Stream Water Quality Responses in a Tornado Damaged Residential Watershed

Abstract

Tornado damage has the potential to impact stream water quality from seeping anthropogenic compounds and scattered debris in affected areas. On 3 March 2020, an EF4 tornado (~282 km h-1 winds) hit Putnam County, Tennessee, destroying structures, trees, and removing vegetation across the area. This study assessed the influence of tornado damage on the water quality of streams draining the damaged area. We compared physiochemical conditions, fecal contamination, and chemical water quality measures for affected and unaffected watersheds over three months. We found differences between stormflow and baseflow conditions between watersheds, with elevated nutrients, dissolved metals, and fecal coliform bacteria after rain events. However, there were no significant differences between affected and unaffected watersheds for any parameter. Similarly, there were no relationships among nutrients or contaminants and distance to, or density of tornado wreckage. This study provides evidence that unlike other natural disasters, such as earthquakes and hurricanes, tornados may have minimal effects on water quality when residential areas are hit, possibly due to the localized area of destruction that tornados leave. However, tornado influence may still be event-specific and depend on the type of structures damaged.