In another sign, the megadrought is wreaking havoc across the Western half of the US. There are multiple portions of the Mississippi River that are nearing record low water levels that may inhibit commercial or private vessels from traversing the critical waterway. The stretch of the Mississippi River at St. Paul, Minnesota, is around 3.2 feet Wednesday. That’s about six inches from the record low of 2.6 feet set in 1976. A camera on the Wabasha Street Bridge that spans the Mississippi River in downtown St. Paul shows the receding waterline.Downstream, the Mississippi River at Red Wing is also near...