A turbidity curtain is a floating barrier used to contain suspended sediment and debris in water, generally near construction sites, dredging operations, logging, mining, and shoreline restoration. They can also be called turbidity barriers, silt barriers or silt curtains. Significant turbidity in any waterway or body of water can suffocate, injure or kill both plants and local wildlife, do physical damage to the local environment, and introduce significant health risks to human populations. Turbidity curtains are employed to encourage silt and other suspended particles to settle out to the bottom of the waterway, allowing clear water to pass through.
The curtain itself consists of a float which supports a skirt that hangs down into the water and is anchored to the bottom. The skirt is often impermeable, but may also be a permeable filtering fabric, which permits water to pass through, trapping sediment as it goes. The choice will depend on local water conditions. The length of the skirt varies to follow any changes in the waterway’s depth, and the specific design must account for variations in water speed, tidal action and waves, as applicable. Use of turbidity curtains is highly recommended wherever activities are expected to create disturbances in a body of water, or even where rain or irrigation runoff may flow into one. In an increasing number of cases, the use of turbidity or silt curtains are required by environmental regulations and in the issuance of operating permits.
