Unterschleißheim – power line moves further into Moos – district of Munich

Some feel threatened and talk about the “monster route”. The others hope for rescue and think of the monstrous consequences of climate change: the planned replacement of the 380-kilovolt high-voltage line from Oberbachern in the Dachau district to Ottenhofen in the Erding district is moving many people. The transmission system operator Tennet is pushing ahead with the planning for the project over a length of 50 kilometers. Higher masts are planned, stronger cables and in some sections the route is also to take a new course near Unterschleißheim and Ismaning. The spatial planning process has now been completed. And a route is emerging that has appeased the toughest critics to date, but has nature conservationists on the scene.

The people of Unterschleißheim and Ismaninger have not yet painted the image of the route as a monster on the wall. The passionate residents of Haimhausen in the Dachau district did just that. In the course of the new planning, the possibility of deviating from the course of the existing route should be discussed if this is possible in order to better protect settlements or natural areas. The section between Haimhausen and Unterschleißheim, where the masts are located in the Inhauser Moos, shows how difficult it can be to make a decision. To the annoyance of many in Haimhausen, the planners conjured up a northern route out of a hat as an alternative that would have moved closer to some residential areas.

Now, after a hard struggle, the government of Upper Bavaria has named a southern route as the preferred variant in terms of spatial planning, which means that the current route would largely remain the same. In Haimhausen, where a citizens’ initiative collected around 1,500 signatures, they see themselves as confirmed. The district association of the Federal Nature Conservation Association, on the other hand, sharply criticizes the fact that the “complete destruction of the Inhauser moss” is accepted. The Dachauer-Moos-Verein is politically in the line of fire because it supports the southern route. In Dachau, the city council faction of the Alliance for Dachau accuses the association of failing to fulfill its mandate.

In the district of Munich, Ismaning has unsuccessfully spoken out against the replacement route being laid a little to the south on municipal land near the Isar, which is to lead past the Gleitnerhof at a distance of 200 meters in the outside area. In Unterschleißheim the project is viewed differently. The concern is relative. The city is not officially heard in the proceedings because its territory is not affected. Walkers will come across the pylons about 400 meters west of Lake Unterschleißheim. It is to cross the Hollerner See leisure area in the Echinger area.

An important point is Unterschleißheim’s second mayor Tino Schlagintweit (Greens), who sits on the board of the Dachauer-Moos-Verein, of course the protection of the moor – and the climate. It is important to weigh things up carefully, says Schlagintweit, who also doesn’t want to wipe the interests of local residents off the table. In any case, it is necessary to expand the power grids for an energy transition, he says and advocates using the existing road as a guide for new construction. Mayor Christoph Böck (SPD) says: “In my opinion and in the city, the few remains of the Dachau moss should definitely be preserved and must not be endangered by the route.”

The old line can no longer meet the demand

The rapid expansion of the power line is considered absolutely necessary in order to secure the supply in the Munich area. The existing 380-kilovolt route dates from the 1970s, as do the substations in Oberbachern and Ottenhofen themselves. According to Tennet, the possibility of upgrading the existing line connection was examined. There would be the possibility of sending more electricity through lines with digital control depending on the outside temperature. In addition, cables that can withstand higher temperatures could be used. But the former would not be able to achieve the increase in capacity that is needed, according to Tennet. And the masts are not designed for the more powerful and heavier cables.

The federal requirements plan includes the Oberbachern-Ottenhofen route as an expansion project in order to increase the current carrying capacity from the previous 2200 amperes to 4000 amperes. Tennet argues that this will strengthen the network so that after the last three nuclear power plants in Germany are shut down at the end of 2022, it will be able to distribute electricity more flexibly. Above all, but not only, it is about north-south connections. The west-east route is also important. Up to 80 meter high masts are to be erected for this, the booms of which have a span of up to 50 meters. On average, they will be around five to 15 meters wider and around ten meters higher than before. After all, the more modern cables are significantly quieter than those currently in use, according to Tennet.

It is disputed whether the larger pylons with their foundations and all the restrictions that an extra-high voltage line otherwise entails will actually have such drastic effects as the Federal Nature Conservation Union fears. The government of Upper Bavaria sees an acceptable impairment of species and biotope protection and the peat soil. Several supply lines would be bundled on the southern route. A 110kV line, which also exists there, would have been preserved anyway if the so-called monster route had been laid in the Moos. Tennet is exploring the possibility of spanning routes that are worthy of protection with cables as far as possible.

The southern route is fatal for both species and climate protection, argues the district association of the Federal Nature Conservation Association in Dachau, with a view to the importance of the moors as CO₂ storage. The only option is to lay the power lines underground in the planned northern corridor. In addition, more regenerative energy should be produced in the region. Then such power lines would be superfluous. The last word has not been spoken. The next step is the planning approval process with public participation. The government of Upper Bavaria has already announced that the FFH compatibility and species protection issues will then have to be checked again.