Every year in spring, the lake level of the Kaunertal reservoir is lowered to provide space for the meltwater. This allows a view of the bottom of the lake, especially where the Fagge river enters; this is where the river’s sediment load is deposited, which it transports from the glaciers, slopes and tributary streams of the catchment area. The emerging delta was surveyed again in June 2019 – in continuation of existing data series – with the help of a laser scanner, which can measure a very large number of points in a short time. Compared to previous surveys and especially to the topography before the dam was built, the sediment volume that has been delivered from the catchment since then can be quantified.