Yu calls the fountains at the Bellagio in Las Vegas “water porn.”

Filming a documentary about the world’s water crisis was scary enough, and the fact that no one seems to care about the crisis made it even more terrifying. So it’s understandable that there were times when Jessica Yu, director of “Last Call at the Oasis,” just wanted to hide under the covers.

“I had several of those moments,” says Yu, whose film opens Friday at the Landmark E Street Cinema. “It’s not on our radar that there are these water problems. We can slow down the destructive path we’ve been taking, but it’s just not on our register.”

With her film, Yu had to address a problem the makers of “Food, Inc.” — the 2008 doc that examined corporate food production — didn’t have to deal with. “There, they have kind of a bad guy,” she says. “Here, in a way, the bad guy is us.”

Humans might be the bad guy, but the film argues that much of our evil stems from ignorance. “A lot of times people don’t trust their tap water, so they think, ‘I’m going to drink bottled water.’ Now we know that bottled water is not as regulated as tap water. What we need to be looking at is upgrading our water infrastructure so we can take care of our populations.”

The film effectively points out we don’t just drink water — it’s necessary for pretty much everything, from the obvious (swimming pools) to the surprising (the film says it takes 70 gallons of water to make a T-shirt). We also use water as entertainment, as seen by long shots of the fountains outside the Bellagio hotel in Las Vegas, which Yu contrasts with footage of droves of people in developing nations lining up for a few gallons of clean water.

“We all take pleasure from images of water, and that [juxtaposition] was a way to expose those idealized images of water porn with the ways we actually treat water. That disconnect was really interesting to me.

“People will go and stand and watch the show at the Bellagio for hours. And it’s just crazy — you’re in the middle of the desert, and we’re going to make water dance for you.” Kristen Page-Kirby (Express)

Landmark E Street Cinema, 555 11th St. NW; opens Fri., $8-$11; 202-452-7672. (Metro Center)