Lake Powell, one of the largest reservoirs in the United States, has reached its lowest level ever recorded, according to recent reports. This decline follows an unusually dry and warm winter, which significantly reduced mountain snowfall in the Colorado River Basin. As a result, the amount of water flowing into major reservoirs in the U.S. West has been sharply reduced. Lake Mead, another critical reservoir on the Colorado River, has also hit record lows, raising concerns about the water and power supply for over 40 million people in the Southwest. The effects of the weak snowpack in the Upper Colorado Basin during the 2025-2026 winter became evident by summer. With far less snowmelt than usual feeding the Colorado River, inflows into Lake Powell dwindled, and the reservoir reached record-low levels in late August and early September 2026. Satellite images from NASA-USGS Landsat 8 show a dramatic visual contrast between Lake Powell's high water levels in 2017 and its drastically lower levels in 2026. The water surface in 2026 was recorded at 3,517.24 feet, far below the previous record low set in 2023. Lake Mead also reached its lowest level in August 2026. The Colorado River system, managed by the U.S. Bureau of Reclamation (USBR) and other agencies, is a vital source of water and electricity for cities like Las Vegas, Phoenix, Los Angeles, and San Diego, as well as for about 5 million acres of farmland. The river's flow relies heavily on mountain snow, which melts in spring and early summer to replenish reservoirs. However, the unusually low snowfall during the 2025-2026 winter, combined with record warmth, led to a "snow drought" that severely limited the water supply. To stabilize Lake Powell and prevent it from dropping below the level needed for hydropower generation, the USBR took emergency measures in April 2026. These included releasing additional water from Flaming Gorge Reservoir and reducing water releases from Lake Powell into Lake Mead. Officials also canceled planned controlled floods and other environmental releases to conserve water. The ongoing megadrought in the Southwest, which began around the start of the 21st century, continues to strain water resources in the region. To better manage these challenges, NASA-supported projects and monitoring systems provide real-time data on drought conditions, helping water managers make informed decisions. Tools like the Drought Severity Evaluation Tool and the Colorado River Integrated Assessment system are helping to track and respond to the complex water challenges facing the region.