Moisture content of the soil also plays an important role in compaction by helping to 'lubricate' the soil during the act of compaction. Dry soil particles will tend to bridge between one another, thus retaining air space. Some moisture allows the particles to give and slide, and thus 'settle' closer together in a more dense position. Too much moisture means the air spaces have been filled with water, physically occupying space and preventing the soil particles to densify. It is required in virtually all specifications because the more air space a soil has, the more room it has for water infiltration, which is called piping.
Infiltration enables water to saturate the soil, causing it to become fluid and potentially mobile.
Fluid and mobile soil converts directly to erosion and sediment transport. Compaction, by definition, is the act of compressing a given volume of material into a smaller volume. Silt Fence is a System Silt fence is a system. The system is only effective operating as a unit. Placement is important because where a fence starts, runs, and ends is paramount to gathering and detaining water.