Yuan River, also known as Yuanshui, is a tributary of Dongting Lake in the Yangtze River Basin. It flows through China's Guizhou Province and Hunan Province. Yuanjiang is the second largest river in Hunan Province. The main stream is 1,033 kilometers (1,133, 1,022, 1,003 kilometers), with a drainage area of 89,163 square kilometers (1,9,000 square kilometers) and a drop of 1,462 meters (1,035 meters). ), the annual average flow of the estuary is 2170 cubic meters per second, and the annual runoff is 66.8 billion cubic meters (65.9 billion cubic meters according to other data). The basin spans the four provinces of Guizhou, Sichuan, Hunan and Hubei. It is the second largest water system in the four waters of Dongting Lake, Xiang, Zi, Yuan and Li.
The Yuanjiang River Basin involves 63 counties (cities, districts) in Guizhou Province, Hunan Province, Hubei Province and Chongqing Municipality. Most of the Yuanjiang River Basin is impoverished mountainous areas, where ethnic minorities are widely distributed and the level of urbanization is generally low. Except for the Changde City in the Weilu area of the lower reaches of the Yuanjiang River, which belongs to the integration of the "3+5" urban agglomeration in Hunan Province and has a relatively high level of economic development, most of the other areas are poor mountainous areas, with 11 pairs of economic development lagging behind.
The Yuanjiang River Basin is rich in hydropower resources. According to the 2013 plan of the Hunan Provincial Water Conservancy Department, the main stream of the Yuanjiang River is planned to be developed at 25 levels, with a total installed capacity of 5,19.34MW, and an average annual power generation of 18.137 billion kW·h. There are countless tributary water conservancy projects. On October 16, 2019, the first river-crossing tunnel on the Yuanjiang River was completed and opened to traffic in Changde City, Hunan Province. One of the central cities in the Dongting Lake Basin, Changde City, Hunan Province entered a new era of "underwater crossing" from "overwater crossing".