Measuring the frequency and intensity of floods of the Traun River (Upper Austria), 1441–1574

The city archive of Wels (Upper Austria) has long time series of accounts, written by the bridge master of Wels. This municipal official was responsible for carrying out repairs to the bridge across the Traun River, one of the major tributaries of the Danube River in Austria. The accounts contain detailed information about the expenses for the craftsmen who performed repairs after the floods. These expenses serve as an important measure of the impact of floods on the bridge. In most cases, it is possible to reconstruct the frequency, duration and intensity of floods, and to date them. The accounts on the “disastrous floods” of 1501, 1567, 1569 and 1572 provide a vivid impression of the management of these floods. Comparing the intensity of these floods with data from Bohemia and Germany, it becomes clear that most of the major floods in modern Austria have been merely regional hazards.