White House Press Secretary Sarah Huckabee Sanders made the announcement at a briefing Thursday.
And she says he’s calling on reporters to help decide which specific organization he will give to.
Trump has been criticized in the past for giving far less of his income to charitable causes than many other multi-billionaires.
Harvey’s flood waters have heavily damaged tens of thousands of homes across Texas and killed at least 30 people. The storm is now threatening the region near the Texas-Louisiana state line.
Harvey wiped out as many as 40,000 homes in Houston
Between 30,000 and 40,000 homes in the Houston area have been destroyed by Tropical Storm Harvey, officials said Wednesday.
The staggering numbers were revealed as Harvey touched down in Cameron, La., before dawn — its third landfall since socking Texas with record-setting rains starting Friday.
“We’ve got probably 30,000 to 40,000 homes that have been destroyed,” Harris County Office of Homeland Security and Emergency Management director Ed Emmett told ABC News.
Harris County includes Houston, which was pummeled with more than 50 inches of rain and extreme flooding. Thousands of people are believed to be stranded in the wake of the storm.
“We have people who are on the second floor of their homes; they’re riding it out, and they’re waiting for the waters to go down,” Emmett said. “The biggest challenge is going to get people back in their homes. We’ve got to get those people back into their normal lives as soon as possible.”
Harvey has claimed the lives of at least 20 people.
Houston Police Chief Art Acevedo said 911 calls for water rescues were down to about 40 as of Wednesday morning. But the Coast Guard said it has still been taking more than 1,000 calls per hour from others needing to be rescued.