top of page

Ökoweiher Tössfeld

Realized:

2018

performed by:

Naturnetz Nordostschweiz

In October 2018, we from the Naturnetz Nordostschweiz team had the opportunity to put a special project into action. As the Winterthur municipal utility is constantly adapting its infrastructure for supplying the population with water and electricity to new circumstances, new buildings are being built and outdated facilities are being dismantled.

Such demolition has now benefited nature in Winterthur Töss in the Meiengstell/Chrebsbach area. An old, partly underground water reservoir was dismantled there and all concrete walls, fences and foundations were removed. What remained was a crater which was not refilled but was to serve as the basis for a new pond. After the rough level had been created and compacted, the installation of clay could begin. Clay because the forestry company specified that no foreign substances such as pond liner could be used. Four layers of very clayey pressed sludge were installed, a waste product from gravel processing, which was repeatedly compacted with a ramming roller. The first three layers were also mixed with lime stabilizer. The lime reacts with the moisture in the clay to form calcium hydrate, which improves the soil mechanical properties of the clay and therefore improves its impermeability. To ensure that the pH value in the pond water does not become too high, this additive was not used in the last layer. Just one week after completion, the pond was half full due to the influx of rainwater, meaning that neighboring amphibian populations immediately found a new habitat.

bottom of page