What Human Activity Uses the Most Water?

SubjectToClimate Team

Jul 30, 2021

When was the last time you had a glass of water? 


What about 82 gallons of water?


That’s how much H2O the average American uses each and every day. This crucial resource enables everything from hydration to hygiene— and that’s only looking at personal usage. Outside of the domestic sphere, water allows us to grow food, create energy, build infrastructure, and manufacture all kinds of goods. 


Although water is a renewable resource, we still need to conserve it in order to meet everyone’s needs. So, how can we preserve the Earth’s most important resource? To begin to answer this question, it might help to identify some of humanity’s most water-intensive activities.


What human activity uses the most water? It depends on how you frame the question.



The Activity That Uses the Most Water Worldwide


When you add up all usage in all spheres and sectors globally, what human activity uses the most water? The biggest piece of the pie, it turns out, is agriculture. Irrigating crops takes a lot of water— we’re talking 70 percent of global freshwater withdrawals


Unsurprisingly, some agricultural methods are more water-intensive than others. For instance, drip irrigation (using plastic pipes with holes in them to send water directly to plants) is much more efficient than flood or furrow irrigation (letting water run along the ground among the crops). Farmers can also conserve water by monitoring soil moisture levels and the seasonal water needs of crops in order to use only as much water as necessary, and by keeping tilling to a minimum so as to keep water in the soil. 


In addition, some agricultural products require much more water than others. As a rule, foods further up the food chain and processed foods tend to be more water-intensive. A 6-ounce steak takes 687 gallons of water to produce!


While agriculture is what uses the most water in the world, it’s not the whole picture. There are opportunities to save water in many aspects of our society.



The Human Activity That Uses the Most Water at Home


Of course, most people aren’t farmers. In our day-to-day lives, in our homes, what human activity uses the most water?


For the average American, the answer is toilet-flushing. However, not all toilets are created equal. If you own your home, consider installing a water-efficient toilet. A 2017 study found that if all toilets in the U.S. were switched to water-efficient models, it could save around 360 billion gallons of potable water per year! Other ways to save water in the bathroom include peeing in the shower and only flushing solid waste.


By identifying what human activity uses the most water, we can hone in one of the top priorities for individual conservation. However, there are many other ways to save water at home. To name a few: 


- Run fewer loads in the washing machine by washing full loads.


- Turn off the faucet while brushing your teeth, shaving, and washing dishes.


- Take shorter and fewer showers.


- If you have a lawn, water it with a sprinkler system instead of by hand. Better yet, don’t have a lawn! You can replace grass with drought-tolerant groundcovers or a vegetable garden. You can ensure the plants are well-suited to your climate —all while supporting local wildlife— by growing native plants.


- A graywater reuse system takes water from your sink, shower, and washing machine, and uses it to irrigate your garden. For a low-tech version, you can place a bucket in the shower, then bring the water you capture to your plants.


- If you have a car, wash it with a sponge instead of a hose. If you do use a hose, make sure it’s one with a shut-off nozzle.


- Many products take a great deal of water to produce. You can save water by buying less stuff, avoiding water-intensive agricultural goods like animal products and processed foods, cutting down on food waste, and using less electricity. 



What’s That in the Air


As we deal with water shortages, we’ll need to get creative. One helpful piece of technology is atmospheric water generation, which draws water out of thin air! Using technology similar to a dehumidifier, AWG collects the tiny water particles that float in the air around us. However, there’s a catch— this technology requires a lot of energy.



Water Shortages


1 in 9 people lack access to safe water. As time goes on, we can expect this problem to get worse. Demand for water is going up at the same time that an increasing number of water supplies are becoming contaminated. To address this crisis, it is important to consider not only what human activity uses the most water worldwide, but also what power dynamics play into that water use. As is the case with most environmental issues, water shortages and contamination disproportionately impact poor communities, communities of color, and formerly and currently colonized people. This disparity is no accident. Polluters leave toxins in marginalized communities, contaminating their water supplies. Wealthy nations divert water from poor ones.


Droughts bring with them many social ills. Crops and livestock die, creating famines. Wildfires become deadlier and more destructive. Scarcity breeds political conflict and war.


We have no choice but to transform human uses of water-- to treat it like the precious resource that it is. Making these changes will require both individual and collective actions. We can combat the global water crisis, individually and together. 


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