The statistics are staggering: Nearly one billion people in the world don't have access to clean drinking water, and 4,500 children die every day from diseases caused by contaminated water, which kills 2.2 million people each year. In an effort to change that, The Thirst Project summoned friends, reporters and celebrity supporters to the Santa Monica Pier on World Water Day, March 22, to announce its mission to raise $50 million to pay for wells needed to provide every citizen of Swaziland with clean water. Seth Maxwell, the nonprofit's founder and CEO, explained that the African country has the highest population density of AIDS in the world, and contaminated water is killing victims faster than the disease because of their compromised immune systems. He hopes to accomplish the goal within ten years by marshaling the support of celebrities, students, corporations, philanthropists and others.

"When I was 19, a photojournalist friend had come back from a trip and had seen people dying of dysentery and cholera from drinking dirty water," said Maxwell. "I started raising awareness on my college campus, the American Academy of Dramatic Arts. Now we have about 200 schools that do fundraisers for us every year. We've raised about $2.6 million and saved 100,000 people so far with clean water."

Julie Benz ("A Gifted Man") said she's been "tweeting up a storm" about the cause "to help raise more awareness and get more people involved." She has eliminated plastic water bottles from her life and takes shorter showers to conserve water at home. "I have a filter on my fridge and I don't leave the water running when I'm brushing my teeth. I have arid landscaping in my back yard. It's drought-friendly," she noted. Next month, she'll head to Toronto to shoot the new Syfy series "Defiance," playing the mayor of the titular town. "It's like a western set in the future."

"Grey's Anatomy" star Chyler Leigh found Maxwell's passion and dedication so infectious that she had to become involved. The mother of three small children, she teaches them about water conservation, "turning the water off when you're washing the dishes or brushing your teeth and taking shorter showers. Every little bit helps, and in the long run it makes a difference," she believes. Coming up on "Grey's," "There are a lot of relationship switches, dynamics that are going on that are very intense," she said, hinting at "a very big ending" to the season. She'll unwind from it by taking her family on a trip to Disney World during her hiatus.

Michael Welch of the "Twilight" movies pointed out the urgency of providing clean water to those who need it, and not only for health reasons. "Countless kids around the world waste the day walking miles for undrinkable water so they can't go to school or have any kind of a life. It severely limits your options," he pointed out, noting the obligation he feels as a person of privilege to help. "The impetus behind all charity is to be able to provide people with the kind of advantages and opportunities that you yourself have," said the actor, who has a water filter at home and carries a metal water bottle with him. "I limit how many times I wash my car. It's dirty most of the time," he added.

Although he's not in the final "Twilight" movie "Breaking Dawn Part 2," Welch has several other films in the can, including "Black Forest: Hansel and Gretel and the 420 Witch," a genre blender that's "very campy and funny on one hand and very dark and gruesome on the other." He plays Hansel to Molly Quinn's Gretel in the movie, set in modern day Pasadena, with the titular witch selling pot instead of candy to lure kids. He's also in "The Boys of Abu Ghraib," set in the infamous prison. He plays the squad mate of the main character played by Luke Moran, who wrote and directed.

"Water is the most precious resource in the world, more than oil, and we should be giving it more attention," believes Allie Gonino of "The Lying Game," who became interested in the cause after her dad told her about an interview he read in which Matt Damon discussed the crisis, after which she volunteered to make a PSA for Damon's "Drugs, fossil fuels — so many things go into our water that make it unhealthy," she noted. "It's a daunting task, but we have to do something. It's our job to take care of the planet if we want to survive. I think a large part of it is making a move toward cleaner energy from wind and the sun," added Gonino, who doesn't shower every day or leave the water running. "I only do laundry once every week and a half," she said.

Gonino's ABC Family series has wrapped for the season, but she anticipates going back to the set in late May or early June once the official pickup is announced. She's thrilled that she's been able to sing on the show, as music is as important to her as acting. "The next step is to record an EP with my band The Good Mad," she said. "We'll see what happens from there."

Photos: Bauer Griffin

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The Thirst Project's mission: Clean water for all
Celebs mark World Water Day by lending support, sharing conservation tips at Thirst Project event.