Here’s The Nature Conservancy’s Brian Richter, in his new book Chasing Water, describing what the solution space for the Colorado River Basin’s water problems might look like:

 

Even though urban water uses (for domestic, commercial, and industrial purposes) account for only a minor share of total water use in most water-stressed places, urban water use is often growing much faster than agricultural use. The need for more water in cities and industries conflicts with the reality that agricultures is already consumptively using most of the renewable water supply. One of the options available to cities or industries wanting to access more water is to find ways to work with farmers to share limited water supplies. Ultimately, the economic, social, and environmental risks associated with water scarcity cannot be adequately addressed in many places without reducing the volume of water being consumptively used in agriculture.

Recall from yesterday’s discussion the relative size of Las Vegas and Imperial Irrigation District bars in the Lower Colorado River Basin 2013 water consumption graph:

There’s no way that urban conservation gets us out of this mess.

I love this picture.

E.C. LaRue was a U.S. Geological Survey hydrologist who in 1916 assembled the first attempt at a rigorous scientific survey of the water resources of the Colorado River Basin. Water Supply Paper No. 395 will never be mistaken for great literature. LaRue was one of America’s early technocrats, intellectual ancestors of a thousand government employees and consultants today laboring over Federal Register Notices and Environmental Impact Statements. And yet, clumsily, LaRue reached for a grand vision when he opened the work with a five paragraph “Comparison With the Basin of the Nile.” This is no ordinary project we are embarking on, he seemed to be saying, but rather an opportunity to build one of humanity’s great societies.

In 1923, LaRue returned as a member of the Birdseye Survey, which returned to gather the data he had lacked when writing his 1916 report. But within a decade, he had left government service, frustrated by what he thought was the failure to listen to science. He thought evaporation would be too high at the Boulder Canyon dam site (what we now call “Hoover Dam”, which was really built at Black Canyon, not Boulder Canyon). He favored building the river’s first great dam at Glen Canyon instead.

Most importantly, LaRue argued that there was less water in the Colorado River than people thought.

• The Colorado River and its Utilization, USGS Water Supply Paper No. 395?

This is a picture of the downstream side of Morelos Dam, on the U.S. Mexico border west of Yuma, Ariz. I took it in March, when there was water flowing downstream, into Mexico. That is an unusual sight. This is usually the point where the Colorado River ends.

It’s not entirely clear to me where in this picture the actual U.S.-Mexico border is – out there somewhere underwater. Normally this is not much of an issue, though I’ve been there when it’s dry and there’s no less clarity on the land itself. I’m pretty sure the day I was there when it was dry I crossed back and forth between the two countries on foot without realizing it quite a few times.

Here’s a map.

tl;dr Vegas is an easy target, but Lake Mead’s problems involve far more than Sin City’s profligacy.

Longer version: As Lake Mead drops toward a record low some time next month, there’s a temptation to draw a dotted line to the Bellagio Fountain, 30 miles to the west, and point a finger of blame. It’s not the fountain itself, but rather the water excess of Las Vegas that it symbolizes, that draws the easy comparison, as the energetic and extremely widely read Eric Holthaus did in a recent Slate post that tripped straight from Mead’s record lows to the gaudy fountain on the strip:

If it wasn’t used to water lawns or wow tourists at the Bellagio, it could be used for drinking.

And this is true, but it misses the crucial point embedded deep within the arithmetic underlying Lower Colorado River Basin’s water balance sheet. The question of whether Las Vegas’s water use is unnecessarily profligate is an important one, but it’s of only marginal importance when talking about the risk the Southern Nevada city faces.

Las Vegas could do a dramatically better job of conserving water – shut down the fountains, get rid of the lawns – and still see Lake Mead drop uselessly from beneath its feet. Here’s a graph of how we use Lower Colorado River Basin water that may help explain this:

The blue bars are 2013 consumptive use by the nine largest water users in the lower basin. The orange bar that I snuck in there for comparison is what we’ve been lately calling the “structural deficit” – the excess water used in the lower basin above and beyond the full annual normal year allocation. Southern Nevada – essentially the greater Las Vegas metro area – consumed 223,563 acre feet of water. (source – pdf) Las Vegas could cut its Colorado River water use to zero – blow up all those casinos and leave Vegas to desert dust – and Lake Mead’s structural deficit would still be close to a million acre feet a year.

Look again at the big bars in the chart above. Have you heard of the Wellton-Mohawk Irrigation District? It uses more water than Vegas. Coachella? In addition to some sort of hipster music festival every year, they also use water to farm the desert – more water than Vegas uses to harvest tourist dollars. You’ve of course heard of the Imperial Irrigation District. It uses ten times as much water as Vegas.

I’m not here to defend Las Vegas’s water use. Could they do more to conserve? Absolutely. There’s a serious conversation to be had about that city’s approach to life in the desert. They will have to be to be part of the solution to Lake Mead’s problems. But until the broad societal conversation embraces all the water users, rather than wagging an accusing finger at the Bellagio Fountain, we’re not going to get anywhere in dealing with this problem.

a note on the data: The numbers in the graph are total consumptive water use, as reported in the U.S. Bureau of Reclamation’s 2013 Colorado River Accounting and Water Use Report for Arizona, California, and Nevada (pdf). The numbers represent all large water users in the Lower Colorado River Basin, those whose water is drawn from Lake Mead. These users account for 95 percent of the U.S. Lower Colorado River Basin consumption. The rest is scattered among a bunch of much smaller users, which I was too lazy to graph, plus it would have been too wide. A number of the users shown, including Las Vegas and the Colorado River Indian Tribes, withdraw more water than shown from the river, but then put some back. The numbers in the bar chart represent the net of those two numbers, what in the jargon is called “consumptive use”. For several, including Yuma County ag, I’ve lumped more than one water user into a single bar.

A century and a half ago, there was enough water in the Yuma stretch of the Colorado River to sink a steamboat:

On this date in 1854, the first steamer on the Colorado River, The Uncle Sam, sank at Pilot Knob.

Today, it’s pickups, stuck in the sand:

Yuma Station agents patrolling near the Colorado River saw an abandoned Jeep Cherokee parked near the Normandy barriers. Upon closer inspection, agents noticed a large part of the Normandy barriers had been cut. Nearby, several individuals were trying to free a Chevy pickup truck stuck in the Colorado River. As agents approached the truck, the individuals fled to Mexico. The truck contained 44 bundles of marijuana with a combined weight of 855 pounds, worth an estimated $427,500.