Streams in the Duck Creek basin gain ground water throughout most of their reaches, however, ground-water pumping of the Green Bay - DePere area may reduce the water being gained by the streams from ground water. The August 11, 12 measurements were made during base-flow period when flow duration was about 50 to 55 percent (table 2), The August 27 measurements were made during a lower base-flow period when flow duration was about 70 to 80 percent. About 80 percent duration is, more representative of low-flow conditions during the summer.