This data set provides digitised daily water-level series reconstructed from nineteenth-century archival charts for three Bavarian Danube gauges (Neu-Ulm, Vilshofen, Passau), overall 75,395 data points, covering the years 1826 to 1894 completely. The original sources are hand-drawn annual water-level charts preserved in the Bavarian State Archives. We convert these analogue records into machine-readable series using a documented computer-vision workflow, complemented by manual quality control and method tracking. For further details, read the data_descriptor.pdf included.