The Difference Between Water Conservation and Efficiency

The Difference Between Water Conservation and Efficiency

Water seems plentiful but droughts and shortages can happen anywhere and it’s helpful to know the difference between conservation and efficiency.

What is Water Conservation and Efficiency?

Many factors affect how much water people use in a day, including where they live, whether they live in a house or an apartment and how they live their day-to-day lives. While water might seem plentiful to meet people’s individual needs, there are many others who share in that water use. In addition, droughts and water shortages can happen anywhere in the country.

Water managers in 40 out of 50 states predict water shortages – regardless of drought – in the coming decade, so it’s not only a good idea to save water – in many places it’s a necessary way of life.

Water conservation and efficiency can help people curb their water use, and while the two terms might seem like the same thing – as both achieve the same goal of using less water – they approach water savings differently.

Water Conservation

Noted water conservation expert, Amy Vickers, author of the book Water Conservation, defines water conservation as: “Beneficial reduction in water loss, waste or use.” Water conservation includes all of the policies, programs and practices designed to help people change their behaviors and use less water. The goal is to use only the water needed; for example, turning off the water when shaving or brushing teeth, or only running the dishwasher when it’s full.

Water Efficiency

Vickers describes water efficiency as: “Minimization of the amount of water used to accomplish a function, task or result.” Water efficiency means doing more with less water; for example, washing dishes or flushing the toilet with the least amount of water necessary to get the job done. Water efficiency normally relies on well-engineered products and fixtures like reduced water use dishwashers, or low-flow toilets and showerheads.

Water efficiency can lead to significant savings in money and energy. In fact, the EPA estimates that by using water- (and energy-) efficient WaterSense-labeled fixtures and ENERGY STAR-rated appliances, the average family could reduce their water and energy use by up to 20 percent and save up to $380 per year.

The Efficiency Rebound Effect

Water efficiency is important because no place is immune from drought, and, as the population grows, everyone will have to be smarter about how they use water resources in order to meet everyone’s needs. It is also important to not be lulled into a sense of bountiful supplies that may not exist, just because appliances and fixtures use less water. This is what’s known as “The Rebound Effect” – the well-known energy conservation concept that improving energy efficiency may save less energy than expected due to a rebound of energy use. 

Efficiency isn’t an excuse to use more or to waste water. A conservation mindset helps ensure that there are adequate and sustainable water supplies for everyone well into the future. While water efficiency is important and it makes saving water automatic, it is still important to conserve water and not waste it because – now more than ever – every drop is precious.

Conservation and Efficiency Examples

The differences between water conservation and water efficiency are best explained through examples in different settings.

Around the House

Washing Clothes

Efficiency: The most efficient way to wash clothes is with an ENERGY STAR-rated washing machine that uses as little as 13 gallons of water per load. Also, some top-loading washing machines are able to adjust the water level to the amount of clothing in the barrel for less than full loads.

Conservation: When washing clothes, conserve water by only washing full loads, unless the washer is designed to do small loads.

Washing Dishes

Efficiency: The most efficient way to wash dishes is with an ENERGY STAR-rated dishwasher that uses less than 5 gallons of water per load.

Conservation: When washing dishes, conserve water by only running the dishwasher when it’s full or by running the faucet as little as possible when washing them by hand.

Flushing the Toilet

Efficiency: Toilets are much more efficient than they used to be, so they use a lot less water – as little as 1.28 gallons per flush. Dual flush toilets are also more readily available to buy. With higher volume toilets, the same effect can be achieved by putting a brick or a water-filled jug in the toilet tank.

Conservation: To conserve water with the toilet, try “letting it mellow” and not flushing after urinating. It’s an easy way to conserve because toilets can be the biggest water users in the house.

Taking Showers

Efficiency: Changing out showerheads for low-flow models is a simple and easy way to practice water efficiency because they automatically save water with every shower.

Conservation: Even with a low-flow showerhead, it’s important to practice conservation and minimize those minutes – shower only for as long as necessary. An easy way to do this is to play music and keep the shower to the length of two songs.

Food and Cooking

Efficiency: Diets that incorporate more fruits, vegetables and grains in place of meat and dairy, have a reduced water use, because it takes a lot of water to produce meat and dairy products.

Conservation: Not wasting food means conserving all the water it took to produce it. The USDA estimates that 31 percent of the available US food supply in 2010 was lost from human consumption at the retail and consumer levels. This is like throwing out all the water (and energy) it took to grow and produce that food. A great way to conserve water is to only purchase food that will be eaten, then don’t throw it away.


Watering the Lawn

Efficiency: There are numerous technologies to help water lawns efficiently. These include things like moisture sensors, drip irrigation systems and irrigation control systems.

Conservation: Watering efficiently doesn’t make much sense if the lawn being watered is in an environment more suitable to a drier landscape. In addition, watering extensive turf grass during times of drought wastes lots of water. Xeriscaping – landscaping with native plants and grasses that use little to no irrigation water – is a much more conservative approach to outdoor water use. Other great ways to conserve water include watering in the cooler parts of the day when evaporation rates are lower, and not watering on windy or rainy days (sounds obvious, but some people don’t realize this).

Washing the Car

Efficiency: The most efficient way to wash a car is at a commercial, self-service car wash because those car washes typically use pistol grip nozzles that turn off automatically, and they use high pressure, so it takes less water to clean more.

Conservation: Washing a car at home is the least efficient method of washing the car, but it can be done with less water by using a spray nozzle that turns off easily and a bucket full of soapy water. If possible, pull the car onto the lawn so the water will go onto the grass, instead of running down the gutter.

At School or Work

Running the Faucet

Efficiency: At this point, it’s likely that most commercial facilities in the country have been retrofitted with low-flow faucets in their bathrooms and, where they exist, kitchens. Many building codes require efficiency measures like installing low-flow fixtures in commercial (and residential) construction and remodels, which has significantly lowered water use across the nation.

Conservation: Even with efficiency measures in place, water can still be saved by running faucets only when necessary. Don’t let good water go down the drain if it’s not needed.

Flushing the Toilet

Efficiency: Similar to low-flow faucets, many building codes require low-flow toilets that use as little as 1.28 gallons per flush. Older, conventional toilets can use anywhere from 5 to 7 gallons per flush. Considering how many times people flush in a day, this is a huge savings.

Conservation: Depending on the situation, it is possible to conserve water by “letting it mellow” and not flushing after urinating in commercial facilities, although people are more reluctant to do this in public restrooms.

Are you an educator?

Check out our free, downloadable lesson plans that help students understand their own dietary water use.