Floating Silt Curtains & Turbidity Barriers
Silt curtains, turbidity curtains and silt barriers also known as floating barriers — are used to minimise 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. Over time, the suspended sediment may travel large distances and affect widespread areas. As environmental mitigation for dredging and marine construction activities becomes an ever-greater focus, using silt curtains to contain fine material locally to the dredging operation is essential.
This fine-grained material can reduce water quality and impact sensitive receivers near the work site — ecology with high sensitivity to light attenuation and sediment deposition, such as mangroves, corals, sea grass and cockles.
Silt Curtain Types
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.
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.
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 |
How to Install a Silt Curtain
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.
Which Type 1, 2 or 3 Silt Curtain Do I Need?
Select the right floating silt curtain based on water movement, wave exposure and project conditions. If you are unsure, share your site conditions with our team for a free recommendation.
| Type | Best For | Water Conditions | Typical Use |
|---|---|---|---|
| Type 1 | Light-duty containment | Calm, sheltered water — no significant current | Ponds, lakes, reservoirs, canals, inshore sheltered sites |
| Type 2 | Medium-duty containment | Moderate current — protected waters | Rivers, estuaries, tidal channels, protected harbours |
| Type 3 | Heavy-duty containment | Stronger current up to 1.5 m/s and wave action up to 1.5m | Open ports, commercial harbours, nearshore construction works |
Not sure which turbidity barrier is right for your site? Contact Enviroguard for guidance, sizing and best pricing — call (+91) 81696-93840 or request a quote.
Floating silt curtain installation best practices
Proper installation helps the turbidity barrier perform effectively during dredging and marine construction. Follow these site-preparation and deployment basics for better sediment control
- Inspect water depth, current speed, wind and wave conditions before deployment.
- Place the curtain parallel to flow where possible to reduce drag load on anchor points.
- Secure all anchor points before deployment in moving water — never deploy unsecured.
- Connect sections tightly using D-ring connectors and minimise the number of joints.
- Check tension, alignment and anchor stability after installation and after any tidal change.
- Inspect the curtain periodically for fouling, fabric wear and anchor drift during deployment.
- Remove sediment from inside the enclosed zone regularly to maintain barrier effectiveness.
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.
Which type of silt curtain do I need for my project?
Check your site's current speed and wave exposure first. If the water is calm with no current — a lake, pond or sheltered inshore site — choose Type 1. If you have moderate tidal or river current, choose Type 2. If your site is an open port, harbour or nearshore area with currents up to 1.5 m/s and waves up to 1.5 m, choose Type 3.
What is the price of a silt curtain in India?
Pricing depends on type, depth, fabric, ballast, anchoring, and project size, so a quote is needed for accurate costing.