The Three Gorges Dam, one of the world's largest hydroelectric projects, spans the Yangtze River in Yichang, Hubei Province. Apart from being a remarkable feat of engineering, the dam is one of the most efficient in flood control, and involved the largest migration project on the planet.

Cai Xiaolong, an engineer with Watershed Cascade Complex Management Bureau, commented that the project not only controls flood, but also integrates comprehensive functions.

"The project delivers massive benefits including flood control, power generation, navigation and water resource utilization," he said, adding that the top priority of the project is flood control, "That is the real reason why we build it." 

The dam has increased the Yangtze River's shipping capacity and reduced the potential for floods downstream with its storage space. 

Wang Hai, director of the Reservoir Management at the Department Watershed Cascade Complex Management Bureau said the dam can control 95 percent of the incoming water for the most dangerous section, and has upgraded flood control standards from preventing once-in-a-decade floods to once-in-a-century.

The Three Gorges project was the result of a serious decision-making process. Deliberations were made regarding the benefits and costs that this century's big project would bring to the people and the environment. Scientific investigation and verification took about 40 years, before the National People's Congress passed a resolution to build the dam.

Cai told CGTN that any project of this scale will have both positive and negative impact on the environment, and for the Three Gorges project, the benefits far outweigh the costs. 

He said the positive impacts on the environment include flood control and renewable clean energy. The project may endanger some creatures but it can be controlled, Cai said.