Lötsch Valley's Schuttberg Resists Overflowing Water Bodies
Situation in Lötschental Valley: Swelling Lake Holds Back Floodwaters During Glacier Collapse Aftermath
Following the collapse of the Birch Glacier in southern Switzerland, the Lötschental valley remains in a delicate state. The Lonza river is backed up and has formed an artificial lake due to the debris pile in the affected area. The pressing question is whether the floodwaters will spill over into the valley. At the moment, the circumstances are "relatively favorable."
All eyes are fixed on the lake formed behind the debris pile witnessing the aftermath of the glacier collapse. While it is certain the floodwaters will eventually flow into the valley, it is uncertain whether this will transpire in an organized or chaotic manner. The initial forecast from the Wallis canton authorities has proven false, as they had speculated that the lake in Lötschental would burst in the early morning hours. As of mid-morning, however, the debris pile has effectively contained the floodwaters, with a growing river forming in the debris instead.
Yannik Seeber, a reporter for ntv, summed up the situation: "A river is steadily forming, growing bigger and bigger."
Raphaël Mayoraz, the canton geologist, offers a more detailed assessment on RTS, the French-language Swiss television network. "The water is slowly finding a path through the almost 2.5-kilometer-long debris," Mayoraz explained. "The more water finds its way through the debris, the lower the risk of an abrupt breach."
Massive quantities of rock, ice, and debris have blocked the Lonza riverbed since the glacier collapse on May 28th. The lake's water level periodically rose by up to three meters per hour.
Residents in two neighboring valleys are being advised to prepare for a quick exit, as the danger is far from over. "We urge residents to make arrangements to leave their homes at short notice," the municipalities of Steg-Hohtenn and Gampel-Bratsch posted on their website. Alertswiss, a notification app, will be used to inform residents of any potential flood wave or debris flow.
Unfortunately, no intervention is possible at this time due to the instability of the debris pile. "We cannot intervene with heavy machinery due to the dangerous conditions in the area," said Christian Studer of the Wallis Natural Hazards Service. Not only is the debris pile unstable, but it is composed of rock fragments, loose debris, and partially melted glacier ice, making it hazardous for both humans and machinery.
Additional concerns arise from the potential for further avalanches as both sides of the valley face future rockfalls. At the original breakaway site on the Kleine Nebelhorn, there is the risk of hundreds of thousands of cubic meters of rock collapsing. Additionally, debris and rubble pushed across the valley floor and up the opposite slope during the glacier break could slide again as a debris avalanche.
Although the immediate risk of major flooding is diminishing due to the natural drainage of the lake, the situation remains volatile. Cleanup operations are currently on hold until the area stabilizes, and the Swiss army has been called in to assist in the response efforts.
Key Actions and Precautions:- Residents are advised to remain prepared for potential evacuations and neighboring villages have already seen some evacuations.- Authorities are dismantling pedestrian bridges, reinforcing infrastructure, and monitoring the stability of the area.- Authorities have emptied a reservoir downstream at Ferden to create a catchment basin for excess water if the natural dam breaks.
- To mitigate the risk of further damage, environmental-science experts are closely monitoring the climate-change impacts on the Lötschental Valley, particularly the swelling lake and potential weather changes that could affect weather-forecasting.
- The community and employment policies of the affected regions are currently under review, as the aftermath of the glacier collapse may require additional resources and manpower for cleanup and recovery efforts.
- As the situation in Lötschental Valley evolves, state-of-the-art environmental-science research on glacier dynamics and climate change is crucial to create more accurate community policy and employment policy initiatives for regions facing similar disasters in the future.
