Sean Fleming: The Necessity of Water

Changes across the globe are placing unprecedented pressure on our water resources. Today, according to a United Nations report, more than one billion people do not have access to clean water, and 1.4 billion live in river basins where water use exceeds recharge rates. Another two billion or so water users will be added to the world’s population by midcentury. This population growth, together with expansion of agricultural and industrial production as poorer nations develop, is expected to increase global water demand by a stunning 55% by 2050.

Not only do these factors increase water demand, they also signify greater global exposure to water-related hazards, including pollution and flood risk, as more people settle on floodplains, for instance, and more municipal, industrial, and agricultural effluent is discharged into the environment. At the same time, there is a strong scientific consensus that the net increase in atmospheric greenhouse gas concentrations is large enough to detectably alter global climate. This can be attributed to activities like massive fossil fuel combustion, industrial livestock production, and widespread deforestation. Current projections suggest that the main hydrological effect for most basins will be to amplify the water cycle, which may increase runoff in many regions but reduce supplies in others. More importantly, it may widely increase the intensity of both the yearly rainy and dry seasons, further increasing flood and drought risks. And river channelization, damming, contamination, and upstream water withdrawals have so degraded aquatic habitat that many freshwater biological populations have collapsed, some species have been entirely extirpated from parts of their home ranges, and others are at risk of extinction altogether. We are facing a dark constellation of regional water resource disasters, growing and coalescing into what appears to be an emerging global catastrophe of human welfare and the environment.

To mitigate the impacts of these changes, we need to invest deeply in a coordinated, broad-based, and large-scale drive to create new science and technology that addresses the needs and aspirations of the current and future global populations in a healthy and sustainable way. Only time will tell which specific directions these innovations will take, but there are a few obvious paths. This includes:

  • Lower-energy, lower-cost, and cleaner desalinization technologies to sustainably extract fresh water from deep aquifers and the ocean
  • Further technology- and policy-driven improvements in the efficiency of water use and, in particular, water distribution systems
  • Public health steps to curb population growth in ways that are new and ambitious, yet fully respectful of individual rights and freedoms
  • And perhaps most importantly of all, improved environmental monitoring and prediction technologies, so we know what’s happening with our water resources today and what to plan for in the future.

There is justification for having faith that we can get real traction on water scarcity. The development of more water-efficient technologies for homes, farms, and factories is an obvious example. Indeed, water use in the United States has leveled off near 1970 rates in spite of both population and economic growth. Granted, unsustainable water practices during regional droughts, such as groundwater mining in California, revealed a chink in the armor. Furthermore, stabilization of water demand seems restricted, at best, to a handful of rich nations. Nevertheless, the overall statistic must be acknowledged as the stunning success, cause for optimism, and clear template for emulation that it is—a shining citadel on the hill, as it were.

Improvements in water quality are another example. Admittedly, over much of the world, rapid agricultural and industrial expansion are making water quality worse, not better. Shortages of potable water due to fecal contamination remains a huge issue globally; in fact, another UN report indicates that inadequate access to clean water kills more people through the associated disease alone than are killed by guns in war. And emerging contaminants, like pharmaceuticals and plastic breakdown products, are an increasingly worrisome threat. Yet improved awareness, legislation, and technology have yielded tremendous gains. The days of rivers ablaze— this happened to the Cuyahoga River in Ohio, which was so polluted with flammable contaminants that in 1969 it actually caught fire—seem to be over. Overall, water quality across the industrialized regions of the developed world is largely much better now than it was, say, forty or fifty years ago.

Another broad reason for optimism is the seeming paradox of water conflict. Ismail Serageldin, a former World Bank vice president, famously warned that the wars of the twenty-first century will be fought over water. It turns out, though, that water resource conflict and cooperation are surprisingly nuanced. While squabbles abound, actual shooting wars solely over water, even in regions that are both arid and troubled, are virtually nonexistent. And cooperation might be at least as common as conflict.

But with exploding global demand, this all might change.

As water resource pressures mount, our efforts to manage these changes must grow commensurately. And at the heart of these efforts must be good hydrologic science, because without that, everything else will merely be a shot in the dark. Advances are required in two directions. First and foremost is improved ability to monitor water, and associated variables like land use and climate. This will be accomplished by growing our networks of ground observation stations, and by expanding the scope, accessibility, and accuracy of airborne and satellite remote sensing data. The second is to further develop our mathematical modeling and prediction technologies for watershed systems. Data analytics, statistical and machine learning-based prediction, and physical process simulation techniques – rivers in silicon, as it were – are how we test our understanding of watersheds and transform observational data and theoretical knowledge into a scientifically defensible and socially responsible basis for informed predictions and sound advice.

Water isn’t optional. Water is necessary for our very existence, for our continued economic development, and for the health of the web of life that supports us. It’s also limited in its availability, and there are no substitutes for it. Whatever path humanity chooses to follow, it will be up to hydrologists to present society with the options available, and the corresponding pros and cons, for the management of our water resources. And to do that, water resource scientists and engineers need to understand watershed systems in detail, and to accurately, precisely, consistently, and quantitatively predict the impacts on those systems from both natural phenomena and human interventions. Viewed from this perspective, it is perhaps not too dramatic to assert that the future of the world will depend, in a small but real way, on a quantum leap forward in our understanding of the physics of rivers.

Sean W. Fleming has two decades of experience in the private, public, and nonprofit sectors in the United States, Canada, England, and Mexico, ranging from oil exploration to operational river forecasting to glacier science. He holds faculty positions in the geophysical sciences at the University of British Columbia and Oregon State University.

Sean Fleming: The Water Year in Review

The top five water-related news stories of 2017—and what to expect for 2018

FlemingThe thing about water is that something’s always happening, and the implications of that fact are growing – fast.  What are the top five water-related news stories of 2017?  Read on to see, along with a little context and some implications for next year and beyond.

Oops!  (The Oroville Dam evacuation)

Possibly the most obvious water story of 2017 happened right after the New Year: nearly 200,000 Californians were evacuated beneath Oroville Dam as it threatened to fail under record flooding, which in turn ended a historic drought that had cost the state billions of dollars.  Previously of little note to most living outside the region, Oroville is in fact the tallest dam in the US.  It’s located on the Feather River, a headwater basin to the Sacramento River that drains the western slopes of the snow-laden Sierra Nevada and Cascades in the wet, northern part of California.  Oroville Dam is a key component the California State Water Project, shifting water into the California Aqueduct to help irrigate the Central Valley, which produces about 25% of the food consumed in the US, and to transport water to southern Californian urban centers.  Critics charge that in spite of its size and status as a cornerstone of the civil works in a heavily populated but largely arid state where water is everything, dam maintenance and upgrading lagged far behind, setting the stage for problems.  Record rains in February provided the trigger, and the main spillway failed – which might in turn have undermined the dam as a whole, sending the entirety of massive Lake Oroville downstream all at once in a wave of destruction and death.  Disaster was averted, but the costs were tremendous and the risks were real.  For thoughts on improving America’s river infrastructure, see my recent Scientific American post.

Water goes bang on the India-China border

The most exciting, yet perhaps most under-reported water story of 2017 took place on the India-China border.  A military buildup and tense standoff over disputed ownership of a Himalayan frontier area shared by China, Nepal, Bhutan, and India this summer may have cooled off, but India charges that China followed up by using water as a weapon – withholding key data that India needs to manage lethal monsoon flooding on transboundary rivers.  Violent international conflict solely over water is extremely rare because it usually doesn’t work strategically, though it does happen from time to time.  For instance, in 1965, when Syria was building an upstream diversion of a tributary to the River Jordan that would deeply reduce Israel’s water supply – a catastrophe for a desert nation – Israel responded with air strikes against the facility.  And water has been used as a weapon in wars that were being fought for other reasons: Chiang Kai-shek’s Nationalist government in China opened the dikes on the Yellow River in 1938 in an effort to hold back the invading Imperial Japanese army. The action was only partially successful and had a disastrous humanitarian cost.  The soaring mountain ranges wrapping around the Tibetan Plateau – including the Hindu Kush, Karakoram, and Himalayas, spanning China, India, Pakistan, and  several other countries – host one of the world’s largest remaining icefields and are the source of the Indus, Yangtze, Yellow, Ganges, Brahmaputra, and Mekong Rivers among others, and thus help provide water to a full quarter of the global human population.  Perhaps nowhere else on Earth is it more important for nations to cooperate over water.

Two inter-state water lawsuits go to the US Supreme Court

The volume was turned up in the country’s water wars, with SCOTUS announcing this fall it will hear both Texas’s lawsuit against New Mexico over Rio Grande water rights, and Florida’s lawsuit against Georgia over the Apalachicola.  Rivers and aquifers don’t respect borders.  The geophysics of where water comes from and how and where it flows is complex, fascinating, and full of surprises, such as flash floods, alternating drought and flood sequences, and abrupt and catastrophic changes in river channel location.  And those are just the natural aspects – the engineering and management part can be just as complicated for some basins, and a high ratio of demand to supply, as we have in the increasingly heavily populated deserts of the Southwest for instance, exacerbates these issues.  Originating from snowy headwaters in the mountains of southern Colorado and northern New Mexico, the Rio Grande flows south through increasingly arid country and then turns southeastward, forming the US-Mexico border until emptying in the Gulf of Mexico.  Water projects abound on the Rio Grande, and each influences the other in some way.  For example, the San Juan-Chama project diverts water from the Colorado River into the Rio Grande, municipal groundwater pumping in Albuquerque interacts with Rio Grande flows through subterranean geologic pathways, and a series of dams withdraws water from the river for agriculture, reducing what’s left for downstream users.  Water law is complicated.  Texas says New Mexico is taking more than its fair share of Rio Grande water; New Mexico says it isn’t.  The potential for disagreement over water will only continue to grow in the Southwest, though there are success stories as well: after some earlier missteps, Las Vegas has invented one of the most advanced and successful water conservation programs around, reportedly reducing its water consumption by almost a quarter over a ten-year period while its population grew by half a million.

Saying goodbye to the Paris Agreement on climate change

Why is climate change important to rivers?  Lots of natural processes and human activities affect how high rivers run and how much water arrives at your tap, and climate variables like precipitation and temperature rank high among these influences.  While the new administration’s withdrawal from the Paris Agreement in 2017 was obviously a setback for action on climate change, it was also a democratic response to widespread sentiment.  And this fact suggests that explaining climate change may be turning into the greatest science communication failure in history.  As scientists, we clearly need to adjust course – but in what direction?  Consider a recent article by a multi-disciplinary team in the respected research journal, Global Environmental Change.  Applying complex network theory (kind of a mathematical formalization of the seven degrees of Kevin Bacon) to social media feeds about climate change, they demonstrated the dominance of so-called echo chambers, and that constructive progress is made only when groups with opposing views actually talk with each other.  Consider also that populism – which is by nature skeptical around the competence and integrity of designated experts – has been growing over the last decade on both the left and right, as evidenced by the mayoralties of Rob Ford in Toronto and Boris Johnson in London, the Tea Party and Occupy movements, Brexit, and Bernie and The Donald.  If there is a silver lining to withdrawal from the Paris accords, it’s that it may teach us valuable lessons around communicating about climate change: reach out to people who don’t believe us yet, treat them with respect, and focus on just explaining our science.

Houston, we have a problem

Hurricane Harvey hit Houston hard.  In late August, the fourth largest city in the US, with over 4 million residents counting Harris County, was at the epicenter of what some are saying will be the costliest natural disaster in US history.  Though no hurricane is to be trifled with, why was the flooding so intense in this case?  To be sure, the rainfall generated by this particular storm was unusually heavy.  But risk is, by definition, what you get when you take the probability that something bad will happen (like record rainfall under a hurricane) and multiply it by the impact it will have if it does happen (like flooding and the associated economic cost and human suffering).  In the case of Harvey’s visit to Houston, it had a lot to do with local-scale choices that affected the second part of that equation.  In fact, parts of the greater Houston metropolitan area have seen a spate of floods over the last few years, and they weren’t all associated with huge storms.  The region has experienced an explosion of population growth and urban sprawl.  Lots of residences were built in low-lying, flood-prone areas, which is the single best of way of increasing flood risk.  And urbanization – the conversion of wild or agricultural land to rooftops, parking lots, and roadways – is another powerful flood risk factor.  Soils and wetlands hold on to rainwater for a while, and then gently release it to natural drainage systems like aquifers and rivers.  If you pave and build over these things, their ability to attenuate flooding is removed.  While these effects are particularly noticeable in Houston, and especially so when the city gets hit by a major hurricane, they’re ubiquitous; increased flooding in the UK over the last decade has been attributed to exactly the same causes.

What will 2018 have in store for us?  If we can be sure about one thing, it’s to expect the unexpected.  But the larger trends are clear.  Global water demand will increase 55% in the next few decades, urbanization will spread, tens of millions more will congregate in floodplain-located megacities, the climate will subtly but profoundly shift overhead, and cooperation and conflict over water will vie for supremacy.  We can, in short, expect that water stories will make the news with increasing frequency and force.

Sean W. Fleming has two decades of experience in the private, public, and nonprofit sectors in the United States, Canada, England, and Mexico, ranging from oil exploration to operational river forecasting to glacier science. He holds faculty positions in the geophysical sciences at the University of British Columbia and Oregon State University. He is the author of Where the River Flows: Scientific Reflections on Earth’s Waterways.

Sean W. Fleming on Where the River Flows

Rivers are essential to civilization and even life itself, yet how many of us truly understand how they work? Why do rivers run where they do? Where do their waters actually come from? How can the same river flood one year and then dry up the next? Where the River Flows by Sean W. Fleming is a majestic journey along the planet’s waterways, providing a scientist’s reflections on the vital interconnections that rivers share with the land, the sky, and us. Fleming recently took the time to answer some questions about his new book.

Your book is unique in that it explores the geophysics of rivers: where their waters come from, why their flows vary from day to day and decade to decade, and how math and physics reveal the hidden dynamics of rivers. Why is this important?

SF: Every aspect of our lives ultimately revolves around fresh water. It’s needed to grow food and brew beer, to build cars and computers, to generate hydroelectric power, to go fishing and canoeing, to maintain the ecological web that sustains the world. Floods are the most expensive type of natural disaster in the U.S., and droughts are the most damaging disasters globally. Yet as the margin between water supply and demand grows narrower, and tens of millions more people congregate in megacities often located on floodplains, we become more vulnerable to the geophysical subtleties of the global water cycle. It’s an important part of life that we need to understand if we’re going to make smart choices going forward.

Your book anthropomorphizes a lot. Is this just a way to make the subjects more accessible, or is there a little more to it?

SF: I ask questions like “how do rivers remember?” and “how do clouds talk to fish?” and “can rivers choose where they flow?” It’s a fun way to broach complicated topics about the geophysics of rivers. But posing questions like that also prepares us to open our minds to new ways of thinking about rivers. For instance, modern information theory allows us to quantitatively describe the coupled atmospheric-hydrologic-ecological system as a communications pathway, in which the weather literally transmits data to fish species using the watershed as a communications channel—modulating water levels almost like Morse code. There may be no intent in that communication, but mathematically, we can treat it the same way.

What are the main threats that rivers face? Are these challenges consistent, or do they vary from river to river?

SF: It does vary, but broadly speaking, watersheds face four main threats: pollution, land use change, climate change, and deliberate human modification. Pollution ranges from industrial effluent to fecal contamination to emerging contaminants like pharmaceuticals. Converting natural areas to urban land uses increases flooding and erosion and reduces habitat quantity and quality. Climate change is modifying the timing, volume, and dynamics of streamflows. And civil works like dams, flood control structures, and of course water withdrawals and consumption, alter river flows and ecosystems more profoundly than perhaps anything else. The common thread behind all these concerns is that human populations and economies—and therefore water needs, and our direct and indirect impacts on rivers—are growing much faster than our development of sustainable technologies.

How will climate change affect river flows?

SF: Global warming is expected to accelerate the water cycle, increasing both flooding and drought. Other impacts are more regional. Some areas will enjoy larger annual flow volumes, whereas others may suffer reduced water supplies. More precipitation will fall as rain instead of snow, and snowpack will melt earlier, changing seasonal flow timing. That may interfere with salmon spawning migration, for example, or render existing water supply infrastructure obsolete. In part due to anthropogenic climate change, mountain glaciers are retreating, effectively shrinking the “water towers” of the Himalayas, Andes, Alps, and Rockies—the headwaters of the great rivers that support much of the global human population, from the Columbia to the Yangtze to the Ganges.

What’s so important about understanding the science of rivers? What does it add to our view of the world?

SF: Just think about floods. Knowing how urbanization or deforestation may affect flooding, or how some kinds of flood control can backfire, or how the flood forecasting behind an evacuation order works, is important for making informed choices. There’s also a philosophical aspect. A dramatic view of a river meandering across a desert landscape of red sand and sagebrush at twilight is made even richer by being able to look deeper and recognize the layers of causality and complexity that contributed to it, from the rise of mountains in the headwaters as a continental plate split apart over millions of years, to the way the river shifts its channel when a thunderstorm descends from the skies to deliver a flash flood.

A consistent theme across the book is the interconnectedness of ideas. Why this emphasis? What’s the significance of those connections?

SF: A fundamental and amazing fact of nature is that not only can so much be so effectively described by math, but the same math describes so many different phenomena. Consider debris flows, a sort of flood-landslide hybrid posing serious dangers from Japan to California to Italy. It turns out we can understand phenomena like debris flows using cellular automata, a peculiar kind of computer simulation originally created to explore artificial life. What’s more, cellular automata also reveal something about the origins of fractal patterns, which occur in everything from tree branches to galaxies to the stock market. Recognizing that ideas from one field can be so powerful in another is important for pushing science forward.

The book seems to present a conflicted view of global water security. It paints an extraordinarily dark picture, but it is also very optimistic. Can you explain?

SF: Grave challenges often drive great achievements. Consider some United Nations numbers. Over a billion people don’t have sufficient water, and deprivation in adequate clean water claims—just through the associated disease—more lives than any war claims through guns. By 2050, global water demand will further increase by a stunning 55%. Little wonder that a former World Bank vice-president predicted the 21st century will see water wars. Yet there’s compelling evidence we can get serious traction on this existential threat. Advances in policy and technology have enabled America to hold its water demand at 1970s levels despite population and economic growth. A focused science investment will allow us to continue that success and replicate it globally.

FlemingSean W. Fleming has two decades of experience in the private, public, and nonprofit sectors in the United States, Canada, England, and Mexico, ranging from oil exploration to operational river forecasting to glacier science. He holds faculty positions in the geophysical sciences at the University of British Columbia and Oregon State University. He is the author of Where the River Flows: Scientific Reflections on Earth’s Waterways.