Nepal to begin work on draining four dangerous glacial lakes after deadly floods

Nepal will begin design work and detailed studies on lowering the water levels of four high-altitude glacial lakes: Thulagi, Lower Barun, Lumding Tsho, and Hongu II. This initiative follows catastrophic floods in August 2026 that killed over 1,400 people in Nepal and left more than 5,000 missing, with communities downstream vulnerable to glacial lake outburst floods (GLOFs). The project, budgeted at $50 million, will be funded by the Green Climate Fund (GCF), the United Nations Development Programme (UNDP), and the Nepali government. The goal is to release water in a controlled manner, preventing the natural dams of these lakes from breaching and causing further devastation.The plan involves creating canals to divert lake water into nearby rivers under regulated conditions, thereby reducing pressure behind the natural barriers. The four lakes targeted are situated between 4,050 meters (13,287 feet) and 5,483 meters (17,989 feet) above sea level, where rising temperatures and unstable terrain increase the risk of GLOFs.A 2020 report by the UNDP and the International Centre for Integrated Mountain Development (ICIMOD) identified Thulagi, Lower Barun, Lumding Tsho, and Hongu II among Nepal’s most dangerous glacial lakes. The urgency of this project was highlighted by the August 2026 floods, which were reportedly triggered by a glacial lake outburst in the Bhotekoshi River basin near the Nepal-China border.Subash Tuladhar, an expert with Nepal’s Centre for Hydrology and Water Resources Research, acknowledged the hazardous nature of the work. Crews will face extended periods at high altitudes and the constant risk of sudden flooding during the draining process. However, Tuladhar affirmed Nepal’s experience and technical capability for such a project, citing previous successful efforts to lower Tsho Rolpa by 3 meters (10 feet) in 2000 and Imja near Mount Everest in 2016.Prime Minister Balendra Shah, speaking at the United Nations in September 2026, said Nepal’s disaster should be taken as a warning to the world and argued that climate change is battering the country despite its negligible emissions.Design work and detailed studies for the four lakes are scheduled to commence in the fiscal year ending in mid-July 2027. Sanjeeb Baral, executive director of Nepal’s Centre for Hydrology and Water Resources Research, said the actual draining of the lakes, which will involve “gated structures,” would begin only after these technical studies are completed and could take as long as six years. The plan also includes sensors, a flood forecasting and warning system, and stronger downstream preparedness to provide communities with more time and better information if water levels change abruptly.