How can cities across the American West reuse and recycle water to combat drought?

This story is one part of a broader series about ways to save water from the drying Colorado River. See the full project here.

We all use the bathroom, clean our clothes, wash our dishes, take showers or baths, why not collect that water and reuse it? It’s already happening around the world and it’s a technology that’s proven to work.

Water providers can collect what’s called grey water from sinks, bathtubs, showers and laundry machines or even sewage, called blackwater, and treat it for reuse. Fort Collins began allowing grey water systems to be installed in the new buildings this summer and that water can be used to flush toilets or for below-ground irrigation.

Mayor Jeni Arndt said using that water twice, whenever possible, is the responsible thing to do. She acknowledged that the approach might only save a few gallons per home each day but everything counts, plus the approach is a good way to encourage residents to think more sustainably about their water use.

In some cases, the water can be treated and transformed back into drinking water. But it’s even easier to use the water again for non-potable purposes like irrigating crops, watering lawns, recharging groundwater sources and industrial uses, depending on how thoroughly it’s treated.

“It’s a reliable source of water,” Dan Beard, former U.S. Bureau of Reclamation Commissioner, said. “It’s always there. It isn’t subject to drought or other changes. People still flush their toilets.”

Unlike desalination plants, Beard said water treatment plants could be built for much less money and within the span of a year or two. So they’re relatively quick and effective and a wise way to care for the water that’s already in use.

Gary Wockner, head of the nonprofit Save the Colorado, added that Southern California pioneered many ways to reuse water decades ago and called for the upstream states to catch up.

“It’s going to be the future,” Wockner said.

There are limitations, he acknowledged. First among them are complications surrounding water rights and dictating which source of water can be used for which application. Water transported into one river basin from another can typically be used to “extinction,” or captured and reused until it’s gone.

But in other cases, water that has been used once must legally be allowed to drain back into the river’s tributaries to be used by the next person or community downstream.

Plus, Jay Famiglietti, director of the Global Institute for Water Security at the University of Saskatchewan, said there’s only ever going to be so much water available for reuse.

“It’s driven by your supply of human waste,” he said. “That’s as much as you’re going to get.”