Erosion and sediment control: Preventing additional disasters after the Southern California fires

Excerpt

Wildfires are a common occurrence in Southern California and much of the State's biologic and geologic character is a direct result of a cycle of fire, flood, and regeneration of plant communities, many of which have adapted to this disturbance. However, while the impact of fires might be considered a natural phenomenon in wild lands and left largely unattended, where human population and resources are affected by the fire cycle, mitigation activities designed to reduce the potential for flooding and mud flows must be included as part of that cycle.

In the fall of 1993, 20 separate fires burned over 186,000 acres of Southern California, extending from northern Los Angeles County to southern San Diego County and the Mexican border (Figure 1). Nearly 1,200 homes were destroyed and four people lost their lives. Unlike the East Bay Firestorm in Oakland, California (1991) where 3,100 structures were destroyed in an 1,800 acre densely populated urban area, the majority of acreage on which the 1993 fires occurred was in wild lands, or away from urban centers (Table 1). However, at the urban interface where wild lands and development meet, the hazard from post-fire flooding, erosion