Mudflows are a very rapid surging flow of debris that has become partially or fully liquified by the addition of significant amounts of water to the source material. This water can come from heavy rainfall, snowmelt, or high levels of ground water flowing through cracked bedrock.
Areas at risk of a dangerous mudflow are areas where vegetation is destroyed due to wildfire or human interaction, areas where landslides have happened before, steep slopes and areas at the bottom of slopes or canyons.
