The surge flushing process involves temporarily backing up sewage or fresh water upstream from the section to be cleaned using specially developed flushing tanks or flushing manholes (figure). When the backed up flow volume is sufficient, the permanent or temporary flushing devices are activated and the flushing gates are abruptly opened. The wave front that is formed by the abrupt release of water stirs up the unconsolidated deposits and transports them further downstream. Usually, the removed deposits and agglomerations remain in the drain and sewer system [DIN EN 14654-1].