Candidate – Belgium
Submission by: Municipality of Wetteren
Project name: Kerktuin Wetteren
“Kerktuin” puts Wetteren in the foreground as a plant community that is fully committed to softening. The project is one of the first realized testing grounds of the project call ‘Flanders breaks out!’, subsidized by the Flemish Government. With this participation, Wetteren undertakes to maintain the decrease of the paved surface for ten years, in exchange for subsidies and broad overarching guidance. By demolishing the existing buildings, more public space was created and the monumental character of the church came to the fore. The new Kerktuin is an attractive place to stay for young and old in the heart of the municipality where there used to be hardly any public green space. The project provides an example of how softening, rainwater and material recovery can be dealt with in an urban context. The project was laureate of the Public Green Award 2021 and was published in “Praktijkboek Publieke Ruimte 2021”.
The Wetter town council consciously opted for a climate-adaptive project by surrounding the Sint-Gertrudis church – right in the center with a garden, which puts this location more in the spotlight. In this way, it realized a missing link in the blue-green network between the market square, the administrative center and the pedestrian and bicycle bridge over the Schelde. The Kerktuin is centrally located in the center of Wetteren and is at a junction of activities: a market square with catering and activities, the administrative center, a church, housing and cultural meeting places. The low-threshold and diversity of the place makes it a meeting place for people with diverse socio-cultural backgrounds and different sections of society, but also attracts a diversity of age groups.
The experiential value for visitors to the center of Wetter is greatly increased by the project. The center will have a high-quality green Kerktuin with lawns, a flower garden and seating. Biodiversity was ensured by alternating grass areas with clover, vegetation and native trees. This creates a dynamic and lively environment. The places with plants and trees attract birds and insects.
Wetteren is known as a community of plants. Planting material was purchased locally and the local plant breeders will manage the new green space with regional plant species. Because the place becomes a gathering place, this gives a boost to the local trade: terraces, ice cream stalls regularly receive visitors from the city garden and vice versa.
The impact of the project on the climate was reduced in several areas: softening, rain garden with infiltration and reuse of rainwater, reuse of materials.
The project functions as a testing ground for softening with the aim of reducing the warming of urban space: urban heat island. By replacing buildings, asphalt and other pavement with grass, infiltration basins, plants and trees, there is more cooling in the warm periods of the year.
- Rain garden
Maximum efforts are made to use water in a sustainable and well-considered manner. All rainwater is collected on site, can be recovered and/or infiltrates into the subsoil. Paving is only provided in function of a minimum accessibility for the expected user flows.
- Recovery materials
In the context of sustainability, it was examined which materials can be reused, both in this project or in other projects.
Wellbeing of visitors/users
Green areas, laid out in terraces, consisting of lawns and perennials, with staircases and footpaths bridge the difference in height between the Schelde and the market square. For this, a retaining wall was erected with ‘sitting walls’ between these zones. Although there is a significant difference in height, a significant part of the Kerktuin is accessible to people with reduced mobility. The walls of the lower part connect without thresholds to the footpath along the Marktdreef, so that the lower three terraces and the upper terrace are fully accessible to these people. The project also caters to citizen participation. In the preparatory process, consultation and participation moments were organised. After completion, activities are organized by and for the citizens.
Selection, origin and quality of the products and materials
In the context of sustainability, it was examined which materials can be reused, both in this project or in other projects:
- The walls of the existing demolished buildings are recuperated to support the new retaining wall that is necessary to compensate for the difference in height between the church and the Kerktuin.
- For the paving, cobblestones that are available in the municipal warehouse were reused.
- The cobblestones from the Marktdreef were transported to the municipal warehouse to be reused, for example, for filling gabions. Due to their irregular shape, they were not suitable for reuse in this project.
- In the planting borders, clay brick rubble from the region was used instead of imported products. Top soil available in the municipal warehouse was reused in the project.
- The concrete pavers from the Marktdreef were broken up and reused to connect the road next to the church and the market Square.
The overall design
The Kerktuin puts Wetteren in the foreground as a plant community that is fully committed to softening. The project is one of the first realized testing grounds of the project call ‘Vlaanderen breekt uit!’, subsidized by the Flemish Government. With its participation, Wetteren undertakes to maintain the decrease in paved surface for ten years, in exchange for subsidies and broad overarching guidance. By demolishing the existing buildings, more public space was created and the monumental character of the church came to the fore. The new Kerktuin is an attractive place to stay for young and old in the heart of the municipality where there used to be hardly any public green space. The green zone contains several terraces with lawns and perennials, a staircase with a footpath. The high location of the market square turned out to be an opportunity for a robust design that clearly visualizes more than five meters in height between the Scheldt and the market square. A perfect connection between the ‘new’ square on Rode Heuvel and the ‘old’ market square.
As a plant municipality, Wetteren set up a working group for the design, composed of, among others, local tree and plant growers and representatives of the horticultural sector from a local school. An underground buffer collects 100,000 liters of rainwater, mainly from the roofs of the church and the natural slope of the pavement. Some green zones have been created bowl-shaped so that they fill naturally with water that can overflow to the lower planting area. The plant sections inside and outside the project are watered with this recovered rainwater. At peak times, the Kerktuin becomes a veritable rain garden that can be partially flooded. Sufficient robust vegetation is provided in the planting areas for this purpose. Maximum effort has been made to recover materials. For example, recycled topsoil for embankment, cobblestones from the municipal depot and clay pavers were used as a mulch layer in the planting areas. The project resulted in approximately 1,700 m² of softened space.
The impact on the environment
The project functions as a testing ground for softening with the aim of reducing the warming of urban space: urban heat island. By replacing buildings, asphalt and other pavements with grass, plants and trees, there is more cooling in the warm periods of the year.
“Rain garden”: With a view to a sustainable future, a climate adaptive project is in the interest of every resident of Wetteren. The project acts as a counterbalance to the increasing densification and offers the local residents more open space and oxygen due to the softening. This not only increases the daily experience of the Wetteraar, but the green layout also increases biodiversity and climate resilience. Providing more grass, plants and trees contributes to a healthier living environment and helps to mitigate extreme temperatures and weather conditions locally.
The difference in height was not seen as a bottleneck but just as an opportunity to realize a climate-robust design. All rainwater drains through the natural slope towards the green areas that have been planted on seven terraces. Green zones were created in a bowl shape so that after heavy rainfall they naturally fill with water that can overflow into the lower planting area. Because the water stays in place longer, it has sufficient opportunity to infiltrate into the subsoil and does not have to be discharged via underground sewer systems. Rainwater runoff from the roofs of the surrounding buildings and from the adjacent pavement overflows into an underground rainwater buffer of 100,000 liters. This recovered rainwater is reused to water the plant sections in the Kerktuin and other green zones in Wetteren. The rainwater buffer in turn overflows to the Kerktuin where the rainwater can infiltrate again. At peak times, the Kerktuin is transformed into a veritable rain garden that can be partially submerged.
Innovative value of the project
The innovation value of the project is reflected in the combination of various points of attention: softening, reuse of materials, the concept of “rain garden” etc. It is the combination of these various points of interest and the courage of the board to implement this , which makes the project so innovative. The design consists on the one hand of lush green areas and lawns, with a generous passage for pedestrians and bicycles on the side of the church. Because the level of the site descends towards the Scheldt, a retaining wall was erected between the slow connection and the Kerktuin, which has to bridge a total difference in height of four meters between Markt and Scheldt quay. In the Kerktuin 4 itself, the levels gradually descend in a playful rhythm of green terraces, which makes the retaining wall and the difference in height less impressive. Sitting walls are provided between each terrace where it is pleasant to relax in a microclimate between the greenery. A staircase at the end of the Kerktuin connects it with the passage along the church, so that passers-by can also walk through the greenery from Markt to the Scheldt Bridge. The new Kerktuin is an attractive place to stay that also forms a crucial and green connection between Markt and Scheldt. These interventions create more public space and the monumental character of the church comes into its own. This softening project is an important step towards climate adaptation in order to develop a more robust and liveable center for the climate. The most important spearheads of the design are the buffering and infiltration of rainwater in attractive, diverse plant borders, the recovery of rainwater thanks to a smart system, the reuse of materials and working with robust new materials.