The Houston Texans' J.J. Watt. Image by Petty Officer 1st Class Andrew Kendrick/U.S. Air Force/Wikimedia Commons.

The floodwaters continue to rise in Houston, with the total rainfall from Hurricane Harvey expected to exceed 50 inches in some parts of the city. Over 30,000 residents may have to seek refuge in shelters. Volunteers are pouring into the city, and FEMA issued a statement asking for help, a request that Houston-based NFL players and teams have already begun to answer, raising funds to help the victims.

Multiple athletes tweeted out words of encouragement over the weekend, and on Sunday, Houston Texans defensive end J.J. Watt announced via a video posted to his Twitter and Instagram accounts that he would be leading a fundraising drive. Watt personally donated $100,000 and announced that he hoped to raise $500,000 in total, a goal he reached in the first 24 hours.

"I'm sitting here watching the news and checking the internet and seeing everything that's going on with Hurricane Harvey and the damage it's causing back home," he says in the video. "It's very difficult. It's very difficult not only because we have family and friends back there, some guys have young kids, some guys have wives and families.”

"But that's our city,” Watt continued. ”It's very tough to watch your city get hit by such a bad storm and not be there to help. Not be there to help with the recovery. Not be there to help with the process. It's very tough."

The Texans gave $1 million to the United Way of Greater Houston Relief Fund, a donation that was matched by the NFL Foundation, the league’s nonprofit charitable organization, on Monday. Both the NFL and the NFL Foundation’s websites posted a statement asking fans to join in. “Our thoughts are with the Houston community during this difficult time and we encourage fans to text HARVEY to 90999 to donate $10 to American Red Cross Hurricane Harvey relief,” the statement read. The Texans relocated today’s practice to the Dallas Cowboys training facility. The two teams were scheduled to play in Houston on Thursday, but the league is considering relocating that game to Dallas’ AT&T Stadium.

Also on Monday, Houston Rockets owner Leslie Alexander donated $4 million to the Hurricane Harvey Relief Fund. Rockets center Clint Capela, who has has been unable to leave his home, has spent the last two days retweeting pleas for help from anyone facing imminent danger or in need of assistance.

"I'm here in downtown," Capela told the Houston Chronicle. "I can't from my house go help people where they are right now. I'm trapped. I saw this stuff on Twitter. I was trying to help. I saw some people couldn't do anything from the roof of their apartment or their houses. Some people were trying to go from their houses with their kayaks. I was just trying to spread the word.

"Of course, I feel really bad for those people. I tried to help any way I could."

For anyone looking for other ways to contribute, the SB Nation Dallas Stars blog, Defending Big D, provided a list of local charities and other organizations in the area, as did SB Nation's main site. Jill Tolentino, a reporter with the New Yorker who was born in Houston, also tweeted a list of organizations that desperately will be in need of financial help as they attempt to deal with this ongoing humanitarian crisis.