Tunnels Pocket gopher tunnels are 1¾ to 3½ inches in diameter, depending on the size of the gopher digging the tunnel. Tunnels occur 4 to 12 inches below ground, whereas the nest and food storage chamber may be as deep as 6 feet.Tunnels tend to be deeper in drier soils.unnels. Pocket gopher tunnels are 1¾ to 3½ inches in diameter, depending on the size of the gopher digging the tunnel. Tunnels occur 4 to 12 inches below ground, whereas the nest and food storage chamber may be as deep as 6 feet. Tunnels tend to be deeper in drier soils.