China began construction of a mega waterway project on Monday, including what is expected to become the world's largest inland ship lock, in response to rising shipping demand along the Yangtze River, the world's third-longest river. The 77.2-billion-yuan (about $11.3 billion) project will add a five-tier, dual-track ship lock north of the existing lock at the Three Gorges Dam, the world's largest water conservancy project, and upgrade navigation facilities at a smaller downstream dam. Once completed, it will nearly double the annual throughput capacity of the Three Gorges to 336 million tonnes.