(CNN) About 4,500 Texas inmates have been moved amid massive flooding spawned by Tropical Storm Harvey, officials said.

Inmates from three units in Rosharon, below Houston, began the daylong trip on Saturday. Ramsey, Terrell and Stringfellow units are located near the Brazos River, which began to rise rapidly as Harvey dumped record levels of rainfall across the region.

The Texas Department of Criminal Justice lined up a fleet of buses and began moving inmates. By 6:30 a.m. Sunday, inmates from all three units had been placed in facilities in east Texas, spokesman Robert Hurst said.

The inmates cannot have visits at their temporary quarters, but they will be able to use the phone. Additional food and water has been delivered to the receiving units, and extra staff has been called in.

At this point, the department does not plan to move more inmates, Hurst said.

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