Geosynthetic liner systems for irrigation and navigation channels
Canal lining describes the installation of a watertight barrier along the bed and sides of a canal or water conveyance structure. Seepage, erosion and water loss reduce efficiency in irrigation and navigation. Bentofix®, Carbofol® and Secutex® provide a proven, long-term sealing solution for irrigation canals, navigation channels and water supply structures worldwide.
Canal construction: geosynthetic liner systems | Naue | Naue
Canal lining: challenges, solutions and measurable results
Challenges
Water loss through seepage reduces irrigation efficiency
Erosion of the canal bed and slopes threatens the structural integrity of the conveyance structure
Compacted clay liners fail under freeze-thaw cycles and desiccation
Complex geometry and variable subgrade conditions complicate conventional lining methods
Solution
Bentofix® GCL as a low-permeability sealing layer; variants for underwater installation without dewatering operations
Carbofol® HDPE geomembrane for maximum barrier performance and chemical resistance
Secutex® nonwoven as a protection layer for geomembranes above the subgrade
System solutions: GCL + HDPE composite or standalone GCL for simpler applications
Result
Hydraulic conductivity k ≤ 5 × 10⁻¹¹ m/s
Up to 50% less excavation compared with compacted clay liner
Self-healing sealing under desiccation and freeze-thaw without manual repair
Easy installation with rolls up to 5 m wide; no welding required for the GCL system
Proven performance on thousands of km of canals worldwide
Typical applications for canal lining in hydraulic engineering
Naue products are used wherever watertight containment, long-term sealing integrity and cost-efficiency are essential.
Navigable waterways
Durable lining for shipping canals and waterways subject to wave action, vessel wash and variable water levels
Water supply channels
Approved lining solutions for potable and non-potable water conveyance structures and headrace channels
Irrigation canals
Sealing agricultural irrigation channels to prevent water loss and protect water supply efficiency
Robustness and installation reliability
Canal lining must perform reliably from day one of installation through decades of service. Bentofix geosynthetic clay liners (GCLs) and Carbofol geomembranes are designed to withstand installation stresses on complex canal geometries. Bentofix GCL rolls are up to 5 metres wide, reducing the number of overlaps and joints. Carbofol HDPE geomembranes combine high elongation with stress crack resistance for durable service.
The dimensioning of geosynthetic canal lining systems is based on recognised standards and project-specific hydraulic requirements. Our technical team and digital geotechnical tools support planners with product selection and system design.
EN 13362: Geomembrane characteristics required for use in canal and waterway lining
EN 13255: Geotextiles and related products: characteristics required for use in canals and waterways
ASTM D5887: Hydraulic conductivity testing for geosynthetic clay liners (GCL) under confining stress
BAW guidelines (Germany): Federal Waterways Engineering and Research Institute guidelines for canal and waterway lining
Bentofix® can be installed in dry and wet conditions – and even underwater (BZ13-B variant).
More than 2 million needle-punched fibres per m² lock the bentonite core and prevent lateral migration.
Carbofol® smooth liner suits canal bases; the textured variant improves interface friction on slopes.
Secutex® nonwoven protection layers safeguard geomembranes from subgrade puncture during installation.
Seepage control – GCL, geomembrane or composite system?
The appropriate sealing system depends on the hydraulic requirements, the canal geometry and the subgrade conditions. Bentofix® GCL provides self-healing, low-permeability sealing. Carbofol® HDPE offers the most chemically resistant barrier. Combining both products creates a redundant composite liner for critical applications.
Key principle: Sealing prevents water loss and protection extends the service life of the liner system where necessary.
GCL standalone system
Bentofix® as the primary sealing layer
Self-healing under desiccation and freeze-thaw conditions
Simpler installation; fewer layers and site interfaces
The selection of the appropriate canal liner depends on the hydraulic conditions, the chemical composition of the water and the project requirements. The table below provides a structured decision guide.
Criterion
Bentofix® (GCL)
Carbofol® (HDPE)
Composite GCL + HDPE
Subgrade type
All soils including soft and reactive subgrades
Stable, compacted subgrade preferred
All subgrades; additional protection via Secutex®
Hydraulic head
Low to moderate hydraulic head
High hydraulic head, high chemical load
High head + redundancy required
Self-healing capacity
Yes – bentonite rehydrates after desiccation
No – punctures require manual repair
Yes (GCL layer provides self-healing)
Installation conditions
Dry, wet or underwater (Bentofix® BZ13-B)
Dry conditions preferred; welded seams
Combined installation sequence
Chemical resistance
Standard freshwater conditions
Excellent – wide chemical resistance
Maximum chemical resistance
Recommended grade
Bentofix® NSP 4900 / BFG 5300 / BZ13-B
Carbofol® HDPE 406 / 507
Carbofol® + Bentofix® + Secutex®
Benefits from canal lining with Naue geosynthetics
Reduced water loss, higher irrigation efficiency
Bentofix® GCL achieves hydraulic conductivity equivalent to or better than 0.5 m of compacted clay. Canal operators reduce water loss significantly, improving the efficiency of irrigation and water supply networks.
No desiccation failure
Conventional compacted clay liners crack during dry periods. Bentofix® bentonite rehydrates and self-seals after desiccation, maintaining the barrier without repair intervention throughout the asset life.
Faster (underwater) installation
Bentofix® rolls are 5 m wide, with simple overlap sealing and no welding requirement. The Bentofix® BZ13-B variant is engineered for underwater installation. This eliminates costly dewatering operations on active or partially filled canals, significantly reducing programme risk and cost.
Canal lining in hydraulic engineering: frequently asked questions
Canal lining is the installation of a watertight barrier along the bed and banks of a canal or water conveyance structure. It is required when seepage losses reduce operational efficiency, when erosion threatens structural integrity, or when environmental regulations require containment of water to prevent groundwater contamination.
The choice depends on hydraulic conditions, chemical exposure and project constraints. Bentofix® GCL suits most irrigation and navigation applications, providing self-healing sealing at lower installation cost. Carbofol® HDPE geomembrane is preferred where chemical resistance or very high hydraulic head is required. A composite system is recommended for critical applications requiring redundant protection.
Key standards include EN 13362 (geomembranes for canals) and EN 13255 (geotextiles for canals) for geosynthetic barriers in hydraulic engineering. GCL hydraulic conductivity is tested in accordance with ASTM D5887. In Germany, the BAW (Federal Waterways Engineering and Research Institute) guidelines apply. National irrigation authority standards may apply for agricultural canals.
Geosynthetic liners are typically more economical than compacted clay liners. Bentofix® GCL requires less excavation and avoids the need to import and compact clay fill. Faster installation also reduces plant and labour costs significantly.
Bentofix® GCL is rolled out from the top of the canal bank downwards. Overlaps of at least 300 mm are maintained and no welding is required. The Bentofix® BZ13-B variant allows underwater installation without dewatering. Once placed, the GCL is anchored at the crest and covered with a protective or structural overlay as specified in the design. Contact Naue for installation manuals.
Bentofix® GCL and Carbofol® geomembranes have been used for canal and water conveyance lining for decades across irrigation, navigation and industrial water management projects worldwide. Case studies and project references are available on the case studies page.
Bentofix® GCL is designed to self-heal after desiccation. When water returns to the canal, the sodium bentonite core rehydrates and swells to restore the low-permeability seal. This self-healing property is a critical advantage over compacted clay liners, which can develop permanent desiccation cracks that require costly repair. The bentonite core remains functional after multiple wet-dry cycles.
Yes. Naue supplies Bentofix® GCL, Carbofol® HDPE geomembrane and Secutex® protection geotextile as a coordinated system from a single source. This simplifies procurement, ensures product compatibility and provides a single point of technical responsibility. Discover digital selection and planning support in the Naue Portal software pool. Naue engineering support is available for composite system design, specification and installation qualification.