Myanmar has two of the globally most intact tropical river systems - the Salween and the Irrawaddy - which are also in one of the most biodiversity-rich regions of the world. The value of these free-flowing rivers is of fundamental importance to the regional biodiversity, the economy of the country, and the health and wellbeing of the people of Myanmar. It can therefore be said that the integrity of the rivers in Myanmar is of global significance. Nonetheless, the Government of Myanmar (GoM) is currently considering building several dams which would put these important free-flowing rivers at risk.
In this study we assessed the connectivity of Myanmar's rivers under two scenarios, following the methodology in Grill et al. (2019):
a) the present situation including existing dams in Myanmar and
b) a potential future scenario of intensive dam development.
This future dam development scenario is based on the "business as usual" scenario laid out by the Strategic Environmental Assessment (World Bank, 2018) and assumes that the 69 known proposed large dam projects are developed.
The study also shows that large-scale dam development, such as planned under the "business as usual" scenario, would result in the loss of long free-flowing rivers in Myanmar. In fact, all rivers longer than 500 km would cease to remain free-flowing and a third of all medium length (100-500 km) free-flowing rivers existing today would suffer the same fate. We would also see a higher decline in the connectivity of the coastal basins, which is worrying in view of the high ecological and social importance of rivers that feed coastal ecosystems.