ILLUSTRATION BY HENRY MCCAUSLAND
In 1976, when I was twenty-one, I spent the summer living in a rented house in Colorado Springs and working on the grounds crew of an apartment complex on what was then the outskirts of the city. During most of day, my co-workers and I moved hoses and sprinklers around the property, to keep the grass green; then we mowed what we had grown. Watering was like a race. The grass began to turn brown almost the moment we moved our sprinklers, partly because we were a mile above sea level in what is essentially a desert, and partly because the apartment complex had been built on porous ground, on the site of an old quarry. One night, I dreamed that one of the Rain Bird rotary sprinklers we used at work was keeping me awake by rhythmically spraying me in bed, and I made a mental note to ask my housemate not to water my room while I was trying to sleep.
Among the many questions I failed to ask myself that summer was where all the water we used at work came from. All I knew was that every time I attached a hose to a spigot and turned it on, I could run it full force until it was time to go home. I now know that the city’s water in those days came from local surface streams and wells. I also know that, since then, the Colorado Springs metropolitan area has more than doubled in population and sprawled far into the Eastern Plains, and that today much of its water comes from the other side of the mountains, from tributaries of the Colorado River.
The Colorado—which I followed from beginning to end while researching an article for The New Yorker and about which I’ve now written a book, called “Where the Water Goes”—isn’t huge. The Mississippi is a thousand miles longer and, in many places, more than a mile wider, and it carries the equivalent of the Colorado’s entire annual flow every couple of weeks. Yet the Colorado is an extraordinarily valuable resource for a huge section of the United States. It and its tributaries supply water to more than thirty-six million people in seven Western states, including residents of Denver, Boulder, Salt Lake City, Albuquerque, Las Vegas, Phoenix, Tucson, San Diego, and Los Angeles. It also powers two of the largest hydroelectric generating plants in America, at Hoover Dam and Glen Canyon Dam, and provides irrigation for more than six million acres of farmland, much of it in Southern California.
All those benefits are threatened by overuse, long-term drought, and climate change, and by the fact that when the seven river states divided the Colorado’s water among themselves, beginning in the nineteen-twenties, they thought the river’s average annual flow was much larger than it was later discovered to be. People who worry about those issues sometimes focus their scorn on Las Vegas, which appears culpable mainly because, of all the cities that draw water from the river, it lies the closest to its banks. But, in actuality, Nevada was so thinly populated when the river was divided up that its allotment is very small—just two per cent of the total—and it actually takes less than that, primarily because Las Vegas has some of most stringent water-conservation regulations in the country.
The principal architect of those regulations was Patricia Mulroy, who in 2014 retired as the general manager of both the Southern Nevada Water Authority and the Las Vegas Valley Water District. She is now a member of the staff of Brookings Mountain West, at the University of Nevada at Las Vegas, and still one of the country’s most visible and influential water experts. I went to see her at U.N.L.V. not long after going for a boat ride on Lake Mead, the enormous reservoir that was created by the construction of Hoover Dam, in the early nineteen-thirties. Lake Mead is the direct source of most of Las Vegas’s water, and it has been a powerful symbol of overuse because it currently contains less than forty per cent as much water as it did in 1998, the last time it was close to full. The decline is easy to envision because as the water recedes it leaves a broad white stripe of mineral deposits on the surrounding canyon walls. At the time of my boat ride, the stripe, known as the bathtub ring, was a hundred and thirty feet tall.
Mulroy has short gray-blond hair and icy blue eyes, and when she talks about water she sometimes looks at you with an expression that can be described only as fierce. “Lake Mead is scary right now,” she said. “I see it suffering the consequences we’ve all known for at least ten years it was going to suffer. It was never a question of if; it was a question of when. The amount of water we thought we had in that river system doesn’t exist. You can’t fault anyone in the nineteen-twenties for their assumptions; that was the best science they had. But today we know better, and Mead is going to be stressed for a long time. Does that mean we can’t have a series of severe weather patterns that would start bringing it back? Sure we can. But I think this is the new normal.”