WASHINGTON RESERVOIR REPORT

Last Updated: December 27, 2025

Washington State's dams and reservoirs are currently experiencing mixed conditions according to the latest observations. Wynoochee Lake near Grisdale is slightly below its average water level, with Mud Mountain Lake near Buckley showing significantly higher levels than average, which could indicate abnormal water management or recent precipitation events. Lake Tapps near Sumner and Howard A Hanson Reservoir near Palmer are both below average levels, suggesting potential concerns for water supply if these trends continue. Conversely, Cedar Lake and Chester Morse Lake at Cedar Falls are at or just above their average levels, which is a positive sign for water availability in those areas.

Notably, Franklin Roosevelt Lake at Grand Coulee Dam is above average, potentially indicating increased river inflows or controlled releases for power generation or flood management. Lake Sammamish near Redmond is slightly higher than average, which could be due to local precipitation or runoff. South Fork Tolt Reservoir near Carnation is also above its average level, which may impact downstream river conditions. However, Baker Lake at Upper Baker Dam near Concrete is below average, which could affect local ecosystems and water supply. Lake Shannon at Concrete is higher than average, raising concerns for potential overflow or flooding issues. Osoyoos Lake near Oroville, Lake Chelan at multiple points, Lenore Lake near Soap Lake, and Moses Lake at Moses Lake are near their average levels, indicating stable conditions. Soap Lake near Soap Lake is below average, which may be a point of concern for local water users. Lake Scenewa near Kosmos data is unavailable, indicating a potential issue with monitoring equipment. In the context of recent weather patterns, the abnormal conditions in some reservoirs could be related to the cold, dry stretch affecting Western Washington or previous historic flooding incidents, which have been swamping the region and impacting water levels.

Readers should note that while some reservoirs are at or near average levels, others show significant deviations. These inconsistencies could be attributed to a mix of factors, including localized weather events, water management strategies, and broader climatic trends like snowpack levels and river flows. It’s crucial to continue monitoring these water sources as they play a vital role in the region's ecology, water supply, and recreational opportunities. For up-to-date and more detailed information regarding each reservoir's status and management, residents and stakeholders should refer to local water authorities and government agencies.

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.