Hydroelectric generation in the Pacific Northwest rebounded month over month between October and November but continued to trail the prior-year level and 10-year average, as warmer weather and dry conditions prevailed in the region.
For the bulk of the Columbia River Basin, temperatures were one degree Fahrenheit to more than six degrees Fahrenheit warmer than normal in November, while precipitation was less than half of normal levels, according to the National Oceanic and Atmospheric Administration.
Data from the U.S. Army Corps of Engineers show that total net generation at 23 hydroelectric plants across the Pacific Northwest was up 39.1% from October to November as it reached 5.09 million MWh. However, it was 1.2% below the year-ago level and 1.9% below the 10-year average.
In the upper Columbia River Basin, the Grand Coulee Dam, the largest of the region, generated 1.61 million MWh, up 2.9% versus the year-ago month and up 6.8% versus the 10-year average for the period. The Chief Joseph Dam generated 878,003 MWh, up 3.3% versus November 2018 and up 9.7% versus the 10-year average for the month.
November flows in the lower Columbia River Basin were lower than the year-ago period. Located on the Washington-Oregon border, the Bonneville Dam produced 387,535 MWh, down 1.7% compared to November 2018 and 2.6% lower than the 10-year average for the month. The Dalles Dam, 50 miles downstream, produced 507,853 MWh, down 2.4% from the year-ago month and down 1.3% from the 10-year average for November.
Calendar year-to-date hydropower production through November totaled 58.17 million MWh, down 19.3% versus the year-ago level and down 15.3% from the 10-year average for the period.