Detailed view for Bahnitz

Concerned RiverHavel
TypeInflatable, water filled
Short Description

Bahnitz weir is located on the Havel River, in Germany, and was built between 2005 and 2009.

It is a water-filled inflatable dam and it is composed of 2 spans of 30.3 meters each.

Main characteristics
Water Head (m)0.31
Upstream height (m)27.99
Downstream height (m)27.68
Discharge (m/s)3.4-290
Total length (m)73
Number of spans & dimensions

2 spans of 36.5 meters each

Weir height (m)2.45
Progress statusCompleted
Date of completion10/15/2009

Federal Republic of Germany


German Waterway administration

Design group

Floecksmühle, Aachen, Germany


Müsing, Bernau, Germany

Cost estimation7,300,000 euros


PIANC References for this project

In progress


The Bahnitz weir is located on the Havel River and is located near one of its confluent : the Elbe-Havel Canal which is very important for navigation. In Bahnitz was an old needle dam built between 1908 and 1911. This latter was obsolete and non satisfactory in terms of stability. That is why it was decided in 1993 to build a new structure.

Its mains goals would be the improvement on draining and navigation conditions. Due to low construction and maintenance costs and simple technical operability, the choice was a water-filled inflatable dam.

A this place, the amount of sediments is quite low, but ice loads have to be taken into account.

An automatic system measures the pressure in the membrane and the water level and can then adjust the settings. Aerators are installed at the top of the membrane to avoid vibration phenomena. A PE backing is also used to protect the membrane from sediments when deflated.

As said before, the ice load had to be taken into account. To avoir any problems, several solutions were found :

  • When the temperature is below +5°C, the cold water is removed from the membrane and replaced by warmer water heated in the tank (used to inflate and deflate the membrane) located next to the dam.
  • When the temperature drops below -5°C, it is supposed that the membrane is overflowed and is protected by a water coating.

The maintenance is quite easy. A simple check is done during 2 days every 8 weeks. A deep checkup has to be done every 6 years.

Regarding the design, there is no codes for inflatable dams in Germany. The designers used Japanese Standards. The expected lifetime is 30 years for the membrane and 15 years for the electromechanic equipment.

Documents to download
  • 108- PReview WG166- Bahnitz Weir.pdf - 108- PReview WG166- Bahnitz Weir.pdf