Floods

In 1950, a lake called Jancarurish, high in Peru's Cordillera Blanca, broke through the ridge of loose rock holding it back and emptied down the valley. An aerial survey photograph kept by the water…

The night of 20–21 June 2024 left the French Alpine village of La Bérarde half buried. The Étançons river, swollen and carrying rock, came through the Écrins massif hamlet and filled it with debris;…

Almost everyone who has bought a house near water has met the 100-year flood line. It shows up on insurance forms and zoning maps, a single crisp boundary that seems to promise certainty: inside, you…

Ask a hydrologist what a "hundred-year" downpour looks like for a given town, and the honest answer is that they are guessing from thin evidence. A rain gauge that has been running for thirty years…

Every flood map carries a quiet assumption: that the future's worst storm will look something like the past's. Engineers size a levee or price an insurance policy against a "one-in-100-year" event,…