More than 100 people walk near the edge of a cliff, and some of them are extremely frightened.

They are the cast of the upcoming film Sky Stream, based on the story of Huang Dafa, Party chief of the village of Caowangba in Zunyi, Guizhou province.

Huang, who turns 83 in November, spent more than 30 years leading locals to chisel an irrigation channel measuring 9,400 meters long into the sides of three karst mountains.

The project was initiated in the 1960s, but the first 13-year effort ended up in vain due to torrential rain and a lack of expertise. Then, Huang decided to learn about water conservation before restarting work on the project.

The project was finally completed after 36 years, ending Caowangba's hard times caused by frequent droughts.

To mark Huang's contribution, villagers named the project after Huang, who won one of this year's 10 "Touching China" awards, an annual honor by state broadcaster China Central Television, which pays tribute to role models.

"Simplicity and sincerity were the guiding principles for those of us working on this film," says director Bo Lin at a promotional event in Beijing on Aug 3.

"From my perspective, Huang is a small figure who achieved something great.

"We didn't want to overstate how great Huang was, in case the audience didn't like it. We just wanted to tell the story in a simple way," adds Bo, who decided to make the film in November 2017.

In the film, the audience can see how Huang puts his heart into his work. Even though his daughter falls ill, Huang delays taking her to see a doctor. Finally, his daughter dies at the age of just 23.

When the project is finally complete, Huang takes a bowl of clean water from the ditch to his daughter's grave, sits on a rock and cries.

In another scene from the film, when a person has to be lowered from the top of a mountain to perform a delicate operation, Huang bravely volunteers to do it.