Water consumption worldwide has been increasing by about 1 percent every year, since the 1980s, and will
continue an upward march till 2050, projects the United Nations. By then, the global water demand, will be around 30 per cent
above today's levels. Already, over two billion people live in countries with high water stress, and about four billion experience
severe water scarcity at least one month every year.
A similar disheartening scenario exists, in the way the world is handling its waste. 80 percent of global wastewater, containing human waste and toxic industrial discharge remains, untreated. At the same time, plastics are choking our water bodies and aquatic life.
A water audit, similar to an energy audit, is the method of quantifying all the flows of water in a system to understand its usage, reduce losses and improve water conservation. It can be performed on a large scale for a city or a state as well on a smaller scale for irrigation projects, industries, and buildings. The audit can begin with an extensive approach to generate the water balance using available data and estimates which helps in identifying specific areas to concentrate in further stages. In Other words, Water auditing is a method of quantifying water flows and quality in simple or complex systems, with a view to reducing water usage and often saving money on otherwise unnecessary water use.
A water footprint shows the extent of water use in relation to consumption by people.The water footprint of an individual, community or business is defined as the total volume of fresh water used to produce the goods and services consumed by the individual or community or produced by the business. Water use is measured in water volume consumed (evaporated) and/or polluted per unit of time. A water footprint can be calculated for any well-defined group of consumers (e.g., an individual, family, village, city, province, state or nation) or producers (e.g., a public organization, private enterprise or economic sector), for a single process (such as growing rice) or for any product or service.
Traditionally, water use has been approached from the production side, by quantifying the following three columns of water use: water withdrawals in the agricultural, industrial, and domestic sector. While this does provide valuable data, it is a limited way of looking at water use in a globalised world, in which products are not always consumed in their country of origin. International trade of agricultural and industrial products in effect creates a global flow of virtual water, or embodied water (akin to the concept of embodied energy).
In 2002, the water footprint concept was introduced in order to have a consumption-based indicator of water use, that could provide useful information in addition to the traditional production-sector-based indicators of water use. It is analogous to the ecological footprint concept introduced in the 1990s. The water footprint is a geographically explicit indicator, not only showing volumes of water use and pollution, but also the locations.Thus, it gives a grasp on how economic choices and processes influence the availability of adequate water resources and other ecological realities across the globe and vice versa.