At the Bahnitz location a needle weir built in 1908 was substituted by a two-span water-filled rubber weir. The principal objective of the weir is to ensure a constant upstream water level for shipping use throughout the year. Either span has a flow rate of 3.4m³/s up to 290m³ maximum.

A costs analysis made at an early stage of the planning process showed the economic benefits of a rubber weir as compared with a traditional steel structure. Even taking into account the possible need to replace the bladders every 20 to 30 years, this solution proved to be the more attractive one from the economical viewpoint.