Comparison of streamflow before and during the flood of Dec. 24, 2002

As is typical of small urban streams, Peachtree Creek in Atlanta, Ga., USA, rises quickly and exhibits a large increase in streamflow when a major rainstorm hits the watershed. Thus, during a storm, many times more water can flow in a few hours as flows in a few days of base flow (generally periods of minimal/near minimal streamflow when no precipitation has fallen for a while). The pie charts below show that a large amount of the total streamflow occuring during a year can occur in just a few days. In 2001, for example, the 10 highest days of daily mean streamflow accounted for 36 percent of the total streamflow for the year.