The effects of a meager mountain snowpack across the Upper Colorado Basin in winter 2025-2026 had made their way downstream to Lake Powell by summer. After seasonal snowmelt declined to a relative trickle, the second-largest reservoir in the U.S. sat at record-low levels in late August and early September.
2025-2026 年冬季，科罗拉多州上游盆地的少量山地积雪所造成的影响，到了夏季，已经向下游蔓延至鲍威尔湖。在季节性融雪减少到相对细流之后，美国第二大水库的水位在八月底和九月初创下历史新低。
These images show a portion of Lake Powell just above Glen Canyon Dam as observed by the OLI (Operational Land Imager) on the NASA-USGS Landsat 8 satellite on September 1, 2017 (left), and September 10, 2026 (right). In the 2026 image, the water level stood at 3,517.24 feet. About a month prior, it had dipped below the previous record-low level of 3,519.92 feet, set on April 13, 2023, and continued to tick downward in early September. The 2017 image represents one of the highest water levels of the past decade.
这些图像显示了 2017 年 9 月 1 日（左）和 2026 年 9 月 10 日（右）由 NASA-USGS Landsat 8 卫星上的 OLI（操作陆地成像仪）观测到的格伦峡谷大坝上方鲍威尔湖的一部分。在 2026 年的图像中，水位为 3,517.24 英尺。大约一个月前，该价格已跌破 2023 年 4 月 13 日创下的历史最低水平 3,519.92 英尺，并在 9 月初继续下跌。 2017 年的图像代表了过去十年中最高的水位之一。
The Colorado River feeds Lake Powell and then Lake Mead farther downstream, which also hit record-low levels in August 2026. Managed by the U.S. Bureau of Reclamation (USBR) and other agencies, the river provides water and electric power to more than 40 million people—including in Las Vegas, Phoenix, Los Angeles, and San Diego—and water to some 5 million acres of farmland in the Southwest.
科罗拉多河为鲍威尔湖和下游的米德湖提供水源，该湖的水位也在 2026 年 8 月创下历史新低。这条河由美国垦务局 (USBR) 和其他机构管理，为包括拉斯维加斯、凤凰城、洛杉矶和圣地亚哥在内的超过 4000 万人提供水和电力，并为西南部约 500 万英亩的农田提供水源。
Much of the Colorado Basin is arid or semi-arid, so a large portion of the river’s flow originates as snowmelt from higher elevations. The Upper Colorado Basin , like many mountainous areas across the U.S. West , saw unusually little snow accumulation in winter 2025-2026, constituting a snow drought . Stretches of record warmth further sapped the snowpack. As a result, water from snowmelt did little to replenish lake levels in spring, as it typically does.
科罗拉多盆地的大部分地区是干旱或半干旱的，因此河流的大部分流量源自高海拔地区的融雪。与美国西部许多山区一样，科罗拉多州上游盆地2025-2026年冬季积雪异常少，构成雪旱。创纪录的温暖进一步削弱了积雪。结果，融雪产生的水几乎无法像通常那样补充春季的湖泊水位。
The USBR took steps in April 2026 to stabilize Lake Powell and keep it from falling below the level needed for hydropower production—an outcome the agency deemed possible by August 2026 without intervention. USBR began releasing water from Flaming Gorge Reservoir in northern Utah and southern Wyoming into Lake Powell. It also reduced releases from Lake Powell into Lake Mead, canceled a “controlled flood” in April intended to build sandbars for fish habitat, and skipped a “cool mix” release in August aimed at protecting native species.
USBR 于 2026 年 4 月采取措施稳定鲍威尔湖，防止其跌至水力发电所需的水位以下，该机构认为无需干预，到 2026 年 8 月就有可能实现这一结果。 USBR 开始将犹他州北部和怀俄明州南部火焰峡谷水库的水排入鲍威尔湖。它还减少了从鲍威尔湖到米德湖的排放，取消了四月份旨在为鱼类栖息地建造沙洲的“控制洪水”，并跳过了八月份旨在保护本地物种的“冷混合”排放。
Drought in the U.S. Southwest has been ongoing since about the start of the 21st century—what experts have called a megadrought —and continues to strain water resources. Several projects and tools funded by NASA and powered in part by NASA Earth observations are helping decision-makers throughout the Colorado Basin monitor drought and respond to its effects.
大约自 21 世纪初以来，美国西南部的干旱一直持续（专家称之为特大干旱），并继续造成水资源紧张。由美国宇航局资助并部分由美国宇航局地球观测提供支持的几个项目和工具正在帮助整个科罗拉多盆地的决策者监测干旱并应对其影响。
At the Colorado River headwaters, for example, a dashboard based on the Western Land Data Assimilation System ( WLDAS ) provides real-time soil moisture, snow water equivalent , and evapotranspiration visualizations that inform Colorado’s drought task force, as well as weekly U.S. Drought Monitor maps.
例如，在科罗拉多河源头，基于西部土地数据同化系统 (WLDAS) 的仪表板提供实时土壤湿度、雪水当量和蒸散量可视化，为科罗拉多州干旱工作组提供信息，并提供每周的美国干旱监测地图。
Nearer to Lake Powell, the Drought Severity Evaluation Tool , co-developed with the Navajo Nation , helps leaders monitor localized drought indices, precipitation trends, and vegetation health across tribal lands. (With funding from NOAA’s National Integrated Drought Information System , its adoption expanded to Oklahoma’s Chickasaw and Choctaw Nations in 2025.) And the Colorado River Integrated Assessment tool, developed by Arizona State University researchers in partnership with the Central Arizona Project , consolidates improved modeling and NASA-satellite-validated information on snowpack, surface and groundwater storage, soil moisture , and more across the entire basin into a single interactive view.
在鲍威尔湖附近，与纳瓦霍部落共同开发的干旱严重程度评估工具可帮助领导人监测部落土地上的局部干旱指数、降水趋势和植被健康状况。 （在 NOAA 国家综合干旱信息系统的资助下，该系统的采用范围于 2025 年扩大到俄克拉荷马州的契卡索和乔克托国家。）科罗拉多河综合评估工具由亚利桑那州立大学研究人员与亚利桑那中心项目合作开发，将整个盆地的积雪、地表水和地下水储存、土壤湿度等方面的改进模型和 NASA 卫星验证的信息整合到一个交互式视图中。
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey and lake elevation data from the U.S. Bureau of Reclamation . Story by Lindsey Doermann.
NASA 地球观测站图像，由 Lauren Dauphin 拍摄，使用美国地质调查局的陆地卫星数据和美国垦务局的湖泊高程数据。林赛·杜尔曼的故事。