Vienna has some streams which may become torrents during and after heavy rainfalls, but most of them are tamed now, as is the Liesing river here:
It was a tiny stream when this shot was taken, but some people already drowned in Liesing river or had a close escape.
Many of these Viennese streams coming down from the hilly area west of the town, the so-called Wienerwald, are even running below earth in canals for quite some distance (as does the Liesing for a few hundred metres) but lately some of these are renaturalised (as is the Liesing further downstream, about five kilometres down from where this shot was taken).
