Many years ago I heard about a tragic incident involving a friend of mine, an experienced guide who knew the mountains well. He had camped with his group in what looked like the safest place imaginable — a dry riverbed that hadn’t seen water for at least seven years. On hot nights it was a favourite spot: sheltered by huge boulders, soft with dry river sand, and always completely still.
That night, everyone went to sleep as usual. Around 3am a wall of water tore through the valley without warning. My friend never heard it coming. Some members of his group were woken by the distant roar and managed to scramble up the bank to safety, forced to watch helplessly as his 4x4 and safari trailer were swept away with him inside.
The flood hadn’t come from their valley at all. A thunderstorm had broken more than 60 miles away in another mountain range, sending a sudden surge of water racing downstream into what had seemed like a harmless, bone‑dry riverbed.
Here is an example of a smaller but powerful flash flood: