Located in one of China’s most densely populated and economically important regions, the tunnel is a key element in the US$5.22bn project which will channel water from the Xijiang River to the Dongjiang River through a 113.2km underground pipeline. Planners aim to alleviate water scarcity in Guangzhou, Shenzhen and Dongguan and also create an emergency water reservoir for Hong Kong.

With a cutterhead power of 990kW, the EPB shield machine has tunnelled through soft ground, lining the tunnel with concrete segments along the way.