Why is Switzerland offering cash prizes to retrieve munitions from lakes?

Lake Lucerne, one of the Swiss lakes in which old munitions were dumped between 1918 and 1964 [Frank Bienewald/LightRocket via Getty Images]

The Swiss Federal Department of Defence Procurement (Armasuisse) is offering 50,000 Swiss francs ($57,800) for the three best ideas on how to retrieve some 12,000 tonnes of old munitions from the country’s lakes, including Lake Thun, Lake Brienz and Lake Lucerne.

“Armasuisse wants to involve academia and industry in the considerations on how environmentally friendly and safe recovery of deep lake ammunition could be carried out,” according to a department statement.