Climate change: Vienna area: hotspot of climate change

“It was always my dream to have a small fish pond and a hut,” says Karl Schmidt. “But today it’s over.” Schmidt, 82 years old, wearing a hunter’s hat, walks through his garden where he made this dream come true. Three steps up a wooden staircase and then he stands on a veranda with a wooden railing. He bought the property in Rohrbach, 40 kilometers south of Vienna, 40 years ago. He created a pond right in front of the hut. »I don’t eat fish myself. But I loved sitting there and watching them catch flies,” says Schmidt wistfully.

Today Algae swim on the surface of the water, the water creates streaks and looks dirty. Three years ago, when there was less and less water coming from the nearby spring, he had to give up his small trout farm. Now only a thin stream of water flows from the mossy inlet pipe. »It was wonderful to sit here in the evening. But it’s over now,” he says. At least he has enough drinking water – no longer a given in southern Lower Austria. The region was hit hard by the drought of recent years and is therefore something of a negative model region for Austria.

Karls Schmidt’s fish pond was one of the first victims of the increasing water shortage, the consequences can now be seen everywhere in the region. Not only have more and more streams disappeared in recent decades. Lakes dry up, wells dry up. The situation is so dramatic that some households have already had to receive emergency care. And last October was the warmest since measurements began. Is it a coincidence that water is missing in several places in this region, or is it climate change? And what can people and communities do about it?

Groundwater levels fluctuate

A call to Martin Angelmaier in St. Pölten: Angelmaier is head of the water management department in the state government and is a popular man these days. After groundwater levels reached lows in the spring, he is now cautiously optimistic: »Although the groundwater levels are still below the long-term average values, they are still well above the lowest values.” This particularly affects the Mitterndorf depression, in the Wiener Neustadt area. It is located around 60 kilometers south of Vienna and is the largest drinking water reservoir in Central Europe.

The lowest levels were sometimes dramatic locally: anyone who took the train from Vienna south in the summer saw sandy deserts where quarry ponds had once been. The water levels of Anemonesee, Föhrensee and Achtersee have fallen by seven meters within 15 years. Residential houses, once in a dream location on the lake, today only offer a sad view. In Bad Fischau-Brunn, in the picturesque thermal spa with Habsburg flair, swimming pools had to be closed in the summer because two of three springs were only trickling weakly. Anyone who wants to see what climate change is doing can find clear examples in eastern Austria.

But it’s not just the amount of rain that’s relevant. The temporal distribution of rain over the year is at least as important. Water from melting snow or long-lasting drizzle slowly seeps into the ground and feeds the groundwater body. But if there is heavy rain, i.e. a lot of water in a short period of time, a good portion of it runs off the surface and ends up in rivers.

»We are also observing that the spring discharge, i.e. the amount of water flowing out of the springs, is decreasing. “That will be less,” says Angelmaier. Whether this is a coincidence or an effect of climate change will only be able to be said reliably in a few years, he says, because: “Groundwater levels fluctuate naturally.” But some researchers are already trying to look into the future.

For Helga Lindinger, Karl Schmidt lives in “scenario region five”. Lindinger is a geographer and groundwater expert; she researches Austria’s available water resources at the Vienna Federal Environment Agency. From this, planning for the water supply of the future can be derived. Lindinger recently investigated for a study commissioned by the Federal Ministry of Agriculture, Forestry, Regions and Water Management together with experts from the University of Natural Resources and Life Sciences Vienna and an engineering firm: Where is there how much water and who needs what amount of it?

It’s not just people who drink water and fill their pools, animals and plants too, Agriculture and industrial companies need water. Groundwater plays the crucial role here. Lindinger and her colleagues can say where in Austria there are large groundwater resources – but the complicated thing is: “The groundwater does not end at administrative borders.” The geographer can therefore only make statements about “scenario regions”. And Rohrbach, where Karl Schmidt lives, is part of the southern Vienna Basin, scenario region five in Lindinger’s categorization.

“Now, and really now”

“Today the intensity of use in the southern Vienna Basin is relatively high,” she says. 70 percent of the available groundwater resource is already being used, the majority of it for water supply for households and industry, and smaller shares for agricultural irrigation and animal husbandry. In the future, water demand in the region will increase, both for households and for irrigation. This is because the drought creates a double problem: Not only is less groundwater being formed; Because there is less rainfall, more water is used to irrigate fields or the lawn in front of the house.

That’s why Lindinger explains: »Forward-looking and long-term measures must be taken now, and really now“So that the demand for water does not exceed the available resources.” Overall, only around 27 percent of precipitation ends up in the groundwater. We are also increasingly confronted with extreme weather conditions. Once dry, then again a lot of precipitation within a short period of time – bad for groundwater formation.

But politics is not idle. In the spring the United Nations has one
Drinking water conference was held, and in Austria the Minister of Agriculture invited people to a “water summit”. Especially in southern Lower Austria
Water associations advise on mergers, new pipelines are built to supply the dry regions from the water-rich areas. In some places, however, only dowsing helps.

Franz Stern is standing in the mud on a meadow three kilometers from Karl Schmidt’s property. It’s January, there are a few centimeters of snow. “With rock, we can cover up to 60 meters a day, but soft ground clogs the drill.” Stern has to raise his voice to drown out the noise of the machines. He is a well driller and travels year and day to all corners of Lower Austria for his employer, the Allinger company.

First he detects water veins with his dowsing rod, then with ground-penetrating radar. It’s hard to prove with scientific methods that dowsing works, but Stern swears by it. Only then does this follow
heavy equipment to tap the sources. Like here, just outside the town of Maria Raisenmarkt. Stern’s work suit is full of dirt splatters. “In-the-hole hammer!” he almost shouts to drown out the noise of the jackhammer.

At 20 bar underground

Imlochhammer is the name of the machine that Stern and a colleague have been operating on the meadow for hours. A blue tracked vehicle with an eight-meter-high drilling arm, the down-the-hole hammer, which eats into the ground. The tip of the drill is a rotating crown, explains Stern, as the machine emits a strange whistling sound, only to immediately return to a staccato noise. The rotary drill hammers its way into the subsurface with a pressure of up to 20 bar.

Stern drills 80 to 90 wells a year. His boss cannot complain about a poor order situation. Wells are running dry everywhere, he says. Previously they had to drill a maximum depth of 30 meters, but today they often have to drill twice as deep. The water level is sinking everywhere. So many households and communities have no choice – and only have to dig into their wallets. Even if the drought does not fundamentally threaten groundwater supplies, it will still become more expensive. The Austrian Ministry of Agriculture wants to provide an additional 100 million euros.

Continuous precipitation helps, as it occurred in the spring and continues currently, after a very dry start to the year. Is everything settling in now? Meteorologist Klaus Haslinger knows this best. He is head of the climate system and climate impacts competence unit at Geosphere Austria. Although the first months of the year brought significantly less rain and snow than usual, in the long term there was no noticeable decrease in the amount of precipitation in the southeast of Lower Austria. “So far, on average over the year, we’ve even had a positive precipitation anomaly,” says Haslinger, meaning more rain than usual.

The problem is not only the amount and weight of precipitation, but also the rising temperatures themselves: “An increase in evaporation is very well documented.” Over the past 40 years, evaporation in Austria has increased by 18 percent. Almost half of this was due to higher temperatures and more solar radiation, and a third was due to the resulting extension of the plants’ vegetation phase. As long as these grow, they draw water from the ground and evaporate it through their leaves: again water that cannot contribute to groundwater formation.

“That’s not the future”

Karl Schmidt looks around his garden. “It’s a bad feeling,” says the 82-year-old. When he was a child, there were streams and ponds with fish and crabs in the area. Today there is often only a trickle left. The water from the spring next to his garden is still enough to supply the few households in the small town. But the water pressure is also falling here. “There’s no future if you have to dig deeper and deeper,” says the pensioner.

Three kilometers further, Franz Stern’s drill has finally reached the water-bearing layer. Muddy dirt falls onto the snow-covered meadow. Every time you blow compressed air through the drill, a mudslide shoots up a good ten meters into the air. Stern is satisfied; in a few days a household will be connected to the new water supply.

Ultimately, it is difficult to say with certainty whether climate change alone is responsible
Karl Schmidt’s fish pond is drying out and the well drillers’ order books are full. For Helga Lindinger from the Federal Environment Agency, the only thing that is certain is that climate change means increased stress on water resources. And that could be just the beginning: “The challenges in water supply can be much, much greater, especially in dry years.” After all, groundwater recharge in a dry year can fall to half of the normal average. “If several dry years follow one another, as we have been observing since 2015, this can lead to very strained usage conditions for groundwater bodies that are already intensively used,” says the expert. Then we need even more crisis summits, even more new lines – and even more dowsing rods.