Combining room for water and city expansion in Herentals

Herentals is a midsize city in Flanders, Belgium, located in the Kleine Nete valley in the province of Antwerp. Historically the river Kleine Nete defined the city as it is today. Increasing urbanization in naturally flood prone areas in combination with the changing climate makes the city vulnerable to (future) flood events. By combining room for water and city expansion in the ‘signal area’ Olympiadelaan (a low lying valley area) new development can happen in a climate adaptive way. Enlarging the storage capacity for water will also create ecological corridors on the river bank and provide ecosystem services.

Within CATCH a hydraulic study is carried out now will take place to investigate the amount of water that can be stored and the necessary measures to make the city more climate resilient in the future. The ambition of the study is to make a preliminary design for fitting resilience measures in the redevelopment of the area without conflict of spatial claims in the area from the different stakeholders. The river plan was brought up to date and was connected to the sewer plan of the city of Herentals. There are also some extra design scenarios that need a hydraulic study.

Different scenarios and cost estimates for the redevelopment of the Olympiadelaan were discussed with all stakeholders. Moreover, nine 3D design sketches and cost estimates were made for different scenarios of a retention area next to the Olympiadelaan for fluvial and pluvial water. At the moment, two of those design sketches are being further developed into preliminary designs. The considerable size of this city development project and the large number of stakeholders result in a time consuming process.

After the redevelopment, an extra buffer capacity of 39.000 m³ is available to temporally store water from the river. Therefore, the valley will be more climate proof in the future. In addition, the redevelopment will create an area for storage of pluvial water (4.500 m³) coming from the town centre by revaluing an old watercourse and the creation of ditches next to the historic city walls.

Signaalgebied Olympiadelaan - watertoetskaart