How Polish rivers die. The agony of the Upper Silesian Slepiotka

There is no water in the Slepiotka for most of the year, says Dr. Jerzy Parusel, who has known this small, eight-kilometer-long river, all of which lies within the borders of Katowice, since childhood. As of 2017. measures its flows every two weeks, trying to document something that for many is still just an impression: that the river is disappearing more than it is flowing. In the background are mining damage, the escape of water into the rock mass and administrative decisions, as well as warmer winters without snow and increasingly long periods of drought. The story of Slepiotka is a study of the breakdown of a system in which man, climate and landscape no longer work in balance. It raises the question of whether we can still stop the process that is turning the river into an archive of memory before our eyes.

Magdalena Gościniak Podziewska: You have known Blind for more than seventy years. If you had to describe the single most important change in her over the course of your life, what would it be?

Jerzy Parusel: For most of the year there is no water in it. As an example, I will give a summary of the measurement days on which I found no flow, unmeasurable flow (that is, I could not use a float) or after calculation had values below the inviolable flow. This is a summary of the years 2017-2022. For all five measurement points, there were 75 such days (51.7 percent), for point 4 (the upper boundary of the reserve in the Slepiotka section) – 84 (57.9 percent). So, every other day of water measurements there was no or not enough water to provide biological life in the Slepiotka and the reserve. I would like to add that in the current Oder River Basin Management Plan, the following environmental objective has been set for the Ochojec Nature Reserve: preservation of the riparian forest as a biotope of the mountain abacus (requires preservation of natural water conditions). Will this goal be achieved? The plan does not set any actions leading to its realization.

M.G.P.: You have been studying Blindness for nine years?

J.P.: Yes. Exactly since March 4, 2017. I conduct measurements of the simplest parameters that a person without a scientific research background can study. I measure the elements that later allow me to calculate the average flow: the cross-section of the channel – its width and depth – as well as the maximum flow velocity and the flow itself.

I test the maximum flow speed using the float method. There is no standardized float for such measurements in Poland, so I made one myself from a piece of wood. I drop it into the water – if there is water, of course – and measure the time it takes to cover a certain distance. I then enter the data into the appropriate formulas (Matakevich’s formula) and calculate the average flow, expressed in m3/s.

This is a key parameter for assessing the condition of a river, and especially for checking whether the so-called inviolable flow is maintained.

M.G.P.: What does “inviolable flow” mean?

J.P.: This is the minimum water flow required to maintain biological life in a river. A fundamental parameter in any hydraulic engineering project, regardless of its scale – from a dyke to the regulation of a large river, such as the Oder.

For the Slepiotka River, the inviolable flow rate is specified in the so-called water rights operative for the Pizamraty pond, located in the Katowice Forestry District, and is 6 l/s (0.006 m3/s). That’s six liter jars of water overflowing in one second. And this amount of water is simply not here today.

M.G.P.: How, then, would you describe the condition of Slepiota? What has changed irreversibly in it?

J.P.: In 2009, we published a monograph of the Ochojec reserve, through which the Slepiotka River flows. One of the chapters, authored by Dr. Czeslaw Grenia, was about aquatic beetles. Thirty-six species of these insects were found in the reserve, including foothill, relict species. Today I don’t see them. They are probably gone. That’s my guess, because they have not been re-surveyed.

And they aren’t there because there is also no flow in the Slepiatka River in July, a crucial time in their development cycle. Water in this river flows only during biologically inactive periods, in early spring and autumn, when the physiological cycles of plants and the biological cycles of animals and other organisms associated with water, and therefore dependent on it, are dormant.

Lack of water during the growing season means the death of biological life.

I would also add that the Ochojec reserve was created, among other things, to protect the mountain abacus – a strictly mountain species, a relic in the Polish lowlands. Seventeen mountain species are found throughout the valley. This is no coincidence. The conditions that prevailed at the Slepiotka River – substrate moisture and low temperature – created a microclimate resembling a mountain environment. The small, fourteen-meter-long valley provided coolness and moisture. That was enough.

M.G.P.: So we have a situation where the Blind River is disappearing more than it is flowing. The processes that have led to this are natural or are they the result of human activity? What has destabilized this river? Where do you draw the line between drought and loss of the river?

J.P.: The decisive factor was anthropogenic influence, primarily deep mining. Slepiotka is located in the mining area of the oldest deep mine in Poland – Murcki has been mining underground since 1769.

The Slepiotka Valley also shows former traces of surface mining, as coal was also dug here by open-pit methods (from the mid-17th century). On the other hand, the decisive factor for the current hydrological regime was underground activity. Water began to escape into the rock mass.

The results of a study by the Central Mining Institute, described, incidentally, in the reserve’s monograph, indicate that about 10 percent of the precipitation from this catchment area flows directly into the mine.

M.G.P.: That precipitation, which is severely scarce today anyway….

J.P.: That’s exactly right. The water regime has been completely disrupted here. And this is only part of the problem. Above the reserve there is a phenomenon of ponding – the water that still flows in the Slepiotka River escapes into the ground through the damaged layers of the ground. Huge amounts of water would be needed to overcome this hole.

M.G.P.: That’s because water always flows down to the lowest point.

J.P.: Yes. This further hit Slepiota. And another blow was the decision of the Katowice Forestry Commission.

In 2015, the Pizamratte dyke, a sinkhole pond dating back to 1910 and created as a result of mining damage, was repaired. Its name is a translation of the German word Bisamratte, meaning muskrat, an earth and water mammal. An overflow monk was installed there to retain water. The problem is that this was done without a water permit.

The mayor issued a decision in 2015 specifying the need to maintain an inviolable flow – 6 l/s. This value has never been maintained. Never.

The expert report commissioned by the forestry division omitted an important element from the water balance, Dr. Tadeusz Molenda pointed out. Evaporation from the surface of the pond was not taken into account, yet it is almost a hectare of water table. In the balance presented, it looked like this: what flowed in, flowed out. There was no room for the fact that some of the water simply evaporates, and only the rest can drain away. The study was created in a very unprofessional manner.

Since then, I have fought with the Forestry Commission to enforce the inviolable flow. After two meetings – including with representatives of the catchment area – I forced an inspection by the Regional Water Management Board in Gliwice. Unfortunately, these inspections were also, to put it bluntly, scandalous.

The water flow was not even measured during the inspection. The protocol only included a note – at the request of foresters – that the water was in the riverbed. In a later protocol, it was also added that the water is found in side tributaries or ditches that in the past arose from natural watercourses as a result of their transformation.

Therefore, I decided that it was impossible to talk without hard data. In 2017. I have started systematic measurements at five points, three of which are now on the reserve. I take measurements every two weeks. That’s more than 200 visits to the Slepiotka Valley.

M.G.P.: When you talked about the impact of the mine on the one hand and evaporation on the other, the line between drought and permanent water loss really begins to be drawn. One affects the other.

J.P.: In the past, the regime of this river was snowmelt – snowmelt recharge was a very important part of the balance. Today we don’t have snow cover, so there is no spring recharge and filling of the riverbed. And then only heavy rains remain, which are unfortunately short-lived. Water flows through the Slepiotka virtually unstopped, undeveloped, unabsorbed by the living organisms associated with the river. This gives it a temporary rise in condition – and that’s it. And most of the year, even if it rains, all that’s left in the riverbed are puddles: isolated little ponds that don’t support anything, don’t give life.

For the rest of the interview, see the March issue.

Dr. Jerzy Parusel – ecologist, botanist, phytosociologist and forester, long-time activist for nature protection in Upper Silesia. For years he documented the most valuable natural areas of the Silesian province. Member of the State Council for Nature Protection (PROP), the most important consultative and advisory body on nature protection in Poland. Co-founded and for many years headed the Center for the Natural Heritage of Upper Silesia (CDPGS), an institution dedicated to research, documentation and popularization of knowledge about the region’s nature. Author of nearly 600 scientific and popular science publications, he initiated the creation of the Ochojec Nature Reserve. For years he has been documenting the hydrological transformations of the Ślepiotka valley.

Magdalena Gościniak Podziewska – environmental project communications specialist, associated with the Polish Society for the Protection of Birds (OTOP). She deals with the topics of biodiversity, peatlands and water retention, combining her experience in nature conservation with many years of media and PR practice. She lives in Upper Silesia.

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pic. main: Jerzy Parusel