No Need to Get Water from the Moon: We Can Use It More Efficiently Right Here

Scientists announced recently that there is more water on the moon than previously thought.  In the floor of one crater, they found up to a billion gallons of frozen water—enough to fill 1,500 Olympic-size swimming pools.

This is interesting to anyone trying to understand our universe, but I imagine it also caught the attention of a few water officials in dry cities here on Earth.  How long, they might have wondered, before they could lay claim to this new source of water (and at what cost to the moon)?

That may sound farfetched, but you’d be surprised by some of the ideas conceived by water agencies desperate for new supply.

Las Vegas officials have considered everything from seeding clouds over the headwaters of the Colorado River to hauling water from the Great Lakes.

Meanwhile, a Texas-based company announced in July that it will be selling water from Alaska to India. S2C will haul almost 3 billion gallons of water each year from crystal clear Blue Lake near Sitka to India’s west coast.  There could be no better image to reinforce the view of many that water is the oil of the 21st century than the sight of hulking tankers hauling pristine water, not oil, out of Alaska.

And I used to think that hoisting water 2,000 feet over California’s Tehachapi Mountains—the highest lift of any water system in the world—used a lot of energy, but that infrastructure was so last century.

In the twenty-first century, are we in the United States, particularly in the arid Southwest, destined to import water from a continent away?

I don’t think so and here is why: Many cities and states haven’t even begun to tap the resource closest to home: water efficiency.

Just as compact florescent bulbs have allowed us to light our homes with less electricity and hybrid cars have allowed us to go farther on less fuel, a host of new measures and technologies are making it possible for communities to do more with less water.

People are starting to embrace these solutions. Innovations like front-loading washing machines, low-flow toilets, and waterless urinals are becoming more common in people’s homes and public buildings. (Click here for NRDC's tips on how you can improve water efficiency in your home.) Even agriculture is getting into the act with smart irrigation systems that use satellite data to adjust flows to replace the more water-intensive drip systems.

Water efficiency has a broad range of benefits.  My colleague, Ed Osann, who heads our water use efficiency team here at NRDC, has pointed out that in most cities, it costs a lot of money to find new sources of urban water, and it costs a lot to build new infrastructure to bring water in. Efficiency cuts down those costs. It provides extra water we don’t have to pay to import.

Many urban water uses, particularly outdoor irrigation, often produce wastewater discharges as well. Efficiency measures help reduce the amount of wastewater, which in turn helps communities meet water quality objectives and hold down infrastructure costs. 

Using water more efficiently also means we can use energy more efficiently as well. In many places, it requires a great deal of energy to deliver water, treat it, heat it for residential and commercial purposes, and then collect and treat it again when it becomes wastewater.

While this cycle may not use as much energy as shipping water around the globe, it does add up. The California State Water Project, for instance, is the largest single user of energy in California. In the process of delivering water from the San Francisco Bay-Delta to Southern California, the project uses 2 to 3 percent of all electricity consumed in the state.

Meanwhile, if a city like San Diego relied on efficiency instead of Northern California water to provide the next 100,000 acre-feet of water, it would save enough energy to provide electricity for 25 percent of all of the households in San Diego.

One powerful way to reap many of these benefits at once is to build and redevelop communities using green infrastructure. These design solutions—including green roofs, rain gardens, and grey water systems—can reuse rainwater, while at the same time greening urban centers and creating a range of related benefits to people.  Where it is energy-intensive to move water, as it is in California, these benefits include using less energy. 

NRDC’s report, A Clear Blue Future: How Greening California Cities Can Address Water Resources and Climate Challenges in the 21st Century, concludes that using green infrastructure solutions at new residential and commercial properties in urban parts of Southern California and the Bay Area has the potential to increase local water supplies by up to 405,000 acre-feet of water per year by 2030. That is equivalent to roughly two-thirds of the water used by the entire City of Los Angeles each year.

Water efficiency is not flashy. But it works. Surely a plan for using local resources more efficiently makes a lot more sense than shipping water from half way around the world—or the moon.