The Triesting is a river of Lower Austria, in the southeastern part of the Vienna Woods. Its drainage basin is 388 km² (150 sq mi).^[2]

The Triesing has a length of 63 km (39 mi). It discharges into the smaller Schwechat at Achau and is part of the catchment area of the River Danube.

• 1846^[3]
• July 1882
• May 1940
• July 1944
• July 1966
• July 1991 (flood wave only in the upper reaches)
• August 1997
• June 2002

The floods of 1944 were the worst ever in the Triesting valley. On 4 July 1944, there were severe floods, following heavy cloudbursts over the upper Triesting valley, in the vicinity of the Schöpfl mountain and in the Further valley. The narrow neck of the valley above Pottenstein was blocked by driftwood and the Fahrafeld Basin turned into a dammed lake. The dam broke and floodwaters up to 2 metres high surged through the valley. In the whole valley 188 people lost their lives, "the majority being foreign workers".^{[4][A 1][3]}