Streamflow at selected gaging stations on the James River in North Dakota and South Dakota, 1953-82, with a section on climatology
Historic stream flow data were compiled and record extension techniques were used, when necessary, to develop a monthly stream flow record for 1953-82 at streamflow-gaging stations on the James River in North Dakota and South Dakota. The record extension techniques included both Maintenance of Variance Extension Type 1 and Ordinary Least Squares. In addition to the historic stream flow record, synthesized unregulated streamflow was computed for gaging stations on the James River for 1953-82 by eliminating the effects of Jamestown Reservoir, Pipestem Reservoir, Sand Lake National Wildlife Refuge, and the consumptive surface-water withdrawals. Maintenance of Variance Extension Type 1, Ordinary Least Squares regression, water-balance procedures, and drainage-area ratio methods were used to compute the unregulated streamflows. Mean annual historic stream flow of the James River at Jamestown is about 7,000 acre-feet less than the mean annual unregulated streamflow. Mean monthly unregulated streamflow is greater than mean monthly historic streamflow during March, April, and May; during all other months, unregulated stream flow is less than historic streamflow. The climate during 1953-82 was compared to the climate records, which range in length from 53 to 102 years, in the James River basin to determine if the climate during 1953-82 was similar to the climate that has occurred during the last 90 years. On the basis of the climate analysis, the data-development period (1953-82) does not represent an abnormally wet or dry period. Thus, the streamflow during the data-development period represents a range of streamflows that might be expected to occur during the last 90 years.