The Pilchowickie Lake, Pilchowice Dam, Hydroelectric Power Station Pilchowice
WHEN, WHO AND WHY built this picturesquely located, monumental building?
On a memorial located at the dam crest there are dates “1904-1912”. At that time people didn’t know elevators, diggers or loaders of concrete. Therefore, such a significant involvement and financial contribution which were connected with this construction may be considered surprising.
The land where Pilchowice (formerly Mauer) is located belonged to the German Empire.In order to understand the reasons that the German government followed 100 years ago, it is necessary to go back to those times and to get to know several facts from the history.
The Franco – Prussian war, a conflict for domination in Europe, was ended by victory of Prussia and by signing a peace treaty on the 10th of May, 1871 in Frankfurt. This treaty envisaged the loss of Alsace and part of the Lorraine by France and the contribution in the amount of 5 billion francs in gold for the German Empire. This financial provision allowed for the considerable increase of economic investments on the territory of the whole German Empire. A large part of these financial measures was intended for development of the industry.
The 19th century was also the period of a great industrial revolution. Numerous inventions changed the approach of the government to economic development. Industry became the prime tool. Hydroelectricity was also a significant, but not very appreciated nowadays, invention of that period. In fact, it is the river’s current that for centuries has been the main source of energy. The first “factory of electricity” was built in 1882 in Appleton (USA) on the Fox river.
Regular floods in the river basin of the Oder river were something usual. From 1200 to 1800, in that region 64 floods were noted down. In the 19th century floods took place in the years 1804, 1845, 1856 and 1888. During the last flood, the water level on the Bóbr was as high as 4.8 m. The huge losses caused by regular floods in the whole basin of the Oder and the rapid development of the industry made the contemporary government formulate and implement plans connected with countering effects of the floods at the same time using the energy carried by water to ensure faster economic development. Great flood which took place in 1897 was the crucial event that caused huge losses in economy. A person responsible for preparing those plans was professor Otto Adolf Ludwig Intze. He formulated not only a wide-action plan of building dams, but he also took part in designing particular objects. In practice, these projects had a very broad application. The most important elements include: reduction of the flood wave and production of electric energy (so important at that time). Development of tourism in that region was supposed to be an additional benefit.
The first building built in the Oder basin was a dam in Leśna. Construction works began in September 1901 and the first reservoir filling took place after four years. A power station with capacity of 2610kW was put into use in 1908. The Royal Inspector of Hydraulic Engineering, D.E. Curt Bachmann, was the main builder. He was also in charge of the second construction located in Pilchowice (formerly Mauer Am Bober).
- On the 3rd of July, 1900, a decision about building a dam in Pilchowice was made. Its main designers were professor Otto Intze and D.E. Curt Bachmann.
- In 1902 first works preparing the grounds for building a dam began.
- At the beginning of 1904 works on the side channel started.
- On the 10th of June, 1906, works at the foundation trench were undertaken (90.000 m3 of soil and 84.000 m3 of rocks were extracted).
- On the 20th of June, 1908, a ceremonial foundation of a cornerstone and groundbreaking plaque took place.
- Three floods which hit Pilchowice during the conducted works (in 1906, 8 August1908 and 2 September 1909) not only delayed the whole construction but also caused changes in the project. At the beginning, the dam was supposed to be made only in stone, but then it was strengthened with concrete.
- In 1911 a construction of the dam wall with the volume of 275.000m3 was completed.
- In Spring 1912 all finishing works on the dam were completed.
- On the 12th of November ,1912 the official opening of the dam in Pilchowice took place. It was made by the Emperor Wilhelm II Hohenzollern.
- In February 1913 the dam was commissioned.
In March 1913 hydro-electric power station was commissioned.
- The cost of purchasing the land was 2,400,000 marks and the cost of building the dam was 5,900,000
- The total amount is 8,300,000 marks.
- The biggest water reservoir in the Western Sudety Mountains.
- Depth next to the dam – about 46 m.
- Surface of the water- 240 ha.
- Length of the lake – 6 km, width – 2 km.
Capacity 50.000.000 m3
- The second-oldest and the second-highest dam in Poland.
- Arch dam, made of stone and concrete.
- Height of the dam – 62m.
- Length of the dam crest – 290m, foot length – 140m.
- Wall thickness of the dam crest - 7,2; base thickness – 50,3m.
- In the late twenties, the reconstruction was carried out and the surface spillway in the shape of a ramp was replaced with staircase rapids.
- 87-metre surface spillway.
- Circular gallery, length – 383m, 3 valves Φ 1500 mm each.
- Two triggers 1500mm in diameter.
Pilchowice Hydroelectric Power Plant I:
- Located in a big, building made of stone and situated at the foot of the dam. Put into use in March 1931. The construction costs of the power plant amounted to 747.585.66 marks. Initially, the design projected installing only 4 generators, each of them with the power of 1,24 MW. However, after finishing the construction, changes to the project were introduced and the fifth generator was added. In 1921 the sixth one was installed, which increased the productivity of the power plant. Until today, energy production takes place with the use of 6 hydro units of Francis system by J.M. Voith company (5 from 1911 and 1 from 1921) and 6 generators (4 synchronous, produced in 1911 by Siemens Schuckert Werke and AEG, as well as 1 from 1951 of Polish production). The power plant is qualified as big, its power is 7,585 MW.
- In the years 2012 -2014, TAURON Ecoenergy LCC will carry a thorough modernization of the power plant in its structural, mechanical and electrical parts. In other words, historic generators will be replaced by modern, more efficient devices. Installed capacity of the power plant will increase by nearly 6MW. After the reconstruction, one turbine unit will be displayed in the machine hall- as a historical exhibit.
After opening of a hydroelectric dam in Pilchowice, city chronicles mentioned:
”…from now, every year’s flooding nightmare will stop oppressing Wleń and villages situated by the river Bóbr’’.
Unfortunately, Bóbr didn’t allow people to forget about itself. As a result of the first big flood which took place on the 5 -7th of July, 1915, it comes to flooding. Other floods were mentioned on the 17th of June, 1926, and in 1930 and 1938. The first big flood in the post-war history of Wleń came between 5th - 7th of July 1958. At that time water in the city centre reached around 1,5 meter. The 1977 flood inflicted very big losses. Water slopped over the dam crest. Within few minutes the flood wave got through Wleń, water at the main square reached up to 2 meters. The army evacuated most of the citizens. Another flood was noted down on the 21st – 22nd of July, 1981. It was much less harmful than the previous one. However, the biggest flood came in 1997. Two flood waves: 5th-8th and 18th -19th of July of the same year caused a next water slope over a dam crest. 162 people were evacuated from Wleń then. The 1997 flood is called the flood of the century. Next flood waves took place in 2001 and in August 2006.
In the course of 100 years history of the water reservoir, maintenance works were conducted four times. The dam was drained in 1932, 1959, 1975 and 1978. The maintenance works and draining of the dam were planned for 2009 too, but they were postponed. At the turn of 1957 – 1958, a repair of the circulating drift took place. After the flood from 1997, large-scale measurement works were held at the dam and new joints were installed. In 1999, a repair of the transfer and cascades was completed.
Today, the hydroelectric power plant still produces ecological electric energy. The dam stops flood wave and Pilchowickie Lake performs a recreational function. Throughout the whole year it is possible to meet anglers here and there is a sailing harbor and a small cruiser at tourists' disposal in the summer season. (Proposal for holidays).
On the 17th-19th of August, 2012, a celebration of "100 years of a dam in Pilchowice" took place. There were exhibitions, talks, picnics, company TAURON Ekoenergia made the power station available for touring. An occasional plaque at the dam crest was also installed.
Pilchowice hydro-electric power station II:
Constant increase of the demand for the electric energy forced contemporary authorities to the design and construct small factories, serving exclusively for generating the electricity. "Pilchowice II " is such a power station. This name is a little bit erroneous today, because the object is located in Nielestno village, in front of the railway station. Opening of the power station took place on the 13th of October, 1927. The power station is fed with water flowing through a 1396 meters long derivative channel. Three units of Francis system by the J.M. Voith company from 1927 and three synchronous generators produced by the AEG also from 1927 were used here to produce the energy. The total power of the power plant is 0,824 MW.
On the 20th of November, 2000, a provincial monument conservation officer in Wrocław made a decision concerning entering into the register of movable monuments the wealth of material culture including: Hydro-units 1, 2, 3 – 1927 year from the hydro-electric power station "Pilchowice II" and hydro-units 1,2,3,4,5,6 - years 1911 and 1921 from hydro-electric power station " Pilchowice I". In justifying this decisions we can read among others that:
Hydro-units, as industrial monuments connected with important stages of the technological progress, with significant structural and historical value, are precious cultural assets (...)