31078 -- U.S. ZIP code Municipality (1990): ROBERTA, Georgia All ZIPs for this municipality (1990): 31078 Population (2000): 3658 Housing Units (2000): 1425 Land area (2000): 97.194678 sq. miles (251.733050 sq. km) Water area (2000): 0.197830 sq. miles (0.512378 sq. km) Total area (2000): 97.392508 sq. miles (252.245428 sq. km) Located within: Georgia (GA) Location: 32.702635 N, 84.038113 W