Water efficiency

Water efficiency can be defined as
 * 1) the accomplishment of a function, task, process, or result with the minimal amount of water feasible;
 * 2) an indicator of the relationship between the amount of water required for a particular purpose and the amount of water used or delivered.

Though the two are often used interchangeably, there is a difference between water conservation and water efficiency. Water efficiency differs from water conservation in that it focuses on reducing waste. A proposition is that the key for efficiency is reducing waste, not restricting use. It also emphasises the influence consumers can have in water efficiency by making small behavioural changes to reduce water wastage and by choosing more water efficient products. Examples of water efficient steps includes fixing leaking taps, taking showers rather than baths, installing displacements devices inside toilet cisterns, and using dishwashers and washing machines with full loads. These are things that fall under the definition of water efficiency, as their purpose is to obtain the desired result or level of service with the least necessary water.

Importance
According to the Second United Nations World Water Development Report, if present levels of consumption continue, two-thirds of the global population will live in areas of water stress by 2025. Increasing human demand for water coupled with the effects of climate change mean that the future of our water supply is not secure. As of now, 2.6 billion people do not have safe drinking water. Added to this, are the changes in climate, population growth and lifestyles. The changes in human lifestyle and activities require more water per capita. This tightens the competition for water amongst agricultural, industrial, and human consumption.

Organisations
In most countries, people have recognized this growing water scarcity problem. Water efficiency, while not yet a major priority in the agendas of governments, has been a growing concern. Global organisations like the World Water Council, the International Water Management Institute , and UNESCO have been promoting water efficiency alongside water conservation.

Waterwise in the UK, the California Urban Water Conservation Council, the  savewater! Alliance in Australia, and Waterbucket in Canada are some non governmental organisations that promote or support water efficiency at local national levels.

Governmental organisations such as Environment Canada, the United States Environmental Protection Agency, the Environment Agency in the United Kingdom, the Department of the Environment and Water Resources in Australia, among others, have recognized and created policies and strategies to raise water efficiency awareness.

A part of the industry sector has also recognised the benefits of water efficiency. Such journals as the Water Efficiency Journal from the US, Water Efficient Solutions Journal and Water Energy and Environment Magazine from the UK, all mainly directed towards the industrial and professional sectors, attest to the growing consciousness of the need to develop more water efficient solutions.

Residential
According to Waterwise, these are some simple solution a person can take at home to be more water efficient :


 * Turning off the tap while brushing teeth- a running tap can waste over six litres per minute.
 * Putting a "hippo" or other displacement device into the toilet cistern.
 * Fixing dripping taps- a dripping tap wastes thousands of litres of water a year.
 * Using a full load in the dishwasher and washing machine. A person should be sure to buy a water efficient model when thinking of buying a new machine.
 * Having a short shower instead of a bath.
 * Washing fruits and vegetables in a bowl rather than under a running tap. Using the leftover water to feed houseplants.
 * Using a watering can or a hosepipe with a trigger nozzle instead of a sprinkler.
 * Using a bucket and sponge when washing the car rather than a running hosepipe.

Manufacturing
According to Savewater!, these are solutions useful to manufacturers :


 * Identifying and eliminating wastage (such as leaks) and inefficient processes (such as continual spray devices on stop-start production lines). This may be the most low cost area for water savings, as it involves minimal capital outlay. Savings can be made through implementing procedural changes, such as cleaning plant areas with brooms rather than water.
 * Changing processes and plant machinery. A retrofit of key plant equipment may increase efficiency. Alternatively, upgrades to more efficient models can be factored in to planned maintenance and replacement schedules.
 * Reusing wastewater. As well as saving on mains water, this option may improve the reliability of supply, whilst reducing trade waste charges and associated environmental risks.

Waterless Products

 * Using waterless carwash products to wash cars, boats, motorcycles and bicycles. This couls save up to 150 gallons of water per wash.

Utilities
According to the United States Environmental Protection Agency, these are some ideas for utilities :


 * Implementing a water-loss management program (e.g. repair leaks).
 * Utilities should strive for universal metering.
 * Ensuring that fire hydrants are tamper proof.
 * Equipment changes - Setting a good example by using water efficient equipment.
 * Installing faucet aerators and low flow shower heads in municipal buildings.
 * As municipal appliances or equipment wear out, replacing them with water-saving models.
 * Minimizing the water used in space cooling equipment in accordance with manufacturer's recommendations. Shut off cooling units when not needed.