Canyons and water: a dangerous combo

The lure of a slot canyon – narrow and serene, with walls that ascend far higher than the canyon's width – is hard for a serious hiker to resist Thousands traipse into these flash-flood factories each year unaware of the risk they face. A downpour in one spot can send water pouring into a slot canyon more than 32km/20 miles away, where it might not have rained at all. This was the case when twelve hikers were trapped by a flash flood in Arizona's Lower Antelope Canyon on August 12,1997. Only one survived, and the canyon was closed for nearly a year afterward. A communications system and heavy-duty ladders are now in place. Flash floods are also a real hazard for canyoners who skitter down gorges and waterfalls with a minimum of equipment. Near Interlaken, Switzerland, 19 canyoners in a group of 53 participants and guides were killed on July 27,1999, as a wall of water containing trees and other debris careered into them. Whenever heading into the wilderness, take care and note the presence of storms all around, not just in your vicinity. A downpour need not be overhead to be deadly.