Flood control and individual precautions

Austria is a water-rich and mountainous country. Due to its geographical situation only 38 percent of Austria’s territory is suited as permanent settlement area. In the western, alpine Federal Provinces, this proportion is far lower (e.g. 12 percent in Tyrol).

Settlements have always developed primarily in river valleys and areas. The hydraulic engineering departments have a long tradition of constructing flood protection structures to reduce the flood risks for people and their settlements. Nevertheless, there is no absolute protection against flooding. Residual risks always remain due to possible overloading or failure of protective structures.

Tasks of flood risk management

It is therefore one of the main tasks of flood risk management not only to respond to flood events on a short-term basis, but to plan ahead and develop strategies. In addition to active flood control through the construction of river regulation structures, flood protection dams and retention basins, passive flood control is becoming increasingly important. This includes keeping areas free where flood discharge can be retained and managing river catchment areas carefully. The protection of the water body and the protection from the water body have to be prudently anchored and implemented in modern flood control.

Despite the responsibility of public authorities for flood protection measures, it is the duty of every individual to make provisions for his or her own protection to a reasonable extent.

Personal responsibility starts already when purchasing a specific piece of land.

Even before a planned purchase of land, information about a possible hazard should be obtained from the municipality or the competent departments of the water engineering services. This is the only way to prevent a favourable price or a nice location being obtained with the serious disadvantage of permanent flood danger and possible damage.

The hazard zone maps, the maps of the flood discharge areas as well as the flood hazard and risk maps comprise information on the existing risks. They are available for inspection at the municipal offices, the district administration authorities, the offices of the provincial governments and the regional headquarters of the Forest Engineering Service in Torrent and Avalanche Control or are accessible online. With non-binding consultation and guidance, experts from the Federal Water Engineering Authority and the Torrent and Avalanche Control Service offer valuable support.

Private precautions in building and rehabilitating

When planning new buildings or rehabilitating existing ones it is indispensable to take into account information on potential risks of flooding or high groundwater levels. Construction techniques and materials adapted to the situation and the respective risk levels help reduce potential damage and costs linked to it. Such measures include, for example, doing without cellars in the case of high groundwater levels or appropriate designing of building apertures. Information on locally applied measures and on suitable ways of construction and materials can be obtained from the municipal and provincial building authorities.

Residual risk in spite of flood control

There is no 100 percent protection against flooding. Thus, according to the relevant guidelines, flood protection for residential areas and other high-value-added areas is tailored to a “one-hundred-year flood event”. This is an event which statistically occurs on average once in hundred years. However, as the years 2002 and 2013 along the Danube teach us, this does not mean that 100-year events cannot occur within a few years. In the case of floods exceeding the flood levels used as the calculation basis for flood control installations (“extreme events”), we have to reckon with inundations and damage also in protected areas, “behind the dike”.

Engineering strategies to minimise damage

Flood and high levels of groundwater cause damage on buildings and outside structures due to the flow of water, the pressure exerted by the water, water entering the building, debris and mudflow.

At the building itself or on the piece of land various measures can be taken to protect against damage caused by flood or high-standing groundwater.

• Water-proof and buoyancy-proof basement- tanking solutions for new buildings
• Prevent water backup from sewage system (check valves).
• Water barriers at the plot boundaries, sand bag barrier
• Water-proof closings for windows and doors
• Building materials for walls and ceilings which are water-proof or water insensitive and which have little hollow space
• Transfer heating facilities, current distribution boards and precious furniture to the upper floors.
• Do not use oil heating or fix oil tank against uplift (risk that oil escapes).

Other preventive and protection measures

Each household can plan its individual emergency provisions:

• Keep sand bags, mobile closing components and other equipment available for use, maintain pumps at regular intervals, store supplies.
• Define rules of conduct and distribution of tasks for emergencies and communicate them (neighbours, children, etc.).
• Take out a building insurance against natural disasters and/or floods.
• Observe flood warnings of works organisations, municipalities or provincial services.

The best thing you can do is keep away from areas at risk or leave them rapidly in the case of an event.