Despite near- to above-normal precipitation in November, hydroelectric generation in the Pacific Northwest came in below average levels for the month.
Data from the U.S. Army Corps of Engineers show that total net generation at 23 hydroelectric plants across the Pacific Northwest was 19.6% lower than the year-ago level and 5.8% below the 10-year average as it reached 4.83 million MWh. That figure is up 25.4% from October.
Year-to-date hydropower production through November totaled 73.39 million MWh, up 11.5% versus the year-ago level and up 9.2% from the 10-year average for the period.
In the upper Columbia River Basin, the Grand Coulee Dam, the largest of the region, generated 1.26 million MWh, down 28.1% versus the year-ago month and down 15.5% versus the 10-year average for the period. The Chief Joseph Dam generated 682,652 MWh, down 26.4% versus November 2016 and down 13.4% versus the 10-year average for the month.
November flows in the lower Columbia River Basin were also lower versus the year-ago period. Located on the Washington-Oregon border, the Bonneville Dam produced 392,340 MWh, down 3.6% versus November 2016 and 0.6% lower versus the 10-year average for the month. The Dalles Dam, 50 miles downstream, produced 494,222 MWh, down 15.6% from the year-ago month and down 2.3% from the 10-year average for November.