The 3S rivers, as the Sesan, Sekong and Sre Pok rivers are collectively known, are the only trans-boundary tributaries of the Mekong. The 3S river basin provides sustenance to over 3 million people across three countries, and will continue to play a significant role in the economic growth of the region.

Collaborative governance is central to the sustainable and efficient use of the water resources of the trans-boundary 3S rivers. IUCN, under the umbrella of the BRIDGE project funded by the Swiss Agency for Development and Cooperation, supports Cambodia, Lao PDR and Viet Nam in establishing frameworks to implement a long term water resources management strategy for the basin.