Silt Curtain

What are floating silt curtains?

Floating silt curtains are designed to control and manage sediment flow within water. In brief, floating silt curtains consist of a top flotation pocket using an environmentally safe and 100% recyclable closed cell foam. In addition to foam buoyancy we can manufacture our PVC range of silt curtains to be air filled.

A floating silt curtain (also called a turbidity curtain or silt screen) is a temporary water barrier used to contain and manage sediment stirred up by construction, dredging, or piling works in rivers, lakes, harbours, and coastal waters. SSI Environmental supply and advise on floating silt curtains across Ireland, with options to suit calm harbour conditions, tidal estuaries, and open water environments. All curtains feature closed-cell recyclable foam floatation and PVC skirt panels that extend below the waterline to contain silt within a controlled area.

Silt Curtain Type Guide (Calm to Turbulent Water)

Type	Type 1  Calm	Type 2  Moderate	Type 3  Turbulent
Water Condition	Still / minimal current	Moderate tidal / river flow	Open sea, tidal estuary, fast river
Applications	Harbours, lakes, ponds	Estuaries, marina works, river bridge	Coastal dredging, offshore pile driving
Skirt Depth	0.5–1.5m	1.0–2.0m	1.5–3.0m+
Anchor Method	Light anchoring	Mid-point anchors + shore pins	Heavy chain ballast + multi-point mooring

Irish Applications

• Harbour dredging  Cork, Wicklow, Waterford, Drogheda
• River bridge pier construction across OPW-managed watercourses
• Offshore wind foundation piling in Irish coastal waters
• Marina expansion and berth dredging
• Inland lake and reservoir maintenance
• CFRAM and OPW flood relief scheme construction

Definition of a Silt Curtain :

 A temporary sediment barrier installed parallel to the bank of a stream or lake. Used to contain and manage the sediment produced by civil construction operations in close proximity to streams and lakes.

SILT CURTAINS create a flexible, water permeable barrier that extends downwards in the body of water, where it is typically anchored or weighted to prevent the silt from moving.

Silt Curtains create a limited area for the silt to settle, allowing most areas to remain unaffected by silt.

SSI Environmental can supply and offer advice in relation to suitability and installation where necessary. It is our goal to respond as quickly as possible pending on information supplied and qualified.

FAQ

Q: What is a floating silt curtain and how does it work?

A: A floating silt curtain is a water-deployed barrier consisting of a buoyant foam-filled top section and a weighted PVC skirt that extends below the waterline. It is anchored across or around a work area to contain suspended sediment within a defined zone, allowing particles to settle before clean water passes beyond the curtain.

Q: What is the difference between Type 1, 2, and 3 silt curtains?

A: Type 1 curtains are designed for still or near-still water such as harbours and ponds. Type 2 suits moderate tidal or river flow. Type 3 is specified for high-energy environments like open coastal waters or fast-flowing rivers, with heavier ballast chains and deeper skirts.

Q: Can silt curtains be used in tidal water?

A: Yes, provided the correct curtain type is specified. Type 2 and Type 3 curtains are manufactured with reinforced PVC and robust anchor systems to perform in tidal environments. SSI Environmental will advise on the correct specification for your site.

Q: Are there regulations governing silt curtain use in Irish waters?

A: Yes. Works in tidal or navigable waters require foreshore licences under the Foreshore Act 1933. EPA Pollution Prevention Guidelines and Water Framework Directive obligations apply to all in-water construction. Silt curtains are a recognised Best Management Practice for compliance.

nd protect water quality. Compliance with local laws is essential.