Residents on Alert as Water Levels Rise in Swiss Lötschental

The Swiss Lötschental region is facing a critical situation as water levels behind a massive debris cone continue to rise following a recent landslide. Experts are warning that the reservoir created by the landslide could overflow at any moment, prompting evacuation preparations in nearby communities.

Authorities have advised residents of Gampel and Steg, located approximately 20 kilometers downstream from the affected area, to pack essential belongings and remain ready to evacuate quickly. The local governments have issued alerts through the Alertswiss emergency app, urging those in vulnerable areas to be prepared for possible flooding or debris flows.

Matthias Ebener, a spokesperson for the Regional Command Center in Lötschental, indicated that the situation remains uncertain as it is unclear whether the water will flow through the debris or become trapped. Currently, the water has not yet breached the debris cone, but experts are closely monitoring the situation.

The communities affected encompass over 2,000 residents, although immediate evacuation orders are targeted at those living near the valley floor. The Lonza River, which runs near these towns, is at heightened risk due to the unstable conditions caused by the landslide.

As a precaution, water has been released from a dam and collection basin located above Gampel and Steg. However, it remains uncertain if these structures can handle the potential influx of water from the landslide.

Raphaël Mayoraz, a geologist from the canton, expressed cautious optimism, noting that the water is gradually finding its way through the 2.5-kilometer-long debris deposit. He mentioned that as time progresses, the risk of a catastrophic event appears to diminish.

Christian Studer, from the Natural Hazards Department of the Valais canton, described a worst-case scenario where an unexpected surge of water and debris could overwhelm the dam at Ferden, leading to severe flooding.

There is a possibility that the water might navigate through the debris and return to its natural riverbed, flowing down the valley. However, given the instability of the debris, experts cannot rule out the risk of a sudden, uncontrolled flow of water and rock.

The landslide has rendered the village of Blatten nearly uninhabitable, with most buildings now buried under several meters of debris. The few homes that survived the initial impact are now at risk of flooding from the rising waters of the Lonza River. Evacuations of Blatten's approximately 300 residents were carried out last week, though one local remains unaccounted for.

Authorities and residents can do little but wait and observe the situation, as any attempt to manage the water flow through the debris has been deemed too dangerous. Heavy machinery cannot be deployed due to the risk of further destabilizing the area. The military is on standby to assist with evacuations and clean-up operations once conditions allow.

Additional concerns linger regarding the potential for further rockfalls at the original landslide site, which continues to pose a threat to the region. The risk remains high as loose rock and debris could create additional hazards for the surrounding communities.