River systems of Thailand divides into two major branches, the " Tiền Giang" (Front River) and "Hậu Giang" (Back River). These in turn enter the South China Sea through nine estuaries. The following are the principal tributaries of Mekong River which flow through Thailand (tributaries entirely outside the Thai border not shown). The Mekong drains a considerable portion of northeast Thailand. In terms of Thai territory drained, it is second only to the Chao Phraya system. The Salawin River rises in Tibet (Tibetan: རྒྱལ་མོ་རྔུལ་ཆུ།) after which it flows through Yunnan, where it is known as the "Nujiang" River (), although either name can be
Mekong River Commission including China, Burma (Myanmar), Laos, Thailand, Cambodia, and Vietnam. From its conception until 1995 the organization was under the leadership of an "executive agent". Since then it has had CEO's. The Mekong River Commission and its predecessors have never included the People's Republic of China (which was not a member of the United Nations in 1957) or Burma (which does not significantly rely on or tap the Mekong), whose territory contains the upper Basin of the Mekong. Although a New York-based organization called SERVIR has started a joint initiative project, SERVIR Mekong project, with five countries, Thailand, Cambodia, Laos and