Jon E. Keeley and Paul H. Zedler. 2009. Large, high-intensity fire events in southern California shrublands: debunking the fine-grain age patch model. Ecological Applications 19:69–94.

Appendix C. Lessons from the 2007 Santiago Fire applied to the reconstruction of the 1889 Santiago Canyon Fire.

Daily fire activity for the 2007 Santiago Fire (Fig. C1, from Mike Ferdig, Orange County Fire Authority, OCFA). This recent fire ignited in close proximity to the origin of the 1889 Santiago Canyon Fire and provides a potential model of burning behavior for that historical fire.

FIG. C1. The 2007 Santiago Fire ignited near the upper left hand portion of the fire perimeter and burned predominantly in a south east direction for the first 24 hours. Then it turned eastward and continued burning for another 9 days. Specifically, it originated at 17:55 on 21 Oct and was pushed to the west and southwest until the Santa Ana winds abated about 24 hours later. Onshore winds then pushed the fire eastward for another 9 days, ultimately carrying it to the top of the Santa Ana Mountain Range.

Historical newspaper reports cited in the main text show that the 1889 Santiago Canyon Fire had a similar progression during the first 24 hours, reaching as far south as El Toro. However, the 1889 fire continued burning under another two days of strong Santa Ana winds and ultimately burned into San Diego County. Once this offshore flow abated the 1889 fire burned eastward under an onshore flow and reportedly burned a bridge south of Temecula in San Diego County. We estimate the ultimate size of this fire was more than an order of magnitude larger than the 2007 Santiago Fire due to the much longer influence of Santa Ana suppression, in stark contrast to the efforts at suppression of the 2007 fire.

According to the Incident Commander (Mike Rohde, OCFA, email 2 Jan 2008) the 2007 fire was aggressively attacked at many points. “Engines actively held roads along Santiago Canyon Rd., north of Silverado Canyon, and on the south and west flanks in Tustin and Irvine. A big graded area north of Portola Parkway also helped a lot. The firing on the north was anchored to an 86 acre burn from earlier in the summer, and this firing kept it out of a very dangerous corridor in Orange/Cowen heights. Another very important backfire was conducted adjacent to the 100 year old chaparral fuel bed along Live Oak Canyon Road, keeping the fire out of the Trabuco Canyon area. Retardant held the fire to ridge lines on the SE side where no other natural breaks were available. Firing was done behind homes in Modjeska and Harding Canyons, saving many of them.”

Fire suppression action comprised “1,100 firefighters and a squadron of helicopters and air tankers” (Overley et al. 2007) and was responsible for halting the fire on several fronts by backfires and related actions, all of which played major roles in containing the size of that fire.

LITERATURE CITED

Overley, J., G. Driscoll, S. Tully, D. Irving, K. Edds, S. Hernandez, and E. Chavez. 2007. Santiago fire feasts on brush in national forest. The Orange County Register October 24, 2007.