The recommended minimum barrier length helps compensate for loss of protection due to end effects. Barriers with an opening or gap at ground level allow snow to be blown through the barrier. A bottom gap of 10 to 15 percent of H causes a greater proportion of the blowing snow to be stored in the leeward instead of the windward drift. In order for a barrier to store snow in the smallest area possible, a bottom gap is not recommended. A dense barrier with no bottom gap can be located closer to the protected area or road.
Snow is stored both up and down wind of the barrier and downwind drift length is minimized.
In designing a living snow fence, many site factors must be considered along with planting objectives and number and spacing between and within rows. Landowners may request aesthetic qualities in the form of spring flower or fall foliage colors. The windward drift of the downwind row will build back to the leeward drift of the upwind row as it tapers off. Closer spaced rows will only add to snow storage an amount equal to the space between the rows. One reason to plant rows closer would be to insure closure and maximize density of the barrier.