Once, this side arm of the Donau River often flooded the Krieau. It stretched from Messe Wien to Lusthaus like an island. This is the Unteres Heustadelwasser.
Let’s delve into the story of this Viennese waterway. A hay barn once stood on this “island”. It provided wild animal feeding, giving the Heustadelwasser its name. The Unteres Heustadelwasser and Oberes Heustadelwasser were one body of water back then.
In 1875, Vienna regulated the Danube. This act cut off the Heustadelwasser’s inflow. Today, the Prater Hauptallee splits the Heustadelwasser into two parts. We are now at the Unteres Heustadelwasser.
Its water quality declined in the early 2000s. But the city took action. A special water treatment plant was installed. It helped to restore the water’s purity.
This “Neptun-Anlage” cleans the water since 2007. Murky water filled with algae is extracted. It’s sprayed over a biological soil filter. Turbidity like microalgae get caught and broken down in this filter.
The cleaned water then goes to a shaft. A phosphorus filter binds the nutrients there. Finally, the purified water re-enters the Unteres Heustadelwasser.
The results were impressive. Oxygen levels rose in 2007. By 2010, phosphorus and algal biomass significantly decreased. No blue-green algae bloom occurred. From 2016 to 2018, phosphorus and plankton algae further declined. The restoration goals were exceeded.
Underwater plants have reappeared. They compete with plankton algae. This stabilizes the improved water quality.
The Unteres Heustadelwasser is part of the green Prater. You can rent paddle boats near Stadionallee. The water here is up to eight meters deep.
You can even paddle under a small footbridge into the Rosenteich. This small lake offers good swimming spots. Especially for people with dogs, and a children’s playground.
The large bridge above the Heustadelwasser carries the Südosttangente highway. Cyclists and pedestrians use other bridges beneath the Autobahn bridge.
Beautiful paths surround the Unteres Heustadelwasser. The Liliputbahn’s terminal is near the boat rental. Pleasant walks lead to the Jesuitenwiese and Konstantinteich in the Prater.
If you are in need of a break, visit the Schutzhaus Heustadlwasser in the Kleingartenverein Unteres Heustadelwasser. It is located at Stemmerallee Parzelle 81. You can access it at Wehlistrasse 311. Enjoy refreshments and local charm. Please be aware of the short-term parking zone in Wehlistrasse if you arrive by car.
The Unteres Heustadelwasser shows Vienna’s dedication to preserving its natural spaces. It is a place where recreation and environmental care meet.