Fish on the up
Fish can now ‘take the lift’ between the Merwede Canal and the Amsterdam-Rhine Canal. A brand-new fish pass has been installed for this purpose at the Zuidersluis in Nieuwegein.
On the north side of Zuidersluis Island is a partially buried fish lift that enables fish to move between the 2 waterways.
Underground connection
To preserve the character of the lock island, the fish lift has been built underground. Fish can enter it through an opening in the sheet piling and a series of pipes connecting the Merwedekanaal and the Amsterdam-Rhine Canal. Inside the fish pass, they swim up or down through a succession of chambers.
The lift works like a spiral staircase, allowing fish to move over the barrier. To do so, they swim through a series of chambers before exiting through an outlet pipe.
An attraction flow helps fish locate the entrance. This is a gentle current that fish instinctively swim against, guiding them to the mouth of the lift. Footage from a camera inside the lift confirms that it is working as intended.
For clean, healthy water
Fish play a vital role in maintaining clean, healthy waterways. A diverse and healthy fish population is essential for water quality. Fish passes allow fish to migrate between different areas to spawn and grow. The Zuidersluis fish lift came into use in July 2026 as a measure under the Water Framework Directive.
Over the years, more than 100 fish passes have been built in the area covered by the Stichtse Rijnlanden Water Authority, connecting regional waterways. The water authority and Rijkswaterstaat are also working together to connect national waterways, such as the Amsterdam-Rhine Canal, with the surrounding polder waters behind them.
The water authority made a financial contribution to Rijkswaterstaat towards the Zuidersluis fish pass.