Sealing hydropower structures describes the application of geosynthetic barrier systems to dams, reservoir slopes and hydraulic structures. Hydraulic head, seepage and slope erosion create long-term risks. Carbofol® HDPE geomembranes and Bentofix® geosynthetic clay liners provide proven, watertight solutions for run-of-river plants, storage reservoirs and pumped-storage schemes.
Naue geosynthetics are used wherever watertightness, slope stability and long service life are essential.
Permanent sealing of upstream dam faces against hydraulic head and seepage loss using Carbofol® HDPE geomembranes
Erosion protection and liner systems for reservoir and intake-canal embankments using Bentofix® GCL and Secumat®
Composite sealing for upper and lower basins under cyclic water-level fluctuation using Carbofol® HDPE with a textured surface
Hydropower dam and reservoir liners must withstand permanent hydraulic head, temperature cycles and construction loads. Carbofol HDPE geomembranes and Bentofix geosynthetic clay liners are engineered for exactly these conditions. Their installation has been proven on large-scale projects with steep and rocky slopes, including sections requiring mechanical rock-bolt anchorage.
The dimensioning of geosynthetic sealing systems for hydropower structures is based on recognised international and national design standards. Naue engineers support project teams from concept through to installation qualification.
Watertight lining of headrace canals and inlet works to prevent water loss using Carbofol® HDPE geomembranes
Practical advantages:
Hydropower sealing requires matching the barrier system to the subgrade, load class and drainage requirements.
Key principle: The sealing function and the drainage function must be addressed independently.
Where redundancy is required by regulation or design, both components Carbofol® and Bentofix® are combined. The composite system achieves permeation rates as low as 2.59 × 10⁻¹³ m³/s per defect.
Secudrain® drainage composites supplement the selected sealing system where water accumulation behind the liner would impose mechanical stress or cause uplift (particularly on steep embankments and reservoir slopes with variable water levels).
Use this table to identify the correct sealing approach for your hydropower project. More than one criterion may apply. Contact Naue technical support or use the Naue Portal for project-specific selection and design advice.
| Criterion | Site condition | Primary product | Supporting products |
|---|---|---|---|
| Subgrade type | Compacted embankment, smooth substrate | Carbofol® HDPE (smooth or textured) | Secutex® protection nonwoven above and below |
| Subgrade type | Natural slope, rocky or irregular surface | Bentofix® GCL (needle-punched, scrim-reinforced) | Secudrain® in steep sections; Secutex® |
| Load class | Permanent high hydraulic head (dam, reservoir) | Carbofol® HDPE 2.0–2.5 mm structured | Bentofix® as a redundant mineral layer |
| Load class | Cyclic load (pumped-storage, tidal) | Carbofol® HDPE with a textured surface (F/F or MF/MF) | Secutex® R401 protection layer |
| Filtration need | Seepage and particle migration through embankment | Bentofix® GCL as a mineral seal | Secudrain® drainage composite |
| Installation condition | Underwater or fast-current sections | Bentofix® BZ13-B (integral sand ballast) | A certified underwater installer is required |
Planners and engineers
Carbofol® HDPE geomembranes are manufactured by flat-die extrusion to ensure consistent thickness and density. They meet the stringent requirements of BAM approvals (e.g., Carbofol® HDPE 510 No. 08/BAM IV.3/08/15) and GRI GM13 test standards. Engineers can verify performance against DIN 18195, EN 13361 and ICOLD bulletin 135 guidelines.
Buyers and decision-makers
A 10 mm hydrated Bentofix® GCL layer delivers equivalent sealing performance to a 600 mm compacted clay liner. This translates into less material transport, reduced earthworks – a significant ROI argument for procurement managers on large hydraulic projects.
Site engineers and contractors
Naue certified installers are trained in geosynthetic sealing on steep rocky dam faces using rock-bolt anchorage systems. Detailed installation manuals, QA plans and weld-test protocols are available for every project.
Long service life and maintenance reduction
HDPE geomembranes exhibit excellent chemical resistance, UV stability and long-term dimensional stability. Secumat® erosion control mats provide permanent slope protection through root reinforcement, eliminating repeat maintenance cycles over the asset life.
Geosynthetic sealing for hydropower plants describes the use of HDPE geomembranes and geosynthetic clay liners (GCLs) to prevent seepage through dam bodies, reservoir slopes and hydraulic structures. It is required wherever permanent hydraulic head, variable water levels or erosive flow conditions create unacceptable seepage risk that cannot be addressed by compacted clay or concrete alone.
Choose Carbofol® HDPE geomembrane as the primary polymeric barrier for smooth or prepared substrates with high hydraulic head. Choose Bentofix® GCL where a self-healing mineral layer is required, where compacted clay is uneconomic or where a secondary redundant barrier is specified. For maximum sealing performance, both products are combined in a composite system.
Relevant standards include DIN 18195 (waterproofing of structures), EN 13361 (geomembranes for reservoir lining), ICOLD bulletin 135 (geomembranes in dams), DVWK 113 and BAM approval requirements for Germany. Carbofol® HDPE 510 2.5 MF/MF holds BAM approval No. 08/BAM IV.3/08/15. Project-specific standards and national regulations must be verified by the design engineer. For any assistance please contact our engineering team via contact request form.
A 10 mm hydrated Bentofix® GCL layer matches the sealing performance of a 600 mm compacted clay liner at significantly lower cost. Savings arise from reduced material volume, fewer transport movements, shorter installation time and lower earthworks requirements. Exact savings depend on project scale and local material costs.
Installation on steep slopes requires specialist contractors with certified welding equipment. For rocky surfaces, rock-bolt anchorage (typically 0.6 m cemented bolts with a 20 mm diameter) secures the upper section of the liner. Geomembrane welds are double-track fused and pressure-tested. Naue provides installation service, manuals, QA plans and technical supervision.
ICOLD bulletin 135, EN 13361-1 and DVWK 113 govern geomembrane performance in hydraulic engineering. Design permeation calculations for composite systems (geomembrane + GCL) are based on published leakage models (e.g., Giroud and Bonaparte, 1989). Naue provides design support in accordance with current international guidelines and national requirements. Respective digital calculators are available in the Naue Portal to assist your solution selection and design process.
Carbofol® HDPE geomembranes are manufactured from food-grade HDPE resin and are suitable for contact with drinking water. BAM-approved variants comply with German regulatory requirements for sensitive hydraulic applications. For specific certifications and approvals relevant to your project country, please contact the Naue sales team.
Secudrain® is placed immediately behind the geomembrane or GCL to collect and convey any water that passes the primary seal. In steep embankment sections, it prevents the build-up of pore-water pressure that could cause uplift or lateral displacement of the liner. Drainage is directed to a controlled collection point at the dam toe. The composite is specified in accordance with DVWK 113 drainage requirements.
All geomembrane welds are double-track extrusion-fused and tested by air-lance or pressure-channel method after completion. Naue provides project-specific QA plans, weld test records and material traceability documentation. For BAM-approved projects, additional destructive test frequency is specified. Naue´s certified installation teams are trained in both welding and the safety requirements for steep dam-face installation.
Naue Carbofol® is a HDPE liner for landfill sealing, mining containment, and groundwater protection.
Naue Bentofix® is a geosynthetic clay liner (GCL) for waterproofing in landfill engineering, groundwater protection and hydraulic applications.
Naue Secutex® is a mechanically bonded nonwoven geotextile for separation, filtration and protection in roads, railways and hydraulic engineering projects.
Naue Secudrain® is a geosynthetic drainage geocomposite for landfill, groundwater protection and building structures.
Naue Secumat® is an erosion control mat for the protection of slopes, channels and embankments.