Water resources in China are unevenly distributed. Generally speaking, the south is rich in water while the north is short of this resource; and the east is rich in water whereas the west lacks it. With the increase of population and rapid economic development, the problem of water shortage in the north is getting even more serious. One solution is to divert water from one drainage area to another, namely, from south to north.

The project of water diversion from south to north includes three lines - the east, middle, and west lines

The east line will carry water from the lower reaches of Yangtze River northward along the Beijing-Hangzhou Canal to North China Plain. It is about 1,150 km diverting 30 billion m of water annually. There is no need to dig new channels along the east line. The facilities of the established Jiangdu and Huai'an pumping stations and Beijing-Hangzhou Canal can be uesed to divert water, and many lakes along the line can serve as reservoirs for water regulation.

The middle line will draw water from the middle of Yangtze River and its main tributary, Hanjiang River, to the western side of North China Plain. It is over 1,000 km long and could divert 30 billion m of water annually. It is not only divert a large volume of water but also make use of the drop in altitude to build hydropower plants.

The west line will be a channel water from the upper reaches of Yangtze River to supply water for the upper and middle reaches of the latter and the northwestern regions. The west line will have to pass through mountain and gorges at high altitude. Due to the lack of construction materials and inconvenient transpotation, this project will entail great efforts and investment.

The three lines can support one another and be developed by several stages according to national economic development and the existing financial capacity. In the near feature, the east and middle lines will be constructed while the west line is for a long-term plan.