New Isar: Guided Walk on a Reconstructed River

Thanks to the renaturation project “Plan Isar”, you can once again swim in the river – and enjoy an area of ​​Munich where people and animals can relax and unwind. Here we present the most important stops of our renaturation tour.

Many companies are now trying to become more sustainable in more and more areas of operation. But, for example, the transition to more climate-neutral production is often far from simple. In such cases, it is helpful to learn about a project that has made a very successful transition to being more environmentally friendly. The Isar renaturation project is a prime example – and this is one of the reasons why the Munich Water Authority offers tours along the river. “Environmental awareness and a positive attitude towards our water bodies are a major concern for us,” says Stefan Homilius, head of the Munich Water Authority. “That’s why we offer tours upon request, preferably to institutions that focus on ecology, environment, water and environmental education.”

Adventure and sustainability enthusiasts can also explore the restored river on their own. During the half-day excursion, you can follow the Nature themed trail outside the city - less than 10 km between the Dürnsteiner Bridge near Sheftlarn and the Ikinger Dam, with eleven information panels along the way. A shorter walk through the city with four stops starts at the Wittelsbacher Bridge and ends at Isarwerk 2 near Flauchar. It is a good 2.5 km long and can easily be covered in an hour. The most important stops during the tour are described below. Happy learning!

We start from the Wittelsbach Bridge. When Munich was flooded in 1899, the previous iron bridge was one of the few bridges that survived the water masses. But in the late 1950s, after even more devastating floods, the city decided to straighten the Isar even further. “The city's sections of the Isar were largely canalized until we started implementing the Isar plan,” explains Stefan Homilius. Isar's "corset" had many negative consequences, as straightening measures undertaken in the 1960s and 1970s almost completely destroyed coastal habitat for humans and animals.

This is where Izar's plan came into play. “The goals of the Isar plan can be boiled down to three points: to protect the inhabitants of Munich from floods, to improve the environment and recreational function,” says Stefan Homilius. The Isar was carefully restored between 2000 and 2011. For example, to the north of the Wittelsbach Bridge you can now see the willow island, created during renaturation as a refuge for flora and fauna. Now animals and people are enjoying the Isar again: the steps built around the Wittelsbach Bridge as part of a renaturation project are often visited in the summer. Many Munich residents gather here to enjoy the joys of nature in the middle of the city.

The tour now continues south along the Isar.

Welcome to our second stop - the Braunau railway bridge. Bridges are vulnerable points during flooding due to entanglement hazards: any wood carried by a flooded river can become lodged in bridge supports. So, during the renaturation work of this section of the bridge, the embankment was strengthened with limestone. The idea was to prevent the Isar from flowing to the east and thus direct the section of the river with the strongest current away from the supports of the Braunau railway bridge.

On the way to our next stop, you can't help but notice the occasional tree trunks that Munich residents like to rest on. Remnants of the flood? No, the trunks were specially placed there so that trails would not form. During flooding, trails can cause deep erosion and deepen the river bed. If you want, you can just stop here.

We continue to Flaucher, a place for swimming, barbecuing and relaxing in the Munich summer. Why not plan a little picnic here for your colleagues? Clear water is not something that is taken for granted here. “In the upper reaches of the Isar, we have installed treatment plants equipped with disinfection systems to prevent pathogens from entering the water. This ensures proper bathing water quality,” explains Stefan Gomilius.

Before renaturation, it was unthinkable that fish could breed around Flowhar. That is why the Isar Plan provided special recreation areas for fish. “But it’s not just fish that are showing environmental improvements,” he explains. “You can also see similar examples in beetles and small insects. It is now home to butterfly species such as Adonis Blue and Checkered Skipper Butterfly.”

And now we have reached the last stop - Izarverka. At the beginning of the 20th century, several hydroelectric power stations were built along the Isar along with the Isar-Werkkanal, where electricity is generated in the Isar branch. Here you always need to think about nature conservation, that is, the water level in the Isar, and the production of clean energy, that is, the Werkkanal.

So we have come to the end of our tour. “Just dive into the Isar and experience it for yourself,” recommends Stefan Homilius. “In my opinion, this is an even better way to understand renaturation than having it explained to you.”

About a quarter of a century after the renaturation project began, the Isar River and its floodplains have become one of the most important features of the city . At the same time, they are an encouraging sign that large-scale sustainability projects can succeed, even if they take some time. And this is useful to know for any company that has set ambitious sustainability goals.

Text: Nansen & Piccard; Photos: Frank Stolle, Dominik Morbitzer