A lone house in Ridgely, Tennessee stands dry amid a sea of floodwater — protected only by a makeshift levee the family built themselves. Last week, after days of torrential rain, the Mississippi River and its tributaries overflowed, inundating much of northwest Tennessee in one of the worst flood events in the region’s recorded history. Over 15 inches of rain fell in under 72 hours, overwhelming drainage systems and prompting mass evacuations. More than 400 homes were damaged or destroyed in La