After 13 years of immense effort and technical ingenuity, China has put the finishing touches to its controversial Three Gorges dam, the world’s largest hydropower project.

"I can announce to the Chinese people . . . that the Three Gorges dam is completed," construction manager Li Yong’an said after the last load of cement was poured on to the top of the dam on Saturday.

The 2309m-long, 185m-high dam across the Yangtze River is meant to control floods and generate electricity for a power-hungry nation. However, critics argue that silt build-up and other problems mean the dam won’t provide the hoped-for flood relief.

Opponents also see damage to the environment, ruin to China’s heritage and misery to residents forced from their homes for the project. The immense structure will not be fully operational for another two years. About 100 workers have died completing the project.