Close calls at Michigan’s dams are a climate warning to America

Flooding across northern Michigan last month pushed rivers to record levels, testing the limits of the state’s aging dams so severely that officials in one city nearly ordered evacuations as water threatened to spill over the top of a key barrier — a close call that highlights the growing risk that intensifying storms pose to similar infrastructure around the country.

Nationwide, the average dam is 64 years old and most were built for rainfall patterns that no longer reflect today’s changing climate.