BLOG
March 16th, 2016
Via Nikkei Asian Review, some interesting commentary on the concerns arising in Asia that China is seeking to turn water into a potential political weapon:
China’s centralized, megaprojects-driven approach to water resources is the antithesis of the situation in another demographic titan, India, where the constitution makes water an issue for state governments and where anti-dam nongovernmental organizations are powerful. Thanks to organized protests, the much-publicized Sardar Sarovar Dam on the Narmada river in western India remains incomplete decades after work began. The largest dam India has built since independence — the 2,000-megawatt Tehri Dam on the river Bhagirathi — pales in comparison to gigantic Chinese projects. These include the 22,500-megawatt Three Gorges Dam and Mekong dams such as Xiaowan, which dwarfs the Eiffel Tower in height, and Nuozhadu, which boasts a 190 sq. km reservoir.
Yet the water situation in India is far worse than in China, including in terms of per capita availability. China’s population is marginally larger than India’s but its internally renewable water resources (2,813 billion cubic meters per year) are almost twice as large as India’s. In aggregate water availability, including external inflows (which are sizable in India’s case but negligible for the People’s Republic), China boasts almost 50% more resources than India.
As China’s dam-builders increasingly target transnational rivers, concern is growing among downstream neighbors that Beijing is seeking to turn water into a potential political weapon. China pays little heed to the interests even of friendly countries, from Kazakhstan to Thailand and Cambodia.
To be sure, dams bring important socioeconomic benefits and help to deal with drought or seasonal imbalances in water availability through their water-storage capacity. A river can be dammed in an environmentally considerate manner. But what China is doing is over-damming rivers.
One manifestation of this aggressive approach is the construction of series of dams in close proximity to each other on international rivers such as the Mekong or the Salween just before they flow out of Chinese territory. These cascades of dams, looking like strings of beads on a map, aim to capture large quantities of water.
Keeping the silt
Major dams tend to change water quality and the rate at which it flows, and reduce the amount of nutrient-rich silt that is carried downstream. As the major Asian rivers flow down from forbidding Himalayan heights through the soft, sedimentary rock on the Tibetan plateau, they bring with them high-quality silt — a lifeline for agriculture, fisheries and marine life. Silt helps to re-fertilize overworked soils in downstream plains, sustains freshwater species and strengthens the aquatic food chain supporting marine life after rivers empty into seas or oceans.
China’s upstream damming of rivers originating on the Tibetan plateau is not just obstructing the silt flow to downstream plains; it is also causing the retreat of major deltas. Several scientific studies have underscored the link between extensive silt retention behind upstream dams and the retreat and subsidence of Asia’s big deltas, which are home to megacities like Tianjin, Shanghai, Guangzhou, Bangkok, Kolkata and Dhaka. In addition, the fall in freshwater disgorged by rivers into the seas is disturbing the delicate balance of salinity needed in estuaries and beyond to support critical species.
China’s reluctance to bind itself to international rules or norms is rooted in the belief that as the source of these rivers it is in a position to reap the benefits of harnessing their water resources, with the costs borne by those downstream. After all, the river-flow hierarchy reflects the geopolitical one, with the most powerful country controlling the headwaters of Asia’s major rivers.
In reality, though, China is inflicting environmental costs not just on the states lower down these rivers but on itself. One example is the impact of its upstream water diversions on its own mega-deltas, which are economic centers, making up a substantial proportion of the country’s total gross domestic product. Thanks to the diminished amount of silt discharged into the seas, there is less sediment to add to the delta land formed and fortified through sustained release or to prevent underground seepage of saltwater into sweet-water aquifers along the coasts.
More broadly, the Asian delta regions have become “much more vulnerable” to the effects of climate change and sea-level rise, according to the United Nations-sponsored Intergovernmental Panel on Climate Change, the gold standard in climate science.
In this light, the discussion of China’s damming activities on the Tibetan plateau should extend beyond the potential diminution of cross-border flows to the likely effects on the quality of river waters, including through silt-movement blockage. Such effects are already evident within China: the loss of nature’s gift of highly fertile silt due to the Three Gorges Dam and other upriver dams has forced farmers in the lower Yangtze basin to use more chemical fertilizers, accelerating soil and water degradation.
Renewed efforts are needed in Asia to co-opt China into institutionalized cooperation. Without China on board, it will not be possible to build water cooperation and protect critical ecosystems.