The Three Gorges Dam, the contested symbol of the Chinese economic miracle, provides the epic backdrop for Up the Yangtze, a feature length documentary by Chinese-Canadian filmmaker Yung Chang. The film follows a luxury cruise boat up the mythical waterway known in China simply as ‘The River’, which is being transformed by the biggest hydroelectric dam in history, crafting a moving depiction of peasant life and a powerful narrative of contemporary China. Below Yung Chang answers some questions.

What inspired you to make Up the Yangtze?

The idea was born in 2002 when I went on one of the so-called 'Farewell' cruises along the Yangtze with my parents and grandfather. The aim is to offer tourists the chance to visit the area before it is flooded by the Three Gorges Dam. It’s very surreal.

And I realised that the people working on the boat were all from the Yangtze area, and that many of their families were affected by the dam. It became a kind of Gosford Park idea that shows the social hierarchy, the lives above and below the decks. The other aspect was this sense of apocalyptic journey - something out of Heart of Darkness.

It’s a strange landscape of chaos and decay - like the photos of Edward Burtynsky. It’s very ghostlike along the river - hazy and grey and difficult to see long distances. Then we visited the Ghost City itself - Fengdu - famous in Chinese mythology as the site of the Gates of Hell. In my mind, the Three Gorges Dam became the Gates of Hell.

Being Chinese-Canadian, growing up hearing my grandfather’s stories of the old China, was also one of my motivations. It added a personal layer to the project.

How did you decide on your subjects – and how did you work with them?

I wanted to find characters that linked the boat to the larger picture, to what was happening onshore. I hooked up with Victoria Cruises - a company based in the US that runs one of the ‘Farewell Cruises’.

Yu Shui’s family was living on the banks of the Yangtze near Fengdu - a peasant family living in extreme poverty. They have three children, which is not unusual for a peasant family - the ultimate goal being to have a son. With the one-child policy, the father would have paid fines for the extra children.

The boy was in a meningitis-related coma, in fact, when we first met them in 2005. It was pretty serious but he survived. Hospital fees combined with school fees put the Yu family in severe debt. In normal circumstances the cruise managers would not have hired Yu Shui - she couldn’t speak English and was below the required height - but I think they empathized with her situation.

Chen Bo Yu is the complete opposite to Yu Shui. He’s an only child, from a small city named Kai Xian, which is located off a tributary of the Yangtze. He’s from a middle class background. His family is separated so he was raised by his grandparents.

He’s like lots of single sons - kind of spoiled and cocky. He’s tall and good-looking, and speaks good English, so he fit the mold of what Victoria Cruises was seeking. And in terms of the wider story, his family too will be displaced by the dam. I wanted to find people whose families were being directly affected by the next phase in flooding.

The Three Gorges Dam has sparked vigorous debate all over the world. How would you like Up the Yangtze to contribute to the discussion?

The official view in China is that the dam is good for the nation. As for the suffering of people like the Yu family, the standard line is the small family must sacrifice to help the big family - the nation. That gets repeated time and again. There’s never been so much nationalist fervour in China, especially with the Beijing Olympics, so many people are very proud of the project.

However all serious studies show that mega-dams like the Three Gorges ultimately have greater negative effects than positive. They cause terrible damage to the environment and destroy the livelihoods of local people. You see this already along the Yangtze – the pollution and silt buildup, the disappearance of certain species like the Baiqi Dolphin, and the hardship caused to so many people.

There has been some opposition in China. People have protested against corruption within the relocation program. Dai Qing, the dissident journalist who’s been critical of the project, was incarcerated for her views. She has since been released, and is speaking out again.