OREGON RESERVOIR REPORT

Last Updated: December 19, 2025

Oregon's dam and reservoir levels exhibit notable variances from their historical averages according to the latest observations. Upper Klamath Lake, typically at 4140.47 feet above the USBRKB Datum, is currently at 4139 feet, suggesting a slight decrease. Bull Run Lake near Brightwood also shows a minor drop from its average of 3171.18 feet to 3170 feet. However, more significant deviations are found in Hills Creek Lake near Oakridge and Lookout Point Lake near Lowell, with current levels at 1445 and 761 feet respectively, well below their averages of 1485.45 and 859.34 feet. Other reservoirs such as Fall Creek, Cottage Grove, Dorena, Fern Ridge, Detroit, Green Peter, Foster, and Applegate Lakes are below their average levels, with drops ranging from 14 to 98 feet. These abnormal conditions can potentially be linked to recent climatic events, including the warmest fall on record and a series of atmospheric rivers leading to irregular precipitation patterns.

The abnormal reservoir conditions across Oregon are likely influenced by a combination of factors including climate change and recent weather phenomena. Oregon Public Broadcasting reports an increase in the strength and frequency of atmospheric rivers in the Pacific Northwest, which can lead to erratic water flow patterns and impact reservoir storage levels. Additionally, the warmest fall on record as reported by the Idaho Capital Sun and various weather forecasting sources like AccuWeather and OregonLive.com, indicate an unusual dry and warm season, further exacerbating water storage concerns. Reports also suggest a recent deluge in Portland and a 'Pineapple Express' weather system targeting Oregon, suggesting that while some areas may have experienced heavy rainfall leading to flooding, the overall seasonal precipitation has not been sufficient to maintain average reservoir levels. The community's response to environmental concerns, such as the discovery of harmful substances in water supplies, underscores the need for careful monitoring and management of Oregon's water resources in the face of changing climate conditions.

Oregon has over 1,200 reservoirs and dams, with the largest being the Owyhee Reservoir, which can hold up to 1.1 million acre-feet of water. Other major reservoirs include the Detroit Reservoir, Wickiup Reservoir, and Crane Prairie Reservoir. The sources of water for these reservoirs include the Columbia River, Snake River, Deschutes River, and their tributaries. The snowpack in the mountains is a crucial factor in filling these reservoirs, with the Cascades and Blue Mountains being the primary sources. Record levels for reservoirs and dams vary depending on location, but generally occur during periods of heavy precipitation or snowmelt. Drought conditions are also a concern, as low snowpack and reduced streamflow can impact water availability for irrigation and recreation. Seasonal trends in precipitation and snowpack influence water levels in reservoirs, with lower levels typically seen in late summer and early fall. Overall, the hydrology in Oregon is heavily influenced by the state's topography, with water sources being mainly mountain-fed and dependent on snowpack accumulation.

Oregon has over 1,200 reservoirs and dams, with the largest being the Owyhee Reservoir, which can hold up to 1.1 million acre-feet of water. Other major reservoirs include the Detroit Reservoir, Wickiup Reservoir, and Crane Prairie Reservoir. The sources of water for these reservoirs include the Columbia River, Snake River, Deschutes River, and their tributaries. The snowpack in the mountains is a crucial factor in filling these reservoirs, with the Cascades and Blue Mountains being the primary sources.

Record levels for reservoirs and dams vary depending on location, but generally occur during periods of heavy precipitation or snowmelt. Drought conditions are also a concern, as low snowpack and reduced streamflow can impact water availability for irrigation and recreation. Seasonal trends in precipitation and snowpack influence water levels in reservoirs, with lower levels typically seen in late summer and early fall. Overall, the hydrology in Oregon is heavily influenced by the state's topography, with water sources being mainly mountain-fed and dependent on snowpack accumulation.