John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
Most Americans don't. Take our quiz to see how you measure up.
What common household fixture sucks up the most water – the shower, the toilet, or the washing machine?
If you're having trouble with this question, don't worry, you're in good company. Most Americans are ignorant of the true water needs of their household activities. At least that's the conclusion of
University of Indiana Indiana University researcher Shahzeen Attari, who recently asked more than a thousand people to estimate how many gallons of water it takes to sprinkle the lawn, flush the toilet, fill the bathtub, and other common at-home water uses. Throughout the experiment, Americans showed a tendency to undervalue water consumption, on average guessing low by a full factor of two.
This bewilderment is not good news in a world struggling with an impending (or ongoing?) water-availability crisis. So what's making people falsely believe they're using less water? One possibility Attari throws out is that public utilities often bill only for the total dollar amount and don't list units of water consumed. Many people also think longer activities like showering consume more water, when shorter but more frequent activities can increase consumption, too. And for whatever it's worth, survey participants who guessed more accurately tended to be better at math, older, and also male. Everybody, commence arguing.
Think you can perform better than this poor-scoring crowd? You can find out by trying to answer the 10 questions below. They're not precisely the same as the ones in the survey, but they should give you insight into the actual impact your behavior has on the communal watering hole. (You can find many of the question's sources here.)