Mudslides, also known as debris flows, are dangerous in areas with certain geological and weather conditions. In California, the mix of steep hills, loose soil, and frequent wildfires increases the risk of these events. Experts explain that the state’s young mountains make slopes unstable, especially when heavy rain falls. Droughts make the problem worse, as the soil becomes hard and cannot absorb water, causing fast runoff that loosens soil. Wildfires add to the risk, as they destroy plants that hold the soil together. The California Department of Conservation reports several deadly events, including the 2018 Montecito disaster, where heavy rain caused a massive debris flow, killing 23 people and damaging many properties. Other tragic incidents include the 1934 Southern California storm, which killed 30 people, and the 2003 Christmas Day disaster, which claimed 16 lives. Climate scientists warn that changing weather patterns could make mudslides more frequent and severe.

To reduce these risks, authorities use methods like building debris basins, setting up containment nets, and monitoring the area for changes. Debris basins help catch sediment and allow water to flow downstream, preventing damage. These structures need regular care, as accumulated sediment can block them. Santa Barbara County spent $20 million on new infrastructure after the 2018 disaster. Experts also use advanced tools like lidar and GPS to track changes in terrain and predict mudslide risks. Reforestation and soil stabilization efforts help reduce erosion and strengthen slopes. The Department of Conservation updates hazard maps to keep communities informed and prepared.