Here’s an image taken at the shore of river Gail near Villach. It’s a detail from a water level. River Gail is notorious for high water, because it runs along the mountain chain on the border to Italy. Moist mediterranean air coming up from northern Italy’s flats encounters the first alpine barrier at that chain, and as the valley runs from west to east, heavy rains always contribute to the river along its full length, making waters rise fast.
Fortunately after the catastrophic high water of 1966, levies and hydroelectric power plants were built. So far they’ve held and the river seems to have been tamed.