Lake Powell, the United States' second largest reservoir, stood at approximately 32% of capacity as of Aug. 14, its lowest level since it was filled in the 1960s, with its water level having dropped roughly 52 feet over the prior year, as drought, record heat and wildfires continued to affect six western states.
Lake Powell hits lowest level since 1960s filling as western US drought, heat and wildfires intensify
Lake Powell, the United States' second largest reservoir, stood at approximately 32% of capacity as of Aug. 14, its lowest level since it was filled in the 1960s, with its water level having dropped roughly 52 feet over the prior year, as drought, record heat and wildfires continued to affect six western states.
The U.S. Bureau of Reclamation has begun releasing water from upstream reservoirs to keep Lake Powell above the level at which hydropower generation at Glen Canyon Dam would be threatened, according to the source.
The UN Intergovernmental Panel on Climate Change published a 4,000-page report on Aug. 9, compiled by 234 authors and drawing on more than 14,000 studies, concluding that human activity has driven climate change whose effects are already present in every region of the planet. The report found that global average temperatures have risen approximately 1.1 degrees Celsius since the Industrial Revolution.
The IPCC report described conditions in the western United States as a 'compound extreme event,' in which simultaneous heat waves, drought and wind together accelerate wildfire spread. California's 2020 fire season was the worst on record; by mid-2021 the state had experienced nearly three times the acreage burned compared with the same point in 2020.
The Dixie Fire, described as the largest single fire in California's history, started July 13 and had burned more than 554,000 acres by Aug. 15, when it was 31% contained. Oregon's Bootleg Fire, which burned more than 413,000 acres and prompted the evacuation of approximately 2,000 homes, was 100% contained by Aug. 15. Forestry officials said the Bootleg Fire was caused by lightning and went undetected for days before being reported on July 6.
Lake Mead reached its lowest level since being filled following construction of the Hoover Dam in the 1930s, and Arizona farmers are expecting the first-ever cuts to their Colorado River water allocation next year. A contingency plan signed by western states in 2019 will supplement some of the lost water. Lake Oroville in California's hydroelectric plant was taken offline in early August after water levels dropped below 645 feet, the previous low set in 1977; the state's water resources department cited 'extremely dry' soils and 'climate change-induced early warm temperatures' as causes of reduced runoff.
Part of the Great Salt Lake dropped to its lowest level since record keeping began in 1847. From April through July, Maricopa County, Arizona, confirmed 47 heat-associated deaths, more than triple the figure confirmed over the same period the prior year. Phoenix experienced an 'unprecedented' 53 days at 110 degrees Fahrenheit or warmer in the prior year, during which the Arizona Burn Center recorded 104 burn injuries related to heat in June, July and August, the highest number since the center began tracking in 2000.
- The source does not state the current water elevation of Lake Powell in feet or the specific threshold below which hydropower generation at Glen Canyon Dam would be threatened.
- The source does not state which upstream reservoirs the Bureau of Reclamation plans to release water from, or the volume of water to be released.
- The source does not state the total number of heat-related deaths confirmed across all western states during the period covered.
- The source does not provide independent scientific assessment of the IPCC report's findings beyond the report itself and its authors.
- The source does not state the current or projected water level of Lake Mead in feet.
- The source does not state how many people sheltered at Portland's Oregon Convention Center cooling station or how many cooling stations operated in the region during the late-June heat event.