California is getting hit again with another round of atmospheric river storms. The phrase “atmospheric river” was first used by climate scientists in the early 1990s to describe those long, narrow plumes of moisture that carry more water than the Mississippi River. 1
Understanding Your Claim After a Mudslide
When these systems make landfall in California, they unload that moisture fast. These storms quickly saturate soil on hillsides burned in recent wildfire seasons and can trigger mudslides. Most homeowners assume these losses are excluded because almost every property policy contains an earth movement exclusion. Mudslide, mudflow, landslide, sinking, rising, shifting — the list is long. Ordinarily, insurers point to that exclusion and deny the claim. But California law does not let them stop there. The efficient proximate cause doctrine, written into California Insurance Code section 530, requires insurers to identify the true cause of the loss. If a covered peril starts the chain of events, the loss is covered even if an excluded peril appears later in the sequence.
How California Treats Post-Fire Mudslides
The California Department of Insurance has been very direct about this. After the Montecito debris flow in January 2018, following the Thomas Fire, the Department issued a Formal Notice reminding carriers that when wildfire removes vegetation and destabilizes a slope, a later mudslide is considered a fire-related loss. CDI repeated this guidance after mudslides in 2021 caused by wildfires, and earlier this year in Bulletin 2025-3, which again instructs insurers that they cannot rely on an earth movement exclusion without first determining whether wildfire set everything in motion. The Department has been consistent for years: if fire is the efficient proximate cause, coverage applies.
If you live below a burn scar and mud or debris comes into your home after one of these storms, do not assume the claim is already lost. Insurers still must look at the full sequence of events, and CDI has been reminding carriers of that for years. These events will always test hillsides, but California’s DOI seeks to protect policyholders when the real cause of the loss begins with wildfire.
1 “Atmospheric Rivers”: Rising Interest in Science and the Media, Center for Western Weather and Water Extremes (Apr. 25, 2015).
