Tourists gazing at the tranquil blue waters of Swiss lakes such as Lucerne, Thun, and Neuchatel might never guess that beneath these pristine surfaces lie thousands of tons of forgotten military munitions.
For decades, the Swiss military disposed of outdated or unused ammunition by sinking it into these lakes, believing that the deep, cold waters would keep the explosives safely contained.
However, as concerns grow about the environmental and safety risks posed by these underwater dumps, the Swiss government has launched a new initiative to address the issue.
The Swiss Defence Department is offering a prize pot of 50,000 Swiss francs (around £45,000) for the best ideas to retrieve the munitions in an environmentally safe manner. But the true cost of any large-scale salvage operation is expected to run into billions.
The Depths of the Problem
Lake Lucerne alone is estimated to contain 3,300 tons of old munitions, while Lake Neuchatel harbors around 4,500 tons, much of it left over from decades of military exercises.
Although some of these munitions are submerged at depths of 150 to 220 meters, others are alarmingly close to the surface. In Lake Neuchatel, for instance, some explosives lie just six or seven meters below the waterline.
The Swiss Air Force used the lake for bombing practice until 2021, adding to the already massive quantity of ammunition beneath its surface. Other lakes, including Lake Brienz, have also served as dumping grounds for military waste.
While the presence of this submerged arsenal has been known for years, recent reports have raised alarms about the potential dangers.
Retired Swiss geologist Marcos Buser, who has long studied the issue, warned in a research paper ten years ago about the double risks these munitions pose.
“The munitions are still a danger because, in many cases, the army did not remove the fuses before dumping them,” Buser explained.
“This leaves the possibility of an explosion, even underwater.” But beyond the risk of detonation, there is also the threat of environmental contamination.
Highly toxic chemicals like TNT could leach into the lake water and sediment, potentially causing long-term harm to the local ecosystem and the communities that rely on these lakes for drinking water, tourism, and recreation.
A Search for Solutions
The Swiss government acknowledges the difficulties of recovering the munitions safely. Factors like poor underwater visibility, the magnetic properties of the iron shells, and the varying weights of individual ammunition pieces make the operation particularly challenging.
An assessment conducted in 2005 explored possible recovery techniques but found that all of them posed severe risks to the sensitive ecosystems of the lakes.
Now, the Swiss Defence Department has called on the public for innovative ideas, offering prize money for the three best solutions. Submissions will be evaluated anonymously by a panel of experts, and the winners will be announced in April 2024.
The government emphasizes that the winning entries may not be implemented immediately but could serve as the basis for further research and development projects.
“It’s a monumental task,” admitted a Defence Department spokesperson. “We are looking for creative, safe, and environmentally friendly methods to tackle this issue, but we recognize that it’s going to be a long and costly process.”
Buser suggests that Switzerland might look to other nations for guidance. Countries like the UK, Norway, and Denmark have faced similar challenges in dealing with wartime wrecks that contain unexploded ordnance.
Drawing on their experience could help Swiss authorities navigate the complexities of recovering munitions from the lakes.
A Troubled Legacy
The issue of unexploded munitions is not a new one for Switzerland, a country with a long history of balancing its armed neutrality with military readiness.
During the Cold War, Switzerland maintained a large militia army, and all Swiss men were required to undergo military service.
Much of the training took place within Switzerland’s densely populated borders, leading to situations where munitions were stored and discarded in potentially hazardous ways.
One of the most notorious incidents occurred in 1947 in the alpine village of Mitholz. There, 3,000 tons of ammunition stored in a mountain depot exploded, killing nine people and destroying the village.
The blast was so powerful that it was heard 160 kilometers away in Zurich. Although most of the village was rebuilt, in 2020 the Swiss military revealed that 3,500 tons of unexploded ammunition still remained buried in the mountain.
Officials admitted that the site was not as safe as previously thought, and the decision was made to remove the remaining munitions. For the residents of Mitholz, this meant abandoning their homes for up to a decade while the clean-up operation takes place.
There have also been concerns about the Swiss military’s Cold War-era defense strategy of mining its bridges and tunnels against potential invasion.
In some cases, modern heavy goods vehicles were found to be at risk of triggering the explosives, forcing the authorities to quickly de-mine key transport routes.
More recently, reports of civilians finding unexploded ordnance in the Swiss countryside increased by 12% in 2023 compared to the previous year.
Even in the glaciers, now retreating due to climate change, remnants of old military training exercises are being uncovered as the ice melts. Both spent and live ammunition have been found in these areas, raising further safety concerns.
An Uncertain Future
The Swiss lakes, long a symbol of natural beauty and serenity, now represent a complex and costly challenge.
The prospect of safely recovering thousands of tons of old munitions from their depths is daunting, but many believe it is a necessary step to protect both the environment and public safety.
“The military thought they were doing the right thing at the time,” said Buser. “But now we know better, and we need to fix it.”
As the search for innovative solutions continues, the Swiss Defence Department remains committed to finding a way forward.
Whether through local ingenuity or international collaboration, the hope is that one day, the lakes will be free of their dangerous cargo, allowing future generations to enjoy their beauty without the shadow of the past lurking beneath.
In the meantime, the clock is ticking, and the race to find a workable solution is on.