India, Dec. 31 -- Atmospheric river storms in the US West have exposed the fragility of ageing levees

Many levees were never designed to protect today's dense towns and cities

Failures disproportionately affect low-income and marginalised communities

Climate change is pushing flood-control systems beyond their limits

In recent weeks, powerful atmospheric river storms have swept across Washington, Oregon and California, unloading enormous amounts of rain. As rivers surged, they overtopped or breached multiple levees - those long, often unnoticed barriers holding floodwaters back from homes and towns.

Most of the time, levees don't demand attention. They quietly do their job, year after year. But when storms intensify, levees suddenly ...