Pond at Erasmus Plaza to become eco paradise

Currently, the pond between the Erasmus Plaza and the Erasmus building is practically dry. Around it are mountains of clay, and workers are busy laying tiles. This is part of a big maintenance project, which also involves the pond getting new plants. The pond needs to be empty so the seams and waterproofing of the pond can be checked.

Besides the repairs, the pond will be changed with the help of a design by the Bureau Stadsnatuur, a Rotterdam organisation with ecologists. The new design of the pond should improve the biodiversity in and around the campus, says Ben van der Kemp, who is the sustainable campus policy adviser. “We asked Bureau Stadsnatuur to look at the quality of the pond. How is the biodiversity, and what kinds of species live there?”

After the stocktaking by the Unit, which is connected to the Natural History Museum, we put together a plan to improve the biodiversity. The integration with the environment played an important role in this. “Biodiversity is obviously not just limited to the campus. It’s also about the province, the country and the world”, Van der Kemp says. When deciding on the new plants, the animal and plant species in the environment around the campus were also taken into account. “What are interesting species that we can connect with?” Buiten Advies, a consulting firm for ecological landscaping, also offered input.

To strengthen biodiversity in and around the pond, we will plant plants such as flowering rushes, which attract a lot of insects. There will be more growth around the pond than just the grass that is there currently, with wild herbs that are good for bees and bumblebees. A small portion of the original pond bed will be replaced by clay. This helps the local animals, says Van der Kemp. “On the west side, where the flagpoles are, we will place a nature-friendly bank that angles down. That way, salamanders and other amphibians can get in and back out again.

The ducks in the pond can benefit from the new bank as well. “There used to be some really dilapidated wooden steps. But they was too steep for ducks to get in or out. It will now be easier for ducks to overwinter and nest in the pond.”

At the end of this week, the repairs will be finished and the pond can be filled. “There is a ditch on the Burgemeester Oudlaan side, and that water will be pumped back in. When it starts to rain again, the excess water on the Plaza will go to the pond”, says Ruud van Eck, site project leader. “And then we can continue as quickly as possible, I suspect by the start of next year. But that depends on when a plant wants to be planted.”

For students and employees, the pond is primarily a paradise to be enjoyed with their eyes, because swimming is not allowed. Van der Kemp explains, “The plants are very sensitive to being flattened. If you walk over them, they pretty much won’t grow back. So any interference by humans will be bad for the biodiversity in the pond.”