Watering a Lawn vs. Putting in a Pool: Nitty-gritty

Q: Now that we are facing drought and climate change, I am wondering about the sustainability of our green lawns we love so much in Sacramento Valley. Which is more efficient, keeping your lawn green or replacing it with a swimming pool? I seem to remember reading once that a swimming pool actually wastes less water per square foot than a lawn. Is that true?

Asked by Bill Tournay, ’65, Sacramento, Calif.

In The Home Water Supply: How to Find, Filter, Store, and Conserve It Stu Campbell reports that for a 1,000-square-foot lawn watered half an inch per day, you use twice as much water as you would to keep a pool of the same area filled. For such a lawn, 600 gallons of water would be used in a day, compared to 300 gallons for a pool of that size. Of course, these numbers are bound to change depending on the type of grass, whether or not your pool is leaky and numerous other variables, but in any case, a pool is better.

Water use is not the only metric to consider when examining sustainability, but before we jump into those other measures let's look at the concept of sustainability.

Sustainability in a Nutshell

We're in love with sustainability these days. It just sounds so right. But what is it exactly?

At its core, sustainability is about sustaining, perpetuating, lasting. But it's not about making everything last—it's about making good things last. We want pandas to be sustainable. Pandas are good. We don't want racism to be sustainable. Racism is bad. We want our individual health and happiness to be sustainable. Health and happiness are good.

As these examples demonstrate, sustainability isn't just about the environment. Sustainability is often thought to be three-fold: environmental, social and personal. That's what makes sustainability so hard to do. A truly sustainable solution is one that makes the good things last for me, for humanity and for mother earth. Let's now consider this three-fold concept in relation to the question at hand: What's more sustainable: a lawn or a pool?

Environmental sustainability

Let's pretend you only care about the Earth. The answer to your question is probably the pool—and not just because of its lower water requirements. Pools are less safe than lawns due to the danger of drowning, or of slipping and falling. This means that pools tend to decrease the human population, which is good for the Earth. According to the Foundation for Aquatic Injury Prevention, residential swimming pools are the main cause of unintentional injury-related death for children ages 1 to 4. Imagine the amount of water saved by having fewer Americans around. Okay, don't imagine that—it's only an extreme example, and while population does matter tremendously for all three kinds of sustainability, backyard deathtraps are not the way to go.

Social Sustainability

Now you only care about society as a whole. This is a toss-up—both pools and lawns have benefits and detriments for society. Pools cost more to build and maintain, so you would be helping to support the economy by owning one. But pools also serve as a threat to public health. They could also be considered good for public health if you allowed your neighbors to use it for exercise. The lawn is more sustainable because it is safer, and would not incite neighborhood conflict by owning a pool when the rest or you neighborhood sweats it out on their lawns. If you put up a tall fence around your pool so that nobody could accidentally drown, the pool would once again be the winner.

Personal sustainability

You're selfish now. It's all about you. What do you want? My guess is that both a pool and a lawn would be suitable, although you'd probably want a bit of both. Wouldn't it be nice to hop in a pool on a hot summer day and play catch on the lawn as the leaves of autumn fall? It's probably not feasible to cover your entire yard with a pool anyway, so you'd probably have a pool-lawn hybrid anyway. In any case, you're going to win!

Overall Sustainability

Adding it up: environmental sustainability (pool) + social sustainability (pool) + personal sustainability (pool). A pool it is! Unless . . .

Rephrasing the Question

Imagine that you asked the question “What is a more sustainable alternative to my green lawn?” That would be even easier to answer. There are number of more sustainable alternatives to green lawns, and you might love them just as much, if not more!

First, you could have a native plant lawn. These are lawn alternatives that support the native ecosystem. Rather than planting invasive species in your yard, which include most popular lawn grasses, you could plant deergrass, sagebrush, coffeeberry or any number of plants native to California. Not only are these native plants beautiful and unique, they are also perfectly evolved to survive in California's climate, so you won't have to water them as much, if at all!

An even better option might be a garden. Unlike lawns, which serve a largely ornamental purpose, gardens can be used to feed your family and local community, helping you become even more sustainable!

If you really must have a green lawn, consider a synthetic lawn that you don't have to water. Or, better yet, if you don't mind having a brown lawn sometimes, just don't water in the summertime. If your neighborhood council comes knocking on your door, just tell them you're following Mother Nature's orders!

Nick Jachowski plans to receive his master's in earth systems in 2010.