Through The Sandglass

A Reverence for Rivers (2)

Turn on the tap in your kitchen so that it's running at a typical (if not particularly conservative) rate of around three US gallons per minute. Ensure that your drain is working well and leave it flowing for 17 years. By then you will have used the amount of water that the State of California consumes in one minute. 

Return after one year and you will have used roughly the volume of groundwater extracted from the Central Valley in one minute.

Last month, I started what I intended to be a series of posts stimulated by "A Reverence for Rivers," the title of the address given by the great hydrogeologist, Luna Leopold, to California Governor Jerry Brown's Drought Conference held nearly thirty years ago. Leopold threw down some challenges in the "philosophy of water management" to an audience that represented all the stakeholders in management of the state's water supplies at a time of what was then a record drought. Today, those records continue to be broken as California enters its fifth consecutive year of drought, and, for much of the state, the third year of "extreme," never mind "exceptional" drought. Yes, some relief is being provided by El Nino precipitation, but that does nothing to change the drought crisis - as shown by the US Drought Monitor image above. At the end of 2014, a NASA analysis indicated that "It will take about 11 trillion gallons of water (42 cubic kilometers) -- around 1.5 times the maximum volume [potential capacity] of the largest U.S. reservoir -- to recover from California's continuing drought." That was a year ago and it's only got worse. At the time of that report, some rains had arrived, but

“It’s not time to start watering your grass,” said Jay Famiglietti, senior water scientist at NASA’s Jet Propulsion Laboratory in Pasadena and the lead researcher of the new analysis. “Looking at the numbers, it’s probably going to take about three years to fill the hole.”

The NASA team found that the Sacramento and San Joaquin river basins, key water sources for cities and farms, lost 4 trillion gallons of water each year since 2011, most of it from farmers tapping the underground supply because rivers and reservoirs were low.

How can California still find itself in this amount of trouble when, nearly thirty years ago, in his first incarnation as drought Governor, Brown declared that “this is an era of limits and there are some very hard choices to be made”? One of the reasons that I have only now embarked on this episode of the series of posts is that there are no easy answers, and research and fact-checking leads only into a black hole of conflicting data, never mind the labyrinthine political abyss of western water politics, policy and history. It is clear that, post 1997, Brown and some of the more enlightened interests in California attempted to embark on reform and future drought preparation - but many of the choices proved to be too hard. Yes, there were initiatives to reduce domestic and municipal consumption and these lasted, although Brown, in his second drought incarnation, still had to declare a State of Emergency in January 2014, and a year later, the first ever state-wide mandatory water reductions. Individual Californians and communities have dramatically reduced their consumption (with the notable exception of Beverly Hills celebrities and billionaires), but by far the largest proportion of the 38 billion gallons per day consumed by California goes to agriculture - and therein lies the rub. 

Exactly how much water does Californian agriculture use? Well, incredibly nobody really knows and nobody has the day-to-day measurements to know. You can easily, depending on the sources and assumptions, find estimates from 40% to 80% of total water use. In order to find a single group of statistics that have some credibility, it's worth consulting a report put out by the Congressional Research Service in June 2015. Attempting to rationalize the data differences, it is titled California Agricultural Production and Irrigated Water Use and begins:

California ranks as the leading agricultural state in the United States in terms of farm-level sales. In 2012, California’s farm-level sales totaled nearly $45 billion and accounted for 11% of total U.S. agricultural sales. Five counties—Tulare, Kern, Fresno, Monterey, and Merced—rank among the leading agricultural counties in the nation.

Given current drought conditions in California, however, there has been much attention on the use of water to grow agricultural crops in the state. Depending on the data source, irrigated agriculture accounts for roughly 40% to 80% of total water supplies. Such discrepancies are largely based on different survey methods and assumptions, including the baseline amount of water estimated for use (e.g., what constitutes “available” supplies). Two primary data sources are the U.S. Geological Survey (USGS) and the California Department of Water Resources (DWR). USGS estimates water use for agricultural irrigation in California at 25.8 million acre-feet (MAF), accounting for 61% of USGS’s estimates of total withdrawals. DWR estimates water use withdrawals for agricultural irrigation at 33 MAF, or about 41% of total use. Both of these estimates are based on available data for 2010. These estimates differ from other widely cited estimates indicating that agricultural use accounts for 80% of California’s available water supplies, as reported in media and news reports.

The differences result from arcane variations in the definitions of the words "use," consumption," "withdrawals," and "application." Welcome to the rabbit-hole of terminology, both technical and political. Oh, and also welcome to the "acre-foot."  An acre-foot is a volume of water equal to 325,851 gallons (around 1200 cubic metres) and represents the amount of water needed to flood an acre of land one foot deep. In the US, it is the long-standing measure of water volume.

Since Brown's initiatives following the 1970s drought, water use has dropped, partly as a result of domestic frugality, partly following increased efficiency irrigation systems - and the brutal realities of maintaining agriculture in a semi-arid land. However, the USGS reports that California in 2010 remained the chart-topper of all US states for water consumption - more than half again as much as the runner-up, Texas. And the USGS estimates that agriculture accounts for 60% of the state's thirst.

Any, even brief, review of media reports will reveal that to say that this is a controversial topic is a gross understatement. Vested interests, lobbies, open and hidden agendas, battle for dominance in issues scarcely tainted by facts or science. And these arguments also take place in a virtually policy-free environment - water regulations and laws in the arid Western US are labyrinthine, opaque, complex beyond normal comprehension and certainly unfit for purpose, particularly in California. In 1991, during yet another drought, Peter Passell, an economics writer for the New York Times, wrote that California's water system - infrastructure and laws - "might have been invented by a Soviet bureaucrat on an LSD trip... While this infrastructure was built with state and Federal money, the benefits are by tradition (and, hazily, by law) reserved for the private interests who lobbied for its construction." 

California's surface water supply system resembles nothing more than a Heath Robinson contraption or a Rube Goldberg machine, deliberately over-engineered to perform a simple task in a complicated fashion. But at least the State Government has some ability to regulate it. In a normal year that's an ability to attempt to manage and allocate perhaps 70% of the state's water consumption. In a typical drought year that drops to less than 40%. In extreme drought conditions, the state can - and does - dramatically reduce surface water allocations but then where does the other 60-70% come from? Groundwater. Over which the government has virtually no control whatsoever. It doesn't even have the knowledge or the data to manage its groundwater, never mind the legal ability to do so.

And here is the vital fact that is mostly ignored or unknown in political and commercial circles, largely because it's highly inconvenient: surface water and groundwater are part of the same system, the hydrological cycle - mess with one and you mess with the other. 

Over 60 years ago, Luna Leopold and his colleague, Harold Thomas, wrote an article titled "Ground Water in North America: The fast-growing demands on this natural resource expose a need to resolve many hydrologic unknowns." Here's an extract:

There are enough examples of streamflow depletion by ground-water development, and of ground-water pollution from wastes released into surface waters, to attest to the close though variable relation between surface water and ground water.

Man has coped with the complexity of water by trying to compartmentalize it. The partition committed by hydrologists—into ground water, soil water, surface water, for instance—is as nothing compared with that which has been promulgated by the legal profession, which has on occasion borrowed from the criminal code to term some waters "fugitive" and others, a "common enemy." The legal classification of water includes "percolating waters," "defined underground streams," "underflow of surface streams," "water-courses." and "diffuse surface waters"; all these waters are actually interrelated and interdependent, yet in many jurisdictions unrelated water rights rest upon this classification

Water habitually does not subscribe to our efforts at compartmentalization according to special interests in irrigation, industrial use, recreational use, municipal use; or to allocations of fields for the chemist, for the geologist, for the sanitary engineer, for the physicist, for this or that government agency, any more than it does to separation into areas bounded by property lines, county lines, state lines, or even some river-basin boundaries. As the areas of heavy demand expand toward each other and the necessity for water management increases, these artificial boundaries and classifications will have to yield more and more to the realities of the hydrologic cycle.

Ah yes, the lessons we have learned in 60 years. In an article in July of last year for the New York Times, Abrahm Lustgarten, an environmental reporter for ProPublica, summarized a report he had written for the site (the whole piece is well-worth reading). From the summary, titled "How the West Overcounts Its Water Supplies": 

In California, the state’s water agency has said that the failure to account for how groundwater withdrawals affect the state’s rivers is a major impediment to a true accounting of its resources. In April, authorities reported that less than half of the state’s local water agencies had complied with a 2002 law that made them eligible for state funds only if they set up groundwater management plans and determined if a connection between surface water and groundwater existed. That connection does not exist uniformly and varies depending on local geology. Only 17 percent of the state’s groundwater basins had been examined.

Indeed, California still doesn’t require that water pumped from underground be measured at all, much less factored into an overall assessment of total water resources; it’s merely an option under a new law signed last September.

California’s new groundwater legislation does require local water authorities to come up with sustainable groundwater plans, but they don’t have to do that until 2020, and they don’t have to balance their water withdrawals until 2040.

So fierce was the pushback by the agriculture industry against any regulation of underground water that the new law, somewhat perversely, explicitly barred any attempt by the state to count the groundwater withdrawals as coming from one overall water supply until local agencies had at least 10 more years to come up with — and implement — their plans.

“Those who have unlimited water supply don’t particularly like the idea of changing that,” said Fran Pavley, a Democrat and the California state senator who drafted two of the three bills that became the groundwater law. “You can’t manage what you don’t measure.”

Thomas Buschatzke, the director of Arizona’s Department of Water Resources, acknowledged that pumping from wells could dry up streams, but said the current law kept the two resources separate, and “it would be a huge upset to the economy to do away with that.”

But John Bredehoeft, a leading hydrogeologist and former director of the federal government’s Western states water program, bluntly emphasized the importance of basic honesty in counting water.

“If you don’t connect the two, then you don’t understand the system,” he said. “And if you don’t understand the system, I don’t know how in the hell you’re going to make any kind of judgment about how much water you’ve got to work with.”

Until state officials do, it seems unlikely that there will be any real solution to managing the Southwest’s strained water resources for the future.

And, in the words of Jay Famiglietti:

Managing our water in this context will require an overhaul of existing water policy that matches our modern understanding of the water cycle. Surface and groundwater are tightly interconnected and should be managed accordingly. The rule of capture for groundwater worked exceedingly well when we shot bears with muskets. Let's not kid ourselves that we're great stewards when most of our available water -- groundwater -- is still offered up in a land rush.

We must treat and price water as the precious commodity that it truly is. That means conserve, reuse, recycle, and then do it all over again. Enhanced conservation and efficiency is cheap, easy, and incredibly effective.

So, turn on your tap for a year and contemplate the disappearance of groundwater in California's Central Valley every minute. You could at least rush home and turn off the tap - the government of the State of California can't. We'll talk about all this some more in the next episode...  

 

 

2016: the year of the Bagnold dunes

Last month, NASA issued a press release to announce that the Curiosity Rover had reached the “Bagnold dunes” and was preparing to investigate. The image above is from that announcement – the landscape covered is only a few meters across, but it is extraordinary and just seems, instinctively, to be unearthly. As Nathan Bridges of the Johns Hopkins University's Applied Physics Laboratory, Laurel, Maryland, and leader of the Curiosity team's planning for the dune campaign remarked in an earlier discussion of the project:

These dunes have a different texture from dunes on Earth. The ripples on them are much larger than ripples on top of dunes on Earth, and we don't know why. We have models based on the lower air pressure. It takes a higher wind speed to get a particle moving. But now we'll have the first opportunity to make detailed observations.

Indeed. The first detailed examination of extra-terrestrial sand dunes, to take place over the next few months, will be incredibly exciting, and it is only appropriate that those dunes are, if only informally, named after Ralph Bagnold. Readers of this blog and my books will have sensed that Bagnold is something of hero of mine, and I like to refer to him as “the man who figured out how deserts work.” One only wishes that he was still around and that we could hear his reactions to Curiosity, the images, the science and engineering. I am of the generation that still has difficulty not finding this whole project incredible, and I know that Bagnold would have been totally engrossed in the science, the technology – and the people.

In his frustratingly short (but fascinating) 1990 autobiography, Sand, Wind, and War, Bagnold cryptically titled Chapter 17, “Later: 1974-1986”. In it, he writes:

One memorable event in 1977 occurred when I was asked by the National Aeronautics and Space Administration (NASA) to give the keynote address at a meeting of geologists and other space scientists.The meeting was to compare the desert landscapes of Earth and Mars. It was held for a week at Palm Desert, a new, up-and-coming offshoot of Palm Springs in Southern California. The site of the meeting had been specially chosen for the desert character of its surroundings. However, during that week it rained every day. The main thoroughfare through town, labeled Bob Hope Street, was still only dirt. It was all but washed away. 

NASA had recently sent spacecraft to orbit Mars and had succeeded in landing an unmanned craft to take close-up pictures. Those photos of the landscape revealed apparent sand dune forms much like those on Earth, in spite of the vastly different atmosphere. This had already started theories, but it was, and still is, mere guesswork as to what the stuff of the so-called dunes really is. We have no tangible evidence, and won’t have until some of it is brought back to Earth. Is it granular, like sand, or fluffy like snowflakes? And we still have but little idea of the scale of the dune heights…

I spent one evening at a McDonald’s with a small group of young scientists from NASA’s Jet Propulsion Laboratory in Pasadena. It was fascinating for an old man of eighty-one to listen to their casual talk of navigating a spacecraft two hundred million miles away as easily as an aeroplane. Man had not begun to fly at all when I was born.

The Bagnold Dunes lie in Gale crater, and are a stopping point for Curiosity on its journey up the slopes of Mount Sharp. The part of the dune field that the rover has arrived at is shown in this image – the dark band of rippled sand in front of Mount Sharp which looms intriguingly in the background.

Bethany Ehlmann of the California Institute of Technology and NASA's Jet Propulsion Laboratory is another member of the project team, and she introduces it in a great little video. As she comments, the dunes are dark because the sand grains are derived from basaltic rocks, and they cover the older, lighter-coloured, sandstones, some of which are themselves ancient dunes. Curiosity will be conducting fieldwork on what was originally called Dune 2, now the high dune, which is but a part of the much larger dune field. This beautiful image shows the dune, part of the larger dune field, and the journey of Curiosity to its current position:

In the image at the head of this post, we are only looking at a small area of the whole dune, but from imagery over the years by NASA’s orbiting HiRISE camera, it is clear that the dune is active and on the move. As Bethany Ehlman describes, echoing Ralph Bagnold, in the reduced gravity, thin atmosphere, and unknown wind conditions on Mars, exactly how sand grains are transported and dunes migrate is still a mystery. But, thanks to Curiosity, perhaps not for long.

Ralph Bagnold became frustrated by the lack of desert wind data critical for developing his pioneering work on the physics of blown sand (he moved on to the physics of water-borne sediment). But Curiosity is already on the job, gathering the wind data that will help us understand how Martian sand moves. And the Rover has an extraordinary array of other instrumentation at the end of its long robotic arm, including a sand sampler and sieves that will tell the stories of grain size distributions that Bagnold determined were so informative.

At the end of Curiosity's robotic arm is a suite of devices that enable Collection and Handling for In-situ Martian Rock Analysis, otherwise known as CHIMRA. This combination of geological tools, operated remotely hundreds of millions of miles away, is incredible:

Ralph Bagnold was not only a scientist but also an engineer who designed, developed and built his own equipment, unique and exquisitely sophisticated. As we remember him working on field measurements in Egypt’s Western Desert in 1938, it doesn’t take much imagination to visualise him not only impressed with CHIMRA, but enthusiastically contributing to the project.

[for the full image of Curiosity’s view of the High Dune, see  http://mars.nasa.gov/imgs/2015/12/mars-curiosity-rover-high-dune-up-close-fullres-pia20168-figA.jpg]