The Harris County Precinct 4 Constable's Office said on Twitter that it would be "delivered back into his natural habitat soon."
Texas Parks and Wildlife officials had warned that alligators may be found in "areas where they aren't normally observed" following the storm.
"Alligators are wary of people but keep your distance," the service said.
"Never approach, harass or feed an alligator. When water levels recede, the alligator will likely disappear as well."
Meanwhile President Donald Trump has met with victims of Hurricane Harvey in Houston and is witnessing the effects of the record-setting storm as he presses for a multi-billion-dollar aid package.
On Saturday Trump, facing the first natural disaster of his administration, was joined by his wife, Melania, as he passed out food and hugged, kissed and played with children at Houston's NRG Center, a 65,000-square-metre facility that is now the city's largest emergency shelter.
Trump, who is making his second trip to the stricken state this week, asked Congress late on Friday for an initial $US7.85 billion for hurricane recovery efforts.