How I Consumed 6373 Gallons of Water in One Day

It was a typical day. I awoke, took a shower, brushed my teeth, had a quick breakfast (~3 scrambled eggs) and jumped in my car. 15 miles, a cup of coffee, and a handful of cashews later, I arrived at my first meeting. I presented my 54-page slide deck while enjoying another cup of coffee, a plate of fruit and a bottle of water. The meeting ended a bit earlier than I had expected. I decided to squeeze in a workout before lunch and took a quick shower after.

For lunch, I had a salad topped with steak and mango while grading a 154 page senior essay that one of my students had just submitted. Although I was genuinely interested in its topic (price and quality transparency in healthcare), I did manage to consume another cup of coffee (and a chocolate bar) during the first 30 pages that I read. I then had three back to back to back conference calls before heading home.   Upon arriving, I made dinner (chicken breast, asparagus, and red-lentil pasta) and poured myself a glass of red wine.  

Over the course of this ordinary and unremarkable day, I consumed ~8 cups of drinking water and used approximately 50 gallons for my two showers, multiple toilet flushes, and my sink-based activities of hand washing, teeth brushing, and shaving (click HERE)

The amount of water I consumed indirectly, known as “virtual water,” was far more noteworthy. At 37 gallons of water per cup of coffee (takes a lot of water to grow coffee beans!), my three cups of coffee added another 111 gallons (click HERE).   Given I used around a cup of almond milk across with my three coffees, I effectively used the 750 gallons or so used to generate the cup of almonds (click HERE). The glass of wine (a healthy pour!) was equivalent to about 50 gallons of water (click HERE), bringing the running tally to 962 gallons of water and water equivalents.

What about the virtual water in the food I ate? The three eggs I consumed required 159 gallons of water to produce (click HERE). 500 gallons for my cashews (click HERE), 100 gallons for the fruit, 1300 gallons went into my steak (click HERE), and an additional 220 into the mango. The bed of kale upon which the beef and mango sat? 25 gallons. Chocolate bar: 317 gallons (click HERE). My chicken “only” consumed 130 gallons of water, less than the 160 gallons consumed by my asparagus, and a water bargain when compared to the 500 gallons consumed by my portion of lentils (click HERE). New total: 4373 gallons.

And then there’s the virtual water in everything else I used. A 60-watt light bulb consumes the equivalent of 5 gallons of water per hour (click HERE); I probably used the equivalent of 25 light bulb hours (125 gallons). A gallon of gasoline in my car took 13 gallons of water to produce (click HERE), and I probably used 3 gallons today (39 gallons). It takes about 3 gallons of water to make a sheet of paper (click HERE). Given I made 20 double-sided copies of my 54-page slide deck and read 72 pages of a double-sided senior essay, my paper use effectively consumed 1836 gallons of water.   Updated tally: 6373 gallons.

While the 6373 gallons may seem like a large number, it likely underestimates my total usage. My actual water footprint is likely much higher!  Consider that it takes 700 gallons of water to make one t-shirt, or 2900 gallons to make a pair of jeans (click HERE). Or that watering a lawn can take tens of thousands of gallons per month. Or that a bath consumes 7-10x more water than a shower. Water is hidden virtually everywhere.

How much water did you consume today?

Vikram Mansharamani is a Lecturer at Yale University in the Program on Ethics, Politics, & Economics and a Senior Fellow at the Mossavar-Rahmani Center for Business and Government at the Harvard Kennedy School. Visit his website for more information or to subscribe to his mailing list. He can also be followed on Twitter.