An engineering professor analysed the flash floods and mudslides in Pua district, Nan, where 384 mm of rain fell in about four hours. He says small upstream reservoirs are silting up, have trees growing on their dams, and are unlikely to withstand earthquakes. He warns that communities below may feel falsely safe. If your business is in or near a valley below a small reservoir, check your flood and evacuation plan and keep stock and equipment off the ground floor.