Post-war Dordrecht city district embraces rainwater
The Dordrecht district of Wielwijk is in urgent need of radical renewal. Both its buildings and its public areas could use renovation. But how do you make an aged city district suitable for a future in which climate change will play a role?
Results
The design studio generated a rich harvest of potential measures, such as the rain barrel principle. This can be translated into a water veranda that collects rainwater on the roof and stores it in columns. Water-permeable paving, such as clinkers with larger spaces between, used in combination with a water-absorbent under layer, ensures that the water can drain away. Water drainage above ground does not always need to be a canal or ditch. It can also be a somewhat lower-lying channel that fills up during wet weather. Incorporating such measures in a building and outside spaces gives rainwater a positive place in the district and ensures that less water needs to flow via the sewer or over the street to a body of water. The feasibility of these types of climate measures is made visible on the Admiraalsplein square, the new centre of Wielwijk. Rainwater that falls on the roofs and the square is carried away here via open gutters to a large pond on the square: the newest pride of Wielwijk.
The intervention point analysis shows that the underground sewer system of Wielwijk is reasonably robust with respect to capacity, but the video inspection also indicated that the technical state of the sewer was poor and that it needed to be replaced. When replacing the sewer lines the municipality wants to have an improved separated system that channels foul water to the treatment plant and clean water to a body of surface water. Above-ground measures can make this system more robust. The outcomes of the design studio have been translated in an urban development Vision 2.0, that includes promising measures to make water management in Wielwijk more climate-resilient.