impassable

What land routes exist in the province are nearly all dirt roads and the wet climate means they are often impassable.

Local officials had warned it could be impassable for days.

By the time the men were found in the early hours of Friday, rising water levels meant the simplest way out was impassable, forcing the rescuers and the cavers to retrace their steps.

The authorities there have ordered a mandatory evacuation of Hatteras Island, warning that the main highway linking Hatteras to other islands could become impassable.

“Normally you would only portage a very small section of the river around an impassable rapid, maybe a waterfall or something,” he said.