How geosynthetic products can help create more efficient waterways?
Commercial, agricultural, and recreational canals continue to be important economic drivers in many countries. A wide range of geosynthetic products, such as geotextiles, geomembranes, and geosynthetic clay liners (GCL), help create more efficient waterways. These geosynthetics improve the long-term performance of canal systems by preventing bed and slope erosion and by decreasing significantly the risk of problematic sedimentation. The oldest canal installation carried out with a Naue nonwoven geotextile is a testament to the long-term durability and success of geosynthetics in erosion control applications. The Mittelland Canal in Germany incorporated Naue geotextiles in 1967. In 2017, the project marks its 50th anniversary.
Water quality is preserved, water flows more dependably, and canals continue to operate as intended. When installed below permeable revetments (e.g., riprap) as a filter layer, needlepunched nonwoven geotextiles (e.g., Secutex® H) prevent erosion and soil displacement, even under high hydrodynamic loads. The high elongation capacity and robustness of the nonwoven geotextiles allow them to easily accommodate to irregular and soft subgrades.
Geotextiles are also used in protection applications with canals, such as to separate a barrier material (e.g., geomembrane) from a cover aggregate. When geotextiles like Secutex® H are used this way, the canal lining system takes full advantage of the durability properties of the nonwoven geotextiles. The lining system is protected against damage during installation, which is crucial to ensuring its proper performance in service.
Barrier geosynthetics such as Bentofix® GCLs and Carbofol® geomembranes are used to improve canal performance in numerous applications.
For irrigation canals, geosynthetic lining systems prevent seepage loss into soils. This improves the economics and sustainability of the irrigation system. The geosynthetic barrier also optimizes water flow in the canal network. Irrigation is conveyed more quickly and efficiently. For hydroelectric canal systems, water is delivered to the power generating stations more dependably and cleanly.
Commercial and recreational canals also benefit from the installation of geosynthetic lining systems. Carbofol® geomembranes and Bentofix® GCL barriers can prevent sedimentation of waterways from high flow or from propellers stirring up the water along the bed. Where water levels are at an elevation higher than the natural groundwater level, the seal guards against seepage loss, thus keeping the canals open to safe navigation.
Bentofix® geosynthetic clay liners can be installed underwater during active canal operations. One type of Bentofix® (BZ 13-B) uses a composite construction with a sand ballast mat. For canals undergoing rehabilitation, this GCL-sandmat composite can give an aging network new life without taking the system out of service.
Carbofol® geomembranes are available in smooth and textured varieties to optimize designs for better flow, more effective transfer of shear forces, and more secure slope lining. These barriers may be used in water-covered, partially exposed, and fully covered (by soil or concrete) designs.
Nonwoven geotextiles, such as Naue Secutex® H, perform many critical functions for canal systems. They cushion and protect containment geosynthetics. They prevent erosion and separate disparate soils. They filter out sedimentation and guard against washout. Ultimately, their robustness and versatility help ensure long-term, successful performance for canals.