Abstract: A silt fence is provided which includes an elongated first strip of material which was a relatively uniform porosity and which is fabricated from filaments of relatively small diameter. The first strip is attached to an elongated second strip of material which is fabricated from yarns in a grid pattern, the yarns being of relatively large diameter relative to the filaments of the first strip of material and having from about 2 to 8 yarns per inch in each direction. The composite strip has a Frazier air permeability of from about 100 to 1000 cubic feet per square foot per minute at 1/2 inch of water pressure. The material may be provided with a hem in which is disposed a tensioning member.In use the tensioning member in the hem is attached to posts and the other edge of the material is buried in a trench in the ground.