Spree Weir Niedergurig

The old guard blocked the Spree over 12 meters with three single shooters of unequal width. The movable lock height was 1.20 m, the wooden ones
Rifle boards were operated with racks and separate crank drives.
The movable locks sat on a fixed weir threshold about 1.80 m
above the bottom of the underwater course. The base height difference was determined by a steep waste floor attached with natural stone, starting at the tree
of the weir dismantled.
The last inventory from 1976 still showed a 7-field semolina weir
with a stone timber tree, wooden semolina stands and double rifle boards. the
Semolina leaned against a steel top tree that holds the total strength
each derived from a side support frame made of natural stone.
After 1976 the semolina racks were removed. The supporting structure
however, it was not changed. The entire movable weir supported itself up to
at the end alone on the two free-standing natural stone posts.
Originally built to operate a water mill, the weir is also used
its controllable accumulation operation today the maintenance of the water management and ecological requirements at the site:
- Water distribution for needs-based management of flowing and
Standing waters
- Preservation of the natural facilities in a sensitive environment protected by nature conservation law
- Securing flood protection
- Bed stabilization in the river section above up to the dam
Due to the erosion of bed load by the Bautzen dam, the
unusually no debris piled up in front of the Spree weir. It came
rather, it leads to the formation of pools, as the river lacks any debris.
After the old weir was demolished, the new building was full within one
built around the construction pit. For this purpose, the Spree was diverted past the construction site on the right via a flood channel. Immediately after the start of the
Construction project, the August flood in 2010 flooded the construction site area.
The associated interruption in the construction process and the sharp rise
Groundwater levels prompted those involved to change the design
the foundation compared to the original plan.
A closed dewatering was dispensed with. Instead, decided
one opts for the installation of the sub-concrete layer using underwater concrete. By
Dredging and the use of industrial divers dug the construction pit, prepared the bottom and plumbed it down to the planned final depth. on
A large area of soil was replaced on a construction pit area of around 500 m² by installing the sub-concrete layer with a thickness of 1.90 m.

The fish passage is arranged as a separate structure to the right of the weir.
Two layers of separating film are installed between the right weir cheek and the left fish pass wall. Expansion joint tapes seal the planned joint above and below the water. The pool slot pass is around 31.60 m long and
contains a total of 14 basins. In the continuous slots, the difference in water level is gently reduced and enables the aquatic fauna
the upward and downward migration
Source: izw.baw.de/publikationen/dresdner-wasserbauliche-mitteilungen/0/Regel_Ersatzneubau%20Spreewehr%20in%20Niedergurig.pdf

The new construction of the Spree weir in Niedergurig was completed in September 2011 and the weir system is now technically state-of-the-art. This made it possible to improve flood protection for Niedergurig and the ecological condition of the Spree. The old weir was beyond repair and therefore had to be demolished. The new building was built on the same site. In order to further improve the continuity of the Spree for fish and other aquatic life, a fish ladder was also built.