JINAN, Nov. 28 (Xinhua) -- An extension of the south-to-north water diversion project broke ground in the city of Linqing in east China's Shangdong Province on Thursday to reinforce water supply to the Beijing-Tianjin-Hebei region.

The extension is expected to channel 490 million more cubic meters of water northbound to the Beijing-Tianjin-Hebei region annually, said Gao Bihua with the China Eastern Route Corporation of South-to-north Water Diversion.

Once completed, the extended stretch will alleviate the over-drilling of underground water, improve the environment and provide emergency water supply for cities in the region, said Vice Minister of Water Resources Jiang Xuguang.

The new waterways along the eastern routes of the south-to-north water diversion project are scheduled to be finished in 21 months.

The first phase of the eastern and middle routes of the south-to-north water diversion project has played an important role in supporting water use in areas along the routes since its completion, benefiting over 100 million people.