Due to climate change, storm surges are becoming more frequent. The coast in the seaside resort of Lubmin, Germany, was exposed to several storm surges over a short time. In case of an additional storm surge, the existing coastal protection dune was in danger of breaking.
In 2017 and 2019, a total of three storm surges hit the coast of Lubmin. As a result of the storm surges, the coastal protection dune was severely affected by erosion. The sand dune is also not designed according to its intended cross-section due to the limited space. An additional construction had to be created as the last barrier against a breakthrough in the event of another storm surge and the imminent complete erosion of the dune. This barrier, which must remain stable in the event of a storm surge, was built with Secutex Soft Rock from NAUE.
Secutex Soft Rock are geotextile sand-filled bags, containers or tubes manufactured from needle-punched Secutex filter nonwovens geotextiles. Geotextile sand containers (GSC) encapsulate fill materials like sand and are used as construction elements. In addition to GSCs made of single-layered nonwovens for covered applications, GSCs made of double-layered nonwovens are also available. These provide an integrated surface protection layer of rough fibers for exposed designs and adapt perfectly to a sandy environment.
The GSCs were placed at the coast of Lubmin after the sand had been removed. Stacked in an offset manner and inclined toward the land side, they form a so-called geotextile wall.
Geotextile walls for dune reinforcement are covered by sand for most of their service life and appear natural. Only after severe erosion caused by one or more storm surges, the geotextile wall becomes visible again. If that happens, the dune is restored in its overall geometry, and its appearance is harmoniously adapted to the landscape again.
Around 33,000 GCSs were installed to reinforce 1.1 miles (1.8 km) of the dune along the coast of Lubmin. Each container was filled with 35 cubic feet (1 m3) of sand directly on the beach. A filled sand container weighs 1.3 tons (1.2 tonnes).
The mayor of Lubmin says that the geotextile wall made of sand containers is the solution that the people of Lubmin have wanted for a long time.
Comparable coastal protection structures had already been realized in Rerik and Warnemünde, Germany.
To watch a video about the coastal protection project in Lubmin, click here.
This article first appeared on the NAUE News website, www.naue.com/news.