Restoration of the Siesel Power Station Canal

The Siesel power station, featuring a channel approximately 200 meters in length, has been operational since its establishment in 1898. The channel relies on the waters of the Lenne River in Plettenberg to power its turbines. However, over time, the aging of the channel's sealing system, constructed with tamped concrete and armour stones in 1921, has resulted in leakage issues. In recent years, the leakage into the drainage system has increased significantly, necessitating a comprehensive maintenance plan. To address the problem, two attempts were made to seal the channel using mortar application during dry conditions, but they did not yield the desired success. As a result, in May 2022, Mark-E, the operator of the power station, decided to explore alternative lining methods and had their first meeting with Huesker Synthetic.

After careful evaluation, the decision was made to employ Incomat^® Standard to achieve impermeabilization and mitigate leakage from the channel. Incomat Standard is a concrete mattress comprising two layers of high tenacity polyamide and polyethylene fabric, connected by binder threads that control the mattress's filled thickness. The woven layers retain concrete fines while allowing the passage of excess water from the fill material. The contract for the renovation works using Incomat Standard was awarded to Hagn Umwelttechnik GmbH. The preliminary works consisted of removing any sharp edges from the old channel to prevent damage to the Incomat material. 3 panels were installed in total, interconnected to each other with prefabricated industrial zippers, thus providing a continuous sealing layer over the entire channel. Each panel was around 55 meters long and 15 meters wide. After placing the panels, the Incomat mattress is filled with a flowable concrete. The Incomat was connected at the start of the canal with metal sheets and bolt anchors. The connection to the walls was also secured with metal sheets. The adaptability of Incomat to the channel made the installation efficient. Even the almost vertical walls close to the weir could be protected only with help of the fixation during filling.

The solution with Incomat provided efficient results when it came to controlling the leakage. During a site visit 6 months after the construction, Mark-E stated that the drainage channel is totally empty of water. This is an important difference compared to the thousands of litres of daily leakage before the restoration. Additionally, the Incomat turned out to be the most economical solution, with a rapid installation. The whole process from the first meeting with Huesker Synthetic to the restart of the electric production took less than 6 months, leaving the client really satisfied from the solution.