On the back of an envelope: That glass of water in a restaurant?

California, and much of the southwestern US, is in a severe drought. Again.

And as appropriate, there is growing debate about what we, as citizens, communities, corporations, and governments should do to tackle water shortages and the bigger question of sustainable water policy. Suggestions range from the large-scale and comprehensive (build more dams, transfer more water from farther and farther away, rethink the entire agricultural sector, use high-quality treated wastewater to meet certain needs) to the small-scale and local (replace your lawns and inefficient water-using fixtures, stop washing your car, turn off the water when brushing your teeth). All of these things are worth considering; plenty of them are worth implementing.

Recently, Don Cheadle (the great actor and producer, anti-genocide activist, and environmental ambassador) tweeted: “Tweeps, next time you’re at a restaurant please inform your waiter that you will ASK for water and not to automatically pour. #noautowater”

Cheadle tweet

Mr. Cheadle’s tweet [I know society thinks using first names of famous people is ok, but I’m not going to presume…] produced a range of responses, including several from people who felt that this recommendation was a tiny and insubstantial gesture, or a “first world problem,” or didn't understand why this might help a water problem as severe as we’re experiencing.

water_glasses_glass_of_water_restaurant_table Water in a restaurant. (Source: Photos Public Domain)

The Pacific Institute has done extensive and groundbreaking research over the past 25 years on a wide range of water, climate, energy, and environmental issues. A major focus of our work has been on how to use water more efficiently to do the things we want to do – a focus on “efficiency” and “productivity” – not deprivation. Our research has shown that we can save vast amounts of water in both agriculturaland urban settings without hurting our economy or lifestyle.

But behavior, information, cultural factors, and education also play a role in our water use. We could certainly have nice lawns while still using less water, but we could also get rid of our lawns and still have beautiful water-efficient gardens. We can have clean teeth and still turn off the water while we’re brushing.

All of these things help individuals and groups change behavior. Think about smoking: We made cigarettes expensive by taxing them to fund health and other programs, made public spaces off limits to second-hand smoke, and launched a massive public education campaign about the health dangers of smoking. These actions have been very effective at changing perceptions, preferences, and public behavior. Even those who still smoke now wouldn't think of lighting up in an airplane, school room, or restaurant.

In the water world, if our choices and decisions and behaviors change in the direction of lower-water-using options, so much the better.

This gets me back to Mr. Cheadle’s suggestion: how much water would such a suggestion actually save, and why bother? So, here is a “back-of-the-envelope” estimate (feel free to do your own, with your own assumptions):


Water saved?

  1. The average American eats at a restaurant five time a week.
  2. Water is automatically delivered to your table by the wait staff.
  3. At the end of the meal, a half a glass of water (6 ounces) is left, undrunk.

But wait, all those glasses have to be washed as well:

  1. Commercial dishwashers use a wide range of water, but average around 4 gallons of water per rack, and a rack holds around 20 glasses.

Water left on the table: [315 million Americans; 260 restaurant meals a year; 6 ounces left on the table per meal; 128 ounces per gallon = 3.8 billion gallons per year]

Water needed to wash those glasses: [315 million Americans; 260 glasses of water per year; 20 glasses per dishwasher rack; 4 gallons to wash each rack = 16.4 billion gallons per year]

Under these assumptions, the total amount of water that could be saved nationwide is around 20 billion gallons of water a year. To use the silly but ubiquitous standard measure: this amount of water would fill 31,000 Olympic-sized swimming pools.

These savings are real: This is water someone won’t have to pay for, the water utility won’t have to collect, treat, and pump to you, and the wastewater utility won’t have to collect, treat, and throw away. And there are energy and ultimately climate costs as well to get that highly treated potable water to you, to wash the dishes, and so on.

In context, it is true that far, far more water could be saved by improving irrigation efficiency in the farm sector, or getting rid of our lawns, or replacing inefficient washing machines. We should do those things too – it is not one or the other. But we must not ignore the power of even modest individual actions, the educational value of raising awareness of the value and scarcity of water, and the importance of exploring all the options available to us.

And don't get me started on bottled water in restaurants...

Peter Gleick

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The idea of not automatically providing water in restaurants is reasonable, both for real water savings and as a symbolic gesture, and I've seen it done in places suffering drought before. But is it really plausible that the average American eats at a sit-down restaurant with waiters five times a week? That would be an impossible budget-buster for most of us. I would guess that the typical American who eats out five days a week is having most of those meals at the sort of place where you carry your own prepaid, paper-wrapped food away from the counter in a tray, and only grudgingly do you get a cup for water instead of $oda.

But where is water provided automatically? In most places the waiter asks what you want for a drink and fetches it. I have not seen water served in 20 or more years that I can recall. Is this post just a bit late, as the restaurant industry long ago realized the savings. Water is not served in chains such as Chilis Olive Garden etc as an example.

Perhaps Mr. Cheadle (and/or Mr. Gleick) are unaware (or have forgotten) that sit-down restaurants that might automatically serve water are *not* something that the average American experiences on a regular basis. Most assume you will want tea, coffee, soft drink, beer or a mixed drink. They'd much rather serve you that for hefty profits than give you free water.

As others have mentioned, I can't remember the last time I was served water. It's no longer standard practice, except perhaps in fancy restaurants in Santa Monica, or the Bay area... :)

By Glenn Dixon (not verified) on 09 Apr 2014 #permalink

Glenn, sure, though what is the water content of the other drinks (or food) we order, but leave on the table at the end of a meal... There are lots of pieces to this bigger puzzle of cutting our water footprints.

#2, I wouldn't be surprised if auto-pouring water results in lower sales of alcohol, which is a major profit source for restaurants. If that's the case, there's good reason why restaurants don't already auto-pour.

By Windchaser (not verified) on 09 Apr 2014 #permalink

Ridiculous assumptions as pointed out above. I'm upper middle class and I eat at a non-fast food restaurant on average 1 time per week. My wife and I leave virtually no water in the glass when we leave, lets assume though 2 oz each. A commercial dish washer can hold about 50 glasses per rack not 20. So that comes to a factor of 5x3x2.5 smaller water usage or about .5 billion gallons. A lot of water yes. What it should be compared to is total rainfall per year over the U.S. Perhaps someone would like to estimate the number of gallons of water that fall in the U.S. - or even just California (where my experience when I've visited is that they do ask).

So, as I said, everyone should feel free to do their own calculation with different assumptions. Envelope backs are cheap. That's not the point. (And comparing the result to total rainfall in the US is NOT an appropriate comparison BTW).

And most of the country is not experiencing drought conditions. Water is never "lost", it is all recycled. There are only opportunity costs in using it for one purpose or another.

Not pouring water indiscriminately in restaurants promotes mindfulness - which is a good thing in itself.

I live in an area where water is plentiful and you usually not only get water without asking at a nice restaurant, you get refills without asking. If I usually don't leave a full glass on the table, it's because I'm conscious of the waste and always ready to fling my hand over the glass when the waiter comes by with a pitcher.

Meanwhile, those glasses of water are recommended to be drank (and them some) by medical and health professionals alike. What figures might you come up with IF everyone drank every ounce of water that they "should" drink each and every day to be their healthiest.?
I always feel somewhat offended when someone reaches to be so conservative with something like a glass of water with a meal. Even considering the exponential of "each person".
To be conservative at this level is asking the tree to stop growing so many leaves as each leaf requires a bit of water. Certainly you cannot tell the tree such a thing lest you remove a branch or cut the whole tree down. And what about industry? Any idea how many billions of gallons of water industry uses on a DAILY basis for various things, much of it wasted. Do we really NEED golf courses with vast areas of lush greens and fairways that need TONS OF WATER?!? Sadly but simply, the answer is NO. When the price of water becomes the answer to drought conditions, and even before then, I will not be wastefull with water. However, to think that a glass of water at a restaurant is wasteful is ludicrous. It encourages us to drink our daily water allowance and could prevent one from choking on the often served bread before the meal.
Of course "Fine" restaurants wouldn't think of not bringing water because they can afford it and must stay classy, so for them its ok.
I guess my point is that the earth and weather does cycle with rainfall. It is a natural thing. Our population continues to grow as leaves populate a given tree. Cities and municipalities have factored irrigation control. Utilizing reservoirs (both natural and man made) and canal systems to store and supply from rainfall and snow melt runoff.
I will worry about a single glass of water when the answer to a drought is not a higher price for said water; when the beverage industry stops making a thousand different drinks all water-based that I don't need or buy; when car washes close and golf courses turn brown and when "Big Industry" stops using water in "acre feet" measurements rather than gallons to make something that is not a life necessity, then I will worry about human consumption of a single glass of water or portion thereof before or during my other human need...eating.

IMHO this is another case where the easy big gains are ignored while we are told to concentrate on the marginally beneficial gains. Savings on dispensation and washing of glasses barely registers on the scale of water uses. The reason we focus on these marginal benefits comes down to our unwillingness to step on the toes of wealthy and powerful interests. So we tip-toe around them and focus on on smaller feel-good changes.

If you want to make a difference you are going to have to step on the toes of very powerful interest groups. You could start with eliminating the watering of golf courses and lawns, limiting watering of crops to ground level, or below, drip irrigation, and running our sewer systems on gray water instead of drinking water.

If you want to make water at the table more beneficial I would suggest that we promote people actually drinking the water. Many Americans are marginally dehydrated and substituting plain water for other drinks is both healthier and more environmentally sound.

I suspect that you are also grossly overestimating the rate of restaurant use and how mush water is used per load by a commercial dish washing machine. I personally only eat out a couple of times a month and most of my neighbors seem to be about the same.

Based upon Feb, 2013 Energy Star standards the commercial washers use significantly less than one gallon per rack (GPR):


The value of small symbolic gestures of this kind is that they create "buy-in" for people who are otherwise uncommitted.

For example your neighbor doesn't care about climate change but buys a solar system to lower the electric bill. (Admittedly that's not a "small" gesture, but it illustrates the point.) After a few months, ta-daa!, your neighbor starts to care about climate change. Next thing you know, they're telecommuting two days a week and taking public transport two days a week, and only driving to work one day a week. Everything counts.

What works for energy also works for water, starting at the restaurant.

Something else you can do: Stick a 5-gallon pail under the shower nozzle while the water is warming up. Normally you lose 2 - 5 gallons as cold water down the drain before each shower. Catch it in a bucket and you can use it for toilet flushes. It's easy and buckets are cheap so it's almost free.

But what we desperately need is a state law that overrides homeowner association requirements for lawns.

You need some kind of liquid to wash a meal down, but that old line that you "need" so-and-so many glasses of water per day no matter what your size or activity level is not true, unless you're sweating a lot for some reason (and it turns out it's more dangerous to guzzle water while engaged in extreme activity than to skimp). Some of our needed water is gotten from food, and like other animals, we have a mechanism called thirst that exists to let us know when we need more. The idea that we "need" to drink much more than we actually want to is fundamentally disempowering and makes no sense - look at all of us who do not regularly choke down eight glasses of water a day or whatever and do not shrivel up like raisins.

I really think the danger is not on the side of the classic eight glasses of water a day side. The biggest danger of water over-consumption seems to be hyponatremia, literally over dilution of the bodies electrolytes. Hard to get to that drinking just eight eight ounce glasses of water. Typical cases of hyponatremia are the result of gallons of water.

From what I've heard the larger danger is dehydration. Dehydration is a frequent issue, or contributing condition, with emergency departments the young, old, and already sick, fall behind in their intake of water and the entire system is thrown for a loop. Not a few elderly people back off their intake of liquids because they are incontinent. Bladder infections, obstructed bowels, weakness and impaired thinking are common with even moderate dehydration. I had a relative end up in the hospital with a severe bladder infection and resulting complications to their existing conditions.

And then again I'm down in Florida, don't like, or use air conditioning, work outdoors and commonly consume over a gallon of water, twice your eight glasses, in a single eight hour period. People who work hard and don't drink fall out.
Last year we had two people suffer heat prostration. Typical tough guys too manly to drink water or moderate their pace.

Yes, if you work hard and sweat a lot you need to drink water to replace it. But you don't necessarily need to replace every drop while you're doing the work. Runners were instructed for decades that if they didn't drink lots of water during races they could drop dead of dehydration. It's recently been acknowledged that this is vanishingly rare and that people much more often collapse from drinking too much water during races, as the kidneys don't process it efficiently when one is engaged in heavy exercise. It's probably less dangerous to be a little dehydrated for a few hours than to be waterlogged. (And of course, most healthy people with indoor jobs are at no significant risk of suffering illness either way.)