… there is already a tangible answer in Soest.

Today in the Soester Anzeiger (17 August 2026, Marion Heier): Volker Stelzig of the Soest office for landscape, ecology and planning is convinced by the JUMBO BLOCK system – and for good reasons.

The system turns existing streets and squares into underground storage and cooling infrastructure:

✅ almost 14 m³ of rainwater per block

✅ installed at a depth of only 2.70 m

✅ passively cools the surface by up to 9.3 °C – without a single watt of electricity

✅ prevents flooding and makes the water usable on site (fire protection, irrigation, cooling)

✅ 792 tonnes of load capacity in the assembly

✅ 80–120 years of service life

Road on top – Sponge City 2.0 below.

While others are still planning retention ponds or discussing trees as the only solution, this system shows that traffic areas can be used twice. And this is not theory: it is already being implemented (in Minden, among other places).

We should all ask ourselves: why does a working solution need five years before it finally gets wider attention?

The article is worth reading (German): soester-anzeiger.de – Neue Idee gegen Hitze und Hochwasser

🫵 Who would like to help bring this topic into the national debate?