Mekong River Basin

Problem Statement:

The Mekong River in Southeast Asia is one of the most important and productive natural systems in the world. Originating in the Tibetan Plateau, it flows 4,800 km through six nations – China’s Yunnan Province, Myanmar (Burma), Laos, Thailand, Vietnam and Cambodia – before forming a complex delta system with several distributaries and entering the South China Sea. It provides more food than any other river and is second only to the Amazon in its biodiversity. In Addition, it sustains some 60 million people who rely on the river for their livelihoods, food production, transport, building materials and cultural enrichment. However, the Mekong is also one of the most threatened in the world.

Approximately 48 major dams, some the largest in the world, are now operating or inevitable, in the Mekong. Another 71 are in prospect, the worst of which could, literally kill the biodiversity and life-giving benefits of the river. The epicenter of development is Laos, Cambodia, which is being driven by investments from China and Thailand.

The greatest threats to the future productivity of the Mekong River posed by these dams are the interruption of sediment and sediment and nutrient flows and the fragmentation of fish migration pathways. The Mekong River is characterized by a very high percentage of long-range migratory fish. These dams present insurmountable barriers to the 87% of the Mekong fish species that must move from the ocean, the delta and Tonle Sap up into the large tributaries coming out of Lao, Cambodia and Vietnam to complete their life cycle and reproduce successfully.

Mekong River. Photo credit: Gregory Thomas

The sediments define the morphology—the physical shape--of the River and its floodplains and delta. This physical substrate determines the quality and variety of the habitats, which, in turn, determine the biological productivity of the system. The associated nutrients nourish the food web, which engenders the amazing biological productivity of the Mekong. It is a stark reality that, under current dam development plans and operations, approximately 94% of the sediments and nutrients that now maintain the Lower Mekong will be captured and taken out of the system over the coming decades. This will fundamentally undermine the exceptionally diverse habitats that make the Mekong the most productive river in the world.

The combined effects of sediment deprivation and sea level rise from global climate change have the potential to create a humanitarian crisis of unprecedented proportions. The Mekong delta has been designated by the Intergovernmental Panel on Climate Change as one of three mega deltas (with more than 1 million people) most threatened by coastal erosion due to sea level rise, along with the accompanying storm surges and salinity intrusion. Some 30% of this delta may be permanently lost. But the fate of the remaining 70% depends on maintaining the inflows of sediments and nutrients, and the annual flood pulse that replenishes the delta landscape and the near shore marine environment.

And, the delta is not the only graphic example of the potential impairment. Actually, the productivity of the entire river system, its floodplains, the magically productive Tonle Sap Great Lake (the most productive freshwater lake in the world), the deep holes in the river bottom, the marine fishery, the 32 biological “hotspots”, indeed, every element that accounts for the extraordinary productivity, will be degraded. Most of this can be saved, IF the sediment processes can be maintained in the face of massive upstream development.

Project Objectives:

The objective of the project is to transform dam development plans and decisions by the national governments, the investors and the power customers, and to generate learning on sustainable hydropower development options that can be widely applied throughout the world. This requires a vigorous program of outreach and briefings on the results of the technical assessments.

Expected Outputs:

Many conduits and venues will be used to propagate the project results to the relevant audiences. These include: 

  • Executive briefings to decision-makers with demonstrations of the analytic tools and results;
  • Presentations in regional and global water management conferences;
  • Briefings for all interested US Government agencies, including the USAID country missions, US embassies, USAID headquarters staff, interested USG executive branch agencies including the Corps of Engineers, US Bureau of Reclamation and US Geological Survey, and key members and committees of the US Congress;
  • Briefings for the international development assistance community, including the bi-lateral aid agencies, the Asian Development Bank, the World Bank, and the specialized agencies of the United Nations (UNDP, UNEP, IFAD, etc.);
  • Briefings for the regional economic cooperation organs such as ASEAN;
  • Interface with and assistance to other RDMA-funded initiatives, including the Mekong Partners for the Environment and the Smart Infrastructure for the Mekong program.
  • Briefings and trainings for civil society organizations in the region and international NGOs;
  • Print and electronic media briefings and informational packets;
  • Published articles in professional and academic journals;
  • An easily accessible internet portal for sharing project documents and results with the interested public.