Bremen's 'Sponge City' Program Turns Concrete Into Green Spaces

Bremen has taken steps to increase its green spaces through initiatives like the 'Sponge City' program and the nationwide 'Unpave' scheme. These efforts aim to replace sealed surfaces with greenery, offering benefits for both the environment and residents. Environmental engineer Elke Meier is among those advising locals on how to participate. In early 2025, Bremen introduced its 'Sponge City' program. It allows private property owners to reclaim 30% of the costs for removing paved areas and replacing them with plants. The city also joined the 'Unpave' initiative the same year, which encourages depaving sealed surfaces across Germany.

The city already had a fee system in place that charges higher rates for properties with more sealed ground. This has pushed more residents to consider depaving. Between 2020 and 2024, only 10 grant applications were submitted for depaving projects. Since the 'Sponge City' program began, that number has more than doubled to 24.

Unpaved soil absorbs rainwater far better than concrete or stone. This reduces the strain on sewers and lowers flooding risks. Green spaces also cool the air, providing relief in hot weather. A 2024 study found that areas with better air quality and more greenery had a lower risk of depression among residents. New plant and animal habitats also emerge when sealed surfaces are removed. The combined efforts of the 'Sponge City' program and the 'Unpave' initiative have accelerated depaving in Bremen. More applications for grants and a growing interest in green roofs show the shift in how residents view their properties. The city expects further environmental and health benefits as sealed surfaces continue to shrink.