OREGON RESERVOIR REPORT

Last Updated: December 18, 2025

Oregon's dam and reservoir conditions are experiencing variances from their average storage levels, with several notable facilities showing decreased water surface elevations. As of the latest observations on December 18, 2025, Upper Klamath Lake near Klamath Falls is slightly below its average at 4139 feet compared to the usual 4140.47 feet. Bull Run Lake near Brightwood is also down, recording 3168 feet against an average of 3171.18 feet. More considerable discrepancies are observed at Hills Creek Lake near Oakridge and Lookout Point Lake near Lowell, with current levels at 1443 and 754 feet, respectively, well below their averages of 1485.46 and 859.36 feet. Other affected bodies include Fall Creek Lake, Cottage Grove Lake, Dorena Lake, Fern Ridge Lake, Detroit Lake, Green Peter Lake, Foster Lake, and Applegate Lake, all reporting lower than average elevations. These conditions may be related to the region having experienced the warmest fall on record, paired with recent high winds and power outages affecting large areas of the Northwest.

The abnormal conditions observed in Oregon's dams and reservoirs could be linked to various environmental factors. The warmest fall on record, as reported by KUOW, possibly contributed to reduced snowpack levels, which in turn affect river flows and reservoir inputs. High winds and severe storms reported by multiple sources, including The Washington Post and New York Post, may have also impacted water capture and storage infrastructure. The observed decrease in staff at the US Fish and Wildlife Service could have implications for efficient management and monitoring of water resources. It is crucial for stakeholders to consider the accumulating effects of climate variability, extreme weather events, and resource management challenges when assessing the health and sustainability of water reservoirs in Oregon.

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.