Determination of Flow Losses in the Cape Fear River between B. Everett Jordan Lake and Lillington, North Carolina, 2008?2010

During 2008-2010, the U.S. Geological Survey conducted a hydrologic investigation in cooperation with the Triangle J Council of Governments Cape Fear River Flow Study Com- mittee and the North Carolina Division of Water Resources to collect hydrologic data in the Cape Fear River between B. Everett Jordan Lake and Lillington in central North Caro- lina to help determine if suspected flow losses occur in the reach. Flow loss analyses were completed by summing the daily flow releases at Jordan Lake Dam with the daily dis- charges at Deep River at Moncure and Buckhorn Creek near Corinth, then subtracting these values from the daily dis- charges at Cape Fear River at Lillington. Examination of long- term records revealed that during 10,227 days of the 1983- 2010 water years,1 408 days (4.0 percent) had flow loss when conditions were relatively steady with respect to the previous day's records. The flow loss that occurred on these 408 days ranged from 0.49 to 2,150 cubic feet per second with a median flow loss of 37.2 cubic feet per second. The months with the highest number of days with flow losses were June (16.7 per- cent), September (16.9 percent), and October (19.4 percent).