A Tectonic Collision Course
At a remote point in Myanmar's Kachin State, two rivers, the Mali and N'mai, merge to form the Irrawaddy, the nation's primary waterway. This confluence was the designated site for the Myitsone Dam, a massive hydroelectric project designed as a concrete-faced rock-fill dam standing 139.6 meters high. The project, a joint venture between Chinese and Myanmar state-owned companies, was planned to have an installed capacity of 6,000 megawatts, with 90% of the electricity slated for export to China.
Construction began in 2009, but geological assessments soon revealed a problem. The dam site is located in a highly active seismic region, less than 100 kilometers from the Sagaing Fault. The tectonic boundary is a right-lateral strike-slip fault that runs the length of the country, accommodating the northward movement of the Indian Plate as it collides with the Eurasian Plate. An environmental impact assessment published in 2009 by a team of Chinese and Burmese scientists concluded the dam should not be built, citing the seismic risks among other environmental concerns. The location's proximity to this active fault line meant that a large earthquake could pose a catastrophic threat to the dam's integrity.
Quantifying the Risk
The primary geological danger is the potential for a major earthquake along the Sagaing Fault. Government officials stated the dam was designed to withstand a magnitude 8.0 earthquake, but independent assessments raised serious doubts. An important concern is a phenomenon known as reservoir-induced seismicity (RIS), where the immense weight of the water in a new, large reservoir can increase pressure on underlying faults, potentially triggering earthquakes. The Myitsone reservoir was expected to flood 447 square kilometers.
A catastrophic failure of the dam would have devastating consequences. Models of a potential breach show a massive flood wave that would inundate downstream areas, including Myitkyina, the capital of Kachin State with a population of several hundred thousand. The risk to life, property, and the agricultural region along the Irrawaddy was immense. Faced with mounting scientific evidence and widespread public opposition, Myanmar's President Thein Sein announced the suspension of the Myitsone Dam project on September 30, 2011, for the duration of his term. The geological dangers were a factor in this decision, halting one of the largest infrastructure projects in the region.