The Dry Garden: More Benefits to Saving Water Outdoors

Emily Green wrote a great article called The Dry Garden: Want to save energy? Start by saving water, for the Los Angeles Times last Friday in which she spoke with Peter Gleick from the Pacific Institute about how to address the topic of water and climate change without leaving everyone in the room “utterly depressed and helpless.” Gleick’s answer: “If you want to save energy, save water.”

For anybody who’s been following this blog, Gleick’s answer seems obvious. But as Green points out:

The knowledge isn’t new, but comprehension is so low… It may be the stealthy quality of water. It simply seems to flow naturally into our sprinklers, garden hoses, toilets, baths and washing machines while it’s actually moved to us. [People don’t realize moving water] takes so much power that the pumps that convey and treat California’s water account for roughly 20% of the electricity consumed in the state.

Gleick goes on to explain how saving hot water has a double benefit by saving both the energy to move and treat the water as well as the energy to heat the water at your home. Not only does saving hot water reduce YOUR energy bills, according to our analysis, water heating represents around three-quarters of all the energy and carbon embedded in water. Fixtures such as showerheads and faucet aerators save a lot of hot water, as do appliances such as water-efficient washing machines and dishwashers.

That is not to say that saving cold water won’t save a lot of energy. As Gleick explains:

“Even if you’re saving cold water, that’s water that doesn’t have to be pumped over the Tehachapi Mountains or water that in the future doesn’t have to be desalinated.”

Green ends her article by explaining that 40% to 60% of our water goes outdoors to irrigate landscapes so now is the time plant native, take out your lawn, or xeriscape. Reusing greywater or harvesting rainwater are also good measures but should only be applied after your landscape is made more efficient - using alternative water supplies should not be an excuse to maintain a water guzzling landscape.

There are also some additional benefits of using less water outdoors that Emily Green left out of her post.

Outdoor irrigation – which takes place primarily in the summer months for much of the country - is a major factor in peak water demand. Peak water demand - like peak energy demand - usually drives the development of new supplies and leveling the peaks can avoid the costs of new dams/diversion, or the development of new energy intensive supplies, such as desalinated seawater or imported water.

Furthermore, the marginal water supplies used to meet peak demands are often more energy and carbon intensive than the least cost supplies used throughout the year, therefore, in many communities, saving a gallon of water in the summer saves more energy than a gallon in the winter.

Finally, peak water demand and peak energy demand usually occur at the same time - during extremely hot weather when air conditioners are turned on high, cooling towers are working overdrive, crops and landscapes need irrigation, etc. Saving water can reduce peak energy demand, as evidenced by Idaho Power's partnership with farmers. To add one more twist, the oldest, dirtiest power plants get kicked into overdrive to meet peak electricity demand, which means that when you water your lawn on the hottest day of summer, the dirtiest, most carbon intensive energy was likely used to deliver that water from the most energy intensive source.

So yes, using less water outdoors really can save energy and help fight climate change.