Many are at extremely low levels, while some smaller streams have dried up completely. Wikimedia Commons by Norbert KaiserLow water levels have also exposed the “hunger stones” found along the Elbe. The stones were historically used to mark exceptionally low water and warn of the difficult conditions that could follow. Much of Europe is experiencing unusually dry conditions this summer, with low rainfall and high temperatures pushing rivers and reservoirs to exceptionally low levels. A European problemThe Danube, Rhine and Vistula have also recorded unusually low water levels, while drought conditions are affecting agriculture, transport and water supplies across the continent.