"They're spending hours each day trying to get their water," White said. "Once they get that water connection, they have water security. ... So it really means that people have this new-found time that they can then turn to their economic benefit and then repay their loan."
"It not only gives them water, it gives them more dignity," he said. "It gives them that ownership of their own lives and making their own way."
Access to water also allows young girls like the one Damon met in Zambia to improve their economic prospects through education.
"Everything changes. Suddenly the girls who are collecting water all day suddenly are in school," Damon said. "It's a huge, huge, huge issue for girls and women."
Damon and White said they hope to attract more donors by showing that they are making smart investments, with Damon leveraging his celebrity to reach people who would not know about the water issue.
"I think that there's an emotional element to this, of course, in terms of the suffering with it," White said. "But people also want to know that the dollar that they're investing is going further."
"If you can prove that there's a solution that works, people are into that. And people want to help with that," Damon added.
"You See How Life Changes"
Damon's philanthropic work was influenced by his mother, who when he was a teenager took him on trips to Guatemala, where he saw extreme poverty in person.
"A few years ago, I started to think, I want to go back and learn more about this," Damon said. "My sphere of influence has increased. I know there's something that I can be doing to help with some of these things."
Damon now regularly travels overseas to see the impact of water.org's projects in places like Africa and India.
"Those trips ... they're very powerful, because you see what happens when people suddenly have clean water. You see how life changes," he said. "It's a very powerful, emotional journey to go on, and so we try to do those trips as much as we can just ... to check up on all of our projects.
"It's the other side to these trips, you see some really hard things," he said. "But to see the life-changing joy is really, really quite something."
Damon said he hopes to pass on his passion for philanthropy to his four daughters.
"They all will start coming with me to these places because, like the gift that my mother gave me, I think it's a really wonderful thing to share with your children," Damon said. "And to give them some context about the world they're living with, understand just how lucky they are."
And while he maintains an active acting career, Damon said his work on access to clean water provides a unique satisfaction.
"When you see the difference that water can make in a community, that feeling of pure joy, there's nothing really that can compete with that in my day job," Damon said.