For the first test the solution is subject to a flow rate of 350 l/s. This flow rate is set for 30 minutes. After these 30 minutesthere is no visible damage to the mat or the underlying grass layer. On the edges of the mat there is some unraveling of the fibers. This does not cause any damage because the mat is folded double on the edges,and they are anchored in the ground. On top of the levee there is a little erosion,and the grass cover is flattened. This has no consequences for the stitches of the mat. This can also be sediment that precipitates that has been sucked up by the pump. After the first test the water flow rate is increased to 540 l/s. This flow rate is also set for 30 minutes. As a result of this test, there is a little change visible. The mat is stretched because of the water friction. This causes bumpers at the anchoring pointsin the mat. In the middle of the levee at the height of the overlapping, the mat starts to unravel. This damage does not get worse with subsequent tests. For a flow rate of 600 to 700 l/s, there is an increase of the bumpers on the anchoring points. At the bottom of the levee there are some sandbags that moved. This movement is caused by the water that flows under the mat.

The removal of the repair works can be done quickly. By loosening the mat from above, it can be slowly rolled down. By rolling, the anchor pins come loose and can be detached from the mat. In this way, no pins will remain in the levee.The clean-up works were completed within ±30 minutes.

See Report for more information and pictures.

We can conclude that the chosen method is certainly sufficient to protect the levee. During the implementation wealsodiscovered a few things. For example, it could be decided that the provided planks that we wanted to place on the sidesarenot practical and also not necessary. The use of the U-pins is also not very practical and can also be omitted. The method used is easy,quick to installand protects the whole levee. Another plus is that the coconut mats and sandbags are biodegradable. The only non-degradable material used are the anchoring pins. These are made of steelbutarefully reusable.If you look at the price it can also be said that this is a fairly cheap solution. Another advantage is that thismatcan also serve as a long-term protection forthe levee. This way the levee is protected against a short-termflooding but meanwhile repairs itself over the next 36 months until the mat is fully degraded. We have approached various companies in the choice of materialsand they allpresented different options. For the damage that has occurred on this leevee the reparation price per square meter would be 14,04 euro. This is only the price for the materials. The work-and manhours have yet to be settled. However, as already mentioned, we can state that this solution does not require any heavy tools or materials. The additional costs will therefore not be immense andthere is still apossibility to further optimize this process.We also want to promote that this method, apart from the fact that it can be used several times, can also be used as a permanent solution.After some time, whenroots have grown through the geotextile, an intertwined system with increased erosion resistance is formed.