10.23.2021 Caldor Fire Update

Quick Facts
Approximate Acreage | 221,835
Containment | 100%
Repair Completed | 55 % Line ; 40% point
Start Date | 8/14/2021
Cause | Under Investigation
Total Personnel | 415
 

Summary|Weather: With the slight break in the weather, crews are continuing to clean culverts, chip material, and install straw wattles across the fire area.  Fire personnel are trying to implement as many measures as possible before the bulk of the storm hits the area tomorrow and Monday. Fire restrictions have been lifted on the Eldorado National Forest (Forest Order 03-21-20).According to Caldor Fire incident weather meteorologist (IMET), Derek Williams, the “atmospheric river” heading for the Sierras is the water equivalent of approximately twelve Mississippi Rivers. Elevations below 7,000 feet may receive five to seven inches of moisture by Monday. Elevations above 7,000 feet could receive several feet of snow. Derek shares a rule of thumb to determine projected snowfall amounts in the Sierras is to multiply rainfall amounts by ten. For example, the five to seven inches of rainfall predicted could equal fifty to seventy inches if it all fell as snow.
 
The potential for debris flows in the Caldor Fire area are of great concern. Areas of high burn severity within the fire, such as Grizzly Flats and above US 50, could be at the greatest risk for debris flows due to hydrophobic soils. Soils that become hydrophobic repel water, reducing the amount of water infiltration. After a high intensity fire the native plant material can form a waxy substance around soil particles causing the surface layer to repel water. This hydrophobic layer is generally ½ inch to 3 inches beneath the soil surface, according a Natural Resource Conservation Service (NRCS) report. On average the Sierras receive a storm such as this every ten to twenty years.  A similar rain event occurred in 2018 within the Thomas Fire burned area in southern California. Heavy rain on freshly burned ground caused devastating debris flows. 
 
The National Weather Service (NWS) has issued a Flash Flood Watch, Flood Watch and a Winter Storm Watch for the area through Monday. Please monitor weather.gov and be alert for possible adverse conditions within the Caldor Fire area.