Liquid Empire: Water and Power in the Colonial World, Corey Ross, Oxford University Press, £35

Europe is in a bad way. It no longer rains when it should. Access to cheap fossil fuels is dwindling, locking industries into decline and creating a ‘fossilised culture’ of interest only to tourists. The worries of the interwar German hydrologist Hermann Sörgel might sound familiar, but his solution to them was insane. He wanted to build immense barrages across the straits of Gibraltar and Gallipoli and the mouth of the Nile. The now-stoppered Mediterranean would shrink under the sun, creating new farmlands. Massive turbine plants could use the gap in sea levels between the Atlantic and the Mediterranean to generate cheap electricity for industry.

When his Atlantropa scheme found no takers on its publication in 1932, he then floated a plan for immense artificial lakes in the Congo to attract white farmers. Unfortunately for Sörgel, Germany’s National Socialists preferred to build their Lebensraum in Eastern Europe. Discredited, he was soon forgotten after his death in a bicycle accident in 1952. For Corey Ross, his schemes encapsulate the hubristic attitudes of colonialism towards the management of water, from which we are yet to escape. His Liquid Empire is an erudite, rueful survey of how European states meddled with the hydrology of their tropical colonies, generating the crises that afflict these places with unequal gravity today: urban floods, drying rivers, saline soils and vanishing drinking water.

It is a received idea that ancient and early modern empires flexed their might by bringing aqueducts to cities and making the desert bloom. Yet modern European imperialism was no less interested in the mastery of water, and of freshwater in particular. Ross argues that historians have wrongly understood it in ‘terracentric’ terms. They have traced the advance of empires from early modern footholds on African and Asian coastlines into the interior, and emphasised their building of railways to knit their colonies into governable wholes. They have naturally stressed the importance of oceans to empires, but represented them as mere mediums of exchange, to be crisscrossed by steamships as quickly and intensively as possible. Coal and, in due course, oil were much weightier than water.

Yet both sovereignty and economic opportunity floated inland. Rivers were hazardous but essential conduits for the ‘brownwater fleets’ that carried troops and missionaries and brought exotic commodities to ports for shipping to Europe. The ‘flotilla-state’ created in the Congo by Léopold II of Belgium is a striking example of how this worked. The Congo Free State’s initial viability depended on the steamers that Leopold had ordered to be hauled eastwards up the Livingstone Falls, then reassembled at Léopoldville (now Kinshasa) on Stanley Pool (now Pool Malembo). The king’s agents used them in the violent extortion of immensely profitable ‘red rubber’ from the peoples that lived along the River Congo upstream from the pool. Rail soon amplified Léopold’s mastery of water. Thousands of press-ganged African, Chinese and West Indian labourers lost their lives building the stupendous narrow-gauge line, which from 1898 connected Léopoldville with the seaport of Matadi on the lower Congo, doing away with the lumbering portage of goods around the Falls and allowing bigger steamers to be transported inland for use upstream.

Empires not only exploited rivers but changed them. They legitimised their power by claiming to develop the lands they had seized for everyone’s benefit. Officials abhorred the ‘waste’ of resources: the vast quantities of water that rivers dumped into the sea without being tapped for agriculture were a case in point. In India they were increasingly sensitive to charges that they were failing to safeguard their subjects against famines if the monsoon rains failed, or deadly floods if they proved too heavy. The result was a flurry of ‘protective’ and ‘productive’ interventions to bring about ‘immunity from the pains and losses which famine brings with it’. The East India Company tried to repair and improve upon Mughal earthworks and built aqueducts and canals to irrigate hitherto barren districts such as the Western Punjab. Most of its enterprises were modest ventures that had to turn a profit, but once the British state assumed responsibility for the Raj after the 1857 rebellion, the schemes mounted. In the later 19th century, Egypt’s new British overlords followed Ottoman predecessors in seeking to turn it into a major cotton exporter. The reliance of farmers on the annual inundation of their fields by the silty Nile, which swelled after autumn rains, had restricted them to winter crops such as beans and barley. Cotton instead needed the steady supply of water throughout the summer. The result was the Aswan Dam, which, after its completion in 1902, supported the irrigation of 1,000 square miles of land.

Environmental histories often encourage a view of empire as a tragi-comic enterprise, in which a headstrong ignorance of local conditions and indigenous experience undoes grand plans to improve the world. In Liquid Empire, unanticipated floods carry off Eiffel Tower-sized chunks of Leopold’s railroad and swiftly overtop dykes in British India. Sandbars shift to strand French steamers on the Mekong. The pipes for Bombay’s water system quickly corrode because sanitary engineers had not investigated the chemical composition of the soils. The sewers of French Hanoi become a paradise for rats, which surface from toilets, to the alarm of their users. Everywhere Ross looks, engineers proved better at providing water for irrigation or sanitation than at draining it away. Water tables rose in consequence, malaria and bilharzia proliferated and soils filled with salts. Ross reports on outright folly as well as ignorance. Sportsmen ruined Indian and African rivers by stocking them with brown trout. British officials in Uganda destroyed the richest freshwater habitat in the world when they ignored warnings not to introduce the voracious Nile perch into Lake Victoria.

It is easy to reduce empire to a plethora of ‘mistakes’. Yet imperial engineers showed dogged persistence in overcoming them. Cultivated men such as Colin Scott-Moncrieff, who worked first in India and then in Egypt (and whose great nephew translated Proust) often became students and even advocates of local ways of dealing with water. The cautiousness and cheapness of imperial officials was a bigger obstacle to the creation of an ‘irrigated despotism’ than the hubris of engineers. Because they expected colonised people to pay for their own improvements, they often shelved schemes that appeared too disruptive or too expensive. In Java, Dutch engineers chafed at officials who were content to follow the locals in taming the River Sampean with improvised teak dams. Hou het klein (keep it small) became their motto.

Just as the food in the restaurant is said in the old Jewish joke to be not just ‘really terrible’ but to come ‘in such small portions’, Ross often detects too little imperial management of water. The British, who turned a third of Hong Kong’s rocky island into reservoirs, did not do enough to provide it with drinking water. Colonial officials should have done much more to regulate and conserve fisheries. By providing flushing toilets only for colonists or local elites in cities, they were guilty of ‘excremental colonialism’, which ‘condemned’ most of the population to the ‘barbaric practices’ of defecation outdoors and near to watercourses.

In the event, it was often colonised elites who pressed hardest for grand projects. Outside Canada, the British were reluctant to spend on hydroelectric infrastructure and so to unleash the power of ‘white coal’. In India, the semi-autonomous princely state of Mysore constructed the first major plant, on the Cauvery Falls. The deep-pocketed Tata family, who had made their pile supplying opium to China, funded the dams that supplied Bombay industrialists with cheap power. By the early 20th century, the damming of rivers to electrify industry was not so much an imperial as a capitalist project, which depended on the global circulation of technology and expertise, especially from the United States. It was telling that H.P. Gibbs, the first manager of the Tata Hydroelectric Company had previously worked for General Electric in Mexico.

The formal end of empire complicated but accelerated the indigenous appropriation of waterworks. Freed from British control, Egypt and Sudan feuded with one another and other riparian African states over who could dam the Nile and where, but nonetheless pressed on with such pharaonic schemes as Nasser’s Aswan Dam. Kwame Nkrumah recruited American firms to complete the gigantic hydroelectric dam that the British had planned for the River Volta, in the vain hope that it would ensure independent Ghana’s economic autonomy. Jawaharlal Nehru regarded the displacement of many thousands of peasants by dams as a price worth paying to build ‘the temples of New India’. All in all, post-colonial states built hydrological schemes on a scale that would have made Hermann Sörgel’s eyes pop: after a peak of activity in the 1970s and 1980s, 58 000 dams had been built worldwide by 2020, which controlled a sixth of the world’s river flow.

This ‘long genealogy’ of modern hydrology is a mordant and lucid read – although its serpentine discussion of complex river systems needs more maps. But it is unlikely to achieve its stated aim of decolonising global policy making about water. Precisely because economic and demographic growth in the post-colonial era hurtled down channels dug by imperial bureaucrats, much more hydrological intervention may be required in future to ‘escape forwards’. The hectic growth of imperial cities in the 20th century means that millions of people now live in precariously managed flood plains and depend on (or demand) piped water from reservoirs. The ruination of marine and riparian environments, such as the destruction of Asia’s mangrove swamps for shrimp farms, now owes less to imperial ideologies than the whims of the West’s voracious consumers and the desire of developing countries to escape subsistence by reaping ‘fertility windfalls’. When it comes to going green, it is very hard to imagine what can be, unburdened by what has been.