China began renovating its 2,261-year-old irrigation system in Dujiangyan City in southwest China's Sichuan Province on Nov.15th, at a cost of 120 million yuan (US$14.8 million).

About 1,120 specific projects around the irrigation system will be finished during the renovation, the most in history, said Zhang Kaiyong, an official with the Dujiangyan Administration Bureau.

Built on the upper reaches of the Minjiang River, a major tributary of China's longest river, the Yangtze, the Dujiangyan irrigation system is said to be the world's oldest irrigation project still in operation.

Built in 256 B.C., the irrigation system has undergone annual dredging and maintenance, a rule established by its builder Li Bing, an official of the Qin Kingdom during the Warring States period (475 B.C-221 B.C.).

At present, the system still irrigates 672,600 hectares of farmland and provides water for daily use and industrial purposes for people and enterprises in 50 large and medium-sized cities in Sichuan Province.

Officials from the local water resources bureau said annual renovation to the irrigation system has efficiently prolonged the life of the ancient system and also helped clean up the riverbed's silt.

 Dujiangyan was included on the World Heritage List of the United Nations Educational, Scientific and Cultural Organization in 2000.