Water: The Epic Struggle for Wealth, Power, and Civilization - Steven Solomon (2010)
Part I. Water in Ancient History
Chapter 2. The Indispensable Resource
In A Study of History, British historian Arnold Toynbee influentially posited that the history of civilizations was centrally driven by a dynamic process of responses to environmental challenges. Difficult challenges provoked exceptional, civilizing responses in ascendant societies, while inadequate responses contributed to stagnancy, subordination, and collapse in declining ones. Prominent among the environmental challenges was water.
Throughout history, wherever water resources have been increased and made most manageable, navigable, and potable, societies have generally been robust and long enduring. Those that succeeded in significantly increasing their command and supply regularly were among the few that broke out of history’s normative condition of changelessness and bare subsistence to enjoy spurts of prosperity, political vigor, and even momentary preeminence. Often major water innovations leveraged the economic, population, and territorial expansions that animated world history. Those unable to overcome the challenge of being farthest removed from access to the best water resources, by contrast, were invariably among history’s poor.
Water’s leading role in civilization was visible in the landscape of natural and man-improved waterways that ever have been history’s directional arrows of exploration, trade, colonial settlement, military conquests, agricultural expansion, and industrial development. Wherever navigable waterways converged or where key river crossings or favorable harbors were established, influential urban centers arose at the center of civilizations. In every age, whoever gained control of the world’s main sea-lanes or the watersheds of great rivers commanded the gateways of imperial power. If the advance of civilization could be charted on an electronic, time-sequenced map of the globe, it would show early city-states unifying up river valleys, along seacoasts, then spreading across nearby seas, and finally extending westward to link all the world’s oceans and waterways in an ever-denser and faster-traveled web that has evolved into today’s fitfully integrated global economy and world civilization.
It was also a common pattern of history that expansions driven by intensified use of water and other vital resources were followed by population increases that in turn so increased consumption that they ultimately depleted the further intensification capacity of the society’s existing resource base and technologies. Such resource depletions thus presented each society with a moving target of new challenges requiring perpetually new innovative responses to sustain growth. This population-resource equation—the ever-shifting balance between each society’s population size and the resources and know-how within its means to produce enough goods to sustain it—and its activating cycle of intensification and resource depletion, too, was one of the central dynamics of human and water history. History was littered with societies that declined simply because they could not overcome the deleterious local-resource depletions and population expansions accompanying their own initial success.
Signature water challenges evolved from era to era. Breakthrough responses that harnessed new water resources by novel means in one epoch sowed new conditions from which emerged the defining water challenges, and opportunities, of the next. At each turn of the cycle, the equation of water advantages recalibrated, altering the power balances among states and interest groups. Successful responses in every epoch, however, were invariably marked by intensified productivity in at least one of the five principal, interrelated ways water has been used throughout world history: (1) domestically for drinking, cooking, and sanitation; (2) economic production for agriculture, industry, and mining; (3) power generation, such as through waterwheels, steam, hydroelectricity, and as coolant in thermal power plants; (4) for transportation and strategic advantage, militarily, commercially, and administratively; and (5) of growing prominence today, environmentally to sustain vital ecosystems against natural and man-made depletions and degradations. Whenever a major breakthrough occurred in any of these principal uses, such as Watt’s improvement of the steam engine, it often had an outsized, transformational impact upon history by converting what had been a water impediment into a dynamic force for expansion. Time and again, too, an ascendant civilization’s expansion involved the fusion of two or three diverse hydrological environments with its original habitats, such as the combining of a river’s swampy delta with its upper river valley, a semiarid farming region of millet and wheat with another dominated by verdant monsoonal hillsides and rice farming, or a zone of wide deserts or temperate, rain-fed river and farming lowlands with the opportunities of open seas. Dynastic declines and the fall of expansive civilizations, when they came, also often occurred along the same hydrological fault lines.
Water tied man to Earth with a special bond. Fetuses gestated in water. Man and environment mutually exchanged water through the natural biological cycles of perspiration, exhalation and evacuation, and replenishment by drinking. A healthy, active person needed to consume at least two to three quarts of freshwater daily to stay alive—there was no substitute. Thirst came with only a 1 percent water deficiency; a 5 percent shortfall produced a fever; a 10 percent dearth caused immobility; death struck after about a week with a 12 to 15 percent water loss.
The special affinity between water and man was reflected in water’s primary role in creation stories in diverse cultures throughout the world. “Almost every mythology sees the origins of life coming out of water,” observed mythologist Joseph Campbell. “And, curiously, that’s true. It’s amusing that the origin of life out of water is in myths and then again, finally, in science, we find the same thing.” Water was one of the Greeks’ four primary terrestrial elements and one of five in ancient China and Mesopotamia. Water still plays a central role in common religious rituals of purification from Hinduism and Shinto to Islam, Christianity, and Judaism. Whether it was the rain dance of a tribal shaman, the ritual opening of an irrigation canal by an ancient king, or the dedication of a giant hydroelectric dam by a twentieth-century president, provision and control of sufficient water has conferred political legitimacy in all forms of human society.
Yet water’s unique natural characteristics always simultaneously presented a double-edged challenge to civilized man: it was at once the necessary resource of survival that when brought under control yielded immeasurable benefits to society, but it also imposed one of the most formidable natural obstacles and limitations to growth. Water sustained life, but also, through the devastating shocks of drought, flood, and mudslide, could obliterate it on a terrifying scale, as witnessed in the quarter of a million deaths in the Indian Ocean tsunami of late 2004 and the traumatic 2005 inundation of New Orleans. While man needed water to live, drinking contaminated water and exposure to stagnant water infested with disease-carrying organisms was by far the leading cause of debilitating illness, infant mortality, and short life spans for all of history. Rivers, seas, and the waterless oceans of the deserts could be protective or constraining, in turn a separating defensive buffer between societies, or a bridge between peoples to open communication and trade, or a highway of invasion and conquest. Irrigation watered cropland, but also raised fertility-killing salts to the soil’s surface. The secret of water’s extraordinary potency to transform history was that whenever a society, in its constant struggle to wrench a surplus from nature, was able to innovate to make its water resources more manageable, abundant, potable, or navigable, it not only merely liberated itself from a major water-bound obstacle and constraint, but also unlocked and harnessed more of water’s inherent, often hidden catalytic potential for growth.
A radical transformation in man’s relationship to water played a pivotal role in the great transition to settled agriculture at the start of history. After eons as hunter-gatherers following their alimentary mainstay of herds of giant herbivores such as steppe bison, giant elk, and woolly mammoth from seasonal water hole to water hole, and gathering wild, edible plants along the way, some human tribes about 10,000 years ago began to adopt a settled economic life predicated upon the artificial transformation of nature through farming. As a hunter-gatherer, primitive man used water as he found it. As a settled farmer, managing water resources became essential to survival and growth.
Environmental change in climate and water conditions offered the most likely explanation of the mystery why hunter-gatherers suddenly traded their relatively undemanding and healthy lifestyle for the more-labor-intensive, less-healthy challenges of farming life. As the ice age glaciers retreated northward due to increased global warming and moisture at the start of the present warm period, tundra mosses and grasses also retreated and were gradually replaced by thick temperate forests. This forced the large herds ever northward after their food supply. An abrupt, 1,300-year-long mini ice age around 12,900 years ago may have accelerated the herds’ disappearance. Some groups gave up following the herds to hunt smaller animals, fish, and gather the wild cereals and other edible plants that flourished on open landscapes. Experiments with settled farming and animal domestication ensued. Gradually, domesticated seed agriculture based on wild barley and emmer wheat grasses emerged in the Middle East’s Fertile Crescent, which had transformed from prairie to semiarid landscapes as the climate changed. Farmers began to work the amply rain-fed, well-drained, and easier-to-work soils of wooded river valley hillsides with simple stone and wooden axes, hoes, and sickles. Slashing the bark killed enough trees for sunlight to nourish seeds planted in the loose leaf mold around the trunks. Scattered ash from burning the dead trees after two or three plantings temporarily revitalized the soil’s depleted fertility for another few seasons. Finally, weed invasion forced such “slash-and-burn” method farmers to abandon the land and move on to clear new plots. Early walled, irrigated farming and trading settlements ultimately arose in a few favored locations. Jericho, possibly the world’s oldest true city from about 7000 BC, with about 3,000 inhabitants, internal cisterns, grain storerooms, and a tower within its 10 acres, was situated at the lower slope of Mount Carmel near an ample “sweet,” or freshwater, spring—in contrast to “bitter” water with traces of salt—known in the Bible as Elisha’s Spring that irrigated the small, fertile, once-forested Jordan River valley and was later to lure the biblical Joshua and his Hebrew followers after the exodus from Egypt. Jericho’s location also gave it access to the precious salt and trade routes of the Dead Sea. Salt had become vital to maintaining body fluid once the human diet had shifted to cereals.
Slash-and-burn farming on hillsides had one major drawback. It was always extremely vulnerable to erratic rainfall. The response to this environmental challenge produced one of history’s most momentous innovations—the rise of large-scale, irrigated agriculture, and with it the birth of civilization. The earliest irrigated farming civilizations all developed along the semiarid plains of large, flooding, soil-bearing rivers where precipitation was too scant for rain-fed agriculture. In Mesopotamia, where civilization arose first, some hillside farmers moved down into the stoneless, muddy floodplains and swamps of the lower Tigris-Euphrates river valley in Sumeria near the mouth of the Persian Gulf. It would seem to be counterintuitive for farmers to relocate into a forbidding, miasmic habitat marked by scant rainfall and infestations of deadly waterborne diseases, and prone to violent floods and droughts. Yet the rivers possessed two prized resources that trumped all drawbacks—an ample, reliable, year-round supply of freshwater and a self-renewing source of fertile silt that spread across the cropland with the floods. If productively managed by the arduous building and maintenance of irrigation waterworks, the water supply and silt could produce bountiful yields many times greater than were possible on the rain-dependent hillsides. By specializing in the mass production on cultivated fields of one or two staples like wheat, barley, or millet, farm communities that mastered the techniques of irrigation ultimately produced grain surpluses that were stored as reserves for bad seasons when the floods were excessive or inadequate. These food surpluses in turn yielded rising populations, big cities, and all the early expressions of civilization—arts, writing, taxation, and the first large states—that were the precursors of modern society. The development of reed and wooden rafts, powered by oar and sail, also turned the rivers into high roads for trade, communication, and political integration. As political power concentrated and production of field seed grains expanded with better organization, these early, river-based irrigation civilizations became cradles of history’s first great empires.
Irrigation farming societies also developed in other hydrological habitats based upon staple crops other than field agriculture of wheat and related grains. By the third millennium BC transplanted rice was being extensively cultivated in paddies along the naturally flooded fields of the monsoonal river valleys of Southeast Asia. This garden cultivation, too, required sophisticated, labor-intensive water management—storing the downpour, transplanting rice plants, and submerging and draining paddies at just the right levels and seasons, for instance, to support much more densely populated, civilized communities. Yet the monsoon-fed wet rice garden cultivation was not done on a scale as grand or politically centralized as in the semiarid wheat field agriculture, river-irrigation states. The seasonal rains delivered sufficient natural water supplies to support independent, smaller communities that did not need, and indeed could better resist, any centralized government command. In fact, the case of early wet rice societies supported the general observation that the way water resources presented themselves exerted a strong influence on the nature of the society’s political system. By and large, where wealth-creating water resources were widely and easily accessible and not dominated by the existence of an arterial transport and irrigating waterway, there was a stronger tendency for smaller, more-decentralized, and less-authoritarian regimes to prevail.
The spread of civilization to cropland watered only by rainfall about a thousand years after the rise of large-scale irrigation societies represented one of history’s most enduring, if slow-moving, expansive forces. In wheat-growing regions, the key development was the diffusion of the animal-powered wooden traction plow that facilitated the cultivation of large enough tracks to sustain fixed village communities. Yet nowhere did rain-fed farming ever produce the food surpluses, population densities, grand civilizations, and empires supported by irrigation; their heyday on the world stage, rather, depended upon the advent of other, later technological developments. Thus, for nearly all of history when wealth came from agriculture, one of the central dividing lines of human civilization lay between water-rich, irrigated agrarian states and water-challenged, sparsely populated, relatively poor, small, rain-fed farming communities.
Two other historical dividing lines were also marked by water usage. One was the gradual emergence of seafaring civilizations on the fringes of antiquity’s irrigation empires in lands with marginal domestic agricultural fertility that earned their wealth principally by trading among neighboring states. Sea trade, which exploited the fast and cheap navigation potential of water’s buoyancy, advanced in the Mediterranean Sea with the development of sail and oar-powered wooden cargo ships suitable for its relatively calm, enclosed waters and evolved very gradually into a significant historical force by the second millennium BC. In the Mediterranean, the Red Sea, and the Indian Ocean, sea traders facilitated cross-cultural and commercial exchange based upon market-set prices that over many centuries helped propagate a small but vibrant unregulated economic sphere in which the early beginnings of the modern market economy were nurtured.
The other great water demarcation line was the barbarian divide—the existential clash of societal organization and lifestyles between the nomadic pastoralist descendants of primitive hunter-gatherers and the expanding, civilized agricultural realm. The militarily skillful barbarian tribes of the central Asian steppes, the desert Bedouins of the Arabian Peninsula, and later the Nordic Vikings in their river longboats were far fewer in number and ranged Earth’s more water-fragile and less-yielding landscapes, herding their animals between water holes, and trading with or, when strong enough, raiding or demanding tribute from civilized settlements. Periodically, they gathered enough strength under great warrior leaders to lead fearsome invasions that disrupted, overwhelmed, and ultimately reinvigorated civilized empires across the world. History recorded four great barbarian waves, starting with the Bronze Age charioteers of 1700–1400 BC and ending with the Turkish-Mongol invasions from the 700s through the fourteenth century, when the age of gunpowder and sheer manpower advantages decided matters for settled civilization. The slow, fitful expansion of civilized society around the globe was always synchronized with the breakthroughs and setbacks in irrigated and rain-fed cultivation, some of which were landmark events of world history. Wherever farming took hold, population advanced. In 8000 BC the planet was populated by about 4 million hunter-gatherers. After 5000 BC it began to double every 1,000 years. By 1000 BC world population had reached about 50 million. Then, under the prosperous shield of order-providing empires, it generally accelerated. By the late second century AD, some 200 million people inhabited the world. Even Watt’s steam engine and the Industrial Revolution did not lessen civilization’s reliance on agriculture. Instead, they provided new tools to enhance innovation production to feed the growing demand of a world inhabited by 6.5 billion by the early twenty-first century. Despite the dramatic expansion of total cropland, water volumes, and agricultural technologies, one thing that has not changed since ancient times is man’s greater reliance on irrigation to feed himself. Today, two-fifths of the world’s food is being grown on less than one-fifth of the planet’s irrigated, arable land. All of human society today shares an irrigation legacy with the cradle civilizations of antiquity.