Hoover Dam, Oct. 17, 2010

If you blow this picture up enough, you can probably see pixels of rock that have not been exposed since the 1930s. Or maybe not.

The surface elevation of Lake Mead hit 1083.18 feet above sea level today between 11 a.m. and noon Pacific time today, when this picture was taken. That is below the previous low – 1083.19 – on April 26, 1956. We can now unequivocally say that the drought of the ’00s and continued water consumption by downstream users has lowered the mighty reservoir to the lowest level it has seen since it was filled in the 1930s.

I tried this morning to explain to one of the tourists visiting Lake Mead the historic significance of the bathtub ring. He had jumped out of his car on an overlook on the Arizona side of Hoover Dam, and he was doing that thing where you hold your digital camera out at arms length to get yourself in the picture.

I told him it was a historic picture – that today Lake Mead had dropped to its lowest level since they built Hoover Dam in the 1930s. He looked puzzled.

Him: “Why’s it so low?”

Me: “Drought upstream. Water use downstream.”

Him: “It’ll fill up some day.”

And he jumped back in his car, headed for Vegas. This is how we do drought, American style.

Lake Mead, Oct. 17, 2010

I tried various explanations of what was going on this morning, from the quick to the complex, sort of testing my message as I wandered among the tourists visiting the dam, oblivious to the history I was trying to document.

It was hard to get across the drama. So far, the people suffering the most from Lake Mead’s decline seem to be the recreational boaters, who keep having to move their floating docks to chase the dropping water. I guess we can count that as a good thing. I mean, no one dies here in a drought, right?

We are sufficiently buffered by affluence that almost no one I talked to today had any inkling of what was going on. Just another tourist Sunday on Hoover Dam. The best I got was from one the folks in this picture, who were on a Sunday drive at one of the Lake Mead overlooks. One of them, a Las Vegas resident, knew the lake was way low, and said the solution was simple – somebody needs to have the political courage to make them release more water from Lake Powell, upstream.

I decided against explaining the Colorado River Compact, and the complex reservoir equalization rules in the 2007 shortage sharing agreement, that upper basin states are using less than their share of the river anyway, that Powell is low too, that it’s not that easy. But ultimately, I guess that’s what I have to figure out how to explain.

KINGMAN, ARIZ. – I made a beeline across two states today, heading for Lake Mead to watch history happen.

It looks as though sometime tomorrow (Sun. 10/17) or Monday, depending on the weather and releases from Hoover Dam for power generation and downstream water users, the surface level of Lake Mead will drop below 1083.19 feet, its low point during drought of the 1950s. As I write this Saturday evening, it’s less than an inch away.

Kingman, Ariz., October 2010

I made it as far as Kingman by sunset, and after checking into my motel grabbed some fast food and headed to a city park. By the time I got there it was pouring, so I hunkered down in the shelter of a utility building and watched. It had the feel of a summer thunderstorm even though it’s mid-October, with thrashing winds, thunder and lightning. It’s fall enough that the wind was blowing leaves off the trees, and my feet got wet and cold (I was wearing sandals.) But it was lovely nonetheless. There is a joy to being in the desert in a downpour. As I drove back to the motel, gutters were running full, and kids were splashing.

On the drive over, across northern Arizona, you could still see big patches of piñon pine that died in the drought of 2002-2003.

Tom Yulsman has an excellent post today on the what’s and why’s of  Lake Mead’s situation, to which I don’t have a lot to add. Well, OK, I have a lot to add, enough to write a book, but there will be time enough for that. For now, head over to Tom’s place for an explanation of our big dry, with the money quote from Brad Udall:

. . . what you’re really seeing here is a combination of drought and an overuse problem amongst the three three lower basin states of California, Nevada and Arizona. And that overuse problem historically has been covered up by a little extra water that flows down from Colorado and the upper basin states. But over the last 11 years, with the most serious drought on record, that water hasn’t been there, and so the overuse problem has become readily apparent.

It’s worth noting that the variables that will determine when we drop below that 1950s low are weather and downstream use – how much water nature provides and how we decide to use it. Drought in this sense is very much a human phenomenon.

The response to the convergence of those problems is the 2007 shortage sharing agreement among the lower basin states. It’s a remarkable thing, a set of guidelines to do something that has never been needed before in a century of industrialized development of the Colorado River – to use less water.

One of the reasons I’m heading to Hoover Dam, Lake Mead and Las Vegas is to learn more about how the shortage sharing agreement was developed, and how it will work in practice.  I’m increasingly dissatisfied with the “OMG we’re screwed” narrative. I’m trying to understand the institutional frameworks that have allowed us to go through the 11 driest years on record without anyone’s water being cut off, and to further understand what happens during year 12, which seems to have a good chance of happening in 2011.

In the time I’ve been writing this, Lake Mead dropped another 1/8th of an inch.

Major water project development in the western US has always depended on federal subsidies. One can view those subsidies in a number of different ways – a boondoggle propping up rich ag interests, a foolish lack of clarity about what it really means to build a society in the arid lands, or a reasonable federal interest in supporting societal development that would otherwise not be possible west of the 100th meridian.

Whichever version of history one prefers, it seems increasingly clear that we are seeing the end of the era of federal subsidies. Yesterday’s story by Judy Fahys and Thomas Burr in the Salt Lake Tribune is a case in point:

The Wasatch Front has labored for decades to channel water from Utah’s eastern mountains to its thirsty and growing population, and Washington, D.C., has pumped more than $2 billion into building the Central Utah Project to support that goal.

Last week, project supporters said, word came that the Obama administration’s budget makers will not let a drop flow from next year’s funding spigot.

Budgets are where governments reify their goals and values. So this bears watching.

I’ve written before about the possibility that we could view Australia’s struggles with long term drought, especially in the Murray-Darling Basin, as a model for how to deal with things here in the arid southwest. This version of the model is perhaps not quite so hopeful. From Australian Broadcasting:

A guide for water allocations in Australia’s beleaguered Murray-Darling Basin is due to be released tomorrow, and already irrigators are up in arms over reports that it might recommend cuts of up to 37 per cent.

Irrigators warn that cuts of this size could send whole communities to the wall in Australia’s most productive agricultural land.

But at the same time, environmentalists insist that despite the recent rain, the Murray-Darling is a still river in crisis and substantial reforms are necessary to ensure its long-term viability.

Is this, also, a preview of some of the issues we can expect in the Colorado River and Rio Grande basins in coming decades? It already sounds a bit like the wrangling in California’s Central Valley.