fences in the middle of no where

I’ve always wanted to know the answer to this one…

Just before winter starts, cities or properties put up these plastic fences. They are normally orange or black and they put them in rows. When it snows, you just see snow drifts in between them. My question is WHY?!! Why do they put up these fences in big open fields?


They tend to back up some of the snow behind them, minimizing the amount that blows where it’s not wanted. E.g., near the bottom of a slope, with a road running along the bottom of the hillside, one puts a fence which retains the greater part of the snow drifting down the hill. They’re generally holey, since the weight of snow backing up behind them would tip them over if some weren’t allowed through.

Actually, Poly, they’re holey not for the weight of the snow, which they probably bear anyway, since a drift can melt into one nearly solid pile.

They’re holey so that the wind can pass through. Imagine gale force winds against several hundred yards of solid sail… ow.

Another purpose of the holes is that it slows down the wind so that the snow being carried can fall out without pushing the wind straight back up as a solid wall would. It keeps the slowed down wind close to the ground.

The same principle applies to dune fences you’d see on a beach. The vertical slats slow down the wind near ground level so that sand particles will then be deposited there.