The Frisian Lakes project has opted for Prolock, the sustainable and innovative soil and flood defence based on recycled plastic, for protecting undefended banks on the Turfroute. The Turfroute is a tourist sailing route through the South-East Friesland, the Western part of Drenthe and the top part of Overijssel. It is one of the tourist spearheads in South-East Friesland. This is the second time that the plastic solution has been applied for a provincial sailing route in Friesland.
The province of Friesland selected the plastic system on the basis of the environmentally friendly properties and the preservation of the natural banks. Through the finish with a rockfill back, the bank is protected against waves and the vegetation can regenerate. The plastic solution is fully under water, due to which the natural appearance is preserved. The province of Friesland also deems the ease of insertion to be of significant importance for their selection process. The plastic screens can easily be inserted due to their light weight. Underwater installation is not required, since the screens are interlocked or pushed together on a pontoon, and no bolts are used. Thanks to the sustainable characteristics – plastic has a minimum lifespan of fifty years – the solution is also virtually maintenance-free for the municipality. Two types of plastic profiles are used for the Turfroute. For the lower banks, Prolock Sigma was used in combination with pinewood posts. For the higher sections, Prolock Omega was used in combination with Clouziana hardwood. In total 1139 metres Prolock Sigma, and 1421 metres Prolock Omega are inserted. Gerit van den Berg, Project Leader for the Frisian Province: “This is the second time that the province is working with Profextru, the manufacturer of Prolock. Last year they replaced the piling at the Helomavaart. The result has such a natural appearance that we decided once again to opt for Profextru.” At present, the Turfroute is suited for boats with a draught of 1.10 metres.
The Frisian Lake Project jointly with the municipalities of Ooststellingwerf and Opsterland are in the process of determining whether the route can be dredged to a depth of 1.30 metres. This would ensure that the route is accessible for boats with a deeper draught. Moreover, it is now more easy for boats to pass each other.