INCREASED FLOODING POTENTIAL IN BURN SCAR AREAS
The changed ecology of burned areas significantly increases the risk of flooding and flash flooding.
- Burned vegetation changes the water balance on denuded hillsides
- Burned organic matter on the soil increases water repellency
- Runoff is increased, carrying debris rapidly downslope
Additionally, runoff flows and debris combine with autumn leaves to clog drains for localized ponding and flooding on and around roadways.
See also https://www.weather.gov/riw/burn_scar_flooding
Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services