In Arizona, talk of water supply augmentation

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There’s a long and important history behind Arizona’s enthusiasm for water supply augmentation. The short arm-wave version is Arizona’s belief that part of the Central Arizona Project’s grand bargain was that the Superhot State would accept a junior priority for its CAP water in return for a commitment to water supply augmentation at some unspecified future time, and in some unspecified way. Arizonans feel like it’s a promise unfulfilled. (Consider the arm-wave a placeholder, I really need to flesh out the story and do some more reading to make sure the arm-wave is correct.)

I say this as preface to this interesting Arizona Republic interview with Pam Pickard, president of the CAP board:

Pickard: We are also working with other water users to augment the flow of the river, such as by cloud seeding to enhance snowpack.

Republic: Will it take a big project, like desalinating Gulf of California water, or lots of smaller measures?

Pickard: Ultimately, both. Large-scale projects, like ocean desalination or importing water from another basin, will likely be needed down the road to meet the demands of projected growth.

But projects like that will take time. That’s why CAP has pushed so hard for the past decade or more to get the Yuma Desalting Plant back into operation, which would save about 100,000 acre-feet every year. We are also supporting tamarisk (salt cedar) removal and other augmentation strategies.

Some day this drought’s gonna end….

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Jim Carlton, in the Wall Street Journal last week (behind paywall, sorry*) does something I wish there was more of – looking at what happens when drought ends. In particular, a visit to Wyoming, where it was dry for a spell, then got wet:

“You can get out of drought if everything goes right, and this year it did,” said Justin Derner, director of the U.S. Department of Agriculture’s Northern Plains Climate Hub in Cheyenne.

Agriculture production has soared. Statewide yields of dryland wheat are running as high as 40 bushels per acre this year, compared with 20 last year and a historical average of 30, said Keith Kennedy, executive director of the Wyoming Wheat Marketing Commission in Laramie.

I don’t know how this generalizes. There are a whole bunch of geographically-specific issues in each manifestation of drought, especially groundwater use and cropping decisions – permanent (almonds) vs. annuals (wheat). But this approach to thinking about drought is worth paying attention to.

* When you really want to read a WSJ story like this, the trick to getting around the paywall seems to be to grab the headline, head on over to Google News and search on the story there. The WSJ sometimes allow clicks from GN to bypass its paywall. Or you can, ya know, pay for the product you wish to consume and thus help enable schlubs like Carlton and I to keep doing what we do.

Contingency planning in the Upper Colorado River Basin

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Water managers in the Upper Colorado River Basin are beginning to roll out details of their contingency planning aimed at preventing Lake Powell from dropping to troublingly low levels.

Flaming Gorge Dam under construction, courtesy USBR

Flaming Gorge Dam under construction, courtesy USBR

Among the key steps being discussed, according to a presentation Monday by New Mexico’s Kevin Flanagan to his state’s Interstate Stream Commission (more over on my work blog):

  • cloud seeding
  • reservoir reoperation to move water from upstream reservoirs, especially Flaming Gorge in Wyoming, to Powell to keep Powell’s levels up
  • “demand management” – willing buyer/seller agreements to fallow farm land, for example

The idea, Flanagan said, is to take proactive steps ahead of trouble, to avoid the more dire problems that might happen if Lake Powell drops too low to generate power or make its legally required deliveries past Lee Ferry to the Lower Basin.

It is a testament to the difficulty of the underlying problems that we don’t quite agree about what those delivery obligations are. The Colorado River Compact clearly says we’ve got to deliver 7.5 million acre feet per year, or 75 million acre feet averaged over any rolling ten consecutive years. A Lower Basin lawyer would argue that we Upper Basinites also owe the river an additional 750k acre feet per year, our share of the water that must be delivered to Mexico. For reasons arcane, all that bundles to an annual obligation to deliver 8.23 million acre feet per year, or 82.3 million acre feet over ten years. Either way, whether the obligation is 75 million or 82.3 million, we’re in good shape for now. The most recent rolling total is 90.8maf, so we’ve got plenty of slack in the system short term.

Longer term, though, there’s a one in twenty chance that Powell would hit minimum power pool elevation of 3,490 between now and 2019, according to Bureau of Reclamation modeling, and a one in five chance between now and 2026.

Backers of the contingency effort are strongly pushing the argument that the power pool stuff matters because power generates something like $200 million per year money (updated per comment, I’m now unclear on the amount) that’s funneled into Upper Basin environmental compliance programs. Upper Basin folks need that money for their Endangered Species Act compliance coverage, I’m told. (I’ve not looked closely at this yet, I’m taking them at their word. The flow of water is hard enough, I’ve no deep understanding of the flow of electricity and the money related thereto.)

If Powell gets really low – 3,440 and below – it becomes impossible to meet delivery obligations at all, because you simply can’t get the water out of the lake to send downstream. By 3,420, the maximum you could release, for example, is 6.4 million acre feet, according to Flanagan’s presentation. I did not know this.

The reoperation of Upper Basin dams – Blue Mesa, Flaming Gorge and Navajo) is the most interesting part of this to me. The scenarios presented by Flanagan show Flaming Gorge doing the bulk of the work. Anywhere from 1.9 maf to 3.4 maf over a 20-year period would be moved to Powell instead of stored at Flaming Gorge. Navajo and Blue Mesa make far smaller contributions. Navajo, for example, contributes 5kaf to 10 kaf per year under the scenarios presented. I don’t really understand the Upper Basin reservoir operating rules, so I’ve no idea how decisions are made now to keep water in Flaming Gorge versus sending it on down, and how that rule set might need to be changed. Readers who know, please fill in gaps in the comments, and once I understand this better, I’ll try to return and write stuff here that explains it all.

Flanagan’s final presentation slide noted something worthy of note – completing these plans will require “navigating difficult political sensitivities”. Yup. That sounds about right.

Alfalfa, a California drought survivor?

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Alfalfa, the crop with the largest acreage in California, could well emerge as a survivor in the state hard hit by drought.

“This plant is a tough plant,” said Dan Putnam, alfalfa and forage specialist with the University of California at Davis. He believes the deeply-rooted plant “will likely survive once the plant is rehydrated,” and he cited previous research trials that showed its ability to survive in the face of deficit or nearly no irrigation.

That is from Western Farm Press.

Cattle, groundwater and “ecological subsidy” in Northern Mexico

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In his book Political Ecologies of Cattle Ranching in Northern Mexico, geographer Eric Perramond offers a fascinating description of the linkages among choice of cattle breed, farm and ranch practices and the resulting groundwater levels in the Río Sonora of northern Mexico, with irrigated farm fields once used to grow food for human inhabitants now providing an “ecological subsidy” for the increasingly meaty cattle raised on the surrounding ranches:

The large, meat-bearing cattle species now common in the Borderlands are a far cry from the rangy, tough criollo cattle that once roamed the deserts. Exotic, largely Euro-American crossbreeds, real hybrids, now lumber across rangelands of northern Mexico. Forage scarcity on the ranges has been “bred,” created by the adoption of these resource-hungry breeds.

This then maps to water use in the farmed valley lands:

The irrigated floodplain of the Río Sonora, once planted in staple food crops and a diverse mix of vegetables and specialty plants, now grows almost entirely alfalfa in both planting seasons.”

Wet subsidizes dry and water tables drop, Perramond writes: “These are hybrid animals, hybrid landscapes, and hybrid livelihoods in the truest sense of the word.”

A mediocre Colorado River Basin forecast

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The Climate Prediction Center’s seasonal outlook, published this morning, is another “meh” for the Colorado River Basin. The good news is that odds favor wet for the southerly part of the basin, especially Arizona and New Mexico. The “meh” part is that the low country doesn’t contribute much of the river’s overall supply. Most of that falls in the Rockies to the north, where the current forecast could be worse – slight tilt in the odds toward wet for a portion of the basin. But only slight:

off02_prcp

Nov-Jan forecast, courtesy Climate Prediction Center


It’ll be a while before we can say much that is actually useful about the impact on the Colorado River Basin’s reservoirs, but this is just a blog and no one reads it, right? So I’ll just find a vague thread of evidence and then improvise, and y’all won’t hold me to it, OK? The vague thread of evidence is this month’s Bureau of Reclamation 24-Month Study (pdf), which projects a bit of bonus water to be released from Lake Powell down to Lake Mead. But even with the extra water, Mead’s still projected to drop another 5 feet. This is the “structural deficit“, which Arizona’s so exercised about, in action:
Total storage in Lakes Mead and Powell. Data by USBR, graph by Fleck

Total storage in Lakes Mead and Powell. Data by USBR, graph by Fleck


For those squinting at the graph and trying to keep score at home, that’s the lowest total storage in Mead and Powell combined since 1967.

Colorado River problems are a threat to beer

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Colorado River, Water Source For Craft Beer, Drying Up:

Some of the best craft beer in the US is produced in the West, in places like Colorado and California. And the craft beer culture in that part of the country is also strong. Many craft brewers, such as Stone Brewing, obtain all of their brewing their water from the Colorado River. So it is a big problem, not just for craft beer but for everyone in the region, that there is a very serious drought in the Colorado River Basin.

Though:

It would be devastating to craft brewing in the US if this trend continued, but compared to the other massive problems that lack of water brings, craft beer seems like a smaller issue.

Fair enough.

How drought shaped Southern California

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From the Orange County (Calif.) Weekly, a story about how drought shaped Southern California:

Orange County as we know it exists because of the Great Drought of 1864. It wrecked Southern California’s cattle industry, then one of the largest in the world and the heart of the area’s economy, and forced ranchers to unload their land at fire-sale rates. Developers swooped in and divided their newly acquired properties into lots that evolved into the cities of today. Those settlements, in turn, drew in Americans who pushed out the state’s original Californio families. Enough people came to make Orange County’s secession from Los Angeles County in 1889 a natural. And those residents transformed pastoral OC into a suburban paradise that brought us national acclaim–and also sowed the seeds for our current water crisis.

 

Plan for a bad news future on the Colorado, or embrace uncertainty?

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In Colorado River Basin planning, there is a common mistake growing out the the Bureau of Reclamation’s Basin Study. It is made by seizing on the study’s finding regarding the impact of climate change (as exemplified by the results of General Circulation Models, or GCM’s) on the river, quoted here from the executive summary (pdf), and then arguing for a portfolio of policy options to make basin water use sustainable given that new reality:

Under the Downscaled GCM Projected scenario, the median of the mean natural flow at Lees Ferry over the next 50 years is projected to decrease by approximately nine percent, along with a projected increase in both drought frequency and duration as compared to the observed historical and paleo-based scenarios.

This is a helpful prod, but it’s not quite right to interpolate that into “Basin Study predicts 9 percent reduction in flow”, as I frequently see done. That 9 percent number is better thought of as the midpoint in a very uncertain future, as the Basin Study goes on to explain:

The range of this result varies amongst the individual GCM projections that comprise this scenario with some of the GCM projections showing a larger decrease in mean natural flow than nine percent while others showing an increase over the observed historical mean.

The problem is nicely explained in this work from a team at RAND, which worked with the Bureau on the Basin Study:

Reclamation and the water agencies must deal not with a future that is uncertain but well understood; instead, they must plan for a future that is deeply uncertain and one that cannot be described statistically because of a lack of knowledge about how changes will unfold. Under these conditions, developing an optimal management strategy designed to perform well for a single deterministic or probabilistic forecast of future conditions is not very useful; rather, planners need a robust and adaptive strategy—robust in that it performs well over a wide range of possible futures and adaptive in that it can adjust over time in response to evolving conditions.

This recent Ensia piece by Melinda Harm Benson and Robin Craig seems to be heading off in the right conceptual direction:

The concept of resilience holds promise as a new way of addressing the challenges ahead. While not inherently incompatible concepts, resilience and sustainability are not the same. The pursuit of sustainability assumes that we a) know what can be sustained and b) have the capacity to maintain stationarity (i.e., keep the system operating within an unchanging envelope of variability). In contrast, resilience thinking acknowledges disequilibrium and nonlinear, continual change — often as a result of crossing a “tipping point” or threshold — and offers a tool for assessing the dynamic relationships between systems.