At the request of Public Works and Water Management, the last 300 m of the Ur in the municipality of Stein has been redesigned. The stream now flows in a gentle meander into the Maas, slightly further south than before. Obstacles such as concrete, debris, and thresholds have been removed.
This allows fish to swim into the mouth of the river unhindered to rest or spawn. The contractor, Consortium Grensmaas, has also placed a new pedestrian bridge over the mouth.
Variation in Flow Speed
The old, narrow stream bed has been filled with gravel that was released during the work. That section now serves as a maintenance path for the Water Board Limburg, the manager of the Ur. South of that, the new stream mouth has been dug: 300 m long, about 3 m wide, and up to 1 m deep. The gentle meandering creates variation in flow speed and creates calm zones where fish, as well as aquatic plants and various small creatures, feel at home.
Gravel Wader Mouth
The released gravel has also been used to create a so-called gravel wader mouth. This fits the character of the Grensmaas. Here, species that thrive in oxygen-rich, fast-flowing water over a gravel bed, such as salmon, river lamprey, and river eel, benefit.
A Stream with a Bend
Before the redesign, the Ur at the mouth had too steep a bottom (slope) with multiple thresholds. As a result, the stream was hardly accessible to fish. By deepening the bottom, distributing the height difference more gradually, and removing the obstacles, the stream has become accessible again.
What also helps is that the stream water now flows into the Maas with sufficient force through a sharp last bend. This strong outflow, a locating current, ensures that fish can find the entrance to the stream. This way, they do not miss the turn to this valuable shelter and spawning area.
Working Dry in Wet Areas
To carry out the work, the stream water was temporarily pumped away and diverted via a pipeline. At the culvert under the bike path and at the new mouth, additional bank protection has been added with rubble stone.
The new pedestrian bridge has also been installed: it falls under the works for the Grensmaas project and reconnects the nature reserves of Natuurmonumenten on either side of the Ur. Consortium Grensmaas will organize an official opening moment for the bridge in the coming period.
European Water Goals
With the new design, the mouth of the Ur meets the European Water Framework Directive Water . This directive stipulates that our rivers must be suitable as habitats for native flora and fauna. This is important for good biodiversity and ecological water quality.
Want to know more about the stream mouth Ur?
Visit the project page mouth Ur or contact us here.
