Adverse impact on ponds of organic debris deposited by tornadoes

On May 3, 1999, 58 tornadoes were reported in Oklahoma in I one of the larg est outbreaks of severe weather in Oklahoma history. The tornadoes killed 4 4 people and destroyed over 3,100 homes. In addition to the obvious damage inflicted on residential areas, the tornadoes caused extensive damage to na tural resources by destroying trees and other vegetation. Several ponds in the path of the largest tornado also were affected. Analysis of water quali ty revealed that the ponds had become incapable of supporting aquatic life because the decay of wind-deposited organic material had created a reducing atmosphere, which caused levels of dissolved oxygen to sink, rising Nation al Weather Service data from the period 1950-1995, researchers calculated t he mean annual area swept by tornadoes in Oklahoma to be approximately 19,0 00 acres. Combining this information with the estimated number of ponds in Oklahoma suggests that approximately 100 ponds would be in the path of a to rnado each year.