The National Geology and Mining Service (Sernageomin) and specialists warned that El Niño, combined with rainfall at a high freezing level, increases the risk of debris flows in Chile's mountains, according to Cooperativa. The warning follows a debris flow in Santiago's foothills, in the San Carlos de Apoquindo area of Las Condes.
The freezing level is the altitude at which the air temperature reaches zero degrees. When it rises, precipitation falls as rain rather than snow in high mountain areas. According to technical reports cited by the outlet, the combination of high temperatures and rainfall at an elevated freezing level favors sudden mass movements.
The World Meteorological Organization (WMO), the United Nations agency specializing in climate, confirmed that El Niño will continue strengthening in the coming months. It projects its peak intensity around December, with changes in rainfall and temperatures in the Southern Cone.
Sernageomin's national director, Mauricio Lorca, said the institution is monitoring mountain watersheds and industrial infrastructure. "At Sernageomin, we are closely monitoring the development of El Niño ahead of the summer months. In a country like Chile, this climate phenomenon has a dual impact," he said.
Lorca explained that higher temperatures and precipitation at a high freezing level "accelerate snowmelt in the high mountains." That, he added, increases susceptibility to debris flows and mass movements in ravines that are usually dry.
The second area of concern is mining. "In mining, water is a critical safety variable. We are intensively inspecting the stability of tailings deposits and high-altitude mining operations," the director said. The source does not specify which operations or how many are being inspected.
In Las Condes, specialists point to previous wildfires. The loss of vegetation reduced the soil's ability to absorb water and accelerated the flow of sediment and mud toward populated areas in the foothills.
Pablo Silva, a water resources specialist and environmental training consultant, compared the Las Condes watershed to "a critically ill patient". He said the debris flow exposed the consequences of the fire, and many years will be needed for the watershed to respond as it did before.
Silva proposed three steps: first, monitoring; second, sediment containment works using mesh barriers and infrastructure to prevent a major flood from hitting the urban area again; and third, reforestation and restoration of the watershed's hydrological condition.
