The monthly cargo throughput via the five-tier ship locks at the Three Gorges Dam, the world's largest hydropower project in the upper stream of the Yangtze, reached a record high of over 15.71 million tonnes in August, according to the China Three Gorges Corporation.

China's longest river, the Yangtze is an east-west inland waterway, and it is regarded as the country's "golden shipping route."

The cargo throughput in August increased 6.76 percent year on year as it hit over 15 million tonnes for the first time since the ship locks began operation 20 years ago.

During August, the ship locks operated 965 times and saw the passing of 3,737 vessels, according to the corporation.

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 power generating capacity of 22.5 million kilowatts.

Since the ship locks opened to trial navigation in June 2003, the volume of freight passing through them has increased rapidly.

Read more: Over 1 million ships pass through Three Gorge Dam in last two decades