I recently read about the new dams planned for the lower Mekong and the expected impacts on the people who rely on this river. It is an interesting case study that on one hand is responding to the global need for low carbon electricity, but on the other will have significant local economic, social and environmental consequences.
The lower Mekong flows through Laos, Thailand, Cambodia and Vietnam. Combined, eleven major hydropower dams have been proposed on the main stem of the river in these four countries, and a further eight are being constructed in China. The proposed dams will change the system’s natural hydrology and block the migration of freshwater fish, which will in turn reduce fish breeding.
Australian National University (ANU) has undertaken research into the impacts of these dams. Their work indicates that fish populations will fall somewhere between 16 and 42 per cent (depending on how many dams are built). Given there are around 60 million people who live in these countries and whose main source of protein is freshwater fish, you can start to see the problem. To give some perspective on the importance of fish, in Australia we each on average consume 6 kg of fish annually; in the lower Mekong the average is 33.7 kg per person per year. In addition to the loss of protein, around 54 per cent of all riverbank gardens along the Mekong would be lost to inundation.
The social and economic impact will be felt primarily by the rural communities who depend on fishing and farming, and raises the broader question of how the protein source is to be replaced. One likely answer is through the consumption of domestic livestock, but the ANU research suggests the additional land required to accommodate such an industry ranges from 7,080 to 24,188 km2 and that the best agricultural land will be flooded by the dams (estimated to be around 1,300 km2). Where does the extra land come from – forested areas?
I think this is a good example of how the global push to lower carbon electricity can deliver unintended consequences and I wonder how these low income farmers can possibly compete with the major power companies and the politics at play. I did see that Oxfam appears to be quite involved in this issue. If you are interested in learning more about the social considerations visit Oxfam
Locals depend on the Mekong for fishing and transport