WASHINGTON RESERVOIR REPORT

Last Updated: January 5, 2026

Washington State's dams and reservoirs are experiencing a mix of conditions, some of which are abnormal for this time of year. Based on the latest observations, a notable variance is observed in the storage levels across different locations. For instance, Mud Mountain Lake near Buckley is significantly higher than its average, with a current elevation of 1092 feet above NGVD 1929, compared to its average of 931.2 feet. Similarly, Lake Shannon at Concrete is also above its average level, with a current elevation of 428 feet versus an average of 420.55 feet. In contrast, Wynoochee Lake near Grisdale and Baker Lake at Upper Baker Dam near Concrete are below their average levels, at 774 feet and 704 feet respectively, compared to their averages of 776.34 feet and 712.4 feet.

These aberrations could be linked to recent weather patterns, such as the absence of expected rainfall and the impacts of an atmospheric river event, which have affected the region's hydrology. For instance, the higher-than-average water levels at Mud Mountain Lake and Lake Shannon may be consequences of the atmospheric river bringing flooding to the region, as reported by AOL.com. Meanwhile, the lower levels at Wynoochee Lake and Baker Lake suggest the areas might not have received anticipated precipitation. The snowpack and river flow data, which have direct implications on reservoir levels, are not provided here but are critical factors that could explain these anomalies. Notably, the absence of data for Lake Scanewa near Kosmos, with an entry of -999999, indicates either a data error or sensor malfunction, highlighting the importance of reliable monitoring systems. These fluctuations in reservoir and lake levels are essential to track as they have implications for water supply, flood control, and ecosystem health within the state. Monitoring these conditions alongside weather forecasts and climate patterns is essential for managing water resources and preparing for potential impacts on communities and the environment.

Washington state has over 700 dams and reservoirs, many of which provide hydroelectric power and irrigation for agriculture. The Columbia River is the largest source of water for the state, with many major reservoirs located along its length. These include Grand Coulee, Banks Lake, and Lake Roosevelt. The Yakima River basin also has several important reservoirs, including Cle Elum Lake, Kachess Lake, and Bumping Lake. Snowpack in the Cascades and Olympics is critical for water supply, particularly for irrigation during the dry summer months. In recent years, drought conditions have affected much of the state, with record low snowpack levels in 2015 leading to restrictions on water use. Seasonal trends generally see peak water levels in the spring as snowmelt increases streamflow, followed by a gradual decline throughout the summer and fall. Overall, the hydrology of Washington is complex, with a mix of natural and human factors affecting the availability and use of water resources.

Washington state has over 700 dams and reservoirs, many of which provide hydroelectric power and irrigation for agriculture. The Columbia River is the largest source of water for the state, with many major reservoirs located along its length. These include Grand Coulee, Banks Lake, and Lake Roosevelt. The Yakima River basin also has several important reservoirs, including Cle Elum Lake, Kachess Lake, and Bumping Lake. Snowpack in the Cascades and Olympics is critical for water supply, particularly for irrigation during the dry summer months. In recent years, drought conditions have affected much of the state, with record low snowpack levels in 2015 leading to restrictions on water use. Seasonal trends generally see peak water levels in the spring as snowmelt increases streamflow, followed by a gradual decline throughout the summer and fall. Overall, the hydrology of Washington is complex, with a mix of natural and human factors affecting the availability and use of water resources.