Cascade effect

Much has been written on the downstream impact of China’s dams on the Mekong River, which flows through or along the borders of Burma, Laos, Cambodia, Vietnam and Thailand after exiting China (where it is known as the Lancang). The discussion largely focuses on the hydrological impact of impounding water in the eight dams along the mainstream upper Mekong River in Yunnan Province. The Mekong Cascade, as it is termed, has caused considerable controversy in downstream countries, most notably during the 2008 floods and the 2010 drought, which many blamed on China’s actions.

Clearly, the cascade has major implications for downstream hydrology, with the potential to exacerbate or ease both floods and droughts and impact on fisheries and other sources of income. (chinadialogue has published recent articles on the implications of altered river hydrology and China’s need for better public relations around its schemes). But China’s dams also have indirect ramifications, which receive less attention. Most notable of these is a revival of dam aspirations among downstream governments.

There are currently proposals for up to 11 dams on the lower Mekong mainstream, the section of the river below China. Some of these are in areas bordering or inside Laos, Cambodia and Thailand, three of the four countries that are member states of the Mekong River Commission (MRC), an inter-governmental agency formed in 1995. Dams have been planned for the lower Mekong since the 1950s, but the Cold War subsequently put development on hold. By the time mainstream dams came back onto the agenda in the early 1990s, environmental concerns over large dams had grown to the extent that simply dusting off these megaprojects designed a generation earlier was unpalatable and, until recently, it was widely assumed mainstream dams were off the agenda altogether.

Several factors help explain the revival of Mekong mainstream dams, and China is implicated in a number of ways. One way in which China’s own development of the river drives the logic of building more dams further downstream is simply the demonstration and equity effect: the Lao government in particular sees no reason why it should hold back on developing a shared river when an upstream country is already doing so.

A more material way in which China’s schemes have helped bring the lower mainstream dams back into the decision-making arena is through the changed hydrology of the Mekong River. Particularly in the upper reaches, immediately below the eight-dam cascade, the altered flood hydrology makes the economics of dams on the lower mainstream more favourable than before.

Early versions of the lower mainstream dams included large storages, for example at the giant Pa Mong dam proposed during the 1960s. However, the scaled-down versions are commonly referred to as “run-of-river” dams, dependent on the seasonal flow of the river to generate power without being able to store more than a few days flow at most. With a more even flow from the upper Mekong dams, with more water available during the dry season and less during the wet season, the prospects for year-round power generation are greater than under an unregulated monsoonal flood regime.

Another role that China is playing in downstream development is as investor. Chinese state-owned power corporations have stakes in several of the key projects. Until the 1990s, most dams in the lower Mekong countries were public investments, based on loans from the World Bank and Asian Development Bank. The game has changed, however, and most dams are now commercial projects. China has weighed in heavily here: it is estimated that up to 40% of the proposed tributary and mainstream hydropower development in coming years in MRC member countries – in other words, outside China – will be done by Chinese companies. These projects include four of the eleven proposed mainstream dams, at Pak Beng, Pak Lay and Xanakham in Laos and at Sambor in Cambodia.

Recent concern within Beijing’s foreign-policy machine over the country’s image abroad has led to some interesting changes in the way the nation conducts its hydro-business. At the MRC summit in Hua Hin in April last year, China agreed to release more data on inflows and outflows from its cascade of dams on the Mekong River. This came in the wake of disquiet over the possible impacts of reservoir filling and releases on low flows and flash floods. While China’s data-sharing still falls far short of full disclosure, the move did reveal awareness of the need to cooperate with downstream countries.

Sino-Hydro and other companies have also been taking environmental-impact assessments more seriously than in the past. Sino-Hydro’s Nam Ngum 5 tributary dam is being used as a test case in a new hydropower sustainability assessment protocol that has been developed by the international hydropower industry in dialogue with some NGOs and other partners.

Another knock-on effect of China’s role as the upstream player in the Mekong is a shift in local geopolitics, driven by the re-entry of the United States into the region through its Lower Mekong Initiative. While the US has yet to decide what material developments will take place under this programme, the announcement of the initiative has included thinly-veiled attempts to trump Chinese influence in the region, sometimes portraying the United States as a downstream friend to counterbalance the upstream environmental foe.

What do these seemingly disparate, indirect aspects of China’s role in Mekong mainstream hydropower beyond the Mekong Cascade tell us about the region’s environmental politics and development trajectories? There are at least two ways in which they paint a more coherent picture than is immediately apparent.

First, it is useful to understand the political logic of the mainstream dams in China and the lower Mekong in terms of path dependency, or the idea that events and their consequences are triggered and explicable in part by previous events and can go on to influence yet further developments. That is, while the immediate considerations of the Mekong Cascade have been considered largely in their own right, there is a bigger set of hydrological, economic and political implications of China’s development within its own territory that seems to be pushing inevitably toward construction of dams on the lower Mekong mainstream. In turn, this is driving a new geopolitics as various players realign based on their position on the mainstream dams.

Second, then, it is clear that the environmental politics around dams on the Mekong mainstream are intricately bound up in a wider world of geopolitics, which include China’s emerging relations with regional neighbours. They also include the regional playing-out of competition between older and newer world superpowers. What is notable is the way in which these geopolitics are now enmeshed in resource and environmental concerns over a shared river system.

It would be dangerous to equate path dependency with fatalism over Mekong mainstream dams. Important decisions are yet to be made. It would equally be wrong to consider that environmental considerations are subject and subsidiary to dominant geopolitical concerns and that international relations rather than concern for a shared river system entirely rule the game. The recent publication by MRC of the Strategic Environmental Assessment (SEA) report on the lower Mekong mainstream dams, which recommends a 10-year moratorium on the 11 projects, presents an opportunity for the countries of the region to move beyond the path dependency that sees one dam leading to another and another, until the river becomes a cascade of still-water lakes – as would be the case for 60% of the length of the lower mainstream if all 11 dams were to go ahead.

A telling decision is imminent that will demonstrate whether or not the cooperative arrangement represented by MRC will take note of the SEA as the most comprehensive scientific assessment to date. The first of the mainstream dams, Xayabouri, has been notified for prior consultation by MRC member states over a six-month period to March, 2011. This is the first time that other MRC countries have been asked to give their opinions on a dam proposed in the territory of one of their neighbours. If a deal is done to go ahead with this dam despite the SEA recommendations, this will more than likely open the floodgates for further dams on the mainstream, at enormous cost to the well-being of the millions who depend on the river for their everyday livelihoods.

Ultimately, this outcome is linked to China’s actions further upstream, without which it is highly unlikely that the mainstream dams would be under discussion, as they are today.

Philip Hirsch is director of the Australian Mekong Resource Centre.

Homepage image from All Points East  shows the Khone Falls in Laos.