Houston sports figures have rallied to raise million of dollars for those affected by the flooding and destruction in the wake of tropical storm Harvey.

Experts say that the city and surrounding area could take years to recover from the damage done by the storm. NFL star JJ Watt – perhaps Houston’s highest-profile athlete - started a fund to help victims of Harvey and the drive has already raised more than $3m. The Houston Texans defensive end has donated more than $100,000 of his own money and says his new goal is to get the fund to $4m.

“I think that it’s been an unbelievable display of what can happen when people come together,” Watt told the Houston Chronicle. “Just to see how many people are sharing it, to see how many people are donating. Whether it’s $5, whether it’s $500, whatever it may be, to see so many people’s support, to see so many people send the message, spread the message, it’s incredible.”

Houston’s NBA team, the Rockets, have also been active. The team’s owner, Leslie Alexander, has donated $4m toward a relief fund while point guard Chris Paul gave $50,000 to Watt’s fundraising scheme.

Meanwhile, Rockets center Clint Capela found himself trapped in his house by the rising waters but offered to use his social media following to tweet out pleas from people in need of rescue.

“I’m here in downtown,” the Swiss player told the Chronicle. “I can’t [leave] 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.”

The charity has not just been restricted to Houston teams. The New England Patriots and their owner Robert Kraft pledged $1m to the Red Cross relief fund. Tennessee Titans majority owner Amy Adams Strunk, a native of Houston, donated $1m to Watt’s fund.

However, one team has come under criticism. The Houston Astros wanted to swap their home series against the Texas Rangers to late September. That scenario would have seen the Astros play the Rangers in Arlington this week before playing in Houston in a month, when the waters will presumably have retreated. However, the Rangers refused and the series will now be played at Tropicana Field in St Petersburg, Florida.

The Rangers’ decision prompted anger among many fans and players. The Astros pitcher Lance McCullers was particularly incensed. “Classy as always, should be absolutely ashamed,” he wrote on Twitter. “Greed never takes off days, apparently. Stay strong #Htown! We hope to be home soon.”

The Rangers said they are not seeking to gain a “competitive advantage” – a swap would have seen them end the regular season with a lengthy road trip – but instead did not want to inconvenience fans who had bought tickets for the Arlington series in September.

“We didn’t feel it was right to give our fans 24 hours’ notice that their tickets in late September were now good this week,” the team’s general manager, Jon Daniels, said. “We were willing to play this series anywhere the Astros and MLB wanted, including here in Arlington.”

The Astros manager, AJ Hinch, said he was concerned for those affected by Harvey rather than any dispute over scheduling. “Obviously there’s a lot of emotion involved on a lot of fronts,” he told ESPN. “Obviously the baseball schedule is going to continue. We would have loved to have played in Arlington and switched series but ... we’re really going to go wherever people tell us to go.

“It sounds like there was a lot of debate on what to do. The right thing to do is really focus on the people back home and start the recovery when this relentless storm finishes. Until then, the emotion is going to come out. That’s the way the world works nowadays.”

The Astros have one of the best record in baseball this season and are set for a place in the playoffs. The Rangers are in a battle for a wildcard spot in the post-season.