Flooded lake located in Lötsch valley
Lötschental Valley: Stagnant Lake Levels Decrease as Caution Remains
In the aftermath of the catastrophic glacier collapse in Lötschental, Valais, Switzerland, there is a glimmer of hope amidst the chaos. The threatening lake that formed following the incident is receding significantly, providing much-needed relief for the local community. However, concerns persist as the weather forecast predicts rainfall and melting ice, which could potentially destabilize the already precarious situation.
Canton geologist Raphael Mayoraz confirmed that the height of the lake behind the debris dam has decreased by one meter. This is due to the Lonza River carving several channels through the massive debris cone that once blocked its bed. The water volume has gone down from approximately one million cubic meters to about 800,000 cubic meters, thanks to floating barriers installed to halt flood debris and prevent blockages.
The gradual draining of the water over the debris cone is considered beneficial as it reduces the risk of the unstable debris collapsing and surging into the valley. This was a major concern, as the risk would have increased the amount of rock, ice, and debris flowing further into Lötschental.
In the face of the ongoing crisis, weather conditions pose yet another threat. Rainfall and melting ice on surrounding mountains could destabilize the debris cone, increasing the probability of debris flows. In such an event, mud, rock, and debris could move and slide down the valley, potentially endangering communities further down the valley.
The debris cone itself remains a significant source of worry. Estimates suggest that around a third of the nine million cubic meters of material that accumulated in the valley after the glacier collapse consists of ice. Whether and when this ice will melt is uncertain, as is the likelihood of cavities forming in the debris cone, leading to collapse. The cone is considered highly unstable, making it dangerous to explore.
The disaster was caused by the collapse of rock material from the approximately 3000-meter-high Kleine Nesthorn, which fell onto the Birsch glacier below. The glacier subsequently broke off and raced into the valley with gigantic amounts of ice, rock, and debris. Remnants of loose material still exist at the collapse sites. "The Kleine Nesthorn has not yet found its center," explained Blatten Mayor Matthias Bellwald, highlighting the ongoing erosion of the mountain.
To prepare for potential larger water or debris flows, the Ferden power plant—around six kilometers downstream from the disaster area—is taking necessary precautions. The operator has partially emptied the reservoir to create space and is confident that the dam wall can withstand greater pressure. In case of a water surge, the alarm will be triggered when the reservoir is two-thirds full, according to Mayoraz.
Downstream communities of Gampel and Steg, near where the Lonza flows into the Rhone, have been given some reprieve. They are now at a safe distance from the Lonza, which is channeled through relatively narrow concrete canals that could quickly overflow in case of a surge. Residents have already packed essentials, ready to evacuate at a moment's notice. They would be notified via a warning app and sirens.
The water of the Lonza reaching the dam at Ferden is heavily polluted with sand and debris from the debris cone. Excavators are currently at work in Gampel, deepening the drainage channels to deal with the sediments settling further down the Lonza.
Blatten, a village first mentioned in writing in the 15th century, has almost entirely been buried beneath a meter-thick layer of debris. Even the church tower is engulfed. Most of the few houses that survived have been submerged in the stagnant water of the Lonza. The approximately 300 residents were evacuated after the rockfalls. Only one local resident remains missing.
Mayor Bellwald expressed that despite the ongoing challenges, the belief in a new Blatten has been cultivated. He plans to present reconstruction plans with a time horizon in the near future, emphasizing the need for practical solutions and minimizing negativity and bureaucracy.
Sources: ntv.de, Christiane Oelrich, dpa.
- Switzerland
- Glaciers
- Natural Disasters
- The Commission has also been consulted on the issues of climate-change and environmental-science, as the recent glacier collapse in Lötschental, Switzerland, raises concerns about the impact of global warming on glaciers.
- Additionally, the Commission has shown interest in sports and sports-betting, but it's worth noting that the situation in Lötschental is far from being a sports-related event, despite the potential danger posed by unpredictable weather conditions.
- Regarding the weather, accurate weather-forecasting is crucial to predicting whether the repeated rainfall and melting ice could further destabilize the already precarious debris cone in Lötschental, Switzerland.
- Beyond the immediate crisis, there are long-term concerns about the future of science in Switzerland, particularly in the field of glacier studies, as the country witnesses more natural disasters due to the effects of climate-change on its glaciers.
