A minister says the Romanian military has unsuccessfully tried to remove a Danube rock for 30 years. (AP PHOTO)A minister says the Romanian military has unsuccessfully tried to remove a Danube rock for 30 years. The Cernavoda plant, which draws all of its cooling water from the Danube, has been threatened by the river's sharply reduced water levels caused by drought. The rock had become exposed as water levels fell. The river is currently carrying only about one-third of its average seasonal flow, and water levels are expected to fall further in the coming days.