TIANJIN, Dec. 12 (Xinhua) -- North China's Tianjin Municipality has received 3.4 billion cubic meters of water diverted from the Yangtze, China's longest river, over the past four years, local authorities said Wednesday.

Around 9.1 million residents, or over 60 percent of the city's permanent population, have benefited from the middle route of the south-to-north water diversion project that began operation in late 2014, according to the Tianjin municipal government during a press conference.

More than 70 percent of the city's urban residential water supply was from the Yangtze in 2017.

Zhang Wenbo, deputy head of the Tianjin water affairs bureau, said the project has eased pressure on water supply and improved water quality in Tianjin.

The south-to-north water diversion project, the world's largest, takes water from the Yangtze to feed dry areas in the north through eastern, middle and western routes. The first phase of the middle route begins at Danjiangkou in Hubei and runs through Henan and Hebei before reaching Beijing and Tianjin.