Water levels in Lake Superior are down a whole foot this year, and scientists say man is to blame. The world's largest body of fresh water by surface area has suffered an on-and-off drought for four years, but levels may reach an all-time low this summer. Climate change is partially responsible, but one environmental group points to another culprit: the constant dredging of the St. Clair River for navigation.
Lake Superior reached its lowest level in 1962, when engineers deepened the river by two feet to ease commercial shipping channels. Now erosion from the project has gotten so bad that the lake is losing 2.5 billion gallons of water to the river every day. And Reuters reports the other Great Lakes are suffering too.