Mekong River Basin
Damming the Mekong
Life on the Mekong
The Mekong's natural flooding provides spawning grounds for these fish. And it enriches cropland like the Mekong Delta — where 50% of Vietnam’s staple food crops grow — with fertile sediments and water for irrigation.
As the countries of the Mekong Basin develop economically, their demand for energy is growing. Hydropower is seen as both a potential source of this needed energy and as a means for economic growth in and of itself.
Dams get in the way
But some dams may end up doing more harm than good. Dams on the mainstream of the lower Mekong would be particularly destructive. Serious impacts include:
- Delta instability: The reduction of sediments as they are trapped by dams would make the Mekong Basin more vulnerable to sea level rise and saline intrusion brought on by climate change.
- Decreases in fish diversity: Dams in the mainstem will impede migration of fish and other aquatic animals potentially reducing productivity of the fishery by 60%.
- Damage to livelihoods: Over 75% of rural households in the Lower Mekong Basin are involved in fisheries. Any impact on the ecological balance of the river also threatens the sustainability of the aquatic resources they depend on.
Mekong River Facts
- Of the Mekong's 1,300 fish species, 600 are long distance migrants that require different habitats throughout the year and their life cycles.
- The Mekong is the largest inland fishery in the world, producing about 2.6 million tons of fish per year.
- Of this catch, 70% are long distance migrants.
Our priority is to identify high conservation value parts of the basin, such as the lower mainstream river, and declare them no-go zones for dams development.
Upper Mekong River dams impact life downstream
Construction is now underway on the Xiaowan dam, which at 292 m high, will be the tallest arch dam in the world. It will span the river over nearly 900 m and create a reservoir that backs up in the narrow gorges for 178 km.
There is little doubt that dams in the upper Mekong are having an impact on downstream hydrology and ecology. Significant reductions in sediments have been measured, stretching as far as southern Laos.
Don Sahong Dam: A mainstream issue
Moreover, the Don Sahong Dam would damage fisheries that are central to people's food security by impeding fish migration. And it could harm the local economy and its developing tourism industry.