Floods

High water levels and floods occur in a variety of different forms. Lake floods usually persist for a long time and are a danger to buildings because of the effects of the waves. Such long periods can cause considerable damage to buildings through rising damp and buoyant forces. Flooding caused by stream and river floods pose a risk to buildings through the high flow velocities and debris and driftwood that is transported. Surface water flooding usually occurs unexpectedly without warning and is common throughout most of Switzerland.