Floating Silt Curtains & Turbidity Barriers
Silt curtains, turbidity curtains and silt barriers also known as floating barriers are used to minimize sediment transportation from a disturbed area in and around a water body. Enviroguard supplies Type 1, Type 2 and Type 3 curtains for dredging operations, marine construction projects, port and harbour development, and environmental protection zones across India.
Soil loss into a water course results in long term suspension of sediment. In time, the suspended sediment may travel large distances and affect wide spread areas. As environmental mitigation for dredging and marine construction activities becomes ever more of a focus of attention. The use of silt curtains to contain fine material locally to the dredging operation has to be considered.
This fine-grained material may reduce water quality and impact on sensitive receivers in the vicinity of the work site area. In this context, ecology that has a sensitive sensitivity to both light attenuation and sediment deposition, like mangroves, corals, sea grass, and cockles.
Types of Silt Curtains
They are classified into three types (1–3) based on water energy and current speed at the deployment site.
Type 1: is a light-weight inshore curtain that is ideal for lower energy environments and sheltered deployments with no significant wind or currents.
Type 2: is a medium-weight curtain, designed for use in moderate currents. Due to its higher tensile strength, it is suitable for higher velocity water flows in protected waters.
Type 3: is a heavy-duty curtain that functions in higher energy environments with currents up to 1.5 m/s. It can be deployed in ports, harbours and nearshore conditions with moderate wave exposure up to 1.5 m.
Silt Barrier Specifications
| Type | Water Conditions | Applications | Section Length | Freeboard / Draft |
|---|---|---|---|---|
| Type 1 | Calm / sheltered, no significant current | Inshore, lakes, ponds, reservoirs | 20–25 m | 30cm / 1–2m |
| Type 2 | Moderate currents, protected waters | Rivers, estuaries, tidal channels | 20–25 m | 30–45cm / 2–3m |
| Type 3 | Currents up to 1.5 m/s, waves up to 1.5 m | Ports, commercial harbours, nearshore | 20–25 m | 45–60cm / 3–4.5m |
Applications of Turbidity Barriers
- Dredging operations.
- Marine construction projects.
- Port and harbour development.
- Bridge construction over water.
- Shoreline and coastal protection works.
- Environmental protection zones.
- Offshore pipeline and cable laying.
How a Silt Curtain Works
1. Float and Freeboard
The foam-filled float runs along the top of the curtain, keeping it upright at the water surface. The freeboard — the section above water — prevents surface-layer sediment plumes from spilling over the barrier.
2. Curtain / Draft
The geotextile skirt (draft) extends below the waterline. The permeable fabric allows water to pass through while trapping fine sediment particles, confining the turbidity plume to the work zone.
3. Chain Ballast
A galvanised chain ballast runs along the bottom hem of the curtain, weighing it down and maintaining a taut vertical profile even in currents, so sediment cannot bypass the barrier underneath.
4. Anchoring and Connecting Sections
Individual 20–25 m curtain sections are connected using D-ring connectors and anchored to the seabed with mooring lines. The anchor system resists drag loads appropriate to Type 1, 2, or 3 water conditions.
5. Sediment Collection and Removal
Sediment accumulates inside the enclosed zone, settles to the bottom, and is removed by dredge or suction pump. On completion, retrieve the curtain by pulling top and bottom cables together to minimise trapped material release.
Installation & Compliance
For more information on silt curtain installation procedures or project-specific engineering support, or to request a best competitive price, call at (+91) 81696-93840. Enviroguard silt curtains are manufactured to meet international marine environmental standards and are designed to comply with local regulatory requirements across India and international project sites. All products are supplied with material test certificates and technical data sheets.
Complement your sediment control with our range of marine environmental products: Oil Absorbent Booms and Oil Containment Booms for spill response, and Oil Spill Response Equipment for comprehensive site protection.