As the Yellow River surges through the Jin-Shaan Gorge, the majestic mountains intertwine with its mighty waters. The Guxian Water Control Project (hereinafter referred to as the "Guxian Project"), located east of Jixian County in Shanxi and west of Yichuan County in Shaanxi, is one of the 102 major projects outlined in China's 14th Five-Year Plan and a pivotal backbone project for the Yellow River's mainstream. Since its official commencement in July 2024, the project has accelerated into full swing. From a blueprint conceived over 70 years ago to its current construction, the Guxian Project carries the dreams of generations. What will it bring to the Mother River?

From the perspective of the Yellow River's winding course, the Guxian Project will join forces with key reservoirs like Longyangxia, Liujiaxia, and Xiaolangdi to regulate sediment, ensure flood control, secure water supply, and generate clean energy. From the national water network standpoint, the project controls 73% of the Yellow River's water volume, 60% of its sediment, and 80% of its coarse sediment. This reservoir will link national, provincial, and local water networks, optimizing water resource allocation and bolstering ecological conservation and high-quality development in the Yellow River Basin.

**Tunneling Through Mountains: Dual Diversion Tunnels Set for Full Completion by Year-End** To build a high dam, diversion comes first. Inside the cliffs on the Yellow River's left bank, two diversion tunnels are advancing side by side. Ventilation pipes line the tunnel walls, while signals from smart equipment flicker. At the tunnel face, a three-arm intelligent drilling jumbo uses laser positioning to precisely mark over 120 boreholes. Seven steps—drilling, charging, blasting, and more—are meticulously executed, advancing the tunnel by 3 meters each cycle.

"The Guxian Project adopts a full-year tunnel diversion approach, redirecting the Yellow River through the mountains to free up space for dam construction," explained Zhou Dewen, head of the Construction Management Section at Guxian Water Control Project Co., Ltd.

But tunneling is no easy feat. The geological challenges are formidable. The rock layers, horizontally stratified with alternating sandstone and siltstone, vary in hardness and thickness, posing stability risks. Each tunnel spans over 1 kilometer with an 18.2-meter-wide arch, requiring advanced techniques and risk management.

Pre-construction surveys employ 3D modeling and ground-penetrating radar for "digital eyes" to preview geological conditions 30 meters ahead. Core samples extracted by drilling rigs further refine the understanding of subsurface conditions.

Narrow workspaces demand agile machinery. Intelligent drilling rigs, crawler drills, and arch installation platforms operate with precision, boosting efficiency. The first layer of the diversion tunnel, completed in 195 days with a mere 9mm alignment error, was fully connected on September 26 this year. The second layer is 90% complete, and the third is 30% done, with full tunnel completion expected by year-end—a critical step toward river closure.

**Building on the "Cloud": Digital Twin Project Advances in Parallel** While hammers and drills shape the riverbank, a digital twin of the Guxian Project rises in the cloud. At the Digital Twin Hydraulic Design Factory of Yellow River Engineering Consulting Co., Ltd., data, algorithms, and computing power construct a "digital dam."

"Real-time monitoring feeds into a smart management platform, making tunnel construction transparent," said Lin Zhigang, deputy general manager of Henan (Yunhe) Information Technology Co., Ltd. The platform serves 42 participating units and over 900 users, offering dynamic hazard alerts and progress tracking.

A multi-layered monitoring system—satellites, drones, ground sensors, and water-level stations—provides comprehensive oversight. Over 1,000 monitoring terminals are deployed across the project.

Algorithms power the "smart brain." AI models analyze rock photos to identify fractures and textures, suggesting optimal construction methods. Safety gear detection and tunnel construction models enable minute-level response times.

Computing hardware forms the project's "heart." Over 20 kilometers of fiber-optic cables transmit data to 18 high-performance servers, ensuring real-time simulation and rendering.

**Engineering Marvel: China's Tallest Roller-Compacted Concrete Gravity Dam** Standing 219.5 meters tall, the Guxian Dam will be China's highest roller-compacted concrete gravity dam. Its foundation rests on challenging "red bed" geology—alternating soft and hard layers with shear zones. To stabilize the structure, deep keyways, shear-resistant tunnels, and counterweights were incorporated after extensive surveys.

The dam's massive scale demands 18 million cubic meters of concrete, peaking at 550,000 cubic meters monthly for 10 consecutive months—a world record for roller-compacted concrete projects.

Sourcing materials posed another hurdle. With local reserves insufficient, a quarry 65 kilometers away in Hejin, Shanxi, was selected. A 400-truck daily convoy would be impractical, so engineers devised a massive belt conveyor system—China's largest—traversing coal mining zones with robotic inspections for reliability.

The dam's innovative design features bottom sediment-flushing outlets, mid-level floodgates, and top spillways, enabling coordinated flood control, sediment management, and power generation.

**Eco-Friendly Impact: Water, Power, and Regional Development** The reservoir will stretch over 200 kilometers, improving regional ecology while generating 6.35 billion kWh annually. Water diversion will shift from costly pumping to gravity-fed supply, benefiting 23 counties, 27 industrial parks, and 4.57 million acres of farmland across Shaanxi and Shanxi.

Facing "one strict, four extreme" challenges—rigorous operation, massive foundation work, intense concrete pouring, long-distance material transport, and high-sediment flows—the project team collaborates with research institutes to deliver a high-standard, corruption-free public works milestone.

As crews race toward deadlines, the Guxian Project promises to transform the Yellow River into a lifeline of prosperity.