China has pledged to improve its underdeveloped water conservancy works over the next five to 10 years, as floods and drought in recent years have exposed weaknesses in the country's water conservancy infrastructure.

The following are some facts about the country's water conservancy development since the founding of the People's Republic in 1949:

-- Reservoir construction

Most of China's reservoirs -- more than 80,000 -- were built before the country's reform and opening-up drive which started in 1978. Less than 4,000 reservoirs were built after 1978.

In 1952, the country's irrigated land stood at 20.16 million hectares. By the end of 2008, the irrigated area expanded to 58.47 million hectares.

At present, more than one third of the reservoirs in China need repairing. Further, only 30 percent of water projects in irrigated farming areas are in good condition.

-- Main projects

In 1988, Gezhouba Dam, the first water conservancy project on the Yangtze River, was completed after 18 years of construction. The project was a milestone in China's water conservancy history. As part of the Three Gorges project, it provided experience for experts and officials who prepared later projects.

China carried out a survey on the site of the Xiaolangdi reservoir on the Yellow River in 1953. Construction of the reservoir's major section began in 1994. The trial operation started in 2000 and the project was completed in 2009. It provided 187.3 billion cubic meters of water to the lower reaches of the Yellow River from 1999 to 2008.

The South-to-North Water Diversion Project is designed to divert water from water-rich south China, mainly from the Yangtze, the country's longest river, to the country's arid northern regions. It will consist of three routes: eastern, middle and western routes. The project started with construction of the eastern route in 2002 and the middle route started in 2003. Pre-construction studies of the western route will soon begin.

In 2009, construction of the Three Gorges Dam on the Yangtze River, one of the world's largest water conservancy projects, was finally completed. The construction lasted 17 years. The Three Gorges reservoir can store water to 175 meters high and generate 79.47 billion kilowatt-hours of electricity per year with full operation of its 26 generators.