Europe’s worst drought in decades has not only scorched farmland and hampered river traffic, it has also revealed some of the almost forgotten history of World War II: the carcasses of dozens of German battleships from the World War II emerged from the Danube that its water levels have dropped.

In the middle of the great river separating Serbia from Romania near the Serbian port of Prahovo, a rusted hull, a broken mast where the swastika flag once flew, an upper deck where a command bridge once stood, a barrel that would have could have been containing fuel – or even explosive materials – resting on a dune of pebbles emerging from the water.

The ships, some still loaded with ammunition, belonged to Nazi Germany’s Black Sea Fleet which was deliberately sunk by the Germans as they retreated from Romania as Soviet forces advanced.

Today, the European Union and the European Investment Bank have agreed to provide loans and grants to finance the operation to withdraw certain vessels near Prahovo in order to improve the traffic capacity of the Danube. The total cost of the operation is estimated at 30 million euros (30 million dollars), including around 16 million in subsidies.

“These ships were sunk and they have been lying on the riverbed ever since,” EU Ambassador to Serbia Emanuele Giaufret said during a recent visit to the wreck site. “And that’s a problem. It’s a problem for traffic on the Danube, it limits the ability to move, it’s a danger because some ships still contain unexploded ordnance.”

Giaufret was accompanied by Alessandro Bragonzi, the director of the European Investment Bank in the Western Balkans. He said the plan was to remove 21 sunken ships.

“It has been estimated that more ships are under water, up to 40, but those currently hampering the state of the Danube channels, especially during periods of low water levels, are 21,” said said Bragonzi.

The exceptionally warm weather across Europe this summer has been linked by scientists to global warming and other factors. Falling water levels have created dangerous conditions for navigation on many of the continent’s rivers, including the Danube, Europe’s second longest river which crosses 10 nations. Serbian authorities used dredging to keep ships moving.

Shipwrecks rising from the depths are an awe-inspiring sight, but they have caused decades of problems for those who use the river, and now the Serbian government, with the support of the European Union, is planning to do something about them.

Experts say the salvage operation will involve removing explosive materials from sunken ships and then destroying the wreckage, rather than dragging the ships out of the river.

Historians say up to 200 German warships were scuttled in September 1944 near Prahovo in the Danube Gorge known as the Iron Gate on the orders of the Fleet Commander as they came under heavy fire of the Soviets. The idea behind the deliberate sinking was to at least slow down the Soviet advance in the Balkans. But that didn’t help because Nazi Germany surrendered months later, in May 1945.

Some of the wrecks were removed from the river by Yugoslav communist authorities just after the war. But most of them remained, hampering navigation, especially in summer when water levels are low. For years it was planned to get the ships out of muddy waters, but the operation was considered too risky due to the explosives they were carrying and there were no funds to do so until recently.