A fish pass for ecological union
Rotterdam is working to improve the quality of the Rotte, an inner city waterway full of paved banks and building backs, its potential often ignored. BOOM Landscape designed a fish ladder for the Leuvekolk, the spot where the Rotte will connect into the New Meuse River in the future. It is a passageway that improves water quality and increases the ecological interchange between the two water habitats.
Bridging the different water levels
Sticklebacks, carp and glass eels travelling from the Rotte to the New Meuse would have to fight strong currents and an obstacle of 1.26 metres without the new fish ladder. Our design makes the climb clearly visible with its stepped incline and the route of travel is deliberately not straight, which gives people a good overview of the fishes’ start and finish line.
The steps are made of cement block modules, incrementally raised by six centimetres each and connected under water by diagonal perforations. The fish do not swim with the current but the inner configuration is such that the fish will naturally navigate towards the corner where the next opening takes them further. At every sixth module there is a resting basin.
We also added extra basins for plants found in the Rotte’s ecosystem, such as the yellow waterlily and the bulrush. A few basins have extra thick raised walls to create niches that attract other animals who inhabit the same ecosystem.