Vegetated Geogrids

Coconut Fiber RollsApproachConstruction CostSoft Hard Low HighMaintenance CostAdaptabilityLow High Low HighDescriptionCoconut fiber rolls are long, cylindricalstructures constructed from the fibers ofa coconut. They are most commonlyconstructed with diameters on the orderof 12 inches and lengths of between 18and 24 inches. The rolls are typicallyheld in place at the toe of a slope usingstakes. Coconut fiber rolls are used toboth prevent minor sliding on the shore,and to impede shoreline erosion.flow and wave energy are the twodominant destabilizing forces whichmust be considered.The first step in the construction processis the digging of a trench at the toe of theslope. The coconut fiber roll is thenplaced in the trench, with stakes utilizedto stabilize it. Back fill is added behindthe roll and vegetation is planted toprovide additional protection.DRAFTFigure 35: Close up of a coconut fiber roll.AdaptabilityFigure 34: Typical coconut fiber rollinstallation.Design and ConstructionCoconut fiber rolls are manufacturedoff-site and must be ordered prior to thecommencement of site preparation. Therolls are normally placed at the toe of theslope at the stream-forming flow stage.Shear stresses related to the dominantThe standard life of a coconut fiber rollis six to ten years. The roll is flexibleand can be formed to fit the curvature ofthe stream bank before placement. Onceplants start growing within the fiber rollthe structure can become rooted into thesoil. Once the roots take hold, thestructure can no longer be easilyrelocated.