A spring cleaning was now needed at Sylvensteinsee. The bank and also the water were cleared of driftwood.
During floods, the tributaries bring a lot of wood into the reservoir. There is a chain of trees on which the flotsam gets stuck and is pulled ashore by the employees of the Weilheim Water Management Office. The campaign in this form is necessary every few years, says Tobias Lang, who is responsible for the reservoir at the water management office. The wood is not removed for aesthetic reasons. It is removed for flood safety and to prevent damage to the bottom drain and headrace tunnel or the associated systems. During the last major flood in 2013, 2,200 cubic meters of material were removed. But of course that is nothing compared to the amounts of gravel that have to be converted every year because the reservoir interrupts the natural transport of gravel. Around 80,000 cubic metres of gravel are removed every year, says Lang. “And on average it’s 700 to 750 cubicmeter of wood.”