The middle route of the south-to-north water diversion project had transferred more than 3.22 billion cubic meters of water to Beijing as of Thursday.
The water has benefited more than 11 million people in Beijing since the project was put into operation in 2014.
Of the delivered water, nearly 2.2 billion cubic meters has been used by water supply companies, 496 million flowed to reservoirs, 167 million to underground water resources, and 363 million to rivers and lakes in Beijing.
The project has greatly eased the pressure on water supply and improved the environment in Beijing, said Sun Guosheng, head of the project's Beijing office.
The water diversion project, the world's largest, was designed to take water from the Yangtze to feed dry areas in the north through eastern, middle, and western routes
The middle route, the most prominent of the three due to its role in feeding water to the national capital, began supplying water on Dec. 12, 2014 as part of the project's first phase.
It begins at the Danjiangkou Reservoir in central China's Hubei Province and runs across Henan and Hebei provinces before reaching Beijing and Tianjin.