This goes back a few years now, but I still remember the shock. After a long stint as a resident of the Midwest, I moved to the Phoenix area in the 1990s. Having previously only driven through our 48th state to visit the Grand Canyon, I didn’t know what to expect.

But I knew that Arizona’s capital was situated on the edge of the Sonoran Desert, was populated with more cactus plants than people (so I thought) and received only about 8 inches of rain a year—in a good year. (In contrast, other Sun Belt cities are far wetter—Miami gets 58 inches of precipitation a year, Atlanta gets 50 inches and even Dallas gets 34 inches of rain annually).

Imagine my surprise, then, when I drove through my new neighborhood in Tempe just south of Phoenix and saw green lawns, shade trees and lots and lots of flowers and shrubbery surrounding the houses, apartments and commercial buildings. Of course, all this greenery was being watered relentlessly against the 100-degree heat, with just about every piece of property seemingly hooked up to automatic sprinkler systems that most mornings would collectively drown out the traffic noise.

I had to ask: Why is everyone watering their lawns and landscaping? I thought this was a desert. Where’s the water coming from?

The short answer was that years ago, much of the valley where Greater Phoenix now sprawls—and I mean sprawls; the municipal area encompasses more than 16,000 square miles—used to be planted in citrus and cotton. Both of those crops, obviously, require immense amounts of irrigation, which was sourced primarily from underground wells and municipal systems that pulled water from nearby rivers originating in the state’s more mountainous central and northern regions. When the Central Arizona Project, a massive pipeline that diverted water from the Colorado River, finally reached Phoenix in the 1980s, it coincided with a massive influx of people and the subsequent transformation of what used to be farm fields into endless red tile-roofed, stucco-sided housing developments.

Those houses, and the tens of thousands of new arrivals living in them, actually use a lot less water per acre than cotton plants, and by the 1990s, Phoenix allowed residents to plant trees, grow gardens and put in luxurious green lawns that looked like they were imported from a Chicago suburb. Who cares? There’s plenty of water!

Only there isn’t.

Runnin’ on empty

As the ironically named author Jonathan Waterman documents in his book, “Running Dry,” the Colorado River no longer flows all the way to the ocean, where it formerly emptied into the Gulf of California separating Baja California from the Mexican mainland. Instead, once-mighty waterway ends in a desolate series of stagnant pools, dusty bottomland and dried-up delta marshes. Thanks to irrigation projects and municipal water diversions, there’s hardly any volume of water left when the Colorado completes its 1,500-mile journey from the Rockies to the sea.

Farther upstream, Lake Powell, the gigantic reservoir formed by Glen Canyon Dam, sports a permanent “bathtub ring” extending 70 or 80 feet up the sides of the rock cliffs along its boundaries, marking the depths to which water levels have sunk in the last couple decades.

The wholesale extraction of Colorado River water is similar to the problems of a number of other river systems around the world, including the Yellow River, the largest river in northern China; the Nile River in Egypt; the Indus River, which supplies most of Pakistan’s irrigation water; and the Ganges River that runs through India’s most populous region—none of which flow normally to their final destination.

It’s symptomatic of a larger problem: The overuse of water for agricultural, industrial and residential uses, exacerbated by surging population growth and more affluent lifestyles.

“There’s just not enough fresh water to handle nine billion people at current consumption levels,” Patricia Mulroy, a board member of the Colorado-based Water Research Foundation, stated in a recent Smithsonian magazine article on the subject. In the southwestern United States, Mulroy argued that “People need a fundamental, cultural attitude change about water supply. It’s not abundant, it’s not reliable, it’s not going to always be there.”

The emergence of “peak water” parallels the energy crisis, in which oil is more difficult and more costly to extract from rock shale and tar sands—only with one difference: We can’t just switch over to some other source for agricultural, industrial and residential usage that requires generous amounts of H2O.

Severe shrinkage

For agriculture, the impact may be severe. In California, according to data compiled by the Earth Policy Institute, a combination of aquifer depletion and diversion of surface water to urban uses has reduced irrigated farmland from nearly 9 million acres in 1997 to an less than 7.5 million acres today. In Texas, irrigated farmland peaked 30 years ago at 7 million acres; it’s now down to less than 5 million acres, as the Ogallala aquifer underlying the Texas panhandle continues to be depleted.

Other important agricultural states with shrinking irrigated acreage include Colorado, Florida and Arizona, all three faced with aquifer depletion and the effects of diversion of irrigation water to cities. Even farm states that were previously expanding irrigated acreage—such as Nebraska and Arkansas—are seeing irrigated farm acreage quickly leveling off.

There are other ominous signs of an impending water crisis, such as:

  • Falling lake levels. Both Lakes Michigan and Huron, two of the world’s largest bodies of fresh water, are at all-time record low levels—all of the Great Lakes are at historically low levels—due, scientists say, to a combination of a severe drought last summer and higher average temperatures that have increased summertime evaporation rates.
  • Middle Eastern crises. In nearly all of the countries across the Middle East—Israel, Jordan, Saudi Arabia, Yemen, Iran and Iraq—oil dollars have brought increased affluence, which means far greater water consumption. Despite extensive desalination projects, the need for increasingly larger amounts of water for farming, commercial and industrial uses is severely and rapidly depleting the region’s once-vast underground aquifers.
  • Virtual water exports. Consider that a significant percentage of wheat, corn, beef, pork, cotton, rice and sugar—much of which is produced in drier regions of the world, like Australia, Argentina, western Canada, Egypt and Pakistan—all represent significant water consumption that ends up getting shipped out the producing country.

All of this is complicated by what we know—the increase in global population—and by what we don’t know—the impact of climate change. It adds up to a potentially disastrous situation for farmers and ranchers.

With the energy crisis, we’re learning to re-think our lifestyles and consumption patterns, and we have the option of investing in alternative, renewable sources of energy that someday could replace much of the fossil fuels upon which we currently depend.

With the world’s dwindling supply of fresh water, the reboot won’t be nearly so straightforward.

The opinions expressed in this commentary are solely those of Dan Murphy, a veteran food-industry journalist and commentator.