What is Water Footprint?
Water Footprint refers to the volume of water used to produce various products and services. One often used example is that of coffee. A cup of java, according to researchers, requires 140 litres of water to produce. Water footprint can apply to a product, a service, an individual, a country and even the world.
How Is Water Footprint Calculated?
An individual may not drink, feel or see all the water he or she uses or consumes. This is called, “Virtual Water” and it actually makes up most of our water footprint. The combined total of direct and indirect usage of water in the lifecycle of products and related services all play a role in the overall footprint calculation.
There are three different types of water footprint; Green, Blue, and Grey.
Green Water Footprint: It refers to the amount of rainwater required to produce a product. It is mainly relevant for forestry, horticultural and agricultural products. As discussed below, its impact may not be as significant as other water types.
Blue Water Footprint: It refers to the amount of groundwater or surface water required to produce a product. Water is derived from sources such as aquifers, rivers or lakes. Domestic water use, industry, and irrigated agriculture can each have a blue water footprint.
Grey Water Footprint: It refers to the amount of freshwater required to dilute pollutants to meet particular water quality standards (like the standards set by the US Clean Water Act).
Water Footprint Calculators
There are several online water footprint calculators available to help you ascertain your water footprint. Some of these include:
Why Water Footprint Is Important But Needs to Be Understood in Context
Measuring water footprint and taking all the necessary steps to keep that level as low as possible is extremely important for mankind. This balance is urgently required because freshwater is vital to our daily life while the supply of freshwater is limited. As the world population expands, so does the need for fresh water. Measures to keep water footprint level low, soon are needed to conserve fresh water supply.
As consumers armed with water footprint data, we should be able to make informed choices to purchase goods and services that have a lower water footprint. The actual fact of the matter is that the impact of water consumption depends on the circumstances. Take for example the case of the water required for a cup of coffee, mentioned above. Almost 99% of the water footprint associated with coffee is associated with the growth of coffee plants, as referenced in the 2003 study cited above. It is important to differentiate between water utilization and consumption. If coffee plants are not irrigated and rely on green water from rainfall, then they are utilizing water but not consuming it, as they would be if the water was being drawn from an aquifer or a body of water. It is important to consider the geographical and climatic context. Where there is abundant rainwater, the impact of water usage by the coffee plants on the ecosystem is minimal compared to more arid growing areas.
As consumers in a global economy, it is difficult to understand how the goods we purchase impact water security in other parts of the world. Water footprint is an important starting point, but it is important to understand the context of geography and climate in determining the overall impact of water usage.