of 20% of the global irrigated land area.
Learn more about World Water Day and find events you can participate in across the globe at worldwaterday.org.
Source: United Nations