Wildfires Boost Water Flow in Feather River

A USGS-led study estimates 2020 and 2021 wildfires increased water available to streams and groundwater in the upper Feather River watershed.

Updated on Nov. 4, 2026 in Current Conditions

Wide view of a river canyon in the Sierra Nevada foothills, with blackened conifers on steep slopes above a clear flowing river with green regrowth. — A USGS-led study estimates that 2020 and 2021 wildfires increased water flowing into streams and groundwater across more than half of the upper Feather River watershed. AI Illustration. Upload story photo >

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A USGS-led study estimated that wildfires in 2020 and 2021 increased water flow through the upper Feather River watershed. The North Complex, Dixie, and Sugar Fires burned more than half of the watershed, reducing plant water use and leaving more water for streams and groundwater.

Why it matters

The upper Feather River watershed drains into Lake Oroville, a key part of the State Water Project that helps supply water to more than 27 million people. The findings show that wildfire can change how water moves through a watershed, with effects that may matter for reservoir supplies.

The USGS-led model estimated about 1 million acre-feet of extra water in water year 2023, which was a very wet year, and about 690,000 acre-feet the next year. The study compared simulations run with and without the fires' effects on plants.

The players

U.S. Geological Survey (USGS)

The USGS is the U.S. science agency that conducts earth and water research, and it led the study estimating the wildfire-related water flow increase.

The details

Fires burned more than half of the upper Feather River watershed, and fewer plants using water afterward left more moisture in soil and streams. Researchers ran a computer model with and without the fires' effects on plants to measure the change in water availability.

2020 and 2021: Wildfires burned parts of Northern California, including the North Complex, Dixie, and Sugar Fires.
October 2022 through September 2023: Water year 2023 showed about 1 million extra acre-feet of water available.
Water year 2024: The increase continued at about 690,000 acre-feet.

Seasonal Patterns

The USGS model applied to the Feather River watershed quantifies how the 2020 and 2021 fires changed water availability relative to a no-fire scenario. The estimates show how wildfire-reduced plant water use can offset some supply pressure on the State Water Project's Lake Oroville.

Residents who rely on State Water Project supplies should watch official water-supply updates, since the study points to wildfire effects on watershed flow. The findings do not provide specific guidance for households, so they should follow water agency notices for any changes.

The takeaway

Wildfires can increase water available in a watershed by reducing plant water use, though the benefit is measured in a model and does not remove fire risk. Readers should view the effect as one factor in regional water planning rather than a reliable supply source.