The Oder Doesn’t Meander Anymore

During trip along the Oder, one of the locals told us that to the people who live there, the history of the region only started after 1945. It is crucial to recreate it; the historical perspective should change the residents’ approach to these areas and help them identify with the river. 

Joanna Wiśniowska: How does one shorten a river by 200 kilometres?

Andrzej Woźnica: By 160 kilometres, to be more precise. The Oder used to be one thousand kilometres long, and now it’s above 850. And how do you do it? In its initial state, a river meanders, so you cut through the bends, connecting the pieces of the riverbed to make one straight line.

J.W.: Even the 160 kilometres sounds quite impressive.

A.W.: Yes, although it is hard to establish how much of its length the Oder lost over the years. Those numbers are just estimates, as the whole process took about two centuries.

J.W.: Why do people shorten rivers?

A.W.: To speed up freight transport to the sea. For centuries, the Oder has been a navigable waterway, a transportation channel. For such purposes, straightening the river’s meanders is not enough. Shallows and depths also had to be levelled to get the most out of the waterway.

J.W.: So it was tailored to human needs?

A.W.: Yes. You could say it has been harnessed.

J.W.: What does a healthy river, not a water‑filled transit route, look like?

A.W.: A river flows. And as it flows, it meanders. This can be observed on orthophotographs as they clearly show traces of river movement, such as oxbow lakes, as we call remnants of old river channels. The number of meandering rivers in Poland is diminishing. The Vistula is said to be Europe’s last wild river but just like the Oder, it is now contained by canals, its banks bound by groynes: hydrotechnical structures designed to interrupt the river’s meandering.

J.W.: What is the purpose of meandering? What does it do?

A.W.: It’s a consequence of a river’s dynamic. The current makes the river wash away its banks on the one side while bringing sand and silt on the other, creating a new shore.

J.W.: What role do rivers play in nature?

A.W.: Their main function is to carry rainwater to the sea. We could also say they provide us with “ecosystem services” of sorts, contributing to our overall well‑being. They provide water for drinking, they irrigate our fields, make habitats for fish, and enable plant growth. Without water, there is no life. And rivers are water reservoirs.

It’s important to consider their historical role, too. Water was the fundamental factor in the process of civilisational development. People would settle near lakes and rivers. Unlike lakes, however, water in rivers was constantly changing and replenishing. And so, cities were built over rivers: Kraków and Sandomierz by the Vistula, Poznań by the Warta, Wrocław and Głogów by the Oder.

J.W.: How important was the Oder to the region it flows through?

A.W.: Without the Oder, there would be no Silesia. Racibórz, Brzeg, Opole, Wrocław, or Głogów are just a few of the many important cities and towns that emerged along this river. The Oder’s historical importance for the local population is further proved by the first water protection laws that the bishops of Wrocław promulgated in Nysa. Those laws were meant to protect the Oder from contamination.

J.W.: Was the decision to harness the Oder for profit made during the time of the industrial revolution?

A.W.: Without a doubt, the river’s history is strongly connected to the industrialisation of Silesia. However, since the Middle Ages, trade between the Oder cities made it logical to use the river as a communication artery. The trade’s intensity increased quite significantly along with the industrial leap in the early 19th century.

J.W.: Is it possible to describe the Oder by dividing it into sections?

A.W.: Yes, it could be divided into four major sections. The first one is the upper Oder, a mountain river that emerges from a spring in the Sudetes on the Czech side and stretches for about a hundred kilometres, crossing the Polish border in Chałupki only to keep on going until it reaches Kędzierzyn‑Koźle. This section includes the flood‑protection reservoir in Racibórz.

A.W.: The next section is the channelised Oder, about two hundred kilometres long and intersected by twenty‑five weirs and locks. This part stretches from Kędzierzyn‑Koźle to Malczyce. It flows through a number of towns and cities, including Opole, Brzeg, and Wrocław. While navigating this section, we are essentially travelling over a cascade of reservoirs we can cross using locks. As we move downstream, the water level goes down at each lock. The first such lock on the Oder waterway route was built in the early 19th century in Kędzierzyn‑Koźle, and the last one just a few years ago in Malczyce.

A.W.: Once it passes Malczyce, the Oder turns into a free‑flowing river. It is a gorgeous part of the river, and I strongly recommend kayaking trips there. It’s a rich habitat for many birds of prey, including the white‑tailed eagle and red kites that feed on fish. There are numerous groynes in this section. These are human‑built structures that narrow the river down, making the current flow through the middle instead of meandering.

A.W.: The shortening of the Oder causes more floods. The river cannot hold as much water as it used to, and flood banks make the naturally occurring reduction of a flood wave no longer possible. It’s also worth mentioning that we often confuse high water levels with a flood. The former is a natural rise of water level in a river due to more water in the drainage area, as a result of rainfall, for example. The latter means the rise of water that causes material damage. And as we built houses and industrial structures in flood‑prone areas, we had to protect them by building flood embankments. Because of our actions, every large water level rise can be a threat to such areas.

J.W.: And what’s the next section?

A.W.: The next section is the border‑area Oder, controlled by groynes as well. This section also deserves more recognition in tourism. It starts at the mouth of the Lusatian Neisse and ends at Lake Dąbie and the Szczecin Lagoon. It’s a border area without many larger towns and cities, save for Słubice and Kostrzyn on the Polish side and Schwedt and Frankfurt (Oder) in Germany.

J.W.: You have navigated the whole river. Did anything surprise you along the way?

A.W.: Yes, it’s gorgeous, and very rich in nature. I have never seen so many white‑tailed eagles or red kites anywhere before.

J.W.: And all this despite humans meddling with its course?

A.W.: The river has its ways to survive, it’s just a matter of time. We can also observe the same thing happening on the Vistula, which used to be channelised, but now nature is gradually reclaiming the old hydrotechnical infrastructure. The Vistula is getting wilder.

J.W.: Does every decision regarding a river’s regulation affect what is going to happen with it?

A.W.: Yes, but as an intelligent species, we should be able to foresee the consequences of our decisions and make choices that do not threaten the river and its environment.

J.W.: Does climate change affect the amount of water in rivers?

A.W.: Certainly. We navigated the Oder in July, and the transit depth (the minimum depth on a navigable route at a specific time) of the river after it passed Malczyce was nine centimetres. We managed to navigate it, but I must admit that year was exceptionally bad. The Oder’s water level got close to the record low from the 1950s.

J.W.: Still, the focus of Polish people seems to be on the Vistula. Do we, as a nation, identify more with the Vistula than we do with the Oder?

A.W.: First of all, let’s keep in mind that the Oder is smaller than the Vistula. They are two very different rivers with different drainage basin types.

J.W.: Perhaps it’s also because Oder flows along the German border while the Vistula crosses the country in the middle.

A.W.: During our research trip along the Oder, one of the locals told us that to the people who live there, the history of the region only started after 1945. I was shocked to hear that. It’s as if to say the region has no historical identity. And it is crucial to recreate it; the historical perspective should change the residents’ approach to these areas and help them identify with the river.

J.W.: You mentioned that you navigated along the entire length of the Oder. What is the “Clean Oder? Why Not” project that you participated in?

A.W.: In July 2021, the Silesian Water Centre, together with the Why Not Foundation, carried out the project “Clean Vistula? Why Not”, designed to study the Vistula’s waters while promoting various pro‑environmental behaviours. In 2022, we conducted a comparative study of the Oder. The kayak trip took place in the second half of July 2022. However it may sound, it was not a holiday. We took measurements every kilometre, and took samples every few dozen kilometres. This way, we gathered a large amount of information that help us understand the river.

J.W.: Such as?

A.W.: During our study of the Vistula, we were already surprised to discover that, contrary to what everyone was saying, only ten per cent of all the salt flowing into the Baltic Sea in the Vistula came from Silesia. The rest of it was discharged by large cities. During the “Clean Oder? Why Not?” project, we could see how the tributaries affect the main river body. It’s quite incredible, because the drainage area of the Warta River is sixty per cent the size of the Oder’s drainage area, and yet, half of the Oder’s water volume past the Warta river’s mouth consists of the Warta waters.

J.W.: After your expedition, you said that “the Oder carries a history of two centuries of water pollution”.

A.W.: Everyone keeps saying that “someone polluted the Oder”, but the facts are that we have been doing it for the past two hundred years or, more accurately, since the Middle Ages when people started dumping waste into the water. At some point, however, we have crossed the line of pollution the river can deal with naturally by removing contaminants from its waters. In the Oder’s case, it’s been at least two centuries of pollution with industrial and domestic waste that came as a consequence of the intensive industrialisation of Silesia and the Legnica‑Głogów Copper District.

J.W.: And what indicates the river is in poor condition?

A.W.: One of the indicators is low biodiversity. There is little to no species diversity, and there are more invasive species appearing and dominating the area. We can see it happening in the upper stretches of both the Oder and the Vistula. It has been noted, for example, that the Japanese knotweed is appearing in those areas, outcompeting other plant species and covering long swathes of riverbanks. There are other symptoms as well, such as bad odour that appears due to water being contaminated with domestic waste. During the Vistula expedition, we could smell Kraków until about the time we reached the mouth of the Dunajec. When we travelled along the Oder, Wrocław air followed us all the way to Malczyce. This is the consequence of intense urbanisation around the drainage areas of these rivers. Industry can be controlled, but regulating municipal discharge is much more of a challenge.

There is one thing I would like to point out: we keep trying to blame others for the Oder’s pollution and we fail to see the role we have played in the process. The same happened when we discussed air pollution. For a long time, everyone thought it was the industries, but even as early as in the 1980s, Professor Mieczysław Chorąży’s team from the Cancer Biology Department at the National Cancer Institute had noticed the main threat was the low emissions of gasses and particulate matter from chimneys in residential areas. It took us forty years to start taking scientific reports seriously. Meanwhile, we still fail to notice our contribution to polluting the waters with biogenic compounds, pharmaceuticals and drugs… Some substances, such as hormones, can drastically affect the lives of organisms in aquatic ecosystems, even in low concentrations.

J.W.: Should we be ashamed that the waters of the Oder are considered “non‑compliant” in the environmental protection classification system, meaning they fail to meet the norms?

A.W.: And which Polish waters are classified as first or second class? It’s not as bad as it used to be before 1989, but years of neglect and ignoring the ecological problems of the rivers have severely degraded their overall condition.

J.W.: How did it feel to be one of the last people to navigate the Oder before the disaster?

A.W.: We saw no symptoms of a looming catastrophe. We were about to finish our journey when the first reports of dead fish started to emerge. We should also keep in mind that sometimes, disasters are part of the ecosystem’s history.

J.W.: What do you mean?

A.W.: Sometimes, even large‑scale disasters are caused naturally, such as the mass extinction of reptiles. That event affected the entire history of our planet. Floods and droughts also tend to be natural phenomena the ecosystem needs to deal with, one way or another. However, the last year’s events in the Oder were of anthropogenic origin, despite what we might suspect, seeing it happened due to the development of living organisms in the water. It seemed natural but it was, in fact, caused by human activity and the chronic pressure on the aquatic environment.

J.W.: How did you feel, as a citizen, not a scientist, when you saw dead fish in a dying river?

A.W.: I was frustrated. Just a few days earlier, I had been watching a great ecosystem. Still, a citizen’s emotions cannot be separated from those of a scientist. We had to think about what had actually happened there. We were among the first to say the catastrophe could have been of natural origin, by which we meant a biological process triggered by human pressure.

J.W.: So the question was not whether a disaster would happen but simply when?

A.W.: There was no information about the presence of golden algae (Prymnesium parvum) in Polish rivers. We had reports from as long ago as 1930, but the algae were observed in the Gulf of Gdańsk. We hadn’t been monitoring the presence of golden algae in any of the inland waters, even though they were observed in many other European countries.

Prymnesium parvum is not a problem only in Poland. For over a century, the fight against them has been going on worldwide. And it’s worth mentioning that our catastrophe wasn’t even the most significant one they ever caused. The worst one took place in Norway in the 1980s when 780 tons of fish died in one of the fiords. It seems to me that we are getting close to uncovering the causes of this phenomenon, and this can help us understand and contain it. It might turn out to be easier than we think.

J.W.: Poland will keep on spending billions on more river regulations while the governments in Germany, France, or the Netherlands are choosing the opposite direction, giving the rivers their space back.

A.W.: Let me be clear: such a strategy is extremely difficult to implement. There are many ideas for removing concrete from riverbeds and letting the rivers meander again. This, however, requires a lot of care as some of such actions could be dangerous for the existing ecosystems. Many of the hydrotechnical devices on the Oder make it possible for the aquatic ecosystems of Wrocław, Brzeg, Opole, and many other riverside cities to exist. If we introduce changes carelessly, we might lose those ecosystems irrevocably, and the cities would lose important protective mechanisms against the consequences of climate change. In the Upper Silesia, there was the anthropogenic river Sztoła, fed by freshwater pumped out from the mines. Today, it no longer exists. Once we stopped pumping the water, the entire ecosystem vanished.

J.W.: And how do you like the idea of granting the Oder legal personhood?

A.W.: It’s more of a legal idea. As a natural scientist, I don’t feel competent to express an informed opinion.

J.W.: Is it now, after the disaster, time for us to rethink our relationship with the river and the way we have been treating it so far?

A.W.: Proverb says a wise man learns from his mistakes while a sage learns from the mistakes of others. Sadly, we rarely try to learn from other people’s failures. Everything needs to be done with caution and based on thorough analyses and scientific research.

J.W.: How should we understand that?

A.W.: Environmental protection needs to be regarded as a cause‑and‑effect process. The reasons for problems must be addressed, rather than just the results. We need a holistic approach to nature and the way it functions. For example, instead of introducing fish to rivers and water basins, we should consider reconstructing the basic food chains for the fish so that their population can grow on its own. Instead of “fixing” nature, let’s just try to provide assistance by creating optimal conditions. It will do the rest just fine.

Translated from Polish by Aga Zano