DOT Turbidity Curtain Types I, II & III — Silt Barrier Solutions
Federal and state regulations under the Clean Water Act and NPDES require turbidity and sediment control at all waterway construction, dredging, and remediation sites. AWTT custom-manufactures all three DOT turbidity curtain types to ensure your project meets every compliance requirement.
Regulatory Requirement
The Clean Water Act and National Pollution Discharge Elimination System (NPDES) require federal and state agencies to enforce sediment control laws. Non-compliance can result in project shutdowns and significant fines.
DOT Compliant
Type I, II & III Available
The Three DOT Turbidity Curtain Types
The DOT specifies three distinct curtain types based on current velocity and wave exposure. Selecting the correct type is critical for regulatory compliance and field performance.
DOT Curtain Type I
Still / Slow WaterDesigned for protected waterways with minimal or no water flow. Ideal for calm lakes, ponds, and enclosed basins where wave action and currents are negligible.
| Parameter | Value |
|---|---|
| Current Velocity | Still to minimal current (< 0.5 ft/sec) |
| Wave Exposure | Protected areas, minimal wave action |
| Typical Use | In-water construction, pond maintenance |
| Skirt Depth | Configured to site depth requirements |
| Floatation | Continuous closed-cell foam float |
| Ballast | Chain or weighted bottom for anchoring |
Typical Applications
- Lakes and ponds
- Enclosed basins
- Protected coves
- Stormwater ponds
DOT Curtain Type II
Moderate CurrentEngineered for moderate current and wave conditions in open waterways, rivers, and tidal areas. Reinforced construction handles currents up to approximately 1.5 ft/sec.
| Parameter | Value |
|---|---|
| Current Velocity | Moderate currents (up to ~1.5 ft/sec) |
| Wave Exposure | Semi-exposed to moderate wave action |
| Typical Use | Bridge construction, dredging, pipeline crossings |
| Skirt Depth | Configured to site depth and current profile |
| Floatation | Heavy-duty foam float sections |
| Ballast | Reinforced chain ballast system |
Typical Applications
- Rivers and streams
- Tidal areas
- Open bays
- Construction coffer dams
DOT Curtain Type III
High Current / ExposedHeavy-duty construction for high-velocity currents, tidal flows, and exposed open-water environments. Built for the most demanding environmental protection requirements.
| Parameter | Value |
|---|---|
| Current Velocity | High current conditions (> 1.5 ft/sec) |
| Wave Exposure | Exposed locations with significant wave action |
| Typical Use | Coastal construction, major dredging, open water |
| Skirt Depth | Deep skirts for turbulent conditions |
| Floatation | Extra-heavy-duty float array |
| Ballast | Heavy chain ballast with anchor systems |
Typical Applications
- High-velocity rivers
- Open ocean/coastal work
- Strong tidal areas
- Major dredging projects
How to Select the Right Curtain Type
Choosing the incorrect curtain type can result in regulatory non-compliance and field failures. AWTT provides free consultation to ensure you specify the correct type.
| Condition | Type I | Type II | Type III |
|---|---|---|---|
| Still or minimal current (< 0.5 ft/sec) | ✓ | — | — |
| Moderate current (0.5 – 1.5 ft/sec) | — | ✓ | — |
| High velocity / tidal (> 1.5 ft/sec) | — | — | ✓ |
| Protected, no wave action | ✓ | — | — |
| Moderate wave exposure | — | ✓ | ✓ |
| Open water / coastal exposure | — | — | ✓ |
| In-water construction & ponds | ✓ | ✓ | — |
| Major dredging operations | — | ✓ | ✓ |
Not Sure Which Type You Need?
Our engineers will review your project conditions and specify the correct DOT curtain type — at no charge. Contact us for a free consultation.
Get a Free Consultation →Custom DOT Turbidity Curtains — Ready to Order
AWTT custom-manufactures all three DOT turbidity curtain types. Submit your project specifications and we'll provide a detailed quote with engineering support.