The south-to-north water diversion project transferred 2.24 billion cubic meters of water to northern China's Hebei Province last year to quench its thirst, refilling some rivers.
The volume was twice the total combined volume the province had received over the previous three years, said an official with the provincial water resources department.
Part of the water was discharged to three local rivers -- Hutuo, Fuyang and Nanjuma -- to ease the groundwater shortage and improve the local ecology.
Thanks to the refill, groundwater levels nearby the rivers rose by 0.76 meters on average, according to the official.
China's northern region has long suffered from water shortage, leading to groundwater overexploitation and river water shrinking, especially in Hebei, a drinking-water supplier for neighboring Beijing.
The south-to-north water diversion project, the world's largest, takes water from the Yangtze River 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 Province and runs through Henan and Hebei provinces before reaching the cities of Beijing and Tianjin.