In 2021, electricity production by hydropower plants across the U.S. will reduce by 14% compared to 2020 levels. This is due to the extreme drought conditions affecting western states. The U.S. Energy Information Administration stated in its latest Short-Term Energy Outlook (STEO) that the drought will significantly affect water levels, causing some rivers to dry.
States such as California and those in the Pacific Northwest, which are major contributors to U.S. hydroelectric power, have faced “extreme and exceptional” drought conditions in 2021. The Columbia River, the country’s fourth-largest river by volume, contributes immensely to hydropower generation. Its watershed runs through four states, including Washington, Idaho, Montana and Oregon. In 2020, the hydropower generated in these states was 136 billion kWh, accounting for 54% of all hydropower generated in the U.S.
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The U.S. Department of Agriculture’s National Water and Climate Center (NWCC) has provided data showing that reservoir storages in Washington and Montana are at or above average. Even so, reservoir storage in Oregon measured just 17%. Historically, reservoir capacity in the state averages 47%. Another drought-affected state, Idaho, reported a reservoir capacity of 34%, compared to its historical average of 51%.
The low water levels in reservoirs threaten power generation. And the situation may get worse as droughts continue. After record-breaking heatwaves hit major areas of the Columbia River Basin, officials issued drought warnings in several counties across Washington, Oregon and Idaho.
The critical role played by these states in hydropower generation has been under continuous threat in the past decade. While California alone accounts for about 13% of the U.S. hydroelectric power generation, plants in California only contributed 7% in 2020. With the state experiencing widespread drought, it is expected that the power generated this year will be even lower than last year.
In August, the second-largest reservoir in California at Lake Oroville hit an all-time low of 35% capacity, forcing a temporary closure of the Edward Hyatt Power Plant. This was the first time the plant went offline since 1967. This year, the state’s power generation has fallen on the lower end of its 10-year range.
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