Fish Doorbell at Weerdsluis Lock

It is easy to forget that the canals that pass through and surround the city center of Utrecht are also home to many inhabitants. Not just the geese or swans that beg for food in the evening on the terraces of the Oudegracht, but fish also swim through these same waters.

While there are many different types of fish to be found in the canals, there are relatively few safe places for them to shelter. This is especially relevant during the breeding season in the spring, during which they tend to migrate to larger bodies of water, like the Kromme Rijn southeast of the city. However, their journey might be interrupted by a sluice gate, preventing water from overflowing the city's canals. If the sluice gate is not automated and a sluice keeper is not present to open the gate for the fish, they are unable to continue their journey. Enter the fish doorbell.

In the Weerdsluis, there is a camera that provides a livestream of the activity in the waters. This feed is available on the linked website along with a doorbell. From the beginning of March until the end of May, if you see fish appear on the feed, you can ring the doorbell to alert the sluice keeper to open the gate for the fish. As long as there aren't too many people on the website at the same time, anyone can ring the doorbell.

This doorbell was first installed in 2021, generating around 32,000 clicks and about 440,000 unique visitors in its first season. In 2024, this number increased to 2.7 million with viewers from around the world, and a weekly update is uploaded to YouTube by the project founder. The Weerdsluis in particular is so historic that it has been declared a National Monument, as the water levels were already regulated at this spot around 1554, and the sluice was first installed around 1613.