Flood in the Desert, the new film from AMERICAN EXPERIENCE, recounts the dramatic story of the St. Francis Dam collapse in 1928 and its aftermath, the second deadliest disaster in California history, and explores lessons that can inform solutions to the current climate crisis.

The resulting flood killed more than 400 people, destroyed millions of dollars of property and washed away the reputation of one of the most celebrated men in Southern California, William Mulholland. A self-taught engineer, Mulholland had ensured Los Angeles’ remarkable growth by building a cement aqueduct that piped water across the Mojave Desert and into the arid city, 233 miles away. On May 3, AMERICAN EXPERIENCE premieres the story of this colossal engineering and human failure.

We caught up with producer, writer and director Rob Rapley to learn more about the film.

What drew you to this story?

It's so topical — western U.S. is now literally on fire. I wanted to learn more about how we got into this situation. I thought that it would be instructive, as we seek a way forward, to look at how we got here. The environmental challenge of the 1920s in California was how to bring water to everyone so they could build these great cities and they solved it through this massive geoengineering project. The building of the aqueduct and its reservoirs was definitely a fork in the road on our way to our current climate situation. It's not my place as a maker of historical documentaries to prescribe the solution, but maybe just to suggest some lessons from history.

What are you hoping that viewers take away from the film?

I think our fondness and our faith in geoengineering is something to be questioned. As we look for solutions to climate change, large-scale engineering will have a role to play, but it's not going to be a silver bullet. The solutions are probably going to be smaller and there are going to be more of them. They may entail some personal sacrifices. A woman at the end of the film says, 'don't trust anyone who says you can have it all.' But we kind of want to have it all. We want to solve climate change, but we don't want to give up anything.

What were the lessons learned from the dam collapse?

There were some very important lessons learned that improved the construction later, in the 1930s, of the Hoover Dam, which has been a flawless dam for decades and decades. And more important than any specific design change, we learned not to entrust one person with a project like this again, as people did at the time with Mulholland. For the Hoover Dam, teams of experts were involved at every stage.

Were there any surprises along the way as you were making this film?

It was all surprises. Many people have a general sense of the time and the politics and money involved in dealing with California’s water from the feature film Chinatown. But the actual details and the human stories are more remarkable than fiction. I found it really stunning the extent to which a small number of people, Mulholland and a few others in Los Angeles, dictated the history of that region.

What did you learn while making the film?

We tend to be very hard on our ancestors. We tend to think, how could they have done this to the environment? But when you look at the plan for the St. Francis Dam — if you didn't know what was coming — it looks like an environmentally sensitive project. It tapped an endlessly replenishable supply of water from the mountains that would be refreshed every year with snowfall — they weren’t emptying an aquifer. And it was creating hydroelectric power to electrify the whole city. It looks different when you see it through the perspective of that time. It reminds me that we should be a little more humble with respect to our forebears.

Watch the premiere of Flood in the Desert on Tuesday, May 3 at 9pm on GBH 2 or stream online.