Plans from the pre-war period of the First World War envisaged a water supply for the Burtscheid industry through the Kupferbach and Diepenbenden dams.
Although the aforementioned dams were built at the end of the 1920s, the planned pressure pipeline was never routed to Burtscheid due to the turmoil of war.
It is particularly interesting that the water level of the Diepenbenden sub-basin has exactly the same water level as the Kupferbach dam.
The Lower Water Authority has various designs for the construction of the dam dating back to 1913. At that time, the decision was made to build the two dams at the same height and therefore the division and size of the basins for Diepenbenden was chosen so that the water pressure in the pipeline to Burtscheid was the same. At the same time, the larger basin and the smaller basin in Diepenbenden were connected by a pipeline. This made it possible to control both dams at the same time or, if necessary, to control both systems alternately without significant pressure losses for the industry in Burtscheid. This original principle has not changed since the renovation. However, the pipeline to Burtscheid was never built, as technical progress in the form of the steam engine made the construction of the pipeline superfluous.
Today, the Kupferbach dam is mainly used for leisure and recreation. Various measures have been taken to reduce the hazard potential. Among other things, old trees on the upstream embankments of the dams were removed and the reservoir level was lowered above the existing operating outlet.
Following reconstruction of the dam in 2009 and recommissioning in 2010, the dam is operated via a monk-like spillway; the original spillway was decommissioned.
The water is fed in via the (northern) Wurm. In the course of the conversion, the north-eastern arm of the Wurm was renaturalized and led past the lower basin.
In the new concept, the dry weather discharge of the dam is routed via a lateral extraction structure (estimated inflow 7 - 30 l/s in dry weather). The height of the permanent water level target(full water level = Zv) is 228.94 m above sea level; the lower edge of the lateral extraction structure is 228.65 m above sea level. A height-adjustable plate can be used to set different basin levels depending on the inflow. The reservoir targets, which have been reduced compared to the 1930 planning status, are as follows for the
500-year event (= ZH1) at 229.11 m above sea level, for the
HQ5000 (= ZH2) at 229.16 m above sea level.
This does not take into account the possibility of additional relief by enlarging the opening of the gate valves at the foot of the extraction structure. During the rehabilitation measures in 2009/2010, particular emphasis was placed on durability in accordance with DIN 19700, so that it can be assumed that, with regard to the structure and the selected rehabilitation methods, a service life of 55 to 60 years can be expected with appropriate maintenance.