The Yangtze River and Three Gorges Dam

01THE RIVER OF THE HEARTLAND

The Yangtze runs from the Tibetan Plateau to the East China Sea, crossing deep gorges, agricultural plains, and dense urban economies. It is water supply, habitat, irrigation, and recurrent flood threat. The river’s scale makes local decisions accumulate into national consequences.

02WHY BUILD A DAM THIS LARGE

The project was designed to generate hydroelectricity, improve navigation through the gorges, and moderate some flood risk downstream. A dam concentrates water-level control at one structure, allowing operators to store water before a forecast event and release it through turbines or spillways under managed conditions.

03CONCRETE, TURBINES, AND LOCKS

The dam is also a transport machine. Ship locks and a ship lift help vessels bypass rapids and elevation changes, while turbines turn falling water into electricity. These functions reinforce one another: a navigable reservoir supports freight, and a large power system supports the industrial corridor below.

04FLOOD CONTROL IS NOT FLOOD ELIMINATION

Storage can reduce the peak of some floods, but it cannot abolish rainfall, tributary inflows, or downstream exposure. The reservoir must preserve space for a possible flood while meeting power and navigation demands. Extreme events may exceed assumptions, and risk can be displaced to tributaries, cities, or communities downstream.

05THE HUMAN RELOCATION

Creating the reservoir submerged towns, archaeological sites, farmland, and river habitats. More than a million people were relocated during the project and associated works. Compensation and new housing changed lives unevenly, and the loss was not reducible to a construction budget. The social geography of the Yangtze was redrawn with its water surface.

06SEDIMENT AND ECOLOGY

A reservoir slows water and captures sediment that would otherwise travel downstream. That can protect turbines but starve wetlands and deltas of material that helps them maintain elevation. Altered temperature, flow timing, and fish migration affect ecology. The dam must be judged as a basin-scale experiment, not only as a wall.

07THE MEGAPROJECT QUESTION

The Three Gorges Dam demonstrates both the reach and limits of centralized infrastructure. It supplies energy and navigation benefits at enormous scale, yet impacts are distributed across people and ecosystems that do not share the same balance sheet. Every river project chooses which risks to reduce, which costs to impose, and who decides.