The Waldnaab crosses the urban area of Weiden from north to south.
The so-called flood channel with three weirs and a culvert was built to protect areas originally used for agriculture from flooding.
Due to the poor structural condition of the concrete structures, these were replaced by new buildings as part of the flood protection measures in Weiden:
The Waldnaab used to meander through the urban area of Weiden. Large areas flooded several times a year. In the 1930s, construction of flood protection measures began. A flood channel was built, which had the task of absorbing the floodwaters of the Waldnaab and channeling them harmlessly through pastures. Various structures were erected in order to preserve the old Waldnaab with its hydroelectric power plants and to prevent the water level from dropping. This also includes the Upper and Middle Weir. These ensure that the outflow is divided between the flood canal and the Waldnaab.
Approximately 5-year flood protection for the predominantly agricultural areas was achieved with small embankments. However, this resulted in increasing development, which more and more conquered the valley area and today in some cases reaches directly to the Waldnaab or the flood canal.
On January 26, 1995, downtown Weiden narrowly escaped disaster. The 50-year flood event could only be prevented from greater damage through the massive deployment of auxiliary workers (river management office through to the German armed forces).
From 1995 to 2007, flood protection for a 100-year flood was built in several construction phases for €5.7 million. In 1990, the Free State of Bavaria bought the flood canal and its structures for DM 1. Since then, the Free State of Bavaria, represented by the Weiden Water Management Office, has been responsible for the facilities. (Source: Water Management Office Weiden)