TheCity Barrage is abarrage inWrocław, Poland, located within theDowntown Water Junction [pl] – Lower Section. It regulates the waters of theOder river, the largest river flowing through the city, specifically on its downtownanabranch that runs through the city center.
The barrage comprises several keyhydrotechnical components, as well as associated buildings and auxiliary structures. The primary components include:[1][2]
In addition to these core water-regulating structures, subsequent investments have resulted in the construction of numerous essential auxiliary and supporting structures. These include the buildings of bothhydroelectric power plants, a bridge at the southern power plant (Access Bridge at the South Hydroelectric Power Plant Complex in Wrocław),wharfs, bank reinforcements above and below the barrage, acanal (City Lock bypass), and others.[1] Within the southern part of the barrage, two small, unnamed islands were formed: one created by the City Lock bypass canal and another partially occupied by the South Power Plant building. Adjacent to the barrage, another investment – thePomeranian Bridges [pl] – was completed, though these bridges are not part of the barrage itself.[1][2]
The current configuration of the City Barrage is the outcome of multiple investments staggered over time, expanding or modifying its scope and functionality. The need for its construction arose initially from river bed erosion caused by the operation of the earlier Piaskowy Barrage upstream.[1] This erosion threatened the stability of the Piaskowy Barrage's structures, prompting the decision to build a downstream barrage to safeguard those constructions and enable the development of new hydroelectric facilities in Wrocław.[1]
| Years | Structure | Event or type of construction |
|---|---|---|
| 1334 | barrage | Start of weir and mill construction |
| 1792–1794 | City Lock | Construction of a wooden lock |
| 1874–1879 | City Lock | Construction of a new masonry lock |
| 1916 | barrage | Start of barrage reconstruction, mill demolition |
| 1921–1924 | South Hydroelectric Power Plant[3] | Construction |
| 1921–1924 | South Power Plant Weir[3] | Construction |
| 1924 | South Hydroelectric Power Plant[3] | Handover to the city |
| 1924–1925 | North Hydroelectric Power Plant[4] | Construction |
| 1926 | North Hydroelectric Power Plant[4] | Handover to the city |
| 1941–1942 | South Power Plant Weir | Reconstruction |
| 1942 | North Power Plant Weir[4] | Construction of a new weir |
| 1959 | South Power Plant Weir[5] | Reconstruction |
| 1959 | barrage[3] | Increase in water retention level |
| 1970 | South Hydroelectric Power Plant[3] | Installation ofKaplan turbines |
| 2003–2005 | City Lock[6] | Renovation |
In thepost-war period in Poland, a standardized naming convention for the barrage's components emerged. The lock is named consistently with the barrage:City Lock.[1] For the two hydroelectric power plants and theirweirs, distinguishing nomenclature varies in literature and publications, with authors interchangeably using eitherRoman numerals (I and II) or positional descriptors: South (I) and North (II). Since the current structures were built when Wrocław was part of Germany, they also had earlier German names.[1]
| Current name | Alternative name | German Name |
|---|---|---|
| Wrocław I Hydroelectric Power Plant[3] | South Hydroelectric Power Plant | Kraftwerk |
| Wrocław I Power Plant Weir[5] | South Power Plant Weir | |
| City Lock[7] | Bürgerwerder-Schleuse | |
| Wrocław II Hydroelectric Power Plant[4] | North Hydroelectric Power Plant | Kraftwerk |
| Wrocław II Power Plant Weir[8] | North Power Plant Weir, Great Dam[1] |
The barrage includes structures situated across two branches of theOder river flowing through the city center: the so-called South Oder and North Oder. Together with numerous smaller branches and canals, these form the Downtown Water Junction, which is divided into:[9]
The section on the South Oder, including the South Power Plant, its weir, and the lock, lies between Kępa Mieszczańska island (north of the lock), part of theNadodrze district, and theOld Town area (south of the power plant). The power plant and weir are downstream (west) of the Southern Pomeranian Bridge, while the lock is upstream (east) of the Middle Pomeranian Bridge.[9] Upstream of the lock, a wharf was built for passenger navigation. The North Oder section, comprising the North Power Plant and its weir, is positioned between Kępa Mieszczańska and the Nadodrze district, slightly upstream (east) of the Northern Pomeranian Bridge. A riversideboulevard runs along theretaining wall here. In 2009, an urbanmarina,Marina Topacz [pl], was established on Kępa Mieszczańska upstream of the barrage on this branch.[9]
The South Power Plant weir is located at kilometer 252.45 of the Oder'scurrent, while the North Power Plant weir is at kilometer 1.2 of the North Oder's current.[9]
Wrocław is situated along a canalized section of the Oder river,[10][11] making the City Barrage one of a series of structures maintaining the required river barrages. The preceding barrage is the Piaskowy Barrage, while the next downstream is the Rędzin Barrage. Within the broader Wrocław Water Junction, parallel (functionally equivalent) structures include the Różanka Barrage on the Main Waterway and, partially, the Psie Pole Barrage – specifically its City Lock – on the Wrocław Urban Waterway.[9]
Although the City Barrage includes achamber lock, the waterway it serves is not classified as an officialinland waterway under Polish law, as per the Council of Ministers' regulation on inland waterways; it is not listed in the regulation's annex ofinland waterways.[12] Nonetheless, the downtown navigation routes have been opened to shipping by the Wrocław Regional Water Management Authority.[12]
The main structures of the barrage maintain the designated water retention level and serve specific functions. Until 1959, the drop was 3.74 m (12.3 ft). Following reconstruction and operational adjustments, the current drop is 5.62 m (18.4 ft).[1]
| Name | Anabranch or canal | Type | Date of construction | Key specifications |
|---|---|---|---|---|
| Wrocław I Hydroelectric Power Plant[2][3] | South Oder – power plant canal | Hydroelectric power plant | 1924 | Installed capacity: 2.4 MW |
| Wrocław I Power Plant Weir[9] | South Oder | Weir | 1924 (rebuilt 1959) | Spans: 6.5 m (21.3 ft) (3 sluices); 22.4 m (73.5 ft) (fixed); 11.0 m (36.1 ft) (4 sluices) |
| City Lock[9] | South Oder – bypass canal | Chamber lock | 1794 (rebuilt 1879, 2000) | Dimensions: 42.8 × 5.3 m (140.4 × 17.4 ft); Gates: Mitre gates |
| Wrocław II Hydroelectric Power Plant[4][13] | North Oder | Hydroelectric power plant | 1925 | Installed capacity: 1 MW |
| Wrocław II Power Plant Weir[9] | North Oder | Weir | 1942 | Spans: 25.7 m (84.3 ft) (flap); 25.7 m (84.3 ft) (flap); 6.5 m (21.3 ft) (sluice) |
The South Power Plant's machine building was designed byMax Berg, in collaboration withLudwig Moshamer [pl] andRichard Konwiarz. It features decorative elements and metalwork crafted byJaroslav Vonka [pl] andRobert Bednorz [pl].[3]
The North Power Plant building was also designed by Max Berg, with decorative metal elements by Jaroslav Vonka.[4]