All 48 shield tunnels of the Pearl River Delta water resources allocation engineering project were broken through on Oct 29.

The project is expected to draw water from Liyuzhou, Foshan, and the main stream of the Xijiang River. It will then supply water to Guangzhou's Nansha district, Dongguan, and Shenzhen.

It also plans to provide emergency standby water supply for Hong Kong, Panyu district and Shunde, which will benefit about 50 million people upon the project's operation.

With a total investment of about 35.4 billion yuan ($4.7 billion) and a design duration of 60 months, the project is about 113 kilometers long and has a design annual water supply of 1.7 billion cubic meters.

The project's deep-buried water transmission pipelines are built underground at a depth of 40 to 60 meters. Of particular note, its shield tunnels' total mileage is about 135 km (double tunnels for some lines), and the excavation diameter is 4.1 to 8.3 m.

With the breaking through of the shield tunnels, the project will enter the comprehensive lining stage and is expected to be completed by the end of next year.