Author(s): H. Haufe; H. -B. Horlacher; J. Stamm
Linked Author(s): Jürgen Stamm
Keywords: No Keywords
Abstract: In the 19th and 20th century safe drinking and industrial water supply and flood protection issues were the main reasons for the construction of dams in the Ore Mountains of Saxony (Germany). Due to these still existing multi-purpose requirements Saxon dams today are in the centre of various conflicts of interests. These conflicts are particularly visible during extreme floods as those which occurred in the past. In August 2002 strong precipitation led to the excess of the spillway design flood at numerous dams. The combination of extremely high reservoir inflows, limited outlet works capacities and short lead times inevitably led to the rapid filling of the flood control space. Spillways started operation and created flooding along the rivers downstream with partial catastrophic effects. Rising reservoir levels endangered the dam crests fortunately not affecting dam safety. Since 2002 flood storage capacities were increased to reduce critical situations in future flood events. According to new hydrological predictions rising reservoir inflows and the effect of the ongoing climate change must be considered. Efficient reservoir operation strategies require modern outlet works at the existing dams. Extensive reservoir routing calculations show that flood protection effects of dams can be optimised by using additional outlets which allow the release of significant discharges right at the beginning of the flood or even before. The paper will focus on these complex issues, considering both hydrological and structural aspects and will present first results and recommendations for adequate reservoir operation during extreme floods and dam modernisation in the 21st century.
Year: 2010