ARE THE DANUBE'S BRANCHES SURVIVING?

The unceasing environmental debate:

These days, it's hard to tell who's right about Gabčíkovo, for the environment of the area is as tangled as the twining arms of the river itself. The area was at risk well before the dam was conceived: the deep bed of the main channel or "Old Danube" was dredged in the beginning of the century to clear a passage for ships. Each year, as the fast river current dragged more and more rock downstream, the gravel bed slipped lower and lower; as the bottom sank, so did the water level. Eventually, the water level in the main channel lay feet below the base of the side branches. Without fresh river water flowing into them, the side branches became stagnant, and then dry.


Environmentalists say the wildlife in the Danube's "inland delta" needs more water.
Peter Áč

These days, it's hard to tell who's right about Gabčíkovo, for the environment of the area is as tangled as the twining arms of the river itself.

The area was at risk well before the dam was conceived: the deep bed of the main channel or "Old Danube" was dredged in the beginning of the century to clear a passage for ships. Each year, as the fast river current dragged more and more rock downstream, the gravel bed slipped lower and lower; as the bottom sank, so did the water level. Eventually, the water level in the main channel lay feet below the base of the side branches. Without fresh river water flowing into them, the side branches became stagnant, and then dry.

Gabčíkovo's designers promised that with the dam they could regulate the Danube's flow and fill its old side branches with water once again; Vodohospodárska Vystavba now shows off pictures of placid streamlets full of water. By maintaining the water levels at a certain height, they say, they can keep some side branches filled while avoiding floods, and maintain a stable, and increasingly popular recreational area. But environmentalists say that the dam has actually destroyed the delta that survives from the branches' water.

"The Danube was choked on October 28, 1992," said Miroslav Bohuš, an ecologist with Comenius University in Bratislava. "Two or three days later I was there. The branch system had totally dried, the fish were dead, and only the deepest sections had water in them." Since 1992, environmentalists have persuaded dam operators to release greater and greater flows of water from the holding reservoir into the branch-filled delta. But many branches have been cut off from the main stream, and others need huge floods of water to flourish.

XXXBut Bohuš said the branches need more. "The water in the branches is stinking," said Bohuš. "There are a lot of dead leaves and they are decaying. You have no floods to clear the branches of organic materials."

In some ways, the delta is like a forest, which needs a fire to clean out old, dead growth, let in sunlight, and release nutrients. Floods keep the area dynamic, and allow a wide range of plants - willows, poplars, reeds and shrubs - to grow in the area, providing homes and food for a variety of wildlife. Without periods of high water, a bland forest of poplars takes over, making the delta seem more like a cornfield than a meadow of wildflowers.

Bohuš and others suggest that it would be possible to flood the old bed of the Danube, perhaps not fully but partway, and thus open up the mouths of the old branches, allowing the water in. It is, he admits, a dream, "but maybe the dream is possible to realize."

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