Lab experiment Ferchenbach

The flood event in Garmisch-Partenkirchen on 12 June 2018 caused considerable damage in the Partnachklamm gorge and the municipal area. The reason for this was a heavy precipitation event, which led to strong bedload and wildwood drift from the orographic right tributary - the Ferchenbach. This led to impoundments in the Partnach gorge and at the weirs in the municipal area downstream of the gorge. The high wildwood load during the event of about 1,000 m³ is due to the dominant Raibler and Partnach layers in the catchment area of the Ferchenbach. Large erosion areas and landslides repeatedly occurred along about 6 km of channel length and consequently the trees growing on the slopes were carried in. This circumstance can repeatedly lead to problems due to the narrowing of the cross-section in the gorge and at the subsequent weirs. In order to avoid such events in the future, a solution is to be found for this problem. The planned measure is a wildwood rake in the area where the river Partnach flows into the gorge, in order to achieve an effective filtering of the wildwood in front of the gorge and the weirs in the lower reaches, in order to avoid endangering people and flooding in the area of the weirs. Due to the novel design of a bag-shaped wildwood rake in the bypass and the associated lack of experience, the investigation of the functionality by means of a hydraulic model lends itself.