We will never run out of water in Tucson.
That’s not a wish or a guess; it’s just simple math and economics. Yet whenever desert communities such as Tucson, Phoenix or Las Vegas broach the subject of water supply, which is vital to the prosperity of each city, a legion of Chicken Littles sally forth with all kinds of dire warnings and predictions about how the end of life as we know it is nigh if we don’t drastically curtail our water consumption.
Why, they claim, if we don’t slow population growth and enforce strict water-use caps we’ll run out of water.
No we won’t. As long as water falls from the sky in the Western United States, there’ll be plenty of water for populations much, much larger than those already living here.
But what will change is the source of that water, its cost and how it’s used and reused. As demand increases and supplies fall, we crafty and clever humans will figure out ways to recycle water to serve multiple uses and we’ll find new water supplies to serve our household, commercial and industrial needs.
All the hand wringing and woe-is-us lamentations about fresh water almost seem laughable when you look at satellite images of the earth. It’s mostly water.
It requires the most extreme of pessimists to stand on a beach and look out to sea and say, “Tsk, too bad it’s got salt in it,” then shrug and walk away.
The reason we don’t use seawater now is because there’s so much fresh water that the supply greatly outstrips demand making it exceedingly cheap. Desalinating water is expensive. If we get to the point where fresh water becomes scarcer and the price begins to rise, it will become more economical to desalinate water. Moreover, just because it’s expensive now doesn’t mean we won’t figure out cheap ways to do it in the future. We humans are pretty smart. We figure stuff out. If it becomes vital that we figure out cheap ways to get salt of out of seawater, we will.
But that doesn’t mean we should be cavalier about the water we’re using now. Last week the U.S. Bureau of Reclamation released the results of a three-year study of water use in the Colorado River Basin, which encompasses six states, from Yellowstone to Yuma.
Using conservative estimates for annual flows and liberal estimates for population growth, the study predicts a 1 trillion gallon annual supply shortfall by 2060.
The expansive study is a starting point for discussions about water use in Western states and cities. What it isn’t is a clarion for hysterical predictions about the end of the West because it’s “running out of water” (an average of between 2 and 3 trillion gallons of water on will still flow down the river annually).
The Colorado is a vital source of water for Tucson but it’s not the sole source of water. We should plan now for how we’re going to provide water to 1 million or more new residents over the next 50 years without relying on the Colorado.