- Since China began damming the Mekong, droughts have become more frequent and intense in downriver countries
- By diverting river water to its mega-dams, China has emerged as Asia’s upstream water controller, giving it great leverage
The building of large dams has increasingly run into opposition in established democracies but gained momentum in autocratic states, which often tout their benefits for combating droughts and water shortages. But, as the Mekong basin illustrates, giant upstream dams can contribute to river depletion and intensify parched conditions. The spate of dam building in Asian autocracies is exacerbating already fraught water security disputes.
India, for its part, shows that dams and democracy normally do not go well together. Whereas China continues to build giant dams, trumpeting them as symbols of its engineering prowess, the public pressures generated by India’s democracy act as a brake on ambitious water projects that displace many people or flood vast areas.
India’s river-linking plan remains in the realm of fantasy but a similar programme in China has been transferring water domestically through the central and eastern routes.
In fact, given the power of non-governmental organisations in India, it has become increasingly difficult to build large dams there, blighting the promise of hydropower. Proof of this was the federal government’s 2010 decision to abandon three dam projects on the Bhagirathi River, a Ganges tributary, including one that was already half-built, with authorities having already spent US$139 million on construction work and ordered equipment worth US$288 million.
Cost and time overruns are common problems in every dam project in India. For example, the cornerstone of western India’s Narmada Dam – which is a fraction of the size of China’s Three Gorges Dam – was laid in 1961. More than 56 years later, Prime Minister Narendra Modi inaugurated the dam. The Narmada project, however, is still not fully complete.
The recent debut of the 1,285-megawatt Xayaburi Dam in Laos illustrates how autocracies defy protests and concerns to complete projects. Xayaburi – the first of at least nine Mekong dam projects in Laos – was commissioned despite concerns that it could worsen the drought in the downstream basin in Cambodia and Vietnam.
No nation, however, can match China’s dam-building frenzy. It is increasingly damming international rivers that serve as the lifeblood for the countries of Southeast and South Asia.
Take the Mekong: just before it crosses from the Tibetan plateau into Southeast Asia, China has erected a cascade of mega-dams. Its 11 Mekong dams have a capacity to generate more than 21,300MW of electricity – greater than the installed hydropower capacity of the downriver countries combined. It is working on at least eight more giant dams on the Mekong.
Ever since the cascade of Chinese dams came up on the Mekong, droughts have become more frequent and intense in the downriver countries. The Mekong, which is normally at least three metres (10 feet) high at this time of the year, is today running at a record low level, with its flow reduced to a trickle in some stretches. This has resulted in seawater intrusion into the Mekong Delta in southern Vietnam, with rice farmers there forced to switch to shrimp farming or growing reeds.
China has promised to release more dam water for the drought-stricken countries. The offer, however, highlights the new-found reliance of downriver countries on Chinese goodwill. By diverting river water to its mega-dams, China has emerged as Asia’s upstream water controller, arming it with powerful leverage.
The downriver countries have also been saddled with long-term environmental costs. For example, the Asian rivers’ monsoon season flooding cycle helps to re-fertilise farmland naturally by spreading nutrient-rich sediment, which rivers bring from the mountain ranges. The flooding cycle also opens giant fish nurseries. China’s dams, however, have disrupted the Mekong’s annual flooding cycle and impeded the flow of sediment, affecting even marine life.
The Mekong Delta exemplifies how heavy upstream damming, by reducing a river’s discharge of fresh water and sediment into the sea, causes a delta to retreat. Indeed, according to a Mekong River Commission study, the upstream dams’ cumulative effect would likely be the extinction of most migratory fish species in the basin. What is happening to the Mekong today could happen tomorrow to the Brahmaputra and other Tibet-originating rivers that are the target of China’s dam builders.
Simply put, the proliferation of upstream dams is beginning to impose costs across much of Asia. Dams are also set to exacerbate water-sharing disputes, which have already become common between Asian nations and provinces. Add to the picture the security dynamic: for example, the Mekong, like the South China Sea, is emerging as a new flashpoint, with US Secretary of State Mike Pompeo slamming China’s dam frenzy for reducing the river’s flow to a record low.
Dams help generate electricity and store water for the dry season. But heavy upstream damming, by irreparably damaging a river system and wreaking broader environmental havoc, eventually leaves only losers.
To avert a parched future, defiant unilateralism must give way to basin-wide institutionalised collaboration, centred on a balance between each county’s rights and obligations.
Brahma Chellaney is a geostrategist and the winner of the Bernard Schwartz Award.
This article appeared in the South China Morning Postprint edition as: Dam frenzy risks creating a parched future.