GeoCurtain™ Class 1 Silt Curtain – Calm Water Sediment Control

Silt curtains are standard specification on marine construction projects involving seabed disturbance - harbour construction, jetty and pier installation, bridge foundation works, pipeline laying, and capital and maintenance dredging. Suspended sediment generated by these activities can migrate significant distances in tidal and current-driven environments. A correctly classed and positioned silt curtain contains the turbidity plume within the work area and allows sediment to settle before water is returned to the surrounding environment.

Port expansion, berth deepening, and harbour infrastructure projects operate in enclosed or semi-enclosed water bodies where turbidity control is critical to protecting adjacent users, marine ecosystems, and water quality. Class 2 and Class 3 curtains are typically required depending on exposure and tidal conditions. Vessel traffic management, navigation marking, and waterways authority approvals are standard requirements for curtain deployments in operational port environments.

Coastal road crossings, culvert installations, bridge works, and shoreline stabilisation projects in estuarine and tidal environments disturb sediment in ecologically sensitive zones. Mangroves, seagrass beds, and estuarine fish nursery habitats are highly sensitive to elevated turbidity and sediment deposition. Silt curtains deployed upstream of these receptors limit sediment transport and support compliance with coastal and environmental permit conditions that are increasingly standard across African regulatory frameworks.

Coral reefs and seagrass beds are vulnerable to turbidity through two mechanisms - daylight attenuation that reduces photosynthesis, and physical sediment deposition that buries and smothers organisms. Construction and dredging works near reef and seagrass environments require active turbidity management as a condition of environmental approval across most African coastal jurisdictions. Silt curtains deployed between the work area and sensitive receptors provide the primary barrier against sediment migration toward these habitats.

River bridge construction, culvert installation, bank stabilisation, in-stream infrastructure works, and river crossing pipeline installations all disturb riverbed and bank sediment in flowing water environments. Class 1 curtains suit low-flow inland sites; Class 2 curtains are required where current velocities and flow volumes are moderate. Curtain deployment in rivers must account for flow direction, tidal reversal in tidal reaches, and the need to maintain a gap between the skirt base and riverbed to prevent jet stream formation beneath the curtain.

For low-energy environments with little to no tidal, wave, or wind forces. Typical applications include lagoons, ponds, streams, and enclosed construction zones. Features 400gsm PVC float chamber, 50mm x 100mm floats, 25mm webbing with 1T breaking strain, 6mm galvanised ballast chain, and skirt depths up to 2m. Bowshackle connectors on float chamber with marine grade zipper on skirt. Suitable for short-term deployments in still or near-still water.

For medium-energy environments with moderate wind and water forces. Typical applications include rivers, calm harbours, canals, and coastal construction in sheltered water. Features 610gsm PVC float chamber, 100mm x 100mm or 150mm x 150mm floats, 50mm webbing with 2T breaking strain above and below float chamber, 6mm–8mm galvanised ballast chain, and skirt depths up to 8m. Standard ASTM F962 extruded aluminium Z-connectors with 2 triangle patches for added strength.

For high-energy environments with strong wind and water forces. Typical applications include open ocean, exposed harbour approaches, river mouths, and long-term deployments subject to variable sea states. Features 900gsm PVC float chamber, 150mm x 150mm or 200mm x 200mm floats, 50mm webbing with 5T breaking strain at three positions including above chain pocket with upgraded load strap, 8mm–13mm galvanised ballast chain, and skirt depths up to 20m. Heavy duty ASTM F962 Z-connectors, optional external HDPE floats, reflective buoys, and toggle pins.