In recent times, Lake Powell, the second-largest reservoir in the United States, has been experiencing a remarkable resurgence in its water levels, defying the odds posed by the decades-long drought that has plagued the region. This resurgence comes as a glimmer of hope following a period of record-low water levels in early 2023. While the temporary relief is attributed to above-average snowmelt from the Rocky Mountains, the specter of long-term drought continues to loom large.
Satellite images captured on September 23, 2022, and October 20, 2023, vividly illustrate the transformation of Lake Powell, situated on the border of Utah and Arizona. As of November 12, 2023, the lake’s water levels stood at 3,572 feet, representing 37 percent of its capacity—just below the 1991–2020 average for that date. The 2023 image was acquired using the OLI (Operational Land Imager) on Landsat 8, while the 2022 image was acquired by the OLI-2 on Landsat 9.
The crucial role of the Colorado River cannot be understated in this context. The Colorado River feeds both Lake Powell and Lake Mead downstream, serving as a lifeline for the arid and semi-arid regions it traverses. Despite receiving less than 10 inches of precipitation per year in most parts of its basin, the river plays a vital role in providing water and electric power to approximately 40 million people, including major cities like Las Vegas, Phoenix, Los Angeles, and San Diego, as well as irrigating 4 to 5 million acres of farmland in the Southwest.
The challenge posed by precipitation patterns becomes apparent. While a series of nine atmospheric rivers brought substantial rain and snow to the western U.S. in December 2022 and January 2023, much of this precipitation remained locked in the frozen heights of the Rocky Mountains, preventing it from replenishing Lake Powell. On April 13, 2023, the lake’s water level dipped to its lowest point since its filling in 1980, reaching just below 3,520 feet.
However, as spring and summer brought rising temperatures, there was a glimmer of hope. Above-average runoff from the Rockies led to a much-needed increase in the reservoir’s water level, which rose from a meager 22 percent in April to approximately 40 percent by early July.
Yet, the path to restoring Lake Powell to its “full pool” at an elevation of 3,700 feet is a long one. Two decades of drought in the American Southwest have taken a toll on the reservoir’s water levels, resulting in record lows in both 2022 and 2023. In April 2023, the U.S. Bureau of Reclamation (USBR) released a draft Environmental Impact Statement for Colorado River Operations, which highlighted the risk of the reservoir falling below the critical elevation of 3,490 feet, known as the “minimum power pool.” This level marks the point at which water can no longer flow through the intake valves in the dam to generate hydroelectric power. Initially, USBR warned of a 57 percent chance of reaching this critical level before 2026. However, revised estimates in October 2023, reflecting above-average runoff, reduced this risk to just 8 percent.
The impact statement emphasizes that while there may be year-to-year variations in flow within the Colorado River and its tributaries, the basin is mired in a prolonged period of aridification driven by climate change. A 23-year period from 2000 to 2022 stands out as “the driest in more than a century and one of the driest in the last 1,200 years.” This sobering reality underscores the enduring challenges posed by drought and the urgent need for sustained efforts to address the water resource crisis in the region.
Image credit: NASA Earth Observatory images by Michala Garrison, utilizing Landsat data from the U.S. Geological Survey and lake elevation data from the Bureau of Reclamation.
Frequently Asked Questions (FAQs) about Lake Powell Resurgence
What is the current status of Lake Powell’s water levels?
As of November 12, 2023, Lake Powell’s water levels stood at 3,572 feet, representing 37 percent of its capacity. This is slightly below the 1991–2020 average for that date.
What caused the recent increase in Lake Powell’s water levels?
The increase in water levels was primarily due to above-average snowmelt from the Rocky Mountains, following a period of record-low levels in early 2023.
What role does the Colorado River play in this context?
The Colorado River serves as the primary source of water for Lake Powell. It also supplies water and electric power to approximately 40 million people, including major cities in the Southwest and irrigates millions of acres of farmland.
How severe is the long-term drought in the American Southwest?
The American Southwest has been facing a prolonged period of aridification, primarily driven by climate change. The period from 2000 to 2022 has been noted as “the driest in more than a century and one of the driest in the last 1,200 years.”
What is the significance of the “minimum power pool” mentioned in the article?
The “minimum power pool” is a critical elevation level (3,490 feet) below which water cannot flow through the intake valves in the dam to generate hydroelectric power. It serves as an important marker for the operational viability of Lake Powell.
Are there ongoing efforts to address the water resource crisis in the region?
Yes, various agencies, including the U.S. Bureau of Reclamation (USBR), are actively monitoring and managing water resources in the Colorado River Basin. However, sustained and comprehensive efforts are needed to mitigate the impacts of drought and ensure water security for the region’s residents and agriculture.
More about Lake Powell Resurgence
- NASA Earth Observatory – Lake Powell Resurgence
- U.S. Bureau of Reclamation – Colorado River Operations
- Climate Change and Aridification in the American Southwest
- Landsat Data from the U.S. Geological Survey
- Bureau of Reclamation – Lake Elevation Data