Record Extension and Streamflow Statistics for the Pleasant River, Maine

Historical streamflow data for the Pleasant River are limited to 11 years (from 1980 to 1991) at the U.S. Geological Survey streamgaging station near Epping. Analysis of these data in conjunction with flow data from other nearby stations indicates that the 11 years of record for the Pleasant River may not be representative of longer-term conditions in the basin. A correlation between the historical streamflows from the Pleasant River station and at the nearby station on the Narraguagus River at Cherryfield provides a means of extending the record at the Pleasant River station, increasing the period of record on the Pleasant River from 11 to 51 years. When used to calculate new streamflow-duration statistics, the extended record shows significant differences from the original 11 years of record, particularly during the summer months. The August median streamflow, an important statistical measure for fisheries habitat, changed from 50 cubic feet per second prior to the record extension, to 35 cubic feet per second after the record extension.