Xiluodu Dam: China's Second-Largest Hydroelectric Dam

The **Xiluodu Dam** is a massive double-curvature arch dam on the Jinsha River — the upper reach of the Yangtze — near the border of Yunnan and Sichuan provinces in southwestern China. Standing **285.5 meters** tall, it is one of the highest arch dams in the world and houses a **13,860 MW** hydroelectric power station, making it the third-largest by installed capacity globally.

Introduction

Completed in 2014, the Xiluodu Dam is a key component of China's cascade development of the Jinsha River, which includes four major dams designed to harness the enormous hydroelectric potential of this high-gradient river as it descends from the Tibetan Plateau toward the Sichuan Basin.

Engineering & Structure

• Type: Double-curvature arch dam
• Height: 285.5 meters
• Crest Length: 698 meters
• Concrete Volume: 5.8 million m³

Xiluodu is a double-curvature arch dam, meaning its wall curves both horizontally and vertically to transfer the immense water pressure into the canyon walls on either side. At 285.5 meters, it is the fifth-tallest dam in the world. The dam's crest stretches 698 meters across the narrow Jinsha River gorge, and its construction required 5.8 million cubic meters of concrete.

The dam's spillway system is designed to handle extreme floods, with a maximum discharge capacity of 32,458 cubic meters per second. The power station houses 18 turbine-generator units, each rated at 770 MW, split between underground powerhouses on both banks of the river.

Geographic Setting

• River: Jinsha River (upper Yangtze)
• Location: Border of Yunnan and Sichuan provinces, China
• Coordinates: 28.27°N, 103.65°E
• Reservoir Capacity: 12.67 km³

The Jinsha River carves a deep canyon through the mountains of southwestern China as it descends from the Tibetan Plateau. At the dam site, the gorge walls rise steeply on both sides, providing the ideal geology for an arch dam. The surrounding landscape is rugged and mountainous, with elevations ranging from 600 to over 3,000 meters within a short distance.

The reservoir extends approximately 200 kilometers upstream, flooding portions of the narrow river valley. The region lies in a seismically active zone, and the dam was engineered to withstand significant earthquakes. Geological surveys confirmed the competence of the canyon's bedrock for anchoring the arch structure.

Hydroelectric Power

• Installed Capacity: 13,860 MW
• Annual Output: ~57.1 TWh
• Turbines: 18 × 770 MW Francis turbines

Xiluodu's 13,860 MW installed capacity makes it the third-largest hydroelectric power station in the world, behind only the Three Gorges Dam and the Itaipu Dam. Its 18 Francis turbines, each rated at 770 MW, are among the largest hydroelectric turbines ever manufactured, representing significant advances in Chinese turbine technology.

The dam generates approximately 57.1 terawatt-hours of electricity annually, transmitted via ultra-high-voltage lines to Guangdong Province and the Yangtze River Delta region. This output displaces an estimated 23 million tonnes of coal per year and is a cornerstone of China's strategy to shift its energy mix toward renewable sources.

Environmental & Social Impact

• People Relocated: ~35,000
• Seismic Concerns: Located in earthquake-prone zone
• Sediment Trapping: Reduces sediment flow to downstream Yangtze

The construction of Xiluodu Dam required the relocation of approximately 35,000 people from the narrow river valleys upstream. While far fewer than the Three Gorges resettlement, the displacement affected remote rural communities with limited alternative land for agriculture. Compensation and resettlement programs were implemented, though some residents reported difficulties adapting.

The dam traps a significant portion of the Jinsha River's sediment, which has both positive and negative consequences. It reduces sedimentation in the Three Gorges Reservoir downstream, extending its useful life, but also deprives downstream floodplains and the Yangtze Delta of nutrient-rich sediment. The dam's location in a seismically active region has prompted careful monitoring for reservoir-induced seismicity.

Key Facts

• Xiluodu Dam stands 285.5 meters tall, making it one of the world's highest arch dams.
• Its 13,860 MW installed capacity ranks third globally among hydroelectric power stations.
• The dam is part of a four-dam cascade on the Jinsha River, the upper Yangtze.
• Each of its 18 turbines generates 770 MW, among the most powerful ever built.
• It generates roughly 57.1 TWh of electricity annually.

Fun Facts

• The Xiluodu Dam's arch design transfers water pressure into the canyon walls, allowing it to use far less concrete than a gravity dam of similar height.
• The Jinsha River's name means "River of Golden Sand," referring to the gold dust historically found in its waters.
• The dam site lies in a gorge so narrow that the valley floor receives only a few hours of direct sunlight per day.

Final Thoughts

Xiluodu Dam showcases the extraordinary scale of China's hydroelectric ambitions on the Jinsha River. Its towering arch structure and massive power output make it one of the most impressive engineering achievements in modern dam building, while its environmental effects continue to shape the ecology of the Yangtze basin.