WUHAN, June 18 -- The total cargo throughput via the ship locks at the Three Gorges Dam, the world's largest hydropower project, has exceeded 1.91 billion tonnes over a period of 20 years, the Three Gorges Navigation Authority said Sunday.

During the past two decades, more than 993,000 ships with about 12.24 million passengers passed through the ship locks, located in the upper stream of the Yangtze, China's longest river.

Ever since the ship locks opened to trial navigation on June 18, 2003, navigation conditions on the Yangtze River have been greatly improved, and the maximum tonnage of vessels has increased from 1,000 tonnes to 5,000 tonnes. The advantages of waterway transportation, such as low energy consumption, less pollution, long shipping distance, and cost-effectiveness, have been brought into full play, said the navigation authority.

The freight volume through the ship locks has also increased rapidly, reaching 156 million tonnes in 2022, a record annual high.

The Three Gorges project is a multi-functional water-control system, consisting of a 2,309-meter-long and 185-meter-high dam, five-tier ship locks on the north and south sides, and 34 turbo-generators with a combined generating capacity of 22.5 million kilowatts.