Streamflows across the nation for the 1986 water year were generally normal to above normal. The exception was the extreme dry conditions that persisted over the Southeast for most of the year, according to the U.S. Geological Survey (USGS).

USGS hydrologists said that of the 174 key index streamflow-gaging stations across the nation, 64 stations (37%) had flows in the above-normal range, 76 stations (44%) had flows in the normal range, and 34 stations (20%) had flows in the below-normal range for the water year, which ended September 30, 1986. The water year that is used by hydrologists runs from October 1 to September 30 of the following calendar year. It is designed to begin and end during a period of generally low streamflow and to roughly follow the growing season.