My guess is that most people would agree that rivers, all of the rivers of the world, are important to our species. There seems nothing startling therefore in the premise of this fascinating, far-ranging book. But what makes Rivers of Power particularly noteworthy is the way that Smith brings precisely into focus how crucial they are.
Towards the book’s close he condenses this many-sided significance into a list. Rivers have, among other things, been providers of fish, irrigators of crops, pathways for continental exploration, resources for industrialisation, disposers of rubbish and poison, generators of green electricity, openers of arid lands, coolant sources for power plants, opportunities for real estate development, soothers of stressed minds and inspirers of technological and environmental movements.
Missing from his inventory is anything about the importance of rivers as imagi-native symbols that have helped us to conceptualise the temporal and spatial shape of both life in its totality and individual human lives. These ideas constellate most clearly in the realms of religious practice, especially for Hindus and Buddhists, for whom rivers are objects of veneration that also supply the itineraries for many religious pilgrimages.
A site such as Mount Kailash in Tibet, whence originate the rivers Indus, Sutlej, Brahmaputra and Karnali (a tributary of the Ganges), is a key destination for peoples of both faiths. Similarly, the Kumbh Mela in India, at the confluence of the Ganges and Yamuna rivers, with its estimated 30 million Hindu attendees, is the largest religious ceremony on the planet. That Smith has nothing to say on these aspects of rivers is perhaps a minor matter.
For me, a more significant omission is any sense that rivers might exist for anything other than human purposes. Smith is an eminent field researcher and professor of environmental studies at Brown University in the US. He seems to be in all roles a doer and pragmatist. He is also fully subscribed to the concepts of “ecosystems services” and “natural capital”. These enshrine an ethical posture that says the living planet is important, but the currency in which it is best measured is human self-interest.
Perhaps it is for these reasons – or possibly it is too much of a truism – that he doesn’t bother to repeat, even in passing, how the Amazon and its associated forest are the Earth’s single largest repository of animal and plant diversity. Its wider geophysical processes literally help to shape the planet. Time after time Smith describes the damming, exploitation and redirection of rivers, and notes how this often impacts upon biodiversity, but never bothers to give a detailed audit of those costs. Ultimately one feels that, for the author, human utility trumps all.
If one sets aside this major objection, there is still an enormous amount of rewarding material in his wider approach. Even in the opening chapters we are made to think how rivers have been fundamental to the development of human civilisation itself. This analysis begins on the banks of the Tigris and Euphrates, whose silt deposits provided the self-renewing resources for our first agricultural societies.
From there Smith moves outwards to show how similar communities flourished in the Harappa region of India and Pakistan, in the basin of China’s Yellow River and, most famously, on the banks of the Nile. In all four localities, fluvial irrigation and its resulting food surpluses were a precondition for the invention of the city state, for written languages and, ultimately, all subsequent hierarchical society.
If rivers have given abundantly to our species, they have also taken away. Some of Smith’s analysis of the flood damage inflicted by rivers is subtle and unexpected. He shows, for instance, that a recurrent result of floods, once the disaster has passed, is population increase and even economic stimulation. This was true historically in the Yellow River basin, but even, as he demonstrates, following the deluge in New Orleans after Hurricane Katrina of 2005. However, another outcome of Katrina was the eviction of a high percentage of its African-American population and their replacement with people of Hispanic background.
Smith loves to find the significance of rivers in major historical events. He argues that George Washington’s crossing of the Delaware in 1776 turned the tide of the American War of Independence, just as Hitler’s failure to capture both banks of the Volga at Stalingrad was finally fatal to the Nazi cause. A more nuanced investigation illuminates how Herbert Hoover’s refusal to relieve African-American suffering in the wake of a forgotten 1927 flood of the Mississippi had enduring political consequences.
Hoover’s response to the flood was to trap black refugees in what were called “concentration camps” and return them forcibly to their cotton-growing employers. According to Smith, this prompted a wholesale switch of their votes from the Republican to the Democratic Party. By the 1964 presidential election all but 6 per cent of black voters supported Lyndon Johnson.
For several decades Smith has been examining the flow rates of melted glaciers below the Greenland ice sheet. Regardless of the overall impact of this process upon sea-level rises, he suggests that riverbanks’ status as the key dwelling place for the world’s population will continue to grow. By 2035 an astonishing 500 million people will be in just 50 mega-cities, almost all of them sited on major rivers. More widely there will be 759 cities with million-plus populations and two-thirds of all the Earth’s nine billion humans will live within 20km of a major river.
One of the lesser known impacts of flowing water is that it has a beneficial effect on our nervous systems. Even noise machines that mimic the acoustics of babbling brooks can induce better sleep, while cancer victims shown footage of meandering streams incur significant reductions in the stress hormones cortisol and epinephrine. Given that in 15 years most of our species could expect to have a million other people as close neighbours, perhaps our largest debt to rivers is not just that they quench our collective thirst, but they chill us out at the same time.
Mark Cocker’s most recent book is “A Claxton Diary: Further Field Notes from a Small Planet” (Jonathan Cape)
Rivers of Power: How a Natural Force Raised Kingdoms, Destroyed Civilisations, and Shapes our World
Laurence C Smith
Allen Lane, 368pp, £20
This article appears in the 15 Jul 2020 issue of the New Statesman, Race for the vaccine