The intense 2020 fire season will be felt for years to come in Douglas County. Fire effects soil stability in fields and slopes, wetlands and streams, mature wildlife habitat, and the spread of weeds. There are measures we can take to reduce erosion, which is the movement of soil particles by water and/or wind.
There are several ways that fire changes soils and their erosion ability. Soils can become more hydrophobic after fire, meaning infiltration decreases and more water stays on the soil surface. This leads to a greater chance of sediment runoff in fields and hillsides, especially during rainstorms, causing poor water quality. Sediment runoff also decreases crop production because there is a loss of topsoil and the ecosystem where the majority of micro-organisms live. Reduced and no-till farming practices have surface residue built-up to prevent such runoff, but fires can also burn this residue security blanket. Geologically hazardous areas on slopes and drainages are at an even greater risk of erosion after fires since vegetation that stabilizes the soils is gone. These fragile landscapes are already acknowledged by the Douglas County’s Voluntary Stewardship Program (VSP) as priority areas that are in need of stewardship practices to mitigate their erosion.
Assessing vulnerable areas around you and noting potential risks that may be associated with them will help you plan and prepare for future fires. For instance, if you live at the bottom of hill or downstream from an area that has burned, sediment movement and debris flows are more likely to affect you. Installing erosion control measures may help limit soil loss by wind and water during springs with rapid snowmelt.
Other tips to prevent soil loss:
We thank the Washington State Department of Ecology for supporting this article.