“We’re doing everything we can to make sure everybody’s safe while the evacuation process is being carried out,” said Robert Hurst, a public information officer with the criminal justice department.

He did not say where the prisoners would be taken, or how long the evacuation process might last.

While away from Rosharon, the prisoners will “not be available for visits at the designated receiving units, but will have the ability to use the offender telephone system,” the criminal justice department said.

Hurricane Harvey made landfall in Texas as a Category 4 hurricane on Friday night. It was downgraded to a tropical storm on Saturday, but heavy rains and serious flooding are expected in the state’s southeast.

By Friday, the criminal justice department had canceled visitations for at least 29 prisons in the vicinity of the storm’s expected path. “This is something that we prepare for each year. Our command center is operating around the clock and we stand ready,” Bryan Collier, executive director of the department, said in a statement on Facebook.

Evacuations of the three prison facilities began on Saturday morning. By noon, the Brazos River near Rosharon had already risen by at least 15 feet since Friday, according to data from the National Weather Service.