Hydroelectric dams in the Sudetenland until 1945 – a history that still protects us

Dr. Przemyslaw Dominas, a historian and researcher who was the first to reach previously unpublished archival documents, tells the story of how Prussia built Europe’s most modern flood protection system after the 1897 flood – with the Emperor’s political support, personnel compromises and an innovative program ahead of the era. What did he discover in the secret files? Who really decided to build the largest dam in Europe at the time? And why does this story turn out to be surprisingly relevant today?

Agnieszka Hobot: In your book Dams in the Sudetenland until 1945, you describe one of the most ambitious turn-of-the-century hydrotechnical projects. What, in your opinion, was truly groundbreaking about it after the disastrous flood of 1897?

Przemysław Dominas: First of all, it should be emphasized that until the beginning of the 20th century, no flood control program of this scale had been implemented anywhere in Europe. Yes, dams had been built for centuries, already in antiquity, and in modern Europe since the 16th century in Spain, among others, or since the end of the 19th century in Scandinavia, where the terrain was favorable for hydropower investments. However, there has never been a comprehensive, systemic flood protection program that has been implemented simultaneously in many places, with specific funding and institutional facilities.

This is what happened after the disastrous 1897 flood in Silesia. Prussia – as the first country in Europe – enacted a special law and allocated nearly 40 million marks for the program, although the cost eventually reached about 70 million. This was an absolute precedent on a European scale.

It is worth mentioning that similar plans had previously existed – for example, in the Loire Valley in France under Napoleon III in the second half of the 19th century. Despite the projects prepared, they were eventually abandoned. In Prussia, on the other hand, full implementation took place. Interestingly, the key impetus for action was … emotional.

As the flood wave swept through Silesia, Kaiser Wilhelm II visited the region and met with the provincial superintendent, Prince Hermann Hatzfeld. The Emperor asked him directly: what do you intend to do now? Hatzfeld replied: If I had the means, I could start acting. To which Wilhelm II: Then build dams. And so the decision was made to implement the grand program. Political, emotional – but very effective.

A well-known hydrotechnician and hydrologist Prof. Otto Intze – considered an authority in Europe and even the world at the time – joined the work. It was he who developed the concept for the construction of the dam system, determined the locations and defined the principles of operation of the entire flood control system in Silesia. On the other hand, the contractors of the individual structures were already other engineers.

Were the technologies used in Prussia innovative? In engineering terms – not necessarily. The Germans began building dams on a large scale only in the 1890s. Other countries had already built larger and more substantial and impressive dams before that. The Aswan Dam on the Nile, for example, had a volume in excess of a billion^{cubic meters} in the early 20th century. By comparison – the reservoir of the largest of the Prussian dams in Pilchowice held 50 million cubic meters. In the United States, the New-Croton Dam supplying New York City with drinking water reached 90 m in height from the base of the foundation – much more than the Pilchowice Dam (about 62 m). The Germans, while building the Pilchowice Dam, in some aspects modeled themselves on the above-mentioned solutions from Egypt and the USA.

The novelty of the Prussian program was therefore not in the technology itself, but in the comprehensiveness of the approach, the scale of the measures and the consistency of implementation. This was the first fully implemented systemic flood protection program in Europe.

The quality of workmanship is also noteworthy. Although the dams were erected according to the technology in force at the time – mainly of broken stone, using chisels and half-timbering, on cement mortar with trass – they were made with remarkable solidity. And it is this durability that is their greatest asset today.

A.H.: So I understand that the uniqueness of this program was primarily in its scale?

P.D.: That’s exactly right. The key element was the scale of the project and the fact that the whole thing was framed by the Flood Control Act of 1900, dedicated exclusively to Silesia. This was a rarity – in the entire German Empire, no other province received such a comprehensive, statutorily regulated flood protection program. Silesia was an absolute exception in this regard.

Why Silesia in particular? The reason was very specific: the terrain. The layout of the mountain ranges – the Sudetes and the Foothills – created a natural barrier for air masses, which favored the occurrence of extremely intense precipitation. The result? Rapidly rising tidal waves that regularly caused catastrophic floods in the then relatively small area of the Silesian province (about 40,000 sq. m.). Nevertheless, more than 20 large damming structures – dry flood control and retention reservoirs – were built in the Sudetenland region between 1903 and 1933. This is very impressive, especially compared to other regions.

Imagine – in the area of Galicia, within the borders of present-day Poland, in the then Austro-Hungarian monarchy, not a single dam was built before World War I, although the problem of river regulation was addressed.

It was not until the 1930s, already in the Second Republic, that the first large hydrotechnical structures were completed there (e.g. Wapienica, Porąbka).

This shows what a huge difference there was between the two regions in terms of their approach to water management. Of course, it must also be acknowledged that Prussia at that time was already a wealthy state. In the mid-19th century, when there were catastrophic floods, they could not yet afford such huge investments – by their own admission. But by the end of the 19th century the situation had changed. They had the means and were able to use them – with great determination and consistency.

Let me cite an example from the Silesian press of the time, which illustrates well the effect of the program. During one of the great floods, that of 1888, the water under the railroad bridge in Jelenia Góra – near today’s Krzywousty Hill – reached more than 5 meters. During the 1897 disaster, the tide was even higher – as high as 7.2 meters at water gauges.

After the implementation of the flood control program, with similar precipitation, the surge in the same section was lowered by as much as about 4 meters, although it must be admitted that all the mentioned surges had different scales and flow dynamics. This is a huge difference and proves that the planned measures had a real, measurable effect. Of course, it was not possible to protect the entire region one hundred percent – that would have required investment on an even larger scale. But that was not the goal of the program. The goal was to significantly reduce the effects of the floods – and this was achieved.

A.H.: Which structures would you consider the most important from the point of view of flood protection? And which of them have survived to this day?

P.D.: They have all survived – and in relatively good technical condition. What’s more, they are still effectively performing their function of protection against flooding, which in itself testifies to their quality. But if I were to point to one symbolic structure, the most important before World War I, it would undoubtedly be the Pilchowice Dam on the Beaver River, near Jelenia Góra.

It was the largest dam of its kind in Europe at the time of construction. In terms of reservoir volume – 50 million^m3 – it was the leader. Its body measures 62 meters in height from the base of the foundation, and, according to sources, even 69 meters from the lowest point of foundation in the ground. These are concrete, impressive numbers.

The importance of this dam was special because it was in Jelenia Góra that the waters from several mountain rivers were concentrated: primarily the Beaver, but also the very dangerous Lomnica with a steep drop in its source section, flowing directly from the Karkonosze, the Kamienna River and a number of smaller streams. Although the Pilchowice River was supported during floods by dams in Mysłakowice, Sobieszów and Cieplice Śląskie Zdrój, the Pilchowice dam was crucial for protection further downstream on the Bober. The cumulative flow caused a flood hazard that could not be effectively controlled without large-scale retention.

The opening of the Pilchowice dam was a big event – Kaiser Wilhelm II himself came. Anyway, from the beginning he was very interested in the whole flood control program, and Pilchowice was its crowning achievement.

The construction was led by Curt Bachmann – an engineer who gained great recognition in the hydro-engineering community thanks to this investment. The Pilchowice Dam, along with the Forest Dam on the Kwisa River, formed the basic backbone of the flood control system in this part of the Sudetenland. Lesna had a smaller capacity – about 15 million m³ – but was also a heavy and strategically important dam. In addition, it had unusual technical solutions, for which the builders received a silver medal at the 1904 Saint Louis World Exhibition.

It is also worth mentioning the scale of the project in Pilchowice. Up to 1,400 people worked there at one time. Modern technologies were used – among other things, most of the machinery had an electric drive, which was not yet common in those days (1902-1912). The entire construction process is perfectly documented today: we know how many workers were hired, where they came from, how much they were paid.

The construction of the circulation adit, for example, involved miners specializing in tunneling, brought in from areas of Tyrol with mining traditions. This was not improvisation – it was an engineering operation at the highest level of the time.

A.H.: You used both Polish and German materials. During your search, did you come across any previously unknown sources that shed new light on these investments? On the buildings, which, after all, still exist and still perform their functions.

P.D.: Yes, indeed. As part of my search, I reviewed about 80 volumes of files in the State Archives in Wroclaw and another 20 volumes of files in the Berlin archives. I also worked with professional and regional press from the turn of the 20th century. As a historian, I try to rely exclusively on source research. Anyway, there was a significant research niche in this dimension, as no serious, scholarly monograph on dams in Silesia had been written to date. And indeed this niche I tried to fill to some extent.

And in terms of curiosities, I came across a number of very interesting documents that have not been published before. For example – a letter I found from the aforementioned Prince von Hatzfeld, then superintendent of the Silesian province. There he writes how the hiring of Curt Bachmann, the chief builder of the Pilchowice dam, came about.

Formally, the project was to be subordinate to the Oder Regulatory Authority in Wroclaw, but Otto Intze refused to be subordinate to the Authority because, according to documents, its director had previously pointed out an error in one of its projects, delaying its implementation by nearly three quarters. Intze vehemently distanced himself from his subordination to the Oder Regulatory Authority in Wroclaw, so it was contrived at the Ministry that technical supervision would be assumed by an independent engineer – precisely Bachmann – who would report directly not to the Oder Regulatory Authority, but to the national starost of Silesia. And so he was hired, outside the official structure, as it were. This shows that even in a system as orderly as Prussia’s, personnel compromises played a big role.

Another example – the act of opening the Pilchowice Dam. It was the largest dam in Europe at the time, and the decision that the ceremony should take place with Kaiser Wilhelm II in attendance was made by… the Imperial Cabinet(Das Geheime Zivilkabinett). There is a whole volume of files that were kept secret at the time – today they are naturally made available. The documents show that the Kaiser’s participation depended on his schedule – a hunting trip to Moszna in the Opole region. In the end, Wilhelm II came, as confirmed by numerous accounts, photos, including his tour of the dam with Bachmann.

The ceremony was prepared with great panache. In Jelenia Gora, 12 thousand people awaited the Emperor. Hundreds of people came to Pilchowice, including important figures of the imperial court and governmental spheres from Berlin. On the day of the ceremony, the dam was not yet finished – the reservoir was empty, the bottom drains and power plant feed lines were not ready – but court protocol stipulated all the details anyway: who would introduce whom, who could speak, and who could only answer the emperor’s questions. For example, engineer Bachmann was not allowed to speak to the emperor on his own – only to answer questions.

The Kaiser was particularly interested in the hydroelectric power plant used there. A photo has survived that shows Bachmann and Wilhelm II talking just near it – it was published in the presented book.

A.H.: And is there any inspiration for today’s decision-makers from this story, from the whole process of building dams in Silesia as described?

P.D.: Definitely yes. For me, the greatest source of inspiration is the consistency with which Prussia pursued this program – even during the interwar crisis. There were economic crises in Poland, Germany, all over Europe and the world between the wars, and yet construction continued with iron determination. The quality of workmanship was very high, and no half-measures were sought – they built solidly and with flair.

I also don’t entirely agree that today’s floods are different. Sure, they have different dynamics and course, but the frequency is very similar. In the book, I cite calculations that show that a major flood occurs on average once a decade – this was the case in the 19th century and is still the case today. Please trace: 1997, 2010, 2024, local climaxes in between – this pattern repeats itself.

The fact that today the effects of flooding are relatively less is due in part to these dams. They have not disappeared – they still perform their functions today. Of course, one can argue about the details – hydrologists and hydrotechnicians may have different opinions – but one thing is certain: if these structures were not there, the losses would be much greater.

Speaking of flood losses, it should also be remembered that their generation, both then and today, is due to the process of bringing developments closer to dangerous watercourses. This is the main cause of many of today’s problems. But that’s another story.

Przemysław Dominas – historian specializing in the history of technology, especially the history of railroads, transport engineering of the 19th and 20th centuries and hydraulic engineering. Graduate of the University of Wroclaw and holder of a doctorate in humanities from the University of Opole. Author of several scientific monographs, including Railway Bridges in Silesia until 1945, Railway Tunnels in Poland until 1945 and Water Dams in the Sudetenland until 1945, as well as numerous scientific articles published in Poland and abroad.