Shenzhen News, September 20, 2025 It was recently learned that the Shenzhen Reservoir Interception and Drainage Project on the Shawan River has achieved significant progress. The project is currently in the tunnel shield tunneling phase, with overall construction progress reaching approximately 35%. Construction on all four regulating lakes has passed the halfway mark. Once completed, the project will undertake the functions of rainwater storage and flood interception and drainage for the upstream area of Shenzhen Reservoir.
The Shenzhen Reservoir Interception and Drainage Project on the Shawan River primarily includes the construction of four regulating lakes and an interception and drainage tunnel with a total length of 6.71 kilometers. As a crucial project to ensure the water quality of Shenzhen Reservoir’s drinking water source, it will further enhance the reservoir’s water protection capabilities and the city’s flood control and drainage levels, playing a significant role in ensuring public safety and promoting sustainable urban development.
“Relying solely on regulating lakes cannot fully handle rainwater and flood regulation. Therefore, the project also involves the construction of a large-diameter interception and drainage tunnel to combine storage and drainage, alleviating flood peak pressure and effectively improving flood safety.” A new Shawan River gate dam will also be built as part of the project, forming the final barrier for Shenzhen Reservoir’s protection and greatly enhancing the water quality of drinking water sources for both Guangdong and Hong Kong.
It is understood that the large-diameter interception and drainage tunnel under construction has an outer diameter of 10 meters and an inner diameter of 9 meters, making it the largest hydraulic tunnel currently under construction in Shenzhen and a rare large-diameter tunnel among similar water conservancy projects nationwide. The tunnel is divided into two sections: from Shawan to Dawang and from Dawang to Donghu.
Tunneling began from the Shawan working shaft, but the geological conditions at the selected site are relatively complex. The tunneling section features alternating layers of soil and rock, with local rock strength reaching 5-6 times that of concrete, posing significant challenges for shield tunneling. To address the complex geological conditions, the project team customized a large-diameter dual-channel shield machine named “Tongze,” with a total length of 115 meters. Equipped with various cutting tools, it can adapt to different geological conditions such as hard rock, soft rock, clay, and fractured zones, significantly improving construction safety and reliability.
“The shield machine has been specially designed to address the geological layers and surrounding environment it will traverse, enabling it to handle multiple risks and difficulties.” The team has implemented targeted technical and management measures, including intelligent equipment, refined management, and scientific scheduling, to ensure that various challenges during tunneling can be smoothly resolved and project safety guaranteed. It is expected that another shield machine will be launched at Dawang in Luohu next June, allowing two shield machines to tunnel simultaneously.