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Aerial view of a large hydroelectric dam constructed with Naue geosynthetics on a wide river, surrounded by earthworks, cranes, and construction equipment in a rural landscape.

Seal hydropower systems

Geosynthetics for canals and penstocks

Hydropower development refers to the construction and operation of run-of-river or storage-based generation facilities. Uncontrolled seepage from conveyance channels, forebay basins and settling ponds reduces hydraulic efficiency and threatens structural integrity. Carbofol® geomembranes, Bentofix® geosynthetic clay liners (GCLs) and Secutex® protective geotextiles provide reliable, long-lasting sealing solutions engineered for the demands of hydropower civil works.

At a glance

  • Sealing and lining of canals, penstocks, basins and ponds for hydropower schemes, where watertightness is critical for efficiency and structural safety.
  • Carbofol® geomembrane, Bentofix® GCL, Secutex® nonwoven geotextile, Secumat® erosion control mat
  • Significant reduction in seepage losses compared with unlined channels
  • EN 13361, EN 13362, EN ISO 12958, GRI GM13, ETN-CCL
  • Run-of-river schemes, diversion canals, pipes, forebay basins, settling ponds, banks of canals and ponds, access roads

Hydropower canal sealing: from seepage problem to reliable power generation

Challenges

  • Seepage losses from unlined canals and basins reduce hydraulic head and energy yield
  • Permeable or fractured subgrade makes conventional clay lining impractical
  • Erosion of channel banks and forebay embankments under variable flow
  • Difficult site access in remote mountain or rural locations
  • Strict environmental requirements near watercourses and protected habitats

Solution

  • Carbofol® HDPE geomembranes for watertight lining of canals, basins and penstocks
  • Bentofix® GCLs as a thin, self-sealing barrier beneath RC structures and on irregular subgrades
  • Secutex® protection nonwoven geotextiles against puncture and installation damage
  • Secumat® erosion control mats for vegetated bank and embankment protection

Result

  • Barrier systems designed for a long service life in buried applications
  • Significant reduction in seepage losses compared with unlined channels
  • Thin lining profile preserves hydraulic cross-section
  • Faster installation compared to compacted clay
  • Integrated system solutions for sealing, protection and drainage in one supply chain
  • Compliance with EN 13361, EN 13362 and project-specific barrier requirements

Hydropower: typical sealing and lining applications

  • Canal construction

    Diversion and conveyance canals

    Reliable sealing of open channels conveying water to the turbine headworks

  • Ponds reservoir

    Basins and headponds

    Watertight retention of hydraulic head upstream of the penstock intake

  • Sedimentation pond

    Settling and desanding ponds

    Impermeable containment to protect turbines from sediment inflows

  • Pipe line construction

    Penstock surrounds and culverts

    Seepage protection and load distribution around buried pressure pipework

  • Unpaved roads access roads

    Embankments and access roads

    Slope stabilisation, erosion control and traffickable access on soft ground

Workers on floating platforms and canal banks installing Naue Carbofol® geomembranes as watertight sealing layer in a hydropower canal.
Workers on floating platforms and canal banks installing Naue Carbofol® geomembranes as watertight sealing layer in a hydropower canal.

Built to last in hydropower environments

Hydropower structures face a demanding combination of hydraulic pressure, UV exposure, freeze-thaw cycling, root penetration and construction traffic. The hydraulic performance of any hydropower scheme depends on the integrity of its water-retaining structures. Naue geosynthetic lining systems are engineered to withstand all of these loads throughout a design life and address every lining requirement from simple channel sealing to complex multi-layer barrier systems.

Practical advantages:

  • Carbofol® HDPE provides high oxidative stability for buried and exposed conditions and is stress-crack resistance to point loads and root intrusion.
  • Bentofix® GCL with its high-swelling sodium bentonite core self-seals on contact with water.
  • Secutex® protective geotextile installed above and below the geomembrane prevents puncture during backfilling.
  • Double-wedge welding with air-pressure test channel: every seam verified on site before backfill.

Hydropower lining: frequently asked questions

Hydropower lining refers to the installation of geosynthetic barrier systems in canals, forebay basins and settling ponds serving hydropower generation plants. Uncontrolled seepage reduces available head, cuts energy yield and can undermine embankments. A correctly specified geomembrane or GCL system maintains hydraulic efficiency and structural integrity for the full design life of the scheme.

Product selection depends on subgrade conditions, hydraulic head, site access and installation constraints. Carbofol® HDPE geomembrane suits prepared granular subgrades with controlled construction traffic. Bentofix® GCL is preferred on irregular or rocky subgrades and beneath reinforced concrete structures. A composite system with Carbofol® over Bentofix® is recommended for high-head or high-risk containment.

Relevant European standards include EN 13361 (reservoirs and dams) and EN 13362 (canals) for geosynthetic barriers, and EN ISO 12958 for drainage geocomposites. The ETN-CCL certification applies to GCLs used as clay liner equivalents. National standards may additionally apply. Carbofol® and Bentofix® carry the required CE marking and third-party certification documentation.

The subgrade is compacted and freed of sharp objects. A Secutex® protection nonwoven geotextile is placed first. Carbofol® rolls are unrolled and welded using a double-wedge machine, creating an intermediate air channel. Each seam is pressure-tested before backfilling. Naue recommends engaging a certified specialist installer and conducting a pre-installation inspection of the subgrade. Full CQA documentation is available. Please see the laying and installation services page for more info on Naue´s installation offer.

Yes. Carbofol® HDPE geomembranes and Bentofix® GCLs are manufactured without plasticisers and are chemically stable in contact with fresh water. On remote sites, the low weight and volume of roll-goods reduces transport requirements compared with bulk clay. Secumat® erosion control mats support revegetation of disturbed banks, aiding compliance with the EU Water Framework Directive.

Bentofix® GCLs are certified as geosynthetic barriers to EN 13361 (reservoirs and dams) and EN 13362 (canals), and to ETN-CCL (clay liner equivalence). The hydraulic conductivity of Bentofix® is k ≤ 5 x 10-11 m/s. CE marking and Declaration of Performance documents are available from Naue on request.

Carbofol® HDPE contains carbon black (2 - 3% by mass) and has an OIT of ≥ 100 min (EN 728), providing resistance to UV degradation and oxidative ageing in exposed conditions. Bentofix® GCL benefits from the resilience of sodium bentonite under freeze-thaw cycling: bentonite re-seals on re-hydration. Both products have been installed at high altitude and in alpine climates.

Carbofol® geomembranes are anchored at the crest of canal banks and basin embankments using a buried anchor trench (typically 500 mm deep and 300 mm wide) filled with compacted soil or concrete. On steep side slopes, intermediate anchor strips or continuous anchor seams may be specified to resist downslope creep under hydraulic head. For floating or exposed liners, ballasting with pea gravel or concrete slabs prevents wind uplift. Naue’s software tools and engineering teams provide assistance for project-specific system design in accordance with EN 13361, EN 13362 and DVWK or BAW guidance.

Bentofix® GCL panels are overlapped at longitudinal and end joints. Bentofix® NSP grades feature a bentonite-enriched border strip on all four edges, which provides self-sealing at the overlap on hydration so that no additional sealant is required for standard installations. For applications with elevated ionic water chemistry (saline or contaminated inflows), contact Naue’s engineers to confirm GCL grade selection and overlap specification.

Hydropower lining design: normative framework and Naue tools

The dimensioning of geosynthetic lining systems for hydropower structures follows recognised European and international standards. Naue’s software tools assist you in selecting the correct product type, barrier class and protection level for your project - compliant and fully documented. You can also request personal advice by the Naue engineering team:

  • EN 13361: Geomembranes for construction of reservoirs and dams
  • EN 13362: Geomembranes for construction of canals
  • ETN-CCL: GCL clay liner equivalence - European Technical Note
  • GRI GM13/ASTM D5397: HDPE geomembrane stress-crack resistance (NCTL)
  • EN ISO 12958: Flow capacity of drainage geocomposites
Hydroelectric power station with transmission lines and a canal which is lined with Naue geosynthetic barriers for watertight sealing.
Hydroelectric power station with transmission lines and a canal which is lined with Naue geosynthetic barriers for watertight sealing.

Hydropower lining system: build-up and function

  1. Carbofol® HDPE geomembrane: very low permeability water barrier, EN 13361/EN 13362 compliant
  2. Secutex® protection geotextile: GRK-rated puncture protection above and below the liner
  3. Bentofix® GCL: self-sealing sodium bentonite core, ideal for irregular subgrades and RC structures
  4. Secumat® erosion control mat: permanent bank and embankment protection with vegetation support
  5. Integrated system: single-source supply, matching certifications and documented compatibility

Downloads and services

  • Renewable energy safe sealing rehabilitation of pumped storage plant Hohenwarte IIYouTubeWatch
  • Renewable energies - hydropower - safe sealing for power channelsYouTubeWatch

Geotechnical software

Naue Portal - the free digital platform for geotechnical engineers.

Naue Portal: your all-in-one free geotechnical software solution for planning and cost estimation

  • One platform – multiple solutions: access a wide range of geotechnical design tools in a single portal.
  • User-friendly and accessible: available anytime, anywhere via desktop or mobile.
  • Optimised cost and material usage: reduce construction costs while ensuring long-term project stability.
  • Compliant with industry standards: aligns with AASHTO, and other engineering guidelines.