In California, clarifying what we mean by “drought”

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Preparing for a lecture for next week for the University of New Mexico Water Resources Program class I’m co-teaching, I’m having the students read this piece by my drought guru Kelly Redmond:

Most concepts of drought involve a water balance. This implies that both supply and demand must be considered, as well as the question of whether there is “enough” (and, enough for what?). Thus, through time I have come to favor a simple definition; that is, insufficient water to meet needs. (emphasis added)

California drought monitor

California drought monitor

I’ll be talking some of the quantitative drought metrics, like the Palmer Drought Severity Index, or the Standardized Precipitation Index, or How Much Water Is In That Big Reservoir. But Kelly’s point is that the key is to understand how systems (people, ecosystems, etc.) are actually using the water. This helps clarify what we mean by “drought” beyond simply “OMG look at that big ugly red Drought Blob of Death that landed on California!”

A second reading assignment is a new white paper by Ellen Hanak and colleagues at the Public Policy Institute of California that does the clarifying work by getting specific about the question of who’s really being forced to go without water, or facing reduced supplies of water, or creating future risks. Hanak and colleagues push this forward with a useful thought experiment: what if California’s drought continues?

Ellen Hanak, Public Policy Institute of California

Ellen Hanak, Public Policy Institute of California

Given the pervasive nature of the red blob in public discourse, one important starting point is the PPIC team’s observation that California’s major municipal areas are doing pretty well, and should continue to do so:

Urban areas are in the best shape, thanks to sustained investments in diversified water portfolios and conservation.

Farmers, they note, have done remarkably well in adapting, especially by crop shifting and fallowing, though excessive groundwater pumping, especially in the Central Valley, may be adaptive in the short run and maladaptive in the long run, what with the surface of the earth actually sinking because they’re pumping so much and so on.

The two greatest problem areas the PPIC team found are rural communities and natural systems. Rural communities lack the resources of L.A. or San Francisco to buy their way into deeper resilience:

Many rural households rely on shallow domestic wells or small, poorly funded community water supply systems.

Natural systems also are suffering:

The most acute and severe impacts of this drought so far are on California’s freshwater habitats and forested lands and on the biodiversity they support. These impacts stem, in part, from the severity of the drought and its combination of low flows and heat. More than a century of water and land practices have increased vulnerability by undermining the natural capacity of these ecosystems to handle occasional droughts.

The environment doesn’t have the same kinds of adaptation tools as other sectors—it generally can’t pump more groundwater in dry times, for example. But this troubling situation also reflects less investment in building drought resilience for the environment. California was unprepared for this environmental drought emergency and is now struggling to implement stopgap measures.

As a communicator, I’ve long struggled with the inadequacies of the word “drought” for two reasons. The first is its binary nature – we’re either in it or we’re not. “Is the drought over?” That’s wrong, but pervasive, because when it’s used out in the wild, in public discourse, I can’t control the meanings regular people take from the word. The second is its hidden imprecision. We use it in water policy and practice discussions without realizing that we may be using the same word but not meaning the same thing. Trying to unpack the word and explain its many shades of meaning for the WRP students is therefore a really fun exercise.

From Peter Gleick, an optimistic take on California drought response

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Peter Gleick in the Sacramento Bee:

As California swelters and burns through the fourth year of the worst drought in 1,200 years, nonpartisan and bipartisan efforts have been increasingly effective. A multibillion-dollar bond measure passed by voters last year is providing funds for drought relief and new supply and conservation programs. Water utilities are expanding investments in water recycling and reuse. Farmers are growing more food with less water. In short, Californians are stepping up in a crisis to do things differently.

The Lower Colorado: no shortage for now, but that pesky structural deficit’s still there

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Hoover Dam, Lake Mead bathtub ring, February 23, 2015. Elevation 1088.97

Hoover Dam, Lake Mead bathtub ring, February 23, 2015. Elevation 1088.97. ©  John Fleck

No Lower Colorado River shortage for now, but don’t break out the party hats.

Lake Mead is forecast to end calendar year 2015 with a surface elevation of 1,082.33 feet above sea level, according to new numbers released yesterday by the U.S. Bureau of Reclamation. The current forecast for the end of 2016 is 1,079.57. The good news is that both of those numbers are greater than 1,075, which means the odds are against there being a “shortage” declared this year or next (when Mead hits 1,075 on some future January 1, rules kick in that reduce Arizona, Nevada, and Mexico allocations – repeat after me “this is not a crisis” – more here).

The bad news is that 1,079.57 is lower than 1,082.33, which means that even in these sorta good times, hydrologically speaking, Lake Mead keeps dropping. By “good times”, I mean that a big boost of precipitation in recent months in the Upper Colorado River Basin means that Lake Powell, the big reservoir at the upstream end of the Grand Canyon, is actually inching up right now. It’s forecast to end this year nearly five feet above last year’s levels, with the chance it could go up again next year. The good hydrology means that, under the river’s operating rules, Lake Powell will release “bonus” water this year and next. Under the rules, the Upper Basin is sorta legally required to release 8.23 million acre feet from Lake Powell down through the Grand Canyon to Lake Mead. This year and next, the current forecast calls for 9 million acre feet.

Lower Basin Water Budget, courtesy USBR

Lower Basin Water Budget, courtesy USBR

But despite that “bonus water”, the Bureau of Reclamation’s latest monthly water management planning report (the “24-month study”, pdf) shows Lake Mead is likely to just keep dropping.

How could that be?

The Lower Colorado “structural deficit”

Water managers call it the “structural deficit” – the hydrologic reality that under the current water allocation rules, there is more water allocated on paper flowing out of Lake Mead than can reliably be expected to flow into Lake Mead. The table describes what happens if Mead gets the legal minimum required, 8.23 million acre feet. With those levels of inflow, the “structural deficit” is 1.2 million acre feet per year. With the “bonus water” of a 9 million acre foot inflow from Lake Powell, the structural deficit shrinks to a few hundred thousand acre feet, give or take some math.

So to reiterate, even with a dollop of extra water flowing in, Lake Mead keeps dropping, as it will continue to do until the water management community comes up with a scheme to reduce allocations and consumption below current levels. As I said above, this is not a crisis. But neither is it a good thing.

I know, I know, y’all are working on it. I’ll quit nagging.

Colorado River produce in Albuquerque (courtesy Fisher Ranch)

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Lissa spotted this California desert treat this morning at Trader Joe’s in Albuquerque:

Fisher melon, from Blythe, Calif.

Fisher melon, from Blythe, Calif.

It’s a cantaloupe from Fisher Ranch in Blythe, Calif., owned by Bart Fisher, vice president of the Palo Verde Irrigation District board and chairman of the Colorado River Board of California. I pronounce this a fine use of senior Colorado River water rights, helping to grow yummy treats.

Palo Verde: what Colorado Basin water problem solving looks like

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Palo Verde Irrigation District, Blythe, Calif.

Palo Verde Irrigation District, Blythe, Calif., by John Fleck

Tony Perry in the Los Angeles Times had a good story this weekend talking about the agreement between the Palo Verde Irrigation District and the Metropolitan Water District of Southern California to move ag water to city use in the cities’ time of need:

Next year the agreement between MWD and the Palo Verde Irrigation District will mean an additional 120,000 acre-feet of water for MWD to supply its customers in six counties — enough for 240,000 families. It may also allow MWD to leave water in Lake Mead, helping slow the lake’s decline.

Fallowed acreage, Palo Verde Irrigation District

Fallowed acreage, Palo Verde Irrigation District

The city pays farmers for the right to fallow, guaranteeing steady cash flow, then more money in a year when the actually fallowing takes place, replacing lost farm income. The result is a patch of desert farm land that looks like this, to the left, where yellow parcels are fallowed land. You can see that it’s a checkerboard, with a lot of the land still in production.

I’ve been tempted to call this “sharing” of Colorado River water, but Brian Devine has pointed out the flaw in that language. This is a mutually beneficial business deal, not handing out cookies on the playground.

Palo Verde and Imperial: a comparison

Perry points in the piece to the contrast between Palo Verde and its neighbor to the south, the Imperial Irrigation District:

In the Imperial Valley, so-called fallowing agreements have caused political upheaval, recriminations and litigation. The federal government had to threaten to take the water without compensation to get the Imperial Irrigation District to agree in 2003 to sell water to San Diego.

But just to the north, in the smaller Palo Verde Valley, a 35-year agreement signed in 2005 with the Metropolitan Water District of Southern California has enjoyed public acceptance by farmers and local officials. More than 90% of landowners signed up for the voluntary program.

That’s right, but I’m not sure it matters. Despite the fussin’ and feudin’ in Imperial, the fact remains that we’re looking at more than 400,000 acre feet of conservation in Imperial this year through various means, including fallowing, a new (and very popular with the farmers, apparently) on-farm conservation program in which farmers get paid for conservation measures short of fallowing, system improvements like canal lining, and fallowing. A lot of that water is being sent on to metropolitan Southern California. Taken together, all of this ag conservation has become a critical piece of the adaptive capacity and resilience that Southern California is calling on to weather the current drought.

That time Lake Mead was full

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Lake Mead, behind Hoover Dam. Undated photo for Historical American Engineering Record survey, courtesy Library of Congress

Lake Mead, behind Hoover Dam. Undated photo for Historical American Engineering Record survey, courtesy Library of Congress

This is part of a Library of Congress collection of photographs taken as part of the Historical American Engineering Record surveys, an amazing body of documentation of America’s built environment. The pictures in this LOC on line archive aren’t dated, but my best guess based on clues (a distinctive URL) is 1987. Mead was close to full that year. I’d love it if any of y’all can suss out other clues to help me figure out if that’s right (lookin’ at you, DG).

Lake Mead Then and Now

I don’t have any pictures from the same vantage point from my most recent trip, but here’s one from the same side, a bit up river and looking back toward the intake towers, taken in February. If I’m right about the dates, Mead’s surface elevation was between 1,205 and 1,210 feet above sea level in 1987 when the above picture was taken. When I took mine in February, it was somewhere around 1,089, 120 feet lower. It’s currently at 1,078, more than 10 feet lower than when I took this picture:

Hoover Dam, February 2015, by John Fleck

Hoover Dam, February 2015, by John Fleck

Here’s another of the HAER images, taken by photographer Jet Lowe, with an angle similar to my shot to allow a better comparison:

Hoover Dam, HAER, by Jet Lowe, courtesy Library of Congress

Hoover Dam, HAER, by Jet Lowe, courtesy Library of Congress

One key lesson (in addition to the fact that we’re using too much water downstream) is that Jet Lowe is a much better photographer than I. But it’s hard to take a bad picture of Hoover Dam.

Phoenix subsidence and groundwater pumping

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A new paper by Megan Miller and Manoochehr Shirzaei at Arizona State describing subsidence in the Phoenix area offers some interesting new data for thinking about the implications of groundwater management. Subsidence is bad, and groundwater pumping is what causes it. Having the ground surface drop is bad all around, cracking building foundations, messing up roads, and such. What’s interesting about the Miller and Shirzaei paper is that it shows subsidence continuing long after groundwater overdraft stops. Here’s the key figure:

Groundwater levels (blue triangles) and surface elevation (red dots). From Miller, M. M., and M. Shirzaei (2015), Spatiotemporal characterization of land subsidence and uplift in Phoenix using InSAR time series and wavelet transforms, J. Geophys. Res. Solid Earth, 120, doi:10.1002/2015JB012017.

Groundwater levels (blue triangles) and surface elevation (red dots). From Miller, M. M., and M. Shirzaei (2015), Spatiotemporal characterization of land subsidence and uplift in Phoenix using InSAR time series and wavelet transforms, J. Geophys. Res. Solid Earth, 120, doi:10.1002/2015JB012017.

This is data from four key areas where the authors were measuring the earth’s surface rising or falling. The red dots are earth’s surface (rising in two areas, dropping in the other two) plotted against the levels of the underlying aquifer, which is rising in all four areas. As the authors explain, central Arizona, the area in and around Phoenix, pumped the hell out of its groundwater through most of the 20th century. That began to reverse with the passage of the state’s Groundwater Management Act in 1980, and there’s good evidence that in the decades since the overpumping has been reversed (see for example this paper from 2010 by a couple of USGS researchers which found 80 percent of the Phoenix area’s wells either stable or rising, and this one from the USGS’s Leonard Konikow, which also shows recovery in southern Arizona aquifers coinciding with the years after the GMA’s passage).

What’s interesting here is the wonky technical discussion of aquifer pore spaces and compaction that leads to the conclusion that subsidence is continuing in some areas even though the aquifer is rebounding.

The Economist gives Las Vegas points for water management

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The notion of using “Las Vegas” and “sustainable” in the same sentence might give a lot of westerners the heebee jeebees, but there’s an interesting case to be made that its water management decisions over the last decade have pointed it in that direction. The Economist, in a look at Vegas water performance in its latest issue, doesn’t use the “s” word, but gives Vegas high marks for getting its water management house in order:

To the casual observer, with most of the West parched, Las Vegas’s water use seems astonishingly wasteful. Visitors flying in see acre on acre of suburban houses, a good proportion of them with pools. Those staying on the Strip find abundant fountains, enormous swimming pools and palm-lined boulevards, all in the middle of the desert. And yet beneath this mirage, quietly, Sin City has proven remarkably effective at managing its water, even as its population booms.

Talking to some folks today who are working on Colorado River water issues, I trotted out the Las Vegas example because the issue The Economist keyed in on is so interesting to me. Vegas looks crazy water wasteful. But the underlying numbers are actually kind of encouraging. Vegas water use and population data is another example of the “decoupling” I’ve been writing about – water use dropping even as population, economic growth, ag productivity, etc., rise. Here’s some of the data I’ve assembled in research for my book, which shows the water use curve bending down, significantly, after 2002, even as population has continued to grow:

 

Las Vegas Colorado River water use

 

Vegas and Candide

A colleague who’s been helping me think about these issues has been properly cautioning me against Panglossian optimism. (In fact, this colleague literally bade me read Candide so I would understand the fallacy of my “Panglossian optimism”. It’s a short book, and the university library a two minute walk from my office offered a choice of translations. I love my new academic posting.) I sometimes get sloppy with my “when people have less water, they use less water” argument, as if the sort of adaptive capacity that happened in Las Vegas is inevitable. This is not, in fact, the best of all possible worlds, as Candide so painfully discovered. But neither is the sort of pessimism, the we’re-completely-doomed rhetoric around Western water management that makes a lot of our current water policy rhetoric sound like Candide’s downer of a traveling companion Martin. (The scenes of Candide and Martin’s trip from South America back to Europe are like a hilarious pastiche of a journalist’s 2015 road trip through California’s Central Valley. “Why, then, was this world formed at all? asked Candide. To drive us mad, answered Martin.”)

These examples of adaptive capacity I’m trotting out, of “decoupling”, are a sign that solving our water problems is tractable, and that there are examples of how one might succeed. But it’s not inevitable. Lake Mead’s still kind of empty.

At the end of the book, Candide realizes that the important thing is to tend your garden.