Mudslide

To get a sense of the enormous amount of water atmospheric rivers dumped on the Western U.S. this year and the magnitude of the flood risk ahead, take a look at California’s Central Valley, where about a quarter of the nation’s food is grown. This region was once home to the largest freshwater lake west of the Rockies. But the rivers that fed Tulare Lake were dammed and diverted long ago, leaving it nearly dry by 1920. Farmers have been growing food on the fertile lake bed for decades. This year, however, Tulare Lake is remerging. Runoff and snowmelt from the Sierra Nevada have overwhelmed waterways and flooded farms and orchards. After similar storms in 1983, the lake covered more than 100 square miles, and scientists say this year’s precipitation is looking a lot like 1983. Communities there and across the West are preparing for flooding and mudslide disasters as record snow begins to melt. Tulare Lake, long dry, begi...

Rivers of muddy water from heavy rainfall raced through city streets as thousands of people evacuated homes downhill from California’s wildfire burn scars amid atmospheric river storms drenching the state in early January 2023. The evacuations at one point included all of Montecito, home to around 8,000 people – and the site of the state’s deadliest mudslide on record exactly five years earlier. Wildfire burn scars are particularly risky because wildfires strip away vegetation and make the soil hydrophobic – meaning it is less able to absorb water. A downpour on these vulnerable landscapes can quickly erode the ground, and fast-moving water can carry the debris, rocks and mud with it. After the 2018 mudslide in Montecito, firefighters checked homes. Twenty-three people died in the disaster. Wally Skalij/Los Angeles Times via Getty Images With more storms expected through mid...