The Lancang-Mekong, with a total basin area of about 810,000km2 and an annual average volume of flow of 475,000 mcm, is a major international river. In Yunnan river gorges are steep; slopes range from 1.5‰ in the upper part of the Lancang to between 0.8‰ and 1.0‰ in the middle and lower parts. Potential hydropower is unevenly distributed, mainly concentrated on the mainstream of the Lancang in China and the tributaries of the lower Mekong. The supply capacity of electricity among most of the riparian countries can't meet the power needs. Data provided by the State Power Corporation of China shows that the total installed capacity of the cascade dams would be over 15,000MW, yielding over 7,000MW of firm power and annual energy production of about 70,000 GWh.