Wetlands4Cities

PROJECT DESCRIPTION

BACKGROUND

The impact of climate change is very significant on medium-sized European cities such as Mechelen (Belgium) and Tilburg (Netherlands). Both cities face the increasing challenges of preventing flooding and reducing heat stress. In turn, adjacent natural and agricultural areas must contend with drought and loss of biodiversity. By addressing these problems together, urban stormwater can contribute to the hydrological restoration of natural wetlands in the urban fringe. Both cities have a lot of paved areas and are very densely populated. During heavy rainfall, water has to be able to quickly flow out of the urban area to prevent flooding. In Tilburg there is not enough room to allow the water, during heavy showers, to infiltrate underground. At the same time, the current sewage system is not robust enough to deal with the changing climate. For this reason the city is working on a system of blue infrastructure that will lead water towards the wetlands being created near the city. Mechelen is situated in a river delta where there is a growing need for more room for water. Large paved areas hinder water infiltration, while several streets do not yet have a separated sewage systems for rainwater, which is why the city wants as much water as possible to infiltrate in the area where it falls. For this reason the infrastructure needs to be adjusted, including the removal of pavement on large areas. This will allow for more infiltration and, during heat waves, for cooling through evaporation. As a consequence of the historical water management around both cities, which was aimed at drainage and reducing groundwater levels, the water-dependent nature around both cities is in poor condition. Due to the expected decrease in the amount of rainfall during the summer months, because of climate change, the situation is expected to worsen. During the recent very dry years, existing streams and ponds tend to dry out completely with negative consequences for flora and fauna, but also for agriculture.

 

OBJECTIVES

The overall objective of the Wetlands4Cities project is to establish an exchange between the urban environment and the wetland habitats surrounding the cities of Tilburg (Netherlands) and Mechelen (Belgium), with the goal of increasing the resilience to climate change of both the cities, and nature and agriculture in the surrounding areas. The project team will apply an integrated approach to water management, with wetlands as a nature-based solution for both storage of water and a cooling effect.

Specific objectives are to:

• Minimise the consequences of flooding and drought by creating natural wetlands as buffers, by increasing the water infiltration in the urban environment and by improving the blue infrastructure connecting the city and its surroundings.
• Increase the quality-of-life for citizens of the two cities, Tilburg and Mechelen, by restoring the natural hydrological system, which would also improve the resilience against flooding, help reduce the urban heat island effect, increase biodiversity, and create possibilities for more recreation in nature.
• Engage citizens, children and entrepreneurs with the implementation of the project, raise their awareness about climate, and stimulate them to work on climate resilience in their own neighbourhoods and gardens. They can achieve this by helping create water-buffers to enable more infiltration and by reducing the paved areas.
• Demonstrate the efficiency of this integrated approach for adaptation to climate change to other European cities and regions with similar population density. In this way, the role of wetlands as natural buffers for climate change will be recognised and the replicability will be improved.

RESULTS

Expected results:

• Creation of a total of 380 ha of water buffer in the form of restored wetlands. With the construction of the wetlands and connected blue green infrastructure the areas of wetlands, swamps and open water will be raised significantly.
• The new and restored habitats will be suitable for the re-establishment of Natura 2000 species.
• 680 tons of CO₂ will be stored in the newly developed habitats annually.
• 4.5 km of stream restoration in the Mechelen region, with more natural eco-hydrological situation.
• Removal of pavement in 11 streets and over a total surface of 10 000 m², allowing annually the infiltration of 2 500 000 litres of water.
• Access to new recreation facilities for 100 000 visitors.
• 600 households committed to join the ‘curieuzeneuzen’ citizen science project, with sensors installed in their gardens to measure heat and drought, providing information on the effect of the measures taken.
• 200 households, guided by a coach, take climate adaptation measures on their own properties.
• Methodology  devloped that improves the effectiveness of water ecosystem restoration measures. The Wetlands4Cities project does this through a collaborative approach, creating synergies between climate-adaptive water strategies of cities and their surrounding wetlands.