A natural Glatt –a win for biodiversity and recreation

Prior to the official start of construction and the creation of the near-natural river course, felling and clearing work is necessary along the Glatt. Around 300 to 400 trees will be felled. The treetops will be removed in winter to take account of the bird breeding season. Care will also be taken to protect bats during the clearing work - the trees will be checked for cave locations beforehand.  

Structuring watercourses by reusing the wood components  

First, the trunks are shortened to a height of around 5 metres. The rootstocks are only pulled out of the ground later and ultimately reused for the ecological enhancement of the watercourse. Several months pass between felling and excavation. By cutting back the trees, they can remain on site instead of being stored temporarily. 
 
During the creation of the new river course, deadwood is introduced approximately every 100 metres. Some of the felled trees, preferably deciduous trees, will be used for this purpose. The branches, trunks and rootstocks ultimately structure the new water course. They become a habitat for flora and fauna and serve as shade cover, spawning grounds or refuge area. 
 
This project promotes 100 rare plant species. The 950 newly planted trees include ash, European white birch, black alder, pedunculate oak, white willow and almond willow.

The first two meanders will be constructed over a length of approximately 240 metres in the pilot line. The planned measures will be implemented for the first time in this section and their effects observed. The knowledge gained will be incorporated into the further work.  
 
Initially, the service lines for Energie 360° AG and Swisscom AG will be laid. The new riverbed will then be excavated. Different depths and widths will allow the course of the river to be designed in a natural way. The banks will now be stabilised and structured with materials such as dead wood and stones. Suitable sites for woody plants, tall herbaceous meadows and reedbeds will then be prepared and planted.  
 
During the construction work, the watercourse will initially still flow in the straightened riverbed so that the measures can largely be implemented in dry conditions. Once the pilot line has been completed, the Glatt will be channelled into the newly created channel in a controlled manner and the old course of the river will be filled in.