JJ Watt on raising $27 million for Harvey relief efforts: 'Humanity steps up for each other'

— -- Football star J.J. Watt opened up about his fundraising efforts to help those impacted by Hurricane Harvey, saying he learned "when things look the bleakest, humanity steps up for each other."

Watt made the realization after the campaign he started raised more than $27 million with donations from over 160,000 people.

"Just to see the snowball effect, and to see how much good there is out there, and how many people wanted to get involved was ... incredible," Watt said in an interview with "Good Morning America" co-anchor Michael Strahan.

Watt said he decided to try and find a way to help Houston as he watched his city become inundated with deadly floodwater from his hotel in Dallas, and he felt "helpless."

"You can't get back home, you can't physically help out in any way," Watt said. "I'm watching it on TV and seeing all these people help out, seeing people get in boats and help, seeing water rush down streets that I drive down every day ... I said, 'How can I help?'"

Watt said he got the idea to tap into his social media following and see if he could start raising funds to help with the much-needed relief efforts.

The star defender for the Houston Texans said he was initially "hoping to raise $200,000, and ... now we're over $27 million."

"There's over 160,000 people that have donated. So while some are big ... there's as big as a $5 million donation, there's also as small as a $5 donation," Watt said. "It's people giving whatever they can."

"I've seen little girls set up lemonade stands. I've seen kids trying to sell, you know, Popsicle on the road. I've seen businesses offering up ... portions of their sales or all of their sales," Watt said. "It's been truly something incredible to witness."

Watt said he and his teammates have also been on the ground in Houston, meeting with those impacted by the storm in an effort to spread goodwill amidst the devastation.

"In a time like this, when things are so difficult, you wouldn't think that seeing your favorite football player would matter all that much," Watt said. "But something as small as a smile, something like a handshake, a selfie ... these people just light up."

"We're giving supplies, we're giving water, we're giving things that they truly, really need," he added. "But I think that some of the best things were our guys just taking photos with them ... having a conversation with them, learning what they went through, learning about their struggle."

Watt also emphasized that he is making sure that all the money raised is all going directly to help the people of Houston.

"I take that responsibility extremely seriously. And I'm gonna make sure ... that what I do is do right by the people who donated, and by the people who need the help," Watt said.

Watt's full interview with Strahan will air on Fox NFL Sunday. Watt's Houston Flood Relief Fund will be accepting donations until Sept. 15, 2017. Donations can be made at YouCaring.com/JJWatt.