science

Water efficiency

Water efficiency is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Water efficiency rather than just read about it. In short: Water efficiency is the practice of reducing water consumption by measuring the amount of water required for a particular purpose and is proportionate to the amount of essential water used. Water efficiency differs from water conservation in that it focuses on reducing waste, not restricting use.

Key takeaways

Water efficiency belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Water efficiency to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Water efficiency from memory before moving on to harder problems.

Reference excerpt

Water efficiency is the practice of reducing water consumption by measuring the amount of water required for a particular purpose and is proportionate to the amount of essential water used. Water efficiency differs from water conservation in that it focuses on reducing waste, not restricting use. Solutions for water efficiency not only focus on reducing the amount of potable water used but also on reducing the use of non-potable water where appropriate (e.g. flushing toilet, watering landscape, etc.). It also emphasizes the influence consumers can have on water efficiency by making small behavioral changes to reduce water wastage, and by choosing more water-efficient products.

Importance According to the UN World Water Development Report, over the past 100 years, global water use has increased by a factor of six. Annually, the rate steadily increases at an estimated amount of one percent as a result of population increase, economic development and changing consumption patterns. Increasing human demand for water coupled with the effects of climate change mean that the future of water supply is not secure. Around 2 billion people do not have consistent access to safe drinking water. In addition, there are changes in climate, population growth, and lifestyles. The changes in human lifestyle and activities require more water per capita. This creates competition for water among agricultural, industrial, and human consumption.

Organizations

Many countries recognize water scarcity as a growing problem. Global organizations such as the World Water Council, continue to prioritize water efficiency alongside water conservation. The Alliance for Water Efficiency, Waterwise, California Water Efficiency Partnership (formally the California Urban Water Conservation Council), Smart Approved WaterMark in Australia, and the Partnership for Water Sustainability in British Columbia in Canada are non-governmental organizations that support water efficiency at national and regional levels. Governmental organizations such as Environment Canada, the EPA in the USA, the Environment Agency in the UK, DEWR in Australia, have recognized and created policies and strategies to raise water efficiency awareness. The EPA established the WaterSense in 2006. The program is a voluntary program to encourage water efficiency in the United States by identifying and testing products that demonstrate improvement over standard models for toilets, bathroom faucets and faucet accessories, urinals, and residential shower heads through the use of the WaterSense label. The government of China created a five-year (2010-2015) plan to deliver safe drinking water to about 54 percent of the population by 2015. It would cost about $66 billion US dollars or ¥410 billion Yuan to upgrade about 57,353 miles (92,300 kilometers) of main pipes and water treatment plants. The government hopes these steps will help to better conserve water and meet demands. The Indian state of Haryana implemented the State Rural Water Policy 2012; under this policy individual household metered connections would be provided to 50% of the rural population by 2017, to stop water wastage in villages.

Water efficient solutions

Residential

Water efficiency solutions in residences include:

Turning off the faucet sink while brushing teeth — saves approximately five gallons (about 19 liters) of water Installing faucet aerators Fixing a water valve leakage Only running the dishwasher and washing machine with a full load Taking a shower instead of a bath Washing fruits and vegetables in a bowl rather than continuously running the tap water Using leftover water for houseplants Using a watering can or garden hose with a trigger nozzle instead of a sprinkler Using a bucket and sponge when washing a car rather than a running a hose Washing clothes and linens in a washing machine rather than washing them by hand Recycling greywater for toilet flushing water and garden use Watering outdoor plants in the morning or in the evening when temperatures are cooler Consumers can voluntarily, or with government incentives or mandates, purchase water-efficient appliances such as low-flush toilets and washing machines.

Manufacturers Water efficiency solutions in manufacturing:

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 into 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 car wash products to wash cars, boats, motorcycles, and bicycles. This could save up to 150 U.S. gallons (570 L) of water per wash.

Utilities The United States Environmental Protection Agency (EPA) makes the following recommendations for communities and utilities:

Implementing a water-loss management program (e.g. locate and repair leaks). Universal metering. Ensuring that fire hydrants are tamperproof. Equipment changes — setting a good example by using water-efficient equipment. Installing faucet aerators and low-flow shower heads in municipal buildings. Replacing worn-out plumbing fixtures, appliances, and equipment with water-saving models. Minimizing the water used in space cooling equipment in accordance with the manufacturer's recommendations. Shutting off cooling units when not needed. Encouraging the use of urinals instead of toilet stalls in school (boys') and work office (men's) restrooms. Utilities can also modify their billing software to track customers who have taken advantage of various utility-sponsored water conservation initiatives (toilet rebates, irrigation rebates, etc.) to see which initiatives provide the greatest water savings for the least cost.

Data centers

Water policies and impact assessments

… excerpt ends here. Continue reading the full article.

Illustrations

Water efficiency: Taking showers instead of baths can save water — Taking showers instead of baths can save water

Worked examples

Example 1 — a first encounter with Water efficiency

Start with the simplest possible case. Write down what Water efficiency claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Water efficiency before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Water efficiency ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Water efficiency

In research: Water efficiency appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Water efficiency in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Water efficiency is common in secondary-school and first-year university syllabi. It links to neighbouring topics Water and the environment, Water conservation, Water supply, so understanding it makes those chapters shorter.
In everyday life: Look for Water efficiency outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Water efficiency in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Water efficiency means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Water efficiency out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Water efficiency in simple terms?

Why does Water efficiency matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Water efficiency?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Water efficiency.