The operating regulations of the hydropower plants on River Drau in Carinthia are to be modified. Following evaluation of the findings from the exceptional flooding of the Drau, and their incorporation in the official rules and standards, the hearing is to take place on 6 November 2014, in Klagenfurt, in the presence of the supreme water regulations authority.
VERBUND operates ten hydropower plants on the Drau, the annual production of which supplies more than half of Carinthia’s entire power requirement. For each Drau power plant there exists an officially authorised set of plant regulations, which specifically provide clear operating instructions in the case of flooding. Comparable with a pilot’s checklist, it was also on this basis that the prevailing regulations were implemented in the case of the flooding of 5 November 2012, as is confirmed in the present final report by the supreme water regulation authorities. The final report on the flooding of 2012 is available under www.verbund.com/drauflooding2012.
Within a few hours, the extreme events of November 2012 represented an increase in the water volume in the lower stretch of the Drau, the likes of which was not predicted in any forecast and which had never before been observed. For this reason, VERBUND has been instructed by the supreme water regulations authority to incorporate the resulting findings into modified plant regulations and to present these for approval.
New regulation envisages the lowering of the large reservoirs in the event of corresponding floodwater forecasts
Following comprehensive floodwater simulation, modified plant regulations have been developed during the course of many coordination meetings with the relevant operational bodies in Austria, Carinthia and Slovenia, and presented to the authority. The hearing is to take place this Thursday, 6 November 2014, in Klagenfurt, in the presence of the supreme water regulations authority.
At the heart of the modified plant regulations is a new ruling, whereby – upon presentation of the corresponding runoff prediction – the large reservoirs at the Drau hydropower plants of Rosegg, Feistritz and Edling will be lowered by up to 2.5 metres in good time prior to the anticipated flooding. This targeted pre-lowering can - and should - ensure the avoidance of detrimental effects on the market town of Lavamünd. However, the fundamental prerequisite for the introduction of this floodwater precaution is the existence of a corresponding forecast, which was not available on 5 November 2012.