Snow Fence

A snow fence is a type of fence similar to a sand fence that forces drifting snow to accumulate in a desired place. They are primarily employed to minimize the amount of snowdrift on roadways and railways. Farmers and ranchers may use temporary snow fences to create large drifts in basins for a ready supply of water in the spring. In the ski industry snow fences are used to catch snow to increase snow depth in specified areas; a practice which may also be considered snow farming. Snow fences are also used in avalanche control.

Temporary snow fences in North America are usually one of two varieties: perforated orange plastic sheeting attached to stakes at regular intervals (the type usually used for construction site fencing or temporary sports field fencing), or a cedar or other lightweight wood strip and wire fence, also attached to metal stakes. A permanent snow fence generally consists of poles set deeply into the ground with planks running across them, or a line of closely spaced shrubs or conifer trees. A permanent snow fence may be installed where a roadway or railway is subject to predictable snow and wind patterns each winter, such as mountain passes.

Snow fences work by making the wind speed on the downwind side and near upwind side less than that on the far windward side, causing blown snow to settle to the ground. Thus, snow fences actually cause snow drifts, rather than preventing them. The fences are placed to cause a snow drift where it is not harmful so that the snow does not drift onto undesired areas, such as roadways.