Water use is lower than it's been in 45 years

U.S. population has grown by 105 million people since 1970, yet we somehow shrank our water footprint.


Okay everyone, time for a little quiz about that most precious of substances, water.

When it comes to water use, the United States,
    A. Withdraws billions of gallons more water from rivers, lakes and aquifers than it did in 1970.
    B. Withdraws the same amount of water
    C. Withdraws less water.

2. The state whose residents use the most domestic water (indoor and outdoor) on a per capita basis is:
    A. Nevada
    B. Arizona
    C. Utah
    D. Idaho

3. The biggest water gulping category in the United States is:
    A. Golf courses
    B. Thermoelectric power
    C. Irrigation

3. The biggest water using category in the West is:
    A. Las Vegas Fountains
    B. Fracking
    C. Irrigation

You'll have to read on to find the answers.

According to a US Geological Survey report on water use released last week, the U.S. in 2010 not only withdrew* less water than it did when the agency conducted its previous survey five years earlier, but it also withdrew less than it had since 1970. As the Pacific Institute’s Peter Gleick, a well-known water guru, put it: We appear to have reached Peak Water, decades ago.

Scarcity of water is forcing conservation of water in the U.S and the West.
Jonathan Thompson
The implications are huge. The U.S. has added 105 million people since 1970, and the economy has grown tremendously. Yet we somehow have managed to shrink our overall water footprint. It’s not only counter-intuitive; it’s baffling. Surely, some of our water guzzling was sent overseas when we outsourced manufacturing and food production. Yet most of the savings can be attributed to simple thrift, and huge gains in efficiency in just about every sector.

It’s proof that conservation is not an impediment to economic growth, and that we can limit our collective environmental impact even as the population grows, without sacrificing quality of life. And the western U.S. is leading the way.

The biggest water user in the country is thermoelectric power — most coal, natural gas and solar thermal power plants need water to produce steam to turn turbines and for cooling purposes. Over a five-year period, U.S. plants were able to cut their water withdrawals by 20 percent by installing dry-cooling technology or simply by becoming more efficient. The West has shown even more progress, cutting use by about 50 percent since 2000.

Irrigation is second in water use nationwide, but in the West, it tops the list, guzzling water at almost ten times the rate of Western power plants. Nationwide, irrigators cut water use by about 9 percent since 2005, about the same as in the West, by increasing efficiency and switching from flood irrigation to micro-irrigation, or drip, systems.

Per capita water use has dropped in every state in the West, primarily in Nevada, which is facing hard limits to its supply.
Graph by Jonathan Thompson. Data: USGS

Domestic use dropped by 5 percent. Some Western cities hit hard by drought have cut water use by incentivizing homeowners to tear out their lawns, or by limiting turf at new homes. Increasing water rates on big guzzlers has also helped, as have more efficient plumbing fixtures. Las Vegas reduced a tremendous amount of waste simply by plugging the leaks in its pipes.

The mining industry, on the other hand, which includes oil and gas extraction, pulled 39 percent more water from the earth than it did in 2005, thanks to the sharp uptick in drilling. The mining industry still only accounts for about 1 percent of all withdrawals, about half of which consist of the otherwise unusable saline byproduct of oil and gas production, which is then re-injected into the well to stimulate production. But drillers use mostly fresh water for the hundreds of thousands of gallons of water used to hydraulic fracture a single well. This use shows up in North Dakota, for example, where mining’s water withdrawals shot up from 5.6 million gallons per day in 2005 to 27 million in 2010. Still, that’s only one-sixth of the state’s withdrawals for agriculture. In Wyoming, which saw a natural gas drilling bust between 2005 and 2010, mining's water use plummeted.

Mining, including oil and gas extraction, uses a fraction of the water of, say, irrigation or thermoelectric power, but its use is growing.
Graph by Jonathan Thompson. Data: USGS

Given the scarcity of water in most of the West, we should be the most miserly water users in our homes. We’re not. Utahns and Idahoans (not folks in Arizona or Nevada) suck up more water per capita for bathing, consumption and watering their lawns than any other state. As for total water use, California is the biggest gulper of water in the nation by far, thanks mostly to all of the crops grown there. But those farmers, too, are improving their efficiency. California's rate of application, or the average amount of water it uses for each acre of crops, dropped by 25 percent between 2000 and 2010.
Irrigation slurps up more water than any other use in the West. Note that California withdraws more than 20 billion gallons per day for its crops.
Graph by Jonathan Thompson. Data: USGS

All of this, and there’s still plenty of waste. Las Vegas has taken great strides in conserving water over the last decade, but it still has entire neighborhoods that look like Connecticut, thanks to gluttonous lawn-watering. Colorado, Arizona, Wyoming and California farmers still rely mostly on flood irrigation for their crops. And folks in some of the driest places pay the least for their water, contrary to economic principles. This is all good news, because it means that despite gains, many low-hanging fruit remain. We must pluck them before we even think of building the next dam, pipeline or groundwater pumping scheme.

*The USGS report tracks total withdrawals, or the amount pulled from the source, whether it’s returned to the source or not, rather than consumptive use, which is arguably a more critical measure. Consumptive use is when the water is precluded from subsequent use (at least for a while) because it’s consumed by humans or livestock or is incorporated into a product or plant. A good deal of the water sucked up by a power plant, for example, goes right back into the source, as does a portion of the water used to flood irrigate a field.

Jonathan Thompson is a senior editor at High Country News.