Aerial photo taken on May 22, 2021 shows the Shahe aqueduct, key project of the middle route of China's South-to-North Water Diversion Project. (Xinhua/Liu Shiping)

BEIJING, Dec. 12 (Xinhua) -- China's mega water diversion project has transferred nearly 50 billion cubic meters of water from major rivers in the south to the drought-prone north over the past seven years, said the company in charge of the project Sunday.

Sunday marked the seventh anniversary of the comprehensive operation of the South-to-North Water Diversion Project. The project has benefited 140 million people and optimized the economic development pattern of more than 40 large and medium-sized cities.

The project has changed the water supply pattern in northern China, promoted the rehabilitation of rivers and lakes, optimized and adjusted the industrial structure, and produced enormous economic, social, and ecological benefits, said a Ministry of Water Resources official.

The South-to-North Water Diversion Project has three routes. The middle route, the most prominent of the three due to feeding water to the nation's capital, starts from the Danjiangkou Reservoir in central China's Hubei Province and runs across Henan and Hebei before reaching Beijing and Tianjin. It began supplying water on Dec. 12, 2014.

The eastern route began operations in November 2013, transferring water from east China's Jiangsu Province to feed areas including Tianjin and Shandong.

The western route is in the planning stage and is yet to be built.