Due to the new technical findings gleaned from the flooding of 2013, modifications to the weir operating regulations have been planned with the agreement of the responsible authorities. Therefore, in the case of flooding, the following measures have been foreseen: limit values have been introduced for the maintenance of the water level heights, the new regulation of maximum speed of the drop-rate of the water, changes to the regulations regarding the sluice release and the extension of the duty to notify any deviations from the weir operating regulations.
The "weir operating regulation" for the Danube power plant is like a set of working instructions for operation, comparable to a check list for airplane pilots. Following every extreme flooding, such as the one in 2013, valid rules are elaborated upon by a group of experts made up of members of the responsible ministry, which is evaluated by donau and VERBUND in order to bring about possible adjustments and improvements.
Such adjustments should be specified following extensive assessment right now within the framework of an approval procedure for the Danube power plants of Wallsee-Mitterkirchen, Abwinden-Asten, Ottensheim-Wilhering and Aschach. The procedure will be headed by the Department IV in the Federal Minstry for Agriculture and Forestry, Environment and Water Management, which is the acting responsible water authority. Due to the large amount of participants, a so-called "edict proceeding" was chosen, the participants will be addressed via articles in daily newspapers and not individually informed.
Adjustments in the Form of Practical Limit Values
Seeing as it is not possible technically to exactly control the water level height centimetre by centimetre in the back water areas due to the sluggish response of changing levels in the modification of the upstream water level, explicit limit values from now on should be determined in order to maintain the water level height.
Moreover, corresponding to the technical possibilities of the control system, the maximum speed of the drop-rate for the power plants should be determined. When opening the lock system for the release of flood waters, the principle of equal flow distribution over the weir fields should be explicitly suspended in the short-term and a temporary abandonment of the given limit for the upstream water level allowed.
The project documents for the foreseen adjustments are available starting on 26 September until 7 November 2014 at the district authorities in Eferding, the Urfahr surroundings, Perg, Linz-Land, Grieskirchen, Schärding, Amstetten and Rohrbach, at the magistrates of the city of Linz as well as the Federal Ministry for Agriculture and Forestry, Environment and Water Management (1010 Vienna, Stubenring 12, 3rd Floor, Room 311) during the respective opening hours for the public and will also be published on www.verbund.com/donauhochwasser2013.
An oral negotiation will take place on Friday, 14 November 2014, starting at 10am in the Congress room in the Design Centre in Linz, Europaplatz 1, 4020 Linz.