Baden gets serious about the sponge city

Heavy rain floods cellars, heat glows on sealed surfaces, sewage systems work at their limit. What was considered normal urban development for decades is now taking its toll with every extreme weather event. The city of Baden is now drawing the consequences and getting allies to break up private concrete. A model that could set a precedent.

Sealed surfaces hardly allow rainwater to seep away and heat up considerably at high temperatures. The problem is mainly found on private properties, in front gardens, courtyards and on asphalted parking lots. This is precisely where the unsealing campaign launched by the city of Baden together with the “Asphalt Crackers” and the Mobiliar Cooperative comes in.

Advice, contributions, pavement disposal
The model has a pragmatic structure. Private individuals, building cooperatives and smaller companies with up to twenty employees can book an on-site appointment with the “asphalt crackers” free of charge and without obligation. They advise on planning and accompany the project for one to two years. If an area is actually unsealed and made more natural, the city of Baden takes over the disposal of the removed surface for areas up to a maximum of 100 square meters.

The sponge city principle as a guiding principle
The concept states that water is retained where it falls. Unsealed soils absorb rainwater, have a cooling effect and relieve the burden on the sewer system during heavy rainfall. At the same time, near-natural habitats are created for plants and animals.

More than climate adaptation
Baden goes one step further. In addition to the unsealing campaign, the city is promoting additional ecological measures. Anyone who goes beyond simply unsealing surfaces and actively strengthens biodiversity can receive up to 50 percent of the costs back, up to a maximum of CHF 1,000 per project. The same applies to tree planting, also up to 50 percent and a maximum of CHF 1,000 per tree.

The window of opportunity is now open for companies and building cooperatives in the canton of Aargau. Anyone who owns land that currently produces more heat than benefits will receive free advice, financial participation and professional support from a single source. The outlay is manageable, the added value for building value, quality of stay and ESG profile is real.