The Salween River (သံလွင်မြစ်; ; also spelled Salwine) rises in Tibet after which it flows through Yunnan, where it is known as the Nujiang river although either name can be used for the whole river. The river is 2815 km long. It then leaves China and meanders through Burma (where it is known as the Thanlwin) and Thailand (where it is known as the Salawin, Thai: สาละวิน) on its way to emptying in the Andaman Sea by Mawlamyaing (Moulmien).
For most of its route the river is of little commercial value, as it passes through deep gorges and is often called China's Grand Canyon. The Salween is navigable for only 89 kilometres from its mouth, and then only in the summer rainy season.
It is home to over 7,000 species of plants and 80 rare or endangered animals and fish. UNESCO said this region "may be the most biologically diverse temperate ecosystem in the world" and designated it a World Heritage Site in 2003.
In October, 2006, Chinese water resources minister Wang Shucheng indicated high-level disapproval of the plan to build a string of large dams on the Nu as it flows through the Three Parallel Rivers National Park in Yunnan province.
Mr. Wang said concerns related to the park - parts of which were designated a UNESCO World Heritage site in 2003 - as well as "downstream national interests," made it impossible to continue with the original plan. However he added that the status quo of no dams on Southeast Asia's largest free-flowing river is not an option either.
There is some controversy over the representation of local opinion in the media. Investigative journalist Liu Jianqiang found little support for the dam projects among locals, who feared they would not get adequate compensation.
The Thai and Burma governments are planning to build several dams. One is said to be larger than the widely controversial Three Gorges Dam. On April 5, 2006 the Thai and Burma governments signed a 6 billion USD agreement to build the Ta Sang dam.
Another Thai-Burma project is for the Hatgyi Dam. A feasibility survey was started in May 2006, but was abandoned until sometime in 2007, due to a military offensive by the State Peace and Development Council against Karen people in the area. The dam's builder, the Electricity Generating Authority of Thailand, had hoped to have the feasibility study completed by April 2006, with construction to start in November 2007.