The Lake Almanor Watershed Group reports that the water quality of Lake Almanor is showing “definite signs of recovery” from the effects of the Dixie Fire.
The 2021 Dixie Fire and subsequent activities to control its spread had resulted in the deposition of a great deal of soil, ash, fire retardant and other debris in the Lake Almanor watershed, said LAWG. Heavy precipitation in late 2022 and spring 2023 washed much of this loose material into the reservoir, causing dissolved oxygen levels to drop to zero in the deeper water of the eastern basin and even in some parts of the shallow western basin.
The pH rose to a more alkaline level, probably due to the dissolving of ash. Water clarity was also reduced. These low dissolved oxygen conditions and increased pH levels persisted into late fall 2023.
LAWG, a citizen committee that has been monitoring water quality of the reservoir since 2009, documented the reservoir’s worsening condition following the fire and its recovery in spring and fall 2025. The dissolved oxygen at depth appears to be back to prefire levels at the two stations in the eastern basin and the station in the western basin. The pH values have also returned to their normal range.
This suggests that much of the debris from the Dixie Fire has been flushed from the reservoir, said LAWG. Below-average precipitation in 2024 and 2025 helped to slow the rate of erosion of unstable debris in the watershed, which also aided in recovery.
LAWG personnel thank Almanor West Country Club and Lake Almanor Country Club for supporting water quality investigations. The entire report for 2025, as well as previous years, can be found on the LAWG section of the Sierra Institute for Community and Environment website.
